低量La~(3+)掺杂S-TiO_2光催化剂的制备、表征及其光催化活性

采用溶胶-凝胶-浸渍法制备了La3+/S-TiO2纳米光催化剂,通过XRD、BET、XPS、UV-Vis等手段进行了表征.以甲基橙溶液为光催化降解反应的模型化合物,考察了光催化剂的活性,探讨了低量La3+掺杂对TiO2纳米粒子光催化活性的影响机制.实验结果表明:S改性TiO2后明显提高了TiO2纳米粒子的光催化活性,而La3+掺杂S-TiO2后,进一步提高了TiO2纳米粒子的光催化活性,La3+的最佳掺杂量(相对于TiO2的质量分数)为0.369%;La3+/S-TiO2(ω(La3+)=0.369%)为纳米光催化剂时,甲基橙的脱色率达到92.4%(光照120min);XRD和BET分析表明,低量La3+掺杂抑制了TiO2由锐钛矿向金红石的转变,阻碍了TiO2晶粒的生长,提高了TiO2的比表面积;XPS分析表明,S、La3+掺杂可以导致粉体的表面羟基含量增加,掺杂S以S6+形式置换TiO2晶格中的Ti4+;UV-Vis分析表明,光催化剂La3+/S-TiO2比纯TiO2具有较强的紫外光吸收性能.与纯TiO2相比,La3+掺杂TiO2纳米粒子光催化氧化活性的提高应归因于La3+掺杂增加了表面羟基含量,增大了比表...     

S与Cr共掺杂TiO2介孔材料的固相合成及其可见光降解中性红

采用固相反应法分别合成了铬掺杂二氧化钛(Cr-TiO2)、硫掺杂二氧化钛(S-TiO2)及硫和铬共掺杂二氧化钛(S-Cr-TiO2)介孔材料,对其进行了物相织构表征,并研究了其对中性红的可见光降解性能. 结果表明,在S-Cr-TiO2中,硫以阳离子S6+形式、铬以同晶取代方式进入TiO2晶格或晶格间隙;S-TiO2, Cr-TiO2及S-Cr-TiO2 (摩尔比S/Cr=1:1)的比表面积分别为148.2, 134.6, 122.8 m2/g,孔半径分布中心依次为2.4, 2.6和3.06 nm. S-Cr-TiO2则随S/Cr比增大比表面积逐渐降低,同时存在Ti?O?S和Cr?O?S键并出现微量Cr2O3与CrO3物相. S与Cr共掺杂能有效限制TiO2微晶的生长,其紫外-可见漫反射吸收光谱覆盖了可见光区并延伸到近红外区域. 在25℃及pH=6.5条件下,S-Cr-TiO2 (S/Cr=3:2)在60 min内对中性红的降解率达91.8%,分别是纯TiO2 (39.6%), S-TiO2 (52.7%)及Cr-TiO2 (43.4%)的2.32, 1.74和2.11倍. Cr3+与Cr6+的相对含量及价态的转化控制中性红的降解率,Cr6+对中性红的降解起决定性作用.     

N,Al共掺杂TiO_2纳米材料的制备及其可见光降解葛根素

采用固相反应法合成了Al掺杂TiO2(Al-TiO2)及N与Al共掺杂TiO2(N-Al-TiO2)纳米材料,采用XRD、SEM、UV-Vis DRS、XPS、Raman以及N2吸附-脱附等手段对材料进行了物相结构表征。同时考察了可见光辐照下催化剂对葛根素降解性能。N-Al-TiO2纳米材料的微观形貌为短棒形;氮以阴离子(N3-)形式取代氧进入TiO2晶格,形成N—Ti键,Al3+以同晶取代方式占据TiO2晶格中Ti的位置;其表面N、Al、Ti及O的原子百分比组成(%)分别为7.8、3.6、32.7和55.9;并对葛根素显示出很高的可见光降解活性,2 h对葛根素的降解率达92.7%。3种材料对葛根素的吸附容量与其对葛根素的可见光降解能力一致,依次为N-Al-TiO2>纯TiO2>Al-TiO。     

微弧氧化法制备硫离子掺杂TiO_2薄膜及光催化制氢性能研究

以Na2SO3作为硫源,采用微弧氧化法法制备了硫离子掺杂TiO2薄膜(S-TiO2),利用XRD、UV-Vis、SEM和XPS等测试手段对上述催化剂进行了表征。分析结果表明,TiO2膜层只生成单一相的锐钛矿,并没有发现金红石相TiO2的特征峰;TiO2膜层的晶相组成及表面形貌没有受到硫源加入的影响;S离子掺杂后TiO2薄膜的吸收边发生红移,表明薄膜对可见光有一定的响应。Na2SO3添加浓度为0.03mol/L时,制备的S-TiO2光催化产氢速率达到0.279μmol/cm2·h。     

啶虫脒/席夫碱改性凹凸棒土缓释体系的制备与性能

采用后接枝法制备了席夫碱铜离子配合物改性凹凸棒土(Cu2+-Sal-ATP),通过浸渍法制备了啶虫脒/凹凸棒土(ATP)缓释体系。利用FTIR、XRD、N2吸附-脱附、SEM和DSC对改性凹凸棒土的结构和性质进行了表征,考察了改性凹凸棒土对农药啶虫脒的吸附行为和缓释体系的释药行为。结果表明:啶虫脒是以非晶相存在于改性凹凸棒土中,药物装载未改变载体的结构。有机改性提高了凹凸棒土对药物的吸附量,经席夫碱铜离子配位改性体系的吸附量最高,为34.17 mg/g,且吸附行为符合准二级动力学模型。Cu2+-Sal-ATP载药体系的缓释效果优于相应的席夫碱改性凹凸棒土(Sal-ATP)体系,其药物在168 h的累积释放率由23.41%降低至19.42%,且其释药行为可用Korsmeyer-Pappas动力学模型来描述。     

Pr^3＋掺杂的TiO2纳米粉体的表面特性和光催化活性

利用酸催化的溶胶-凝胶法制备了纯的和不同Pr^3＋掺杂量的TiO2纳米粉体．以亚甲基蓝（MB）溶液的光催化降解为探针反应，评价了它们的光催化活性．利用XRD和BET技术研究了Pr^3＋掺杂量和焙烧温度对TiO2纳米粉体的相结构、晶粒尺寸和表面织构特性的影响，并用XPS和SPS技术研究了Pr^3＋掺杂的TiO2纳米粉体的表面组成和表面光伏特性，探讨了Pr^3＋掺杂提高纳米TiO2的光催化活性的机制．结果表明：适量Pr^3＋掺杂能显著提高纳米TiO2的光催化活性．当Pr^3＋掺杂量为1．25％（以Pr^3＋／TiO2质量比计），焙烧温度为600℃时，制得粉体的光催化活性最佳．Pr^3＋掺杂强烈地抑制TiO2由锐钛矿相向金红石相的转变，减小晶粒尺寸，增大比表面积，增加表面羟基和吸附氧的含量，提高光生电子和空穴的分离效率，改善粉体表面的光吸收性能，上述因素均有利于光催化活性的提高．     

铁铈共掺杂TiO2纳米复合体的制备及光催化性能

采用微乳法制备了纯TiO2纳米粉体、Fe掺杂TiO2(Fe-TiO2)、Ce掺杂TiO2(Ce-TiO2)和Ce、Fe共掺杂TiO2(Fe/Ce-TiO2)纳米复合体。通过X射线衍射、扫描电镜和紫外漫反射光谱等对样品的结构和形态进行表征。以甲基橙溶液为标准模拟降解物,对Fe/Ce-TiO2、Fe-TiO2、Ce-TiO2和纯TiO2光催化降解性能进行评价。结果表明:Fe、Ce掺杂后TiO2的光催化性能明显提高,原因是Fe、Ce掺杂不仅能抑制TiO2晶粒生长,提高TiO2的热稳定性和比表面积,而且能够拓展TiO2的吸收波长范围至可见光区,降低了光生载流子的复合几率。共掺杂对TiO2光催性能的提高具有双重效应,使Fe/Ce-TiO2光催化活性明显高于Fe-TiO2的和Ce-TiO2的。500℃制备的Fe/Ce-TiO2对甲基橙降解效果最佳,归功于热处理温度对晶型和晶粒尺寸的影响。     

钌掺杂二氧化钛纳米粉体的制备及光催化性能

以钛酸四丁酯为原料,利用溶胶-凝胶法制各了纯TiO2和Ru掺杂的TiO2纳米粉体.利用热重-差热分析、X射线衍射、X射线光电子能谱和紫外-可见分光光度计对粉体进行了表征.在模拟太阳光下,利用含酚水溶液中苯酚的光催化降解反应,考察了TiO2纳米粉体的光催化活性和Ru的掺杂量对光催化活性的影响.结果表明:Ru的掺杂延缓了T...     

N, Al共掺杂TiO2纳米材料的制备及其可见光降解性能

固相反应法合成了铝掺杂二氧化钛(Al-TiO2)及氮与铝共掺杂二氧化钛（N-Al-TiO2）纳米材料,采用XRD、SEM、UV-Vis、XPS等手段对材料进行了物相结构表征。同时研究了可见光辐照下催化剂对葛根素降解性能。结果表明,N-Al-TiO2纳米材料的微观形貌为短棒形;氮以阴离子（N3-）形式取代氧进入二氧化钛晶格,Al3 以同晶取代方式占据TiO2晶格中Ti的位置. 材料表面N、Al、Ti及O的原子百分比组成(%)分别为7.8, 3.6, 32.7和55.9。N-Al-TiO2纳米材料的紫外吸光强度比纯TiO2与Al-TiO2大。对葛根素的降解显示出很高的可见光活性,其可见光降解葛根素的能力依次为N-Al-TiO2＞纯TiO2＞Al-TiO2。     

Ag掺杂TiO_2催化降解活性印染废水

以钛酸四丁酯、硝酸银为原料,通过溶胶-凝胶(sol-gel)法制备了掺杂不同含量银的TiO2纳米粉体,并将其应用于活性染料—活性红195、活性黄145及活性蓝19的印染废水的光催化降解。结果表明:适量的银掺杂可有效提高TiO2对活性染料光催化降解活性;当pH为6~8、银掺杂量为0.6%(Ag/TiO2摩尔比)、活化温度为500℃、催化剂用量为0.1 g/L时,光催化降解效率最高,分别为92.5%(活性红195)、90.8%(活性黄145)、83.6%(活性蓝19)。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

三种煤样燃烧热的测定

本文通过三个厂家提供的三种煤样燃烧热的测定,由测定结果综合得出3号煤样燃烧最完全、燃烧热也最大,是三个煤样中最好的一种。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

小议汽车涂装工艺设计对涂装成本的影响

论述了涂装工艺设计对涂装设备投资、涂装生产成本的影响。     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

Measurement of the gradient of viscosity with composition of mixtures of non-ideal gases

A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

塔设备改造选型的分析

就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后，着重介绍一种新型塔板（导向梯形浮阀塔板）和一种新型填料（波环填料——乾隆帕克）。     

Effect of degree of deacetylation of chitin on the properties of chitin crystallites

In the present article, chitin from crab shell was systematically deacetylated using a NaOH treatment with control of the reaction time. The degree of deacetylation, monitored using solid-state NMR, revealed that the reaction was pseudo-first order. Based on this, swollen and NaOH-saturated particles are proposed as the reaction system. The weight loss of the partially saponified and neutralized samples after HCl hydrolysis increased linearly with the degree of deacetylation. The crystallinity of the samples was found to increase after acid hydrolysis. According to conductimetric titration, the surface charge density of the crystallites, after acid hydrolysis, was found to increase with base treatment time. The effect of surface charge on the formation of a chiral nematic phase, due to the rodlike nature of the crystallites, was explored. These results show that because the contribution of charged particles to the ionic strength was significant the double layer compression was affected, especially since the surface charge density was close to the Manning limit. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:373–380, 1997