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291.
An analysis of the effects of diabetes and generalized atherosclerosis on death due to ischemic heart disease or stroke was conducted using multiple cause mortality statistics. Specifically, all U.S. deaths in 1969 were classified into two groups on the basis of whether diabetes or generalized atherosclerosis was mentioned anywhere on the death certificate. Then race and sex specific analyses were made of ischemic heart disease deaths (or alternately of stroke deaths) using modified life table techniques for each group (one with the specified chronic disease and one without). Comparisons were made of mortality due to the acute circulatory events (ischemic heart disease or stroke) in the two groups to determine the implications of the chronic disease for the progression of the circulatory disease events. It was found, according to expectations, that diabetes and generalized atherosclerosis play very different roles in deaths due to stroke and ischemic heart disease.  相似文献   
292.
A portion of the graduate program in clinical community psychology at SUNY Buffalo was subjected to a jury trial as a form of program evaluation. The theory of the trial as evaluation, the problems of implementation, and a posttrial evaluation are discussed. The trial, while time-consuming, especially in its pretrial phases, has the potential for presenting a dramatic picture of a program through the medium of human testimony. The jury was able to arrive at clear decisions on questions put to it, with a high degree of confidence. Decision makers accepted some of the jury's conclusions, and subjective evidence suggests that many of the controversial issues which generated the trial were resolved for the group by the procedure. The posttrial evaluation revealed limitations, such as evidence which was not presented at the trial. The experience proved useful for purposes of interdisciplinary education, providing another lens through which the evaluation problem could be viewed.  相似文献   
293.
Seven Circles is a substance abuse prevention coalition in Southeast Alaska with a two-tiered structure consisting of local partnerships joined together in a regional coalition. Seven Circles incorporates a youth/adult partnership approach to accomplish its activities. This article describes the results of four annual administrations of a partnership member survey designed to assess the development and implementation of youth/adult partnerships in the local projects, assess the value of the partnerships to the participants, and gather feedback about the functioning of the Seven Circles Coalition. The results support the youth/adult partnership model and are also discussed in the context of youth empowerment.  相似文献   
294.
As part of its periodic re-evaluation of particulate matter (PM) standards, the U.S. Environmental Protection Agency estimated the health risk reductions associated with attainment of alternative PM standards in two locations in the United States with relatively complete air quality data: Philadelphia and Los Angeles. PM standards at the time of the analysis were defined for particles of aerodynamic diameter less than or equal to 10 microm, denoted as PM-10. The risk analyses estimated the risk reductions that would be associated with changing from attainment of the PM-10 standards then in place to attainment of alternative standards using an indicator measuring fine particles, defined as those particles of aerodynamic diameter less than or equal to 2.5 microm and denoted as PM-2.5. Annual average PM-2.5 standards of 12.5, 15, and 20 microg/m3 were considered in various combinations with daily PM-2.5 standards of 50 and 65 microg/m3. Attainment of a standard or set of standards was simulated by a proportional rollback of "as is" daily PM concentrations to daily PM concentrations that would just meet the standard(s). The predicted reductions in the incidence of health effects varied from zero, for those alternative standards already being met, to substantial reductions of over 88% of all PM-associated incidence (e.g., in mortality associated with long-term exposures in Los Angeles, under attainment of an annual standard of 12.5 microg/m3). Sensitivity analyses and integrated uncertainty analyses assessed the multiple-source uncertainty surrounding estimates of risk reduction.  相似文献   
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In this paper the authors, all experienced social workers with research and practice interests in assisted conception, review practices concerning access to genetic origins information in adoption, and consider to what extent these may be relevant for practice in donor‐assisted conception. The paper concludes with policy and practice recommendations that take account of the views of donor offspring and their desire for increased information about their genetic heritage.  相似文献   
297.
Woody vegetation and canopy fragmentation along a forest-to-urban gradient   总被引:9,自引:5,他引:4  
To identify patterns that can be used to predict vegetation and landscape characteristics in urban environments, we surveyed the species composition and size of woody plants, as well as the landscape structure of forest canopies, along a forest-to-urban gradient near Oxford, Ohio, USA. The gradient included six sites of increasingly urban land-use: a preserve, a recreational area, a golf course, a residential subdivision, apartment complexes, and a business district. We recorded species identity and stem diameter for all woody plants greater than 3 cm diameter at breast height (DBH) to examine the distribution of individual species as well as overall community composition. We used digitized aerial photographs to compare the spatial characteristics of the forest canopy at each site. We found predictable patterns in species diversity (Shannon index), spatial heterogeneity in species composition (mean percent dissimilarity), and all measures of patch fragmentation (canopy cover and patch number and size). There were clear differences in tree density and total basal area between forested sites and developed sites, but there was little resolution among developed sites. Species richness and average DBH showed no clear pattern, suggesting that landscaping preference largely determined these values. We present a modified version of an intermediate heterogeneity model that can be used to predict diversity patterns in urban areas. We discuss probable mechanisms that led to these patterns and the potential implications for animal communities in urban environments.  相似文献   
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It is quite common to observe heteroskedasticity in real data, in particular, cross-sectional or micro data. Previous studies concentrate on improving the finite-sample properties of tests under heteroskedasticity of unknown forms in linear models. The advantage of a heteroskedasticity consistent covariance matrix estimator (HCCME)-type small-sample improvement for linear models does not carry over to the nonlinear model specifications since there is no obvious counterpart for the diagonal element of the projection matrix in linear models, which is crucial for implementing the finite-sample refinement. Within the framework of nonlinear models, we develop a straightforward approach by extending the applicability of HCCME-type corrections to the two-step GMM method. The Monte Carlo experiments show that the proposed method not only refines the testing procedure in terms of the error of rejection probability, but also improves the coefficient estimation based on the mean squared error (MSE) and the mean absolute error (MAE). The estimation of a constant elasticity of substitution (CES)-type production function is also provided to illustrate how to implement the proposed method empirically.  相似文献   
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