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991.
Stochastic scenario trees are a new and popular method by which surveillance systems can be analyzed to demonstrate freedom from pests and disease. For multiple component systems—such as a combination of a serological survey and systematically collected observations—it can be difficult to represent the complete system in a tree because many branches are required to represent complex conditional relationships. Here we show that many of the branches of some scenario trees have identical outcomes and are therefore redundant. We demonstrate how to prune branches and derive compact representations of scenario trees using matrix algebra and Bayesian belief networks. The Bayesian network representation is particularly useful for calculation and exposition. It therefore provides a firm basis for arguing disease freedom in international forums. 相似文献
992.
993.
Curtis M. Jolly Budry Bayard Richard T. Awuah Simon C. Fialor Johnathan T. Williams 《Journal of Socio》2009,38(2):280-287
This study uses a modified health belief model (HBM) within a socio-economic framework to evaluate the influence of awareness and knowledge on actions to reduce aflatoxin (AF) contamination in groundnuts (peanuts). Data were collected in 2002 through a self-administered questionnaire from a sample of 367 individuals. Socio-economic factors affecting perceptions, awareness, knowledge, and action were examined using structural equation modeling. The perceived benefits of good quality groundnuts and/or groundnut products were the most important determinants of awareness and knowledge of AF among agricultural and health professionals in Ghana. Awareness, in turn, had a significant causal effect on the professionals’ decisions to take actions to increase the level of awareness of AF in the society. Demographic factors, such as gender and level of education significantly influenced knowledge of AF and the perception of the benefits of good quality groundnut. Type of profession had a significant influence on awareness and perceived seriousness of the AF problem. Education was a significant determinant of awareness of AF in groundnuts. The study generates important information for policy decision making when considering resource allocation to reduce food contamination in developing economies. 相似文献
994.
A positive relationship between FDI and economic growth under two economic conditions has been estimated: a sufficient level of human capital and well-developed financial markets, respectively. However, these two conditions can be fundamentally different catalysts for FDI to promote economic growth in the perspective of growth accounting. Using data from 69 countries over 1970–1989, we find that FDI promotes productivity growth only when the host country reaches a threshold level of human capital; and FDI promotes capital growth only when a certain level of financial development is achieved. ( JEL F21) 相似文献
995.
Annie H. Liu Charles A. Rarick Ph.D. 《International Journal of Value-Based Management》1991,4(1):57-67
The ethical foundations for management behavior are examined for the people in Taiwan and from those within the United States. The influences for ethical actions can be traced to Confucian teachings and Christian doctrines. The authors present the philosophical differences between humanism for Chinese people and spiritualism for Christian people in the United States. Comparisons are made on how these principles affect the management behavior within organizations. 相似文献
996.
Culturally embedded differences in self-interested behavior and perceptions of trust violate the universal assumption of moral hazard held by transaction cost economic theorists. A model of transaction cost advantage is derived and propositions developed using the cultural value diversity literature to test the universal assumptions of transaction cost economics. 相似文献
997.
Gender, Race, and Perception of Environmental Health Risks 总被引:17,自引:2,他引:17
This paper reports the results of a national survey in which perceptions of environmental health risks were measured for 1275 white and 214 nonwhite persons. The results showed that white women perceived risks to be much higher than did white men, a result that is consistent with previous studies. However, this gender difference was not true of nonwhite women and men, whose perceptions of risk were quite similar. Most striking was the finding that white males tended to differ from everyone else in their attitudes and perceptions–on average, they perceived risks as much smaller and much more acceptable than did other people. These results suggest that sociopolitical factors such as power, status, alienation, and trust are strong determiners of people's perception and acceptance of risks. 相似文献
998.
Monk TH 《Work and stress》1990,4(3):227-236
This review is concerned with how chronobiological results concerning the human circadian timekeeping system ('biological clock'), its response to changes in schedule, and its influence on performance ability can be used to improve shift worker wellbeing, safety and productivity. 相似文献
999.
Environmental Tobacco Smoke: Exposure-Response Relationships in Epidemiologic Studies 总被引:1,自引:0,他引:1
Demonstration of a dose-response relationship for environmental tobacco smoke (ETS) is an important indication of causality. Central to the analysis and interpretation of dose-response relations as described in epidemiological studies is the relationship between dose and exposure. It must be recognized that in studies of ETS we have only surrogate measures of dose, and these surrogate measures (based on exposure) are imperfect. The question-based measures of ETS exposure generally have not been standardized, may have limited validity and reliability, and cannot comprehensively describe total ETS exposure, exposure to individual ETS components, nor doses of biologically relevant agents at target sites. Nevertheless, useful data have been yielded in epidemiologic studies linking ETS exposure to increased respiratory infection and symptoms, reduced lung growth in children, and increased lung cancer in nonsmoking adults. The more consistent exposure-response data for studies on acute health in children may reflect the greater difficulty in measuring exposure in studies of chronic health in adults. 相似文献
1000.
Thompson EH 《Omega》1985,16(3):233-242
This paper explores the errors involved in the approximation of both the maximum and sum of two independent Beta random variables, each by another Beta random variable. The principal area of application is the time analysis of PERT networks, and the results are interpreted and discussed in terms of this application. The error was found to be acceptable for the greater part of the range of the parameters involved. The results will help practitioners estimate the mean and standard deviation of the completion time of PERT networks. 相似文献