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   22781篇
  免费   213篇
管理学   3125篇
民族学   146篇
人才学   1篇
人口学   3411篇
丛书文集   78篇
教育普及   2篇
理论方法论   1631篇
综合类   618篇
社会学   10605篇
统计学   3377篇
  2021年   67篇
  2020年   189篇
  2019年   222篇
  2018年   1851篇
  2017年   1954篇
  2016年   1314篇
  2015年   261篇
  2014年   286篇
  2013年   2080篇
  2012年   710篇
  2011年   1419篇
  2010年   1232篇
  2009年   985篇
  2008年   1053篇
  2007年   1233篇
  2006年   216篇
  2005年   567篇
  2004年   534篇
  2003年   458篇
  2002年   345篇
  2001年   319篇
  2000年   308篇
  1999年   314篇
  1998年   209篇
  1997年   205篇
  1996年   241篇
  1995年   188篇
  1994年   204篇
  1993年   177篇
  1992年   236篇
  1991年   232篇
  1990年   211篇
  1989年   219篇
  1988年   203篇
  1987年   185篇
  1986年   190篇
  1985年   174篇
  1984年   207篇
  1983年   200篇
  1982年   165篇
  1981年   137篇
  1980年   139篇
  1979年   166篇
  1978年   136篇
  1977年   119篇
  1976年   102篇
  1975年   101篇
  1974年   95篇
  1973年   93篇
  1971年   65篇
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
341.
Spatially explicit data pose a series of opportunities and challenges for all the actors involved in providing data for long-term preservation and secondary analysis—the data producer, the data archive, and the data user. We report on opportunities and challenges for each of the three players, and then turn to a summary of current thinking about how best to prepare, archive, disseminate, and make use of social science data that have spatially explicit identification. The core issue that runs through the paper is the risk of the disclosure of the identity of respondents. If we know where they live, where they work, or where they own property, it is possible to find out who they are. Those involved in collecting, archiving, and using data need to be aware of the risks of disclosure and become familiar with best practices to avoid disclosures that will be harmful to respondents.
Myron P. GutmannEmail:
  相似文献   
342.
The primary purpose of the present experiment was to examine the effects on the empirical derivation of executive's utility functions caused by the use of random device analogues. The results indicate that utility functions obtained using a random device analogue imply more risk aversion than when these functions are determined by simulating actual decision situations. Furthermore, there is also evidence that the bias is directly related to the monetary amounts involved.  相似文献   
343.
M-quantile models with application to poverty mapping   总被引:1,自引:0,他引:1  
Over the last decade there has been growing demand for estimates of population characteristics at small area level. Unfortunately, cost constraints in the design of sample surveys lead to small sample sizes within these areas and as a result direct estimation, using only the survey data, is inappropriate since it yields estimates with unacceptable levels of precision. Small area models are designed to tackle the small sample size problem. The most popular class of models for small area estimation is random effects models that include random area effects to account for between area variations. However, such models also depend on strong distributional assumptions, require a formal specification of the random part of the model and do not easily allow for outlier robust inference. An alternative approach to small area estimation that is based on the use of M-quantile models was recently proposed by Chambers and Tzavidis (Biometrika 93(2):255–268, 2006) and Tzavidis and Chambers (Robust prediction of small area means and distributions. Working paper, 2007). Unlike traditional random effects models, M-quantile models do not depend on strong distributional assumption and automatically provide outlier robust inference. In this paper we illustrate for the first time how M-quantile models can be practically employed for deriving small area estimates of poverty and inequality. The methodology we propose improves the traditional poverty mapping methods in the following ways: (a) it enables the estimation of the distribution function of the study variable within the small area of interest both under an M-quantile and a random effects model, (b) it provides analytical, instead of empirical, estimation of the mean squared error of the M-quantile small area mean estimates and (c) it employs a robust to outliers estimation method. The methodology is applied to data from the 2002 Living Standards Measurement Survey (LSMS) in Albania for estimating (a) district level estimates of the incidence of poverty in Albania, (b) district level inequality measures and (c) the distribution function of household per-capita consumption expenditure in each district. Small area estimates of poverty and inequality show that the poorest Albanian districts are in the mountainous regions (north and north east) with the wealthiest districts, which are also linked with high levels of inequality, in the coastal (south west) and southern part of country. We discuss the practical advantages of our methodology and note the consistency of our results with results from previous studies. We further demonstrate the usefulness of the M-quantile estimation framework through design-based simulations based on two realistic survey data sets containing small area information and show that the M-quantile approach may be preferable when the aim is to estimate the small area distribution function.  相似文献   
344.
This paper presents a micro-analytic store choice model which eliminates the assumptions of homogeneity of stores and homogeneity of shoppers found in earlier models. The model simulates individual shopping trips within a shopping center and was successful in predicting the stores chosen by a sample of shopping center patrons. Two earlier models were also tested, but the proposed model performs better than either of the simpler models. Besides its predictive value, the model suggests a number of strategic implications for retailers and shopping center developers and provides a methodology that may be useful in other areas of behavioral research.  相似文献   
345.
The evaluation of the lease versus purchase alternative by not-for-profit hospitals presents a problem that stems from the interaction between investment and financial decisions. This paper provides an analytical framework that resolves this issue by neutralizing the impact of the lease contract on the hospital's financial structure and debt capacity. The formulation incorporates the special operating characteristics of not-for-profit hospitals: namely, they are not subject to federal income tax, and part of their revenue is generated through cost-based reimbursement.  相似文献   
346.
The entropy measure H=−σpi log pi is being used with increasing frequency in the analysis of business and economic data. It is, however, simply another measure of dispersion which can be related to the moments of the probability function. Its virtues stem from its decomposition and interpretative properties. This paper surveys the uses to which the measure has been put in the literature, and discusses whether its use has been appropriate and innovative.  相似文献   
347.
This paper presents a comparison of two heuristic methods for assigning a part-time work force to meet varying daily work loads. The authors use actual operating data from Purdue National Bank, Lafayette, Indiana, to make teller staffing decisions. The performance criteria for comparison of the two heuristics is the minimum number of workers employed, minimum number of interbranch transfers, and computer time necessary to attain a solution.  相似文献   
348.
To provide effective managerial support for decisions related to production planning and scheduling processes, it is useful to partition the set of decisions into a hierarchical framework. In the resulting system, higher level decisions impose constraints on lower level actions, and lower level decisions provide the necessary feed-back to reevaluate higher level actions. The purpose of this paper is to suggest optimum procedures to deal with the resulting subproblems and to analyze the interaction mechanisms among the different hierarchical levels. Computational results are given.  相似文献   
349.
350.
Let mathbbF(2n+d)q2mathbb{F}^{(2nu+delta)}_{q^{2}} be a (2ν+δ)-dimensional unitary space of mathbbFq2mathbb{F}_{q^{2}} , where δ=0 or 1. In this paper we construct a family of inclusion matrices associated with subspaces of mathbbF(2n+d)q2mathbb{F}^{(2nu+delta)}_{q^{2}} , and exhibit its disjunct property. Moreover, we compare the ratio efficiency of this construction with others, and find it smaller under some conditions.  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