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关键词： Anthraquinones/chemistry   Cadmium/chemistry   Models, Molecular   Molecular Structure   Nanoparticles/chemistry   Quantum Dots   Quantum Dots   Selenium/chemistry   Tellurium/chemistry   Tellurium/chemistry  

摘要： The size dependence of optical and electronic properties of semiconductor quantum dots (QDs) have been extensively studied in various applications ranging from solar energy conversion to biological imaging. Core/shell QDs allow further tuning of these properties by controlling the spatial distributions of the conduction-band electron and valence-band hole wave functions through the choice of the core/shell materials and their size/thickness. It is possible to engineer type H core/shell QDs, such as CdTe/CdSe, in which the lowest energy conduction-band electron is largely localized in the shell while the lowest energy valence-band hole is localized in the Core. This spatial distribution enables ultrafast electron transfer to the surface-adsorbed electron acceptors due to enhanced electron density on the shell materials, while simultaneously retarding the charge recombination process because the shell acts as a tunneling barrier for the core localized hole. Using ultrafast transient absorption spectroscopy, we show that in CdTe/CdSe-anthraquinone (AQ) complexes, after the initial ultrafast (similar to 770 fs) intra-QD electron transfer from the CdTe core to the CdSe shell, the shell-localized electron is transferred to the adsorbed AQ with a half-life of 2.7 ps. The subsequent charge recombination from the reduced acceptor, AQ(-), to the hole in the CdTe core has a half-life of 92 ns. Compared to CdSe-AQ complexes, the type II band alignment in CdTe/CdSe QDs maintains similar ultrafast charge separation while retarding the charge recombination by 100-fold. This unique ultrafast charge separation and slow recombination property, coupled with longer single and multiple exciton lifetimes in type II QDs, suggests that they are ideal light-harvesting materials for solar energy conversion.

关键词： HOME hemodialysis   HOME care services   MEDICAL care cost control  

摘要： A scheme allowing patients to receive dialysis at home, saving an NHS hospital hundreds of thousands of pounds a year, has won top prize in a national innovation award. [ABSTRACT FROM AUTHOR]

关键词： 教学改革   化工原理   生物分离工程   应用  

摘要： 阐述了化工原理在《生物分离工程》课程中的地位.基于化工原理在《生物分离工程》课程中的重要性,探讨了化工原理在《生物分离工程》课程备课、讲课、组织学生课堂演讲等教学环节中应用的具体思路与做法.并通过教学实践,探索了一些有益的经验,提出了进一步提高教学质量的改进措施.

关键词： 扩建工程   拆除验算   原位重建   基础利用  

摘要： 沪宁高速公路扩建工程中上跨主线的分离式立交桥都因跨度不够而需拆除改建,改建中必须保证在沪宁高速公路和被交路通车的前提条件下进行,因此上跨的分离式立交桥的改扩建方案将直接影响到各公路的通行,是扩建工程中的重点、难点工程.本文就杨家圩分离式立交桥的拆除、改建方案进行论述,同时对原桥桩基础利用、加强方案及新老桩基础的协同受力等展开讨论.

关键词： 水利工程   实行   管养分离   探讨  

摘要： 从政策依据、运行规则和有利于水利工程运行管理三个方面阐述了实行水利工程管养分离的必要性,提出了实行水利工程管养分离的形式和保障措施,用以指导水管单位实行管养分离工作。

关键词： 精品课程   分离工程   课程建设   工程实践  

摘要： 在分离工程省级精品课程的建设与应用实践中,围绕分离工程精品课程的教学思想与理念,我校构建了科学的课程体系,建设了一流师资队伍,以实验中心建设为依托,现代化教学手段为工具,培养了学生解决实际工程问题的能力,提高了教学质量。

关键词： 多媒体教学   分离工程   教学方法  

摘要： 本文简述了多媒体在本科生课堂教学中的作用及存在的问题,结合分离工程课的特点和本校分离工程教学团队的教学经验,以及笔者在德国高校的教学观摩体会,从板书篇幅设计、课件内容选择、教学节奏控制和屏幕位置设置等方面提出了四点建议。

关键词： 分离工程   传质分离   分离科学   论文集   KT   会费   信息交流   参与者  

摘要： In this special issue,23 papers are selected from over a hundred of domestic and foreign contributions to the 4th National Conference on Mass Transfer and Separation Engineering (NCMS2011), which will be held on 18th -21 st of November 2011 in Tianjin.

关键词： Chinese sturgeon   Spawning habitat   Separation Levee Project   Hydrodynamic model   Weighted usable area   Yangtze River  

摘要： Chinese sturgeon (Acipenser sinensis) is a protected anadromous fish species. The migration pattern of the fish has been blocked by the construction of Gezhouba Dam, reducing the natural spawning site length to less than 7 km along the Yangtze River. However, the fish has since established an alternative spawning ground in the narrow reach downstream of Gezhouba Dam. To enhance navigation, a Separation Levee Project (SLP) was implemented in the new-found spawning habitat of the fish. To therefore evaluate the effect of the SLP on Chinese sturgeon spawning habitat suitability, the conditions in the spawning habitat were simulated using River2D (a two-dimensional hydrodynamic model). Two main approaches (habitat kinetic energy and circulation metrics) were used in the simulation. The study showed that SLP only slightly changed the physical conditions in the spawning habitat. Using hydrodynamic simulation, the weighted usable area (WUA) before and after the SLP construction was also computed and habitat preference curve developed for water depth and velocity. On the average, SLP reduced WUA-a finding that was consistent with field-measured data. Based on WUA, the habitat conditions were more sensitive to SLP proximity than metrics based on velocity gradients. SLP posed detrimental impacts on the suitability of spawning habitats of Chinese sturgeon. The findings in this study provide further basis for the protection and restoration of Chinese sturgeon spawning habitats in especially the lower reach of Yangtze River.

关键词： 气液平衡   教学效果   分离工程  

摘要： 根据化工分离工程的课程特点及教学中存在的问题,采用课程小论文和编程大作业并与课堂理论教学相结合的教学方法,强化学生对汽液分离过程的理解,提高了化工分离工程教学质量和教学效果。几年的教学实践表明学生对计算机、数学等公共基础知识与化工专业知识间的交叉渗透的认识加深了,对学习基础知识重要性的认识提高了。