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   934383篇
  免费   67758篇
  国内免费   1391篇
耳鼻咽喉   13001篇
儿科学   24425篇
妇产科学   23274篇
基础医学   133320篇
口腔科学   28289篇
临床医学   80783篇
内科学   184391篇
皮肤病学   19261篇
神经病学   72414篇
特种医学   36950篇
外国民族医学   79篇
外科学   152784篇
综合类   18051篇
现状与发展   1篇
一般理论   235篇
预防医学   61827篇
眼科学   21367篇
药学   72872篇
  3篇
中国医学   2170篇
肿瘤学   58035篇
  2018年   9036篇
  2017年   7080篇
  2016年   7856篇
  2015年   8948篇
  2014年   12115篇
  2013年   17620篇
  2012年   24280篇
  2011年   25267篇
  2010年   14935篇
  2009年   14390篇
  2008年   24834篇
  2007年   25910篇
  2006年   26698篇
  2005年   25641篇
  2004年   24756篇
  2003年   23819篇
  2002年   23350篇
  2001年   54821篇
  2000年   56630篇
  1999年   47041篇
  1998年   10781篇
  1997年   9493篇
  1996年   9619篇
  1995年   8956篇
  1994年   8304篇
  1993年   7607篇
  1992年   35532篇
  1991年   33955篇
  1990年   32782篇
  1989年   31924篇
  1988年   29014篇
  1987年   28298篇
  1986年   26318篇
  1985年   25184篇
  1984年   17867篇
  1983年   15160篇
  1982年   7807篇
  1981年   6782篇
  1979年   15799篇
  1978年   10610篇
  1977年   9061篇
  1976年   7878篇
  1975年   8634篇
  1974年   10474篇
  1973年   9870篇
  1972年   9366篇
  1971年   8857篇
  1970年   8434篇
  1969年   7930篇
  1968年   7211篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
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   
995.
996.
997.
998.
999.
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   
1000.
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   
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