全文获取类型
收费全文 | 1337765篇 |
免费 | 113141篇 |
国内免费 | 6364篇 |
专业分类
耳鼻咽喉 | 16705篇 |
儿科学 | 43005篇 |
妇产科学 | 36554篇 |
基础医学 | 183616篇 |
口腔科学 | 36272篇 |
临床医学 | 120682篇 |
内科学 | 278496篇 |
皮肤病学 | 31886篇 |
神经病学 | 110491篇 |
特种医学 | 55533篇 |
外国民族医学 | 274篇 |
外科学 | 210335篇 |
综合类 | 31527篇 |
现状与发展 | 2篇 |
一般理论 | 414篇 |
预防医学 | 106622篇 |
眼科学 | 28085篇 |
药学 | 93701篇 |
5篇 | |
中国医学 | 2227篇 |
肿瘤学 | 70838篇 |
出版年
2018年 | 13373篇 |
2017年 | 10630篇 |
2016年 | 12794篇 |
2015年 | 14296篇 |
2014年 | 19944篇 |
2013年 | 29731篇 |
2012年 | 36231篇 |
2011年 | 38880篇 |
2010年 | 24368篇 |
2009年 | 23899篇 |
2008年 | 36358篇 |
2007年 | 38771篇 |
2006年 | 39895篇 |
2005年 | 38484篇 |
2004年 | 36721篇 |
2003年 | 35818篇 |
2002年 | 33830篇 |
2001年 | 66052篇 |
2000年 | 67917篇 |
1999年 | 56587篇 |
1998年 | 16723篇 |
1997年 | 15017篇 |
1996年 | 16014篇 |
1995年 | 16232篇 |
1994年 | 15098篇 |
1993年 | 14153篇 |
1992年 | 47098篇 |
1991年 | 45747篇 |
1990年 | 43970篇 |
1989年 | 41815篇 |
1988年 | 38758篇 |
1987年 | 38081篇 |
1986年 | 35859篇 |
1985年 | 34635篇 |
1984年 | 26358篇 |
1983年 | 22108篇 |
1982年 | 13847篇 |
1981年 | 12447篇 |
1980年 | 11718篇 |
1979年 | 23544篇 |
1978年 | 17072篇 |
1977年 | 14385篇 |
1976年 | 13182篇 |
1975年 | 13722篇 |
1974年 | 16093篇 |
1973年 | 15396篇 |
1972年 | 14173篇 |
1971年 | 13036篇 |
1970年 | 11880篇 |
1969年 | 11101篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
Deitelzweig Steve Luo Xuemei Nguyen Jennifer L. Malhotra Deepa Emir Birol Russ Cristina Li Xiaoyan Lee Theodore C. Ferri Mauricio Wiederkehr Danny Reimbaeva Maya Barnes Geoffrey D. Piazza Gregory 《Journal of thrombosis and thrombolysis》2022,54(4):696-696
Journal of Thrombosis and Thrombolysis - 相似文献
13.
14.
A Coupled FEM-BEM Approach for the Solution of the Free-Boundary Axi-Symmetric Plasma Equilibrium Problem
下载免费PDF全文
![点击此处可从《Communications In Computational Physics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M. Bonotto D. Abate P. Bettini & F. Villone 《Communications In Computational Physics》2022,31(1):27-59
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
15.
16.
17.
18.
19.
Elizabeth D. Krebs Robert B. Hawkins J. Hunter Mehaffey Clifford E. Fonner Alan M. Speir Mohammed A. Quader Jeffrey B. Rich Leora T. Yarboro Nicholas R. Teman Gorav Ailawadi 《The Journal of thoracic and cardiovascular surgery》2019,157(4):1533-1542.e2
Objectives
Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.Methods
Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.Results
A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.Conclusions
Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight. 相似文献20.
Metabolism describes the series of chemical reactions that are concerned with the provision of energy to biological systems. They may be divided into reactions involved in energy yield (catabolism: demand exceeds supply), and energy storage (anabolism: supply exceeds demand). Regulation of these pathways is critical for homeostasis, and derangements in metabolism are seen in a wide variety of pathological processes. Understanding metabolism is key to the treatment of many diseases, notably diabetes, as well as underpinning clinical nutritional support. 相似文献