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901.
This article describes a Delphi‐based expert judgment study aimed at the selection of indicators to identify the occurrence of emerging mycotoxin hazards related to Fusarium spp. in wheat supply chains. A panel of 29 experts from 12 European countries followed a holistic approach to evaluate the most important indicators for different chain stages (growth, transport and storage, and processing) and their relative importance. After three e‐mailing rounds, the experts reached consensus on the most important indicators for each of the three stages: wheat growth, transport and storage, and processing. For wheat growth, these indicators include: relative humidity/rainfall, crop rotation, temperature, tillage practice, water activity of the kernels, and crop variety/cultivar. For the transport and storage stage, they include water activity in the kernels, relative humidity, ventilation, temperature, storage capacity, and logistics. For wheat processing, indicators include quality data, fraction of the cereal used, water activity in the kernels, quality management and traceability systems, and carryover of contamination. The indicators selected in this study can be used in an identification system for the occurrence of emerging mycotoxin hazards in wheat supply chains. Such a system can be used by risk managers within governmental (related) organizations and/or the food and feed industry in order to react proactively to the occurrence of these emerging mycotoxins.  相似文献   
902.
如果以松江府及其周边五州县的明初历史人口数据为计算原点,再以人口增长率3.4‰为基础,便有可能算出明清各时代自然增长下的人口数字。可是如此推算18世纪末的人口,较诸同时期准确的统计人口,竟高出达200多万之谱。要处理这庞大的人口差异,其实就是要说明这数以百万计的人口是如何消失的。我们采取的方法是针对1641年至1680年间四个天灾人祸设定级别而作出微调,从而估算明末该地区的人口损失及人口发展状况。若将有关估算结果继续上推至18世纪末,也与乾嘉时代的统计人口相当吻合。这种方法一如其他估算之道,虽非定论,但可为史无明文但处于非常重要时空的中国历史人口,提供一个新的推算方法。此外,以我们的方法计算,1640年左右松江府及周边州县的人口已达500万之谱,这与乾嘉盛世同地区的人口相比,可谓毫不逊色。  相似文献   
903.
Domestic violence is a prevalent social issue in Korea affecting a significant number of people every day. It is thus important to examine how the experience of domestic violence affects their mental health to better address their needs. Using stress‐coping theory as a theoretical framework, this study examines the domestic violence and depression relationship among Korean men and women. Two aspects of self‐esteem and informal and formal social support are examined as potential mediators of this relationship. The data was the first wave of Korean Welfare Panel Study data including 2477 individuals with experiences of abuse. Structural equation modeling procedures were used for analyses. Domestic violence was significantly associated with self‐worth, self‐deprecation, and depression. The experiences of violence eroded self‐worth while reinforcing self‐deprecation and those with more exposure to violence showed a higher level of depression. Self‐deprecation played a significant role in mediating the effect of domestic violence on depression. However, different findings were yielded for social support. While informal social support was significantly associated with domestic violence, formal social support was not associated with domestic violence. Findings suggest for mental health interventions targeting self‐esteem, particularly the diminution of self‐deprecation in working with the victims. Suggestions for future research and implications for social work are also discussed.  相似文献   
904.
Behavioral economics has captured the interest of scholars and the general public by demonstrating ways in which individuals make decisions that appear irrational. While increasing attention is being focused on the implications of this research for the design of risk‐reducing policies, less attention has been paid to how it affects the economic valuation of policy consequences. This article considers the latter issue, reviewing the behavioral economics literature and discussing its implications for the conduct of benefit‐cost analysis, particularly in the context of environmental, health, and safety regulations. We explore three concerns: using estimates of willingness to pay or willingness to accept compensation for valuation, considering the psychological aspects of risk when valuing mortality‐risk reductions, and discounting future consequences. In each case, we take the perspective that analysts should avoid making judgments about whether values are “rational” or “irrational.” Instead, they should make every effort to rely on well‐designed studies, using ranges, sensitivity analysis, or probabilistic modeling to reflect uncertainty. More generally, behavioral research has led some to argue for a more paternalistic approach to policy analysis. We argue instead for continued focus on describing the preferences of those affected, while working to ensure that these preferences are based on knowledge and careful reflection.  相似文献   
905.
Most travel behaviour studies that seek to promote cycling define market segments based on socio-demographics, travel mode use or attitudes. They do not address the stages of change process in travel behaviour, whereas this information can be instrumental in influencing travel behaviour change. This paper adopts the stages of change model to identify potential cycling market segments and to analyse and profile each of the market segments based on socio-economic factors, current travel behaviour, attitudes, perceptions and motivations. A survey was conducted among 620 individual regular commuters in the city of Dar-es-Salaam. On the basis of cycling behaviour attitudinal-variable statements, as developed from the stages of change model, the survey data were classified in six different segments: pre-contemplation, contemplation, prepared for action, action, maintenance and relapse. The study revealed that the different segments have different needs and are motivated by different factors suggesting that they need to be treated in different ways. These market segments can have important implications for designing cycling policies and promotional strategies that best serve the needs of each segment. The results indicate that urban policies and marketing strategies which aim to promote bicycle use may first target the contemplation, prepared for action and action segments that are most motivated to change and willing to cycle.  相似文献   
906.
In this paper we have provided a general result on the moments of a function of nonnormal random vector. The results for the normal case follow as a special case of this result. It is also indicated that the moments of a large class of econometric estimators and test statistics can be obtained by using our general result. This includes least squares estimator in the dynamic model, unit root tests, and the two step semiparametric estimators, among others.  相似文献   
907.
Several models are proposed in the literature for modeling fatigue data resulting from materials subject to cyclic stress and strain. Accelerated Weibull and accelerated Birnbaum–Saunders distributions are most commonly used models. Whereas the accelerated Weibull model is easier compared to accelerated Birnbaum–Saunders, it fails to represent the situation equally well. The present article focuses on Bayes analysis of the two models and provides a comparison based on some important Bayesian tools. Model compatibility study using predictive simulation ideas is preceded by the said comparison. Throughout, the posterior simulations are carried out by Markov chain Monte Carlo procedure.  相似文献   
908.
In an earlier article Mathai (1980) has given compact representations for the moments and cumulants of the trace of a noncentral Wishart matrix. He has also shown that (trA-ntr;∑)/(2ntri∑2)172. is asymptotically standard normal where A is a noncentral wishart matrix with n degrees of freedom and covariance matrix [0, In the present article explicit expressions for the exact density of the trace are given in terms of confluent hypergeometric functions and in terms of zonal polynomials for the general case and as finite sums when the sample size is odd. As a consequence of some of these representations some summation formulae for zonal polynomials are also given  相似文献   
909.
The problem of testing suspected outliers from a linear model with constant intraclass correlation is considered from a Bayesian viewpoint. The main objective of this paper is to develop an outlier test procedure based on the predictive distribution of suspected outlier observations given a set of existing inlier observations. The test procedure is easily performed with the usual F and t distributions.  相似文献   
910.
The investigation of multi-parameter likelihood functions is simplified if the log likelihood is quadratic near the maximum, as then normal approximations to the likelihood can be accurately used to obtain quantities such as likelihood regions. This paper proposes that data-based transformations of the parameters can be employed to make the log likelihood more quadratic, and illustrates the method with one of the simplest bivariate likelihoods, the normal two-parameter likelihood.  相似文献   
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