水力压裂护巷煤柱卸压机理与工程应用

以新元公司9108工作面回风顺槽水力压裂卸压为工程背景,通过理论分析,得出了煤柱体上部基本顶悬伸部分长度过大是导致护巷煤柱变形的主要原因,然后通过水力压裂技术来对煤柱上部顶板进行压裂,使得顶板在工作面回采后能够及时垮落,不会形成悬顶效应,减小对煤柱体的压力,从而保护护巷煤柱,使得下一工作面在回采时巷道围岩变形量保持在可控范围之内,从而减少了巷道维护成本。     

煤矿智能化开采新进展

智能化开采是煤炭工业高质量发展的核心技术支撑。经过多年发展,我国智能化开采形成了薄煤层和中厚煤层智能化无人操作,大采高煤层人-机-环智能耦合高效综采,综放工作面智能化操控与人工干预辅助放煤,复杂条件智能化+机械化4种智能化开采模式。为了解决工作面综机装备智能决策难题,研发了工作面智能协同控制系统,实现采煤机自适应割煤与自主感知防碰撞,基于煤流量智能感知的采煤机、液压支架、刮板输送机等综采装备的协同联动,工作面综采装备与端头和超前支架的联动控制。上述研究成果在陕北侏罗纪1.1 m硬煤薄煤层、金鸡滩煤矿8 m超大采高综采、金鸡滩煤矿9 m以上硬煤特厚煤层综放开采进行应用,效果显著,实现了陕北侏罗纪1.1 m硬煤薄煤层高效智能化无人开采,8 m超大采高工作面人-机-环智能耦合高效综采,9 m以硬煤上特厚煤层超大采高智能化综放开采。     

超大采高综放工作面板裂化片帮特征及合理护帮控制

针对榆神矿区超大采高综采工作面煤壁板裂化片帮问题,基于金鸡滩煤矿超大采高综放工作面开采技术条件,采用理论分析与工程实践相结合的方法,分析了超大采高工作面煤壁板裂化片帮特征,研究了适宜的护帮板结构形式和合理护帮控制措施。发现板裂化片帮具有多种特征:板状板裂化、“洋葱皮状”板裂化、弹射型板裂化(俗称“炸帮”)和护帮板动载扰动下板裂化片帮,提出并求解了整体式和分体式护帮板承载能力曲线,将护帮板承载能力曲线作为护帮板承载性能评价指标,分别分析和对比了2种结构形式护帮板运动特性及其与煤壁结构耦合关系,从力学特性和运动学特性角度得出整体式护帮板具有承载性能优、灵活性好和结构耦合适应性强等优点,建议在满足护帮高度要求的前提下,优先选用整体式二级护帮板结构。结合工业性生产实践,对煤壁板裂化片帮特征及危害进行分析,提出并讨论了相应的煤壁板裂化片帮防治措施。分析和借鉴同一盘区相邻8.2 m超大采高一次采全厚工作面分体式三级护帮板应用情况及其对煤壁维护效果,结合7.0 m超大采高综放工作面支架-围岩结构耦合关系,认为7.0 m超大采高综放工作面宜采用整体式二级护帮板。生产实践表明:整体式二级护帮板能有效维护超大采高综放工作面煤壁稳定,便于自动化控制和工作面高效开采。     

湿N2退火HfTiO和HfO2栅介质 Ge MOS电特性研究

采用反应磁控溅射方法在Ge衬底上分别制备了HfTiO和HfO2高κ栅介质薄膜,并研究了湿N2和干N2退火对介质性能的影响。由于GeOx在水气氛中的水解特性,湿N2退火能分解淀积过程中生长的锗氧化物,降低界面态和氧化物电荷密度,有效提高栅介质质量。测量结果表明,湿N2退火Al/HfTiO/n-GeMOS和Al/HfO2/n-GeMOS电容的栅介质等效厚度分别为3.2nm和3.7nm,-1V栅偏压下的栅极漏电流分别为1.08×10-5A/cm2和7.79×10-6A/cm2。实验结果还表明,HfTiO样品由于Ti元素的引入提高了介电性能,但是Ti的扩散也使得界面态密度升高。     

Ti(C,N)与45钢钎焊接头组织及力学性能

以不同厚度的铜箔、镍箔作为缓解接头残余应力的中间层材料,在钎焊温度820℃,保温时间20min的工艺参数条件下对Ti（C,N）基金属陶瓷与45钢进行了钎焊试验。结果表明,无论是采用铜箔还是镍箔,当其厚度从100μm增加到300μm时,接头三点弯曲强度上升趋势平缓;由于铜箔在钎焊过程中大量溶解,削弱了钎料与Ti（C,N）基金属陶瓷的化学相容性,降低了界面结合力,从而严重制约了接头强度的提高;使用镍箔的突出特点表现在具有较高的界面强度,与施加铜箔的钎焊接头相比强度显著提高,但其缓解接头残余应力的效果不如铜箔,在靠近钎缝的Ti（C,N）基金属陶瓷一侧易引发残余应力集中现象。     

弧面分度凸轮机构在YB47型硬盒包装机包装轮中的应用

YB47型硬盒包装机包装轮的间歇运动对机器造成的冲击,易使包装轮包装过程产生铝箔纸破损或铝箔纸缺失现象.为此,利用弧面分度凸轮机构在高速运动中的高精度分度功能,应用于3号包装轮的驱动机构中,采用弧面分度凸轮机构代替槽轮机构,以减少分度机构对机器造成的冲击.应用效果表明,采用该机构的3号包装轮分度精度高,定位准确,传动平稳,结构紧凑,装配弧面分度凸轮机构步骤简化,操作方便.与YB45型硬盒包装机3号包装轮相比,YB47型包装机中的弧面分度凸轮机构有效减少了3号轮在高速运动中的振动和对机器的冲击;与YB45小包铝箔纸缺陷数据相比(5～9包/月),改进后YB47在3号轮包装过程中未出现铝箔纸破损或铝箔纸缺失现象,提高了烟包包装质量.     

近距离坚硬顶板薄煤层开采支护技术

近距离薄煤层在准备采煤工作面时的巷道掘进中,受上层残余压力的影响,矿压显现突出,采用常规的巷道支护方法不能有效控制矿压。文章根据大同煤矿集团公司晋华宫矿实际情况,介绍了关于近距离采空区下半煤巷掘进工艺、支护和工作面开采期间有效控制矿压的方法。     

The viscoelastic properties of soybean curd (tofu) as affected by soymilk concentration and type of coagulant

The viscoelastic properties of different types of tofu were investigated. Soymilk concentrations were 5, 6, 7, 8 and 9%. Coagulants used were 30 mm CaSO₄ or 30 mm glucono‐delta‐lactone (GDL). As the concentration of soymilk was increased viscosity and handling difficulties increased. A high concentration of soymilk in tofu gave a high break stress and produced hard tofu. The four‐element Burgers model fitted the creep behaviour and both viscous and elastic parameters could be acquired from model analysis, reflecting changes in elasticity and viscosity of tofu. The constant viscous parameter in the model increased with increasing soymilk concentration. The viscous parameters of viscoelastic materials like tofu gel, obtained from small deformation tests, seemed to correlate, to some extent, with the break stress obtained from large deformation tests. For hard tofu production increasing the soymilk concentration within a certain range and the partial replacement of calcium sulphate coagulant by GDL could be effective options.     

Preparation of sharp-melting hard palm midfraction and its use as hard butter in chocolate

Preparation of hard palm midfractions (PMF) and its use as a cocoa butter equivalent ingredient were studied. Hard PMF is obtained by multistep fractionation of palm oil involving dry fractionation (DF) and/or solvent fractionation (SF), usually using hexane or acetone. From our experience, in acetone, a polar solvent, symmetrical 1,3-disaturated triacylglycerols tend to selectively crystallize more than nonsymmetrical 1,2- or 2,3-disaturated triacylglycerols, making it suitable for obtaining the solid midfraction. Unfortunately, triacylglycerols are very soluble in hexane, and temperatures at least 15 degrees lower than those required for acetone must be used for equivalent crystal yields. On the other hand, DF is a less expensive and safer process. Thus, multistep fractionation combining DF and SF using acetone was developed to achieve sufficient removal of high-melting components, and further enrichment of 1,3-dipalmitoyl-2-oleoylglycerol and the hard PMF was obtained by triple-step fractionation of palm olein or double-step fractionation of soft PMF. Compared to conventional hard PMF, this hard PMF had a steeper melting curve and better snapping and sharp-melting qualities when used in chocolate. Heat resistance of the hard PMF chocolate was similar to the conventional hard PMF chocolate, and its bloom resistance could be improved by adding polyglycerol fatty acid esters.     

植物硬空心胶囊成型工艺研究

研究以羧甲基葡甘聚糖-大豆分离蛋白复合物为主料,卡拉胶和K 组成凝固体系制备植物硬空心胶囊的成型工艺。结果表明:当复合物和卡拉胶的质量比例为80∶20,溶胶温度为80℃,K 浓度为0.02 mol/L,保温时间为30 min,溶胶流动性较好,凝胶强度达到6.53 N/cm2,蘸模成型好,胶囊壁厚达标。