某发动机运输支架仿真分析及优化

针对某型发动机运输支架存在的强度安全问题,提出相应的改进优化方案.利用HyperMesh和ABAQUS有限元软件对运输支架系统结构进行仿真分析,并主要从静强度、滑移量、面压三方面对其进行评估,计算结果表明该优化方案均可满足设计要求.通过对运输支架结构的仿真研究分析,可为支架类部件设计提供一定的参考意义和技术指导,并且有...     

风光互补发电系统安装与调试赛项光伏电站控制设计法

PLC梯形图有3种设计方法,即经验设计法、顺序功能图设计法和以转换为中心的设计方法。顺序功能图是用于工业顺序控制的图形化编程语言,它将复杂的逻辑关系描述为包含不同状态里的各个动作的工艺流程图,再按照顺序功能图转化规则将其转化PLC梯形图程序,即顺序功能图设计法。在实践教学、指导学生参加大赛和企业职工培训过程中,学员对复杂逻辑顺序PLC控制系统的梯形图程序设计无从下手。以"2018风光互补发电系统安装与调试"国赛赛项任务书样题为例,介绍逻辑清晰、有规律可循且易于调试的PLC顺序控制设计方法 ,有助于高职院校学生、工程技术人员快速掌握梯形图设计方法。     

Preparation and uncertainty evaluation of standard samples for testing of dye transfer inhibition in washing北大核心CSCD

As for domestic washing the problem of fabric dye transfer in washing is becoming more and more serious which leads to the decrease of added value of fabrics and affects the aesthetics. With the improvement of people's living standards the demand for fabrics with high color saturation is increasing day by day. However fabrics with high color saturation are often accompanied by problems such as fabric dye transfer in the washing process which has become a pain point in clothing washing. For this reason washing machines at home and abroad are generally equipped with dye transfer inhibition and color protection washing procedures to alleviate the dye transfer phenomenon caused by mixed washing. Jiangnan University and Wuxi Little Swan Electric Co. Ltd. have carried out a series of studies on the formulation of dye transfer inhibition washing standards and the development of standard samples. In order to realize scientific and objective evaluation of dye transfer inhibition performance and solve the problem of lack of standard samples in washing dye transfer inhibition tests white cloth standard samples and red cloth standard samples for washing dye transfer inhibition tests were prepared to simulate light color clothes and dark color clothes in mixed washing. The color depth and water fastness of the prepared standard color cloth are 0. 2% and grade 3 respectively which comply with the provisions of GB / T 12490 - 2014 Textiles—Tests for Colour Fastness—Color Fastness to Domestic and Commercial Laundering. The homogeneity of standard white cloth and standard red cloth were tested by variance analysis the short-term stability test and long-term stability test were carried out for the data with an interval of one month and one year respectively by using the stability test formula. For the whiteness and color difference data tested by seven laboratories in order to analyze the normality of the fixed value data it is necessary to conduct a normality test on the obtained data. For this reason the skewness and kurtosis methods are used to conduct a normality test. The indicators tested include the average standard error standard deviation skewness skewness standard deviation kurtosis and kurtosis standard deviation etc. And Cochrane criterion and Dixon criterion are used to judge whether there are outliers. The indicators tested include statistics low-end outliers and high-end outliers. When calculating the uncertainty the uniformity short-term stability long-term stability and uncertainty introduced in the process of setting are calculated respectively to obtain the combined uncertainty. The results show that the standard white cloth and standard colored cloth have good uniformity and high stability. The combined uncertainty of the standard white cloth is 0. 365 8 and the combined uncertainty of the standard color cloth is 0. 358 0. The uncertainty mainly comes from the uncertainty introduced in the process of value determination. The uncertainty introduced by the uniformity short-term stability and long-term stability has little impact. This paper has prepared the standard sample for washing dye transfer inhibition test and provided the standard sample that is missing in the washing dye transfer inhibition test which is expected to realize the objective evaluation of the dye transfer inhibition performance promote the development of the dye transfer inhibition program carried by the washing machine and realize the scientific evaluation of the washing dye transfer inhibition performance. © 2022 Authors. All rights reserved.     

优化 GE9FB机组燃机排气温度以提高测点的稳定性

文章对某厂燃机排气温度故障情况进行分析,对影响排气温度稳定性的一些因素展开深入的研究,最后提出优化排气温度元件的措施,以提高电厂设备的应用的稳定性。     

TFT-LCD HADS显示模式下黑白Mura机理研究及设计优化

随着高分辨率TFT-LCD HADS产品的开发,一种与像素ITO图形密切相关、有明暗(黑白)亮度差异、不同视角观察下存在黑白反转现象的Mura不良高发。经过对不良产品的参数测量和模拟分析,确定发生该不良的原因是在邻近区域内,像素开口区内的像素电极ITO(1ITO)图形和公共电极ITO(2ITO)图形发生了不同程度的相对偏移,电场分布存在差异,因此亮度发生明显差异;而且由于图形间的相对偏移导致电极间的电场发生偏移,形成像素左右两侧的一侧为强电场,一侧为弱电场,因而会出现从一侧观察发亮而从另一侧观察发暗、左右视角观察的黑白反转现象。Mura区与相邻OK区1ITO?2ITO对位差异为0.5μm。通过1ITO和2ITO的线宽设计优化,可提高产品对此偏移不均一的容忍度。最终采用最佳1ITO、2ITO线宽条件生产,配合1ITO和2ITO共用设备及TP非线性补正等条件并举,此不良由高发时的14.2%降至0.2%以下。本文研究成果对于高分辨率HADS产品的设计和性能改善,有着重要的指导和参考意义。     

烷基环己烷在不同分子筛催化剂上开环裂化制低碳烯烃

以环己烷(CHA)、甲基环己烷(MCHA)、乙基环己烷(ECHA)、丁基环己烷(BCHA)为模型化合物，研究了烷基环己烷在不同分子筛催化剂上的催化转化规律；计算了烷基环己烷的开环选择性及支链C-C键能；阐述了烷基环己烷的开环裂化和支链裂化对低碳烯烃选择性分布的影响以及不同分子筛对烷基环己烷裂化生产低碳烯烃的影响。结果表明：相同分子筛上4种模型化合物的转化率由大到小为丁基环己烷、乙基环己烷、甲基环己烷、环己烷；具有较大孔径的Beta和USY分子筛催化剂有利于烷基环己烷的转化，较小孔径的ZSM-5分子筛催化剂上烷基环己烷转化率较低，但低碳烯烃选择性较高；烷基环己烷侧链链长增加，支链裂化性能提高，环烷环开环选择性降低。     

浅谈机械加工工艺对金属零件加工精度的影响及控制

随着机械制造业的发展进步,各类机器设备精密度不断提升,因而在当前的金属零件加工当中,对于加工精度的要求越来越高,而机械加工工艺,对金属零件加工精度有着重要的影响。为了保证金属零件加工精度满足要求,就需要采取有效的控制措施。基于此,本文首先概括了机械加工工艺,然后分析了机械加工工艺对金属零件加工精度的影响,进而提出了加工精度的控制策略。     

堆积状态下面粉层最低着火温度实验研究

为了评估面粉粉尘的危险性,为面粉加工厂防爆设备以及防爆工艺选型提供依据,利用恒温热板装置,研究加热板温度和堆积厚度对面粉层最低着火温度(MITL)、着火延迟时间的影响。结果表明:面粉的燃烧方式为阴燃;根据GB 16430-1996,面粉最低着火温度超过标准规定的最高温度400℃;随着堆积厚度的增大,面粉层最低着火温度呈线性减小,堆积厚度为12.5 mm时,面粉层最低着火温度为280℃;当堆积厚度≥15 mm时,面粉层最低着火温度不再变化,即面粉层最低着火温度为270℃。     

割孔注浆技术在西部全深冻结立井防治水中的应用

为了推进割孔注浆技术在西部富水软岩地层全深冻结立井井筒防治水中的应用,以大海则煤矿主立井防治水为工程实例,详细介绍了割孔注浆技术的现场应用情况及取得的成果。实践表明,合理地采用该技术可成功地封堵冻结管外环形空间导水通道,并对受注地层导水裂隙起到了封填堵水的作用,达到了防治水的目的,确保了矿井井筒的安全。     

‘印度青’苹果合成与分解代谢通量研究及贮藏温度的优化

本研究以‘印度青’苹果为原料，研究在不同贮藏温度下合成与分解代谢网络通量，并在此基础上优化其贮藏温度。将‘印度青’苹果放置在7 个不同温度（0、2、5、10、15、20、40 ℃）条件下，测定‘印度青’苹果不同部位糖酵解途径、三羧酸循环、蔗糖合成途径、磷酸戊糖途径的代谢通量。结果显示：2 ℃时蔗糖有较高的合成通量，由外到内4 个部位分别为32、42、47和33，乳酸盐也在2 ℃时有较高的代谢通量，由外到内4 个部位分别为1.87、1.86、1.86和1.86，在此温度下有较低的分解代谢和较高的蔗糖合成代谢，因此，2 ℃是‘印度青’苹果较好的贮藏温度。通过不同温度下‘印度青’苹果的各个部位之间代谢通量上的变化，可以建立以乳酸盐与蔗糖通量为评价标准的定量化模型，这可为今后更好地研究延长水果的贮藏寿命提供新的研究方法和理论参考。