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   116390篇
  免费   5933篇
  国内免费   138篇
耳鼻咽喉   1784篇
儿科学   5229篇
妇产科学   3936篇
基础医学   16128篇
口腔科学   2848篇
临床医学   8331篇
内科学   22046篇
皮肤病学   3358篇
神经病学   8984篇
特种医学   5048篇
外国民族医学   32篇
外科学   19050篇
综合类   1614篇
一般理论   29篇
预防医学   5846篇
眼科学   3397篇
药学   8066篇
中国医学   324篇
肿瘤学   6411篇
  2018年   897篇
  2017年   778篇
  2016年   1091篇
  2015年   1227篇
  2014年   1610篇
  2013年   2370篇
  2012年   3107篇
  2011年   3152篇
  2010年   1979篇
  2009年   1941篇
  2008年   3262篇
  2007年   3496篇
  2006年   3640篇
  2005年   3756篇
  2004年   3706篇
  2003年   3566篇
  2002年   3521篇
  2001年   7027篇
  2000年   6964篇
  1999年   5869篇
  1998年   1626篇
  1997年   1561篇
  1996年   1335篇
  1995年   1203篇
  1994年   1093篇
  1993年   1121篇
  1992年   3768篇
  1991年   3584篇
  1990年   3569篇
  1989年   3356篇
  1988年   2988篇
  1987年   2905篇
  1986年   2809篇
  1985年   2627篇
  1984年   1948篇
  1983年   1599篇
  1982年   930篇
  1981年   917篇
  1980年   765篇
  1979年   1826篇
  1978年   1347篇
  1977年   1115篇
  1976年   936篇
  1975年   1184篇
  1974年   1215篇
  1973年   1204篇
  1972年   1045篇
  1971年   977篇
  1970年   890篇
  1969年   788篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Fire fighter helmet ventilation analysis   总被引:1,自引:0,他引:1  
A series of wind tunnel tests was conducted on selected fire fighter helmets to identify design factors which affect helmet ventilation at various air velocities and head orientation angles. Biomedical heat flux transducers were mounted on the surface of an electrically heated mannequin head to monitor convective heat loss. Under the experimental conditions, specific helmet design features were identified which can contribute to improved helmet ventilation and thus improve body metabolic heat loss. Attention to helmet design and helmet suspension systems is recommended to reduce fire fighter heat stress.  相似文献   
52.
53.
54.
55.
Presented in this work is a rare injury of a blunt abdominal trauma in a child. Besides a partial rupture of the kidney and a retro-/intraperitoneal haematoma, a further injury occurred from the accident: an initially clinically indetectable tear of the A. iliaca communis which was found intraoperatively and with systematic CT analysis. Traumatic blood vessel lesions of the abdominal aorta and in particular the iliac blood vessels are very rare in children. By such violent impact injuries, it is therefore vital to perform a clinical examination of the foot pulse, systematic analysis of radiology diagnostics, and intraoperative exploration. The growth phase should be considered for therapy of the blood vessels depending on the child's age group. As the long-term results of graft implants are practically unknown, if possible a primary suture or vein patch should be performed.  相似文献   
56.
57.
By oxygen concentration measurements (Oximeter Oxydig Dräger, Lübeck) in the EC 145 helicopter two oxygen transport and application systems were compared. The new liquid oxygen system (LOX) for the oxygen therapy was assessed in an application observation. For physical reasons fluid oxygen evaporates during the stand-by phase and an increased concentration (22.8% O2) in the exhaust valve of LOX arises. On the other hand a high oxygen concentration (22.7% O2) was measured in the operation mode of the conventional pressure flask gas system (GAS). No increased concentration could be measured within the helicopter cabin (HEMS, PAX) comparing both oxygen systems. For transport and application of oxygen with a very big reserve for the air dependent intensive transport the results show that LOX is a sure low pressure system (3.4 bar).  相似文献   
58.
59.
P Hildebrand  U J Roblick  R Keller  M Kleemann  L Mirow  H-P Bruch 《Der Chirurg》2007,78(6):494, 496-494, 500
Minimizing the access trauma of surgical interventions is becoming an essential task in modern surgery in order to make the treatment more comfortable for the patient. Minimally invasive surgery has had a major impact on the improvement of surgical results over the last decade. This is why such surgery is often named as the third patient friendly revolution in surgery after the introduction of asepsis and anesthesia. Operations that caused a huge strain on the patients in the past and led to immense costs for society because of the patient's lost working time and extensive rehabilitation, have lost their fear thanks to this technique. The physical strain is lower, the cosmetic effect is considerable and the costs for society might be reduced due to the significantly shorter duration of convalescence.Despite its known advantages, which have been reported in numerous studies, minimally invasive surgery has recently gained increased interest because of the installation of new accounting systems as well as strict budgeting and restricted resources.Realistic cost-benefit analysis and objectified quality controls are needed in order to guarantee innovative and patient friendly basic approaches in medicine in the future.  相似文献   
60.
The ability of 12 new thiazole derivatives to influence the muscle contractility mediated by purine P2X receptors has been studied in vitro using isolated tissues of rats and guinea pigs. Most of the synthesized compounds did not cause significant effects, but two compounds exhibited pronounced antagonism with respect to P2X-mediated contractility response. These compounds offer a good starting point for the synthesis of new effective antagonists of P2 receptors. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 6, pp. 22 – 25, June, 2005.  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