气流粉碎B4C粉末的掺碳活化烧结研究

开展了气流粉碎B4C粉末(比表面积2．53m2/g)的掺碳烧结实验，研究了掺碳剂种类、掺碳量、烧结温度、比表面积等对B4C烧结密度的影响．结果表明，掺碳显著促进B4C的烧结；在炭黑、葡萄糖和酚醛树酯三种掺碳剂中，掺入酚醛树酯可以获得最高的烧结密度；并且最佳的掺碳量为3％-5％C．B4C 3％C(酚醛树酯)分别经2200和2250℃烧结后的密度为92．1％TD和94．4％TD．若采用振动球磨B4C粉末(8．30m2／g)进行掺碳烧结实验，则可使2200℃的烧结密度提高到95．6％TD．     

添加剂硼对合成细颗粒金刚石单晶的影响

实验在国产六面顶压机上利用高温高压方法,在铁基粉末触媒中添加硼粉,合成出了细颗粒金刚石单晶,找到了合成含硼细颗粒金刚石单晶的最佳添加比例。实验结果表明：随着硼添加量的增加,晶体的颜色逐渐加深,合成细颗粒金刚石单晶的最低压力点呈动态变化趋势。在铁基粉末触媒中添加硼粉,合成的金刚石单晶容易出现包裹体,且颗粒细化后依旧没有大的改善,原因与硼的电子结构有关。     

制取硼酸的相图工艺过程解析

以青海大柴旦盐湖富硼镁卤水及固态硼酸盐沉积为原料,以H3BO3-MgCl2-H2O体系、H3BO3-MgCl2-CaCl2-H2O体系0℃和25℃的相图为依据,分别制订了制取硼酸的不同的工艺过程解析方案,单次循环硼的理论收率分别为65.74%、99.41%.     

Changes of intramuscular phospholipids and free fatty acids during the processing of Nanjing dry-cured duck

In this study, changes of intramuscular phospholipids and free fatty acids were tracked during the processing of Nanjing dry-cured duck. Phospholipids were identified and quantified by high performance liquid chromatography combined with UV and evaporative light scattering detectors. The types and quantities of free fatty acids and fatty acids derived from phospholipids were analyzed by capillary gas chromatography. The results showed that raw duck meat had high quantities of phosphatidylethanolamine, and phosphatidylcholine (37.95% and 54.07% of total phospholipids, respectively), which contained high percentages of polysaturated fatty acids. The percentages of total phospholipids, phosphatidylethanolamine, and phosphatidylcholine decreased during processing, with a concomitant increase in quantities of free fatty acids. The lipolysis of phospholipids, especially phosphatidylethanolamine is the main contributor to the increase of free fatty acids.     

Microstructural studies of the temperature-dependence of deformation structures around hardness indentations in ceramics

Various light microscopy and SEM techniques have been used to study the temperature dependence of deformation structures around hardness indentations in highly brittle ceramics (including single crystals of silicon and silicon carbide and polycrystalline forms cf SiC, Si₃N₄ and B₄C). Nomarski differential interferometry has enabled slip steps to be resolved around high-temperature indentations, allowing identification of the dominant slip systems and measurement of the extent of surface plasticity as a function of temperature. The occurrence of indentation fracture as a function of both temperature and specimen microstructure was studied by SEM methods (including stereo imaging), Nomarski differential interferometry and polarized reflection light microscopy. Generally, radial and lateral crack sizes increased with increasing temperature, due to increasing residual stresses around indentations caused by increasing indentation plasticity. Examples of microstructural control of crack paths are given for various single crystal and polycrystalline materials.     

烟田土壤中有效硼的测定

提出了一种测定烟田土壤中有效硼的改进方法。该法用普通的聚乙烯瓶代替昂贵的石英三角瓶和石英回流器 ,在沸水中提取土壤中的有效硼 ,用等离子体原子发射光谱法代替姜黄素比色法测定提取物中的有效硼含量。方法的检出限为 0 .0 0 87mg/kg ,相对标准偏差为 6.5 5 %。采用该法对国家土壤有效态一级标准物质GBW0 74 12和GBW0 74 14中的硼进行了测定 ,测定结果与标准值接近 ,并采用该法测定了 2 0个土壤样品中的有效硼     

Mg(OH)2对海水中硼的吸附效果

文章提出了利用海水镁砂生产过程的中间产物Mg(OH)2作为吸附剂,用来对海水进行脱硼处理,并从理论和实验的角度加以论证和阐述.     

硼的分离方法研究进展

主要介绍了溶液体系中硼的几种分离方法，如沉淀法、吸附法、萃取法、反渗透法、离子交换法等，并对联合法分离硼的研究进行了展望。     

我国盐湖资源开发利用的现状及对策分析

我国盐湖资源丰富,蕴藏着极其丰富的石盐、钾、锂、镁、溴、硼、芒硝、铷、铯等有用资源,开发及应用前景极其广阔.盐湖资源综合利用新技术研究及整体开发,有利于提高资源利用率和企业经济效益,保障资源的可持续发展.文章概述了我国盐湖的资源概况,论述了盐湖资源综合利用的研究及开发现状,指出了盐湖资源综合开发利用中存在的问题,并提出了相应的建议.     

影响PcBN可加工性的因素

聚晶立方氮化硼复合片作为优异的刀具材料,其可加工性的好坏直接影响着它的推广使用。影响P cBN复合片可加工性的主要因素是粘结剂的种类、粒度和加入量,CBN的粒度,复合片的制造方法,前处理工艺等。文章通过实验,研究了这些因素是如何影响P cBN复合片可加工性的,并对这种影响因素进行了分析。