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   1917篇
  免费   1篇
  国内免费   1篇
电工技术   1篇
化学工业   13篇
金属工艺   4篇
建筑科学   15篇
矿业工程   2篇
轻工业   7篇
水利工程   1篇
无线电   15篇
一般工业技术   7篇
冶金工业   1845篇
自动化技术   9篇
  2023年   1篇
  2021年   1篇
  2020年   2篇
  2019年   2篇
  2018年   2篇
  2017年   1篇
  2015年   1篇
  2014年   2篇
  2013年   1篇
  2012年   1篇
  2011年   2篇
  2010年   2篇
  2009年   3篇
  2008年   3篇
  2007年   5篇
  2006年   3篇
  2005年   4篇
  2004年   5篇
  2003年   5篇
  2002年   2篇
  2001年   4篇
  2000年   2篇
  1999年   52篇
  1998年   617篇
  1997年   321篇
  1996年   228篇
  1995年   106篇
  1994年   96篇
  1993年   107篇
  1992年   12篇
  1991年   22篇
  1990年   23篇
  1989年   37篇
  1988年   28篇
  1987年   17篇
  1986年   24篇
  1985年   35篇
  1984年   1篇
  1983年   2篇
  1982年   5篇
  1981年   4篇
  1980年   16篇
  1979年   1篇
  1978年   3篇
  1977年   33篇
  1976年   69篇
  1975年   3篇
  1955年   3篇
排序方式: 共有1919条查询结果,搜索用时 15 毫秒
61.
62.
Smith-Magenis syndrome (SMS), caused by del(17)p11.2, represents one of the most frequently observed human microdeletion syndromes. We have identified three copies of a low-copy-number repeat (SMS-REPs) located within and flanking the SMS common deletion region and show that SMS-REP represents a repeated gene cluster. We have isolated a corresponding cDNA clone that identifies a novel junction fragment from 29 unrelated SMS patients and a different-sized junction fragment from a patient with dup(17)p11.2. Our results suggest that homologous recombination of a flanking repeat gene cluster is a mechanism for this common microdeletion syndrome.  相似文献   
63.
A 22-year-old Chinese man, a HBsAg carrier, presented with relapse of thyrotoxic Graves' disease complicated by thrombocytopenia and hepatitis. Platelet count and liver enzymes gradually improved following successful treatment of the thyrotoxicosis with radioactive iodine. Possible pathogenetic links and therapeutic implications are discussed.  相似文献   
64.
65.
To test the null hypothesis that limb dominance (laterality) and side of complaint are not associated in a diverse population, nearly 400 patients (40% male, 60% female) of varying age and body size from three South Florida podiatric medical teaching facilities were surveyed in 1995-1996. Radiographs of feet were available for 15% of the patients, and the metatarsus adductus angle was measured on each x-ray. The typical patient was a women (median age, 49 years) of average body weight and average body-mass index. No statistical association was found between laterality and side of complaint in the broader sample, although a significant association did appear in the subsample of patients with bilateral x-rays. The prevalence of metatarsus adductus deformity (metatarsus adductus angle > 15 degrees) among patients with x-rays was 62%. No sex-specific, age-specific, or body size-specific associations were found between handedness and metatarsus adductus deformity.  相似文献   
66.
67.
68.
Lesions of the oral mucosa are frequently described in association with psoriasis, particularly in the pustular type. Controversy surrounds the question whether mucosal lesions can be considered as oral manifestation of psoriasis. Two patients presented with concurrent pustular psoriasis and mucosal lesions with the characteristic picture of geographic tongue. Histopathology of the mucosa showed typical features of psoriasis such as marked acanthosis, clubbing of the rete ridges, focal parakeratosis and neutrophilic infiltrates. There was parallel improvement of the skin and the mucosal lesions with systemic retinoid treatment. On the basis of the histopathological features and the clinical course we favour the hypothesis that geographic tongue is an oral manifestation of pustular psoriasis.  相似文献   
69.
70.
We describe a female stillbirth with duplication of 3q21-->qter and deletion of 11q23-->qter resulting from an unbalanced segregation of a maternal t(3;11) reciprocal translocation. The proband had some of the clinical features consistent with those seen in patients with dup(3q) syndrome or distal del(11q) syndrome. Prenatal sonographic examination showed short limbs, intrauterine growth retardation, and an omphalocele containing the liver.  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