全文获取类型
收费全文 | 14782篇 |
免费 | 393篇 |
专业分类
管理学 | 1965篇 |
民族学 | 62篇 |
人才学 | 2篇 |
人口学 | 1232篇 |
丛书文集 | 89篇 |
教育普及 | 2篇 |
理论方法论 | 1424篇 |
综合类 | 346篇 |
社会学 | 7588篇 |
统计学 | 2465篇 |
出版年
2023年 | 77篇 |
2021年 | 83篇 |
2020年 | 224篇 |
2019年 | 277篇 |
2018年 | 308篇 |
2017年 | 448篇 |
2016年 | 359篇 |
2015年 | 281篇 |
2014年 | 341篇 |
2013年 | 2397篇 |
2012年 | 462篇 |
2011年 | 383篇 |
2010年 | 297篇 |
2009年 | 302篇 |
2008年 | 344篇 |
2007年 | 362篇 |
2006年 | 301篇 |
2005年 | 412篇 |
2004年 | 368篇 |
2003年 | 322篇 |
2002年 | 332篇 |
2001年 | 372篇 |
2000年 | 338篇 |
1999年 | 354篇 |
1998年 | 253篇 |
1997年 | 250篇 |
1996年 | 239篇 |
1995年 | 227篇 |
1994年 | 234篇 |
1993年 | 203篇 |
1992年 | 259篇 |
1991年 | 267篇 |
1990年 | 234篇 |
1989年 | 230篇 |
1988年 | 206篇 |
1987年 | 194篇 |
1986年 | 194篇 |
1985年 | 189篇 |
1984年 | 228篇 |
1983年 | 218篇 |
1982年 | 181篇 |
1981年 | 142篇 |
1980年 | 147篇 |
1979年 | 174篇 |
1978年 | 140篇 |
1977年 | 127篇 |
1976年 | 108篇 |
1975年 | 106篇 |
1974年 | 98篇 |
1973年 | 94篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
31.
教学管理是教学工作运转的支柱,教学管理的优劣影响着教学质量。该文介绍了外语学院教学管理工作的基本内容,包括教学任务的布置落实、教学检查、教学文件的建设、学籍管理,以及结合学院的实际情况完善考试制度、制定成绩管理细则和考试结果奖励办法等。 相似文献
32.
Mark S. Pearce Heather O. Dickinson Murray Aitkin Louise Parker 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2002,165(3):523-548
Summary. This study investigates whether there was evidence of increasing risk of still-birth with increasing paternal exposure to ionizing radiation received during employment at the Sellafield nuclear installation before the child was conceived. A significant positive association is found between the total paternal preconceptional exposure to external ionizing radiation and the risk of still-birth (after adjustment for year of birth, social class, birth order and paternal age, odds ratio at 100 mSv 1.24 (95% confidence interval 1.04–1.45)). A summary of the principal scientific findings of this study has been published in the Lancet . This paper describes in detail the statistical methods that were used in the investigation and presents the results in full. 相似文献
33.
Mark Carpenter 《Journal of statistical planning and inference》2002,100(2):197-208
In this paper, we study the estimation of the minimum and maximum location parameters, respectively, representing the minimum guaranteed lifetime of series and parallel systems of components, within a general class of scale mixtures. The conditional or underlying distribution has only the primary restriction of being a location-scale family with positive support. The mixing distribution is also quite general in that we only assume that it has positive support and finite second moment. For demonstrative purposes several special cases are highlighted such as the gamma, inverse-Gaussian, and discrete mixture. Various estimators, including bootstrap bias corrected estimators, are compared with respect to both mean-squared-error and Pitman's measure of closeness. 相似文献
34.
Carmen Fernández Eduardo Ley Mark F. J. Steel 《Journal of the Royal Statistical Society. Series C, Applied statistics》2002,51(3):257-280
Summary. We model daily catches of fishing boats in the Grand Bank fishing grounds. We use data on catches per species for a number of vessels collected by the European Union in the context of the Northwest Atlantic Fisheries Organization. Many variables can be thought to influence the amount caught: a number of ship characteristics (such as the size of the ship, the fishing technique used and the mesh size of the nets) are obvious candidates, but one can also consider the season or the actual location of the catch. Our database leads to 28 possible regressors (arising from six continuous variables and four categorical variables, whose 22 levels are treated separately), resulting in a set of 177 million possible linear regression models for the log-catch. Zero observations are modelled separately through a probit model. Inference is based on Bayesian model averaging, using a Markov chain Monte Carlo approach. Particular attention is paid to the prediction of catches for single and aggregated ships. 相似文献
35.
Medical fraud and overservicing are estimated to cost the Australian community between $130 and $200 million per annum, a figure far greater than the national cost of burglary and almost the same as the total property loss from all conventional crime. An examination of the social antecedents of medical fraud and overservicing suggests that the predisposition of some doctors to engage in these practices occurs because of the following: (1) medical training and professional socialization that orientate student doctors away from altruistic health issues towards narrower self-interested professional concerns; (2) career expectations of a high pattern of material consumption that are often frustrated by an increasingly competitive medical market place; and (3) professional medical organizations that lobby for national health policies which reflect the mercenary self-interest of doctors rather than the health interest of the nation. 相似文献
36.
Amy H. Herring Joseph G. Ibrahim Stuart R. Lipsitz 《Journal of the Royal Statistical Society. Series C, Applied statistics》2004,53(2):293-310
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
37.
For a wide variety of applications, experiments are based on units ordered over time or space. Models for these experiments generally may include one or more of: correlations, systematic trends, carryover effects and interference effects. Since the standard optimal block designs may not be efficient in these situations, orthogonal arrays of type I and type II, which were introduced in 1961 by C.R. Rao [Combinatorial arrangements analogous to orthogonal arrays, Sankhya A 23 (1961) 283–286], have been recently used to construct optimal and efficient designs for many of these experiments. Results in this area are unified and the salient features are outlined. 相似文献
38.
39.
40.
The theory of incapacitation involves reducing an offender's ability or capacity to commit further crimes. Capital punishment accomplishes this goal. An executed murderer never murders again. However, we do not execute all murderers, only capital murderers. This policy produces several research questions. Do capital murderers present a special risk to society? Are capital murderers more likely to murder or commit other violent crimes again than other murderers or the average citizen? To answer these questions, many states require a prediction of future dangerousness of a newly convicted murderer. To what extent has the judgment of future dangerousness matched actuarial data of subsequent murders and serious crimes? Using a secondary analysis, this investigation attempted to assemble available data of postconviction dangerousness of death sentenced capital murderers to create a more comprehensive actuarial account of subsequent dangerousness and to present the data in a common format used by the Federal Bureau of Investigation and the Bureau of Justice Statistics. Across 14 studies identified with relevant data, there were 13 instances of subsequent murder and 462 serious crime or prison rule violations. 相似文献