Methane sensor based on palladium/MWNT nanocomposites

Methane gas sensor was fabricated based on electrocatalytic properties of the Pd/MWNT nanocomposites on indium tin oxide (ITO)glass substrates.A linear response for methane was obtained in the range of 0-16%(v/v)with a detection limit of 0.167%(v/ v)and R.S.D.of 4.1%.After 100 times sensing or stable stored more than 12 months in atmosphere,unconspicuous measurable decrease was observed.The response time was less than 60s at room temperature and ambient pressure.Some common potential interferents in samp...     

色谱—傅里叶变换红外光谱联用技术

色谱和傅里叶红外光谱的联用是现代分析化学中重要的联用技术之一。本文介绍了最常用的气相色谱(GC)、高效液相色谱(HPLC)以及最近发展的超临界流体色谱(SFC)与傅里叶变换红外光谱(FTIR)联用技术的最新进展,并对联用中常用的两种接口方式,即流动池法和色谱流动相消除法的优缺点作了讨论。     

固体炭对一氧化氮低温催化解离还原反应的影响——Ⅰ.复合催化剂还原活性的考察

考察了担载在活性炭上的以铜、铁为主的复合催化剂对一氧化氮催化解离还原活性的影响,并通过TPR和XRD研究了不同金属组份配比和不同助剂(K、Na)对催化剂性能的影响。结果表明,通过选择不同催化剂配比和添加不同助剂,降低主催化剂在载体炭上的还原温度和提高主催化剂在载体炭上的分散度,将有利于提高催化剂对一氧化氮催化解离还原的活性。文中还采用电镜方法研究了不同组成复合催化剂的金属颗粒大小和Cu、Fe复合催化剂经反应后其表面的形貌结构,发现在这种炭载型复合催化剂上进行一氧化氮催化解离还原反应的过程中,有催化剂表面金属颗粒迁移、生成炭丝和金属颗粒在载体炭上打洞等迹象。     

MECHANISM FOR CS_2 HYDROLYSIS OVER γ-ALUMINA——FTIR STUDIES OF THE ADSORPTION BEHAVIOR OF CS_2 AND H_2O

研究了ＣＳ２在ｇ氧化铝上的水解反应机理，考察了ＣＳ２和Ｈ２Ｏ在ｇ氧化铝上的吸附行为。结果表明，ＣＳ２的弱化学吸附与强化学吸附同时存在。ＦＴＩＲ对ＣＳ２和Ｈ２Ｏ在ｇ氧化铝上的共吸附研究结果表明，ＣＳ２的水解反应为被吸附的ＣＳ２与吸附在ｇ氧化铝Ｌｅｗｉｓ碱中心上的Ｈ２Ｏ的反应。ＣＯＳ是ＣＳ２水解反应的中间产物。     

自锁模Cr4+∶YAG激光器的色散补偿研究

从棱镜对补偿色散的原理出发,介绍了Cr4+∶ YAG锁模激光器中色散补偿的特点,发现熔融石英作为色散补偿元件,不仅可以完全补偿二阶色散,而且三阶色散也得到了一定的补偿,并得到了脉冲宽度最小为65 fs,中心波长为1520 nm,重复频率为120 MHz的脉冲序列.     

Recent Technological Developments in Cobalt Catalysts for Fischer-Tropsch Synthesis

Co-based catalysts are often utilized due to their high Fischer-Tropsch synthesis (FT) activity, G5+ hydrocarbon selectivity, low water-gas shift reaction (WGS) activity and relatively low cost. Selective control of C5+ hydrocarbons and the catalyst longevity are critical in the design of cobalt catalysts. Thus, various methods to improve the performance of Co catalysts have been suggested. The progress in cobalt catalysts reviewed in the last few decades, mainly involved the support, promoter, preparation and deactivation of Co-based catalysts.     

Synthesis and characterization of SBA-15 macrospheres with hierarchical pore structure

The new macroscopic-scale SBA-15 spheres with diameter of 0.2-0.5 mm are prepared by a sol-gel method,in which the tetrabutylorthosilicate(TBOS) is used as silicon source and triblock copolymer(P123) and polyoxyethylene octylphenol ether(OP- 10) are used as templates.The resulting spherical samples are characterized by XRD,N_2 adsorption-desorption,TEM and SEM methods.The results show that the inner structure of SBA-15 macrospheres has macroporous channels(0.5μm) and mesoporous skeleton(4-5 nm).These SBA...     

STUDIES ON CATALYST POISONING DEACTIVATION MODEL IN FIXED BED

Four major deactivation types of catalyst particles, namely parallel, series, side-by-side and independent deactivation were discussed. The effects of distribution of poison along the fixed bed were examined for a number of poisoning equations in detail, which have a simple type of deactivationequations as -da/dt ∝ad, where d is the deactivation order, and a is the activityof fresh catalyst.     

含有萘环荧光团的共聚高分子电荷转移配合物的形成和发光特性研究

利用荧光法研究了甲基丙烯酸－β-萘基酯（NMA）与咔唑（VCZ）合成的共聚功能高分子Copolymer（NMA－VCZ）的发光特性，结果表明，Copolymer（NMA－VCZ）可表现出萘和咔唑两种荧光团特征的激发和发射光谱，但在低的浓度下（约10^-9mol.L^-1），主要表现出萘环的发光特性。其荧光可被电子体化合物对苯二甲酸二甲酯（DMPT）以及电子给体合物三乙胺（Et3N）所猝灭。通过对相应吸收光说煌测定，发现DMPT，Et3N均能与Copolymer（NMA－VCZ）形成1：1的电荷转移配合物。     

镧对心肌细胞钾通道的作用研究

用全细胞膜片钳记录方式研究了La^3^+对大鼠心室肌细胞钾通道的作用机理。对酶解分离的大鼠心室肌细胞施一跃迁电压可引出一非钙依赖性电压去激活的外向钾电流。将10μmol/LLa^3^+加入细胞外液后，非钙依赖性电压去激活的外向钾电流明显减小，这提示在大鼠心室肌细胞钾通道上存在La^3^+结合位点。