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   12890篇
  免费   387篇
管理学   1499篇
民族学   63篇
人口学   1100篇
丛书文集   72篇
教育普及   3篇
理论方法论   1217篇
综合类   126篇
社会学   7162篇
统计学   2035篇
  2023年   73篇
  2021年   70篇
  2020年   187篇
  2019年   281篇
  2018年   315篇
  2017年   447篇
  2016年   316篇
  2015年   243篇
  2014年   319篇
  2013年   2591篇
  2012年   377篇
  2011年   383篇
  2010年   273篇
  2009年   253篇
  2008年   284篇
  2007年   295篇
  2006年   312篇
  2005年   263篇
  2004年   245篇
  2003年   201篇
  2002年   235篇
  2001年   290篇
  2000年   271篇
  1999年   278篇
  1998年   181篇
  1997年   161篇
  1996年   216篇
  1995年   214篇
  1994年   218篇
  1993年   223篇
  1992年   235篇
  1991年   222篇
  1990年   245篇
  1989年   215篇
  1988年   204篇
  1987年   183篇
  1986年   170篇
  1985年   177篇
  1984年   183篇
  1983年   129篇
  1982年   123篇
  1981年   106篇
  1980年   117篇
  1979年   113篇
  1978年   97篇
  1977年   85篇
  1976年   82篇
  1975年   86篇
  1974年   57篇
  1973年   54篇
排序方式: 共有10000条查询结果,搜索用时 484 毫秒
1.
2.
Managing risk in infrastructure systems implies dealing with interdependent physical networks and their relationships with the natural and societal contexts. Computational tools are often used to support operational decisions aimed at improving resilience, whereas economics‐related tools tend to be used to address broader societal and policy issues in infrastructure management. We propose an optimization‐based framework for infrastructure resilience analysis that incorporates organizational and socioeconomic aspects into operational problems, allowing to understand relationships between decisions at the policy level (e.g., regulation) and the technical level (e.g., optimal infrastructure restoration). We focus on three issues that arise when integrating such levels. First, optimal restoration strategies driven by financial and operational factors evolve differently compared to those driven by socioeconomic and humanitarian factors. Second, regulatory aspects have a significant impact on recovery dynamics (e.g., effective recovery is most challenging in societies with weak institutions and regulation, where individual interests may compromise societal well‐being). And third, the decision space (i.e., available actions) in postdisaster phases is strongly determined by predisaster decisions (e.g., resource allocation). The proposed optimization framework addresses these issues by using: (1) parametric analyses to test the influence of operational and socioeconomic factors on optimization outcomes, (2) regulatory constraints to model and assess the cost and benefit (for a variety of actors) of enforcing specific policy‐related conditions for the recovery process, and (3) sensitivity analyses to capture the effect of predisaster decisions on recovery. We illustrate our methodology with an example regarding the recovery of interdependent water, power, and gas networks in Shelby County, TN (USA), with exposure to natural hazards.  相似文献   
3.
Perceptions of infectious diseases are important predictors of whether people engage in disease‐specific preventive behaviors. Having accurate beliefs about a given infectious disease has been found to be a necessary condition for engaging in appropriate preventive behaviors during an infectious disease outbreak, while endorsing conspiracy beliefs can inhibit preventive behaviors. Despite their seemingly opposing natures, knowledge and conspiracy beliefs may share some of the same psychological motivations, including a relationship with perceived risk and self‐efficacy (i.e., control). The 2015–2016 Zika epidemic provided an opportunity to explore this. The current research provides some exploratory tests of this topic derived from two studies with similar measures, but different primary outcomes: one study that included knowledge of Zika as a key outcome and one that included conspiracy beliefs about Zika as a key outcome. Both studies involved cross‐sectional data collections that occurred during the same two periods of the Zika outbreak: one data collection prior to the first cases of local Zika transmission in the United States (March–May 2016) and one just after the first cases of local transmission (July–August). Using ordinal logistic and linear regression analyses of data from two time points in both studies, the authors show an increase in relationship strength between greater perceived risk and self‐efficacy with both increased knowledge and increased conspiracy beliefs after local Zika transmission in the United States. Although these results highlight that similar psychological motivations may lead to Zika knowledge and conspiracy beliefs, there was a divergence in demographic association.  相似文献   
4.
Population Research and Policy Review - In February 2020, the U.S. government began to implement a new Public Charge rule that greatly expands the definition of “public charge” when...  相似文献   
5.
The journey out of care and towards independent living is a challenge for many care-leavers. There has been little research into the social processes involved in this care-leaving journey. This paper presents the results of a grounded theory investigation into the care-leaving journeys of nine young men who had, several years previously, been in the care of Girls & Boys Town in South Africa. Working from a resilience perspective, with an ecological emphasis, four central social processes emerged that together explain the care-leaving experiences of the participants. These processes are striving for authentic belonging; networking people for goal attainment; contextualised responsiveness and building hopeful and tenacious self-confidence. These four processes are located within contextual boundaries and at the social environmental interface. The paper presents these processes in detail, drawing on selected narratives of the participants and integrated with additional theory. It is hoped that this paper may contribute to theory building concerning care-leaving processes and enhance youth care practices for youth in care and leaving care.  相似文献   
6.
Changing Frameworks in Attitudes Toward Abortion   总被引:1,自引:0,他引:1  
For more than two decades, legal abortion has been the subject of heated political debate and adversarial social movement activity; however, national polls have shown little change in aggregate levels of support for abortion. This analysis examines how the determinants of abortion attitudes have changed between 1977 and 1996, using data from the General Social Surveys. While in early time periods, whites were more approving of abortion than blacks, that pattern had reversed by the late 1980s. After controlling for other factors, older people are more accepting of abortion throughout the two decades, while gender is generally unrelated to abortion views. Catholic religion weakens slightly as a predictor of abortion attitudes, while religious fundamentalism and political liberalism increase in explanatory power. The associations between attitudinal correlates and abortion approval also change over this time period. Religiosity becomes a less powerful predictor of abortion attitudes, while respondents' attitude toward sexual freedom and belief in the sanctity of human life increase in their predictive power. Support for gender inequality remains a weak but stable predictor of abortion attitudes. This pattern of results suggests that the public is influenced more by the pro-life framework of viewing abortion than by the pro-choice perspective.  相似文献   
7.
The authors maintain that the social learning theory of career development and counseling has not been applied to diverse populations. To address this gap in the literature, the authors conducted a qualitative analysis of interviews with 21 middle school students in a low‐income, culturally diverse, inner‐city public school. Four themes emerged, reflecting the influence of discrimination on participants' career learning: contextual barriers and resources for learning, and psychological barriers and resources for learning. The authors provide a conceptual framework for assessing resources and barriers and a rationale for why these aspects often remain hidden or unexamined in career assessment with clients who are vulnerable to discrimination.  相似文献   
8.
The authors use an ecological framework and grounded theoretical analysis to explore the circumstances in which working‐class and low‐income custodial African American fathers gain custody of their children, their transition from part‐time to full‐time parents, and the role of support networks in enhancing or inhibiting these men's parenting. Twenty‐four men from an impoverished Midwestern urban area participated in the study. The findings suggest that these men, and perhaps others sharing their demographic profiles, generally become parents by default and are often reluctant to take on a full‐time, single parenting role. Adaptation to the role seems to be enhanced by these men's use of extended kin support networks and shared living arrangements. However, low wages, a lack of sufficient assistance from public assistance programs, and informal custody arrangements often inhibit their fathering.  相似文献   
9.
A study sample of 162 six‐month‐old children was selected from a larger sample of 346 infants on the basis of parents' report of their infants' temperament and a laboratory assessment of temperament. Infants were classified as easily frustrated and less easily frustrated and compared on a number of emotion regulation, physiology, and temperament measures. Results indicated that male and female infants were equally likely to be classified as frustrated and less easily frustrated; however, male infants were less able to regulate physiologically. Easily frustrated infants used different emotion regulation strategies and were observed to be less attentive and more active than less easily frustrated infants when observed in the laboratory. These infants were also characterized by their parents as more active, less attentive, and more distressed to novelty. Infants classified as easily frustrated were more reactive physiologically and less able to regulate physiological reactivity than their less easily frustrated counterparts. It is hypothesized that this cluster of characteristics may constitute a unique temperamental type that may have implications for other types of behavioral functioning. Limitations of the study are that observations are based on a single brief assessment of the infant, modest effect sizes were found, and the study is cross‐sectional.  相似文献   
10.
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