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   4936925篇
  免费   393427篇
  国内免费   15630篇
耳鼻咽喉   69267篇
儿科学   158434篇
妇产科学   130409篇
基础医学   742253篇
口腔科学   137362篇
临床医学   455011篇
内科学   902978篇
皮肤病学   117285篇
神经病学   414522篇
特种医学   193707篇
外国民族医学   968篇
外科学   741182篇
综合类   139001篇
现状与发展   24篇
一般理论   2810篇
预防医学   411955篇
眼科学   115969篇
药学   352359篇
  25篇
中国医学   13004篇
肿瘤学   247457篇
  2021年   57199篇
  2019年   59567篇
  2018年   76413篇
  2017年   58267篇
  2016年   64709篇
  2015年   77110篇
  2014年   111646篇
  2013年   177470篇
  2012年   141069篇
  2011年   149016篇
  2010年   131334篇
  2009年   131247篇
  2008年   134184篇
  2007年   144055篇
  2006年   151550篇
  2005年   145678篇
  2004年   146476篇
  2003年   136262篇
  2002年   124892篇
  2001年   197331篇
  2000年   194288篇
  1999年   174364篇
  1998年   75901篇
  1997年   70619篇
  1996年   68788篇
  1995年   64370篇
  1994年   58198篇
  1993年   54018篇
  1992年   128603篇
  1991年   123422篇
  1990年   118843篇
  1989年   115412篇
  1988年   106288篇
  1987年   104351篇
  1986年   98442篇
  1985年   95854篇
  1984年   77816篇
  1983年   68475篇
  1982年   51642篇
  1981年   47726篇
  1980年   44736篇
  1979年   67699篇
  1978年   53062篇
  1977年   46618篇
  1976年   43259篇
  1975年   44064篇
  1974年   49002篇
  1973年   46938篇
  1972年   43932篇
  1971年   40630篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Cancer Causes & Control - Congenital malformations are strong risk factors for childhood cancer. Our objective was to determine whether cancer survival differs by birth defect status among...  相似文献   
83.
European Surgery - Treatment of pilonidal sinus disease (PSD) requires a tailored approach. A national guideline was published in 2014. The current status of surgical PSD therapy...  相似文献   
84.
In this paper we present a coupled Finite Element Method – Boundary Element Method (FEM-BEM) approach for the solution of the free-boundary axi-symmetric plasma equilibrium problem. The proposed method, obtained from an improvement of the Hagenow-Lackner coupling method, allows to efficiently model the equilibrium problem in unbounded domains by discretizing only the plasma region; the external conductors can be modelled either as 2D or 3D models, according to the problem of interest. The paper explores different iterative methods for the solution of the nonlinear Grad-Shafranov equation, such as Picard, Newton-Raphson and Newton-Krylov, in order to provide a robust and reliable tool, able to handle large-scale problems (e.g. high resolution equilibria). This method has been implemented in the FRIDA code (FRee-boundary Integro-Differential Axisimmetric – https://github. om/matteobonotto/ FRIDA), together with a suitable Adaptive Integration Technique (AIT) for the computation of the source term. FRIDA has been successfully tested and validated against experimental data from RFX-mod device, and numerical equilibria of an ITER-like device.  相似文献   
85.
86.
87.
Post-induction hypotension is common and associated with postoperative complications. We hypothesised that pneumatic leg compression reduces post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy. In this double-blind randomised study, patients were allocated randomly to the pneumatic leg compression group (n = 50) or control (n = 50). In the intervention group, pneumatic leg compression was initiated before induction of anaesthesia. In the control group, pneumatic leg compression was initiated 20 min after anaesthesia induction. The primary outcome was the incidence of post-induction hypotension in these groups. Post-induction hypotension was defined as systolic blood pressure < 90 mmHg during the first 20 min after induction. Haemodynamic variables and area under the curve of post-induction systolic blood pressure over time were assessed. Complications associated with pneumatic leg compression were recorded, including: peripheral neuropathy; compartment syndrome; extensive bullae beneath the leg sleeves; and pulmonary thromboembolism. The incidence of post-induction hypotension decreased in the pneumatic leg compression group compared with that in the control group; 5 (10%) vs. 29 (58%), respectively, p < 0.001. In the pneumatic leg compression group, the lowest systolic, diastolic and mean blood pressures 20 min after induction of anaesthesia were significantly greater than the control group. Pneumatic leg compression resulted in an increased area under the curve of systolic blood pressure in the first 20 min after induction, p = 0.001. There were no pneumatic leg compression-related complications. Pneumatic leg compression reduced post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy, suggesting that it is an effective and safe intervention to prevent post-induction hypotension among elderly patients undergoing general anaesthesia.  相似文献   
88.
89.
90.
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