Efficient ternary polymer solar cells by optimizing photogenerated exciton dissociation and photon harvesting with a short wavelength absorption polymer acceptor as the third component

Ternary blend films, obtained by introducing a third component (a second acceptor as the third component) to a binary polymer solar cell (PSC), are a promising ternary strategy because the light absorption range, surface morphology, and charge carrier transport of the photoactive layer may be optimized, as can the energy level alignment between the donor and the acceptor. In this work, acceptors such as the short-wavelength-absorption polymer N2200 and the long-wavelength-absorption small molecule FOIC were combined with the donor PBDB-T-2F to construct ternary blends. The optimized ternary PSC could achieve a power conversion efficiency (PCE) of 13.98%, which is higher than the efficiencies of binary PSCs based on PBDB-T-2F:FOIC (12.65%) and PBDB-T-2F:N2200 (9.36%). The enhanced PCE of the ternary PSC is based on the high electron mobility, balanced charge transport, optimized surface morphology and charge carrier kinetics and the extended light absorption of the ternary photoactive layer, realized by adjusting the ratio of FOIC:N2200. Our results indicate that mixing a polymer acceptor into a binary photoactive layer to form a ternary blend photoactive layer is a valuable strategy for improving photovoltaic performance.     

IP/MPLS网络与GMPLS网络互联的研究

文章研究了网际协议／多协议标签交换（IP／MPLS）网络升级为通用多协议标签交换（GMPLS）网络的过程中存在的几种演进模型，并重点分析了岛式模型。同时，还分析了MPLS网络和GMPLS网络互联时存在的问题、两种协议问的差异以及解决这些问题所采用的路由、信令和通道计算技术。     

Pilot self-coding applied in optical OFDM systems

This paper studies the frequency offset correction technique which can be applied in optical OFDM systems. Through theoretical analysis and computer simulations, we can observe that our proposed scheme named pilot self-coding (PSC) has a distinct influence for rectifying the frequency offset, which could mitigate the OFDM performance deterioration because of inter-carrier interference and common phase error. The main approach is to assign a pilot subcarrier before data subcarriers and copy this subcarrier sequence to the symmetric side. The simulation results verify that our proposed PSC is indeed effective against the high degree of frequency offset.     

在5ESS交换机上实现SCCP动态负荷分担

首先介绍了福州各PSC交换端局之间信令链路的负荷情况;接着在分析小灵通组网结构的基础上比较了解决各PSC间信令链路过负荷问题的几种方法;然后着重介绍了虚拟信令点编码的原理及其在5ESS交换机上实现的方法。     

Thermodynamic modeling of partially stratified charge engine characteristics for hydrogen-methane blends at ultra-lean conditions

A thermodynamic model considering flame propagation is presented to predict SI engine characteristics for hydrogen-methane blends. The partially charge stratification approach which involves micro direct injection of pure fuel or a fuel–air mixture, to create a rich zone near the spark plug, is proposed as a method to improve engine performance. Presented approach was validated with experimental data for the natural gas at lean condition. The model was generalized to predict the performance of engine for a variety of hydrogen contents in hydrogen-methane blends. Hydrogen molar concentrations of 0%, 15%, 30%, and 45% were used in the simulations. Results showed that partially charge stratification improves engine performance by increasing indicated mean effective pressure and decreasing specific fuel consumption. The results indicated that increasing mole fraction of hydrogen content would improve the PSC effect on engine performance. An advantage of the presented model is the flexibility and simplicity that make it possible to investigate several effects such as mixture distribution and fuel constituents on engine performance more practical than other types of simulation.     

我国PPP项目前期决策体系的改进和完善

随着中国的城市化改革持续推进,公众对基础设施项目的需求不断增长,越来越多的项目采用PPP模式提供基础设施和公共服务。但是,我国目前的项目前期决策体系还不够完善,造成有些PPP项目的决策出现问题,进而造成实施结果不理想。针对我国PPP模式应用现状,通过专家访谈,并借鉴英国、澳大利亚、中国香港和南非等国家和地区的实践经验,引入VFM评价体系和PSC计算方法对我国PPP项目的前期决策体系提出改进和完善建议,希望能为我国合理有效地推广PPP模式提供参考。     

基于贡献度分层的主动配电网供电能力评估

主动配电系统（active distribution system,ADS）的供电能力（power supply capacity,PSC）受配电网络的拓扑结构、元件故障、负荷水平及分布式能源资源出力波动性等诸多不确定性因素的影响。为快速评估中长期配电网的供电能力,首先从影响中长期供电能力的因素入手,对分布式电源（distributed energy resource,DER）、负荷出力进行了不确定性建模,采用贡献度分层抽样算法进行抽样,得到具有代表性的样本,对于元件运行的不确定性,基于线路重要度进行网络不确定性建模;其次,定义了适用于中长期供电能力评估的指标;最后,采用改进的IEEE 14节点算例进行验证,通过与传统蒙特卡洛法的对比证明本文所提模型及算法的正确性和有效性。     

一种混合型模块化多电平换流器的改进载波移相调制方法

混合型模块化多电平换流器(MMC)桥臂中既包含半桥子模块,又包含全桥子模块,原有载波移相调制方法并不适用。文中在分析子模块混合型MMC拓扑结构工作原理及其调制方法的基础上,提出了一种适用于混合型MMC且带电容电压均衡策略的改进载波移相调制方法。在PSCAD/EMTDC中搭建了详细仿真模型,仿真结果证明了该调制策略的有效性。     

高压力下聚酰亚胺薄膜热激电流的研究

由于压力参数的引入可以在热激电流（TSC）测量中获得更多实用信息，故自行设计了高压力下测量TSC装置，并且用该装置测量了聚酰亚胺（PI）薄膜在不同压力下的TSC谱和恒温下降低压力时的压激电流（PSC）说，结果表明：在相同条件下极化的样品，随着压力的增加，其热激电流峰移向高温，压力因素显著地影响聚酰亚胺薄膜的松驰参数。     

基于部分采样点辅助校正OFDM信号的准无损压缩算法

传统的正交频分复用(Orthogonal frequency division multiplexing,OFDM)信号压缩算法由于低的压缩比和低的信号量化误差比(Signal to quantization-error ratio,SQR)造成较高的误码率,无法满足OFDM系统的需求。为了实现高的压缩比和低的误码率,提出了一种联合削峰尾插(Clipping with tail plug,CTP)技术、几何级数压扩(Geometric series companding,GSC)技术及部分采样点校正(Partial sample calibration,PSC)技术的准无损压缩算法。计算机仿真结果表明,对于4096-正交幅度调制(Quadrature amplitude modulation,QAM)的OFDM信号,压缩比最高可达1.86∶1,误码率低于10-7,量化误差对应的平均SQR高达70 dB,因而能够很好地满足光纤到分配点+千兆数字用户线路(Fiber to the distribution point+GCga digital subscriber line,FTTdp+GDSL)系统的需求。