Study of methoxyphenylquinoxalines (MOPQs) as photoinitiators in the negative photo-resist

To develop photoinitiator systems of high performance for the negative photo-resist, we synthesized six methoxyphenylquinoxalines (MOPQs) and investigated the photopolymerization of 2,2-bis(4-(acryloxypolyethoxy)phenyl)propane (A-BPE-10) initiated by these MOPQs in the negative photo-resist. MOPQs possess suitable UV–vis maximum absorption wavelengths in the range of 349–402 nm, along with high extinction coefficients ?. Except for T3MOP-DQ and T4MOP-DQ, the other four MOPQs, D3MOP-Q, D4MOP-Q, D3MOP-BenQ and D4MOP-BenQ, could initiate photopolymerization of A-BPE-10 in the negative photo-resist very efficiently. In particular, D3MOP-BenQ was the most efficient, with almost 100% final conversion in the presence of 2-mercaptobenzothiazole (MBO) as a coinitiator. Among the four coinitiators LCV, MBO, NPG and MDEA, MBO was the best coinitiator for MOPQs. The negative photo-resist containing MOPQs as a photoinitiator can also form good patterns on copper through photolithography. These characteristics make MOPQs potential photoinitiators in the negative photo-resist.     

The influence of particle size of slurry on life on BME-MLCC

Four slurries and base metal electrode multiplayer ceramic capacitor (BME-MLCC) samples（0603-X7R-50V-104）were prepared by using different grinding ways. The particle sizes of slurries were characterized by grading analysis and the micro-morphology of films and samples were analyzed by scanning electronic microscopy (SEM). The structure was characterized by X-ray powder diffraction (XRD). Finally, the life of samples were tested by highly accelerated life testing (HALT). Results showed that the particle size distribution of slurry which was made using smaller grinding media by sander was narrow. The micromorphology of as-prepared films and samples were more tightly, the numbers of particles in single dielectric were more, the initial reliability was better and the life was longer.     

更换零件能力对手工装配系统合格率的影响

漏装和错装是手工装配系统的主要质量问题,更换零件是应对这类问题的主要方式。为了合理地规划手工装配系统的零件更换能力,研究了零件更换能力对手工装配系统合格率的影响。拓展了手工装配系统,建立了包含更换零件能力的手工装配系统概念模型,构建了手工装配系统合格率的计算表达式。分析了零件更换能力充分和不充分两种情况下,手工装配系统合格率和零件更换能力之间的关系,得出了在零件更换能力不充分时,合格率随零件更换能力的增大而增大,当零件更换能力达到某个值时,合格率不再变化。求解了合格率不变时的零件更换能力临界值的表达式。最后用企业实例进行了说明,并分析了手工装配系统合格率和首检合格率、返工合格率与首检合格率的比值ρ的敏感性。     

铅晶质玻璃在不同环境下的铅析出性能研究

铅水晶玻璃具有折射率高、透过率高等优异性能,被广泛应用于工艺品、高档餐具、首饰等,但其中氧化铅成分存在潜在析出的风险,因此对使用者的健康有一定的影响。通过制备3种不同Pb_3O_4质量分数的铅水晶玻璃样品,分别研究了80℃条件下样品在白酒、洗洁精中浸泡后的铅析出情况,并通过失重法、光学显微镜以及元素分析(ICP)测试,对铅水晶玻璃在侵蚀过程中的铅析出速率和表面形貌等进行了测定。研究结果表明,铅水晶玻璃在不同溶液中长时间浸泡会导致铅析出,析出量和析出速率与其Pb_3O_4质量分数有关,其中低、中铅玻璃相对稳定,高铅玻璃的铅析出量大幅提升。     

TiO_2对Ag/Al_2O_3吸附剂的柴油吸附脱硫性能的影响

采用浸渍法制备不同Ti O2含量的Ag/Ti O2-Al2O3吸附剂,以含硫量为245.36 mg·L-1的商品柴油作为考察对象,常温、常压条件下采用静态评价进行吸附脱硫性能研究。结果表明,经过Ti O2改性的Ag/Al2O3吸附剂柴油吸附脱硫活性有较大幅度提高。通过X射线衍射、N2物理吸附、O2化学吸附和NH3程序升温脱附等研究Ti O2改性剂的影响。关联活性测试和表征结果发现,吸附剂的吸附脱硫活性受吸附剂比表面积、活性金属Ag分散度和吸附剂表面酸协同影响。吸附剂比表面积越大,活性金属Ag分散度越高,吸附剂表面弱酸性位点数量越多,强酸性位点数量越少,吸附剂吸附脱硫活性越高。2%Ag/4%Ti O2-Al2O3的吸附脱硫活性最高,饱和硫容达2.11 mg·g-1。     

复合网状阴极增强电化学水软化系统性能研究

针对工业循环冷却水系统中低除垢速率限制电化学水软化技术应用的问题,采用多层不同孔径金属丝网耦合的复合网状阴极增强电化学水软化系统性能。结果表明:采用复合阴极的水软化系统除垢速率高达29.16g/(m2·h),能量消耗低至6.0 kW·h/kgCaCO3。系统性能的提升归因于阴极特殊的结构,该结构可将化学反应(碱度产生和水垢沉积)分离和定位到复合网状阴极的不同区域,从而提高了除垢速率。     

Sonochemical Synthesis of Two New Nano-structured Cadmium(II) Supramolecular Complexes

Nano-particles of two new Cd(II) supramolecular complexes, [Cd(4,4-di-tert-bubipy)Cl₂(DMSO)] (1) and [CdI₂(4,4′-dmbpy)(DMSO)] (2) have been synthesized by sonochemical process and characterized by scanning electron microscopy, X-ray powder diffraction, IR spectroscopy and elemental analyses. The structure of compound 1 has been characterized by single crystal X-ray diffraction. The prepared nano-structure was characterized by scanning electron microscopy and X-ray powder diffraction. The nano-structures of supramolecular complexes have been synthesized with calcination of complexes at oleic acid as a surfactant at 190 ºC too. The size of the samples prepared by sonochemical method and calcination are about 30–40 and 40–50 nm respectively.     

Investigation of the electrochemical behavior of some catecholamines in the presence of 4-aminobenzoic acid

Electrochemical oxidation of some catecholamines such as dopamine (1), l-dopa (2) and methyldopa (3) has been studied in the presence of 4-aminobenzoic acid (4). Some electrochemical techniques such as cyclic voltammetry using diagnostic criteria derived by Nicholson and Shain for various electrode mechanisms and controlled-potential coulometry were used. Variation in cathodic peaks due to the competition between intramolecular and intermolecular Michael addition reaction was studied in various pH values, and the best conditions for reaction with 4-aminobenzoic acid was obtained. The results indicate an ECE mechanism. The observed homogeneous rate constant (k_obs) for Michael addition reaction was estimated by comparing the experimental cyclic voltammetric responses with the digital simulated results. Also, the Michael addition reaction rate constants (k_m) were calculated using microscopic acidic dissociation constant of ammonium groups in 4-aminobenzoic acid. The chemical oxidation reaction of catecholamines with periodate in the presence of 4-aminobenzoic acid was also studied spectrophotometrically.