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61.
We evaluate the effect of a 2003 reform in the Spanish income tax on fertility and the employment of mothers with small children. The reform introduced a tax credit for working mothers with children under the age of three, while also increasing child deductions for all households with children. Theoretically, given the interplay of these two components, the expected effect of the reform is ambiguous on both outcomes. We find that the combined reforms significantly increased both fertility (by almost 5%) and the employment rate of mothers with children under three (by 2%). These effects were more pronounced among less-educated women. In addition, to disentangle the impact of the two reform components, we use an earlier reform that increased child deductions in 1999. We find that the child deductions affect mothers' employment negatively, which implies that the 2003 tax credit would have increased employment even more (up to 5%) in the absence of the change in child deductions.  相似文献   
62.
Energy supply and demand, and as a consequence energy prices, are likely to represent one of the biggest challenges of the 21st century. Commodity markets exhibit increased volatility when there is little or no underutilized supply capability to meet natural fluctuations in demand. In the case of energy markets, the large capital requirements and significant lead times associated with energy production and delivery make them more susceptible to the imbalances in supply capability and demand. Energy price volatility has destructive impact on market agents, and this impact is intensified when the prices exhibit asymmetric volatility. This article pursues two aspects of the issue. First we consider general aspects, especially the asymmetric pattern of volatility of daily returns of different types of energy products. Then, we analyze the behaviour of daily returns by using traditional models of volatility that include AGARCH, TGARCH, EGARCH, and ARSV strategies, as well as a threshold asymmetric autoregressive stochastic volatility (TA-ARSV) model that we propose. The energy products considered in this analysis are probably the most relevant energy products for the economic activity of the nations and the economic relations between countries: Crude Oil (OPEC reference basket and London Brent index), Gasoline, Natural Gas, Butane, and Propane. We use spot prices and the time reference ranges from 1986–1993 to 2009 depending on the product.  相似文献   
63.
The persistent uncertainty that looms over the search for solutions to health problems offers important conceptual insights for the study of technological change. This paper explores the notion of hybridization, namely the embodiment of multiple competing operational principles within a single medical device, as strategy to deal with the practical shortcomings due to said uncertainty. The history of the development of the hybrid artificial disc affords the elaboration of an alternative view of hybridization and, at the same time, the articulation of a dualism between medical science as area of basic research (e.g. what disease is) and as practical knowledge (e.g. how disease can be tackled).  相似文献   
64.
Ordered data arise naturally in many fields of statistical practice. Often some sample values are unknown or disregarded due to various reasons. On the basis of some sample quantiles from the Rayleigh distribution, the problems of estimating the Rayleigh parameter, hazard rate and reliability function, and predicting future observations are addressed using a Bayesian perspective. The construction of β-content and β-expectation Bayes tolerance limits is also tackled. Under squared-error loss, Bayes estimators and predictors are deduced analytically. Exact tolerance limits are derived by solving simple nonlinear equations. Highest posterior density estimators and credibility intervals, as well as Bayes estimators and predictors under linear loss, can easily be computed iteratively.  相似文献   
65.
This paper analyzes the main determinants influencing environmental innovators (i.e. firms developing or adopting environmental innovations) in Spain with respect to non‐environmental innovators. Similarly to other contributions in the literature, our results show that Spanish environmental innovators respond to regulatory stimulus in the form of demand‐pull and technology‐push instruments. They have a high internal technological capability and combine internal and external information sources, mostly in cooperation with knowledge institutions. Environmental innovators are more concentrated in mature, traditionally highly polluting sectors, but new firms are not more environmentally innovative than incumbents. Most importantly, in contrast to other environmental innovation studies, mostly carried out in a German context, we have not found evidence of a market pull from either the domestic or international markets. Furthermore, cost savings are not found to be a distinctive driver for environmental innovators. These differential results are possibly related to the special features of Spain regarding its national innovation system and the degree of stringency of environmental regulation and environmental consciousness of its consumers. Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment.  相似文献   
66.
Quality & Quantity - The content of this article is a paper about a complex mathematical model of terrain passability which respects geographical and meteorological conditions in terrain and...  相似文献   
67.
A Fuzzy clustering approach to the key sectors of the Spanish economy   总被引:1,自引:0,他引:1  
The search for key sectors in an economy has been and still is one of the more recurrent themes in input–output analysis. When using clustering techniques, sectors can only belong to a group, having a particular performance. But, actually, the same sector could be important from different perspectives at the same time, to a different degree. So, a fuzzy clustering approach is needed. In this work we propose a multidimensional approach to classify the productive sectors of the Spanish input–output table for 1995, based on three groups of variables: those related to their productive integration, others measuring their specific weight in the economy and finally some showing their economic dynamic. We also incorporate into the analysis the technological level, which being a categorical variable presents special methodological problems. All these questions are tackled applying a robust and fuzzy clustering analysis, which gives as a result a classification of sectors illustrating the role that each one plays in the Spanish economy.  相似文献   
68.
Climate change governance is increasingly being conducted through urban climate change experiments, purposive interventions that seek to reconfigure urban sociotechnical systems to achieve low‐carbon and resilient cities. In examining how experiments take effect, we suggest that we need to understand not only how they are made and assembled, but also how they are maintained within specific urban contexts. Drawing on literatures from urban political ecology and the specific debate on urban repair and maintenance, this article examines maintenance in two case studies of climate change experiments in housing in Bangalore (India) and Monterrey (Mexico). We find that maintenance is a crucial process through which not only urban obduracy is preserved, but also the novel and innovative character of the experiment is asserted and reproduced. The process of ‘maintaining’ experiments is a precarious one, which requires a continuous external input in terms of remaking the experiment materially and discursively. This process causes further reconfigurations beyond the experiment, changing the patterns of responsibility attribution and acceptability that configure the urban fabric.  相似文献   
69.
70.
Empirical research has recently paid considerable attention to the role of environmental factors in explaining regional variations in entrepreneurial activity. However, cognitive models have not usually included these factors in their analyses. Therefore, the main objective of this study is to identify some of the environmental cognitive elements that may explain regional differences in start-up intentions. Thus, an entrepreneurial intention model is developed, theoretically based on the planned behaviour approach, institutional economic theory and social capital theory. The empirical analysis is carried out using structural equation techniques over a sample of 549 final year university students from two Spanish regions (Catalonia and Andalusia). Results confirm that valuation of entrepreneurship in each region helps explain regional differences in entrepreneurial intentions. As expected, social valuation of the entrepreneur was higher in the more developed region (Catalonia), positively affecting perceived subjective norms and behavioural control. In Andalusia, the influence of perceived valuation of the entrepreneur in the closer environment was more important, affecting attitude towards the behaviour and subjective norms. These results explain some of the differences in the pool of potential entrepreneurs in each region. They also justify the need by public-policy decision-makers to promote more positive entrepreneurial values in relatively backward regions.  相似文献   
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