基于效用的机会网络缓存替换策略

机会网络具有节点流动性较大、数据时延长、资源有限等特点,如何合理和高效地使用节点提供的缓存资源、增加节点间的协作来减少机会网络时延、节省带宽、防止拥塞是一个关键问题.通过对机会网络缓存策略研究,提出了基于效用的概率缓存替换策略,该策略分别计算数据的流行度和最短机会路径的权重,得出节点的效用值,通过比较效用值确定了节点要缓存的数据.实验结果表明提高了节点获取资源的成功率并减少了协作缓存资源请求的平均响应时间.     

基于Android平台的变电站智能巡检系统

针对目前人工抄写变电站巡检信息效率低下、可靠性不高和采集到的数据不易于统计和分析的问题,依据国家电网公司的相关标准及规范,以广泛使用的Android平板电脑为载体,利用无线通讯技术、XML解析技术和二维码扫描技术等先进技术开发了基于Android 平台的变电站智能巡检系统;论述了系统的总体结构设计和功能设计,详细阐述了各模块的功能,给出了实现各模块的功能使用到的关键技术;据此完成了变电站智能巡检系统的编码,变电站智能巡检系统具有完整的巡检功能,运行稳定可靠,实现了智能移动巡检,对提高变电站巡检质量,保障电力设施的安全性和供电可靠性有促进作用;该系统已在四川省绵阳市电网试点应用,验证了系统的实用性和可靠性。     

Structural Probing on the Sn-C_(C5 ring) Bond of the Sn(Ⅱ) Metallocenes in Both the Solid State and the Temperature-dependent Solution Relaxation State

Various bond modes of the M-C_(C5 ring) exist in metallocene compounds of group 14 heavier elements,mostly due to an intricate interaction between the lone electron pairs at the M center and the 6 p-electrons of the C_5 ring.The tin(Ⅱ) metallocene complexes LSn R(L = HC[CMe(N-2,6-iPr_2C_6H_3)]_2,R = cyclopentadienyl,C_5H_5(1); indenyl,C_9H_7(2); fluorenyl,C_(13)H_9(3)) stabilized by the β-diketiminato ligand were prepared and utilized in the study on their solid and solution state structures.X-ray single-crystal diffraction data revealed an η~1-mode of the Sn-C_(C5 ring) bond in each 1~3.However,the room temperature ~1H NMR spectral studies disclosed such a fluxional bonding mode in solution.The 119 Sn NMR studies suggested a quadruple coordination nature of the Sn center in 1 while the triple coordination manner was for the Sn atom in both 2 and 3.Then the variable-temperature(25~–75 ℃) ~1H NMR spectral studies for each 1~3 were performed,which detected the relaxation state structures of 1~3 at lower temperature.All of these results indicate a stereochemical activity of the lone electron pairs at the tin(Ⅱ) atom that definitely has an electronic interaction with the 6 p-electrons of the C_5 ring.The observed Sn-C_(C5 ring) bond modes appear influenced by either the metallocene size or the compound state existed.     

基于带隙可调的MAPbI(3-x)Brx钙钛矿电池

采用一步溶液法制备了MAPbI_((3-x))Br_x钙钛矿太阳电池,研究了MABr掺杂含量变化对薄膜形貌及光电性能的影响。研究结果表明,在MAPbI_((3-x))Br_x体系中,随着MABr含量的增加,钙钛矿层晶粒尺寸明显增大;紫外-可见吸收光谱和稳态荧光测试表明峰位发生蓝移;构筑的MAPbI_((3-x))Br_x电池器件的开路电压V_(oc)=1.02 V,光电转换效率PCE为12.68%。