On the Effect of the Rotating Chamber Reverse Speed on the Mixing of SiC Ceramic Particles in a Dry Granulation Process

In order to control the accumulation of SiC ceramic particles on the wall of the rotating chamber in the frame of a dry granulation process,the effect of the wall reverse speed on the mixing process is investigated.In particular,an Euler-Euler two-phase flow model is used to analyze the dynamics of both SiC particles and air.The numerical results show that by setting a certain reverse rotating speed of the rotating chamber,the accumulation of SiC particles on the wall can be improved,i.e.,their direction of motion in proximity to the wall can be changed and particles can be forced to re-join the granulation process.Experimental tests conducted to verify the reliability of the numerical findings,demonstrate that when the reverse rotating speed of the rotating chamber is 4 r/min,the sphericity of SiC particles in the rotating chamber is the highest and the fluidity is the best possible one.

Preparation of high performance ceramic tiles using waste tile granules and ceramic polishing powder

This paper presents an innovative approach to reusing waste tile granules(TG) and ceramic polishing powder(PP) to produce high performance ceramic tiles.We studied formulations each with a TG mass fraction of 25.0% and a different PP mass fraction between 1.0% and 7.0%.The formulations included a small amount of borax additive of a mass fracton between 0.2% and 1.2%.The effects of these industrial by-products on compressive strength,water absorption and microstructure of the new ceramic tiles were investigated.The results indicate that the compressive strength decreases and water absorption increases when TG with a mass fraction of 25.0% are added.Improvement of the compressive strength may be achieved when TG(up to 25.0%) and PP(up to 2.0%) are both used at the same time.In particular,the compressive strength improvement can be maximized and water absorption reduced when a borax additive of up to 0.5% is used as a flux.Scanning electron microscopy reveals that a certain amount of fine PP granules and a high content of fluxing oxides from borax avail the formation of glassy phase that fills up the pores in the new ceramic tiles,resulting in a dense product with high compressive strength and low water absorption.

Preparation of TiO_2 film on granulated ceramic and application of disposal in water

Early research mainly studies the performance of TiO2 power condition.As a result of using power condition TiO2,its power is slight,not easy to precipitate,and creates another pollutants.Therefore,the ceramic granulated substance carrier material was used to prepare the TiO2 thin film to carry on the water treatment to obtain the good effect.The gangue of coal was used to make the ceramic granulated substance basis,then in a ceramic granulated basis place TiO2 thin film was painted,advancing together the running water processing experiment.The test result is as follows:The TOC content reduces by above 80%,and used to filter the material to be possible to replace at will,which has obtained good effect.In the testing,using the scanning electron microscope analyzer,carrying on the superficial appearance view to the TiO2 ceramic sand leach material to scratch,finally indicated,it has some turtle crack in the TiO2 ceramic granulated substance surface,has crystal boundary surface flaw,causes it to have bigger catalytic activity.

Preparation and Performance of Zirconia Ceramic Ring for Slide Plate

The zirconia ceramic ring was prepared using fused monoclinic zirconia as main starting material, adopting composite stabilizer of magnesia, yttria and calcium nitrate, and applying recombination technology of traditional refractories and ceramics. Effect of the preparation process on material properties was comparatively studied, and the microstructure and phase composition were analyzed. The results show that adopting the high-speed mixing granulation process and the appropriate heat treatment can realize the control on the phase composition and microstructure, the zirconia ceramic ring with good thermal shock resitance and mechanical properties can be prepared.

MULTI-SCALE AND MULTI-PHASE NANOCOMPOSITE CERAMIC TOOLS AND CUTTING PERFORMANCE

An advanced ceramic cutting tool material Al2O3/TiC/TiN （LTN） is developed by incorporation and dispersion of micro-scale TiC particle and nano-scale TiN particle in alumina matrix. With the optimal dispersing and fabricating technology, this multi-scale and multi-phase nanocomposite ceramic tool material can get both higher flexural strength and fracture toughness than that of A1203/TiC （LZ） ceramic tool material without nano-scale TiN particle, especially the fracture toughness can reach to 7.8 MPa . m^0.5. The nano-scale TiN can lead to the grain fining effect and promote the sintering process to get a higher density. The coexisting transgranular and intergranular fracture mode induced by micro-scale TiC and nano-scale TiN, and the homogeneous and densified microstructure can result in a remarkable strengthening and toughening effect. The cutting performance and wear mechanisms of the advanced multi-scale and multi-phase nanocomposite ceramic cutting tool are researched.

粉煤灰基陶瓷膜支撑体的制备与尺寸放大试验

选取固体废物粉煤灰作为支撑体骨料,TiO_(2)为烧结助剂,羧甲基纤维素(CMC)为黏结剂,木炭粉为造孔剂,采用固态粒子烧结法制得初始陶瓷膜支撑体样品,并对其进行等比尺寸(直径)放大制备。探究支撑体尺寸放大制备中烧结温度、造孔剂添加量、尺寸(直径)放大倍数等因素对支撑体性能的影响,对物质组成、微观形貌、抗折强度、纯水通量、酸碱腐蚀率及孔径分布等性能进行表征。结果表明:最高烧结温度为1 050℃,造孔剂木炭粉添加量为15%(质量分数),放大到原尺寸(直径)的2倍时,所制得支撑体性能最佳,其内部孔隙均匀,颈型结构明显,纯水通量为4 728.26 L/(m^(2)·h·MPa),抗折强度为25.15 MPa,中值孔径为3.06μm,孔隙率为38.56%,酸、碱质量损失率分别为0.33%、0.25%。

Further investigations on the influence of scale-up of a high shear granulator on the granule properties

This study focuses on the characterisation of strength, density, and size of granules produced in various scales of a high shear granulator. Calcium carbonate （Durca165） was used as the feed powder and aqueous polyethylene glycol （PEG 4000） as the binder. The dried granules were analysed for their strength, density, size distribution, and wall make-up. Granules were produced in granulators with four scales, 1, 5, 50, and 250 L under three scale-up rules of constant tip speed, constant shear stress, and constant Froude number. The results show that regardless of equipment scale, increasing the impeller speed has a great effect on crushing strength and stress. The underlying cause is an increase in granule density due to more consolidation at higher impeller speeds. Wall make-up is significantly reduced to less than 5% as the scale is increased from 1 to 250 L. The results of this study corroborate our previous findings that the constant tip speed rule is the best criterion for scale-up of high shear granulators.

爆轰驱动陶瓷面背板碎裂行为研究

为研究陶瓷平板在爆轰载荷下的碎裂行为,采用AUTODYN软件对其爆轰驱动过程进行了数值计算,通过爆轰波与陶瓷平板的作用过程分析及陶瓷破片的特征尺寸统计,得到了陶瓷平板的裂纹拓展规律及陶瓷破片尺度分布规律。结果表明:不同陶瓷平板药室中爆轰波的传播及其与陶瓷平板的作用过程类似,但陶瓷裂纹拓展及形态不同,无拼接陶瓷平板形成网格化裂纹,而拼接陶瓷平板则呈现环向裂纹及径向裂纹;爆轰载荷下陶瓷平板药室形成的陶瓷破片尺度满足Rosin-Rammler分布模型;不同尺度陶瓷破片质量分布的比重由幂指数系数k决定,陶瓷平板的整体损伤程度可用平均特征尺寸系数λ评判,考虑到陶瓷平板药室的低附带损伤特性,选择小尺寸的陶瓷片进行陶瓷平板拼接较合适,研究结果可为陶瓷平板药室在轻型装甲车辆上的应用提供参考。

通脉助孕颗粒的工艺放大及其质量研究

目的:对通脉助孕颗粒的制备进行工艺放大,并建立其质量标准。方法:对通脉助孕颗粒依次进行小试和中试的放大,获得3批中试样品。对中试样品的性状进行规范化描述,采用薄层色谱法(TLC)对通脉助孕颗粒中的陈皮、炒白芍、赤芍和北柴胡进行定性鉴别,采用高效液相色谱法(HPLC)对芍药苷进行定量分析。色谱柱为C18(5μm,4.6 mm×250 mm),以乙腈-0.1%磷酸(14∶86)为流动相,流速1.0 mL/min,检测波长230 nm,柱温30℃。结果:通脉助孕颗粒的小试、中试工艺验证均符合要求。陈皮、炒白芍、赤芍和北柴胡的薄层色谱主斑点清晰,分离良好,阴性对照无干扰;芍药苷在58.3~583.0 ng范围内线性关系良好,测得平均回收率为99.97%,RSD为0.35%。结论:通脉助孕颗粒的处方工艺稳定可靠,制备的样品性状稳定、质量均一。建立的TLC和HPLC专属性强、重复性好、准确可靠,能够有效评价通脉助孕颗粒的质量。

大型挤压造粒机组检维修技术要点探讨

本文介绍了大型挤压造粒机组的组成,并从检维修角度出发,对大造粒机组常见技术问题要点进行了阐述与探讨,从而达到机组长周期稳定运行的目的,保证生产经济效应。

多尺度邻域决策信息系统的特征子集选择

多尺度决策信息系统的特征子集选择是处理多尺度分类问题的一种有效的数据预处理方法.在实际应用中,数据类型往往多样混合,现有的多尺度模型无法有效处理这类数据.针对该问题,文中面向多源异构多尺度数据,提出多尺度邻域半径的形式化定义,构造多尺度邻域信息粒并讨论其相关性质.在此基础上,探讨特征的重要度,提出可同步进行最优尺度选择和特征选择的特征子集选择算法.改进原有的Wu-Leung模型,在一定程度上扩展其在实际问题上应用的范围.最后,在UCI数据集上验证模型和算法的可行性和有效性.

桑丹通络颗粒治疗阴虚血瘀证缺血性脑卒中恢复期的回顾性队列研究

目的评价桑丹通络颗粒治疗阴虚血瘀证缺血性脑卒中恢复期的临床有效性与安全性。方法采用回顾性队列研究方法,通过湖南省中医药研究院附属医院门诊与住院病历系统收集2021年7月至2022年6月收治的缺血性脑卒中恢复期患者临床资料,选择应用桑丹通络颗粒联合西医常规治疗的51例患者为暴露组,匹配仅应用西医常规治疗的102例患者为对照组,两组均治疗2周。比较治疗前后总有效率、美国国立卫生研究院卒中量表(National Institute of Health Stroke Scale,NIHSS)评分、日常生活活动能力(activity of daily living,ADL)评分、血脂水平、血液流变学指标和症状总积分等,并对所有患者治疗期间不良反应事件进行记录。结果暴露组临床总有效率84.31%,高于对照组的67.65%(P<0.05)。与治疗前比较,两组治疗后NIHSS、TC、LDL降低(P<0.01或P<0.05),且暴露组低于对照组(P<0.05);两组ADL升高(P<0.01),且暴露组高于对照组(P<0.01)。与治疗前比较,暴露组治疗后症状总积分、血液流变学各项指标降低(P<0.01或P<0.05),且暴露组低于对照组(P<0.01或P<0.05);HDL-C升高(P<0.01),且暴露组高于对照组(P<0.01)。结论桑丹通络颗粒联合西医常规治疗可明显改善阴虚血瘀证缺血性脑卒中恢复期患者症状,降低其神经缺损程度,改善血脂水平和血液流变学指标,有效提高其生存质量,疗效确切且安全稳定。因此,推测桑丹通络颗粒具有一定的临床应用与推广价值。

低温下PAA/载钴陶粒基反硝化滤池处理含杂环类药物生化尾水研究

本课题组前期构建了载钴陶粒活化过氧乙酸(PAA)体系(PAA浓度为150mg/L),实现了对典型杂环类药物(磺胺甲恶唑(SMX)、磺胺嘧啶(SDZ)、卡马西平(CBZ)和甲氧苄啶(TMP),浓度均为20mg/L)的高效降解.为实现对反硝化滤池功能的原位升级,本研究进一步探索低温下PAA/载钴陶粒基反硝化滤池处理含上述杂环类药物生化尾水的效能.在15℃、进水COD为60mg/L、NO_(3)^(-)-N为20mg/L、四种杂环类药物均为20μg/L、载钴陶粒投加比例为3%、PAA浓度为150μg/L和300μg/L时,滤池取得了较好的总氮和杂环类药物去除及急性毒性削减效果,出水TN达到一级A标准要求,SMX、SDZ、CBZ、TMP的平均降解率分别为67.20%、75.17%、80.90%和70.26%;随着HRT的缩短,出水急性毒性上升,但均属于低毒;反应器浸出钴离子浓度低于1mg/L,符合地表水环境质量标准规定.该滤池中微生物物种分布更加均匀,且关键菌属Paracoccus和Gordonia和napA、narG、nirK基因丰度提高对杂环类药物和TN的去除发挥显著作用.在不考虑反冲洗情况下,本研究PAA/载钴陶粒基反硝化滤池每深度处理5mg/L NO_(3)^(-)-N的运行成本(按1m^(3)计)为0.1567~0.3475元/m^(3),具有较好技术经济性.

Multi-scale thermodynamic analysis method for 2D SiC/SiC composite turbine guide vanes

Ceramic Matrix Composite （CMC） turbine guide vanes possess multi-scale stress and strain with inhomogeneity at the microscopic scale. Given that the macroscopic distribution cannot reflect the microscopic stress fluctuation, the macroscopic method fails to meet the requirements of stress and strain analysis of CMC turbine guide vanes. Furthermore, the complete thermodynamic properties of 2D woven SiC/SiC-CMC cannot be obtained through experimentation, Accordingly, a method to calculate the thermodynamic properties of CMC and analyze multi-scale stress and strain of the turbine guide vanes should be established. In this study, the multi-scale thermodynamic analysis is investigated. The thermodynamic properties of Chemical Vapor Infiltration （CVI） pro- cessed SiC/SiC-CMC are predicted by a Representative Volume Element （RVE） model with porosity, leading to the result that the relative error between the calculated in-plane tensile modulus and the experimental value is 4.2%. The macroscopic response of a guide vane under given conditions is predicted. The relative error between the predicted strain on the trailing edge and the experimental value is 9.7%. The calculation of the stress distribution of micro-scale RVE shows that the maximum value of microscopic stress, which is located in the interlayer matrix, is more than 1.5 times that of macroscopic stress in the same direction and the microscopic stress distribution of the interlayer matrix is related to the pore distribution of the composite.

赤红颗粒的制剂工艺研究

目的研究赤红颗粒的制备工艺。方法采用单因素试验对加水量、稠膏比重、混合制软材时间、颗粒含水量进行筛选,从而选择最优的工艺条件,制备颗粒,并进行质量检查。结果最佳制备工艺条件是处方药材加水量为6倍,稠膏比重为1.20~1.30(80℃),混合时间确定为15 min,制得产品的重量差异及外观、熔化度、薄层鉴别及含量测定均符合药典要求。结论制定的制备工艺可控,适用于规模化生产。

Synthesis of monodisperse erbium aluminum garnet (EAG) nanoparticles via a microwave method

Abstract： Uniform Er3A15O12 spheres are of great value for fabricating optical ceramics. The highly monodisperse and size-controllable erbium aluminum garnet （EAG） precursors for transparent ceramics were successfully synthesized through a new microwave process. The precursors constituted of ultrafine particles joining together by a hydroxyls formed compact network structure in the absence of SO42 , however, the morphologies of the precursors exhibited spheres with trace amount of SO42-. With manipulated programming of microwave irradiation parameters, narrow distributed particles of 40-50 nm were finally obtained by a separation of nu- cleation and nanocrystal growth. The mechanism behind the influence of microwave irradiation parameters on the growth of EAG precursors was preliminarily analysed. Easily dispersible and pure phase EAG were obtained at 950℃. The as-prepared EAG powders were used to fabricate transparent ceramics and transparent polycrystalline EAG ceramics were obtained under hydrogen furnace at 1750℃ for 8 h.

Sb-SnO_(2)掺杂量对Al_(2)O_(3)-13%TiO_(2)复合陶瓷涂层抗结垢性能的影响

以Al_(2)O_(3)-13%TiO_(2)(AT13)和纳米掺锑SnO_(2)(Sb-SnO_(2))粉体为原料,采用等离子喷涂工艺在4145H合金钢基体表面制备了掺杂不同质量分数(0~16%)Sb-SnO_(2)的AT13复合陶瓷涂层,研究了复合陶瓷涂层的表面性能、微观形貌、显微硬度、结合强度以及在地层采出水中的抗结垢性能,并与电镀铬层和未处理4145H合金钢进行对比。结果表明:与电镀铬层和未处理4145H合金钢相比,复合陶瓷涂层的水接触角较大,表面能较低,随着Sb-SnO_(2)掺杂量的增加,水接触角基本呈先增大后减小的趋势,表面能先减小后增大;复合陶瓷涂层具有大量的孔隙;随着Sb-SnO_(2)掺杂量的增加,硬度整体呈降低趋势,但均高于4145H合金钢和电镀铬层,单位面积结垢质量先减小后增大;掺杂质量分数10%Sb-SnO_(2)的复合陶瓷涂层具有最大的水接触角、最小的表面能、最小的单位面积结垢质量,平均结合强度为25.7 MPa。

多尺度模拟计算方法在超高温高熵陶瓷材料中的应用进展

超高温高熵陶瓷材料以难熔金属碳化物、硼化物、氮化物等为组元,具有较高的硬度、高温强度以及良好的热稳定性,已成为超高温陶瓷领域研究的热点方向之一。与传统材料相比,超高温高熵陶瓷涉及复杂成分空间、多个尺度维度、极端多场耦合服役环境,采用传统经验试错法开发超高温高熵陶瓷效率过低,故而需要改变材料研究范式,依靠多尺度模拟计算方法提高超高温高熵陶瓷研发与应用效率。本文首先简要介绍了具有代表性的多尺度材料计算方法,进而综述了多尺度材料计算方法在超高温高熵陶瓷研究中的典型应用成果,最后对多尺度材料计算方法在超高温高熵陶瓷研究中的前景进行了展望。

Pore-scale lattice Boltzmann simulation of flow and mass transfer in bioreactor with an immobilized granule for biohydrogen production

The photo bioreaction combined with flow and mass transfer is simulated with pore-scale lattice Boltzmann(LB) method, which is the scenario of a bioreactor filled with a porous granule immobilized photosynthetic bacteria cells for hydrogen production. The quartet structure generation set(QSGS) is used to generate porous structure of the immobilized granule. The effects of porosity of the immobilized granule on flow and concentration fields as well as the hydrogen production performance are investigated. Higher porosity facilitates the substrate solution smoothly flowing through the porous granule with increasing velocity, and thus results in higher product concentration inside the immobilized granule. Additionally, the substrate consumption efficiency increases, while hydrogen yield slightly decreases with increasing porosity, and they tend to stable for the porosity larger than 0.5. Furthermore, the LB numerical results have a good agreement with the experimental results. It is demonstrated that the pore-scale LB simulation method coupling with QSGS is available to simulate the photo hydrogen production in the bioreactor with porous immobilized granules.

我国陶瓷墙地砖制粉工艺的进展

坯体粉料的制备是陶瓷墙地砖生产中的重要一环,影响着产品的最终质量。我国的陶瓷制粉技术从20世纪80年代起,通过借鉴国外先进技术和自主研发等方式发展形成了各种不同的制粉工艺。本文通过介绍我国近三十年陶瓷墙地砖制粉技术的发展历程,分析了近年来关于陶瓷砖制粉工艺的专利、造粒机结构及其工作原理,比较了用不同造粒工艺制备粉料的性能,并针对目前陶瓷砖制粉工艺存在的问题,提出了未来的发展方向。