检索结果-南通市图书馆

Cadmium(Cd)exposure through Hyphantria cunea pupae reduces the parasitic fitness of Chouioia cunea:A potential risk to its biocontrol efficiency

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2023年第10期22卷 3103-3114页

作者： YAN Shan-chun wu Hong-fei ZHENG Lin TAN Ming-tao jiang Dun School of Forestry Northeast Forestry UniversityHarbin 150040P.R.China Key Laboratory of Sustainable Forest Ecosystem Management Ministry of EducationNortheast Forestry UniversityHarbin 150040P.R.China

Heavy metal contamination has been regarded as an environmental variable that affects the efficiency of pest biological control,but the parasitic fitness of parasitoids under heavy metal stress is poorly ***,the effect of Cd exposure through the host pupa of Hyphantria cunea on the parasitic fitness of Chouioia cunea was investigated,and the mechanism by which Cd exposure affects the interaction between *** and *** from the perspective of innate immunity in host insect and the oxidative status in the parasitoid offspring was *** results indicated that Cd can be transferred from the *** pupae to the parasitoid offspring,and the transfer coefficient reflected biological *** were no significant differences in the rates of parasitism success and offspring emergence between the untreated and Cd-treated ***,after parasitizing Cd-accumulated pupae,the parasitic fitness of offspring wasps(e.g.,the number,individual size and life span)decreased *** Cd exposure,the cellular and humoral immunity of *** pupae decreased *** with the untreated group,the H_(2)O_(2)content of parasitoid offspring in the Cd-treated group was significantly *** exposure significantly inhibited superoxide dismutase activity in parasitoid offspring,but the contents of ascorbic acid and glutathione were significantly increased by Cd *** together,these results indicate that Cd exposure reduces the cyclic utilization efficiency of *** on *** *** oxidative status of parasitoid offspring triggered by Cd exposure could be responsible for the reduced parasitic fitness of *** on Cd-accumulated *** pupae.

关键词： heavy metal Hyphantria cunea parasitic fitness Chouioia cunea oxidative status innate immunity

Smith Form of Triangular Multivariate Polynomial Matrix

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2023年第1期36卷 151-164页

作者： LIU Jinwang wu tao LI Dongmei School of Mathematics and Computing Sciences Hunan University of Science and TechnologyXiangtan 411201China

The Smith form of a matrix plays an important role in the equivalence of *** is known that some multivariate polynomial matrices are not equivalent to their Smith *** this paper,the authors investigate mainly the Smith forms of multivariate polynomial triangular matrices and testify two upper multivariate polynomial triangular matrices are equivalent to their Smith forms respectively.

关键词： Degree-Lexicographical order equivalence of matrix multidimensional system multivariate polynomial matrix Smith form

同方期刊数据库

基于多维邻近性的药学领域科技创新主导力扩散仿真研究

在线全文

学校读者我要写书评

暂无评论

现代情报 2025年第1期45卷 60-80页

作者：贺超城黄茜徐雨舒吴江武汉大学信息管理学院湖北武汉430072

[目的/意义]科技创新主导力与创新团队的产出绩效息息相关,在日益庞杂的科技创新合作中至关重要。然而现有科技创新主导力的研究大多集中在定性讨论方面,本文从定量角度深入探讨科技创新主导力网络的演化机制,有助于进一步促进科技创新... 详细信息

[目的/意义]科技创新主导力与创新团队的产出绩效息息相关,在日益庞杂的科技创新合作中至关重要。然而现有科技创新主导力的研究大多集中在定性讨论方面,本文从定量角度深入探讨科技创新主导力网络的演化机制,有助于进一步促进科技创新合作。[方法/过程]本文以药学领域的数据驱动,设定创新主体的搜索规则、主导规则、创新规则,以平均科技创新增益及其扩散速率为评价指标来衡量科技创新主导力的扩散效果,模拟科技创新主导力的扩散过程,并进一步探究多维邻近性与科技创新主导力扩散的动态关系。[结果/结论]结果显示,多维邻近性对科技创新主导力扩散具有重要影响,且不同邻近性在网络演化的不同阶段发挥着不同的作用。本文全面细致地刻画了多维邻近性在科技创新主导力网络演化的不同阶段所发挥的具体作用,进而为机构/企业和创新个体的发展提供参考。

关键词：科技创新主导力扩散机制多维邻近性仿真模拟科研合作网络

Misfit St rain-induced Buckling for Transition-Me tai Dichalcogenide Lateral Heterostructures:A Molecular Dynamics Study

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2019年第1期32卷 17-28页

作者： Jin-wu jiang Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and MechanicsShanghai UniversityShanghai 200072China

Molecular dynamics simulations are performed to investigate the misfit straininduced buckling of the transition-metai dichalcogenide(TMD)lateral heterostructures,denoted by the seamless epitaxial growth of different TMDs along the in-plane *** Stillinger-Weber potential is utilized to describe both the interaction for each TMD and the coupling between different TMDs,i.e.,MX2(with M=Mo,W and X=S,Se,Te).It is found that the misfit strain can induce strong buckling of the freestanding TMD lateral heterostructures of large area,resulting from the TMDs'atomic-thick *** buckling phenomenon occurs in a variety of TMD lateral heterostructures of different compositions and in various *** findings raise a fundamental mechanical challenge for the structural stability of the freestanding TMD lateral heterostructures.

关键词： Transition-metal dichalcogenide Lateral heterostructure Stillinger-Weber potential Molecular dynamics simulation

An empirical description for the hinge-like mechanism in single-layer black phosphorus:The angle–angle cross interaction

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2017年第3期30卷 227-233页

作者： Jin-wu jiang Shanghai Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai University Shanghai 200072 China

The single-layer black phosphorus is characterized by its puckered configuration that pos- sesses the hinge-like behavior, which leads to the highly anisotropic in-plane Poisson＇s ratios and the negative out-of-plane Poisson＇s ratio. We demonstrate that the hinge-like mechanism can be described by the angle-angle cross interaction, which, combined with the bond stretching and angle bending interactions, is able to provide a good description for the mechanical properties of single-layer black phosphorus. We also propose a nonlinear angle-angle cross interaction, which follows the form of Stillinger-Weber potential and can be advantageous for molecular dynamics simulations of single-layer black phosphorus under large deformation.

关键词： Black phosphorus Stillinger-Weber potential Hinge-like mechanism Molecular dynamics simulation Mechanical properties

Composition dependence of phase structure and electrical properties of(1-y)Bi_(1-x)Nd_xFeO_(3-y)BiScO_3 ceramics

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2016年第7期59卷 1029-1035页

作者： tao Hong wu JiaGang Department of Materials Science Sichuan University

In this work, we have studied a new lead-free ceramic of（1-y）Bi1-xNdxFeO3-yBiScO3（0.05≤x≤0.15 and 0.05≤y≤0.15） prepared by a conventional solid-state method, and the influences of Nd and Sc content on their phase structure and electrical properties were investigated in detail. The ceramics with 0.05≤x≤0.10 and 0.05≤y≤0.15 belong to an R3 c phase, and the rhombohedral-like and orthorhombic multiphase coexistence is established in the composition range of 0.125≤x≤0.15 and y=0. The electrical properties of the ceramics can be enhanced by modifying x and y values. The highest piezoelectric coefficient（d33～51 p C/N） is obtained in the ceramics with x=0.075 and y=0.125, which is superior to that of a pure BiFeO3 ceramic. In addition, a lowest dielectric loss（tan δ～0.095%, f=100 k Hz） is shown in the ceramics with x=0.15 and y=0 due to the involvement of low defect concentrations, and the improved thermal stability of piezoelectricity at 20–600℃ is possessed in the ceramics. We believe that the ceramics can play a meaningful role in the high-temperature lead-free piezoelectric applications.

关键词： BiFeO_3 ceramics composition design phase structure piezoelectric properties

Low Cycle Fatigue Behavior and Deformation Mechanism of TWIP Steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2014年第3期21卷 352-358页

作者： Yan-xin wu Di TANG Hai-tao jiang Zhen-li MI Yao XUE Hai-peng wu Engineering Research Institute University of Science and Technology Beijing

Low cycle fatigue behavior of TWIP （twinning induced plasticity） steel was investigated in axial symmetric tension-compression cyclic loading pattern. Fracture surfaces and microstructures were examined by optical, scanning electron and transmission electron microscopes. It was found that the fatigue life at the strain amplitude of 0.4 % is up to 15 000 cycles, which is much longer than TRIP780 and HSLAS00 steels. The strain hardening and softening features are significant until the strain amplitude comes to 1.25 ~. Persistent slip bands and tiny mechanical twinning layers were observed after fatigue deformation. Deformation mechanism of TWIP steel at low cycle fatigue process is not only twinning, but a complex of both twinning and persistent slip bands.

关键词： TWIP steel low cycle fatigue fatigue property persistent slip band

Element distribution and difusion behavior in Q&P steel during partitioning

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2013年第11期20卷 1050-1059页

作者： Hai-tao jiang Bao-tong Zhuang Xiao-ge Duan Yan-xin wu Zheng-xu Cai National Engineering Research Center for Advanced Rolling Technology University of Science and Technology Beijing

Carbon, manganese, and silicon distribution in quenching and partitioning （Q＆P） steel during partitioning process was investigated to reveal the diffusion behavior. The microstructure and chemical composition were analyzed by means of scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and three-dimensional atom probe. It is shown that the studied Q＆P steel consisted of martensite laths and thin, film-like retained austenite showing extraordinary phase transformation stability. Carbon atoms mostly diffused to the retained austenite from martensite at a higher partitioning temperature. In the experimental steel partitioned at 400℃ for 10-60 s, carbides or cementite formed through carbon segregation along martensite boundaries or within the martensite matrix. As a result of carbon atom diffusion from martensite to austenite, the carbon content in martensite could be ignored. When the partitioning process completed, the constrained carbon equilibrium （CCE） could be simplified. Results calculated by the simplified CCE model were similar to those of CCE, and the difference between the two optimum quenching temperatures, where the maximum volume fraction of the retained austenite can be obtained by the Q＆P process, was little.

关键词： steel heat treatment quenching partitioning element distribution diffusion microstructure

Microstructure and mechanical properties of HIP-ZTC4 during thermal exposure and tensile deformation

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2015年第10期34卷 692-697页

作者： Hai-tao jiang Xiao-Qian Yan Ji-Xiong Liu Xiao-Ge Duan Shang-wu Zeng National Engineering Research Center for Advanced Rolling Technology University of Science and Technology Beijing Baoti Research Institute Baoti Group Co.Ltd.

Casting titanium alloy TC4(ZTC4) after hot isostatic pressing(HIP) is one of the preferred materials in the field of aerospace manufacturing. In this paper, HIPZTC4 after a long-term thermal exposure was *** order to evaluate the variation of mechanical properties with service time, the tensile properties of this alloy after exposure at 400 °C for 100, 500, and 1,000 h were investigated. Microstructure of samples was observed by the means of optical microscopy(OM), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). Tensile test was carried out under different test temperatures and fracture appearance was studied. The results show that the strength increases with exposure time due to the harder a2(Ti3Al) phase precipitated in the a phase and superficial oxygen layer formed, which results in the fact that the resistance of crack propagation could be increased and cracks first initiate between surface oxidation and the matrix. Besides, the tensile temperature also has a significant effect on the mechanical properties of HIPZTC4. The yield strength and tensile strength decrease with the increase of tensile temperature, while the total elongation increases.

关键词： Casting titanium alloy Microstructure Mechanical p