计算机仿真技术在生产系统中的应用

针对生产系统在设计与运行过程中面临的问题,分析了在生产系统中应用仿真技术的必要性.并以Flexsim仿真软件为例介绍了在生产系统中如何利用仿真技术对方案进行虚拟仿真,同时根据仿真结果对方案进行分析、评价和改进.     

综合化学实验的教学实践与改革

针对综合化学实验教学实践,对学生在综合化学实验中结果情况进行统计,并对实验结果及实验中的问题进行了总结分析,找出原因所在,对该综合化学实验中相关问题提出了指导性意见.     

全密度聚乙烯聚合反应釜气相在线色谱仪采样系统改造

对某全密度聚乙烯装置反应釜气相在线色谱仪的采样系统进行改造,解决了分析气体中异戊烷、1-丁烯在样品传输中液化而导致的分析结果波动的问题.     

基于CAE技术的磁疗仪注射模设计

利用CAE技术可在模具制造前,对模具设计方案进行分析和模拟来代替实际的试模.以医用磁疗仪后壳为研究对象,利用Moldflow软件对不同位置浇口、冷却系统进行模拟,利用分析结果解决注射模的设计及成型过程中出现的问题.     

石灰乳测定所存在两个问题的探析

在纯碱厂中控分析项目中,石灰乳测定一直让分析人员产生许多疑问,其原因是因为石灰乳本身是一含各类杂质的悬浮液,所需进行分析的组份(活性氧化钙、死石灰、碳酸钙),在溶液中并非以离子状态存在,而是颗粒大小不一的各类沉淀,且三者与酸的反应活性各不相同。所以测定结果常令人怀疑,进行仲裁时结果极不易平行。本文试就石灰乳分析中所存在的下列两个问题进行探讨:1.活性氧化钙滴定终点的判断;2.灰乳温度对测定结果的影响。1　关于活性氧化钙的滴定终点石灰乳的三个常规分析项目均采用酸碱滴定法进行分析,实验证明,在用盐酸标准溶液对石灰乳进…     

扁平绕带式压力容器在冲击载荷作用下的动力特性研究

在石油化工这一特殊行业中,这一类型的压力容器往往处于高温和高压下运行,在突发故障下可能引起的爆炸是不可避免的,扁平绕带式压力容器有望解决这类缺陷问题而被开发为新型高压容器.在实验的基础上,对扁平绕带式压力容器的动力响廑问题进行了分析.对扁平绕带式压力容器在冲击载荷作用下进行模拟,模拟结果与实验结果基本吻合,研究结果对扁...     

节能工作的经济分析

在节能工作中,如何才能取得最大的经济效果是当前需要研究的一个重要问题.本文试就保温层的厚度、余热的回收、低压废蒸汽的利用以及多级换热等方面的问题进行经济分析,并提出了相应的关联式.附有例题以得出具体的定量结果.     

耐火材料能谱分析准确性讨论

采用扫描电镜-能谱组合对耐火材料进行微区成分分析时,除了对由能谱能量分辨率引起的谱线峰重叠及峰干扰等问题外,还应对由其空间分辨率所引起的分析结果不准确问题予以重视.本文主要从能谱的空间分辨率考虑,结合一些分析实例,来讨论能谱对耐火材料样品进行点分析时,所选取的分析点对结果准确性的影响.实践结果表明,电镜操作参数的正确选择和试样适宜装置是影响能谱分析可靠性的重要因素.一些尺寸细小的、薄片状的晶体和纤维要特别注意形状因子对电子束取样有效容积的影响,要确保3D尺寸全都在X射线的发射广度Rx和穿透深度Zm范围内,至少要>1 μm.耐火材料中普遍存在的微晶团聚体的测定值可信度低.微轻元素如B、N、C、Na等的测定结果只能作参考,不宜直接引用,需做波谱分析.     

文氏管煤粉混合器的数值模拟

在煤粉工业锅炉系统中,煤粉混合器存在呼吸帽正压、风速偏低和供粉波动等问题.使用CFD软件FLUENT对煤粉工业锅炉文氏管煤粉混合器不同工况下的速度场、压力场、颗粒轨迹和供粉浓度等进行了模拟和分析,并通过实验对模拟结果进行了验证.结果表明,上述问题是由下游阻力过大、风机工作点偏差和文氏管负压区偏差等原因导致的.     

基于NX和Moldflow的汽车灯罩注射模设计与分析

利用Moldflow对汽车灯罩注射工艺方案分析,得出最佳成型工艺条件；同时对整个塑件成形过程模拟分析,预测成型中可能出现问题.根据分析结果,利用UG模具制造模块时汽车灯罩进行注塑模设计.     

Partikelgrößenanalysen < 10 μm Meßmethoden und Schwierigkeiten

Particle size analysis of particles < 10 μm – methods and difficulties . A review of possible methods for the determination of particle size distributions in the range < 10 μm is presented. Important factors regarding the specimen dispersion are dealt with, particularly those which must be taken into consideration in the “fines” region, and the limits and difficulties of individual analytical equipment are illustrated with the aid of examples. Finally, analytical results obtained by various methods of measurement are compared and the criteria of assessment such as operational possibility and costing are discussed.     

Potentiale regenerativer Festbrennstoffe und die Notwendigkeit der Charakterisierung ihres Brennverhaltens

Potentiality of Solid Regenerative Fuels and the Necessity of the Characterization of Combustion Processes Apart from coal, solid regenerative fuels will obtain increasing importance in overlapping fuel markets. The combustion process depends on the properties of the fuel and fuels can be characterized using standard analytical tests. These standard test methods are simplified and only valid for the specific fuel type. The transfer to other fuel types can not be made without further analytical tests. The development of new highly informative analytical methods is necessary to compare the different reactions of a combustion process by using fuels of different origin. A new analytical principle fulfils these demands. The main difference to common techniques is that it uses large fuel particles. This leads to a better statistical validation of the analytical results and information about the fragmentation behavior of large fuel particles can be gained. The definition of characteristic parameters enables the practical use of the analytical data.     

A Systematical Study on Factors Influencing the Determination of the Total Glucosinolate Content in Rapeseed by the X-RF Method

The X-RF method for the determination of the total glucosinolate content in rapeseed is a comparatively new method, which is, due to its striking features in precision and speed, becoming the most favoured method for glucosinolate analyses within the European Community. This contribution presents a first systematic study on sources of variations in analytical results obtained with the X-RF method. Sample born sources of variations (immaturity, contaminations with weeds and fungi, inhomogeneity) primary cause deviations of the results obtained by chemical reference or control methods. One of the most striking problems is the immaturity of seeds which leads to systematically lower glucosinolate values by chemical methods so that the results obtained by the X-RF method appear to high. Compared to this possible error, variations caused by mistakes during preparation and measurement are of less importance. However, the knowledge of these factors may give helpful hints when deviations to results of other analytical methods want to be explained and to optimize the routine work in order to avoid systematic errors in the analytical procedure.     

A rigid poly(vinyl chloride) compound with improved combustion characteristics

By means of compounding, we have developed a rigid poly(vinyl chloride) (PVC) formulation with improved overall combustion properties. Newly developed analytical methods indicate a considerable reduction in the level of gases released during combustion, in addition to excellent flammability characteristics and low visible smoke emission levels. The analytical methods discussed are expected to aid in the selection of a feasible protocol for biological testing and in the interpretation of results obtained from such testing. The under-lying compounding technology is currently restricted to normal impact rigid PVC cube compounds but expected to be expanded into high impact PVC, flexible PVC, PVC powder compounds and cellular PVC.     

陶瓷原料分析方法研究进展

陶瓷原料决定着陶瓷成品的质量,所以对陶瓷原料的分析显得尤为重要。综述了陶瓷原料分析方法包括常规化学分析方法和仪器分析方法的研究进展情况,并对不同分析方法进行了总结。     

Towards properly controlled analytical measurement methods

It is of great practical importance to develop simple methods for the automatic detection ofthe controlled state of the analytical method being applied. The key point is to find quantities that greatly affect the quality of the analytical results and that can be easily estimated during the measurement process from the measured data. The signal-to-noise ratio has proved to be such a quantity in gas chromatographic methods. The statistical properties of the estimation of the signal-to-noise ratio from gas chromatographic data have been investigated. The suggested practical method for estimating the signal-to-noise ratio proved to be biased from a mathematical statistical point of view, but the bias is usually not greater than 10%. It has been shown by practical examples that the signal-to-noise ratio affects the quality of the analytical results and it is easy to estimate its value from practical data.     

压力容器标准应用的探讨

本文对目前压力容器行业中常关注的一些强度计算问题,如对国内外规范或分析设计和规则设计规范人相互套用问题,有限元法在设计中的应用问题等,根据规范,标准的制订背景,各种应力分析方法之间的关系,提出一些粗浅看法共同参考。     

煤及其燃烧产物中无机组分分析方法比较

从三个方面对煤及其燃烧产物中无机组分的分析方法进行了比较和评价：1)比较和评价了煤及其燃烧产物中矿物分析方法，其中主要讨论了XRD法和CCSEM法；2)比较和评价了煤及其燃烧产物中元素含量的分析方法，主要包括X-射线和v-射线技术；原子吸收或发射技术(AAS／AES)和质谱法(MS)；3)比较和评价了煤及其燃烧产物中微量元素的赋存形态分析方法，主要包括直接分析方法和间接分析方法．