Synthesis, characterization and electrical properties of the new solid electrolyte materials Ce6-xErxMoO15-delta (0.0 < x < 1.5)

A new series of oxides, Ce6-xErxMoO15-delta (0.0 less than or equal to x less than or equal to 1.5), was synthesized using wet-chemistry techniques. The precursors and resultant oxide powders were characterized by differential thermal analysis/thermogravimetry, x-ray diffraction, and IR, Raman and x-ray photoelectron spectroscopy. The formation temperature of the powders was found to be as low as 350degreesC. Ce6-xErxMoO15-delta crystallized to a fluorite-related cubic structure. The electrical conductivity of the samples was investigated by using ac impedance spectroscopy. This showed that the presence of Er was related to the oxygen-ion conductivity, and that the highest oxygen-ion conductivity was found in Ce6-xErxMoO15-delta (x = 0.4), ranging from 5.9 x 10(-5) S cm(-1) at 300degreesC to 1.26 x 10(-2) S cm(-1) at 700degreesC, respectively. This kind of material shows a potential application in intermediate-temperature solid oxide fuel cells.

两种新的手性1,6-双膦的合成

由D-甘露醇出发合成了两种新型的手性1,6-双膦:1,6-双(二苯膦基)-2,3,4,5-二亚(艹卡)基-D-甘露醇和1,6-双(二苯膦基)-3,4-亚(艹卡)基-2,5-亚甲基-D-甘露醇。 以这两种手性配位体的Rh(Ⅰ)配合物为催化剂用于α-乙酰氨基肉桂酸的不对称氢化反应,但都未观察到对映选择性,而且由第一种配位体参加的反应,也未显示氢化活性,对此本文也作了初步的说明。

压阻式高量程微加速度计的冲击校准

采用体硅微机械加工技术和扩散技术，制作压阻式高量程微加速度计，设计量程为50000 g_n。芯片材料为单晶硅，采用双列扁平陶瓷封装。为了测量其动态灵敏度，使用Hopkinson杆在约40000 g_n的加速度水平下进行了冲击校准。在电桥电压为6.33V的情况下，被测微加速度计的灵敏度为1.26 μV/g_n。

太阳日冕环的运动(二)

<正> 天空实验室观测期间,用白光日冕照相观测太阳日冕区,发现多数瞬变过程是以环状形式发生质量喷射.从太阳表面上二个太阳半径到六个太阳半径的观测范围内,测得环状瞬变过程前导边缘的运动是加速运动或者等速运动.这些日冕瞬变过程是细长的环,环的根部固定在太阳表面上.Dulk等人用白光观测和用无线电米波观测日冕瞬变过程时,比较了日冕环中的各种能量密度,得出结论:在日冕环中磁能密度大约是热能密度的十倍,磁能密度稍大于动能密度.Gergely等人也得出类似的结论.由此说明:在日冕环朝外运动时,磁场是控制日冕环的主要因素.

流场显示技术在流体力学中的应用和展望

<正> 一 前言 在现代科学研究中,实验技术是其最活跃的重要方面。现代科学研究首要的问题是根据实验结果(而不是根据猜测)建立研究对象的物理模型,然后再进行研究分析。流体力学研究中的流场显示技术,其任务就是把存在于透明介质(空气、水……等)中的流动现象,(其中很多现象是直接看不见的。)不仅设法用图像显示出来,并力求做到根据这些图像作流场某些物理量的定量测定。

纪念谈镐生先生诞辰九十周年暨基础力学学术会议介绍

2006年12月1日是国际著名的力学家、应用数学家谈镐生院士诞辰九十周年纪念日．为纪念谈先生在力学学科的卓越贡献，缅怀他对推动我国力学基础研究和培养科技人才所作出的杰出贡献，中科院力学所于这天上午在所礼堂隆重举行“纪念谈镐生先生诞辰九十周年暨基础力学学术会议”．会前举行了《谈镐生先生文集》首发式，该文集由胡文瑞院士主持编辑，科学出版社出版，收录了谈镐生先生在流体力学、稀薄气体动力学和应用数学研究领域的论文和研究报告26篇，谈先生倡导和推行力学基础研究的有关文章和论述21篇，谈先生的学术活动和生活图片多幅，简介了谈先生生平.

加载速率对位错发射、层错宽度及位错速度影响

应用分子动力学方法研究了Cu和Al单晶在Ⅱ型加载条件下，加载速率对位错发射、层错宽度W及位错速度V_d的影响。结果表明，加载速率对W和V_d有显著影响。随着加载速率的增大，层错宽度减小，位错速度增大。当加载速率达到某一临界值时，能量不仅以发射位错的形式释放，而且形成孪晶，以降低体系的能量。

海底管土相互作用研究概述

在阅读文献的基础上,对海底管线与海床之间的相互作用进行了系统的阐述。介绍了海底管道稳定性的设计方法、国内外管土相互作用的试验情况和数值计算的进展。指出了管土相互作用要解决的一些问题。

Algorithm for simulating fracture processes in concrete by lattice modeling

To simulate fracture behaviors in concrete more realistically, a theoretical analysis on the potential question in the quasi-static method is presented, then a novel algorithm is proposed which takes into account the inertia effect due to unstable crack propagation and meanwhile requests much lower computational efforts than purely dynamic method. The inertia effect due to load increasing becomes less important and can be ignored with the loading rate decreasing, but the inertia effect due to unstable crack propagation remains considerable no matter how low the loading rate is. Therefore, results may become questionable if a fracture process including unstable cracking is simulated by the quasi-static procedure excluding completely inertia effects. However, it requires much higher computational effort to simulate experiments with not very high loading rates by the dynamic method. In this investigation which can be taken as a natural continuation, the potential question of quasi-static method is analyzed based on the dynamic equations of motion. One solution to this question is the new algorithm mentioned above. Numerical examples are provided by the generalized beam (GB) lattice model to show both fracture processes under different loading rates and capability of the new algorithm.

针尖扫描原子力显微镜的光点跟踪设计

提出了一种用于针尖扫描原子力显微镜（AFM）的光点跟踪设计方案，结构简单，容易实现。设计方案对扫描器的负载能力要求不高，而且能使原子力显微镜实现较大范围的针尖扫描。实验结果表明，采用此光点跟踪设计方案的针尖扫描原子力显微镜能实现最大100μm×100μm范围的扫描，z方向上的误差最大1nm，能很好地满足大样品扫描的需要。