煤层瓦斯的形成及瓦斯灾害的预防

文章通过分析煤层瓦斯的形成、瓦斯在煤层中的储积与运移及影响瓦斯储积与运移的因素,阐述了瓦斯灾害的预防措施.     

罗茨鼓风机传动齿轮齿面疲劳强度快速试验研究

用模拟快速试验与实际试件试验的对比方法,对齿面接触强度进行了研究,表明两者之间有异同之处。本实验结果表明,选用40Cr进行辉光离子氯化处理,用于罗茨风机齿轮,齿面强度可达到预期指标。     

Cholinesterase in the atherosclerotic intima and in fibroblast cultures.

Cholinesterase activity was present in the atheromatous plaque of the rabbit's atherosclerotic aorta. Cholinesterase activity was significantly increased in rat fibroblast cultures grown in the presence of hypercholesterolemic serum. Cholesterol ester synthesis in these cultures was inhibited by neostigmine, a cholinesterase inhibitor.     

5-取代-1,3,4-噁二唑-2-硫基乙酸的合成

利用２－巯基－５－取代－１,３,４－口恶二唑与一氯乙酸反应,合成了９种新的５－取代－１,３,４－口恶二唑－２－硫基乙酸。产物结构经元素分析和红外光谱确认。     

基于知识的集成化CAPP方法研究

研究基于知识的集成化ＣＡＰＰ方法,针对ＣＡＤ／ＣＡＰＰ的实时并行的需求,提出分层规划的零件工艺设计方法。基于知识进行特征工艺设计,基于知识进行定位方案评价和零件工艺过程优化。ＣＡＰＰ系统借助于ＳＴＥＰ文件,自动获取零件设计信息,基于知识进行零件工艺设计,实现了ＣＡＤ／ＣＡＰＰ的信息集成,为实现ＣＡＤ／ＣＡＰＰ的实时并行打下良好的基础。     

横波在各向异性复合介质中的传播

横波在各向异性介质中传播时将发生横波的分裂。把玻璃和水泥组成的复合介质看做是对裂缝简单而合理的近似,对裂缝引起的各向异性介质中横波的分裂进行了较详细的观察,当横波沿着平行于层面的方向传播时,可以观察到明显的横波分裂。裂缝引起的各向异性与裂缝参数和声源之间有密切的关系。在一定范围内,介质的横波速度各向异性程度随裂缝密度及裂缝宽度的增加而变大,且较高频率的探头对介质的各向异性更敏感。     

Effects of MgO and TiO<Subscript>2</Subscript> on the viscous behaviors and phase compositions of titanium-bearing slag

The effects of MgO and TiO₂ on the viscosity, activation energy for viscous flow, and break-point temperature of titanium-bearing slag were studied. The correlation between viscosity and slag structure was analyzed by Fourier transform infrared (FTIR) spectroscopy. Subsequently, main phases in the slag and their content changes were investigated by X-ray diffraction and Factsage 6.4 software package. The results show that the viscosity decreases when the MgO content increases from 10.00wt% to 14.00wt%. Moreover, the break-point temperature increases, and the activation energy for viscous flow initially increases and subsequently decreases. In addition, with increasing TiO₂ content from 5.00wt% to 9.00wt%, the viscosity decreases, and the break-point temperature and activation energy for viscous flow initially decrease and subsequently increase. FTIR analyses reveal that the polymerization degree of complex viscous units in titanium-bearing slag decreases with increasing MgO and TiO₂ contents. The mechanism of viscosity variation was elucidated. The basic phase in experimental slags is melilite. Besides, as the MgO content increases, the amount of magnesia–alumina spinel in the slag increases. Similarly, the sum of pyroxene and perovskite phases in the slag increases with increasing TiO₂ content.     

Effect of Cr_2O_3 addition on the oxidation induration mechanism of Hongge vanadium titanomagnetite pellets

As part of a research project to develop a novel clean smelting process for the comprehensive utilization of Hongge vanadium titanomagnetite(HVTM), in this study, the effect of Cr2O3 addition on the oxidation induration mechanism of HVTM pellets(HVTMPs) was investigated in detail. The results showed that the compressive strength of the HVTMPs was greatly weakened by the Cr_2O_3 addition, mainly because of a substantial increase in the porosity of the HVTMPs. The Cr_2O_3 addition marginally affected the phase composition but greatly affected the microstructural changes of the HVTMPs. Increased amounts of Cr_2O_3 resulted in a decrease in the uniform distribution of the hematite grains and in an increase in the Fe–Cr solid solutions(Fe_(1.2)Cr_(0.8)O_3 and Fe_(0.7)Cr_(1.3)O_3) embedded in the hematite grains. Moreover, the compact hematite was destroyed by forming a dispersed structure and the hematite recrystallization was hindered during the oxidation induration, which adversely affected the compressive strength. On the basis of these results, a schematic was formulated to describe the oxidation induration mechanism with different amounts of added Cr_2O_3. This study provides theoretical and technical foundations for the effective production of HVTMPs and a reference for chromium-bearing minerals.