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51.
基于生产前沿理论的绿色经济增长核算模型,不仅将技术无效率和环境代价纳入了分析框架,而且还与“物质平衡思路”一致;该模型将绿色经济增长的源泉分解为环境约束下的技术进步、技术效率变化和资本深化3大部分.对重庆市27个制造行业的经验分析结论表明:经济增长中普遍存在着技术无效率现象,但50%以上行业的技术效率都得到了改善或维持不变;资本深化是经济增长的主要源泉,而技术进步主导的全要素生产率变动在其中的贡献相对较小;技术进步是引致全要素生产率增长的主要原因.为充分发挥重庆市制造业可持续发展潜力,后续发展中必须转变经济发展方式,在环境约束下走技术进步和技术效率改善的绿色全要素生产率增长之路.  相似文献   
52.
【目的】通过定量方法准确评估农业综合开发对区域优势产业发展的影响有重要意义。【方法】从农业综合开发对蔬菜产业的项目干预效应入手,以县级为单位,将当年农业综合开发项目扶持内容包括蔬菜产业的县级单位划分为干预组,其他为控制组。采用可以有效解决样品选择偏差的倾向得分匹配方法,通过引入协变量、平衡检验、匹配等步骤,在控制组中找到与干预组成员单位特征相似的成员,构建反事实研究框架。【结果】结果得出,项目干预组比控制组区域的蔬菜播种面积占比高出1~3个百分点,说明农业综合开发项目对蔬菜产业的扶持对蔬菜播种面积的扩大有促进作用,利于蔬菜产业壮大。通过协变量影响力分析得出,地区的蔬菜生产优势是最重要的影响因素,从侧面证明了农业综合开发项目的扶持方向紧跟区域优势的政策宗旨。【结论】可见,通过有方向性的农业综合开发项目实施扶持特定产业对促进区域优势产业发展和实现农业结构优化是有效的。  相似文献   
53.
This paper employs matching techniques to investigate the effects of facility export status on environmental performance. Using facility-level criteria air emission data in the US manufacturing industry, we find the industry-specific effects of export status on emission intensity, measured by emissions per value of sale. In some industries, there is consistent and robust evidence supporting the superior environmental performance of exporters relative to non-exporters in terms of emission intensity for all criteria air pollutants tracked. In other industries, we find weak evidence that exporters appear to have a higher emission intensity than non-exporters. This industrial heterogeneity in the effects of exporting on the environment is closely related to industrial characteristics including pollution abatement capital expenditure, trade costs, capital intensity and others.  相似文献   
54.
在广义空间调制(GSM)系统中,最大似然(ML)检测可以取得最优的检测性能,然而其计算复杂度随激活天线数的增加急剧增长。针对这一问题,提出了一种基于稀疏重构理论的低复杂度检测算法——正则化正交匹配追踪(ROMP)算法。该算法首先根据信道矩阵和当前残差的内积选取多个候选激活天线索引,接着对候选天线索引按正则化标准进行可靠性验证,剔除错误索引,缩小信号的搜索空间,最后通过求解最小二乘问题估计信号。仿真结果表明,与经典的正交匹配追踪(OMP)算法相比,所提算法以少许复杂度的增加为代价极大提升了检测性能,能够在检测性能与复杂度之间取得更好的折中。  相似文献   
55.
Research in economic geography has paid increasing attention to regional innovation systems (RISs) as a potential vehicle for growth and development. Yet despite an increasing amount of research studying RISs in particular and economic regions in general, we have limited knowledge about their influence on entrepreneurs and entrepreneurship. We respond to this knowledge gap and study if entrepreneurs’ localization in thick vs. thin RISs affects their innovativeness and growth ambitions. Thick RISs are predominately urbanized spaces that include organizations of higher-level education, R&D intensive milieus, and an ample industry sector, while thin RISs to a lesser degree encompass these features. Empirically, we analyse 870–917 entrepreneurial firms in Agder of Southern Norway. Based on trade and labour markets, as defined by the EU’s classification of local administrative units (LAU1), we identify two thick and six thin RISs in Agder. Econometric analyses show that entrepreneurs located in thick RISs are more innovative than entrepreneurs located in thin RISs, but there are no significant differences concerning entrepreneurs’ growth ambitions. In light of our findings, we discuss the potential agency role played by entrepreneurial firms at a micro level on path dependent features of RISs at a macro level.  相似文献   
56.
This paper analyzes the relationship between local poverty and food manufacturing growth in Chile and Mexico using propensity score matching, differences in differences and spatial econometrics methods. We focus on food manufacturing as a sector with a number of characteristics that make it potentially pro-poor, and whose incentives for spatial distribution may either strengthen or dampen its poverty reduction potential. The overall results indicate growth in food manufacturing employment contributes to local poverty reduction.  相似文献   
57.
战略性新兴产业的发展对国民经济和社会发展具有重要的战略意义,目前中国战略性新兴产业仍面临着“高端产业,低端技术”的发展困境,如何突破产业关键技术促进产业健康、可持续发展已成为亟待解决的问题。战略性新兴产业集群创新网络的形成是突破产业关键技术、共性技术及前瞻性技术的核心环节,中国正在兴起的产业技术研究院、航空高技术产业园等跨组织知识集成平台为培育和发展战略性新兴产业集群创新网络提供了重要的支撑平台。本文依托跨组织知识集成平台探究了战略性新兴产业集群创新网络的形成机制,构建了创新主体间的灰靶双边匹配模型,并采用平衡计分法建立了以创新能力为重要衡量标准的综合评价指标体系,最后通过案例进行了分析,证明了其有效性和实用性,可为促进战略性新兴产业集群创新网络的形成提供理论指导。  相似文献   
58.
Ski areas are known to expand by linking their lifts to neighbouring systems. Based on data from approximately 250 winter sport destinations in Austria, pooled over the years 1998–2014, this study explores the effects of such horizontal collaboration on the number of overnights stays in the area. A difference-in-differences (DID) approach combined with propensity score matching shows that new lift-linkages or expansions lead to a consolidation in the number of overnight stays at a level 12 per cent higher than before the introduction of the lift-link. However, there is a certain degree of heterogeneity in the causal effects. Satellite ski areas, remote villages and those who combine lift-linking with new connecting slopes benefit the most. More recent lift-linkages seem to lead to smaller gains than those established in the early years.  相似文献   
59.
In Maasai culture, responsibilities are traditionally divided between genders. Men are in charge of grazing and managing the livestock herds. Women take care of the family, administer food supplies, and are responsible for milking. For them, balancing home consumption of milk (for the family and for the calves), milk sale, and food purchase is a major task. In this article, we first investigate how different milk sales groups vary regarding the use of different food items and the respective quantities consumed by the enkaji, i.e., a Maasai subhousehold. Then, we address the commercialization decision and assess the effect of milk sales on the enkaji's food item use and food consumption. Using the data of Maasai enkajijik in the milk catchment area of a milk collection center in Ngerengere, Tanzania, we estimate the effects by employing propensity score matching procedures. Our findings suggest that milk sellers, especially those selling to the milk collection center, have a more diverse diet. In terms of per person consumption, the groups are markedly similar. Therefore, we conclude that income generated by milk sales is invested in diet diversification rather than in increasing the quantity of food consumed, hence the enkajijik appear not to make use of caloric terms of trade.  相似文献   
60.
《Applied economics》2012,44(21):2777-2783
We use data from the Cebu Longitudinal Health and Nutrition Survey (CLHNS) in the Philippines to link vaccination in the first 2 years of life with later physical and cognitive development in children. We use propensity score matching to estimate the causal effect of vaccination on child development. We find no effect of vaccination on later height or weight, but full childhood vaccination for measles, polio, Tuberculosis (TB), Diphtheria, Pertussis and Tetanus (DPT) significantly increases cognitive test scores relative to matched children who received no vaccinations. The size of the effect is large, raising test scores, on average, by about half an SD.  相似文献   
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