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   1587篇
  免费   61篇
  国内免费   10篇
管理学   274篇
民族学   12篇
人口学   194篇
丛书文集   9篇
理论方法论   126篇
综合类   48篇
社会学   603篇
统计学   392篇
  2023年   19篇
  2022年   16篇
  2021年   16篇
  2020年   37篇
  2019年   45篇
  2018年   51篇
  2017年   88篇
  2016年   47篇
  2015年   38篇
  2014年   44篇
  2013年   301篇
  2012年   62篇
  2011年   64篇
  2010年   31篇
  2009年   38篇
  2008年   42篇
  2007年   41篇
  2006年   36篇
  2005年   43篇
  2004年   37篇
  2003年   25篇
  2002年   28篇
  2001年   44篇
  2000年   34篇
  1999年   30篇
  1998年   24篇
  1997年   23篇
  1996年   24篇
  1995年   17篇
  1994年   22篇
  1993年   18篇
  1992年   17篇
  1991年   10篇
  1990年   15篇
  1989年   22篇
  1988年   21篇
  1987年   17篇
  1986年   17篇
  1985年   23篇
  1984年   17篇
  1983年   18篇
  1982年   18篇
  1981年   20篇
  1980年   12篇
  1979年   4篇
  1978年   4篇
  1977年   4篇
  1976年   7篇
  1973年   6篇
  1972年   4篇
排序方式: 共有1658条查询结果,搜索用时 8 毫秒
121.
122.
In scientific studies objects are often very rough. Mathematically these rough objects are modelled by fractal functions, and the fractal dimension is usually used to measure their roughness. This paper investigates fractal function estimation by wavelet shrinkage. It is shown that wavelet shrinkage can estimate fractal functions with their fractal dimensions virtually preserved.  相似文献   
123.
124.
125.
We consider a generalization of the proportionate flow shop problem with the makespan objective. Each job has a processing requirement and each machine has a characteristic value. In our case, we assume that the time a job occupies a machine is equal to the processing requirement of the job plus a setup time that is equal to the characteristic value of that machine. In this paper, we consider permutation schedules and show that the problem is solvable in polynomial time when the number of machines is fixed.  相似文献   
126.
The performance of Anderson's classification statistic based on a post-stratified random sample is examined. It is assumed that the training sample is a random sample from a stratified population consisting of two strata with unknown stratum weights. The sample is first segregated into the two strata by post-stratification. The unknown parameters for each of the two populations are then estimated and used in the construction of the plug-in discriminant. Under this procedure, it is shown that additional estimation of the stratum weight will not seriously affect the performance of Anderson's classification statistic. Furthermore, our discriminant enjoys a much higher efficiency than the procedure based on an unclassified sample from a mixture of normals investigated by Ganesalingam and McLachlan (1978).  相似文献   
127.
All social groups live according to a variety of rules or social norms. In many societies, many of these norms govern female sexual behavior. This article explores the male voice and the potential governance of female sexuality in women's magazines. A ten-year textual analysis of two women's magazines targeted to different racial readerships revealed the strong presence of male authors in these magazines. Some of these male authors helped women to better understand men and build stronger relationships, but others attempted to govern the sexuality of women in a variety of ways. Her current projects explore gender, race, and sexuality in media.  相似文献   
128.
Y Tang 《人口研究》1989,(5):24-29
An important cause of resistance to China's family planning (FP) program in rural areas is the need to have children to support parents in their old age. Provision of insurance for old age support will facilitate the implementation of the FP program among the rural population. A trial project was initiated in five cities and counties in Fujian province i 1986. The program included schemes for both eligible couples and for single children. The township or the village pays a lump sum or monthly premium to the insurance company for each couple, which enables them to collect 30-35 Yuan/month after they reach 55 years of age. To further expand the insurance program, a survey was conducted in 1987 to determine whether rural farmers would be willing and able to pay the insurance premium themselves. 77% of the respondents reported that they could afford to pay 60% of the premium. Among them, 59% were willing to pay. It was suggested that besides individual purchase of the insurance plan, the rural communities could contribute to the payment of the premium from the fines for unplanned births, from the local tax, and from the country government budget. Preferential treatment should be given to the couples of two daughters who receives sterilization; the communities should pay for a larger share of their premium. The current insurance scheme needs to be reformed so that the plan can offer more than the individual's bank savings. To do so, the insurance company needs to be able to invest their premium income and obtain higher returns. The employees of the insurance company need to improve their work efficiency to win the trust of the people in the program.  相似文献   
129.
This note provides more results on moments and cumulants of the D compound Poisson distribution through the properties of the multivariate generalized power series distribution.  相似文献   
130.
Single-objective-based decision-tree analysis has been extensively and successfully used in numerous decision-making problems since its formal introduction by Howard Raiffa more than two decades ago. This paper extends the traditional methodology to incorporate multiple noncommensurate objective functions and use of the conditional expected value of the risk of extreme and catastrophic events. The proposed methodology considers the cases where (a) a finite number of actions are available at each decision node and (b) discrete or continuous states of nature can be presented at each chance node. The proposed extension of decision-tree analysis is introduced through an example problem that leads the reader step-by-step into the methodological procedure. The example problem builds on flood warning systems. Two noncommensurate objectives—the loss of lives and the loss of property (including monetary costs of the flood warning system)–are incorporated into the decision tree. In addition, two risk measures—the common expected value and the conditional expected value of extreme and catastrophic events—are quantified and are also incorporated into the decision-making process. Theoretical difficulties associated with the stage-wise calculation of conditional expected values are identified and certain simplifying assumptions are made for computational tractibility. In particular, it is revealed that decisions concerning experimentation have a very interesting impact on the noninferior solution set of options—a phenomenon that has no equivalence in the single-objective case.  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