Laboratory assessment of insecticidal effectiveness of natural zeolite and diatomaceous earth formulations against three stored-product beetle pests

The insecticidal effectiveness of two natural zeolite formulations (Minazel plus and Minazel), applied to wheat at selected rates of 0.25, 0.50 and 0.75 g/kg, and a diatomaceous earth formulation (DE) (Protect-It™), applied at the recommended rates of 0.15 g/kg for Sitophilus oryzae, 0.20 g/kg for Rhyzopertha dominica and 0.30 g/kg for Tribolium castaneum, were tested under laboratory conditions (24 ± 1 °C temperature and 45 ± 5% relative humidity). The highest adult mortality was observed after the longest exposure period of 21 days and 7 days of recovery, when all three zeolite dosage rates and the recommended DE dosage caused 97-100% mortality of S. oryzae and 94-100% of T. castaneum. On the other hand, 100% mortality was not achieved in any test variant involving R. dominica; the highest (about 92%) was detected for DE, while 52% and 79% mortality was achieved with the zeolites at the highest rate of 0.75 g/kg. Progeny reduction by >90% was achieved after 21 days of contact of all three beetle pests with DE-treated wheat, while the same level of reduction was achieved for S. oryzae and T. castaenum only after contact with the highest rate of the zeolite product, Minazel. Thus the two zeolite formulations are comparable to diatomaceous earth in controlling adult S. oryzae, R. dominica and T. castaneum, but only the Minazel formulation could effectively protect wheat from attack by S. oryzae or T. castaneum, and only with a higher rate of application than for the DE formulation.     

Alkane cracking reactions in zeolites with coadsorbed metal halides

HY which is loaded with SbF₅, BCl₃, or BF₃ at low coverages, one metal halide molecule per Brønsted acid site, is shown to be active in the isomerization and cracking of n-hexane and n-butane at room temperature. In contrast, NaY with the same metal halide loading shows greatly reduced activity under identical reaction conditions. The cracking reaction was repeated with DY in place of HY, demonstrating deuterium incorporation into the hexane isomer and light alkane products through interaction with the Brønsted site. Flow reactor studies demonstrate that the conversion is not constant as a function of time on stream, going through an induction period, reaching a maximum, at around 400 s, and then decaying to ~1% after 1 h.     

超微BETA沸石的合成及性能研究

本文采用静态法和动态地合成超微ＢＥＴＡ沸石,研究了反应物ＳｉＯ２／Ａｌ２Ｏ３配比,原始物料碱度、水量和划板剂含量及晶化方式对产物粒度的影响．通过ｘ－射线结构分析和红外光谱对合成物进行了结构表征,用扫描电镜对产物进行了形貌分析,同时测定了其吸附性能和酸性。研究结果表明,合成物粒径可达０．０７μｍ,并得到了一些有规律的结果。     

Gas-phase hydrodechlorination of pentachlorophenol over supported nickel catalysts

The gas-phase hydrodechlorination of pentachlorophenol (PCP) over nickel/silica and nickel/Y zeolite catalysts at 573 K has been studied. Each catalyst was 100% selective in cleaving the C–Cl bonds, leaving the hydroxyl substituent and benzene ring intact. The variation of catalytic activity and selectivity (in terms of partial and full dechlorination) with time-on-stream is illustrated and catalyst deactivation is addressed. Dechlorination efficiency is quantified in terms of dechlorination rate constants, phenol selectivity/yield and the ultimate partitioning of chlorine in the parent organic and product inorganic host. Increasing the nickel loading on silica was found to raise the overall level of dechlorination while the use of a zeolite support introduced spatial constraints that severely limited the extent of dechlorination. Product composition was largely determined by steric effects where resonance stabilisation had little effect. The reaction pathways, with associated pseudo-first-order rate constants, are also presented. This revised version was published online in November 2006 with corrections to the Cover Date.     

一种制备细胞色素C的方法

为了保证细胞色素Ｃ药用的安全性，需要高纯度的细胞色素Ｃ。对新鲜猪心采取提取、吸附、洗脱、去杂、沉淀、树脂纯化等一系列方法，从而制得了纯度较高的细胞色素Ｃ。     

HAT-097B甲苯歧化催化剂反应性能的研究

研究了以β沸石为主体的HAT-097B催化剂在催化甲苯和C₉芳烃歧化与烷基转移反应中，反应空速、温度及原料中C₁₀芳烃含量对反应性能的影响。结果表明，该催化剂在重量空速2.5h^-1，反应温度380℃时反应转化率高达47%，并可使用C₁₀芳烃含量达8%的反应原料，可综合利用芳烃资源，具有良好的工业化前景。     

Mass transfer simulation on pervaporation dehydration of ethanol through hollow fiber NaA zeolite membranes

A multi‐layer series‐resistance mass transfer model was developed to simulate mass transfer behaviors of water/ethanol mixture through hollow fiber NaA zeolite membranes. The mass transfer through zeolite layer was described by Maxwell‐Stefan mechanism based on adsorption and diffusion parameters obtained from molecular simulation. The mass transfer through asymmetric hollow fiber support was described by dusty gas model involving Knudsen diffusion and viscous flow. It was found that the sponge‐like layer of support besides of zeolite layer made an important contribution to overall membrane transfer resistance while the finger‐like layer had less effect. When permeate pressure shifted from 0.2 to 7.5 kPa, the mass transfer resistance contribution of sponge‐like layer varied from 27.1 to 17.8%. Effects of microstructure parameters of support on mass transfer through membrane were investigated extensively. Large pore size and thin thickness for sponge‐like layer of support were beneficial to improve water permeation flux. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2468–2478, 2016     

零长柱技术用于分子筛晶内扩散的研究进展

分子筛晶内扩散系数对吸附分离和择形催化具有重要的指导作用。概述了重量法、核磁共振法和分子模拟等分子筛晶内扩散研究方法,并对零长柱技术用于分子筛晶内扩散的原理和应用等方面研究进行了详细阐述,包括两种进样方式（气相进样和液相进样）的单组分气相扩散、二元体系气相扩散和互扩散、液相扩散以及吸附扩散数学模型修正和拓展,还探讨了当前存在的一些问题,最后对零长柱法用于烃类分子在多孔材料中的扩散研究进行了展望。     

二次生长法制备微纤复合纯硅分子筛膜

以正硅酸乙酯为硅源,采用二次生长法制备了不锈钢微纤复合纯硅分子筛膜,考察了载体预处理方式、晶化温度和晶化时间对分子筛膜性能的影响,利用X射线衍射仪(XRD)、扫描电镜(SEM)和ASAP-2020自动吸附仪对其形态和微观结构进行分析表征。结果表明,采用阳极氧化法预处理载体所制备的纯硅分子筛膜较采用高温煅烧法预处理的膜表观形态更为连续规整。随着晶化温度从100℃升高到160℃或晶化时间从12 h延长到96 h,分子筛膜表面更加致密,晶体颗粒尺寸增加。不锈钢微纤复合纯硅分子筛膜的比表面积、总孔容和微孔孔容分别为93.24 m2?g?1、0.0654cm3?g?1和0.0382 cm3?g?1,微孔孔容占总孔容的58%,相应的纯硅分子筛膜负载量为23.3%(wt)。     

变色硅胶与ZSM-5沸石分子筛的吸附脱附特性

针对吸附材料在太阳能吸附空调系统中的应用, 对变色硅胶和ZSM-5沸石对水蒸气的吸附脱附特性进行了实验研究。结果表明, 在一定温度下, 两种吸附材料对水蒸气的吸附速率随相对湿度增大而增加, 但增加幅度逐渐减小。环境温度对材料的吸附脱附性能有重要影响, 低温下易吸附, 高温时易脱附。温度升高, 材料的吸附脱附速率增加, 但平衡吸附量降低, 平衡脱附百分比升高。比较两种吸附材料的吸附特性发现, ZSM-5沸石具有较快的吸附速率, 但是其平衡吸附量低于变色硅胶。与变色硅胶的渐近线型吸附等温线不同, ZSM-5沸石的吸附等温线呈S型。比较两种材料的脱附特性发现, 在温度低于100℃时, ZSM-5沸石的脱附百分比大于变色硅胶。此外ZSM-5沸石能够在高温下进行脱附, 而变色硅胶在高温环境下会失去结晶水而变质, 因此脱附温度必须控制在120℃以下。