全文获取类型
收费全文 | 6504篇 |
免费 | 139篇 |
专业分类
管理学 | 989篇 |
民族学 | 39篇 |
人才学 | 3篇 |
人口学 | 603篇 |
丛书文集 | 40篇 |
理论方法论 | 788篇 |
综合类 | 56篇 |
社会学 | 3362篇 |
统计学 | 763篇 |
出版年
2023年 | 25篇 |
2021年 | 27篇 |
2020年 | 102篇 |
2019年 | 140篇 |
2018年 | 125篇 |
2017年 | 177篇 |
2016年 | 185篇 |
2015年 | 138篇 |
2014年 | 173篇 |
2013年 | 1075篇 |
2012年 | 211篇 |
2011年 | 183篇 |
2010年 | 157篇 |
2009年 | 177篇 |
2008年 | 195篇 |
2007年 | 185篇 |
2006年 | 164篇 |
2005年 | 218篇 |
2004年 | 238篇 |
2003年 | 194篇 |
2002年 | 223篇 |
2001年 | 160篇 |
2000年 | 124篇 |
1999年 | 150篇 |
1998年 | 126篇 |
1997年 | 113篇 |
1996年 | 99篇 |
1995年 | 108篇 |
1994年 | 99篇 |
1993年 | 112篇 |
1992年 | 84篇 |
1991年 | 92篇 |
1990年 | 63篇 |
1989年 | 64篇 |
1988年 | 71篇 |
1987年 | 50篇 |
1986年 | 54篇 |
1985年 | 66篇 |
1984年 | 60篇 |
1983年 | 56篇 |
1982年 | 62篇 |
1981年 | 51篇 |
1980年 | 50篇 |
1979年 | 46篇 |
1978年 | 44篇 |
1977年 | 44篇 |
1976年 | 47篇 |
1975年 | 43篇 |
1974年 | 33篇 |
1973年 | 29篇 |
排序方式: 共有6643条查询结果,搜索用时 15 毫秒
991.
John B. Gentry 《Researches on Population Ecology》1968,10(1):21-30
Summary Enclosed populations of pine mice were studied over a 28-month period and compared with populations in surrounding natural
areas. The enclosed populations reached densities far greater than any observed in surrounding natural areas. It is suggested
that the restriction placed on dispersal by the enclosure walls and the addition of food in the form of trap bait could have
allowed the enclosed populations to reach higher densities than normally observed at SRP. 相似文献
992.
John Casparls 《Demography》1969,6(2):125-131
Retail sales in 1963 in 116 Standard Metropolitan Statistical Areas (SMSA’s) are related to SMSA size in 1960. Nucleated sales occur in the Central Business District (CBD) and in Major Retail Centers (MRC’s). As SMSA’s grow, the proportion of sales in MRC’s increases and that in the CBD decreases. The ratio of nucleated sales to dispersed sales remains constant. The laws of economic location operate to place shopping goods primarily in the CBD and in MRC’s whereas convenience and other types of stores disperse throughout the SMSA. Plotting the straight line distance of every MRC relative to the CBD and computing the mix of trade types in MRC’s reveals that, with some modifications, most MRC’s have a mix of store types similar to the CBD. Convenience stores are somewhat more important and all other stores less so than they are in the CBD. The findings support the Harris-Ullman multiple nuclei hypothesis. 相似文献
993.
994.
995.
996.
997.
998.
Barbara J. Bank Bruce J. Biddle Daphne M. Keats John A. Keats 《The Sociological quarterly》1977,18(4):574-588
The concept of attitude often subsumes normative, preferential, and belief components; some attitude scales are composed of items exhibiting two or more of these modalities. Beliefs may, in turn, be classified as reports, stereotypes, consequences, and intentions. This article shows that attitude questions in different modes have differing origins and implications, and that it is an error to continue to use an attitude concept and attitude scales that are modally ambiguous. As well, it is an error to use factor analyses and lack of co-scalability as the only criteria for assessing modality differences within attitude scales. In support of this argument we show that adolescents respond differently to attitude questions concerning school integration that are phrased in the normative, preferential, and belief modes, although these same questions are also found to co-scale. A distinction is made between two ways of learning attitudes: through personal experience and through information from others. On the basis of this distinction, parallel results were predicted and found for preferences and intentions. These differed from results that we predicted and found for norms and stereotypes. 相似文献
999.
Expert Scientific Judgment and Cancer Risk Assessment: A Pilot Study of Pharmacokinetic Data 总被引:1,自引:0,他引:1
When high-dose tumor data are extrapolated to low doses, it is typically assumed that the dose of a carcinogen delivered to target cells is proportional to the dose administered to test animals, even at exposure levels below the experimental range. Since pharmacokinetic data are becoming available that in some cases question the validity of this assumption, risk assessors must decide whether to maintain the standard assumption. A pilot study of formaldehyde is reported that was undertaken to demonstrate how expert scientific judgment can help guide a controversial risk assessment where pharmacokinetic data are considered inconclusive. Eight experts on pharmacokinetic data were selected by a formal procedure, and each was interviewed personally using a structured interview protocol. The results suggest that expert scientific opinion is polarized in this case, a situation that risk assessors can respond to with a range of risk characterizations considered biologically plausible by the experts. Convergence of expert opinion is likely in this case of several specific research strategies ar executed in a competent fashion. Elicitation of expert scientific judgment is a promising vehicle for evaluating the quality of pharmacokinetic data, expressing uncertainty in risk assessment, and fashioning a research agenda that offers possible forging of scientific consensus. 相似文献
1000.
The effectiveness of the Relationship Enhancement (RE) program (Guerney, 1987a) in increasing functional and basic levels of differentiation of self (Bowen, 1987a) was examined. Participants were 20 married couples who received training in relationship enhancement skills over six 2 1/2-hour sessions. Measures of differentiation of self, quality of relationship, and anxiety were obtained before and after training and at follow-up. The data show that significant increases in the functional and basic levels of differentiation of self occurred, a significant increase in the quality of relationship occurred, and significant negative correlations were found between differentiation of self and anxiety. 相似文献