全文获取类型
收费全文 | 9762篇 |
免费 | 413篇 |
国内免费 | 210篇 |
专业分类
电工技术 | 137篇 |
综合类 | 49篇 |
化学工业 | 1763篇 |
金属工艺 | 431篇 |
机械仪表 | 174篇 |
建筑科学 | 321篇 |
矿业工程 | 29篇 |
能源动力 | 260篇 |
轻工业 | 1005篇 |
水利工程 | 49篇 |
石油天然气 | 357篇 |
武器工业 | 15篇 |
无线电 | 468篇 |
一般工业技术 | 1186篇 |
冶金工业 | 2953篇 |
原子能技术 | 95篇 |
自动化技术 | 1093篇 |
出版年
2023年 | 57篇 |
2022年 | 144篇 |
2021年 | 235篇 |
2020年 | 154篇 |
2019年 | 161篇 |
2018年 | 250篇 |
2017年 | 248篇 |
2016年 | 263篇 |
2015年 | 205篇 |
2014年 | 286篇 |
2013年 | 495篇 |
2012年 | 434篇 |
2011年 | 591篇 |
2010年 | 471篇 |
2009年 | 447篇 |
2008年 | 445篇 |
2007年 | 349篇 |
2006年 | 387篇 |
2005年 | 336篇 |
2004年 | 288篇 |
2003年 | 291篇 |
2002年 | 309篇 |
2001年 | 233篇 |
2000年 | 204篇 |
1999年 | 198篇 |
1998年 | 279篇 |
1997年 | 254篇 |
1996年 | 169篇 |
1995年 | 161篇 |
1994年 | 174篇 |
1993年 | 182篇 |
1992年 | 109篇 |
1991年 | 61篇 |
1990年 | 107篇 |
1989年 | 114篇 |
1988年 | 87篇 |
1987年 | 80篇 |
1986年 | 81篇 |
1985年 | 78篇 |
1984年 | 63篇 |
1983年 | 62篇 |
1981年 | 76篇 |
1979年 | 56篇 |
1978年 | 47篇 |
1977年 | 48篇 |
1976年 | 56篇 |
1975年 | 48篇 |
1974年 | 39篇 |
1971年 | 89篇 |
1970年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Hybrid Approach for Addressing Uncertainty in Risk Assessments 总被引:3,自引:0,他引:3
Dominique Guyonnet Bernard Bourgine Didier Dubois Hélène Fargier Bernard C?me Jean-Paul Chilès 《Canadian Metallurgical Quarterly》2003,129(1):68-78
Parameter uncertainty is a major aspect of the model-based estimation of the risk of human exposure to pollutants. The Monte Carlo method, which applies probability theory to address model parameter uncertainty, relies on a statistical representation of available information. In recent years, other uncertainty theories have been proposed as alternative approaches to address model parameter uncertainty in situations where available information is insufficient to identify statistically representative probability distributions, due in particular to data scarcity. The simplest such theory is possibility theory, which uses so-called fuzzy numbers to represent model parameter uncertainty. In practice, it may occur that certain model parameters can be reasonably represented by probability distributions, because there are sufficient data available to substantiate such distributions by statistical analysis, while others are better represented by fuzzy numbers (due to data scarcity). The question then arises as to how these two modes of representation of model parameter uncertainty can be combined for the purpose of estimating the risk of exposure. This paper proposes an approach (termed a hybrid approach) which combines Monte Carlo random sampling of probability distribution functions with fuzzy calculus. The approach is applied to a real case of estimation of human exposure, via vegetable consumption, to cadmium present in the surficial soils of an industrial site located in the north of France. The application illustrates the potential of the proposed approach, which allows the uncertainty affecting model parameters to be represented in a way that is consistent with the information at hand. Also, because the hybrid approach takes advantage of the “rich” information provided by probability distributions, while retaining the conservative character of fuzzy calculus, it is believed to hold value in terms of a “reasonable” application of the precautionary principle. 相似文献
62.
No authorship indicated 《Canadian Metallurgical Quarterly》2003,58(11):897a
Announces that Phyllis A. Katz has won the Award for Distinguished Senior Career Contributions to the Public Interest. The award is presented for the honoree's research on the origins and development of both racial and gender attitudes and her contributions to psychology in the public interest within the American Psychological Association. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
63.
No authorship indicated 《Canadian Metallurgical Quarterly》2004,59(5):352
The 2004 Gold Medal Award for Life Achievement in the Application of Psychology was awarded to Edwin A. Fleishman, for his significant contributions to the science and applications of psychology, which he has sustained over his remarkable career. He is cited for his research, which has had a profound influence on our understanding of human capabilities, their measurement, their development, and their application in the world of work. Through his many influential leadership roles, as president of the International Association of Applied Psychology and three divisions of the American Psychological Association, and as editor of the Journal of Applied Psychology, he has helped shape our profession. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
64.
No authorship indicated 《Canadian Metallurgical Quarterly》2004,59(5):468
Presents the 2004 address list of editors of APA journals. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
65.
贵金属及其合金铆钉型复合电触点除了应考核其冷态复合强度之外,还必须增加在热态下复合强度的考核,只有这样才能满足用户在产际运行时对复合触点复合强度的要求。 相似文献
66.
67.
No authorship indicated 《Canadian Metallurgical Quarterly》1995,50(8):633
Reports minutes representing the official record of the actions of the American Psychological Association (APA) taken during 1994 by both the Board of Directors and the Council of Representatives. The Board held 6 official meetings, discussing issues related to the following topics: (1) minutes of previous meetings (2) elections, awards, membership, and human resources, (3) ethics, (4) the Board of Directors, (5) divisions and state and provincial associations, (6) the APA organization, (7) publications and communications, (8) convention affairs, (9) educational issues, (10) professional affairs, (11) scientific affairs, (12) public interest, (13) ethnic minority affairs, (14) international affairs, (15) the Central Office, and (16) financial affairs. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
68.
69.
No authorship indicated 《Canadian Metallurgical Quarterly》1995,50(4):243
Presents the citation, biography, and selected bibliography for Robert B. McCall, one of the 1994 recipients of the American Psychological Association's Award for Distinguished Professional Contributions--Distinguished Professional Contributions to Public Service. From McCall's citation: "Building on a prolific research career in child development, Robert B. McCall communicated the scientific findings of his colleagues to the public through the mass media, winning four national awards and demonstrating to a sometimes skeptical profession that such articles and TV programs could be both accurate and interesting. Subsequently, he became the inaugural director for the University of Pittsburgh Office of Child Development, a unique interdisciplinary, university-community facilitative unit that has broadened the definition of university public service to embrace partnerships among faculty and community service professionals, funders, and policymakers that have created innovative interdisciplinary training and research programs, human service demonstration and evaluation projects, and policy studies." (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
70.
为了更好地指导现场钻井液施工,利用微机建立有关数据库和相应的设计软件,根据地质、工程的要求和井下情况进行钻井液设计,其特点是资料全面、程序运行可靠且操作简便,设计符合现场情况,施工顺利。在千12区块,用微机设计的109口井与人工设计的75口井相比,钻井速度提高,井下复杂情况减少,提高了经济效益。 相似文献