全文获取类型
收费全文 | 454篇 |
免费 | 21篇 |
专业分类
管理学 | 56篇 |
民族学 | 5篇 |
人口学 | 42篇 |
丛书文集 | 2篇 |
理论方法论 | 53篇 |
综合类 | 12篇 |
社会学 | 288篇 |
统计学 | 17篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 7篇 |
2021年 | 8篇 |
2020年 | 15篇 |
2019年 | 23篇 |
2018年 | 31篇 |
2017年 | 46篇 |
2016年 | 30篇 |
2015年 | 19篇 |
2014年 | 23篇 |
2013年 | 68篇 |
2012年 | 27篇 |
2011年 | 20篇 |
2010年 | 20篇 |
2009年 | 16篇 |
2008年 | 19篇 |
2007年 | 14篇 |
2006年 | 11篇 |
2005年 | 10篇 |
2004年 | 12篇 |
2003年 | 6篇 |
2002年 | 11篇 |
2001年 | 7篇 |
2000年 | 2篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有475条查询结果,搜索用时 0 毫秒
1.
Charles W. Griffiths Chris Dockins Nicole Owens Nathalie B. Simon Daniel A. Axelrad 《Risk analysis》2002,22(4):679-688
To quantify the health benefits of environmental policies, economists generally require estimates of the reduced probability of illness or death. For policies that reduce exposure to carcinogenic substances, these estimates traditionally have been obtained through the linear extrapolation of experimental dose-response data to low-exposure scenarios as described in the U.S. Environmental Protection Agency's Guidelines for Carcinogen Risk Assessment (1986). In response to evolving scientific knowledge, EPA proposed revisions to the guidelines in 1996. Under the proposed revisions, dose-response relationships would not be estimated for carcinogens thought to exhibit nonlinear modes of action. Such a change in cancer-risk assessment methods and outputs will likely have serious consequences for how benefit-cost analyses of policies aimed at reducing cancer risks are conducted. Any tendency for reduced quantification of effects in environmental risk assessments, such as those contemplated in the revisions to EPA's cancer-risk assessment guidelines, impedes the ability of economic analysts to respond to increasing calls for benefit-cost analysis. This article examines the implications for benefit-cost analysis of carcinogenic exposures of the proposed changes to the 1986 Guidelines and proposes an approach for bounding dose-response relationships when no biologically based models are available. In spite of the more limited quantitative information provided in a carcinogen risk assessment under the proposed revisions to the guidelines, we argue that reasonable bounds on dose-response relationships can be estimated for low-level exposures to nonlinear carcinogens. This approach yields estimates of reduced illness for use in a benefit-cost analysis while incorporating evidence of nonlinearities in the dose-response relationship. As an illustration, the bounding approach is applied to the case of chloroform exposure. 相似文献
2.
Chris Dockins Robin R Jenkins Nicole Owens Nathalie B Simon Lanelle Bembenek Wiggins 《Risk analysis》2002,22(2):335-346
This article explores two problems analysts face in determining how to estimate values for children's health and safety risk reductions. The first addresses the question: Do willingness‐to‐pay estimates for health risk changes differ across children and adults and, if so, how? To answer this question, the article first examines the potential effects of age and risk preferences on willingness to pay. A summary of the literature reporting empirical evidence of differences between willingness to pay for adult health and safety risk reductions and willingness to pay for health and safety risk reductions in children is also provided. The second dimension of the problem is a more fundamental issue: Whose perspective is relevant when valuing children's health effects—society's, children's, adults‐as‐children, or parents'? Each perspective is considered, followed ultimately by the conclusion that adopting a parental perspective through an intrahousehold allocation model seems closest to meeting the needs of the estimation problem at hand. A policy example in which the choice of perspective affects the outcome of a regulatory benefit‐cost analysis rounds out the article and emphasizes the importance of perspective. 相似文献
3.
4.
Studies of the determinants of English language ability have generally focused on the largest immigrant groups in the United States. Much less is known about smaller, but significant regional concentrations of immigrants and refugees. This article presents data on four very distinct and understudied groups: Russians, Somalis, Hmong, and Mexicans in the Midwest. We found large differences in English language proficiency across the different national origin groups, even after controlling for background variables. These differences were not attributable to refugee status or to linguistic distance from English. Being Somali, migrating to the United States at a young age and having a college diploma were the best predictors of both spoken and written proficiency. The returns to higher education were particularly noteworthy — respondents with college diplomas were more than 29 times more likely than non‐high school graduates to speak English well, and more than 20 times as likely to read well. Women appear to have benefited more than men from completing college in terms of spoken English proficiency since the male‐female gap narrows among the highly educated. Length of time in the United States was a good predictor of whether an individual speaks English at home, regardless of age of entry to the country. 相似文献
5.
This study examined the emergence of affect specificity in infancy. In this study, infants received verbal and facial signals of 2 different, negatively valenced emotions (fear and sadness) as well as neutral affect via a television monitor to determine if they could make qualitative distinctions among emotions of the same valence. Twenty 12‐ to 14‐month‐olds and 20 16‐ to 18‐month‐olds were examined. Results suggested that younger infants showed no evidence of referential specificity, as they responded similarly to both the target and distracter toys, and showed no evidence of affect specificity, showing no difference in play between affect conditions. Older infants, in contrast, showed evidence both of referential and affect specificity. With respect to affect specificity, 16‐ to 18‐month‐olds touched the target toy less in the fear condition than in the sad condition and showed a larger proportion of negative facial expressions in the sad condition versus the fear condition. These findings suggest a developmental emergence after 15 months of age for affect specificity in relating emotional messages to objects. 相似文献
6.
GM Foods and the Misperception of Risk Perception 总被引:3,自引:0,他引:3
George Gaskell Nick Allum Wolfgang Wagner Nicole Kronberger Helge Torgersen Juergen Hampel Julie Bardes 《Risk analysis》2004,24(1):185-194
Public opposition to genetically modified (GM) food and crops is widely interpreted as the result of the public's misperception of the risks. With scientific assessment pointing to no unique risks from GM crops and foods, a strategy of accurate risk communication from trusted sources has been advocated. This is based on the assumption that the benefits of GM crops and foods are self-evident. Informed by the interpretation of some qualitative interviews with lay people, we use data from the Eurobarometer survey on biotechnology to explore the hypothesis that it is not so much the perception of risks as the absence of benefits that is the basis of the widespread rejection of GM foods and crops by the European public. Some respondents perceive both risks and benefits, and may be trading off these attributes along the lines of a rational choice model. However, for others, one attribute-benefit-appears to dominate their judgments: the lexicographic heuristic. For these respondents, their perception of risk is of limited importance in the formation of attitudes toward GM food and crops. The implication is that the absence of perceived benefits from GM foods and crops calls into question the relevance of risk communication strategies for bringing about change in public opinion. 相似文献
7.
Benchmarking airports is currently popular both in the academic literature and in practice but has proved rather problematic due to the heterogeneity inherent in any reasonably sized dataset. Most studies either treat the airport production technology as a black box, or separate the terminal and airside activities, assessing them individually. In this article we analyze airports as a single unit due to the direct complementarities, thus avoiding the artificial separation of inputs. Using data envelopment analysis (DEA), we open the black box in which a network describes the production process, thus demonstrating the sequential effects that separate final from intermediate outputs, including those under partial managerial control and those that are known to be non-discretionary. To further improve the benchmarking process, we identify appropriate peers for a case study of 43 European airports over 10 years, through a restricted reference mechanism according to pre-defined characteristics. Compared to basic DEA models, the results of the proposed structure provide more meaningful benchmarks with comparable peer units and target values that are potentially achievable in the medium term. By identifying each unit's individual reference set, unique outliers influence the performance measurement less severely than occurs under basic DEA. In addition, the formulations produce an implementation path that moves the airport towards the Pareto frontier gradually, taking into account the regulatory and business environment in which the unit is located. 相似文献
8.
9.
We qualitatively explored reasons why transgendered women may engage in sexual risk that could lead to HIV infection. Specifically, we conducted this investigation with transgendered women identifying as Black/African American. Interviews from 17 participants were audio taped and analyzed. Four themes emerged. Women commonly reported they had a strong need/desire to be loved by men. Many stated they had and would engage in unprotected sex to obtain and preserve such a relationship. Nearly all were currently using female hormones. Nine obtained their hormones through non-medical means including the Internet, transgendered friends, and street vendors. For these women hormone injections often involved sharing needles/syringes. Selling sex was a common practice and many women did so without the benefit of condom use. Finally, women experienced multiple forms of societal discrimination. By being caught between worlds (straight, gay, male, and female) transgendered women may be placed into situations where avoiding HIV risk is extremely difficult. 相似文献
10.
Neighbors C Lostutter TW Whiteside U Fossos N Walker DD Larimer ME 《Journal of gambling studies / co-sponsored by the National Council on Problem Gambling and Institute for the Study of Gambling and Commercial Gaming》2007,23(3):259-273
Two studies examined the relationships among injunctive norms and college student gambling. In study 1 we evaluated the accuracy
of perceptions of other students’ approval of gambling and the relationship between perceived approval and gambling behavior.
In study 2 we evaluated gambling behavior as a function of perceptions of approval of other students, friends, and family.
In study 1, which included 2524 college students, perceptions of other students’ approval of gambling were found to be overestimated
and were negatively associated with gambling behavior. The results of study 2, which included 565 college students, replicated the findings of
study 1 and revealed positive associations between gambling behavior and perceived approval of friends and family. Results highlight the complexity of
injunctive norms and the importance of considering the reference group (e.g., peers, friends, family members) in their evaluation.
Results also encourage caution in considering the incorporation of injunctive norms in prevention and intervention approaches. 相似文献