换热温差对升温型吸收式热泵回收废热的影响

以升温型溴化锂吸收式热泵系统的传热、传质平衡以及各部件的热力学关系为理论依据,建立一个回收废水热量的稳态数学模型,运用正交实验法,提出了综合考虑系统总换热面积、总循环流量和系统性能系数COP的经济参数F,阐述了系统各参数受各部件换热温差及其相互耦合作用影响的敏感度,分析了各部件换热温差对系统总面积A、总循环流量M、COP及参数F的影响。结果表明：各温差因素的耦合作用相比各温差因素对系统的影响力度要弱很多,可以忽略其作用;当蒸发温差、冷凝温差、吸收温差和发生温差分别取4℃、4℃、9℃和6℃时经济参数F值最大,为0.4515,相应的COP为0.455。     

Tb~(3+)/Ce~(3+)掺杂硼酸盐玻璃的发光性能

采用高温熔融冷却法制备了Tb3+,Ce3+掺杂和Tb3+/Ce3+共掺硼酸盐玻璃,并利用荧光光谱研究了其发光性能。结果表明:在紫外光激发下,Tb3+掺杂玻璃最强发射峰位于545 nm;Ce3+掺杂玻璃的发射光谱是峰值位于387 nm附近的不对称宽带;Tb3+/Ce3+共掺玻璃的发射光谱是由380 nm附近的不对称宽带和491,545,588,623 nm附近的4个发射峰组成;在Tb3+/Ce3+共掺玻璃中,Ce3+是Tb3+的高效敏化剂,Tb3+的发射强度是Tb3+掺杂玻璃的8倍以上。     

基于图像的虚拟光影技术研究热点

 基于图像的虚拟光影技术是直接改变图像场景中物体的光影效果或者估计场景光照，在光影维度对图像进行增强，并保留图像物体的视觉特征。从光影效果迁移、虚实光照融合两个方面盘点了虚拟光影技术的重要研究成果，展望了该领域关键技术的发展趋势。     

同心双扭旋元件内外叶片数量对管内传热性能的影响

为探究同心双扭旋元件组合方式变化对换热管传热特性的影响规律，采用数值模拟方法对雷诺数Re=200~1 800范围内恒壁温条件下的管内传热进行了分析，并进行了实验验证。研究结果表明：在Re=200~1 800的范围内，含有4-4同心双扭旋元件换热管的努赛尔数Nu值最大，其次为3-3同心双扭旋元件，2-4与2-2同心双扭旋元件的Nu相差不大，最大仅相差5%；4-4同心双扭旋元件换热管的阻力系数f最大，其次为3-3同心双扭旋元件，2-4同心双扭旋元件的阻力系数略高于2-2同心双扭旋元件；2-2同心双扭旋元件换热管的综合传热性能评价因子（PEC）值最大，为1.50，且明显高于其他3种换热管，其余3种换热管的PEC值相差不大；4-4同心双扭旋元件换热管的场协同数F_c值最大，其余3种换热管的F_c值相差不大。     

生态退杨对洞庭湖湿地景观格局变化影响研究

对比“生态退杨”政策实施前后洞庭湖湿地景观格局变化，综合分析洞庭湖区景观格局总体变化特征，为洞庭湖的景观格局优化提供科学依据。     

Flow and heat transfer behaviour of nanofluids in microchannels

Flow and heat transfer of aqueous based silica and alumina nanofluids in microchannels were experimentally investigated. The measured friction factors were higher than conventional model predictions at low Reynolds numbers particularly with high nanoparticle concentrations. A decrease in the friction factor was observed with increasing Reynolds number, possibly due to the augmentation of nanoparticle aggregate shape arising from fluid shear and alteration of local nanoparticle concentration and nanofluid viscosity. Augmentation of the silica nanoparticle morphology by fluid shear may also have affected the friction factor due to possible formation of a core/shell structure of the particles. Measured thermal conductivities of the silica nanofluids were in approximate agreement with the Maxwell-Crosser model, whereas the alumina nanofluids only showed slight enhancements. Enhanced convective heat transfer was observed for both nanofluids, relative to their base fluids (water), at low particle concentrations. Heat transfer enhancement increased with increasing Reynolds number and microchannel hydraulic diameter. However, the majority of experiments showed a larger increase in pumping power requirements relative to heat transfer enhancements, which may hinder the industrial uptake of the nanofluids, particularly in confined environments, such as Micro Electro-Mechanical Systems (MEMS).     

The landing zone – Ground for model transfer in chemistry

This essay proposes a new notion - the landing zone - in order to identify conceptual features that allow modelers to transfer mathematical tools across disciplinary borders. This discussion refers to the transferable models as ‘templates’. Templates are functions, equations, or computational methods that are capable of being generalized from a particular subject matter. There are formal and conceptual prerequisites for the transfer of a template to a new domain. A landing zone is an ontology that contributes to the satisfaction of these conditions for successful transfer. This paper presents a case study on a model in chemistry - the Quantum Theory of Atoms in Molecules (QTAIM) - that makes use of transferred templates from physics - the virial theorem and the wave function. The landing zone in this case is a new ontological notion, that of the topological atom, which prepares ground for the use of the virial theorem and the wave function in chemistry. The virial theorem requires that there exists in-principle stability to the system that it represents, and the wave function requires transformation in its representation that is justified. The ontology of QTAIM - the landing zone for these templates - grounds the scientific use of these templates in the context of chemistry.     

定-转子反应器在水脱氧工艺中的应用研究

在定-转子反应器中采用N₂-水脱氧、CO₂-水脱氧两个体系脱除水中的溶氧，考察了转子转速、液体体积流量以及气体体积流量对脱氧率和传质系数的影响，并对比了两个水脱氧体系的脱氧效果。实验结果表明：脱氧率随转子转速和气体体积流量的增加而升高，随液体体积流量的增加而降低；传质系数随着转子转速、液体体积流量、气体体积流量的增加而增加；此外，N₂-水脱氧体系的脱氧效果要优于CO₂-水脱氧体系。     

西部地区产业转移背景下高校毕业生就业路径选择研究——以陕西省为例

在当前西部地区产业转移的背景下,结合西部地区区域特点和"互联网+"发展的时代特征,通过分析近些年陕西省高校毕业生就业的基本情况,产生一个基本判断,即西部地区高校毕业生就业的路径选择应是逐步向非公、中小微型企业流动,特别是东部向西部转移的产业类的小企业中流动.为印证这一判断,本文运用马克思的有机构成理论和凯恩斯的有效需求理论对这一就业途径进行深入分析,并运用实证的方式加以验证和后续预测,明确该途径确实符合当前实际,应是缓解当前高校毕业生就业的重要途径.而在这一路径选择下,本文从承载适合西部发展的东部转移产业、夯实西部新区发展实现承载、以互联网金融等创新融资方式缓解中小微企业资金压力,同时承载地政府应积极履行责任,帮助转移企业的落地升级,并扶持青年创业等角度提出建议.