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   2449篇
  免费   97篇
管理学   322篇
民族学   16篇
人口学   227篇
丛书文集   12篇
理论方法论   250篇
综合类   13篇
社会学   1280篇
统计学   426篇
  2023年   9篇
  2021年   14篇
  2020年   27篇
  2019年   63篇
  2018年   67篇
  2017年   94篇
  2016年   74篇
  2015年   52篇
  2014年   61篇
  2013年   477篇
  2012年   73篇
  2011年   104篇
  2010年   63篇
  2009年   71篇
  2008年   70篇
  2007年   74篇
  2006年   67篇
  2005年   63篇
  2004年   60篇
  2003年   61篇
  2002年   68篇
  2001年   54篇
  2000年   48篇
  1999年   43篇
  1998年   40篇
  1997年   48篇
  1996年   50篇
  1995年   25篇
  1994年   39篇
  1993年   29篇
  1992年   35篇
  1991年   35篇
  1990年   36篇
  1989年   25篇
  1988年   20篇
  1987年   20篇
  1986年   18篇
  1985年   34篇
  1984年   28篇
  1983年   23篇
  1982年   24篇
  1981年   12篇
  1980年   21篇
  1979年   19篇
  1978年   12篇
  1977年   14篇
  1976年   16篇
  1975年   8篇
  1974年   12篇
  1973年   8篇
排序方式: 共有2546条查询结果,搜索用时 974 毫秒
1.
Food assumes enormous importance in prison: for many prisoners it conditions their life in custody and, in many respects, is symbolic of the prison experience. This article explores the complex relationship between gender, food and imprisonment through an analysis of data obtained from in‐depth interviews and group discussions conducted in three women's prisons in England. The findings indicate that, in prison, where control is taken away as the prisoner and her body become the objects of external forces, food is experienced not only as part of the disciplinary machinery, but also as a powerful source of pleasure, resistance and rebellion. The implications of such findings for health promotion in the prison context are discussed. Here, the pleasures and consolations of food may well constitute a redefinition of what it is to be healthy in this context, one that challenges the dominant meaning constructed in current health promotional discourse.  相似文献   
2.
3.
4.
Summary.  Non-ignorable missing data, a serious problem in both clinical trials and observational studies, can lead to biased inferences. Quality-of-life measures have become increasingly popular in clinical trials. However, these measures are often incompletely observed, and investigators may suspect that missing quality-of-life data are likely to be non-ignorable. Although several recent references have addressed missing covariates in survival analysis, they all required the assumption that missingness is at random or that all covariates are discrete. We present a method for estimating the parameters in the Cox proportional hazards model when missing covariates may be non-ignorable and continuous or discrete. Our method is useful in reducing the bias and improving efficiency in the presence of missing data. The methodology clearly specifies assumptions about the missing data mechanism and, through sensitivity analysis, helps investigators to understand the potential effect of missing data on study results.  相似文献   
5.
6.
SUMMARY. The past decade has shown increased awareness, concern and understanding about the extent of child abuse, particularly sexual abuse, and the caring agencies response to listen to and to support the young victims. This article looks at the response of the police service over that decade to meet such demands and to work jointly and responsively with social services to further the welfare and protection of children. It also examines the constraints and limitations of the police and social services when they attempt to uphold the rights of child victims and to gain redress through the criminal justice system  相似文献   
7.
8.
Summary.  When evaluating potential interventions for cancer prevention, it is necessary to compare benefits and harms. With new study designs, new statistical approaches may be needed to facilitate this comparison. A case in point arose in a proposed genetic substudy of a randomized trial of tamoxifen versus placebo in asymptomatic women who were at high risk for breast cancer. Although the randomized trial showed that tamoxifen substantially reduced the risk of breast cancer, the harms from tamoxifen were serious and some were life threaten-ing. In hopes of finding a subset of women with inherited risk genes who derive greater bene-fits from tamoxifen, we proposed a nested case–control study to test some trial subjects for various genes and new statistical methods to extrapolate benefits and harms to the general population. An important design question is whether or not the study should target common low penetrance genes. Our calculations show that useful results are only likely with rare high penetrance genes.  相似文献   
9.
Summary.  Official employment-related performance indicators in UK higher education are based on the population of students responding to the 'First destination supplement' (FDS). This generates potentially biased performance indicators as this population of students is not necessarily representative of the full population of leavers from each institution. University leavers who do not obtain qualifications and those who do not respond to the FDS are not included within the official analysis. We compare an employment-related performance indicator based on those students who responded to the FDS with alternative approaches which address the potential non-random nature of this subgroup of university leavers.  相似文献   
10.
Summary.  Wavelet shrinkage is an effective nonparametric regression technique, especially when the underlying curve has irregular features such as spikes or discontinuities. The basic idea is simple: take the discrete wavelet transform of data consisting of a signal corrupted by noise; shrink or remove the wavelet coefficients to remove the noise; then invert the discrete wavelet transform to form an estimate of the true underlying curve. Various researchers have proposed increasingly sophisticated methods of doing this by using real-valued wavelets. Complex-valued wavelets exist but are rarely used. We propose two new complex-valued wavelet shrinkage techniques: one based on multiwavelet style shrinkage and the other using Bayesian methods. Extensive simulations show that our methods almost always give significantly more accurate estimates than methods based on real-valued wavelets. Further, our multiwavelet style shrinkage method is both simpler and dramatically faster than its competitors. To understand the excellent performance of this method we present a new risk bound on its hard thresholded coefficients.  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