82B盘条脆断原因分析

大规格82B盘条尽管经过时效处理,但在吊运或酸洗后置于放线架上或仅经过第1道拉拔后还会产生断裂。通过对3类典型断口的分析和讨论,说明82B盘条中的异常组织和表面缺陷是造成其自然脆断的主要原因。     

A study of the acidic and catalytic properties of pure and sulfated zirconia–titania and zirconia–silica mixed oxides

Protonated pyridine (PyH⁺) was not found on ZrO₂ (Z) or ZrO₂–TiO₂ (ZT), but was detected on sulfated oxides (ZS, ZTS) by IR spectroscopy. In contrast, ZrO₂–SiO₂ samples containing about 30–80 mol% ZrO₂ showed Brønsted acidity both in nonsulfated (ZS) and sulfated (ZSS) forms. The total acidity was determined by NH₃TPD. Introduction of sulfate ions increased the sitespecific catalytic activity (TOF) in the conversion of cyclopropane or nhexane. The effect of sulfate ions was more significant on samples rich in zirconia. Results suggest that Zr is homogeneously distributed in ZS samples rich in silica. Zirconiabound dimeric sulfate, generating strong acidity, could not be formed in these preparations due to the absence of fairly large ZrO₂ domains.     

一种高速核脉冲测量仪的研制

采用嵌入式单片机、高计数率的82C54芯片和高速比较器组成的多用核测量仪,具有电路简单、可靠性高、功耗低等点,同时实现了高的计数率、减少了死时间对测量结果的影响。该系统可适配α、γ、X等探测器,组成多用途轻便核测量仪。     

Influence of low-temperature nitridation on low-frequency magnetization of Fe82Nb7B10Cu1 nanocrystalline alloy ribbons

The nanocrystaUine Fe82Nb7B10Cu1 soft magnetic ribbons were treated with the mixture gas flow of ammonia and hydrogen at 673 K. The influence of the nitridation treatment was studied by the low-frequency permeability spectra. The result shows that this kind ofnitridation treatment can improve the soft magnetic properties under some application conditions. The reason for the improvement of the soft magnetic properties by slight nitridation was discussed on the basis of domain wall bulging model. Therefore for the Fe-based nanocrystalline soft magnetic alloy ribbons, the nitridation treatment can be used as an effective and easy method to control the magnetic properties.     

网格门户开发研究

网格门户担当着网格大门的角色,使人们能更顺利地使用网格资源.介绍网格门户的发展历程,重点阐述了开发第二代网格门户的技术规范和开发方法,分析网格门户的发展趋势.     

Heterogeneous nucleation of clathrates from supercooled tetrahydrofuran (THF)/water mixtures, and the effect of an added catalyst

The statistics of liquid-to-crystal nucleation are measured for clathrate-forming mixtures of tetrahydrofuran (THF) and water using an automatic lag time apparatus (ALTA). We measure the nucleation temperature using this new apparatus in which a single sample is repeatedly cooled, nucleated and thawed. This is done for a series of tetrahydrofuran concentrations and in several different sample tubes since the nucleation is heterogeneous and so occurring on the tube wall. The measurements are also done at the same concentrations and tubes but with an added catalyst, a single crystal of silver iodide.     

新型肾上腺显影剂——6-(~(82)Br)溴甲基胆固醇的合成及其在动物组织内的分布

自从1968年Nagai等首次将~(131)I标记胆固醇作为肾上腺示踪剂以来,1970年Counsell等报道了19-(~(131)I)碘胆固醇的合成和在动物肾上腺中有明显的浓集。1975年Kojima等制备了6-(~(131)I)碘甲基去甲胆固醇,动物实验表明它具有更高的亲肾上腺组织特性。其后,王世真、刘伯里等研制了6-(~(131)I)碘胆固醇,显示有较好的亲肾上腺功能和更为优良的热稳定性和辐射稳定性。为了寻找更佳的肾上腺显影剂,将胆固醇的结构进行     

连铸小方坯生产大规格82B盘条的实践

预应力钢绞线用优质高碳盘条82B在拉拔过程中常出现脆断现象。通过对碳偏析、缩孔、表面横裂等质量影响因素的分析，提出并实施了相应的工艺改进措施；通过优化炼钢、连铸、控轧控冷以及拉拔工艺等，提高了盘条质量．降低了用户在使用过程中的断丝率。     

原材料质量对82B盘条深加工性能的影响

对使用82B盘条制作钢绞线过程中常见断裂现象进行了总结，分析了导致脆性断裂的原因，并对生产82B盘条和用户深加工过程中如何减少断丝率提出了建议。     

基于JES平台的典型标准门户组件的设计与实现

介绍了企业门户技术与门户组件技术以及门户组件标准的发展,研究了门户页面的产生过程,将门户组件标准定义的门户组件生命周期模型化,基于JES平台构建典型标准门户组件,并对其生命周期进行分析.