全文获取类型
收费全文 | 2240篇 |
免费 | 243篇 |
国内免费 | 109篇 |
专业分类
电工技术 | 74篇 |
综合类 | 275篇 |
化学工业 | 61篇 |
金属工艺 | 16篇 |
机械仪表 | 58篇 |
建筑科学 | 172篇 |
矿业工程 | 38篇 |
能源动力 | 38篇 |
轻工业 | 69篇 |
水利工程 | 22篇 |
石油天然气 | 30篇 |
武器工业 | 228篇 |
无线电 | 295篇 |
一般工业技术 | 99篇 |
冶金工业 | 687篇 |
原子能技术 | 13篇 |
自动化技术 | 417篇 |
出版年
2023年 | 20篇 |
2022年 | 56篇 |
2021年 | 54篇 |
2020年 | 47篇 |
2019年 | 48篇 |
2018年 | 50篇 |
2017年 | 61篇 |
2016年 | 67篇 |
2015年 | 65篇 |
2014年 | 124篇 |
2013年 | 89篇 |
2012年 | 136篇 |
2011年 | 185篇 |
2010年 | 170篇 |
2009年 | 163篇 |
2008年 | 149篇 |
2007年 | 178篇 |
2006年 | 150篇 |
2005年 | 131篇 |
2004年 | 122篇 |
2003年 | 122篇 |
2002年 | 93篇 |
2001年 | 92篇 |
2000年 | 33篇 |
1999年 | 11篇 |
1998年 | 10篇 |
1997年 | 13篇 |
1996年 | 6篇 |
1995年 | 7篇 |
1994年 | 9篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1979年 | 3篇 |
1968年 | 3篇 |
1966年 | 8篇 |
1965年 | 4篇 |
1964年 | 3篇 |
1963年 | 11篇 |
1962年 | 5篇 |
1961年 | 4篇 |
1960年 | 5篇 |
1959年 | 6篇 |
1958年 | 3篇 |
1957年 | 7篇 |
1956年 | 3篇 |
1955年 | 14篇 |
排序方式: 共有2592条查询结果,搜索用时 15 毫秒
81.
围绕作战工程保障行动中战士、装备和任务的指派问题,构建了一个包括战士操作水平、装备技术状态和协作影响因素的三维指派模型。考虑战士多技能、装备多功能的战备要求和“人歇车不歇”作战原则,给出了该模型的约束条件。基于目标函数和约束条件的形式,采用虚拟装备法将多功能装备分解为单功能装备的组合,并在此基础上设计了一套快速求解算法。实例分析结果表明:该指派模型能够实现作战工程保障行动中最优指派方案的求解;同时快速求解算法可以极大地缩小可行域,从而显著提高求解效率。 相似文献
82.
针对现阶段无人机智能化程度相对有限的问题,分析有人/无人机协同作战。梳理有人/无人机协同作战
的概念、特点需求及历史概况;描述美国、俄罗斯、英国等国有人/无人机协同作战的研究现状;结合科技进步与战
争形态发展,重点梳理有人/无人机协同作战的关键技术,对有人/无人机协同作战的发展前景进行展望。结果表明,
该分析可为我军发展有人/无人机混合编队提供参考。 相似文献
83.
为应对现代战争智能化的新挑战、赢得空中作战优势,在空战模拟训练中进行人工智能(artificial intelligence,AI)技术的应用研究。将空战中的人工智能关键技术作为切入点,阐述空战模拟训练中智能算法的优势及适用性;立足当前空战模拟训练需求以及人工智能应用中存在的不足,对空战模拟中的人工智能应用研究趋势进行分析。结果表明,该研究能对空战模拟训练领域的相关研究人员带来启发。 相似文献
84.
为适应高新科技发展对军事行动带来的冲击,加强我军无人战场研究,提高无人机专业建设能力,提出未来无人机作战专业建设的发展方向.通过分析无人机在纳戈尔诺-卡拉巴赫冲突中的应用和遇到的问题,结合无人机作战特点,从无人机的作战优势、集群建设、核心技术自主可控、功能集成以及编制体制建设5个方面展开分析.结果表明:加强无人机专业建设及技术的自主可控具有重大意义. 相似文献
85.
为增强应对暴力冲突事件能力,建立有效的反恐力量,采用美国国防部体系结构框架(department of defense architecture framework,DoDAF)设计一种空地无人平台与特战班组协同反恐系统的总体结构.以特种破袭使命为任务背景,建立特战系统的视点模型,对整体框架进行规范化和系统化的描述.结果表明:该设计能为军事概念建模提供形式化描述,对有/无人协同反恐系统顶层设计具有参考价值. 相似文献
86.
The primary purpose of this study is to determine if recent combat veterans discriminate between different sources of social support, and then preliminarily investigate the relationship of social support source on posttraumatic stress disorder (PTSD) symptomatology. Participants included 83 married male combat veterans. Principal-axis factor analysis with equamax rotation observed four distinct latent factors for each source of support examined. ANOVAs were performed to determine the relationship of each source of support from the distinct latent factors on the level of PTSD. Results indicate that the level of PTSD is related to support received from a significant other, F(1, 81) = 30.36, p F(1, 81) = 8.10, p = .006, and military peers, F(1, 81) = 6.70, p = .011, but not friends, F(1, 81) = 1.79, p = .18. In general, higher levels of support from each category were associated with lower levels of PTSD in combat veterans. The results suggest that combat veterans distinguish between specific sources of social support, which may have a protective effect on the level of PTSD. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
87.
The traditional psychological approach of studying aggression among schoolchildren in terms of individual differences in aggression and in victimization has been valuable in identifying prevalence rates, risk, and consequences of involvement in aggression. However, it is argued that a focus on aggressor–victim relationships is warranted based on both conceptual and empirical grounds. Such a shift in focus requires modification and integration of existing theories of aggression, and this paper integrates social-cognitive theory and interdependence theory to suggest a new, interdependent social-cognitive theory of aggression. Specifically, this paper identifies points of overlap and different foci between these theories, and it illustrates their integration through a proposed model of the emergence of aggressor–victim interactions and relationships. The paper concludes that expanding consideration to include aggressor–victim relationships among schoolchildren offers considerable theoretical, empirical, and intervention opportunities. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
88.
Wright Kathleen M.; Cabrera Oscar A.; Bliese Paul D.; Adler Amy B.; Hoge Charles W.; Castro Carl A. 《Canadian Metallurgical Quarterly》2009,6(2):108
The present study examined the effects of leadership and unit cohesion on mental health stigma and perceived barriers to care. A sample of 680 soldiers from combat support units were surveyed 3 months after their return from combat operations in Iraq. The survey included scales on psychological symptoms and perceptions of leader behaviors and unit cohesion, as well as items assessing stigma and barriers to care. The sample was used to test the independent and interactive effects of leadership and unit cohesion on soldiers’ perceptions of stigma and barriers to care. Analyses yielded significant interaction effects between leadership and cohesion in predicting stigma and barriers to care, while controlling for the effects of mental health symptoms. Soldiers who rated their leaders more highly and who reported higher unit cohesion also reported lower scores on both stigma and perceived barriers to care. Thus, positive leadership and unit cohesion can reduce perceptions of stigma and barriers to care, even after accounting for the relationship between mental health symptoms and these outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
89.
Davidson Oranit B.; Eden Dov; Westman Mina; Cohen-Charash Yochi; Hammer Leslie B.; Kluger Avraham N.; Krausz Moshe; Maslach Christina; O'Driscoll Michael; Perrewé Pamela L.; Quick James Campbell; Rosenblatt Zehava; Spector Paul E. 《Canadian Metallurgical Quarterly》2010,95(5):953
A rigorous quasi-experiment tested the ameliorative effects of a sabbatical leave, a special case of respite from routine work. We hypothesized that (a) respite increases resource level and well-being and (b) individual differences and respite features moderate respite effects. A sample of 129 faculty members on sabbatical and 129 matched controls completed measures of resource gain, resource loss, and well-being before, during, and after the sabbatical. Among the sabbatees, resource loss declined and resource gain and well-being rose during the sabbatical. The comparison group showed no change. Moderation analysis revealed that those who reported higher respite self-efficacy and greater control, were more detached, had a more positive sabbatical experience, and spent their sabbatical outside their home country enjoyed more enhanced well-being than others. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
90.
Zuroff David C.; Fournier Marc A.; Patall Erika A.; Leybman Michelle J. 《Canadian Metallurgical Quarterly》2010,51(1):58
A comprehensive evolutionary personality psychology can be developed by identifying individual differences within each of the evolved systems that regulate social behaviour. We developed a questionnaire measure of social rank style, defined as individual differences in preferred strategies for pursuing, defending, and, when necessary, relinquishing social rank. The 17-item Rank Style with Peers Questionnaire (RSPQ) comprises three nearly independent scales: dominant leadership, coalition-building, and ruthless self-advancement. A series of studies demonstrated that: (a) the RSPQ’s, factor structure is robust; (b) the three rank style variables are not redundant with the five-factor traits or adult attachment styles; (c) they are related in theoretically expected ways to adjustment outcomes, to agentic and communal interpersonal behaviours, and to social reputations; (d) they predict group and individual performance outcomes relevant to organisational psychology; and (e) they are related in theoretically expected ways to psychopathology, including social anxiety disorder and depressive symptoms. Future directions for research on social rank styles and prospects for an evolutionary personality psychology are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献