全文获取类型
收费全文 | 22248篇 |
免费 | 360篇 |
国内免费 | 2篇 |
专业分类
管理学 | 3088篇 |
民族学 | 151篇 |
人口学 | 3469篇 |
丛书文集 | 49篇 |
理论方法论 | 1533篇 |
综合类 | 455篇 |
社会学 | 9702篇 |
统计学 | 4163篇 |
出版年
2023年 | 86篇 |
2021年 | 80篇 |
2020年 | 233篇 |
2019年 | 308篇 |
2018年 | 2000篇 |
2017年 | 2088篇 |
2016年 | 1379篇 |
2015年 | 309篇 |
2014年 | 378篇 |
2013年 | 2354篇 |
2012年 | 778篇 |
2011年 | 1450篇 |
2010年 | 1306篇 |
2009年 | 1022篇 |
2008年 | 1128篇 |
2007年 | 1304篇 |
2006年 | 256篇 |
2005年 | 436篇 |
2004年 | 444篇 |
2003年 | 373篇 |
2002年 | 286篇 |
2001年 | 249篇 |
2000年 | 229篇 |
1999年 | 203篇 |
1998年 | 167篇 |
1997年 | 170篇 |
1996年 | 190篇 |
1995年 | 143篇 |
1994年 | 125篇 |
1993年 | 162篇 |
1992年 | 187篇 |
1991年 | 167篇 |
1990年 | 162篇 |
1989年 | 139篇 |
1988年 | 157篇 |
1987年 | 128篇 |
1986年 | 123篇 |
1985年 | 121篇 |
1984年 | 144篇 |
1983年 | 137篇 |
1982年 | 118篇 |
1981年 | 85篇 |
1980年 | 115篇 |
1979年 | 127篇 |
1978年 | 111篇 |
1977年 | 98篇 |
1976年 | 93篇 |
1975年 | 106篇 |
1974年 | 79篇 |
1972年 | 74篇 |
排序方式: 共有10000条查询结果,搜索用时 718 毫秒
871.
L'analyse, axée sur les tâches, de la structure de l'emploi urbain du Brésil, de la Colombie et du Mexique montre que celui-ci a nettement diminué entre 2002 et 2015 dans des professions semi-qualifiées et augmenté dans les professions faiblement et fortement qualifiées. La décomposition des résultats suggère que le déclin de l'emploi des secrétaires et des sténographes s'explique entièrement par les changements intrabranche (hypothèse de «routinisation»), tandis que dans la conduite des machines et l'artisanat l'explication tient aux changements interbranches. Sous l'angle sociodémographique, le changement technologique affecte négativement les femmes, mais il profite aux travailleurs plus jeunes et plus instruits. 相似文献
872.
Ortega-Rosas Carmen Isela Enciso-Miranda Carlos Alberto Macías-Duarte Alberto Morales-Romero Daniel Villarruel-Sahagún Leopoldo 《Urban Ecosystems》2020,23(6):1191-1207
Urban Ecosystems - Green cover and air quality are important components of life quality and human ecology in arid lands. In the Sonoran Desert of Mexico, Hermosillo is the largest city with a... 相似文献
873.
H. William Amos 《Journal of Sociolinguistics》2020,24(1):55-74
In recent decades, sociolinguists have begun to challenge the traditional view that multilingualism is fundamentally composed of discrete systems known as ‘languages’. Supporting the assessment that languages are not bounded entities but sociocultural and ideological constructions, this article explores commercial advertisements in France, which are subject to language policies assuming that ‘French’ is easily separable from ‘foreign languages’. Employing the Bakhtinian‐influenced notion of bivalency developed by Woolard (1998), the article argues for a special consideration of mixed‐language advertising in France, rooted not only in linguistic form, but also in the specific contextual tension produced by the socio‐political statuses of French and English. The resulting creativity challenges the monolectal assumptions within French language management, indicating a clash of segregational language ideology with integrational language practices. The article further argues that this language mixing is bidirectional, as advertisements may both erase and emphasise the assumed boundaries between codes. 相似文献
874.
Individual differences in infants’ engagement with their environment manifest early in development and are noticed by parents. Three views have been advanced to explain differences in seeking novel stimulation. The optimal stimulation hypothesis suggests that individuals seek further stimulation when they are under‐responsive to current sensory input. The processing speed hypothesis proposes that those capable of processing information faster are driven to seek stimulation more frequently. The information prioritization hypothesis suggests the differences in stimulation seeking index variation in the prioritization of incoming relative to ongoing information processing. Ten‐month‐old infants saw 10 repetitions of a video clip and changes in frontal theta oscillatory amplitude were measured as an index of information processing speed. Stimulus‐locked P1 peak amplitude in response to checkerboards briefly overlaid on the video at random points during its presentation indexed processing of incoming stimulation. Parental report of higher visual seeking did not relate to reduced P1 peak amplitude or to a stronger decrease in frontal theta amplitude with repetition, thus not supporting either the optimal stimulation or the processing speed hypotheses. Higher visual seeking occurred in those infants whose P1 peak amplitude was greater than expected based on their theta amplitude. These findings indicate that visual sensory seeking in infancy is explained by a bias toward novel stimulation, thus supporting the information prioritization hypothesis. 相似文献
875.
To perform variable selection in expectile regression, we introduce the elastic-net penalty into expectile regression and propose an elastic-net penalized expectile regression (ER-EN) model. We then adopt the semismooth Newton coordinate descent (SNCD) algorithm to solve the proposed ER-EN model in high-dimensional settings. The advantages of ER-EN model are illustrated via extensive Monte Carlo simulations. The numerical results show that the ER-EN model outperforms the elastic-net penalized least squares regression (LSR-EN), the elastic-net penalized Huber regression (HR-EN), the elastic-net penalized quantile regression (QR-EN) and conventional expectile regression (ER) in terms of variable selection and predictive ability, especially for asymmetric distributions. We also apply the ER-EN model to two real-world applications: relative location of CT slices on the axial axis and metabolism of tacrolimus (Tac) drug. Empirical results also demonstrate the superiority of the ER-EN model. 相似文献
876.
877.
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
878.
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
879.
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
880.
Over the twentieth and twenty-first centuries, veterans have been more likely to enter into race/ethnic intermarriages than non-veterans. Theories of race/ethnic intermarriage variously point to how minority race/ethnicity, race/ethnically diverse social settings, progressive racial attitudes, and high socioeconomic status increase individuals’ likelihood of intermarrying. Veterans’ unique racial and socioeconomic characteristics may contribute to their greater likelihood of intermarrying relative to non-veterans: larger percentages of veterans than non-veterans are members of racial and ethnic minority groups, while military service increases individual service members’ long-term economic and educational prospects. At the same time, veterans share in common their exposure to the unique military environment, which may increase their likelihood of intermarriage by diversifying their social circles, and subjecting their attitudes and behavior to group norms that are more explicitly egalitarian than those of society at large. The present study considers these two possible explanations for veterans’ greater likelihood of intermarriage. We use data on seven cohorts of men over six decades in the Current Population Survey, representing a total of 1,456,742 observations, to decompose the difference in likelihood of racial intermarriage between veterans and non-veterans among married men aged 18–65. We find that across cohorts and decades, veterans’ greater likelihood of intermarrying is not fully explained by their race/ethnic and socioeconomic composition. We argue that veterans’ greater likelihood of intermarrying may therefore be driven by their exposure to the military environment. 相似文献