全文获取类型
收费全文 | 7913篇 |
免费 | 138篇 |
专业分类
管理学 | 1126篇 |
民族学 | 32篇 |
人才学 | 1篇 |
人口学 | 721篇 |
丛书文集 | 33篇 |
理论方法论 | 698篇 |
综合类 | 283篇 |
社会学 | 3349篇 |
统计学 | 1808篇 |
出版年
2021年 | 52篇 |
2020年 | 90篇 |
2019年 | 129篇 |
2018年 | 167篇 |
2017年 | 244篇 |
2016年 | 199篇 |
2015年 | 149篇 |
2014年 | 175篇 |
2013年 | 1359篇 |
2012年 | 296篇 |
2011年 | 218篇 |
2010年 | 175篇 |
2009年 | 159篇 |
2008年 | 192篇 |
2007年 | 180篇 |
2006年 | 139篇 |
2005年 | 198篇 |
2004年 | 174篇 |
2003年 | 215篇 |
2002年 | 231篇 |
2001年 | 217篇 |
2000年 | 192篇 |
1999年 | 185篇 |
1998年 | 143篇 |
1997年 | 112篇 |
1996年 | 127篇 |
1995年 | 105篇 |
1994年 | 97篇 |
1993年 | 105篇 |
1992年 | 125篇 |
1991年 | 115篇 |
1990年 | 112篇 |
1989年 | 102篇 |
1988年 | 110篇 |
1987年 | 110篇 |
1986年 | 103篇 |
1985年 | 121篇 |
1984年 | 97篇 |
1983年 | 105篇 |
1982年 | 74篇 |
1981年 | 74篇 |
1980年 | 69篇 |
1979年 | 74篇 |
1978年 | 77篇 |
1977年 | 54篇 |
1976年 | 45篇 |
1975年 | 59篇 |
1974年 | 48篇 |
1973年 | 41篇 |
1972年 | 39篇 |
排序方式: 共有8051条查询结果,搜索用时 0 毫秒
41.
42.
该文在查阅古文献的基础上 ,对我国古代在城市水资源合理利用与开发的同时 ,如何与改善人居环境、城市景观相结合进行了分析研究。古人的这种做法对于如何改善我国目前日益恶劣的城市生态环境以及如何使人居环境工程建设与城市景观建设密切结合 ,给予了很好的启示作用 相似文献
43.
邵玉铮 《北京林业大学学报(社会科学版)》2003,2(4):73-76
该文依据分类学的原则 ,剖析了沿用一千多年的“永字八法” ,减撇加折 ,构成了“新永字八法”。同时推出了“方圆米格” ,不仅适用于楷书 ,也可传习行、草、隶、篆诸种书体。改进后的“大小多用方圆米格” ,既可写大小多种字体 ,又能提高利用率。 相似文献
44.
Sources of drug information among adolescent students 总被引:1,自引:0,他引:1
E Mirzaee P M Kingery B E Pruitt G Heuberger R S Hurley 《Journal of drug education》1991,21(2):95-106
A sample of 1023 eighth and tenth grade students in small to medium-sized central Texas school districts was assessed to determine the amount of information they receive from ten sources about six categories of drugs. The amount of information males reported receiving about each drug category was significantly greater than what females reported, and the amount of information that eighth graders reported receiving about each drug category was significantly greater than what tenth graders reported. Television was the primary source of drug information for all categories of drugs except inhalants, for which friends and television were equally important sources. Parents and printed media (magazines or newspapers) were of secondary importance, followed by friends and teachers. Adolescents were less likely to receive drug-related information from experience, siblings, church, doctors, and police. The reliance on the mass media for drug information in smaller school districts is a pattern which has been previously observed in larger urban districts. This consistency suggests that mass media approaches to drug education are likely to be as effective in rural areas and smaller towns as they are among urban adolescents. Implications for television programming are discussed. 相似文献
45.
盆景艺术风格是盆景艺术家的创作个性在作品中的外在表现 ,它对盆景艺术的发展起着很重要的作用 ,人们对盆景的感性认识直接来源于盆景的风格。大部分盆景方面的书和文章都会涉及到盆景艺术风格的问题 ,但是 ,迄今为止对盆景艺术风格的形成和发展进行过系统研究的人还不是很多。基于对艺术发展规律和中国各种艺术风格盆景发展历史的研究 ,该文详细论述了影响盆景艺术风格形成和发展的内在、外在因素及它们之间的关系 ,并对怎样给我国盆景艺术注入新的活力提出了一些建议 ,对我国盆景艺术的发展和创新起到一定的指导作用 相似文献
46.
To protect public-use microdata, one approach is not to allow users access to the microdata. Instead, users submit analyses to a remote computer that reports back basic output from the fitted model, such as coefficients and standard errors. To be most useful, this remote server also should provide some way for users to check the fit of their models, without disclosing actual data values. This paper discusses regression diagnostics for remote servers. The proposal is to release synthetic diagnostics—i.e. simulated values of residuals and dependent and independent variables–constructed to mimic the relationships among the real-data residuals and independent variables. Using simulations, it is shown that the proposed synthetic diagnostics can reveal model inadequacies without substantial increase in the risk of disclosures. This approach also can be used to develop remote server diagnostics for generalized linear models. 相似文献
47.
经济系统的演化与政策作用 总被引:1,自引:0,他引:1
该文根据耗散结构的基本原理 ,将经济系统划分为平衡态、过渡态和自组织状态。并将政策因素看成是一种外部调控手段 ,分析了在经济系统的不同状态下 ,政策因素对改变系统的结构及变化趋势所起的不同作用 相似文献
48.
James P. McDermott G. Jogesh Babu John C. Liechty Dennis K. J. Lin 《Statistics and Computing》2007,17(4):311-321
We consider the problem of density estimation when the data is in the form of a continuous stream with no fixed length. In
this setting, implementations of the usual methods of density estimation such as kernel density estimation are problematic.
We propose a method of density estimation for massive datasets that is based upon taking the derivative of a smooth curve
that has been fit through a set of quantile estimates. To achieve this, a low-storage, single-pass, sequential method is proposed
for simultaneous estimation of multiple quantiles for massive datasets that form the basis of this method of density estimation.
For comparison, we also consider a sequential kernel density estimator. The proposed methods are shown through simulation
study to perform well and to have several distinct advantages over existing methods. 相似文献
49.
50.
Jason P. Fine David V. Glidden Kristine E. Lee 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2003,65(1):317-329
Summary. We propose a simple estimation procedure for a proportional hazards frailty regression model for clustered survival data in which the dependence is generated by a positive stable distribution. Inferences for the frailty parameter can be obtained by using output from Cox regression analyses. The computational burden is substantially less than that of the other approaches to estimation. The large sample behaviour of the estimator is studied and simulations show that the approximations are appropriate for use with realistic sample sizes. The methods are motivated by studies of familial associations in the natural history of diseases. Their practical utility is illustrated with sib pair data from Beaver Dam, Wisconsin. 相似文献