基于萤火虫烯醇式氧化荧光素的一系列衍生物的结构和光学性质

通过密度泛函理论(DFT)MPW3PBE泛函,对甲基、甲氧基、氰基、氟原子、氨基、硝基取代的萤火虫生物发光底物烯醇式氧化荧光素进行了全优化。计算了他们的电离能(IP)、电子亲和势(EA)、空穴抽取能(HEP)、电子抽取能(EEP)、空穴和电子重组能(λ),评估了它们的空穴和电子传输能力。用含时密度泛函理论(TDDFT)MPW3PBE/6-31+G(d)方法计算了吸收光谱,优化了最低单重态S1,最终研究了它们的荧光光谱。理论计算结果表明,E-CN是具有双重功能的OLEDs材料的优良候选者,即可同时作为电子传输层和发光层材料。E-NO2、E-F和E-OCH3可以作为电子传输材料。而E-NH2可作为空穴传输材料。     

两种池沸腾强化换热管的传热性能实验研究

对两种用于池沸腾换热的强化管在蒸发温度为5℃的工况下进行了水平管外传热性能的实验研究.两种管子为管内外双侧强化管,管外表面同属于TURBO-B类的强化换热管,但表面形状有区别.利用威尔逊图解法确定这两种管型的管内外换热系数的关联式,同时,根据实验测得的数据对这两种管型的换热性能进行比较.结合金相显微镜拍摄的外观形状,分析尺寸结构对强化换热管的换热性能的影响.结果得出:在相同工况下,准三角形形状的管内螺纹换热性能要比梯形好,且管内螺纹数越多,换热性能越好;在一定热流密度范围内,管外换热系数随着热流密度的增加而变大,这主要与管子外表面结构的凹穴半径、凹穴开口尺寸、次级表面通道的宽度和形状等因素有关,且翅顶表面刻画的浅槽有利于池沸腾换热.     

非晶硅薄膜晶体管的泄漏电流模型

当对a-Si:H TFT施加较大的漏-栅电压时,其泄漏电流主要取决于空穴在漏端耗尽区内的产生过程以及被有源层内中立陷阱捕获的过程.基于价带空穴和被陷阱所捕获空穴的一维连续性方程,推导出空穴在有源层内纵向传导的逃逸率.通过描述漏端耗尽区内空穴的产生率以及在a-Sic H层内空穴传导的逃逸率,建立了a-Si:H TFT的泄漏电流模型,并进行了相应验证.     

具有复合空穴传输层的高效低压有机电致发光器件

报道了用m-MTDATA掺杂NPB作复合空穴传输层(c-HTL)的高效率、低电压有机电致发光器件(OLED),器件的最高发光效率达到了5.3cd/A,比NPB作HTL的器件(3.4cd/A)提高了约50%.这是由于c-HTL具有较低的空穴迁移率,改善了发光层中两种载流子的平衡,从而提高了器件性能.进一步在ITO与c-H...     

Transport Layer Optimization for Cloud Computing Applications via Satellite： TCP Noordwijk＋

Cloud computing can significantly improve efficiency in Internet utilization and data management.Several cloud applications（file sharing,backup,data up/download etc.） imply transfers of large amount of data without real-time requirements.In several use-cases cloud-computing solutions reduce operational costs and guarantee target QoS.These solutions become critical when satellite systems are utilized,since resources are limited,network latency is huge and bandwidth costs are high.Using satellite capacity for cloud-computing bulk traffic,keeping acceptable performance of interactive applications,is very important and can limit the connectivity costs.This goal can be achieved installing in the Set Top Box（STB） a proxy agent,to differentiate traffic and assign bandwidth according to priority,leaving spare capacity to bulk cloud computing traffic.This aim is typically reached using a specific QoS architecture,adding functional blocks at network or lower layers.We propose to manage such a process at transport layer only.The endpoint proxy implements a new transport protocol called TCP Noordwijk＋,introducing a flow control differentiation capability.The proxy includes TPCN＋ which efficiently transfers low-priority bulk data and handles interactive data,keeping a high degree of friendliness.The outcomes of Ns-2simulations confirm applicability and good performance of the proposed solution.     

Explicit Rate Based Transmission Control Scheme in Vehicle-to-lnfrastructure Communication Networks

In Vehicle-to-Infrastructure （V2I） communication networks, mobile users are able to access Internet services, such as video stre- aming, digital map downloading, database acc- ess, online gaming, and even safety services like accident alarm, traffic condition broadcast, etc., through fixed roadside units. However, the dynamics of communication environment and frequent changing topology critically challe- nge the design of an efficient transport layer protocol, which makes it difficult to guarantee diverse Quality of Service （QoS） requirements for various applications. In this paper, we pre- sent a novel transport layer scheme in infra- structure based vehicular networks, and aim to resolve some challenging issues such as sou- rce transfer rate adjustment, congestion avoid- ance, and fairness. By precisely detecting pac- ket losses and identifying various causes of th- ese losses （for example, link disconnection, cha- nnel error, packet collision, buffer overflow）, the proposed scheme adopts different reacting mechanisms to deal with each of the losses. Moreover, it timely monitors the buffer size of the bottleneck Road-Side Unit （RSU）, and dyn- amically makes transfer rate feedbacks to sou- rce nodes to avoid buffer overflow or vacancy. Finally, analysis and simulation results show that the proposed scheme not only successfully reduces packet losses because of buffer over- flow and link disconnection but also improves the utilization efficiency of channel resource.     

染料敏化纳米薄膜太阳能电池的研究进展

本文简要地介绍了染料敏化纳米薄膜太阳能电池的结构和原理；对其中关键问题，如纳米TiO2膜、敏化染料、空穴传输材料的研究进展进行了综述。     

滑动轴承油膜空穴压力理论确定研究

采用基于质量守恒边界条件的不可压缩流体空穴算法对稳态工况下滑动轴承进行理论计算,并将计算结果与已有实验结果比较,发现空穴压力的取值对计算结果有影响.通过分析比较,发现其中蕴涵的规律,得到理论倒推确定空穴压力值的方法,为今后理论确定空穴压力提供了研究方向.