全文获取类型
收费全文 | 67021篇 |
免费 | 4254篇 |
国内免费 | 283篇 |
专业分类
耳鼻咽喉 | 676篇 |
儿科学 | 1548篇 |
妇产科学 | 1115篇 |
基础医学 | 8823篇 |
口腔科学 | 1271篇 |
临床医学 | 7315篇 |
内科学 | 14131篇 |
皮肤病学 | 1301篇 |
神经病学 | 7504篇 |
特种医学 | 2974篇 |
外国民族医学 | 5篇 |
外科学 | 10150篇 |
综合类 | 431篇 |
一般理论 | 27篇 |
预防医学 | 4482篇 |
眼科学 | 911篇 |
药学 | 4106篇 |
中国医学 | 82篇 |
肿瘤学 | 4706篇 |
出版年
2024年 | 69篇 |
2023年 | 672篇 |
2022年 | 1133篇 |
2021年 | 2225篇 |
2020年 | 1270篇 |
2019年 | 2051篇 |
2018年 | 2279篇 |
2017年 | 1715篇 |
2016年 | 1970篇 |
2015年 | 2238篇 |
2014年 | 2881篇 |
2013年 | 3476篇 |
2012年 | 5532篇 |
2011年 | 5549篇 |
2010年 | 3134篇 |
2009年 | 2779篇 |
2008年 | 4466篇 |
2007年 | 4537篇 |
2006年 | 4168篇 |
2005年 | 4041篇 |
2004年 | 3607篇 |
2003年 | 3301篇 |
2002年 | 2983篇 |
2001年 | 495篇 |
2000年 | 392篇 |
1999年 | 454篇 |
1998年 | 608篇 |
1997年 | 449篇 |
1996年 | 355篇 |
1995年 | 273篇 |
1994年 | 270篇 |
1993年 | 205篇 |
1992年 | 164篇 |
1991年 | 150篇 |
1990年 | 105篇 |
1989年 | 102篇 |
1988年 | 110篇 |
1987年 | 72篇 |
1986年 | 81篇 |
1985年 | 78篇 |
1984年 | 111篇 |
1983年 | 89篇 |
1982年 | 83篇 |
1981年 | 65篇 |
1980年 | 66篇 |
1979年 | 50篇 |
1978年 | 52篇 |
1977年 | 55篇 |
1976年 | 59篇 |
1974年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 7 毫秒
1.
Stephanie Kay Kolar 《Addiction Research & Theory》2016,24(1):25-31
Aims: Relapse rates among cigarette smokers are high. Few studies have examined time-to-relapse using survival analysis in racially/ethnically diverse smokers and initial abstinence criteria have been inconsistent or unspecified. This study compared survival curves using two common definitions of initial abstinence. We hypothesized greater relapse rates among participants abstinent for only 24 hours (h) at the end-of-therapy (EOT) compared with 7 days. Methods: Adult smokers (59% Black, 22% Hispanic and 17% White) received 8-sessions of group cognitive behavioural therapy (CBT) plus transdermal nicotine patches and were assessed monthly up to 12 months post-EOT. Participants reporting abstinence (7-day point prevalence abstinence [ppa] or 24-h ppa) at the EOT were included in Kaplan–Meier curves. Results: Of 301 participants, 120 (40%) reported 7-day ppa at the EOT and an additional 29 (10%) reported 24-h ppa only. Over the 12-month follow-up period, nearly 50% remained abstinent. Of those who resumed smoking, most relapses occurred within the first three months. Survival curves indicated that median survival was 207 and 225 days for 7-day and 24-h definitions of abstinence, respectively. The difference in time-to-relapse between participants abstinent for 24?h at the EOT versus 7-days was not significant (p?=?0.14). Conclusions: Operationalization of initial abstinence is important for relapse analyses and comparisons of survival curves across samples. Participants reported high rates of abstinence and relapse rates were relatively low. Contrary to expectations, 24-h ppa at the EOT was not associated with greater relapse than 7-day abstinence. This suggests either measure may be utilized in relapse prevention research in racially/ethnically diverse treatment-seekers. 相似文献
2.
3.
Christian Holm Hansen Shelley Lees Saidi Kapiga Janet Seeley Tony Barnett 《Global public health》2020,15(3):402-413
ABSTRACTMeasuring hope reliably and accurately remains an important research objective, not least in less prosperous settings where ‘holding on to hope’ may be critically important in the struggle against adverse life conditions. The State Hope Scale was designed for use in the US. Despite reported application in diverse cultures and using translations the scale has not been extensively validated outside US populations. This study contributes to a larger project exploring the measurement of hope and provides a critique of Snyder’s scale as used in a Tanzanian female population of 1021 urban microfinance participants. We evaluate the scale’s validity through assessment of the empirical distribution of scores, item response profiles, internal consistency and discriminatory ability. Participants mostly scored very high and many reached very near the maximum attainable score. Hardly any endorsed the negative half of the response scale. Several problems are discussed including poor discrimination and strong evidence of acquiescence response bias. We also found little association of the scale scores with hypothesised correlates of hope. Future improvements on the measurement of hope are recommended, especially in studies outside the narrow Western context in which the scale was devised. 相似文献
4.
5.
6.
7.
8.
9.
10.