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   9089篇
  免费   257篇
  国内免费   1篇
管理学   1276篇
民族学   55篇
人口学   772篇
丛书文集   29篇
理论方法论   853篇
综合类   85篇
社会学   4031篇
统计学   2246篇
  2023年   53篇
  2022年   35篇
  2021年   66篇
  2020年   164篇
  2019年   244篇
  2018年   267篇
  2017年   357篇
  2016年   254篇
  2015年   168篇
  2014年   275篇
  2013年   1716篇
  2012年   282篇
  2011年   285篇
  2010年   231篇
  2009年   219篇
  2008年   237篇
  2007年   227篇
  2006年   243篇
  2005年   222篇
  2004年   193篇
  2003年   167篇
  2002年   205篇
  2001年   235篇
  2000年   222篇
  1999年   215篇
  1998年   155篇
  1997年   150篇
  1996年   121篇
  1995年   107篇
  1994年   151篇
  1993年   113篇
  1992年   133篇
  1991年   139篇
  1990年   124篇
  1989年   116篇
  1988年   96篇
  1987年   97篇
  1986年   95篇
  1985年   96篇
  1984年   99篇
  1983年   75篇
  1982年   73篇
  1981年   56篇
  1980年   68篇
  1979年   66篇
  1978年   55篇
  1977年   53篇
  1976年   44篇
  1975年   50篇
  1974年   42篇
排序方式: 共有9347条查询结果,搜索用时 15 毫秒
251.
Abstract

In this paper we find the maximum likelihood estimates (MLEs) of hazard rate and mean residual life functions (MRLF) of Pareto distribution, their asymptotic non degenerate distribution, exact distribution and moments. We also discuss the uniformly minimum variance unbiased estimate (UMVUE) of hazard rate function and MRLF. Finally, two numerical examples with simulated data and real data set, are presented to illustrate the proposed estimates.  相似文献   
252.
Listeria monocytogenes is a leading cause of hospitalization, fetal loss, and death due to foodborne illnesses in the United States. A quantitative assessment of the relative risk of listeriosis associated with the consumption of 23 selected categories of ready‐to‐eat foods, published by the U.S. Department of Health and Human Services and the U.S. Department of Agriculture in 2003, has been instrumental in identifying the food products and practices that pose the greatest listeriosis risk and has guided the evaluation of potential intervention strategies. Dose‐response models, which quantify the relationship between an exposure dose and the probability of adverse health outcomes, were essential components of the risk assessment. However, because of data gaps and limitations in the available data and modeling approaches, considerable uncertainty existed. Since publication of the risk assessment, new data have become available for modeling L. monocytogenes dose‐response. At the same time, recent advances in the understanding of L. monocytogenes pathophysiology and strain diversity have warranted a critical reevaluation of the published dose‐response models. To discuss strategies for modeling L. monocytogenes dose‐response, the Interagency Risk Assessment Consortium (IRAC) and the Joint Institute for Food Safety and Applied Nutrition (JIFSAN) held a scientific workshop in 2011 (details available at http://foodrisk.org/irac/events/ ). The main findings of the workshop and the most current and relevant data identified during the workshop are summarized and presented in the context of L. monocytogenes dose‐response. This article also discusses new insights on dose‐response modeling for L. monocytogenes and research opportunities to meet future needs.  相似文献   
253.
An asymptotic series for sums of powers of binomial coefficients is derived, the general term being defined and usable with a computer symbolic language. Sums of squares of coefficients in the symmetric case are shown to have a link with classical moment problems, but this property breaks down for cubes and higher powers. Problems of remainders for the asymptotic series are mentioned. Using the reflection formula for I'(.), a continuous form for a binomial function is set up, and this becomes oscillatory outstde the usual range. A new contmued fraction emerges for the logarithm of an adjusted sum of binomial squares. The note is a contribution to the problem of the interpretation of asymptotic series and processes for their convergence acceleration.  相似文献   
254.
255.
Samuels interviewed Dimen in lieu of a book review for her Sexuality, Intimacy, Power. The interview was unstructured and dialogical and covered the following main topics: (a) professional issues in the field of psychoanalysis such as the relation of theory to practice and reflections on the nature and content of trainings in psychoanalysis; (b) issues in the broad areas of sexuality and gender including the question of moral relativism with respect to sexual behaviors historically designated as “perverse” and considerations of masculinity, femininity, and patriarchy; (c) intellectual considerations such as the relations between anthropology and psychoanalysis and the as yet indeterminate nature of the discipline of psychoanalysis, neither art nor science and not a hybrid of the two; and (d) the political, social, and cultural contexts within which psychoanalytic endeavors including the interview itself are taking place.  相似文献   
256.
257.
258.
A class of asymptotically nonparametric test with contains a test proposed by Wei(1980), is considered for testing the equality of two continuous distribution funcitons when paired observations are subject to arbitrary right censorship. It is shown that under the null hypothesis each test statistic converges in distribution to the standard normal random variable. Furthermore. the Monte Carlo simulation results indicate that some tests in this class are more powerful than Wei's test. A generalization to incomplete censored paired data is also included.  相似文献   
259.
The 2008 spike in world grain prices is widely recognised to have had serious impacts on food security and poverty, but these high grain prices are commonly described as low in historical terms – an inconsistency resulting from the use of advanced‐ and global‐economy price indices in calculating real prices. This ignores the high share of food in poor people's expenditures and the indirect effects of income growth on expenditure patterns of rich consumers. Poor consumers have not experienced the same falls in real food prices and are more vulnerable to price shocks. Different price indices must be developed to take account of differences between consumer groups.  相似文献   
260.
While all children may be the victims of abuse, disabled children are particularly vulnerable. This paper explores the views of professionals working with children using alternative/augmented communication systems on the issues relating to communication about abuse. Interviews were carried out with 20 staff from eight establishments for disabled children across Scotland. It describes the range of alternative/augmented communication systems used and the barriers to communication about abuse. Staff generally accepted the importance of providing the appropriate vocabulary in augmented communication systems, but systems that provide such vocabulary were not widely used. Staff considered that a major difficulty concerned the level of understanding disabled children might have about concepts of abuse. They were unsure how the appropriate vocabulary could be introduced in a natural way and how links could be made between the signs and their meanings. Staff saw themselves as those most able to protect the children, but it was felt that discovery of abuse was more likely to come from them noticing physical signs, behaviour or mood changes than from the child communicating explicitly about abuse. The need for appropriate training and increased coordination between social work, health and education is highlighted. Copyright © 2001 John Wiley & Sons, Ltd.  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