全文获取类型
收费全文 | 25165篇 |
免费 | 1162篇 |
国内免费 | 596篇 |
专业分类
电工技术 | 1049篇 |
技术理论 | 7篇 |
综合类 | 2266篇 |
化学工业 | 3142篇 |
金属工艺 | 885篇 |
机械仪表 | 1658篇 |
建筑科学 | 2999篇 |
矿业工程 | 969篇 |
能源动力 | 774篇 |
轻工业 | 2120篇 |
水利工程 | 721篇 |
石油天然气 | 1332篇 |
武器工业 | 291篇 |
无线电 | 1406篇 |
一般工业技术 | 1857篇 |
冶金工业 | 2343篇 |
原子能技术 | 341篇 |
自动化技术 | 2763篇 |
出版年
2024年 | 84篇 |
2023年 | 232篇 |
2022年 | 425篇 |
2021年 | 579篇 |
2020年 | 680篇 |
2019年 | 407篇 |
2018年 | 381篇 |
2017年 | 527篇 |
2016年 | 635篇 |
2015年 | 742篇 |
2014年 | 1753篇 |
2013年 | 1362篇 |
2012年 | 1673篇 |
2011年 | 1806篇 |
2010年 | 1464篇 |
2009年 | 1465篇 |
2008年 | 1244篇 |
2007年 | 1539篇 |
2006年 | 1582篇 |
2005年 | 1320篇 |
2004年 | 1094篇 |
2003年 | 1060篇 |
2002年 | 851篇 |
2001年 | 688篇 |
2000年 | 589篇 |
1999年 | 478篇 |
1998年 | 381篇 |
1997年 | 288篇 |
1996年 | 228篇 |
1995年 | 168篇 |
1994年 | 143篇 |
1993年 | 116篇 |
1992年 | 91篇 |
1991年 | 63篇 |
1990年 | 95篇 |
1989年 | 49篇 |
1988年 | 50篇 |
1987年 | 35篇 |
1986年 | 30篇 |
1985年 | 22篇 |
1984年 | 46篇 |
1982年 | 20篇 |
1966年 | 29篇 |
1965年 | 21篇 |
1964年 | 21篇 |
1963年 | 22篇 |
1959年 | 35篇 |
1958年 | 26篇 |
1955年 | 34篇 |
1954年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
论文将Fermat素性检验的思想运用于不可约多项式的判断,给出了一个对于不可约判断问题的Monte Carlo 算法,分析了该算法的计算复杂度问题,并且给出了次数在200以内的检验结果。 相似文献
12.
关于我国石油钻机技术的现状及其研发思考 总被引:13,自引:6,他引:7
介绍了我国石油钻机的技术现状,在肯定我国石油钻机发展所取得成绩的同时,指出我国石油钻机整体技术与国外钻机技术的差距,提出要把石油钻机作为国家战略装备来对待,加快我国石油钻机新技术、新产品研发工作,以满足我国石油工业发展的需要。 相似文献
13.
Reviews the book by Baruss (see record 2003-02669-000), which reviews the experimental and phenomenological research on alterations of consciousness, ranging from sleep and dreaming to mystical and near-death experience. The reviewer suggests there is a clear agenda announced by the book's subtitle, "An Empirical Analysis for Social Scientists." In the view of Baruss, all too often in states of consciousness research a preoccupation with theory has kept investigators from full engagement with the actual data. The book provides readable and at times appropriately controversial discussions of empirical literature on dreaming and lucid dreams, daydreaming and fantasy proneness, hypnosis, dissociative identity disorder, shamanism and possession states, psychedelic drug research, parapsychology, trance-chanelling and mediumship, the alien abduction syndrome, classical mystical experience, out-of-body and near-death experiences, and recent attempts by MacDonald and others to assess individual differences in spirituality through multifactor questionnaires. However, the reviewer believes that the breadth of coverage of both recent and past research is too often highly selective, and that the author's rejection of theory is both questionable in itself and more illusion than reality. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
14.
Reviews the book, Constructing the subject: Historical origins of psychological research by Kurt Danziger (1990). Kurt Danziger's Constructing the Subject: Historical Origins of Psychological Research is a book of singular importance because it provides such a penetrating analysis, and does so in a manner that is cause for considerable reflection. In brief, Danziger provides a history lesson that not only situates the names and the projects of experimental psychology in the first part of this century, but also aims to clarify the project of knowledge generation both past and present. Indeed, shades of Quine, Kuhn, and Hesse permeate this book in a way that demands psychologists examine their own investigative practices and logics of justification. Through Wundt, through Galton, through Ebbinghaus and others, Danziger illuminates the development of experimental psychology along with the historical and philosophical vicissitudes that have given rise to numerous psychological knowledge claims. If it is true that we must understand our history in order to understand our present, then Danziger's book should be required reading in all research laboratories. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
15.
16.
以入世为契机,进一步推进电力科研院所企业化转制 总被引:1,自引:1,他引:0
我国入世和融入经济全球化,将给中国经济运行的大环境带来深刻变化,科技事业也面临着全新挑战。电力科研所实行企业化转制,与国际接轨,按照国际规则办事势在必行。作者作为电力科研单位的一把手就电力科研院所的企业化转制阐述了个人的观点。转制必须有利于回忆科技创新和高新技术产品的开发;必须有利于抓紧培养和造就复合型人才队伍;必须有利于更好地为电网、为发供电企业提供规范化、制度化、长期化和现代化的全方位服务。 相似文献
17.
18.
对"比较法"原理和应用情况进行了分析,说明其在房地产开发中能够科学地预测房地产的价格和收益,从而提高财务分析的科学性和权威性,为项目决策提供科学依据,以促进"比较法"在房地产开发中的应用。 相似文献
19.
Education-driven research in CAD 总被引:1,自引:0,他引:1
We argue for a new research category, named education-driven research (EDR), which fills the gap between traditional field-specific research that is not concerned with educational objectives and research in education that focuses on fundamental teaching and learning principles and possibly on their customization to broad areas (such as mathematics or physics), but not to specific disciplines (such as CAD). The objective of EDR is to simplify the formulation of the underlying theoretical foundations and of specific tools and solutions in a specialized domain, so as to make them easy to understand and internalize. As such, EDR is a difficult and genuine research activity, which requires a deep understanding of the specific field and can rarely be carried out by generalists with primary expertise in broad education principles. We illustrate the concept of EDR with three examples in CAD: (1) the Split and Tweak subdivisions of a polygon and its use for generating curves, surfaces, and animations; (2) the construction of a topological partition of a plane induced by an arbitrary arrangement of edges; and (3) a romantic definition of the minimal and Hausdorff distances. These examples demonstrate the value of using analogies, of introducing evocative terminology, and of synthesizing the simplest fundamental building blocks. The intuitive understanding provided by EDR enables the students (and even the instructor) to better appreciate the limitations of a particular solution and to explore alternatives. In particular, in these examples, EDR has allowed the author to: (1) reduce the cost of evaluating a cubic B-spline curve; (2) develop a new subdivision curve that is better approximated by its control polygon than either a cubic B-spline or an interpolating 4-point subdivision curve; (3) discover how a circuit inclusion tree may be used for identifying the faces in an arrangement; and (4) rectify a common misconception about the computation of the Hausdorff error between triangle meshes. We invite the scientific community to encourage the development of EDR by publishing its results as genuine research contributions in peer-reviewed professional journals. 相似文献
20.