快速测定水泥中SO3含量的新方法

本文研究了以吐温-80作为介质，硫酸钡浊度法测定水泥中的SO3吐温一80的引入，使沉淀颗粒分散均匀，体系稳定性显著提高，体系可稳定90min。本文选400nm作为测定波长，硫酸根的含量在50～500μg／25mL。范围内呈良好的线性关系，用于水泥样品中SO3的测定，取得了令人满意的结果。     

吐温-20对PB-g-PS胶乳改性水泥砂浆的性能影响

通过半连续胶乳接枝聚合反应合成了m(聚丁二烯)/m(苯乙烯)比例为50/50的聚丁二烯接枝聚苯乙烯(St)共聚胶乳(PB-g-PS).并向胶乳中加入了占固体质量为3％、5％和7％的吐温-20,制备三种水泥改性剂.水灰比为0.5(质量比),将三种水泥改性剂用于制备胶乳改性水泥砂浆,考察了吐温-20含量和聚灰比对改性砂浆的流动度、抗压和抗折强度、以及水吸收速率的影响.研究表明:在一定掺量范围内,改性砂浆的流动度随吐温-20含量和聚灰比的增加而增加;三种水泥改性剂均能够显著降低改性砂浆的吸水率;合适的水泥改性剂和吐温-20掺量,可使砂浆的力学性能损失较少;利用SEM进行了微观形貌分析,观察到了桥接结构、互穿网络结构以及孔洞结构,这些结构上的变化均有利于改善砂浆的性能;并对吐温-20的作用机理进行了分析,认为是水分子层的隔离作用.综上,吐温-20可以作为PB-g-PS胶乳的稳定剂.     

硫酸钡填充改性聚酰胺66的研究

研究了聚酰胺66（PA66）／硫酸钡复合材料的形态结构和力学性能，探讨了硫酸钡的表面处理对复合材料形态结构的影响以及活化硫酸钡对复合材料力学性能的影响。结果表明，在20％（质量分数，下同）活化硫酸钡和5％的乙烯-辛烯共聚物熔融接枝马来酸酐共混改性PA66复合体系中，少部分的硫酸钡对PA66具有异相成核剂的作用，大部分的硫酸钡对PA66具有增韧作用。与未加活化硫酸钡的相比，材料的拉伸强度提高了11SPa、弯曲强度提高了12SPa，简支梁缺口冲击强度提高了9kJ／m^2。     

纳米NaY分子筛的合成

在合成NaY分子筛时，向合成体系中添加少量的吐温系列表面活性剂(吐温20,吐温40,吐温60)可以显著地降低分子筛的晶粒尺寸。这是由于吐温系列表面活性剂在体系的强碱作用下发生皂化反应，生成聚氧乙烯山梨酸糖醇酐和酸钠皂，有利于降低NaY分子筛的表面能。但棕榈酸钠和硬脂酸钠在高含量Al³⁺的合成体系中，会形成不溶于水的棕榈酸铝和硬脂酸铝, 因此，吐温40和吐温60在合成纳米分子筛中的作用不如吐温20。在添加吐温20合成纳米分子筛时，较适宜的合成条件为：晶化温度90 ℃，晶化时间17 h，吐温20的添加量n(吐温20)/n(Al₂O₃)=0.2%。产品的粒度约75 nm，产率≥92%，硅铝比为3.46。     

微细NaY分子筛的合成及粒度分布的控制

以工业水玻璃和偏铝酸钠为原料，表面活性剂吐温20为添加剂，采用导向剂法水热合成了微细NaY分子筛。结果表明，添加适量的吐温20能有效降低NaY分子筛的粒度，但由于吐温20的水溶性较差，产物粒度分布范围宽。选择醇类溶剂为添加剂，考察了醇的种类、浓度及配比对产物粒度和粒度分布的影响。研究结果表明，乙醇对吐温20的增溶效果较好，在一定配比条件下，可以有效控制微细NaY分子筛产物的粒度大小及分布。     

表面活性剂对丹参酮增溶作用的研究

以乙醇和一些药用非离子表面活性剂作增溶剂，对丹参酮IIA进行了增溶实验。结果发现，丹参酮IIA在水中几乎不溶，而在乙醇中溶解度可达6mg/g。而在所考察的表面活性剂中，随着HLB值的增加，其对丹参酮IIA的增溶作用逐渐增强，它们的增溶效果由大到小依次为：吐温－20＞吐温－40＞APG－650＞吐温－80＞吐温－60＞吐温－65＞PEG－4000。在此基础上，选用增溶效果最好的吐温－20，作吐温－20／水／丹参酮IIA（乙醇溶液）的三元相图。该相图可以为配制丹参酮IIA制剂提供一定的参考。     

吐温-40存在下以PAN作指示剂络合滴定铝

1 简介PAN是用作测定金属离子的常用指示剂和显色剂。由于该试剂本身及其配合物的水溶性差,实验中通常采用加入乙醇或加热等手段来消除指示剂的僵化现象。本文利用非离子表面活性剂吐温-40的增溶增敏作用,以PAN为指示剂研究了EDTA-氟置换-铜盐回滴法测定铝的试验条件。试验结果表明,吐温-40的加入使滴定终点非常敏锐,加宽了PH值的测定范围,因而在测定水泥生料、熟料、钾长石和粘土等样品中的铝含量     

表面活性剂对HPMA阻垢分散性能的影响

表面活性剂作为添加剂在水处理当中应用研究很少。本文采用静态试验方法、黏附系数法和浊度试验方法，探讨了表面活性剂吐温-80、聚乙二醇和异丙醇对HPMA的影响。结果表明：三种表面活性剂能够提高HPMA的阻垢分散性能；同时，对于加药量为20mg／L的HPMA来说，表面活性剂有一个最佳用量，分别为吐温-80 1.8mg／L、聚乙二醇1.6mg／L和异丙醇1.4mg／L；从浊度法和黏附系数法可以得出，聚乙二醇可明显提高HPMA的分散性能。     

基质组成对熔铝池用浇注料抗侵蚀性能的影响

为了制备抗铝熔体侵蚀性能优良的熔铝池用浇注料,以高铝矾土(8~5、5~3、3~1和≤1 mm)为骨料,莫来石细粉、α-Al_2O_3微粉、硅灰、硫酸钡、高铝水泥为粉料,辅以一种抗侵蚀剂,采用四因素三水平正交试验,探讨了基质组成中硅灰(A)、抗侵蚀剂(B)、硫酸钡(C)和水泥(D)含量对浇注料在1 200℃保温72 h抗铝熔体侵蚀性能的影响。结果表明:基质中硫酸钡为抗侵蚀性能的主要影响因素。极差分析所得到的最优配方为A_3B_2C_3D_1,即硅灰、抗侵蚀剂、硫酸钡、水泥的掺量(w)分别为3%、3%、4%和4%。     

艾士卡法测定脱硫粉煤灰中SO3的含量

随着电厂干法脱硫技术的推广,作为脱硫副产物的脱硫粉煤灰的应用也受到水泥行业的广泛关注。使用脱硫灰后,最主要的问题是水泥的凝结时间显著延长。其原因主要是由于脱硫粉煤灰中含有大量的亚硫酸盐导致,而目前测定粉煤灰及水泥中SO3的方法主要为硫酸钡重量法及离子交换法,试验证实此两种方法在测定脱硫灰中的亚硫酸盐含量时均存在较大偏差。尤其是硫酸钡重量法,     

采用纳米Al203和碳纳米管颗粒强化CO2吸收的理论及实验研究（英文）

The influence of nano-particles on CO2 absorption was studied experimentally in a stirred thermostatic reactor. Nano-A1203 and carbon nanotube （CNT） particles which showed different hydrophobic properties were chosen for the investigation. The experimental results were compared with that of micron-size activated carbon （AC） and Al2O3 particles. From the results, no enhancement by micron-size A1203 was found, and with the increase of A1203 concentration, the enhancement factor decreased. However, nano-Al203 showed a weak enlaancement tor me COz absorption. AC and CNT particles all intensified the gas-liquid mass transfer effectively, yet the trend of the enhancement factor with stirring speed for the two particles was different. With increasing stirring speed, the enhancement factor of AC particles was decreased, wl＇iereas in CNT suspensions it was increased. The experimental phenomena demonstrated a difference in enhancement mechanism for different size particles. For nano-particles, besides the influence of adsorbability and hydrophobicity, the micro-convection caused by Brownian motion should be also taken into account. Considering the micro-convection effect, a theoretical model was developed to shed light on the absorption enhancement bv nano-oarticles.     

Experimental and Theoretical Studies of CO2 Absorption Enhancement by Nano-Al2O3 and Carbon Nanotube Particles

The influence of nano-particles on CO2 absorption was studied experimentally in a stirred thermostatic reactor. Nano-Al2O3 and carbon nanotube (CNT) particles which showed different hydrophobic propert...     

Effect of fine solid particles on absorption rate of gaseous CO2

The influence of the properties of solid particles in slurry on the absorption of CO₂ in the slurry was investigated in a stirred thermostatic reactor. The absorption experiments were carried out in three different slurries consisting of water, cyclohexane and soybean oil, respectively, and three kinds of solid particles (active carbon, active alumina and silica gel) were incorporated into each of the above mentioned slurries separately. The experimental results show that the active carbon particles could enhance the absorption rate of gaseous CO₂ in the aqueous slurry, while in the cyclohexane slurry, active carbon particles indicated no the absorption enhancement effect. However, it was observed that the active alumina and silica gel particles could enhance the absorption rate of CO₂ in the cyclohexane slurry. These phenomena indicate that the solid particles, which could enhance the gaseous CO₂ absorption rate, should possess two properties simultaneously, i.e. they rejected the solvent and had higher adsorption capacity for the solute. The experimental results also show that, as for those solid particles which could enhance the gas absorption rate, the enhancement increased quickly with the increase of solid concentration in slurry at first, and then reached a constant value gradually. It was also found that the enhancement factor was related to the coverage fraction of solid particles on the gas-liquid interface, and due to the reduction of surface fraction with increasing stirred speed, the enhancement factor decreased. __________ Translated from Journal of Chemical Engineering of Chinese Universities, 2008, 22(2): 356–360 [译自: 高校化学工程学报]     

高压电场强化空气对流传热实验及其数值模拟

以空气为实验介质,对水平光管、横纹管、缩放管和螺旋槽管的强制对流传热进行了高压电场强化实验,研究了高压电场强化传热的一些基本规律。实验验证了当外加高压大于15 kV后,对强制对流传热有较好的综合传热效果,最大强化率达2.8,而阻力系数的增大倍数在1.5—1.9。并对横纹管进行了数值模拟,从场协同的角度研究了速度场与温度场夹角对传热膜系数的影响。结果表明,速度、温度梯度的大小,及两者夹角的余弦值均会影响传热效果,在三者的值都是最大的位置,其传热膜系数也最大。     

强化传热技术及其应用

重点介绍了有源强化传热和无源强化传热的原理和方法。列举了一些强化传热的典型应用,如电场强化传热、流体诱导振动强化传热、超声波强化传热,翅片管、波纹管、多孔物质结构、纳米材料强化传热等。     

水溶液中甲苯分散相增强难溶气体吸收

利用难溶气体的物理吸收过程,在具有恒定气液界面面积的吸收装置中研究了常压和室温条件下分散液相(甲苯)对气液传质的增强作用。通过测定气相(丙烷和氢气)压力随时间的变化,计算出液侧传质系数和传质增强因子。试验发现,当传质组分在分散液相与连续液相内的分配系数较大,或在两相间的相对扩散系数较大,且分散相形成的液滴较小时,加入分散液相可显著增强气液传质;增强因子随分散液相含率的增大而增大,但增大幅度逐渐减小;当气体在纯水中的传质系数增大时,同等条件下分散相对气液传质的增强作用减小。     

化学吸收CO2的初步研究

以NaOH水溶液和Na2CO3水溶液吸收CO2属于化学吸收,吸收液的pH值随着吸收剂流量的增大而增大,呈现出对CO2完全吸收的趋势。由于化学反应增加了吸收速率,可根据增强因子利用物理吸收的方法计算化学吸收时所需的填料层高度。     

NIR enhancement induced by refractive index differences between noble metal particles and nanocrystals in glass-ceramics

The use of optically active ions doped into photonic media containing noble metals is an intriguing area of photoluminescence (PL) research. In this paper, we present a new approach using nickel ions doped into photonic glass ceramics (GCs) containing Au metal NCs. We exploit the unique PL properties of Ni²⁺ embedded in ZnAl₂O₄ nanocrystals (NCs). Under the same conditions, the Au-ZAO duplex samples exhibit 2–3 times higher near-infrared (NIR) emission intensity and higher absorption intensity compared to the samples without Au metal. We provide direct evidence of energy harvesting around NCs through numerical simulations. The significant NIR PL properties of Ni²⁺ in Au-ZAO GCs can be explained by the significant dielectric coefficient difference between the Au metal, the surrounding medium, and the ZAO NCs. Furthermore, the intense and broad emission spectra of our samples cover the entire second biological NIR region, which makes them particularly useful for biomedical applications.     

国外强化传热技术的研究与进展

本文综述了国外传热技术中开发出的各种强化传热表面以及其它一些强化手段、强化传热机理、不同学者在这一领域的研究成果。     

表面活性剂在分光光度法中的应用研究进展

综述了表面活性剂在分光光度法中的应用研究。在分光光度法中加入适量表面活性剂,可大大提高灵敏度,提高反应速度,增强反应稳定性,降低检测限等。