SS7 over IP的关键技术SCTP概述

介绍了SCTP在信令传输中的使用，随后就SCTP的基本特性、分组格式和协议行为进行了阐述。     

基于ARM7的应用程序在线升级设计

以NXP公司LPC2138为例,介绍了ARM7 IAP功能的应用,通过介绍下栽所使用的通信协议,给出了应用程序在线升级的下栽流程以及需要注意的问题,阐述了下载方案的实现过程.实验表明,该系统设计合理、性能稳定可靠.     

基于S7-300控制的音乐演奏系统仿真设计

针对西门子S7-300可编程控制器的脉冲输出功能,将25个半音阶音符的周期及对应的脉冲数存放S7-300相应的内存单元中,通过合理分配S7-300的I/O端口,设计了一种音乐演奏控制系统.在硬件电路和软件编程的基础上,结合Wincc flexible仿真软件进行仿真与调试,实现了音乐演奏系统的功能需求.实践表明,该设计具有功能强、运用灵活、可靠性高、稳定性好、编程简单、使用方便以及体积小、功耗低等特点.     

Evolution of soluble carbohydrates during the development of pea, faba bean and lupin seeds

Seeds of pea (Pisum sativum L. cv. Ergo), faba bean (Vicia faba ssp. minor Harz., cv. Tibo) and yellow pea lupin (Lupinus luteus L. cv. Juno) were sampled at different days after flowering (DAF) and their content of soluble carbohydrates was determined: Analysis of samples showed thatmyo-inositol, fructose, glucose, galactose and sucrose were found in high abundance early in development and their content decreased gradually during maturation. -Galactosides, which includes the content of raffinose, stachyose and verbascose, started to appear later in seed development, at 37 DAF in peas, 40 DAF in faba beans and 45 DAF in lupins. Their accumulation increased considerably during seed growth, and the maximum content was obtained in mature seeds; 3.8% in peas, 4.5% in faba beans and 10.4% in lupins. Results obtained for these sugars during seed development were fitted to modelling curves in order to predict sugar content at different development stages.     

基于PLC的CNG加气站数据处理与联动控制

本文介绍了CNG加气站现场的运行参数的收集以及基于设定报警值进行联动控制的设计。本方案使用S7-12001214C可编程控制器,配以两个RS485通讯模块,采用MODBUS RTU 通讯协议,RS485半双工模式与现场其它PLC和智能设备进行通讯。     

Electronic structure of polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7) derivatives for organic solar cell applications

Among the new materials currently employed as electron donor element in active layers of organic solar cells (OSCs), PTB7 holds the best results. It has been extensively studied and now there is a search for new derivatives to improve its properties. In this work, a set of 24 polymers derived from polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7) was studied theoretically, using chemical modifications in the benzodithiophene (BDT) moiety of the PTB7 monomeric units. After evaluations of the electronic and optical properties, including the open circuit voltage and exciton dissociation and recombination conditions, the results indicate that employing chlorine as substituent yields the most promising material for application in active layers together with Phenyl-C₆₁-Butyric-Acid-Methyl-Ester (PCBM) as electron acceptor material.     

超低温烧结X7R特性环保型陶瓷材料的研制

研制的陶瓷材料可在超低温度(1 030 ℃±15 ℃)下烧结,获得瓷料的相对介电常数高于2 100,介质损耗不高于1.5%,温度特性满足X7R特性要求标准.与传统的X7R特性材料比较,本材料烧结温度更低,同时材料中不添加Pb、Hg、Cd、Cr等有害元素,符合绿色环保要求及欧盟RoHS指令要求.     

三维纳米结构FOX-7的构筑与热分解性能

以具有三维纳米网格结构且可降解的聚缩醛胺气凝胶(PHA)作模板,采用蒸发结晶法,原位诱导1,1-二氨基-2,2-二硝基乙烯(FOX-7)结晶析出,得到FOX-7/PHA复合物,然后利用硫酸的稀溶液(10%)降解去掉模板,即可得到具有三维纳米结构的FOX-7(nano-FOX-7)。高效液相色谱(HPLC)测定nano-FOX-7的纯度为99%,说明模板基本去除完全。对样品的形貌、物相、结构和热分解性能进行了表征测试。结果表明,去模板后的nano-FOX-7较为完整地保留了模板PHA的三维纳米网络结构,其中FOX-7的平均晶粒尺寸为83.68 nm。与raw-FOX-7相比,特殊的纳米多孔结构使FOX-7的转晶峰和低温分解峰分别延后11.3℃和21.3℃,放热几乎集中在高温分解峰291.0℃处,分解焓从原料的1309 J·g-1增加到1421 J·g-1,表观活化能提高了128.62 kJ·mol^-1,增幅达31.46%,能量释放效率和热稳定性大幅提高。     

FOX-7在DMF/H2O二元体系中的冷却结晶动力学

为解决直接合成所得1,1-二氨基-2,2-二硝基乙烯(FOX-7)存在的晶体形貌不规则,粒度分布不均匀等问题,采用激光动态法和间歇动态法分别测定了FOX-7在N,N-二甲基甲酰胺(DMF)与水(H2O)二元体系(V(DMF)∶V(H2O)=7∶3)中的溶解度和超溶解度及冷却结晶动力学数据,利用最小二乘法拟合得到了晶体成核速率与生长速率方程。结果表明,FOX-7在上述体系中溶解度方程为lnx=16.42-5019.51/T-0.45lnT;在冷却结晶过程中呈粒度无关生长模型;在成核速率与生长速率方程中,过饱和比S的指数分别为0.61与0.45,悬浮密度MT指数的为2.30,搅拌强度ωr的指数为0.22。     

Epitaxial Growth of High-J c NdBa2Cu3O7−δ Films on RABiTS by Pulsed Laser Deposition

NdBa₂Cu₃O_7−δ (NdBCO) films were grown on rolling-assisted biaxially textured substrates (RABiTS) via pulsed laser deposition. c-Axis-oriented epitaxial NdBCO films with high performance were obtained under optimal deposition conditions. Transmission electron microscopy analysis shows that the NdBCO film grown on RABiTS has a clear interface with a CeO₂ cap layer and a nearly perfect lattice structure. The NdBCO film exhibits higher T _c of 93.7 K and better in-field J _c in magnetic fields and at all field orientations, compared to pure YBCO films.