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21.
Thrushes (Turdus spp., Turdidae) are among the most common frugivorous birds in urban areas around the world, where they disperse the seeds of a variety of plant species. We studied the abundance, habitat use, foraging behavior and diet of four thrush species (Turdus rufiventris, T. amaurochalinus, T. leucomelas, and T. albicollis) in a suburban area in south Brazil. Abundance, habitat use and foraging behavior were based on birds surveyed along a 3,240 m transect crossing open (formed by lawns, streets, and buildings) and forested areas. Diet was based on fecal samples collected from mist-netted birds. Turdus rufiventris was the most abundant species, followed by T. amaurochalinus, T. leucomelas, and T. albicollis. All species used forest fragments more frequently than expected by chance. A total of 91.8% (n = 147) of the fecal samples contained fruit remains, while 42.2% contained only animal matter. Most of the foraging records were on the ground, where birds got mainly invertebrates. Fruits and invertebrates were eaten more frequently in open than in forested areas. A total of 25 seed morfospecies were found in the droppings, including five exotic plant species. Thrushes overlapped widely in the fruit composition of their diets. The high abundance and degree of frugivory, coupled with the frequent use of forest patches, indicate that thrushes are among the great bird contributors to the seed dispersal occurring in urban forest patches, potentially influencing the vegetation dynamics of such habitats so important for the maintenance of the biodiversity in urban areas.  相似文献   
22.
Tree-based methods similar to CART have recently been utilized for problems in which the main goal is to estimate some set of interest. It is often the case that the boundary of the true set is smooth in some sense, however tree-based estimates will not be smooth, as they will be a union of ‘boxes’. We propose a general methodology for smoothing such sets that allows for varying levels of smoothness on the boundary automatically. The method is similar to the idea underlying support vector machines, which is applying a computationally simple technique to data after a non-linear mapping to produce smooth estimates in the original space. In particular, we consider the problem of level-set estimation for regression functions and the dyadic tree-based method of Willett and Nowak [Minimax optimal level-set estimation, IEEE Trans. Image Process. 16 (2007), pp. 2965–2979].  相似文献   
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In this paper, we argue that Norbert Elias's concept of survival unit is a distinctive part of the development of his figurational sociology and one of the most consistent contributions to relational thinking. The survival unit is a particular form of figuration which provides security and the material foundations for life such as food and shelter. Every human being is born into a survival unit. This unit is a relational concept which cannot be conceived outside a relationship with other survival units.
By introducing the concept of survival unit Elias overcomes one of the key problems in relational sociology: how to demarcate primary social relations. Elias argues that human societies from very early on have been divided into survival units. These survival units are demarcated and constituted in their relationship to other survival units. Consequently, their boundaries are generated in a confrontation with other survival units.
This relationship can be peaceful or conflict ridden but in the last resort it can end with violent confrontation. Only the survival unit with the ability to defend a domain of sovereignty will survive. This observation places Elias among the few sociologists with an understanding of the role of warfare in social relationships.  相似文献   
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26.
This article offers insights into a new educational adventure in Israel that attempts to overcome interethnic conflict through bilingual coeducation. These insights were gathered during a two-year research project in which the authors followed the activities of two recently established Arab-Jewish bilingual schools. Their analysis is based primarily on qualitative data of educational and sociocultural processes involved in the functioning and development of the schools as they relate to four major areas: language, cultural and religious identity, national identity, and social interactions. The study showed the potential benefits of one type of intergroup contact, namely, bilingual long-term coeducation, but also shed light on the complexity and the difficulties facing all of the parties involved in such an adventurous enterprise.  相似文献   
27.
Latinos tend to have significantly lower levels of access to general and top quality medical care than do non-Latino whites, and although disparities in access to health care have diminished for all other minority groups over time, they have widened for Latinos. Given these trends, current attempts to provide universal health care at both the national and state levels across the United States have large implications for the health status of Latinos. The objective of this analysis is to determine whether Latinos have different attitudes regarding health reform than non-Latino whites. Our data are from a statewide random digit dialing telephone survey of New Mexico residents, age 18 and older, conducted in the Fall of 2007. With a Latino population of 44% and ongoing health care reform efforts by the state legislature, New Mexico is an ideal location for this analysis. After controlling for a host of individual level factors, our findings suggest that while Latinos are less likely to identify health care as a salient state issue relative to the economy and crime, they are more likely than non-Latino whites to believe affordable health care programs are important. Finally, Latinos view employers, more than government or individuals, to be responsible for expanding health care coverage.  相似文献   
28.
This paper is based on the results of anational survey of the quality of life of 999randomly sampled people aged 65 and over,living at home in Britain. The survey wassemi-structured, and a sample of surveyrespondents was followed up and interviewedin-depth in order to explore their perceptionsof quality of life in full. Comparisons aremade here between the results of (i) ahierarchical multiple regression model basedon theoretically derived indicators of survey respondents' ratings of their overall quality of life, with (ii) the samerespondents' own definitions of quality oflife, categorised from their responses toopen ended survey questions, and (iii) theviews of a sub-sample of these survey respondents who were subsequently interviewed in greater depth. Respondents were asked theopen ended questions on quality of life at theoutset of the survey interview in order toprevent any respondent bias from thestructured measures used.The core components, and the central planks,of quality of life, which were consistentlyemphasised by the three approaches, were psychological characteristics and outlook,health and functional status, personal andneighbourhood social capital. The lay modelsalso emphasised the importance of financialcircumstances and independence, which need tobe incorporated into a definition of broader quality of life.  相似文献   
29.
While ethical implications of direct taxation systems have recently received renewed attention, a more veiled scheme remains unnoticed: inflation. We overview the causes of inflation and assess its consequences. Salient wealth redistributions are a defining feature of inflation, as savers and fixed income individuals see a relative wealth reduction. While avoiding this “tax” is difficult in many instances because of the primacy of money in a monetary economy, the tax codes of most developed countries allow avoidance techniques to be employed. We analyze three ways that inflation may be avoided in an attempt to preserve personal wealth, as well as the consequences of such practices.  相似文献   
30.
Despite their conceptual importance, the effects of time preference, expected longevity, uncertainty, and risk aversion on behavior have not been analyzed empirically. We use data from the Health and Retirement Study (HRS) to assess the role of risk and time preference, expected longevity, and education on demand for three measures used for early detection of breast and cervical cancer—regular breast self-exams, mammograms, and Pap smears. We find that individuals with a higher life expectancy and lower time preference are more likely to undergo cancer screening. Less risk averse individuals tend to be more likely to undergo testing.  相似文献   
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