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   8822篇
  免费   231篇
  国内免费   1篇
管理学   1224篇
民族学   32篇
人口学   799篇
丛书文集   37篇
理论方法论   752篇
综合类   135篇
社会学   4065篇
统计学   2010篇
  2020年   122篇
  2019年   188篇
  2018年   181篇
  2017年   287篇
  2016年   192篇
  2015年   169篇
  2014年   199篇
  2013年   1645篇
  2012年   265篇
  2011年   221篇
  2010年   201篇
  2009年   176篇
  2008年   253篇
  2007年   246篇
  2006年   205篇
  2005年   184篇
  2004年   170篇
  2003年   144篇
  2002年   156篇
  2001年   204篇
  2000年   177篇
  1999年   168篇
  1998年   142篇
  1997年   140篇
  1996年   138篇
  1995年   128篇
  1994年   102篇
  1993年   137篇
  1992年   148篇
  1991年   125篇
  1990年   135篇
  1989年   110篇
  1988年   112篇
  1987年   119篇
  1986年   104篇
  1985年   97篇
  1984年   126篇
  1983年   106篇
  1982年   100篇
  1981年   67篇
  1980年   98篇
  1979年   106篇
  1978年   75篇
  1977年   86篇
  1976年   75篇
  1975年   93篇
  1974年   73篇
  1973年   56篇
  1972年   62篇
  1971年   54篇
排序方式: 共有9054条查询结果,搜索用时 15 毫秒
71.
Abstract Past research suggests that mail surveys encourage a primacy effect, which is a tendency to choose the first answers from a list, whereas telephone surveys encourage a recency effect, a tendency to choose the last answers from a list. This paper summarizes results from 82 new experiments conducted in 12 separate surveys in seven states. Only four of 33 mail survey comparisons exhibited significant primacy effects, while five of 26 experiments in telephone surveys exhibited recency effects. In addition, only three of 23 cross-method comparisons produced a significant primacy/recency effect in the expected manner. The conclusion is that the prevalence of primacy and recency effects has been over-estimated by past research and a new theoretical approach that takes into account multiple causation is needed for examining these effects.  相似文献   
72.
Surprisingly little research has sought to explain differential participation after recruitment into social movement organizations (SMOs). This study examines the influence of several sets of predictors on participation by members of a national organization in the antihunger movement. The findings highlight the importance of incentive, ideological, and microstructural factors for differential participation and suggest that favorable perceptions of SMOs also promote participation. Final remarks address the implications of the findings for the social movement and voluntary organization literatures.  相似文献   
73.
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   
74.
THE SOLUTION-ORIENTED GENOGRAM: A COLLABORATIVE APPROACH   总被引:1,自引:0,他引:1  
Developed primarily by Bowenian intergenerational therapists, genograms have evolved into largely atheoretical tools used by many therapists. Given that constructivist-based therapies have become the most popular genre of contemporary family therapies (Sprenkle & Piercy, 1992), the author examines how genograms can be used to augment a solution-oriented approach. Specific interventions, case examples, and potential problems associated with such an approach are discussed, along with potential implications for family-of-origin work.  相似文献   
75.
76.
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   
77.
78.
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   
79.
This article examines the relationship between donations to the American Red Cross and the profits, sales, costs, and prices of health and safety classes offered by local chapters. Two important questions are examined: Do profits from sales of services “crowd out” donations to local chapters of the American Red Cross? Do managers respond to changes in donations by changing prices, output, or costs of saleable services? The results suggest that nonprofit managers should pay close attention to the potential impact on donations of any change in the prices charged for saleable goods and services, and that profits, costs, and prices of services are influenced by donations.  相似文献   
80.
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   
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