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   2533923篇
  免费   194670篇
  国内免费   7045篇
耳鼻咽喉   33685篇
儿科学   84015篇
妇产科学   71138篇
基础医学   366793篇
口腔科学   70158篇
临床医学   237896篇
内科学   492600篇
皮肤病学   55877篇
神经病学   211980篇
特种医学   94853篇
外国民族医学   790篇
外科学   365189篇
综合类   56599篇
现状与发展   4篇
一般理论   926篇
预防医学   207567篇
眼科学   56881篇
药学   182948篇
  7篇
中国医学   5843篇
肿瘤学   139889篇
  2021年   20022篇
  2019年   21370篇
  2018年   30725篇
  2017年   23540篇
  2016年   26495篇
  2015年   29197篇
  2014年   40366篇
  2013年   62172篇
  2012年   84362篇
  2011年   89875篇
  2010年   52446篇
  2009年   48361篇
  2008年   83310篇
  2007年   88151篇
  2006年   88488篇
  2005年   85865篇
  2004年   81691篇
  2003年   78252篇
  2002年   75752篇
  2001年   117061篇
  2000年   121007篇
  1999年   100017篇
  1998年   29045篇
  1997年   26248篇
  1996年   25905篇
  1995年   24646篇
  1994年   22701篇
  1993年   21300篇
  1992年   76296篇
  1991年   73855篇
  1990年   71558篇
  1989年   68026篇
  1988年   62892篇
  1987年   61294篇
  1986年   57774篇
  1985年   55304篇
  1984年   42083篇
  1983年   35796篇
  1982年   21996篇
  1981年   19495篇
  1979年   37857篇
  1978年   26895篇
  1977年   22384篇
  1976年   21497篇
  1975年   22011篇
  1974年   26702篇
  1973年   25997篇
  1972年   24015篇
  1971年   22212篇
  1970年   20914篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
51.
52.
53.
54.
55.
56.
There is a sharp difference in how one views TCR structure–function–behaviour dependent on whether its recognition of major histocompatibility complex‐encoded restriction elements (R) is germline selected or somatically generated. The generally accepted or Standard model is built on the assumption that recognition of R is by the V regions of the αβ TCR, which is not driven by allele specificity, whereas the competing model posits that recognition of R is allele‐specific. The establishing of allele‐specific recognition of R by the TCR would rule out the Standard model and clear the road to a consideration of a competing construct, the Tritope model. Here, the case for allele‐specific recognition (germline selected) is detailed making it obvious that the Standard model is untenable.  相似文献   
57.
Monitoring variations in the functioning of the autonomic nervous system may help personalize training of runners and provide more pronounced physiological adaptations and performance improvements. We systematically reviewed the scientific literature comparing physiological adaptations and/or improvements in performance following training based on responses of the autonomic nervous system (ie, changes in heart rate variability) and predefined training. PubMed, SPORTDiscus, and Web of Science were searched systematically in July 2019. Keywords related to endurance, running, autonomic nervous system, and training. Studies were included if they (a) involved interventions consisting predominantly of running training; (b) lasted at least 3 weeks; (c) reported pre- and post-intervention assessment of running performance and/or physiological parameters; (d) included an experimental group performing training adjusted continuously on the basis of alterations in HRV and a control group; and (e) involved healthy runners. Five studies involving six interventions and 166 participants fulfilled our inclusion criteria. Four HRV-based interventions reduced the amount of moderate- and/or high-intensity training significantly. In five interventions, improvements in performance parameters (3000 m, 5000 m, Loadmax, Tlim) were more pronounced following HRV-based training. Peak oxygen uptake () and submaximal running parameters (eg, LT1, LT2) improved following both HRV-based and predefined training, with no clear difference in the extent of improvement in . Submaximal running parameters tended to improve more following HRV-based training. Research findings to date have been limited and inconsistent. Both HRV-based and predefined training improve running performance and certain submaximal physiological adaptations, with effects of the former training tending to be greater.  相似文献   
58.
59.
Background: Lay belief systems about the malleability of human attributes have been shown to impact behavior change in multiple domains. Addiction mindset—i.e., beliefs about the permanence (vs. malleability) of addiction — may affect cigarette smokers’ ability to quit, but this has never been examined. Objectives: The aims of the present research were to develop a measure of addiction mindset (study 1) and examine its associations with various psychological aspects of quitting smoking (study 2). Methods: In Study 1, using factor analysis of current smokers’ and nonsmokers’ (n?=?600) responses to 22 items designed to measure addiction mindset, we developed a reliable six-item Addiction Mindset Scale (AMS). In Study 2, adult smokers (n?=?200) completed the AMS, and measures of a number of psychological processes related to smoking. Results: Higher scores on the AMS, indicative of the belief that addiction is malleable (referred to as a growth mindset), were positively and significantly associated with greater motivation to quit, greater commitment to quitting, greater self-efficacy to abstain, less attribution of failure to lack of ability to change addiction, and fewer self-reported barriers to cessation (all p’s < .05). Conclusions: The results of this study show a relationship between the beliefs about the permanence of addiction and psychological processes relevant to quitting smoking. The findings underscore the potential of future research exploring how addiction mindsets relate to successful smoking cessation as well as other types of addictive behavior and how they can be applied to change people’s behavior.  相似文献   
60.
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was...  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