Highly Efficient Three Primary Color Organic Single‐Crystal Light‐Emitting Devices with Balanced Carrier Injection and Transport

Organic single crystals have a great potential in the field of organic optoelectronics because of their advantages of high carrier mobility and high thermal stability. However, the application of the organic single crystals in light‐emitting devices (OLEDs) has been limited by single‐layered structure with unbalanced carrier injection and transport. Here, fabrication of a multilayered‐structure crystal‐based OLED constitutes a major step toward balanced carrier injection and transport by introducing an anodic buffer layer and electron transport layer into the device structure. Three primary color single‐crystal‐based OLEDs based on the multilayered structure and molecular doping exhibit a maximum luminance and current efficiency of 820 cd cm^?2 and 0.9 cd A^?1, respectively, which are the highest performance to date for organic single‐crystal‐based OLEDs. This work paves the way toward high‐performance organic optoelectronic devices based on the organic single crystals.     

Zn‐MOF‐74 Derived N‐Doped Mesoporous Carbon as pH‐Universal Electrocatalyst for Oxygen Reduction Reaction

It is of increasing importance to explore new low‐cost and high‐activity electrocatalysts for oxygen reduction reaction (ORR), which have had a substantial impact across a diverse range of energy conversion system, including various fuel cell and metal–air batteries. Although engineering carbon nanostructures have been widely explored as a candidate class of Pt‐based ORR electrocatalysts owing to their proved high activity, outstanding stability, and ease of use, there still remains a daunting challenge to develop high activity metal‐free electrocatalysts in pH‐universal electrolyte system. Here, a reliable and controllable route amenable to prepare nitrogen‐doped porous carbon (NPC) with high yields and exceptional quality is described. The as‐prepared NPC shows advantages of high activity, high durability, and methanol‐tolerant as an efficient pH‐universal electrocatalyst for ORR, showing comparable or even better activity as compared with the commercial Pt/C catalysts not only in alkaline media but also in acidic and neutral electrolyte. Systematic electrochemical studies, combining with density functional theory calculation, demonstrate the unique nitrogen‐doping species and favorable pores in the as‐designed NPC synergistically contribute to the significantly improved catalytic activity in pH‐universal medium. The present work potentially presents an important breakthrough in developing ORR electrocatalysts for various fuel cells.     

糖厂蒸发工序凝结水直接串罐排除的初步探讨

本文主要从工艺设计的角度介绍糖厂蒸发工序采用凝结水直接串罐排除的工艺。作者着重阐述了该工艺的特点以及设计所必须注意的问题,并将这种工艺的经济效益和蒸汽利用等方面与自蒸发器进行了比较,指出,该工艺具有实用性,而且已在一些新设计的糖厂中投入使用。     

A new N-type doping precursor for MOCVD-IMP growth of detector quality MCT

A new indium precursor, triisopropyl indium (TIPIn), has been used for doping MCT at low carrier concentrations. Previous attempts using indium organometallics resulted in a strong memory effect where residual doping would persist for many growth runs. Introducing TIPIn on the tellurium inject line resulted in a similarly strong memory doping but this was not observed when feeding the dopant in on the cadmium injection line. The TIPIn is believed to have been forming a low volatility adduct with diisopropyl tellurium (DIPTe) in the feed line and to have continued to evaporate at a low but significant rate. By keeping the TIPIn and DIPTe precursors separate until they entered the reactor, the desired low 10¹⁵ cm⁻³ carrier concentration and flat indium profiles could be achieved with good reproducibility. Good electrical characteristics were measured for these layers with Auger limited lifetime >1 μs at 77K.     

核爆炸信号参数化方法及其应用

本文提出了一种经过改进的瞬态信号参数化方法并讨论了这种方法在核爆炸探测领城内的应用。重点阐述了信号建模及参数提取的计算方法,最后给出了本方法在核爆炸识别中的典型实例及计算机仿真结果。     

Link set sizing for networks supporting SMDS

To size networks that support switched multimegabit data service (SMDS), one must determine how much additional capacity is needed and where it is needed so as to minimize the total capacity augmentation cost. Two combinatorial optimization problem formulations are considered and compared for their relative applicability and complexity. A solution procedure based on Lagrangean relaxation is proposed for one of the formulations. In computational experiments, the proposed algorithm determines solutions that are within a few percent of an optimal solution in minutes of CPU time for networks with 10-26 nodes. The proposed algorithm is compared with a most congested first (MCF) heuristic. For the test networks, it achieves up to 152% improvement in the total cost over the MCF heuristic     

A transconductance spectroscopy approach to device level surfacestate characterization

A device level transconductance spectroscopy approach is developed for characterizing surface states in metal-semiconductor field-effect transistors. A comparison of the theoretical results and the available experimental observations shows that the model can successfully explain both the surface leakage current dependence of transconductance dispersion magnitude reported by M. Ozeki et al. (1982) and the temperature dependence of transconductance dispersion observed by S.R. Blight et al. (1986)     

10吉比特长途DWDM系统工程设计中关键问题的探讨

本文从色散、色散斜率、光信噪比和可升级性等方面论述了10Gbit/s长途DWDM系统工程设计应该关注的问题.     

无线通信智能天线技术的未来发展趋势

介绍了智能天线收发机结构的最新进展及其优点,探讨了无线通信智能天线技术的未来发展趋势以及所面临的问题.     

UMTS无线接口系统的规划和优化

针对无线接口讨论了UMTS系统规划和优化所面临的问题以及相应的解决方案,介绍了WCDMA的空中接口,提出了系统规划的方案,包括覆盖、容量、频率和码子的规划,最后讨论了WCDMA网络性能优化和监测的关键指标。