全文获取类型
收费全文 | 7265篇 |
免费 | 290篇 |
国内免费 | 396篇 |
专业分类
电工技术 | 92篇 |
技术理论 | 8篇 |
综合类 | 924篇 |
化学工业 | 690篇 |
金属工艺 | 106篇 |
机械仪表 | 205篇 |
建筑科学 | 637篇 |
矿业工程 | 187篇 |
能源动力 | 139篇 |
轻工业 | 335篇 |
水利工程 | 121篇 |
石油天然气 | 69篇 |
武器工业 | 1028篇 |
无线电 | 654篇 |
一般工业技术 | 801篇 |
冶金工业 | 669篇 |
原子能技术 | 44篇 |
自动化技术 | 1242篇 |
出版年
2024年 | 31篇 |
2023年 | 78篇 |
2022年 | 128篇 |
2021年 | 148篇 |
2020年 | 154篇 |
2019年 | 115篇 |
2018年 | 99篇 |
2017年 | 348篇 |
2016年 | 359篇 |
2015年 | 360篇 |
2014年 | 502篇 |
2013年 | 401篇 |
2012年 | 353篇 |
2011年 | 565篇 |
2010年 | 414篇 |
2009年 | 485篇 |
2008年 | 377篇 |
2007年 | 455篇 |
2006年 | 434篇 |
2005年 | 337篇 |
2004年 | 270篇 |
2003年 | 274篇 |
2002年 | 219篇 |
2001年 | 196篇 |
2000年 | 172篇 |
1999年 | 134篇 |
1998年 | 78篇 |
1997年 | 60篇 |
1996年 | 55篇 |
1995年 | 37篇 |
1994年 | 50篇 |
1993年 | 25篇 |
1992年 | 21篇 |
1991年 | 15篇 |
1990年 | 22篇 |
1989年 | 21篇 |
1988年 | 11篇 |
1987年 | 6篇 |
1986年 | 15篇 |
1985年 | 10篇 |
1984年 | 8篇 |
1982年 | 6篇 |
1966年 | 6篇 |
1965年 | 5篇 |
1964年 | 10篇 |
1963年 | 7篇 |
1961年 | 6篇 |
1960年 | 6篇 |
1955年 | 7篇 |
1954年 | 5篇 |
排序方式: 共有7951条查询结果,搜索用时 15 毫秒
1.
2.
20世纪以来,人类采用技术工程治理、法律制裁和经济惩罚等措施,一定意义上改善了局部的生态环境,但是未能遏制住全球环境问题的恶化态势。生态危机的根本解决,关键在于人类自身必须进行深刻的利益观念和价值观念的变革。重新审视人与自然界的关系,对自然进行伦理关怀,寻求和建立以保护地球环境和人类生存与可持续发展的生态平衡理念。 相似文献
3.
Two studies are presented. The first aimed to identify possible barriers to the uptake and use of commonly available telephony features and to determine whether greater knowledge of features/access codes and availability of user manuals could increase feature usage under certain conditions. Results showed that feature-usage patterns were not affected by any of the manipulations, but that they were determined by specific job demands. Using Constantine and Lockwood's (1999) conceptualization of user roles, a method to support feature bundling decisions for specific target markets was developed and tested in the second study. The method - Strategic User Needs Analysis (SUNA) - was shown to yield a useful balance between high- and low-level information about selected roles. SUNA provided sufficient information to distinguish between PDA feature usage patterns of two similar target user groups as well as to suggest additional features each of the two target groups would find useful. The development of SUNA and observational findings of actual PDA usage are reported. 相似文献
4.
Jost John T.; Glaser Jack; Kruglanski Arie W.; Sulloway Frank J. 《Canadian Metallurgical Quarterly》2003,129(3):383
A meta-analysis by J. T. Jost, J. Glaser, A. W. Kruglanski, and F. J. Sulloway (2003) concluded that political conservatism is partially motivated by the management of uncertainty and threat. In this reply to J. Greenberg and E. Jonas (2003), conceptual issues are clarified, numerous political anomalies are explained, and alleged counterexamples are incorporated with a dynamic model that takes into account differences between "young" and "old" movements. Studies directly pitting the rigidity-of-the-right hypothesis against the ideological extremity hypothesis demonstrate strong support for the former. Medium to large effect sizes describe relations between political conservatism and dogmatism and intolerance of ambiguity; lack of openness to experience; uncertainty avoidance; personal needs for order, structure, and closure; fear of death; and system threat. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
5.
Why was there a preponderance of women engaged in laboratory-based studies of animal behavior in Britain in the early years of the 20th century? As a new experimental subject with recently neglected potential, animal psychology then represented an opportunity for women to make further inroads into academic science. Because the study of psychology before World War I offered negligible professional opportunities for the application of the subject, the intake of students was restricted. Perhaps this encouraged academic access to it by aspiring female scientists who felt that career prospects, uncertain and socially unexpected of them in any case, were worth chancing for greater long-term rewards. The academic circumstances and contributions of 3 British female pioneers in experimental comparative psychology are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
Comments on the original article "A New Big Five: Fundamental Principles for an Integrative Science of Personality," by Dan P. McAdams and Jennifer L. Pals (see record 2006-03947-002). McAdams and Pals (April 2006) presented a new model to integrate the field of personality psychology. Cultural and evolutionary factors interact with an individual's basic traits, characteristic adaptations, and life narratives, which in turn are linked to roles, demands, and behaviors. The current authors welcome McAdams and Pals's (2006) model for providing a way to integrate much of the previously disparate empirical findings in personality psychology. However, the current authors also think that McAdams and Pals (2006) overstated the inclusiveness of the model, and more generally, the current authors dispute their assertion that the grand theories of personality can be integrated within a single model. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
7.
This study tested a partial version of R. W. Lent, S. D. Brown, and G. Hackett's (1994) social-cognitive career theory model. Among 204 high school girls who attended science, math, and engineering (SME) career conferences, the authors used a 4-year longitudinal design to predict the choice of an SME college major and SME self-efficacy and outcome expectations in college. In addition, among students who had declared SME majors, variables assessed in high school and college were used to predict aspirations to become leaders in SME fields. The results generally provided empirical validation of the model. Regression analyses revealed that college SME outcome expectations were associated with plans to become a leader in an SME field. Implications for research and interventions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
8.
9.
纳米科学技术将成为21世纪最重要的高技术之一。纳米技术的最终目标是直接操纵单个原子和分子,制造量子功能器件,从而开拓人类崭新的生产生活模式。文章评述利用电子束、离子束的精细技术和STM原子操纵技术的研究现状,介绍原子层蚀刻,单层抗蚀剂自形成蚀刻,纳米自然蚀刻和电子束全息纳米蚀刻等高技术前沿动态,展望纳米技术的发展前景。 相似文献
10.
揭示了城市环境的基本性质的基本特征,研究了城市环境对人的心理影响和生理影响。指出城市环境建设不公要满足人的物质需要,还要满足人的精神需要。 相似文献