全文获取类型
收费全文 | 3239篇 |
免费 | 66篇 |
国内免费 | 1篇 |
专业分类
管理学 | 494篇 |
民族学 | 15篇 |
人才学 | 1篇 |
人口学 | 265篇 |
丛书文集 | 25篇 |
理论方法论 | 341篇 |
综合类 | 23篇 |
社会学 | 1734篇 |
统计学 | 408篇 |
出版年
2023年 | 18篇 |
2021年 | 12篇 |
2020年 | 37篇 |
2019年 | 55篇 |
2018年 | 70篇 |
2017年 | 79篇 |
2016年 | 79篇 |
2015年 | 55篇 |
2014年 | 67篇 |
2013年 | 540篇 |
2012年 | 97篇 |
2011年 | 86篇 |
2010年 | 80篇 |
2009年 | 88篇 |
2008年 | 102篇 |
2007年 | 104篇 |
2006年 | 102篇 |
2005年 | 108篇 |
2004年 | 101篇 |
2003年 | 102篇 |
2002年 | 112篇 |
2001年 | 63篇 |
2000年 | 57篇 |
1999年 | 66篇 |
1998年 | 55篇 |
1997年 | 65篇 |
1996年 | 72篇 |
1995年 | 41篇 |
1994年 | 49篇 |
1993年 | 49篇 |
1992年 | 45篇 |
1991年 | 50篇 |
1990年 | 48篇 |
1989年 | 38篇 |
1988年 | 34篇 |
1987年 | 33篇 |
1986年 | 21篇 |
1985年 | 26篇 |
1984年 | 43篇 |
1983年 | 39篇 |
1982年 | 35篇 |
1981年 | 46篇 |
1980年 | 31篇 |
1979年 | 24篇 |
1978年 | 23篇 |
1977年 | 30篇 |
1976年 | 29篇 |
1975年 | 17篇 |
1974年 | 11篇 |
1973年 | 21篇 |
排序方式: 共有3306条查询结果,搜索用时 15 毫秒
51.
In conjunction with TIMET at Waunarlwydd (Swansea, UK) a model has been developed that will optimise the scheduling of various blooms to their eight furnaces so as to minimise the time taken to roll these blooms into the finished mill products. This production scheduling model requires reliable data on times taken for the various furnaces that heat the slabs and blooms to reach the temperatures required for rolling. These times to temperature are stochastic in nature and this paper identifies the distributional form for these times using the generalised F distribution as a modelling framework. The times to temperature were found to be similarly distributed over all furnaces. The identified distributional forms were incorporated into the scheduling model to optimise a particular campaign that was run at TIMET Swansea. Amongst other conclusion it was found that, compared to the actual campaign, the model produced a schedule that reduced the makespan by some 35%. 相似文献
52.
Richard T. Middleton Iv 《Social Identities》2013,19(5):567-585
This research paper investigates the effect political institutions have on black racial identity. In particular, I study individual inculcation in contexts where political institutions institutionalize either of two forms of racial social structures – a pigmentocracy (the Dominican Republic), or the rule of hypodescent (the US South), and the effect such inculcation has on black racial identity. I sampled 101 respondents from the Dominican Republic and 102 from the state of Mississippi, USA. Consistent with the basic assumptions of my hypotheses, respondents in the Dominican Republic study sites showed a weaker degree of identification with blackness vis-à-vis something ‘whiter’. Nevertheless, respondents in the Dominican Republic sites demonstrated a stronger identification with blackness than what most conventional observers would have anticipated. Respondents in the Mississippi study sites showed a stronger sense of identification with blackness. Surprisingly, however, Mississippi respondents demonstrated a larger degree of neutrality than expected in their belief of being of a mixed racial heritage rather than just a black African heritage. 相似文献
53.
Richard Mohr 《National Identities》2013,15(1):53-66
Law has had a traditional reference to land, conceived as territory, in the notion of a jurisdiction, where the law of the land applies equally to all individuals. Recent critiques of this view have suggested that a plurality of laws may apply in particular places. How this spatial pluralism impacts on dominant views of law is considered through two instances in which law has interacted with competing conceptions of place and territory in relations between European and Indigenous Australians. Space, law and identity are seen to constitute each other in complex forms. Indigenous beliefs and practices challenge the claims to universality of Western conceptions of law and space deriving from Roman law and spatial practices. 相似文献
54.
Using distributions of time spent at various ventilation levels, ranges of inhalation exposure in the population can be established. Distributions of exposure time were determined using results of a study by the California Air Resources Board (CARB) which focused on time spent by humans participating in various activities and the locations where the activities occurred. The daily at-home activities from the CARB study were assigned to one of three ventilation levels, generating aggregate time periods. Distinct age and gender populations were identified, and distributions for aggregate time were established for these populations at each of the ventilation levels. In addition to aggregate time spent at home, distributions for various ages and genders were established for aggregate time spent at school and work. By combining distributions of aggregate time with corresponding ventilation rates, the distribution of inhalation rates can be established for at home, at work, and at school exposures. 相似文献
55.
Methodological Approaches to Assessing Risk Perceptions Associated with Food-Related Hazards 总被引:1,自引:0,他引:1
The psychometric approach developed by Slovic and his co-workers has been effectively used to assess risk perceptions associated with different food-related hazards. However, further examination (using questionnaire data and partial correlation techniques) has indicated that technological hazards are highly differentiated from lifestyle hazards, in terms of both hazard control and knowledge about the hazard. Optimistic bias was also seen to vary between hazards. Further research has focused on a particular hazard, genetic engineering. Risk perceptions associated with genetic engineering are underpinned by ethical concern and questions relating to perceived need for the technology, as well as perceptions of risk or harm. However, increasing the specificity of hazard stimuli was found to alter the factor structure of underlying risk perceptions. The utility of preference mapping procedures in determining individual differences in trust in risk regulators is also discussed. 相似文献
56.
57.
Gray George M. Allen Jon C. Burmaster David E. Gage Stuart H. Hammitt James K. Kaplan Stanley Keeney Ralph L. Morse Joseph G. North D. Warner Nyrop Jan P. Stahevitch Alina Williams Richard 《Risk analysis》1998,18(6):773-780
The North American Free Trade Agreement (NAFTA) and the General Agreement on Tariffs and Trade (GATT) have focused attention on risk assessment of potential insect, weed, and animal pests and diseases of livestock. These risks have traditionally been addressed through quarantine protocols ranging from limits on the geographical areas from which a product may originate, postharvest disinfestation procedures like fumigation, and inspections at points of export and import, to outright bans. To ensure that plant and animal protection measures are not used as nontariff trade barriers, GATT and NAFTA require pest risk analysis (PRA) to support quarantine decisions. The increased emphasis on PRA has spurred multiple efforts at the national and international level to design frameworks for the conduct of these analyses. As approaches to pest risk analysis proliferate, and the importance of the analyses grows, concerns have arisen about the scientific and technical conduct of pest risk analysis. In January of 1997, the Harvard Center for Risk Analysis (HCRA) held an invitation-only workshop in Washington, D.C. to bring experts in risk analysis and pest characterization together to develop general principles for pest risk analysis. Workshop participants examined current frameworks for PRA, discussed strengths and weaknesses of the approaches, and formulated principles, based on years of experience with risk analysis in other setting and knowledge of the issues specific to analysis of pests. The principles developed highlight the both the similarities of pest risk analysis to other forms of risk analysis, and its unique attributes. 相似文献
58.
Periodic autoregressions are characterised by autoregressive structures that vary with the season. If a time series is periodically integrated, one needs a seasonally varying differencing filter to remove the stochastic trend. When the periodic regression model contains constants and trends with unrestricted parameters, the data can show diverging seasonal deterministic trends. In this paper we derive explicit expressions for parameter restrictions that result in common deterministic trends under periodic trend stationarity and periodic integration. 相似文献
59.
Sarah Darby Harz Deo Richard Doll & Elise Whitley 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2001,164(1):205-207
Parallel individual and ecological analyses of data on residential radon have been performed using information on cases of lung cancer and population controls from a recent study in south-west England. For the individual analysis the overall results indicated that the relative risk of lung cancer at 100 Bq m−3 compared with at 0 Bq m−3 was 1.12 (95% confidence interval (0.99, 1.27)) after adjusting for age, sex, smoking, county of residence and social class. In the ecological analysis substantial bias in the estimated effect of radon was present for one of the two counties involved unless an additional variable, urban–rural status, was included in the model, although this variable was not an important confounder in the individual level analysis. Most of the methods that have been recommended for overcoming the limitations of ecological studies would not in practice have proved useful in identifying this variable as an appreciable source of bias. 相似文献
60.