Matlab仿真在通信原理教学中的应用

通信原理是信息类专业的主干课程,其原理性内容较丰富,如何将这门课程更加透彻并且以学生容易接受的方式讲解清楚,各高校都开展了相关研究。根据通信原理的这一特点提出使用Matlab仿真进行可视化教学。实践证明,它不仅可以在课堂教学中以更加直观的方式进行讲解,而且还可以改善硬件实验的不足之处,激发了学生的学习兴趣,教学效果得到明显改善。     

论冀中地区O、C—P凝析气藏的形成条件

据凝析油轻烃组成、甲烷及其同系物碳同位素组成、天然气与源岩吸附气指纹时比、双环倍半萜组合特征及地质结构的综合分析,查明O、C—P大多数提析气藏的油气主要来源于石炭—二叠系煤系腐植型有机质,混入了部分下第三系的油气。对石炭—二叠系成烃特点的分析表明,R。=0.6%～1.3%,以成气为主,生油为辅,原始油气比一般大于1OOCm3/t。成熟期的石炭—二叠系有机质的成烃特点和具备油气富集的良好地质条件是O、C—P凝析气藏形成的基本条件。     

透明介质相位栅衍射条纹研究方法

本文介绍了油腆相位栅衍射条纹分布规律的实验测量方法,以及如何用现有条件实现测量所需的特殊要求。最后介绍了测量结果在大屏幕投影显示整机设计的应用。     

基于TTCN的通信协议一致性测试

通信产品遵循的通信协议是确保不同厂商的产品能够互通的关键,因此协议一致性测试便成为产品开发过程中的重要环节之一。介绍了作为 Ｉ Ｓ Ｏ／ Ｉ Ｅ Ｃ９６４６ 与 Ｘ２９０ 定义的协议一致性测试标准的 Ｔ Ｔ Ｃ Ｎ（ Ｔｒｅｅ ａｎｄ Ｔａｂｕｌａｒ Ｃｏｍｂｉｎｅｄ Ｎｏｔａｔｉｏｎ） ,讨论了测试模型、 Ｔ Ｔ Ｃ Ｎ 工作流程及其特点。     

Synthesis of mesoporous polymeric carbon nitride exhibiting enhanced and durable visible light photocatalytic performance

A thiourea precursor was employed to synthesize mesoporous carbon nitride(C3 N4) by a thermal polycondensation process with high surface area SiO2 and nanosphere SiO2 as two types of hard templates. The resultant mesoporous C3 N4 samples have high surface areas(105–112 m2/g) and mesopores with narrow sizes distribution(9.3 nm). Photocatalytic performance was evaluated by removal of NO in air under visible light irradiation. The results showed that mesoporous C3 N4 samples exhibited significantly improved photocatalytic activity in comparison with bulk C3 N4, which also exceeded that of N-doped TiO2 and C-doped TiO2. The activity enhancement can be ascribed to the synergistic effects of large surface area and pore volume, enhanced light-harvesting ability, increased redox potential, and reduced recombination of charge carriers. In addition to the high activity, the mesoporous C3 N4 samples also showed high photochemical stability. The mesoporous C3 N4 photocatalysts with enhanced and durable activity could provide a new efficient material for environmental pollution control.     

通信网络互连中的ATM技术

首先分析了ＩＰ协议和ＩＥＥＥ８０２局域网规程分别与ＡＴＭ（异步转移模式）技术的特性，并对它们进行了比较，然后针对国际标准化组织和ＡＴＭ论坛提出的局域网仿真和基于传统ＩＰ协议ＡＴＭ技术这两种方案进行分析和讨论     

某车型正面碰撞耐撞性与轻量化研究

针对国内某款微型MPV,首先用有限元方法进行正面100%碰撞工况数值模拟和对标,在基础模型和试验数据的基础上进行正面碰撞的结构耐撞性优化。然后在保证车身结构满足耐撞性要求,刚度、模态等其他性能基本不变的前提下,最大限度地减轻各零部件的质量,实现车身的轻量化和成本控制。最后通过100%正碰实车试验验证了此结构优化和轻量化方案是可行的。     

彩扩机混光筒空腔内光的互反射特性

彩扩机成象过程中，混光筒的光均匀性将直接影响扩印照片的质量，本文就混光筒空腔内光的互反射特性可获得需要的光均匀分布，为混光筒的设计提供理论参考和依据     

数字通信在押出机中的应用

介绍了可编程控制器 ( PLC)与变频调速器 ,可编程控制器与温度控制仪构成的多分支通信网在押出机 (用于生产电线电缆的机器 ,国外又名挤出机 )中的应用 .用通信方式实现了对温控仪进行读、写以及温度报警等一系列功能 .同时给出了工艺流程图和系统框图和部分最基本的 PLC程序     

INVESTIGATION ON A FLOWRATE MEASURING SYSTEM USING LIGHT FIBRE FLUOROMETERS

In this paper a flowrate measurement method in pipe directly using light fibres with some fluorescent tracer is proposed. This method will work better than traditional tracers measurement such as using radioactive or salt tracers. It is shown that the flowrate signals are sensitive and intensive also if the injected tracer volume is very small and if the tracer concentration is very lew (<10ppm) ico. It is also show that the calibration factor K is constant within a certain flowrate range. An estimation of uncertainty of flowrate measurement is given, which shows that the measuring accuracy can be within ±2%.