Chemical Liquid Phase Deposition of Thin Aluminum Oxide Films

Introduction Inorganic oxide films have attracted a lot of interest in the last several decades. Among them, silicon dioxide films are widely used in modern microelectronics, optics and mechanics. This material has been grown by various methods including thermal oxidation, chemical vapor phase deposition, plasma-enhanced chemical vapor phase deposition, and so on.1,2 Recently, Nagayama et al.3 have reported that SiO2 thin films could be produced by a new chemical method of liquid phase depos…     

光敏型季铵盐类阳离子表面活性剂的合成及表面活性和泡沫性质

本文报道了一种光敏型的阳离子表面活性剂（AZO），其分子结构中含有偶氮苯基团，并研究了光照对表面活性和泡沫性能的影响。经紫外光照射后，表面活性剂的饱和吸附量（Г_max）减小，临界胶束浓度（cmc）、最低表面张力（γ_cmc）和分子极限占有面积（A_min）增大；气泡数目增多，直径变小，发泡能力和泡沫稳定性降低。实验结果证实，该表面活性剂的表面活性和泡沫稳定性可以用光照进行调控。     

叠氮二乙基铝合成及其相关反应的研究

在芳烃溶剂中用氯化二乙基铝和叠氮化钠反应合成了叠氮化二乙基铝(DEAA),其产率高达87%,比文献值高出17%。在正己烷中没有合成出DEAA,在含30%四氢呋喃(THF)的正己烷中合成出DEAA·THF配合物。在芳烃溶剂中,随着苯环上甲基数目的增加,DEAA的收率增加。测定了氯化二乙基铝、氯化二乙基铝的正己烷溶液、氯化二乙基铝的甲苯溶液的 ²⁷Al NMR谱。由 ²⁷Al NMR谱数 据确定了氯化二乙基铝在甲苯中解离平衡式,计算了氯化二乙基铝在甲苯中解离平衡的热力学数据。用DEAA与苯甲酸甲酯直接合成了苯甲酰叠氮,并表征了其结构。这是一个新反应,至今无文献报导。用实验证明了在正己烷溶液中,用氯化二乙基铝、叠氮化钠与苯甲酸甲酯合成苯甲酰叠氮,没有经过氯化二乙基铝和叠氮化钠反应生成中间体DEAA的这一步。依据实验事实建立了上述三种反应的反应机理。     

无火焰原子吸收测定血清中的铝

用无火焰原子吸收法测定血清中的铝,样品用高纯水十倍稀释后,用标准加入法进行测定,不需使用基体改进剂和氘灯扣除背景。方法简单、准确、灵敏度高。用含铝20ng/ml的一份十倍稀释血清样,重复测十次,变异系数5%左右。     

Stabilization of p-block organoelement terminal hydroxides, thiols, and selenols requires newer synthetic strategies

Metal hydroxides represent a very interesting and highly useful class of compounds that have been known to chemists for a very long time. While alkali and alkaline earth metal hydroxides (s‐block) are commonplace chemicals in terms of their abundance and their use in a chemical laboratory as bases, the interest in Brønsted acidic molecular terminal hydroxides of p‐block elements, such as aluminum and silicon, has been of recent origin, with respect to the variety of applications these compounds can offer both in materials science and catalysis. Moreover, these systems are environmentally friendly, relative to the metal halides, owing to their ‐OH functionality (resembling that of water). Design and conceptualization of the corresponding terminal thiols, selenols, and tellurols (M? SH, M? SeH, and M? TeH) offer even more challenging problems to synthetic inorganic chemists. This concept summarizes some of the recent strategies developed to stabilize these otherwise very unstable species. The successful preparation of a number of silicon trihydroxides a few years back resulted in the generation of several model compounds for metal–silicates. The recent synthesis of unusual aluminum compounds such as RAl(OH)₂, RAl(SH)₂, and RAl(SeH)₂ with terminal EH (E=O, Se, or Se) groups is likely to change the ways in which some of the well‐known catalytic conversions are being carried out. The need for very flexible and innovative synthetic strategies to achieve these unusual compounds is emphasized in this concept.     

人工神经网络X射线荧光光谱法测定钢中酸溶铝

建立了一种人工神经网络-X射线荧光光谱法测定钢中酸溶铝的方法，用X射线荧光光谱法测定低合金钢中总铝值，应用所建立的ANN-BP网络模型，输入总铝含量直接预测出酸溶铝含量。同时使用改进的BP算法，避免了神经网络学习中可能产生的麻痹现象。该方法用于钢中酸溶铝的测定，结果满意。     

贫水电解质体系制备多孔阳极氧化铝模板的研究

在有机溶剂为主的含草酸电解质中,研究了大孔径有序度高的阳极氧化铝(AAO)的一步法电化学制备.实验证实,电解质中水含量的降低能够有效抑制铝的电氧化速率和溶解速率,使得其氧化膜孔道的生长能够稳定进行,所得到的六方孔道排列有序度明显高于纯水溶剂制备的电解质体系下的产物.考察了水含量、有机溶剂种类以及电解质浓度对AAO模板孔道形貌的影响.结果表明,有机溶剂贫水电解质体系使得电氧化电压的选取范围比水溶液电解质体系更宽,孔径连续可调,反应条件温和.该方法适合于制备均匀大孔径的AAO模板.     

Enhanced glucose production from cellulose using coimmobilized cellulase and β-glucosidase

β-Glucosidase was covalently immobilized alone and coimmobilized with cellulase using a hydrophilic polyurethane foam (Hypol®FHP 2002). Immobilization improved the functional properties of the enzymes. When immobilized alone, the K_m for cellobiose of β-glucosidase was decreased by 33% and the pH optimum shifted to a slightly more basic value, compared to the free enzyme. Immobilized β-glucosidase was extremely stable (95% of activity remained after 1000 h of continuous use). Coimmobilization of cellulase and β-glucosidase produced a cellulose-hydrolyzing complex with a 2.5-fold greater rate of glucose production for soluble cellulose and a four-fold greater increase for insoluble cellulose, compared to immobilized cellulase alone. The immobilized enzymes showed a broader acceptance of various types of insoluble cellulose substrates than did the free enzymes and showed a long-term (at least 24 h) linear rate of glucose production from microcrystalline cellulose. The pH optimum for the coimmobilized enzymes was 6.0. This method for enzyme immobilization is fast, irreversible, and does not require harsh conditions. The enhanced glucose yields obtained indicate that this method may prove useful for commercial cellulose hydrolysis.     

混合稀土对ZL108铝合金组织与性能的影响

对稀土处理前后的ZL108合金进行了机械性能测试和断口分析, 表明稀土处理有利于提高合金的塑性和强度. 对稀土处理前后合金中氢总量进行了分析, 未加稀土的合金内氢总量与稀土处理后的合金相当, 结合性能与断口形态, 从侧面表明稀土改变了氢的存在形式.     

Three-component catalytic method for synthesis of α-amino phosphonates with the use of α-amino acids as amine component

Interaction of aliphatic and aromatic aldehydes and ketones with optically active L-α-amino acids or their esters in the three-component catalytic one-pot synthesis of α-aminophosphonates was studied. The corresponding α-amino phosphonates are formed in high yields as mixtures of diastereomers. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 768–774, April, 2007.