全文获取类型
收费全文 | 8331篇 |
免费 | 219篇 |
国内免费 | 1篇 |
专业分类
管理学 | 1138篇 |
民族学 | 29篇 |
人口学 | 729篇 |
丛书文集 | 31篇 |
理论方法论 | 712篇 |
综合类 | 136篇 |
社会学 | 3824篇 |
统计学 | 1952篇 |
出版年
2020年 | 121篇 |
2019年 | 178篇 |
2018年 | 178篇 |
2017年 | 266篇 |
2016年 | 188篇 |
2015年 | 162篇 |
2014年 | 188篇 |
2013年 | 1550篇 |
2012年 | 255篇 |
2011年 | 206篇 |
2010年 | 191篇 |
2009年 | 169篇 |
2008年 | 226篇 |
2007年 | 230篇 |
2006年 | 197篇 |
2005年 | 170篇 |
2004年 | 149篇 |
2003年 | 136篇 |
2002年 | 157篇 |
2001年 | 191篇 |
2000年 | 169篇 |
1999年 | 150篇 |
1998年 | 131篇 |
1997年 | 131篇 |
1996年 | 131篇 |
1995年 | 110篇 |
1994年 | 83篇 |
1993年 | 127篇 |
1992年 | 140篇 |
1991年 | 122篇 |
1990年 | 132篇 |
1989年 | 109篇 |
1988年 | 106篇 |
1987年 | 113篇 |
1986年 | 100篇 |
1985年 | 87篇 |
1984年 | 121篇 |
1983年 | 101篇 |
1982年 | 95篇 |
1981年 | 64篇 |
1980年 | 93篇 |
1979年 | 108篇 |
1978年 | 72篇 |
1977年 | 82篇 |
1976年 | 70篇 |
1975年 | 85篇 |
1974年 | 70篇 |
1973年 | 54篇 |
1972年 | 62篇 |
1971年 | 52篇 |
排序方式: 共有8551条查询结果,搜索用时 31 毫秒
171.
172.
We propose new dynamic measures of uncertainty based on the notion of generalized dynamic entropy introduced in Di Crescenzo and Longobardi (2006). These can uniquely determine distribution functions in continuous and discrete cases, and the characterizations of some well-known distributions are provided. We also define some orderings and aging notions based on the generalized dynamic measures, and prove some of their properties, obtaining as corollaries results that have recently appeared in the literature. 相似文献
173.
Gabriel L. Schlomer H. Harrington Cleveland Mark E. Feinberg Jessica L. Murray David J. Vandenbergh 《Journal of research on adolescence》2021,31(1):189-203
The most extensively studied influence on adolescent conduct problem behaviors is peers, and the literature points to genetics as one source of individual differences in peer influence. The purpose of this study was to test the hypothesis that an environmental sensitivity genetic index comprised of DRD4, 5‐HTTLPR, and GABRA2 variation would moderate the association between peer and adolescent conduct problems. Latent growth modeling was applied to PROSPER project longitudinal data from adolescents and their peers. Results showed the hypothesis was supported; adolescents with more copies of putative sensitivity alleles were more strongly influenced by their peers. The interaction form was consistent with differential susceptibility in follow‐up analyses. Strengths and weaknesses of genetic aggregates for sensitivity research are discussed. 相似文献
174.
175.
A critical component of aviation security consists of screening passengers and baggage to protect airports and aircraft from terrorist threats. Advancements in screening device technology have increased the ability to detect these threats; however, specifying the operational configurations of these devices in response to changes in the threat environment can become difficult. This article proposes to use Fisher information as a statistical measure for detecting changes in the threat environment. The perceived risk of passengers, according to prescreening information and behavior analysis, is analyzed as the passengers sequentially enter the security checkpoint. The alarm responses from the devices used to detect threats are also analyzed to monitor significant changes in the frequency of threat items uncovered. The key results are that this information‐based measure can be used within the Homeland Security Advisory System to indicate changes in threat conditions in real time, and provide the flexibility of security screening detection devices to responsively and automatically adapt operational configurations to these changing threat conditions. 相似文献
176.
Zahra Mansourvar Torben Martinussen Thomas H. Scheike 《Scandinavian Journal of Statistics》2016,43(2):487-504
The mean residual life measures the expected remaining life of a subject who has survived up to a particular time. When survival time distribution is highly skewed or heavy tailed, the restricted mean residual life must be considered. In this paper, we propose an additive–multiplicative restricted mean residual life model to study the association between the restricted mean residual life function and potential regression covariates in the presence of right censoring. This model extends the proportional mean residual life model using an additive model as its covariate dependent baseline. For the suggested model, some covariate effects are allowed to be time‐varying. To estimate the model parameters, martingale estimating equations are developed, and the large sample properties of the resulting estimators are established. In addition, to assess the adequacy of the model, we investigate a goodness of fit test that is asymptotically justified. The proposed methodology is evaluated via simulation studies and further applied to a kidney cancer data set collected from a clinical trial. 相似文献
177.
Emotional Climate in Families Experiencing Homelessness: Associations with Child Affect and Socioemotional Adjustment in School 下载免费PDF全文
This study examined associations among family‐level risks, emotional climate, and child adjustment in families experiencing homelessness. Emotional climate, an indirect aspect of emotion socialization, was indexed by parents’ expressed emotion while describing their children. Sociodemographic risk and parent internalizing distress were hypothesized to predict more negativity and less warmth in the emotional climate. Emotional climate was expected to predict observer‐rated child affect and teacher‐reported socioemotional adjustment, mediating effects of risk. Participants were 138 homeless parents (64 percent African‐American) and their four‐ to six‐year‐old children (43.5 percent male). During semi‐structured interviews, parents reported demographic risks and internalizing distress and completed a Five Minute Speech Sample about their child, later rated for warmth and negativity. Children's positive and negative affect were coded from videotapes of structured parent‐child interaction tasks. Socioemotional adjustment (externalizing behavior, peer acceptance, and prosocial behavior) was reported by teachers a few months later. Hypotheses were partially supported. Parent internalizing distress was associated with higher parent negativity, which was linked to more negative affect in children, and parent warmth was associated with children's positive affect. Neither emotional climate nor child affect predicted teacher‐reported externalizing behavior or peer acceptance, but parental negativity and male sex predicted lower prosocial behavior in the classroom. Future research directions and clinical implications are discussed. 相似文献
178.
The literature reports some contradictory results on the degree of phonological specificity of infants’ early lexical representations in the Romance language, French, and Germanic languages. It is not clear whether these discrepancies are because of differences in method, in language characteristics, or in participants’ age. In this study, we examined whether 12‐ and 17‐month‐old French‐speaking infants are able to distinguish well‐pronounced from mispronounced words (one or two features of their initial consonant). To this end, 46 infants participated in a preferential looking experiment in which they were presented with pairs of pictures together with a spoken word well pronounced or mispronounced. The results show that both 12‐ and 17‐month‐old infants look longer at the pictures corresponding to well‐pronounced words than to mispronounced words, but show no difference between the two mispronunciation types. These results suggest that, as early as 12 months, French‐speaking infants, like those exposed to Germanic languages, already possess detailed phonological representations of familiar words. 相似文献
179.
Marloes de Lange Maarten H. J. Wolbers Maurice Gesthuizen Wout C. Ultee 《Revue europeenne de demographie》2014,30(2):161-185
In this paper, we study the impact of macro- and micro-economic uncertainty on family formation between 1970 and 2000 in The Netherlands. Using data of the Family Survey Dutch Population, we analysed the monthly hazard rates of experiencing the transition into first union, first marriage and parenthood after the start of the relationship of 365 male and 364 female partners by applying piecewise-constant exponential models. The results show that macro-economic uncertainties, i.e. high unemployment rates, lead to postponement of the first union and marriage, but not of the first child. In addition, we found that this relationship is not interpreted by individual-level employment insecurity, i.e. temporary employment or unemployment, which does not seem to prevent people from making long-term family commitments. Although hypothesized, we did not find that the negative effects of macro- and micro-level insecurities on family formation reinforce each other or that they vary between individuals with different educational qualifications. 相似文献
180.
Gay guys using gay language: friendship,shared values and the intent‐context‐effect matrix 下载免费PDF全文
This article draws on in‐depth interviews with 35 openly gay male undergraduates from four universities in England to develop an understanding of the changing nature of language related to homosexuality. In addition to finding a diminution in the prevalence of homophobic language, we demonstrate that participants maintain complex and nuanced understandings of phrases that do not use homophobic pejoratives, such as ‘that's so gay’. The majority of participants rejected the notion that these phrases are inherently homophobic, instead arguing that the intent with which they are said and the context in which they are used are vital in understanding their meaning and effect. We conceptualize an intent‐context‐effect matrix to understand the interdependency of these variables. Highlighting the situated nature of this matrix, we also demonstrate the importance of the existence of shared norms between those saying and hearing the phrase when interpreting such language. 相似文献