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101.
We consider the problem of estimating the scale parameter of an exponential or a gamma distribution under squared error loss when the scale parameter θ is known to be greater than some fixed value θ0. Natural estimators in this setting include truncated linear functions of the sufficient statistic. Such estimators are typically inadmissible, but explicit improvements seem difficult to find. Some are presented here. A particularly interesting finding is that estimators which are admissible in the untruncated problem which take values only in the interior of the truncated parameter space are found to be inadmissible for the truncated problem.  相似文献   
102.
This article interweaves the ideas of sustainable development, sustainable societies, and the power of advanced information technologies toward developing recommendations for social science research on information technology in society. Worldwide concern has arisen over the potentially catastrophic consequences of global climate and environmental change. As a result, sustainable development (i.e., the simultaneous protection of both the global environment and the global economy) is receiving considerable attention. Necessary for achieving sustainable development are sustainable societies, which are capable of designing, implementing, managing and evaluating long-term environmental programs. This article presents ten characteristics that describe sustainable societies and discusses how information technologies, from wireless personal digital assistants to intelligent agents to multi-media database systems, could support the evolution of sustainable societies. Topics for social science research related to designing and ameliorating the negative consequences of eight hypothetical computer-based systems are presented. Bruce E. Tonn is leader of the policy systems analysis group at Oak Ridge National Laboratory and co-principal investigator of the National Center for Environmental Decision-making Research. His research interests include environmental and energy policy, computers in society, decision making, and futures studies. He is past president of the Social Science Computing Association. His research focuses on planning, assessment and evaluation, energy use and conservation, and education.  相似文献   
103.
A review of the Leslie matrix model theory and its literature 1941-1987 is presented. The point of view is that of a mathematician who focuses on the parts of the theory which are relevant to demography. Works of a decidedly applied nature are not dealt with.  相似文献   
104.
This paper is concerned with sequences of policies that occur over time in voting models and planning procedures. The framework for our analysis includes assumptions that are satisfied by models in the corresponding literatures, together with other standard assumptions for microeconomic analysis that involve time. The starting point for our analyses is the prespective that results from combining the following (widely held) views: 1) certain voting models and planning procedures can be interpreted as being non-tatonnement or sequential processes (where each policy in the sequence that is generated is actually experienced by voters or consumers) and 2) an alternative being Pareto optimal in any given period (temporal Pareto optimality) is the appropriate efficiency criterion only if the alternative is the final outcome from a tatonnement process-and that, otherwise, one should examine the efficiency of the entire path (using intertemporal Pareto optimality). Our first observation about the planning literature is that is has (by and large) neglected the efficiency criterion that is appropriate for the discrete-time procedures that can be interpreted as non-tatonnement or sequential processes-and that, what's more, such trajectories will (in general) fail to meet this criterion. Our second observation identifies some results that can be used to establish that some of these trajectories will at least be ultimately intertemporally Pareto optimal. In our discussion of voting theory, we review Buchanan's opposition to requiring (social) choice consistency for voting procedures-and his argument for this position on (Pareto) efficiency grounds. We then consider voting procedures that can be interpreted as non-tatonnement or sequential processes and arrive at the conclusion that, in these cases, (i) majority rule cycles are intertemporally Pareto inefficient and (ii) achieving intertemporal Pareto optimality requires choice consistency. We then go on to show that related observations apply to Kramer's normative conclusions about his dynamical model of political equilibrium — and identify some further references where similar observations apply. In the final part of our discussion of voting models, we arrive at the further conclusion that, in the most relevant cases, a trajectory that stays in the temporal Pareto set is not necessarily more desirable (on efficiency grounds) than one that doesn't.This paper has been improved by helpful comments and suggestions that have been provided by Kenneth Arrow, an anonymous referee, and the editor who handled the paper.Peter Coughlin gratefully acknowledges financial support provided by (i) National Science Foundation Grant No. SES-8409352, and (ii) the Center for Advanced Study in the Behavioral Sciences at Stanford (with support from National Science Foundation Grant No. BNS-8700864 and the Alfred P. Sloan Foundation).  相似文献   
105.
In a six-year study on a locked psychiatric hospital unit for adolescents, first patients and then their families became integrated into the interdisciplinary treatment team. The results were universally beneficial. After initial resistance and some fine tuning of their skills, the staff became strong supporters of the program. Parents, no longer one down, developed a close working relationship with the therapists and milieu staff. Treatment planning and implementation was enriched by the interaction and dissension was minimized. Most important of all, the adolescents improved more rapidly and hospital stays were significantly shortened.  相似文献   
106.
"Net undercount rates in the U.S. decennial census have been steadily declining over the last several censuses. Differential undercounts among race groups and geographic areas, however, appear to persist. In the following, we examine and compare several methodologies for providing small area estimates of census coverage by constructing artificial populations. Measures of performance are also introduced to assess the various small area estimates. Synthetic estimation in combination with regression modelling provide the best results over the methods considered. Sampling error effects are also simulated. The results form the basis for determining coverage evaluation survey small area estimates of the 1900 decennial census."  相似文献   
107.
"This article revises the Coale-Trussell method for analyzing data from the World Fertility Survey by proposing and testing alternative log-linear and log-multiplicative models. The models, in one form or another, represent the structural constraint underlying the Coale-Trussell method on the variation in the age pattern of human fertility. With a Poisson distribution assumption for the number of births, several parameters of the models are simultaneously estimated via maximum likelihood. It is shown that the new approach can be adopted whenever fertility limitation is compared across multiple populations or subpopulations."  相似文献   
108.
This research note briefly outlines International Labour Organization concerns about return migration in developing countries, research being done in the field, and activities in related fields. Attention is being focused on the following topics and areas of study: 1) recommendations and conventions which cover workers generally and migrant workers particularly; 2) measures to avoid the departure of skilled workers from developing countries; 3) special problems encountered in improving migrant professionals' working conditions; 4) developing a central pool of information on labor markets and employment at the international level; 5) bilateral or multilateral migration agreements to optimize the flows of health personnel, scientific workers, engineers, and high level technicians, protecting their rights, and facilitating their reintegration into the country of origin; 6) creating a compensation scheme for skill outflows and training substitutes to fill the gaps left behind by migration; 7) classifying migratory policies adopted by developing countries; 8) reattraction of needed skills to developing countries of origin; 9) transfer of know-how through expatriate nationals; 10) labor reinsertion patterns of migrants returning to Greece, Italy, Portugal, and Spain; 11) Socioeconomic reintegration of migrants returning to Pakistan and Uruguay; and 12) Sri Lanka's experience with self-employment schemes for returned migrants.  相似文献   
109.
The author analyzes international migration patterns of Caribbean populations, with particular attention to the persistence of significant return flows. A typology of migration in the region is presented, which includes categories of transients or shuttle migrants and settlers or long-stay migrants. Skill or occupational changes, principal remittances, and migration objectives of each group are summarized. The social, economic, and policy implications of international circulation in the Caribbean are considered. (SUMMARY IN FRE AND SPA)  相似文献   
110.
Puerto Rican migration to the US has been a more or less continuous process since 1917. The perspective of viewing return migration as a circulation process suggests that there are entries, exits, and reintergration into the metropolitan labor market. This study explores the circulatory movements of Puerto Rican families, events that influence the adaptation process when returning to Puerto Rico, and cultural identity aspects. Data collected by means of 2 research instruments that were administered to the respondents simultaneously were used: 1) a life history matrix and 2) an open-ended questionnaire. These interviews outlined the principal problems of adaptation as mentioned by the circulating migrants. The most difficult problems to adjust to were economic and employment (58%), followed by social acceptance (23%), education (17%), and language (15%). Transportation, medical services, and recreational facilities were also problems mentioned as being significant. It is expected that a great majority of migrant laborers will go to live in immigrant residential locations in large US cities. It is also expected that these migrants will meet with certain value conflicts by living in urban ghettos. These families will have serious difficulties finding economic stability and will possibly consider migrating once again as an alternative to their social reality. This study illustrates that: 1) the migrants return in family groups; 2) they face discriminatory problems in employment agencies and schools; 3) they look forward to a formal education as a means of social mobility; 4) they identify themselves with values, habits, and Puerto Rican traditions; and 5) they value the quality of life in Puerto Rico.  相似文献   
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