全文获取类型
收费全文 | 1225篇 |
免费 | 10篇 |
专业分类
电工技术 | 19篇 |
综合类 | 1篇 |
化学工业 | 106篇 |
金属工艺 | 27篇 |
机械仪表 | 16篇 |
建筑科学 | 31篇 |
矿业工程 | 2篇 |
能源动力 | 9篇 |
轻工业 | 55篇 |
水利工程 | 7篇 |
石油天然气 | 7篇 |
无线电 | 102篇 |
一般工业技术 | 132篇 |
冶金工业 | 440篇 |
原子能技术 | 19篇 |
自动化技术 | 262篇 |
出版年
2021年 | 10篇 |
2019年 | 8篇 |
2018年 | 12篇 |
2015年 | 10篇 |
2014年 | 15篇 |
2013年 | 45篇 |
2012年 | 25篇 |
2011年 | 43篇 |
2010年 | 43篇 |
2009年 | 45篇 |
2008年 | 44篇 |
2007年 | 39篇 |
2006年 | 28篇 |
2005年 | 29篇 |
2004年 | 33篇 |
2003年 | 22篇 |
2002年 | 19篇 |
2001年 | 20篇 |
2000年 | 16篇 |
1999年 | 28篇 |
1998年 | 88篇 |
1997年 | 55篇 |
1996年 | 55篇 |
1995年 | 28篇 |
1994年 | 32篇 |
1993年 | 38篇 |
1992年 | 14篇 |
1991年 | 9篇 |
1990年 | 18篇 |
1989年 | 22篇 |
1988年 | 18篇 |
1987年 | 18篇 |
1986年 | 15篇 |
1985年 | 12篇 |
1984年 | 31篇 |
1983年 | 14篇 |
1982年 | 29篇 |
1981年 | 20篇 |
1980年 | 13篇 |
1979年 | 12篇 |
1978年 | 14篇 |
1977年 | 17篇 |
1976年 | 20篇 |
1975年 | 10篇 |
1974年 | 16篇 |
1973年 | 13篇 |
1972年 | 11篇 |
1971年 | 8篇 |
1970年 | 7篇 |
1966年 | 6篇 |
排序方式: 共有1235条查询结果,搜索用时 21 毫秒
1.
Examined the psychological characteristics of the children of holocaust survivors. 38 males and females in their late 20's were interviewed; the parents of 19 Ss were holocaust survivors, and the parents of the other 19 Ss were in Israel during World War II and did not suffer directly. It was hypothesized that reactions of the children of the holocaust survivors would include guilt rather than external aggression and a tendency not to externalize aggressive impulses in reaction to frustrating events. The Ss' reactions to a projective test were analyzed, and the responses provide support for the major hypothesis. Results show that sons and daughters of holocaust survivors were less likely to externalize aggression than were those in a control group. This finding is supported by the content analysis of the structured interview conducted with the Ss in both groups. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
2.
Arie Ben-David 《Expert systems with applications》1991,2(4):353-359
Many expert system researchers have reported in recent years that situation-action symbolic production rules frequently fail to provide adequate knowledge representation schemes without resorting to numeric computation. However, despite the need to integrate symbolic and quantitative computation into one coherent framework of knowledge, surprisingly few architectures have been proposed for achieving this goal. This paper explores the integration of qualitative and numeric processing in expert systems. We address the topic with respect to the construction of expert systems that perform the tasks of design and multiple fault troubleshooting. This paper shows that these tasks can be handled effectively when an appropriate interface is established between the heuristic and the numeric knowledge-based components. Specifically, we demonstrate how to interface heuristic knowledge with non-linear optimization models in order to allow an expert system greater expressiveness. An actual example is presented from the machining domain. 相似文献
3.
4.
Heidi Bernas Arie J. Plomp Johannes H. Bitter Dmitry Yu. Murzin 《Catalysis Letters》2008,120(1-2):8-13
The density functional theory (DFT/B3LYP) calculations were applied to investigate the interaction of a Pt6 particle with the ZSM-5 zeolite framework. The electronic structure of the metal particle is strongly affected by the interaction with basic framework oxygens and acid sites of the zeolite support. Adsorption on basic sites (Eads = 6 kcal/mol) favors the formation of the electron enriched metal cluster. Interaction of the platinum cluster with the acid site characterized by stabilization energy of 47 kcal/mol results in oxidation of the metal particle and suppression of Brønsted acidity of the support. The hypothesis is put forward that the oxidized platinum particle can function as an active site for the alkane isomerisation on platinum supported high silica zeolites. 相似文献
5.
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
6.
We could not imagine a more appropriate inauguration of the Psychology of Aesthetics, Creativity, and the Arts (PACA) going to four issues per year than with a special issue honoring the life and work of the great aesthetician and psychologist, Rudolf Arnheim. PACA is off to a great start. With this move to four issues per year, we are restarting our numbering system, so this special issue is Volume 1, Issue 1. As you read the articles in this issue, we hope that you enjoy reflecting on how much Rudolf Arnheim has contributed to the field of psychology of aesthetics. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
7.
8.
9.
Essential contribution of caspase 3/CPP32 to apoptosis and its associated nuclear changes 总被引:1,自引:0,他引:1
M Woo R Hakem MS Soengas GS Duncan A Shahinian D K?gi A Hakem M McCurrach W Khoo SA Kaufman G Senaldi T Howard SW Lowe TW Mak 《Canadian Metallurgical Quarterly》1998,12(6):806-819
Caspases are fundamental components of the mammalian apoptotic machinery, but the precise contribution of individual caspases is controversial. CPP32 (caspase 3) is a prototypical caspase that becomes activated during apoptosis. In this study, we took a comprehensive approach to examining the role of CPP32 in apoptosis using mice, embryonic stem (ES) cells, and mouse embryonic fibroblasts (MEFs) deficient for CPP32. CPP32(ex3-/-) mice have reduced viability and, consistent with an earlier report, display defective neuronal apoptosis and neurological defects. Inactivation of CPP32 dramatically reduces apoptosis in diverse settings, including activation-induced cell death (AICD) of peripheral T cells, as well as chemotherapy-induced apoptosis of oncogenically transformed CPP32(-/-) MEFs. As well, the requirement for CPP32 can be remarkably stimulus-dependent: In ES cells, CPP32 is necessary for efficient apoptosis following UV- but not gamma-irradiation. Conversely, the same stimulus can show a tissue-specific dependence on CPP32: Hence, TNFalpha treatment induces normal levels of apoptosis in CPP32 deficient thymocytes, but defective apoptosis in oncogenically transformed MEFs. Finally, in some settings, CPP32 is required for certain apoptotic events but not others: Select CPP32(ex3-/-) cell types undergoing cell death are incapable of chromatin condensation and DNA degradation, but display other hallmarks of apoptosis. Together, these results indicate that CPP32 is an essential component in apoptotic events that is remarkably system- and stimulus-dependent. Consequently, drugs that inhibit CPP32 may preferentially disrupt specific forms of cell death. 相似文献
10.
Of 1,666 patients who underwent fine needle aspiration for breast lumps, 4 developed pneumothorax as a complication. The incidence of this complication in our patients is 1:417. The clinical manifestations were immediate chest pain, shoulder pain and, occasionally, dyspnea that developed later. Observation is sufficient treatment in most patients, and rarely is drainage of the pneumothorax required. 相似文献