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   210篇
  免费   15篇
管理学   3篇
民族学   6篇
人口学   21篇
丛书文集   3篇
理论方法论   31篇
综合类   12篇
社会学   54篇
统计学   95篇
  2023年   5篇
  2021年   3篇
  2020年   6篇
  2019年   6篇
  2018年   8篇
  2017年   15篇
  2016年   4篇
  2015年   4篇
  2014年   9篇
  2013年   92篇
  2012年   7篇
  2011年   4篇
  2010年   3篇
  2009年   4篇
  2008年   3篇
  2007年   1篇
  2006年   8篇
  2005年   7篇
  2004年   4篇
  2003年   6篇
  2002年   5篇
  2000年   2篇
  1998年   2篇
  1996年   3篇
  1995年   1篇
  1993年   3篇
  1992年   3篇
  1991年   1篇
  1988年   1篇
  1985年   1篇
  1982年   1篇
  1980年   1篇
  1977年   1篇
  1975年   1篇
排序方式: 共有225条查询结果,搜索用时 15 毫秒
101.
Snug Harbor     
No abstract available for this article.  相似文献   
102.
Linear discriminant analysis and quadratic discriminant analysis are used to predict group membership. Rare populations present situations in which group sizes differ drastically. This article examined k = 2 and k = 4 predictor variables for groups with different levels of rarity and different levels of sensitivity and specificity. Sample size recommendations were generated for both minimum and maximum group overlap using the leave-one-out (L-O-O) method of estimation. Minimum sample size recommendations are provided in tables for immediate implementation by applied researchers.  相似文献   
103.
Men who have sex with men (MSM) are at risk for certain physical and psychological health conditions. Ethnic minority MSM are at an increased risk related to the combination of sexual minority and ethnic minority status. The purpose of this pilot study was to compare the levels of depressive symptoms, self-esteem, and sexual behaviors by ethnicity in a sample of MSM (N = 70) residing in South Florida. More than one-third of the sample (N = 26; 37%) had high levels of depressive symptoms. Using non-parametric statistics, statistically significant differences were noted in the levels of depressive symptoms as African-American MSM had higher levels of depressive symptoms when compared to the other ethnic groups. Statistically significant differences were not found when self-esteem and sexual behaviors were compared by ethnicity. Regardless of ethnicity, MSM in this study were at risk for the sequela of depressive symptoms and infections with HIV and/or sexually transmitted infections because of the high levels of unsafe sexual behaviors. More research is needed to explore the relationship of mental health and sexual behaviors among the various ethnic groups of MSM.  相似文献   
104.
With the progression of the HIV pandemic and the unique challenges it brings to community-based health and social services, comprehensive service planning becomes essential for the well-being of those affected by AIDS. This article reports on an educational program using an empowerment-based community practice model in responding to the AIDS crisis. This was a service planning coordination effort tbat included compiling a comprehensive directory and profile of local services, measuring practitioner knowledge and attitudes toward working with persons affected by AIDS, and analyzing planning policies of HIV service agencies. This joint work included faculty, students, and community service providers.  相似文献   
105.
106.
ABSTRACT

Inactivity has been identified as a major contributor to the burden of disease in older women. Study aims were: (a) to assess the personal, social, and environmental facilitators and impediments to physical activity in older women from ethnic communities; and (b) to determine the factors associated with physical activity participation. Older women (aged 60–84 years) were recruited from the local Italian (n = 20), Vietnamese (n = 26) and Anglo-Celtic (n = 26) communities. A survey questionnaire was administered in the participants' preferred language. The most common barriers were: “I am not in good health,” “I am self-conscious about my looks,” “I am too tired,” “I don't have time,” and “The weather is bad.” When comparing the ethnic groups, the Vietnamese women reported fewer barriers than the Italian women (2.6 vs. 5.9). While the Vietnamese women were much more likely to report being “self-conscious about my looks,” the Italian women more commonly reported poor health, being too tired, and not liking exercise as barriers. Overall, those living alone were more likely to be active and those who reported fear of injury, less active. Recognizing ethnospecific differences in the prevalence of barriers may be important when devising strategies to increase activity levels of older women.  相似文献   
107.
Human activities have indirectly modified the dynamics of many populations, accelerating considerably the natural rate of species extinction and raising strong concerns about biodiversity. In many such cases, the underlying ‘natural’ dynamics of the population has been modified by human‐induced increases in mortality, even if the populations are not exploited or harvested in the strict sense. Both dynamical and statistical models are needed to investigate the consequences of human‐induced mortality on the overall dynamics of a population. This paper reviews existing approaches and the potential of recent developments to help form a conceptual and practical framework for analysing the dynamics of exploited populations. It examines both the simple case of an extra source of mortality instantaneously in time, and the theory involved when both risks compete over a continuous time scale. This basic theory is expanded to structured populations, using matrix population models, with applications to the conservation biology of long‐lived vertebrates. The type and degree of compensation expected and approaches to detect it are reviewed, and ways of handling uncertainty are discussed.  相似文献   
108.
Exposure duration is an important component in determining long-term dose rates associated with exposure to environmental contaminants. Surveys of exposed populations collect information on individuals' past behaviors, including the durations of a behavior up to the time of the survey. This paper presents an empirical approach for determining the distribution of total durations that is consistent with the distribution past durations obtained from surveys. This approach is appropriate where the rates of beginning and ending a behavior are relatively constant over time. The approach allows the incorporation of information on the distribution of age in a population into the determination of the distribution of durations. The paper also explores the impact of "longevity" bias on survey data. A case study of the application of this approach to two angler populations is also provided. The results of the case study have characteristics similar to the results reported by Israeli and Nelson ( Risk Anal. 12, 65-72 (1992)) from their analytical model of residential duration. Specifically, the average period of time for the total duration in the entire population is shorter than the average period of time reported for historical duration in the surveyed individuals.  相似文献   
109.
Using the example of the seasonal population of ``snowbirds' that spend the winter in Arizona and other Sunbelt states, this paper examines the issues involved with estimating temporary populations. Specifically using the experience of ASU's ongoing research efforts on Arizona snowbirds, the paper discusses some of the problems associated with estimating a seasonal population – in particular: (1) defining the population under study and (2) developing effective procedures to collect information relating to the population. The concluding section emphasizes the growing national importance of temporary populations and the needs of both the public and private sector to have better information on both their size and characteristics.  相似文献   
110.
Fischer  Ilan 《Theory and Decision》2003,55(4):289-314
The computer simulation study explores the impact of the duration of social impact on the generation and stabilization of cooperative strategies. Rather than seeding the simulations with a finite set of strategies, a continuous distribution of strategies is being defined. Members of heterogeneous populations were characterized by a pair of probabilistic reactive strategies: the probability to respond to cooperation by cooperation and the probability to respond to defection by cooperation. This generalized reactive strategy yields the standard TFT mechanism, the All-Cooperate, All-Defect and Bully strategies as special cases. Pairs of strategies interacted through a Prisoner's Dilemma game and exerted social influence on all other members. Manipulating: (i) the initial distribution of populations' strategies, and (ii) the duration of social influence, we monitored the conditions leading to the emergence and stabilization of cooperative strategies. Results show that: (1) The duration of interactions between pairs of strategies constitutes a crucial factor for the emergence and stabilization of cooperative strategies, (2) Unless sufficient learning intervals are provided, initializing the simulations with cooperative populations does not guarantee that cooperation will sustain.  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