四氯化碳与镁的反应及其反应机理的研究──产生二氯卡宾的新方法

四氯化碳与镁的反应及其反应机理的研究──产生二氯卡宾的新方法林海霞,徐良衡,黄乃聚（温州师范学院化学系,温州,３２５００３）（复旦大学化学系）关键词二氯卡宾,偕二氯环丙烷衍生物,单电子转移偕二氯环丙烷衍生物是一类重要的有机合成中间体,它主要通过二氯卡...     

Electronic structure and optical properties of Nb doped Al2O3 on Si by atomic layer deposition

Nb₂O₅ and Nb doped Al₂O₃ have proved to be good candidates as resistive switch materials or optical materials. In this letter, we focus on the complex electronic structure and optical properties of Nb doped Al₂O₃ to give chemical physical images of the films. With the help of SE, XPS and XPS valence band spectra, the detailed electronic structure with atomic bonding structure and optical properties are given. The band gap of a thin oxide film is determined to be 5.05 eV, and the evolution of VBO and CBO of the film on Si are also discussed.     

Controlling dark current in type-II superlattice photodiodes

Limiting the defect-mediated dark currents in type-II superlattice (T2SL) IR photodiodes remains the key challenge to focal plane arrays (FPAs) based on this material system. In spite of its larger effective mass to suppress tunneling and more than an order of magnitude longer Auger lifetime, the T2SL photodiode performance still lags behind that of the incumbent HgCdTe-based technology. The tunneling and generation–recombination currents can be strongly suppressed by employing a “W” T2SL structure and gradually increasing the energy gap in the depletion region. For maximum quantum efficiency, this graded-gap geometry is combined in a hybrid structure with two-constituent T2SL absorbers that exhibit roughly twice the diffusion length of the “W” structure. Finally, if the etch used to isolate neighboring pixels is stopped just beyond the junction in the graded-gap device, narrow-gap regions are not exposed and the total sidewall area is reduced by a factor of 20. We have combined all of these approaches to produce a 10.5 μm cutoff FPA with diffusion-limited performance and noise-equivalent differential temperature (NEDT) of 35 mK at 70 K.     

Generation of Photocurrent by Visible‐Light Irradiation of Conjugated Dawson Polyoxophosphovanadotungstate–Porphyrin Copolymers

Four hybrid polyoxometalate–porphyrin copolymer films were obtained by the electrooxidation of zinc octaethylporphyrin in the presence of four different Dawson‐type polyoxometalates bearing two pyridyl groups (POM(py)₂) with various spacers. The POM monomers were designed around 1,3,5‐trisubstituted benzene rings. Two of the substituents of the benzene ring are linked to the pyridyl groups, and the third is connected to the POM subunit. The four monomers vary in the relative positions of the nitrogen atoms of the pyridine rings or in the distance from the carbonyl group. The monomers were fully characterized by ¹H, ³¹P, and ¹³C NMR spectroscopy, electrospray mass spectrometry, IR and UV/Vis spectroscopy, and electrochemistry. The copolymers were characterized by UV/Vis spectroscopy, X‐ray photoelectron spectroscopy, electrochemistry, and AFM. Their photovoltaic performance under visible light irradiation was investigated by photocurrent transient measurements under visible illumination.     

SPECTRAL RADIUSES OF THE GALTON-WATSON BRANCHING PROCESSES

§1IntroductionSuppose that(X,Px)is a Markov chain on a countable(or finite)state space E.Givenany x,y∈E,we say that y can be reached from x and write x y,if there is n≥1suchthat Px(Xn=y)>0.If x y and y z,then x z.The markov chain X is said to beirreducible if any two states can be reached from each other.(See[1]or[2]).If X isirreducible,then there is a number r,with0≤r≤1,such that lim supn→∞[Px(Xn=y)]n1=r forany x,y∈E.The number r is called the spectral radius of X(refer to[3]).…     

血卟啉醚类化合物的裂解反应及乙烯基烷氧乙基 次卟啉类化合物的合成

本文考察了3,8-二溴乙基次卟啉Ⅸ与醇(酚)、水的反应产物及血卟啉单、双醚的合成方法,研究了血卟啉醚类的裂解反应,合成了一系列乙烯基烷氧乙基次卟啉类化合物。     

Interaction between a simplified soft palate and compressible viscous flow

Fluid–structure interaction in a simplified 2D model of the upper airways is simulated to study flow-induced oscillation of the soft palate in the pharynx. The goal of our research has been a better understanding of the mechanisms of the Obstructive Sleep Apnea Syndrome and snoring by taking into account compressible viscous flow. The inspiratory airflow is described by the 2D compressible Navier–Stokes equations, and the soft palate is modeled as a flexible plate by the linearized Euler–Bernoulli thin beam theory. Fluid–structure interaction is handled by the arbitrary Lagrangian–Eulerian formulation. The fluid flow is computed by utilizing 4th order accurate summation by parts difference operators and the 4th order accurate classical Runge–Kutta method which lead to very accurate simulation results. The motion of the cantilevered plate is solved numerically by employing the Newmark time integration method. The numerical schemes for the structure are verified by comparing the computed frequencies of plate oscillation with the associated second mode eigenfrequency in vacuum. Vortex dynamics is assessed for the coupled fluid–structure system when both airways are open and when one airway is closed. The effect of mass ratio, rigidity and damping coefficient of the plate on the oscillatory behavior is investigated. An acoustic analysis is carried out to characterize the acoustic wave propagation induced by the plate oscillation. It is observed that the acoustic wave corresponding to the quarter wave mode along the length of the duct is the dominant frequency. However, the frequency of the plate oscillation is recognizable in the acoustic pressure when reducing the amplitude of the quarter wave mode.     

BREAKDOWN OF CLASSICAL SOLUTIONS TO QUASILINEAR HYPERBOLIC SYSTEMS

This paper deals with the asymptotic behavior of the life-span of classical solutions to Cauchy problem for general first order quasilinear strictly hyperbolic systems in two independent variables with weaker decaying initial data, and obtains a blow-up result for C1 solution to Cauchy problem.     

CXN天然沸石的研究Ⅲ.新型 LiCl/H-STI主/客体固电解质的制 备与表征

利用自发热扩散法,将易潮解流失的LiCl(客体)固全到CXN沸石改所得的H－STI沸石(主体)上,形成新型主/客体材料,粉未XRD,SEM,FT-IR和TG/STA等方法表征显示LiCl已经分散到H－STI孔道中,实现了客体的稳定化,其分散阈值0.14g/g。负载量为阈值的样品在绝湿条件下的电导率比主体H－STI提高了四个数量级,是一种良好的固体电解质。