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931.
Developmental trajectories of risky sexual behavior were identified in a multiethnic sample of 1,121 youth drawn from the Children of the National Longitudinal Survey of Youth data set (NLSY79). Group-based trajectory modeling of a composite index of sexual risk taking revealed four sexual risk groups from ages 16 to 22: low risk, decreasing risk, increasing risk, and high risk. The Low Risk group exhibited low levels of risk across the study period. The Decreasing Risk group had high levels of sexual risk in adolescence that declined in early adulthood. The Increasing Risk and High Risk groups showed distinct risk patterns during adolescence but converged in early adulthood. When compared with adolescents in the low-risk group, individuals in the other groups were more likely to be male, had mothers who had an early birth, were less likely to live with both biological parents in early adolescence, had higher risk proneness, and reported more negative peer pressure.  相似文献   
932.
Urban Ecosystems - Communication systems rely upon specific social contexts and environments that permit effective transmission, and thus, are particularly vulnerable to disruption by anthropogenic...  相似文献   
933.
Urban Ecosystems - Urbanisation is causing rapid land-use change worldwide. Populations of freshwater turtles are vulnerable to impacts of urbanisation such as habitat loss, fragmentation and...  相似文献   
934.
935.
Thomas KJ 《Demography》2012,49(2):477-498
This study uses data from the 2000 U.S. census to examine whether the schooling advantage of black immigrants’ children found in previous studies is robust. According to the results, the advantage associated with having migrant parents is not restricted to the children of immigrants. Black migrant parents, regardless of foreign-born status, have children with favorable schooling outcomes. Such parental-level influences, however, seem stronger among some immigrant groups than among native internal migrants. The study also suggests that the collective advantage of the children of immigrants is driven by positive migrant selectivity. Accordingly, comparisons between the children of native migrants and children in various immigrant groups reveal that the immigrant advantage is not robust. In fact, the results suggest that when immigrant ethnicity is considered, some children of immigrants may be disadvantaged relative to the children of native migrants. Among recent migrants, the children of native internal migrants also have more favorable outcomes than the children of immigrants, although these differences disappear after background factors are controlled. Further, internal-migrant and immigrant households are less likely to have characteristics that adversely affect schooling than nonmigrant households. Unsurprisingly, the children of nonmigrants have the worst outcomes among black youths.  相似文献   
936.
Schwartz CR  Mare RD 《Demography》2012,49(2):629-650
This paper adapts the population balancing equation to develop a framework for studying the proximate determinants of educational homogamy. Using data from the National Longitudinal Survey of Youth on a cohort of women born between 1957 and 1964, we decompose the odds of homogamy in prevailing marriages into four proximate determinants: (1) first marriages, (2) first and later marital dissolutions, (3) remarriages, and (4) educational attainment after marriage. The odds of homogamy among new first marriages are lower than among prevailing marriages, but not because of selective marital dissolution, remarriage, and educational attainment after marriage, as has been speculated. Prevailing marriages are more likely to be educationally homogamous than new first marriages because of the accumulation of homogamous first marriages in the stock of marriages. First marriages overwhelmingly account for the odds of homogamy in prevailing marriages in this cohort. Marital dissolutions, remarriages, and educational upgrades after marriage have relatively small and offsetting effects. Our results suggest that, despite the high prevalence of divorce, remarriage, and continued schooling after marriage in the United States, the key to understanding trends in educational homogamy lies primarily in variation in assortative mating into first marriage.  相似文献   
937.
The importance of meeting the unmet need for contraception is nowhere more urgent than in the countries of sub-Saharan Africa, where the fertility decline is stalling and total unmet need exceeds 30 per cent among married women. In Ghana, where fertility levels vary considerably, demographic information at sub-national level is essential for building effective family planning programmes. We used small-area estimation techniques, linking data from the 2003 Ghana Demographic and Health Survey to the 2000 Ghana Population and Housing Census, to derive district-level estimates of contraceptive use and unmet need for contraception. The results show considerable variation between districts in contraceptive use and unmet need. The prevalence of contraceptive use varies from 4.1 to 41.7 per cent, while that of the use of modern methods varies from 4.0 to 34.8 per cent. The findings identify districts where family planning programmes need to be strengthened.  相似文献   
938.
This article will examine the social implications for African American homosexual males seeking to achieve the American Dream. Invisible Life and Just as I Am-the first two novels in a trilogy by the late E. Lynn Harris writing from a semi-autobiographical perspective in late-twentieth century America-will serve as the texts that drive this research topic. Careful analysis of these works will substantiate the assertion that the American Dream, even on the cusp of the new millennium, is just beyond the grasp of this specific subpopulation.  相似文献   
939.
This study uses data from the 2002 Rwandan census to situate the discourse on migration and orphan well-being within the context of the household. According to its findings, migrant orphans are less likely than non-migrant orphans to live in households with less favorable structural characteristics such as single-parent households. Significant differences are also found in the implied gains to living standards and schooling associated with migration among paternal, maternal, and double-orphans. However, the higher living standards and schooling attainment of orphan migrants relative to their non-migrant counterparts disappear within child-headed household contexts. More generally, the results indicate that the higher living standards of migrant orphans are in part driven by the fact that they mostly live in households with migrant household-heads or migrant spouses. Yet the analysis also suggests that orphans living within these contexts experience higher levels of intra-household discrimination in investments in their schooling, relative to their orphan counterparts who live in non-migrant households.  相似文献   
940.
This study estimates the effects of food hypersensitivity on individuals?? perceived welfare and well-being compared to non-food hypersensitive individuals. Study respondents were recruited in the Netherlands, Poland, Spain and UK. The difference in welfare between food hypersensitive respondents and those asymptomatic to foods was estimated using a subjective welfare approach, including income evaluation. Well-being was measured using the Cantril Ladder-of-Life Scale, and health status using the Self-Perceived Health Scale. The difference in well-being, welfare and health status between participant groups was explained further using a number of background variables. No significant within-country differences in welfare between food hypersensitive respondents and respondents asymptomatic to foods were found. In terms of well-being, adult food hypersensitive respondents and their spouses reported significantly less happiness than respondents and their spouses asymptomatic to foods in the Netherlands and Poland. In Spain, the spouses of the food hypersensitive respondents were significantly less happy than respondents aymptomatic to foods. The well-being of children did not significantly differ between groups. The degree of severity of food hypersensitivity was negatively related to overall health status. In Poland, food hypersensitive respondents reported worse health status compared to asymptomatic respondents. In Spain, the converse was true. Food hypersensitive respondents were generally less happy with their life as a whole than respondents asymptomatic to foods, presumably because they experienced more negative effects, which were not related to perceived health status.  相似文献   
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