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   2306篇
  免费   96篇
  国内免费   58篇
电工技术   47篇
综合类   262篇
化学工业   174篇
金属工艺   31篇
机械仪表   233篇
建筑科学   139篇
矿业工程   11篇
能源动力   12篇
轻工业   135篇
水利工程   5篇
石油天然气   13篇
武器工业   7篇
无线电   80篇
一般工业技术   186篇
冶金工业   806篇
原子能技术   3篇
自动化技术   316篇
  2024年   5篇
  2023年   10篇
  2022年   38篇
  2021年   90篇
  2020年   42篇
  2019年   36篇
  2018年   29篇
  2017年   32篇
  2016年   35篇
  2015年   43篇
  2014年   80篇
  2013年   120篇
  2012年   91篇
  2011年   156篇
  2010年   137篇
  2009年   185篇
  2008年   163篇
  2007年   170篇
  2006年   159篇
  2005年   178篇
  2004年   126篇
  2003年   108篇
  2002年   88篇
  2001年   65篇
  2000年   27篇
  1999年   22篇
  1998年   13篇
  1997年   27篇
  1996年   13篇
  1995年   13篇
  1994年   16篇
  1993年   17篇
  1992年   11篇
  1991年   3篇
  1990年   12篇
  1989年   19篇
  1988年   12篇
  1987年   12篇
  1986年   9篇
  1985年   6篇
  1984年   2篇
  1979年   4篇
  1967年   3篇
  1966年   4篇
  1964年   3篇
  1963年   5篇
  1961年   2篇
  1956年   1篇
  1955年   2篇
  1954年   1篇
排序方式: 共有2460条查询结果,搜索用时 312 毫秒
101.
对我国家族企业面临的发展机遇及发展障碍进行分析,提出了我国家族企业要实现持续发展的变革要求、变革时间和变革建设。  相似文献   
102.
民宅作为传统建筑的重要形式 ,凝聚着厚重的传统伦理文化。我国传统民宅比较集中地体现了中国传统文化中独立与中庸 ;尊卑有序、男女有别 ;天人合一 ;整体主义 ;崇祖等伦理思想。只有考察凝结在传统建筑中的伦理观念与规范 ,才能更深入地认识和理解中国的民宅建筑 ,并进而寻求传统建筑的现代价值  相似文献   
103.
The authors examined the role of family factors and the course of schizophrenia by carrying out additional assessments and analyses in 2 previously published studies of Mexican American and Anglo American patients and families. The authors found partial support for an attributional model of relapse for families who are low in emotional overinvolvement. Attributions of control, criticism, and warmth together marginally predicted relapse. The data also indicated that for Mexican Americans, family warmth is a significant protective factor, whereas for Anglo Americans, family criticism is a significant risk factor. These findings suggest that the sociocultural context shapes the pathways by which family processes are related to the course of illness. Moreover, the warmth findings suggest that families may contribute to preventing relapse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
104.
Four years of longitudinal data from 373 families participating in a randomized intervention-control clinical trial were used to examine whether intervention effects on adolescent alcohol and tobacco use trajectories were moderated by family risk, as defined by parental social emotional maladjustment. Consistent with earlier outcome evaluations based on analyses of covariance, analyses confirmed that both the Preparing for the Drug Free Years program and the Iowa Strengthening Families Program favorably influenced alcohol use index trajectories across the time frame of the study; only the latter program, however, evidenced positive effects on a tobacco use index. Concerning the primary research question, analyses provided no support for family risk moderation of any intervention effect. Findings indicate the feasibility of developing universal preventive interventions that offer comparable benefits to all families. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
105.
Presents the obituary for Robert A. Harper (1915-2004). Dr. Harper is noted for his contributions to the field of psychotherapy, particularly to the areas of marriage, family, and sex therapy. In addition, his expertise, good nature, and no-nonsense style made him a popular figure amongst his peers, who elected him to leadership positions in numerous professional organizations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
106.
This study followed baseline samples of 424 unipolar depressed patients and 424 community controls across 10 years to investigate the association between depression and alcohol-related coping and to examine how life context vulnerabilities underlie the risk for depressed individuals to rely on drinking to cope. Findings supported all hypotheses. Depressed patients engaged in more drinking to cope than did community controls. Within individuals, more negative life events and less family support were associated with more drinking to cope across the 4 observations. Depressed patients experienced more negative life events and less family support than did community controls. These underlying life context vulnerabilities explained the relationship between depressed patient status and drinking to cope. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
107.
This longitudinal study examined the relations between multiple risk indexes representing contextual adversity, income-to-needs ratios, and the elementary school adjustment of children from economically disadvantaged families. The results provide evidence for volatility in family circumstances over 2-year intervals from preschool to 5th grade, for relations between the contextual risk indexes and change in externalizing behavior, and for relations between the income-to-needs ratios and change in academic competence. The results also show differences in the timing of the effects. Little evidence was found for persistence effects. Theoretical implications concern conceptualizations of the diverse and dynamic nature of the family circumstances experienced by disadvantaged children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
108.
Process capability indices are widely regarded as a flexible means of evaluating the quality and performance of a process. Accreditation by the Quality System Requirement QS9000 requires an agent to conduct a global evaluation on the process capability over the entire product family from a plant. Generally, the process capability of the whole product family is an important reference for evaluation when producing a new product or designing a new process. Therefore developing a scheme to evaluate the process capability of the whole product family or series is crucial for industry. This paper takes the production of capacitors as an example of a new method for evaluating the process capability of a whole product family. As the quality characteristic for producing capacitors is "the smaller the better", the upper specification limits of the capacitors of various specifications should first be established. The process capability index Cpu for products for which "smaller is better" is then used as an evaluation tool to calculate the process capability indices for individual specified products. The relationship between the process capability indices and the yield will be studied. A process capability index is proposed to reflect the global yield of the whole product family and to serve as a reference for evaluating process capability for designing new processes or developing new products. The process capabilities for all products can thus be evaluated and the performance of each process can be evaluated according to the colour management method. Managers can determine easily whether products meet their specifications and take action to improve them if necessary, according to the colour management method.  相似文献   
109.
面向大批量定制的产品族设计技术研究   总被引:3,自引:0,他引:3  
杜纲  张雪峰 《工具技术》2007,41(4):43-47
介绍了产品族与产品平台的概念和特征,分析了典型产品族的设计开发过程,提出了一种适合于大批量定制生产模式的产品族设计框架。分析并指出了目前产品族优化设计研究中的不足,提出了基于主从关联结构的层次优化设计理念以及实现这一理念的方法和模型框架,阐述了模型的学形式——模糊层次优化。  相似文献   
110.
《国际计算机数学杂志》2012,89(16):2274-2279
In this paper, we introduce a one-step iterative scheme for finding a common fixed point of a countable family of multivalued quasi-nonexpansive mappings in a real uniformly convex Banach space. We establish weak and strong convergence theorems of the proposed iterative scheme under some control conditions.  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