Upgrading Pectin Production from Apple Pomace by Acetic Acid Extraction

Applied Biochemistry and Biotechnology - Pectin, as one of the most widely used functional polysaccharide, can be abundantly extracted from apple pomace which is the main by-product of apple juice...     

硅中硼离子注入层的卤钨灯辐照快速退火研究

本文研究了SiO_2掩蔽膜硼离子注入硅的卤钨灯辐照快速退火,测量了注入层表面薄层电阻与退火温度及退火时间的关系,得到了最佳的退火条件。对于采用920(?)SiO_2膜,25keV、1×10~(15)cm~(-2)的~(11)B离子注入样品,经不同时间卤钨灯辐照退火后,测量了注入层的载流子浓度分布,并与950℃、30分钟常规炉退火作了比较。结果表明,卤钨灯辐照快速退火具有电激活率高、注入杂质再分布小以及快速、实用等优点。     

用拓扑指数S_i研究碳氢化合物的沸点(Ⅲ)

定义了拓扑指数Ｓｉ（ｉ＝１，２，３，４），并选取包含双、三键、环及苯环的碳氢化合物为研究对象，计算了这些化合物的拓扑指数Ｓｉ，同时用Ｓｉ相关了它们的沸点．结果较文献值有所改善．并从Ｓｉ中筛选出了Ｓ     

含2,3-二氯-5,6-二氰基对苯醌(DDQ)或其自由基离子(DDQ~)的多元配合物研究

通过联苯甲酰双缩肼（Ｌ）与不同金属乙酸盐［Ｍ（ＯＡｃ）２］及２，３－二氯－５，６－二氰基对苯醌自由基离子（ＤＤＱ－·）反应，合成了３个分子式为（ＭＬ）２＋（ＤＤＱ－·）２（Ｍ＝Ｍｎ、Ｚｎ、Ｃｄ）的三元配合物及２个分子式为（ＭＬ）２＋（ＤＤＱ－·）（ＯＡｃ－）（Ｍ＝Ｎｉ、Ｐｂ）的四元配合物．元素分析确定了它们的组成，经红外光谱、紫外－可见光谱及摩尔电导的测定对其配位情况进行了讨论．另将丁二酮双缩肼（Ｌ）与不同金属乙酸盐［Ｍ（ＯＡｃ）２］，及中性ＤＤＱ反应，合成了分子式分别为（ＭＬ）２＋（ＤＤＱ－·）（ＯＡｃ－）（Ｍ＝Ｃｕ、Ｃｄ）、（ＭＬ）２＋（ＤＤＱ）（ＯＡｃ－）２（Ｍ＝Ｃｏ、Ｎｉ）及（ＨｇＬ）２＋（ＤＤＱ）１．５（ＯＡｃ－）２的五个四元配合物．经元素分析、红外光谱、紫外－可见光谱，对它们进行了表征．固体电导的测定结果表明，含中性ＤＤＱ的配合物均属半导体范畴，其中Ｈｇ配合物的室温粉末固体电导率达３．７×１０－４Ω－１ｃｍ－１．     

海生物附著对钢板管椿腐蚀之影响

为了解海生物对钢板管椿腐蚀之影响 ,将SS4 1金属试片浸渍于高雄港 #1 4码头水深 3m处及实验室人造海水中 .试验期间 ,以DC直流动电位极化曲线扫描与AC交流电阻抗分析现场量测各试片的瞬间腐蚀速率 .结果发现 :宏观地看 ,海生物在金属 (或锈层 )表面的附著可以减缓金属腐蚀 ,但从微观 (micro)的观点推论 ,海生物在金属表面的附著亦可以造成氧差或浓度差异电池 ,促成局部腐蚀 .此外 ,等效电路的模拟 ,有助于了解海生物附著对金属腐蚀的影响 ,即随浸渍时间的延长 ,金属表面因锈层增厚且趋于致密 ,以致锈层电阻增加 ;又因海生物种类不同 ,含水量不同 ,海生物电阻可能会有极大的差异     

Novel and potent Lewis acid catalyst: Br2-catalyzed Friedel–Crafts reactions of naphthols with aldehydes

A discovery that the inexpensive Br₂ can serve as a potent Lewis acid catalyst for bis(2-hydroxy-1-naphthyl)methanes synthesis is presented. Under the catalysis of Br₂ at room temperature, naphthols reacted smoothly with various aldehydes with high efficiency and broad substrate scope. This reaction used to require highly acidic conditions and/or high temperature and/or pressure, and sometimes featured poor yields. Moreover, theoretical calculations suggested that Br₂ is a potent Lewis acid to activate the carbonyl group, yet it was not the primary cause for the remarkable activity of Br₂ in the current communication.     

Isolation of a new carboline alkaloid from Trigonostemon lii

A new carboline alkaloid, 1-(7-methoxy-quinolinyl-4′-yl)-3,4-dihydro-β-carboline (1), was isolated from the leaves and twigs of Trigonostemon lii Y.T. Chang, together with three known ones, trigonostemonines C and D (2 and 3), and trigonoliimine A (4). Their structures were elucidated by spectroscopic analyses, including 2D-NMR techniques.     

Dry Reforming of Methane on a Highly‐Active Ni‐CeO2 Catalyst: Effects of Metal‐Support Interactions on C−H Bond Breaking

Ni‐CeO₂ is a highly efficient, stable and non‐expensive catalyst for methane dry reforming at relative low temperatures (700 K). The active phase of the catalyst consists of small nanoparticles of nickel dispersed on partially reduced ceria. Experiments of ambient pressure XPS indicate that methane dissociates on Ni/CeO₂ at temperatures as low as 300 K, generating CH_x and CO_x species on the surface of the catalyst. Strong metal–support interactions activate Ni for the dissociation of methane. The results of density‐functional calculations show a drop in the effective barrier for methane activation from 0.9 eV on Ni(111) to only 0.15 eV on Ni/CeO_2?x(111). At 700 K, under methane dry reforming conditions, no signals for adsorbed CH_x or C species are detected in the C 1s XPS region. The reforming of methane proceeds in a clean and efficient way.