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1.
High fertilizer price volatility makes production planning and inventory management difficult, so accurate fertilizer price forecasts would be beneficial. This article evaluates commercial forecasts for urea and diammonium phosphate (DAP) prices based on forecast accuracy and optimal forecast properties. Most forecasts pass the tests, but forecasts for the US New Orleans urea and the US Gulf DAP markets, in particular, do not and thus show potential to be improved.  相似文献   
2.
[目的]过量施用化肥导致水体富营养化是造成洱海流域上游面源污染的主要原因之一,调查分析农户减少化肥用量和采用有机肥的意愿有助于了解其调整施肥结构的行为。当前研究忽视了农户减少化肥施用强度和采用有机肥的意愿间的替代性,未能开展联立研究。[方法]基于洱海流域上游397个水稻种植户的问卷调查数据,通过Bivariate-Probit模型对农户减少化肥用量和采用有机肥两种意愿进行分析。[结果]年龄负向影响农户减少化肥量的意愿,农户对有机肥好处的认知正向影响其减少化肥量的意愿,农户参加农业社会化服务对其减少化肥用量和采用有机肥的意愿均产生正向影响,相比之下,对农户采用有机肥意愿的促进作用更大。[结论]引导农户参加农业社会化服务以及加强宣传和培训,提高农户对有机肥作用的认知可能是加强其减少化肥用量和增加有机肥施用量意愿的有效途径。  相似文献   
3.
This study analyses the economics of conservation tillage (CT) with respect to its effect on maize yield and chemical fertiliser, herbicide, and female and male labour demand. We estimate production and input demand functions using seemingly unrelated regressions on plot‐level cross‐sectional farm household data collected in the north‐west of Ethiopia. A two‐step control function is applied to address potential endogeneity bias due to the inclusion of the CT adoption decision as an explanatory variable. Our results show that CT increases maize yield and chemical fertiliser demand. Additionally, the results show that the adoption of CT reduces female and male labour required for crop production. However, this is achieved through the increased use of herbicides, which might have an undesirable health and environmental effects.  相似文献   
4.
ABSTRACT

A key question for promoting international competition is how to improve the position of countries and industries in global value chains (GVCs). The first step is to properly measure industrial upgrading in GVCs. This is not a trivial issue because upgrading has not been defined unambiguously. Several authors have used different (and sometimes related) measures, all of which indicate certain aspects of upgrading. Rather than trying to find the single, ultimate measure of upgrading, we propose a different approach. We examine the multidimensionality of industrial upgrading, using eight indicators in factor analysis. Four of the eight indicators adopt the GVC perspective and include, for example, the growth of the share in value-added exports. We provide three quantitative dimensions of industrial upgrading: process upgrading, product upgrading, and skill upgrading. With these dimensions, we compare and analyze the upgrading of different countries and industries using the World Input–Output Database.  相似文献   
5.
Recent empirical assessments revealed that footprint indicators calculated with various multi-regional input–output (MRIO) databases deliver deviating results. In this paper, we propose a new method, called structural production layer decomposition (SPLD), which complements existing structural decomposition approaches. SPLD enables differentiating between effects stemming from specific parts in the technology matrix, e.g. trade blocks vs. domestic blocks, while still allowing to link the various effects to the total region footprint. Using the carbon footprint of the EU-28 in 2011 as an example, we analyse the differences between EXIOBASE, Eora, GTAP and WIOD. Identical environmental data are used across all MRIO databases. In all model comparisons, variations in domestic blocks have a more significant impact on the carbon footprint than variations in trade blocks. The results provide a wealth of information for MRIO developers and are relevant for policy makers designing climate policy measures targeted to specific stages along product supply chains.  相似文献   
6.
This article uses China’s input–output (I-O) tables in 2002, 2007, and 2012 to estimate the real energy consumption of each sector after the I-O adjustment. The relationship between the sectors is further analyzed using the utility analysis method based on ecological network analysis. The empirical results show that although the traditional energy-intensive industries are the major energy-consuming sectors from a direct energy consumption perspective, large energy consumption by energy-intensive industries is transferred to downstream industries through intermediate products after the I-O adjustment. Specifically, the building industry and service sector are the sectors with the highest real energy consumption. With the upgrading and optimization of the industrial structure, the proportion of energy-intensive sectors in China is declining. However, the development of the service sector and infrastructure construction still requires large intermediate inputs. Thus, industrial restructuring cannot significantly reduce China’s total energy consumption.  相似文献   
7.
[目的]生物菌肥对于土壤改良、环境改善、食品安全具有重要意义,但目前生物菌肥在整个肥料产业中所占份额较小,迫切需要探讨如何从农户角度提高生物菌肥的施用比例。[方法]基于设施蔬菜农户的数据,构建Bivariate Probit模型,对农户生物菌肥的购买意愿和行为的影响因素进行比较研究。[结果]农户的生物菌肥购买意愿和行为总体上呈现一致性,愿意购买的农户中有97. 77%的农户具有实际的购买行为;但两者的影响因素有所差异,从差异因素来看,质量安全检测对购买意愿具有显著的正向影响,但对购买行为的影响并不显著;农户文化程度、种植年限、对无公害、绿色、有机蔬菜的了解程度,经销商推荐,施肥指导对购买行为具有显著的正向影响。从共同因素来看,生态环境认知变量对购买意愿和购买行为影响不显著。[结论]要推广生物菌肥,需要进一步加强质量安全检测体系对农业行为的约束性,提升经销商的规范经营意识,采用集中招标等灵活的价格政策,提升农户的生态技能,并在保护生态环境方面出台更完善的农业绿色发展政策。  相似文献   
8.
ABSTRACT

We propose a new approach for tracing the so-called ‘value-added-(re)distribution-important coefficients’ (in short the VARDI coefficients) in a world input–output model. From the perspective of a selected group of economies, VARDI coefficients may be defined as those elements in world input–output matrix in the case of which a small change in their levels leads to the maximization of a share of this group of economies in value added in global value chains. Due to the rapid development of the World Input Output Database, this approach may be easily applied in empirical research to different groups of countries and sectors in world IO models. In an illustrative empirical case study, we use the new approach in order to answer a question regarding what the main directions of the future macroeconomic policy of the U.S. could be in order to ensure the maximization of the country’s share in global value added.  相似文献   
9.
[目的]我国粳稻产量现阶段呈连续增长的态势,然而粳稻生产效率却存在无效率或波动剧烈的现象,研究我国的粳稻生产效率,有助于提升和稳定中国粳稻区域生产效率和水平从而间接保障我国粮食安全。[方法]使用超效率DEA方法测算中国13个粳稻生产省份的生产效率,分别从时间和区域上的差异进行分析。[结果]中国粳稻生产技术效率在时间趋势上逐渐趋于平稳,但是在2004—2007年间存在短暂的波动;在区域上主要是西南和东北粳稻生产区的技术效率水平较高,西北区在技术效率、纯技术效率与规模效率上都处于较低的水平;虽然河南、湖北、宁夏3个省份出现技术无效率,但规模报酬都处于递增的状态,仍有提升生产效率的潜力,应通过减少要素投入冗余来改变其无效率状态。[结论]粳稻生产技术无效率主要是由于种子费用、农药费用等生产要素的投入冗余造成的;若将来在保持纯技术效率和其他条件不变的情况下,通过提升规模效率水平会进一步提升我国粳稻的整体技术效率水平。基于上述分析有针对性地提出制定粳稻生产区域规划、发展适度规模经营、改善生产要素使用效率3方面的政策建议。  相似文献   
10.
利用手工收集的政府审计公告数据,以2013—2017年的国有上市公司为样本,采用PSM+DID方法检验政府审计对国有上市公司创新活动的影响,并进一步根据内部控制质量和是否存在内部控制缺陷对样本进行分组检验两者之间的关系。研究结果表明:政府审计显著增加了国有上市公司的创新投入和创新产出;在内部控制质量高和不存在内部控制缺陷的样本企业中,政府审计对企业创新活动的促进作用更加显著。  相似文献   
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