SiCp/Al复合材料超精密车削仿真与试验研究

针对SiC_p/Al复合材料因脆性相SiC的加入而导致难以形成高质量加工表面等问题,采用分子动力学模拟和超精密车削试验的方法对SiC_p/Al复合材料纳米尺度材料去除过程进行研究,重点分析了单晶金刚石超精密切削SiC_p/Al复合材料中的加工表面形成机理、脆塑性转变以及刀具磨损机理。结果表明:高压相变是引起SiC_p/Al复合材料中SiC脆性材料的脆塑性转变的主要原因。随着切削深度的增加,SiC_p/Al复合材料中SiC颗粒加工方式由延性去除,到脆塑性混合方式去除,最后演变为纯脆性去除方式。SiC_p/Al复合材料中SiC-Al界面和Al基体存在,影响了SiC_p/Al复合材料中SiC颗粒去除的脆塑性转变机制。待加工表面上拉应力的存在会诱导微裂纹尖峰,是切削区域脆性SiC材料裂纹萌生的直接诱因。单晶金刚石刀具主要磨损机理为硬质SiC颗粒的磨粒磨损和切削诱导的石墨化。     

KINETICS OF HYDRODESULFURIZATION OF HEAVY GAS OIL DERIVED FROM OIL-SANDS BITUMEN

With gradual shortage in the supply of crude oil, the importance of producing synthetic crude oil from oil sands and shale oil is increasing day by day. In the present paper, the effects of various process variables such as temperature, liquid hourly space velocity and hydrogen/heavy gas oil volumetric ratio on the removal of sulfur compounds from oil sands derived heavy gas oil has been studied. The experiments have been carried out in a micro scale trickle bed reactor over a commercial Ni-Mo catalyst. The temperature, liquid hourly space velocity and hydrogen/heavy gas oil volumetric ratio have been varied from 365 to 415°C, 0.5 to 1.9 h^-1 and 400 to 1000 ml, respectively. Under optimum reaction conditions over 96% conversion of sulfur compounds was achieved. The kinetics of the rate of sulfur removal from the oil sands derived heavy gas oil has also been discussed in this article.     

基于格子Boltzmann方法的3D数字岩心渗流特征分析

页岩气储层物性差、各向异性突出且孔隙结构存在多尺度特性,内部流动非常复杂,由于纳米孔隙的存在,宏观连续理论不适用。基于页岩二维扫描电镜图片和计算机处理技术,采用随机生长方法分别重建大孔隙和小孔隙的三维数字岩心,将大孔隙和小孔隙初始模型组合在一起构成多尺度的页岩气储层三维数字岩心组合模型,在此基础上,应用格子Boltzmann方法研究不同尺度孔隙的渗流行为。四参数随机方法重建的图像能较好体现原图的性质,储层的孔隙结构特征对其渗透率具有重要影响,渗透率随着孔隙度的增大而增大,组合模型数字岩心的渗透率大于大孔隙数字岩心和小孔隙数字岩心的渗透率,并且大于二者的总和,说明小孔隙的存在可以极大提高储层连通性。     

CVD涂层硬质合金刀具的耐磨性和破损特性

通过系统的实验研究和理论分析，揭示了化学气相沉积（ＣＶＤ）涂层质合金刀具在磨损和破损状态下不同的失效特性和机理。，在耐磨性方面，重点分析了涂层的耐靡屏障作用，固体润滑作用和涂层与基体间的匹配作用，在破损特性方面，分析了表现残余应力与涂层剥落，脆性η相与界面裂纹，刃口钝化与塑性变形等内在规律。在此基础上又阐明了涂层质合金刀具对于切削条件的特殊适用性和选择性。     

Epoxidation of Canola Oil with Hydrogen Peroxide Catalyzed by Acidic Ion Exchange Resin

Canola oil with an iodine value of 112/100 g, and containing 60% oleic acid and 20% linoleic acid, was epoxidised using a peroxyacid generated in situ from hydrogen peroxide and a carboxylic acid (acetic or formic acid) in the presence of an acidic ion exchange resin (AIER), Amberlite IR 120H. Acetic acid was found to be a better oxygen carrier than formic acid, as it produced about 10% more conversion of ethylenic unsaturation to oxirane than that produced by formic acid under otherwise identical conditions. A detailed process developmental study was then performed with the acetic acid/AIER combination. The parameters optimised were temperature (65 °C), acetic acid to ethylenic unsaturation molar ratio (0.5), hydrogen peroxide to ethylenic unsaturation molar ratio (1.5), and AIER loading (22%). An iodine conversion of 88.4% and a relative conversion to oxirane of 90% were obtained at the optimum reaction conditions. The heterogeneous catalyst, AIER, was found to be reusable and exhibited a negligible loss in activity.     

Recovery,characterization and conceptual modelling of Non-Bituminous organic materials from oil sands

The hot water process has recovered approximately 90% of the bitumen in oil sands, but the remaining 10% of bitumen and naphtha has been lost to the tailings pond. Recovery of bitumen and non-bituminous combustibles (NBC) from centrifuge, scroll and final tailings has been considered. The effects of four sequestering agents, and of chemical additives such as CaCl₂ and FeCl₃ on the flotation behavior of bitumen, NBC and minerals in these tailings have been investigated. A simple method of isolating NBC materials has been developed. The flotation of both bitumen and NBC was enhanced by phosphate treatment and depressed by EDTA. NBC was characterized by its physical properties, energy content, functionality and chemical analysis. A conceptual model explains the interactions between the bitumen, minerals and NBC fractions present in tailings slurries.     

牛血清白蛋白与Hg(Ⅱ)配合物作用的热力学研究

采用紫外-可见吸收光谱法和荧光光谱法研究了XO-Hg(Ⅱ)配合物与牛血清白蛋白(BSA)的相互作用。研究结果表明,XO-Hg(Ⅱ)配合物对BSA有强的荧光猝灭作用,为静态猝灭。根据荧光猝灭数据,由Stern-Volm er方程得到了不同温度下XO-Hg(Ⅱ)配合物与BSA之间的结合位点数和结合常数,推出了结合反应的主要作用力类型。据F rster非辐射能量转移理论,探讨了给体-受体间的作用距离,阐明了XO-Hg(Ⅱ)配合物对BSA的猝灭作用不是由非辐射能量转移机制导致。     

PCrNi3MoVA高速侧铣加工研究

PCrN娼MoVA是一种应用广泛的高强度钢，主要应用于炮筒和小型炮后备箱的制造。本文主要研究了利用直径10mm的整体硬质合金铣刀高速侧铣PCrNi3MoVA钢时的铣削力，以及加工后表面粗糙度的情况。同时与端铣加工进行对比，找到了2种加工方式影响粗糙度和铣削力的主要因素，并总结了铣削力的预测公式。     

滇西南晚第三纪含煤盆地的形成与演化

在分析滇西南晚第三纪区域构造背景的基础上，阐述了含煤盆地的形成，按其成因将盆地分为剪切盆地、剪切－拉张盆地和拉分盆地３种类型。盆地为冲积扇、湖泊、沼泽和河流相沉积物所充填，其演化过程可分为５个阶段：强烈沉陷阶段、稳定发展阶段、萎缩封闭阶段、剥蚀阶段和再沉陷阶段。