数控铣床主轴热负荷研究

应用Pro/E对某型号数控铣床主轴进行建模,运用ANSYS软件对主轴进行温度场和热变形分析,讨论数控铣床主轴在单一热源作用下的熟特性.     

二阶双螺杆挤出机流场分析

在阶梯状双螺杆挤出机参数一定情况下,利用三维软件建立实体模型,在ANSYS Workbench有限元软件Fluent模块中,分析阶梯状双螺杆挤出机中熔融段速度分布、压力分布、流体迹线分布的情况。     

基于管道排列的背心式液冷服研发与测评

为了提高夏季高温作业人员的舒适性，设计研发了3款液冷管道降温服。该液冷服由基础服装和液冷系统构成，液冷管道排列于躯干不同部位。气候舱以温度32℃、相对湿度50%模拟高温环境，进行真人着装试验，并对液冷服热湿舒适性及降温效果进行评价。结果表明:3款液冷服均具有一定的降温效果;与对照组服装相比，液冷服使人体平均皮肤温度、躯干皮肤温度、衣下温度、热感觉均有所下降，而热舒适感提升;其中，躯干前后均排列液冷管的冷却服对人体的降温效果最为显著。     

电动汽车电池液冷板MIG焊接工艺设计

锂离子电池热管理已成为制约电动汽车商业化的瓶颈,为解决此问题,在锂离子电池散热和加热系统中加装液冷板。有效提高电池低温放电性能和高温耗能,从而提高电池持续充放电过程的稳定性和安全性。液冷板采用铝硅合金型材,两端加装封堵和连接管。加装的端部封堵需要通过焊接完成与型材的连接,通过铝合金自动焊接和半自动焊接与手工焊接的多次试验,由于自动焊接的局限性及气孔缺陷,手动焊接的效率太低,最后通过摸索完善焊接工艺设计,采用手工MIG熔化极氩弧焊取得了非常好的生产效率及焊接质量。     

大型汽轮发电机转子系统的模态分析与仿真

运用有限元分析软件ANSYS对转轴系统的模态进行分析,并运用三维软件Pro/E的NC加工功能实现对转子的数控加工,得到前20阶频率.计算出汽轮发电机转子弯曲振动的固有频率,得到临界转速位于第二、三阶临界转速之间,避免工作转速与临界转速相同产生的共振现象,达到优化转子动力特性的目的.利用三维软件PRO/E的加工仿真功能实现了转轴车削加工和铣削加工的模拟,为实际转子模型的NC加工奠定了基础.     

门式起重机金属结构模态分析

本次分析为箱型门式起重机,通过ANSYS软件进行建模并对其进行模态分析,从而得出固有频率和振形位移云图,根据数据和图对门式起重机进行分析。     

基于Pro／E和ANSYS的瓦楞辊力学性能分析与研究

通过运用三维软件Pro/E对瓦楞辊进行三维建模,并将其导入有限元分析软件ANSYS中,利用ANSYS导入功能建立起瓦楞辊有限元模型。通过对瓦楞辊进行静力学分析,求出了其应力与应变,并对其脆弱部位进行表面处理,从而增强了瓦楞辊的机械性能并提高了其使用寿命。     

一种电池箱动力电池火情报警系统设计

电池箱动力电池的内部短路、过充过放和外部短路易导致热失控的发生,在其过程中会产生大量的烟雾和气体。为了能够准确判断火情报警情况,本系统采用高灵敏度的传感器,研究电池箱动力电池发生热失控前期烟雾和气体浓度变化,根据热失控发展规律,设定探测阈值,当传感器探测烟雾和气体浓度达到报警阈值时,向报警主机或电池管理系统(BMS)发出报警信号,以实现高效的早期报警,准备可靠的火灾判断。该系统经多次试验验证,稳定可靠。     

基于ANSYS软件的注塑机定模板的设计与优化

在PRO/E软件和ANSYS Workbench软件的协同环境下,直接采用ANSYS软件提供的先进的拓扑优化功能,在有限元分析的基础上对160 t注塑机定模板进行拓扑优化.首先对注塑机模板系统进行实体建模和有限元分析,确定应力和应变的分布情况.在此基础上建立目标函数并对其进行优化,根据研究结论对原模板设计提出改进方案.优化后的结构在刚度和强度上将有很大提高,从而解决了如上所述的工程实际问题,也就是在满足最大刚度的前提下,找出最佳的材料分配方案.即最佳的筋板分布形式.     

框架浮筏功率流的有限元分析

提出了一种框架型浮筏隔振系统,通过三维软件对浮筏系统进行建模,利用ANSYS分析软件对框架浮筏隔振系统进行谐响应分析,求得系统在外力作用下的振动情况,再以功率流方法分析浮筏系统的隔振效果。得出框架浮筏系统的隔振效果较为理想,特别是当激励处于在高频段时。     

Methodology for design of suitable dishes for dysphagic people

A methodology to adapt dishes for cerebral palsy (CP) dysphagic people was developed. Five conventional dishes were cooked, blended and texturized with mixtures of thickeners and gelling agents based on xanthan gum. The most appropriate texturizing agents were selected, the textural thermostability of the dishes was studied, and the shelf-life was evaluated by back extrusion, sensory and microbiology analysis. Information about the acceptability of the adapted dishes by CP dysphagic people was obtained through the control of the consumed fraction and the liking or disliking reaction after eating the dishes. The adapted dishes considered suitable for swallowing process showed maximum force between 6.2(0.1) N and 18.9(3.3) N, minimum force between −3.9(0.3) N and −9.2(1.3) N, and F_min/F_max ratio between 0.4(0.0) and 0.7(0.0). Regarding sensory characteristics, the adapted dishes showed low stickiness, residue and firmness, and high suitable texture score. The methodology was appropriate for developing suitable dishes, sensorially accepted by dysphagic people, thermostable for 7 days refrigerated storage and ready-to-eat.Industrial relevanceThis study presents the technological basis for the standardized design of suitable ready-to-eat dishes for dysphagic people. The methodology developed is of great interest to the industry of ready-to-eat dishes.     

游戏机手柄上盖注射模设计

文章分析了游戏机手柄上盖塑料件的工艺特点,介绍了游戏机手柄上盖注射模结构设计和工作过程。该模具采用浇口开设在顶杆上,在分型时实现自动拉断凝料,同时将曲面分型改为平面分型,降低模具加工的难度,节约成本和提高注塑、脱模的稳定性。生产实践证明,该套模具结构合理,运行可靠。     

Computation method for optimization of recipes for protein content

The authors propose a calculated protein utilization coefficient. This coefficient considers the difference between the utilization rates of the proteins being contained in the mixture and their amino-acid composition. The proposed formula allows calculations by computer. The data obtained show high correlations with the results received by biological tests with Tetrahymena cultures.     

Comparison of Iterative Procedures for Solving Equations for Sire Evaluation

Gauss-Seidel, successive overrelaxation, end-of-round relaxation, and block iteration methods of obtaining solutions for sire effects from equations rising from progeny with records in mixed model procedures were compared. Equations transformed to provide direct solutions for genetic group plus sire effects as well as constrained and unconstrained equations were compared also. Equations for milk yield for the Northeast Artificial Insemination Sire Comparison numbered 301 for Ayrshires, 325 for Brown Swiss, 6,010 for Holsteins, and 926 for Jerseys after absorption of herd-year-season effects. Numbers of coefficients were 15 to 20% less for transformed equations, which decreased computing time per round of interation about 15%. Solutions for transformed equations converged more rapidly than solutions for untransformed equations with convergence criterion the ratio of the residual norm to the norm of the right-hand sides. Successive overrelaxation generally was more efficient than Gauss-Seidel iteraton. Solutions for equations constrained to full rank converged more slowly than unconstrained equations. Block iteration was more efficient than single equation iteration.     

圆形钢丝断面收缩率的快速计算法

按照ＧＢ２２８—８７《金属拉力试验法》中的公式计算断面收缩率既费时又复杂。在对原公式作进一步推导之后得出一新的计算式，按此公式可快速、难确地计算出值。     

大豆热风烘干机的设计计算

大豆脱皮对提高大豆油质量及豆粕蛋白含量至关重要.作为大豆脱皮中的关键设备,烘干机的设计质量对脱皮效果影响很大.以50 t/d大豆烘干机为例,介绍了大豆烘干过程中的物料衡算、热能衡算等计算方法和参数的选取,对实际应用具有一定指导作用.     

Screening of industrial enzymes for deproteinization of shrimp head for chitin recovery

Food grade proteolytic enzymes were examined for deproteinization of shrimp head. Shrimp head was easily deproteinized by Alcalase ® and trypsin at a pH of 8.0. Alcalase was chosen as the most efficient commercial enzyme for deproteinization of shrimp head. Alcalase treatment of shrimp head recorded 61% of weight loss on dry basis and a residual protein of 275 mg/g dried shrimp head. The enzymatically deproteinized shrimp head was later demineralized with lactic acid using microwave radiation at 400W. The combination of enzymatic and physicochemical treatments promoted the chitin recovery from dried shrimp head under eco-friendly conditions.     

FTA滤膜用于PCR检测单核细胞增生李斯特氏菌的研究

建立单核细胞增生李斯特氏菌(Listeria moncytones,LM)快速、敏感、特异的PCR检测方法.利用FTA滤膜提取模板DNA,采用PCR特异性扩增单增李斯特菌的溶血素基因(HIyA),并评价该方法的特异性与灵敏性.引物能特异性的扩增单增李斯特的HIyA基因,而其他细菌的扩增结果均呈现阴性:利用FTA滤膜提取模板直接检测单增李斯特具有较高的灵敏度,灵敏度为l 02 cfu/mL.利用FFA滤膜提取模板,操作简便,成本低且具有较高的灵敏度,为食品中单核细胞增生李斯特氏菌的快速检测提供新的手段.