Sufficient Conditions for Amalgamated 3-Manifolds to be ∂-Irreducible∗

In this paper, the authors give some sufficient conditions for an amalgamated 3-manifold along a compact connected surface F with boundary to be ?-irreducible in terms of distances between some kinds of vertex subsets of the curve complex and the arc complex of F.     

稀土磷酸盐发光材料的微波合成

稀土磷酸盐发光材料的微波合成徐文国，田一光，刘淼，刘海堂，方光华，庞文琴（吉林大学化学系，环境科学系，长春，１３００２３）关键词微波合成，稀土磷酸盐，微晶玻璃，玻璃态，发光材料稀土磷酸盐发光材料的研究是当前材料科学的热门研究课题。它们一般通过高温固相...     

N-(6-甲基-2-亚甲基吡啶)-( )-樟脑亚胺体系的不对称烷基化反应

目前,不对称合成光学活性化合物取得了较大进展,不对称合成α-氨基酸、β-氨基醇、α-取代苄胺的报道很多。但是,不对称合成生物碱类物质——α-取代氨甲基吡啶类化合物还未见文献报道,而此类化合物有潜在的应用前景。为此,我们以( )-樟脑为手性试剂     

Synthesis and In Vitro Antiviral Activities of Some New 2-Arylthiomethyl-4-tertiaryaminomethylsubstituted Derivatives of 6-Bromo-3-ethoxycarbonyl-5-hydroxyindoles

Some new derivatives of 3-ethoxycarbonyl-6-bromo-5-hydroxyindoles were designedand prepared, their antiviral activity were determined in cell culture with virus cytopathic effect assay. The results showed compound Ⅶ b, Ⅶ h exhibited potential antiviral activity.     

THE COMPARISON OF LANZHOU LOESS PROFILE WITH VOSTOK ICE CORE IN ANTARCTICA OVER THE LAST GLACIATION CYCLE

Loess near Lanzhou in the late Pleistocene is very sensitive to climatic fluctuations. The Beiyuan terrace profile in Linxia City, of which the curve of susceptibility tallies with the trend of isotopic curves of Vostok 2083 m ice core in Antarctica, is 35m thick. There are five layers of paleosols under Malan loess(L_1). Upper three layers (S_(1-a),S(1-b)and S_(1-c) correspond to three warm stages in last interglaciation, Interstadial of Last Glacial (C stage in Antarctic ice core)was clearly recorded in the Beiyuan profile, in which three layers of paleosols and two of loess were formed. The lowest section of the profile belongs to penultimate glaciation, in which fossils of cold-drought-resistant mammal and mollusc have been discovered.     

2-取代亚肼基-1,3-二硫杂环戊烷类化合物的合成及其生物活性研究

以取代苯甲醛、取代吡啶和取代苯甲酸酯等为原料合成了 10种含硫杂环化合物 (其中 2a～ 2g化合物为国内外未见报道 ) .在合成过程中采用了超声波技术 ,极大地缩短了反应时间 ,提高了收率 .所得化合物的结构经IR ,1 HNMR ,MS和元素分析证实 .对其生物活性进行了初步测试 ,结果证明一些化合物具有良好的抑菌或杀菌作用 ,其中 2b ,2c ,2e ,2h ,2i和2j对大肠杆菌 ( 10 40 7号 )的抗菌效果与CET和SMZ相当 ;2b ,2c ,2f对草绿色链球菌 ( 112 3号 )的抗菌效果与CET和SMZ相当 .     

光学薄膜氧气传感器研究进展

光学薄膜氧气传感器具有检测精度高、选择性好、抗干扰能力强等优点,近年来日益得到人们的广泛重视,研究工作也在不断深化和拓展,展现出十分广阔的应用前景。本文按光学薄膜氧气传感器的制备方法分类扼要综述了光学薄膜氧气传感器的研究现状,并展望了其研究前景。     

THE PARAMETER KERNELS FOR THE LINEAR INVERSION OF THE FREE OSCILLATION OF THE EARTH (Ⅰ)

In the linear inversion of the radial variation of the parameters of the Earth by usingthe observed frequencies of various normal modes of free oscillation of the earth, it is neces-sary to know the values of the kernels of the parameters ρ, μ and λ. This paper describesthe methods of the derivation of the formulas of these kernels. This is the first part of thepaper in which only the toroidal oscillations are considered. They are much simpler thanthose of the spheroidal ones, that we will consider in the second part of the paper. The data of the two types of oscillations are equally important in the solution of theinversion problem, and should be employed simultaneously, and we know that the toroidaloscillations are much simpler than the spheroidal ones, it seems wise to divide the whole programof the inversion problem into steps: first, by employing the toroidal data to correct the twoparameters ρ and μ in the mantle, then by using the spheroidal data to correct the remain-ing parameters, i.e. th     

高效液相色谱-串联质谱法测定食品添加剂中蛇床子素含量

蛇床子素(osthole)又名甲氧基欧芹酚或欧芹酚甲醚,其化学名称为7-甲氧基-8-异戊烯基香豆素,是最先从伞形科植物中提取分离出的天然香豆素类化合物[1].