科创中国

系统阐述了数据包络分析(DEA)的基本思想及其改进模型,在此基础上利用所构建的投入产出指标体系实证比较研究了2010年北京市、河南省、吉林省、江西省、山东省、福建省、宁夏回族自治区七大区域的物流效率,结论表明各区域效率由高至低依次为北京市、宁夏回族自治区、山东省、河南省、江西省、福建省、吉林省,其中北京和宁夏属于DEA有效,而这一结果具有较高的一致性与可靠性.

选取我国大陆除西藏以外30个省(自治区、直辖市)作为样本,考虑群众体育财政投入产出时滞性,运用数据包络分析方法的CCR、BCC和 SE-DEA模型对2011年我国地方群众体育财政投入效率进行了分析评价。结果显示:1)我国地方群众体育财政投入效率普遍较低,只有5个省(自治区、直辖市)达到DEA完全有效,全国综合效率的均值只有0.6666;2)效率标准差为0.2650,表明各地区群众体育财政投入效率存在较大的差异;3)从综合效率分解来看,不同地区影响综合效率的原因不同,有的是群众体育财政投入规模的问题,有的是群众体育财政投入管理的问题;4)超效率模型使地区群众体育财政投入效率差异更加明显化,江苏效率值最高。提出不同地区要采取不同群众体育财政投入对策、不断加大群众体育财政投入力度、加强群众体育财政管理、建立健全群众体育财政投入绩效评价等政策建议。

不同行业的创新资源吸引力存在较大差异,同类行业间获取创新资源的比例也不同.为了优化高技术产业的产业结构,要改善不同行业科技创新资源配置效率,实现新增科技创新资源在不同行业间的合理配置.

分别以专利和新产品作为产业创新效率体系的产出以及投入,分两阶段对2001-2010年间的中国专利密集型产业与非专利密集型产业的创新效率体系进行了对比研究.其中,2001-2005年为第一阶段,专利密集型产业专利R&D投入的技术效率要高于非专利密集型产业;2006-2010年为第二阶段,专利密集型产业的经济产出绩效要低于非专利密集型产业,两阶段的不同主要是由于纯技术效率的变化引起的.总的来说,2001-2010年间的综合阶段的整体效率主要由第二阶段的经济产出绩效决定.文末对此现象进行了分析并据此提出了相关政策与建议.

DC-inverter split air-conditioner is widely used in Chinese homes as a result of its high-efficiency and energy-saving. Recently, the researches on its outdoor unit have focused on the influence of surrounding structures upon the aerodynamic and acoustic performance, however they are only limited to the influence of a few parameters on the performance, and practical design of the unit requires more detailed parametric analysis. Three-dimensional computational fluid dynamics(CFD) and computational aerodynamic acoustics(CAA) simulation based on FLUENT solver is used to study the influence of surrounding structures upon the aforementioned properties of the unit. The flow rate and sound pressure level are predicted for different rotating speed, and agree well with the experimental results. The parametric influence of three main surrounding structures(i.e. the heat sink, the bell-mouth type shroud and the outlet grille) upon the aerodynamic performance of the unit is analyzed thoroughly. The results demonstrate that the tip vortex plays a major role in the flow fields near the blade tip and has a great effect on the flow field of the unit. The inlet ring's size and throat's depth of the bell-mouth type shroud, and the through-flow area and configuration of upwind and downwind sections of the outlet grille are the most important factors that affect the aerodynamic performance of the unit. Furthermore, two improved schemes against the existing prototype of the unit are developed, which both can significantly increase the flow rate more than 6 %(i.e. 100 m3·h-1) at given rotating speeds. The inevitable increase of flow noise level when flow rate is increased and the advantage of keeping a lower rotating speed are also discussed. The presented work could be a useful guideline in designing the aerodynamic and acoustic performance of the split air-conditioner in engineering practice.