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Independent N-Electron Method and High Accuracy Calculations of the Ground State Energy of the Nonrelativistic Light Atoms (3 Ne 10)

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Communications in Theoretical Physics 2001年第7期36卷 79-84页

作者： xie yan-Bo Department of Modern Physics University of Science and Technology of China Hefei 230026 China

A new method based on the independent electron-pair approximation is developed to calculate the correlation energy and the basis size truncation error. The formalisms for the nondegenerate systems are described in this paper. Because all important terms are very efficiently selected and the calculations can be separated into several parts, this new method gives very accurate results and does not require expensive computing facilities. As a test, the ground state energies (GSE) of the nonrelativistic atoms for (3 ≤ Ne ≤ 10) are calculated using this new method. The calculated results are found to be in close agreement with the most recent available version of the exact GSE which is derived from the experimental data after subtracting the contributions from the relativistic effect, QED radiative corrections, finite nucleon mass corrections, and the finite radius of the nuclear size. Those accurate results have not been reproduced for Ne ≥ 5 by any direct theoretical calculations in literatures. Since this method is not restrained to nonrelativistic or Coulomb systems, it should become powerful to study other quantum interacting systems.

关键词： correlation energy basis truncation error independent N-electron approximations Ground state Independent Energy sources Atoms Correlation energy Energy level

A Behavior Level Analytical Method of Electromagnetic Susceptibility for Radio Frequency Receiver

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Chinese Journal of Aeronautics 2011年第1期24卷 74-80页

作者： yan Zhaowen YU Xiaofeng xie Shuguo LIU yan School of Electronics and Information Engineering Beijing University of Aeronautics and Astronautics Beo'ing 100191 China

Based on simplified Volterra model, a behavior-level simulation analysis approach of electromagnetic susceptibility （EMS） for radio frequency （RF） receiver is presented in this article. Third order simplified Volterra model is adopted to analyze receiver EMS. A general criterion for EMS is proposed according to EMS response characteristics in frequency domain, and then the simulation flow charts for calculating susceptibility thresholds are given. This approach is superior to the previous EMS analysis method on receiver, which mainly relies on experiments but lack simulation analysis. Take the dual frequency GPS receiver and zero IF receiver interfered by continue wave as examples for in-band and out-of-band susceptibility threshold calculation. Simulation results show that the proposed method is not only valid and effective, but also reduces the internal storage and simulation time, which is suitable to RF receiver EMS analysis and practical in engineering and technology field.

关键词： radio frequency receiver electromagnetic susceptibility Volterra series sensitivity threshold behavior-level simulation

A Correlational Study between Teachers＇ Emotional Factors and Class Interactive Teaching Efficacy

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学术界 2015年第7期 310-316页

作者： xie yan Department of Foreign Languages Ming De College of Northern Polytechnical University Xi' an Shaanxi 710124

The author brought forward two suppositions in this thesis:The students' achievements have the direct proportion with the degree of the appreciation to their *** at the supposition,the author developed a set of statistics modeling and simulation study,which focused on the teachers' characters,the students' appreciations and students' exam scores in order to reveal the influence of teachers' affective variables on students' ***,according to the series of the suppositions,the author suggested that teachers should pay full attention to the students' emotional needs and decrease the negative effects on ***,the students should encourage the teachers to be absorbed in their instruction by cooperating with their teachers actively in order to acquire abundant knowledge in the limited time.

关键词：情感因素互动教学教师学生成绩课堂统计建模考试成绩作者

Conservation status of Chinese species:(2)Invertebrates

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Integrative Zoology 2007年第2期2卷 79-88页

作者： yan xie Sung WANG Institute of Zoology Chinese Academy of SciencesBeijingChina

A total of 2441 invertebrate species were evaluated using the IUCN Red List Criteria and Regional *** 30 experts were involved in this project,which covered a wide range of species,including jellyfish,corals,planarians,snails,mollusks,bivalves,decapods,benthic crustaceans,arachnids(spiders,scorpions),butterflies,moths,beetles,sea cucumbers,sea urchins,sea stars,acorn worms and *** general,invertebrate species in China were found to be severely threatened,with 0.9%being critically endangered,13.44%endangered and 20.63%*** species of hermatypic corals and planarians are *** than 80%of evaluated species face serious threat due to habitat destruction by coral collection,logging,non-woody vegetation collection,timber plantations,non-timber plantations,extraction and/or *** threats are intrinsic factors,harvesting by humans,alien invasive species and *** main intrinsic factors contributing to the high levels of threat are limited dispersal and restricted *** conservation measures have been taken for 70%of the threatened invertebrates *** conservation measures include:strengthening of national and international legislation(Convention on International Trade in Endangered Species of Wild Fauna and Flora),increasing public awareness,studying population trends/monitoring,and establishment of protected *** major conservation measure employed is strengthening of *** to the situation worldwide(2006 IUCN Red List),there is little information available about invertebrate extinctions in China.

关键词： Chinese invertebrates conservation status major threats Red List

Conservation status of Chinese species: (1) Overview

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Integrative Zoology 2007年第1期2卷 26-35页

作者： yan xie Wang SUNG Institute of Zoology Chinese Academy of SciencesBeijingChina

The first comprehensive evaluation of more than 10000 species in China based on the IUCN Red List Criteria and Regional Guidelines is *** than 100 experts have been involved in this evaluation,which covers a wide range of species,including invertebrates,vertebrates,gymnosperms and *** present paper summa-rizes the major conclusions of the *** number of threatened species in China was found to be much high than previously *** the past,the estimated percentages of species in each phylum that were endangered was 2-30%.In this comprehensive evaluation,the percentages of threatened species were found to be 7.4-100%.Compared with the status of threatened species worldwide(IUCN Red List 2006),groups such as fish,mammals and gymno-sperms face much higher levels of threat in China then they do globally,and other groups,such as crustaceans,reptiles and birds,face lower levels of *** the dire conclusions of this study,we recommend that more research be done on the threats faced by those groups of organisms that are most threatened.

关键词： China Red List threatened species status IUCN.

Conceptual design,modeling and compliance characterization of a novel 2-DOF rotational pointing mechanism for fast steering mirror

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Chinese Journal of Aeronautics 2020年第12期33卷 3564-3574页

作者： Muhammad ABID Jingjun YU yan xie Abdus SALAM Robotics Institute School of Mechanical Engineering and AutomationBeihang UniversityBeijing 100083China School of Aeronautic Science and Engineering Beihang UniversityBeijing 100083China

In this paper,a novel 2-DOF rotational pointing mechanism(RPM)is designed inspired by the guidelines of the graphical *** mechanism integrates with a fast steering mirror(FSM)for compensating pointing errors of a laser *** design intends to achieve an angular travel of±10 mrad and steers a 25 mm mirror aperture.A planar flexure with beam flexures accompanied in parallel with an axial flexure build-up mechanism *** mechanismbased RPM ensures high precision and *** characteristics are established based on the stiffness matrix method for four different planar flexure *** layout with best in-plane rotational compliance is then assessed for performance sensitivity to mechanism dimension parameters and parasitic error,thus informing the design *** stiffness in both the inplane rotational axes and stress is determined based on finite element analysis(FEA).The wire electrical discharge machining(EDM)is employed for developing the proof of concept for the RPM and is then assembled in *** are conducted to determine the rotational stiffness and angular travel about both in-plane rotational *** among theoretical,numerical and experiments reveal excellent linearity of rotational stiffness along the rotational travel *** maximum theoretical error is less than 5.5%compared with FEA while,the experimental error has a mean of 5%and 3%for both rotational axes thus satisfying the intended design requirement.

关键词： Compliant mechanism Finite element analysis Graphical approach Rotational stiffness Sensitivity analysis

A DECOUPLING TWO-GRID METHOD FOR THE STEADY-STATE POISSON-NERNST-PLANCK EQUATIONS

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Journal of Computational Mathematics 2019年第4期37卷 556-578页

作者： Ying yang Benzhuo Lu yan xie School of Mathematics and Computing Science Guangxi Colleges and Universities Key Laboratory of Data Analysis and Computation Guilin University of Electronic Technology Guilin 541004 China LSEC Institute of Computational Mathematics and Scientific/Engineering Computing the National Center for Mathematics and Interdisciplinary Sciences Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China LSEC Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China

Poisson-Nernst-Planck equations are widely used to describe the electrodiffusion of ions in a solvated biomolecular system. Two kinds of two-grid finite element algorithms are proposed to decouple the steady-state Poisson-Nernst-Planck equations by coarse grid finite element approximations. Both theoretical analysis and numerical experiments show the efficiency and effectiveness of the two-grid algorithms for solving Poisson-Nernst-Planck equations.

关键词： Poisson-Nernst-Planck equations Two-grid finite element method Decoupling method Error analysis Gummel iteration

Corridor connecting giant panda habitats from north to south in the Min Mountains, Sichuan, China

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Integrative Zoology 2006年第4期1卷 170-178页

作者： Kaipu YIN yan xie Ning WU Chengdu Institute of Biology Chinese Academy of SciencesChengduSichuanChina Institute of Zoology Chinese Academy of SciencesBeijingChina

The giant panda faces severe threats from habitat fragmentation and ***,giant panda populations have been fragmented into 30 habitat *** disappearance of isolated small populations and studies on the genetic diversity of various populations have shown that small isolated panda populations are at a high risk of dying out *** fragmentation has seriously impaired the ability of the giant panda to resist climate changes and other natural disasters,such as large-scale,synchronous bamboo *** Min Mountains have the largest population of pandas in China,numbering 581 individuals and accounting for 52%of the total(1114)in *** isolation means that giant pandas in the Min Mountains are divided into two populations(population A in the north and population B in the south).Population B,which had only 42 individuals in 1989,is severely threatened by high-density human populations and the loss of genetic ***,we have identified an important corridor connecting the two *** paper explains the importance and the feasibility of reestablishing this *** to the special geographic locations of these two populations(two rivers block the migration of giant pandas between south and north),the corridor is the only passage for giant pandas in the *** studies have also shown an increase of giant panda activity in the area of the ***,vegetation in the corridor has been severely *** forest must be restored in this area to provide food for the pandas during *** effects of human activities must be reduced in order to maintain panda *** believe that a restored corridor will be of great benefit to the survival of giant pandas in the Min Mountains,especially for population *** re-establishment of a corridor will be a valuable model for corridor construction in the future.

关键词： corridor giant panda habitat fragmentation Min Mountains Sichuan

Human disturbance, climate and biodiversity determine biological invasion at a regional scale

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Integrative Zoology 2006年第3期1卷 130-138页

作者： Zhibin ZHANG yan xie Yuming WU State Key Laboratory of Integrated Management on Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijingChina

Many factors may affect biological invasion,but their effects have not been quantitatively *** studies on the relationship between biodiversity and biological invasion are still *** biodiversity and alien species diversity are often positively correlated in large-scale observation studies,but negatively correlated in smallscale experimental *** using partial correlation and principal component regression methods,we found that human disturbance,climate,native biodiversity and their interactions explained,respectively,30.3,34.6,26.4 and 4.4%of the variation in alien species diversity(ASD)and 50.3,22.2,10.8 and 5.5%of the variation in the relative invasibility of alien species(RIA=ASD/native biodiversity)at the regional scale in *** correlation between ASD and native biodiversity is positive,but the correlation between RIA and native biodiversity is *** and coastal provinces have suffered heavier biological invasions than inland *** findings indicate that biological invasion is mostly determined by human disturbance and favorable climate,but less determined by native biodiversity.A disturbance-dependent niche-vacancy hypothesis is proposed to explain the contradictory observations in largeand small-scale studies.

关键词： biodiversity climate disturbance invasive alien species principal component regression