全文获取类型
收费全文 | 34249篇 |
免费 | 454篇 |
国内免费 | 1篇 |
专业分类
管理学 | 4777篇 |
民族学 | 215篇 |
人才学 | 7篇 |
人口学 | 4744篇 |
丛书文集 | 105篇 |
教育普及 | 1篇 |
理论方法论 | 2610篇 |
现状及发展 | 1篇 |
综合类 | 585篇 |
社会学 | 15711篇 |
统计学 | 5948篇 |
出版年
2023年 | 169篇 |
2021年 | 149篇 |
2020年 | 408篇 |
2019年 | 506篇 |
2018年 | 2180篇 |
2017年 | 2418篇 |
2016年 | 1665篇 |
2015年 | 483篇 |
2014年 | 608篇 |
2013年 | 4291篇 |
2012年 | 1193篇 |
2011年 | 1751篇 |
2010年 | 1515篇 |
2009年 | 1259篇 |
2008年 | 1325篇 |
2007年 | 1481篇 |
2006年 | 555篇 |
2005年 | 741篇 |
2004年 | 751篇 |
2003年 | 646篇 |
2002年 | 591篇 |
2001年 | 560篇 |
2000年 | 543篇 |
1999年 | 534篇 |
1998年 | 407篇 |
1997年 | 386篇 |
1996年 | 379篇 |
1995年 | 337篇 |
1994年 | 317篇 |
1993年 | 321篇 |
1992年 | 359篇 |
1991年 | 342篇 |
1990年 | 346篇 |
1989年 | 376篇 |
1988年 | 327篇 |
1987年 | 306篇 |
1986年 | 293篇 |
1985年 | 338篇 |
1984年 | 306篇 |
1983年 | 304篇 |
1982年 | 249篇 |
1981年 | 235篇 |
1980年 | 216篇 |
1979年 | 277篇 |
1978年 | 219篇 |
1977年 | 186篇 |
1976年 | 200篇 |
1975年 | 187篇 |
1974年 | 162篇 |
1973年 | 148篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Anthony C. Atkinson 《Journal of the Royal Statistical Society. Series C, Applied statistics》2003,52(3):261-278
Summary. The paper develops methods for the design of experiments for mechanistic models when the response must be transformed to achieve symmetry and constant variance. The power transformation that is used is partially justified by a rule in analytical chemistry. Because of the nature of the relationship between the response and the mechanistic model, it is necessary to transform both sides of the model. Expressions are given for the parameter sensitivities in the transformed model and examples are given of optimum designs, not only for single-response models, but also for experiments in which multivariate responses are measured and for experiments in which the model is defined by a set of differential equations which cannot be solved analytically. The extension to designs for checking models is discussed. 相似文献
72.
We examine how attention to animacy information may contribute to children's developing knowledge of language. This research extends beyond prior research in that children were shown dynamic events with novel entities, and were asked not only to comprehend sentences but to use sentence structure to infer the meaning of a new word. In a 4 × 3 design, animacy status (e.g., animate agent, inanimate patient) and labeling syntax (agent, patient, nonlabel control) were varied. Across most events, 2 1/2‐year‐old participants responded as if they expected animate entities to be named. However, in a prototypical (animate agent‐inanimate patient) event condition, children responded differentially across different syntactic structures. Thus, the clearest evidence for attention to syntactic cues was found in the prototypical event condition. These results suggest that young children attend to the animacy status of unfamiliar entities, that they have expectations about animacy relations in events, and that these expectations support emerging syntactic knowledge. 相似文献
73.
Jerald F. Lawless 《Revue canadienne de statistique》2004,32(3):327-331
Oiler, Gomez & Calle (2004) give a constant sum condition for processes that generate interval‐censored lifetime data. They show that in models satisfying this condition, it is possible to estimate non‐parametrically the lifetime distribution based on a well‐known simplified likelihood. The author shows that this constant‐sum condition is equivalent to the existence of an observation process that is independent of lifetimes and which gives the same probability distribution for the observed data as the underlying true process. 相似文献
74.
75.
Donald B. Rubin 《Scandinavian Journal of Statistics》2004,31(2):161-170
Abstract. The use of the concept of ‘direct’ versus ‘indirect’ causal effects is common, not only in statistics but also in many areas of social and economic sciences. The related terms of ‘biomarkers’ and ‘surrogates’ are common in pharmacological and biomedical sciences. Sometimes this concept is represented by graphical displays of various kinds. The view here is that there is a great deal of imprecise discussion surrounding this topic and, moreover, that the most straightforward way to clarify the situation is by using potential outcomes to define causal effects. In particular, I suggest that the use of principal stratification is key to understanding the meaning of direct and indirect causal effects. A current study of anthrax vaccine will be used to illustrate ideas. 相似文献
76.
Banks winners in tournaments are difficult to recognize 总被引:1,自引:0,他引:1
Gerhard J. Woeginger 《Social Choice and Welfare》2003,20(3):523-528
Given a tournament T, a Banks winner of T is the top vertex of any maximal (with respect to inclusion) transitive subtournament of T. In this technical note, we show that the problem of deciding whether some fixed vertex v is a Banks winner for T is NP-complete.
Received: 22 February 2002/Accepted: 20 June 2002
Supported by the START program Y43-MAT of the Austrian Ministry of Science.
I would like to thank two thank the referees for a careful reading of the paper, for helpful remarks, and for many suggestions
how to improve the presentation. 相似文献
77.
Abstract Using data from a national survey in Bolivia and from a regional sample of poor communities in two regions of Bolivia, we model the effects of community conditions, household characteristics, and social relations on child health as measured by child mortality and stunted growth. Based on national data, children in rural areas are twice as likely to die before the age of two than are children in large cities, and about one‐third of the children in rural areas are stunted. Including measures of community, household, and maternal characteristics accounts for at least two‐thirds of the urban/rural difference in child health. We conclude that expansion of health services, improvements in household and community sanitation, and socioeco‐nomic development are all needed to overcome the rural disadvantage in child health. 相似文献
78.
Gayane Novikova 《Transition Studies Review》2004,11(3):213-223
The collapse of the USSR was accompanied by transformation of the South Caucasian latent ethnopolitical conflicts into local wars. Today the situation in the area of the conflicts is “neither war, nor peace”. Three unresolved conflicts of the South Caucasus can be considered as one of the most serious obstacles for establishing a regional security system.The article gives the general characteristics of these conflicts, the trends of their development, taking into account the time factor, and analyzes the behavioral models of the main players – de jure recognized and unrecognized de facto states of the South Caucasus. The basic objective of the main players should be to keep the situation on a level preventing the resumption of the armed conflicts. The attempts of forced resolution of the conflicts are fraught with destabilization of the situation not only in the area of any of these conflicts but in the whole region. 相似文献
79.
Mohammad Salehi M. George A.F. Seber 《Australian & New Zealand Journal of Statistics》2004,46(3):483-494
Not having a variance estimator is a seriously weak point of a sampling design from a practical perspective. This paper provides unbiased variance estimators for several sampling designs based on inverse sampling, both with and without an adaptive component. It proposes a new design, which is called the general inverse sampling design, that avoids sampling an infeasibly large number of units. The paper provide estimators for this design as well as its adaptive modification. A simple artificial example is used to demonstrate the computations. The adaptive and non‐adaptive designs are compared using simulations based on real data sets. The results indicate that, for appropriate populations, the adaptive version can have a substantial variance reduction compared with the non‐adaptive version. Also, adaptive general inverse sampling with a limitation on the initial sample size has a greater variance reduction than without the limitation. 相似文献
80.
Lu Lin 《Statistical Papers》2004,45(4):529-544
The quasi-score function, as defined by Wedderburn (1974) and McCullagh (1983) and so on, is a linear function of observations.
The generalized quasi-score function introduced in this paper is a linear function of some unbiased basis functions, where
the unbiased basis functions may be some linear functions of the observations or not, and can be easily constructed by the
meaning of the parameters such as mean and median and so on. The generalized quasi-likelihood estimate obtained by such a
generalized quasi-score function is consistent and has an asymptotically normal distribution. As a result, the optimum generalized
quasi-score is obtained and a method to construct the optimum unbiased basis function is introduced. In order to construct
the potential function, a conservative generalized estimating function is defined. By conservative, a potential function for
the projected score has many properties of a log-likelihood function. Finally, some examples are given to illustrate the theoretical
results.
This paper is supported by NNSF project (10371059) of China and Youth Teacher Foundation of Nankai University. 相似文献