全文获取类型
收费全文 | 22932篇 |
免费 | 297篇 |
专业分类
管理学 | 3161篇 |
民族学 | 147篇 |
人才学 | 1篇 |
人口学 | 3444篇 |
丛书文集 | 78篇 |
教育普及 | 2篇 |
理论方法论 | 1636篇 |
综合类 | 624篇 |
社会学 | 10672篇 |
统计学 | 3464篇 |
出版年
2021年 | 67篇 |
2020年 | 190篇 |
2019年 | 221篇 |
2018年 | 1881篇 |
2017年 | 1989篇 |
2016年 | 1334篇 |
2015年 | 264篇 |
2014年 | 288篇 |
2013年 | 2079篇 |
2012年 | 713篇 |
2011年 | 1445篇 |
2010年 | 1253篇 |
2009年 | 1010篇 |
2008年 | 1074篇 |
2007年 | 1257篇 |
2006年 | 216篇 |
2005年 | 571篇 |
2004年 | 540篇 |
2003年 | 473篇 |
2002年 | 350篇 |
2001年 | 318篇 |
2000年 | 307篇 |
1999年 | 314篇 |
1998年 | 209篇 |
1997年 | 204篇 |
1996年 | 241篇 |
1995年 | 188篇 |
1994年 | 204篇 |
1993年 | 177篇 |
1992年 | 236篇 |
1991年 | 232篇 |
1990年 | 211篇 |
1989年 | 219篇 |
1988年 | 204篇 |
1987年 | 185篇 |
1986年 | 189篇 |
1985年 | 174篇 |
1984年 | 207篇 |
1983年 | 200篇 |
1982年 | 165篇 |
1981年 | 137篇 |
1980年 | 139篇 |
1979年 | 166篇 |
1978年 | 136篇 |
1977年 | 119篇 |
1976年 | 102篇 |
1975年 | 101篇 |
1974年 | 95篇 |
1973年 | 93篇 |
1971年 | 64篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
931.
Jordan Belisle Kate Huggins Meghan Doherty Caleb R. Stanley Mark R. Dixon 《The Analysis of verbal behavior》2020,36(2):233
We sought to evaluate the efficacy of successive matching training for establishing generalized reflexive matching across 4 children with autism. In Experiment 1, differential reinforcement with delay fading was efficacious in establishing “yes” and “no” matching and nonmatching responses in 2 participants when 2 identical or nonidentical picture stimuli were presented. In addition, emergent visual–visual reflexive relational responses were observed using novel picture stimuli in a transfer test phase. In Experiment 2, differential reinforcement alone was efficacious in establishing matching and nonmatching responses in the other 2 participants when 2 identical or nonidentical objects were presented. Transfer to identical objects presented through touch (i.e., tactile discrimination) was additionally observed for both participants. Procedures in the study were adapted from the PEAK Relational Training System to aid in clinical replication, and the translational results have implications for language training with individuals with autism. 相似文献
932.
933.
Jana Vietze Maja K. Schachner Linda Juang Fons J.R. van de Vijver Peter Noack 《Journal of research on adolescence》2020,30(3):616-632
We examined how perceived acculturation expectations from parents and school, and ethnic discrimination predicted early adolescents’ heritage and mainstream acculturation orientations at home (private domain) and in school (public domain) one year later. We surveyed 263 early adolescents of immigrant background in Germany (Mage = 10.44 years, 60% female). Multigroup path analyses revealed that perceived acculturation expectations and ethnic discrimination were more strongly related to adolescents’ private than public acculturation orientations. Parental heritage expectations were the strongest predictor of adolescents’ acculturation orientations. Boys were more susceptible than girls to ethnic discrimination and acculturation expectations in school, which affected their private and public acculturation orientations. Results highlight the importance of integrating domain‐specific and gendered experiences when analyzing adolescents’ acculturative development. 相似文献
934.
Urban Ecosystems - Residential yardscapes are at the forefront of human interaction with nature for those living in urban areas across Europe and North America. In recent years a significant amount... 相似文献
935.
Urban Ecosystems - Generalist wildlife species often thrive in urban environments because of increased anthropogenic resources. However, human-wildlife interactions, especially if negative, raise... 相似文献
936.
Identifying patterns of fearful behaviors early and accurately is essential to identify children who may be at increased risk for psychopathology. Previous work focused on the total amount of fear by using composites across time. However, considering the temporal dynamics of fear expression might offer novel insights into the identification of children at risk. One hundred and twenty‐five toddlers participated in high‐ and low‐fear tasks. Data were modeled using a novel two‐step approach. First, a hidden Markov model estimated latent fear states and transitions across states over time. Results revealed children's behavior was best represented by six behavioral states. Next, these states were analyzed using sequence clustering to identify groups of children with similar dynamic trajectories through the states. A four‐cluster solution found groups of children varied in fear response and regulation process: “external regulators” (using the caregiver as a regulation tool), “low reactive” (low reaction to stimulus), “fearful explorers” (managing their own internal state with minimal assistance from the caregiver), and “high fear” (fearful/at‐caregiver state regardless of task). The combination of analytic tools enabled fine‐grained examination of the processes of fearful temperament. These insights may help prevention programs target behaviors that perpetuate anxious behavior in the moment. 相似文献
937.
938.
Tom Wilson Huw Brokensha Francisco Rowe Ludi Simpson 《Population research and policy review》2018,37(1):137-155
Local area population forecasts have a wide variety of uses in the public and private sectors. But not enough is known about the errors of such forecasts, particularly over the longer term (20 years or more). Understanding past errors is valuable for both forecast producers and users. This paper (i) evaluates the forecast accuracy of past local area population forecasts published by Australian State and Territory Governments over the last 30 years and (ii) illustrates the ways in which past error distributions can be employed to quantify the uncertainty of current forecasts. Population forecasts from the past 30 years were sourced from State and Territory Governments. Estimated resident populations to which the projections were compared were created for the geographical regions of the past projections. The key features of past forecast error patterns are described. Forecast errors mostly confirm earlier findings with regard to the relationship between error and length of projection horizon and population size. The paper then introduces the concept of a forecast ‘shelf life’, which indicates how far into the future a forecast is likely to remain reliable. It also illustrates how past error distributions can be used to create empirical prediction intervals for current forecasts. These two complementary measures provide a simple way of communicating the likely magnitude of error that can be expected with current local area population forecasts. 相似文献
939.
Johann Fuchs Doris Söhnlein Brigitte Weber Enzo Weber 《Population research and policy review》2018,37(1):33-58
This paper presents a stochastic model to forecast the German population and labor supply until 2060. Within a cohort-component approach, our population forecast applies principal components analysis to birth, mortality, emigration, and immigration rates, which allows for the reduction of dimensionality and accounts for correlation of the rates. Labor force participation rates are estimated by means of an econometric time series approach. All time series are forecast by stochastic simulation using the bootstrap method. As our model also distinguishes between German and foreign nationals, different developments in fertility, migration, and labor participation could be predicted. The results show that even rising birth rates and high levels of immigration cannot break the basic demographic trend in the long run. An important finding from an endogenous modeling of emigration rates is that high net migration in the long run will be difficult to achieve. Our stochastic perspective suggests therefore a high probability of substantially decreasing the labor supply in Germany. 相似文献
940.
Arthur Sakamoto Christopher R. Tamborini ChangHwan Kim 《Population research and policy review》2018,37(1):91-116
This paper investigates long-term earnings differentials between African American and white men using data that match respondents in the Survey of Income and Program Participation to 30 years of their longitudinal earnings as recorded by the Social Security Administration. Given changing labor market conditions over three decades, we focus on how racial differentials vary by educational level because the latter has important and persistent effects on labor market outcomes over the course of an entire work career. The results show that the long-term earnings of African American men are more disadvantaged at lower levels of educational attainment. Controlling for demographic characteristics, work disability, and various indicators of educational achievement does not explain the lower long-term earnings of less-educated black men in comparison to less-educated white men. The interaction arises because black men without a high school degree have a larger number of years of zero earnings during their work careers. Other results show that this racial interaction by educational level is not apparent in cross-sectional data which do not provide information on the accumulation of zero earnings over the course of 30 years. We interpret these findings as indicating that compared to either less-educated white men or highly educated black men, the long-term earnings of less-educated African American men are likely to be more negatively affected by the consequences of residential and economic segregation, unemployment, being out of the labor force, activities in the informal economy, incarceration, and poorer health. 相似文献