首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   19653篇
  免费   605篇
  国内免费   1篇
管理学   2613篇
民族学   111篇
人口学   1732篇
丛书文集   75篇
教育普及   1篇
理论方法论   1782篇
综合类   182篇
社会学   10002篇
统计学   3761篇
  2023年   132篇
  2022年   80篇
  2021年   133篇
  2020年   349篇
  2019年   518篇
  2018年   611篇
  2017年   798篇
  2016年   614篇
  2015年   407篇
  2014年   570篇
  2013年   3544篇
  2012年   737篇
  2011年   691篇
  2010年   503篇
  2009年   407篇
  2008年   542篇
  2007年   496篇
  2006年   526篇
  2005年   411篇
  2004年   426篇
  2003年   358篇
  2002年   369篇
  2001年   469篇
  2000年   415篇
  1999年   409篇
  1998年   315篇
  1997年   261篇
  1996年   280篇
  1995年   290篇
  1994年   246篇
  1993年   257篇
  1992年   302篇
  1991年   295篇
  1990年   291篇
  1989年   253篇
  1988年   240篇
  1987年   202篇
  1986年   229篇
  1985年   251篇
  1984年   216篇
  1983年   192篇
  1982年   159篇
  1981年   130篇
  1980年   156篇
  1979年   171篇
  1978年   134篇
  1977年   114篇
  1976年   87篇
  1975年   91篇
  1974年   94篇
排序方式: 共有10000条查询结果,搜索用时 734 毫秒
301.
There is some concern in Australia that immigration contributes to a widening of its current account deficit. Several cross-section studies have found that migrant households have a lower saving rate than the local born households. In conjunction with a well-known national income identity that the current account deficit is equal to the excess of investment over saving, such findings have been interpreted by many to mean that the migrants contribute to increasing the level of foreign liabilities at a rate greater than that by the local-born.
However, it should be realized that immigration impacts on the economy in a complex way through various demand and supply side channels. Its direct and chain effects on such variables as the current account are spread over both the short and the long term. These effects are neither unidirectional nor always easy to isolate. The final outcome, which is the sum total of all the effects, is uncertain, and cannot be fully understood from a knowledge of cross-sectional saving performance alone.
This article utilizes aggregate time series data to investigate the relationship between the current account and immigration. It finds that although an increase in net migration tends to raise the current account deficit, the longer term effect of immigration on the current account is negligible.  相似文献   
302.
303.
Immigration has long been a national and state concern. The 1989 Legalized Population Survey (LPS-1) collected data on illegal immigrants to the US who subsequently became legalized aliens under the provisions of the 1986 Immigration Reform and Control Act. These data are used in a study assessing whether undocumented male and female immigrants improve their earnings and occupational status over time and the extent of variation in occupational status and mobility by gender and region. The data indicate that both undocumented men and women, on average, improved their earnings and occupational status between their first jobs in the US and their jobs just before applying for legalization under the 1986 Immigration Reform and Control Act. However, the earnings, occupational status, and occupational mobility of men were greater than for women.  相似文献   
304.
305.
306.
A non-linear model for examining genotypic responses across an array of environments is contrasted with the 'joint regression' formulation, and a rigorous approach to hypothesis testing using the conditional error principle is demonstrated. The model is extended to cater for situations where single straight-line response patterns fail to characterize genotypic behaviors over an environmental array: a combination of two straight lines, with slope in below-average and in above-average environments, is offered as the 1 2 simplest representation of convex and concave patterns. A protocol for classifying genotypes according to the results of hypothesis tests, i.e. H( = ) and H( = = = 1), is 1 2 1 2 presented . A doubly desirable response pattern is convex ( < 1< ), while a doubly 1 2 undesirable pattern is concave ( > 1> ). 1 2  相似文献   
307.
Recent trends in immigration to Poland are reviewed, including both voluntary migration and migration forced by extreme political or economic circumstances. Data are also presented on illegal immigrants and on their countries of origin.  相似文献   
308.
This paper considers two types of chaotic map time series models, including the well-known tent, logistic and binary-shift maps as special cases; these are called curved tent and curved binary families. Deterministic behaviour is investigated by invariant distributions, Lyapunov exponents, and by serial dependency. Stochastic time reversal of the families is shown to produce models which have a broader range of stochastic and chaotic properties than their deterministic counterparts. The marginal distributions may have concentrations and restricted supports and are shown to be a non-standard class of invariant distribution. Dependenc y is generally weaker with the reversed stochastic models. The work gives a broad statistical account of deterministic and stochastically reversed map models, such as are emerging in random number generation, communica tion systems and cryptography  相似文献   
309.
Relatively little is known about Asian American tobacco and alcohol use patterns. This is particularly true of Chinese living in the United States--either U.S.-born or non-U.S.-born Chinese. This article presents data from a research project studying tobacco and alcohol use patterns in San Francisco's Chinese community. Data were secured both from focus groups and a self-report telephone survey of a random sample of 1,808 Chinese residents in San Francisco. This results indicate that the prevalence of both tobacco and alcohol use is lower for San Francisco's Chinese population than for the general population. Moreover, those persons who report smoking tend to be different from those who report consuming alcohol. The study concludes that specific, culturally relevant tobacco and alcohol prevention programs should be designed to better reach this target population.  相似文献   
310.
Siblings who have suffered severe trauma and disrupted attachment relate to one another in ways that interfere with individual development, the chance to benefit from connections with adults, the establishment of healthy sibling relationships, and the working through of traumatic experiences. The authors use case examples to illustrate four distinct sibling patterns: absent, adult lockout, half and half, and trauma shield. The authors highlight the importance of recognizing these types and then varying the therapist's treatment stance to pursue five goals. These include suspending problematic sibling relationships to create room for bonding with caring adults, transferring attachment behaviors and impulses to a receptive adult, resuming healthy individual development, forming more adaptive sibling connections, and expressing shared traumatic content.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号