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   21052篇
  免费   960篇
  国内免费   69篇
耳鼻咽喉   349篇
儿科学   632篇
妇产科学   507篇
基础医学   3091篇
口腔科学   384篇
临床医学   1964篇
内科学   4389篇
皮肤病学   620篇
神经病学   2263篇
特种医学   1355篇
外国民族医学   3篇
外科学   2714篇
综合类   187篇
一般理论   6篇
预防医学   833篇
眼科学   575篇
药学   1275篇
中国医学   30篇
肿瘤学   904篇
  2022年   161篇
  2021年   285篇
  2020年   200篇
  2019年   272篇
  2018年   340篇
  2017年   288篇
  2016年   341篇
  2015年   409篇
  2014年   545篇
  2013年   813篇
  2012年   1095篇
  2011年   1072篇
  2010年   666篇
  2009年   635篇
  2008年   1019篇
  2007年   1141篇
  2006年   1093篇
  2005年   1046篇
  2004年   999篇
  2003年   1011篇
  2002年   935篇
  2001年   371篇
  2000年   281篇
  1999年   294篇
  1998年   211篇
  1997年   200篇
  1996年   166篇
  1995年   160篇
  1994年   165篇
  1993年   139篇
  1992年   228篇
  1991年   217篇
  1990年   210篇
  1989年   196篇
  1988年   200篇
  1987年   219篇
  1986年   218篇
  1985年   173篇
  1984年   158篇
  1983年   177篇
  1982年   125篇
  1981年   117篇
  1980年   110篇
  1979年   127篇
  1978年   119篇
  1977年   86篇
  1974年   99篇
  1973年   79篇
  1933年   93篇
  1931年   82篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
ABSTRACT

Forest workers, including loggers, foresters, and wildland firefighters, are regularly exposed to some of the most fatal occupational environments in the United States. These hazardous work environments may become even more complex and dynamic when subject to bark beetle outbreaks that have resulted in significant tree mortality. The impacts of tree death from bark beetles are significant, with the cumulative 17-year (2000–2016) footprint for bark beetle caused tree mortality estimated at 54 million acres. However, how workers think about and act in these environments is understudied. This study, therefore, approaches the issue of beetle kill and forest worker safety by examining the perspectives or workers themselves. Its contribution is to leverage ethnographic research to provide insights that can generate new research questions, better inform outreach, and ultimately improve worker safety outcomes. The resulting insights show that beetle kill was understood by workers as a hazard that increased the complexity and dynamism of the work environment, making situational awareness both more necessary and more difficult to maintain. While much research about situational awareness focuses on hazardous situations, it is suggested that building adequate situational awareness should also include broader considerations of organizational communication, as well as training and experience considered over the course of entire careers.  相似文献   
2.
Abstract

Purpose: We examined underlying psychosocial processes of a behavioral treatment for urinary incontinence (UI) of prostate cancer survivors.

Design: Secondary analysis of data collected from a clinical trial.

Sample: Two hundred forty-four prostate cancer survivors who participated in a clinical trial of behavioral intervention to UI as intervention or control subjects.

Methods: The participants had a 3-month behavioral intervention or usual care and were followed up for an additional 3?months. They were assessed at baseline, 3, and 6?months. Latent growth curve models were performed to examine trajectories of each study variable and relationships among the variables.

Findings: Increasing self-efficacy and social support were significantly and independently associated with more reduction of urinary leakage frequency over time.

Implications for psychosocial oncology: Providing problem-solving skills and social support, including peer support, are essential for empowering patients to reduce UI.  相似文献   
3.
4.
5.
6.
7.
Occupational diseases Nos. 2108 and 2110 correspond to intervertebral disc-related diseases of the lumbar spine from many years of carrying or lifting heavy loads, occupations in extreme postures of full flexion or oscillation of the whole body when seated, and which compel the cessation of all activities which are or could be the cause for the origin, exacerbation or recurrence of the disease. These occupational diseases came into force at the start of 1993, but there have been considerable problems in their implementation. The present Part I of the contribution is the result of the work of an interdisciplinary study group and contains medical criteria for the assessment of possibly strain-related clinical characteristics and the evaluation of other possible causes. Part II is to be published in Volume 4/2005 and will deal with questions related to forced cessation and to the assessment of the loss of earning ability. Agreement was reached in many areas related to the assessment of occupational claims. This should allow for evidence-based decision making in the future for the occupational diseases Nos. 2108 and 2110.  相似文献   
8.
9.
10.
Age determines memory for face identity and expression   总被引:1,自引:1,他引:0  
Background: The recognition of facial expressions is an important component of emotion processing which contributes to interactional behavior. One of the factors highly associated with potential decline of ability in behavioral tasks is age. Methods: We have investigated age‐related changes in facial identity and expression memory of healthy subjects in three age groups: young adults (20–40 years), elderly adults (60–80 years) and, for the first time in the literature, very old adults (over 80 years of age). Using a picture test, photographs of faces with happy or angry expressions were presented to study participants during the encoding task, and the memory for identity and emotional facial expression was investigated in a subsequent recognition task showing emotionally neutral faces. Half of the faces presented in the recognition task were initially shown in the encoding task. Results: Age interacted with the memory process: the ability to recognize both facial identity and emotional expression declined with advanced age. Happy facial expressions were better recognized in all age groups. Although there was a continuous overall decrease in recognition of both happy and angry expressions with advanced age, the effect favoring happy facial expressions was stable also in very old adults. Other factors such as gender or educational level did not affect the memory process for facial expressions. Conclusions: Our findings suggest that age is a significant determinant of memory for facial identity and emotional expression, and that, similar to younger adults, the recognition process of the elderly favors happy emotional facial expressions.  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