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   21042篇
  免费   762篇
  国内免费   322篇
管理学   2219篇
劳动科学   2篇
民族学   75篇
人才学   3篇
人口学   417篇
丛书文集   1004篇
理论方法论   475篇
综合类   8896篇
社会学   875篇
统计学   8160篇
  2024年   34篇
  2023年   221篇
  2022年   339篇
  2021年   374篇
  2020年   516篇
  2019年   688篇
  2018年   789篇
  2017年   990篇
  2016年   783篇
  2015年   746篇
  2014年   1142篇
  2013年   2982篇
  2012年   1507篇
  2011年   1238篇
  2010年   1026篇
  2009年   1013篇
  2008年   1099篇
  2007年   1077篇
  2006年   988篇
  2005年   859篇
  2004年   724篇
  2003年   600篇
  2002年   511篇
  2001年   471篇
  2000年   312篇
  1999年   226篇
  1998年   155篇
  1997年   138篇
  1996年   97篇
  1995年   89篇
  1994年   68篇
  1993年   53篇
  1992年   54篇
  1991年   48篇
  1990年   34篇
  1989年   21篇
  1988年   22篇
  1987年   16篇
  1986年   13篇
  1985年   19篇
  1984年   14篇
  1983年   14篇
  1982年   5篇
  1981年   1篇
  1980年   2篇
  1979年   4篇
  1978年   2篇
  1977年   1篇
  1975年   1篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Detection and correction of artificial shifts in climate series   总被引:6,自引:0,他引:6  
Summary.  Many long instrumental climate records are available and might provide useful information in climate research. These series are usually affected by artificial shifts, due to changes in the conditions of measurement and various kinds of spurious data. A comparison with surrounding weather-stations by means of a suitable two-factor model allows us to check the reliability of the series. An adapted penalized log-likelihood procedure is used to detect an unknown number of breaks and outliers. An example concerning temperature series from France confirms that a systematic comparison of the series together is valuable and allows us to correct the data even when no reliable series can be taken as a reference.  相似文献   
52.
Oiler, Gomez & Calle (2004) give a constant sum condition for processes that generate interval‐censored lifetime data. They show that in models satisfying this condition, it is possible to estimate non‐parametrically the lifetime distribution based on a well‐known simplified likelihood. The author shows that this constant‐sum condition is equivalent to the existence of an observation process that is independent of lifetimes and which gives the same probability distribution for the observed data as the underlying true process.  相似文献   
53.
Summary.  The pattern of absenteeism in the downsizing process of companies is a topic in focus in economics and social science. A general question is whether employees who are frequently absent are more likely to be selected to be laid off or in contrast whether employees to be dismissed are more likely to be absent for the remaining time of their working contract. We pursue an empirical and microeconomic investigation of these theses. We analyse longitudinal data that were collected in a German company over several years. We fit a semiparametric transition model based on a mixture Poisson distribution for the days of absenteeism per month. Prediction intervals are considered and the primary focus is on the period of downsizing. The data reveal clear evidence for the hypothesis that employees who are to be laid off are more frequently absent before leaving the company. Interestingly, though, no clear evidence is seen that employees being selected to leave the company are those with a bad absenteeism profile.  相似文献   
54.
优化专业结构,提高毕业生就业竞争力   总被引:1,自引:0,他引:1  
随着社会以及高等教育改革的不断深化,高校毕业生就业形势日益严峻,根据用人单位对大学毕业生综合素质的要求和高校毕业学生对学校教学的意见反馈以及就业工作的现状,高等学校应优化专业结构,调整教学计划和课程设置体系,改革人才培养模式,努力提高毕业生就业竞争力。  相似文献   
55.
大比例多项选择考试模式在大学英语四、六级考试中己实施多年 ,它对推动我国的外语教育功不可没。但在我国的国情发生了巨大变化、整个国家正朝着国际化社会快速发展、社会各界急需实用型外语人才的今天 ,多年不变的大比例多项选择考试模式己经显示出它的不足。特别是IELTS;ESOL等国际实用性测试模式不断引入我国 ,它的确面临着改进和完善的挑战。  相似文献   
56.
In this paper we discuss a new theoretical basis for perturbation methods. In developing this new theoretical basis, we define the ideal measures of data utility and disclosure risk. Maximum data utility is achieved when the statistical characteristics of the perturbed data are the same as that of the original data. Disclosure risk is minimized if providing users with microdata access does not result in any additional information. We show that when the perturbed values of the confidential variables are generated as independent realizations from the distribution of the confidential variables conditioned on the non-confidential variables, they satisfy the data utility and disclosure risk requirements. We also discuss the relationship between the theoretical basis and some commonly used methods for generating perturbed values of confidential numerical variables.  相似文献   
57.
基于知识链的管理   总被引:38,自引:0,他引:38  
论述了知识链的有关概念和特点,通过分析以往的知识链模型,提出了改进的知识链模型;对知识链管理的机制进行了分析;从控制论的角度,对知识链内部知识成长的机制进行了分析,并指出知识链内部知识转移的影响因素,为知识管理的发展提供了一定的理论依据。  相似文献   
58.
We used two statistical methods to identify prognostic factors: a log-linear model (logistic and COX regression, based on the notions of linearity and multiplicative relative risk), and the CORICO method (ICOnography of CORrelations) based on the geometric significance of the correlation coefficient. We applied the methods to two different situations (a "case-control study' and a "historical cohort'). We show that the geometric exploratory tool is particularly suited to the analysis of small samples with a large number of variables. It could save time when setting up new study protocols. In this instance, the geometric approach highlighted, without preconceived ideas, the potential role of multihormonality in the course of pituitary adenoma and the unexpected influence of the date of tumour excision on the risk attached to haemorrhage.  相似文献   
59.
以原型的方法对司空图《诗品》天人合一思维模式进行了全面分析。指出司空图《诗品》的思维模式遵循了中国古代由诗歌品阶、天时、时律、时历等形成的系统的天人合一模式,是典型的中国思维。  相似文献   
60.
本文简述建立数学教学新模式的必要性;论述了知识、能力、品质、方法之间的辨证关 系;提出了“知识、能力、品质”相结合的教学模式和一定的方法。  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