几种常见水果的微量元素分析

运用原子吸收分光光度法测定了几种常见水果中部分微量元素含量。其中榴莲的Mg、Zn、Cu、K含量位于四种水果之首。美国提子中Ca含量最高，芒果中Fe含量最高。以上差别具有统计学意义。六种元素的回收率为90％-106．5％。连续6次测定样品，变异系数(CV)为0．96％。     

关于meso—四苯基卟啉在冰醋酸中的存在形式

前言卟啉在生物化学、分析化学、药物化学等领域有着广泛研究和重要应用［１～３］。近年来虽然对卟啉类化合物的研究报道很多［４～６］，但对卟啉在酸性介质中的研究很少。较早期的研究工作认为卟啉类化合物在酸性介质中仅以其二酸形式存在［７］。本文实验结果显示ｍｅ...     

二氧化碳多相催化加氢的新进展

就近年来关于ＣＯ２活化、几个重要的ＣＯ２多相催化加氢反应及廉价氢的供给的研究进展进行综述。参考文献３４篇。     

Research on Crystal Structure of the Complex of 10－Hydroxy－10－（3－indolyl）－9－phenanthrenone with Tetrahydrofuran

ＲｅｓｅａｒｃｈｏｎＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆｔｈｅＣｏｍｐｌｅｘｏｆ１０－Ｈｙｄｒｏｘｙ－１０－（３－ｉｎｄｏｌｙｌ）－９－ｐｈｅｎａｎｔｈｒｅｎｏｎｅｗｉｔｈＴｅｔｒａｈｙｄｒｏｆｕｒａｎＭｅｎｇＪｉ－Ｂｅｎ；ＷｅｎＺｈｏｎｇ；Ｗａｎｇ...     

透射电镜薄样品倾转过程中的附加旋转及其计算

模拟透射电镜双倾台进行样品位向调整过程,推导出反映样品倾转前后其合成倾转轴(即共有菊池线对的法线)方向变化规律的计算公式,称为附加旋转角计算公式。指出,实现样品位向调整的双倾操作,等效于样品绕其合成倾转轴的倾转及该倾转轴绕Z轴(平行入射束方向)的旋转之和。利用双倾台对薄膜样品进行的系列倾转实验表明,由附加旋转角公式计算的附加旋转角和实测值相一致。还根据双倾操作过程导出了合成倾转角的计算公式,它可用于判断样品位向调整的准确度。     

Facile synthesis of exfoliated and highly conductive poly(arylene disulfide)/graphite nanocomposites

Exfoliated graphite has been synthesized by first synthesizing H₂SO₄ intercalated compound in a H₂O₂‐H₂SO₄ mixture, followed by exfoliation under microwave irradiation. Poly(arylene disulfide)/graphite nanocomposites were then fabricated by absorbing cyclic(arylene disulfide) oligomers into the pores of exfoliated graphite. Subsequently, the nanocomposite precursor was subjected to heat treatment to carry out the in situ ring‐opening polymerization of the oligomers via free radical mechanism. The as‐prepared nanocomposite exhibited a exfoliated nanostructure as evidenced by transmission electron microscopy (TEM) observation. The nanocomposite with a very small amount of graphite, 5 wt%, possesses a highly electrical conductivity of 4 S/cm, therefore, many applications can be found as conductive materials. Copyright © 2004 John Wiley & Sons, Ltd.     

Synthesis and characterization of perfluorohexylated poly(3,4-ethylenedioxythiophene)

The perfluorohexylated 3,4-ethylenedioxythiophene 5 was prepared via Mitsunobu reaction of perfluorohexylatyed diol 2 with diethyl 3,4-dihydroxythiophenedicarboxylate followed by decarboxylation. The polymerization of 5 was conducted with both oxidative chemical and electrochemical polymerizations. The polymers were characterized by cyclic voltammogram, UV, IR, TGA and DSC.     

反相高效液相色谱法的多波长同时测定预混合饲料中的脂溶性维生素A，α－E，D_3，K_3

反相高效液相色谱法的多波长同时测定预混合饲料中的脂溶性维生素Ａ，α－Ｅ，Ｄ＿３，Ｋ＿３李桂凤，李缙扬，郝征红，聂燕，孟兆宏，李学春（山东省农业科学院中心实验室济南２５０１００）１前言对脂溶性维生素的分析，被许多国内外分析专家认为是高难度的分析项目。本...     

Structure, Stability and Vibrational Spectra of LaC_5~n(n=-1,0,+1) Clusters

用密度泛含方法研究了ＬａＣ５ｎ（ｎ＝－１，０，＋１）分子簇的结构和稳定性及振动光谱，对这个六原子体系提出了三种可能构型，点群结构为Ｃ２ｖ对称性．第一个构型为Ｌａ接在弯曲的Ｃ５链上，第二个是Ｌａ通过二个键与Ｃ５环相连第三个是Ｌａ通过一个键与Ｃ５环相连；结果表明，第一个构型即当Ｌａ接在弯曲的Ｃ５链上时能量最低．振动光谱分析指出，当ｎ＝－１时，第二个构型为局域极小值；当ｎ＝＋１时，第一个和第二个构型为局域极小值；对ｎ＝０，局域极小值没有找到．