多媒体通信的新发展

本文介绍了各种多媒体通信终端的新标准,对于开发PSTN 多媒体可视电话终端,提出了有关建议,分析了适用于多媒体通信的各种通信网络,最后论述了多媒体通信中的两项关键技术,即多媒体信息压缩技术和同步技术。     

松辽盆地齐家—古龙凹陷青山口组黑色页岩岩相类型与沉积环境

为研究松辽盆地齐家—古龙凹陷白垩系青山口组黑色页岩的沉积环境,利用岩心描述、薄片资料及地球化学数据开展岩相分析与沉积模式建立。结合有机碳含量和矿物组成划分出6种岩相,即富有机质黏土质页岩、富有机质长英质页岩、富有机质含生屑长英质页岩、贫有机质长英质泥岩、贫有机质含生屑长英质泥岩及贫有机质介壳灰岩。青山口组富有机质页岩并不全是静滞水体中悬浮沉积的产物,大量微米级的微波状纹层、透镜状层理、交错层理、粒序层理、冲刷充填构造以及定向排列的介屑佐证了浊流和底流作用的存在。微量元素分析表明,青一段湖盆面积大,水体深,虽有底流和浊流作用,但保持较强的还原环境,形成富有机质的黏土质页岩、粉砂质页岩和含生屑粉砂质页岩的互层,发育各种纹层。青二段、青三段随着湖平面下降,三角洲注入能力增强,贫氧环境受到破坏,有机质保存条件变差,岩相向贫有机质块状泥岩转变。     

TNT和RHT-906炸药起爆过程的电导率研究

建立了凝聚炸药起爆过程电导率的平面测试方法,运用该方法对RHT-906炸药起爆过程的电导率,以及TNT炸药在不同冲击压力起爆过程的电导率进行了研究.分析了冲击压力对炸药起爆过程电导率的影响,结果表明,TNT的最大电导率随起爆压力的减小而减小,TNT中加入RDX后最大电导率减小.四发实验得到TNT炸药爆炸的化学反应时间分别为0.11 μs、0.12μs、0.16μs和0.15μs.     

大型相控阵雷达系统效能评估

大型相控阵雷达系统效能评估,先确定系统效能评估指标体系,再用G1法求解一级指标的权重,应用"云重心"理论对定性指标和定性、定量相结合的指标构造云模型,计算多维加权综合云的重心,最后通过云重心评价方法进行效能评估.其效能子模型涉及探测、情报处理、目标跟踪、目标编目、生存、环境适应、可靠性和维修性等方面,评估模型还包括大型相控阵雷达系统效能综合评估模型.     

住宅建筑能耗的特点及其评价指标的确定

本文首先回顾了国际上对于住宅建筑能耗的研究工作,然后对住宅建筑能耗的特点进行了分析,指出在研究的初始阶段,可以使用单位地板面积上的能耗等指标作为住宅建筑能耗的评价指标,但是由于这些指标都是针对某一特定的能耗系统提出的,因而都具有一定的局限性,所以如何确定一个更为全面、更为客观的评价指标仍是今后的一个研究内容。     

激光驱动飞片冲击应力实验研究

为了对激光驱动飞片的冲击应力进行测试,利用PVDF压电材料,自制了满足测试需要的应力计,并给出了应力计的动态标定曲线。通过对激光驱动复合飞片和单层飞片的冲击应力进行测试分析,可知对于激光驱动飞片起爆系统,应用较厚复合飞片可获得较大的冲击应力以及较长的持续时间,并指出了PVDF应力计测试中的若干注意事项。     

Nano-Cu catalyze hydrogen production from formaldehyde solution at room temperature

In this paper, high efficient production of CO-free hydrogen from formaldehyde (HCHO) aqueous solution catalyzed by various nano-metal catalysts was reported. It was found that nano-metal catalyst could catalyze formaldehyde into hydrogen and formic acid under room temperature and atmospheric pressure. Among Pt, Au, Ni, and Cu nano-metal particles, nano-Cu catalyst exhibited the highest activity and the long-term stability. The temperature seems influence the reaction significantly. For example, when the temperature was increased from 0 to 60 °C, the rate of hydrogen production increases from 2.34 to 140 mL min⁻¹ g⁻¹ catalyst over nano-Cu catalyst. Hydrogen was produced via the formic acid intermediate. When NaOH concentration was high, Cannizzaro reaction occurred, which resulted in the retardation of hydrogen generation at high concentration of NaOH and HCHO.     

激光冲击片雷管中飞片的结构优化及性能测试

为有效提升激光冲击片雷管的能量利用率,需对雷管中的飞片结构进行设计和优化。在对飞片进行结构设计的基础上,采用磁控溅射和扫描电镜(SEM)的方法完成了C/Al/Al2O3/Al飞片的制备和表征,获得了飞片各层的制备速率和表面形貌;采用光子多普勒测速系统(PDV)测试了不同参数C/Al/Al2O3/Al飞片的加速历程,发现在相同激光入射能量下,不同参数飞片的加速历程有所不同,设计制备的0.05/0.7/0.7/20.0μm复合飞片(Φ1.0mm)能量利用率最高,飞片速度达到2301 m·s-1。结合飞片各层材料的物理特性分析得到,石墨吸收层的反光系数、汽化能与导热性能,及Al2O3隔热层的表观致密度、电离势能和导热性能直接影响飞片的速度,而飞片加速时间与石墨吸收层较高的导热率相关。     

Ti/B多层结构含能点火元件的制备与表征

设计了含能桥的结构,采用磁控溅射方法制备硼/钛多层含能桥。对含能薄膜进行X射线衍射图谱测试,并用扫描电镜对含能桥进行了断面和表面形貌观察,可以看到多层连续结构。用HS4540MX12高速摄像系统记录下来含能桥发火过程,火花溅射距离可达到30 mm左右。进行了含能桥对BNCP药柱的点火试验,成功隔离点火。     

Robust design of battery/fuel cell hybrid systems—Methodology for surrogate models of Pt stability and mitigation through system controls

With increasing interest in energy storage and conversion devices for automobile applications, the necessity to understand and predict life behavior of rechargeable batteries, PEM fuel cells and super capacitors is paramount. These electrochemical devices are most beneficial when used in hybrid configurations rather than as individual components. A system model helps us to understand the interactions between components and enables us to determine the response of the system as a whole. However, system models that are available predict just the performance and neglect degradation. The objective of this research is to provide a framework to account for the durability phenomena that are prevalent in fuel cells and batteries in a hybrid system. Toward this end, the methodology for development of surrogate models is provided, and Pt catalyst dissolution in proton exchange membrane fuel cells (PEMFCs) is used as an example to demonstrate the approach. Surrogate models are more easily integrated into higher level system models than the detailed physics-based models. As an illustration, the effects of changes in control strategies and power management approaches in mitigating platinum instability in fuel cells are reported. A system model that includes a fuel cell stack, a storage battery, power-sharing algorithm, and dc/dc converter has been developed; and preliminary results have been presented. These results show that platinum stability can be improved with only a small impact on system efficiency. Thus, this research will elucidate the importance of degradation issues in system design and optimization as opposed to just initial performance metrics.