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981.
982.
Motivated by the asset recovery process at IBM, we analyze the optimal disposition decision for product returns in electronic products industries. Returns may be either remanufactured for reselling or dismantled for spare parts. Reselling a remanufactured unit typically yields higher unit margins. However, demand is uncertain. A common policy in many firms is to rank disposition alternatives by unit margins. We propose a profit‐maximization approach that considers demand uncertainty. We develop single period and multiperiod stochastic optimization models for the disposition problem. Analyzing these models, we show that the optimal allocation balances expected marginal profits across the disposition alternatives. A detailed numerical study reveals that our approach to the disposition problem outperforms the current practice of focusing exclusively on high‐margin options, and we identify conditions under which this improvement is the highest. In addition, we show that a simple myopic heuristic in the multiperiod problem performs well. 相似文献
983.
984.
This study compares aspects of the health-related behaviors and working life of first-year university students with those of their working counterparts and assesses the roles of these aspects as predictors of each groups' perceived quality of life (QoL). Subjects were taken from two cross-sectional data sets (a student survey and a population survey) from the Swedish central-western region of Osterg?tland. Male and female respondents aged 20-35 years were extracted and comparison were made considering in turn socio-demographic characteristics, health-related behaviors, exposure to abusive events at work and perceived QoL. University students smoked and used oral snuff in smaller proportions, they were not as frequent drinkers as their working counterparts, but they tended to drink more when they did drink. Threats and violence were less prevalent among students, but sexual harassment, were almost as common. The strongest predictors of perceived QoL for both groups are expected and former perceived QoL, followed by current self-rated health. 相似文献
985.
Principal axis factoring (PAF) and maximum likelihood factor analysis (MLFA) are two of the most popular estimation methods in exploratory factor analysis. It is known that PAF is better able to recover weak factors and that the maximum likelihood estimator is asymptotically efficient. However, there is almost no evidence regarding which method should be preferred for different types of factor patterns and sample sizes. Simulations were conducted to investigate factor recovery by PAF and MLFA for distortions of ideal simple structure and sample sizes between 25 and 5000. Results showed that PAF is preferred for population solutions with few indicators per factor and for overextraction. MLFA outperformed PAF in cases of unequal loadings within factors and for underextraction. It was further shown that PAF and MLFA do not always converge with increasing sample size. The simulation findings were confirmed by an empirical study as well as by a classic plasmode, Thurstone's box problem. The present results are of practical value for factor analysts. 相似文献
986.
987.
Chile represents almost one third of the world’s copper production. Mining is one of the main industries that contributes to our country’s development with resources and is globally recognized. Due to the end of the commodity cycle, improving productivity will be a key variable in mining performance in incoming years. This paper studies mining productivity in Chile by relying on two indicators: measure of the total factor productivity (TFP) using the traditional Solow methodology, and labor productivity. Since 2000, we found a decrease in TFP, explained mainly by the participation of capital as well as diverse factor adjustments to labor and capital inputs. Average labor productivity also decreases 42% from 1999 to 2010, a decrease explained by four determinants: real mining wages, electricity prices, copper prices and mineral grade. Since 2010, average labor productivity has increased 30%, and there is also an opportunity for additional improvement by reducing energy costs as well as by aligning productivity and labor performances. 相似文献
988.
J J Shulkin J A Mayer L G Wessel C de Moor J P Elder L R Franzini 《Journal of American college health : J of ACH》1991,40(2):75-79
Acquired immune deficiency syndrome (AIDS) has become a major health threat to university students. This study evaluated a peer-led AIDS intervention program with university students (1) increase knowledge of human immunodeficiency virus (HIV) transmission and infection; (2) change attitudes to reflect scientific information on AIDS-related facts; and (3) change behavioral intentions to correspond with safer sexual practices. Subjects were students (N = 142) from four undergraduate classes and were predominantly female (65%), white (82%), and sexually active (86%). A non-equivalent control group design was used, with two classes receiving the intervention and two classes receiving no information. For the intervention, peer educators presented AIDS-related information, modeled ways to use condoms safely and ways to discuss condom use with sexual partners, and led discussions on HIV infection and use with sexual partners, and led discussions on HIV infection and AIDS, relationships, sexuality, and condom use. A questionnaire was administered to assess differential changes in AIDS-related knowledge, attitudes, and behavioral intentions between the intervention and control groups. The results showed significant improvements among intervention subjects on the knowledge, attitudes, and behavioral intentions scales compared with the control group. 相似文献
989.
990.
M de Young 《Child welfare》1984,63(4):333-339
That multiply molested children are somehow responsible for their victimization is a conclusion unacceptable to the author, who examines one possible cause for the paradoxical behavior of these children. 相似文献