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971.
School–community collaboration has become an important approach to enhancing the quality of services to meet the multifaceted needs of students. However, there is little understanding of how to create and maintain successful school–community collaboration. Drawing on a critical paradigm, this study developed a comprehensive framework for transformative school–community collaboration (TSCC) and developed a valid scale to assess the major dimensions of TSCC. Using school survey data, an exploratory factor analysis identified four multidimensional constructs: (a) critical member capacity representing members' organizing, interpersonal, and critical analysis skills, (b) equal relations with respect to joint membership, interaction, and outcome distribution, (c) democratic network governance measuring the basic elements of democracy in decision‐making, and (d) empowering coordination reflecting a responsive, flexible, and supportive coordination system. This study also showed that low‐income and urban schools reported significantly lower levels of equal relations and empowering coordination. The developed scale can be used as an evaluation tool that monitors and evaluates school–community collaboration ensuring equal, democratic, and empowering structures and processes. Furthermore, the results of this study suggest practice implications and future research agendas to create and maintain successful school–community collaboration.  相似文献   
972.
Inaccurate perceptions of audience can cause public relations practitioners to overreact or underreact to a situation, which brings about unintended consequences. We draw on the third-person effect research to identify examples and outline the conditions when the overestimation or underestimation of media effects can motivate key players to engage in restrictive, corrective, promotional, and resistance behaviors. Then, we recommend approaches that can help public relations practitioners better reflect and manage corporate communication. In short, the approaches involve: (a) determining the nature of the presumed effect from the audience perspective and going beyond the categorical positive/negative message, (b) assessing the level of the presumed effect and considering also the possibility of the first- as well as the second-person effect, and (c) assessing the influence of the perceived effect on behaviors that have the potential to directly as well as indirectly affect the company.  相似文献   
973.
We examine bulk discounts, which are claimed to explain the Deaton and Paxson puzzle about household size and food demand, and which may matter to household behavior studied in other literatures. Most previous studies use unit values, which are subject to several biases and reflect economizing choices made by households, so may not reliably estimate the bulk discount schedule. Instead, individual transaction records in household expenditure diaries are used, which report expenditure, quantity, brand, unit size and number purchased per transaction. The bulk discount schedule is estimated for four foods (rice, canned meat, canned fish and chicken) that make up one-third of the total food budget in a survey in urban Papua New Guinea. For each food we use the dominant brand(s) so there is no quality variation and the estimated price schedule only reflects discounts due to variations in purchase quantity. All foods have precisely measured but small elasticities of unit price with respect to quantity purchased.  相似文献   
974.
Incomplete data subject to non‐ignorable non‐response are often encountered in practice and have a non‐identifiability problem. A follow‐up sample is randomly selected from the set of non‐respondents to avoid the non‐identifiability problem and get complete responses. Glynn, Laird, & Rubin analyzed non‐ignorable missing data with a follow‐up sample under a pattern mixture model. In this article, maximum likelihood estimation of parameters of the categorical missing data is considered with a follow‐up sample under a selection model. To estimate the parameters with non‐ignorable missing data, the EM algorithm with weighting, proposed by Ibrahim, is used. That is, in the E‐step, the weighted mean is calculated using the fractional weights for imputed data. Variances are estimated using the approximated jacknife method. Simulation results are presented to compare the proposed method with previously presented methods.  相似文献   
975.
Integer-valued time series models make use of thinning operators for coherency in the nature of count data. However, the thinning operators make residuals unobservable and are the main difficulty in developing diagnostic tools for autocorrelated count data. In this regard, we introduce a new residual, which takes the form of predictive distribution functions, to assess probabilistic forecasts, and this new residual is supplemented by a modified usual residuals. Under integer-valued autoregressive (INAR) models, the properties of these two residuals are investigated and used to evaluate the predictive performance and model adequacy of the INAR models. We compare our residuals with the existing residuals through simulation studies and apply our method to select an appropriate INAR model for an over-dispersed real data.  相似文献   
976.
We examined the range of sexual intentions and behaviors preceding sexual initiation among 211 African-American pre-teens assigned to the control arm of a longitudinal community-based intervention trial. Stage of sexual readiness was assessed using the stage of change construct from the Transtheoretical Model, and patterns of stage movement during a 6-month period were examined. Overall, 90% of participants were in precontemplation at baseline, with the proportion of participants in this stage declining with each year of age. There was substantial stability in stage of sexual readiness during the 6-month period (87% stable). While definitive conclusions regarding exact patterns of movement are not yet possible, stage movement does not appear to be linear for all pre-teens, and there is evidence of both stage progression and regression. We present emerging patterns of stage movement, which suggest potential variation by age, gender, and baseline stage, and discuss potential implications.  相似文献   
977.
Given a k-connected graph G=(V,E) and V V, k-Vertex-Connected Subgraph Augmentation Problem (k-VCSAP) is to find SVV with minimum cardinality such that the subgraph induced by V S is k-connected. In this paper, we study the hardness of k-VCSAP in undirect graphs. We first prove k-VCSAP is APX-hard. Then, we improve the lower bound in two ways by relying on different assumptions. That is, we prove no algorithm for k-VCSAP has a PR better than O(log (log n)) unless P=NP and O(log n) unless NPDTIME(n O(log log n)), where n is the size of an input graph.  相似文献   
978.
Lifetime Data Analysis - There has arisen a considerable body of research addressing the estimation of association between paired failure times in the presence of competing risks. In a 2002 paper,...  相似文献   
979.
980.
This article develops a statistical test for the presence of a jump in an otherwise smooth transition process. In this testing, the null model is a threshold regression and the alternative model is a smooth transition model. We propose a quasi-Gaussian likelihood ratio statistic and provide its asymptotic distribution, which is defined as the maximum of a two parameter Gaussian process with a nonzero bias term. Asymptotic critical values can be tabulated and depend on the transition function employed. A simulation method to compute empirical critical values is also developed. Finite-sample performance of the test is assessed via Monte Carlo simulations. The test is applied to investigate the dynamics of racial segregation within cities across the United States.  相似文献   
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