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   930152篇
  免费   67582篇
  国内免费   1340篇
耳鼻咽喉   12954篇
儿科学   24361篇
妇产科学   23231篇
基础医学   132852篇
口腔科学   28249篇
临床医学   80442篇
内科学   183106篇
皮肤病学   19226篇
神经病学   72140篇
特种医学   36798篇
外国民族医学   79篇
外科学   152097篇
综合类   18045篇
现状与发展   1篇
一般理论   234篇
预防医学   61661篇
眼科学   21293篇
药学   72512篇
  3篇
中国医学   2162篇
肿瘤学   57628篇
  2018年   8968篇
  2017年   7027篇
  2016年   7761篇
  2015年   8864篇
  2014年   11993篇
  2013年   17495篇
  2012年   24084篇
  2011年   25038篇
  2010年   14804篇
  2009年   14268篇
  2008年   24599篇
  2007年   25697篇
  2006年   26479篇
  2005年   25430篇
  2004年   24569篇
  2003年   23611篇
  2002年   23159篇
  2001年   54726篇
  2000年   56549篇
  1999年   46956篇
  1998年   10734篇
  1997年   9466篇
  1996年   9596篇
  1995年   8926篇
  1994年   8283篇
  1993年   7593篇
  1992年   35493篇
  1991年   33921篇
  1990年   32738篇
  1989年   31871篇
  1988年   28994篇
  1987年   28251篇
  1986年   26289篇
  1985年   25146篇
  1984年   17836篇
  1983年   15144篇
  1982年   7795篇
  1981年   6773篇
  1979年   15781篇
  1978年   10599篇
  1977年   9057篇
  1976年   7872篇
  1975年   8628篇
  1974年   10466篇
  1973年   9858篇
  1972年   9357篇
  1971年   8852篇
  1970年   8426篇
  1969年   7923篇
  1968年   7200篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
991.
992.
993.
In-flight encounters with hazardous weather represent one of the most significant safety issues in civil aviation operations. Aircrew judgment is often cited as the probable cause of incidents and accidents involving weather, although lack of information is also a factor. The present study examines how information, presented at different times and in different forms, affects the awareness and decision-making behavior of aircrews in a flight simulation study of a recent microburst/windshear incident. In order to examine the influence of enhanced information transfer on aircrew behavior, intracrew communications and approach-to-land decisions were evaluated with conventional ATC communications and with automated cockpit alerting and display of weather information. Results of the study revealed that aircrews provided only with conventional ATC transmissions of weather information had difficulty discriminating conditions conducive to microburst events from less hazardous windshear events. Improved situation awareness for microburst events was found when ground-based convective weather information was provided in real time to aircrews. Avoidance decision-making was found to be less efficient with conventional ATC alert transmissions when compared to the performance of crews provided with a visual display of microburst events. The importance of information transfer on aircrew situation awareness and decision-making in hazardous weather avoidance is discussed.  相似文献   
994.
995.
996.
997.
998.
The presented report is fibrosarcoma arising from renal capsule in a 64-year-old woman. The tumor is very rare and is the 25th case in Japan. The patient visited our hospital with the complaint of macroscopic hematuria for several days. Abdominal examination revealed a painless lump from the left lumbar region to para-median abdomen. A diagnosis of hydronephrosis caused by neoplasma or tuberculosis was considered by CT, AG, etc., and transperitoneal nephrectomy was performed on 6-July-1984. Pathology of the tumor was fibrosarcoma arising from the renal capsule. Three months later, the tumor was growing on the peritoneal surface from the left renal region and she died on Nov. 10, 1984.  相似文献   
999.
Priapism: a refined approach to diagnosis and treatment   总被引:4,自引:0,他引:4  
The recent introduction of intracorporeal injections of papaverine and phentolamine for the diagnosis and treatment of impotence has resulted in an increased incidence of iatrogenic priapism. Based on our research into penile hemodynamics we propose a refined approach to all types of priapism. Intracorporeal blood gas and pressure monitoring should be used to differentiate ischemic (low flow) from nonischemic (high flow) types. Most cases of papaverine-induced or phentolamine-induced priapism will respond to aspiration alone or in combination with intracorporeal instillation of a diluted alpha-adrenergic agent. In spontaneous priapism alpha-adrenergic agents can be tried first if patients have only mild or no ischemia. In patients with severe ischemia stagnant blood should be evacuated and a shunt procedure should be performed to allow metabolic replenishment of tissue. Intracorporeal pressure monitoring will help to determine the size and number of shunts needed to re-establish corporeal circulation.  相似文献   
1000.
The technique and use of a percutaneous subclavian vein catheter for haemodialysis in 20 patients are reported. The catheterization procedure carried a very low morbidity, and blood flow rates of 200–250ml/min were achieved through the catheters. Use of this angioaccess saves future possible sites for permanent vascular access. Infectious complications were not encountered. Subclavian vein catheterization is a favourable alternative to external Silastic Teflon shunt.  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