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   3228篇
  免费   79篇
  国内免费   3篇
电工技术   39篇
综合类   1篇
化学工业   432篇
金属工艺   53篇
机械仪表   53篇
建筑科学   98篇
矿业工程   7篇
能源动力   40篇
轻工业   341篇
水利工程   16篇
石油天然气   6篇
无线电   215篇
一般工业技术   439篇
冶金工业   1136篇
原子能技术   17篇
自动化技术   417篇
  2022年   20篇
  2021年   33篇
  2020年   36篇
  2019年   42篇
  2018年   37篇
  2017年   41篇
  2016年   37篇
  2015年   33篇
  2014年   52篇
  2013年   137篇
  2012年   89篇
  2011年   118篇
  2010年   92篇
  2009年   85篇
  2008年   110篇
  2007年   117篇
  2006年   100篇
  2005年   76篇
  2004年   76篇
  2003年   73篇
  2002年   77篇
  2001年   50篇
  2000年   60篇
  1999年   80篇
  1998年   278篇
  1997年   185篇
  1996年   126篇
  1995年   76篇
  1994年   78篇
  1993年   88篇
  1992年   40篇
  1991年   35篇
  1990年   31篇
  1989年   42篇
  1988年   30篇
  1987年   29篇
  1986年   32篇
  1985年   40篇
  1984年   26篇
  1983年   31篇
  1982年   39篇
  1981年   34篇
  1980年   37篇
  1979年   26篇
  1978年   22篇
  1977年   27篇
  1976年   49篇
  1975年   24篇
  1973年   13篇
  1963年   13篇
排序方式: 共有3310条查询结果,搜索用时 281 毫秒
11.
The shortage of suitable liver donors for children has motivated the use of ABO-incompatible (ABO-I) grafts for transplantation in urgent situations. However, survival after ABO-I liver grafts has been reported at about 30% as compared with 80% in cases of ABO-identical or -compatible liver grafts. This difference has been attributed to antibody-mediated, hyperacute or chronic liver rejection, due to preformed ABO antibodies (alloantibodies). In this study, we report our results with ABO-I livers in children without alloantibodies at the time of transplantation. From January 1988 to June 1993, 143 OLT were performed in 122 children. Eight children received 8 ABO-I liver grafts. Of these, 7 patients were included in the study. All 7 were alloantibody free before OLT. Five children were spontaneously alloantibody free, while in 2 children, the plasma alloantibodies were eliminated before and after transplantation using intravenous infusion of specific blood group antigens of the donor blood group (soluble antigens). Immunosuppression consisted of a triple-drug treatment combining CsA, AZA, and steroids. The follow-up period was between 10 and 48 months. One child died from a surgical complication. Six children survived, but 1 died 10 months later from intestinal obstruction. There were no graft losses and no episodes of hyperacute or chronic rejection. The graft and patient survival rate was 71%. There was a 28% incidence of rejection, but all were mild (requiring steroid boluses only). Our results suggest that the absence of ABO alloantibodies at the time of and after transplantation can protect ABO-I liver grafts against antibody-mediated rejection, whether hyperacute or chronic, and that soluble antigens are effective in eliminating alloantibodies in children.  相似文献   
12.
The retiring editor of the Journal of Family Psychology (1997-2003) offers final thoughts on the passing on of the editorship and extends thanks to journal associates. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
13.
14.
Two studies identified and labeled the dimensions that people use to judge others' attitudes. In the 1st study, 50 male and 50 female undergraduates viewed pairs of attitude statements drawn from 1 or 2 large sets. For each pair of statements, Ss judged whether or not a person who agreed with one statement in the pair would be likely to agree with the other. The dimensions of liberalism and traditional values were found to underlie perceived attitudes. Validity was confirmed in a 2nd study with 60 male and 60 female undergraduates who rated the characteristics of hypothetical people who agreed strongly with particular statements. Results suggest that there is a common structure to people's perceptions of others' attitudes. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
15.
16.
Examines, in the context of cancer illness, S. E. Taylor and J. D. Brown's (see record 1988-16903-001) claim that mental health is to a degree predicated on illusory beliefs about the self, one's control, and the future. The Heroic Model (HM), a stance toward cancer characterized by belief that positive thoughts and feelings, a fighting spirit, and an optimistic outlook will promote cancer remission, is presented as paradigmatic of Taylor and Brown's thesis. Strong and weak formulations of the HM (the former affirming a direct influence of mental states over physical processes, and the latter affirming indirect effects only) are examined with respect to their potential adaptive value as true or false beliefs, with different consequences for well-being. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
17.
18.
19.
Comments on an article by T. R. Elliott and E. K. Byrd (see record 1987-23075-001), in which the authors conducted a citation analysis of articles in Rehabilitation Psychology, Volumes 27-29. They claimed to identify influential authors and publications useful for training and research in rehabilitation psychology. Their method of citation analysis, however, appears to have distorted their results. Crisp discusses the problems with their methodology, and makes suggestions for using a different citation method, using more than three volumes of the journal, and including other journals in the analysis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
20.
Broadband dielectric measurements (10 -2 to 3 GHz) are reported on the effects of exposure of thick film adhesive-bonded structures to moisture. Measurement of the dielectric properties over a broad frequency range allows identification of water both in voids and as a molecular dispersion in the matrix. Changes in the low frequency region of the dielectric spectrum can be attributed to a combination of processes associated with plasticisation of the adhesive, interfacial polarisation effects, and hydration of the surface oxide layer. The data obtained are complemented by mechanical testing and failure analysis of the bond structure measured as a function of the time of exposure. This study indicates that for thick film adhesives the ageing characteristics are apparently independent of the surface treatment. In one of the joints studied an additional feature is identified which appears to correlate with the premature aging of the joint structure.  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