Preparation and Properties of Smart Thermal Control and Radiation Protection Materials for Multi-functional Structure of Small Spacecraft

Considering the unique properties of small spacecraft,such as light weight,low power-consumption and high heat flux density,a new kind of lightweight boron carbide(B 4 C) radiation-protection coating material was proposed.New techniques for preparing LSMO thermal control coating and B 4 C radiation-protection coating were developed.The sample piece of multi-functional structure was manufactured by using the proposed materials,and a series of performance tests,such as thermal control and radiation-protection behaviors were evaluated.Test results show that:the emissivity of the multi-functional structure varies from 0.42 to 0.86 at 240 K to 353 K and the phase transition temperature is about 260 K.The electron radiation-protection ability of the multi-functional structure is 3.3 times better than that of Al material.The performance index of this multi-functional structure can meet the requirements for space application in on-board electronic equipment.     

Electrical Conductivity and Sensitive Characteristics of Ag-Added BaTiO_3-CuO Mixed Oxide for CO_2 Gas Sensing

Carbon dioxide gas sensors based on BaTiO3-CuO composite with different concentrations of Ag addition(1,1.5 and 2 wt%) have been prepared by stander ceramic method and sintered at 500 and 700℃ for 5 h.Electrical conductivity and gas sensing properties of the prepared samples were investigated.Electrical conductivity measurement was used to characterize the obtained sintered sensor pellets.It was found that electrical conductivity and the sensitivity to CO2 were improved with Ag addition and sintering.The correlation between Ag content at different sintering temperature and sensing characteristics towards CO2 is discussed.     

Influence of Lithium Oxide Addition on the Sintering Behavior and Electrical Conductivity of Gadolinia Doped Ceria

Ceria-based electrolytes have been widely researched in intermediate-temperature solid oxide fuel cell (SOFC), which might be operated at 500-600?C. Sintering behavior with lithium oxide as sintering additive and electrical conductivity of gadolinia doped ceria (Gd0.1Ce0.9O2δ, GDC10) electrolyte was studied in this paper by X-ray di?raction (XRD), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). As the results, the fully dense GDC10 electrolytes are obtained at a low temperature of 800?C with 2.5 mol% Li2O as sintering additive (called 5LiGDC800). During sintering process, lithium oxides adsorbed by around GDC10 surface help to sinter at 800?C and are kept at the grain boundary of GDC10 in the end. The fine grains of 100-400 nm and high electrical conductivity of 0.014 S/cm at 6000C in 5LiGDC800 were achieved, which contributed to the lower sintering temperature and enhanced grain boundary conductivity, respectively. Lithium, staying at grain boundary, reduces the depletion of oxygen vacancies in the space charge layers and increases the oxygen vacancy concentration in the grain boundary, which leads to improve the total electrical conductivity of 5LiGDC800.     

Analysis of Dielectric and Electro-optic Responses of Nanomaterials Doped Ferroelectric Liquid Crystal Mixture

Dielectric and rotational viscosity measurements of a multi-component ferroelectric liquid crystal mixture were performed by adding a small concentration (0.01 wt%) of silica and multi walled carbon nanotubes (MWCNTs). Liquid crystals turn out to be outstanding hosts for nanomaterials. A remarkable increase in the rotational viscosity was noticed in CNT doped system as compared to silica doped same liquid crystal system. Comparison of dielectric studies shows higher value of permittivity and dielectric losses for silica-doped sample than those of CNT doped sample. The results have been interpreted both experimentally and theoretically.     

柴达木盆地复杂构造带综合地质建模技术

英东地区位于英雄岭断褶带以东,是柴达木盆地地表构造集中发育的地区,由于地表及地下地质结构复杂,使得该区的地震资料品质较低,落实构造难度较大。文中从地面地质露头、钻井资料和构造演化入手,采用"综合地质建模技术"构建了"浅层滑脱、深层块断"双层构造解释模式,采用合成地震记录与速度分析相结合的多井、多层次综合标定方法标定了层位,从形成机制上对两期断裂系统的组合关系及晚期断层对构造的影响进行了探讨。根据新的解释成果,在英东地区部署的S37井见到了丰富油气显示,说明"综合地质建模技术"在复杂地区地震资料解释中具有较好的应用价值。     

利用AVO正、反演预测深水浊积扇储层

针对赤几G区块深水浊积扇岩性复杂、流体识别难度大的特点,本文在精细井震标定与子波提取的基础上,首先进行了井旁道射线追踪正演模拟,含油砂岩振幅响应表现为近道弱、远道强的Ⅱ类AVO异常。基于AVO正演模型,对严重影响中深层成像与振幅保持的近道多次波进行了压制,采取的方法是在数据分解的基础上对多次波进行倾角扫描相干拟合消除,然后再对剩余有效数据进行重构。根据保幅处理后CDP道集上目的层位的AVO截距、梯度属性,合理划分了部分叠加道集的角度范围,判断了界面异常的大致分布。岩石物理分析与AVO反演结果均表明,研究区目的层段内纵、横波速度比小于2.0、纵波阻抗小于6.5×106kg.m-2.s-1的区域为含油砂岩,横向上自东向西发育两支水道,沉积上以朵叶体为主,含油砂体面积大、横向连通性好,厚度大、孔渗高,储量丰度大。     

利用零井源距VSP资料进行品质因子反演

品质因子Q值是描述地震波衰减的一个重要物理参数,它描述了介质非完全弹性特征,是地层内部本质特征,所以研究和估算Q值在地震勘探中的作用越来越重要。谱比法和质心频移法是现在常用的两种方法。本文详细介绍了两种方法的原理并用无噪声理论模型验证了两种方法的可行性。反演结果显示在无噪声的条件下两种方法都能很好地估算介质的品质因子。通过对含有不同强度噪声的理论数据、全波场理论数据和实际零井源距VSP数据的处理,对两种方法进行了比较。结果表明,质心频移法反演的结果比谱比法更精确、更可信。     

等旅行时面共反射面元叠加的应用研究

本文基于克希霍夫成像理论,对共反射面元(CRS)叠加方法进行了深入分析,阐述了等旅行时面共反射面元叠加方法(CRS-OIS)原理及其测试效果。指出CRS-OIS是对于传统共反射面元叠加方法的重要改进,它简化了传统CRS叠加方法,可以同时得到信噪比大幅度提高的叠前道集与零炮检距成像剖面。该方法首次被用于南海深水二维地震数据处理,处理结果表明基底与莫霍面的成像品质得到明显改善,提高了剖面的可解释性。     

低温钢焊接接头CTOD断裂韧性试验研究

与传统的夏比V型缺口冲击韧性试验比较,CTOD更能有效准确地评价钢材的抗脆断能力。文章按照BS 7448-1991(1997)断裂韧度试验标准,对海洋平台工艺管道用ASTM A333-2005 Gr.6低温钢焊接接头的低温(0℃,-29℃)裂纹尖端张开位移(CTOD)进行了测试。取尺寸为B×2B(B为试样厚度)、缺口方向为NP的试样进行三点弯曲试验,然后由得到的焊缝和热影响区(HAZ)的P-V曲线来计算CTOD值,并对试验结果进行了分析和讨论。     

渤海湾海上动力沉桩监测及分析

PDA(动态打桩分析仪)系统是由美国PDI专用传感器(美国桩基动力公司)研制的专用于桩基施工数据信号采集和处理的设备,它采用了专用传感器和Case法计算分析原理。这套设备在海上打桩作业中应用较少,本文介绍了使用动态打桩分析仪在渤海湾辽河滩海油田海上打桩作业中的应用情况,评估了停锤复打时桩的阻力。