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Tytuł:
From transocean routes to global networks: a framework for liner companies to build service networks
Autorzy:
Shi, X.
Voss, S.
Powiązania:
https://bibliotekanauki.pl/articles/308099.pdf
Data publikacji:
2008
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
liner
port
logistics
networks
decision support systems
Opis:
During the previous two decades liner carriers within maritime shipping have broken the barriers from being pure transportation providers towards being logistics service providers. Most of the top 20 liner carriers worldwide hale set up spin-offs providing services from local booking up to 3rd party logistics services, combining the business advantages of tight linkages with liners together with the negotiation freedom with demanding customers by providing an extension of service coverage. Economical evaluations of transocean routes and global networks are of interest for decision makers responsible for business strategies as well as for operations. It is crucial to achieve appropriate judgements about which liner routes are profitable and how to build better service networks so that the companies' brand could be attractive to, e.g., ship- pers, including exporters, importers and forwarding agents. In this paper we discuss the corresponding trade-offs as well as related decision support systems of relevant service providers and companies.
Źródło:
Journal of Telecommunications and Information Technology; 2008, 3; 35-43
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Symmetry of Current of the Coherent State from the View of O(3) σ-Model
Autorzy:
Shi, X.
Qin, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1419664.pdf
Data publikacji:
2012-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
03.65.-w
02.40.-k
Opis:
In this paper, we apply the reduced density trajectory, ϕ-mapping topological current theory and Ginzburg-Landau model to study the current of the coherent state. We give the new expression of the current of the coherent state. Based on this expression, the symmetry of the coherence is studied. We find that the current of the coherent state corresponds to the supercurrent of two-condensate system. The partial wave functions of the coherence carry new charges and their interaction is mediated by new U(1) gauge potential.
Źródło:
Acta Physica Polonica A; 2012, 122, 1; 31-37
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Apparatus for Measuring the Bending Fatigue Properties of High Performance Polyethylene Fibre
Aparat do pomiarów właściwości zmęczeniowych przy zginaniu wysoko-sprawnych włókien polietylenowych
Autorzy:
Cai, G.
Shi, X.
Yu, W.
Powiązania:
https://bibliotekanauki.pl/articles/232608.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
włókno HPPE
kąt zginania
temperatura
aparatura
wytrzymałość zmęczeniowa włókien polietylenowych
HPPE fibre
bending fatigue
apparatus
fracture morphology
temperatures
Opis:
A test method for bending fatigue has been developed to determine the bending fatigue strength of fibres. This new equipment is capable of performing the bending fatigue testing of fibres under different pre-tensions, bending angles and temperatures. This article presents results from tests on single high performance polyethylene fibre (HPPE) to characterise its bending fatigue behaviour under cyclic loading and temperatures. The curve of the cyclic tension shows that the cyclic tension changes in periods during the cyclic bending process. The S-N and č-N curves indicated that the pre-tension and bending angle had great influences on the bending fatigue life of HPPE fibre. A CCD camera was utilised to allow observation of the bending fatigue fracture morphology of the fibre. It showed the fracture mechanism of the HPPE fibres. The bending fatigue life of HPPE fibre was tested at different temperatures to show that its bending fatigue strength is strongly influenced by the temperature.
Opracowano metodę oceny wytrzymałości zmęczeniowej włókien polietylenowych przy zginaniu. Przewidziano możliwość badania włókien przy rożnym obciążeniu wstępnym, kącie zginania i temperaturze. Przeprowadzono próby badania włókien polietylenowych w różnych temperaturach i przy rożnym kącie zginania. Stwierdzono, że naprężenie zginające zmienia się okresowo podczas cyklicznego procesu zginania. Stwierdzono również, że wstępne naprężenie oraz kąt zginania mają istotny wpływ na wytrzymałość zmęczeniową badanych włókien. Kamerę CCD zastosowano dla obserwacji morfologii przełomu zmęczeniowego włókien, pozwalającego na identyfikację mechanizmu przełomu. Stwierdzono wyraźny wpływ temperatury, w której przeprowadzano próby.
Źródło:
Fibres & Textiles in Eastern Europe; 2012, 4 (93); 37-40
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Properties of RDX-Nitrocellulose Microspheres
Autorzy:
Shi, X.
Wang, J
Li, X.
Powiązania:
https://bibliotekanauki.pl/articles/358363.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
RDX
nitrocellulose
flash vaporization process
thermal stability
Opis:
A new insensitive explosive based on RDX and with Nitrocellulose (NC) as binder has been prepared using a flash vaporization process. Scanning electron microscopy was used to characterize the morphology and particle size of the resulting RDX-NC microspheres. X-ray photoelectron spectroscopy, Differential Scanning Calorimetry, impact sensitivity, vacuum stability and burning rate of raw RDX, RDX-NC and RDX-1 were also used to characterize the explosive. The RDX-NC microspheres were found to have a fibrous surface. The microspheres ranged in size from 0.5 μm to 4 μm. The NC formed a coat on the surface of the RDX. The activation energies of raw RDX, RDX-1 and RDX-NC were found to be 200.8 kJ·mol−1, 183.9 kJ·mol−1 and 187.2 kJ·mol−1, respectively. The drop heights of raw RDX, RDX-1 and RDX-NC were found to be 21.3 cm, 51.7 cm and 82.9 cm, respectively. The friction sensitivity of RDX-NC was lower than that of raw RDX and RDX-1. In the vacuum stability test, the volumes of evolved gas from raw RDX, RDX-1 and RDX-NC were 0.12 mL·g−1, 0.12 mL·g−1, and 0.09 mL·g−1, respectively. The burning rates of RDX-NC-based propellants were higher than that of RDX-1 and raw RDX based propellants at 5-15 MPa. The burning rate pressure exponent of RDX-NC based propellants is 0.9929 at 40-200 MPa.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 4; 871-881
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Jurassic ammonites of the Wulong area, Tingri County, Tibet
Autorzy:
Morton, N.
Meister, Ch.
Ruellau, L.
Shi, X.
Powiązania:
https://bibliotekanauki.pl/articles/2061072.pdf
Data publikacji:
2015
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
ammonites
Jurassic
Tibet
systematics
biostratigraphy
amonity
jura
Tybet
systematyka
biostratygrafia
Opis:
The Jurassic succession west of Wulong village, Tingri County, southern Tibet, is described. Lithostratigraphical classification uses pre-existing terminology for formations, and an informal subdivision into members is proposed. An important structural dislocation, in the form of a small-scale flower structure, affects the Zhamure Formation straddling the Triassic/Jurassic boundary but does not affect the underlying Derirong Formation (Rhaetian) or the overlying Wulong Formation (Lower Jurassic). No other major structural discontinuities could be recognised. New finds of ammonites in situ include a new genus and species of possible schlotheimiid, Womalongiceras inflatum, with a probable age of Sinemurian or slightly younger. Two separate beds yielded rich assemblages of crushed ammonites identified as Nyalamoceras nyalamensis Chao and Wang (1956) here interpreted as a hammatoceratid. The age of these is reinterpreted as uppermost Aalenian on the basis of an accompanying specimen of ?Pseudolioceras (Tugurites) sp. nov. and poorly preserved ammonites from higher beds identified as graphoceratids (?Graphoceras).
Źródło:
Volumina Jurassica; 2015, 13, 2; 1--21
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Characterization of HMX/Estane Nanocomposites
Autorzy:
Shi, X.
Wang, J.
Li, X.
An, Ch.
Powiązania:
https://bibliotekanauki.pl/articles/358274.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HMX
Estane 5703
spray drying
nanocomposites
thermal stability
Opis:
A new insensitive explosive based on octahydro-1,3,5,7-tetranitro1,3,5,7-tetrazocine (HMX) was prepared by spray drying using Estane 5703 as a binder. Scanning electron microscopy was used to characterize the morphology and particle size of the HMX/Estane 5703 nanocomposites. The composites were analyzed by X-ray diffractometry and differential scanning calorimetry and their impact sensitivity was determined. For comparison, raw HMX was also tested using these three methods. The nanocomposite morphology was found to be microspherical (1 to 8 μm diameter) and composed of many tiny particles, 30 to 150 nm in size. The crystal type of the HMX/Estane 5703 nanocomposites was unchanged. The activation energy, self-ignition temperature and average drop height of the raw HMX were 515.66 kJ·mol-1, 278.63 °C and 18.4 cm, respectively. In comparison, the corresponding values for the HMX/Estane 5703 nanocomposites were 488.92 kJ·mol-1, 279.3 °C and 75.4 cm, respectively.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 3; 433-442
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Process Optimization and Characterization of an HMX/Viton Nanocomposite
Autorzy:
Shi, X.
Wang, C.
Wang, J.
Li, X.
An, C.
Ji, W.
Powiązania:
https://bibliotekanauki.pl/articles/358667.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HMX
spray drying
processing parameters
optimization
impact sensitivity
nanoparticles
Opis:
HMX/Viton A nanocomposites were prepared by a spray drying process using different processing parameters, which included the dry gas inlet temperature, the air flow rate, and the solution feed flow rate. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the nanocomposites. The effects of the processing parameters on the morphology of the samples were investigated and are discussed. The thermal decomposition behaviour and impact sensitivity of the raw HMX and HMX/Viton A nanocomposites were also measured and compared. Optimal morphology and dispersion of the coated samples was achieved when the dry gas inlet temperature and the air and solution feed flow rates were 55 °C, 660 L/h and 1.5 mL/min, respectively. Under these optimal processing conditions, the nanocomposites were spherical in shape, ranged from 0.2-2 μm in size, and were composed of many tiny particles of 50-100 nm in size. The crystal phase of the nanocomposites was the same as that of raw HMX. Compared with those of raw HMX, the melting point and impact sensitivity of the nanocomposites were lower and the thermal decomposition rate was slightly higher.
Źródło:
Central European Journal of Energetic Materials; 2015, 12, 3; 487-495
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and Characterization of Metal Derivatives of 1,1,2,2-Tetranitraminoethane (TNAE)
Autorzy:
Zhu, C.
Meng, Z.
Xu, Z.
Liu, W.
Liu, Y.
Shi, X.
Xie, T.
Powiązania:
https://bibliotekanauki.pl/articles/358571.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
Ionic compound
1,1,2,2-tetranitraminoethane
thermal property
safety performance
thermal decomposition kinetics
Opis:
The introduction of anions and cations into energetic materials can significantly improve their physicochemical and energetic properties. The K, Zn, Ba, Cu and Pb salts of 1,1,2,2-tetranitraminoethane (TNAE) were synthesized using TNAE as the starting material, and were characterized by IR spectroscopy, NMR spectroscopy and elemental analysis. All of the energetic salts exhibited relatively high thermal stabilities (decomposition temperatures ranging from 195.1 °C to 279.3 °C) and high densities (ranging from 2.1 g·cm–3 to 3.7 g·cm–3). It was demonstrated that the introduction of metal ions conveys better thermal stability than covalent TNAE itself. More importantly, the Zn, Ba and Cu salts exhibited good thermal stability, high density, low sensitivity, and therefore have the potential to be a new class of insensitive, highly energetic explosives for practical applications.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 3; 435-444
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of hadronic rescattering on the elliptic flow after the hydrodynamics model
Autorzy:
Ma, G.
Ma, Y.
Sa, B.
Cai, X.
He, Z.
Huang, H.
Long, J.
Shen, W.
Zhong, Ch.
Chen, J.
Zuo, J.
Zhang, S.
Shi, X.
Powiązania:
https://bibliotekanauki.pl/articles/148372.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
elliptic flow
hydrodynamic model
hadronic rescattering
LUCIAE model
Opis:
Abstract A hydrodynamics + hadronic rescattering model is used to simulate Au+Au collisions at 200 GeV and a Cooper-Frye method is adopted for hadronization. The effect of hadronic rescattering on elliptic flow V2 in 20 40% Au+Au collisions at 200 GeV has been investigated. It is found that the hadronic rescattering can suppress elliptic flow V2 and makes an asymmetric system in momentum space tend to be less anisotropic. The suppression effect becomes weak with increasing transverse momentum. In addition, the effect of hadronic rescattering on transverse momentum spectra and anisotropy of hadronic coordinate space is presented.
Źródło:
Nukleonika; 2006, 51,suppl.3; 21-27
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A key metric and its calculation models for a continuous diagnosis capability based on a dependency matrix
Autorzy:
Shi, J.-Y.
Lin, X.-G.
Shi, M.
Powiązania:
https://bibliotekanauki.pl/articles/221741.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fault diagnosis
dependency matrix
measurement
Opis:
This paper is devoted to measuring the continuous diagnosis capability of a system. A key metric and its calculation models are proposed enabling us to measure the continuous diagnosis capability of a system directly without establishing and searching the sequential fault tree (SFT) of the system. At first a description of a D matrix is given and its metric is defined to determine the weakness of a continuous diagnosis. Then based on the definition of a sequential fault combination, a sequential fault tree (SFT) is defined with its establishment process summarized. A key SFT metric is established to measure the continuous diagnosis capability of a system. Two basic types of dependency graphical models (DGMs) and one combination type of DGM are selected for characteristics analysis and establishment of metric calculation models. Finally, both the SFT searching method and direct calculation method are applied to two designs of one type of an auxiliary navigation equipment, which shows the high efficiency of the direct calculation method.
Źródło:
Metrology and Measurement Systems; 2012, 19, 3; 509-520
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Salicylic acid induces physiological and biochemical changes in peony under waterlogging stress
Autorzy:
Zhu, X.
Shi, H.
Li, X.
Jin, S.
Powiązania:
https://bibliotekanauki.pl/articles/12703759.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Opis:
In this study, the effects of salicylic acid to antioxidative activity and photosynthetic characteristics in waterlogging stress of two peony cultivars (‘Fengdanbai’ and ‘Mingxing’) were investigated. 4-year-old peony grown in different levels of waterlogging stress and then different concentration prepared SA (0.0, 0.1, 0.5 and 1.0 mmol L⁻¹) sprayed on fresh leaves of peony. The antioxidative enzymes activities include superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), chlorophyll content, relative conductivity and MDA content were measured in leaves about different waterlogging treatment, the photosynthetic characteristics were also measured using photosynthetic measurement system. The results showed that waterlogging stress decreased the chlorophyll content in all peony cultivars leaves, but with SA treatment can inhibit the decrease of chlorophyll content. Relative conductivity increased as the extension of waterlogging time in two cultivars. SA treatment could effectively inhibit the increase of relative conductivity, and 0.5 mmol L⁻¹ of SA was the most suitable concentration. SOD, POD, CAT activity increased first and then decreased in different waterlogging condition, SA significantly increased the activity of various enzymes. MDA content was increase as the expansion of waterlogging time in two cultivars. SA inhibits the increase of MDA content. Of all concentration of SA, 0.5 mmol L⁻¹ was the best concentration to inhibit the waterlogging stress. For the photosynthetic characteristics, the net assimilation rate (Pn), stomatal conductance (Gs), transpiration rate (Tr) and intercellular CO₂ (Ci) were decreased under different waterlogging condition. SA treatment can increase Pn, Gs, Tr and Ci of peony.
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2020, 19, 1; 41-52
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomass partition and carbon storage of Cunninghamia lanceolata chronosequence plantations in Dabie Mountains in East China
Autorzy:
Xie, X.
Cui, J.
Shi, W.
Liu, X.
Tao, X.
Wang, Q.
Xu, X.N.
Powiązania:
https://bibliotekanauki.pl/articles/41359.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
biomass
carbon storage
Cunninghamia lanceolata
Chinese fir
chronosequence
plantation forest
Dabie Mountains
China
Opis:
The quantification of biomass carbon pools is important for understanding carbon cycling in forest ecosystems. This study was designed to reveal the effects of stand age on biomass partitioning and carbon storage of Chinese fir plantation stands in Dabie Mountains of Anhui, East China. A total of six even-aged Chinese fir plantation stands along an age-sequence from 10 to 50 years were selected. To quantify the biomass of different tree components, 18 trees with diameter at breast height (D1.3) from 6.5 to 35.2 cm were harvested from the different aged stands. Biomasses of understory vegetation, forest floor and standing dead trees were also investigated. Total biomass carbon storages ranged from 57.6 to 211.4 Mg ha–1 in the different aged stands. Tree layer comprised from 93.7% to 96.4% of the total biomass C pools in the different aged stands. The C pools of the necromass were from 1.8 to 6.2 Mg ha–1. Stand age had a significant effect on tree biomass partitioning, with an increase in proportion of root biomass. The root/shoot ratios were from 0.187 to 0.312, which was significantly positively correlated to stand age. The existing plantation stands are still developing and have somewhat high rate of biomass and carbon accumulations beyond the normal rotation period (usually 25–30 years) even over an age of 50 years. Appropriate prolongation of the rotation period of Chinese fir plantation will be effective in maintaining long-term productivity and providing large carbon sink. The measurements provide valuable data for modelling productivity of Chinese fir plantation forest.
Źródło:
Dendrobiology; 2016, 76
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Health index synthetization and remaining useful life estimation for turbofan engines based on run-to-failure datasets
Synteza wskaźników stanu technicznego oraz ocena pozostałego okresu użytkowania silników turbowentylatorowych z wykorzystaniem zbiorów danych o pracy do czasu uszkodzenia
Autorzy:
Shi, J.
Li, Y.
Wang, G.
Li, X.
Powiązania:
https://bibliotekanauki.pl/articles/301447.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
hierarchical clustering
relevance vector machine
run-to-failure
remaining useful life
health indices
prognostics
grupowanie hierarchiczne
maszyna wektorów istotnych
praca do czasu uszkodzenia
pozostały okres użytkowania
wskaźnik stanu technicznego
prognostyka
Opis:
Turbofan engines will gradually degrade until failure occurs or life ends if without maintenance. Reliable degradation assessment and remaining useful life (RUL) estimation make sense on both aviation safety and rational maintenance decisions. This paper proposes a data-driven prognostic method on the premise of run-to-failure (RtF) data which are multivariate sensory data collected from the engines operating from normal to failure. After necessary pre-processing to the data, clustering analysis is executed to generate the clusters which represent the multi-states of the degradation process. The failure state cluster is extracted, and then the distance between the pre-processed data and the cluster is calculated. Therefore, one-dimensional time series are generated and defined as the health indices. Afterwards the degradation models are built based on the health indices. Finally, the RUL of a testing unit can be estimated by similarity analysis with the models. Hierarchical clustering (HC) and relevance vector machine (RVM) are the main algorithms employed in this paper. To validate the proposition, a case study is performed on turbofan engines data from Prognostics Center of Excellence (PCoE) at NASA Ames Research Center, and sufficient comparisons were given.
Silniki turbowentylatorowe niepoddane konserwacji ulegają stopniowej degradacji aż do czasu wystąpienia uszkodzenia lub zakończenia cyklu życia. Rzetelna ocena degradacji oraz pozostałego okresu użytkowania (RUL) mają wpływ zarówno na bezpieczeństwo maszyn lotniczych jak i racjonalne podejmowanie decyzji dotyczących utrzymania ruchu. W artykule zaproponowano sterowaną danymi metodę prognostyczną opartą na danych o pracy do czasu uszkodzenia (run-to failure, RTF), które są wielowymiarowymi danymi sensorycznymi zbieranymi podczas normalnej pracy silnika aż do jego uszkodzenia. Po niezbędnej wstępnej obróbce danych, przeprowadzono analizę skupień w celu wygenerowania skupień reprezentujących multi-stany procesu degradacji. Wyodrębniono klaster stanów uszkodzenia, a następnie obliczono odległość między wstępnie przetworzonymi danymi a wyodrębnionym klastrem. Następnie wygenerowano jednowymiarowe szeregi czasowe, które zdefiniowano jako wskaźniki stanu technicznego. Na podstawie tych wskaźników zbudowano modele degradacji. Wreszcie, w oparciu o analizę podobieństwa do opracowanych modeli oceniono RUL jednostki testowej. Główne algorytmy zastosowane w niniejszym opracowaniu to algorytmy grupowania hierarchicznego (HC) oraz maszyny wektorów istotnych (RVM). Aby zweryfikować zaproponowaną w pracy metodę, przeprowadzono studium przypadku z wykorzystaniem danych dot. silników turbowentylatorowych pochodzące z Prognostic Center of Excellence (PCoE) przy NASA Ames Research Center oraz przedstawiono odpowiednie porównania.
Źródło:
Eksploatacja i Niezawodność; 2016, 18, 4; 621-631
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel method of handling tolerances for analog circuit fault diagnosis based on normal quotient distribution
Autorzy:
Ao, Y.
Shi, Y.
Zhang, W.
Li, X.
Powiązania:
https://bibliotekanauki.pl/articles/221119.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
soft-fault diagnosis
analog circuit
Normal Quotient Distribution
Slope Fault Model
Opis:
While the Slope Fault Model method can solve the soft-fault diagnosis problem in linear analog circuit effectively, the challenging tolerance problem is still unsolved. In this paper, a proposed Normal Quotient Distribution approach was combined with the Slope Fault Model to handle the tolerances problem in soft-fault diagnosis for analog circuit. Firstly, the principle of the Slope Fault Model is presented, and the huge computation of traditional Slope Fault Characteristic set was reduced greatly by the elimination of superfluous features. Several typical tolerance handling methods on the ground of the Slope Fault Model were compared. Then, the approximating distribution function of the Slope Fault Characteristic was deduced and sufficient conditions were given to improve the approximation accuracy. The monotonous and continuous mapping between Normal Quotient Distribution and standard normal distribution was proved. Thus the estimation formulas about the ranges of the Slope Fault Characteristic were deduced. After that, a new test-nodes selection algorithm based on the reduced Slope Fault Characteristic ranges set was designed. Finally, two numerical experiments were done to illustrate the proposed approach and demonstrate its effectiveness.
Źródło:
Metrology and Measurement Systems; 2012, 19, 4; 817-830
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Forest in Karst Mountain sinkhole of southeastern China provides refugium for the preservation of bryophyte diversity
Autorzy:
Li, X.
Zhang, Z.
Wang, Z.
Shi, K.
Powiązania:
https://bibliotekanauki.pl/articles/2130582.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
negative landform
natural refuge
complex microenvironment
karst rocky
desertification
Opis:
The negative landform of sinkholes provides belowground level refugia for a high diversity of forest species compared to the forests on the surface of surrounding karst plateaus in southeastern China. Bryophyte diversity in sinkhole forests is also likely to be high. In this study, bryophytes of an underground forest sinkhole (UFS), and two forests (Forest Karst Mountain 1; FKM1) and (Forest Karst Mountain 2; FKM2) on the surface of the karst plateau were compared to understand the role of the sinkhole forest in the conservation of bryophyte diversity and the relationships between bryophyte diversity, environmental factors, and soil nutrients. Significantly more bryophyte taxa were recorded from the sinkhole forest (71 taxa, 36 genera, 23 families) than those in the forest on the plateau surface, which was the closest to the sinkhole (FKM1; 29 bryophyte taxa, 16 genera, 12 families), and even fewer bryophytes were found in the forest more distant to the sinkhole (FKM2; 22 taxa, 17 genera, eight families). Twenty-four liverwort taxa were collected from the sinkhole forest, two from the closest surface forest (FKM1) and none from the furthest surface forest (FKM2). Ninety-three percent of the bryophytes in karst mountain sinkhole were not found on surface forest. The diversity index trend was as follows: UFS > FKM1 > FKM2, and the evenness index trend was in the opposite direction as follows: UFS < FKM1 < FKM2. The beta diversity showed that the Jaccard index among the three forests was 0–0.25, reflecting a huge difference between the sinkhole forest and the two surface forests. Canonical correspondence analysis showed that light was the most important factor affecting the distribution of bryophytes in the sinkhole forest, while temperature and humidity were key factors for the distribution of bryophytes in the two surface forests. Further, soil parameters, namely, soil organic carbon, total nitrogen, total phosphorus, total potassium, alkali- hydrolyzed nitrogen, and available phosphorus changed gradually from UFS to FKM1 and to FKM2. The sinkhole forest, located in a landform with the unique negative topography enclosed by cliffs, and with a complex microenvironment, provides a natural refuge for bryophyte species in areas where forests have been negatively impacted by karst rocky desertification.
Źródło:
Acta Societatis Botanicorum Poloniae; 2020, 89, 4
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł

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