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   47297篇
  免费   2602篇
  国内免费   1272篇
电工技术   1443篇
技术理论   4篇
综合类   2801篇
化学工业   11811篇
金属工艺   6503篇
机械仪表   1197篇
建筑科学   6670篇
矿业工程   1631篇
能源动力   1073篇
轻工业   4195篇
水利工程   1833篇
石油天然气   1682篇
武器工业   147篇
无线电   843篇
一般工业技术   3487篇
冶金工业   4943篇
原子能技术   254篇
自动化技术   654篇
  2024年   165篇
  2023年   436篇
  2022年   1098篇
  2021年   1302篇
  2020年   1218篇
  2019年   864篇
  2018年   874篇
  2017年   1134篇
  2016年   1151篇
  2015年   1292篇
  2014年   2467篇
  2013年   2394篇
  2012年   3160篇
  2011年   3440篇
  2010年   2938篇
  2009年   3078篇
  2008年   2345篇
  2007年   3209篇
  2006年   3160篇
  2005年   2700篇
  2004年   2304篇
  2003年   2129篇
  2002年   1729篇
  2001年   1339篇
  2000年   1070篇
  1999年   818篇
  1998年   628篇
  1997年   509篇
  1996年   393篇
  1995年   381篇
  1994年   261篇
  1993年   199篇
  1992年   188篇
  1991年   151篇
  1990年   93篇
  1989年   122篇
  1988年   72篇
  1987年   66篇
  1986年   49篇
  1985年   46篇
  1984年   45篇
  1983年   36篇
  1982年   19篇
  1980年   6篇
  1979年   5篇
  1966年   9篇
  1965年   7篇
  1964年   9篇
  1959年   7篇
  1951年   4篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Reviews the book, Child sexual abuse: Critical perspectives on prevention, intervention, and treatment edited by Christopher R. Bagley and Ray J. Thomlison (1991). This book is a compilation of a series of literature reviews originally commissioned by Health and Welfare Canada in 1987 and completed in 1988. The individual papers included in this edited version represent a cross section of Canadian academicians, clinicians, and case workers who are integrally involved in the policies and practices regarding child sexual abuse in Canada. The work provides a comprehensive perspective on prevention at the primary, secondary, and tertiary levels. The list of authors is impressive in terms of their expertise and experience. At a time when numerous books on child sexual abuse are appearing on the market, it is nice to see a book that has some unusual aspects. Aside from its distinctly Canadian perspective, the book addresses several important, yet frequently ignored, topics. The book provides an up-to-date review of several core issues: conceptualization of the problem, prevention strategies, impact of sexual abuse, investigative interviewing, treatment outcome studies, and treatment issues for child molesters. The more unique topics include a review of the strategies used to evaluate prevention programs, prevalence rates among a number of special populations, the role of medical practitioners in preventing and intervening in child sexual abuse, and sexual abuse and exploitation among disabled individuals. Overall, I can recommend this book for clinicians and researchers in Canada and elsewhere who are interested in child sexual abuse. This compilation of literature reviews highlights the leading role that Canadian social service agencies have taken in developing programs for sexually abused children and their families. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
52.
本文简要介绍了国外在开发超酸性气体过程中遇到的材料选择、腐蚀监测、水化物堵塞、超酸性气的处理和加工等问题所采取的措施和办法。  相似文献   
53.
A new route to carbon nanotubes   总被引:3,自引:0,他引:3  
H Shioyama  T Akita 《Carbon》2003,41(1):179-181
  相似文献   
54.
55.
This paper describes the parameters that are important in the industrial practice of silver removal from photographic fixers. The experiments were performed under potentiostatic control using synthetic solutions. The current efficiency was analysed as a function of the cathodic potential taking into account the deposit quality. A cathodic potential of ?0.5 V against a saturated calomel electrode is recommended. The conditions to prevent the darkening of the electrodeposit were investigated. The determination of silver concentration in the solution was made by direct potentiometry. The results obtained with synthetic fixers were corroborated by making the silver deposition from commercial fixers in an electrochemical reactor with rotating cylinder electrode intercalated in an electrolytic flow circuit in order to simulate practical conditions.  相似文献   
56.
钱进 《现代铸铁》2003,1(6):53-55
K-9曲拐质量不合格主要是由于热处理后,珠光体数量太少所引起。因此应用正交试验,合理地选择了热处理工艺参数,提高了出炉温度,增加了珠光体数量,解决了K-9曲拐的质量问题。  相似文献   
57.
淀粉液化液灭酶方法的研究   总被引:5,自引:1,他引:4  
某些情况下淀粉液化液需要严格控制液化的程度 ,因此需要及时终止残余淀粉酶的活性。实验用降低液化液 pH值、升高温度、以及两者并用等 3种方法结束液化反应过程 ,实验结果可作为工业生产过程参考。  相似文献   
58.
Changes in maladaptive cognitions may constitute therapeutic processes of multidisciplinary pain programs. A cross-lagged panel design was used to determine whether (a) early-treatment cognitive change predicted late-treatment outcome index change, but not vice versa; and (b) these effects remained significant with depression change controlled. Ninety chronic pain patients, in a 4-week multidisciplinary program, completed measures of catastrophizing, pain helplessness, depression, pain, interference, and activity level at pre-, mid-, and posttreatment. With depression changes controlled, early-treatment catastrophizing and pain helplessness changes predicted late-treatment outcome index changes, but not vice versa; early-treatment depression changes predicted late-treatment activity changes, but not vice versa. Findings advance understanding of pain treatment process and suggest that negative cognition changes may indeed affect improvements in treatment outcome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
59.
提出了自动合成四方连续面料图案的数学模型;介绍了人机交互色彩调配算法;从数学模型、色彩处理、应用前景库三方面对有关设计思想和实现方法作了详细说明.  相似文献   
60.
介绍了引进VCM生产技术中,有关含汞污水的处理方法及在生产工艺上所采取的减少汞污染的措施,解决了催化剂的汞污染问题。  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