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   3914篇
  免费   123篇
  国内免费   55篇
管理学   376篇
民族学   36篇
人口学   81篇
丛书文集   247篇
理论方法论   93篇
综合类   2449篇
社会学   89篇
统计学   721篇
  2024年   14篇
  2023年   29篇
  2022年   51篇
  2021年   51篇
  2020年   76篇
  2019年   83篇
  2018年   99篇
  2017年   108篇
  2016年   113篇
  2015年   131篇
  2014年   223篇
  2013年   382篇
  2012年   289篇
  2011年   271篇
  2010年   219篇
  2009年   215篇
  2008年   258篇
  2007年   260篇
  2006年   237篇
  2005年   214篇
  2004年   167篇
  2003年   173篇
  2002年   120篇
  2001年   93篇
  2000年   57篇
  1999年   26篇
  1998年   21篇
  1997年   24篇
  1996年   17篇
  1995年   12篇
  1994年   12篇
  1993年   10篇
  1992年   8篇
  1991年   3篇
  1990年   6篇
  1989年   8篇
  1988年   4篇
  1987年   4篇
  1986年   1篇
  1984年   1篇
  1982年   1篇
  1981年   1篇
排序方式: 共有4092条查询结果,搜索用时 9 毫秒
71.
我国少数民族构成要素的因子分析   总被引:2,自引:0,他引:2  
黄行 《民族研究》2001,4(1):45-51
本文用总人口、自治地方本民族人口、自治地方少数民族人口、人均GDP、农业人口、识字人口、在校生、母语人、单语人、双语人人数等 10项指标作为民族的地区、经济、教育和语言构成要素 ,对这些要素在我国现有少数民族中的构成情况作了描述、相关和因子提取等统计分析 ,以说明目前我国少数民族构成的基本社会状况 ,以及这些要素对少数民族整体和个体的构成的作用或代表的信息量有多大。文章还依据已有的经验知识对统计分析结果作了相应的说明和解释。结论是 ,目前我国少数民族之间的区别特征主要在于经济发展水平、人口的教育水平、居住地区、使用语言等方面的社会差别 ;但是从发展趋势看 ,传统意义上的各民族构成要素的作用将逐渐减弱 ,民族间的差别将逐渐缩小  相似文献   
72.
In Portugal, there is a gap regarding psychological tests validated for forensic contexts, particularly those related to child custody issues. The Parent–Child Relationship Inventory (PCRI) is one of the most used instruments in child custody contexts. This study aimed to analyze the psychometric properties of PCRI in a Portuguese forensic sample. PCRI factorial structure and psychometric properties were analyzed in a sample of 144 parents involved in child custody assessments. The questionnaire showed good internal consistency, except for the parental support, autonomy, and role orientation scales. It also showed good discriminant capacity. The confirmatory factor analysis did not replicate the 7-factor model proposed by Gerard. The results were discussed based on the use of PCRI in the context of child custody assessment.  相似文献   
73.
This article discusses the role played by stylized features of financial time series in constructing better estimators for the model parameters. We study in detail one such estimator for the transition probabilities of a simple regime switching model. The estimator is based on the squared autocovariances of the time series, which has been discussed in several empirical studies of economic and financial time series. The effectiveness of this estimator in improving the estimation accuracy is investigated, using both finite sample and asymptotic computations. We also report simulation results to confirm our findings and to extend our conclusions over a bigger region of the parameter space.  相似文献   
74.
ABSTRACT

The Aging Semantic Differential (ASD) is the most widely used instrument to measure young people’s attitudes towards older adults. This study translated the ASD to Mandarin and examined its psychometric properties. The Mandarin-ASD contains three latent factors (Personality and Mental Health, Societal Participation, and Physical) that have high internal reliability and reasonable discriminate validity. Social work researchers, practitioners and allied professionals may utilize the ASD-Mandarin instrument to measure young people’s attitudes towards older adults in China. We issue a call for a universal-ASD that can be applied across different cultural contexts.  相似文献   
75.
Eunju Hwang 《Statistics》2017,51(4):904-920
In long-memory data sets such as the realized volatilities of financial assets, a sequential test is developed for the detection of structural mean breaks. The long memory, if any, is adjusted by fitting an HAR (heterogeneous autoregressive) model to the data sets and taking the residuals. Our test consists of applying the sequential test of Bai and Perron [Estimating and testing linear models with multiple structural changes. Econometrica. 1998;66:47–78] to the residuals. The large-sample validity of the proposed test is investigated in terms of the consistency of the estimated number of breaks and the asymptotic null distribution of the proposed test. A finite-sample Monte-Carlo experiment reveals that the proposed test tends to produce an unbiased break time estimate, while the usual sequential test of Bai and Perron tends to produce biased break times in the case of long memory. The experiment also reveals that the proposed test has a more stable size than the Bai and Perron test. The proposed test is applied to two realized volatility data sets of the S&P index and the Korea won-US dollar exchange rate for the past 7 years and finds 2 or 3 breaks, while the Bai and Perron test finds 8 or more breaks.  相似文献   
76.
This paper addresses the collinearity problems in semi-parametric linear models. Under the difference-based settings, we introduce a new diagnostic, the difference-based variance inflation factor (DVIF), for detecting the presence of multicollinearity in semi-parametric models. The DVIF is then used to device a difference-based matrix perturbation method for solving the problem. The electricities distribution data set is analyzed, and numerical evidences validate the effectiveness of the proposed method.  相似文献   
77.
When there are many explanatory variables in the regression model, there is a chance that some of these are intercorrelated. This is where the problem of multicollinearity creeps in due to which precision and accuracy of the coefficients is marred, and the quest to find the best model becomes tedious. To tackle such a situation, Model selection criteria are applied for selecting the best model that fits the data. Current study focuses on the evaluation of the four unmodified and four modified versions of generalized information criteria—Akaike Information Criterion, Schwarz's Bayes Information Criteria, Hannan-Quinn Information Criterion, and Akaike Information Criterion corrected for small samples. A simulation study using SAS software was carried out in order to compare the unmodified and modified versions of the generalized information criteria and to discover the best version amongst the four modified model selection criteria, for identifying the best model, when the collinearity assumption is violated. For the proposed simulation, two samples of size 50 and 100, for three explanatory variables X1, X2, and X3, are drawn from Normal distribution. Two situations of collinearity violations between X1 and X2 are looked into, first when ρ = 0.6 and second when ρ = 0.8. The outcomes of the simulations are displayed in the tables along with visual representations. The results revealed that modified versions of the generalized information criteria are more sensitive in identifying models marred with high multicollinearity as compared to the unmodified generalized information criteria.  相似文献   
78.
Bootstrap forecast intervals are developed for volatilities having asymmetric features, which are accounted for by fitting EGARCH models. A Monte-Carlo simulation compares the proposed forecast intervals with those based on GARCH fittings which ignore asymmetry. The comparison reveals substantial advantage of addressing asymmetry through EGARCH fitting over ignoring it as the conventional GARCH forecast. The EGARCH forecast intervals have empirical coverage probabilities closer to the nominal level and/or have shorter average lengths than the GARCH forecast intervals. The finding is also supported by real dataset analysis of Dow–Jones index and financial times stock exchange (FTSE) 100 index.  相似文献   
79.
Psychological capital (PsyCap) has been a topic of increasing interest in the last decade. However, there is a lack of validated instruments in Spanish to map PsyCap and its consequences for individuals’ well-being. Consequently, the goal of this study is to adapt the 12-item short version of the Psychological Capital Questionnaire (PCQ-12) to the Spanish context by analysing its internal consistency and reliability, factor solution and external validity. Results indicated that the PCQ-12 exhibited good Cronbach’s alpha (.87) and omega coefficient (.93) values in a sample from a vehicle inspection company (n = 798). As expected, results also revealed that a second-order factor structure provided the best fit. Moreover, PsyCap is associated with increased job engagement (β = .579; R2adjusted = .333), decreased job burnout (β = ?.409; R2adjusted = .166), and lower psychological distress (β = ?.349; R2adjusted = .121) (all < .01), which provided additional support for using the PCQ-12 in the Spanish context. Implications for theory and practice are discussed.  相似文献   
80.
We derive a simplified version of the model of Fudenberg and Levine, 2006, Fudenberg and Levine, 2011 and show how this approximate model is useful in explaining choice under risk. We show that in the simple case of three outcomes, the model can generate indifference curves that “fan out” in the Marschak–Machina triangle, and thus can explain the well-known Allais and common ratio paradoxes that models such as prospect theory and regret theory are designed to capture. At the same time, our model is consistent with modern macroeconomic theory and evidence and generates predictions across a much wider set of domains than these models.  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