摘要：Thermophotovoltaic (TPV) system has been regarded as one promising means to alleviate current energy demand because it can directly generate electricity from radiation heat via photons. However, the presently available TPV systems suffer from low conversion efficiency and low throughput. A viable solution to increase their efficiency is to apply micro/nanoscale radiation principles in the design of different components to utilize the characteristics of thermal radiation at small distances and in microstructures. Several critical issues are reviewed, such as photovoltaic effect, quantum efficiency and efficiency of TPV system. Emphasis is given to the development of wavelength-selective emitters and filters and the aspects of micro/nanoscale heat transfer. Recent progress, along with the challenges and opportunities for future development of TPV systems are also outlined.

摘要：In this paper, the problems of chaos and chaos control for a class of susceptible-infected-removed (SIR) epidemic model with seasonal fluctuation are investigated. The seasonality in outbreak is natural among infectious diseases, as the common influenza, A type H1N1 influenza and so on. It is shown that there exist chaotic phenomena in the epidemic model. Furthermore, the tracking control method is used to control chaotic motions in the epidemic model. A feedback controller is designed to achieve tracking of an ideal output. Thus, the density of infected individuals can converge to zero, in other words, the disease can be disappeared. Finally, numerical simulations illustrate that the controller is effective.

摘要：This work investigates the machining temperatures of ultra-fine-grained titanium(UFG Ti),prepared by equal channel angular extrusion,through analytical *** Ti has great usefulness in biomedical applications because of its high mechanical strength,sufficient manufacturability,and high *** temperatures were predicted using a physics-based predictive model based on material constitutive relation and mechanics of the orthogonal cutting *** minimization between the stress calculated using Johnson–Cook constitutive model and the same stress calculated using mechanics model yields the estimation of machining temperatures at two deformation *** agreements are observed upon validation to the values reported in the *** machinability of UFG Ti is investigated by comparing its machining temperature to that of Ti–6Al–4V alloy under the same cutting *** lower temperatures are observed in machining UFG *** computational efficiency of the presented model is investigated by comparing its average computational time(~0.5 s)to that of a widely used modified chip formation model(8900 s)with comparable prediction *** work extends the applicability of the presented temperature model to a broader class of materials,specifically ultra-fine-grained *** high computational efficiency allows the in situ temperature prediction and optimization of temperature condition with process parameters planning.

摘要：任何东西(近海风汽轮机) 当前被看作可更新的精力的可靠来源。为首都的 20%-25% 的任何东西支持结构报道花费了为近海风安装。包含风汽轮机结构的初步的尺寸的评价的可行性前研究需要为到达工程的商业生存能力的起始的花费被表现。论文的主要目的是为商业生存能力并且基础堆积的近似缩放获得初步的配置。设计方程和诺模图被建议因为 monopile 的快初步的设计成立了 Gujarat 近海的定位的风汽轮机。参量的研究在由改变水深度和沙的性质的空 monopile 的各种各样的配置上是带外面的。基础的非线性的静态的分析被执行考虑空气动力学的力量和水动力学力量为各种各样结构并且土壤参数。风汽轮机的基础设计基于 API (美国石油研究所) 标准。为在装载状况的极端下面的 monopile 支持结构的简化设计方法论基于 multivariable 被介绍线性回归分析。为回归分析的输入变量是水动力学数据，沙的内部磨擦的角度，和输出变量是长度和 monopile 的外部直径。这简化方法论是适用的在风力量公园预先学习。

摘要：设计了具有高Flory-Huggins相互作用参数的嵌段共聚物聚(对叔丁基苯乙烯)-b-聚(甲基丙烯酸羟乙酯)(PtBS-b-PHEMA),并分别采用阴离子聚合和原子转移自由基聚合(ATRP)方式制备了不同嵌段比例、不同分子量的窄分子量分布的该嵌段共聚物。利用核磁共振分析了嵌段共聚物的组分,利用小角X射线散射(SAXS)分析了嵌段共聚物相分离后的尺寸及结构,对比研究了两种聚合方式对嵌段共聚物性能的影响。结果表明,采用阴离子聚合方式得到的嵌段共聚物分子量分布更窄,相同分子量下发生微相分离的尺寸更小,其在150℃真空烘箱中加热18h后可以形成尺寸为9.96nm的柱状相及8.42nm的层状相。

摘要：随着全球教育背景的快速变化,国家对中高职教育人才的要求也越来越高,但是中职教育到高职教育的顺利衔接还存在着诸多不尽如人意的地方。本文试图借鉴美国经验为我国在中高职衔接问题上的解决提供有益的帮助并提出一种基于工作过程的中高职课程衔接体系设计。

摘要：喷杆喷雾机具有作业效率高、雾滴覆盖率高、沉积分布均匀、防治效果好等优点,是目前大田作物最主要的施药机具。但受作物冠层遮挡和侧风等气象条件的影响,导致喷杆喷雾机作业时雾滴难以穿透到植株中下部并伴随飘失。为改善喷杆喷雾机喷雾雾滴在作物冠层的穿透性并降低飘移量,本文优化设计了一种适用于大田作物的喷杆喷雾机冠层推拨装置。并分别使用两种喷头(标准扇形雾喷头ST110-02、射流喷头IDK120-02)对该装置的减飘性和在小麦上的沉积特性进行了对比试验。结果表明:该冠层推拨装置对标准扇形雾喷头ST110-02的减飘效果强于射流喷头IDK120-02,其减飘效果分别为59.0%和9.5%;冠层推拨装置可以提高药液的沉积率,对于ST110-02喷头可增加18.0%,IDK120-02喷头增加了8.6%;同时该推拨装置对小麦植株的推拨作用增加了雾滴向冠层中下方的穿透效果,有利于药液在植株上的均匀沉积。