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Wyszukujesz frazę "Zhou, Z" wg kryterium: Autor


Tytuł:
Low to middle vibro-acoustic noise prediction in ship cabin by using plate-cavity coupling model
Autorzy:
Zhou, Z.
Wu, J.
Powiązania:
https://bibliotekanauki.pl/articles/260260.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
low to middle frequencies
vibration
ship noise
analysis model
rapid calculation method
Opis:
A plate-cavity coupling method based on modal expansion technique in the closed sound cavity was introduced, aiming at ship cabin structural noise. Using this method, a coupled equation was established. The structural vibration acceleration of the target cabin was extracted from a ship vibration response calculation, applied to the model. Then the target cabin noise value was obtained through numerical calculation. The effectiveness and reliability of the method were validated through experiments. The coupled model predicts noise in the cabin does not require fluid finite element model of the cabin air, thus greatly reducing the calculation time compared with the pure finite element method. It was shown that the method is suitable for the calculation of noise in a single ship cabin; the method has a high calculation efficiency. Furthermore, the calculated result is a continuum. On the one hand, it can be conveniently converted to an octave or 1/3 octave according to the specification. On the other hand, the form of the continuum also provides a corresponding response to the subsequent vibration and noise control.
Źródło:
Polish Maritime Research; 2018, S 2; 149-157
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on Community Garden Practice – Taking “the Kid’s Garden” in Hunan Agricultural University as an Example
Autorzy:
Zhou, Z.
Huang, Y.
Zhou, C.
Powiązania:
https://bibliotekanauki.pl/articles/1191265.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Przyrodniczy we Wrocławiu
Tematy:
community garden
Kid’s garden
urban agriculture
university support model
ogród społeczny
ogród dla dzieci
zieleń miejska
uniwersytecki model wsparcia
Chiny
Opis:
As a form of urban green space, community gardens have provided urban residents with various environments, to satisfy their social, economic and health interests. For the purposes of creating public, open and shared spaces, this article summarizes and contrasts the history of the community garden development in Europe and America, while analyzing the development situation of China as well. Taking “the Kid’s Garden” in Hunan Agricultural University as an example, the authors discuss the whole practice process in three aspects: the layout design, the construction process, and the operation and maintenance plan. Finally, the conclusion of the article presents a community garden building model, which is supported by universities with the goals to reward the society, as well as to provide a win-win result between practice and teaching. This experience is hoped to popularize community gardens and to make a contribution towards a harmonious society.
Źródło:
Architektura Krajobrazu; 2017, 3; 34-43
1641-5159
Pojawia się w:
Architektura Krajobrazu
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seedling growth, root development and nutrient use efficiency of Cypress clones in response to calcium fertilizer
Autorzy:
Zhang, Z.
Jin, G.
Zhou, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2078194.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Cupressus funebris
root development
nutrient accumulation efficiency
calcium response
fertile
soil
low fertility soil
Opis:
Cypress (Cupressus funebris Endl.) is an important tree species in the subtropical regions of China; it is also a major tree species for afforestation and forest land restoration under low-fertility soil conditions. Cypress is considered a calcicolous tree, and its growth and development can be promoted significantly by exchangeable calcium (Ca2+) in the soil. However, most of the subtropical regions have low-fertility acidic soils, in which Ca2+ gradually becomes a limiting element for Cypress growth. In this study, different concentrations of Ca2+ fertilizer were added under fertile soil (3 g kg−1 NPK fertilizer added) and low-fertility soil (0 g kg−1 NPK fertilizer added) conditions. Cypress clones responded differently to Ca2+ addition in different soil conditions. The seedling height and dry matter quality of Cypress in fertile soil were significantly greater than those in low-fertility soil, but plant height and dry biomass did not differ significantly among Ca2+ treatments. The accumulation efficiencies of nitrogen (N), phosphorous (P) and Ca all differed significantly among the Ca2+ treatments. In low-fertility soil, the addition of 3 g kg-1 Ca2+ significantly promoted development of roots 0.5–2 mm in diameter, and both the C1 and C2 clones achieved their highest N, P and Ca accumulation efficiencies. When the Ca2+ concentration increased to 6 g kg−1, the seedling height, dry matter quality and root development were lower than those of the 3 g kg−1 Ca2+ treatment. In the fertile soil, the addition of Ca2+ significantly inhibited development of roots 0.5–1 mm in diameter. The highest N accumulation efficiency was achieved under the 0 g kg−1 Ca2+ treatment, and the highest Ca accumulation efficiency was achieved under the 6 g kg−1 Ca2+ treatment. Seedling height, root dry weight, roots 0–1.5 mm in diameter and Ca accumulation showed a significant interaction effect between NPK fertilizer and Ca2+. Therefore, Ca accumulation was more efficient in low-fertility soils. Under low-fertility soil conditions, the addition of CaSO4 can promote the root development of seedlings and advance and prolong the fast growth period of seedling height. Cypress clones can be used as an important tree species for afforestation under low-fertility soil conditions, especially under calcareous soil conditions.
Źródło:
Dendrobiology; 2020, 84
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Boiling, steaming or rinsing? (the physics of chinese cuisine)
Gotować, gotować na parze czy może płukać? (fizyka kuchni chińskiej)
Autorzy:
Varlamov, A.
Zhou, Z.
Chen, Y.
Powiązania:
https://bibliotekanauki.pl/articles/129558.pdf
Data publikacji:
2018
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
complex organic molecules
proteins
damplings
heat transfer
temperature conductivity
Fourier law
Newton's law of cooling
złożone molekuły organiczne
proteiny
kluski
przenoszenie ciepła
przewodnictwo temperaturowe
prawo Fouriera
Newtonowskie prawo chłodzenia
Opis:
Some physical aspects of Chinese cuisine are discussed. We start from the cultural and historical particularities of Chinese cuisine and their food production technologies. What is the difference between raw and boiled meat? What is the difference in the physical processes of heat transfer during either the steaming of dumplings or during cooking them in boiling water? Why is it possible to cook meat stripes in a "hot pot" in ten seconds, whilst baking a turkey requires several hours? This article is devoted to a discussion of these questions.
W artykule zostały przedyskutowane niektóre aspekty kuchni chińskiej. Autorzy zaczynają od omówienia szczegółów kuchni chińskiej i technologii produkcji żywności. Autorzy zadają następujące pytania: jaka jest różnica pomiędzy mięsem surowym a gotowanym? Jaka jest różnica w fizyce procesu przenoszenia ciepła podczas przyrządzania klusków na parze wodnej a w gotującej się wodzie? Dla czego jest możliwe przyrządzanie kawałków mięsa w "gorącym garnku" w ciągu kilku sekund, podczas gdy po to, aby upiec indyka potrzebujemy kilku godzin? Artykuł ten udziela odpowiedzi na te i inne pytania.
Źródło:
Physics for Economy; 2018, 2, No.1; 55-68
2544-7742
2544-7750
Pojawia się w:
Physics for Economy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimized design and analysis of offshore Beidou maritime foundation reinforcement system pseudolite ranging-codes
Autorzy:
Su, D.
Zhou, A.
Zhou, Z.
Chen, W.
Powiązania:
https://bibliotekanauki.pl/articles/260498.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
Beidou pseudolite
ranging-codes
optimized
3-taps
Opis:
Under the bad sea conditions and weak Beidou navigation signal environment, it is difficult to locate the ship on the sea, and the Beidou navigation system can’t work well. Beidou pseudolite system can improve the performance of Beidou navigation system as a navigation signal transmitter fixed on the ground, the signal of which can improve satellite positioning constellation structure, and improve the system availability reliability and precision. In order to ensure the interoperability and non-correlation of the Beidou pseudolite and the Beidou navigation system, the pseudolite ranging-codes should be selected in the same code space of the satellite ranging-codes and the residual pseudo random code generated by the 2 taps design scheme does not satisfy the performance requirements of the ranging-codes. To solve this issue, a combined design scheme with 3 taps is proposed, and 12 kinds of pseudolite ranging-codes are optimally selected according to the optimum design parameters of ranging-codes. The waveform and correlation of the selected pseudolite ranging-codes are analyzed by MATLAB, the acquisition simulation is carried out by using the new pseudolite ranging-codes. The experimental results show that the new 3-taps based ranging codes design scheme behaves a good balance, correlation and spectral characteristics.
Źródło:
Polish Maritime Research; 2017, S 2; 45-52
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Peridynamic analysis of 2-dimensional deformation and fracture based on an improved technique of exerting traction on boundary surface
Autorzy:
Zhou, Z.
Yu, M.
Wang, X.
Huang, Z.
Powiązania:
https://bibliotekanauki.pl/articles/38695705.pdf
Data publikacji:
2022
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
peridynamics
peridynamic motion equation
adaptive dynamic relaxation
traction boundary conditions
Opis:
For 2-dimensional problems in peridynamics, the transfer functions of boundary traction are constructed. The peridynamic motion equation introducing the boundary traction is improved and used to solve some typical 2-dimensional deformation and fracture problems, including the uniaxial tension and pure bending of plate, and fracture of a plate with the small circular hole or central crack. The acquired numerical solutions are close to the analytical solutions of elasticity and numerical solutions given by the finite element method. The results show that the improved technique of exerting traction on a boundary surface is valid for calculating the deformation and failure of solid. It provides a new method and path for the analysis of traction boundary value problems in peridynamics.
Źródło:
Archives of Mechanics; 2022, 74, 6; 441-461
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New bird remains from the Middle Eocene of Guangdong, China
Autorzy:
Wang, M.
Mayr, G.
Zhang, J.
Zhou, Z.
Powiązania:
https://bibliotekanauki.pl/articles/21279.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
new taxon
bird
remains
Middle Eocene
Guangdong Province
China
Aves
Ciconiiformes
Threskiornithidae
Eocene
fossil record
fossil bird
paleontology
Sanshuiornis zhangi
Huayong Formation
Opis:
We describe a new avian taxon (Sanshuiornis zhangi gen. et sp. nov.) from Middle Eocene black oil shales in the Huayong Formation of Guangdong Province, south China. The specimen consists of a distal tibiotarsus and a complete foot with tarsometatarsus and pedal digits in articulation. A preliminary phylogenetic analysis does not resolve the affinities of the fossil, but the bones show resemblances to some “ciconiiform” birds. The peculiar hypotarsus morphology, which is block−like and exhibits four cristae, resembles that of the early Eocene Rhynchaeites, which is a stem group representative of the Threskiornithidae. The new Chinese fossil has, however, proportionally longer legs than Rhynchaeites and its phylogenetic affinities probably cannot be resolved without further material.
Źródło:
Acta Palaeontologica Polonica; 2012, 57, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Image encryption combining discrete fractional angular transform with Arnold transform in image bit planes
Autorzy:
Zhou, Z.
Yu, J.
Liao, Q.
Gong, L.
Powiązania:
https://bibliotekanauki.pl/articles/173704.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Arnold transform
bit plane
discrete fractional angular transform
image encryption algorithm
Opis:
A new image encryption algorithm by using a discrete fractional angular transform and Arnold transform in image bit planes is investigated. In the image encryption algorithm, the original image is encrypted by the Arnold transform in image bit planes firstly, and then the resulting image is encrypted by the discrete fractional angular transform further. The key of the image encryption algorithm includes the parameters of the Arnold transform and the order of the discrete fractional angular transform. It is shown that the proposed image encryption algorithm is of high security and strong enough to counteract some conventional image attack manners.
Źródło:
Optica Applicata; 2018, 48, 2; 225-236
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Near-field multiple optical trapping using high order axially symmetric polarized beams
Autorzy:
Zhou, Z
Tan, Q
Zhu, L
Yang, C
Powiązania:
https://bibliotekanauki.pl/articles/174886.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optical trapping
surface plasmon polaritons
axially symmetric polarized beams
Opis:
The near-field multiple optical trapping using high order axially symmetric polarized beams (ASPBs) is studied for the first time. First, a near-field optical trapping scheme is proposed based on the Kretschmann–Raether configuration, and surface plasmon polaritons (SPPs) field distributions excited by incident ASPBs are calculated, which present a multi-focal-spot pattern and the size of spots is much smaller than that of the diffraction limitation. Then, the gradient forces on Rayleigh dielectric particles formed by the multi-focal-spot focused field are computed, which indicates that multiple ultra-small particles with the refractive index higher than that of the ambient medium can be trapped simultaneously on the metal surface. The number and size of trapped particles can be manipulated by flexibly modifying the polarization order of incident beams, which is expected to enhance the capability of traditional optical trapping systems and provide a solution for massively parallel optical trapping of nanometer-sized particles.
Źródło:
Optica Applicata; 2013, 43, 2; s. 287-296
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Image encryption algorithm by using the logistic map and discrete fractional angular transform
Autorzy:
Yu, J.
Li, Y.
Xie, X.
Zhou, N.
Zhou, Z.
Powiązania:
https://bibliotekanauki.pl/articles/173813.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
image encryption
logistic map
discrete fractional angular transform
Opis:
A new image encryption scheme based on logistic map and discrete fractional angular transform has been proposed. In the proposed scheme, the original image is encrypted with the random sequence generated by the logistic map, and the encrypted image is subsequently processed by the discrete fractional angular transform, which produces the ciphertext after double encryptions. The parameters of the logistic map and the order of the discrete fractional angular transform serve as the main keys of the image encryption algorithm. Simulation results show that the proposed image encryption algorithm can effectively resist the attacks of statistical analysis, and has acceptable encryption effect and security.
Źródło:
Optica Applicata; 2017, 47, 1; 141-155
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Provenance-specific climate sensitivity of Pinus massoniana – a multi-environmental trial in subtropical China
Autorzy:
Zhang, Z.
Jin, G.
Feng, Z.
Sun, L.
Zhou, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2078265.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Pinus massoniana
provenance
climate change
wood density
radial growth
Opis:
Climate change is causing changes in tree species performance and distribution, impacting breeding programme effectiveness. Our aim was to analyse the effects of provenance and climatic factors on the annual ring density of Masson pine (Pinus massoniana Lamb.) at different experimental sites and potential breeding strategies that may be developed in response to future climate change. The study trees represented provenances originating from the western, east-central, northern, and southern regions of P. massoniana distribution in China. The wood density differed significantly among provenances. A multisite variance analysis test showed that the type B correlation coefficients for ring density at the two sites stud- ied were less than 0.8, indicating an interaction effect of genotype by environment (G×E) on tree ring density. Climatic factors directly affected the wood density properties. At Chun’an (CA), the maximum latewood density (MXD) and minimum earlywood density (MND) were positively correlated with absolute maximum temperatures in August and May of the current growing season, respectively. At Taizi Mountain (TZS), MXD was significantly positively correlated with absolute maximum temperature in September of the current year and significantly negatively correlated with precipitation in June. MND was significantly positively correlated with absolute maximum temperature in May of the current year and significantly negatively correlated with precipitation in April. The climatic effects on P. massoniana wood density differed among seed-source origins. This study showed that ring density characteristics differed significantly among provenances, and provenance selection could promote wood density. MXD and MND exhibited significant genotype-by-environment interaction effects, and significant correlations were found between ring density and temperature and precipitation conditions. These findings suggest that climatic factors and site condi- tions in addition to genetics could be strong drivers of wood density variation, and/or that wood density is a highly plastic trait.
Źródło:
Dendrobiology; 2021, 85; 3-18
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural Stabilities and Elastic Constants of EuX (X = O, S, Se, and Te) Compounds at High Pressure
Autorzy:
Kong, B.
Zhou, Z.
Sun, X.
Zhang, L.
Ling-Hu, R.
Powiązania:
https://bibliotekanauki.pl/articles/1400144.pdf
Data publikacji:
2013-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.66.-f
46.70.-p
61.43.-j
75.50.-y
Opis:
The structural stabilities, elastic properties and charge transfers of EuX (X = O, S, Se, Te) compounds as a function of pressure are investigated extensively using first-principles calculations. The ground-state parameters, such as lattice constants, bulk modulus are predicted and compared with the available data, our results are satisfactory. The calculated phase transition pressures from the NaCl-type (B1) structure to the CsCl-type (B2) structure for EuX (X = O, S, Se, Te) also accord with the experiments. Particularly, the elastic constants of EuX (X = O, S, Se, Te) under zero pressure and high pressure are simulated appropriately for the first time via density functional theory. The softening behaviors of the elastic shear modulus $C_{44}$ under pressure for the B1 phase of EuX (X = O, S, Se, Te) are captured, which should be responsible for the pressure-induced structural phase transition in the EuX system. It is also suggested that the softening behavior might be induced partly by the p → d and f → d electron transfers of Eu atom under pressure. In addition, the aggregate elastic modulus (B, G, E), Poisson's ratio (σ), Debye temperature $\Theta p_{D}$ are also successfully obtained for both B1 and B2 phases of EuX.
Źródło:
Acta Physica Polonica A; 2013, 123, 4; 720-727
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameter Description of the Surface Metal Fiber Arrangement of Electromagnetic Shielding Fabric
Wpływ rozmieszczenia włókien metalowych na skuteczność ekranowania tkanin osłonowych
Autorzy:
Liu, Z.
Su, Y.
Pan, Z.
Li, Y.
Wang, X.
Zhou, Z.
Powiązania:
https://bibliotekanauki.pl/articles/232915.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
electromagnetic shielding fabric
surface metal fiber blends
surface metal arrangement
tkanina ekranująca
tkanina osłonowa elektromagnetyczna
układ metalowy powierzchni
Opis:
The influence of the surface metal fiber (SMF) arrangement on the shielding effectiveness (SE) of electromagnetic shielding fabric (EMSF) is important, but there is no reasonable description method for it at present, making the further exploration of the relationship between SMF and SE difficult. In order to scientifically describe the SMF arrangement of EMSF, this paper constructs a binary feature matrix of SMF based on a previous study of SMF region recognition. According to the feature matrix, three parameters of the exposure ratio, the discrete mean and disorder degree are proposed and the calculation equations for the three parameters given. Experiments were designed and testing samples determined to test the SE, and the exposure ratio, discrete mean and disorder degree of each sample are calculated. The relationship between the three parameters and the SE is analysed for effectiveness validation of the three parameters. Results show that the exposure ratio, discrete mean and disorder degree can describe three aspects of the SMF arrangement: the percentage content, porosity and orientation, which are positively correlated, negatively correlated and positively correlated to the SE, respectively. The research in this paper provides a basis for the study of the shielding mechanism, the transmission model, the shielding rule and the rapid non-destructive evaluation of the EMSF, and puts forward a new idea for the study of shielding theory and the application of the EMSF.
Ze względu na istotny wpływ rozmieszczenia włókien metalowych (SMF) na skuteczność ekranowania (SE) tkanin osłonowych (EMSF) w pracy przedstawiono macierz binarną opartą na trzech parametrach włókien metalowych tj.: współczynniku ekspozycji, średniej wartości odległości między włóknami metalowymi i stopniu ich nieuporządkowania. Analizowano zależności pomiędzy wyżej wymienionymi parametrami a skutecznością ekranowania. Przedstawione wyniki stanowią podstawę do opracowania szybkiej i nieniszczącej metody oceny skuteczność ekranowania oraz do dalszych badań mechanizmu ekranowania.
Źródło:
Fibres & Textiles in Eastern Europe; 2017, 2 (122); 62-67
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A planning model for the chemical integrated system under uncertainty by grey programming approach
Autorzy:
Ren, J.
Tan, S.
Dong, L.
Zhou, Z.
Gao, S.
Pan, C.
Powiązania:
https://bibliotekanauki.pl/articles/778898.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
planning
chemical integrated system
grey programming
Opis:
A model to optimize the planning of the chemical integrated system comprised by multi-devices and multi-products has been proposed in this paper. With the objective to make more profits, the traditional model for optimizing production planning has been proposed. The price of chemicals, the market demand, and the production capacity have been considered as mutative variables, then an improved model in which some parameters are not constant has been developed and a new method to solve the grey linear programming has been proposed. In the grey programming model, the value of credibility can be suggested by the decision-makers, and the results of the production planning calculated by the model can help them to achieve their desired target. An actual case has been studied by the proposed methodology, and the proposed methodology can be popularized to other cases.
Źródło:
Polish Journal of Chemical Technology; 2013, 15, 2; 16-22
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improved feature extraction method for rolling bearing fault diagnosis based on MEMD and PE
Autorzy:
Zhang, H.
Zhao, L.
Liu, Q.
Luo, J.
Wei, Q.
Zhou, Z.
Qu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/259770.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
improved feature extraction method
rolling bearing fault diagnosis
MEMD
PE
Opis:
The health condition of rolling bearing can directly influence to the efficiency and lifecycle of rotating machinery, thus monitoring and diagnosing the faults of rolling bearing is of great importance. Unfortunately, vibration signals of rolling bearing are usually overwhelmed by external noise, so the fault frequencies of rolling bearing cannot be readily obtained. In this paper, an improved feature extraction method called IMFs_PE, which combines the multivariate empirical mode decomposition with the permutation entropy, is proposed to extract fault frequencies from the noisy bearing vibration signals. First, the raw bearing vibration signals are filtered by an optimal band-pass filter determined by SK to remove the irrelative noise which is not in the same frequency band of fault frequencies. Then the filtered signals are processed by the IMFs_PE to get rid of the relative noise which is in the same frequency band of fault frequencies. Finally, a frequency domain condition indicator FFR(Fault Frequency Ratio), which measures the magnitude of fault frequencies in frequency domain, is calculated to compare the effectiveness of the feature extraction methods. The feature extraction method proposed in this paper has advantages of removing both irrelative noise and relative noise over other feature extraction methods. The effectiveness of the proposed method is validated by simulated and experimental bearing signals. And the results are shown that the proposed method outperforms other state of the art algorithms with regards to fault feature extraction of rolling bearing.
Źródło:
Polish Maritime Research; 2018, S 2; 98-106
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, Crystal Structure, and Properties of a Novel, Highly Sensitive Energetic, Coordination Compound: Iron (II) Carbohydrazide Perchlorate
Autorzy:
Liu, R.
Zhou, Z.
Qi, S.
Yang, L.
Wu, B.
Huang, H.
Zhang, T.
Powiązania:
https://bibliotekanauki.pl/articles/358343.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
iron (II) carbohydrazide perchlorate
energetic material
high
sensitivity
DFT
energy gap
Opis:
A single crystal of iron (II) carbohydrazide perchlorate [FeII (CHZ)3](ClO4)2 (FeCP), a novel, lead-free, energetic coordination compound, was synthesized and its structure determined by X-ray single crystal diffraction for the frst time. The crystal belongs to the monoclinic system P2(1)/n space group, with a = 1.0066(2) nm, b = 0.8458(2) nm, c = 2.1194(4) nm, β = 100.693(3)° and Z = 4. The central Fe(II) ion is coordinated to three bidentate carbohydrazide units through the carbonyl oxygen atom and an amino nitrogen atom, forming a six-coordinated, non-centrosymmetric complex cation. The thermal analyses by differential scanning calorimetry and thermogravimetry show that the onset temperature of thermal decomposition (152.7 °C) and the critical temperature of thermal explosion of FeCP (161.2 °C) are both much lower than those of other transition metal carbohydrazide perchlorate compounds, and also those of some other primary explosives in service. FeCP has a high enthalpy of combustion, as measured by oxygen bomb calorimetry. The impact, friction and fame sensitivity tests indicate that FeCP is extremely sensitive and hazardous. Unexpected explosions occurred even during the operational processes. In order to explore the intrinsic cause of these explosions, theoretical calculations of the orbital energies were performed based on DTF. These results reveal that the impact sensitivity is positively correlated with the energy gap between HOMO and LUMO: the smaller energy gap results in the higher impact sensitivity.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 1; 17-36
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Comprehensive Study of the Electrostatic Discharge Sensitivity and Chargeability of Tris(carbohydrazide)zinc Perchlorate
Autorzy:
Li, Z.
Zeng, D.
Zhou, Z.
Zhou, M.
Zhang, T.
Huang, H.
Zhang, J.
Yang, L.
Powiązania:
https://bibliotekanauki.pl/articles/358298.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
primary explosive
tris(carbohydrazide)zinc perchlorate
electrostatic discharge sensitivity
chargeability
Opis:
Most primary explosives are non-conductors, easily accumulate charge when contacting with and separating from other materials, and are sensitive to electrostatic discharge (ESD). In order to reduce the number of accidents caused by ESD initiation of primary explosives, studies on their electrostatic hazards are necessary. This work presents comprehensive experimental results of electrostatic discharge sensitivity and chargeability of tris(carbohydrazide)zinc perchlorate (ZnCP) under different conditions. The influences of the testing conditions, of devices, particle size, ambient temperature and relative humidity on the electrostatic discharge sensitivity and chargeability have been investigated in detail, and the quantitative regression equations obtained.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 4; 553-573
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heavy Metal Contamination of Surface Water and Groundwater in and Around Gejiu Tin Mine, Southwest China
Zanieczyszczenie wód powierzchniowych i podziemnych metalami ciężkimi w kopalni Gejiu Tin, południowo-zachodnie Chiny i jej okolicach
Autorzy:
Cheng, X.
Qi, W.
Danek, T.
Matysek, D.
Huang, Q.
Zhao, X.
Zhou, Z.
Fang, R.
Zou, L.
Xu, J.
Powiązania:
https://bibliotekanauki.pl/articles/317873.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
metale ciężkie
zanieczyszczenie
kopalnia cyny Gejiu
wody powierzchniowe
wody kopalniane
heavy metals
contamination
Gejiu tin mine
surface water
mine water
Opis:
Heavy metal contamination due to mining activity is a global major concern because of its potential health risks to local inhabitants. The heavy metal contamination of surface water and ground water by mining activities in Gejiu tin-polymetallic mining area, Southwest China, was studied. Surface water and ground water were sampled and analyzed using AAS for Cr6+, Cd, As, Hg, Cu, Pb, Zn, Se, Fe and Mn. Analysis of HCO3–, Cl–, SO42–, F– and NO3– in water samples was also undertaken by ion chromatography. It was shown that none of water samples exceeded the guideline of Cr6+, Se and Hg, while the contamination degree of heavy metals was Mn > Fe > Cd > Zn > Pb > As > Cu, all of which were serious contamination except mild contamination for Cu. The ground waters were polluted much worse than surface water.
Zanieczyszczenie metalami ciężkimi spowodowane działalnością kopalń jest światowym problemem z powodu ryzyka utraty zdrowia przez okolicznych mieszkańców. Zbadano zanieczyszczenie wód powierzchniowych oraz wód podziemnych wywołane działalnością kopalni cyny w rejonie górniczym Gejiu, południowo-zachodnie Chiny. Pobrano próbki wody powierzchniowej oraz podziemnej i zanalizowano je ze względu na obecność Cd, As, Hg, Cu, Pb, Zn, Se, Fe oraz Mn. Analizy HCO3–, Cl–, SO42–, F– oraz NO3– w próbkach wody również zostały przeprowadzone za pomocą chromatografii jonowej. Ukazano, że żadna z badanych wód nie przekroczyła dopuszczalnych poziomów dla Cr6+, Se oraz Hg. Jednakże poziom zanieczyszczenia metali ciężkimi tj. Mn > Fe > Cd > Zn > Pb > As > Cu był wysoki, za wyjątkiem niewielkiego przekroczenia norm dla Cu. Wody podziemne były znacznie bardziej zanieczyszczone niż wody powierzchniowe.
Źródło:
Inżynieria Mineralna; 2016, R. 17, nr 1, 1; 93-98
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relationship of adiponectin, leptin, visfatin and IGF-1 in cow’s venous blood and venous cord blood with calf birth weight
Autorzy:
Shen, L.
Zhu, Y.
Xiao, J.
Deng, J.
Peng, G.
Zuo, Z.
Yu, S.
Ma, X.
Zhong, Z.
Ren, Z.
Zhou, Z.
Liu, H.
Zong, X.
Cao, S.
Powiązania:
https://bibliotekanauki.pl/articles/2087491.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
adiponectin
leptin
IGF-1
birth weights
cow
Źródło:
Polish Journal of Veterinary Sciences; 2019, 3; 541-548
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of matrine on reducing damage to bovine mammary epithelial cells induced by Staphylococcus aureus alpha-hemolysin
Autorzy:
Feng, F.
Ma, W.W.
Luo, H.X.
Guan, C.P.
Zhou, X.Z.
Powiązania:
https://bibliotekanauki.pl/articles/2087720.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
α-hemolysin
BMECs
matrine
cell damage
Źródło:
Polish Journal of Veterinary Sciences; 2018, 21, 2; 409-413
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication of polymer microcomponents using CO2 laser melting technique
Wytwarzanie mikroelementów polimerowych z zastosowaniem techniki topienia laserem CO2
Autorzy:
Tan, W. S.
Zhou, J. Z.
Huang, S.
Zhu, W. L.
Meng, X. K.
Powiązania:
https://bibliotekanauki.pl/articles/947347.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
molding
polymer microcomponents
CO2 laser
irradiation
numerical simulation
formowanie
mikroelementy polimerowe
laser CO2
napromienianie
symulacja numeryczna
Opis:
A new method of laser melting molding to produce high-efficiency and high-quality polymer microcomponents was proposed. Numerical simulation was used to analyze the temperature changes of polymer melt during the laser irradiation process. An orthogonal experiment was also employed to investigate the factors influencing molding accuracy. The molding experiments were conducted on molds with various degrees of roughness, and the surface quality of the molded pieces was tested. The simulation analysis and experimental results showed that the laser power plays a critical role in improving the repetition accuracy. The next factors are irradiation time and mold temperature, followed by molding force. Optimized technological parameters (1.2 W of laser power, 6 mm of laser beam width, 6 s irradiation time, 150 N molding force, and 80 °C mold temperature) were applied to obtain a molded pieces with high repetition accuracy and a microstructure dimensional deviation of less than 1 µm. Using a mold with lower surface roughness provides that we can obtain a molded piece with lower roughness, the roughness difference between the mold and the molded piece was less than 0.012 µm.
Zaproponowano nową metodę formowania mikroelementów polimerowych z zastosowaniem topienia laserowego, zapewniającą wysoką wydajność oraz dobrą jakość wytwarzanych mikroelementów. Istotnym parametrem procesu, wpływającym na jakość formowanych elementów, jest temperatura stopu polimeru. Do analizy zmian tej temperatury pod wpływem napromieniania laserem zastosowano symulację numeryczną. Zastosowano także ortogonalny plan eksperymentu w celu zbadania czynników wpływających na dokładność formowania. Formowania przeprowadzono z użyciem form o różnych stopniach chropowatości i zbadano jakość powierzchni mikroelementów. Analiza wyników symulacji i badań eksperymentalnych wykazała, że moc lasera odgrywa kluczową rolę w uzyskaniu powtarzalnej dokładności. Kolejnymi czynnikami są czas napromieniowania i temperatura formy oraz siły formujące. Zoptymalizowane parametry technologiczne (moc lasera 1,2 W, szerokość wiązki lasera 6mm, czas napromieniania 6 s, siła formująca 150 N i temperatura formowania 80 °C) zastosowano do formowania elementów z powtarzalną dużą dokładnością odtwarzania wymiarów (odchylenia wymiarów nie przekraczały 1 µm). Użycie form o mniejszej chropowatości powierzchni pozwalało także uzyskać mniejszą chropowatość mikroelementów, przy czym różnica chropowatości formy i otrzymanego elementu była mniejsza niż 0,012 µm.
Źródło:
Polimery; 2015, 60, 3; 192-198
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sea wave energy converter - WAVE DRAGON MW for few megawatts power range
Przekształtnik energii fal morskich MW WAVE Dragon na poziomie mocy w zakresie kilku megawatów
Autorzy:
Kaźmierkowski, M.
Jasiński, M.
Malinowski, M.
Płatek, T.
Styński, S.
Antoniewicz, P.
Kołomyjski, W.
Świerczyński, D.
Soerensen, H. C.
Friis-Madsen, E.
Christiansen, L.
Knapp, W.
Zhou, Z.
Igic, P.
Powiązania:
https://bibliotekanauki.pl/articles/159473.pdf
Data publikacji:
2007
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Elektrotechniki
Tematy:
energia odnawialna
energia fal morskich
przekształtnik energoelektroniczny
generatory
renewable energy
energy from sea waves
power electronics converters
generators
Opis:
The paper has as an objective to combine and disseminate a brief knowledge on generators and power electronics for Wave Dragon MW (WDMW) Power Take Off system. Wave Dragon MW captures power from sea waves by means of low-head turbines and converts it into rotating mechanical power. In recent years because of energy saving problem on almost whole world power electronics and electric machines as well as renewable energy market has been intensively developed. Problems which can appear in conversion mechanical power to electrical power in WDMW can be expected to be similar as in wind turbine. Therefore, state of the art briefly can base on state of the art for wind turbines. However, subject of the mechanical energy conversion from sea waves to electrical energy is not well identified and further research should be curried out.
Artykuł ma na celu zebranie i przedstawienie podstawowych informacji na temat przekształtnika energii fal morskich Wave Dragon MW (WDMW). Ponadto również wstępne wyniki symulacyjne zespołu generator-przekształtnik energoelektroniczny - sieć.
Źródło:
Prace Instytutu Elektrotechniki; 2007, 231; 5-16
0032-6216
Pojawia się w:
Prace Instytutu Elektrotechniki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
17 beta-estradiol affects proliferation and apoptosis of canine bone marrow mesenchymal stem cells in vitro
Autorzy:
Zhou, Z.-H.
Gu, C.-W.
Li, J.
Huang, X.-Y.
Deng, J.-Q.
Shen, L.-H.
Cao, S.-Z.
Deng, J.-L.
Zuo, Z.-C.
Wang, Y.
Ma, X.-P.
Ren, Z.-H.
Yu, S.-M.
Powiązania:
https://bibliotekanauki.pl/articles/2087308.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
apoptosis
bone marrow mesenchymal stem cells (BMSCs)
canine
proliferation
17 beta-estradiol (E2)
Źródło:
Polish Journal of Veterinary Sciences; 2020, 23, 2; 235-245
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of serum adiponectin and leptin in healthy perinatal dairy cows or cows with ketosis, and their effectson ketosis involved indices
Autorzy:
Shen, L.
Qian, B.
Xiao, J.
Zhu, Y.
Hussain, S.
Deng, J.
Peng, G.
Zuo, Z.
Zou, L.
Yu, S.
Ma, X.
Zhong, Z.
Ren, Z.
Wang, Y.
Liu, H.
Zhou, Z.
Cai, D.
Hu, Y.
Zong, X.
Cao, S.
Powiązania:
https://bibliotekanauki.pl/articles/2087289.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
adiponectin
dairy cows
ketosis
leptin
perinatal period
Źródło:
Polish Journal of Veterinary Sciences; 2020, 23, 3; 373-381
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal maintenance of a series production system with two multi-component subsystems and an intermediate buffer
Optymalna strategia utrzymania ruchu dla seryjnego systemu produkcji złożonego z dwóch podsystemów wieloskładnikowych oraz buforu pośredniego
Autorzy:
Zhou, Y.
Zhang, Z.
Powiązania:
https://bibliotekanauki.pl/articles/301663.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
series-parallel systems
intermediate buffers
Markov decision process
policy iteration
generalized minimum residual method
układ szeregowo-równoległy
bufor pośredni
proces decyzyjny Markowa
iteracja strategii
uogólniona metoda najmniejszego residuum
Opis:
Intermediate buffers often exist in practical production systems to reduce the influence of the breakdown and maintenance ef subsystems on system production. At the same time, the effects of intermediate buffers also make the degradation process of the system more difficult to model. Some existing papers investigate the performance evaluation and maintenance optimisation of a production system with intermediate buffers under a predetermined maintenance strategy structure. However, only few papers pay attention to the property of the optimal maintenance strategy structure. This paper develops a method based on the Markov decision process to identify the optimal maintenance strategy for a series-parallel system with two multi-component subsystems and an intermediate buffer. The structure of the obtained optimal maintenance strategy is analysed, which shows that the optimal strategy structure cannot be modelled by a limited number of parameters. However, some useful properties of the strategy structure are obtained, which can simplify the maintenance optimisation. Another interesting finding is that a large buffer capacity cannot always bring about high average revenue even through the cost of holding an item in the buffer is much smaller than the production revenue per item.
W systemach produkcyjnych często stosuje się bufory pośrednie w celu zmniejszenia wpływu awarii i konserwacji podsystemów na system produkcji. Jednocześnie, oddziaływanie buforów pośrednich utrudnia modelowanie procesu degradacji systemu. Istnieją badania dotyczące oceny funkcjonowania i optymalizacji utrzymania systemów produkcyjnych wykorzystujących bufory pośrednie przy założeniu wcześniej określonej struktury strategii utrzymania ruchy. Jednak tylko nieliczne prace zwracają uwagę na własności optymalnej struktury strategii utrzymania ruchu. W przedstawionej pracy opracowano opartą na procesie decyzyjnym Markowa metodę określania optymalnej strategii utrzymania ruchu dla układu szeregowo-równoległego z dwoma podsystemami wieloskładnikowymi oraz buforem pośrednim. Przeanalizowano strukturę otrzymanej optymalnej strategii utrzymania i wykazano, że struktury takiej nie można zamodelować przy użyciu ograniczonej liczby parametrów. Jednak odkryto pewne przydatne właściwości struktury strategii, które mogą ułatwić optymalizację utrzymania ruchu. Innym interesującym odkryciem było to, że duża pojemność bufora nie zawsze daje wysoką średnią przychodów mimo iż koszty przechowywania obiektu w buforze są znacznie mniejsze niż przychody z produkcji w przeliczeniu na jeden obiekt.
Źródło:
Eksploatacja i Niezawodność; 2015, 17, 2; 314-325
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł

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