全文获取类型
收费全文 | 10296篇 |
免费 | 307篇 |
国内免费 | 1篇 |
专业分类
管理学 | 1437篇 |
民族学 | 43篇 |
人才学 | 1篇 |
人口学 | 865篇 |
丛书文集 | 42篇 |
理论方法论 | 974篇 |
综合类 | 143篇 |
社会学 | 4922篇 |
统计学 | 2177篇 |
出版年
2023年 | 64篇 |
2020年 | 153篇 |
2019年 | 230篇 |
2018年 | 234篇 |
2017年 | 346篇 |
2016年 | 255篇 |
2015年 | 206篇 |
2014年 | 270篇 |
2013年 | 1868篇 |
2012年 | 315篇 |
2011年 | 272篇 |
2010年 | 271篇 |
2009年 | 230篇 |
2008年 | 313篇 |
2007年 | 312篇 |
2006年 | 267篇 |
2005年 | 224篇 |
2004年 | 208篇 |
2003年 | 195篇 |
2002年 | 210篇 |
2001年 | 244篇 |
2000年 | 205篇 |
1999年 | 193篇 |
1998年 | 170篇 |
1997年 | 177篇 |
1996年 | 149篇 |
1995年 | 148篇 |
1994年 | 112篇 |
1993年 | 155篇 |
1992年 | 161篇 |
1991年 | 154篇 |
1990年 | 154篇 |
1989年 | 120篇 |
1988年 | 120篇 |
1987年 | 121篇 |
1986年 | 110篇 |
1985年 | 100篇 |
1984年 | 135篇 |
1983年 | 116篇 |
1982年 | 111篇 |
1981年 | 70篇 |
1980年 | 101篇 |
1979年 | 113篇 |
1978年 | 77篇 |
1977年 | 90篇 |
1976年 | 77篇 |
1975年 | 91篇 |
1974年 | 70篇 |
1973年 | 55篇 |
1972年 | 61篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
101.
Approximations of the Bayesian estimators of the survival function based on the censored data of the log-logistic distribution are obtained under squared-error and log-odds squared-error loss functions. A numerical example is presented. Through a Monte Carlo simulation study, the behavior of the approximations found by Tierney & Kadane and Lindley are compared with a method suggested by Weiss & Howlader. 相似文献
102.
Regina Thompson Paul H. Templet John K. Gamman Scott T. McCleary Margaret A. Reams 《Risk analysis》1994,14(5):857-861
The goal of Louisiana's 1990–1991 comparative risk project, also called the Louisiana Environmental Action Plan (LEAP), was to incorporate risk assessment into state environmental planning and policymaking. Scientists, government officials, and citizens were brought together to estimate the relative risk to human health, natural resources, and quality of life posed by 33 selected environmental issues. The issues were then ranked according to their relative estimated risks. It was hoped that this ranking of "comparative risks" would enable state policymakers to target the most important environmental problems and allocate scarce public resources more rationally and efficiently. As a result of the project, the governor issued an Executive Order forming a permanent Public Advisory Committee to continue this type of comparative risk assessment in Louisiana. 相似文献
103.
104.
Mark Conaway Carolyn Pillers Tim Robertson Jim Sconing 《Revue canadienne de statistique》1991,19(3):283-296
Several methods exist for the problem of testing the equality of several treatments against the one-sided alternative that the treatments are better than the control. These methods include Dunnett's test, Bartholomew's likelihood-ratio test, the Abelson-Tukey-Schaafsma-Smid optimal-contrast test, and the multiple-contrast test of Mukerjee, Robertson, and Wright. A new test is proposed based on an approximation of the likelihood-ratio test of Bartholomew. This test involves using a circular cone in place of the alternative-hypothesis cone. The circular-cone test has excellent power characteristics similar to those of Bartholomew's test. Moreover, it has the advantages of being simpler to compute and may be used with unequal sample sizes. 相似文献
105.
Although concerns have frequently been raised recently regarding the quality of life of intercollegiate athletes, information is seldom available on which college and university administrators can base policy decisions. Particularly lacking are studies that provide administrators with assessments of their own athletics programs relative to athletics programs at other institutions. We describe here a method we used in conducting a comparative evaluation of the status of student-athletes at a large public university, involving comparisons of student-athletes at this university to student-athletes at a subset of the institutions that participated in the 1987–88 National Study of Intercollegiate Athletes. By utilizing existing data sets to construct comparison samples, relative assessments of the status of student-athletes at a given institution can be performed without the excessive costs of gathering data on student-athletes at comparison institutions. Techniques employed in data collection and analysis are discussed as well as the format of the report in which the findings of the study were presented. 相似文献
106.
107.
The skin is a route of exposure that needs to be considered when conducting a risk assessment. It is necessary to identify the potential for dermal penetration by a chemical as well as to determine the overall importance of the dermal route of exposure as compared with inhalation or oral routes of exposure. The physical state of the chemical, vapor or liquid, the concentration, neat or dilute, and the vehicle, lipid or aqueous, is also important. Dermal risk is related to the product of the amounts of penetration and toxicity. Toxicity involves local effects on the skin itself and the potential for systemic effects. Dermal penetration is described in large part by the permeability constant. When permeability constants are not known, partition coefficients can be used to estimate a chemical's potential to permeate the skin. With these concepts in mind, a tiered approach is proposed for dermal risk assessment. A key first step is the determination of a skin-to-air or skin-to-medium partition coefficient to estimate a potential for dermal absorption. Building a physiologically-based pharmacokinetic (PBPK) model is another step in the tiered approach and is useful prior to classical in vivo toxicity tests. A PBPK model can be used to determine a permeability constant for a chemical as well as to show the distribution of the chemical systemically. A detailed understanding of species differences in the structure and function of the skin and how they relate to differences in penetration rates is necessary in order to extrapolate animal data from PBPK models to the human. A study is in progress to examine anatomical differences for four species. 相似文献
108.
Mark L. Savickas 《The Career development quarterly》1991,39(4):315-324
Examining concepts about work and love can help people increase their career success and life satisfaction. Career counselors may initiate this examination by eliciting clients' concepts about work and love. After hearing a client's ideas about work and love, counselors can compare this personal meaning to the social meaning of work and love. When this comparison reveals dysfunctional beliefs about work and love, counselors can link these beliefs to their client's career concerns. Such a linkage typically provokes a cognitive dissonance that motivates clients to modify their beliefs. Counselors can facilitate meaning modification by using client-centered and social influence techniques. 相似文献
109.
Mark J. Schafer 《The Sociological quarterly》2006,47(4):665-691
This study examines school enrollment in two sub-Saharan African nations, Malawi and Kenya. The article advances a refined family economy theoretical framework for understanding variations in school enrollment. It recasts family economy frameworks to consider not only how the household institution mediates a broad social change, but also how the family institution itself may be influenced by a macroinstitutional change. The findings suggest that household structural changes, as well as changes in parents' activities and perceptions, help explain enrollment practices in rural Malawi and Kenya. 相似文献
110.
In the design of experiments for estimating the slope of a response surface, slope-rotatability is a desirable property. In this paper, a measure is introduced that enables us to assess the degree of slope-rotatability for a given response surface design. The measure takes the value zero if and only if the design is slope-rotatable, and becomes larger as the design deviates from a slope-rotatable design. Examples of applying this measure to some response surface designs are also given. 相似文献