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   96412篇
  免费   29196篇
  国内免费   1067篇
耳鼻咽喉   2384篇
儿科学   2617篇
妇产科学   2301篇
基础医学   2412篇
口腔科学   5028篇
临床医学   25811篇
内科学   24140篇
皮肤病学   3236篇
神经病学   12227篇
特种医学   3525篇
外科学   17579篇
综合类   112篇
现状与发展   40篇
一般理论   4篇
预防医学   13343篇
眼科学   2100篇
药学   1011篇
中国医学   6篇
肿瘤学   8799篇
  2024年   740篇
  2023年   5020篇
  2022年   1099篇
  2021年   2699篇
  2020年   5303篇
  2019年   1959篇
  2018年   6810篇
  2017年   7296篇
  2016年   7875篇
  2015年   7971篇
  2014年   10326篇
  2013年   12046篇
  2012年   3631篇
  2011年   3398篇
  2010年   6734篇
  2009年   9033篇
  2008年   3361篇
  2007年   2293篇
  2006年   3451篇
  2005年   2018篇
  2004年   1390篇
  2003年   1085篇
  2002年   1018篇
  2001年   1797篇
  2000年   1121篇
  1999年   1665篇
  1998年   2069篇
  1997年   1900篇
  1996年   1955篇
  1995年   1690篇
  1994年   1086篇
  1993年   909篇
  1992年   748篇
  1991年   626篇
  1990年   506篇
  1989年   511篇
  1988年   506篇
  1987年   374篇
  1986年   351篇
  1985年   292篇
  1984年   252篇
  1983年   308篇
  1982年   231篇
  1981年   208篇
  1980年   128篇
  1978年   129篇
  1977年   125篇
  1976年   94篇
  1974年   74篇
  1972年   73篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
11.
12.
13.
The aim of this study was to design a new intravenous blood–gas exchange device and to estimate the design characteristics of the device with a dimensionless function by using a substance that can be used instead of bovine blood. In addition, the characteristics of oxygen transfer were estimated using empirical formulas and the reliability of the equations was ascertained by comparing their output with an experiment performed using bovine blood. The dimensionless function was derived using distilled water and bovine blood to estimate the oxygen transfer rate. Using the derived equations, the calculated oxygen transfer rates for bovine blood and distilled water were similar for Reynolds numbers ranging from 0.7 to 7.0. Therefore, it is possible to estimate the oxygen transfer rate in bovine blood, which is a non-Newtonian fluid, using distilled water, which is a Newtonian fluid. Moreover, it was possible to verify the related equations because the oxygen transfer rate could be estimated using the derived equations, according to the diameters of the various device modules.  相似文献   
14.
15.
The present study demonstrates that alcohol-induced memory impairment can be attenuated by pretreatment with an oral tryptophan supplementation. These results provide support for the role of a brain serotonin deficit in this impairment and highlight the impact a dietary manipulation can have on a complex behavioral process.  相似文献   
16.
17.
The definition of envy is commonly based on psychoanalytical views of organizational culture. The purpose of this paper is to describe envy in a nursing community. The population study consisted of random sample of 120 subjects drawn from among the employees of one central hospital in Finland. The study material consisted of data collected by questionnaires (response rate 65%). The data were processed by various statistical methods. Open-ended questions were analysed by inductive content analysis. The results of this study indicated that the employee's view of his/her official position in the nursing community, his/her relationships with his/her fellow workers and the management as well as relationships with other nursing communities are all related to envy. The employee's view of his/her official position intensified his/her feelings of envy, if he/she had other negative feelings, anxiety, dissatisfaction with him/herself, and negative feelings towards fellow workers. The major object of envy was fellow workers' salaries. Envy towards other nursing communities was generated by alleged differences in the amount of labour, or by the charge nurse's greater interest in other sections. Employees coped with envy by hiding these feelings and being modest. Women coped with envy by being silent, while men denied the value of the object of envy.  相似文献   
18.
19.
Psychological Consequences of Food Restriction   总被引:1,自引:0,他引:1  
A review of the literature and research on food restriction indicates that inhibiting food intake has consequences that may not have been anticipated by those attempting such restriction. Starvation and self-imposed dieting appear to result in eating binges once food is available and in psychological manifestations such as preoccupation with food and eating, increased emotional responsiveness and dysphoria, and distractibility. Caution is thus advisable in counseling clients to restrict their eating and diet to lose weight, as the negative sequelae may outweigh the benefits of restraining one's eating. Instead, healthful, balanced eating without specific food restrictions should be recommended as a long-term strategy to avoid the perils of restrictive dieting. J Am Diet Assoc. 1996; 96:589-592.  相似文献   
20.
Summary: This is the first report of the largest study of blood pressure measurement in pregnancy in a New Zealand population using standardized definitions and methodology. Over 3,800 women who delivered in an 8-month period in the Wellington region were included in the study. Blood pressure measurement and the presence of oedema and proteinuria were recorded from booking until delivery and in the puerperium. Only 2.7% of women were unable to be contacted after delivery for details on outcomes. The results established normal ranges for blood pressure throughout pregnancy. The data show that Mood pressure greater than 140/90 until 35 weeks' gestation is outside 2 standard deviations at all gestations and justifies using these measurements as the definition of hypertension in pregnancy. The fall in blood pressure in the 2nd trimester was less than 1 mm Ffg per week in both the systolic and diastolic pressures. This fall was smaller than previously recorded in other studies. Gestational hypertension was the commonest blood pressure abnormality occurring in 15.2% of the population. This represented 69% of the pregnant women with a hypertensive disorder. The overall incidence of both gestational hypertension and preeclampsia was 18.5% which is higher than reported in other parts of the world. In this study obesity was significantly associated with hypertensive disorders in pregnancy. An arm circumference of >33 cm, one of the measurements of obesity, was found in 6.8% of the study population. Even after the effect of arm circumference was taken into account, hypertensive disorders were also more common in Pacific Island women. Ankle oedema was significantly associated with the development of both gestational hypertension and preeclampsia but the incidence of oedema was noted in only 11.9% of the subjects.  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