The theoretical study of the bimetallic Ni/Pd,Ni/Pt and Pt/Pd catalysts for hydrogen spillover on penta-graphene

The catalytic property of the bimetallic Ni/Pd, Ni/Pt and Pt/Pd particles for hydrogen spillover on penta-graphene (PG) are studied by using the first-principles and kinetic Monte Carlo (KMC) calculations. The bimetallic Ni/Pd, Ni/Pt and Pt/Pd particles can be stably decorated on PG surface with binding energies in the range of 4.15–5.52 eV. The adsorption enthalpies of H₂ molecules on bimetallic particles are in the range of ?11.56–?15.35 kcal/mol. The H atom can migrate from the bimetallic particles to PG with the migration barriers range from 0.67 to 0.95 eV. The KMC simulations show that the hydrogen spillover reactions can occur at a suitable temperature (260–361 K), which meet DOE target for onboard hydrogen storage systems applied to light-duty vehicles. In the study, the highest occupied molecular orbital and electric field analysis shows that the bimetal mixing can reduce the hydrogen adsorption enthalpy, and thereby reduce the H migration barrier, which displays a synergistic effect for hydrogen spillover.     

大型风电机组塔筒应力监测点的选取与预警

针对大型风电机组塔筒应力监测缺失的情况,提出基于ANSYS软件应力点的选取和person相关系数法与灰色神经网络相结合的塔筒应力预警方法。通过软件分析和现场实验,研究风电数据和塔筒应力的关系并进行塔筒预测,并首次应用到风电机组塔筒监测中。通过实例分析验证,结果表明,该方法能够有效地进行塔筒应力监测,为风电机组塔筒的检测提供依据。     

新疆西南天山含金红石脉的显微构造变形机制

新疆西南天山变质带是研究有关洋壳型俯冲变质演化的重要地区之一。岩石、矿物的显微构造是其变形、变质等各种地质作用的直观记录。选择含金红石绿辉石脉的变质岩作为样品进行显微构造研究。通过显微镜观察了解脉体中绿辉石的须状增生、晶内裂隙、穿晶张裂隙,金红石的锯齿状颗粒边界和主岩中石榴子石的变斑晶包迹结构,蓝闪石的晶内裂隙和显微分层现象,白云母的波状消光、亚晶粒旋转重结晶现象和扭折带,铁白云石的机械双晶等显微变形现象。说明西南天山变质带中的变质岩在俯冲—抬升至地表的过程中,变质岩及脉体的主要变形机制为有流体参与的压溶作用和固态扩散物质迁移、晶质塑性变形和微破裂为主要变形机制,局部存在颗粒边界滑移。     

曲柄驱动双肘杆传动机构的设计与优化

为加工高强度、回弹大的轻量化板材,设计了一种曲柄驱动的立式传动肘杆伺服压力机。采用ADAMS软件对比分析了两种不同传动机构的工作特性。针对曲柄立式传动肘杆机构,通过矢量法建立滑块变速移动特性的运动学方程;运用ADAMS对传动机构各尺寸变量进行敏感度分析,以减少设计变量,再运用遗传算法对传动机构进行多目标优化,以减小滑块最大速度、滑块最大加速度和机构高度为优化目标。研究结果表明,优化后的曲柄立式传动肘杆机构的工作性能有较大提高,滑块最大速度降低了8.5%,滑块最大加速度降低了37.6%,曲柄最大扭矩降低了9%,机构高度降低了1%;同时该机构具有良好的保压性能和急回特性。     

利用水力旋流器对广西典型钙基膨润土的湿法提纯研究

利用水力旋流器对广西典型钙基膨润土进行湿法提纯试验研究,主要探讨了给矿浓度、给矿压力和底流口直径对膨润土提纯效果的影响。研究结果表明,给矿浓度、给矿压力及底流口直径三者间存在一定交互作用。该膨润土的最佳提纯条件为:给矿浓度为15%,底流口直径为6 mm,给矿压力为0.35 Mpa;膨润土经提纯处理后各项性能指标均获得相应提高,其蒙脱石含量由62.50%提高到80.03%,阳离子交换量从41.87 mmol/100 g提高到76.63 mmol/100 g,胶质价从46.50 m L/15 g提高到60.0 m L/15 g。     

Protein Extraction from Porcine Myocardium Using Ultrasonication

Porcine myocardium is regarded as a byproduct in slaughterhouses and is rarely used as a food source due to its unsuitability for processing and consumption. In this study, we sought to develop an efficient ultrasonication method to extract protein from porcine myocardium. Comparisons of protein yield using various ultrasonication conditions with porcine myocardium revealed that treatment with 0.2 M NaCl, with pH 8.0, at an extraction temperature of less than 40 °C and an amplitude of 60% to 80% was optimal, yielding an extraction rate of 90%. In addition, SDS‐PAGE analysis showed that increasing the time interval for ultrasonication increased the presence of myosin heavy chain and actin protein content. Functional analysis of the physiological properties of the isolated proteins using an ATPase assay showed that Ca and Mg ATPase activity was virtually undetectable in the early stages of ultrasonic treatment and that the proteins denatured rapidly. An analysis of protein digestion also showed that the digestive capacity of proteins treated by ultrasonication methods was greater. These results demonstrate that the ultrasonication method is effective for high‐yield protein extraction from cardiac myofibrils of porcine myocardium with low salt concentrations, low Ca and Mg ATPase activities, and high digestive capacities.     

热电冷联产中溴化锂制冷-热泵系统设计与性能分析

对热电冷联产中一种新型热回收系统——溴化锂制冷-热泵系统进行了系统设计与性能分析.该系统利用热泵回收溴化锂制冷系统的冷凝热来加热锅炉除盐水,可以减少除氧器中加热用的背压蒸汽消耗量,提高能源利用率,产生显著的节能、经济、环保效益.     

热处理对高温钛合金TG6铸造组织及性能的影响

对熔模精铸TG6合金进行了热等静压和退火热处理试验,研究了其铸态、热等静压态和退火态的显微组织和力学性能。结果表明,该合金在铸态下为晶粒粗大的魏氏组织,组织中存在缩松缺陷,合金抗拉强度为871.3MPa,塑性0.8%,合金组织中的疏松缺陷为断裂的裂纹起始源;通过热等静压后该合金抗拉强度及伸长率提高到950.7 MPa和3.7%;经过750℃退火热处理后,组织中β板条部分溶解,并析出(TiZr)6Si3硅化物,合金的室温拉伸延伸率提高到5%以上,强度相对于热等静压未发生明显改变,断口表现为解理断裂。     

三角形微通道内纳米流体流动与换热特性

以去离子水为基液,通过两步法制备出粒子体积分数为0.1%的SiO₂、Al₂O₃、TiO₂纳米流体,并分别在流体内添加一定量的表面活性剂以提高其稳定性。利用紫外分光光度计和热物性分析仪,对3种纳米流体稳定性和热导率进行测试。此外,为研究纳米流体在三角形微通道内的流动与换热特性,利用红外热像仪观察通道底面温度分布。结果表明,表面活性剂会对纳米流体吸光度产生影响,且粒子会随着时间的增加逐渐团聚。纳米颗粒的添加可有效提高工质的热导率并强化对流换热,微通道底面温度明显降低,且均温性得到改善。3种纳米流体中,TiO₂纳米流体呈现出更加良好的导热和换热性能。