In what sense is the rational interpolation problem well posed

It is well known that the nonlinear problem of interpolatingm+n+1 data by a rational function of type (m, n) may have no solution, but that the corresponding linearized problem (obtained by multiplying through by the denominator) always leads to a unique rational function, which is often still called the rational interpolant. For fixedm andn, and fixed (possibly multiple) interpolation points, the dependence of this interpolant on the prescribed function values is studied here. For ten notions of convergence in the space _{m, n} the question of the continuity of this interpolation operator is investigated.Communicated by William B. Gragg.AMS classification: 41A24, 30E05, 41A20, 65D05.     

超声搅拌悬浮液进样FAAS法测定铁皮石斛(枫斗)中的铜

研究了铁皮石斛 (枫斗 )中铜的分析方法。样品在 80± 2℃烘干 4h ,研磨过 2 0 0目筛 ,然后加入 5mL 0 1 5 %琼脂悬浮液 ,用超声搅拌混匀后直接上机测定。测定结果与传统湿法一致 ,t检验表明两者无显著性差异 ,相对误差小于 0 96%。该法简便、快速、准确。     

A Novel High Efficient Catalyst AgBr/CaMoO4 for the Reduction of p‐Nitrophenol

A new composite catalyst AgBr/CaMoO₄ was successfully fabricated by loading AgBr nanoparticles on CaMoO₄ support via a convenient precipitation/deposition method, without any controlling agent and template. The microstructure, chemical composition, and morphologies of the AgBr/CaMoO₄ were characterized by X‐ray diffraction, Fourier transform infrared, X‐ray photoelectron spectroscopy, and scanning electron microscopy. A series of comparative experiments showed that the composite AgBr/CaMoO₄ exhibits higher catalytic activity than pure AgBr or CaMoO₄ for the reduction of p‐nitrophenol (4‐NP). Moreover, the AgBr content greatly impacted the catalytic activity of composite AgBr/CaMoO₄ . The conversion rate of 4‐NP with AgBr/CaMoO₄ ‐5% as catalyst could reach 100% within only 4 min, which might be attributed to more number of available active sites from the highly dispersed AgBr nanoparticles on the surface of CaMoO₄ microspheres. In addition, the composite catalyst AgBr/CaMoO₄ displayed a good structural and cycling stability. The present study might provide a new strategy to design composite materials with excellent catalytic performance.     

Some modifications to Sima’s model for total efficiency calculation of well-type detectors

Some modifications are presented to Sima’s simple analytical model for the calculation of the total detection efficiency of a well-type γ-ray detector, aiming at improving its accuracy and broadening its applicability. The modifications pertain to some general improvements in the photon transmission probabilities through absorbing materials and implementation of specific equations for solid angle and mean path length through materials that describe the case of eccentrically positioned sources as well as volume sources. In particular, some improvement is achieved by implementing a contribution from elastic scattering effects.     

Screen‐Printed Electrochemical 96‐Well Plate: a High‐Throughput Platform for Multiple Analytical Applications

A new screen‐printed electrochemical array formed by 96 three‐electrode electrochemical cells with carbon‐based working electrodes (DRP‐96X110) was developed by DropSens. The electrochemical and electro(analytical) performance of this multiple‐analysis plate is herein presented. Different proofs of concept relying on reference benchmark redox compounds, streptavidin‐biotin high affinity interactions and magnetic‐based immunoassays were carried out. The results showed the electrochemical plate versatility and usefulness as an innovative high‐throughput transducer surface for multiple and decentralized applications.     

Ge_xSi_(1-x)/Si超晶格量子阱红外探测器和焦平面阵列现状

文章主要介绍 Ge_xSi_(1-x)/Si 超晶格量子阱长波红外探测器和新颖的红外焦平面阵列的现状。     

宽带半导体材料分子束外延的最新进展

本文评述了分子束外延在以 ZnSe 为代表的宽带半导体材料及其超晶格结构研究中的最新进展。介绍了在晶格匹配和不匹配的衬底上分子束外延生长 ZnSe等Ⅱ-Ⅵ族宽带半导体和有关的材料分析。叙述了在 ZnTe,Zn(S、Se)以及磁性半导体 MnSe 和低磁性半导体 Zn_(1-x)Mn_xSe 上生长 ZnSe 所形成的超晶格和多量子阱结构,并在此基础上说明了一些相关的物理现象。     

调制掺杂AlGaAs/InGaAs/GaAs应变量子阱结构的研究

报道调制掺杂AlGaAs/InGaAs/GaAs应变量子阱结构的分子束外延生长、变温霍尔效应和电化学c—v测量,并对输运性质进行了讨论。用这种材料研制的PM-HEMT(pseudomorphic high electron mobility transistors)器件,栅长0.4μm,在12GHz下噪声系数1.03dB,相关增益7.5dB。     

量子电子器件——谐振隧道热电子晶体管(RHET)

RHET是一种新型高速功能器件,在这种器件中,电子谐振隧穿量子阱谐振隧道势垒(RTB)从发射极注入到基极中,然后以准弹道方式传输到收集极。其主要特点是,高速的电荷传输和宽的负微分电阻。本文综述了RHET的研究与进展,并介绍了采用RHET构成的集成电路。     

卡尔曼滤波在钻井地层电阻率测量中的应用

卡尔曼滤波的主要思想是用状态方程和量测方程描述线性动态系统。本文将卡尔曼滤波应用于测井数据处理，利用滤波参数的特殊性，使处理过程得到简化，计算量减小。实例证明，经过卡尔曼滤波处理后，测井曲线的纵向分辨率有了显著提高，定量解释结果也接近于地层真值。