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   4124篇
  免费   126篇
  国内免费   2篇
电工技术   62篇
综合类   4篇
化学工业   1189篇
金属工艺   83篇
机械仪表   57篇
建筑科学   218篇
矿业工程   30篇
能源动力   65篇
轻工业   458篇
水利工程   16篇
石油天然气   7篇
无线电   236篇
一般工业技术   645篇
冶金工业   654篇
原子能技术   36篇
自动化技术   492篇
  2022年   34篇
  2021年   47篇
  2020年   38篇
  2019年   40篇
  2018年   62篇
  2017年   52篇
  2016年   83篇
  2015年   105篇
  2014年   90篇
  2013年   186篇
  2012年   142篇
  2011年   185篇
  2010年   132篇
  2009年   128篇
  2008年   149篇
  2007年   175篇
  2006年   148篇
  2005年   132篇
  2004年   124篇
  2003年   103篇
  2002年   101篇
  2001年   80篇
  2000年   65篇
  1999年   85篇
  1998年   199篇
  1997年   137篇
  1996年   106篇
  1995年   94篇
  1994年   85篇
  1993年   60篇
  1992年   56篇
  1991年   55篇
  1990年   37篇
  1989年   56篇
  1988年   40篇
  1987年   50篇
  1986年   43篇
  1985年   56篇
  1984年   41篇
  1983年   41篇
  1982年   40篇
  1981年   41篇
  1980年   39篇
  1979年   29篇
  1978年   37篇
  1977年   39篇
  1976年   53篇
  1975年   53篇
  1973年   31篇
  1970年   37篇
排序方式: 共有4252条查询结果,搜索用时 15 毫秒
1.
ABSTRACT

The digital age of the future is ‘not out there to be discovered’, but it needs to be ‘designed’. The design challenge has to address questions about how we want to live, work, and learn (as individuals and as communities) and what we value and appreciate, e.g.: reflecting on quality of life and creating inclusive societies. An overriding design trade-off for the digital age is whether new developments will increase the digital divide or will create more inclusive societies. Sustaining inclusive societies means allowing people of all ages and all abilities to exploit information technologies for personally meaningful activities. Meta-design fosters the design of socio-technical environments that end-user developers can modify and evolve at use time to improve their quality of life and favour their inclusion in the society. This paper describes three case studies in the domain of assistive technologies in which end users themselves cannot act as end-user developers, but someone else (e.g.: a caregiver or a clinician) must accept this role requiring multi-tiered architectures. The design trade-offs and requirements for meta-design identified in the context of the case studies and other researchers’ projects are described to inform the development of future socio-technical environments focused on social inclusion.  相似文献   
2.
Lateral scattering of retrograde well implants is shown to have an effect on the threshold voltage of nearby devices. The threshold voltage of both NMOSFETs and PMOSFETs increases in magnitude for conventional retrograde wells, but for triple-well isolated NMOSFETs the threshold voltage decreases for narrow devices near the edge of the well. Electrical data, SIMS, and SUPREM4 simulations are shown that elucidate the phenomenon.  相似文献   
3.
PURPOSE: To assess the role postoperative mydriatics play after extracapsular cataract extraction (ECCE) and posterior chamber intraocular lens (IOL) implantation in causing iris modifications and in controlling inflammation. SETTING: Outpatients Department, Ninewells Hospital, Dundee, Scotland. METHODS: The prospective study comprised 136 patients who had standardized ECCE. Half the patients used a mydriatic for 2 weeks postoperatively. Anterior chamber activity, pain, and eye redness were evaluated at 2 weeks postoperatively; pupil shape, peripheral anterior synechias, IOL position, and iris adhesions, at 6 weeks. RESULTS: Iris-lens adhesions were significantly more common in the group using a mydriatic. There was no difference between the two groups in postoperative inflammation. CONCLUSION: Mydriatics should not be used routinely after ECCE with posterior chamber IOL implantation.  相似文献   
4.
In a prospective study we found good results concerning postoperative complications (21%), perioperative lethality (3.2%) and lethality during hospital stay (6.5%) after implantation of dynamic hip screws (DHS) in patients with per- and subtrochanteric fractures of the femur. The ability to walk, as well as housing and social care postoperatively and follow-up for at least six months after dismissal demonstrates the importance of these fractures for the elderly. One of three patients needs professional care, 21% at home, 13% in nursing homes. Six months after operation the lethality is nearly 20%, i.e. three times higher than in hospital. These are the essential data for all techniques of osteosynthesis used in patients with these fractures, which could only be documented in prospective studies.  相似文献   
5.
6.
7.
Semi‐Markovian processes (SMP) serve as a versatile means to model various traffic types generated by sources or superposed from links in ATM networks. An efficient discrete time analysis method is proposed for SMP/G/1 queueing systems to evaluate ATM switches with non‐renewal input. Some basic results are derived for the autocorrelation function of semi‐Markovian processes and for the effect of state space reduction on autocorrelation, which show how to represent correlated traffic with given characteristic by an adequate SMP model of limited size. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
8.
9.
10.
How critical is the therapeutic alliance in the treatment of sexual offenders? To date such process issues have been neglected in the field of sex offender treatment. This article reviews the literature on the influence on behavior change of therapist features, clients' perceptions, and the therapeutic alliance. Among the many therapist features identified as helpful are empathy, warmth, and being directive and rewarding. Therapists who are aggressively confrontational appear not to foster beneficial changes in their clients. These issues are directly related to treatment issues faced by therapists who work with sexual offenders, such as dealing with cognitive distortions, lack of empathy, and lack of motivation to change. (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