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91.
Roberta L. Grant Joseph Haney Angela L. Curry Michael Honeycutt 《Risk analysis》2009,29(12):1726-1742
The Texas Commission on Environmental Quality (TCEQ) has developed an inhalation unit risk factor (URF) for 1,3-butadiene based on leukemia mortality in an updated epidemiological study on styrene-butadiene rubber production workers conducted by researchers at the University of Alabama at Birmingham. Exposure estimates were updated and an exposure estimate validation study as well as dose-response modeling were conducted by these researchers. This information was not available to the U.S. Environmental Protection Agency when it prepared its health assessment of 1,3-butadiene in 2002. An extensive analysis conducted by TCEQ discusses dose-response modeling, estimating risk for the general population from occupational workers, estimating risk for potentially sensitive subpopulations, effect of occupational exposure estimation error, and use of mortality rates to predict incidence. The URF is 5.0 × 10−7 per μg/m3 or 1.1 × 10−6 per ppb and is based on a Cox regression dose-response model using restricted continuous data with age as a covariate, and a linear low-dose extrapolation default approach using the 95% lower confidence limit as the point of departure. Age-dependent adjustment factors were applied to account for possible increased susceptibility for early life exposure. The air concentration at 1 in 100,000 excess leukemia mortality, the no-significant-risk level, is 20 μg/m3 (9.1 ppb), which is slightly lower than the TCEQ chronic reference value of 33 μg/m3 (15 ppb) protective of ovarian atrophy. These values will be used to evaluate ambient air monitoring data so the general public is protected against adverse health effects from chronic exposure to 1,3-butadiene. 相似文献
92.
A framework for time varying parameter regression models is developed and employed in modeling and forecasting price expectations, using the Livingston data. Alternative model formulations, which include various choices for both the stochastic processes generating the varying parameters and the sets of explanatory variables, are examined and compared by using this framework. These models, some of which have appeared elsewhere and some of which are new, are estimated and used to assess the expectations formation process. 相似文献
93.
This case study sought to identify the relationships that can exist between open innovation, entrepreneurship, and the introduction of new business models at the enterprise level. Eleven Korean enterprises and five Indonesian enterprises were chosen, to obtain minimum research generality. While the number of enterprises is not great, it provides enough samples to determine the concrete relationships among these factors. The article starts by pointing out the general relationship between entrepreneurship, open innovation, and the introduction of a new business model. It examines two different contexts: the difference between the Seoul and Daegu regional innovation systems, and the difference between the Indonesian and Korean national innovation systems. 相似文献
94.
Dr. Joseph G. Pickard PhD LCSW Jing Tan Nancy Morrow-Howell Yunkyung Jung 《Journal Of Human Behavior In The Social Environment》2013,23(2):213-229
Purpose: This study uses the selection, optimization, and compensation (SOC) model to compare older adults who have given up driving, those who still drive, and those who drive less to identify differences in the three groups. Design and Methods: This cross-sectional study of 281 older adults is part of the Naturally Occurring Retirement Community Demonstration Project. Study participants completed interviews that included questions on demographics, health and functioning, mental health, social support, and current levels of engagement in activities including current driving status. Results: Data suggest that driving retirement is a process and that a substantial number of people are in the transitional stage, where they are less functional than those who still drive and more similar to those who have retired from the road. Implications: Given the similarity of those who drive less to those who have given up driving, front-line professionals and policy makers must work together to ease the transition to driving retirement for those without adequate ability to effectively compensate for their inability to continue to drive safely. 相似文献
95.
96.
The following study reviews the image repair strategies used by Olympic swimmer Michael Phelps, his sponsors and the organizations that govern him as an amateur swimmer after a picture of Phelps allegedly smoking from a marijuana pipe appeared in a British tabloid. Additionally, the study reviews media coverage of the controversy to determine whether Phelps was successful in repairing his image. The study concludes that Phelps’ image repair campaign was a success. Implications for public relations practitioners and suggestions for future research also are discussed. 相似文献
97.
98.
Joseph M. Hilbe 《The American statistician》2013,67(3):255-265
The importance of random number generators has increased over the years. This follows from the fact that contemporary research methods rely more and more on simulation and the increased importance of encryption technology. The output of a random number generator is created by either an algorithm or a physical device. The most popular method for random number generation is through the use of an algorithm. This article presents a new category of physical random bit generator that is packaged by several manufacturers. A statistical analysis of the output from the generators is given. 相似文献
99.
While teen homelessness, like all homelessness, is increasing, there have been few solid estimates of the actual number of teens effected. A twofold methodology to count homeless teens was used in the Seacoast region of New Hampshire and Maine. Social service agencies were contacted to obtain a count of homeless adolescents, and over 3000 high school age teens were surveyed in the seacoast ofNew Hampshire and southwestern Maine to identify how many were homeless. By using different definitions of homelessness, it was found that a minimum of 5% of all teens in high school reported that they had been homeless sometime during the past year. When using a broadened definition of homelessness, it was found that 20% of the teens regularly stayed with others. However, this experience was not identified by social service providers, who reported that teen homelessness simply was not a problem in their communities. In order to more accurately describe the phenomenon experienced by teens, it is proposed that the term “homelessness” should be replaced with a more inclusive word, such as “housing distress.” 相似文献
100.
Joseph Soffen 《Journal of Social Work Education》2013,49(1):73-77
This study compares the efficacy of experimental, competency-based methods of teaching the interpersonal skills of empathic communication, respect, and genuineness with traditional didactic methods. An experimental design using randomly-chosen experimental and control groups of first-year graduate students was employed. Experimental conditions involved communication laboratories consisting of didactic and experiential learning opportunities organized in a systematic and sequential fashion. The findings supported the hypothesis that the experimental groups would significantly outperform the control groups on the criterion variable. A second hypothesis, that the control groups would not achieve significant gains, was refuted. 相似文献