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Tytuł:
Effect of boron on ZSM-5 catalyst for methanol to propylene conversion
Autorzy:
Xu, A.
Ma, H.
Zhang, H.
Ying, W.
Fang, D.
Powiązania:
https://bibliotekanauki.pl/articles/777971.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
methanol to propylene
ZSM-5
boron modifi cation
propylene
Opis:
B-ZSM-5 catalysts were prepared by various modification methods with boric acid, including ion-exchange, impregnation and direct synthesis. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), NH3-Temperature Programmed Desorption (NH3-TPD), N2 adsorption-desorption, Fourier Transform Infrared spectrometry (FT-IR), 27Al and 11B MAS NMR spectra. The results revealed that the weak acidity of catalysts was significantly increased by modification. The catalytic activity was measured in a fixed bed at 460°C for methanol to propylene (MTP) reaction. The results of MTP reaction showed a great increment of the propylene selectivity for the boron modified samples, especially for the directly synthesized B-ZSM-5 which also displayed high activity and selectivity towards C2 =-C4 = olefins. It was found that the remarkable selectivity strongly depended on the intensity of weak acidity.
Źródło:
Polish Journal of Chemical Technology; 2013, 15, 4; 95-101
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The forwarding indices of graphs - a survey
Autorzy:
Xu, J.-M.
Xu, M.
Powiązania:
https://bibliotekanauki.pl/articles/255669.pdf
Data publikacji:
2013
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
graph theory
vertex-forwarding index
edge-forwarding index
routing
networks
Opis:
A routing R of a connected graph G of order n is a collection of n(n — 1) simple paths connecting every ordered pair of vertices of G. The vertex-forwarding index £(G,R) of G with respect to a routing R is defined as the maximum number of paths in R passing through any vertex of G. The vertex-forwarding index £(G) of G is defined as the minimum £(G,R) over all routings R of G. Similarly, the edge-forwarding index π (G,R) of G with respect to a routing R is the maximum number of paths in R passing through any edge of G. The edge-forwarding index π (G) of G is the minimum π(G, R) over all routings R of G. The vertex-forwarding index or the edge-forwarding index corresponds to the maximum load of the graph. Therefore, it is important to find routings minimizing these indices and thus has received much research attention for over twenty years. This paper surveys some known results on these forwarding indices, further research problems and several conjectures, also states some difficulty and relations to other topics in graph theory.
Źródło:
Opuscula Mathematica; 2013, 33, 2; 345-372
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rat robot motion state identification based on a wearable inertial sensor
Autorzy:
Chen, Yuxin
Xu, Haoze
Yang, Wei
Yang, Canjun
Xu, Kedi
Powiązania:
https://bibliotekanauki.pl/articles/1849133.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
inertial sensor
real-time measurement
rat robot
motion state
Opis:
Rat robots have great potential in rescue and search tasks because of their excellent motion ability. However, most of the current rat-robot systems relay on human guidance due to variable voluntary motor behaviour of rats, which limits their application. In this study, we developed a real-time system to detect a rat robot’s transient motion states, as the prerequisite for further study of automatic navigation. We built the detection model by using a wearable inertial sensor to capture acceleration and angular velocity data during the control of a rat robot. Various machine learning algorithms, including Decision Trees, Random Forests, Logistic Regression, and Support Vector Machines, were employed to perform the classification of motion states. This detection system was tested in manual navigation experiments, with detection accuracy achieving 96.70%. The sequence of transient motion states could be further used as a promising reference for offline behaviour analysis.
Źródło:
Metrology and Measurement Systems; 2021, 28, 2; 255-268
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Antibiofilm activity against Staphylococcus aureus and content analysis of Taraxacum Officinale phenolic extract
Autorzy:
Xu, P.
Xu, X.B.
Khan, A.
Fotina, T.
Wang, S.H.
Powiązania:
https://bibliotekanauki.pl/articles/2087162.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Taraxacum Officinale
phenolic
antibacterial mechanism
HPLC
Staphylococcus aureus
Źródło:
Polish Journal of Veterinary Sciences; 2021, 24, 2; 243-251
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
More on even [a,b]-factors in graphs
Autorzy:
Khodkar, Abdollah
Xu, Rui
Powiązania:
https://bibliotekanauki.pl/articles/743747.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
[a,b]-factor
spanning graph
edge-connectivity
Opis:
In this note we give a characterization of the complete bipartite graphs which have an even (odd) [a,b]-factor. For general graphs we prove that an a-edge connected graph G with n vertices and with δ(G) ≥ max{a+1,an/(a+b) + a - 2} has an even [a,b]-factor, where a and b are even and 2 ≤ a ≤ b. With regard to the edge-connectivity this result is slightly better than one of the similar results obtained by Kouider and Vestergaard in 2004 and unlike their results, this result has no restriction on the order of graphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2007, 27, 1; 193-204
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simultaneous measurement of refractive index and thickness for optically transparent object with a dual-wavelength quantitative technique
Autorzy:
Xu, X.
Wang, Y.
Xu, Y.
Jin, W.
Powiązania:
https://bibliotekanauki.pl/articles/174666.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
digital holography
phase measurement
cell measurement
red blood cell
Opis:
We present a new dual-wavelength quantitative measurement approach that can be employed for simultaneously measuring both the refractive index and the thickness of the homogenous specimen. This method is realized by dual-wavelength in-line phase-shifting digital holography, and then the phase images are obtained by using four-phase step algorithm for each wavelength separately. Based on computer simulation technology, the feasibility and the effectiveness of our proposed method are demonstrated by comparing our simulation results with the experimental results of the spherical silica bead and the red blood cell, respectively. Our work will provide some guidance in the experimental research for transparent phase objects.
Źródło:
Optica Applicata; 2016, 46, 4; 597-605
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The s-packing chromatic number of a graph
Autorzy:
Goddard, Wayne
Xu, Honghai
Powiązania:
https://bibliotekanauki.pl/articles/743305.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
graph
coloring
packing
broadcast chromatic number
Opis:
Let S = (a₁, a₂, ...) be an infinite nondecreasing sequence of positive integers. An S-packing k-coloring of a graph G is a mapping from V(G) to {1,2,...,k} such that vertices with color i have pairwise distance greater than $a_i$, and the S-packing chromatic number $χ_S(G)$ of G is the smallest integer k such that G has an S-packing k-coloring. This concept generalizes the concept of proper coloring (when S = (1,1,1,...)) and broadcast coloring (when S = (1,2,3,4,...)). In this paper, we consider bounds on the parameter and its relationship with other parameters. We characterize the graphs with $χ_S = 2$ and determine $χ_S$ for several common families of graphs. We examine $χ_S$ for the infinite path and give some exact values and asymptotic bounds. Finally we consider complexity questions, especially about recognizing graphs with $χ_S = 3$.
Źródło:
Discussiones Mathematicae Graph Theory; 2012, 32, 4; 795-806
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fruit biomechanics based on anatomy: a review
Autorzy:
Li, Z.
Yang, H.
Li, P.
Liu, J.
Wang, J.
Xu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/24093.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Opis:
Fruit biomechanics is needed for quality determination, multiscale modelling and engineering design of fruit processes and equipments. However, these determined fruit biomechanics data often have obvious differences for the same fruit or tissue. In order to investigate it, the fruit biomechanics based on anatomy was reviewed in this paper. First, the anatomical characteristics of fruit biomaterials were described at the macroscopic ‘tissue’ level and microscopic ‘cellular’ level. Subsequently, the factors affecting fruit biomechanics based on anatomy and the relationships between fruit biomechanics, texture and mechanical damage were summarised according to the published literature. Fruit biomechanics is mainly affected by size, number and arrangement of cells, quantity and volume of intracellular spaces, structure, thickness, chemical composition and permeability of cell walls, and pectin degradation level and turgor pressure within cells based on microanatomy. Four test methods and partial determined results of fruit biomechanics were listed and reviewed. The determined mechanical properties data of fruit are only approximate values by using the existing four test methods, owing to the fruit biomaterials being non-homogeneous and living. Lastly, further aspects for research on fruit biomechanics were proposed for the future.
Źródło:
International Agrophysics; 2013, 27, 1
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A note on the p-domination number of trees
Autorzy:
Lu, Y.
Hou, X.
Xu, J.-M.
Powiązania:
https://bibliotekanauki.pl/articles/255183.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
p-domination number
trees
Opis:
Let p be a positive integer and G = (V (G), E(G)) a graph. A p-dominating set of G is a subset S of V (G) such that every vertex not in S is dominated by at least p vertices in S. The p-domination number ϒp(G) is the minimum cardinality among the p-dominating sets of G. Let T be a tree with order n ≥ 2 and p ≥ 2 a positive integer. A vertex of V (T) is a p-leaf if it has degree at most p - 1, while a p-support vertex is a vertex of degree at least p adjacent to a p-leaf. In this note, we show that ϒp(T) ≥ (n + /Lp(T)/ - /Sp(T)/)/2, where Lp(T) and Sp(T) are the sets of p-leaves and p-support vertices of T, respectively. Moreover, we characterize all trees attaining this lower bound.
Źródło:
Opuscula Mathematica; 2009, 29, 2; 157-164
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Risk sharing markets and hedging a loan portfolio: a note.
Autorzy:
Broll, Udo
Guo, Xu
Welzel, Peter
Powiązania:
https://bibliotekanauki.pl/articles/943134.pdf
Data publikacji:
2017-12-20
Wydawca:
Uniwersytet Ekonomiczny w Poznaniu
Tematy:
risk management
credit risk
loan portfolio
derivatives
hedging effectiveness
Opis:
Our study features a financial institute facing credit risk. Hedging credit risk by offsetting an open position with an opposite one in the financial market is important for financial intermediaries, which are concerned with both the profitability and risk of their operations. As risk management is crucial for the financial institute, the issues of how it is optimally determined and how it adjusts to changes in the financial environment deserve closer scrutiny. We extend the analysis of hedging with financial instruments against credit risk to the case of multiple types of credit risk. We show that standard results on the optimal hedge ratio and risk management effectiveness in the case of one single source of credit risk to carry over a loan portfolio in a non-trivial but intuitive way. While we focus on credit risk and credit derivatives, our analysis can be easily applied to other financial assets, which can be traded in futures market.
Źródło:
Economics and Business Review; 2017, 3(17), 4; 47-54
2392-1641
Pojawia się w:
Economics and Business Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of medicinal plant Schisandra chinensis using a potential DNA barcode ITS2
Autorzy:
Li, X.-K.
Wang, B.
Han, R.-C.
Zheng, Y.-C.
Yin, H.-B.
Xu, L.
Zhang, J.-K.
Xu, B.-L.
Powiązania:
https://bibliotekanauki.pl/articles/56996.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
identification
internal transcribed spacer
medicinal plant
Schisandra chinensis
DNA barcode
Opis:
To test whether the internal transcribed spacer 2 (ITS2) region is an effective marker for using in authenticating of the Schisandra chinensis at the species and population levels, separately. And the results showed that the wild populations had higher percentage of individuals that had substitution of C→A at site 86-bp than the cultivated populations. At sites 10-bp, 37-bp, 42-bp and 235-bp, these bases of the Schisandra sphenanthera samples differed from that of S. chinensis. Two species showed higher levels of inter-specific divergence than intra-specific divergence within ITS2 sequences. However, 24 populations did not demonstrate much difference as inter-specific and intra-specific divergences were concerned. Both S. chinensis and S. sphenanthera showed monophyly at species level, yet the samples of different populations shown polyphyly at population level. ITS2 performed well when using BLAST1 method. ITS2 obtained 100% identification success rates at the species level for S. chinensis, with no ambiguous identification at the genus level for ITS2 alone. The ITS2 region could be used to identify S. chinensis and S. sphenanthera in the “Chinese Pharmacopoeia”. And it could also correctly distinguish 100% of species and 100% of genera from the 193 sequences of S. chinensis. Hence, the ITS2 is a powerful and efficient tool for species identification of S. chinensis.
Źródło:
Acta Societatis Botanicorum Poloniae; 2013, 82, 4
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A characterization of (γₜ,γ₂)-trees
Autorzy:
Lu, You
Hou, Xinmin
Xu, Jun-Ming
Li, Ning
Powiązania:
https://bibliotekanauki.pl/articles/744036.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
domination
total domination
2-domination
(λ,μ)-tree
Opis:
Let γₜ(G) and γ₂(G) be the total domination number and the 2-domination number of a graph G, respectively. It has been shown that: γₜ(T) ≤ γ₂(T) for any tree T. In this paper, we provide a constructive characterization of those trees with equal total domination number and 2-domination number.
Źródło:
Discussiones Mathematicae Graph Theory; 2010, 30, 3; 425-435
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of bubble-particle interactions in a column flotation process
Autorzy:
Cheng, G.
Shi, C.
Yan, X.
Zhang, Z.
Xu, H.
Lu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/109635.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
particle
bubble
column flotation
collision
attachment
detachment
Opis:
Bubble-particle interactions play an important role in flotation. This study examines the behaviour of bubble clusters in a turbulent flotation cell. Particularly, the bubble-particle interaction characteristics in flotation are investigated. The bubble size in a flotation column was measured using an Olympus i-SPEED 3 high-speed camera. Relationships between the circulating volume, bubble size and bubble terminal velocity were discussed. Probabilities of collision, attachment, detachment and acquisition between bubbles and particles in different circulating volumes were calculated based on the flotation kinetic theory. Using the extended Derjaguin–Landau–Verwey–Overbeek (EDLVO) theory, the relationship between the potential energy and distance in bubble-particle interaction was analysed. The results demonstrated that as the circulating volume increased, the bubble size and velocity decreased. When the circulating volume increased from 0.253 to 0.495 m3/h, the bubble diameter decreased from 511 to 462 μm, and the corresponding bubble velocity decreased from 43.1 to 37.5 mm/s. When the circulating volume remained constant as the particle size increased, probabilities of collision, attachment, detachment and acquisition increased. When the particle size remained constant as the circulating volume increased, these probabilities also increased. At a constant circulating volume as the particle size increased, the absolute value of the total potential energy between the particle and bubble increased. When the distance between the bubble and particle was 30 nm, the energy barrier appeared.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 1; 17-33
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A review of inflation from 1906 to 2022: a comprehensive analysis of inflation studies from a global perspective
Autorzy:
Wang, Xindi
Xu, Zeshui
Wang, Xinxin
Skare, Marinko
Powiązania:
https://bibliotekanauki.pl/articles/19322576.pdf
Data publikacji:
2022
Wydawca:
Instytut Badań Gospodarczych
Tematy:
bibliometrics
visualization tool
policy suggestions
inflation
Opis:
Research background: Inflation has always been the core issue of economic research and there are many academic research achievements in this field. In recent years, global inflation has intensified, and many scholars focus on research in this field again, providing certain reference value for countries around the world to formulate corresponding macro policies. Purpose of the article: The five-year impact factors are used as the evaluation criteria in this paper, and 1,637 high-quality documents on inflation from 1906 to 2022 are collected from the Web of Science Core Collection database. Using bibliometrics, a comprehensive review of influential literature in the field of inflation is conducted to reveal the evolution and trends of the field. Methods: First, we focus on these high-quality documents about the descriptive statistical characteristics, high cited documents and high impact factor journals. Then, based on the visualization tool, the cooperative network of countries/regions, authors and institutions is depicted and the cooperative relationship between them is determined. At the same time, the most influential countries/regions, authors and institutions are identified by analyzing the citation structure. In addition, through thematic and keyword analysis, the topic hotspots and future research trends of high-quality literature in the field of inflation are deduced. Findings & value added: On the whole, the research on inflation in the United States is relatively mature, and has produced a large number of influential academic cooperation results. Finally, we have a series of discussions on the history of inflation in the United States and policy suggestions. In the future, governments of various countries, especially the United States, will still face certain challenges in how to formulate policies and measures to mitigate the impact of inflation.
Źródło:
Oeconomia Copernicana; 2022, 13, 3; 595-631
2083-1277
Pojawia się w:
Oeconomia Copernicana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tang Ping, The Magic and the Reality: A Study of the Supernatural in Shakespearean Drama (Chengdu: Sichuan University Press, 2015. Pp. 320).
Autorzy:
Jia, Xu
Powiązania:
https://bibliotekanauki.pl/articles/960274.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Źródło:
Multicultural Shakespeare: Translation, Appropriation and Performance; 2018, 17, 32; 122-124
2083-8530
2300-7605
Pojawia się w:
Multicultural Shakespeare: Translation, Appropriation and Performance
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Buckling of cylindrical shells under external pressure in a Hamiltonian system
Autorzy:
Sun, J.
Xu, X.
Lim, C. W.
Powiązania:
https://bibliotekanauki.pl/articles/280390.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
buckling
cylindrical shells
external pressure
Hamiltonian system
Opis:
In this article, the elastic buckling behavior of cylindrical shells under external pressure is studied by using a symplectic method. Based on Donnell’s shell theory, the governing equations which are expressed in stress function and radial displacement are re-arranged into the Hamiltonian canonical equations. The critical loads and buckling modes are reduced to solving for symplectic eigenvalues and eigenvectors. The buckling solutions are mainly grouped into four categories according to the natures of the buckling modes. The effects of geometrical parameters and boundary conditions on the buckling loads and modes are examined in detail.
Źródło:
Journal of Theoretical and Applied Mechanics; 2014, 52, 3; 641-653
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Isolation and genetic analysis of a variant porcine epidemic diarrhea virus in China
Autorzy:
Li, R.-f.
Tian, X.-g.
Liu, Y.
Xu, J.
Liu, D.-y.
Powiązania:
https://bibliotekanauki.pl/articles/30492.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
Porcine epidemic diarrhea virus (PEDV) is having a severe effect on the pig breeding industry in central China. The mucosa and the content of the small intestine from newborn pre-weaned piglets with diarrhea were tested for the presence of PEDV by molecular and morphologic methods, and found to be positive. Negative-staining electron microscopy (EM) revealed the presence of coronavirus- like particles in the samples. The result of molecular detection by nested RT-PCR based on the amplification of the M gene was positive. Using a novel alternative method we successfully propagated the PEDV strain (CH/QX-2) in Vero cells, confirmed by ultrathin sections of the cells and Immunofluorescence assay (IFA). Phylogenetic analysis based on the partial S gene showed that the CH/QX-2 isolate was genetically closer to strains more commonly found in China, but differed genetically from two domestic strains (CH/S, 1986 and LZC, 2007), Korean strains (DR13, 2007), and the vaccine strain (CV777 vs) currently being used in China. CH/QX-2 formed a unique clade in the derived phylogenetic tree indicating that the CH/QX-2 strain currently circulating in central China is a new variant of PEDV. This study extends current knowledge on the diversity and epidemiology of PEDV.
Źródło:
Polish Journal of Veterinary Sciences; 2016, 19, 1
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A stability based neural networks controller design method
Autorzy:
Song, J.
Xu, X.
He, X.
Powiązania:
https://bibliotekanauki.pl/articles/206120.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
sieć neuronowa
stabilność
sterowanie nieliniowe
neural networks control
nonlinear control
sliding mode
stability
Opis:
The use of neural networks in control systems can be seen as a natural step in the evolution of control methodology to meet new challenges. Many attempts have been made to apply the neural networks to deal with non-linearities and uncertainties of the control systems. Research in neural network applications to control can be classified according to the major methods depending on structures of the control system, such as NN-based NON-linear System Identification, NN-based Supervised Control, NN-based Direct Control, NN-based Indirect Control, NN-based Adaptive Control, NN-based Self-learning Control, NN-based Fuzzy Control, and NN Variable Structure Control. All these control methods cannot, however, effectively guarantee system stability, i.e. none of these neural network controls, except for NN-based Variable Structure Control, is based on system stability. This also limits the application and development of the neural networks in control theory. The paper shows the effort to solve this difficulty and give a way for the design method of the stability based neural networks controller using Lyapunov second stability theorem. This kind of controller can not only guarantee system stability, but also fully compensate for the influence of system uncertainties and non-linearities.Simulation results also show the effectiveness of the controller.
Źródło:
Control and Cybernetics; 1998, 27, 1; 119-133
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A sandwich type Hahn-Banach theorem for convex and concave functionals
Autorzy:
Xu, Jingshi
Powiązania:
https://bibliotekanauki.pl/articles/2052376.pdf
Data publikacji:
2021
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
Hahn-Banach theorem
convex functional
concave functional
twierdzenie Hahna-Banacha
funkcja wypukła
funkcja wklęsła
Opis:
We give a sandwich type Hahn-Banach theorem for convex and concave functionals.
Źródło:
Journal of Mathematics and Applications; 2021, 44; 119-122
1733-6775
2300-9926
Pojawia się w:
Journal of Mathematics and Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Evidence for Jahn-Teller Transition in a Fe(II)Fe(III) Bimetallic Oxalate
Autorzy:
Tang, G.
He, Y.
Xu, F.
Zhang, Q.
Powiązania:
https://bibliotekanauki.pl/articles/1400401.pdf
Data publikacji:
2013-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Xx
76.80.+y
Opis:
Bimetallic oxalate ${[N-(n-C_4H_9)_4][FeFe(C_2O_4)_3]}_{n}$ has been investigated by the Mössbauer spectroscopy. The Mössbauer studies confirm that high-spin Fe(III) (S=5/2) and Fe(II) (S=2) ions are present in the compound. These spectra above 60 K consist of three quadrupole doublets, indicating that there are three different Fe sites in the material. The Mössbauer results reveal that spontaneous magnetization of Fe(II) sublattices increases more steeply than that of Fe(III) sublattices as the temperature decreases from $T_{C}$. Great increase of quadrupole splitting at 50 K provides compelling evidence for the predicted Jahn-Teller transition.
Źródło:
Acta Physica Polonica A; 2013, 123, 1; 118-120
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tunable Entanglement Sudden Death and Birth in Cavity QED with Nonlinear Kerr-Like Medium
Autorzy:
He, Q.
Xu, J.
Powiązania:
https://bibliotekanauki.pl/articles/1493398.pdf
Data publikacji:
2011-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
03.65.Ud
03.67.-a
03.67.Mn
Opis:
The influence of nonlinear Kerr-like medium on the phenomenon of entanglement sudden death and birth in a double Jaynes-Cummings model is investigated. It is shown that the entanglement sudden death and birth phenomenon may appear in this system and the duration of entanglement sudden death and birth can be controlled by the nonlinear Kerr-like medium. Particularly, the phenomenon of entanglement sudden death and birth disappears one after another if we increase the value of the Kerr coefficient χ continuously, and all disappears if the value of the Kerr coefficient χ is large enough.
Źródło:
Acta Physica Polonica A; 2011, 120, 3; 390-396
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biochemical characterization of a catalase from Vibrio vulnificus, a pathogen that causes gastroenteritis
Autorzy:
Pei, Jihua
Wang, Haijun
Wu, Limin
Xia, Shenglong
Xu, Changlong
Zheng, Bo
Li, Tianya
Jiang, Yi
Powiązania:
https://bibliotekanauki.pl/articles/1038620.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
catalase
Vibrio vulnificus
kinetics
mutation
gastroenteritis.
Opis:
Vibrio vulnificus is a virulent human pathogen causing gastroenteritis and possibly life threatening septicemia in patients. Most V. vulnificus are catalase positive and can deactivate peroxides, thus allowing them to survive within the host. In the study presented here, a catalase from V. vulnificus (CAT-Vv) was purified to homogeneity after expression in Escherichia coli. The kinetics and function of CAT-Vv were examined. CAT-Vv catalyzed the reduction of H2O2 at an optimal pH of 7.5 and temperature of 35°C. The Vmax and Km values were 65.8±1.2 U/mg and 10.5±0.7 mM for H2O2, respectively. Mutational analysis suggests that amino acids involved in heme binding play a key role in the catalysis. Quantitative reverse transcription-PCR revealed that in V. vulnificus, transcription of CAT-Vv was upregulated by low salinity, heat, and oxidative stresses. This research gives new clues to help inhibit the growth of, and infection by V. vulnificus.
Źródło:
Acta Biochimica Polonica; 2017, 64, 3; 543-549
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy feature of a multi-flow column flotation process
Autorzy:
Cheng, G.
Yu, Y.
Ma, L.
Xia, W.
Xu, H.
Powiązania:
https://bibliotekanauki.pl/articles/109768.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation column
turbulent kinetic energy
turbulent dissipation rate
bubble
Opis:
A cyclonic-static micro-bubble flotation column (FCSMC) has been widely used in mineral separation. FCSMC includes countercurrent, cyclone and jet flow mineralization zones in a single column. In this study, the energy feature of the three different zones was compared. The turbulent flow was evaluated in terms of the turbulent kinetic energy (k) and the turbulent dissipation rate (ε). An appropriate computing model was determined by comparing the flow field value measured by PIV with the results of the Fluent numerical simulation. Jet flow separation exhibited the maximum k and ε values among the three columns, whereas counter-current separation displayed the minimum values. The high circulating volumetric flowrate means great energy input and turbulent intensity. The higher turbulent dissipation rate, the smaller the bubble is. The better performance of the FCSMC was mainly attributed to the multiple mineralization steps. The floatability of mineral particles gradually decreases with an increase in flotation time, the mineralization energy gradually increased to overcome the decrease in mineral floatability. By contrast, the countercurrent was beneficial for recovering the coarse particles, and the jet flow was beneficial for recovering the fine particles.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1266-1284
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability control of propeller Autonomous Underwater Vehicle based on combined sections method
Autorzy:
Qi, D.
Feng, J.
Liu, A.
Hu, J.
Xu, H.
Li, Y.
Ashraf, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/259119.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
propeller AUV
dynamic model
stability control
simulation
Opis:
Learning from the motion principle of quadrotor, a symmetric propeller AUV, which has small size and low velocity is designed. Compared with the AUV equipped with rudders, it has better maneuverability and manipulation at low velocity. According to the Newton-Euler method, the 6 DOF kinematic model and dynamic model of the propeller AUV are established. A stability controller that consists of 3 different PID controllers is designed. It makes the depth and attitude angle as trigger conditions, and the relevant controller is chosen in different moving process. The simulation experiments simulate ideal motion state and disturbed motion state, and experiments results show that the stability controller based on combined sections method can make the best of mature technology of PID, and meet the control requirements in different stages. It has a higher respond speed and accuracy, improving the stability of the propeller AUV under the disturbance of complex ocean currents.
Źródło:
Polish Maritime Research; 2015, S 1; 157-162
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Systematic Analyses of the Genus Architricha and Pleurotricha curdsi (Ciliophora, Oxytrichidae), with Redescriptions of Their Morphology
Autorzy:
Xu, Yuan
LI, Lifang
Fan, Xinpeng
Pan, Hongbo
GU, Fukang
Al-Farraj, Saleh A.
Powiązania:
https://bibliotekanauki.pl/articles/763754.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Opis:
Two oxytrichids Architricha indica Gupta et al., 2006 and Pleurotricha curdsi (Shi et al. 2002) Gupta et al., 2003 collected in East China, were studied using live observation and the silver staining method. The description and morphometric characterization of the new populations were supplied. The Shanghai population of A. indica differs from the Indian population in the number of cirri in the third right marginal row (average of 16.8 vs. 21.1). The Shanghai population of P. curdsicorresponds well with the Indian population, but it differs from the other Chinese population in the number of right marginal rows (two vs. three). The early process of reorganization of A. indica was studied, and a difference on the formation of anlage V was found compared to the original report. The small subunit rRNA genes of both species were sequenced for the first time. The phylogenetic analyses based on SSU rRNA gene sequence data revealed that Architricha is sister to the assemblage of Pseudouroleptus caudatus and two Strongylidium, while P. curdsi clusters with its congener P. lanceolata and is located in Stylonychinae.
Źródło:
Acta Protozoologica; 2015, 54, 3
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A reassessment of the purported ankylosaurian dinosaur Bienosaurus lufengensis from the Lower Lufeng Formation of Yunnan, China
Autorzy:
Raven, T.J.
Barrett, P.M.
Xu, X.
Maidment, S.C.R.
Powiązania:
https://bibliotekanauki.pl/articles/21669.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
The earliest definitive ornithischian dinosaurs are from the Early Jurassic and are rare components of early dinosaur faunas. The Lower Lufeng Formation (Hettangian–Sinemurian) of Yunnan Province, China, has yielded a diverse Early Jurassic terrestrial vertebrate fauna. This includes several incomplete specimens have been referred to Ornithischia, including the type specimen of the thyreophoran “Tatisaurus” and other generically indeterminate material. The highly fragmentary Lufeng ornithischian Bienosaurus lufengensis was described briefly in 2001 and identified as an ankylosaurian dinosaur. Recent studies have cast doubt on this hypothesis, however, and given that the referral of Bienosaurus to Ankylosauria would result in an extensive ghost-lineage extending between it and the first definitive eurypodans (ankylosaurs + stegosaurs) in the Middle Jurassic, the holotype specimen is re-examined and re-described. We identify Bienosaurus as a probable thyreophoran dinosaur, although the fragmentary nature of the material and the absence of autapomorphies means that the specimen should be regarded as a nomen dubium.
Źródło:
Acta Palaeontologica Polonica; 2019, 64, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combined load buckling for cylindrical shells based on a symplectic elasticity approach
Autorzy:
Sun, J.
Xu, X.
Lim, C. W.
Powiązania:
https://bibliotekanauki.pl/articles/281463.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
buckling mode
combined loads
critical load
cylindrical shell
symplectic method
Opis:
Buckling behavior of cylindrical shells subjected to combined pressure, torsion and axial compression is presented by employing a symplectic method. Both symmetric and non- -symmetric boundary conditions are considered. Hamiltonian canonical equations are established by introducing four pairs of dual variables. Then, solution of fundamental equations is converted into a symplectic eigenvalue problem. It is concluded that the influence of pressure on buckling solutions is more significant than that due to compressive load, in particular for a longer external pressured cylindrical shell. Besides, buckling loads and circumferential wavenumbers can be reduced greatly by relaxed in-plane axial constraints.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 3; 705-716
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy Router for Emergency Energy Supply in Urban Cities: A Review
Autorzy:
Nie, Yu
Xu, Hui
Hu, Yihua
Ye, Xianming
Powiązania:
https://bibliotekanauki.pl/articles/2175929.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
emergency electric power source
emergency power supply method
energy router
Opis:
The current emergency power supply (EPS) measures are not perfect and standardised in response to large-scale power failures, such as city-wide ones. This review paper focuses on reasonably using the emergency electric power source to supply power in case of an abnormal urban power grid, to ensure the regular operation of urban electrical equipment and the daily life of the people. This study first introduces the different kinds of main emergency electric power sources and analyses their advantages and disadvantages. The battery of an electric vehicle as a new potential emergency power source is introduced that can also avoid the loss caused by unexpected power failure. Finally, three different EPS methods are explained in detail for different emergency occasions. Among them, the energy router is reviewed comprehensively considering it is the most potential emergency power distribution approach in the future because of its various applications.
Źródło:
Power Electronics and Drives; 2022, 7, 42; 246--266
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A numerical simulation method for a repairable dynamic fault tree
Autorzy:
Xu, Zhixin
Guo, Dingqing
Wang, Jinkai
Li, Xueli
Ge, Daochuan
Powiązania:
https://bibliotekanauki.pl/articles/1841835.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
repairable dynamic fault tree
numerical simulation
Monte Carlo
sequential failure region
minimal cut sequence set
Opis:
Dynamic fault trees are important tools for modeling systems with sequence failure behaviors. The Markov chain state space method is the only analytical approach for a repairable dynamic fault tree (DFT). However, this method suffers from state space explosion, and is not suitable for analyzing a large scale repairable DFT. Furthermore, the Markov chain state space method requires the components’ time-to-failure to follow exponential distributions, which limits its application. In this study, motivated to efficiently analyze a repairable DFT, a Monte Carlo simulation method based on the coupling of minimal cut sequence set (MCSS) and its sequential failure region (SFR) is proposed. To validate the proposed method, a numerical case was studied. The results demonstrated that our proposed approach was more efficient than other methods and applicable for repairable DFTs with arbitrary time-to-failure distributed components. In contrast to the Markov chain state space method, the proposed method is straightforward, simple and efficient.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 1; 34-41
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of a novel laccase purified from the fungus Hohenbuehelia serotina and its decolourisation of dyes
Autorzy:
Xu, Yingyin
Lu, Yuxiao
Zhang, Rui
Wang, Hexiang
Liu, Qinghong
Powiązania:
https://bibliotekanauki.pl/articles/1038810.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Hohenbuehelia serotina
laccase
purification
decolouration
Opis:
A novel laccase was purified from the white rot fungus, Hohenbuehelia serotina, to investigate the applications of this laccase in the decoloration of various dyes. SDS-PAGE revealed a single band of this laccase corresponding to a molecular weight of approximately 57.8 kDa. The enzyme showed activity towards several substrates, the most sensitive of which was 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS). The highest enzymatic activity using ABTS as a substrate was observed at pH 6.8 and 30°C. The enzyme activity was found to be significantly enhanced in the presence of Zn2+ ions and inhibited by Fe2+ ions. Moreover, SDS and β-mercaptoethanol were inhibitory, and inhibition by L-cysteine was observed while EDTA and DMSO had almost no inhibitory effect. The laccase could effectively decolorize seven different dyes within 30 minutes at 40°C.
Źródło:
Acta Biochimica Polonica; 2016, 63, 2; 273-279
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A two-step fall detection algorithm combining threshold-based method and convolutional neural network
Autorzy:
Xu, Tao
Se, Haifeng
Liu, Jiahui
Powiązania:
https://bibliotekanauki.pl/articles/1848958.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wearable
fall detection
MPU6050
threshold-based method
convolutional neural network
Opis:
Falls are one of the leading causes of disability and premature death among the elderly. Technical solutions designed to automatically detect a fall event may mitigate fall-related health consequences by immediate medical assistance. This paper presents a wearable device called TTXFD based on MPU6050 which can collect triaxial acceleration signals. We have also designed a two-step fall detection algorithm that fuses threshold-based method (TBM) and machine learning (ML). The TTXFD exploits the TBM stage with low computational complexity to pick out and transmit suspected fall data (triaxial acceleration data). The ML stage of the two-step algorithm is implemented on a server which encodes the data into an image and exploits a fall detection algorithm based on convolutional neural network to identify a fall on the basis of the image. The experimental results show that the proposed algorithm achieves high sensitivity (97.83%), specificity (96.64%) and accuracy (97.02%) on the open dataset. In conclusion, this paper proposes a reliable solution for fall detection, which combines the advantages of threshold-based method and machine learning technology to reduce power consumption and improve classification ability.
Źródło:
Metrology and Measurement Systems; 2021, 28, 1; 23-40
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A model of degree of scattering polarization for oil spilling
Autorzy:
Wang, Xiao
Xu, Jiang
Qian, Weixian
Ouyang, Jingyi
Powiązania:
https://bibliotekanauki.pl/articles/1835805.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optical mechanism
surface microstructure
degree of scattering polarization
Fresnel formula
oil slick
Opis:
Oil slicks often show uncertain surface roughness and Fresnel reflection parameters. Consequently, differentiating oil spilled on the seawater in these areas using optical sensors is a challenge. Therefore, the optical mechanism of the oil film has been studied by the Maxwell equation. It is found that the polarization characteristics of the oil slicks can help us to overcome this problem. According to the Fresnel formula, the scattering coefficient and scattering rate of the homogeneous oil film have been deduced, and the phase difference of the scattering electromagnetic wave has also been calculated to verify the accuracy of the model. The parameter, a degree of scattering polarization, has been derived to identify the oil slicks on the sea wave. It depends on accurately knowing the Stokes parameter for the reflected light, and varies with the refractive index of the surface layer and viewing angles. The actual spilled oil has been measured by this model, and the oil film can be accurately identified at various angles. These preliminary results suggest that the potential of multi-angle polarization measurement of ocean surface needs further researches.
Źródło:
Optica Applicata; 2020, 50, 3; 433-445
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Expression and immunogenicity study of a novel mhp183 gene fragment of Mycoplasma hyopneumoniae
Autorzy:
Xu, M.
Zheng, J.
Hu, S.
Wang, G.
Powiązania:
https://bibliotekanauki.pl/articles/2087132.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Mycoplasma hyopneumoniae
Mhp183 gene
new generation vaccines
Źródło:
Polish Journal of Veterinary Sciences; 2021, 24, 4; 553-561
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exergetic sustainability indicators of a polymer electrolyte membrane fuel cell at variable operating conditions
Autorzy:
Xu, Bing
Chen, Yan
Ma, Zheshu
Powiązania:
https://bibliotekanauki.pl/articles/1845491.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PEM fuel cell
exergy balance
exergy analysis
exergetic sustainability indicators
Opis:
Based on the exergetic sustainability indicators of polymer electrolyte membrane (PEM) fuel cell, this paper studied the effects of irreversibility of thermodynamics on some exergetic sustainability indicators of PEM fuel cell under changing operating temperature, operating pressure and current density. Some conclusions are drawn by analyzing the curves. As the operating temperature increases, the negative impact of PEM fuel cell on various parameters due to irreversibility decreases; As the operating pressure increases, the negative impact of PEM fuel cell on various parameters due to irreversibility decreases; On the other hand, with the increase of current density, the negative impact of the PEM fuel cell on various parameters due to irreversibility increases.
Źródło:
Archives of Thermodynamics; 2021, 42, 1; 183-204
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling and Calculation of the Initial Ignition Gas Pressure Flow through a Rigid Porous Medium in a 100 mm Ignition Simulator
Autorzy:
Xiao, Z.
Ying, S.
He, W.
Xu, F.
Powiązania:
https://bibliotekanauki.pl/articles/358563.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
ignition
ignition simulator
porous media
propellant
modelling
simulation
Opis:
To acquire a better understanding of the early ignition phenomena in a 100 mm ignition simulator loaded with a packed propellant bed, a theoretical model of the ignition gas flow through the rigid porous medium was developed. Three pressure gauges were installed in the lateral side of the ignition simulator for post ignition measurement of the chamber pressure. The pseudo-propellant loaded into the chamber was similar in size to the standard 13/19 single-base cylindrical propellant. It was composed of a rigid ceramic composite with low thermal conductivity. It was assumed that the pseudo-propellant bed was rigid in contrast to the assumption of an elastic porous medium. The calculated pressure values were well verified by the experimental data at a low loading density of the pseudo-propellant bed of 0.18 g•cm-3. However, there was still error between the experimental and the calculated results in the early pressure peak position closest to the ignition primer when the loading density of the pseudo-propellant bed was increased to 0.73 and 1.06 g•cm-3. This error is attributed to the change in local permeability of the pseudo-propellant bed at high loading densities, which is assumed, for ease of modelling, to be constant in the model. These calculations may enable a better understanding of the physical processes of ignition gas flow in an ignition simulator loaded with a pseudo-propellant bed.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 4; 475-489
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and Characterization of PolyNIMMO-HTPB-polyNIMMO Triblock Copolymer as a Potential Energetic Binder
Autorzy:
Wang, X.
Shu, Y.
Lu, X.
Mo, H.
Xu, M.
Powiązania:
https://bibliotekanauki.pl/articles/358529.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
triblock copolymer
cationic ring opening polymerization
polymer
DSC
Opis:
Triblock copolymer polyNIMMO-HTPB-polyNIMMO was synthesized by cationic ring opening polymerization of NIMMO (3-nitratomethyl-3-methyloxetane) in the presence of hydroxyl-terminated polybutadiene catalyzed by BF3·OEt2. The polymer was characterized by FT-IR, 1H NMR, 13C NMR spectroscopy, and GPC. DSC was used to investigate the thermal behaviour of the triblock copolymer and its exothermic decomposition peak was found to be at 215 °C. All of the results indicated that the triblock copolymer polyNIMMO-HTPB-polyNIMMO might serve as a potential energetic propellant binder.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 3; 456-467
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The deviation from eutectic composition in boundary layer for eutectic growth: a phase-field study
Autorzy:
Tu, Zhixin
Zhou, Jianxin
Yin, Yajun
Ji, Xiaoyuan
Shen, Xu
Powiązania:
https://bibliotekanauki.pl/articles/355773.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
phase field
eutectic growth
solidification
composition deviation
Opis:
In this paper, the deviation from eutectic composition in boundary layer for eutectic growth is studied by phase-field method. According to a series of artificial phase diagram, the lamellar eutectic growth of these alloy is simulated during directional solidification. At steady state, average growth velocity of eutectic lamella is equal to the pulling velocity. With the increasing of the liquidus slope of β phase, the average composition in boundary layer would deviate from eutectic composition and the deviation increases. The constitutional undercooling difference between both solid phases caused by the deviation increases with the increasing of the deviation. The β phase would develop a depression under the influence of the deviation.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 1; 119-123
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel laccase from fresh fruiting bodies of the wild medicinal mushroom Tricholoma matsutake
Autorzy:
Xu, Lijing
Zhu, Mengjuan
Chen, Xiao
Wang, Hexiang
Zhang, Guoqing
Powiązania:
https://bibliotekanauki.pl/articles/1039125.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Tricholoma matsutake
wild mushroom
isolation
laccase
decolorization
Opis:
The knowledge about biological activities of constituents from medicinal mushrooms belonging to the genus Tricholoma is limited. A 59-kDa laccase has now been purified from fresh fruiting bodies of the mushroom Tricholoma matsutake. The purification protocol entailed ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on CM-cellulose, affinity chromatography on ConA-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. Of the various affinity and ion exchange chromatographic media employed, the laccase bound only on Con A-Sepharose. The activity of the laccase did not undergo major changes over the temperature range 20-80°C. However, all activity vanished following exposure to 100°C for 10 minutes. The enzyme activity varied only slightly over the pH range 3-5, with the optimal pH of 5, but exhibited a precipitous decline when the pH was increased to 6, and was undetectable at pH 8 and 9. The laccase showed activity in the decolorization of azo dyes without a mediator. Its N-terminal sequence demonstrated only slight resemblance to those of other mushroom laccases. The newly described laccase is distinctive from the previously isolated Tricholoma mushroom laccases in a number of aspects.
Źródło:
Acta Biochimica Polonica; 2015, 62, 1; 35-40
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generation and characterization of a monoclonal antibody against duck Tembusu virus envelope protein
Autorzy:
Han, K.
Zhao, D.
Liu, Y.
Liu, Q.
Huang, X.
Yang, J.
Bi, K.
Xu, T.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/31495.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
Duck Tembusu virus (DTMUV) is a newly emerging pathogenic flavivirus that has caused massive economic losses to the duck industry in China. Envelope (E) protein of DTMUV is an important structural protein, which is able to induce protective immune response in target animals and can be used as specific serological diagnosis tool. In this study, a novel monoclonal antibody, designated mAb 3E9, was generated against DTMUV E protein. It is positive in indirect ELISA against both His-E protein and the purified whole viral antigen. Also, this mAb showed positive reaction with DTMUV in Western blot and indirect immunofluorescence assay, and the isotype was IgG1. End-point neutralizing assay performed in BHK-21 cells revealed that the neutralization titer of 3E9 against DTMUV JS804 strain reached 1:50. Furthermore, functional studies revealed that 3E9 blocks infection of DTMUV at a step on viral attachment. The anti-E mAbs produced in the present work may be valuable in developing an antigen-capture ELISA test for antigen detection or a competitive ELISA test for antibody detection or therapeutic medicine for DTMUV in poultry.
Źródło:
Polish Journal of Veterinary Sciences; 2016, 19, 4
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A flotation combined extraction process for improving the whiteness of phosphogypsum
Autorzy:
Li, Jiangli
Guo, Yongjie
Fan, Peiqiang
Li, Haibin
Chen, Ciyun
Xu, Shuai
Du, Lingpan
Powiązania:
https://bibliotekanauki.pl/articles/24085918.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phosphogypsum
whiteness
desilication
high-value utilization
floatation
extraction
Opis:
Every year, the production of industrial phosphoric acid generates more than 100 Tg of phosphogypsum (PG), leading to significant environmental damage and the occupation of a vast amount of land space. The urgent need to explore applications for PG has become increasingly apparent. However, impurities such as organic substances, slime, phosphorite, and SiO2 reduce the whiteness of PG, making it difficult to utilize for high-value applications. To address this issue, this study employed a two-stage flotation process to remove the majority of impurities, including SiO2, organic substances, and fine slime adhered to the surface of PG particles. The raw PG sample was first sieved to remove some SiO2 particles. After flotation, sulfuric acid and tributyl phosphate were introduced to decompose the PG particles and remove the impurities wrapped inside. Following this flotation combined extraction process, the whiteness of the PG sample improved from 54.1% to 92.9%, meeting the requirements for building walls and filters.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 3; art. no. 170043
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A systematic literature review on business cycle approaches: Measurement, nature, duration
Autorzy:
Pu, Zhongmin
Fan, Xuecheng
Xu, Zeshui
Skare, Marinko
Powiązania:
https://bibliotekanauki.pl/articles/19908376.pdf
Data publikacji:
2023
Wydawca:
Instytut Badań Gospodarczych
Tematy:
business cycle
business cycle approach
business cycle model
business cycle measurement
literature review
Opis:
Research background: The business cycle (BC) approaches have found extensive use in economic analysis and forecasting. Especially in the last 40 years, various modern BC models have been proposed and have experienced rapid development. However, there are no recent studies that provide a systematic review of the publications on this topic. Purpose of the article: This paper aims to comprehensively review publications of BC approaches based on the cause, nature and methods of measurement BC, with the goal of identifying the current research states, research gaps and future trends of BC approaches. Methods: A systematic literature review of BC approaches is conducted by qualitatively introducing the cause and the nature of BCs and quantitatively analyzing the methods of measurement BCs.  We selected 206 articles related to BC approaches from the WoS Core Collection and Google Scholar database, spanning the years 1946 to 2022, for comprehensive statistical and content analysis. The statistical analysis presents the distribution of publication years, the most popular journals and the highly cited publications. The content analysis classifies the selected publications into 6 categories based on methods of measurement BCs, and the theory, technique and applications of each category are analyzed in detail. Findings & value added: The analysis results indicate that BC approaches have progressively evolved in sophistication and have found widespread application in decomposing trends within economic time series, quantifying the nature of business cycles, and elucidating the causes and transmission mechanisms underlying them. This review paper provides current states, research challenges and future directions in effectively employing BC approaches for empirical study.
Źródło:
Oeconomia Copernicana; 2023, 14, 3; 935-976
2083-1277
Pojawia się w:
Oeconomia Copernicana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface Green’s function of a soft elastomer with the gravity effect
Autorzy:
Liang, Xiaodong
Liu, Junxiu
Xu, Peibao
Li, Kai
Powiązania:
https://bibliotekanauki.pl/articles/280502.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
surface Green’s function
gravity
distributed pressure
soft materials
neo-Hookean model
Opis:
Gravity can play a tremendous effect on deformation of rubberlike materials and biological soft tissues. In this paper, considering the gravity effect, we proposed a surface Green’s function of a soft elastomer based on the neo-Hookean model. The proposed surface Green’s function is applied to analyze the elastic deformation of a soft elastomer subjected to uniform pressure. The surface normal displacement of the soft elastomer is calculated and the results show that gravity has a large impact on the surface deformation of the elastomer. Generally, the surface normal displacement decreases with the increasing gravitational force.
Źródło:
Journal of Theoretical and Applied Mechanics; 2020, 58, 1; 35-44
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Theoretical Study of Polyethylene Glycol Polynitrates as Potential Highly Energetic Plasticizers for Propellants
Autorzy:
Wang, Guixiang
Xu, Yimin
Zhang, Wenjing
Gong, Xuedong
Powiązania:
https://bibliotekanauki.pl/articles/358877.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
polyethylene glycol polynitrates
density functional theory
density
specific impulse
stability
Opis:
Polyethylene glycol polynitrates may be used as plasticizers in propellants. In this study, ten derivatives of ethylene glycol dinitrate were investigated using the density functional theory method. The fitted densities (ρ’exp.) were obtained and were very close to the experimental values. The detonation properties were predicted using the modified Kamlet-Jacobs equations and the specific impulse (Is) was evaluated according to the largest exothermic principle. A new indicator, K = Is · ρ’exp., is proposed to evaluate the energetic characteristics of the plasticizers. Thermal stability is discussed by calculating the bond dissociation energies or energy barriers. The O−NO2 bond is the trigger bond for all of the compounds studied. Considering the energetic properties and stability, diethylene glycol tetranitrate, triethylene glycol hexanitrate, tetraethylene glycol octanitrate, pentaethylene glycol decanitrate and hexaethylene glycol dodecanitrate are potential energetic plasticizers for solid propellants. The influences of the −O−CH2−CH2− and −O−CH(ONO2)−CH(ONO2)− groups are also discussed, which will be helpful for the design of new highly energetic plasticizers by modifying the structures as required.
Źródło:
Central European Journal of Energetic Materials; 2019, 16, 2; 194-215
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability and Hopf bifurcation analysis for a Lotka-Volterra predator-prey model with two delays
Autorzy:
Xu, C.
Liao, M.
He, X.
Powiązania:
https://bibliotekanauki.pl/articles/907822.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
opóźnienie
stabilność
bifurkacja Hopfa
predator-prey model
delay
stability
Hopf bifurcation
Opis:
In this paper, a two-species Lotka-Volterra predator-prey model with two delays is considered. By analyzing the associated characteristic transcendental equation, the linear stability of the positive equilibrium is investigated and Hopf bifurcation is demonstrated. Some explicit formulae for determining the stability and direction of Hopf bifurcation periodic solutions bifurcating from Hopf bifurcations are obtained by using normal form theory and center manifold theory. Some numerical simulations for supporting the theoretical results are also included.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2011, 21, 1; 97-107
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reverse anionic flotation of dolomitic collophanite using a mixed fatty acid collector : adsorption behavior and mechanism
Autorzy:
Xu, Wei
Liang, Qun
Tian, Yan
Mei, Guangjun
Powiązania:
https://bibliotekanauki.pl/articles/2146926.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
collophanite
anionic collector
dolomite
QCM-D
adsorption mechanism
Opis:
Collophanite in south China generally has a high MgO level, which negatively impacts wet-process phosphoric acid production and cannot be utilized directly. A novel mixed fatty acid soap (GSWF01) was employed as a collector for dolomite. A single reverse flotation experiment was performed on a dolomitic collophanite from Guizhou, China under different pH and collector dosages. A phosphate concentrate with P2O5 grade of 33.73%, MgO content of 1.07%, MER value (ω(MgO+Al2O3+Fe2O3)/ω(P2O5)) of 4.86% and phosphorus recovery of 91.06% was obtained. The beneficiation indexes of GSWF01 were better than that of sodium oleate (NaOL). The adsorption behavior and mechanism of GSWF01 on dolomite surface were investigated using quartz crystal microbalance with dissipation (QCM-D), atomic force microscope (AFM), infrared spectrometer (IR), and zeta potentiometer. The results revealed that GSWF01 chemically reacted with metal ions (Ca2+, Mg2+, etc.) on the surface of dolomite to generate fatty acid salt precipitation (chemisorption). The adsorbed layer transitioned from dense to loose in two stages, resulting in a stable double-layer adsorption structure. Moreover, in a weak acidic solution environment, physical adsorption of fatty acid molecules (RCOOH ((aq)) and fatty acid ion-molecular association compounds (RCOOH• RCOO-) generated by hydrolysis can also occur on the dolomite surface. These are the main reasons for the hydrophobic floating of dolomite. This is of great significance to the development of a novel high-efficiency dolomite collector and the enhancement of flotation process for carbonate collophanite.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 4; art. no. 151519
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of injection pressure and strategy in a Jaguar V6 diesel engine
Autorzy:
Abdullah, N. R.
Mamat, R.
Rounce, P.
Wyszynski, M. L.
Tsolakis, A.
Xu, H. M.
Tian, G.
Powiązania:
https://bibliotekanauki.pl/articles/242414.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
combustion
emissions
injection strategies
premixed combustion
ignition delay
Opis:
In recent years, the improvement of engine performance and emissions has become an extremely important concern. This study focuses on the injection strategy based on the injection pressure (IP) and duration between pilot injection and the main injection (dMI) using a multi cylinder common rail multiple injections diesel engine. The study was designed to produce improvements in fuel mixing via the injection strategy, to reduce the main ignition delay. This would contribute to a minimum amount of fuel burnt in the premixed combustion phase, leading to a reduction in emissions. Recent evidence shows that premixed combustion is significant in the controlling of emissions of nitrogen oxides (NOx) and soot. Six different IPs combined with a short and long dMI were compared in the attempt to improve engine performance and emissions. The engine performance was measured in terms of brake specific fuel consumption, ignition delay, heat release and peak in-cylinder pressure and emissions, specifically nitrogen oxides (NOx), total unburned hydrocarbons (THC), carbon monoxide (CO) and smoke emissions for each engine test condition. The evidence from this study shows that the effect of IP is more dominant than dMI in terms of peak cylinder pressure, heat release, brake specific fuel consumption and emissions. However, the dMI shows a strong effect at a higher engine speed.
Źródło:
Journal of KONES; 2009, 16, 2; 9-22
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Global behavior of a multi-group SEIR epidemic model with spatial diffusion in a heterogeneous environment
Autorzy:
Liu, Pengyan
Li, Hong-Xu
Powiązania:
https://bibliotekanauki.pl/articles/2134056.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
global stability
multigroup epidemic model
spatial heterogeneity
spatial diffusion
globalna stabilność
wielogrupowy model epidemii
różnorodność przestrzenna
dyfuzja przestrzenna
Opis:
In this paper, we propose a multi-group SEIR epidemic model with spatial diffusion, where the model parameters are spatially heterogeneous. The positivity and ultimate boundedness of the solution, as well as the existence of a global attractor of the associated solution semiflow, are established. The definition of the basic reproduction number is given by utilizing the next generation operator approach, whereby threshold-type results on the global dynamics in terms of this number are established. That is, when the basic reproduction number is less than one, the disease-free steady state is globally asymptotically stable, while if it is greater than one, uniform persistence of this model is proved. Finally, the feasibility of the main theoretical results is shown with the aid of numerical examples for a model with two groups.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2022, 32, 2; 271--283
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High Cycle Fatigue Performance of Hollow-Extruded 6005A-T6 Aluminum Alloy Characterized by a Layered Microstructure
Autorzy:
Ma, Zhongwei
Ma, Lin
Xu, Bo
Dan, Chuchen
He, Zhaokun
Wang, Yue
Powiązania:
https://bibliotekanauki.pl/articles/354038.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
friction stir welding
hollow-extruded 6005A-T6 aluminum alloy
fatigue
fracture
microstructure
Opis:
Sound joint of hollow-extruded 6005A-T6 aluminum alloy was achieved by friction stir welding and its high cycle fatigue performance was mainly investigated. As a result, the joint fatigue limit reaches 128.1 MPa which is 55% of the joint tensile strength. The fatigue fracture mainly occurs at the boundary between the stir zone and thermo-mechanically affected zone due to the large difference in the grain size. This difference is caused by the layered microstructure of the base material. The shell pattern with parallel arcs is the typical morphology in the fracture surface and the distance between arcs is increased with the increase of stress level. The specimen with the fracture located in the stir zone possesses a relatively low fatigue life.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 1; 285-292
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Water entry of a wedge into waves in three degrees of freedom
Autorzy:
Sun, Shi Yan
Chen, Hai Long
Xu, Gang
Powiązania:
https://bibliotekanauki.pl/articles/259045.pdf
Data publikacji:
2019
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
water entry
nonlinear waves
three degrees of freedom
boundary element method
auxiliary function method
Opis:
The hydrodynamic problem of a two-dimensional wedge entering into a nonlinear wave in three degrees of freedom is investigated based on the incompressible velocity potential theory. The problem is solved through the boundary element method in the time domain. To avoid numerical difficulties due to an extremely small contact area at the initial stage, a stretched coordinate system is used based on the ratio of the Cartesian system in the physical space to the distance travelled by the wedge in the vertical direction. The mutual dependence of body motion and wave loading is decoupled by using the auxiliary function method. Detailed results about body accelerations, velocities and displacements at different Froude numbers or different waves are provided, and the mutual effect between body motion and wave loading is analysed in depth.
Źródło:
Polish Maritime Research; 2019, 1; 117-124
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of finite element meshing accuracy on a welding machine for offshore platform’s modal analysis
Autorzy:
Xie, J.
Sun, D.
Xu, C.
Wu, J.
Powiązania:
https://bibliotekanauki.pl/articles/260126.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
finite element analysis
meshing
meshing accuracy
modal analysis
Opis:
The purpose objective of this study was to investigate the influence of finite element meshing accuracy on modal analysis which is one of the basic factors affecting the accuracy of finite element analysis and mostly preoccupies the working staff in pre-processing finite element simulation models. In this paper, we established several finite element models of a welding machine for offshore platform, with the meshing accuracy as the variable and workbench software as the platform for modal analysis, as the same time, comparing the analysis results. The results indicated that for some specific structures and simulation types, mesh refinement alone does not achieve desired results, and the authors indicate that mesh refinement is rarely related to the equipment’s low-frequency modal analysis but it’s great related to the equipment’s high-frequency modal analysis. The findings of this study may serve as breaking the opinion that smaller mesh size means higher calculation precision and provides references for mesh division practices in low frequency modal analysis.
Źródło:
Polish Maritime Research; 2018, S 3; 147-153
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A reassessment of Kelmayisaurus petrolicus, a large theropod dinosaur from the Early Cretaceous of China
Autorzy:
Brusatte, S.L.
Benson, R.B.J.
Xu, X.
Powiązania:
https://bibliotekanauki.pl/articles/21593.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
Kelmayisaurus petrolicus
large theropod dinosaur
theropod dinosaur
Early Cretaceous
China
Dinosauria
Theropoda
Carcharodontosauridae
anatomy
Cretaceous
Opis:
The Early Cretaceous fossil record of large−bodied theropods from Asia is poor, hindering comparison of Asian predatory dinosaur faunas with those from other continents. One of the few large Asian theropod specimens from this interval is a partial skull (maxilla and dentary) from the Lianmugin Formation (?Valanginian–Albian), the holotype of Kelmayisaurus petrolicus. Most authors have either considered this specimen as an indeterminate basal tetanuran or a nomen dubium. We redescribe K. petrolicus and note that it possesses a single autapomorphy (a deep accessory groove on the lateral surface of the anterior dentary), as well as a unique combination of characters that differentiates it from other theropods, affirming its validity. A phylogenetic analysis recovers K. petrolicus as a basal carcharodontosaurid, which is supported by various features: very deep interdental plates (a carcharodontosaurid synapomorphy), fused interdental plates (present in carchardontosaurids and a limited number of other theropods), and the absence of diagnostic features of other clades of large−bodied theropods such as abelisaurids, megalosauroids, and coelurosaurs. As such,Kelmayisaurusis the second known carcharodontosaurid from Asia, and further evidence that this clade represented a global radiation of large−bodied predators during the Early–mid Cretaceous.
Źródło:
Acta Palaeontologica Polonica; 2012, 57, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polyamine plays a role in subculture growth of in vitro callus of indica rice
Autorzy:
Tan, Yanping
Hu, Wen
Xu, Xin
Zhou, Jie
Wang, Chuntai
Liu, Xuequn
Cheng, Gang
Powiązania:
https://bibliotekanauki.pl/articles/952026.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
browning
callus
gene expression
indica rice
polyamine
Opis:
In vitro embryogenic callus is a critical factor for genetic transformation of rice, especially for indica varieties. In this study, we investigated the relationship between polyamines, including putrescine (Put), spermidine (Spd) and spermine (Spm), and callus browning, and we studied the effect of exogenous Put on callus regeneration and on the content of endogenous polyamines. In addition, the expression levels of arginine decarboxylase gene (Adc1) and S-adenosylmethionine decarboxylase gene (Samdc) in embryogenic callus were studied by quantitative Real-time PCR analysis. The results showed that the contents of endogenous Put and Spd in the browning callus were significantly lower than those in normal callus. Exogenous Put could effectively improve the growing state of callus of indica rice and enhance the development of embryogenic callus. The content of endogenous polyamines in embryogenic callus, especially Spd and Spm, was increased after addition of exogenous Put. Additionally, exogenous Put also had an obvious impact on the expression levels of Adc1 but partial effect on the expression levels of Samdc gene. This study could increase the knowledge of both embryogenic callus induction and polyamine catabolism in callus in indica rice.
Źródło:
Acta Biologica Cracoviensia. Series Botanica; 2017, 59, 1
0001-5296
Pojawia się w:
Acta Biologica Cracoviensia. Series Botanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of biodiesel blended fuel on the performance and emission characteristics of diesel engines – a review
Autorzy:
Zheng, Fangyuan
Cho, Haeng Muk
Xu, Changchun
Powiązania:
https://bibliotekanauki.pl/articles/2174181.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
biodiesel
paliwo
emisja spalin
diesel engine
fuel properties
engine performance
exhaust emission
Opis:
The internal combustion engine plays a vital role in transportation, industry, and shipping. However, diesel as one of the main fuels for internal combustion engines, caused many environmental and human health problems. In order to solve the problems, more researchers have been committed to the research of alternative fuels. Biodiesel is a renewable, sustainable alternative fuel, and its characteristics are similar to traditional diesel. It can be mixed with pure diesel. It has been found that a mix with pure diesel in a certain ratio can effectively reduce the negative effects caused by its characteristics, improve the combustion performance, and reduce the NOx and PM emissions. This article mainly reviews the effects of the mixture of biodiesel and diesel on engine combustion characteristics and exhaust emissions, including three parts: part (1) summarizes and analyzes the biodiesel’s production and characteristics, part (2) analyzes the engine’s performance under different working conditions, and part (3) studies and analyzes the exhaust emission under different working conditions.
Źródło:
International Journal of Applied Mechanics and Engineering; 2022, 27, 1; 215--231
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the Knittability of Metallic Yarns in the Warp-knitted Mesh of a Deployable Antenna
Autorzy:
Haiyan, Xu
Nanliang, Chen
Jinhua, Jiang
Powiązania:
https://bibliotekanauki.pl/articles/24200963.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
metallic yarn
knittability
knitted yarn strength
utilisation factor
tensile properties
bending stiffness
Opis:
Metallic yarns are difficult to be knitted. To resolve the problem, the paper used the knitted yarn strength utilization factor to quantitatively characterize knittability, which was the ratio of yarn strength after being knitted to that of the original yarns. Furthermore, the relationship between the yarns’ basic mechanical properties and the knitted yarn strength utilization factor was investigated by testing the yarns’ basic mechanical properties. The results showed that it was feasible to quantitatively characterize the yarns’ knittability using the knitted yarn strength utilization factor. And also the breaking strength of yarn was not correlated with the knittability. The elongation at break of the yarn was positively correlated with knittability. The bending stiffness of the yarn was negatively correlated with the knittability. Finally, a multiple linear regression model of the knittability and the mechanical properties of the yarn was developed. The model showed that there was a significant linear relationship between knittability and the elongation of yarns at break and the bending rigidity of yarns, with the bending stiffness of yarns being more significant.
Źródło:
Fibres & Textiles in Eastern Europe; 2023, 31, 2; 51--55
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Global well-posedness of a class of fourth-order strongly damped nonlinear wave equations
Autorzy:
Yanbing, Yang
Ahmed, Md Salik
Lanlan, Qin
Runzhang, Xu
Powiązania:
https://bibliotekanauki.pl/articles/255961.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
fourth-order nonlinear wave equation strong damping
blow up
global existence
Opis:
Global well-posedness and finite time blow up issues for some strongly damped nonlinear wave equation are investigated in the present paper. For subcritical initial energy by employing the concavity method we show a finite time blow up result of the solution. And for critical initial energy we present the global existence, asymptotic behavior and finite time blow up of the solution in the framework of the potential well. Further for supercritical initial energy we give a sufficient condition on the initial data such that the solution blows up in finite time.
Źródło:
Opuscula Mathematica; 2019, 39, 2; 297-313
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Construction of a reduced mechanism for diesel-natural gas -hydrogen using HCCI model with Direct Relation Graph and Sensitivity Analysis
Autorzy:
Rui, Zhao
Leping, Xu
Shiquan, Feng
Powiązania:
https://bibliotekanauki.pl/articles/779831.pdf
Data publikacji:
2020
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
diesel
natural gas
hydrogen
reduced mechanism
DRG
SA
Opis:
Based on the theory of direct relation graph (DRG) and sensitivity analysis (SA), a reduced mechanism for diesel CH4-H2 tri-fuel is constructed. The detailed mechanism of Lawrence Livermore National Laboratory, which has 654 elements and 2827 elementary reactions, is used for mechanism reduction with DRG. Some small thresholds are used in the process of simplifying the detailed mechanism via DRG, and a skeletal mechanism of 266 elements is obtained. Based on the framework of the skeletal mechanism, the time-consuming approach of sensitivity analysis is used for further simplification, and the skeletal mechanism is reduced to 262 elements. Validation of the reduced mechanism is done via a comparison of ignition delay time and laminar flame speed from the calculation using the reduced mechanism and the detailed mechanism or experiment. The reduced mechanism shows good agreement with the detailed mechanism and with related experimental data.
Źródło:
Polish Journal of Chemical Technology; 2020, 22, 4; 55-60
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A numerical and experimental study of marine hydrogen–natural gas–diesel tri–fuel engines
Autorzy:
Zhao, Rui
Xu, Leping
Su, Xiangwen
Feng, Shiquan
Li, Changxiong
Tan, Qinming
Wang, Zhongcheng
Powiązania:
https://bibliotekanauki.pl/articles/1573839.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
hydrogen
tri-fuel engine
combustion performance
emission performance
Opis:
Maritime shipping is a key component of the global economy, representing 80–90% of international trade. To deal with the energy crisis and marine environmental pollution, hydrogen-natural gas-diesel tri-fuel engines have become an attractive option for use in the maritime industry. In this study, numerical simulations and experimental tests were used to evaluate the effects of different hydrogen ratios on the combustion and emissions from these engines. The results show that, in terms of combustion performance, as the hydrogen proportion increases, the combustion ignition delay time in the cylinder decreases and the laminar flame speed increases. The pressure and temperature in the cylinder increase and the temperature field distribution expands more rapidly with a higher hydrogen ratio. This means that the tri-fuel engine (H2 +CH4 +Diesel) has a faster response and better power performance than the dual-fuel engine (CH4 +Diesel). In terms of emission performance, as the hydrogen proportion increases, the NO emissions increase, and CO and CO2 emissions decrease. If factors such as methane escape into the atmosphere from the engine are considered, the contribution of marine tri-fuel engines to reducing ship exhaust emissions will be even more significant. Therefore, this study shows that marine hydrogen-natural gas-diesel tri-fuel engines have significant application and research prospects.
Źródło:
Polish Maritime Research; 2020, 4; 80-90
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of a Compton backscattering wall defects detection device using the Monte Carlo method
Autorzy:
Qin, Xuan
Yang, Jianbo
Du, Zhengcong
Xu, Jie
Li, Rui
Li, Hui
Liu, Qi
Powiązania:
https://bibliotekanauki.pl/articles/24202748.pdf
Data publikacji:
2023
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
compton backscattering
Monte Carlo
nondestructive testing
wall defect
Opis:
In view of the shortcomings of traditional wall defect detection methods, such as small detection range, poor accuracy, non-portable device, and so on, a wall defects detection device based on Compton backscattering technology is designed by Monte Carlo method, which is mainly used to detect the size and location information of defects in concrete walls. It mainly consists of two parts, the source container and the detection system: first, through the simulation and analysis of the parameters such as the receiving angle of thebackscattered particles and the rear collimating material of the detector, the influence of the fluorescent X-ray peak of the detector collimating material on the backscattered particle counts is eliminated and the detected error is reduced; second, the ring array detector design, compared with single array detector and surface array detector, can facilitate real-time detection of defect orientation, expanding the single scan range and improving the detection efficiency. After simulation and comparative analysis, the relevant optimal parameters are obtained: the object is detected using a Cs-137 γ-ray source with an activity of 6 mCi, and a ring detector consisting of four 0.5-inch cube-shaped CsI scintillator detectors is placed at 150° to receive the backscattered photons. The simulation analysis using the Monte Carlo FLUKA program showed that the maximum depth of wall defect detection is 8 cm, the maximum error fl uctuation range of defect depth and thickness is ±1 cm, the overall device weight is <20 kg, and the measurement time is <5 min.
Źródło:
Nukleonika; 2023, 68, 2; 57--63
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Limits of stabilization of a networked hyperbolic system with a circle
Autorzy:
Gugat, Martin
Huang, Xu
Wang, Zhiqiang
Powiązania:
https://bibliotekanauki.pl/articles/31342765.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
hyperbolic system
exponential stability
circle
network
Opis:
This paper is devoted to the discussion of the exponential stability of a networked hyperbolic system with a circle. Our analysis extends an example by Bastin and Coron about the limits of boundary stabilizability of hyperbolic systems to the case of a networked system that is defined on a graph which contains a cycle. By spectral analysis, we prove that the system is stabilizable while the length of the arcs is sufficiently small. However, if the length of the arcs is too large, the system is not stabilizable. Our results are robust with respect to small perturbations of the arc lengths. Complementing our analysis, we provide numerical simulations that illustrate our findings.
Źródło:
Control and Cybernetics; 2023, 52, 1; 79-121
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of the ducted propeller and application to a semi-submerged vehicle
Autorzy:
Zou, Jin
Tan, Guoge
Sun, Hanbing
Xu, Jie
Hou, Yongkang
Powiązania:
https://bibliotekanauki.pl/articles/259041.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
open water test
self-propulsion test
ducted propeller
unmanned semi-submerged vehicle
Opis:
The self-propulsion test of underwater vehicles is the key technique for predicting and evaluating the navigation performance of these submersibles. In this study, the numerical simulation of a standard propeller JD7704+Ka4-70 is first presented and the results are compared with experiments to validate the numerical approaches. The reason why the propulsion efficiency of the ducted propeller is higher than that of the conventional propeller is explored. Then, the paper proposes a series of numerical simulations conducted to test the performance of the ducted propeller designed according to the JD7704+Ka4-70 in order to match with the unmanned semi-submerged vehicle (USSV), and the propeller’s open water characteristic curves are obtained. The results show a reasonable agreement with the regression analysis. Afterwards, the numerical simulations focus on a self-propulsion test of the USSV with the designed ducted propeller and the self-propulsion point is obtained. The streamlines through the hull as well as the ducted propellers are clearly obtained, together with the velocity distributions of the propeller plane. The results vividly demonstrate the hydrodynamic performance of the USSV with the designed propellers. In this paper, all the CFD simulations are based on the numerical software, Star-CCM+, and use the Reynolds-averaged Navier‒Stokes (RANS) equations with the shear stress transport (SST) k-omega turbulence model.
Źródło:
Polish Maritime Research; 2020, 2; 19-29
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An articulated pes from a small parvicursorine alvarezsauroid dinosaur from Inner Mongolia, China
Autorzy:
Hone, D.W.E.
Choiniere, J.N.
Tan, Q.
Xu, X.
Powiązania:
https://bibliotekanauki.pl/articles/21549.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
paleontology
Dinosauria
Theropoda
maniraptoran
arctometatarsalian organism
Cretaceous
Inner Mongolia
alvarezsauroid dinosaur
dinosaur
China
Opis:
A near complete and articulated parvicursorine pes from the Campanian Wulansuhai Formation is described. This pes is referred to the genus Linhenykus and is one of the first foot skeletons to be described for a derived alvarezsaur, providing new information on the first digit of the pes. The evolution of a laterally directed flange of the anterior face of the distal third metatarsal in arctometatarsalian taxa is described and discussed. This flange may have increased stability of the foot during cursorial locomotion and may also provide useful taxonomic and systematic data.
Źródło:
Acta Palaeontologica Polonica; 2013, 58, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of progressive collapse of a super-long span latticed steel arch structure
Autorzy:
Guo, Shuangchao
Xu, Delin
Shang, Kaiguang
Yang, Shuo
Wang, Di
Li, Gen
Zheng, Bing
Jiao, Yong
Powiązania:
https://bibliotekanauki.pl/articles/2200875.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
progressive collapse
steel arch truss structure
compression instability
Opis:
The progressive collapse of a space grid structure which has a large number of members and a large span is the focus of current research. Before the progressive collapse of the structure, there is a problem of instability of the members. In this paper, dynamic nonlinear analysis of a super-long span latticed steel arch structure is carried out to study its progressive collapse process using a Kinematic Hardening Plasticity constitutive model compiled by Vumat material subprogram in Abaqus, which takes into account instability of the members. Differences in the dynamic response process of the structure at the collapse moment and the failure sequence of the members using the member stability model and the material failure constitutive model are compared. Compared with the material failure constitutive model, when the member stability constitutive model is used, the proportion of compressive buckling members in the structural failure is higher, and the bearing capacity of the structure is lower when the initial failure occurs. The structure suffers from localized member compressive failure rather than material yielding, which leads to the progressive collapse of the structure.
Źródło:
Journal of Theoretical and Applied Mechanics; 2023, 61, 1; 103--117
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A double-iterative learning and cross-coupling control design for high-precision motion control
Autorzy:
Xu, Wan
Hou, Jie
Yang, Wei
Wang, Cong
Powiązania:
https://bibliotekanauki.pl/articles/140531.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
iterative learning control
cross-coupled control
contour tracking performance
double-iterative learning and cross coupling
Opis:
In multi-axis motion control systems, the tracking errors of single axis load and the contour errors caused by the mismatch of dynamic characteristics between the moving axes will affect the accuracy of the motion control system. To solve this issue, a biaxial motion control strategy based on double-iterative learning and cross-coupling control is proposed. The proposed control method improves the accuracy of the motion control system by improving individual axis tracking performance and contour tracking performance. On this basis, a rapid control prototype (RCP) is designed, and the experiment is verified by the hardware and software platforms, LabVIEW and Compact RIO. The whole design shows enhancement in the precision of the motion control of the multi- axis system. The performance in individual axis tracking and contour tracking is greatly improved.
Źródło:
Archives of Electrical Engineering; 2019, 68, 2; 427-442
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shock Waves and Other Solutions to the Benjamin-Bona-Mahoney-Burgers Equation with Dual Power-Law Nonlinearity
Autorzy:
Wang, G.
Xu, T.
Abazari, R.
Jovanoski, Z.
Biswas, A.
Powiązania:
https://bibliotekanauki.pl/articles/1377509.pdf
Data publikacji:
2014-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.30.Ik
02.30.Jr
02.20.Qs
Opis:
We study the hybrid Benjamin-Bona-Mahoney-Burgers equation with dual power-law nonlinearity. Three different techniques - the ansatz method, Lie-symmetry analysis and the (G'/G)-expansion method - are used to find shock wave solutions. Several constraint conditions naturally emerge that guarantee the existence of shock waves. We discuss the nature of the solutions generated by the different methods.
Źródło:
Acta Physica Polonica A; 2014, 126, 6; 1221-1225
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Morphological Studies on Five Trachelocercids from the Yellow Sea coast of China, with a Description of Tracheloraphis huangi spec. nov. (Ciliophora, Karyorelictea)
Autorzy:
Xu, Yuan
Esaulov, Anton
Lin, Xiaofeng
Mazei, Yuri
Hu, Xiaozhong
Al-Rasheid, Khaled A. S.
Warren, Alan
Powiązania:
https://bibliotekanauki.pl/articles/763700.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Infraciliature, Karyorelictea, marine ciliates, Trachelocerca, Tracheloraphis
Opis:
The morphology and infraciliature of five trachelocercid ciliates: Tracheloraphis huangi spec. nov., T. colubis (Kahl, 1933) comb. nov., T. phoenicopterus (Cohn, 1866) Dragesco, 1960, T. oligostriata (Raikov, 1962) Foissner and Dragesco, 1996 and Trachelocerca incaudata Kahl, 1933, isolated from the intertidal zone of a beach at Qingdao, China, were studied in live and protargol impregnated specimens. Tracheloraphis huangi spec. nov. was distinguished from its congeners mainly by its single nuclear group composed of 25–30 round macronuclei and 29–37 somatic kineties. The poorly known T. colubis is redescribed including for the first time information on its infraciliature. An improved diagnosis is also provided. In light of its infraciliature, T. colubis is transferred to Tracheloraphis from the genus Trachelocerca. Additional data on other three species is supplied based on the Qingdao populations.
Źródło:
Acta Protozoologica; 2011, 50, 3
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Friele Model of Rotor Spun Multi-Primary-Colour-Blended Yarn
Model Friele’a dla wielobarwnej przędzy mieszanej uzyskanej przędzeniem rotorowym
Autorzy:
Yang, Ruihua
Xu, Yaya
Han, Ruiye
Powiązania:
https://bibliotekanauki.pl/articles/233596.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
rotor spun
colour blended yarn
Friele model
wirnik
mieszanie kolorów
model Friele
Opis:
Multi-channel rotor spinning equipment can produce multi-colour mixed yarn by changing the feed speeds of three primary coloured slivers separately. The method realises the mixing of colour fibres during the spinning process, and has the characteristics of high production flexibility, simplicity and quickness. The colour mixing effect and colour blending ratio prediction are important conditions for industrial production. In this paper, two-component and three-component samples were spun with rovings of red, yellow and blue with different blending ratios. A colour model of the rotor spun multi-primary-colour-blended yarn was established based on Friele theory by determining the σ value, which is the model parameter determined by experiments. Two methods were employed to calculate the σ value to improve the accuracy of the model:1. under the condition of all wavelengths and 2. at various wavelengths. The results showed that the model parameters calculated at various wavelengths could better predict the colour of multi-channel rotor spun colour-blended yarn.
Wielokanałowy wirnik może wytwarzać wielobarwną przędzę mieszaną zmieniając oddzielnie prędkości podawania trzech podstawowych kolorowych taśm. Zaprezentowana metoda pozwala na mieszanie włókien barwnych podczas procesu przędzenia i ma cechy wysokiej elastyczności produkcji, prostoty i szybkości. Efekt mieszania kolorów i przewidywania stosunku mieszania kolorów są ważnymi czynnikami w produkcji przemysłowej. W pracy wyprzędziono próbki dwuskładnikowe i trójskładnikowe z niedoprzędami koloru czerwonego, żółtego i niebieskiego o różnych stosunkach mieszania. W oparciu o teorię Friele’a ustalono model barwny przędzy wielobarwnej mieszanej określając wartość σ, która jest parametrem modelu określonym przez eksperymenty. W celu poprawy dokładności modelu do obliczenia wartości σ zastosowano dwie metody: 1) w warunkach wszystkich długości fal i 2) przy różnych długościach fal. Wyniki pokazały, że parametry modelu obliczone przy różnych długościach fali służą do lepszego przewidywania koloru przędzy.
Źródło:
Fibres & Textiles in Eastern Europe; 2019, 5 (137); 34-38
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and verification of a high-precision laser measurement system for straightness and parallelism measurement
Autorzy:
Xu, Peng
Li, Rui Jun
Zhao, Wen Kai
Chang, Zhen Xin
Ma, Shao Hua
Fan, Kuang Chao
Powiązania:
https://bibliotekanauki.pl/articles/1849006.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
straightness
parallelism
laser measurement system
machine tool
Opis:
A laser measurement system for measuring straightness and parallelism error using a semiconductor laser was proposed. The designing principle of the developed system was analyzed. Addressing at the question of the divergence angle of the semiconductor laser being quite large and the reduction of measurement accuracy caused by the diffraction effect of the light spot at the long working distance, the optical structure of the system was optimized through a series of simulations and experiments. A plano-convex lens was used to collimate the laser beam and concentrate the energy distribution of the diffraction effect. The working distance of the system was increased from 2.6 m to 4.6 m after the optical optimization, and the repeatability of the displacement measurement is kept within 2.2 m in the total measurement range. The performance of the developed system was verified by measuring the straightness of a machine tool through the comparison tests with two commercial multi-degree-of-freedom measurement systems. Two different measurement methods were used to verify the measurement accuracy. The comparison results show that during the straightness measurement of the machine tool, the laser head should be fixed in front of the moving axis, and the sensing part should move with the moving table of the machine tool. Results also show that the measurement error of the straightness measurement is less than 3 m compared with the commercial systems. The developed laser measurement system has the advantages of high precision, long working distance, low cost, and suitability for straightness and parallelism error measurement.
Źródło:
Metrology and Measurement Systems; 2021, 28, 3; 479-495
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method for measuring the quality parameters of image intensifier based on projecting phase-shifting gratings
Autorzy:
Sun, S.
Cao, Y.
Chen, C.
Fu, G.
Wang, Y.
Xu, X.
Powiązania:
https://bibliotekanauki.pl/articles/174300.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phase measurement
phase-shifting grating
distortion
image intensifier
imaging quality parameter
Opis:
A method for measuring the quality parameters of image intensifier based on projecting phase-shifting gratings is proposed. A set of designed phase-shifting gratings are projected into the measuring system orderly to obtain the magnification parameter of the measured image intensifier, and the phase caused by the measured image intensifier. After obtaining the referential phase caused by only the magnification of the measured image intensifier, the phase caused by the distortion of the measured image intensifier is extracted by phase calculating and phase unwrapping. Both the global distortion and the partial distortion of the measured image intensifier can be measured by phase-to-distortion matching at the same time. The experimental results show that the proposed method can measure the multiple quality parameters of image intensifier effectively.
Źródło:
Optica Applicata; 2018, 48, 1; 39-51
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and Curing of Allyl Urethane NIMMO-THF Copolyether with Three Functional Groups as a Potential Energetic Binder
Autorzy:
Wang, Xiaochuan
Li, Ping
Lu, Xianming
Mo, Hongchang
Xu, Minghui
Liu, Ning
Shu, Yuanjie
Powiązania:
https://bibliotekanauki.pl/articles/358158.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
energetic binder
copolyether
nitrile oxide
elastomer
Opis:
A tri-functional NIMMO-THF copolyether (T-NT) was synthesized by polymerization of 3-nitratomethyl-3-methyloxetane (NIMMO) and tetrahydrofuran (THF) in the presence of trimethylolpropane and catalyzed by BF3·OEt2. The allyl urethane NIMMO-THF copolyether with three functional groups (AUT-NT) was synthesized from tri-functional NIMMO-THF copolyether and allyl isocyanate. The polymer was characterized by FT-IR, 1H NMR, and 13C NMR. Furthermore, an elastomer that was prepared from allyl urethane NIMMO-THF copolyether with three functional groups and trimethylisophthalodinitrile oxide (TINO) had satisfactory mechanical properties and good thermal stability. The elastomer is expected to be used in composite solid propellants and polymer-bonded explosives (PBX).
Źródło:
Central European Journal of Energetic Materials; 2020, 17, 1; 141-163
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Lifting Wavelet Domain Audio Watermarking Algorithm Based on the Statistical Characteristics of Sub-Band Coefficients
Autorzy:
Tao, Z.
Zhao, H.
Wu, J.
Gu, J.
Xu, Y.
Wu, D.
Powiązania:
https://bibliotekanauki.pl/articles/177956.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
audio watermarking
lifting wavelet transform
statistical characteristics
sub-band coefficients
Opis:
In this paper, a new lifting wavelet domain audio watermarking algorithm based on the statistical characteristics of sub-band coefficients is proposed. First of all, an original audio signal was segmented and each segment was divided into two sections. Then, the Barker code was used for synchronization, the LWT (lifting wavelet transform) was performed on each section, a synchronization code and a watermark were embedded into the first section and the second section, respectively, by modifying the statistical average value of the sub-band coefficients. The embed strength was determined adaptively according to the auditory masking property. Experiments show that the embedded watermark has better robustness against common signal processing attacks than present algorithms based on LWT and can resist random cropping in particular.
Źródło:
Archives of Acoustics; 2010, 35, 4; 481-491
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of forest growth conditions on the wood density: the case of Amur Region
Autorzy:
Romanova, Natalia A.
Zbirnov, Alexander B.
Yust, Natalia A.
Fucheng, Xu
Powiązania:
https://bibliotekanauki.pl/articles/2045741.pdf
Data publikacji:
2018
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
forest growth conditions of the Amur region
Amur region
wood density
Dahurian larch
Scots pine
wood moisture content
Asian white birch
Opis:
The problem of determining the dependence of the chainsaw on the density of wood, substantiation of effective options for the number of chainsaws in the assortment and whiplash method of logging is quite relevant. In the Far East of Russia, in particular, in the Amur region, the forest growth conditions are different from the western ones, and therefore, the properties of the wood differ from the generally accepted ones. The article describes forest growth conditions that influence the properties of the wood in areas of the Amur region. Using the method of density determination, the density of larch, pine and birch were studied for first time in the areas of the region. The dependence of the density on humidity, age, species, season of the year and the area of growth was found out. The results of the research showed that under humidity of 70%, the density of larch was 1088.99 kg/m3, it was 919.8 kg/m3 for pine and it was for birch 915.9 kg/m3.
Źródło:
Folia Forestalia Polonica. Series A . Forestry; 2018, 60, 4; 292-298
0071-6677
Pojawia się w:
Folia Forestalia Polonica. Series A . Forestry
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Morphology of Two Novel Species of Chaenea (Ciliophora, Litostomatea): Chaenea paucistriata spec. nov. and C. sinica spec. nov.
Autorzy:
Fan, Xinpeng
Xu, Yuan
GU, Fukang
LI, Jiqiu
Al-Farraj, Saleh A.
Al-Rasheid, Khaled A. S.
Hu, Xiaozhong
Powiązania:
https://bibliotekanauki.pl/articles/763652.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Chaenea, ciliary pattern, identification key, marine ciliates, new species, taxonomy
Opis:
During faunistic studies of ciliates in coastal waters of Daya Bay and Bohai Bay, China, two previously unknown ciliates were discovered and investigated using standard taxonomic methods. Morphological comparative analyses revealed that they represent two novel species in the genus Chaenea. Chaenea paucistriata spec. nov. can be distinguished from its congeners by the following traits: body length in vivo about 180–250 µm; eight somatic kineties; dorsal brush rows 1–4 consisting of three, five, seven, and two dikinetids, respectively; rod-like extrusomes, 8 µm long; 63–94 macronuclei; cortical granules minute and colourless. Chaenea sinica spec. nov. differs from its congeners in having: body length in vivo about 140–240 µm; 17–21 somatic kineties; dorsal brush rows 1–4 consisting of 3–7, 10 or 11, 11–13, and 3–6 dikinetids, respectively; rod-like extrusomes about 6–8 µm long; 71–164 macronuclei. A key is presented to assist the identification of all Chaenea species.
Źródło:
Acta Protozoologica; 2015, 54, 2
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
How Clean is Clean Enough? Maintaining Thermal Protective Clothing Under Field Conditions in the Oil and Gas Sector
Autorzy:
Crown, E. M.
Feng, A.
Xu, X.
Powiązania:
https://bibliotekanauki.pl/articles/90475.pdf
Data publikacji:
2004
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
protective clothing
decontamination
flammability
przemysł wydobywczy
gaz kopalniany
odzież ochronna
izolacja cieplna
tkaniny na odzież ochronną
Opis:
The purpose of this research was to develop practical care procedures to help maintain the protective quality of flame resistant workwear laundered by workers in the field. Based on observed field conditions, experiments were conducted that simulated domestic laundry procedures. The first experiment involved two flame resistant (FR) fabrics, contaminated or not contaminated with oil. Independent variables also included detergent type and laundry pre-treatment. Other laundry parameters were controlled. Results indicated that it is easier to maintain the FR performance of the FR-treated blend than it is for the aramid fabric. It is hypothesized that energy generated by initial ignition of oil on the specimens triggers the FR mechanism of the treatment, which in turn inhibits further combustion. A second experiment using larger specimens and a domestic washing machine also supported the hypothesized mechanism.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2004, 10, 3; 247-254
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the effect of variable compression ratios performance on opposed piston 2-stroke engine
Autorzy:
Alqahtani, A.
Wyszynski, M. L.
Mazuro, P.
Xu, H.
Powiązania:
https://bibliotekanauki.pl/articles/133658.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
opposed-piston
AVL BOOST
VCR
compression ratio
numerical simulation
tłok przeciwbieżny
stopień sprężania
symulacja numeryczna
Opis:
Numerous skills involving the introduction of (OP) opposed piston engine have been developed in the recent past. Indeed, novel techniques can help to improve the performance of the engine. The aim of this paper is to model and simulate a simple single-cylinder two-stroke opposed-piston engine and minimise fuel consumption and heat loss, using the software programme AVL BOOST™. AVL BOOST is an engine modelling software, which analyses the performance of a modelled single cylinder two-stroke opposed-piston engine by changing desired parameters. In order to meet this aim, experimental results from a unique engine are used to make a comparison with the results obtained from AVL BOOST model. Six combinations of compression ratios (12, 13.5, 15, 16.5, 18 and 19.5) are analysed in this study with the engine speed running at 420 rpm and 1500 rpm. In addition to the compression ratios, the effect of stroke-to-bore (S/B) ratios on OP2S performance is investigated. Various values of S/B ratios, whilst maintaining a constant swept volume, port geometry and combustion timing, and their effect on fuel consumption and heat loss are analysed in this study. A comparison between the two engine speeds with increasing combinations of compression ratios, and the S/B ratios revealed minimal differences in peak pressure, peak temperature, IMEP, ISFC, indicated efficiency and total heat loss. Detailed analyses of these parameters are highlighted in discrete sections of this paper.
Źródło:
Combustion Engines; 2017, 56, 4; 97-106
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and verification of a high-precision laser measurement system for straightness and parallelism measurement
Autorzy:
Xu, Peng
Li, Rui Jun
Zhao, Wen Kai
Chang, Zhen Xin
Ma, Shao Hua
Fan, Kuang Chao
Powiązania:
https://bibliotekanauki.pl/articles/1849049.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
straightness
parallelism
laser measurement system
machine tool
Opis:
A laser measurement system for measuring straightness and parallelism error using a semiconductor laser was proposed. The designing principle of the developed system was analyzed. Addressing at the question of the divergence angle of the semiconductor laser being quite large and the reduction of measurement accuracy caused by the diffraction effect of the light spot at the long working distance, the optical structure of the system was optimized through a series of simulations and experiments. A plano-convex lens was used to collimate the laser beam and concentrate the energy distribution of the diffraction effect. The working distance of the system was increased from 2.6 m to 4.6 m after the optical optimization, and the repeatability of the displacement measurement is kept within 2.2 m in the total measurement range. The performance of the developed system was verified by measuring the straightness of a machine tool through the comparison tests with two commercial multi-degree-of-freedom measurement systems. Two different measurement methods were used to verify the measurement accuracy. The comparison results show that during the straightness measurement of the machine tool, the laser head should be fixed in front of the moving axis, and the sensing part should move with the moving table of the machine tool. Results also show that the measurement error of the straightness measurement is less than 3 m compared with the commercial systems. The developed laser measurement system has the advantages of high precision, long working distance, low cost, and suitability for straightness and parallelism error measurement.
Źródło:
Metrology and Measurement Systems; 2021, 28, 3; 479-495
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and verification of a high-precision laser measurement system for straightness and parallelism measurement
Autorzy:
Xu, Peng
Li, Rui Jun
Zhao, Wen Kai
Chang, Zhen Xin
Ma, Shao Hua
Fan, Kuang Chao
Powiązania:
https://bibliotekanauki.pl/articles/1849061.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
straightness
parallelism
laser measurement system
machine tool
Opis:
A laser measurement system for measuring straightness and parallelism error using a semiconductor laser was proposed. The designing principle of the developed system was analyzed. Addressing at the question of the divergence angle of the semiconductor laser being quite large and the reduction of measurement accuracy caused by the diffraction effect of the light spot at the long working distance, the optical structure of the system was optimized through a series of simulations and experiments. A plano-convex lens was used to collimate the laser beam and concentrate the energy distribution of the diffraction effect. The working distance of the system was increased from 2.6 m to 4.6 m after the optical optimization, and the repeatability of the displacement measurement is kept within 2.2 m in the total measurement range. The performance of the developed system was verified by measuring the straightness of a machine tool through the comparison tests with two commercial multi-degree-of-freedom measurement systems. Two different measurement methods were used to verify the measurement accuracy. The comparison results show that during the straightness measurement of the machine tool, the laser head should be fixed in front of the moving axis, and the sensing part should move with the moving table of the machine tool. Results also show that the measurement error of the straightness measurement is less than 3 m compared with the commercial systems. The developed laser measurement system has the advantages of high precision, long working distance, low cost, and suitability for straightness and parallelism error measurement.
Źródło:
Metrology and Measurement Systems; 2021, 28, 3; 479-495
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of elevated pressure on gas-solid flow properties in a powder feeding system
Autorzy:
Ren, Guanlong
Sun, Haijun
Xu, Yihua
Li, Chao
Powiązania:
https://bibliotekanauki.pl/articles/2174817.pdf
Data publikacji:
2022
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Powder engine
Pressure effect
Dense gas-solid two-phase flow
Euler-Euler two-fluid model
Numerical simulation
Opis:
In view of the powder feeding system, a multi-physical coupling model of the gas-powder-piston was established based on the Euler-Euler two-fluid model. The numerical simulation method was applied to explore the effects of dense gas-solid flow characteristics under different operating pressures. The results show that gas-solid pulsations at different operating pressures are mainly concentrated in the upper part of the powder tank. An elevated operating pressure efficiently decreases the powder layer area (εp = 0.1) fluctuation. As the operating pressure increases from 0.5 MPa to 3.0 MPa, the rising time and fluctuation rate of pressure are reduced by 71.4% and 62.3%, respectively, and the pressure in the tank has a long stabilization period. Meanwhile, the variation of the instantaneous powder flow rate is more stable and its average value is closer to the theoretical. A high-pressure environment is more conducive to the stable transportation of powder.
Źródło:
Polish Journal of Chemical Technology; 2022, 24, 3; 41--52
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integrated system of health management-oriented reliability prediction for a spacecraft software system with an adaptive genetic algorithm support vector machine
Zorientowane na zintegrowane zarządzanie kondycją systemu prognozowanie niezawodności systemów oprogramowania statków kosmicznych z wykorzystaniem opartej na adaptacyjnym algorytmie genetycznym maszyny wektorów nośnych
Autorzy:
Xu, J.
Meng, Z
Xu, L.
Powiązania:
https://bibliotekanauki.pl/articles/300804.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
spacecraft software system
reliability
integrated system health management
adaptive genetic algorithms support vector machine
system oprogramowania statku kosmicznego
niezawodność
zintegrowane zarządzanie kondycją systemu
adaptacyjne algorytmy genetyczne
maszyna wektorów nośnych
Opis:
Software reliability prediction is very important to minimize cost and improve software development effectiveness, especially in a spacecraft’s software system. In this paper, a new spacecraft software system reliability definition is given and a new reliability prognostics-oriented life cycle integrated system health management for a spacecraft software system is focused on. Adaptive genetic algorithms are then combined with a support vector machine to build an adaptive genetic algorithm support vector machine reliability prediction model. This model attempts to overcome the genetic algorithm weaknesses, such as the local minima and premature convergence problems, and solves the parameter selection difficulties often encountered in a support vector machine. After construction, the proposed adaptive genetic algorithm support vector machine model is employed to predict the reliability of a spacecraft software system. Finally, a numerical example is given to show how the proposed approach has a superior prediction performance compared to a standard support vector machine and artificial neural network.
Przewidywanie niezawodności oprogramowania odgrywa ważną rolę w minimalizowaniu kosztów i poprawie efektywności tworzenia oprogramowania, zwłaszcza w odniesieniu do systemów oprogramowania statków kosmicznych. W niniejszej pracy, podano nową definicję niezawodności systemu oprogramowania statku kosmicznego koncentrując uwagę na opartym na prognozowaniu niezawodności oraz cyklu życia modelu zintegrowanego zarządzania kondycją systemu opracowanego dla systemu oprogramowania statku kosmicznego. Skonstruowano następnie model przewidywania niezawodności oparty na połączeniu adaptacyjnych algorytmów genetycznych oraz maszyny wektorów nośnych. Model ten stanowi próbę przezwyciężenia słabości algorytmów genetycznych, takich jak problem minimów lokalnych czy problem przedwczesnej zbieżności, a także rozwiązania trudności związanych z doborem parametrów, jakie często występują przy zastosowaniu maszyny wektorów nośnych. Skonstruowany model opartej na adaptacyjnym algorytmie genetycznym maszyny wektorów nośnych zastosowano do przewidywania niezawodności systemu oprogramowania statku kosmicznego. Wreszcie, przedstawiono przykład liczbowy, który pokazuje że opracowany model charakteryzuje się wyższą dokładnością prognozowania w porównaniu do standardowej maszyny wektorów nośnych oraz sztucznej sieci neuronowej.
Źródło:
Eksploatacja i Niezawodność; 2014, 16, 4; 571-578
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhanced separation efficiency of low–rank coal using waste engine oil as a flotation collector
Autorzy:
Li, Ming
Xia, Yangchao
Guo, Fangyu
Rong, Guoqiang
Li, Guosheng
Xu, Baolin
Xing, Yaowen
Gui, Xiahui
Powiązania:
https://bibliotekanauki.pl/articles/109613.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
low rank coal
engine oil
waste engine oil
flotation
Opis:
Because of the rich oxygen-containing functional groups and developed pores on the Surface of low-rank coal, it is difficult to realize efficient separation during low-rank coal flotation using common oil collectors. Waste engine oil (WEO) is abundant in polar oxygen-containing functional groups and could be an alternative collector. In this study, the effect of WEO on low-rank coal floatation was assessed and engine oil (EO) was also used for comparison. The results show that the separation efficiency of low-rank coal can be significantly improved using WEO; additionally, 96.73% of the clean coal yield can be obtained when the WEO dosage was only 4 kg/t. Compared with EO, the bubble–particle induction time in the presence of WEO shortened from 430 to 220 ms. Moreover, more low-rank coal particles were captured and adhered to the bubble surface using WEO, which indicated a higher probability of bubble–particle attachment. Nonpolar components, polar components and metal ions synergistically promote the flotation separation enhancement of low-rank coal using WEO.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 2; 252-263
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of ISO (9001) Certification and Article Type Produced on Lean Six Sigma Application Successes: a Case Study Within Textile Companies
Autorzy:
Nedra, Abbes
Jun, Xu
Nèjib, Sejri
Jiajia, Duan
Powiązania:
https://bibliotekanauki.pl/articles/2171948.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
textile
SMEs
small and medium enterprises
ISO 9001 standard
Lean Six Sigma
Opis:
This study focused on how the ISO 9001:2008 standard has influenced organisational Lean Six Sigma (LSS) implementation success. Data were collected through a survey, followed by interviews with the quality managers/representatives of 85 small and medium enterprises (SMEs) in the textile industry. Additionally, case studies on four of the textile SMEs were carried out to validate the results. Our analysis revealed that the main benefits of LSS, among others, are problem solving improvement, reduction of the quality problem, waste reduction, and increase of productivity. However, certified companies are aware of continuous improvements to tools, which ensures the continuity of improvements made by the LSS project and facilitates the integration of Lean Six Sigma tools, which can help to make better use of the Lean Six Sigma project. The type of article produced was also found to have a considerable effect on the success of the Lean Six Sigma project.
Źródło:
Fibres & Textiles in Eastern Europe; 2022, 2 (151); 17--22
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Clothing Image Classification Models: A Comparison Study between Traditional Machine Learning and Deep Learning Models
Autorzy:
Xu, Jun
Wei, Yumeng
Wang, Aichun
Zhao, Heng
Lefloch, Damien
Powiązania:
https://bibliotekanauki.pl/articles/2200761.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
e-commerce
clothing image classification
traditional machine learning
CNN
HOG
SVM
small VGG network
Opis:
Clothing image in the e-commerce industry plays an important role in providing customers with information. This paper divides clothing images into two groups: pure clothing images and dressed clothing images. Targeting small and medium-sized clothing companies or merchants, it compares traditional machine learning and deep learning models to determine suitable models for each group. For pure clothing images, the HOG+SVM algorithm with the Gaussian kernel function obtains the highest classification accuracy of 91.32% as compared to the Small VGG network. For dressed clothing images, the CNN model obtains a higher accuracy than the HOG+SVM algorithm, with the highest accuracy rate of 69.78% for the Small VGG network. Therefore, for end-users with only ordinary computing processors, it is recommended to apply the traditional machine learning algorithm HOG+SVM to classify pure clothing images. The classification of dressed clothing images is performed using a more efficient and less computationally intensive lightweight model, such as the Small VGG network.
Źródło:
Fibres & Textiles in Eastern Europe; 2022, 5 (151); 66--78
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finite Element Treatment of Vortex States in 3D Mesoscopic Cylindrical Superconductors in a Tilted Magnetic Field
Autorzy:
Peng, Lin
Hu, Yahua
Li, Zhijian
Deng, Ke
Zhu, Yanyan
Xu, Li
Zhou, Yun
Powiązania:
https://bibliotekanauki.pl/articles/1030584.pdf
Data publikacji:
2018-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
three-dimensional mesoscopic cylinders
TDGL equations
finite element method
vortex states
Opis:
The time-dependent Ginzburg-Landau equations have been solved numerically by a finite element analysis for the mesoscopic superconducting samples with cylindrical shape in a uniform axial magnetic field. We obtain the different vortex patterns as a function of the applied field perpendicular to its surface. We find that multi-vortex states are ground state in three-dimensional mesoscopic cylinders. These results show that our approach is an effective and useful to interpret experimental data on vortex states in the mesoscopic superconductors.
Źródło:
Acta Physica Polonica A; 2018, 133, 1; 152-156
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A unified approach to stability analysis of switched linear descriptor systems under arbitrary switching
Autorzy:
Zhai, G.
Xu, X.
Powiązania:
https://bibliotekanauki.pl/articles/907764.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
układ komutowany
układ deskrypcyjny
stabilność
komutacja dowolna
nierówność macierzy
LMI
switched linear descriptor systems
stability
arbitrary switching
linear matrix inequalities (LMIs)
common quadratic Lyapunov functions
Opis:
We establish a unified approach to stability analysis for switched linear descriptor systems under arbitrary switching in both continuous-time and discrete-time domains. The approach is based on common quadratic Lyapunov functions incorporated with linear matrix inequalities (LMIs). We show that if there is a common quadratic Lyapunov function for the stability of all subsystems, then the switched system is stable under arbitrary switching. The analysis results are natural extensions of the existing results for switched linear state space systems.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2010, 20, 2; 249-259
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Isolation and expression pattern of RGS21 gene, a novel RGS member
Autorzy:
Li, Xin
Chen, Lei
Ji, Chaoneng
Liu, Bing
Gu, Jiefeng
Xu, Jian
Zou, Xianqiong
Gu, Shaohua
Mao, Yumin
Powiązania:
https://bibliotekanauki.pl/articles/1041351.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
RGS21
G-protein signaling pathway
G-protein α subunit (Gα)
Opis:
Regulators of G-protein signaling (RGS) proteins are known for the RGS domain that is composed of a conserved stretch of 120 amino acids, which binds directly to activated G-protein α subunits and acts as a GTPase-activating protein (GAP), leading to their deactivation and termination of downstream signals. In this study, a novel human RGS cDNA (RGS21), 1795 bp long and encoding a 152-amino acid polypeptide, was isolated by large-scale sequencing analysis of a human fetal brain cDNA library. Unlike other RGS family members, RGS21 gene has no additional domain/motif and may represent the smallest known member of RGS family. It may belong to the B/R4 subfamily, which suggests that it may serve exclusively as a negative regulator of αi/o family members and/or αq/11. PCR analysis showed that RGS21 mRNA was expressed ubiquitously in the 16 tissues examined, implying general physiological roles.
Źródło:
Acta Biochimica Polonica; 2005, 52, 4; 943-946
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Time Resolved IR and X-Ray Simultaneous Spectroscopy: New Opportunities for the Analysis of Fast Chemical-Physical Phenomena in Materials Science
Autorzy:
Marcelli, A.
Hampai, D.
Xu, Wei
Malfatti, L.
Innocenzi, P.
Powiązania:
https://bibliotekanauki.pl/articles/1808498.pdf
Data publikacji:
2009-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
07.85.Qe
61.05.cj
82.20.-w
78.47.-p
Opis:
New powerful sources and advanced analytical techniques have been considered in the last decade to face up the continuously increasing scientific demands, in particular, in materials science. As an example, nano- science and nanotechnology researches are characterized by ultimate spatial resolution, fast and ultrafast time-resolved analysis, but the complexity of the investigated phenomena requires new analytical capabilities and new experimental techniques were introduced in the research arena. The availability all over the world of brilliant synchrotron radiation sources offers incredible opportunities. Many challenging experiments were made possible by these sources and understanding of many complex dynamical problems was obtained. Nevertheless, a strong demand of new analytical approaches, mainly based on concurrent and possibly simultaneous time-resolved experimental techniques, is emerging. Pioneering time resolved experiments combining X-ray and infrared radiation with a conventional source were performed more than a decade ago. Nowadays, many beamlines at third generation synchrotron radiation facilities are equipped with conventional sources to allow complementary techniques and the strategy of a concurrent analysis is mandatory in the investigation of many phenomena in frontier multidisciplinary researches. Moreover, new opportunities will be available by means of concurrent spectroscopic experiments investigating complex phenomena on a short timescale, from the sub-second to the microsecond time domain. We will present and discuss researches where the combination of IR and X-ray simultaneous experiments may return unique information on complex dynamical processes and phase transitions occurring in materials science. Finally, we will briefly describe the conceptual layout of a synchrotron radiation beamline to perform concurrent IR and X-ray experiments.
Źródło:
Acta Physica Polonica A; 2009, 115, 2; 489-500
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Traditional Chinese herb, Astragalus: possible for treatment and prevention of COVID-19?
Autorzy:
Law, S.
Lo, C.
Han, J.
Leung, A.W.
Xu, C.
Powiązania:
https://bibliotekanauki.pl/articles/2049190.pdf
Data publikacji:
2020
Wydawca:
Instytut Włókien Naturalnych i Roślin Zielarskich
Tematy:
Astragalus
herb
Chinese herb
treatment
blood circulation
prevention
COVID-19
antiinflammatory activity
traganek
tradycyjna chińska roślina lecznicza
leczenie
zapobieganie
Opis:
Astragalus is a traditional herb which has been used in China for a long time. It regulates blood circulation (vital energy), invigorates body fluid circulation, protects the flow of blood to fight against the attack of pathogens, and strengthens “blood deficiencies” according to Bencao Congxin. Astragalus was approved by the Food and Drug Administration in 2009 as a dietary supplement for upper respiratory infections, allergic rhinitis (hay fever), asthma, chronic fatigue syndrome, and chronic kidney disease. Thirty journals published in the past ten years were reviewed by using library search engines such as SCI/SCIE, PubMed, and Scopus. In this mini-review, we focus on the anti-inflammatory of Astragalus features, discuss the background of Astragalus and its function in various diseases from water-extracted Astragalus membranaceus, Astragalus saponins, and Astragalus polysaccharides. Based on the traditional Chinese medicine theory, Astragalus is a potential candidate to treat and prevent COVID-19.
Źródło:
Herba Polonica; 2020, 66, 4; 79-84
0018-0599
Pojawia się w:
Herba Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation into particulate size distributions in the exhaust gas of diesel engines fuelled with biodiesel blends
Autorzy:
Chuepeng, S.
Theinnoi, K.
Xu, H. M.
Wyszynski, M. L.
York, A. P. E.
Hartland, J. C.
Qiao, J.
Powiązania:
https://bibliotekanauki.pl/articles/248072.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
biodiesel
PM
combustion
diesel
PM size distribution
Opis:
Particulate matter (PM) size distributions in the exhaust gas of biodiesel blend fuelled diesel engines have been studied by experimenting firstly on a single cylinder equipped with a pump-line-injector injection system and secondly for comparison on a V6 DI engine equipped with a common rail fuel injection system. Both engines were operated with a biodiesel (RME) blend of B30 and ultra low sulphur diesel fuel (ULSD). Several engine load conditions with and without exhaust gas recirculation (EGR) were selected. Particulate number concentrations vs. the electrical mobility equivalent diameter were examined using a fast differential mobility spectrometer. The effect of engine operating conditions including EGR rates on particulate emissions has been investigated. It is found that PM sizes from combustion of B30 without EGR operation are generally smaller than those from ULSD while number concentrations are higher. This can result in lower PM mass estimates for the B30 case if due care is not taken. When EGR is applied to control nitrogen oxides emissions, both the total PM number and mass are increased and shifted toward the larger sizes for both fuels used in the test. The calculated total PM mass from B30 combustion is lower than in the ULSD case for all the tested engine operating conditions.
Źródło:
Journal of KONES; 2008, 15, 3; 75-82
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonlinear actuator fault estimation observer: an inverse system approach via a T-S fuzzy model
Autorzy:
Xu, D.
Jiang, B.
Shi, P.
Powiązania:
https://bibliotekanauki.pl/articles/331464.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
model rozmyty Takagi-Sugeno
obserwator ślizgowy
system odwrotny
actuator fault estimation
Takagi-Sugeno fuzzy models
robust sliding mode observer
inverse system method
Opis:
Based on a Takagi-Sugeno (T-S) fuzzy model and an inverse system method, this paper deals with the problem of actuator fault estimation for a class of nonlinear dynamic systems. Two different estimation strategies are developed. Firstly, T-S fuzzy models are used to describe nonlinear dynamic systems with an actuator fault. Then, a robust sliding mode observer is designed based on a T-S fuzzy model, and an inverse system method is used to estimate the actuator fault. Next, the second fault estimation strategy is developed. Compared with some existing techniques, such as adaptive and sliding mode methods, the one presented in this paper is easier to be implemented in practice. Finally, two numerical examples are given to demonstrate the efficiency of the proposed techniques.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2012, 22, 1; 183-196
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of optimal cyclic uniaxial stretches for stem cell-to-tenocyte differentiation under a wide range of mechanical stretch conditions by evaluating gene expression and protein synthesis levels
Autorzy:
Morita, Y.
Watanabe, S.
Ju, Y.
Xu, B.
Powiązania:
https://bibliotekanauki.pl/articles/951825.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
hBMSC
differentiation
mechanical stretch
tenocyte
różniczkowanie
wydłużanie
Opis:
We examined optimal cyclic uniaxial stretches for stem cell-to-tenocyte differentiation by applying a wide range of cyclic mechanical stimuli. Human bone marrow mesenchymal stem cells (hBMSCs) were subjected to three types of cyclic elongation of 5%, 10%, or 15% at a cyclic frequency of 1 Hz for 24 h or 48 h, and differentiation into tenocytes was assessed by two methods: real-time polymerase chain reaction determination of gene expression levels and western blotting analysis of protein expression levels. The gene expression levels of the differentiation markers type I collagen (Col I), type III collagen (Col III), tenascin-C (Tnc), and scleraxis (Scx), all of which are constituents of tendon tissue, were increased when cells were exposed to 10% stretching stimulation. The levels of Col I and Tnc protein synthesis levels were also higher in the cells with 10% stretching stimulation than in those subjected to other stimuli. The results indicated that 10% stretching stimulus was efficient to induce the differentiation of hBMSCs into tenocytes. In addition, the changes in gene and protein expression levels were strongly correlated with cell orientation angle. The results presented here suggest that mesenchymal stem cell-to-tenocyte differentiation is strongly associated with cumulative elongation load on the cells. This work provides novel insights into the differentiation of tenogenesis in a strain-induced environment and supports the therapeutic potential of hBMSCs.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 3; 71-79
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automatic pavement macrotexture depth calculation using a statistical approach based on the tire/road noise signal by directional microphones
Autorzy:
Liu, Hao
Zhang, Yiying
Xu, Zhengwei
Liu, Xiaojiang
Powiązania:
https://bibliotekanauki.pl/articles/2173668.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
statistical approach
directional microphone
pavement
macrotexture depth
automation
podejście statystyczne
mikrofon kierunkowy
chodnik
głębokość makrotekstury
automatyzacja
Opis:
This paper develops an automatic method to calculate the macrotexture depth of pavement roads, using the tire/road noise data collected by the two directional microphones mounted underneath a moving test vehicle. The directional microphones collect valid tire/road noise signal at the travel speed of 10–110 km/h, and the sampling frequency is 50 kHz. The tire/road noise signal carries significant amount of road surface information, such as macrotexture depth. Using bandpass filter, principal component analysis, speed effect elimination, Gaussian mixture model, and reversible jump Markov Chain Monte Carlo, the macrotexture depth of pavement roads can be calculated from the tire/road noise data, automatically and efficiently. Compared to the macrotexture depth results by the sand-patch method and laser profiler, the acoustic method has been successfully demonstrated in engineering applications for the accurate results of macrotexture depth with excellent repeatability, at the test vehicle’s travel speed of 10-110 km/h.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 3; art. no. e140519
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of mining and geology on mining-induced seismicity – a case study
Autorzy:
Khalil, Heba
Chen, Tuo
Xu, Yu-Hang
Mitri, Hani
Powiązania:
https://bibliotekanauki.pl/articles/2201413.pdf
Data publikacji:
2022
Wydawca:
Główny Instytut Górnictwa
Tematy:
underground mining
mining-induced seismicity
moment tensor inversion
magnitude-frequency distribution
górnictwo podziemne
sejsmiczność indukowana górnictwem
inwersja tensora momentu
rozkład wielkościowo-częstotliwościowy
Opis:
Mining-induced seismicity is a commonly occurring phenomenon in underground mines. This poses a greater challenge to the safety of the mining operation. This paper presents a case study of the Young-Davidson mine in northern Ontario, Canada, where seismic events of magnitude Mn 2.0+ have been observed at mining depths of 600 to 800 m below the surface. The occurrence of large seismic events at such shallow depths is the key issue of this study. A comprehensive study of the microseismic database has been conducted to discern the root causes for the unusually strong seismic activities recorded at shallow depths. The effects of mining activities in the vicinity of two dykes intersecting the orebody on the seismic response are investigated. Variation of the b-value derived from the magnitude-frequency distribution is examined, and moment tensor inversion for three large seismic events is carried out to determine the source mechanisms. It is shown from this investigation that the influence of the sill pillar is more critical, leading to high mining-induced stress and the occurrence of large events. While the findings from this research are specific to this case study, they could be used to shed light on the causes of induced seismicity at other mines with similar conditions.
Źródło:
Journal of Sustainable Mining; 2022, 21, 3; 200--215
2300-1364
2300-3960
Pojawia się w:
Journal of Sustainable Mining
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A model-free direct predictive grid-current control strategy for grid-connected converter with an inductance-capacitance-inductance filter
Autorzy:
Guo, Leilei
Zheng, Mingzhe
Yu, Changzhou
Xu, Haizhen
Li, Yanyan
Powiązania:
https://bibliotekanauki.pl/articles/2202543.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
grid-connected converter
GCC
model-free predictive current control
MFPCC
parameter mismatch
robustness
Opis:
The disadvantages of the conventional model predictive current control method for the grid-connected converter (GCC) with an inductance-capacitance-inductance (LCL) filter are a large amount of calculation and poor parameter robustness. Once parameters of the model are mismatched, the control accuracy of model predictive control (MPC) will be reduced, which will seriously affect the power quality of the GCC. The article intuitively analyzes the sensitivity of parameter mismatch on the current predictive control of the conventional LCL-filtered GCC. In order to solve these issues, a model-free predictive current control (MFPCC) method for the LCL-filtered GCC is proposed in this paper. The contribution of this work is that a novel current predictive robust controller for the LCL-filtered GCC is designed based on the principle of the ultra-local model of a single input single output system. The proposed control method does not require using any model parameters in the controller, which can effectively suppress the disturbances of the uncertain parameter variations. Compared with conventional MPC, the proposed MFPCC has smaller current total harmonic distortion (THD). When the filter parameters are mismatched, the control error of the proposed method is smaller. Finally, a comparative experimental study is carried out on the platform of Typhoon and PE-Expert4 to verify the superiority and effectiveness of the proposed MFPCC method for the LCL-filtered GCC.
Źródło:
Archives of Electrical Engineering; 2023, 72, 1; 23--42
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Note on Upper Bounds for Some Generalized Folkman Numbers
Autorzy:
Xu, Xiaodong
Liang, Meilian
Radziszowski, Stanisław
Powiązania:
https://bibliotekanauki.pl/articles/31343184.pdf
Data publikacji:
2019-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
Folkman number
Ramsey number
Opis:
We present some new constructive upper bounds based on product graphs for generalized vertex Folkman numbers. They lead to new upper bounds for some special cases of generalized edge Folkman numbers, including the cases Fe(K3, K4 − e; K5) ≤ 27 and Fe(K4 − e, K4 − e; K5) ≤ 51. The latter bound follows from a construction of a K5-free graph on 51 vertices, for which every edge coloring with two colors contains a monochromatic K4 − e.
Źródło:
Discussiones Mathematicae Graph Theory; 2019, 39, 4; 939-950
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A practical application of kernel-based fuzzy discriminant analysis
Autorzy:
Gao, J. Q.
Fan, L. Y.
Li, L.
Xu, L. Z.
Powiązania:
https://bibliotekanauki.pl/articles/908344.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
analiza dyskryminacyjna
algorytm najbliższego sąsiada
SVD
kernel fuzzy discriminant analysis
fuzzy k-nearest neighbor
QR decomposition
singular value decomposition (SVD)
fuzzy membership matrix
t-test
Opis:
A novel method for feature extraction and recognition called Kernel Fuzzy Discriminant Analysis (KFDA) is proposed in this paper to deal with recognition problems, e.g., for images. The KFDA method is obtained by combining the advantages of fuzzy methods and a kernel trick. Based on the orthogonal-triangular decomposition of a matrix and Singular Value Decomposition (SVD), two different variants, KFDA/QR and KFDA/SVD, of KFDA are obtained. In the proposed method, the membership degree is incorporated into the definition of between-class and within-class scatter matrices to get fuzzy between-class and within-class scatter matrices. The membership degree is obtained by combining the measures of features of samples data. In addition, the effects of employing different measures is investigated from a pure mathematical point of view, and the t-test statistical method is used for comparing the robustness of the learning algorithm. Experimental results on ORL and FERET face databases show that KFDA/QR and KFDA/SVD are more effective and feasible than Fuzzy Discriminant Analysis (FDA) and Kernel Discriminant Analysis (KDA) in terms of the mean correct recognition rate.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2013, 23, 4; 887-903
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interception of a hypersonic vehicle by low-speed interceptors: novel perspectives and cost optimisation
Autorzy:
Liu, Shuangxi
Liu, Shijun
Yan, Binbin
Zhang, Tong
Zhang, Xu
Yan, Jie
Powiązania:
https://bibliotekanauki.pl/articles/2173726.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
small speed ratio
hypersonic vehicle
interception performance
boundary conditions
współczynnik prędkości mały
pojazd hipersoniczny
wydajność przechwytywania
warunki brzegowe
Opis:
The conditions for accurately intercepting hypersonic vehicles by low-speed interceptors in the terminal guidance process are examined, considering the general form of a guidance scheme. First, based on the concept of the engagement geometry, three interception scenarios are established considering different manoeuvring configurations of the interceptors and hypersonic vehicle. Second, the boundary conditions for intercepting hypersonic vehicles (with speeds higher than those of the interceptors) are specified for the three scenarios, considering several factors: the speed, path angle, line-of-sight angle, and available overload of the interceptor; path angle and manoeuvrability of the hypersonic vehicle; and relative distance between the interceptor and vehicle. A series of simulations are performed to clarify the influence of each factor on the interception performance in the three interception scenarios. The challenges associated with accurately intercepting hypersonic vehicles by low-speed interceptors are summarised, and several recommendations for designing guidance laws are presented.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 6; art. no. e143537
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The mechanism of $CaCO_3$ in the gas-based direct reduction of a high-phosphorus oolitic iron ore
Autorzy:
Wu, Shichao
Li, Zhengyao
Sun, Tichang
Kou, Jue
Xu, Chengyan
Powiązania:
https://bibliotekanauki.pl/articles/1446124.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
high-phosphorus oolitic iron ore
gas-based direct reduction
magnetic separation
$Fe_3PO_7$
$CaCO_3$
Opis:
Gas-based direct reduction and magnetic separation process was applied in treating a high-phosphorus oolitic iron ore, of which phosphorus mainly occured as $Fe_3PO_7$ and apatite. The mechanism of $CaCO_3$ was investigated using XRD, SEM-EDS, and mineral phase analysis. Results showed that when no CaCO3 was added, most of the iron minerals were reduced to metallic iron, while $Fe_3PO_7$ was reduced to elemental phosphorus and mixed with the metallic iron particles. When a small amount of $CaCO_3$ was added, $CaCO_3$ preferentially reacted with $SiO_2$, $Al_2O_3$ and other components, preventing them from reacting with FeO and resulting in the increase of iron recovery. When the amount of $CaCO_3$ reached 25%, apatite was produced from the reaction of CaO and $Fe_3PO_7$, which could be later removed by grinding and magnetic separation.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 4; 117-124
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative study of fault-tolerant performance of a segmented rotor SRM and a conventional SRM
Autorzy:
Sun, X.
Xue, Z.
Han, S.
Chen, L.
Xu, X.
Yang, Z.
Powiązania:
https://bibliotekanauki.pl/articles/200893.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fault tolerance
segmented rotor SRM
phase failure
finite element method
dynamic performance
rotor segmentowy SRM
metoda elementów skończonych
wydajność dynamiczna
tolerancja błędu
awaria jednej fazy
Opis:
Due to the separation of magnetic field, electrical isolation and thermal isolation, motor drives possess a high fault-tolerance characteristic. In this paper, comparative study of mutual inductance between the proposed segmented rotor switched reluctance motor (SSRM) and the conventional switched reluctance motor (SRM) is carried out first, illustrating that the proposed SSRM has less mutual inductance between phases than the conventional SRM. In addition, if winding faults or power converter faults lead to phase failure, a comparative analysis on fault-tolerant performance under phase failure condition between the proposed SSRM and the conventional SRM is simulated in detail using the finite element method (FEM). Simulation results reveal that dynamic performance of the proposed SSRM, including output torque and phase current, is better than that of the conventional SRM. That is, the capacity of operating with the fault under phase failure condition in the proposed SSRM is superior to that in the conventional SRM.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2017, 65, 3; 375-381
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combined effects of NQO1 Pro187Ser or SULT1A1 Arg213His polymorphism and smoking on bladder cancer risk: Two meta-analyses
Autorzy:
Wang, Xiao-Chun
Wang, Jian
Tao, Hui-Hui
Zhang, Chao
Xu, Li-Fa
Powiązania:
https://bibliotekanauki.pl/articles/2161894.pdf
Data publikacji:
2017-07-14
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
polymorphisms
meta-analysis
NQO1
urinary bladder neoplasms
smoking
SULT1A1
Opis:
Objectives Objectives: Cigarette smoking is the major risk factor of bladder cancer via exposure to chemical carcinogens. Nicotinamide adenine dinucleotide phosphate (NADP+): quinine oxidoreductase 1 (NQO1) and sulfotransferase 1A1 (SULT1A1) have been reported to involve in the metabolism of polycyclic aromatic hydrocarbons (PAHs) and aromatic amines. Therefore, the risk of bladder cancer (BC) may be influenced by polymorphisms in the genes that modulate metabolic detoxification in particular by interacting with cigarette smoking. Considering the limited power by the individual studies with a relatively small sample size, especially when analyzing the combined effect of polymorphisms in NQO1 and SULT1A1 genes and smoking, these 2 meta-analyses have aimed to clarify the combined effects of them on BC risk by integrating related studies. Material and Methods Two meta-analyses included 1341 cases and 1346 controls concerning NQO1 Pro187Ser and smoking, and 1921 cases and 1882 controls on SULT1A1 Arg213His and smoking were performed. Odds ratios (OR) and 95% confidence intervals (CI) were used for assessing the strength of the association. Results The result has demonstrated that smokers with NQO1 Pro/Ser or Ser/Ser genotypes have a prominent association with the risk of BC as compared with non-smokers with NQO1 Pro/Pro genotype, with OR equal to 3.71 (95% CI: 2.87–4.78, $ \text{p}_\text{heterogeneity} $ = 0.376). Besides, smokers carrying SULT1A1 Arg/Arg genotypes were observed to confer 2.38 fold increased risk of BC (95% CI: 1.44–3.93, $ \text{p}_\text{heterogeneity} $ = 0.001) when compared with non-smokers with SULT1A1 Arg/Arg or His/His genotypes. Conclusions These findings have suggested that the NQO1 Pro187Ser or SULT1A1 Arg213His polymorphism combination with smoking significantly confer susceptibility to BC. Int J Occup Med Environ Health 2017;30(5):791–802
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2017, 30, 5; 791-802
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Tradeoff between Growth and Environment: Evidence from China and the United States
Kompromis pomiędzy wzrostem a środowiskiem: Przykład Chin i USA
Autorzy:
Xu, Jing
Li, Jianjun
Powiązania:
https://bibliotekanauki.pl/articles/371378.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Komitet Człowiek i Środowisko PAN
Tematy:
economic growth
environmental protection
trade-off
individual preference
public opinion
rozwój ekonomiczny
ochrona środowiska
kompromis
indywidualne preferencje
opinia publiczna
Opis:
This paper empirically analyzes individual attitudes on the tradeoff between environment and economy, and factors that might influence such choice for two representative countries: China and the United States. Based on the World Value Survey, the Chinese are found more inclined to support environmental protection, while people from the United States choose economic growth as priority. Considering three sets of correlates of sociodemo-graphics, environmental attitude and social context, variables such as education, political affiliation and envi-ronmental consciousness show significance in influencing personal preferences, and the effect of health, age, employment and marital status demonstrates heterogeneity across countries. Such micro-level evidence on how the public weighs the economy versus environment can provide policy guidance for the government to better respond to public opinions.
Artykuł poddaje analizie indywidualne postawy odnoszące się do kompromisu pomiędzy środowiskiem a eko-nomią, a także czynniki, które mają wpływ na kształtowanie się takich postaw, w odniesieniu do dwóch ważnych krajów: Chin i USA. Według danych World Value Survey okazuje się, ze Chińczycy są bardziej skłonni wspierać ochronę środowiska, podczas gdy Amerykanie za priorytet uznają rozwój ekonomiczny. Uwzględniając trzy zbiory korelatów odnoszące się do socjodemografii, postaw wobec środowiska i kontekstu społecznego, zmienne takie jak edukacja, orientacja polityczna i świadomość ekologiczna, okazuje się, że te czynniki odgrywają istotne znaczenie w kształtowaniu indywidualnych priorytetów, a kwestie zdrowia, wieku, zatrudnienia i stanu cywilnego wypadają podobnie w różnych krajach. Dane z takiego mikro poziomu pokazują, jak ludzie indywidualnie rozstrzygają spór pomiędzy ekonomią a środowiskiem, co stanowi polityczną wskazówkę dla rządu, dzięki której można lepiej odpowiadać na nastroje społeczne.
Źródło:
Problemy Ekorozwoju; 2018, 13, 1; 15-20
1895-6912
Pojawia się w:
Problemy Ekorozwoju
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-100 z 125

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