检索结果-南通市图书馆

Intrinsic Carrier Concentration as a Function of Stress in(001),(101) and(111) BiaxiallyStrained-Si and Strained-Si_(1-x)Ge_x

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2015年第5期30卷 888-893页

作者：靳钊 QIAO Liping liu lidong HE Zhili GUO Chen liu Ce School of Information Engineering Chang'an University School of Information Engineering Xizang University for Nationalities

Intrinsic carrier concentration(ni) is one of the most important physical parameters for understanding the physics of strained Si and Si1-xGex materials as well as for evaluating the electrical properties of Si-based strained devices. Up to now, the report on quantitative results of intrinsic carrier concentration in strained Si and Si1-xGex materials has been still lacking. In this paper, by analyzing the band structure of strained Si and Si1-xGex materials, both the effective densities of the state near the top of valence band and the bottom of conduction band( Nc and Nv) at 218, 330 and 393 K and the intrinsic carrier concentration related to Ge fraction(x) at 300 K were systematically studied within the framework of KP theory and semiconductor physics. It is found that the intrinsic carrier concentration in strained Si(001) and Si1-xGex(001) and(101) materials at 300 K increases significantly with increasing Ge fraction(x), which provides valuable references to understand the Sibased strained device physics and design.

关键词： strain intrinsic carrier concentration KP theory density of state

Thermal expansion behavior of a β-LiAlSiO_4/Cu composite

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2009年第1期28卷 82-85页

作者： WANG lidong XUE Zongwei liu Zhe FEI Weidong School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

A copper matrix composite reinforced by β-LiAlSiO4 with negative thermal expansion coefficient was fabricated using vacuum hot-pressed sintering technique. The thermal expansion behavior of the composite was investigated, and the average residual stress in the matrix was analyzed by a simple model. The results indicate that the residual stress in the matrix affects the thermal expansion properties. After heat treatment, the coefficient of thermal expansion （CTE） of the composite decreases greatly. The CTE of the composite after thermal cycling between 50-350°C is the lowest.

关键词： copper matrix composite β-eucryptite thermal expansion residual stress

Preparation and research on poisoning resistant Zr-Co based hydrogen storage alloys

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2008年第4期27卷 367-370页

作者： LI Hualing WANG Shumao JIANG Lijun ZHANG lidong liu Xiaopeng LI Zhinian Research Institute of Energy Materials and Technology General Research lnstitute of Nonferrous Metals Beijing 100088 China

At present, all hydrogen storage alloys are poisoned by hydrogen mixed with CO, CO2, etc, which decreases the hydrogen storage property sharply. Zr-Co based hydrogen storage alloys with good poisoning resistance were prepared by alloying, fluorinating, and electroless plating. The experiment results show that the poisoning resistance of the Zr-Co based alloy was improved remarkably after the treatments. The poisoning resistance mechanism of the Zr-Co based hydrogen storage alloys was analyzed.

关键词： hydrogen storage material poisoning resistance alloy electroless plating fluorination

在线全文

学校读者我要写书评

暂无评论

微动技术在城区不良地质体勘察中的应用研究

铁道工程学报 2019年第5期36卷 1-5,46页

作者：刘黎东中铁第六勘察设计院集团有限公司

研究目的:城区物探环境品质恶劣,地表、地物状态复杂,不同物性的干扰源众多,常规物探方法应用皆存在很大的局限性。在城区物探环境品质评价与对策分析的基础上,引入微动技术作为城区主要物探手段,以城市轨道交通不良地质体勘察为主要工... 详细信息

研究目的:城区物探环境品质恶劣,地表、地物状态复杂,不同物性的干扰源众多,常规物探方法应用皆存在很大的局限性。在城区物探环境品质评价与对策分析的基础上,引入微动技术作为城区主要物探手段,以城市轨道交通不良地质体勘察为主要工程领域进行微动技术应用,评估、研究其适用性、准确性及可靠性,探寻一条适于城区物探环境的新的有效技术途径。研究结论:(1)通过对城区物探环境品质的综合评价和对策研究,探讨了城区物探面临的局限性和受制约性现状,表明城区物探具有方法创新的技术必要和应用需求;(2)将微动技术作为城区主要勘察手段,在城市轨道交通项目中成功探查并确定了多种不良地质体的地质特征及赋存状况;(3)微动技术在城区物探环境中表现出良好的场地适用性和成果准确性,能为轨道交通等城区工程的设计、施工、排险提供重要物探依据,并进一步消减地质隐患,具备推广应用的潜力。

关键词：微动技术物探环境品质强干扰不良地质体地质隐患

Glutamate and GABAA receptor crosstalk mediates homeostatic regulation of neuronal excitation in the mammalian brain

在线全文

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2022年第11期7卷 4156-4173页

作者： Ya Wen Zhifang Dong Jun liu Peter Axerio-Cilies Yehong Du Junjie Li Long Chen Lu Zhang lidong liu Jie Lu Ning Zhou Dong Chuan Wu Yu Tian Wang DM Centre for Brain Health and Department of Medicine Vancouver Coastal Health Research InstituteUniversity of British ColumbiaVancouverBCV6T 2B5Canada Pediatric Research Institute Ministry of Education Key Laboratory of Child Development and DisordersNational Clinical Research Center for Child Health and DisordersChina International Science and Technology Cooperation Base of Child Development and Critical DisordersChongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory DisordersChildren’s Hospital of Chongqing Medical UniversityChongqing400014P.R.China iHuman Institue ShanghaiTech UniversityShanghaiP.R.China

Maintaining a proper balance between the glutamate receptor-mediated neuronal excitation and the A type of GABA receptor(GABAAR)mediated inhibition is essential for brain functioning;and its imbalance contributes to the pathogenesis of many brain disorders including neurodegenerative diseases and mental *** we identify a novel glutamate-GABAAR interaction mediated by a direct glutamate binding of the *** HEK293 cells overexpressing recombinant GABAARs,glutamate and its analog ligands,while producing no current on their own,potentiate GABA-evoked *** potentiation is mediated by a direct binding at a novel glutamate binding pocket located at theα+/β−subunit interface of the ***,the potentiation does not require the presence of aγsubunit,and in fact,the presence ofγsubunit significantly reduces the potency of the glutamate *** addition,the glutamate-mediated allosteric potentiation occurs on native GABAARs in rat neurons maintained in culture,as evidenced by the potentiation of GABAAR-mediated inhibitory postsynaptic currents and tonic *** importantly,we found that genetic impairment of this glutamate potentiation in knock-in mice resulted in phenotypes of increased neuronal excitability,including decreased thresholds to noxious stimuli and increased seizure *** results demonstrate a novel cross-talk between excitatory transmitter glutamate and inhibitory *** a rapid and short feedback loop between the two principal excitatory and inhibitory neurotransmission systems may play a critical homeostatic role in fine-tuning the excitation-inhibition balance(E/I balance),thereby maintaining neuronal excitability in the mammalian brain under both physiological and pathological conditions.

关键词： excitation thereby maintained

FSEC赛车轮边行星齿轮减速器的设计与优化

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

汽车实用技术 2025年第1期50卷 46-51页

作者：陈胜新贾浩张添淇郝建民赵茂丰白鸿飞刘立东辽宁工业大学汽车与交通工程学院辽宁锦州121000

为了提高中国大学生电动方程式大赛(FSEC)赛车在急加速及过弯时,极限工况条件下的传动效率,文章介绍了轮边减速器系统及其工作原理,对系统各项设计参数进行了具体的研究计算,简要描述了系统零件的研究设计及ANSYS静力学仿真分析的过程... 详细信息

为了提高中国大学生电动方程式大赛(FSEC)赛车在急加速及过弯时,极限工况条件下的传动效率,文章介绍了轮边减速器系统及其工作原理,对系统各项设计参数进行了具体的研究计算,简要描述了系统零件的研究设计及ANSYS静力学仿真分析的过程。研究结果表明,轮边行星齿轮减速器运行稳定可靠、装配方便,整体质量相对于其他传动方式较轻,传动效率较高;该系统将装配在辽宁工业大学万得电车队10号赛车上,以实际验证其设计合理性。研究结果可为后续赛车的轮边系统设计提供参考,以提高赛车的传动效率,满足赛车的轻量化要求,提高赛车性能。

关键词： FSEC 轮边系统行星齿轮减速器 AMK轮毂电机 ANSYS仿真分析结构创新

维普期刊数据库博看期刊

Electromagnetic and Microwave Absorption Properties of Carbonyl-Iron/Fe91Si9 Composites in Gigahertz Range

在线全文

学校读者我要写书评

暂无评论

Journal of Electromagnetic Analysis and Applications 2011年第5期3卷 140-146页

作者： Jingbo Guo Yuping Duan lidong liu Liyang Chen Shunhua liu 不详

Carbonyl-iron/Fe91Si9 composites for thin microwave absorbers were firstly prepared by a simple blending technique. The patterns of carbonyl-iron and Fe91Si9 were characterized by scanning electron microscope (SEM). The complex permittivity, permeability and microwave absorption properties of the composites were studied in the frequency range of 2 - 7GHz by a HP8720B vector network analyzer. Complex permittivity and permeability decrease gradually with increasing weight percentage of Fe91Si9 in the composites, the variation of permittivity was very large but the variation of permeability was very small. The composites exhibited excellent microwave absorption properties with increasing Fe91Si9 content. The reflection loss (RL) values less than –20 dB were obtained in the 3.7 - 6.7 GHz frequency range for the paraffin matrix composites with 80 wt% carbonyl-iron/Fe91Si9 powders (weight ratio of carbonyl-iron to Fe91Si9 was 1:1), with thickness of 4.0 - 2.4 mm, respectively. The optimal RL of –45 dB was observed at 5.2 GHz with a matching thickness (dm) of 3.0 mm. The excellent microwave absorption properties were attributed to a better electromagnetic impedance match and a higher electric resistivity.

关键词： Carbonyl-iron Fe91Si9 Electromagnetic Properties Microwave Absorption

图书馆即教育——杭州图书馆为公民终身学习的服务实践

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

图书馆 2010年第4期 126-127,141页

作者：刘丽东杭州图书馆浙江杭州310016

文章认为,无偿为读者提供文献信息和相关的学习条件,使读者实现终身教育是图书馆永恒的使命。这一使命既是社会对图书馆的独特要求,也是图书馆在社会大系统中寻求自身存在位置的唯一手段。文章介绍了杭州市图书馆在建立学习型社会活动... 详细信息

文章认为,无偿为读者提供文献信息和相关的学习条件,使读者实现终身教育是图书馆永恒的使命。这一使命既是社会对图书馆的独特要求,也是图书馆在社会大系统中寻求自身存在位置的唯一手段。文章介绍了杭州市图书馆在建立学习型社会活动中为广大读者提供服务的思路和对策,对公共图书馆的现实工作及未来发展具有一定的启迪作用。

关键词：公共图书馆学习型社会杭州

THE PALEOCURRENT PATTERN OF EARLY TERTIARY REDBEDS IN THE HOH XIL BASIN,NORTHERN TIBET PLATEAU:IMPLICATIONS FOR AN EARLY UPLIFT AND UNROOFING

在线全文

学校读者我要写书评

暂无评论

地学前缘 2000年第S1期7卷 198-199页

作者： Yi Haisheng, Wang Chengshan,Lin Jinhui, Zhu lidong, liu Dengzhong, Huang Jijun[WT5,5”BX](Chengdu University of Technology,Chengdu 610059,China)

We focus on early Cenozoic uplift, erosion and growth of northern Tibet plateau by reconstructing paleo\|drainage pattern in the Hoh Xil basin. Stratigraphical infilling sequences and lithic type orogenic basins are determined largely by contemporaneous tectonic activity. It is therefore reasonable to infer that paleoflow variability record give useful information about regional tectonic events. We now report paleocurrent data from outcrop measurement of 4 expedition profiles across the basin during 1997—*** west\|east trending Hoh Xil basin is the largest redbeds basin in northern Tibet plateau. It is 400km in axial length and has maximum width of 200km, which extends along Jin zone, separated the Qiangtang from the Bayankara block. It accommodates more than 5000m of terrestrial sediments during the Eocene to Oligocene dated by preliminary magnetostratigraphy and minor *** sedimentological observation and lithic facies associations analysis of the Eocene Fenghuoshan Group show to have evolved vertically from alluvial fan system in the lowest part, into stacked megasequences of coarsening\|upward fan\|delta system in the middle and upper part. The braided fluvial conglomeratic deposits occur at intervals along the basin margin and grade basin ward interbedded sandstone and mudstone. The Oligocene Yaxicuo Group is locally present and forms as laterally elongate sub\|basins, which is of a maximum thickness of 2000m, as seen in the Wudaoliang and the Hantaishan area. Alluvial fan associations in this sub\|basin in the proximal part adjacent to the southern faulted border and prograded northward to floodplain in distal part.

关键词： paleocurrent pattern early Tertiary redbeds uplift e rosion Hoh Xil Northern Tibet