HZSM-5分子筛负载SrTiO_3光催化降解活性艳红X-3B

采用溶胶-凝胶法制备HZSM-5分子筛负载SrTiO_3,对其进行XRD、FTIR和N2吸附-脱附表征,研究负载对活性艳红X-3B光催化降解过程的影响。通过分析降解液的FTIR谱图、紫外-可见光谱和总有机碳(TOC)数据,对活性艳红X-3B的光催化降解过程进行了探讨。结果表明:催化剂的主要成分为钙钛矿结构SrTiO_3,负载对SrTiO_3晶粒尺寸几乎没有影响。纯SrTiO_3没有明显的孔结构,负载后样品的比表面积和孔隙主要由HZSM-5提供。负载之后催化剂的降解活性显著提高,30%SrTiO_3/HZSM-5对活性艳红X-3B染料溶液的脱色和TOC去除速率最快。     

DE型锌酸盐镀锌液中香草醛的气相色谱分析

从DE型锌性盐镀锌液这样一种含有大量无机物和有机物的体系中测定微量香草醛是比较困难的,至今未见报道,但它对电镀质量的控制至关重要。本文通过对镀液样品酸化,用苯甲醚萃取分离,然后取有机相在OV-17柱上进行气相色谱分析,可定量测定香草醛的含量,对色谱分析的条件和参数也进行了研究。     

超声波-Fe3＋掺杂TiO2纳米管光催化降解活性艳红X-3B的研究

以超声波作用制备的Fe3＋掺杂TiO2纳米管作为光催化剂,氙灯模拟紫外光为光源,降解活性艳红X-3B,探讨了超声预处理时间、催化剂煅烧温度、pH值、催化剂加入量等因素对活性艳红X-3B降解率的影响,结果表明,超声波预处理时间为20min,催化剂煅烧温度为400℃,pH为强酸或强碱,催化剂加入量为1.0g/L时对活性艳红X-3B处理效果较好。     

MWCNT/Bi2WO6复合光催化剂的制备及其活性研究

采用水热合成法将多壁碳纳米管(MWCNT)和Bi_2WO_6有效复合,制备了具有高效光催化活性的MWCNT/Bi_2WO_6催化剂。利用XRD、SEM、TEM、XPS、BET和UV-Vis等技术对样品进行表征分析,以罗丹明B为目标污染物,考察了催化剂的光催化性能。结果表明,合成的样品均为斜方晶体结构,MWCNT交互附着在Bi_2WO_6片层结构的周围,两者紧密接触形成了复合物。合成的MWCNT/Bi_2WO_6样品具有较大的比表面积和较小的禁带宽度,能有效抑制光生电子和空穴的复合,增加了量子的传递效率,更容易被光照激发。当MWCNT负载量为2%(质量分数)时,催化剂表现出了最佳的催化性能,在模拟太阳光试验中,该催化剂对10 mg/L的罗丹明B溶液光降解效率高达98. 8%。     

碳纳米管内外担载NiO催化剂的可控制备及其性能研究

采用不同处理方法对碳纳米管进行预处理,后通过超声浸渍法制备得到新型构型的催化剂:以碳纳米管为载体,内外管壁担载金属活性中心Ni基催化剂。在制得催化剂样品后,采用SEM、TEM、BET和TPR等表征手段,对碳纳米管、催化剂样品的形貌及性质等方面进行研究。并将催化剂样品用于CO2甲烷化反应中,探索Ni的不同活性位对催化活性的影响规律。     

新型可见光催化剂Bi6O26N5H9/AgCl的制备及其性能研究

以硝酸铋和硝酸银为主要原料,采用水解法制备了可见光响应型高效复合催化剂Bi6O26N5H9/AgCl。利用X射线仪(XRD)、扫描电镜(SEM)等手段对样品进行表征,并以碱性染料罗丹明B为目标污染物,金属卤化物灯为可见光光源测试其光催化性能,研究了初始Bi 3+/Ag+物质的量比、废水pH及浓度等对Bi6O26N5H9/AgCl光催化活性的影响,并对光催化过程中产生的活性物种进行了检测。结果表明,当罗丹明B的质量浓度为20 mg/L、AgCl/Bi6O26N5H9催化剂用量为0.5g/L、pH=4.6、光照30min条件下,罗丹明B脱色率、COD和TOC去除率分别为98.73%、88%和69%。活性物种的检测表明光催化过程产生的主要活性物种为·OH自由基,而非空穴和超氧阴离子。     

水热法合成纳米ZnWO4/Ag及其光催化性能研究

以Na2WO4·2H2O和Zn(NO3)2·6H2O为原料,采用水热法制备了掺Ag+的ZnWO4催化剂.利用XRD、TEM和UV-vis吸收光谱对该催化剂进行表征;以曙红B为目标降解物,研究了ZnWO4/Ag催化剂的光催化性能.结果表明,一定量Ag+的掺入使复合光催化剂活性明显优于单一的ZnWO4,Ag+的掺入量为0.5%(原子分数)样品光催化效果最佳,1h内对5mg/L曙红B溶液的脱色率达到93%,是改性前的1.26倍.     

具有可见光活性的Na掺杂ZnO光催化剂的制备研究

以二水乙酸锌为锌源、氢氧化钠为沉淀剂和钠源,采用溶液沉淀法和煅烧处理合成了具有可见光活性的Na掺杂ZnO光催化剂。采用X射线衍射仪、扫描电子显微镜及紫外-可见漫反射光谱仪对合成的催化剂样品进行表征。结果表明,Na掺杂ZnO光催化剂的带隙为3.1eV,具有可见光吸收活性,添加聚乙二醇合成的催化剂样品经550℃煅烧后表现出较高的活性,在光照时间70min内对亚甲基蓝的降解率达到了96%。     

磁性活性碳负载F掺杂纳米二氧化钛的光催化性质研究

通过溶胶-凝胶法制备F掺杂纳米TiO₂ (F-TiO₂), 将其负载到磁性活性碳(MAC)上, 制得易回收分离的高效催化剂(F-TMAC)。通过XRD、SEM、UV-Vis、XPS、VSM对样品进行表征。以合成样品为催化剂降解模拟废水活性染料艳红(X-3B), 结果表明该负载型催化剂在紫外光和可见光照射下光催化效果均优于P25催化剂。0.2 g负载型催化剂分别在紫外光和可见光照射下降解200 mL浓度为100 mg/L的X-3B溶液, 90 min后经18?W紫外光照射X-3B去除率达到99.8%; 250 W可见光照射X-3B去除率为83.1%。溶液中的复合催化剂可以用磁铁很容易分离, 具有优良的重复利用性能。经5次重复试验, 复合催化剂F-TMAC对X-3B的降解率仅下降了约6.0%。     

钛表面固定纤维连接蛋白及其体外细胞培养

通过低温等离子聚合的方法,以丙烯酸为单体在钛表面沉积含有羧基的薄膜,以羧基为接入点固定纤维连接蛋白。样品表面用X射线光电子能谱、傅里叶红外光谱仪进行表征。将固定了纤维连接蛋白的样品进行体外细胞培养,所用的细胞为MG63骨瘤细胞,对照样为纯钛。结果表明, 钛表面聚丙烯酸薄膜能有效地固定纤维连接蛋白,并且固定纤维连接蛋白的样品能促进骨瘤细胞的生长和黏附,具有更高的成骨活性。      

气相色谱法测定异丙醇及影响因素讨论

采用气相色谱法测定脱蜡装置用异丙醇溶液的浓度,内标法定量,简便、快速、准确。对测定结果影响因素进行讨论。     

400m^3液化石油气球形储罐失效分析

针对长春液化气厂４００ｍ＾３号球罐的内壁裂缝及鼓包问题，利用射线探伤，材质成分检测以及金相组织，扫描电镜与电子探针等分析手段进行了失效分析。结果表明，球罐失效原因主要是液化气中Ｈ２Ｓ产生的应力腐蚀及氢脆所致。     

顶空-气相色谱法测定水中一氯苯

实验采用顶空-气相色谱法对水样的一氯苯进行分析,优化顶空的前处理条件及气相色谱条件,方法最低检测浓度可达0．005mg／L,标准曲线的线性相关系数r^2=0．9999,线性范围为0．1～2mg／L,样品平均加标回收率在101．4％～103．4％之间,相对标准偏差在1．6％～6．94％之间。该方法操作操作简单,重现性好、检出限低,适合水中一氯苯的检测。     

Identification of diisobutyl phthalate (DIBP) suspected as possible contaminant in recycled cellulose for take‐away pizza boxes

Italian law specifically requires the use of regenerated, rather than recycled, cellulose in the production of pizza boxes. We investigated the frequent failure to comply with this law: the identification and determination of phthalates, which have widespread use, contribute to the quality control of various food packaging materials. Diisobutyl phthalate (DIBP) has similar structural and application properties to di‐n‐butyl‐phthlate (DBP), and it is used as a substitute for DBP. We standardized an analytical method that allows the calculation of an ‘exposure index’ (EI) for DIBP in take‐away pizza boxes. The technique, which relies on Solid‐Phase Micro Extraction/Gas Chromatography/Mass Spectrometry (SPME/GC/MS), allows the definition of a large range of DIBP content in the headspace within various take‐away pizza boxes. Data concerning pizza boxes purchased in 16 restaurants in 2006 were reported, and the ‘EIs’ were estimated to range between 6 and 72 µg. Copyright © 2007 John Wiley & Sons, Ltd.     

应用FOSS 2300自动定氮仪测定复混肥料中总氮含量

使用foss2300自动定氮仪对复混肥料中总氮含量进行测定,本文考察了方法的准确性和重现性。实验数据表明,结果令人满意。     

Batchwise growth of silica cone patterns via self-assembly of aligned nanowires

Silica-cone patterns self-assembled from well-aligned nanowires are synthesized using gallium droplets as the catalyst and silicon wafers as the silicon source. The cones form a triangular pattern array radially on almost the whole surface of the molten Ga ball. Detailed field-emission scanning electron microscopy (SEM) analysis shows that the cone-pattern pieces frequently slide off and are detached from the molten Ga ball surface, which leads to the exposure of the catalyst surface and the growth of a new batch of silicon oxide nanowires as well as the cone patterns. The processes of growth and detachment alternate, giving rise to the formation of a volcano-like or a flower-like structure with bulk-quantity pieces of cone patterns piled up around the Ga ball. Consequently, the cone-patterned layer grows batch by batch until the reaction is terminated. Different to the conventional metal-catalyzed growth model, the batch-by-batch growth of the triangular cone patterns proceeds on the molten Ga balls via alternate growth on and detachment from the catalyst surface of the patterns; the Ga droplet can be used continuously and circularly as an effective catalyst for the growth of amorphous SiO(x) nanowires during the whole growth period. The intriguing batchwise growth phenomena may enrich our understanding of the vapour-liquid-solid (VLS) growth mechanism for the catalyst growth of nanowires or other nanostructures and may offer a different way of self-assembling novel silica nanostructures.     

Lecture On “Estimatlon of Specific Surface Of Developed Silver By Thiosulphate Adsorption” Given By G. W. W. Stevens (Fellow).

Silver dye-bleach systems are mainly used for positive-positive colour printing. Materials of different types are on the market, which allow either prints or transparencies to be made. The processing is dependent on the structure and the components of these materials. ere are three main processing steps: Silver development, dye-bleaching and removing of silver. The transparencies used for printing need a low contrast of the printing system, therefore, silver halide emulsions of low contrast are needed. During processing, the gradation can be controlled with the silver developer and/or the dye-bleach bath. Reducing the activity of the silver developer reduces printing speed. New “aterials allow the use of ordinary hydroquinone-phenidone developers, therefore only the dye-bleach bath is the controlling step.

The dye-bleach bath, which has a low pH-value, contains a silver complexing substance (e.g., thiourea or iodide) and a bleach catalyst 9.g., substituted quinoxaline). As thiourea forms soluble silver complexes which influence the sensitometric properties, iodide is often preferred. The bleach catalyst must be adapted to the dyestuffs used, and it must fulfil a number of conditions. Such dye-bleach baths are degraded by small amounts of thiosulphate used for fixing the silver image and need then a high regeneration rate. It is therefore preferred to use no stop-six bath before the dye-bleach step.

If the removing of silver is made in two steps (oxidation, fixing), the processing sequence needs four photographic solutions. All the silver can be recovered from the fixing bath. Such a process compares favourably with chromogenic reversal processes.     

A new stability--indicating RP-HPLC method to determine assay and known impurity of Celecoxib API

A simple, rapid and accurate Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) method was developed to determine assay and known impurity of Celecoxib API. The chromatographic separation was performed on reversed-phase C-18 column. Eluents were monitored on photo-diode array detector at a wavelength of 254 nm using a mixture (40:60) of buffer and acetonitrile. Solution concentrations were measured on a weight basis to avoid the use of an internal standard. The method was statistically validated for forced-degradation study, linearity and range, accuracy, precision, stability of analytical solutions, and selectivity. Due to its simplicity, rapid, and accuracy, we believe that the method will be useful to determine assay and known impurity of Celecoxib.     

Retrieval analysis of aerosol-size distribution with simulated extinction measurements at SAGE III wavelengths

The retrieval of aerosol-size distribution from simulated aerosol-extinction-coefficient measurements of the new satellite instrument, the Stratospheric Aerosol and Gas Experiment (SAGE) III, is investigated. A detailed discussion on the aerosol-size-distribution information content of the SAGE III aerosol-extinction-coefficient measurement is provided. Results of the investigation indicate that unimodal as well as bimodal log-normal size distributions can be inferred. In addition, it is shown that a shape-constraint-free size distribution can be derived from SAGE III aerosol measurements by use of the randomized minimization search technique and the optimal estimation theory.     

气相色谱法测定黄酒中的高级醇

本文采用毛细管气相色谱法,以峰面积外标法定量测定黄酒中的高级醇,测得的相对标准偏差为0.01%～1.03%。该方法具有操作简捷、精密度好、准确度高等特点。