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   4432篇
  免费   111篇
  国内免费   21篇
管理学   160篇
民族学   48篇
人才学   1篇
人口学   30篇
丛书文集   344篇
理论方法论   89篇
综合类   1937篇
社会学   42篇
统计学   1913篇
  2024年   2篇
  2023年   16篇
  2022年   11篇
  2021年   24篇
  2020年   42篇
  2019年   80篇
  2018年   83篇
  2017年   172篇
  2016年   91篇
  2015年   107篇
  2014年   138篇
  2013年   725篇
  2012年   241篇
  2011年   200篇
  2010年   174篇
  2009年   168篇
  2008年   204篇
  2007年   271篇
  2006年   280篇
  2005年   282篇
  2004年   217篇
  2003年   219篇
  2002年   194篇
  2001年   148篇
  2000年   98篇
  1999年   67篇
  1998年   42篇
  1997年   40篇
  1996年   29篇
  1995年   40篇
  1994年   28篇
  1993年   24篇
  1992年   24篇
  1991年   15篇
  1990年   9篇
  1989年   8篇
  1988年   8篇
  1987年   7篇
  1986年   4篇
  1985年   4篇
  1984年   8篇
  1983年   7篇
  1982年   2篇
  1981年   2篇
  1980年   1篇
  1979年   4篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
排序方式: 共有4564条查询结果,搜索用时 281 毫秒
51.
The problem of modelling multivariate time series of vehicle counts in traffic networks is considered. It is proposed to use a model called the linear multiregression dynamic model (LMDM). The LMDM is a multivariate Bayesian dynamic model which uses any conditional independence and causal structure across the time series to break down the complex multivariate model into simpler univariate dynamic linear models. The conditional independence and causal structure in the time series can be represented by a directed acyclic graph (DAG). The DAG not only gives a useful pictorial representation of the multivariate structure, but it is also used to build the LMDM. Therefore, eliciting a DAG which gives a realistic representation of the series is a crucial part of the modelling process. A DAG is elicited for the multivariate time series of hourly vehicle counts at the junction of three major roads in the UK. A flow diagram is introduced to give a pictorial representation of the possible vehicle routes through the network. It is shown how this flow diagram, together with a map of the network, can suggest a DAG for the time series suitable for use with an LMDM.  相似文献   
52.
本文认为知识是流动的 ,而且它会超越组织边界 ,使企业与客户之间形成知识互动的合作伙伴关系。全文从知识和关系紧紧联系在一起 ,构成了可持续竞争优势的唯一源泉和知识向客户转移 ,即知识向客户流动的结果 ,使客户更加知识化并产生增值 ,其本身又会导致更深层的客户关系 ,而开发客户关系又提高了知识的双向转移等方面进行了论述。得出结论 :开发客户关系最终与知识共享是难以分离的  相似文献   
53.
道德与道德教育   总被引:2,自引:0,他引:2  
通过对道德含义的剖析 ,指出道德属于关系范畴 ,并从道德起源的角度阐明道德产生的一般条件 ,进而指出我国当前道德教育存在的一些问题 ,得出道德教育应选择的途径。  相似文献   
54.
IntroductionCulturegivesanindividualananchoringpoint,ani dentity ,aswellascodesofconduct (MichaelR ,Iikka ,andMichaelH 2 0 0 2 :33) .Ofmorethan 16 0definitionsofculture (AlfredandClyde 1985 :11) ,mostagreeonsomebasicprinciples ,butthereisalotofvariationonthedetails .Cultureisalsomultidimensional ,consistingofanumberofcommonelementsthatareinterdependent.Thedifferencesinculturehaveanimportantimpactonmanyaspectsofamultinationalcompany’sactivity .Thispaperwillmainlydiscusstheeffectofsomeofthe…  相似文献   
55.
Factor analytic variance models have been widely considered for the analysis of multivariate data particularly in the psychometrics area. Recently Smith, Cullis & Thompson (2001) have considered their use in the analysis of multi‐environment data arising from plant improvement programs. For these data, the size of the problem and the complexity of the variance models chosen to account for spatial heterogeneity within trials implies that standard algorithms for fitting factor analytic models can be computationally expensive. This paper presents a sparse implementation of the average information algorithm (Gilmour, Thompson & Cullis, 1995) for fitting factor analytic and reduced rank variance models.  相似文献   
56.
This paper studies optimum designs for linear models when the errors are heteroscedastic. Sufficient conditions are given in order to obtainD-, A- andE-optimum designs for a complete regression model from partial optimum designs for some sub-parameters. A result about optimality for a complete model from the optimality for the submodels is included. Supported by Junta de Andalucía, research group FQM244.  相似文献   
57.
The authors extend the block external bootstrap to partially linear regression models with strongly mixing, nonstationary error terms. In addition to providing an approximate distribution for the semiparametric least square estimator of the parametric component, they propose a consistent estimator of the co‐variance matrix of this estimator.  相似文献   
58.
孔子仁学思想强调爱人、克己、崇德,把这种仁学思想落实到教育工作中就是教师要爱学生,要克制自我中心主义的倾向,要修身立德。这种思想对正确处理好师生关系从而赢得教育教学的成功具有极大的启示意义。  相似文献   
59.
The quantification of the relationship between the amount of microbial organisms ingested and a specific outcome such as infection, illness, or mortality is a key aspect of quantitative risk assessment. A main problem in determining such dose-response models is the availability of appropriate data. Human feeding trials have been criticized because only young healthy volunteers are selected to participate and low doses, as often occurring in real life, are typically not considered. Epidemiological outbreak data are considered to be more valuable, but are more subject to data uncertainty. In this article, we model the dose-illness relationship based on data of 20 Salmonella outbreaks, as discussed by the World Health Organization. In particular, we model the dose-illness relationship using generalized linear mixed models and fractional polynomials of dose. The fractional polynomial models are modified to satisfy the properties of different types of dose-illness models as proposed by Teunis et al . Within these models, differences in host susceptibility (susceptible versus normal population) are modeled as fixed effects whereas differences in serovar type and food matrix are modeled as random effects. In addition, two bootstrap procedures are presented. A first procedure accounts for stochastic variability whereas a second procedure accounts for both stochastic variability and data uncertainty. The analyses indicate that the susceptible population has a higher probability of illness at low dose levels when the combination pathogen-food matrix is extremely virulent and at high dose levels when the combination is less virulent. Furthermore, the analyses suggest that immunity exists in the normal population but not in the susceptible population.  相似文献   
60.
线性科学与非线性科学哲学思想研究   总被引:1,自引:0,他引:1  
在简述线性科学的科学基础、科学方法和哲学思想的基础上,研究了非线性科学的科学基础、科学方法和哲学思想,其中较为详细地探讨了非线性科学的哲学范畴和哲学思想,认为要多角度观察事物,要从变化中认识主要矛盾,事物的发展是多元竞争与协同的统一,这一结果将对非线性科学的哲学思想的进一步研究有一定的启发和借鉴作用。  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