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   5775篇
  免费   99篇
管理学   863篇
民族学   31篇
人才学   2篇
人口学   543篇
丛书文集   37篇
理论方法论   699篇
综合类   51篇
社会学   2925篇
统计学   723篇
  2023年   22篇
  2020年   91篇
  2019年   107篇
  2018年   92篇
  2017年   135篇
  2016年   147篇
  2015年   100篇
  2014年   142篇
  2013年   943篇
  2012年   173篇
  2011年   157篇
  2010年   134篇
  2009年   150篇
  2008年   166篇
  2007年   168篇
  2006年   155篇
  2005年   193篇
  2004年   220篇
  2003年   188篇
  2002年   192篇
  2001年   148篇
  2000年   117篇
  1999年   130篇
  1998年   114篇
  1997年   101篇
  1996年   88篇
  1995年   96篇
  1994年   89篇
  1993年   100篇
  1992年   74篇
  1991年   85篇
  1990年   61篇
  1989年   59篇
  1988年   70篇
  1987年   50篇
  1986年   52篇
  1985年   65篇
  1984年   58篇
  1983年   57篇
  1982年   59篇
  1981年   48篇
  1980年   47篇
  1979年   46篇
  1978年   44篇
  1977年   46篇
  1976年   44篇
  1975年   44篇
  1974年   32篇
  1973年   29篇
  1971年   22篇
排序方式: 共有5874条查询结果,搜索用时 15 毫秒
51.
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   
52.
Since children, particularly daughters, are among the most important sources of help and support for older Americans, it has been suggested that women's increasing employment will affect filial relations. Empirical evidence on this issue is inconsistent, in part due to the use of nonprobability samples. Few studies have measured effects for men. We attempt to broaden the scope of this question beyond help to the frail elderly by asking whether employment affects filial relations in general. We examine effects of hours employed on telephone contact, visiting, feelings of closeness, filial attitudes, and assistance to biological parents, for an area probability sample of men and women over 40. There are no effects of employment for men or women on contact, closeness, or assistance. For the vast majority of this population sample, contact and assistance involve few hours per week, and thus do not seem to conflict with employment.  相似文献   
53.
Religious affiliation and the family   总被引:1,自引:0,他引:1  
The process of religious affiliation is mediated by institutions such as the family, which provide a network of ties to the public sphere. Variations in the likelihood of those with no religious affiliation in high school (N=900) becoming church members by the time they reach 30 are explained in terms of a combination of individual attributes, such as educational and spatial mobility, and changes in structural location, such as the transition to marital and parental status. Panel data from the Career Development Study show that women's chances of affiliation are more affected than are men's by parents' religious homogamy, getting married, and having children.  相似文献   
54.
Ethics can be divided into a theory of prudential values and a theory of morality in a narrower sense. My paper proposes a utilitarian — a rule-utilitarian — theory of morality. But it deviates from most of the utilitarian tradition by rejecting the hedonistic and subjectivistic accounts of prudential values favored by many utilitarian writers. While economists tend to define people's utility levels in terms of their actual preferences, ethics must define them in terms of their informed preferences. To prefer A over B does not mean to have a stronger desire for A than for B. Rather, it means to regard one's access to A as being more important than one's access to B. Even though different people often have quite different preferences, their basic desires seem to be much the same. We must choose our moral rules, and our society's moral code as a whole, by their social utility. An important factor in determining their social utility are their expectation effects. Unlike the rule — utilitarian more code, the act — utilitarian moral code would be unable to give proper weight to these expectation effects. It would also unduly restrict our individual freedom. Finally, I shall argue against Kant that morality is primarily a servant of many other human values rather than itself the highest value of human life.  相似文献   
55.
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   
56.
This paper presents empirical evidence that an individual's decision to drive while drunk is negatively affected by the expected full price of driving drunk. The analysis uses a unique data set containing information on self-reported drunk driving matched to state-level drunk driving policies as well as to state excise taxes on beer. These are hypothesized and found to affect drunk driving. Further, we find interesting racial differences but surprisingly small differences by gender in the effect of socioeconomic and policy variables on drunk driving propensities.  相似文献   
57.
The authors consider the issue of map positional error, or the difference between location as represented in a spatial database (i.e., a map) and the corresponding unobservable true location. They propose a fully model‐based approach that incorporates aspects of the map registration process commonly performed by users of geographic informations systems, including rubber‐sheeting. They explain how estimates of positional error can be obtained, hence estimates of true location. They show that with multiple maps of varying accuracy along with ground truthing data, suitable model averaging offers a strategy for using all of the maps to learn about true location.  相似文献   
58.
Recent scholarship on the 'Americanization' of economic and cultural practices emphasize that the Europeans were not passive victims of this 'colonizing' project but selectively appropriated or even completely rejected aspects of it. This paper extends these insights to a scientific field. It describes the failed attempt to export to NATO a theory-based, computer-dependent model of operations research which embedded civilian scientists deeply in the military decision-making process. This conception of operations research and its related social practices was blocked by the British, who rejected a model of operations research which called for a training in advanced mathematics and computing, and who insisted that NATO maintain a strict civil/military divide. 'Americanization' was a negotiated and contested project which, while stimulating an awareness for change in Europe, did not necessarily determine its trajectory.  相似文献   
59.
60.
This article overviews prevention and early intervention approaches focusing specifically on their relevance to the health of children and young people in Australia. Australian public health has a sound track record although concealed within the aggregate profile are a number of sub-populations with poorer health indicators. Recognition of this has increased efforts to improve the health of children and young people especially in exploring the impact of social environments within the communities where children are raised. This paper examines emerging research in this area drawing out key lessons and learning from Australian experience in the field of early intervention and prevention in community settings.  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