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Using ecosystem service supply and ecosystem sensitivity to identify landscape ecology security patterns in the Lanzhou-Xining urban agglomeration, China

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Journal of Mountain Science 2020年第11期17卷 2758-2773页

作者： TONG Hua-li shi Pei-ji College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730070China Gansu Province Land Use and Comprehensive Improvement Engineering Research Center Lanzhou 730070China

The construction of an ecological security pattern(ESP)is an important way to ensure regional ecological security and to achieve sustainable regional *** is also one of the hotspot topics of landscape ecology *** paper identifies the ecological source through the evaluation of the ecosystem service and ecosystem sensitivity of the Lanzhou-Xining(Lan-Xi)urban *** minimum cumulative resistance(MCR)model modified by night light data NPP/VIIRS(National Polar-orbiting Operational Environmental Satellite System Preparatory Project/Visible Infrared Imaging Radiometer Suite)was used to measure the relative resistance of the materials and energy circulation between the source areas,and to establish the resistance surface of the ecological source area *** ecological corridors were identified based on ecological sources and resistance *** ecological strategic node is the ecological fragile point in the ecological *** ecological strategic node is identified with hydrological module by superimposing the"ridge line"of cumulative ecological resistance with the ecological *** with ecological sources,corridors and strategic nodes,the ESP of the Lan-Xi urban agglomeration can be *** ecological source of the Lan-Xi urban agglomeration accounts for 28.42%of the total area,most of which is distributed within Qinghai *** nature reserves in the area are all located within the ecological source area.A total of 41 potential ecological corridors have been identified in the study *** total length of the potential corridors is 1201.03 km,comprising 23 source corridors and 18 radiation *** are 30 strategic nodes identified in the Lan-Xi urban *** locations are the most vulnerable areas of the ecological *** engineering should be applied in the construction of *** by the ecological source,the potential ecological corridor extends from

关键词： Ecological security pattern Ecosystem service Ecosystem sensitivity Ecological source Ecological corridor Urban agglomeration

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Layer-wise domain correction for unsupervised domain adaptation

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Frontiers of Information Technology & Electronic Engineering 2018年第1期19卷 91-103页

作者： Shuang LI shi-ji SONG Cheng WU Automation Department Tsinghua University

Deep neural networks have been successfully applied to numerous machine learning tasks because of their impressive feature abstraction ***,conventional deep networks assume that the training and test data are sampled from the same distribution,and this assumption is often violated in real-world *** address the domain shift or data bias problems,we introduce layer-wise domain correction(LDC),a new unsupervised domain adaptation algorithm which adapts an existing deep network through additive correction layers spaced throughout the *** the additive layers,the representations of source and target domains can be perfectly *** corrections that are trained via maximum mean discrepancy,adapt to the target domain while increasing the representational capacity of the *** requires no target labels,achieves state-of-the-art performance across several adaptation benchmarks,and requires significantly less training time than existing adaptation methods.

关键词： Unsupervised domain adaptation Maximum mean discrepancy Residual network Deep learning

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The effect of interface roughness on the perpendicular exchange bias of NiO/CoPt/Pt stacking structure

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Science China(Technological Sciences) 2021年第3期64卷 605-610页

作者： GAO Ying HARUMOTO Takashi NAKAMURA Yoshio shi ji Department of Materials Science and Engineering Tokyo Institute of Technology2-12-1OokayamaMeguro-kuTokyo 152-8550Japan

An orthogonal coupling structure of NiO/CoPt/Pt/glass with perpendicular exchange bias effect has been *** exchange bias is found to be strongly dependent on the interface roughness between NiO and CoPt *** conventional inverse proportionality of the exchange bias field with the ferromagnetic thickness is not applicable to this top-pinned stacking ***,an anomalous ferromagnetic thickness dependence of blocking temperature is also observed.A simulation on the basis of a spin configuration model with defects at the interface agrees well with the experimental *** findings suggest considerable contribution of the interface roughness to the perpendicular exchange bias.

关键词： perpendicular exchange bias interface roughness FM thickness blocking temperature

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INFLUENCE OF CLAY ON THE MORPHOLOGY AND PHASE SEPARATION BEHAVIOR OF POLY(METHYL METHACRYLATE)/POLY(STYRENE-co-ACRYLONITRILE) BLENDS

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Chinese Journal of Polymer Science 2013年第11期31卷 1470-1483页

作者： De-zheng Pang 左敏 ji-shi Zhao 郑强 Key Laboratory of Macromolecule Synthesis and Functionalization Ministry of EducationDepartment of Polymer Science and EngineeringZhejiang University

The effect of clay on the morphology and phase-separation behavior of poly（methyl methacrylate）/poly（styrene- co-acrylonitrile）（PMMA/SAN） blends and the variation of clay dispersion have been investigated. With the evolution of phase separation in PMMA/SAN, most of the clays are first located at the boundaries between PMMA and SAN, and then gradually move to the PMMA-rich domain, owing to the affinity of clay to PMMA. The introduction of clay causes the increase of binodal and spinodal temperatures of PMMA/SAN and enlarges their metastable region, indicating the phase stabilizing effect of clay on the matrix. But the influence of clay on the cloud points obviously depends on the composition of PMMA/SAN. The selective adsorption of PMMA on the clay results in the difference between the composition of surface layer and that of polymer matrix. Hence, the clay plays the role of an agent changing the conditions of phase structure formation.

关键词： Nanocomposites PMMA/SAN blend Clay Phase separation behavior Morphology.

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Effect of Nanoclay on the Phase Separation Behavior of Poly(methyl methacrylate)/Poly(vinyl acetate) Binary Polymer Blends

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Chinese Journal of Polymer Science 2014年第11期32卷 1419-1419,1420-1430页

作者： ji-shi Zhao 左敏 Chao-ying Lin Qiang Zheng Key Laboratory of Macromolecule Synthesis and Functionalization Ministry of EducationDepartment of Polymer Science and EngineeringZhejiang University

The effect of nanoclay on the phase-separation behavior of poly（methyl methacrylate）/poly（vinyl acetate）（PMMA/PVAc） blends has been mainly investigated by small-angle laser light scattering. It is found that the effect of clay on the thermodynamics and kinetics of phase-separation for PMMA/PVAc blends seems inconsistent. The kinetics phaseseparation rate decreases, while the thermodynamics parameters, cloud points Tc and delay time tD of isothermal phaseseparation also decrease, and the variation amplitude depends on the matrix composition. The affinity of clay to PMMA results in the composition difference between the border layer and the polymer matrix and further causes the concentration fluctuation at the early stage of phase separation to reduce Tc and tD. On the other hand, the decrease of phase-separation rate is caused by the mechanical barrier effect of clay on the macromolecular diffusion of blend matrix. Hence, such seemingly counterintuitive results on the thermodynamics and kinetics of phase-separation are attributed to different dominant factors.

关键词： Nanocomposites PMMA/PVAc blend Clay Phase separation behavior Morphology.

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Vector and Spinor Decomposition of SU（2） Gauge Potential, Their Equivalence, and Knot Structure in SU（2） Chern-Simons Theory

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Communications in Theoretical Physics 2007年第5期47卷 875-878页

作者： DUAN Yi-shi REN ji-Rong LI Ran Institute of Theoretical Physics Lanzhou University Lanzhou 730000 China

In this paper, spinor and vector decompositions of SU（2） gauge potential are presented and their equivalence is constructed using a simply proposal. We also obtain the action of Faddeev nonlinear 0（3） sigma model from the SU（2） mass/ve gauge field theory, which is proposed according to the gauge invariant principle. At last, the knot structure in SU（2） Chern-Simons filed theory is discussed in terms of the Φ-mapping topological current theory, The topological charge of the knot is characterized by the Hopf indices and the Brouwer degrees of Φ-mapping.

关键词： SU(2) gauge potential decomposition massive gauge theory Chern-Simons knot

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Improved positioning algorithm based on two step least square in NLOS environments

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The Journal of China Universities of Posts and Telecommunications 2011年第5期18卷 58-63页

作者： WU shi-xun LI ji-ping-yin LIU Shou Department of Electronics and Communication Engineering Central China Normal University Wuhan 430079 China

Non-line-of-sight （NLOS） propagation is a major source of error for accurate time-of-arrival （TOA） location estimation. The two-step least square （LS） method, which does not need any information about the distribution of the NLOS error, has been studied in related researches to provide efficient location estimation of the mobile terminal （MT）. By observing the estimation of the error covariance matrix in the two-step LS method, this paper finds that the measured distances are more suitable than the initial estimated distances by maximum likelihood （ML） algorithm in NLOS environments. Moreover, by making use of the geometry relations among fixed terminals （FTs）, some measured distances which are corrupted by big NLOS errors may be reduced. Further, an iteration method can be adopted to further improve the performance of the algorithm. Accordingly, an improved algorithm based on the two-step LS method is proposed. Simulation results demonstrate that the improved algorithm has better performance than the two-step LS method and converges more quickly. Meanwhile, it is robust in different NLOS environments.

关键词： NLOS propagation TOA least square position algorithm maximum likelihood

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Influence of temperature on performance of anaerobic digestion of municipal solid waste

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Journal of Environmental Sciences 2006年第4期18卷 810-815页

作者： ZHANG ji-shi SUN Ke-wei WU Man-chang ZHANG Lei National Engineering Research Center of Solid Waste Resource Recovery Kunming 650033 China Faculty of Environmental Science and Engineering Kunming University of Science and Technology Kunming 650093 China

The influence of temperature on the performance of anaerobic reactors for treating the organic fraction of municipal sohd waste （OFMSW） was studied. Batch digestion of OFMSW was carded out for 32 d at different temperature （25℃, 35℃, 45℃ and 55℃） conditions for total solid concentrations （TS） 17% with the ratio of total organic carbon to nitrogen （C/N） being, 25：1 respectively, while keeping other parameters constant such as inoculum, start-up pH, reactor volume （2 L） and so on. Temperature can influence the methanogenic bacteria activity, accordingly inhibiting the OFMSW biodegradation and stabilization efficiency. Anaerobic reactors excelled at TS reduction, total volatile solid reduction, chemical oxygen demand reduction, increasing cumulative biogas production, whose rate was at temperature （35℃ and 55℃） conditions. Methane concentration in the biogas was above 65% in four reactors. In addition, the fluctuation of temperatures resulted in the biogas production variation. The data obtained indicated that temperature had a significant influence on anaerobic process.

关键词： municipal solid waste anaerobic digestion batch processing temperature

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Tempering stability of Fe–Cr–Mo–W–V hot forging die steels

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International Journal of Minerals,Metallurgy and Materials 2017年第10期24卷 1145-1157页

作者： Yuan-ji shi Xiao-chun Wu Jun-wan Li Na Min School of Materials Science and Engineering Shanghai University Shanghai 200072 China

The tempering stability of three Fe–Cr–Mo–W–V hot forging die steels(DM, H21, and H13) was investigated through hardness measurements and transmission electron microscopy(TEM) observations. Both dilatometer tests and TEM observations revealed that DM steel has a higher tempering stability than H21 and H13 steels because of its substantial amount of M_2C(M represents metallic element) carbide precipitations. The activation energies of the M_2C carbide precipitation processes in DM, H21, and H13 steels are 236.4, 212.0, and 228.9 kJ/mol, respectively. Furthermore, the results indicated that vanadium atoms both increase the activation energy and affect the evolution of M_2C carbides, resulting in gradual dissolution rather than over-aging during tempering.

关键词： tempering stability hot forging die steels carbide precipitation

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Homologous Comparisons of Photosynthetic System I Genes among Cyanobacteria and Chloroplasts

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Journal of Integrative Plant Biology 2008年第8期50卷 929-940页

作者： jie Yu Pei-Jun Ma Ding-ji shi shi-Ming Li Chang-Lu Wang School of Matin Science & Engineering Tianjin University of Science & Technology Tianjin 300457 China Institute of Botany the Chinese Academy of Sciences Beijing 100093 China

It has now believed that chloroplasts arose from cyanobacteria, however, during endosymbiosis, the photosynthetic genes in chloroplasts have been reduced. How these changes occurred during plant evolution was the focus of the present study. Beginning with photosystem I （PSI） genes, a homologous comparison of amino acid sequences of 18 subunits of PSI from 10 species of cyanobacteria, chloroplasts in 12 species of eucaryotic algae, and 28 species of plants （including bryophytes, pteridophytes, gymnospermae, dicotyledon and monocotyledon） was undertaken. The data showed that 18 genes of PSI can be divided into two groups： Part Ⅰ including seven genes （psaA, psaB, psaC, psal, psaJ, ycf3 and ycf4） shared both by cyanobacteria and plant chloroplasts; Part Ⅱ containing another 11 genes （psaD, psaE, psaF, psaK, psaL, psaM, btpA, ycf37, psaG, psaH and psaN） appeared to have diversified in different plant groups. Among Part Ⅰ genes, psaC, psaA and psaB had higher homology in all species of cyanobacteria and chloroplasts. Among Part Ⅱ genes, only psaG, psaH and psaN emerged in seed plants.

关键词： chloroplast cyanobacteria homologous comparison photosynthesis evolution PSI (photosystem I) genes

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