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   8710篇
  免费   3篇
  国内免费   1篇
电工技术   6篇
综合类   5篇
化学工业   48篇
金属工艺   11篇
机械仪表   2篇
建筑科学   6篇
能源动力   1篇
轻工业   26篇
水利工程   1篇
石油天然气   3篇
武器工业   1篇
无线电   30篇
一般工业技术   17篇
冶金工业   8530篇
原子能技术   2篇
自动化技术   25篇
  2020年   3篇
  2016年   5篇
  2014年   4篇
  2013年   10篇
  2012年   4篇
  2011年   3篇
  2010年   11篇
  2009年   7篇
  2008年   11篇
  2007年   12篇
  2006年   17篇
  2005年   13篇
  2004年   14篇
  2003年   21篇
  2001年   7篇
  2000年   8篇
  1999年   279篇
  1998年   2706篇
  1997年   1498篇
  1996年   958篇
  1995年   553篇
  1994年   427篇
  1993年   529篇
  1992年   63篇
  1991年   104篇
  1990年   103篇
  1989年   91篇
  1988年   98篇
  1987年   93篇
  1986年   100篇
  1985年   70篇
  1984年   3篇
  1983年   14篇
  1982年   41篇
  1981年   43篇
  1980年   81篇
  1979年   3篇
  1978年   13篇
  1977年   188篇
  1976年   443篇
  1975年   13篇
  1974年   3篇
  1972年   3篇
  1971年   4篇
  1970年   5篇
  1967年   3篇
  1964年   3篇
  1963年   3篇
  1955年   8篇
  1924年   3篇
排序方式: 共有8714条查询结果,搜索用时 15 毫秒
131.
132.
133.
134.
The purpose of this study was to investigate self-disclosure, emotion-focused, and problem-focused coping styles among men with borderline hypertension and two groups of normotensive men differentiated by parental hypertension. Because blood pressure reactivity may discriminate between hypertensive and normotensive men, subjects in these three groups were categorized as high or low cardiovascular reactors based on their blood pressure response to a mental arithmetic task. Self-disclosure and coping styles were investigated in relation to status effects within the doctor-patient relationship. Men with exaggerated blood pressure reactivity were less self-disclosive and used fewer emotion-focused coping strategies than men with no blood pressure reactivity. Normotensives with a history of parental hypertension were less self-disclosive than normotensives without a history of parental hypertension.  相似文献   
135.
To determine the extent to which published randomized controlled trials (RCTs) of psychotherapy can be generalized to a sample of community outpatients, the authors used a method of matching information obtained from outpatient charts to inclusion and exclusion criteria from published RCT studies. They found that 80% of the patients in their sample who had diagnoses represented in the RCT literature were judged eligible for at least 1 published RCT; however, 58% of the patients had primary diagnoses such as adjustment disorder or dysthymia, which were not represented in the existing psychotherapy outcome literature. The most common reasons that patients in their sample did not match with published RCTs for psychotherapy are listed, and the implications of these findings for research and practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
136.
Data from 296 sibling pairs (mean ages 10 and 13 years), their primary caregivers, and census records were used to test the hypothesis that African American children's likelihood of developing conduct problems associated with harsh parenting, a lack of nurturant-involved parenting, and exposure to an older sibling's deviance-prone attitudes and behavior would be amplified among families residing in disadvantaged neighborhoods. A latent construct representing harsh-inconsistent parenting and low levels of nurturant-involved parenting was positively associated with younger siblings' conduct disorder symptoms, as were older siblings' problematic attitudes and behavior. These associations were strongest among families residing in the most disadvantaged neighborhoods. Future research and prevention programs should focus on the specific neighborhood processes associated with increased vulnerability for behavior problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
137.
138.
139.
140.
Animals with spontaneous mutations affecting myelin formation have provided useful information about the genetic and cellular mechanisms regulating normal and abnormal myelination. In this paper we describe a novel murine mutation termed hindshaker (hsh), which is inherited in an autosomal recessive manner. Affected mice are characterised by a variable tremor of the hind end which commences at about 2 weeks of age and largely disappears in animals older than 6 weeks. There is hypomyelination affecting predominantly the spinal cord, although the optic nerves and brain are involved to a much lesser degree. The defect of thinly myelinated and naked axons is maximal at 20 days of age and largely resolves with time so that in the adult most axons are myelinated. The myelin structure appears normal and immunostains for the major proteins. Although the distribution of oligodendrocytes in the spinal cord is similar to normal during the period of hypomyelination, there are fewer mature cells. The hsh mutation appears to delay the maturation of oligodendrocytes, particularly in the spinal cord. Additionally, there is a considerable variation in phenotypic expression and in penetrance when the mutation is expressed on different genetic backgrounds, suggesting the hsh locus is subject to the influence of modifying gene(s). Identification of the hsh gene should identify a factor important in the development of oligodendrocytes, particularly those in the spinal cord.  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