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   1388篇
  免费   70篇
管理学   197篇
民族学   12篇
人口学   102篇
丛书文集   5篇
理论方法论   201篇
综合类   14篇
社会学   783篇
统计学   144篇
  2023年   10篇
  2022年   6篇
  2021年   12篇
  2020年   28篇
  2019年   41篇
  2018年   50篇
  2017年   73篇
  2016年   61篇
  2015年   33篇
  2014年   40篇
  2013年   212篇
  2012年   52篇
  2011年   59篇
  2010年   41篇
  2009年   35篇
  2008年   51篇
  2007年   53篇
  2006年   46篇
  2005年   36篇
  2004年   57篇
  2003年   35篇
  2002年   37篇
  2001年   32篇
  2000年   29篇
  1999年   25篇
  1998年   30篇
  1997年   19篇
  1996年   21篇
  1995年   10篇
  1994年   10篇
  1993年   14篇
  1992年   14篇
  1991年   13篇
  1990年   13篇
  1989年   8篇
  1988年   9篇
  1987年   9篇
  1986年   8篇
  1985年   12篇
  1984年   9篇
  1983年   7篇
  1982年   15篇
  1981年   9篇
  1980年   11篇
  1978年   13篇
  1977年   6篇
  1976年   6篇
  1975年   5篇
  1973年   6篇
  1969年   4篇
排序方式: 共有1458条查询结果,搜索用时 31 毫秒
851.
The purpose of this study is to highlight the experiences of individuals who participate in the Responsible Conduct of Research (RCR) training program held at various universities in Malaysia. In response to a mailing request sent to 40 individuals who had undertaken a RCR training program, 15 participants agreed to be interviewed. The results of the study showed that the three main reasons for participating in the training were as follows: anticipation for knowledge gained; personal experience with research misconduct; and establishing a new network of researchers. In terms of the positive effects gained from undertaking the training, the participants highlighted an increased awareness of the issues and problems related to research misconduct; the need to promote integrity in research conduct; a change in the way they conduct their research; and a change in the way they confront and address misconduct. The findings of this study should be valuable for policy makers and those involved in the management of research programs and ethics, as it demonstrated the importance of RCR training in equipping researchers with the necessary knowledge to conduct research responsibly, and to avoid research misconduct.  相似文献   
852.
853.
The hazard function plays an important role in cancer patient survival studies, as it quantifies the instantaneous risk of death of a patient at any given time. Often in cancer clinical trials, unimodal hazard functions are observed, and it is of interest to detect (estimate) the turning point (mode) of hazard function, as this may be an important measure in patient treatment strategies with cancer. Moreover, when patient cure is a possibility, estimating cure rates at different stages of cancer, in addition to their proportions, may provide a better summary of the effects of stages on survival rates. Therefore, the main objective of this paper is to consider the problem of estimating the mode of hazard function of patients at different stages of cervical cancer in the presence of long-term survivors. To this end, a mixture cure rate model is proposed using the log-logistic distribution. The model is conveniently parameterized through the mode of the hazard function, in which cancer stages can affect both the cured fraction and the mode. In addition, we discuss aspects of model inference through the maximum likelihood estimation method. A Monte Carlo simulation study assesses the coverage probability of asymptotic confidence intervals.  相似文献   
854.
855.
We show that Bayesian population reconstruction, a recent method for estimating past populations by age, works for data of widely varying quality. Bayesian reconstruction simultaneously estimates age-specific population counts, fertility rates, mortality rates, and net international migration flows from fragmentary data, while formally accounting for measurement error. As inputs, Bayesian reconstruction uses initial bias-reduced estimates of standard demographic variables. We reconstruct the female populations of three countries: Laos, a country with little vital registration data where population estimation depends largely on surveys; Sri Lanka, a country with some vital registration data; and New Zealand, a country with a highly developed statistical system and good quality vital registration data. In addition, we extend the method to countries without censuses at regular intervals. We also use it to assess the consistency of results between model life tables and available census data, and hence to compare different model life table systems.  相似文献   
856.
Both advocates of residential group care and therapeutic foster care claim that their programs serve the most troubled children and youth. Prior research, often limited to single sites and small numbers of subjects, have not confirmed such claims. The authors describe the evidence regarding these claims, the research literature pertaining to program effectiveness, and a means for empirically evaluating the impact of residential group care and therapeutic foster care.  相似文献   
857.
858.
859.
A comparison of the determinants of white and nonwhite interstate migration   总被引:2,自引:0,他引:2  
The primary objective of this study is to present an explanation of the interstate migratory movements of white and nonwhite persons which occurred over the period 1955–1960. The study is similar to several other recent studies in that we estimate the magnitudes in which various factors have influenced interstate or interregional migration in the United States. It differs from earlier studies in two important respects. First, we estimate and compare the magnitudes in which certain factors have influenced both white and nonwhite interstate migration. Second, unlike previous studies, many of which have made “country-wide” estimates of the determinants of migration, we have disaggregated data to the state level and obtained white and nonwhite “migration elasticities” for every state. These elasticities are in turn used to test several additional hypotheses relating to racial and regional differences in the elasticities themselves. We argue that discrimination against nonwhites and/or differences in “social milieu” between South and nonsouth provide a unifying explanation for most of the observed differences in white and nonwhite migration elasticities.  相似文献   
860.
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