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   19167篇
  免费   2147篇
  国内免费   61篇
耳鼻咽喉   302篇
儿科学   775篇
妇产科学   510篇
基础医学   2757篇
口腔科学   590篇
临床医学   2385篇
内科学   3705篇
皮肤病学   204篇
神经病学   1091篇
特种医学   823篇
外科学   2691篇
综合类   481篇
一般理论   18篇
预防医学   2011篇
眼科学   395篇
药学   1447篇
中国医学   87篇
肿瘤学   1103篇
  2021年   276篇
  2019年   218篇
  2018年   305篇
  2017年   223篇
  2016年   247篇
  2015年   254篇
  2014年   424篇
  2013年   598篇
  2012年   886篇
  2011年   930篇
  2010年   488篇
  2009年   396篇
  2008年   794篇
  2007年   869篇
  2006年   832篇
  2005年   831篇
  2004年   738篇
  2003年   717篇
  2002年   637篇
  2001年   652篇
  2000年   600篇
  1999年   593篇
  1998年   246篇
  1997年   265篇
  1996年   232篇
  1995年   216篇
  1994年   197篇
  1992年   460篇
  1991年   443篇
  1990年   411篇
  1989年   393篇
  1988年   400篇
  1987年   371篇
  1986年   373篇
  1985年   379篇
  1984年   280篇
  1983年   253篇
  1982年   191篇
  1981年   184篇
  1980年   156篇
  1979年   262篇
  1978年   216篇
  1977年   188篇
  1976年   169篇
  1975年   163篇
  1974年   193篇
  1973年   213篇
  1972年   168篇
  1971年   161篇
  1970年   160篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Abstract

Objectives: This study examined word use as an indicator of interpersonal positive reframing in daily conversations of couples coping with breast cancer and as a predictor of stress.

Design: The Electronically Activated Recorder (EAR) and Linguistic Inquiry and Word Count (LIWC) were used to examine naturally occurring word use conceptually linked to positive reframing (positive emotion, negative emotion, and cognitive processing words).

Sample: Fifty-two couples coping with breast cancer.

Methods: Couples wore the EAR, a device participants wear, that audio-recorded over one weekend (>16,000 sound files), and completed self-reports of positive reframing (COPE) and stress (Perceived Stress Scale). LIWC, a software program, measured word use.

Findings: Both partners’ word use (i.e., positive emotion and cognitive processing words) was associated with their own reported positive reframing, and spouses’ word use was also indicative of patients’ positive reframing. Results also revealed that, in general, words indicating positive reframing predicted lower levels of stress.

Conclusions: Findings supported the hypothesis that partners—and particularly spouses of breast cancer patients—may assist each other’s coping by positively reframing the cancer experience and other negative experiences in conversation.  相似文献   
2.
3.
4.
We describe a familial case of Marfan's syndrome with associated intrathoracic stomach detected during the neonatal period. The patient developed a primitive leukemia at 3 months of age. Acute leukemia in a patient with Marfan's syndrome has not previously been reported.  相似文献   
5.
6.
Two hundred and thirty pregnancies were studied in 196 diabetic women. Seven women with babies found to have major malformations had a higher median first trimester haemoglobin A1 (12.9%) than the median HbA1 (10.8%) in those with normal babies (p = 0.06). No relationship was found between the occurrence of minor malformations and first trimester maternal haemoglobin A1. Two of the seven congenital malformations were diagnosed antenatally at a time when therapeutic abortion could be offered. Expert antenatal ultrasound scanning should be offered to all pregnant diabetic women as poor glycaemic control at the time of conception and organogenesis, as evidenced by raised first trimester HbA1, predisposes to congenital malformation.  相似文献   
7.
Wright  John L. 《JAMA》2005,293(11):1301
  相似文献   
8.
The interaction of an organic acid with sodium bicarbonate in water produces an effervescent reaction. The reaction products are carbon dioxide, water, and the sodium salt of the acid. The kinetic rate-determining step for this reaction is the dehydration of carbonic acid. The solid-solid interaction with known amounts of moisture was followed by quantitatively determining carbon dioxide evolution as a function of time. The aqueous solubilities, diffusion coefficients, dissociation constants, and solid-solid interaction rates of six different substituted benzoic acids were determined. Using a model based on diffusion of the organic acid through the aqueous layer coupled with chemical reaction, predicted rates and levels of carbon dioxide production were compared with experimental results. Included in the model were the effects of the reaction products on the solution properties of the reactants. It was found that high concentrations of substituted sodium benzoate were generated very quickly and affected the solubility of the reactants, diffusion coefficient of the acid, and the carbonic acid dehydration rate constant. Moisture content was found to have a profound influence on the interaction rate. Water provides a medium for diffusion of the reacting species as well as the reaction solvent.  相似文献   
9.
10.
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