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   5280篇
  免费   49篇
  国内免费   1篇
管理学   186篇
民族学   96篇
人才学   16篇
人口学   176篇
丛书文集   240篇
理论方法论   3169篇
综合类   834篇
社会学   494篇
统计学   119篇
  2023年   5篇
  2022年   7篇
  2021年   8篇
  2020年   16篇
  2019年   25篇
  2018年   17篇
  2017年   25篇
  2016年   17篇
  2015年   26篇
  2014年   89篇
  2013年   34篇
  2012年   149篇
  2011年   112篇
  2010年   82篇
  2009年   86篇
  2008年   104篇
  2007年   147篇
  2006年   158篇
  2005年   137篇
  2004年   118篇
  2003年   90篇
  2002年   112篇
  2001年   127篇
  2000年   104篇
  1999年   42篇
  1998年   39篇
  1997年   23篇
  1996年   25篇
  1995年   34篇
  1994年   30篇
  1993年   176篇
  1992年   212篇
  1991年   276篇
  1990年   102篇
  1989年   206篇
  1988年   196篇
  1987年   209篇
  1986年   225篇
  1985年   257篇
  1984年   266篇
  1983年   254篇
  1982年   306篇
  1981年   335篇
  1980年   215篇
  1979年   42篇
  1978年   14篇
  1966年   4篇
  1963年   3篇
  1959年   9篇
  1957年   6篇
排序方式: 共有5330条查询结果,搜索用时 15 毫秒
81.
82.
Selected data concerning the USSR are presented. They concern vital statistics by republic for 1989 for rural and urban areas, birth order, life expectancy by sex, and population change and vital statistics for cities with a population over one million.  相似文献   
83.
84.
85.
"Teacher, what are we going to do next class?" This is an exciting question which I often hear from my students. As an English conversation teacher, I can make the learning of English either a dull and boring duty, or an exciting adventure. It is very important that I make my students hate missing my class, and keep them guessing just what will happen the next time! Let us consider some important ways that any teacher can help his other students want to do their  相似文献   
86.
This article reviews scientific and other literature during the 1990s that links migration and mobility with the spread of sexually transmitted diseases (STDs), including HIV/AIDS. The focus is on key population groups linked to the spread of HIV and STDs in West and Central Africa: migrant laborers, truck drivers, itinerant traders, commercial sex workers (CSWs), and refugees. Countries with high emigration and immigration tend to have high levels of HIV infection, with the exception of Senegal. The main destination of immigrants are Senegal, Nigeria, and Cote d'Ivoire in West Africa and Cameroon, Congo, Gabon, and Congo in Central Africa. The risk of infection and the spread of HIV is variable among migrants. There is little in the literature that substantiates hypotheses about the strong association between migration and HIV-positive status. Information is needed on the duration, frequency of return visits, living conditions, sexual activities with multiple partners, and information before departure, along the routes, at final destination, and at the time of returns. Action-based research in five West African countries (Burkina Faso, Cote d'Ivoire, Mali, Niger, and Senegal) should produce results in late 1998. Comparable studies in Central Africa are unknown. Regional studies should be complemented by local studies. Prevention would benefit from studies on the relative size of these five population groups by geographic location.  相似文献   
87.
USAID has assisted the Ghanian Ministry of Health since 1991 to boost family planning services under the Ghana Family Planning and Health Project by providing supplies and information and increasing the effectiveness of HIV/AIDS prevention and control. The sustainability of the health system is endangered by favoring capital expenditures in lieu of continuous expenditures; the lack of linkage between project activities and regular activities; the centralization of resource flow; and too ambitious targeting. Capital outlays provided by USAID featured in the construction of four public health laboratories, but their operation also requires continuous financing amounting to about 10% of the whole investment. The latter is the responsibility of the government, although the details of these recurrent costs were not detailed at the outset and providing these funds for continuous operation may impair the operation of other systems. The resource constraints could be alleviated by an effective cost-recovery system or by the general improvement of the economy. The lack of linkage between project and regular activities is serious at regional and district levels. The centralization of resource flow means that most resources are kept for headquarter level activities, thus other activities suffer and the health sector becomes excessively reliant on donor support. Too ambitious planning stems from pressure on donors and hastily implemented projects result in duplication and waste. Closer consultation with the parties involved would improve the situation. The rivalry of technical and policy groups has contributed to past deficiencies. Double funding for the same activity has also occurred further increasing the dependence on donor funding. By concentration on people and systems sustainability would be enhanced, while cost recovery would help the operation of the laboratories. The Health Education Unit (HEU) recognized the importance of IEC and obtained financing for such activities.  相似文献   
88.
In thousands, Thailand's total population as of July 1, 1997, was 60,440, of which 30,202 were male and 30,238 were female. 19,087 live in urban areas and 41,353 live in rural areas. 12,141 live in the northern region, 19,678 to the northeast, 7566 in the South, 13,112 centrally, and 7943 in the Bangkok metropolis. 16,288 were under age 15, 39,073 aged 15-59, and 5079 aged 60 and over. There were 15,558 women of reproductive ages 15-44. Crude birth and death rates per 1000 population were 15.6 and 5.0, respectively, with an overall natural growth rate of 1.1%. Infant mortality was 25.0 per 1000 live births. Male and female life expectancies at birth were 66.6 and 71.7 years, respectively. Further life expectancies at age 60 for males and females were 18.8 and 22.0 years, respectively. The rate of total fertility per woman was 1.98 with a contraceptive prevalence rate of 72.2% and an anticipated population of 70,642 in the year 2012.  相似文献   
89.
The purposes of this study were to examine the prevalence of gambling among youth, compare rates of gambling between 1992 and 1995, and determine what levels of gambling frequency may be considered common and uncommon. The two samples included 122,700 Minnesota public school students in the 6th, 9th, and 12th grades in 1992; and 75,900 9th and 12th grade students in 1995. Students were administered the Minnesota Student Survey, a 126-item, anonymous, self-administered, paper-and-pencil questionnaire that inquires about multiple content domains, including gambling behaviors. The same questionnaire, with minor revisions to the gambling items, was administered in both 1992 and 1995 to students in their classrooms by the Minnesota Department of Education. There were slight decreases in overall gambling rates from 1992 to 1995. The majority of students gambled at least once during the past year. However, most did not play any game on a weekly/daily rate and did not report any problems associated with their gambling. Gender, grade, and race effects were found for gambling frequency. Boys gambled more often than girls, and 9th and 12th grade students gambled more often than 6th grade students. Asian American and White students reported lower rates of gambling frequency than Mexican/Latin American, African American, and American Indian students. From a statistical standpoint (i.e., beyond the 97.7 percentile), it may be considered in the uncommon range for girls to play two or more games at a weekly/daily rate, and for boys to play four or more games at a weekly/daily rate. Variables associated with gambling frequency included antisocial behavior, gender, and alcohol use frequency. Although the finding that gambling did not increase from 1992 to 1995 is encouraging, this is the first generation of youth to be exposed to widespread accessability to gambling venues and gambling advertising and it will be important to continue monitoring the prevalence of youth gambling.  相似文献   
90.
"In this paper, we use simulation models to demonstrate the complexity of the relationship between the marriage selection process and the resulting RMRs [relative mortality ratios]. In particular, we show that marriage selection alone can produce a relative mortality ratio which remains large and relatively constant at ages far beyond the marriage span....Our general objective...is to determine the range of age patterns of relative mortality which could, in theory, result from marriage selection on the basis of health characteristics. We also evaluate the effects of variations in the marriage selection mechanisms on the resulting mortality patterns....We develop and apply several simple mathematical models of the marriage selection process. In order to distinguish the potential consequences of marriage selection from marriage protection, we consider hypothetical populations in which causal effects are absent....We begin by considering an extremely simple marriage selection process and subsequently explore a more realistic selection model based on recent death and marriage rates for Japan."  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