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951.
Mei Wan Zhenjing Zhuang Jianyuan Dai Dan Xiao 《Russian Journal of Electrochemistry》2011,47(1):96-101
An amperometric sensor using foam nickel electrode as the working electrode for the measurement of ethanol in alkaline solution
has been developed. Cyclic voltammetry and chronoamperometry are employed to analyze electrochemical behavior of the electrode.
The results show that the oxidation of ethanol is more efficient on the foam nickel electrode than that on the nickel foil
electrode. The sensor exhibits a good linear relationship between response current and ethanol concentration in the range
of 4 to 1400 ppm with a detection limit of 0.8 ppm. The sensitivity and the response time of the sensor are 4.63 μA/ppm and
10 s respectively. Additionally, the sensor has 60 days shelf-life time at least. 相似文献
952.
In this paper, a general solution for three-dimensional static piezothermoelastic problems of crystal class 6mm solids is
presented. The general solution involves four piezoelastic potential functions and a piezothermoelastic potential function,
of which four piezoelastic potential functions are governed by weighted harmonic differential equations. Compared with the
general solution given by Ashida et al., in which seven potential functions are introduced, the general solution proposed
in the present paper is more rigorously derived. Moreover, it has a simple form and is convenient for application. As an illustrative
example, the problem of a pyroelectric half-space subjected to axisymmetric heating is studied. Numerical results of displacements
stresses, electric potential and electric displacements are obtained for a cadmium selenide half-space. Thermally induced
displacements and stress distribution are compared with those obtained for the same material without piezoelectric and pyroelectric
effects.
Project supported by the National Natural Science Foundation of China (19872060). 相似文献
953.
The methanolysis of 2‐(2‐aryl ethynyl)benzonitriles is accelerated when the polar aprotic solvents are added, which could enhance the 6‐endo pathway and give isoquinolones, though the 5‐exo pathway is occupied mostly. The yields of products would also be in creased. 相似文献
954.
Orazio Attanasi Paolino Filippone Amedeo Mei Franco Serra-Zanetti 《Journal of heterocyclic chemistry》1986,23(1):25-28
The direct synthesis of a new class of unknown 1-heterocyclamino-3-carbonylpyrroles and 1-heterocyclamino-3-carboxypyrroles by copper(II) chloride-catalyzed reaction of heterocyclic conjugated azoalkene derivatives with β-diketones and β-ketoesters is reported. 相似文献
955.
在PTC条件下合成了多亚甲基桥连的双巴比妥类化合物1~3,并通过了元素分析,IR及^1HNMR予以鉴定。 相似文献
956.
Ke Min Mei Li Krzysztof Matyjaszewski 《Journal of polymer science. Part A, Polymer chemistry》2005,43(16):3616-3622
Spontaneous gradient copolymers were prepared in both bulk and miniemulsion systems via Atom Transfer Radical Polymerization (ATRP) utilizing a Simultaneous Reverse and Normal Initiation (SR & NI) process. Both instantaneous and cumulative compositions were used to characterize the gradient copolymers. The gradient copolymers were obtained with an array of gradient compositions ranging from a subtle to strong variation in monomer distribution along the polymer backbones, depending on the ratio of comonomers initially added to the copolymerization system. The compositions of the gradient copolymer produced in miniemulsion systems were similar to those generated in bulk. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3616–3622, 2005 相似文献
957.
958.
Alexandra Zamboulis Nicolas J. Rahier Matthias Gehringer Xavier Cattoën Gilles Niel Catherine Bied Joël J.E. Moreau Michel Wong Chi Man 《Tetrahedron: Asymmetry》2009,20(24):2880-2885
New heterogenised silica-based organocatalysts have been prepared via the sol–gel process from two silylated derivatives of l-proline, featuring either a carbamate or an ether linker. Co-gelification with variable amounts of TEOS was performed with and without porogen to yield high surface area solids. These materials were evaluated as heterogeneous phase organocatalysts for the asymmetric aldol reaction of p-nitrobenzaldehyde with acetone. 相似文献
959.
测定了19个2-硫代-2-(二乙基氨基)-3-取代苯甲(磺)酰基-1,3,2-氧氮磷杂环戊烷的13C NMR参数.在苯甲酰类化合物中,邻位有非氢取代基时,非环的2J(PNC)随温度而变化(0~6.1Hz),这是因羧基与苯环空间位置(构象)随温度变化所致. 相似文献
960.
人工神经网络应用于维生素B族4组分同时测定 总被引:7,自引:0,他引:7
应用人工神经网络原理,采用Levenberg-Marquardt BP算法,对于吸收光谱严重重叠的维生素B1,B2,B6和烟酰胺4组分同时进行含量测定。四者的平均回收率分别为100%,98%,96%,100%。该方法用于复合维生素B片剂中B1,B2,B6和烟酰胺的同时测定,获得较满意的结果。实验表明,该方法与现有的算法相比具有训练速度快、预测结果准确度高等特点,有望能成为多组分分析的有效方法之一。 相似文献