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Nest-site selection pattern of Grus japonensis in Zhalong Nature Reserve of northeast China 被引量:11
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作者 WU Qing-ming ZOU Hong-fei 《Journal of Forestry Research》 SCIE CAS CSCD 2011年第2期281-288,共8页
Nest-site selection patterns of Red-crowned cranes(Grus japonensis) and the effects of environmental variables were studied during the years of 2002-2008 in Zhalong Nature Reserve,Qiqihar city,northeast China.The ne... Nest-site selection patterns of Red-crowned cranes(Grus japonensis) and the effects of environmental variables were studied during the years of 2002-2008 in Zhalong Nature Reserve,Qiqihar city,northeast China.The nest-site selection pattern of Red-crowned cranes included two orders and three choices:the choice of nest-site habitat type within the macro-habitat order,nest zone selection and nest-site micro-habitat selection within the micro-habitat order.Various habitats(such as Carex swamps and reed fire districts) can be selected as the nest sites for Red-crowned cranes,of which reed swamps(93.15%) are given a preference.Factor Analysis reveals that the micro-habitat selection are affected by four main factors:fire,security(concealment /disturbance),incubation(conditions,nest-material),and food.Further analysis reveals that Red-crowned cranes have certain adaptability to the changes of nesting habitat quality in the Zhalong wetlands.In conclusion,fire,reeds,and water were the most important variables for nest-site habitat selection of Red-crowned Cranes in Zhalong Nature Reserve. 展开更多
关键词 conservation factor analysis nest-site selection pattern Red-crowned crane Zhalong Nature Reserve
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Turing pattern selection for a plant-wrack model with cross-diffusion
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作者 孙颖 王进良 +2 位作者 李由 江南 夏娟迪 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期128-136,共9页
We investigate the Turing instability and pattern formation mechanism of a plant-wrack model with both self-diffusion and cross-diffusion terms.We first study the effect of self-diffusion on the stability of equilibri... We investigate the Turing instability and pattern formation mechanism of a plant-wrack model with both self-diffusion and cross-diffusion terms.We first study the effect of self-diffusion on the stability of equilibrium.We then derive the conditions for the occurrence of the Turing patterns induced by cross-diffusion based on self-diffusion stability.Next,we analyze the pattern selection by using the amplitude equation and obtain the exact parameter ranges of different types of patterns,including stripe patterns,hexagonal patterns and mixed states.Finally,numerical simulations confirm the theoretical results. 展开更多
关键词 plant-wrack model CROSS-DIFFUSION Turing instability pattern selection amplitude equation
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Turing pattern selection in a reaction-diffusion epidemic model 被引量:3
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作者 王玮明 刘厚业 +1 位作者 蔡永丽 李镇清 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第7期286-297,共12页
We present Turing pattern selection in a reaction-diffusion epidemic model under zero-flux boundary conditions. The value of this study is twofold. First, it establishes the amplitude equations for the excited modes, ... We present Turing pattern selection in a reaction-diffusion epidemic model under zero-flux boundary conditions. The value of this study is twofold. First, it establishes the amplitude equations for the excited modes, which determines the stability of amplitudes towards uniform and inhomogeneous perturbations. Second, it illustrates all five categories of Turing patterns close to the onset of Turing bifurcation via numerical simulations which indicates that the model dynamics exhibits complex pattern replication: on increasing the control parameter v, the sequence "H0 hexagons → H0-hexagon-stripe mixtures →stripes → Hπ-hexagon-stripe mixtures → Hπ hexagons" is observed. This may enrich the pattern dynamics in a diffusive epidemic model. 展开更多
关键词 epidemic model pattern selection amplitude equations T^ring instability
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Poly-view Analysis on Endogenous Innovation and Corporation’s Selection of Innovation Patterns 被引量:2
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作者 田海峰 李凯 《Journal of Electronic Science and Technology of China》 2006年第4期402-406,共5页
Today, there are still some amphibolous understanding on the concepts of endogenous innovation and its three patterns in academia field. Grasping the intension and extension of these concepts will contribute to direct... Today, there are still some amphibolous understanding on the concepts of endogenous innovation and its three patterns in academia field. Grasping the intension and extension of these concepts will contribute to direct the innovation undertakers engaging innovation and the governments establishing innovation system. In order to achieve such aims, we firstly introduced the concept of endogenous innovation and its three patterns. Secondly, this paper established a concept model to describe the typical route of a technology's forming. Based on this model, we went deep into analysis on original innovation, integrative innovation, and re-innovation after digesting the introduced technology from different views. Through these analyses, we also discussed which kind of innovation is suitable for different corporations. In the last part of this paper, we summarized our main conclusions and gave some suggestions to the corporations and governments. 展开更多
关键词 endogenous innovation original innovation integrative innovation selection of innovation patterns
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Pattern selection in a predation model with self and cross diffusion
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作者 王玮明 王文娟 +1 位作者 林晔智 谭永基 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第3期300-307,共8页
In this paper, we present the amplitude equations for the excited modes in a cross-diffusive predator-prey model with zero-flux boundary conditions. From these equations, the stability of patterns towards uniform and ... In this paper, we present the amplitude equations for the excited modes in a cross-diffusive predator-prey model with zero-flux boundary conditions. From these equations, the stability of patterns towards uniform and inhomogenous perturbations is determined. Furthermore, we present novel numerical evidence of six typical turing patterns, and find that the model dynamics exhibits complex pattern replications: for μ1 〈μ ≤μ2, the steady state is the only stable solution of the model; for μ2 〈 μ ≤ μ4, by increasing the control parameter μ, the sequence Hπ-hexagons→ Hπ- hexagon-stripe mixtures → stripes → H0-hexagon-stripe mixtures → H0-hexagons is observed; for μ 〉 μ4, the stripe pattern emerges. This may enrich the pattern formation in the cross-diffusive predatorprey model. 展开更多
关键词 CROSS-DIFFUSION turing instability pattern selection amplitude equations
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Nest site selection of white-naped crane(Grus vipio) at Zhalong National Nature Reserve, Heilongjiang, China 被引量:3
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作者 Qing-ming WU Hong-fei ZOU Jian-zhang MA 《Journal of Forestry Research》 SCIE CAS CSCD 2014年第4期947-952,共6页
White-naped crane (Grus vipio) is a globally threatened spe- cies. It is very important to analyze its nest site selection in circum- stances where there are multiple disturbances, and also helpful to accu- mulate v... White-naped crane (Grus vipio) is a globally threatened spe- cies. It is very important to analyze its nest site selection in circum- stances where there are multiple disturbances, and also helpful to accu- mulate valuable information about this threatened species and supply scientific suggestions for conservation and management. We studied nest site selection and the effects of environmental variables on nesting habits of white-naped crane at Zhalong National Nature Reserve, Qiqihar City, Heilongiiang, China, during March-May of 2002-2008. White-naped crane responded and adapted to changes in the quality of the spatial environments of landscape and microhabitat under multiple environ- mental disturbances. Nest site selection included two scales and two choices, namely the choice of nest site habitat type within the macro-habitat scale and nest site micro-habitat selection within the mi- cro-habitat scale. Nest sites were recorded only in reed marshes. The choice of nest site micro-habitat included three basic elements and six factors, namely incubation element (nest parameters factor, incubation temperature factor and incubation humidity factor), safety element (pro- tection factor and concealment factor), and food element (water factor). Water, remnant reed clusters, and fire were major resource management challenges during the breeding period for the white-naped crane in this Reserve. 展开更多
关键词 factor analysis environmental variable Grus vipio nestsite selection pattern Zhalong Nature Reserve
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Characteristics of La-Pr-Nd Electrodes for Nickel-Metal Hydride Batteries
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作者 靳红梅 李国勋 +3 位作者 王瑞坤 王超群 张昭良 孙丽虹 《Rare Metals》 SCIE EI CAS CSCD 1997年第3期22-27,共6页
The effects of replacement of lanthanum by neodymium and praseodymium on the electrode characteristics were studied. The result indicated that the discharge capacity and cycle life are closely related with the alloy s... The effects of replacement of lanthanum by neodymium and praseodymium on the electrode characteristics were studied. The result indicated that the discharge capacity and cycle life are closely related with the alloy structure decided by alloy composition. The electrode with praseodymium have higher discharge capacity than that with neodymium. The replacement of lanthanum by both neodymium and praseodymium gave the electrodes higher discharge capacity and longer cycle life. The selected area diffraction pattern from the interface between two particles after 120 charge discharge cycles showed that the polycrystalline diffraction rings created from oxides and hydroxides can be observed and X ray diffraction analysis verified this conclusion. 展开更多
关键词 Alloy structure Dischage capacity Cycle life Selected and diffraction pattern Capacity
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On the direct searches for non-smooth stochastic optimization problems
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作者 Huang Tianyun 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第4期889-898,共10页
Many difficult engineering problems cannot be solved by the conventional optimization techniques in practice. Direct searches that need no recourse to explicit derivatives are revived and become popular since the new ... Many difficult engineering problems cannot be solved by the conventional optimization techniques in practice. Direct searches that need no recourse to explicit derivatives are revived and become popular since the new century. In order to get a deep insight into this field, some notes on the direct searches for non-smooth optimization problems are made. The global convergence vs. local convergence and their influences on expected solutions for simulation-based stochastic optimization are pointed out. The sufficient and simple decrease criteria for step acceptance are analyzed, and why simple decrease is enough for globalization in direct searches is identified. The reason to introduce the positive spanning set and its usage in direct searches is explained. Other topics such as the generalization of direct searches to bound, linear and non-linear constraints are also briefly discussed. 展开更多
关键词 non-linear programming non-smooth optimization stochastic simulation direct searches positive spanning set convergence analysis pattern selection.
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Pattern dynamics of a reaction-diffusion predator-prey system with both refuge and harvesting 被引量:2
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作者 Lakshmi Narayan Guin Sudipta Pal +1 位作者 Santabrata Chakravarty Salih Djilali 《International Journal of Biomathematics》 SCIE 2021年第1期1-29,共29页
We are concerned with a reaction-diffusion predator–prey model under homogeneous Neumann boundary condition incorporating prey refuge(proportion of both the species)and harvesting of prey species in this contribution... We are concerned with a reaction-diffusion predator–prey model under homogeneous Neumann boundary condition incorporating prey refuge(proportion of both the species)and harvesting of prey species in this contribution.Criteria for asymptotic stability(local and global)and bifurcation of the subsequent temporal model system are thoroughly analyzed around the unique positive interior equilibrium point.For partial differential equation(PDE),the conditions of diffusion-driven instability and the Turing bifurcation region in two-parameter space are investigated.The results around the unique interior feasible equilibrium point specify that the effect of refuge and harvesting cooperation is an important part of the control of spatial pattern formation of the species.A series of computer simulations reveal that the typical dynamics of population density variation are the formation of isolated groups within the Turing space,that is,spots,stripe-spot mixtures,labyrinthine,holes,stripe-hole mixtures and stripes replication.Finally,we discuss spatiotemporal dynamics of the system for a number of different momentous parameters via numerical simulations. 展开更多
关键词 Two species reaction-diffusion system ratio-dependent functional response diffusion-driven instability pattern selection stationary patterns
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Self-nucleation of Patterned Polymer Thin Films Defined by Soft Lithography
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作者 Ze-Qian Wang Yi-Meng Wang +4 位作者 Xing-Yu Wang Bing-Hua Wang Jing-Bo Chen Chang-Yu Shen Bin Zhang 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2022年第6期651-657,共7页
The nucleation of crystals is often a determining step in the phase transition of materials,but it remains a challenge to control the density and specific location of nuclei simultaneously.Here we fabricated the isola... The nucleation of crystals is often a determining step in the phase transition of materials,but it remains a challenge to control the density and specific location of nuclei simultaneously.Here we fabricated the isolated single crystals of uniform size with controlled number density and spatial distribution by self-nucleation of patterned dendritic crystals.Imprint lithography creates the periodic void space on the surface of poly(ethylene oxide)-b-poly(2-vinyl pyridine)(PEO-b-P2VP)block copolymer thin films and provides spatial redistribution of polymers,leading to the preferential nucleation and subsequent oriented growth of dendrites in the periodic arrays of imprinted lines.The morphology and thermal stability of the patterned crystals can be adjusted by tuning embossing conditions(e.g.,temperature and pressure).Furthermore,in the self-nucleation technique,the annealing temperature and heating rate are used as the feedback parameters to map the number density and spatial distribution of regrown single crystals.Such PEO-b-P2VP crystalline pattern can be used as a versatile template for large-area manufacturing of selective metal patterns for electronic devices and other applications. 展开更多
关键词 SELF-NUCLEATION Imprint lithography Atomic force microscopy Crystallization pattern Selective metal pattern
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Effects of Multiple Strengthening Treatments on Mechanical Properties and Stability of Nanoscale Precipitated Phases in an Aluminum-Copper-Lithium Alloy 被引量:5
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作者 S.Ahmadi H.Arabi A.Shokuhfar 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2010年第12期1078-1082,共5页
Effects of multiple strengthening treatments (i.e. ag mechanical properties and stability of nanoscale prec in this research. Various tests such as hardness, tensi ng either at three or four consecutive temperatures... Effects of multiple strengthening treatments (i.e. ag mechanical properties and stability of nanoscale prec in this research. Various tests such as hardness, tensi ng either at three or four consecutive temperatures) on pitated phases in an AA2090 alloy have been evaluated e, electrical resistance, differential scanning calorimetric (DSC), and transmission electron microscopy (TEM) have been performed. The results show that the ultimate tensile strength (UTS) and the yield strength of the samples aged at four consecutive temperatures (i.e. natural aging+190℃+150℃+100℃) can be increased approximately to 660 and 610 MPa, respectively. It is also found that precipitation of T1 phase occurs during multiple aging process of the alloy and the higher amounts of enthalpies shown in DSC charts are linked to higher volume fraction of this precipitate. Furthermore, TEM observations reveal that T1 phase has plate shape morphology and its crystal structure is in the form of hcp with lattice parameters of a=0.467 nm and c=0.878 nm. 展开更多
关键词 Multiple strengthening Thermo mechanical treatment (TMT) Selected area electron diffraction (SAED) pattern Inter planar spacing (d)
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