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   11678篇
  免费   1060篇
  国内免费   696篇
电工技术   499篇
技术理论   11篇
综合类   1791篇
化学工业   585篇
金属工艺   184篇
机械仪表   225篇
建筑科学   3819篇
矿业工程   261篇
能源动力   126篇
轻工业   583篇
水利工程   309篇
石油天然气   186篇
武器工业   51篇
无线电   806篇
一般工业技术   747篇
冶金工业   881篇
原子能技术   62篇
自动化技术   2308篇
  2024年   63篇
  2023年   203篇
  2022年   344篇
  2021年   404篇
  2020年   397篇
  2019年   314篇
  2018年   278篇
  2017年   345篇
  2016年   348篇
  2015年   383篇
  2014年   890篇
  2013年   825篇
  2012年   787篇
  2011年   910篇
  2010年   720篇
  2009年   746篇
  2008年   762篇
  2007年   790篇
  2006年   744篇
  2005年   612篇
  2004年   490篇
  2003年   389篇
  2002年   351篇
  2001年   244篇
  2000年   200篇
  1999年   168篇
  1998年   103篇
  1997年   93篇
  1996年   71篇
  1995年   52篇
  1994年   56篇
  1993年   48篇
  1992年   32篇
  1991年   28篇
  1990年   38篇
  1989年   32篇
  1988年   24篇
  1987年   6篇
  1986年   9篇
  1985年   10篇
  1984年   11篇
  1983年   10篇
  1982年   13篇
  1980年   6篇
  1966年   7篇
  1965年   6篇
  1964年   7篇
  1958年   5篇
  1957年   9篇
  1956年   5篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Despite the universal and understandable distress associated with the death of a child from pediatric illness, do psychologists help surviving families in ways that match their need for assistance? Many families do not seek psychological help and cope adaptively with their loss. Indications for psychotherapy with bereaved families are based largely on experience with families who engage in treatment and who have greater distress. Other families may not receive sufficient services but are at risk for ongoing difficulties and unlikely to engage in treatment. Suggestions for intervention are made, with attention to the fit of therapeutic approaches with family needs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
12.
Based on the principle of annexation and phase diagrams, the structural units of In-Pb-Sb and In-Bi-Pb melts were determined, and their calculating models of mass action concentrations were formulated. Calculated results agree well with practical values, which in turn show that the models deduced can reflect the structural realities of corresponding melts and the principle of annexation is applicable not only to some binary metallic melts, but also to ternary metallic melts.  相似文献   
13.
钢筋混凝土圆形水池裂缝分析与处理   总被引:1,自引:0,他引:1  
本文针对某钢筋混凝土圆形水池在使用过程中出现的裂缝进行计算和分析,讨论了温度对水池的影响,特别是考虑储水区与非储水区存在温差的条件对水池池壁裂缝的影响,并提出处理方案。  相似文献   
14.
构造作用对油气生成和运聚的影响   总被引:3,自引:2,他引:1  
有机质从埋藏开始,就处于极其复杂的地球物理化学场中,环境提的能量,一是热量,二是机械能,机械能,主要是通过机械力作用传递给系统的,另外还以机械波的形式赋予系统一定的机械能。当发生断褶构造运动时,机械力对油气运移的影响尤为突出,它经能量的迁移转化,促成了包括机械力降解和地应力驱动等一系列的连锁反应,制造了一次次高效的成油(生运)事件,本文以突变论为着眼点,按照改造控制建造的思路,大胆提出构造运动制造生排烃事件,成就含油气系统的假说。  相似文献   
15.
隔震结构在省防震减灾中心大楼工程中的应用   总被引:2,自引:1,他引:1  
结合工程实例介绍了隔震结构在工程设计中的应用  相似文献   
16.
咸味米粥增稠稳定剂的研究   总被引:1,自引:0,他引:1  
以粘度和悬浮时间这两项指标作为性能评价指标,对常见的几种增稠稳定剂进行复配增效实验的研究评价,筛选出一种高粘度的复合增稠稳定剂,应用于咸味米粥罐头中,有效解决了咸味米粥罐头分层、稳定性能差的难题。  相似文献   
17.
Presents an obituary for Nicholas Hobbs. Just at the end of his stellar career of public service through psychology, Nick Hobbs received very appropriate honors showing that psychologists and many others knew what a precious national resource his life had been. Only days before his death from cancer on January 23, 1983, he participated in the dedication of the Nicholas Hobbs Laboratory of Human Development of the Peabody College for Teachers of Vanderbilt University, part of the Kennedy Center for Research on Education and Human Development that he founded and directed at its beginning. Two years earlier, he had received two parallel American Psychological Association (APA) awards--one for Distinguished Contributions to Psychology in the Public Interest and another for Distinguished Professional Contributions "utilizing psychological knowledge in the public interest and social policy." As the citations and testimonials on these occasions variously noted, Nick gave creative, responsible, and effective service to the institutions that he helped administer, to the Southern region from which he sprang, to the APA, and to the profession of psychology, but above all to the nation's children and youth, especially those who grew up with disadvantage and difficulty. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
18.
Stereotype threat research has demonstrated that stereotypes can harm student performance in the face of public evaluation by peers or an experimenter. The current study examined whether stereotypes can also threaten in private settings. Female students completed a math test in 3-person groups, which consisted of either 2 other women (same gender) or 2 men (minority). In addition, students either believed their performance would be broadcasted to their peers (public) or not (private). Results revealed that minority students performed worse than same-gender students in both public and private environments. This finding supports the concept of threatening intellectual environments and shows how far reaching the effects of stereotypes can be. The authors discuss these findings in relation to research on tokenism and to stereotype threat and its educational implications. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
19.
高压线走廊下建设大型公共绿地的探索   总被引:2,自引:0,他引:2  
通过闵行经济技术开发区范围内高压线走廊下的40万m~2非生产性用地建设成大型公共绿地的实践,提出了“以绿养园,以园养园”的新思路,充分体现“谁种养,谁保护,谁得益”的原则,给上海地区乃至全国开发利用高压线走廊下的土地资源,提供了借鉴。  相似文献   
20.
This paper presents an approach of measuring in real-time the vector of finger that is pointing to an object. DSP is used in the operation processing unit in order to do the real-time processing. The steps include the extraction of flesh-colored regions from an image, the labeling of the flesh-colored regions, and the detection of two characteristic positions on the finger so that the direction that the finger is pointing at will be calculated. The entire process takes about 29 msec, which makes it possible to have the frame rate of 34 fps. With this frame rate, this measurement approach is considered real-time and promising to be merged into other application systems. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008  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