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61.
A macro-scale methodology for vehicle emissions estimation is described. The methodology is based on both correlations between activity level and PM, CO, THC and NO x vehicle emissions and relationships between demographic and socio-economic variables and transportation activity level. First, pollutant emissions were correlated with transportation activity, expressed as vehicle-km/year, using existing data collected from mobile sources emission inventories in nine urban cities of Chile. Second, demographic and socio-economic variables were pre-selected from those that could intuitively be correlated with vehicle activity level and considering the data availability. Using the individual R 2 correlation coefficient as variable selection criterion, population, the number of vehicles, fuel consumption, gross domestic product, average family incomes and road kilometers were finally chosen. A different set of explicative variables was considered for different vehicle categories, based on the selection criterion above mentioned. Then, correlation functions between these variables and transport activity were obtained by non-linear Gauss–Newton least square method. This methodology was applied to eighteen provinces of the country obtaining total annual emission for mobile sources, divided into six main vehicles categories.  相似文献   
62.
This study aimed to examine the gender-related differences in demographics, gambling measures, psychological functioning, and motivation for therapy in an outpatient sample of pathological gamblers seeking treatment. Participants in this multisite study included 103 adult outpatients (51 women and 52 men) meeting current DSM-IV-TR criteria for PG. Logistic regression was used to examine if gender was related together to categorical and continuous independent variables. Female gamblers were older than men and more likely to be divorced or widowed and to have a lower annual income. Women became more dependent on bingo and men on slot machines. Gambling motivation and the course of illness for both sexes were also different. Female gamblers were more anxious and with a poorer self-esteem than male gamblers and more affected by depressive symptoms; in turn, men were more impulsive and higher sensation seekers than women and more affected by drug/alcohol abuse. The 68.6% of female gamblers reported being victims of intimate partner violence. There were no gender differences about the motivation for treatment. Future research should examine gambling behaviors and psychological functioning and suggest treatment approaches to address specific goals according to these gender-related differences.  相似文献   
63.
Genetic differences (polymorphisms) among members of a population are thought to influence susceptibility to various environmental exposures. In practice, however, this information is rarely incorporated into quantitative risk assessment and risk management. We describe an analytic framework for predicting the risk reduction and value-of-information (VOI) resulting from specific risk management applications of genetic biomarkers, and we apply the framework to the example of occupational chronic beryllium disease (CBD), an immune-mediated pulmonary granulomatous disease. One described Human Leukocyte Antigen gene variant, HLA-DP beta 1*0201, contains a substitution of glutamate for lysine at position 69 that appears to have high sensitivity (approximately 94%) but low specificity (approximately 70%) with respect to CBD among individuals occupationally exposed to respirable beryllium. The expected postintervention CBD prevalence rates for using the genetic variant (1) as a required job placement screen, (2) as a medical screen for semiannual in place of annual lymphocyte proliferation testing, or (3) as a voluntary job placement screen are 0.08%, 0.8%, and 0.6%, respectively, in a hypothetical cohort with 1% baseline CBD prevalence. VOI analysis is used to examine the reduction in total social cost, calculated as the net value of disease reduction and financial expenditures, expected for proposed CBD intervention programs based on the genetic susceptibility test. For the example cohort, the expected net VOI per beryllium worker for genetically based testing and intervention is $13,000, $1,800, and $5,100, respectively, based on a health valuation of $1.45 million per CBD case avoided. VOI results for alternative CBD evaluations are also presented. Despite large parameter uncertainty, probabilistic analysis predicts generally positive utility for each of the three evaluated programs when avoidance of a CBD case is valued at $1 million or higher. Although the utility of a proposed risk management program may be evaluated solely in terms of risk reduction and financial costs, decisions about genetic testing and program implementation must also consider serious social, legal, and ethical factors.  相似文献   
64.
Social scientists often estimate models from correlational data, where the independent variable has not been exogenously manipulated; they also make implicit or explicit causal claims based on these models. When can these claims be made? We answer this question by first discussing design and estimation conditions under which model estimates can be interpreted, using the randomized experiment as the gold standard. We show how endogeneity – which includes omitted variables, omitted selection, simultaneity, common-method variance, and measurement error – renders estimates causally uninterpretable. Second, we present methods that allow researchers to test causal claims in situations where randomization is not possible or when causal interpretation could be confounded; these methods include fixed-effects panel, sample selection, instrumental variable, regression discontinuity, and difference-in-differences models. Third, we take stock of the methodological rigor with which causal claims are being made in a social sciences discipline by reviewing a representative sample of 110 articles on leadership published in the previous 10 years in top-tier journals. Our key finding is that researchers fail to address at least 66% and up to 90% of design and estimation conditions that make causal claims invalid. We conclude by offering 10 suggestions on how to improve non-experimental research.  相似文献   
65.
In southern Chile, the building of roads has triggered profound socio-material transformation in indigenous worlds. In this article, we attempt to comprehend and conceptualize the capacities of roads to reconstitute radically a relationally constituted world, a world that is therefore in itself contingent. We suggest that the material alteration of indigenous worlds produce uncertain results, including possibly its own destruction. The arguments raised in this article indicate that the analytical and political problem of ontological self-determination can be advanced once reshaped in infrastructural terms.  相似文献   
66.
Abstract

Growing dependence on suppliers for production and innovation, together with increasing consumer demands, has prompted recent discussions of the importance of purchasing–marketing functional integration. However, empirical studies are needed to understand how to manage this interface within a new product development (NPD) context. This study, grounded in information processing theory, proposes a new model to classify integrating mechanisms as either information-sharing forums or optimizers. This model further postulates the greater capacity of optimizer mechanisms for improving NPD commercial and financial performance, as well as speed. The empirical results, obtained from a sample of 141 firms, show that forums only improve NPD speed, whereas optimizer mechanisms evoke better commercial and financial performance. This study therefore highlights the potential of different integrating mechanisms and contributes to the on-going debate about the very concept of functional integration itself.  相似文献   
67.
68.
A model is developed to identify factors that are important in determining whether a municipality employs a labor relations specialist as chief negotiator and, if not, whether a municipality has a labor relations specialist on its collective bargaining team. Results indicate that municipal organizational structure for collective bargaining is influenced by the economic and legal environments within which collective bargaining occurs, the complexity of municipal collective bargaining, and various other demographic characteristics of the municipality.  相似文献   
69.
A review of the various etiological possibilities for child abuse and neglect, designed to offer an additional and different possibility. Consideration is first given to problems, namely the lack of universal definition, heterogeneous effects, and retrospective research. The probability of multifactor models is noted, and sexual abuse is given separate consideration, followed by an exploration of the existing models termed ecological, transactional, transitional, and attachment. An interactive aggression model is then offered as the new possibility. Empirical evidence for cultural and/or ethnic predispositions suggests that society can be a supporting or inhibiting factor in terms of promoting or opposing violence.  相似文献   
70.
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