A Novel Synthesis of Some Hexasubstituted Cyclotriphosphazenes

In recent years, many efforts were focused on the preparation and characterization of phosphazene which contained a framework of alternating phosphorous and nitrogen atoms with two substituent groups attached to each phosphorous atom1. It is noticeable that cyclophosphazene, especially hexaaryloxyphosphazene and perfluoroaryloxyphosphazene exhibit excellent thermal and chemical stability which can be used as fireproof materials, high temperature lubricants, vacuum pump oils and hard disk surfac…     

The Synthesis of N-Morphine Hapten and Production of Monoclonal Antibody

The drug overdose and addiction is a serious international problem. Therefore developing a rapid, accurate, convenient and cheap method for detecting morphine in urea is useful and necessary, especially for investigation of epidemiology, identification of medical jurisprudence and determination of drug addict etc. There are many compounds that are similar to morphine in chemical structure and tend to have cross-reaction with the anti-morphine antibody. In order to reduce the cross reaction a…     

Preparing Nano-ZnS by Solid State Reaction at Room Temperature

Solid-state reaction has been studied for a long time1-3. In recent years, some researches have been focused on the preparation of coordination compounds at low temperatures or even at room temperature4-5. In this letter, preparation of ZnS nanoparticles by using solid state reaction at room temperature is reported.ZnS nanoparticles were prepared as follows: Zn(CH3COO)2 and Na2S?9H2O, in equal molar ratio, were ground in agate mortar. After 20 minutes, the powder was washed by water and …     

Concise Synthesis of(±)-epi-Chrysotricine

Chrysotricine 1 was isolated from the Chinese herb medicine Hedyotis Chrysotricha and was shown to possess antitumor activity1. Its structure has been elucidated as a novel zwitterionic (-carboline alkaloid containing a 2,2,5-trisubstituted tetrahydrofuranyl group. The (-carboline compounds have attracted considerable attraction in recent years because of their promising and intriguing biological activities2. Recently, we have established the absolute configuration of chrysotricine by the fir…     

New diterpenoid glucosides from Siegesbeckia pubescens

Plants of the genus Siegesbeckia are annual herbs widely distributed in tropical and temperate zones and they are used as a traditional medicine to treat rheumatic arthritis, hypertension, malaria, neurasthenia and snake-bite in China. In previous papers, we reported on five new ent-kaurane and ent-pimarane diterpenoids, siegesbeckioside, siegesbeckiol and siegesbeckic acid1, orientalin A and B, and eight know compounds2,3. The present paper describes the isolation and structural elucidation …     

A Novel Acoustic Emission Fiber Optic Sensor Based on a Single Mode Optical Fiber Coupler

Ａｓｗｅｋｎｏｗ ,ａｓｉｎｇｌｅｍｏｄｅｆｉｂｅｒｃｏｕｐｌｅｒｉｓａｓｉｍｐｌｅｂｕｔｖｅｒｙｉｍｐｏｒｔａｎｔｆｉｂｅｒｏｐｔｉｃｄｅｖｉｃｅ ,ｗｈｉｃｈｃａｎｂｅｕｓｅｄｉｎｃｏｍｍｕｎｉｃａｔｉｏｎａｎｄｓｅｎｓｏｒｓ.Ｕｓｉｎｇｓｉｎｇｌｅｍｏｄｅｏｐｔｉｃａｌｆｉｂｅｒｄｅｖｉｃｅｓ,ｗｅｃａｎｆａｂｒｉｃａｔｅｓｅｖｅｒａｌａｃｏｕｓｔｉｃ ｏｐｔｉｃｄｅｖｉｃｅｓ ,ｓｕｃｈａｓｆｒｅｑｕｅｎｃｙｓｈｉｆｔｅｒｓ ,ｍｏｄｕｌａｔｏｒｓａｎｄｔｕｎａｂｌｅｆｉｌｔｅｒｓ .Ｓｅｖｅｒａｌ…     

New Soluble Fluorinated Polyimides

Aromatic polyimides have been widely used in aerospace, electrical and electronic applications due to their outstanding thermal stability, mechanical strength at elevated temperature and electrical properties1-3. However, polyimide materials are usually difficulty to fabricate owing to their insolubility in most organic solvents and infusibility. Besides solubility, low moisture uptake of polyimide is also a major concern for microelectronics and optical applications. The present article descr…     

Crystal and Molecular Structure of 1-Phenoxy(α-methyl)acetyl-2-diethylamino-3-phenyl-1,3,2-diazaphospholidin-4-one-2-sulfide

1　INTRODUCTIONAsherbicides,thearyloxycarboxylicacidssuchas2,4-D(2,4-Dichlorophenoxyaceticacid)etc.havenotbeenusedwidelysince1970sbecauseoftheircausingenvi-ronmentalpollutionandinjuriestothecrops.Studiesonthenewtypeofherbicideshavebeendevelopinginrecentyears.Itwasreportedrecentlythatthederivativesofdiazaphospholidinoneorthecorrespondingthionespossessinterestingherbicidalactiv-ity[1～3].Itwasalsoknownthat1,4,2-diazaphospholidine-5-thione-2-oxideshasgoodselectiveherbicidalactivity[4,5],but…     

数值地震预测的关键物理问题*

数值地震预测是地震物理研究中的一个重要课题,具有基础性的科学意义和潜在的应用价值.文章介绍了数值地震预测的三个关键物理问题——地震发生率与应力变化的关系、地震断层的摩擦函数、地球中应力的传递问题,讨论了这些问题的意义、研究现状和发展趋势.     

中国(英文)物理期刊上的各单位贡献比较

对于中国学术界出版英文学术期刊现在是没有人反对的,而且一般地讲大家都会赞成要把它办好。但是对于在中国出版英文期刊的目的和作用,对于这些刊物和刊物论文的评价尺度、以及对于办刊的回报预期,从论文作者到读者,从出版社到相关的主管机构(如中国科学技术协会及其下属学会、国家自然