检索结果-南通市图书馆

Interface defeat studies of long-rod projectile impacting on ceramic targets

Defence Technology（防务技术） 2020年第1期16卷 50-68页

作者： Y.X.Zhai H.Wu Q.Fang Amy Engineering University of PLA Nanjing210007China Research Institute of Structural Engineering and Disaster Reduction College of Civil EngineeringTongji UniversityShanghai200092China

The interface defeat phenomenon always occurs when a long-rod projectile impacting on the ceramic target with certain velocity,i.e.,the projectile is forced to flow radially on the surface of ceramic plates for a period of time without significant *** defeat has a direct effect upon the ballistic performance of the armor piercing projectile,which is studied numerically and theoretically at ***,by modeling the projectiles and ceramic targets with the SPH(Smoothed Particle Hydrodynamics)particles and Lagrange finite elements,the systematic numerical simulations on interface defeat are performed with the commercial finite element program *** different responses,i.e.,complete interface defeat,dwell and direct penetration,are reproduced in different types of ceramic targets(bare,buffered,radially confined and oblique).Furthermore,by adopting the validated numerical algorithms,constitutive models and the corresponding material parameters,the influences of projectile(material,diameter,nose shape),constitutive models of ceramic(JH-1 and JH-2 models),buffer and cover plate(thickness,constraints,material),as well as the prestress acted on the target(radial and hydrostatic) on the interface defeat(transition velocity and dwell time) are syste matically ***,based on the energy conservation approach and taking the strain rate effect of ceramic material into account,a modified model for predicting the upper limit of transition velocity is proposed and *** present work and derived conclusions can provide helpful reference for the design and optimization of both the long-rod projectile and ceramic armor.

关键词： Interface defeat Ceramic Transition velocity Numerical simulation Parametric study

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of confining prestress on the transition from interface defeat topenetration in ceramic targets

引用

Defence Technology（防务技术） 2016年第3期12卷 263-271页

作者： Patrik LUNDBERG RenéRENSTROM Olof ANDERSSON FOI Swedish Defence Research AgencySE-164 90 StockholmSweden

Replica scaled impact experiments with unconfined ceramic targets have shown that the transition velocity,i.e.,the impact velocity at which interface defeat ceases and ceramic penetration occurs,decreased as the length scale increased.A possible explanation of how this scale effect is related to the formation of a cone crack in the ceramic has been presented by the authors in an earlier ***,the influence of confinement and prestress on cone cracking and transition velocity is *** hypothesis is that prestress will suppress the formation and growth of the cone crack by lowering the driving stress.A set of impact experiments has been performed in which the transition velocity for four different levels of prestress has been *** transition velocities as a function of the level of confining prestress is compared to an analytical model for the influence of prestress on the formation and extension of the cone crack in the ceramic *** experiments and model indicate that prestress has a strong influence on the transition from interface defeat to penetration,although the model underestimates the influence of prestress.

关键词： Impact Ceramic Armour Interface defeat Dwell Confinement Prestress

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The Risk Role of defeat on the Mental Health of College Students:A Moderated Mediation Effect of Academic Stress and Interpersonal Relationships

引用

International Journal of Mental Health Promotion 2024年第9期26卷 731-744页

作者： Ruiyang Han Tingting Xu Yin Shi Wuyi Liu School of Public Health Shandong Second Medical UniversityWeifang261053China Faculty of Education Beijing Normal UniversityBeijing100875China School of Clinical Medicine Shandong Second Medical UniversityWeifang261053China

Background:College students face significant academic and physiological changes,making them more susceptible to psychological issues such as depression,self-injury,and suicidal *** of defeat can exacerbate these risks by increasing academic ***,interpersonal relationships can moderate the impact of academic stress on students’mental *** the presage–process–product model,this study aims to empirically investigate how feelings of defeat influence depression,self-injury,and suicidal ideation among college ***,it explores the mediating role of academic stress and the moderating role of various types of interpersonal ***:A total of 1612 college students(750 females,862 males,mean age=19.64±0.62 years)were recruited through cluster *** were collected via offline questionnaires administered by a trained psychology teacher and a postgraduate student,ensuring high reliability with two examiners per *** profile analysis(LPA)was used to examine the impact of defeat on mental health outcomes,while mediation analysis was conducted to assess the roles of academic stress and interpersonal ***:*** is identified as a significant risk factor for mental health issues among college students;*** distinct patterns of interpersonal relationships were identified:the interpersonal-relationship risk group,the father–child-relationship high-risk group,the general interpersonal-relationship group,and the superior interpersonal-relationship group;*** stress partially mediates the relationship between defeat and mental health issues such as depression,self-injury,and suicidal ideation;*** interpersonal relationship models moderate the impact of academic stress on depression and suicidal ***:defeat is a significant risk factor for mental health problems in college *** stress partially mediates the negative impact of defeat on mental he

关键词： Student mental health defeat academic stress interpersonal relationships mediation test

来源：

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

Effects of the Novel Anti-Asthenic Drug Ladasten on Behavior and T-Cell Subsets Alterations in a Social defeat Animal Model of Depression

引用

Pharmacology & Pharmacy 2014年第1期5卷 4-10页

作者： Anna V. Tallerova Larisa P. Kovalenko Iosif B. Tsorin Andrey D. Durnev Sergey B. Seredenin Federal State Budgetary Institution “Research Zakusov Institute of Pharmacology” under the Russian Academy of Medical Science Moscow Russia Federal State Budgetary Institution “Research Zakusov Institute of Pharmacology” under the Russian Academy of Medical Science Moscow Russia.

The aim of the present study was to investigate the effects of the anti-asthenic drug ladasten on behavioral patterns and T-cell subsets in blood, spleen, and thymus in socially stressed male C57Bl/6 mice. Mice subjected to social defeat stress (SDS) for 25 days developed a depressive-like phenotype. The submissive SDS animals were assigned to one of two treatment groups: one group was treated with ladasten (30 mg/kg, i.p.) for up to 5 days, and the other one was administered vehicle as a control. Twenty four hours after the last injection, behavioral parameters were tested, and trunk blood and tissue samples were collected. SDS mice from the vehicle-treated group showed a subordinate and passive avoidance behavior with significantly decreased spontaneous locomotor activity (SLA) and exhibited impaired parameters in the forced swimming test (FST). Changes in behavioral status were correlated with an increase spleen weight, a decrease in thymic index and a shift in the CD4/CD8 balance toward T-cytotoxic cells. The behavior parameters were reversed in the group treated with ladasten compared to the untreated SDS group and were similar to those of unstressed mice. Treatment of socially stressed mice with ladasten normalized the amount of T-lymphocyte cells in the blood, spleen, and thymus. These findings support the notion that depression is accompanied by cell-mediated immune activation and that targeting this pathway may be a new therapeutic approach for treatment. Furthermore, our data support further investigations of ladasten as a potent anti-depressive drug which can be used alone as well as in combination with other anti-depressants.

关键词： Ladasten Social defeat Stress Depression Cytokines T-Cells

来源：

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

Social defeat enhanced learning and memory abilities and the related central mechanism

Social defeat enhanced learning and memory abilities and the...

引用

中国神经科学学会第十二届全国学术会议

作者： Liu Yang Lijun Shi Yuqiu Zhang Institutes of Brain Science and State Key Laboratory of Medical Neurobiology Collaborative Innovation Center for Brain Science Fudan University

Objective Social derived stresses account for the highest proportion in today’s psychotogenic stresses. To study the social-stress-induced mental disorders like depression and anxiety, we established the social defeat（SD） model in mice and observed various behavioral phenotype, including the social behaviors, anxiety, despair, anhedonia, exercise capacity, and learning and memory（L＆M）.Methods Social avoidance was assessed by Social Interaction Test. Anxiety-like behaviors were tested by Open Field test and Elevated Plus Maze test. Learning and memory was assessed by various of learning and memory tests（Morris water maze,Y-maze,Spatial Object Recognition and Fear Conditioning）.Results（1） The 10-day SD exposure induced social avoidance and anxiety-like behaviors, and unexpectedly, enhanced the L＆M capability including the spatial memory, cue fear memory and working memory.（2） The antidepressant clomipramine improved social avoidance and anxiety-like behaviors without reserving the enhancement of L＆M.（3） SD exposure increased the serum corticosterone level.（4） In hippocampus, the SD group exhibited increased newborn neurons（DCX+cells） in the dentate gyrus,and higher density, as well as more mature morphologies, of the secondary and third dendritic spines of the pyramidal neurons in the CA1 zone.（5） Also, we observed an increase in the protein levels the synapse associated protein 25（SNAP25） and NR2B（a subunit of the excitatory amino acid receptor NMDA） in hippocampus of the stressed animals.（6） After cannulas burying and NR2B blocking by RO-25-6981, the stressed animals exhibited an impaired working Memory.（7） In bilateral hippocampus, SNAP25 interference by Sh RNA adenovirus impaired the SD-derived enhancement of L＆M and decreased of the dendritic spine density. Conclusion Social defeat could enhance learning and memory. Hippocampal SNAP25 and NR2B participate in the formation of SD-enhanced learning and memory abilities.

关键词： Social defeat anxiety hippocampus learning memory SNAP25 NR2B

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

浅析fault, defeat, falling, flaw, shortcoming

引用

活力 2004年第7期 90-90页

作者：任波齐齐哈尔大学黑河分校，黑河164300

Fault, defeat, falling, flaw, shortcoming,这组词(n．)都指人或物在某方面有缺陷，不够完善，以faulI和defeat为常用。

关键词： fault defeat falling flaw 英语词汇词义同义词

来源：

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

Academician Glushkov and Grandmaster Fisher

引用

Journal of Mathematics and System Science 2019年第1期9卷 21-39页

作者： Karachenets Dmitryi St. Derevlyanskaya 19a of. 54 Kyiv 04119 Ukraine

In the first part of the article, the incomprehensible victories of the American grandmaster Robert Fisher over the candidates Mark Taimanov, Bent Larsen and Tigran Petrosyan in 1971 for the right to play the match for the World Chess Champion title with the former champion Boris Spassky and the victory over the champion himself in 1972 are first served as a detective story hypothesis proposed by Academician Viktor Glushkov. According to this hypothesis, R. Fisher used the prompts of a super-productive computer installed in the United States, in which a highly efficient computer chess program was played along with the matches. Communication with the computer provided a team of employees of the CIA. In the second part, the author, having reviewed briefly the history of computer chess programs, rejects the hypothesis of the academician and proposes his own.

关键词： Chess game chess match chess competition international chess tournament chess championship chess player computer chess program international master grandmaster candidate (contender, applicant, challenger) world chess champion debut defense endgame victory draw defeat

来源：

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

A BRIEF ANALYSIS ON SANTIAGO IN THE OLD MAN AND THE SEA

引用

西昌学院学报(自然科学版) 1999年第1期 54-57页

作者： Qiu Shifeng Wu Jianping (Xichang Agricultural College,Sichuan 615013)

The purpose of this paper is to analyse Santiago’s disposition and to de-scribe his ***,his dreams will be ***,the relation-ship between Santiago and Hemingway,the author himself,will be researched anddiscussed.

关键词： defeat Destroy Courage Determination

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：