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   6588篇
  免费   5篇
电工技术   3篇
化学工业   29篇
机械仪表   1篇
建筑科学   6篇
能源动力   1篇
轻工业   23篇
水利工程   2篇
石油天然气   1篇
无线电   6篇
一般工业技术   10篇
冶金工业   6496篇
自动化技术   15篇
  2022年   6篇
  2019年   4篇
  2018年   1篇
  2017年   3篇
  2016年   1篇
  2015年   2篇
  2014年   3篇
  2013年   3篇
  2012年   3篇
  2011年   2篇
  2010年   4篇
  2009年   4篇
  2008年   1篇
  2007年   6篇
  2006年   4篇
  2005年   3篇
  2003年   11篇
  2002年   5篇
  2001年   6篇
  2000年   7篇
  1999年   159篇
  1998年   1929篇
  1997年   1137篇
  1996年   759篇
  1995年   390篇
  1994年   345篇
  1993年   390篇
  1992年   49篇
  1991年   101篇
  1990年   104篇
  1989年   90篇
  1988年   101篇
  1987年   87篇
  1986年   77篇
  1985年   59篇
  1984年   1篇
  1983年   13篇
  1982年   32篇
  1981年   48篇
  1980年   57篇
  1978年   27篇
  1977年   180篇
  1976年   350篇
  1975年   11篇
  1974年   1篇
  1973年   4篇
  1971年   2篇
  1955年   4篇
  1954年   3篇
  1913年   1篇
排序方式: 共有6593条查询结果,搜索用时 15 毫秒
991.
Phagocytic cells were obtained from children at ages comparable to those at which the disease is most commonly seen during pregnancy. The effect of P-HCl on the phagocytic action of these cells on opsonized red blood cells was studied in vitro.  相似文献   
992.
A child with truncus arteriosus communis, characterized by the posterior origin of an individualized pulmonary trunk is presented. This relationship between the great arteries is unusual in truncus arteriosus communis and the spatial orientation resembles that seen in transposition of the great vessels. A brief discussion is proposed about a proper terminology in this type of complex anomaly.  相似文献   
993.
994.
995.
996.
Primary breast lymphoproliferative disorders are rare lesions and include both the malignant lymphomas and the benign pseudolymphomas. We reviewed 4,491 consecutive cases of breast cancer diagnosed and treated between 1973 and 1988. Patients with lymphoma in other sites and those with lymphomas limited to axillary nodes were excluded. RESULTS. Five patients (0.11%) presented with primary lymphoreticular lesions, of which three were primary non-Hodgkin's lymphoma and two were pseudolymphomas. Patients were followed clinically through to the present time or until death occurred. Surgical procedures included incisional or excisional biopsy in four patients and modified radical mastectomy in one. Two patients received chemo-therapy and one received radiotherapy. One patient with pseudolymphoma subsequently developed infiltrating ductal carcinoma of the same breast. Three patients with primary breast non-Hodgkin's lymphoma died within the follow-up period, with a mean survival of 33 months. CONCLUSIONS. We conclude that primary breast lymphoma is a rare and aggressive breast malignancy with a poor prognosis despite different treatment options.  相似文献   
997.
Twenty-two male and 20 female adults with Down's syndrome were examined. Ten of the men and two of the women had a follicular rash consistent with Malassezia folliculitis. Oral itraconazole treatment produced a significant improvement in the rash, accompanied by a decrease in the skin Malassezia count. Clinical relapse occurred when therapy was discontinued, and was accompanied by return of the Malassezia yeasts.  相似文献   
998.
The rate and extent of dissolution of various approved marketed carbamazepine (CBZ) tablets exposed to 33, 52, 75, and 97% relative humidities at both room temperature and 40 degrees C, and saturated water vapor at room temperature were compared to fresh unstressed tablets. The dissolution data indicate that exposure of CBZ tablets to high humidity and temperature can have a profound effect on tablet disintegration and dissolution. The dissolution rates of some batches of CBZ products exposed to 97% humidity at 40 degrees C or saturated water vapor at room temperature were drastically reduced in only 6-7 days.  相似文献   
999.
1000.
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