Syntheses of fluorinated ligands to probe binding of antigenic determinants of Vibrio cholerae O:1, serotypes Inaba and Ogawa,to antibodies

Derivatives of methyl α-glycosides of antigenic determinants of Vibrio cholerae O:1, serotypes Inaba and Ogawa, specifically fluorinated at position 2′ or 4′ have been synthesized by coupling the appropriately fluorinated derivatives of 3-deoxy-l-glycero-tetronic acid with the methyl α-glycosides of perosamine. The compound having the fluorine atom at position 2 was obtained by electrophilic addition of fluorine to the glycal derived from the parent antigenic determinant, serotypes Inaba, using Selectfluor^™ as a fluorination reagent.     

不同铝源合成的β沸石结构表征与热分解行为的研究

考察了以固体硅胶为硅源、 NaAlO2及α Al2O3· H2O两种铝源、以及不同晶化混合液的 SiO2/Al2O3比（ 15～ 50）对β沸石合成的影响。通过 XRD、 DSC/TGA、 29Si NMR及 ICP研究表明,以 NaAlO2为铝源合成的β沸石更易形成 Si(0Al)、 Si(1Al)、 Si(O－ )配位,且化学 SiO2/Al2O3比与晶化混合液 SiO2/Al2O3比基本一致,以α Al2O3· H2O为铝源合成的β沸石更易形成 Si(0Al)、 Si(O－ )、 Si(2Al)配位,且化学 SiO2/Al2O3比低于晶化混合液的 SiO2/Al2O3比; TGA失重量随β沸石 SiO2/Al2O3比增加而增加, DSC吸热量随β沸石 SiO2/Al2O3增加而减少。     

A MIXED SUPERLINEARLY CONVERGENT ALGORITHM WITH NONMONOTONE SEARCH FOR CONSTRAINED OPTIMIZATIONS

§ 1　 IntroductionConsider the optimization problemmin{ f(x) :gj(x)≤ 0 ,j∈ I,gj(x) =0 ,j∈ L,x∈ Rn} ,(1 )where f(x) ,gj(x) :Rn→R,j∈I∪L.I={ 1 ,2 ,...,m} ,L={ m 1 ,...,m p} .We know thatthe sequential quadratic programming(SQP) [1～ 4] is one of the mostef-ficient methods to solve problem(1 ) because of its superlinear convergence.In order toovercome the Maratos effect[5] ,SQP should solve two quadratic sub-programmings ateachiteration,which,however,causes the amountof computation…     

新型三维微孔砷酸铟InAsO4(H2O)2的合成及结构

首次以有机胺为结构导向剂,在水热条件下合成了微孔砷酸铟材料InAsO4-1,并对其进行了结构及性质表征。X射线单晶结构解析表明InAsO4-1分子式为InAsO4(H2O)2。晶体学数据为：Pbca,a=0.9090(4)nm,b=1.0344(4)nm,c=1.0468(4)nm,α=β=Υ=90°,V=0.9843(7)nm^3,Z=8,R=0.0480,Rw=0.1045。InAsO4-1具有三维结构,其a,b方向分别有4元环及6元环的一维孔道,结构中还含有一8^16^44^2笼,热重分析显示其结构水较稳定。     

四元数广义奇异值分解及其应用

This paper derives a theorem of generalized singular value decomposition of quaternion matrices(QGSVD),studies the solution of general quaternion matrix equation AXB-CYD=E,and obtains quaternionic Roth's theorem.This paper also suggestssufficient and necessary conditions for the existence and uniqueness of solutions and explicit forms of the solutions of the equation.     

Piezoresistive elements of polycrystalline semiconductor thin films

Polycrystalline Si and Ge films have been prepared by the CVD method and have been used as sensing elements of pressure sensors that have a semiconductor/insulator/stainless steel structure. Values of the gauge factor were 20 and 30 for polycrystalline Si and Ge films, respectively. Hysteresis and deviation from linearity were less than 0.6%.     

Monopoles connected by strings and the monopole problem

To clarify the status of proposed causality arguments limiting the annihilation rate of monopoles, we present a three-dimensional model for the formation of monopoles connected by strings. The length distribution of the strings has been found using a Monte carlo simulation of the phase transition. The result is that long strings connecting monopoles are exponentially suppressed in agreement with the theoretical predictions of Mitchell and Turok [1]. The implications of our results for the monopole problem are discussed.     

On the stable sampling rate for binary measurements and wavelet reconstruction

This paper is concerned with the problem of reconstructing an infinite-dimensional signal from a limited number of linear measurements. In particular, we show that for binary measurements (modelled with Walsh functions and Hadamard matrices) and wavelet reconstruction the stable sampling rate is linear. This implies that binary measurements are as efficient as Fourier samples when using wavelets as the reconstruction space. Powerful techniques for reconstructions include generalized sampling and its compressed versions, as well as recent methods based on data assimilation. Common to these methods is that the reconstruction quality depends highly on the subspace angle between the sampling and the reconstruction space, which is dictated by the stable sampling rate. As a result of the theory provided in this paper, these methods can now easily use binary measurements and wavelet reconstruction bases.