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551.
The purpose of this study was to determine the number of residents requiring corrective lenses in a youth detention center for juveniles from 12 to 18 years old over a 2-year period. A greater number of adolescents incarcerated for criminal activity in a detention center had uncorrected refractive errors (34.87 %) as compared to a comparable population in the public school system (22 %). The prevalence of significant refractive errors among incarcerated adolescents in this study is significantly higher than has been reported previously. The current study found a refractive error rate of almost 35 %. This difference can be explained by a number of factors in their social environments and identifies an area for potential intervention to reduce antisocial behavior in this population.  相似文献   
552.
This paper discusses the relationship between corporate volunteering and civic engagement outside the workplace in Russia, proceeding from a mixed-method approach. The quantitative findings are based on a comparison between employees in 37 Russian companies who participated in corporate volunteering (N = 399) and those who did not (N = 402). Using binary logistic regression analysis, we demonstrate that employee participation in corporate volunteering is positively related to four forms of civic engagement outside the workplace: informal volunteering, formal volunteering, formal monetary donation, and informal monetary donation. In addition, we draw on information obtained from interviews with 10 corporate volunteers, as well as with all 37 company corporate volunteering managers, to develop a general explanation for why corporate volunteering might lead to civic engagement. We identify three primary explanations. First, trust in companies can be converted into increased trust in social institutions. Second, corporate volunteering can expose employees to other realities, thereby leading them to rethink their priorities. Third, corporate volunteering socializes employees to volunteering, thus making them more likely to incorporate volunteering into their personal repertoires of activities. Corporate volunteering appears to be an effective mechanism for stimulating civic engagement and volunteering infrastructure in post-communist countries.  相似文献   
553.
This paper examines the recent rise of, and interest in social forecasting. It reviews the various ways in which social forecasts are attempted: particularly through the techniques of modelling which have been taken from, and developed beyond the models used by the basic science and technologies. It then describes the shifts in thinking emerging from different beliefs and attitudes which seem to portend a new ideology in our global society. Finally the paper briefly addresses the crucial issue known as the ‘World Problematique’ and evaluates the role that social forecasting has to play in devising possible solutions, particularly from the viewpoint of industry, trade and commerce.  相似文献   
554.
It is well known that two-phase (or double) sampling is of significant use in practice when the population parameter(s) (say, population mean X¯) of the auxiliary variate x is not known. Keeping this in view, we have suggested a class of ratio-product estimators in two-phase sampling with its properties. The asymptotically optimum estimators (AOEs) in the class are identified in two different cases with their variances. Conditions for the proposed estimator to be more efficient than the two-phase sampling ratio, product and mean per unit estimator are investigated. Comparison with single phase sampling is also discussed. An empirical study is carried out to demonstrate the efficiency of the suggested estimator over conventional estimators.  相似文献   
555.
我国林业工程项目管理研究   总被引:3,自引:0,他引:3  
以大工程带动大发展是我国实现林业跨越式发展的重大战略决策。林业项目单位是工程的主要参与者 ,其管理水平高下直接关系到项目成败。该文通过总结现代项目管理理念 ,结合林业工程项目管理的现状和特点 ,提出林业工程项目管理系统 ,并指出了现代项目管理理念和方法是提高林业项目管理水平的有效途径。  相似文献   
556.
Leadership efficacy: Review and future directions   总被引:1,自引:0,他引:1  
The concept of leader efficacy has received relatively little attention in the leadership literature. This is somewhat surprising given that effective leadership requires high levels of agency (i.e., deliberately or intentionally exerting positive influence) and confidence. This review uses existing theory and research on leader efficacy as a point of departure for proposing an expanded and multi-level framework for understanding the domain of leadership efficacy that includes leader, follower, and collective efficacies. The primary goals are to provide a conceptual framework to stimulate future theory and research on building efficacious leadership and to understand how such leadership develops and has implications for effective performance.  相似文献   
557.
Our current views of economic competition are still rooted in the imagery of the isolated firm that transacts with its buyers, suppliers, and competitors via largely anonymous factor and product markets. Yet this view is fundamentally at odds with the growing importance of business groups in the global economy. We thus need a reconceptualized version of our idea of economic competition, which is capable of explaining competitive advantage at the group-versus-group rather than firm-versus-firm level of analysis. In the present paper we build on insights derived from organizational sociology and organizational economics to develop a business group-level theory of competition and competitive advantage based on embedded competencies.
Stelios C. Zyglidopoulos (Corresponding author)Email:
  相似文献   
558.
We examine optimal control decisions regarding pricing, network size, and hiring strategy in the context of open source software development. Opening the source code to a software product often implies that consumers would not pay for the software product itself. However, revenues may be generated from complementary products. A software firm may be willing to open the source code to its software if it stands to build a network for its complementary products. The rapid network growth is doubly crucial in open source development, in which the users of the firm's products are also contributors of code that translates to future quality improvements. To determine whether or not to open the source, a software firm must jointly optimize prices for its various products while simultaneously managing its product quality, network size, and employment strategy. Whether or not potential gains in product quality, network size, and labor savings are sufficient to justify opening the source code depends on product and demand characteristics of both the software and the complementary product, as well as on the cost and productivity of in‐house developers relative to open source contributors. This paper investigates these crucial elements to allow firms to reach the optimal decision in choosing between the open and closed source models.  相似文献   
559.
Ethylene oxide is a gas produced in large quantities in the United States that is used primarily as a chemical intermediate in the production of ethylene glycol, propylene glycol, non-ionic surfactants, ethanolamines, glycol ethers, and other chemicals. It has been well established that ethylene oxide can induce cancer, genetic, reproductive and developmental, and acute health effects in animals. The U.S. Environmental Protection Agency is currently developing both a cancer potency factor and a reference concentration (RfC) for ethylene oxide. This study used the rich database on the reproductive and developmental effects of ethylene oxide to develop a probabilistic characterization of possible regulatory thresholds for ethylene oxide. This analysis was based on the standard regulatory approach for noncancer risk assessment, but involved several innovative elements, such as: (1) the use of advanced statistical methods to account for correlations in developmental outcomes among littermates and allow for simultaneous control of covariates (such as litter size); (2) the application of a probabilistic approach for characterizing the uncertainty in extrapolating the animal results to humans; and (3) the use of a quantitative approach to account for the variation in heterogeneity among the human population. This article presents several classes of results, including: (1) probabilistic characterizations of ED10s for two quantal reproductive outcomes-resorption and fetal death, (2) probabilistic characterizations of one developmental outcome-the dose expected to yield a 5% reduction in fetal (or pup) weight, (3) estimates of the RfCs that would result from using these values in the standard regulatory approach for noncancer risk assessment, and (4) a probabilistic characterization of the level of ethylene oxide exposure that would be expected to yield a 1/1,000 increase in the risk of reproductive or developmental outcomes in exposed human populations.  相似文献   
560.
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