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On superintegrable systems with a position-dependent mass in polar-like coordinates

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Chinese Physics B 2020年第10期29卷 96-100页

作者： hai zhang School of Mathematics and Physics Anqing Normal UniversityAnqing 246133China

For a superintegrable system defined in plane polar-like coordinates introduced by Szumiński et al. and studied by Fordy, we show that the system with a position-dependent mass is separable in three distinct coordinate systems. The corresponding separation equations and additional integrals of motion are derived explicitly. The closure algebra of integrals is deduced. We also make a generalization of this system by employing the classical Jacobi method. Lastly a sufficient condition which ensures flatness of the underlying space is derived via explicit calculation.

关键词： superintegrable system separation of variables position-dependent mass polar-likecoordinates Jacobi method

Comparison of the fraction of olfactory receptor pseudogenes in wolf (Canis lupus) with domestic dog (Canis familiaris)

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Journal of Forestry Research 2011年第2期22卷 275-280页

作者： zhang Hong-hai WEI qin-guo zhang Huan-xin CHEN Lei College of Life Science Qufu Normal University Qufu 273165 Shandong Province China.

Olfactory receptors（ORs）,the first dedicated molecules with which odorants physically interact to arouse an olfactory sensation,constitute the largest gene family in *** and wolves,like many other mammals,have a highly developed capability to detect and identify odorant molecules,even at minimum *** this study,the olfactory receptor repertoire from domestic dog and its closest relative,the wolf,were sequenced to estimate the fraction of pseudogenes in each *** fraction of disrupted olfactory receptor genes in dog was 17.78%,whereas,that in wolf was 12.08%.As expected the dog was less dependent on olfaction than the wolf,and the dog had more olfactory receptor ***,the observed difference between the two subspecies was not at the significant level（χ2 = 1.388,p = 0.239 0.05）.The values indicated that although domestication might play a role in the reduction of OR genes,it could not be concluded that the living environment provided by domestication lead to a significant reduction of the functional olfactory receptor ***,the purpose of domestication may also have influence on the ratio of functional olfactory receptor genes reduction.

关键词： olfactory receptor wolf domestic dog pseudogene

The impact of OFDI on firm pro-environmental behavior:Evidence from China

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Advances in Climate Change Research 2023年第5期14卷 778-788页

作者： hai-Yue LIU qin zhang Xin XIA Yi-Le WANG Rui XUE Yuli SHAN Business School Sichuan UniversityChengdu 610065China La Trobe Business School La Trobe UniversityMelbourne VIC 3086Australia School of Geography Earth and Environmental SciencesUniversity of BirminghamBirmingham B152TTUK

Outward Foreign Direct Investment(OFDI)is a crucial decision in the internationalization strategy of firms and they confront diversified environmental policies and practices of host countries,when engaging in cross-border ***,there is a lack of research to investigate whether foreign direct investment(OFDI)is an important factor affecting the environmental commitment of *** study aims to empirically analyze the impact and mechanism by which firm outward foreign direct investment(OFDI)influences pro-environmental commitments,utilizing data collected from Chinese listed companies between 2010 and *** results show:1)there is a significant positive relationship between firm OFDI and pro-environmental commitments;2)mechanistic tests show that the OFDI can promote pro-environmental commitments through two channels:public attention and technological learning capacity;3)heterogeneity analysis reveals that the green effects of OFDI are more pronounced firms with institutional investors and state ownership,as well as in firms situated in host countries with more stringent environmental regulations;4)further analysis reveals OFDI-induced greater green commitments generated real environmental and economic outcomes:firms invested more in environmental protection and reduced CO_(2)*** the meantime,they experienced lower excessive debt risk and higher innovative *** findings have positive implications for the promotion of firms’pro-environmental behavior and sustainable development.

关键词： OFDI Pro-environmental commitments Technological learning capacity Public attention Environmental performance Sustainable development

Electromagnetic scattering and imaging simulation of extremely large-scale sea-ship scene based on GPU parallel technology

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Journal of Electronic Science and Technology 2024年第2期22卷 16-23页

作者： Cheng-Wei zhang Zhi-qin Zhao Wei Yang Li-Lai Zhou hai-Yu Zhu Southwest China Institute of Electronic Technology Chengdu610036China School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China Tencent Company Shenzhen518054China

Aiming to solve the bottleneck problem of electromagnetic scattering simulation in the scenes of extremely large-scale seas and ships,a high-frequency method by using graphics processing unit(GPU)parallel acceleration technique is *** the implementation of different electromagnetic methods of physical optics(PO),shooting and bouncing ray(SBR),and physical theory of diffraction(PTD),a parallel computing scheme based on the CPU-GPU parallel computing scheme is realized to balance computing ***,a multi-GPU framework is further proposed to solve the computational difficulty caused by the massive number of ray tubes in the ray tracing *** using the established simulation platform,signals of ships at different seas are simulated and their images are achieved as *** is shown that the higher sea states degrade the averaged peak signal-to-noise ratio(PSNR)of radar image.

关键词： Multi graphics processing unit Radar imaging Sea-ship Shooting and bouncing rays

Insight into vertical piezoelectric characteristics regulated thermal transport in van der Waals two-dimensional materials

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Rare Metals 2024年第2期43卷 770-779页

作者： Dong-hai Wei E Zhou Jin-Yuan Xu Hui-Min Wang Chen Shen Hong-Bin zhang Zhen-Zhen qin Guang-Zhao qin State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha410082China Hunan Key Laboratory for Micro-Nano Energy Materials and Device and School of Physics and Optoelectronics Xiangtan UniversityXiangtan411105China Institute of Materials Science Technical University of DarmstadtAlarich-Weiss-Str.264287DarmstadtGermany School of Physics and Microelectronics Zhengzhou UniversityZhengzhou450001China

The urgent demand of extreme(ultra-high/low)thermal conductivity materials is triggered by the high-power device,where exploring the theories and mechanisms of regulating thermal transport properties plays a key ***,we elaborately investigate the effect of vertical(out-of-plane)piezoelectric characteristics on thermal transport,which is historically *** different stacking-order(AA and AB)bilayer boron nitride(Bi-BN)in two-dimensional(2D)materials are selected as study *** performing state-of-the-art first-principles calculations,it is found that the polarization charge along the out-of-plane orientation ascends significantly with the increasing piezoelectric response in AB stacked Bi-BN(Bi-BN-AB)followed by the enhanced interlayer B–N atomic ***,the amplitude of phonon anharmonicity in Bi-BN-AB increases larger than that in the AA stacked Bi-BN(Bi-BN-AA),resulting in the dramatic weakening of the thermal conductivity by 20.34%under 18%*** research reveals the significant role of the vertical(out-of-plane)piezoelectric characteristic in regulating thermal transport and provides new insight into accurately exploring the thermal transport performance of 2D van der Waals materials.

关键词： Thermal conductivity Piezoelectric effect 2D materials Bilayer BN Strain engineering

Two-phase nonlocal integral models with a bi-Helmholtz averaging kernel for nanorods

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Applied Mathematics and Mechanics(English Edition) 2021年第10期42卷 1379-1396页

作者： Pei zhang hai qinG State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

In this work,the static tensile and free vibration of nanorods are studied via both the strain-driven(Strain D)and stress-driven(Stress D)two-phase nonlocal models with a bi-Helmholtz averaging *** adjusting the limits of integration,the integral constitutive equation of the Fredholm type is converted to that of the Volterra type and then solved directly via the Laplace transform *** unknown constants can be uniquely determined through the standard boundary conditions and two constrained conditions accompanying the Laplace transform *** the numerical examples,the bi-Helmholtz kernel-based Strain D(or Stress D)two-phase model shows consistently softening(or stiffening)effects on both the tension and the free vibration of nanorods with different boundary *** effects of the two nonlocal parameters of the bi-Helmholtz kernel-based two-phase nonlocal models are studied and compared with those of the Helmholtz kernel-based models.

关键词： two-phase nonlocal integral model bi-Helmholtz kernel tensile analysis free vibration exact solution Laplace transform

New Results on Nonexistence of Perfect p-Ary Sequences and Almost p-Ary Sequences

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Acta Mathematica Sinica,English Series 2016年第1期32卷 2-10页

作者： hai Ying LIU Ke qin FENG School of Mathematical Sciences Peking University Department of Mathematical Sciences Tsinghua University

Complex periodical sequences with lower antocorrelation values are used in CDMA comnmnieation systems and cryptography. In this paper we present new nonexistence results on perfect p-ary sequences and almost p-ary seq... 详细信息

关键词： Perfect sequence p-ary and almost p-ary sequence difference set cyclotomic field imag-inary quadratic field

On well-posedness of two-phase nonlocal integral models for higher-order refined shear deformation beams

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Applied Mathematics and Mechanics(English Edition) 2021年第7期42卷 931-950页

作者： Pei zhang hai qinG State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Due to the conflict between equilibrium and constitutive requirements,Eringen’s strain-driven nonlocal integral model is not applicable to nanostructures of engineering *** an alternative,the stress-driven model has been recently *** this paper,for higher-order shear deformation beams,the ill-posed issue(i.e.,excessive mandatory boundary conditions(BCs)cannot be met simultaneously)exists not only in strain-driven nonlocal models but also in stress-driven *** well-posedness of both the strain-and stress-driven two-phase nonlocal(TPN-Strain D and TPN-Stress D)models is pertinently evidenced by formulating the static bending of curved beams made of functionally graded(FG)*** two-phase nonlocal integral constitutive relation is equivalent to a differential law equipped with two restriction *** using the generalized differential quadrature method(GDQM),the coupling governing equations are solved *** results show that the two-phase models can predict consistent scale-effects under different supported and loading conditions.

关键词： well-posedness strain-and stress-driven two-phase nonlocal(TPN-Strain D and TPN-Stress D)models refined shear deformation theory functionally graded(FG)curved beam generalized differential quadrature method(GDQM)

Fitness consequences of divorce in the azure-winged magpie depends on the breeding experience of a new mate

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Current Zoology 2021年第1期67卷 17-25页

作者： Li-Fang GAO hai-Yang zhang Wen zhang Xiao-Dan zhang Zhen-qin ZHu Bo Du School of Life Sciences Lanzhou UniversityTianshui South Road 222#Lanzhou CityGansu Province730000China

Sexual conflict in producing and raising offspring is a critical issue in evolutionary ecology *** experience affects their breeding performance,as measured by such traits of provisioning of offspring and engagement in extra-pair copulations,and may cause an imbalance in sexual ***,divorce is hypothesized to occur within aged social pairs,irrespective of current reproductive *** concept was explored in the azure-winged magpie Cyanopica cyanus by investigating the divorce of a social pair and its relationship to their changes in breeding performance with prior *** engaging in extra-pair copulation may intensify sexual conflicts and may be the main reason for *** divorced,females repairing with an inexperienced male realized higher reproductive success than that repairing with an experienced male;males repairing with an experienced female realized higher reproductive success than that repairing with an inexperienced *** finding indicates that the fitness consequence of divorce depends on the breeding experience of new *** females can obtain more extra-pair copulations,whereas divorced males cannot,when they repair with inexperienced *** females provisioned a brood at lower rates than inexperienced females whereas divorced males had no such *** appears that divorced females can obtain an advantage in sexual conflicts with inexperienced mates in future ***,females are probably more active than males in divorcing their aged mates so as to select an inexperienced male as a new ***-winged magpies thus provide novel insights into the implicaticns of sexual conflict in birds.

关键词： breeding experience extra-pair copulation parental care provisioning rate sexual conflict