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31.
Urban Ecosystems - Anthropocentric defaunation affects critical ecological processes, such as seed dispersal, putting ecosystems and biomes at risk, and leading to habitat impoverishment. Diverse...  相似文献   
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This study uses natural, everyday social interaction within Salvadoran families living in Southern California to examine the use of the 2nd‐person singular pronouns and vos (and their corresponding morphologies) in this contact variety of Spanish. An in‐depth, qualitative analysis reveals that the employment and significance of these forms of address do not conform entirely to Salvadoran norms, nor to those of the surrounding Mexican‐based Spanish koiné. Accommodation to the pronominal repertoire of the region's majority serves as a communicative resource driven by questions of U.S./Los Angeles identity and solidarity with speakers in‐the‐moment interlocutor(s), a process which has caused the original Salvadoran pronouns to also be reallocated and refunctionalized (Britain and Trudgill 1999 ) as resources for accomplishing Salvadoran identity. Members of this community make active use of their pronominal options in real‐time interaction as they navigate the fluid, multifaceted identities that they and their interlocutors now embody in the U.S. context.  相似文献   
34.
Urban Ecosystems - Anthropogenic activities are the main cause of habitat loss and fragmentation, which directly affects biodiversity. Disruption in landscape connectivity among populations may...  相似文献   
35.
Many Bayes factors have been proposed for comparing population means in two-sample (independent samples) studies. Recently, Wang and Liu presented an “objective” Bayes factor (BF) as an alternative to a “subjective” one presented by Gönen et al. Their report was evidently intended to show the superiority of their BF based on “undesirable behavior” of the latter. A wonderful aspect of Bayesian models is that they provide an opportunity to “lay all cards on the table.” What distinguishes the various BFs in the two-sample problem is the choice of priors (cards) for the model parameters. This article discusses desiderata of BFs that have been proposed, and proposes a new criterion to compare BFs, no matter whether subjectively or objectively determined. A BF may be preferred if it correctly classifies the data as coming from the correct model most often. The criterion is based on a famous result in classification theory to minimize the total probability of misclassification. This criterion is objective, easily verified by simulation, shows clearly the effects (positive or negative) of assuming particular priors, provides new insights into the appropriateness of BFs in general, and provides a new answer to the question, “Which BF is best?”  相似文献   
36.
Changes in survival rates during 1940–1992 for patients with Hodgkin's disease are studied by using population-based data. The aim of the analysis is to identify when the breakthrough in clinical trials of chemotherapy treatments started to increase population survival rates, and to find how long it took for the increase to level off, indicating that the full population effect of the breakthrough had been realized. A Weibull relative survival model is used because the model parameters are easily interpretable when assessing the effect of advances in clinical trials. However, the methods apply to any relative survival model that falls within the generalized linear models framework. The model is fitted by using modifications of existing software (SAS, GLIM) and profile likelihood methods. The results are similar to those from a cause-specific analysis of the data by Feuer and co-workers. Survival started to improve around the time that a major chemotherapy breakthrough (nitrogen mustard, Oncovin, prednisone and procarbazine) was publicized in the mid 1960s but did not level off for 11 years. For the analysis of data where the cause of death is obtained from death certificates, the relative survival approach has the advantage of providing the necessary adjustment for expected mortality from causes other than the disease without requiring information on the causes of death.  相似文献   
37.
An Iterative Choice Approach to Valuing Clean Lakes,Rivers, and Streams   总被引:1,自引:0,他引:1  
This article introduces an iterative choice procedure for valuing inland water quality. This approach breaks up the valuation into a series of component tasks. The water quality ladder approach is not valid empirically. Consequently, respondents in Colorado and North Carolina assessed the value of making water quality rated good by EPA, which has a value of $22.40 per additional percent improvement. Nonuse and probabilistic use are highly valued. The results also indicate how water quality valuations differ for aquatic environment, edible fish, and swimming, as well as for water that is cloudy, smelly, or polluted by toxics. Minorities are particularly likely to rely upon monitorable water quality attributes.  相似文献   
38.
Within the context of the multiviriate general linear model, and using a Bayesian formulation and Kullback-Leibler divergences this paper provides a framework and the resultant methods for the problem of detecting and characterizing influential subsets of observations when the goal is to estimate parameters. It is further indicated how these influence measures inherently depend upon one's exact estimative intent. The relationship to previous work on observations influential in estimation is discussed. The estimative influence measures obtained here are also compared with predictive influence functions previously obtained. Several examples are presented illustrating the methodology.  相似文献   
39.
Communication of ambiguous risk information   总被引:2,自引:0,他引:2  
This paper reports on the responses of 646 individuals to environmental risk information involving different forms of risk ambiguity. Recipients of more than one set of risk information do not simply average the risk levels provided. Rather, a variety of aspects of the nature of the risks that are communicated influence their probabilistic beliefs. Individuals' perceptions of the risk levels to which they are exposed are likely to be greater: (i) for more ambiguous risks, (ii) for risks for which the unfavorable risk evidence is presented last even when there is no temporal order, (iii) for risks for which the most unfavorable risk studies have been performed most recently, and (iv) for risks where there is asymmetry in the risk ambiguity that imposes substantial potential downside risks. Although these effects are modest for the median individual, the potential for extreme responses that reflect only the most adverse or the most favorable piece of information provided is quite prevalent. These findings are of interest more generally in that they indicate how individuals form their risk perceptions in the presence of risk ambiguity.The authors would like to thank the U.S. Environmental Protection Agency for support of this work under Cooperative Agreements Number CR-815445-01-2 and Number CR-814388-02-1. Dr. Alan Carlin and Dr. Ann Fisher provided valuable guidance in the design of the project, and Dr. Doyle Graham and Dr. Douglas Anthony offered generous assistance in communicating the medical consequences of nerve disease to subjects. Jon LaScala assisted superbly in the administration and analysis of the survey, and Patricia Born provided additional computer programming assistance.  相似文献   
40.
OBJECTIVE: The authors examined whether alcohol-related negative consequences decreased among students exposed to an intervention. PARTICIPANTS: Beginning in 1999, approximately 2,500 randomly selected undergraduates from a 4-year US university annually participated in a Web-based survey over 6 years. METHODS: The educational intervention used social norms initiatives. Main outcome measures included recall of intervention, estimated blood alcohol content (eBAC) when drinking, and 10 negative consequences from alcohol within the past year. RESULTS: First-year students recalling exposure had lower odds of negative consequences (odds ratio [OR] = 0.78, 95% confidence interval [CI] = 0.64-0.95) and of having an eBAC higher than .08 (OR = 0.76, 95% CI = 0.62-0.92). Over the 6 study years, the odds among all participants of experiencing (a) none of 10 alcohol consequences nearly doubled (OR = 2.13, 95% CI = 1.82-2.49) and (b) multiple consequences decreased by more than half (OR = 0.43, 95% CI = 0.36-0.50). CONCLUSIONS: These findings have important implications for US colleges and universities engaged in the reduction of harm associated with alcohol misuse.  相似文献   
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