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   2158篇
  免费   24篇
  国内免费   1篇
管理学   264篇
民族学   19篇
人口学   259篇
丛书文集   7篇
理论方法论   164篇
综合类   26篇
社会学   995篇
统计学   449篇
  2022年   14篇
  2020年   38篇
  2019年   56篇
  2018年   76篇
  2017年   95篇
  2016年   97篇
  2015年   49篇
  2014年   66篇
  2013年   407篇
  2012年   54篇
  2011年   63篇
  2010年   49篇
  2009年   34篇
  2008年   52篇
  2007年   60篇
  2006年   29篇
  2005年   37篇
  2004年   44篇
  2003年   28篇
  2002年   33篇
  2001年   41篇
  2000年   34篇
  1999年   33篇
  1998年   35篇
  1997年   23篇
  1996年   18篇
  1995年   29篇
  1994年   26篇
  1993年   28篇
  1992年   28篇
  1991年   30篇
  1990年   22篇
  1989年   23篇
  1988年   36篇
  1987年   24篇
  1986年   20篇
  1985年   25篇
  1984年   18篇
  1983年   21篇
  1982年   23篇
  1981年   22篇
  1980年   17篇
  1979年   20篇
  1978年   26篇
  1977年   17篇
  1976年   22篇
  1975年   21篇
  1973年   11篇
  1970年   12篇
  1968年   12篇
排序方式: 共有2183条查询结果,搜索用时 0 毫秒
61.
An integer linear programming model is presented for the scheduling of n products on m identical machines. The particular problem studied is one that occurs frequently in the fiberglass and textile industries. The model incorporates setup costs, lost production costs, and overtime costs. Due to the structure of the model, integer solutions can be obtained by explicitly restricting only a small number of the integer variables. This allows those responsible for scheduling to solve realistically sized problems in an efficient manner. Computational results are provided for a set of generated test problems.  相似文献   
62.
The UK Lotto game was introduced in November 1994 with a standard 6/49 format and an entry fee of £1 per ticket. After several years, revenue began to fall despite extensive publicity and a variety of inducements. By 2013, nominal weekly revenue was less than half the 1995 level. In October 2013, the operator doubled the price of a ticket to £2 and made a number of changes to the pay-out structure of smaller prizes. The intent of the changes was to reverse the long downward trend in game revenue by encouraging higher jackpots and offering more pay-out opportunities for each ticket. We use draw by draw revenue and other data to evaluate how players responded to these changes and find that, while ticket sales fell dramatically, total revenue rose following the changes. Primarily this appears to have been the consequence of increased frequency of rollovers (and therefore of more frequent high jackpot draws) rather than ticket price inelasticity. However, although there was a short-term gain in revenue, the changes did not arrest, and indeed seem to have accentuated, the long-run trend decrease in the revenue generated by the game.  相似文献   
63.
We present a time-domain goodness-of-fit (gof) diagnostic test that is based on signal-extraction variances for nonstationary time series. This diagnostic test extends the time-domain gof statistic of Maravall (2003 Maravall, A. (2003). A class of diagnostics in the ARIMA-model-based decomposition of a time series. Memorandum, Bank of Spain. Available at http://www.bde.es/servicio/software/tramo/diagnosticsamb.pdf [Google Scholar]) by taking into account the effects of model parameter uncertainty, utilizing theoretical results of McElroy and Holan (2009 McElroy, T., Holan, S. (2009). A local spectral approach for assessing time series model misspeci?cation. Journal of Multivariate Analysis 100:604621.[Crossref], [Web of Science ®] [Google Scholar]). We demonstrate that omitting this correction results in a severely undersized statistic. Adequate size and power are obtained in Monte Carlo studies for fairly short time series (10 to 15 years of monthly data). Our Monte Carlo studies of finite sample size and power consider different combinations of both signal and noise components using seasonal, trend, and irregular component models obtained via canonical decomposition. Details of the implementation appropriate for SARIMA models are given. We apply the gof diagnostic test statistics to several U.S. Census Bureau time series. The results generally corroborate the output of the automatic model selection procedure of the X-12-ARIMA software, which in contrast to our diagnostic test statistic does not involve hypothesis testing. We conclude that these diagnostic test statistics are a useful supplementary model-checking tool for practitioners engaged in the task of model-based seasonal adjustment.  相似文献   
64.
65.
ABSTRACT

With the rapid growth in incarceration in the United States over the past few decades came dramatic growth in the number of the incarcerated parents with at least one minor child. Parental incarceration places extra stresses and strains on families and children. Almost all of those incarcerated will eventually be released. However, the majority of those released from prison will be rearrested within a year. Finding interventions that can decrease the likelihood of returning to crime and to incarceration are of utmost importance. Using a social bond theory framework, the authors examine the moderating effect of living with a child before incarceration on program outcomes related to a prison-based parent management training program. A significant effect was found. Implications for these findings are discussed for future research and practice.  相似文献   
66.
Crime or disease surveillance commonly rely in space-time clustering methods to identify emerging patterns. The goal is to detect spatial-temporal clusters as soon as possible after its occurrence and to control the rate of false alarms. With this in mind, a spatio-temporal multiple cluster detection method was developed as an extension of a previous proposal based on a spatial version of the Shiryaev–Roberts statistic. Besides the capability of multiple cluster detection, the method have less input parameter than the previous proposal making its use more intuitive to practitioners. To evaluate the new methodology a simulation study is performed in several scenarios and enlighten many advantages of the proposed method. Finally, we present a case study to a crime data-set in Belo Horizonte, Brazil.  相似文献   
67.
This study explores the emotional and communicative profiles of young adults who have experienced a parental divorce and the emergence of a stepfamily to better understand influences on stepfamily satisfaction. Results of regression analyses indicate that strong negative emotions experienced at the time of the divorce are a negative predictor of current stepfamily satisfaction, even after controlling for age at the time of the divorce. In addition, level of open self-disclosure to a stepparent, although not parents, is a positive predictor of current stepfamily satisfaction. Finally, the extent to which the father has now fully explained the circumstances of the divorce is a positive predictor of current stepfamily satisfaction, whereas the extent to which mother has now fully explained the circumstances of the divorce is a negative predictor of current stepfamily satisfaction. These findings are discussed and future directions for research on stepfamily interaction and satisfaction are offered.  相似文献   
68.
In this article we examine data from a national U.S. adult survey of gambling to determine correlates of problem gambling and discuss them in light of theories of the etiology of problem gambling. These include theories that focus on personality traits, irrational beliefs, anti-social tendencies, neighborhood influences and availability of gambling. Results show that males, persons in the 31–40 age range, blacks, and the least educated had the highest average problem gambling symptoms. Adults who lived in disadvantaged neighborhoods also had the most problem gambling symptoms. Those who attended religious services most often had the fewest problem gambling symptoms, regardless of religious denomination. Respondents who reported that it was most convenient for them to gamble had the highest average problem gambling symptoms, compared to those for whom gambling was less convenient. Likewise, adults with the personality traits of impulsiveness and depression had more problem gambling symptoms than those less impulsive or depressed. Respondents who had friends who approve of gambling had more problem gambling symptoms than those whose friends did not approve of gambling. The results for the demographic variables as well as for impulsiveness and religious attendance are consistent with an anti-social/impulsivist pathway to problem gambling. The results for depression are consistent with an emotionally vulnerable pathway to problem gambling.  相似文献   
69.
Factitious Disorder Imposed by Another (FDIA) can be difficult to expeditiously identify. Understanding personality characteristics of FDIA perpetrators via psychological assessment may decrease the time between initial abuse and identification of FDIA. Personality characteristics of FDIA mother-perpetrators were examined through a comparative analysis of MMPI-2 profiles. It was predicted that mother-perpetrators would have significantly higher overall profile elevations on the MMPI-2 and elevations on specific clinical scales than a comparative control group. Results indicated that mother-perpetrators displayed significantly higher, elevations on the Psychasthenia (Pt) and Schizophrenia (Sc) scales and a trend toward significantly higher elevation on the Psychopathic Deviate (Pd) scale than the control group. These findings, along with the demographic information obtained, establish a preliminary foundation for understanding an overall profile of mother-perpetrators.  相似文献   
70.
This study assessed the knowledge and attitudes of young adults without children in regard to discipline and parenting practices. A qualitative design was utilized (n?=?26) with semistructured focus groups. Results indicated participants believed discipline is important, with spanking and loss of privileges being the most effective strategy for behavior change. The majority of participants reported plans to discipline future children the way in which they were disciplined, suggesting a high percentage intend to utilize spanking. Findings suggest that personal experiences shape parenting beliefs, attitudes, and knowledge. Results inform efforts at educating future parents on appropriate parenting practices and indicate the need for protocols for young adults to educate about practices that may diverge from their personal experiences.  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