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1.
Learning curves have recently been widely adopted in climate-economy models to incorporate endogenous change of energy technologies, replacing the conventional assumption of an autonomous energy efficiency improvement. However, there has been little consideration of the credibility of the learning curve. The current trend that many important energy and climate change policy analyses rely on the learning curve means that it is of great importance to critically examine the basis for learning curves. Here, we analyse the use of learning curves in energy technology, usually implemented as a simple power function. We find that the learning curve cannot separate the effects of price and technological change, cannot reflect continuous and qualitative change of both conventional and emerging energy technologies, cannot help to determine the time paths of technological investment, and misses the central role of R&D activity in driving technological change. We argue that a logistic curve of improving performance modified to include R&D activity as a driving variable can better describe the cost reductions in energy technologies. Furthermore, we demonstrate that the top-down Leontief technology can incorporate the bottom-up technologies that improve along either the learning curve or the logistic curve, through changing input-output coefficients. An application to UK wind power illustrates that the logistic curve fits the observed data better and implies greater potential for cost reduction than the learning curve does.  相似文献   
2.
在熔体直纺环吹风冷却工艺路线上,使用“—”型喷丝板,设置缓和的冷却条件,适当的无风区高度,纺丝温度及纺丝速度,开发生产50D/144F扁平丝。  相似文献   
3.
Capital, corporate income taxes, and catastrophe insurance   总被引:2,自引:0,他引:2  
We provide estimates of the equity capital needed and the resulting tax costs incurred when supplying catastrophe insurance/reinsurance using a partial equilibrium model that incorporates a specific loss distribution for US catastrophe losses. After consideration of insurer investment in tax-exempt securities, tax loss carry-back/forward provisions, and personal taxes, our results imply that the tax costs of equity finance alone have a substantial effect on the cost of supplying catastrophe reinsurance. These results help explain a variety of industry developments that reduce tax costs. Also, when coupled with non-tax costs of capital, these results help explain the limited scope of catastrophe insurance/reinsurance.  相似文献   
4.
对我国风电发展目标、风电设备国产化及制造产业的发展时机、风电市场培育以及其他事关我国风电发展的相关问题进行了分析和思考,供关注我国风电发展的社会各界参考.  相似文献   
5.
对国内外风力发电的现状进行了总结,然后对国内外风电设备制造业的现状作了详细的分析,指出我国风电设备制造业要想尽快实现大中型风电设备国产化,降低风电电价,就必须准确把握当今风电设备的发展趋势,准确选型,积极购买或引进专利技术,逐步实现固产化,最终形成产品系列自主开发的能力。最后指出了当今风电机组设备的主流和发展趋势,并作了一些比较。  相似文献   
6.
7.
Nepal’s population continues to grow, but the agricultural sector’s performance remains almost stagnant. This has led to a decline in the per capita availability of food. Increasing agricultural productivity is the key to agricultural growth, and one strategy for increasing agricultural productivity is to use improved seeds. This study investigates the impact of contract farming (CF) in high yielding varieties (HYV) of paddy seed production on costs, yield, and profits of smallholder farms in Nepal. Using farm-level data and a non-parametric propensity score matching estimator, the study finds a significant positive impact of contract HYV seed farming on revenues, profits, and yield, and a significant negative impact on total costs of production. Additionally, very small farms (⩽0.43 ha) with CF in HYV paddy seeds tend to gain the most when it comes to yield per hectare. Our estimates reveal that the average smallholder household in Nepal engaged in CF with input conditions receives higher profits. However, farmers engaged in CF with output conditions tend to have higher yields but smaller profits. Finally, farmers engaged in CF in HYV paddy seeds with both input and output conditions have the highest yield gains and significantly higher profits.  相似文献   
8.
In recent years, the traditionally pasture‐based dairy farms in New Zealand have become more intensive by using higher proportions of supplementary feed. This trend has been attributed to a range of factors, such as productivity enhancement, overcoming pasture deficits and the improvement of body condition scores. However, there is a lack of knowledge as to how feed use intensification affects the technical efficiency of dairy farms in New Zealand. This paper addresses the research gap by estimating the impact of feed use intensification on the technical efficiency of New Zealand dairy farms, using a fixed effects stochastic production frontier model and a balanced panel of 257 farms from 2010 to 2013. The empirical results show that technical efficiency on New Zealand dairy farms is positively and significantly influenced by feed use intensification, herd size and milking frequency.  相似文献   
9.
A combined travel cost – contingent behaviour survey of residents and tourists in Catalonia is conducted on-site to examine the effects on beach recreational demand of developing an offshore wind farm (OWF) project. The survey considers four potential OWF scenarios with different degrees of visual impact. We allow for heterogeneity in trip preferences among individuals and control for on-site sampling through the use of a random parameters negative binomial (RPNB) model and a Multivariate Poisson log-normal (MPLN) model, respectively. The welfare measures derived from the RPNB model relate to the current beach users only, whereas those from the MPLN model refer to the general population of residents and tourists in Catalonia. The results show the importance of the specific place of location of the OWF project and how the installation of wind turbines would significantly decrease the demand for trips, depending on their degree of visual impacts, leading to a substantial welfare loss. However, the results also show that the project mainly would cause a displacement of trips to other beaches within Catalonia rather than outside Catalonia and that the welfare per trip measures generated by the RPNB and MPLN models substantially differ. Policy implications of these findings are discussed.  相似文献   
10.
We explore how firms’ operations in Offshore Financial Centers (OFCs) through subsidiaries or affiliates affect the quality of financial reporting. Using a unique and large sample of firms that have headquarters in the 15 countries with the strictest legal regimes and have subsidiaries or affiliates in OFCs, we find that such firms exhibit lower financial reporting quality than comparable firms without OFC operations. We also find that as OFC characteristics become more prevalent, firms are more likely to engage in both accrual‐based and real earnings management. More importantly, after disentangling OFC characteristics into the opportunity for tax avoidance, regulation arbitrage and secrecy policies, we find that beyond tax avoidance, regulation arbitrage and the secrecy policies of OFCs significantly affect financial reporting quality. The causal effect of OFC operations is supported by the analysis of financial reporting quality when firms set up OFC operations. Our findings are robust to various additional tests addressing potential endogeneity issues. We conclude that the assessment of a firm's institutional environment must encompass the registration status of its subsidiaries or affiliates as well as its own.  相似文献   
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