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   26386篇
  免费   2492篇
  国内免费   1423篇
电工技术   889篇
技术理论   8篇
综合类   3490篇
化学工业   1649篇
金属工艺   512篇
机械仪表   750篇
建筑科学   8131篇
矿业工程   1640篇
能源动力   746篇
轻工业   904篇
水利工程   3092篇
石油天然气   778篇
武器工业   236篇
无线电   1224篇
一般工业技术   1399篇
冶金工业   1086篇
原子能技术   168篇
自动化技术   3599篇
  2024年   92篇
  2023年   368篇
  2022年   765篇
  2021年   849篇
  2020年   791篇
  2019年   626篇
  2018年   541篇
  2017年   705篇
  2016年   781篇
  2015年   887篇
  2014年   1760篇
  2013年   1443篇
  2012年   1611篇
  2011年   2069篇
  2010年   1683篇
  2009年   1825篇
  2008年   1710篇
  2007年   2049篇
  2006年   1829篇
  2005年   1502篇
  2004年   1275篇
  2003年   1090篇
  2002年   938篇
  2001年   728篇
  2000年   565篇
  1999年   437篇
  1998年   297篇
  1997年   228篇
  1996年   182篇
  1995年   128篇
  1994年   109篇
  1993年   94篇
  1992年   73篇
  1991年   49篇
  1990年   46篇
  1989年   33篇
  1988年   29篇
  1987年   15篇
  1986年   12篇
  1985年   14篇
  1984年   13篇
  1983年   10篇
  1982年   5篇
  1981年   4篇
  1979年   5篇
  1978年   4篇
  1977年   3篇
  1966年   4篇
  1965年   3篇
  1959年   5篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
102.
浅议朱提商业街规划设计中的文化传承   总被引:2,自引:2,他引:0  
王健 《山西建筑》2006,32(21):39-40
以朱提文化商业街为例,从地域文化分析、规划设计原则、人文环境设计、建筑造型四方面探讨了设计中的文化传承问题,以展示现代商业街街区的文脉,体现城市的文化。  相似文献   
103.
Subsurface Characterization at Ground Failure Sites in Adapazari, Turkey   总被引:4,自引:0,他引:4  
Ground failure in Adapazari, Turkey during the 1999 Kocaeli earthquake was severe. Hundreds of structures settled, slid, tilted, and collapsed due in part to liquefaction and ground softening. Ground failure was more severe adjacent to and under buildings. The soils that led to severe building damage were generally low plasticity silts. In this paper, the results of a comprehensive investigation of the soils of Adapazari, which included cone penetration test (CPT) profiles followed by borings with standard penetration tests (SPTs) and soil index tests, are presented. The effects of subsurface conditions on the occurrence of ground failure and its resulting effect on building performance are explored through representative case histories. CPT- and SPT-based liquefaction triggering procedures adequately identified soils that liquefied if the clay-size criterion of the Chinese criteria was disregarded. The CPT was able to identify thin seams of loose liquefiable silt, and the SPT (with retrieved samples) allowed for reliable evaluation of the liquefaction susceptibility of fine-grained soils. A well-documented database of in situ and index testing is now available for incorporating in future CPT- and SPT-based liquefaction triggering correlations.  相似文献   
104.
The role of attention processes as possible mediators between family environment and school readiness was analyzed with data from 1,002 children and their families. Data on children's sustained attention, impulsivity, and school readiness (i.e., cognitive, achievement, language, and social development) were obtained at 54 months of age, and quality of the family environment was assessed throughout the first 54 months. Mediation tests showed that children's sustained attention partially accounted for the link between family environment and achievement and language outcomes. Impulsivity partially accounted for the link between family environment and achievement, social competence, and externalizing behaviors. The roles of sustained attention and of inhibition of impulsive responding in the relation between family characteristics and school readiness are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
105.
本介绍了将氰化钠镀锌溶液转换为氯化钾镀锌溶液的镀锌工艺过程,从工艺、健康、环保、成本等方面进行阐述。  相似文献   
106.
叶玲玲 《安徽建筑》2007,14(4):9-10
时代赋予建筑可持续发展的概念,即有生命的建筑。建筑必须服从于总体空间环境,注重建筑的生态环境,重视建筑环境的物理条件,传承历史文脉,创作富有生命力的建筑作品。  相似文献   
107.
杭州湾跨海大桥在极其复杂的海洋环境下施工,外露钢筋极易腐蚀,锌加钢筋能提高钢筋的抗腐蚀能力,本文简介锌加防腐钢筋在大桥施工中的应用情况。  相似文献   
108.
The present paper aims to present a distant-learning training module that concerns the environmental design of urban buildings. The whole approach attempts to integrate topics that concern the design of urban buildings from various points of views, e.g. active and passive systems, automation systems, indoor air quality, economic aspects, energy and resources management. The package offers both printed and electronic material that gives the possibility to the students to study the various topics by using different educational methods. Additionally, the present package contains software tools that permit the students to examine real or hypothetical situations and to study further the influence of various parameters that concern the environmental building design.  相似文献   
109.
Ecological momentary assessment (EMA) consists of assessing phenomena in real time in the natural environment. EMA allows for more fine-grained analyses of addictive behavior and minimizes threats to internal validity, such as recall biases and errors. However, because of the intensive monitoring involved in EMA, measurement reactivity is a concern. To test whether EMA with palmtop personal computers induces reactivity, the authors compared smoking-related outcomes between smokers using EMA and those not using EMA during a quit attempt. The use of no-EMA control groups has been rare in reactivity investigations to date. The EMA protocol included event-contingent assessments (smoking episodes, urge episodes) and random assessments. Outcomes included biologically confirmed abstinence and self-report measures of withdrawal, self-efficacy, motivation, affect, and temptations. Participants were smokers motivated to quit (N = 96). They were randomized to 1 of 3 groups: EMA for the week preceding a planned quit date, EMA for the week following the quit date, and no EMA. Abstinence rates did not differ between the groups at Day 7 or at Day 28 postcessation. For the 20 subscales assessed at each of 3 assessment times, there were significant differences between participants with and without EMA experience for 3 subscales at the 1st of 3 assessment times, and significant differences for 3 different subscales at the 3rd assessment time. These differences suggest some reactivity to EMA, although the inconsistent pattern across time indicates that further research is needed to definitively conclude that EMA induces reactivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
110.
以乌海地区为例透视矿业环境问题   总被引:3,自引:2,他引:1  
以乌海地区为例,全面剖析了采矿对地质环境的破坏及其对生态、经济、社会带来的影响,旨在有助于社会对此问题严重性的认识,以便为区域可持续发展制定良策。  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