测量温度及恒温时间对催化原料密度的影响

油品密度在油品检验过程中是一项基本而重要的指标,在测量过程中常受多种条件的影响。本文在对催化原料密度测量时从测量温度和被测原料在恒温浴中恒温时间等方面对其的影响结果进行了充分的探讨,从而对影响液体石油产品密度测定的因素进行了分析。     

黏度法测定UHMWPE黏均相对分子质量影响因素分析

研究了黏度法测量超高相对分子质量聚乙烯(UHMWPE)特性黏数过程中恒温浴温度、溶剂、溶解时间对测试结果的影响.结果表明,恒温浴内部测试点附近的温度和温度控制器显示温度之差对最终计算结果影响较小;三氯苯和十氢萘分别作为溶剂所得到的结果较为接近,二者均可作为UHMWPE黏均相对分子质量的测试溶剂;聚合物完全溶解的标准是测试结果平行性好,并且随着时间延长,UHMWPE溶液流出时间不再变化.     

升温方法对气相色谱检测硅烷偶联剂结果的影响

考察了气相色谱仪两种升温方法对γ-氨丙基三乙氧基硅烷测试结果的影响.结果表明,程序升温法和恒温法检测出的含量一样;但采用恒温法更简便、快速.单从检测KH-550含量考虑,气相色谱仪恒温检测发是一种快速有效的好方法.     

特殊气体含氧量测量的实现

采用高温取样、高温测量的方法对高含水量、易自聚样品组分中的氧含量进行测量.预处理系统设计成高温恒温型,仪表选用高温型磁力机械式氧分析仪,整个测量系统的温度恒定在90℃左右,避免了样品可能发生自聚对测量造成的影响,同时可以完全真实地测量样品中的组分含量.     

低分辨率小核磁测定塑料等规度研究

研究低分辩率核磁法测定等规度,试验了测量时恒温的温度和时间、样品的用量、不同的样品管等对等规度测定的影响,结果表明:恒温的温度为40℃、恒温时间30分钟、样品用量为4.9～5.1 g时,等规度的测量结果比较接近萃取重量法的测定值,不同的装样管对等规度的测定没有影响。在此条件下,与萃取重量法比较,相对误差小于0.29%,相对标准偏差小于0.22%,体现了较好的准确度稳定性。且具有分析时间短,没有二次污染等优点。     

油品运动黏度测量的影响因素及理论计算研究

油品运动黏度是衡量其流动性能的重要指标,油品运动黏度的测量为油品输送过程中工艺条件调整及输送泵型号选择提供技术支撑.对黏度计的选择及安装位置、恒温浴温度控制、黏度管装入的样品量等影响因素进行分析讨论,同时结合理论公式推导,对同一油品或几种混合油品不同温度或不同比例混合下油品黏度进行计算,理论计算结果与实际测量结果一致,该方法可为科研工作提供指导.     

影响水泥凝结时间测量结果因素研究

标准GB/T 1346—2011对凝结时间的测量方法有明确规定,但在实际操作过程中,同一样品在不同的检测人员测量下都会存在一定差异,目前鲜有研究对影响水泥凝结时间测量结果的因素进行研究和分析,因此本文主要针对检测操作过程中的人员习惯,分别对影响凝结时间结果的几个因素（在恒温恒湿箱中的摆放位置、恒温恒湿箱的开关频率、坩埚和搅拌叶片是否洗净和湿润充分以及终凝杆针中间镂空位置是否堵塞）进行研究对比,将异常结果进行分析,补充水泥检测行业中的空白,为水泥检测中的异常结果提供参考依据。     

新型全自动毛细管式粘度测量系统的设计

叙述一种基于毛细管法的新型全自动粘度测量系统，该系统采用双气室气路结构，通过89C52单片机系统控制恒温，自动检测，计算，可用于工业现场实时测量。     

影响水泥凝结时间测量结果因素研究

标准GB/T 1346—2011对凝结时间的测量方法有明确规定，但在实际操作过程中，同一样品在不同的检测人员测量下都会存在一定差异，目前鲜有研究对影响水泥凝结时间测量结果的因素进行研究和分析，因此本文主要针对检测操作过程中的人员习惯，分别对影响凝结时间结果的几个因素（在恒温恒湿箱中的摆放位置、恒温恒湿箱的开关频率、坩埚和搅拌叶片是否洗净和湿润充分以及终凝杆针中间镂空位置是否堵塞）进行研究对比，将异常结果进行分析，补充水泥检测行业中的空白，为水泥检测中的异常结果提供参考依据。     

HRY-03S型高温荷软蠕变试验机计算机控制系统

HRY－03S型高温荷软蠕变试验机采用STD型工控计算机控制，升温温差±2℃，恒温温差±1℃，温度测量分辨率0．5℃，位移测量分辨率0．0025mm，实验结果自动处理，实验结束自动停机。     

用双液理论局部组成模型关联缔合体系核磁共振化学位移

¹H NMR化学位移被广泛用于研究缔合体系溶液微观结构和溶液热力学性质.本文基于局部组成思想和双液理论,提出了一个半经验的缔合体系核磁共振化学位移关联模型,模型中含有两个代表分子间相互作用力的待定参数.利用新提出的模型,对不同的缔合体系进行了关联,包括自缔、交叉缔等缔合体系.关联的结果表明,该模型能很好地描述各种不同缔合形式的缔合体系¹H NMR化学位移随浓度的变化关系.同时利用模型参数中含有的温度关系,预测了同一体系在不同温度时的核磁共振化学位移,预测偏差和模型自身关联偏差基本在同一数量级上.     

The lifetime assessment of low infrared emissivity composite coatings in chloride environments

The microstructural-electrochemical model is employed to predict the lifetime of low infrared emissivity composite coatings in chloride environments. Electrochemical data collected in 3.5 wt.% NaCl solution is presented for the low infrared emissivity coating, and these values are used as inputs for a mechanistic-based corrosion model which yields the salt spray life of the coating. To check the calculated results, the model predictions were compared with the results of salt spray tests. The current work showed that the model was able to predict lifetime of low infrared emissivity coating under salt spray, but tended to under-predict lifetime at short times and over-predict at long times. Under-prediction may be associated with corrosion protection of metallic pigment particles by polymer. Over-prediction by the model at longer exposure times may be associated with the fact that an influence of porosity is not included as a part of this simple model.     

The lifetime assessment of low infrared emissivity composite coatings in chloride environments

The microstructural-electrochemical model is employed to predict the lifetime of low infrared emissivity composite coatings in chloride environments. Electrochemical data collected in 3.5 wt.% NaCl solution is presented for the low infrared emissivity coating, and these values are used as inputs for a mechanistic-based corrosion model which yields the salt spray life of the coating. To check the calculated results, the model predictions were compared with the results of salt spray tests. The current work showed that the model was able to predict lifetime of low infrared emissivity coating under salt spray, but tended to under-predict lifetime at short times and over-predict at long times. Under-prediction may be associated with corrosion protection of metallic pigment particles by polymer. Over-prediction by the model at longer exposure times may be associated with the fact that an influence of porosity is not included as a part of this simple model.     

A solution strategy for the film model for non-isothermal gas–liquid reactions

A general solution strategy for the film model for gas–liquid reaction has been proposed using the boundary element method (BEM) of discretization over subintervals in gas–liquid films. Non-isothermal effects in the film are included and the associated temperature changes near the gas–liquid interface are computed. The accuracy of the solution procedure is first established using some simple isothermal and non-isothermal benchmark problems and with semi-analytical solutions. Then illustrative results are presented for a non-isothermal series reaction system to illustrate effects of various parameters such as Arrhenius number, solubility changes with temperature, effect of volatility of the liquid phase reactant, etc. The proposed solution method provides fast and accurate values for interfacial fluxes and fluxes into the bulk liquid in addition to concentration profiles. Hence the method is extremely useful for coupling local effects of the film model with global effects based on CFD coupled compartmental model for gas–liquid reactors.     

Correlation and estimation of solubilities of fatty acids in supercritical carbon dioxide using solution model approach

In this study, solid solubility data of five fatty acids in supercritical carbon dioxide (CO₂) at different temperatures and pressures are correlated using a two-parameter solution model developed from the regular solution model coupled with the Flory⿿Huggins equation. The developed solution model with fewer parameters yields correlated results comparable to those from commonly used semi-empirical equations. In addition, both parameters in the solution model can be further generalized with the chain length of fatty acids and a new predictive solution model is proposed for solubility prediction. The predictive solution model proposed in this study provides better predicted results and yields average deviation in predicted solubilities of 22.1%. To further apply this solution model to other compounds, solid solubility data of three triglycerides in supercritical CO₂ at 313 K are also correlated. After model simplification and generalization, a new predictive solution model for triglycerides is also proposed, which yields average deviation in predicted solubilities of 29.8%. These results demonstrate that the solution model used in this study is applicable for correlation and prediction of solid solubilities of structure-related compounds in supercritical CO₂.     

Liquid diffusion into epoxy resin composites

Dynamic sorption behavior of four epoxy resin matrix composites derived from fly ash, jute, mica, or vermiculite was studied in water and salt solution at 24°, 35°, and 45°C. The mass of water uptake per mass of sample was determined as a function of time. Diffusion coefficients were higher for distilled water than those for salt solution. The diffusion parameters were computed from the Arrhenius plots and the results analyzed in terms of a Fickian model. The results as obtained from weight gain assays are consistent with the view that the activation energy of diffusion is associated with the energy required to produce a space of sufficient cross-section for the diffusing molecule to pass.     

Kinetics of volume expansion during infusion of Ringer’s solution based on single volume model

In this work the kinetics of volume changes of fluid spaces associated with infusion of Ringer’s solution are analyzed by using the single-fluid space model. During infusion of Ringer’s solution, the human body is assumed to be characterized by the single-fluid space model into which fluid is fed and from which fluid leaves. Various infusion types were tested to accommodate different medical situations. Volunteers were given Ringer’s solution and the changes in blood hemoglobin were detected. From the comparison with experimental data, the single-fluid space model was found to represent adequately the kinetics of human volume expansion during infusion of Ringer’s solution.     

Errors associated with swelling in the analysis of polymer-solvent diffusion measurements

Sorption curves are generated from a mathematical model which includes the influence of the polymer swelling for unsteady-state sorption of a vapor or liquid by a polymer. To investigate the simultaneous effects of the specific volumes of the polymer-penetrant pair and the difference between the final and initial equilibrium concentrations on the sorption curves, statistical experimental design approach is used. Simulation results obtained from the numerical solution of model equations are utilized to estimate the error that would occur if one simply evaluates the diffusion coefficient using the traditional formulas derived from the analytical solution of the sorption equation. An empirical expression is developed that describes the effects of the difference between the final and initial equilibrium concentrations and the specific volumes of the polymer and the penetrant on the magnitude of error in diffusivity associated with the use of one of these traditional formulas so called the initial slope method. The predictive ability of the regression model is tested by performing additional simulations not used in the regression analysis.     

A simulation model to approximate penetration of a non-Newtonian fluid into a porous media during slot die coating

A computational fluid dynamics (CFD) model has been developed to predict the penetration depth of a non-Newtonian fluid as it is directly coated onto porous media by a slot die coating process. The model couples 1-D modified Blake–Kozeny equations and Navier–Stokes equations. Experiments of coating a non-Newtonian solution (black strap molasses) onto carbon paper (Toray 090) are conducted and the penetration depths are measured to validate the model. Preliminary results show that predicted and measured penetration depths follow the same trend; that is, as the coating speed increases the penetration depth decreases. However, the simulated penetration depths are found to be one to two times higher than measured values at low coating speeds. Even so, the results are considered reasonable, due to imposed simplifications and approximations of the CFD model and errors associated with the experiments and measurements.     

Kinetics of volume expansion during infusion of Ringer’s solution based on two volume model

In this work mathematical models were developed to represent the kinetics of volume changes of fluid spaces associated with infusion of Ringer’s solution. During infusion of Ringer’s solution, the human body is assumed to be characterized by the two-fluid space model which has second volume space in addition to the first volume so that fluid exchanges between these two spaces are possible. Various infusion types were tested to accommodate different medical situations. Volunteers were given Ringer’s solution and the changes in blood hemoglobin were detected. From the comparison with experimental data, the two-fluid space model was found to represent adequately the kinetics of human volume expansion during infusion of Ringer’s solution.