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   248076篇
  免费   17927篇
  国内免费   1141篇
耳鼻咽喉   2778篇
儿科学   6512篇
妇产科学   4647篇
基础医学   32276篇
口腔科学   4555篇
临床医学   24958篇
内科学   52081篇
皮肤病学   3485篇
神经病学   23766篇
特种医学   8326篇
外国民族医学   11篇
外科学   38407篇
综合类   3523篇
一般理论   320篇
预防医学   20847篇
眼科学   6510篇
药学   17048篇
  4篇
中国医学   422篇
肿瘤学   16668篇
  2023年   1206篇
  2022年   922篇
  2021年   4196篇
  2020年   3217篇
  2019年   5238篇
  2018年   5918篇
  2017年   4481篇
  2016年   4905篇
  2015年   5806篇
  2014年   8602篇
  2013年   11813篇
  2012年   18032篇
  2011年   18929篇
  2010年   10633篇
  2009年   9507篇
  2008年   16627篇
  2007年   17480篇
  2006年   17386篇
  2005年   17281篇
  2004年   16178篇
  2003年   15039篇
  2002年   14040篇
  2001年   2065篇
  2000年   1545篇
  1999年   2153篇
  1998年   2625篇
  1997年   2169篇
  1996年   1865篇
  1995年   2107篇
  1994年   1761篇
  1993年   1587篇
  1992年   1265篇
  1991年   1172篇
  1990年   1023篇
  1989年   984篇
  1988年   973篇
  1987年   955篇
  1986年   955篇
  1985年   965篇
  1984年   1202篇
  1983年   1115篇
  1982年   1330篇
  1981年   1293篇
  1980年   1132篇
  1979年   703篇
  1978年   753篇
  1977年   631篇
  1976年   576篇
  1975年   457篇
  1974年   471篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
AIDS and Behavior - Although misperceived norms often drive personal health behaviors, we do not know about this phenomenon in the context of antiretroviral therapy (ART) adherence. We conducted a...  相似文献   
2.
Clinical Rheumatology - To examine the mortality rates and causes of death among French decedents with Behçet’s disease (BD). Data collected between 1979 and 2016 by the French...  相似文献   
3.
Coates  Laura C.  Mease  Philip  Kronbergs  Andris  Helt  Cameron  Sandoval  David  Park  So Young  Combe  Bernard  Nash  Peter  Deodhar  Atul 《Clinical rheumatology》2022,41(10):3035-3047
Clinical Rheumatology - To evaluate the three-year efficacy and safety of ixekizumab with and without concomitant conventional synthetic disease-modifying antirheumatic drug (csDMARD) use in...  相似文献   
4.
Journal of Neuro-Oncology - Molecular glioblastomas (i.e. without the histological but with the molecular characteristics of IDH-wild-type glioblastoma) frequently lack contrast enhancement, which...  相似文献   
5.
Clinical Oral Investigations - To validate a questionnaire for the identification of factors associated with erosive tooth wear (ETW) in adolescents. Based on previous questionnaires, a 73-question...  相似文献   
6.
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - The main aim of the present study was: to assess the agronomic and nutritional value of an intensive...  相似文献   
7.
Thomas Behrens  Calvin Ge  Roel Vermeulen  Benjamin Kendzia  Ann Olsson  Joachim Schüz  Hans Kromhout  Beate Pesch  Susan Peters  Lützen Portengen  Per Gustavsson  Dario Mirabelli  Pascal Guénel  Danièle Luce  Dario Consonni  Neil E. Caporaso  Maria Teresa Landi  John K. Field  Stefan Karrasch  Heinz-Erich Wichmann  Jack Siemiatycki  Marie-Elise Parent  Lorenzo Richiardi  Lorenzo Simonato  Karl-Heinz Jöckel  Wolfgang Ahrens  Hermann Pohlabeln  Guillermo Fernández-Tardón  David Zaridze  John R. McLaughlin  Paul A. Demers  Beata Świątkowska  Jolanta Lissowska  Tamás Pándics  Eleonora Fabianova  Dana Mates  Vladimir Bencko  Lenka Foretova  Vladimír Janout  Paolo Boffetta  Bas Bueno-de-Mesquita  Francesco Forastiere  Kurt Straif  Thomas Brüning 《International journal of cancer. Journal international du cancer》2023,152(4):645-660
There is limited evidence regarding the exposure-effect relationship between lung-cancer risk and hexavalent chromium (Cr(VI)) or nickel. We estimated lung-cancer risks in relation to quantitative indices of occupational exposure to Cr(VI) and nickel and their interaction with smoking habits. We pooled 14 case-control studies from Europe and Canada, including 16 901 lung-cancer cases and 20 965 control subjects. A measurement-based job-exposure-matrix estimated job-year-region specific exposure levels to Cr(VI) and nickel, which were linked to the subjects' occupational histories. Odds ratios (OR) and associated 95% confidence intervals (CI) were calculated by unconditional logistic regression, adjusting for study, age group, smoking habits and exposure to other occupational lung carcinogens. Due to their high correlation, we refrained from mutually adjusting for Cr(VI) and nickel independently. In men, ORs for the highest quartile of cumulative exposure to CR(VI) were 1.32 (95% CI 1.19-1.47) and 1.29 (95% CI 1.15-1.45) in relation to nickel. Analogous results among women were: 1.04 (95% CI 0.48-2.24) and 1.29 (95% CI 0.60-2.86), respectively. In men, excess lung-cancer risks due to occupational Cr(VI) and nickel exposure were also observed in each stratum of never, former and current smokers. Joint effects of Cr(VI) and nickel with smoking were in general greater than additive, but not different from multiplicative. In summary, relatively low cumulative levels of occupational exposure to Cr(VI) and nickel were associated with increased ORs for lung cancer, particularly in men. However, we cannot rule out a combined classical measurement and Berkson-type of error structure, which may cause differential bias of risk estimates.  相似文献   
8.
9.
Journal of Interventional Cardiac Electrophysiology - Delineate retrospectively and prospectively the incidence and characteristics of transient ST-segment elevation during transseptal puncture....  相似文献   
10.
The simulation of rarefied gas flows through complex porous media is challenging due to the tortuous flow pathways inherent to such structures. The Lattice Boltzmann method (LBM) has been identified as a promising avenue to solve flows through complex geometries due to the simplicity of its scheme and its high parallel computational efficiency. It has been proposed to model the stress-strain relationship with the extended Navier-Stokes equations rather than attempting to directly solve the Boltzmann equation. However, a regularization technique is required to filter out non-resolved higher-order components with a low-order velocity scheme. Although slip boundary conditions (BCs) have been proposed for the non-regularized multiple relaxation time LBM (MRT-LBM) for planar geometries, previous slip BCs have never been verified extensively with the regularization technique. In this work, following an extensive literature review on the imposition of slip BCs for rarefied flows with the LBM, it is proven that earlier values for kinetic parameters developed to impose slip BCs are inaccurate for the regularized MRT-LBM and differ between the D2Q9 and D3Q15 schemes. The error was eliminated for planar flows and good agreement between analytical solutions for arrays of cylinders and spheres was found with a wide range of Knudsen numbers.  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