过滤压榨机模型的研究

通过由过滤及压榨过程组合而成的小型装置对脱水性能极差的活性污泥进行脱水试验，提出其试验方法、压榨模型。得到过滤压榨过程的关系曲线并证明压榨理论曲线与试验曲线存在的偏差。     

Fe_3O_4纳米颗粒的磁后效研究

用Preisach磁滞模型模拟了Fe3O4纳米颗粒的磁后效行为,并与实验测量结果进行了比较。结果表明:理论计算和实验结果符合的较好。其磁化强度随时间单调减小,与时间的对数成线性变化,磁场越接近负的矫顽力时衰减越快。通过Preisach模拟得到体系的涨落场和激活体积,激活体积大于实验测得的平均颗粒尺寸,由此解释了Fe3O4纳米颗粒的反磁化机制。     

对循环流化床Siegen流体动力学模型的改进

应用多尺度能量最小理论对循环流化床Ｓｉｅｇｅｎ流体动力学模型进行了改进,加强了模型理论基础的一致性,增加了模型的解析性,建立了空隙率轴向分布上、下行固体质量流量计算的新方法,改进的模型预测值与文献的实验数据吻合一体。     

碳化硅超细粉球团热风干燥特性及干燥模型的研究

利用热风干燥实验装置并采用130℃、150℃、170℃的风温及2m/s、3m/s的风速对碳化硅超细粉球团的干燥特性及干燥模型进行研究。结果表明:碳化硅超细粉球团的干燥过程分为三个阶段,即升速、恒速和降速阶段,其中升速阶段的干燥时间较短约为20～30min,恒速阶段的干燥时间约为50～80min,降速阶段的干燥时间约为180～210min;在碳化硅超细粉球团干燥的恒速阶段,干燥速率由高到低的顺序为:170℃150℃130℃,在降速阶段,风温170℃时干燥速率下降最快;当风速高于2m/s时,碳化硅超细粉球团的干燥速率变化不大。通过对在不同温度和不同风速条件下的碳化硅超细粉球团干燥的实验数据与8个常用的干燥模型进行拟合分析,发现修正Page模型(Ⅱ)干燥模型拟合度最好,可以较好地反映出碳化硅超细粉球团在不同温度和不同风速下的干燥特性。     

基于纵向力的轮胎模型及参数分析

通过垂直负荷分布修正和滑动摩擦因数参数化,建立轮胎纵向力模型,利用其对轮胎纵向力特性进行分析,并研究各因素对轮胎纵向力的影响。结果表明,随着静摩擦因数的增大,接地胎面完全滑移的滑移率增大,滑移力（Fsx）和附着力（Fax）增大;纵向刚度主要影响峰值前的纵向合力,随着轮胎纵向刚度和接地印痕长度的增大,接地胎面完全滑移的滑移率减小,Fax减小,Fsx增大。     

杨楼油田杨浅19断块的岩性测井识别模型研究

杨楼油田杨浅19断块常规测井曲线在对岩性进行识别时,各类测井曲线对岩性识别都有一定影响,采用简单的反映线性关系的交会图和直方图难以达到岩性定量精细识别的目的。通过对杨浅19断块岩性识别模型的研究,确立了人工神经网络的岩性识别模型,提高了该区的岩性辨识能力,使识别结果更加准确、可信。     

基于减压渣油组成及性质的连续分布模型的研究

进行了基于减压渣油组成及性质的连续分布模型研究。采用超临界流体萃取分馏技术,分别将三种减压渣油分离成若干窄馏分,并测定了各个窄馏分的性质和组成。在此基础上,建立了基于减压渣油组成及性质的连续分布模型,并利用连续分布模型对减压渣油的二次加工性能进行初步评价。再对此模型进行验证,尽管实测值与计算的KH值有一定的偏差,但是对该馏分的二次加工性能评价基本没有影响,说明该模型的应用成功。     

芳纶抗拉伸曲线模型的探讨

探讨了芳纶的抗拉伸断裂宏观力学模型,并对纤维的力学性能进行了模拟。利用3组件非线性力学模型对应力应变进行分析计算,结果实际与理论吻合的很好。此模型对芳纶的抗拉伸性能有预测作用。同时,对芳纶的抗钩接强度和抗打结强度也作了简介。     

石墨烯基铁氧化物对水体中草甘膦的动态吸附性能及模型

采用热沉积法制备出石墨烯/四氧化三铁（RGO-Fe₃O₄）复合材料,针对草甘膦（GLY）污染水体,开展该吸附材料对GLY的动态柱实验,通过考察污染物浓度、pH、流速、柱高等因素对穿透过程的影响,研究复合材料对GLY的动态吸附性能,并结合扫描电子显微镜（SEM-EDS）、X射线光电子能谱仪（XPS）、全自动比表面和孔隙分析仪（BET）等表征手段和Thomas、Yoon-Nelson和Yan等吸附模型分析吸附机理。实验结果表明：随着柱高增加,穿透时间延长,吸附柱对GLY的吸附总量增大;随着GLY初始浓度的升高,穿透时间缩短,吸附柱对GLY的吸附总量增大;随着流速和pH的升高,穿透时间缩短,吸附柱对GLY的吸附总量减小。此外,Thomas、Yoon-Nelson和Yan模型拟合得到的R²均大于0.9,且理论单位吸附量均与实际值相差不大,即3种模型均可较好地描述石墨烯复合材料对GLY的动态吸附过程。本实验的研究对石墨烯材料的推广应用及实际GLY污染水体的修复具有重要意义。     

改进的液膜传递模型

本文提出了一种新的用来描述乳状液型的液膜,Ⅰ型促进传递分离体系的数学模型。引入了内相对流和分离过程中乳液平均滴径随时间变化的概念。提出了用两阶段模型来描述实际液膜分离体系的观点。即:在前一阶段应该考虑内相对流和乳液滴径变化,而后一阶段则可不考虑上述二因素的渐近前沿模型来描述。     

掺杂对钡铁氧体吸波性能影响研究

本实验采溶胶-凝胶法制备钡铁氧体前驱体,煅烧前驱体。用X射线衍射仪（XRD）、微波分光仪对煅烧后产物的物相、微波吸收性能进行研究。结果表明用溶胶-凝胶法制备了钡铁氧体前驱体,二价金属阳离子微过量制备了较纯的铁氧体;铁氧体的烧成温度为800℃,掺杂后烧成温度为900℃。在11GHz,钡铁氧体和掺杂锶的钡铁氧体的反射损耗分别为-12．0dB和-15．9dB。     

Preparation and Properties of Barium Ferrite Using Hot-Rolled Mill Scale

Commercial-quality barium ferrite was made on a laboratory scale by the solid-state reaction of raw hot-rolled mill scale and barium carbonate. The quality of the isotropic magnets reached coercivity H _c 1750 Oe, remanence B _r 2200 G, and maximum energy product ( BH )_max 1.0 × 10⁶ G · Oe and that of the anisotropic magnets formed by dry powder die pressing H _c 2000 Oe, B _r 3500 G, and ( BH )_max 2.6 × 10⁶ G · Oe. The amount of the additives was in the range 0.4 to 0.8 wt%. The processing parameters were reported. The mechanism of ferrite formation was proposed.     

Magnetic Properties of Barium Ferrite Formed by Crystallization of a Glass

A glass with composition 0.265 B₂O₃-0.405 BaO-0.33 Fe₂O₃ (mole ratio) was prepared by a fast-quenching technique. When it is heat-treated, this glass exsolves up to ∼45 wt% BaFe₁₂O₁₉ as the only magnetic phase. Magnetic measurements of glasses heated at various temperatures show that superparamagnetic, single-domain, or multidomain magnetic behavior is present, depending on the thermal history. The volume of a typical superparamagnetic particle (calculated from the magnetic data) is equivalent to that of a sphere 47 Å in diameter. The intrinsic coercive forces of two heat-treated glasses were independent of temperature at high levels of H_ci (2600 and 2900 Oe) from 77° to 300°K. Another heat-treated glass has an H_ci of 5350 Oe at 300°K. Apparently, the coherent rotation model of Stoner and Wohlfarth describes the magnetic behavior of BaFe₁₂O₁₉ very well. The single-domain critical size for BaFe₁₂O₁₉ was ∼0.5 μm. An attractive feature of this system is that the BaFe₁₂O₁₉ powder can be recovered from the barium-borate-rich matrix by leaching with a weak acid.     

Effect of Milling on the Intrinsic Coercivity of Barium Ferrite Powders

The effect of milling on the intrinsic coercive force of Ba ferrite powders has been ascribed to (1) thermal fluctuations caused by superparamagnetic fine particles and (2) lattice defects introduced by milling. To test these interpretations, the Moessbauer absorption spectra and angular variation of coercive force for ball-milled powders were determined. With increasing milling time, the Moessbauer absorption spectrum becomes ambiguous, and the absorption lines are broadened; the quadrupole-split center line corresponding to superparamagnetic BaFe₁₂O₁₉ cannot be detected. The angular variation of coercive force shows that milling considerably lowers either the nucleation field of the reverse domain or the effective anisotropy field or both. It is concluded that lattice defects, rather than superparamagnetic fine particles introduced by milling, greatly affect the intrinsic coercive force of Ba ferrite powders.     

Ti-Mn-Cu替代的M-型钡铁氧体的制备和表征

为了改善钡铁氧体的性能,利用共沉淀-熔盐法制备了Ti、Mn、Cu掺杂的M型钡铁氧体,借助各种分析手段对样品进行了表征.结果表明:制备的样品呈现平面六角形结构,粒径在50mm左右.助熔剂对样品粒径的影响很小,对样品形貌的影响很大.得到这样的结论:经由共沉淀一熔盐法制备的Ti、Mn、Cu掺杂的M型钡铁氧体在助熔剂与前驱体比为(质量比)0.75∶1时获得规则的六角形并具有最佳的磁性能:σS(26.58e.m.u/g),Hc(3580 Oe),σr(15.18e.m.u/g).     

Effects of Excess Barium Ions on Aqueous Barium Titanate Tape Properties

The effects of excess free barium ions in aqueous barium titanate slip on the resulting BaTiO₃ tape properties were investigated in terms of the slip behavior, green/sintered tape density and morphology, and dielectric properties. The excess free barium ions expressed by means of the Ba/Ti ratio adversely affected most tape properties. Increase in the slip viscosity, green porosity, and agglomeration along with a decrease in mechanical properties and green/sintered density were found with the increase in the Ba/Ti ratio. However, dielectric permittivity was increased with increase in the Ba/Ti ratio. An effort was made to correlate these phenomena with Ba²⁺ leaching in water for realistic multilayer ceramic capacitor applications.     

塑料用铁酸锌黄颜料性能的研究

采用混合、煅烧-研磨法制备耐高温颜料铁酸锌黄。测试了不同改性剂制备的颜料对颜色的影响,通过CIE测色系统对添加有耐高温颜料铁酸锌黄的通用塑料外观颜色进行表征。结果表明:选用氧化铝作改性剂时,生产出的颜料着色力高、颜色鲜艳。     

Adsorption of Sulfonic Acid Doped Poly(vinyl chloride) on Barium Ferrite Particles

Adsorption of sulfonic acid doped poly(vinyl chloride) (PVC–SO₃H) and poly(vinyl chloride) (PVC) on barium ferrite particles is described. The maximum surface adsorption of PVC–SO₃H on barium ferrite was twice that of PVC. Surface chemical interaction between the sulfonic acid groups and barium ferrite surfaces was examined by adsorption of toluene-4-sulfonic acid. Sulfonic acid groups were found to adsorb selectively on both Ba–OH and Fe–OH sites by an acid–base interaction. Increasing the hydroxyl content on the barium ferrite surface creates increased dispersion stability in the presence of sulfonic acid doped PVC.     

Electrical Properties of PTCR Barium Titanate

When properly doped, barium titanate ceramics display positive temperature coefficient resistance (PTCR) behavior. This has been proved to be a Schottky barrier type of grain-boundary effect. However there has not yet been a complete point-to-point comparison between the experimental data and theory for the entire set of the material nonlinear dielectric properties. In this study, a methodology has been developed which allows the study of the depletion layer dielectric properties while the PTCR effect is being investigated. An equivalent dielectric constant, the value of which is to be determined from this experiment, is treated as an average of the dielectric properties of the depletion layer and is used to analyze the grain-boundary resistance and capacitance data based on a simple double-depletion-layer model. The theoretical relationship between this equivalent dielectric constant and the material dielectric properties is also explored in this study.     

Effects of Transition-Metal Substitution on the Catalytic Properties of Barium Hexaaluminogallate

The effects of the substitution of transition-metal ions and/or reductant gases on the catalytic properties of barium hexaaluminogallate were investigated. Transition-metal-substituted hexaaluminogallates (BaM(Al,Ga)₁₁O₁₉, M = transition metal, Al/Ga = 9/3) were synthesized from aqueous metal nitrates and ammonium carbonate by the coprecipitation followed by crystallization at 1100°C. The direct NO _x reduction was observed over BaM(Al,Ga)₁₁O₁₉ to be around 10%. The NO _x removal activity of BaM(Al,Ga)₁₁O₁₉ powders was improved by addition of C₃H₆ as a reductant gas. Co-, Ni- and Cu-substituted BaM(Al,Ga)₁₁O₁₉ catalysts exhibited about 40% NO _x reduction with C₃H₆ in excess oxygen at a high space velocity of 10 000 h⁻¹. The NO _x reduction on Mn- and Fe-substituted BaM(Al,Ga)₁₁O₁₉ catalysts was less than 10% even in the presence of C₃H₆. The temperature of the effective NO _x reduction on BaM(Al,Ga)₁₁O₁₉ catalysts could be adjusted from 350° to 500°C by the selection of the transition-metal substitution in the catalysts. The catalysts hold high activities for NO _x reduction even at 500°C in water vapor produced in the combustion system of reductant gases.