首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1746篇
  免费   35篇
电工技术   13篇
综合类   25篇
化学工业   511篇
金属工艺   28篇
机械仪表   22篇
建筑科学   89篇
矿业工程   3篇
能源动力   36篇
轻工业   313篇
水利工程   15篇
石油天然气   1篇
无线电   90篇
一般工业技术   215篇
冶金工业   168篇
原子能技术   13篇
自动化技术   239篇
  2024年   13篇
  2023年   19篇
  2022年   49篇
  2021年   49篇
  2020年   43篇
  2019年   52篇
  2018年   35篇
  2017年   45篇
  2016年   62篇
  2015年   59篇
  2014年   60篇
  2013年   87篇
  2012年   79篇
  2011年   113篇
  2010年   118篇
  2009年   63篇
  2008年   107篇
  2007年   82篇
  2006年   56篇
  2005年   41篇
  2004年   50篇
  2003年   48篇
  2002年   40篇
  2001年   28篇
  2000年   34篇
  1999年   27篇
  1998年   61篇
  1997年   40篇
  1996年   17篇
  1995年   16篇
  1994年   23篇
  1993年   17篇
  1992年   19篇
  1991年   13篇
  1990年   10篇
  1989年   8篇
  1988年   8篇
  1987年   12篇
  1986年   8篇
  1985年   4篇
  1984年   4篇
  1983年   7篇
  1981年   7篇
  1980年   4篇
  1978年   3篇
  1977年   7篇
  1976年   7篇
  1973年   4篇
  1965年   2篇
  1954年   2篇
排序方式: 共有1781条查询结果,搜索用时 15 毫秒
101.
Nachdem als letzter Mitgliedstaat der Europ?ischen Union auch Tschechien im November 2009 den Lissaboner Vertrag ratifiziert hatte, konnte das Vertragswerk1 zum 01. Dezember 2009 in Kraft treten. Seither sind allerdings die mit der neuen Rechtsgrundlage der Europ?ischen Union verbundenen vielf?ltigen Wirkungen kaum ins Bewusstsein der europ?ischen ?ffentlichkeit gelangt. Sie werden von den globalen Banken- und Wirtschaftsproblemen sowie von der aktuellen Krise der europ?ischen W?hrungsunion überlagert, die die nationalen Politiken der EU-Mitgliedstaaten und die gemeinschaftliche europ:aische Politik vor gro?e Herausforderungen stellen und deren Aufmerksamkeit in hohem Ma?e in Anspruch nehmen. Es mag also noch dauern, bis Europa in absehbarer Zeit und hoffentlich ohne an seinen politischkonstitutiven Fundamenten Schaden zu nehmen die aktuellen Krisen überwunden haben wird. Erst dann dürfte den Bürgerinnen und Bürgern Europas deutlicher werden, dass mit dem Inkrafttreten des Vertrages von Lissabon eine unter mehreren Gesichtspunkten neue Epoche des Europ?ischen Integrationsprozesses begonnen hat. Das gilt nicht nur, aber vor allem für die Innen- und Rechtspolitik — für jene Bereiche europ?ischer Politik also, die die Herstellung des seit 1999 im Amsterdamer Vertrag avisierten „Raumes der Freiheit, der Sicherheit und des Rechts“ zum Ziel haben. Innerhalb dieser im hohen Ma?e grundrechtssensiblen Politikfelder wird die neue Epoche vor allem von erheblichen Ver?nderungen sowohl im materiellen, rechtlichen als auch im institutionellen, gerichtlichen Schutz der Grund- und Freiheitsrechte der europ?ischen Bürgerinnen und Bürger gepr?gt sein.  相似文献   
102.
. On the basis of a longitudinal field study of 29 commercial software development projects, the pros and cons of user centredness in software development were analysed. We looked at two concepts: user participation-an organizational device-involving a user representative in the team, and user orientation-a cognitive-emotional concept-which pertains to positive attitudes towards users. Both were found to be associated with project difficulties relating to process and product quality as well as overall project success. We suggest that the issue is no longer whether or not to involve users, but instead to develop a realistic understanding of the difficulties associated with user centredness.  相似文献   
103.

Current Research Activities

The Swedish approach to research and development in fire protection  相似文献   
104.
This article addresses the relation between day-specific experiences of job stressors and the pursuit of off-job activities. Following the limited-resources model of self-regulation, the authors proposed that job stressors and long working hours are negatively related to pursuit of sport activities after work because, after stressful days, employees have no resources left for initiating and persisting in effortful behaviors such as sport. Routines for off-job activities were hypothesized to be positively related to the pursuit of sport activities after work. Seventy-eight police employees completed a daily survey over 5 working days and indicated that they perceive sport to be highly useful for recovery. Random coefficient modeling showed that job stressors (particularly situational constraints) encountered on a specific day were negatively related to self-regulatory resources and to the amount of time spent on sport activities after work, whereas the relation with low-effort activities was positive. Thus, after a stressful day when an effective recovery activity such as sport is highly needed, persons tend to engage less in such an activity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
105.
[Correction Notice: An erratum for this article was reported in Vol 7(3) of Psychological Services (see record 2010-17074-004). The copyright for the article was listed incorrectly. This article is in the Public Domain. The online version has been corrected.] The present study examined interest in family involvement in treatment and preferences concerning the focus of family oriented treatment for veterans (N = 114) participating in an outpatient Veterans Affairs outpatient posttraumatic stress disorder (PTSD) program. Most veterans viewed PTSD as a source of family stress (86%) and expressed interest in greater family involvement in their treatment (79%). These results suggest the need to consider increasing family participation in the clinical care of individuals with PTSD and to develop specialized family educational and support services for this population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
106.
BACKGROUND: The emergence of psychogenic seizures after surgery for epilepsy is not well recognized. OBJECTIVES: To identify the frequency of psychogenic seizures in an 11-year surgical experience and to characterize the patients with this complication. METHODS: Ninety-six patients underwent surgery for epilepsy between 1985 and 1996. The surgical database was reviewed and all patients who experienced postoperative psychogenic seizures were identified. Patients were characterized by sex, age, psychopathologic conditions, full-scale IQ, duration of epilepsy, surgical procedure, and operative complications. Patients were compared with the surgical group as a whole for these variables. SETTING: A comprehensive epilepsy center. RESULTS: Five patients were identified: 3 men and 2 women. Mean full-scale IQ was 73 (range, 66-82). Mean age was 29.8 years (range, 22-36 years). Three patients were diagnosed as having psychosis, 1 with borderline personality disorder and 1 with generalized anxiety. Operations included 4 anterior temporal lobectomies and 1 occipital lobectomy. Two patients experienced operative complications. Compared with the surgical cohort, patients had a higher frequency of preoperative psychopathologic conditions, lower mean full-scale IQ, and a greater occurrence of operative complications. CONCLUSIONS: (1) Patients can develop new-onset psychogenic seizures after surgery for epilepsy. (2) Low full-scale IQ, serious preoperative psychopathologic conditions, and major surgical complications may be risk factors. (3) Atypical postoperative seizures should be evaluated with video electroencephalographic monitoring before concluding that they are epileptic.  相似文献   
107.
Reviews the book, Schreber: Father and son by Han Isra?ls (see record 1989-98605-000). In 1911, Sigmund Freud published a long paper about a German judge, Daniel Paul Schreber (1842-1911), who had been an inpatient in three psychiatric clinics from 1893 to 1902. Beginning in the 1940s and 1950s, psychiatrists and psychoanalysts began to give intensive attention to the life and illness of Schreber, an interest that has continued to the present day. Now Han Isra?ls, has written a compelling and most unusual book about Schreber and his father, Moritz Schreber. From one point of view it is a historical tour de force, bound to evoke admiration from any professional historian for its research and scholarship. From another vantage point, it is an example of historical overkill. The dominant theme of Isra?ls's book is an exposé of the corrupt scholarship that has grown up around Moritz Schreber and hence Isra?ls's argument that after his death Moritz achieved fame and notoriety far out of proportion to his actual contributions. A second, minor theme is Isra?ls's agreement with the discovery made by the psychoanalyst Niederland that Moritz Schreber's writings provide information about the way he reared his children: "It has become apparent that the method of upbringing has left traces in the psychotic illness [of Paul Schreber]." When all is said and done, we are left with a book which, in spite of its compelling scholarship, yields almost no new information about Judge Schreber that would help us to understand him better. Furthermore, Isra?ls's book is likely to have little impact on the modern and incorrect views about Schreber's father. In the end, Isra?ls's book stands as a cautionary tale to lazy researchers and sloppy scholars. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
108.
A monoenergetic MeV positron (e+) beam, with a flux at present of 6 × 104 e+/s in the energy range of 0.5 to 6.5 MeV, has been installed at the Stuttgart Pelletron accelerator. The stabilization and the absolute calibration of the energy E is monitored by a Ge detector with real-time feedback; a relative energy stability of ΔE/E 10−4 is obtained. So far, e+e scattering and annihilation-in-flight experiments for investigating the low-energy e+e interaction as well as β+ γ positron lifetime measurements in condensed matter have been performed. The advantages of the β+ γ method compared to the conventional γγ coincidence technique have been demonstrated. Recently, triple-coincidence positron “age-momentum correlation” measurements have been carried out on fused quartz. A brief account is given on the development of a “positron clock” aiming at a substantial improvement of the time resolution of the β+ γ positron lifetime measurements.  相似文献   
109.
110.
This study reports the psychometric properties of a 45-item diabetes-specific questionnaire, the Questionnaire on Stress in Patients with Diabetes—Revised (QSD-R), a modified and shortened version of the QSD (G. Duran et al; see record 1996-18805-001). The QSD-R was filled out by 1,930 individuals with insulin-dependent diabetes mellitus and noninsulin-dependent diabetes mellitus. Eight consistent scales were identified (values of Cronbach's α: .69–.81). The test-retest reliability for the total score after a 5-week interval was rtt?=?.63. The results provide evidence for the reliability and validity of this instrument. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号