微波水热法制备CdS球形团簇

以醋酸镉[Cd(CH3COO)2·2H2O]和硫代硫酸钠(Na2S2O3·5H2O)为镉源和硫源,采用微波水热法制备了具有球形团簇结构的CdS微晶。研究了微波水热温度、时间以及n(S)/n(Cd)(摩尔比)等因素对合成CdS团簇结构的物相和微观形貌的影响以及样品的光学性能。结果表明:以Cd(CH3COO)2·2H2O为镉源合成的CdS微晶具有球形团簇结构的特殊形貌,CH3COO–在形成该球形团簇结构的过程中起到了模板剂的作用。水热反应温度升高与时间延长有利于产物结晶性增强,晶粒尺寸也会随之增大。随着n(S)/n(Cd)的增大,产物CdS会出现由团簇结构逐渐转变为准球形结构的规律变化。UV–Vis光谱研究表明,所制备的CdS微晶具有较强的可见光吸收特性,存在一定红移现象。     

CdS-K2Ti4–xPbxO9复合物的制备及其光催化制氢

采用高温固相法合成铅掺杂的K2Ti4–xPbxO9,微波辅助通过酸交换、胺柱撑、离子交换等步骤制备了硫化镉(CdS)插层的K2Ti4–xPbxO9(CdS-K2Ti4–xPbxO9)复合光催化剂。催化剂的结构利用X射线粉末衍射、紫外–可见漫反射吸收光谱和X射线光电子能谱等进行表征。考察了CdS-K2Ti4–xPbxO9在紫外光及可见光下催化制氢活性。催化剂的可见光吸收范围在Pb掺杂和CdS插层共同作用下得到了扩展,光催化活性也随之提高。催化剂在紫外光和可见光下3h产氢量分别为150.43mmol/(g cat)和2.43mmol/(g cat)。最后对光催化机理进行了分析。     

可见光催化分解水制氢的研究进展

阐述了近五年来可见光催化分解水制氢的国内外最新研究进展。重点介绍了离子掺杂型光催化剂、价带控制型光催化剂、固溶体催化剂、Z型体系光催化剂、复合型光催化剂以及一些新型可见光催化剂。对今后可见光催化分解水制氢的研究工作进行了展望。     

JCdS／ZnO复合半导体光催化剂的制备、表征及分解水制氢

在超声条件下,采用溶胶凝胶法制备Zn（OH）2溶胶,然后在其上沉积沉淀CdS,制备CdS／Zn（OH）2催化剂前驱体。前驱体分别在空气和氮气下焙烧,制得两种CdS／ZnO复合光催化剂。催化剂表征和分解水制氢实验结果表明,两种CdS／ZnO复合光催化剂在可见光区均有强吸收。空气条件下焙烧制得的光催化剂中有CdO存在,经XRF测量其组成为29.3％CdS-18.6％CdO／ZnO（物质的量分数）,其光催化分解水制氢效果明显高于氮气下焙烧制得的光催化剂,平均产氢速率达5.2mmol（h·gcat）^-1。     

非金属元素掺杂CdS/S,N-TiO_2复合光催化剂的制备及性能研究

以硫脲(TU)为非金属掺杂物,TiO_2-P25为原料,经浸渍-焙烧制备出S,N-TiO_2,而后通过水热合成出CdS/S,N-TiO_2复合光催化剂。催化剂的分析结果表明,S是以S~(6+)的形式取代了TiO_2晶格中的Ti~(4+),形成了S6+的阳离子掺杂,N则形成了O-Ti-N的结构,S和N的掺杂改变了TiO_2的电子结构,使其吸收边红移约10nm,电荷分离效率提高。可见光催化分解硫化氢制氢结果表明,CdS/S,N-TiO_2催化性能明显改善,CdS/S,N-TiO_2-2/1-600-1/2-240复合催化剂的催化分解硫化氢分解产氢速率可达62.24m L/h,CdS/S,N-TiO_2-2/1-600-1/2-240复合催化剂在不同p H值溶液中的产氢性能明显优于未掺杂的C d S/TiO_2复合催化剂。     

水溶性Ni_2P纳米粒子的制备及其光催化分解水产氢研究

本工作成功制备了单分散水溶性Ni_2P纳米粒子并将其用于光催化分解水助催化剂。实验结果表明,在可见光照射下Ni_2P/CdS体系是一个高效、稳定、廉价的光催化分解水制氢体系。     

CdS/r-TiO_2复合催化剂的制备及其在光催化分解硫化氢制氢中的应用

以钛酸四丁酯,乙酸镉为前驱体,以Na BH4为还原剂,采用溶胶凝胶辅助溶剂热法制备了负载CdS的还原TiO_2光催化剂(CdS/r-TiO_2),并运用扫描电子显微镜、X射线衍射仪、紫外可见漫反射吸收光谱仪和X射线光电子能谱仪等方法探讨了CdS负载量及TiO_2还原对光催化分解H2S制氢的影响。结果表明:负载CdS可使催化剂的光响应区间拓展至可见光区,Na BH4还原可进一步增加样品对可见及红外光的吸收性能。负载CdS增加了催化剂分解H2S制氢的反应活性位点,并有利于光生载流子的分离传输,使材料的光催化活性大幅增加。当CdS负载量为5%时,CdS/rTiO_2在全光谱光照下的产氢速率达2.4 mmol·h-1·g-1。     

CdS/CdSe核壳结构半导体纳米晶结构及光谱特性

采用共沉淀法在水相中将CdS外延生长于CdSe半导体纳米晶(CdSe NCs)表面,制备了结晶形态较好的CdSc/CdS核壳结构半导体纳米晶(CdSe/CdS C/S NCs),并改善了CdSe NCs的荧光性能.通过X射线衍射,透射电镜和选区电子衍射分析证明了核壳结构的形成,并通过紫外可见光吸收光谱和荧光光谱分析证明了核壳结构对CdSe NCs荧光性能的改善.此外,实验结果表明:控制CdSe核合成中Cd前驱体溶液pH值能获得粒径分布较窄的CdSe/CdS C/S NCs;采用不同浓度比的Cd和Se前驱体溶液可以有效调节核壳结构半导体纳米晶的粒径;选择合适的CdSe与CdS摩尔比及壳层中Cd与S摩尔比能改善CdSe/CdS C/S NCs的荧光性能.     

CdS/TiO2复合纳米粒子的制备及其产氢性能研究

采用化学沉淀法制备了CdS包覆TiO2（CdS/TiO2）复合纳米粒子,利用XRD、TEM、SEM、UV-vis吸收光谱等对其进行了表征分析,并以可见光分解水制氢为探针反应考察了复合纳米粒子的活性。结果表明,CdS/TiO2 复合纳米粒子的颗粒大小约为40nm,TiO2 以锐钛矿型存在,CdS以六方相存在;复合纳米粒子的吸收光谱较TiO2 发生“红移”,大幅拓宽了对可见光区的吸收范围。光解水制氢实验表明,CdS/TiO2 复合纳米粒子具有良好的可见光释氢活性和光学稳定性。     

CdS/TiO_2复合纳米粒子的制备及其产氢性能

采用化学沉淀法制备了CdS包覆TiO2(CdS/TiO2)复合纳米粒子,利用XRD、TEM、SEM、UV-Vis吸收光谱等对其进行了表征分析,并以可见光分解水制氢为探针反应考察了复合纳米粒子的活性。结果表明,CdS/TiO2复合纳米粒子的颗粒大小约为40 nm,TiO2以锐钛矿型存在,CdS以六方相存在;复合纳米粒子的吸收光谱较TiO2发生"红移",大幅拓宽了对可见光区的吸收范围。光解水制氢实验表明,CdS/TiO2复合纳米粒子具有良好的可见光释氢活性和光学稳定性。     

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.     

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。     

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.     

我国聚碳酸酯工业发展概况

介绍我国聚碳酸酯生产能力和消费需求,对聚碳酸酯在信息工业中的应用作了简短介绍     

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。     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003     

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%.