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   7767篇
  免费   130篇
  国内免费   1篇
管理学   1000篇
民族学   35篇
人口学   788篇
丛书文集   33篇
理论方法论   702篇
综合类   91篇
社会学   3807篇
统计学   1442篇
  2023年   45篇
  2020年   105篇
  2019年   156篇
  2018年   186篇
  2017年   264篇
  2016年   187篇
  2015年   132篇
  2014年   172篇
  2013年   1352篇
  2012年   240篇
  2011年   224篇
  2010年   160篇
  2009年   143篇
  2008年   163篇
  2007年   156篇
  2006年   178篇
  2005年   162篇
  2004年   155篇
  2003年   146篇
  2002年   166篇
  2001年   171篇
  2000年   175篇
  1999年   177篇
  1998年   140篇
  1997年   136篇
  1996年   128篇
  1995年   113篇
  1994年   109篇
  1993年   114篇
  1992年   119篇
  1991年   131篇
  1990年   127篇
  1989年   146篇
  1988年   88篇
  1987年   110篇
  1986年   96篇
  1985年   119篇
  1984年   98篇
  1983年   107篇
  1982年   80篇
  1981年   82篇
  1980年   78篇
  1979年   83篇
  1978年   84篇
  1977年   60篇
  1976年   66篇
  1975年   61篇
  1974年   59篇
  1973年   48篇
  1971年   41篇
排序方式: 共有7898条查询结果,搜索用时 62 毫秒
121.
122.
Summary In Matlab Bazaar Thana the Cholera Research Laboratory has registered the births, deaths and migrations in a population of approximately 125,000 since 1966. Although this rural area was not the scene of any significant armed encounters, striking changes in birth and death rates were registered during and after the conflict. Birth rates did not change during the relatively brief period of the civil war, but a small decline was registered for one year after the war. Fertility rates which had been declining slightly and irregularly in the pre-war baseline period may have increased slightly during the war and fell substantially in all age groups in the year following the war. The crude death rate, which rose by 37 per cent during the war, was a very sensitive reflection of the administrative and economic problems. Overall infant mortality rose by only 15 per cent over pre-war levels because all of the increase was observed in the post-neo-natal component, which traditionally accounts for less than one-third of the total infant mortality in Bangladesh. Children and older adults accounted for the majority of excess deaths which were largely attributed to acute diarrhoeas and other gastro-intestinal causes. The death rate at ages 1-4 rose by 43 per cent and at ages 5-9 soared to 208 per cent above pre-war baseline rates. All increases in age-specific mortality rates fell to baseline levels during the year following the war, except the 5-9-year age group, in which rates continued to be high largely because of deaths due to dysentery.  相似文献   
123.
Jose D. Drilon, Jr., president of Food Terminal, Inc., and a former undersecretary of the then Department of Agriculture and Natural Resources in the Philippines, attributes the widening gap between food supply and demand in developing countries to the high rate of population growth and to the inability of poor countries to produce more food. This situation, in which many countries are facing hunger, was predicted by Thomas Robert Malthus as early as the 16th century. The primary concern of Malthus was the problem of making the food supply keep pace with a constantly growing population. The question arises as to how reliable is Malthusian theory. According to Drilon, Malthus was correct in predicting that population would expand at a rate not previously imagined but that the other aspects of Malthusian theory might not hold true due to the intervention of human beings. For example, it is hoped that the imbalance between population growth and food production can be minimized in the future. In the Philippines there is good reason to be concerned about the validity of Malthusian theory. Although the country's growth rate has been reduced from 3.01% in 1970 to 2.6%, it is still quite high. However, the Philippines has actually been producing sufficient food to feed its population. To make the Philippines self-sufficient in rice, the government initiated the Masagana 99 program in May 1973. Technical and material resources from the public and private sectors were provided to aid rice producers. A nationwide information campaign was also launched to familiarize the farmers with the new methods of rice culture. Masagana 99 has been costly but effective. Since the launching of the program, rice production in the Philippines has been increasing at 7% a year. The government is now using the Masagana 99 formula to increase the production of other crops.  相似文献   
124.
125.
126.
The administration of higher education, as with other administrative environments, has become increasingly complex. This paper presents a mathematical model which addresses one of the administrative tasks concerning administrators in all institutions, the establishment of faculty teaching schedules. The assignment technique utilized by the model is linear programming with two special characteristics: goal programming and mixed-integer programming. The goal programming characteristic refers to the provision of explicit stack variables to take on values representing deviations from assignment criteria that may result in resolving conflicts which arise from interactive administrative priorities. The mixed-integer programming characteristic refers to a requirement of the model that certain variables take on only integer values if they appear in the final solution. The model is demonstrated using two different sets of preference orderings for goal achievement.  相似文献   
127.
Environmental and human health issues associated with outdoor air pollution, such as ozone, sulfur dioxide, and other pollutants in metropolitan regions, are an area of growing concern for both policy officials and the general public. Increasing attention from the news media, new health data, and public debate over the effectiveness of clean air regulations have raised the importance of air quality in the public consciousness. While public perceptions of air quality have been studied thoroughly dating back to the 1960s, little empirical research has been conducted to explain the spatial aspects of these perceptions, particularly at the local level. Although recent studies suggest characteristics of local setting are important in shaping perceptions of air quality, the roles of proximity, neighborhood characteristics, and location have not been clarified. This study seeks to improve understanding of the major factors shaping public perceptions of air quality by examining the spatial pattern of local risk perception, the role of socioeconomic characteristics in forming these perceptions, and the relationship between perceived and scientifically measured air pollution. First, we map the spatial pattern of local air quality perceptions using Geographic Information Systems (GIS) across the Dallas and Houston metropolitan areas. Next, we explain these perceptions through local contextual factors using both bivariate correlations and multivariate regression analysis. Results indicate that perceptions of air quality in the study areas are not significantly correlated with air quality based on readings of air monitoring stations. Instead, perceptions appear to be influenced by setting (urban vs. rural), state identification, access to information, and socioeconomic characteristics such as age, race, and political identification. We discuss the implications of the findings and provide direction on how further research can provide a deeper understanding of the local contextual factors influencing public perceptions.  相似文献   
128.
Ivanenko  V.I.  Munier  B. 《Theory and Decision》2000,49(2):127-150
It is shown that the uncertainty connected with a `random in a broad sense' (not necessarily stochastic) event always has some `statistical regularity' (SR) in the form of a family of finite-additive probability distributions. The specific principle of guaranteed result in decision making is introduced. It is shown that observing this principle of guaranteed result leads to determine the one optimality criterion corresponding to a decision system with a given `statistical regularity'.  相似文献   
129.
Unmet need for family planning has been a core concept in international population discourse for several decades. This article reviews the history of unmet need and the development of increasingly refined methods of its empirical measurement and delineates the main questions that have been raised about unmet need during the past decade, some of which concern the validity of the concept and others its role in policy debates. The discussion draws heavily on empirical research conducted during the 1990s, much of it localized, in‐depth studies combining quantitative and qualitative methodologies. Of the causes of unmet need other than those related to access to services, three emerge as especially salient: lack of necessary knowledge about contraceptive methods, social opposition to their use, and health concerns about possible side effects. The article argues that the concept of unmet need for family planning, by joining together contraceptive behavior and fertility preferences, encourages an integration of family planning programs and broader development approaches to population policy. By focusing on the fulfillment of individual aspirations, unmet need remains a defensible rationale for the formulation of population policy and a sensible guide to the design of family planning programs.  相似文献   
130.
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