TD-SCDMA覆盖与容量规划分析

作为中国自主研发3G标准,TD-SCDMA倍受瞩目,其优质无线网规需求亦提上日程。基于TD-SCDMA系统所赋予的技术特色,就无线网覆盖规划方面的部分关键参数如干扰余量、处理增益、智能天线赋形增益及业务Eb/N0等值的选取及相应的覆盖能力与WCDMA系统进行对比解析,同时对容量设计方法予以探讨,并以实例结果列出,其思路及结果可供实际商用网设计参考。     

有线电视双向网络设计和回传调试

较详细阐述了有线电视双向网络光节点的设置,电缆干线网、用户分配网的设计等问题,最后介绍了回传调试的有关操作事宜。     

A highly luminescent organic crystal with the well-balanced charge transport property: The role of cyano-substitution in the terminal phenyl unit of distyrylbenzene

1,4-bis(2-cyano styryl)benzene (2-CSB) crystal with cyano substituent groups introduced to the terminal phenyl rings of distyrylbenzene (DSB) has been prepared and its luminescence efficiency could be as high as ∼55%. Based on the analyses of cyclic voltammetry and crystal structure, cyano substituents not only lower the LUMO level but also result in a change of the packing mode from the herringbone arrangement to the face-to-face slipped π stacking motif. Then field-effect transistors (FETs) based on high-quality 2-CSB crystals grown by the physical vapor transport method have been fabricated and the highest hole and electron mobilities were measured as 0.66 and 0.29 cm²/Vs, which enhanced the corresponding values of DSB crystal by up to one and two orders of magnitude, respectively. 2-CSB crystal simultaneously combined the high luminescence and the well-balanced mobility is expected to be of interest for the fundamental research of organic light-emitting devices.     

Smart Hybrids of Zn2GeO4 Nanoparticles and Ultrathin g‐C3N4 Layers: Synergistic Lithium Storage and Excellent Electrochemical Performance

Smart hybrids of Zn₂GeO₄ nanoparticles and ultrathin g‐C₃N₄ layers (Zn₂GeO₄/g‐C₃N₄ hybrids) are realized by a facile solution approach, where g‐C₃N₄ layers act as an effective substrate for the nucleation and subsequent in situ growth of Zn₂GeO₄ nanoparticles. A synergistic effect is demonstrated on the two building blocks of Zn₂GeO₄/g‐C₃N₄ hybrids for lithium storage: Zn₂GeO₄ nanoparticles contribute high capacity and serve as spacers to isolate the ultrathin g‐C₃N₄ layers from restacking, resulting in expanded interlayer and exposed vacancies with doubly bonded nitrogen for extra Li‐ion storage and diffusion pathway; 2D g‐C₃N₄ layers, in turn, minimize the strain of particles expansion and prevent the formation of unstable solid electrolyte interphase, leading to highly reversible lithium storage. Benefiting from the remarkable synergy, the Zn₂GeO₄/g‐C₃N₄ hybrids exhibit highly reversible capacity of 1370 mA h g^?1 at 200 mA g^?1 after 140 cycles and excellent rate capability of 950 mA h g^?1 at 2000 mA g^?1. The synergistic effect originating from the hybrids brings out excellent electrochemical performance, and thus casts new light on the development of high‐energy and high‐power anode materials.     

谐波电流与谐波阻抗的估算——工业与建筑电气系统谐波问题之二

本文介绍了电气设备发射的谐波电流大小以及与设备的哪些参数有关和如何估算大小，指明了近代出现电压型谐波源的谐波量更大，比较分析了单相负载中有不同的谐波源时，如何估算中性线电流IN的大小，简单介绍了谐波阻抗计算的难点所在。     

SDN中基于KMOBPSO的高可靠性控制器部署算法

针对SDN中控制器系统的单节点故障问题,兼顾系统成本和系统时延,应用N+1冗余备份模型来提高SDN控制器部署的可靠性,并将其抽象为多目标优化问题.同时,提出了一种融合K-means聚类算法和遗传算子的多目标二进制粒子群算法——KMOBPSO算法,以求解SDN控制器高可靠性部署问题的解.仿真结果表明,所提算法具有求解精度高、分布均匀、沿Pareto前沿面覆盖广的特点,能够显著提高SDN中控制器部署的可靠性.     

基于组件对象模型的上位机—PLC串行通讯程序设计

通过应用COM技术及对三菱公司FX-2N系列PLC串行通讯协议的分析,建立了用于微机-FX-2NPLC控制器的自动化服务程序的实用模型,并且完成了和上位机用户程序的集成,通过实际的运行测试,成功地对PLC中的参数进行监控和改写。     

Incorporating Graphitic Carbon Nitride (g‐C3N4) Quantum Dots into Bulk‐Heterojunction Polymer Solar Cells Leads to Efficiency Enhancement

Graphitic carbon nitride (g‐C₃N₄) has been commonly used as photocatalyst with promising applications in visible‐light photocatalytic water‐splitting. Rare studies are reported in applying g‐C₃N₄ in polymer solar cells. Here g‐C₃N₄ is applied in bulk heterojunction (BHJ) polymer solar cells (PSCs) for the first time by doping solution‐processable g‐C₃N₄ quantum dots (C₃N₄ QDs) in the active layer, leading to a dramatic efficiency enhancement. Upon C₃N₄ QDs doping, power conversion efficiencies (PCEs) of the inverted BHJ‐PSC devices based on different active layers including poly(3‐hexylthiophene‐2,5‐diyl):[6,6]‐phenyl‐C61‐butyric acid methyl ester (P3HT:PC₆₁BM), poly(4,8‐bis‐alkyloxybenzo(l,2‐b:4,5‐b′)dithiophene‐2,6‐diylalt‐(alkyl thieno(3,4‐b)thiophene‐2‐carboxylate)‐2,6‐diyl):[6,6]‐phenyl C₇₁‐butyric acid methyl ester (PBDTTT‐C:PC₇₁BM), and poly[4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b:4,5‐b′]dithiophene‐co‐3‐fluorothieno [3,4‐b]thiophene‐2‐carboxylate] (PTB7‐Th):PC₇₁BM reach 4.23%, 6.36%, and 9.18%, which are enhanced by ≈17.5%, 11.6%, and 11.8%, respectively, compared to that of the reference (undoped) devices. The PCE enhancement of the C₃N₄ QDs doped BHJ‐PSC device is found to be primarily attributed to the increase of short‐circuit current (J_sc), and this is confirmed by external quantum efficiency (EQE) measurements. The effects of C₃N₄ QDs on the surface morphology, optical absorption and photoluminescence (PL) properties of the active layer film as well as the charge transport property of the device are investigated, revealing that the efficiency enhancement of the BHJ‐PSC devices upon C₃N₄ QDs doping is due to the conjunct effects including the improved interfacial contact between the active layer and the hole transport layer due to the increase of the roughness of the active layer film, the facilitated photoinduced electron transfer from the conducting polymer donor to fullerene acceptor, the improved conductivity of the active layer, and the improved charge (hole and electron) transport.     

GaP：（N）的背景光谱和发光尖峰

获得高分辨ＧａＰ（Ｎ）光致发光光谱，观察到等电子陷陆束缚激子发光中ＬＯ和ｌｏｃ多声子发射，其强度分布答合泊松分布。将声子伴带区分为直接光跃迁和间接光跃迁，并进行了相应讨论，还观察到局域声子效应－－光谱相似定律和相当显著的背景光谱。