光活性拟除虫菊酯的研究与展望

某些光学活性拟除虫菊酯具有优越的生物活性 ,在拟除虫菊酯研究中占重要地位。结合作者多年的研究工作 ,对光学活性拟除虫菊酯及其中间体的制备方法做了系统的总结 ,并介绍了光学异构体的分析方法和展望。     

高效合成光学活性噁唑啉-2-酮

手性噁唑啉-2-酮类化合物是不对称有机合成中应用最广泛的手性辅基之一。通常以光学活性的氨基酸为起始原料,经过羧基的还原、一碳基团酰化、环化等单元反应合成该类化合物。由于制备该类化合物过程中涉及到的试剂价格昂贵、工艺要求较高、产物分离较复杂等原因,手性噁唑啉-2-酮的价格一直相当昂贵。上海有机化学研究所开发了一条新的合成路线,使用的试剂价廉易得且使用方便,每一环节都有明显优势,成本大幅度降低,具有较好的发展前景。     

Study of Lanthanum Aluminum Silicate Glasses for Passive and Active Optical Fibers

We are reporting on SiO₂-Al₂O₃-La₂O₃ glasses—with and without Yb₂O₃—suitable for nonlinear and fiber laser applications. We will also be presenting successful supercontinuum generation and fiber laser operation around 1060 nm in step-index fibers. We optimized the glass compositions in terms of thermal and optical requirements for both a high La₂O₃ and Yb₂O₃ concentration and good compatibility with a silica cladding. We also produced bulk samples, unstructured fibers, and structured fibers with a SiO₂-Al₂O₃-La₂O₃ core and silica cladding for this purpose.     

A Homogeneous Catalyst for Reduction of Optically Active Esters to the Corresponding Chiral Alcohols without Loss of Optical Purities

A ruthenium complex was found to catalyze the hydrogen reduction of esters under mild and neutral conditions. A variety of optically active esters can be reduced to the corresponding alcohols in excellent yield without loss of their optical purity or causing undesirable side reactions. Hydrogen reduction needs such simple operations – reaction, concentration, and purification – that the violent quench step and extraction step, which accompany conventional sodium borohydride or lithium aluminum hydride reduction, can be omitted.     

Effect of the Chiral Center Position of an Optically Active Terminal Group on the Induction of Optical Activity in Polysilanes

Summary Polysilanes with an optically active alkoxy group, i.e., (S)-(+)-2-butoxy, (R)-(-)-2-butoxy, (S)-(-)-2-methyl-1-butoxy, and (S)-(+)-3,7-dimethyl-1-octoxy, at the terminal positions, the chiral carbon centers of which were located at the α, β, and γ positions relative to the oxygen, respectively, were prepared, and the effect of the position of chiral center of the terminal optically active group on the induction of optical activity in polysilanes was investigated. The circular dichroism (CD) spectra of these polymers showed positive Cotton signals around 340 nm at temperatures below -20 °C, but the intensities were small, indicating that the optically active groups at the terminal positions have some ability, albeit small, to induce optical activity to the polysilanes. Further, the optically active (S)-(+)-2-butoxy and (R)-(-)-2-butoxy groups did not control the helical sense direction of the polymers, despite the different chiral stimuli from the 2-butoxy groups introduced to the terminal positions. To control the helical structure of polysilanes by the use of optically active terminal groups, appropriate optically active groups are required.     

Active coating

Preventing the corrosion of metal substrates by applying an active coating was studied. The active coating was prepared by addition of metal powder and polyaniline in xylene solution. Trials were conducted by coating a blast-cleaned, mild steel round bar with a brush. The coating was dried in the air and the steel samples were immersed in water collected from the open sea. Open circuit potential of steel was measured with silver/silver chloride reference electrode. The potential in seawater was in the range of — 740mV to — 956mV, indicating complete protection of steel against corrosion. This potential meets the criteria for protection as per clause 5.4.1 of Det Norsk Veritas Recommended Practice RPB 401 (1993), page 8.¹ The active coating system can be used for protecting the steel against corrosion in marine and any other highly corrosive environment. Accelerated tests in accordance with ASTM D5894 — 96² with freeze cycle developed by U.S. Federal Highway Administration are planned.     

Optical Storage

Abstract

Digital and holographic optical storage systems are compared. Requirements for the improvement of current storage systems are defined. Techniques to study storage properties of polymer liquid crystals (PLCs) are described; they include diffraction grating, polarization holography, spectroscopic methods, refractive index determination (interferometry, birefringence), methods of surface characterization, and testing reversibility and the number of write-read cycles. Results are reported for several PLCs and interpreted in terms of the effects of the choice of the main chain, the spacer, the chromophore, the LC components, the molecular weight, photoorientation and the surface morphology.     

Synthesis and Optical Properties of Nonlinear Optical Polyarylates

Several polyarylates based on bisbenzylidenoketones have been synthesized by interfacial polycondensation. Two distinct types of polymers have been obtained: guest-host systems and polyarylates with NLO (nonlinear optical) side chains. The dispersion of the linear refractive index (n ₀) is measured over the wavelength range from 800 to 2000 nm. The Holing formula, based on a semiclassical model of a simple harmonic oscillator, is used to calculate the NLO susceptibility X⁽³⁾.     

活性阻隔树脂

M＆G集团公司生产出新型PET树脂,商品牌号为ActiTUF,用其生产出的单层容器产品具有主动或被动阻隔气体的性能。主动阻隔气体功能是利用一种专利的抑氧技术,而被动阻隔气体功能是根据使用要求,采用萘二甲酸酯或聚加成反应技术生产而成。与其他阻隔技术不同,这种     

光纤涂料

0301 147光纤涂料用的辐射固化聚醚聚氨醋液体组合物:JPZo02一145 970旧本专利公开]/日本:Shin一Etsu Chemieal Industry Co.,Ltd.(Konishi,Shigeru等)一2002.5.22一8页一2000/344 568(2000.11.13);IPC C08F290/14 题述组合物含有(A)数均相对分子质量800一10000、带有》2个(甲基)丙烯酸基的聚醚聚氨醋100份,(B)含乙烯基醚的化合物1一100份,有时可有(C)相对分子质量(500、带(甲基)丙烯酸基和/或N一乙烯基的活’!生稀释剂l一200份。例如,将含环己烷二甲醇二乙烯基醚和聚醚氨基甲酸醋低聚物(由丙烯酸异冰片醋、2,4一甲苯二异氰酸醋、丙…     

聚合物光纤

本文介绍了聚合物光纤的特性及其分类,论述了9种聚合物光纤的性能及其应用,综述了当今聚合物光纤的发展和现状。     

Optical fiber fabrics

A brief survey is given of the history of technologies for making optical fiber fabrics. Major areas of use are demonstrated and prospects for using them in engineering and design. Translated from Khimicheskie Volokna, No. 4, pp. 14–17, July–August, 2008.     

光纤涂料

0403418用于光纤涂料的树脂组合物,使用其的被涂光纤和光纤单元:CNI 456 622A〔中国发明专利申请公开]/日本:大日本油墨化学工业株式会社(押尾笃等卜2003.11.19一03 130 687.X(2003.5.7):IPCC09D175/14光纤涂料~~