反气相色谱法研究前沥青烯的表面性质

采用反气相色谱法表征前沥青烯的表面性质,测定了其表面色散自由能及酸碱常数,并基于极性探针的吸附,得到极性探针在前沥青烯表面的极性吸附自由能?G~(sp)和极性吸附焓?H~(sp)。结果显示,温度在60~100℃范围内,前沥青烯的表面色散自由能随着温度的升高而逐渐减小。前沥青烯表面的酸常数K_a为0.91,碱常数K_b为2.98,K_b/K_a=3.27。由此可知,前沥青烯为两性偏碱性材料。     

反气相色谱法研究前沥青烯的表面性质

采用反气相色谱法表征前沥青烯的表面性质,测定了其表面色散自由能及酸碱常数,并基于极性探针的吸附,得到极性探针在前沥青烯表面的极性吸附自由能DG^sp和极性吸附焓DH^sp。结果显示,温度在60～100℃范围内,前沥青烯的表面色散自由能随着温度的升高而逐渐减小。前沥青烯表面的酸常数K_a为0.91,碱常数K_b为2.98,K_b/K_a=3.27。由此可知,前沥青烯为两性偏碱性材料。     

热处理对针状焦电化学性能的影响

利用X射线衍射(XRD)、扫描电子显微镜(SEM)和恒流充放电方法对不同热处理温度下针状焦的微观物理结构和充放电循环性能进行了研究.结果表明,随着热处理温度的升高,针状焦石墨化程度增加,微观晶体结构趋于完整,表面缺陷减少,800℃下热处理样品初次嵌锂容量达到463 mA·h/g;随着热处理温度的升高,材料的循环稳定性显著提高,2 800℃石墨化处理样品50次循环后可逆容量可达360 mA·h/g.     

热处理温度对低硅含量SiO2微粉固废性能的影响

对回收的w（SiO₂）<85%的低硅含量SiO₂微粉固废进行了不同温度（400、500、600、700、800、900和1 000℃）保温5 h的热处理，并对热处理后的粉体进行了分析。结果表明：随着热处理温度升高，试样逐渐烧结。热处理温度低于800℃时，SiO₂微粉保持原有粒状、球状SiO₂颗粒团聚体结构。但热处理温度为500℃及以下时，团聚体强度较低。热处理温度800℃以上结块严重，并析出方石英相。热处理温度控制在600～800℃可制得具有一定强度，体积密度在0.73～0.95 g·cm^-3的球壳结构的球状粉体，该粉体可以作为轻质原料用在低温保温浇注料，也可以作为其他行业填料。     

Sol-Gel法合成锌铝尖晶石的影响因素研究

以Zn(NO3)2·6H2O,Al(NO3)3·9H2O为原料,柠檬酸为络合剂,采用sol-gel法制备了尖晶石型ZnAl2O4粉体.得到干凝胶后在不同温度下(600～ 800℃)进行热处理.探究pH值对凝胶的影响以及煅烧温度对粉体相组成和显微结构的影响.用热分析,X射线衍射分析(XRD),扫描电镜(SEM)等手段对制备的锌铝尖晶石粉体进行了表征.结果表明:当煅烧温度为600℃时,ZnAl2O4开始生成,随着煅烧温度的提高,ZnAl2O4晶粒逐渐长大、发育完整,其他物相含量减少,粉体趋于单一尖晶石晶体结构;随着溶液pH值的增加,ZnO含量增加,ZnAl2O4含量减少,当pH值为3时,得到纯度较高的ZnAl2O4粉体.     

超细硼化锆粉体纯化工艺探究

探究了超细ZrB2粉体化学提纯、热处理等纯化工艺过程中的影响因素.并采用热重-差热分析仪、X射线衍射仪、扫描电镜、透射电镜和X射线荧光光谱分析仪对ZrB2粉体及热处理后的水洗产物进行表征和分析.结果表明:B2O3易溶于热水生成硼酸溶液,为了有效地除去B2O3,需经过热水反复洗涤、过滤;随着热处理温度增加,粉体中的C杂质逐渐氧化挥发,但当热处理温度升至700℃时,产物中的ZrB2被氧化生成ZrO2,致使产物迅速增重;热处理温度650℃和热处理时间80min为最佳热处理除杂工艺,此时产物中残留的碳基本全部被除去,但是产物中氧含量较高,后期研究建议选择在惰性气氛中进行.     

CdS的制备及其光催化性能研究

以硫化钠、醋酸锌和醋酸镉为原料,采用沉淀法制备了CdS粉体。用傅立叶红外（FT-IR）、X射线衍射仪（XRD）以及紫外-可见漫反射（UV-Vis DRS）对制备的粉体进行了表征。并研究了焙烧温度对其晶型以及光催化降解甲基橙的影响。结果表明：随着焙烧温度的升高,六方相晶型CdS含量逐渐增加;且都对甲基橙有一定的催化降解作用,当热处理温度为80℃时,CdS光催化剂的光催化降解活性最高。     

热处理对电气石远红外比辐射率的影响

对天然电气石进行高温热处理,并采用远红外比辐射仪、DTA、XRD、SEM及EDS等测试技术分析了电气石的红外比辐射率及物相变化规律,探讨了热处理的影响规律.结果表明,随着热处理温度的升高,电气石的远红外比辐射率呈增大趋势,在900℃时比辐射率值最大,达到0.927;电气石的物相由镁电气石、铁电气石、黑电气石向钙镁电气石、钠长石、钙长石转化,并呈现出烧结现象;物相成分变化、离子价态改变及晶体结构缺陷是热处理后电气石远红外辐射率提高的根本原凶.     

电气石/硅藻土基内墙砖釉层热处理温度对其结构与性能的影响

采用固相烧结和低温煅烧工艺,制备了硅藻土基多孔陶瓷支承体。以硅藻土为主要原料,在釉料里添加适量电气石和烧结助剂,结合不同的釉层热处理温度,制备了电气石/硅藻土基内墙砖。用热重–差示扫描量热分析、X射线衍射、扫描电子显微镜对不同热处理温度下釉层进行了表征,探讨了热处理温度对釉层微观形貌与结构的影响。以甲醛为目标降解物,考察了釉层不同热处理温度下电气石/硅藻土基内墙砖对甲醛去除效果的影响。结果表明:随着热处理温度的提高,硅藻土原始孔洞减少,比表面积和孔隙率下降,电气石结构发生变化。850℃时材料的表面结构稍有破坏,强度较高,对甲醛的去除效果较好,1 m3的环境舱内,300 min甲醛去除率达到73.6%;升温至950℃及以上,硅藻土和电气石结构遭到破坏,材料对甲醛的吸附和降解能力下降。     

二氧化硅喷雾造粒粉体的热处理

研制了一种以SiO2为基体的高温可磨耗封严涂层，为了改善二氧化硅喷雾造粒粉体的性能，研究了热处理工艺对粉体松装密度、流动速度及粒度分布的影响：结果表明，热处理过程中伴随着SiO2颗粒的烧结，热处理温度对粉体性能的影响较热处理时间更为显著，随着温度的升高，喷雾造粒SiO2球逐渐烧结，粉体粒度减小，松装密度增加，流动性提高，采用1000～1050℃、30～60min的工艺对粉体进行热处理能够获得最优的粉体性能。     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

用两个形状指数表征粉煤灰颗粒形貌的研究

引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。     

典型煤碳燃烧特性研究和数值模拟

本文以三种典型煤的碳燃烧为研究对象，分别采用简单一维沉降燃烧方式和等温加热燃烧方式，实验研究了煤在快速加热条件下，其碳的初期和中，后期燃烧过程。以实验为基础，建立了煤的碳燃烧模型，变工况数值模拟了煤的碳燃烧过程，揭示了煤不同条件下的单颗粒碳燃烧特性。     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

制备板状玻璃炭工艺中固化曲线的确定

固化处理是在玻璃炭制备工艺中很关键的阶段．在差热分析和热失重分析的基础上．建立了玻璃炭（GC）固化升温曲线，并与等速升温法作了比较．