Coherent Phonon-Induced Modulation of Charge Transfer in 2D Hybrid Perovskites

Electron–phonon interactions play an essential role in charge transport and transfer processes in semiconductors. For most structures, tailoring electron–phonon interactions for specific functionality remains elusive. Here, it is shown that, in hybrid perovskites, coherent phonon modes can be used to manipulate charge transfer. In the 2D double perovskite, (AE2T)₂AgBiI₈ (AE2T: 5,5“-diylbis(amino-ethyl)-(2,2”-(2)thiophene)), the valence band maximum derived from the [Ag_0.5Bi_0.5I₄]^2– framework lies in close proximity to the AE2T-derived HOMO level, thereby forming a type-II heterostructure. During transient absorption spectroscopy, pulsed excitation creates sustained coherent phonon modes, which periodically modulate the associated electronic levels. Thus, the energy offset at the organic–inorganic interface also oscillates periodically, providing a unique opportunity for modulation of interfacial charge transfer. Density-functional theory corroborates the mechanism and identifies specific phonon modes as likely drivers of the coherent charge transfer. These observations are a striking example of how electron–phonon interactions can be used to manipulate fundamentally important charge and energy transfer processes in hybrid perovskites.     

基于Ad hoc网络的联合有效用户识别与信道安全编译码方法

Ad hoc网络是一种无中心的自组织网络,由于用户能量受限当信噪比较低时有效用户识别的可靠性和信道安全性下降.该文针对这个问题提出一种联合有效用户识别与信道安全编译码方法.将发送用户的正交地址码与接收用户的伪随机地址码异或产生基于发送用户与接收用户的有效用户识别码.为提高信道安全性以信道安全码作为密钥加密有效用户识别码得到正交随机安全序列.为实现扩频并提高传输效率将发送数据以6 bit信息作为一个符号进行分组,将每个符号与一个正交随机安全序列对应.接收用户采用基于子空间的方法处理接收信号,通过建立判决模型识别有效用户.实验结果表明该方法与已有方法相比,当有效用户识别的漏警概率为10–3时信噪比增益改善1.6 dB.     

基于BP神经网络的电网安全性预警系统研发

对紧急情况下的电力系统做到快速预警且提供相应的应急预案,是一个急需解决的重要课题。从电力系统防灾容灾预警机制出发,针对电网故障的时空分布特性,采用BP神经网络对其安全隐患进行识别,构建了基于季节气候、地形地貌及自然灾害等影响电力系统安全状态的预警系统,并通过吉林电网常见故障对该系统的实用性进行了有效验证。     

A software wrapping approach based on resource access rules and behavior interception

在分析软件系统接口框架体系和软件资源访问接口特征之后,给出了一个通用资源定义模型及其描述语言和一个资源访问规则映射机制及其描述语言.在此基础之上,提出了一种面向二进制的基于资源访问抽象描述和软件行为截获的黑盒遗留软件封装方法,而且设计并实现了一个自动软件封装器原型TinyWrapper.对该方法在典型的软件重用场景中的作用进行了评估,结果表明,方法可以成功处理场景中的所有复用需求,同时验证了该方法的有效性,证明了该方法容易部署且对改造后的遗留软件产生的负载低.     

地铁车辆-轨道耦合振动响应分析及轨道结构参数优化

针对在建杭州地铁3号线下穿某文教区工程,根据车辆-轨道耦合动力学理论,分别建立车辆-普通整体道床轨道耦合动力学模型和车辆-钢弹簧浮置板轨道耦合动力学模型.基于赫兹非线性接触关系,实现轮轨间的力平衡和位移协调.利用有限元软件ABAQUS,对两种轨道结构模型的动力响应进行计算,研究轮轨耦合动力相互作用机理和轨道振动源强特性...     

管道瓦斯监测系统应用开发

结合集团公司的信息化实际情况,可采用有效的技术手段对各工作面及某区域钻孔、钻场进行有效的连续的瓦斯抽采参数的准确计量,实现对井下各监测点管道瓦斯浓度、流量、压力、温度参数的在线监测;实现历史曲线及报表的查询、打印功能,进而准确把握抽采进度,及时进行准确调整。     

动能拦截导弹弹道数据计算研究

动能拦截弹脱靶量要求为零,其杀伤目标为近地轨道运行的弹道导弹和低轨卫星等,目标运行速度极快,与其它类型导弹相比,动能拦截弹的弹道计算精度要求更高。针对这一问题,介绍了动能拦截弹的拦截段弹道数学模型,分析了弹道数据计算流程,将诸元解算转化为方位角和程序角的计算问题,采用计算精度较高的积分算法,得到了导弹拦截过程的弹道数据,仿真表明,导弹数据计算精度满足作战仿真要求。     

A new ship energy management algorithm to the smart electricity grid system

In this paper, a new energy management algorithm has been suggested for the ships connected with alternative energies considering the smart electricity grid features. The algorithm focuses on the use of optimum energy source on the shipboard based on the priorities of authorities such as the most economic, environmental, or both criteria at the ports. The algorithm is performed in MATLAB, and several case studies are simulated to validate the results. The 5 maritime nations, which are at different regions: United States, Belgium, Turkey, China, and Australia, are taken into account in the case studies. The actual data of a bulk carrier ship have been used to achieve tangible results in the simulations. The results of the case studies are compared to determine the changes of energy cost and released emission to meet demand of electricity on the ships. Capital cost of the proposed concept is also given to make an economic evaluation. The results show that the ship energy management algorithm provides the significant economic and environmental advantages. This paper aims to contribute to the importance of the ships in the smart electricity grid concept for the maritime and electricity sector representatives.