Asymmetric Cyclopropanation Catalyzed by Four Stereoisomers of a Copper-(Schiff-base) Complex with Double Chiral Centers

Catalytic asymmetric cyclopropanation of diazoacetates with olefins has attracted much attention. Those catalysts containing various metals and optically active ligands have been employed for this reaction1,2. The first catalytic asymmetric cyclopropanation reaction was reported in 1966 by Nozaki et al.3. The author used the copper(II) complex 1 bearing a salicyladimine ligand as catalyst though with a low e.e. value of 6%. Aratani and his coworkers designed the copper-(Schiff-base) comp…     

LIMIT CYCLES AND BIFURCATION CURVES FOR THE QUADRATIC DIFFERENTIAL SYSTEM(III)_(m=0)HAVING THREE ANTI-SADDLES(II)

ＬＩＭＩＴＣＹＣＬＥＳＡＮＤＢＩＦＵＲＣＡＴＩＯＮＣＵＲＶＥＳＦＯＲＴＨＥＱＵＡＤＲＡＴＩＣＤＩＦＦＥＲＥＮＴＩＡＬＳＹＳＴＥＭ（ＩＩ）ｍ＝０ＨＡＶＩＮＧＴＨＲＥＥＡＮＴＩＳＡＤＤＬＥＳ（Ｉ）ＹＥＹＡＮＱＩＡＮＡｂｓｔｒａｃｔＡｓａｃｏｎｔｉ...     

纳米TiO2薄膜光阳极的制备及性能

本文以钛酸正丁酯为前驱物、乙醇作为分散剂、二乙醇胺作为螯合剂、聚乙二醇作为表面活性剂,采用溶胶-凝胶法制备得到一种TiO2溶胶,并通过乙酸或氨水作用后制得另外两种溶胶,分别在室温于ITO导电玻璃上涂制,得到5种单一粒径范围纳米TiO2薄膜和具有两种粒径范围膜层的6种纳米TiO2薄膜;XRD和SEM等测试结果表明,纳米TiO2薄膜为锐钛矿相或锐钛矿与金红石相的混合相,其粒径分布范围在15～30nm,30～50 nm,40～80 nm区间。采用浸渍法将所制备的膜进行染料的敏化,得到染料敏化纳米TiO2薄膜半导体光阳极,测试结果表明,在所制备的纳米TiO2薄膜中,具有两种粒径范围膜层的纳米TiO2薄膜的光电性能相对较好。     

Synthesis and Crystal Structure of α-( N-Protected a mino)β- lactam Derivative of 1 ,5-Benzothiazepine

１　ＩＮＴＲＯＤＵＣＴＩＯＮＲｅｃｅｎｔｌｙ,ａｎｕｍｂｅｒｏｆｄｅｒｉｖａｔｉｖｅｓｏｆｂｅｎｚｏｔｈｉａｚｅｐｉｎｅｈａｖｅｂｅｅｎｐｒｅｐａｒｅｄａｎｄｓｔｕｄｉｅｄｆｏｒｔｈｅｉｒｐｈａｒｍａｃｏｌｏｇｉｃａｌａｃｔｉｖｉｔｉｅｓ〔１５〕．Ｉｎｏｕｒｐｒｅｖｉｏｕｓｗｏｒｋ,ｗｅｈａｖｅｉｎｃｏｒｐｏｒａｔｅｄｔｈｅβｌａｃｔａｍｒｉｎｇｉｎｔｏ１,５ｂｅｎｚｏｔｈｉａｚｅｐｉｎｅｂｙｒｅａｃｔｉｏｎｏｆ１,５ｂｅｎｚｏｔｈｉａｚｅｐｉｎｅｗｉｔｈｓｏｍｅａｃｙｌｃｈｌｏｒｉｄ…     

Synthesis and Crystal Structure of Dicesium trans Dicarbonatotetraaquomagnesium, Cs_2[Mg(CO_3)_2(H_2O)_4]

ＩｎｔｒｏｄｕｃｔｉｏｎＰｒｅｖｉｏｕｓｌｙ,ｗｅｒｅｐｏｒｔｅｄｔｈｅｃｒｙｓｔａｌｓｔｒｕｃｔｕｒｅｏｆＫ２［Ｎｉ（ＣＯ３）２（Ｈ２Ｏ）４］［１］,ｗｈｉｃｈｃｒｙｓｔａｌｌｉｚｅｄｉｎｔｈｅｂａｙｌｉｓｓｉｔｅｔｙｐｅｓｔｒｕｃｔｕｒｅａｎｄｗａｓｆｏｕｎｄｔｏｂｅｉｓｏｓｔｒｕｃｔｕｒａｌｗｉｔｈＫ２［Ｃｏ（ＣＯ３）２（Ｈ２Ｏ）４］［２］ａｎｄＫ２Ｍｇ（ＣＯ３）２·４Ｈ２Ｏ［３］．Ｉｎｏｒｄｅｒｔｏｓｙｓｔｅｍａｔｉｃａｌｌｙｉｎｖｅｓｔｉｇａｔｅｔｈｅｏｃｃｕｒｒｅｎｃｅｏｆｔｈｅｃｏ…     

三甲川菁染料敏化TiO2纳米 结构电极的光电化学

The photoelectrochemical behaviors of the TiO₂ nanostructured porous film sensitized by cyanine dye were investigated in this paper.The results showed that the excitaed state level matched the conduction band edge of TiO₂ nanoparticle.Therefore the sensitization of the dye can increase the photocurrent intensity of the TiO₂ nanostructured electrode obviously and results in a red-shift of optical absorption from the ultra-violet region to the visible.As a result,the light-to-electricity conversion efficiency was improved evidently,the maximum value of IPCE has reached 12.1%.     

A Fluorescence Optical Fiber Sensor for Amrinon Using a New Oxazole Compound

ＩｎｔｒｏｄｕｃｔｉｏｎＡｍｒｉｎｏｎ,ａｓｙｎｔｈｅｔｉｃｂｉｐｙｒｉｄｉｎｅｄｅｒｉｖａｔｉｖｅ,ｎｏｎｇｌｙｃｏｓｉｄｅａｎｄｎｏｎｃａｔｅｃｈｏｌａｍｉｎｅｃａｒ－ｄｉｏｔｏｎｉｃｓｔｉｍｕｌａｎｔ,ｉｓｃｕｒｒｅｎｔｌｙｕｓｅｄｉｎｔｈｅｔｒｅａｔｍｅｎｔｏｆｔｈｅｈｅａｒｔｆａｉｌｕｒｅａｎｄｆｏｒｃａｒｄｉｏｖａｓｃｕ－ｌａｒｓｕｐｐｏｒｔｉｎｐｅｄｉａｔｒｉｃｐａｔｉｅｎｔｓ．Ｉｔｐｏｓｓｅｓｓｅｓｐｏｔｅｎｔｃａｒｄｉａｃａｎｄｂｌｏｏｄｖｅｓｓｅｌｓｐｒｅａｄｉｎｇｅｆ－ｆｅ…     

The Elastic Continuum Limit of the Tight Binding Model

The authors consider the simplest quantum mechanics model of solids,the tight binding model,and prove that in the continuum limit,the energy of tight binding model converges to that of the continuum elasticity model obtained using Cauchy-Born rule.The technique in this paper is based mainly on spectral perturbation theory for large matrices.