Development of Several New Reactions and Their Application to the Total Synthesis of Biologically Active Natural Products ：Synthesis of Linderol A and Determination of Its Absolute Configuration

Linderol A （1）, a monoterpene-polyketide, was isolated in 1995 from the fresh bark of Lindera umbellata （Lauraceae）, and its absolute structure was not determined. It was also reported potent inhibitory activity of 1 on the melanin biosynthesis of the cultured B-16 melanoma cells. See Fig. 1. On the other hand, we reported in 1995 an interesting multi-tandem reaction of coumarin derivatives （2; W = electron withdrawing group） by treatment with CH2 = S（O）Me2 to yield stereoselectively a tricyclic 2-substituted （4） via a cyclopropane intermediate （3） cyclopenta [ b ] benzofuran-3-ol derivative （Scheme 1）.     

Development of Several New Reactions and Their Application to the Total Synthesis of Biologically Active Natural Products :Synthesis of Linderol A and Determination of Its Absolute Configuration

1Introduction Linderol A (1), a monoterpene-polyketide, was isolated in 1995 from the fresh bark of Lindera umbellata (Lauraceae), and its absolute structure was not determined[1]. It was also reported potent inhibitory activity of 1 on the melanin biosynthesis of the cultured B-16 melanoma cells[1]. See Fig. 1. On the other hand,we reported in 1995 an interesting multi-tandem reaction of coumarin derivatives (2; W = electron withdrawing group) by treatment with CH2 = S(O)Me2 to yield stereoselectively a tricyclic 2-substituted cyclopenta [ b ] benzofuran-3-ol derivative (4) via a cyclopropane intermediate (3) (Scheme 1)[2].     

二正丙基四硫合成的研究

以一氧化硫和正丙基硫醇为原料，用石油醚作溶剂，在－9℃下反应，合成了二正丙基四硫，产率由文献报道的46．6％提高到97．2％；通过气相色谱、红外光谱和色谱－质谱联用等分析手段证实了其结构．     

硫化钠法处理SO_2烟气的吸收液脱砷研究

研究了在采用硫化钠吸收低浓度二氧化硫烟气制硫磺粉的工艺过程中吸收液除砷的工艺条件，包括反应时间、反应温度、溶液ｐＨ值以及沉降条件等因素对除砷率的影响．结果表明，当反应时间为５０ｍｉｎ，反应温度为３０～５０℃，溶液ｐＨ值在２～５范围内时，可以达到除砷的目的．同时，还确定了以聚合硫酸铝为絮凝剂的沉降分离方法，当聚合硫酸铝的用量（质量分数）为５×１０－６～１０×１０－６时，可加快沉降速率，提高脱砷率．     

金山汉字编辑系统加密剖析

该文分析了在金山汉字编辑系统中文本文书文件密码处理方法，对密本身加密和文本加密方法进行了剖析，并提出了如何取得未知密码的方法和提供文本文书文还原的程序。     

烟气二氧化硫污染控制技术发展及现状

对烟气脱硫技术的发展和现状进行了较为详尽的介绍，给烟气脱硫用户选择符合自己的实际情况的脱硫方法提供了参考。     

Preparation of activated ceria and its desulfurization performance

Activated ceria (CeO₂/γ-Al₂O₃) prepared by impregnation was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and hydrogen temperature-programmed reduction (TPR). The desulfurization of the activated ceria was investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TG). The results showed that ceria could be highly dispersed or crystallized on the surface of γ-alumina. The reduction temperatures of 0.1CeO₂/γ-Al₂O₃, 0.45CeO₂/γ-Al₂O₃, and CeO₂ ranged from 250℃ to 470℃, 330℃ to 550℃, and 350℃ to 550℃, respectively. The reduction peak temperature of 0.45CeO₂/γ-Al₂O₃ was higher than that of 0.1CeO₂/γ-Al₂O₃, which was consistent with the reduction temperature of CeO₂. O₂ participated in the reaction between ceria and sulfur dioxide. The desulfurization product was cerium(Ⅲ) sulfate. The intensity of the hydroxyl band decreased with the formation of sulfate species.     

硫的非质量分馏在晚太古代环境中的应用研究进展

硫的非质量分馏是研究大气环境变化的重要指示剂,在太古代缺氧的环境下,二氧化硫的光化学反应会产生带正和负δ~(33)S的两个硫同位素端元,其产物分别赋存于黄铁矿和古海水硫酸根中。但前人的研究多集中于黄铁矿端元,而对于硫酸根,由于缺乏指示矿物,其研究较为薄弱且多有争议。从硫的非质量分馏产生机理、晚太古代地质记录中硫的非质量分馏的研究及大气化学实验的模拟研究三个方面进行综述,结合研究实例,分析了古海水硫酸根的可能来源,预测了硫的非质量分馏值的范围,提出晚太古代海水硫酸盐硫的非质量分馏效应将是今后研究的重点。     

利用炼油装置的多余干气蒸汽转化制氢

为安全清洁环保 ( H SE)的汽、柴油生产 ,提出了利用炼油装置的多余干气制氢向加氢精制装置提供高纯度氢的工艺路线 ,干气经脱烯烃、脱硫、脱氯、蒸汽转化、PSA一系列装置产氢和提纯 ,可年产 492 0吨 99.9%纯氢 ,加上重整氢提纯后可脱除 60万吨 /年汽、柴油中的有机硫 ,减少 5 5 0 8吨 /年的二氧化硫的大气排放