外插齿刀变位系数设计与计算程序

变位系数计算是插齿刀设计的重要工作。文章讨论了插齿刀变位系数选取原则以及应当满足不产生齿顶变尖、被切齿轮齿根过渡曲线干涉、根切和顶切等四个约束条件,给出了新刀设计的最大变位系数和根据刃磨到最后刀齿仍有必要强度所允许的最小变位系数计算公式,编制了插齿刀变位系数计算机辅助运算流程,使插齿刀设计简单快速且便于判断设计的可行性。     

人眼3D肌肉控制模型

根据解剖学原理及人眼运动特征,提出了一种人眼3D肌肉控制模型.该模型由内部模型和外部模型组成,其3D运动由3类共8条肌肉控制.模型建模及驱动比较方便,并已在PC机上进行了模拟.模拟结果表明,人眼模型逼真,可较好地模拟人眼运动及表情.     

Genome-Wide Identification and Expression Analysis of the 14-3-3 Gene Family in Mango (Mangifera indica L.)

Members of the Mi14-3-3 gene family interact with target proteins that are widely involved in plant hormone signal transduction and physiology-related metabolism and play important roles in plant growth, development and stress responses. In this study, 14-3-3s family members are identified by the bioinformatic analysis of the mango (Mangifera indica L.) genome. The gene structures, chromosomal distributions, genetic evolution, and expression patterns of these genes and the physical and chemical properties and conserved motifs of their proteins are analysed systematically. The results identified 16 members of the 14-3-3 genes family in the mango genome. The members were not evenly distributed across the chromosomes, and the gene structure analysis showed that the gene sequence length and intron number varied greatly among the different members. Protein sequence analysis showed that the Mi14-3-3 proteins had similar physical and chemical properties and secondary and tertiary structures, and protein subcellular localization showed that the Mi14-3-3 family proteins were localized to the nucleus. The sequence analysis of the Mi14-3-3s showed that all Mi14-3-3 proteins contain a typical conserved PFAM00244 domain, and promoter sequence analysis showed that the Mi14-3-3 promoters contain multiple hormone-, stress-, and light-responsive cis-regulatory elements. Expression analysis showed that the 14-3-3 genes were expressed in all tissues of mango, but that their expression patterns were different. Drought, salt and low temperature stresses affected the expression levels of 14-3-3 genes, and different 14-3-3 genes had different responses to these stresses. This study provides a reference for further studies on the function and regulation of Mi14-3-3 family members.     

低浓度城市污水兼性生化工艺参数的优化

主要研究低浓度城市污水处理生物／生态型组合工艺中的兼性生化前处理单元技术。通过正交试验,得出利用兼性生化反应技术处理城市的污水优化工艺参数：反应器水力停留时间（HRT）8h,混合液悬浮固体浓度（MLSS）5500mg／L,进水COD浓度180mg／L。     

不同喷油提前角对缸内碳烟生成影响的计算与分析

应用计算流体动力学对某小型高速增压直喷式柴油机缸内燃烧过程进行了数值计算,得出了不同喷油提前角下增压直喷式柴油机缸内混合气、温度和碳烟的分布情况,分析了不同喷油提前角下,上止点前后的喷油量的比例对碳烟排放的影响,并通过实际工况下的碳烟排放试验进行了验证。为增压柴油机性能与排放优化提供了参考。     

铜山口铜矿水力旋流器数值优化试验研究

为提高大冶有色铜山口铜矿选矿厂FX500水力旋流器的分级精度、降低底流夹细量,通过数值模拟方法系统考察了旋流器结构参数和操作参数对旋流器分离性能的影响,结果表明：①适当增加入口流速、降低给矿浓度,可从整体上降低底流夹细量和溢流跑粗量;②适当增大柱段高度和小锥锥角,可进一步降低底流夹细量;③适当增大沉砂口上锥角角度,对底流中的微细粒级有洗涤作用,能进一步降低底流夹细量;④现场对比试验证实,旋流器结构优化后底流-75 μm粒级夹细率下降了1.78个百分点。研究结果为铜山口铜矿水力旋流器的优化与改造提供了技术支撑。     

矿井地面风硐的改造方案比选与施工

为解决通风系统改造后原地面风硐断面偏小、风速超限的问题,通过在原有地面风硐东侧并联一道钢制矩形通风管道的方法,从而增加风硐断面积,降低风硐内的风速和通风阻力,效果明显。     

等离子喷涂-物理气相沉积涡轮叶片7YSZ热障涂层

以纳米团聚的氧化钇稳定氧化锆(7YSZ)粉末为原料,通过等离子喷涂-物理气相沉积(PS-PVD)技术在涂覆有NiCoCrAlY粘结层涡轮叶片表面制备了羽毛柱状热障涂层,对不同部位涂层的微观结构进行表征.结果表明:PS-PVD技术在涡轮叶片上不同部位制备的热障涂层结构相同,能够在非视线沉积区域的叶缘板表面获得典型的PS-PVD热障涂层结构.涂层沉积过程中,涡轮叶片构型对涂层沉积效率有明显影响,当喷枪垂直叶片旋转轴时,涂层在远离叶片旋转轴区域的厚度较低,原因在于凹型曲面对反射粒子具有汇聚作用而凸型曲面对粒子具有分散作用,两种因素结合可预测复杂构型叶片表面的涂层厚度分布规律.PS-PVD技术制备的热障涂层具有良好的抗热震性能,采用涂层表面镀铝改性工艺能减缓循环热应力造成的涂层失效.     

六盘水市煤炭行业竞争战略分析

我国是富煤贫油少气的国家,煤炭是我国最重要的一次能源。但从能源激烈的竞争市场环境而言,当前我国煤炭行业发展出现了困境。为了更好地发展六盘水地区的煤炭行业,结合竞争战略理论和六盘水市的煤炭行业发展状况,运用PEST分析法和波特五力模型对六盘水市煤炭行业进行分析,得出整合资源,结合自身优势大力吸引人才,最终达到产业转型的生态化煤炭发展战略模型。分析结果可为提高六盘水煤炭行业竞争力提供理论支持。     

Oxygen concentration measurement and control of lead-bismuth eutectic in a small,static experimental facility

ABSTRACT

Oxygen measurement and control system is critical for minimizing corrosion in nuclear systems. Oxygen measurement and control tools use lead-bismuth eutectic (LBE) and pure lead as a coolant or as a spallation target. Oxygen can be supplied by either gas phase (H₂O or O₂) or solid phase (PbO dissolution); thus, oxygen control includes both gas phase and solid phase methods. This article focuses on oxygen concentration measurement and control of lead-bismuth eutectic in a small, static experimental facility. This facility was developed for oxygen sensor calibration and gas/solid phase control systems test programs. The oxygen sensor with Nano Cu/Cu₂O closely the Nernstian behavior down to 195°C; the oxygen sensor measurement accuracy satisfied the requirements of subsequent experiments. The gas phase control system (verified according to different type of mass transfer, such as air, H₂O, gas injection, and coverage) and the solid phase control system were very successful in small experimental devices. Accurate oxygen concentration control was achieved with both the gas and solid phase control systems.