不同结构及材料下阻燃光缆烟密度测试结果的分析

本文对阻燃光缆烟密度试验设备、燃烧过程、试验样品等进行了简要介绍。按照单一变量原则,根据光缆结构和材料,设计了多种试验方案;经试验和统计分析,给出了每种结构及材料下阻燃光缆烟密度测试结果,分析了原因。另外,简化的验证方案,针对某个构件或材料,验证了各自的发烟能力。     

Synthesis,Crystal Structure and Photoluminescence of a New Cd-organic meso-Helicate

One-pot solvothermal reaction of transition metal Cd(Ⅱ) salt with (2E,2’E)-3,3’-((propane-1,3-diylbis(oxy))bis(2,1-phenylene))diacrylic acid (H2ppa) and 1,10-phenanthroline (phen) generates a meso-helicate, [Cd(ppa)(phen)(H2O)]2, and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy, and photoluminescent property. The complex crys-tallizes in monoclinic, space group P21/c with a = 13.4622(7), b = 24.8452(12), c = 8.9314(4) , β = 97.564(1)o, V = 2961.3(2) 3, C66H56N4O14Cd2, Mr = 1353.97, Dc = 1.518 g/cm3, μ(MoKα) = 0.789 mm-1, F(000) = 1376, Z = 2 , the final R = 0.0248 and wR = 0.0667 for 4673 observed reflections (I > 2σ(I)). The 1-D supramolecular chain is built up from the complex by π-π stacking interactions, and inter-chain hydrogen bonds prompt the 1-D chains into a 2-D layer. The title compound shows strong photoluminescence with emission maximum at λ = 445 nm upon λEx, max = 240 nm.     

A 3-Connected 3D Microporous Metal-organic Framework with Intersected Channels and Rare DEH Topology

A novel metal-organic coordination polymer {[Cd(mppdc)(H2O)]·H2O}n(1, H2 mppdc = 2,6-dimethyl-4-phenylpyridine-3,5-dicarboxylic acid) was synthesized from the reaction of H2 mppdc, Cd(NO3)2·4H2O and CH3 OH under solvothermal conditions. The crystal is of tetragonal system, space group I41/a, with a = 19.109(2), b = 19.109(2), c = 24.317(7) A, V = 8880(3) A3, Z = 16, Mr = 417.68, Dc = 1.250 Mg/m3, F(000) = 3328, the final R = 0.0516 and w R = 0.1185(I 2σ(I)). Complex 1 displays a 3D microporous metal-organic framework with intersected channels and rare(8210) DEH topology. The complex exhibits strong photoluminescence at room temperature in the solid state.     

基于PSO-PID的超声电源频率跟踪系统设计

针对多数超声波电源存在频率漂移、跟踪性能差、易失谐,造成能量转换效率低、甚至设备损坏等诸多问题,设计了一种基于数字控制、可实现快速频率跟踪的超声波电源.将改进的粒子群算法(particle swarm optimization,PSO)结合比例积分微分(proportional integral derivative,...