硫酸介质中铅阳极膜阴极还原过程的研究

采用光电化学技术和实时交流阻抗测量等现场方法研究铅阳极膜的阴极还原过程，发现ＰｂＯ电位区阳极氧化形成的阳极膜在阴极还原时有两种ＰｂＯ的还原，即ｏ－ＰｂＯ和ｔ－ＰｂＯ二种氧化物的还原，还原过程中的电极阻抗变化情况表明ＰｂＯ层是均匀还原的，且是ｔ－ＰｂＯ先还原，ｏ－ＰｂＯ后还原．还分析了铅阳极膜在阴极还原过程中所表现出来的阴极光响应．     

钼酸铵在Na_2O改性Al_2O_3载体上的热分解研究

本文利用热重分析（ＴＧ）和差热分析（ＤＴＡ）研究了Ｎａ_２Ｏ改性的Ａ１_２Ｏ_３担载的钼酸铵的热分解．实验发现，载体表面的酸碱性对钼酸铵分解的热效应有明显影响．Ｎａ_２Ｏ担载量低的样品在５７３～７７３Ｋ温度范围内有强放热效应；当Ｎａ_２Ｏ担载量适中时，放热效应随载体表面碱性的增强逐渐减弱；而Ｎａ_２Ｏ担载量高的样品则伴有吸热效应．本文还利用激光拉曼光谱（ＬＲＳ）对烘干和焙烧Ｍｏ／Ａｌ_２Ｏ_３样品分别进行了研究．     

VHS录像机HQ技术的探讨

本文阐述VHS录像机HQ技术的主要内容以及如何运用HQ技术改善重放画面的质量。     

无限冷硬球铁轧辊去应力退火温度的确定

通过比较无限冷硬球铁轧辊经过不同温度退火处理后组织和硬度的变化,测定了该材料在凝固和冷却过程中的铸造应力,在此基础上提出了无限冷硬球铁轧辊去应力退火处理的度为４００℃左右。     

Analysis of nuclear apoptotic process in a cell-free system

We report an analysis of the apoptotic process of mouse liver nuclei induced in a cell-free carrot cytosol system by cytochrome c. Typical characteristics of apoptosis were observed, such as chromatin condensation, margination, apoptotic bodies and DNA ladders. Furthermore, transmission and scanning electron microscope analysis of the apoptotic nuclei detected chromatin-free nuclear vesicles before apoptotic bodies appeared at a comparatively late phase. When AC-YVAD-CHO, an inhibitor of caspase 6, was introduced into the system, these vesicles and apoptotic bodies disappeared completely within our study sections. We confirmed the results using whole-mount electron microscopy, and found that although the nuclear lamina was destroyed early, the nuclear matrix largely remained intact during the course of apoptosis. The nuclear matrix played an important role in maintaining the integrity of apoptotic cells and connecting the apoptotic bodies and apoptotic nucleus. Received 29 September 2000; revised 10 December 2000; accepted 13 December 2000     

Thermodynamic characterization of two novel spin-crossover complexes

Spin-crossover complexes are of great interest to the scientists because of their potential application in molecular-based electronic devices. Some octahedral metal compounds with 3dn (4 ≤ n ≤ 7) configuration can induce a spin state conversion through a fine tuning condition (temperature, pressure, light irradiation, etc.). If the conversion occurs reversibly with a hystersis loop and color change, it will make the system possessing memory effect. The memory effect can be magnified and the …     

循环流化床锅炉内掺高硫石油焦混烧脱硫灰的矿物相组成

粉煤灰的矿物相组成对其资源化具有重要意义,它主要取决于燃料品种和燃烧过程.由于燃烧过程的差异,循环流化床锅炉(CFBC)内掺加高硫石油焦和煤混烧而排放的脱硫灰与煤粉炉粉煤灰在矿物相组成上具有较大差异.利用扫描电镜(SEM)、X-ray衍射(XRD)和傅立叶转换红外光谱(FT-IR)对CFBC掺高硫石油焦混烧脱硫灰的矿物相组成进行了研究,同时采用选择性溶解分离和重力分离的方法富集脱硫灰中的微量矿物,研究表明CFBC掺高硫石油焦混烧脱硫灰的矿物相组成以高α-石英、硬石膏和石灰含量为其主要特征,同时含有少量的方解石、莫来石、钙长石、钙铝黄长石、赤铁矿、硅酸二钙(2CaO·SiO2,C2S)、铝酸三钙(3CaO·Al2O3,C3A)、七铝酸十二钙(12CaO·7Al2O3,C12A7)及透辉石等矿物,可能含有少量玻璃相.如果样品在空气中存放时间较长,石灰吸收空气中的水分会导致羟钙石生成.而煤粉炉粉煤灰中的矿物主要为莫来石、石英和少量的赤铁矿,并含有大量的玻璃相.     

随机序及其随机序之间的关系

文章先介绍了几种主要的随机序,其中包括期望效用准则、随机占优、单调风险率条件、单调似然率条件和均值-方差准则,然后在此基础上研究了它们之间的关系。     

提高屋面工程质量的几种新工艺

文章概要介绍了提高屋面工程质量的几种新工艺。     

秦巴山区食粮和水中微量元素含量的分析

采用光谱分析法测定了陕南秦巴山区宁强县部分地区６种主要食粮（小麦、大米、荞麦、黄豆和马铃薯），以及环境水（溪水、井水、泉水、河水和自来水）中微量元素（铜、铁、锌、锰和硒）的含量，并同西北大学自来水和矿泉水，以及有关文献进行了比较对照和归纳总结。从而，为营养、卫生和地方病学领域内的研究者和当地人民改善饮食配比，保持健康，增强体质提供了依据。