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   22119篇
  免费   336篇
管理学   2958篇
民族学   146篇
人才学   1篇
人口学   3293篇
丛书文集   64篇
教育普及   3篇
理论方法论   1560篇
综合类   403篇
社会学   10803篇
统计学   3224篇
  2023年   67篇
  2021年   71篇
  2020年   155篇
  2019年   233篇
  2018年   1876篇
  2017年   1970篇
  2016年   1320篇
  2015年   248篇
  2014年   318篇
  2013年   2494篇
  2012年   643篇
  2011年   1428篇
  2010年   1250篇
  2009年   982篇
  2008年   1035篇
  2007年   1206篇
  2006年   263篇
  2005年   457篇
  2004年   444篇
  2003年   378篇
  2002年   274篇
  2001年   289篇
  2000年   270篇
  1999年   277篇
  1998年   177篇
  1997年   158篇
  1996年   241篇
  1995年   209篇
  1994年   221篇
  1993年   225篇
  1992年   238篇
  1991年   223篇
  1990年   242篇
  1989年   213篇
  1988年   208篇
  1987年   181篇
  1986年   169篇
  1985年   179篇
  1984年   181篇
  1983年   127篇
  1982年   126篇
  1981年   105篇
  1980年   117篇
  1979年   116篇
  1978年   98篇
  1977年   87篇
  1976年   84篇
  1975年   88篇
  1974年   60篇
  1973年   58篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
821.
We used a longitudinal community study of 674 grade school children (Grades 5, 6, 7, and 8; 337 males, 337 females) of Mexican origin to examine outcomes of school attachment. Attachment to school is important in this population given the high level of school dropout rates of Mexican‐origin students. Results indicated that, on average, school attachment from fifth to sixth grade remains stable, but declines from sixth to eighth grade. Boys had lower levels of school attachment at fifth grade but followed similar patterns of change as girls did. Attachment to teachers, peer competence, school aspirations and expectations, and substance‐use cognitions emerged as longitudinal outcomes of level or changes in school attachment. Gender moderated associations of school attachment.  相似文献   
822.
Association of demanding kin relations and family routine with adolescents' psychological distress and school achievement was assessed among 200 low‐income, African American mothers and adolescents. Demanding kin relations were significantly associated with adolescents' psychological distress. Family routine was significantly related to adolescents' school achievement. Demanding kin relations were negatively associated with school achievement for adolescents from families low in routine, but unrelated to achievement for adolescents in families high in routine. Additional research is needed on poor families and their social networks.  相似文献   
823.
It is generally difficult to separate the effects of divorce from selection when analyzing the effects of parental divorce on children’s risk behaviors. We used propensity score matching and longitudinal data methods to estimate the effects of parents’ divorce on their children’s binge drinking, alcohol consumption, tobacco use, marijuana use, and hard drug use. The children were between 12 and 18 years old in the first survey and between 18 and 24 years old in the second survey. Our results suggest that parental divorce significantly increased the probability of risk behaviors in their children. Moreover, many of these adverse impacts persisted over time, especially among teenage girls.  相似文献   
824.
This study examined the association of financial access and alternative financial services (AFS) using a nationally representative sample from the 2012 National Financial Capability Study (N = 25,509). Structural equation modeling was used to examine the relationship between financial access and AFS usage. Ordinary least squares regression was used to estimate the relationship between banked status and the overall AFS usage as a latent variable while controlling for sociodemographic variables, financial education, financial knowledge, and home ownership. Results suggested that being unbanked was positively associated with AFS usage after controlling for other covariates. Financial education and knowledge, age, gender, marital status, education, household income, and homeownership were significantly associated with AFS usage. These findings have implications for public policy and programs that work with the unbanked.  相似文献   
825.
Financial education sans opportunities for hands-on experience and knowledge operationalization may be insufficient for promoting healthy financial behaviors. Financial capability combines financial education with financial inclusion via a savings account, thereby giving an opportunity translate knowledge into practice. This study used data from the 2012 National Financial Capability Study to examine relationships between the financial capability and financial behaviors of United States Millennials (N = 6865). Compared to their financially excluded peers, Millennials who were financially capable were 176 % more likely to afford unexpected expenses, 224 % more likely to save for emergencies, 21 % less likely to use alternative financial services, and 30 % less likely to carry burdensome debt. Interventions that focus solely on financial education or inclusion may be insufficient for facilitating Millennials’ healthy financial behaviors; interventions should instead develop financial capability.  相似文献   
826.
Rates of food insecurity in the US have been rising since 2000 spiking with the onset of the Great Recession in 2008, and have remained essentially unchanged since then despite improvements in the economy. The present study employed a series of indices adapted from the poverty literature to examine the depth and severity of food insecurity across the decade by race and ethnicity among low-income households with and without children. The most rapid increases in the depth and severity of food insecurity were found among low-income households without children. Non-Hispanic White households with and without children had lower prevalence rates but steeper increases in the depth and severity of food insecurity throughout the decade. Non-Hispanic Black households with and without children were at the most disadvantaged among low-income populations.  相似文献   
827.
This study used longitudinal, nationally representative data from the 2008 Survey of Income and Program Participation to explore how each of six sources of instability (employment shocks, household formation shocks, residential changes, income changes, household size changes, and disability shocks) impacted the key domains of material hardship (food insecurity and medical, housing and essential expense hardship). The study found that income shocks and having a person with a disability join the household were the only consistent triggers for all types of material hardship, and that overall, sources of instability had an asymmetrical impact on material hardship; that is, sources of instability did not help households when they were removed as much as they harmed households when introduced. These results provided a nuanced understanding of the household dynamics that result in economic and family instability in the US and provided new evidence regarding why some households were unable to cover basic needs.  相似文献   
828.
Why similar people have different patterns of wealth accumulation is puzzling. The behavioral life-cycle hypothesis indicates self-control is an important aspect of household saving behavior. This study investigated if household wealth creation from 1994 to 2008 could be predicted by self-control among a sample of young baby boomers using National Longitudinal Survey of Youth (NLSY79) data. Variables that significantly predicted 2008 net worth included homeownership, 1994 net worth, income, bankruptcy filing, inheritance, education level, race, marital status, children, retirement planning activities, locus of control, and self-mastery. The addition of self-control predictors to a regression model improved the model’s ability to predict net worth by 1.3 % above and beyond the human capital, financial status, and demographic predictor variables. In total, the model explained 60 % of the variance in net worth. Findings indicated that individuals who invested in their human capital, were homeowners, and had higher self-control, accumulated more wealth.  相似文献   
829.
This study used data from Waves 1 (1987–1989) and 2 (1992–1994) of the National Survey of Families and Households in the United States and a series of regression models, some of which included individual-specific fixed effects, to estimate associations of particular types and levels of debt with adult depressive symptoms. Results suggest that household debt is positively associated with greater depressive symptoms. However, this association appears to be driven by short-term (unsecured) debt; we found little evidence of associations with depressive symptoms for mid- or long-term debt. The link between short-term debt and depressive symptoms persisted with alternative estimation strategies, including defining debt in absolute and relative terms. Furthermore, this association was particularly concentrated among 51–64 year-old adults, those with a high school education or less, and those who were not stably married throughout the observation period. These findings suggest that short-term debt may have an adverse influence on psychological wellbeing, particularly for those who are less educated, approaching retirement age, or unmarried.  相似文献   
830.
Urbanization has been identified as a threat to biodiversity due to landscape modifications. Studies of parasite ecology in urbanized areas lagged behind those made on macro organisms. Here we studied infection prevalence of haemosporidian parasites in an avian community of an urban forest from Germany, and its relationship with bird abundance and body mass. We used PCR to amplify a fragment of the mtDNA cyt b gene to determine the infection status of birds, and bird point counts to determine bird relative abundances. The avifauna was dominated by two small sized insectivore passerines (Parus major, Cyanistes caeruleus), representing ~40 % of the total bird records. The highest haemosporidian prevalence was recorded for Turdus philomelos (100 %) and for Fringilla coelebs (75 %). Bird abundance and body mass were positively associated with infection status for two haemosporidian genera: Plasmodium and Leucocytozoon. Infection rate was lower in juveniles compared to adult birds. We recorded a total of 7 Plasmodium, 26 Haemoproteus, and 10 Leucocytozoon lineages. Avian malaria (P. relictum) was detected infecting 5 individuals of P. major, the most abundant species in the community. These results, together with those of previous studies at the same site, suggest that potentially any of the genetic haemosporidian lineages detected in this urban forest can be transmitted across native and pet bird species, and to species of conservation concern housed at aviaries.  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