全文获取类型
收费全文 | 2863篇 |
免费 | 132篇 |
专业分类
管理学 | 337篇 |
民族学 | 28篇 |
人口学 | 324篇 |
丛书文集 | 17篇 |
理论方法论 | 340篇 |
综合类 | 33篇 |
社会学 | 1388篇 |
统计学 | 528篇 |
出版年
2023年 | 31篇 |
2022年 | 11篇 |
2021年 | 37篇 |
2020年 | 76篇 |
2019年 | 113篇 |
2018年 | 134篇 |
2017年 | 180篇 |
2016年 | 106篇 |
2015年 | 82篇 |
2014年 | 87篇 |
2013年 | 560篇 |
2012年 | 136篇 |
2011年 | 110篇 |
2010年 | 95篇 |
2009年 | 80篇 |
2008年 | 95篇 |
2007年 | 86篇 |
2006年 | 91篇 |
2005年 | 79篇 |
2004年 | 60篇 |
2003年 | 69篇 |
2002年 | 61篇 |
2001年 | 54篇 |
2000年 | 44篇 |
1999年 | 44篇 |
1998年 | 30篇 |
1997年 | 25篇 |
1996年 | 28篇 |
1995年 | 25篇 |
1994年 | 29篇 |
1993年 | 32篇 |
1992年 | 32篇 |
1991年 | 28篇 |
1990年 | 15篇 |
1989年 | 17篇 |
1988年 | 14篇 |
1987年 | 14篇 |
1986年 | 12篇 |
1985年 | 19篇 |
1984年 | 20篇 |
1983年 | 18篇 |
1982年 | 13篇 |
1981年 | 23篇 |
1980年 | 14篇 |
1979年 | 10篇 |
1978年 | 8篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1975年 | 11篇 |
1974年 | 10篇 |
排序方式: 共有2995条查询结果,搜索用时 390 毫秒
891.
Huang TT Harris KJ Lee RE Nazir N Born W Kaur H 《Journal of American college health : J of ACH》2003,52(2):83-86
The authors surveyed 738 college students aged 18 to 27 years to assess overweight, obesity, dietary habits, and physical activity. They used BMI (body mass index) > or = 25 kg/m2 or BMI > or = 85th percentile and BMI > or = 30 kg/m2 or BMI > or = 95th percentile to estimate overweight and obesity in those aged < or = 19 years. To define overweight and obesity in those > or = 20 years, they used BMI > or = 25 kg/m2 and > or = 30 kg/m2. They found overweight rates of 21.6% using BMI directly and 16.2% using BMI percentile and obesity rates of 4.9% using BMI directly and 4.2% using BMI percentile. More than 69% of the participants reported < 5 servings of fruits and vegetables per day and more than 67% reported < 20 g of fiber per day; participants reported physical activity on fewer than 3 d/wk. Most college students are not meeting dietary and physical activity guidelines, suggesting the need for prevention interventions and increased understanding of overweight in college students. 相似文献
892.
Lee CC Connolly PM Dietz EO 《Journal of psychosocial nursing and mental health services》2005,43(6):32-39
1. High arrest rates among people with mental illnesses may suggest that the illness is a factor in their arrests. 2. The increased number of individuals with severe and persistent mental illnesses in the criminal justice system reflects deficient community-based mental health services. 3. Jails and prisons act as revolving-door treatment facilities and are a poor substitute for proper community-based mental health care. 4. Mandatory discharge medication and follow-up treatment for ex-inmates with mental illnesses may lower the rate of recidivism. 相似文献
893.
894.
The purpose of this study is to identify characteristics that would increase the likelihood that a Korean older adult with dementia being cared for by a family caregiver is at risk of being abused. This analysis was based on a sample of 481 primary family caregivers from the data of Comprehensive Study for the Elderly Welfare Policy in Seoul (2003). Multiple regression analysis was used to examine predictors among the demographic characteristics of caregivers and care recipients, the severity of cognitive impairment, functional ability, caregiver burden, and social support for the degree of elder abuse. The degree of elder abuse was significantly associated with caregiver burden, mental impairment, dependency of daily living of care recipient, and use of formal services. 相似文献
895.
This meeting report documents the exciting ongoing research aimed at developing new therapeutic agents for neurodegenerative diseases at the interface between academia and industry, and illustrates the direction the NIH "roadmap" for medical research is taking. Some of the projects have resulted in very promising drugs, identified and developed by academic centers, entering clinical trials. 相似文献
896.
897.
John P. Mandeli F.-C.Helen Lee Walter T. Federer 《Journal of statistical planning and inference》1981,5(3):267-272
Complete sets of orthogonal F-squares of order n = sp, where g is a prime or prime power and p is a positive integer have been constructed by Hedayat, Raghavarao, and Seiden (1975). Federer (1977) has constructed complete sets of orthogonal F-squares of order n = 4t, where t is a positive integer. We give a general procedure for constructing orthogonal F-squares of order n from an orthogonal array (n, k, s, 2) and an OL(s, t) set, where n is not necessarily a prime or prime power. In particular, we show how to construct sets of orthogonal F-squares of order n = 2sp, where s is a prime or prime power and p is a positive integer. These sets are shown to be near complete and approach complete sets as s and/or p become large. We have also shown how to construct orthogonal arrays by these methods. In addition, the best upper bound on the number t of orthogonal F(n, λ1), F(n, λ2), …, F(n, λ1) squares is given. 相似文献
898.
The evolution of opinion as to how to analyse the AB/BA cross‐over trials is described by examining the recommendations of three key papers. The impact of these papers on the medical literature is analysed by looking at citation rates as a function of various factors. It is concluded that amongst practitioners there is a highly imperfect appreciation of the issues raised by the possibility of carry‐over. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
899.
900.
The purpose of this article is to examine how American children under age 13 spend their time, sources of variation in time use, and associations with achievement and behavior. Data come from the 1997 Child Development Supplement to the Panel Study of Income Dynamics. The results suggest that parents' characteristics and decisions regarding marriage, family size, and employment affect the time children spend in educational, structured, and family activities, which may affect their school achievement. Learning activities such as reading for pleasure are associated with higher achievement, as is structured time spent playing sports and in social activities. Family time spent at meals and time spent sleeping are linked to fewer behavior problems, as measured by the child's score on the Behavior Problems Index. The results support common language and myth about the optimal use of time for child development. 相似文献