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   659篇
  免费   26篇
管理学   74篇
民族学   8篇
人口学   59篇
丛书文集   4篇
理论方法论   99篇
综合类   9篇
社会学   380篇
统计学   52篇
  2023年   8篇
  2022年   7篇
  2021年   5篇
  2020年   7篇
  2019年   15篇
  2018年   21篇
  2017年   35篇
  2016年   18篇
  2015年   27篇
  2014年   20篇
  2013年   114篇
  2012年   22篇
  2011年   23篇
  2010年   19篇
  2009年   15篇
  2008年   15篇
  2007年   22篇
  2006年   25篇
  2005年   16篇
  2004年   18篇
  2003年   16篇
  2002年   13篇
  2001年   18篇
  2000年   14篇
  1999年   8篇
  1998年   15篇
  1997年   12篇
  1996年   4篇
  1995年   8篇
  1994年   14篇
  1993年   4篇
  1991年   8篇
  1990年   6篇
  1989年   7篇
  1988年   7篇
  1987年   5篇
  1986年   5篇
  1985年   8篇
  1984年   5篇
  1983年   9篇
  1982年   4篇
  1981年   7篇
  1980年   5篇
  1979年   4篇
  1978年   4篇
  1977年   2篇
  1976年   3篇
  1975年   3篇
  1974年   2篇
  1970年   4篇
排序方式: 共有685条查询结果,搜索用时 296 毫秒
631.
632.
Serious injuries and deaths of three samples of boys were examined in an inner-city, longitudinal study. By age 19, almost 1 in 10 of the 506 participants in the oldest sample had been seriously wounded or killed. Two thirds of this group had been either wounded or killed by guns. Victims, compared to controls, tended to have a history of engaging in serious delinquency, gang fights, and selling drugs. They also tended to carry guns. The delinquent lifestyle of the victims was also evident from their court records. Victims tended to do poorly academically in school, received poorer parental supervision, had poorer communication with their parents, and had a long history of behavior problems.  相似文献   
633.
Relying on the 1980 US Census of Foreign-Born Population and the 1979 Immigration and Naturalization Service Public Use File, this article compares Israeli-born Americans (including Arabs) to both the US and Israeli populations with respect to age, marital status, unemployment, education, industry, occupation, and income as of 1979-1980. Some of the results, mainly those pertaining to the demographic and socioeconomic characteristics of Israeli immigrants as compared to their society of origin, corroborate previous research. Thus, Israeli-born immigrants in the US held top white-collar jobs and were less likely to be unemployed than the rest of the Israeli labor force. Once in America, however, it seems that not all Israeli-born Americans are as successful as portrayed by past research. In fact, the Census data reveal occupational and economic dualism among the population of Israeli-born Americans. The reasons for this dualism are discussed.  相似文献   
634.
635.
Previous studies have observed a 7-day cycle with the least number of births occurring on Sundays. This study was aimed at characterizing the daily effect on the number of births in Israel, where Sunday is a regular working day and Saturday is a nonworking day. It was hypothesized that fewer births would be noted on Saturday rather than Sunday and fewer births on Jewish holidays. The data consisted of a random sample of live births during 1975. A robust time series procedure was used for the data analysis. As expected, the number of births was much smaller on Saturdays than on other weekdays (10% reduction). The seasonal component for Sundays was greater than that for any other day due to births delayed from Saturday and scheduled induced births. The number of births was not reduced as much on Saturdays during spring and summer as during fall and winter. In addition, fewer births occurred on most Jewish holidays. However, an unexpected and extremely high number of births was noted on Yom Kippur and the day after. It is speculated that the strain and fasting during this holiday promoted labor induction. In 21 of the 52 weeks in the study period, the least number of births occurred on a Saturday, and the number of births was less than the mean of the remaining 6 days in 46 of these weeks. Similarly, in 17 of the 52 weeks, the greatest number of births occurred on a Sunday, and the Sunday births exceeded the mean of Monday-Friday births in 35 of these weeks. Thus, these results confirm the study hypothesis and are believed to reflect intervention in childbirth.  相似文献   
636.
Phthalic acid esters (phthalates) are used as plasticizers in numerous consumer products, commodities, and building materials. Consequently, phthalates are found in human residential and occupational environments in high concentrations, both in air and in dust. Phthalates are also ubiquitous food and environmental contaminants. An increasing number of studies sampling human urine reveal the ubiquitous phthalate exposure of consumers in industrialized countries. At the same time, recent toxicological studies have demonstrated the potential of the most important phthalates to disturb the human hormonal system and human sexual development and reproduction. Additionally, phthalates are suspected to trigger asthma and dermal diseases in children. To find the important sources of phthalates in Europeans, a scenario-based approach is applied here. Scenarios representing realistic exposure situations are generated to calculate the age-specific range in daily consumer exposure to eight phthalates. The scenarios demonstrate that exposure of infant and adult consumers is caused by different sources in many cases. Infant consumers experience significantly higher daily exposure to phthalates in relation to their body weight than older consumers. The use of consumer products and different indoor sources dominate the exposure to dimethyl, diethyl, benzylbutyl, diisononyl, and diisodecyl phthalates, whereas food has a major influence on the exposure to diisobutyl, dibutyl, and di-2-ethylhexyl phthalates. The scenario-based approach chosen in the present study provides a link between the knowledge on emission sources of phthalates and the concentrations of phthalate metabolites found in human urine.  相似文献   
637.
638.
Social security and strategic inter-vivos transfers of social capital   总被引:2,自引:1,他引:1  
This paper explains public provision of social capital in an overlapping generations model with gerontocracy, without resort to any bequest motive. The old generation has an incentive to provide education and infrastructure because these goods shift the Laffer curve of social security taxation, thereby increasing old-age income in the political equilibrium. The incentive is stronger if population growth is larger. The marginal productivity of social capital in the political equilibrium may exceed or fall short of the marginal productivity of social capital in an efficient allocation.Comments by Ursula Arlt, Tom G. McCarthy, Wolfgang Peters, the participants in seminars at the Universities of Cologne and Dortmund and two anonymous referees are gratefully acknowledged. The usual caveat applies.  相似文献   
639.
A challenge with multiple chemical risk assessment is the need to consider the joint behavior of chemicals in mixtures. To address this need, pharmacologists and toxicologists have developed methods over the years to evaluate and test chemical interaction. In practice, however, testing of chemical interaction more often comprises ad hoc binary combinations and rarely examines higher order combinations. One explanation for this practice is the belief that there are simply too many possible combinations of chemicals to consider. Indeed, under stochastic conditions the possible number of chemical combinations scales geometrically as the pool of chemicals increases. However, the occurrence of chemicals in the environment is determined by factors, economic in part, which favor some chemicals over others. We investigate methods from the field of biogeography, originally developed to study avian species co‐occurrence patterns, and adapt these approaches to examine chemical co‐occurrence. These methods were applied to a national survey of pesticide residues in 168 child care centers from across the country. Our findings show that pesticide co‐occurrence in the child care center was not random but highly structured, leading to the co‐occurrence of specific pesticide combinations. Thus, ecological studies of species co‐occurrence parallel the issue of chemical co‐occurrence at specific locations. Both are driven by processes that introduce structure in the pattern of co‐occurrence. We conclude that the biogeographical tools used to determine when this structure occurs in ecological studies are relevant to evaluations of pesticide mixtures for exposure and risk assessment.  相似文献   
640.
This study attempted to validate distinctions between popularity and social acceptance in the cultural context of Hong Kong. We recruited 280 Chinese children (132 girls, 148 boys, mean age = 9.5) from Hong Kong primary schools. These children completed a peer nomination inventory assessing popularity, social acceptance, social rejection, aggression, peer victimization, and social behavior. Consistent with research conducted in western samples, we found that social acceptance was correlated primarily with positive behavioral characteristics (i.e., assertiveness‐leadership and low levels of submissiveness‐withdrawal). In contrast, popularity was associated with a more mixed pattern of features including high levels of aggression. The overall pattern of findings closely replicates past research conducted in North American and European settings.  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