Design Techniques of CMOS Ultra-Wide-Band Amplifiers for Multistandard Communications

This paper presents design techniques of CMOS ultra-wide-band (UWB) amplifiers for multistandard communications. The goal of this paper is to propose a compact, simple, and robust topology for UWB low-noise amplifiers, which yet consumes a relatively low power. To achieve this goal, a common-gate amplifier topology with a local feedback is employed. The first amplifier uses a simple inductive peaking technique for bandwidth extension, while the second design utilizes a two-stage approach with an added gain control feature. Both amplifiers achieve a flat bandwidth of more than 6 GHz and a gain of higher than 10 dB with supply voltages of 1.8-2.5 V. Designs with different metal thicknesses are compared. The advantage of using thick-metal inductors in UWB applications depends on the chosen topology.     

Ionothermal synthesis of a three-dimensional zinc phosphate with DFT topology using unstable deep-eutectic solvent as template-delivery agent

A three-dimensional zinc phosphate compound with DFT topology, designated as ZnPO₄-EU1, has been synthesized by an ionothermal approach from the system HF-ZnO–P₂O₅-choline chloride-imidazolidone. Ethylenediamine, derived from decomposition of the imidazolidone component of the deep-eutectic solvent (DES) itself, is delivered to the synthesis and serves as an appropriate template for ZnPO₄-EU1. Experiments in which the synthesis conditions were varied showed that ZnPO₄-EU1 may be prepared over a wide molar ratio of P/Zn = 0.55–13.0. Powder X-ray diffraction patterns have been obtained at intervals to track the crystallization process of this material. The experimental data show that Zn₃(PO₄)₂ · 4H₂O (a dense phase) was first isolated from the DES after reaction for 1 h. Subsequently, the pure phase of ZnPO₄-EU1 was obtained with increasing crystallization time from 12 h to 72 h. The experimental results show that the nucleation and crystallization take place with relatively low levels of solvent degradation, demonstrating that zinc phosphate with a three-dimensional framework can be synthesized by in situ generation of an appropriate template using an unstable DES at high temperatures (150–200 °C).     

熟悉而又陌生

《Frame》总第46期向读者展示了许多有意思的想法和创意的细节下面是从中摘选出来的设计和空间方案他们都运用到了我们身边很熟悉的元素，在这里“腐朽”一下化神奇了。[编者按]     

The effect of nitrogen oxides in air on the performance of proton exchange membrane fuel cell

The effects of NO_x on the performance of proton exchange membrane (PEM) fuel cell were investigated through the introduction of a mixture containing NO and NO₂, in a ratio of 9:1, into the cathode stream of a single PEM fuel cell. The NO_x concentrations used in the experiments were 1480 ppm, 140 ppm and 10 ppm, which cover a range of three orders. The experimental results obtained from the tests of durability, polarization, reversibility and electrochemical impedance spectroscopy (EIS) showed a detrimental effect of NO_x on the cell performance. The electrochemical measurements results suggested that the impacts of NO_x are mainly resulted from the superposition of the oxygen reduction reaction (ORR), NO and HNO₂ oxidation reactions, and the increased cathodic impedance. Complete recovery of the cell performance was reached after operating the cell with clean air and then purging with N₂ for hours.     

Global practical stabilization of planar linear systems in the presence of actuator saturation and input additive disturbance

In this note, we revisit the problem of global practical stabilization for planar linear systems subject to actuator saturation and input additive disturbances. A parameterized linear state feedback law is designed such that, by tuning the value of the parameter, all trajectories of the closed-loop system converge to an arbitrarily small neighborhood of the origin in a finite time and remain in there.     

A Tutorial on GrÖbner Bases With Applications in Signals and Systems

This paper is a tutorial on GrÖbner bases and a survey on the applications of GrÖbner bases in the broad field of signals and systems. A reasonably detailed review is given of several fundamental theoretical issues that occur in the use of GrÖbner bases in multidimensional signals and systems applications. These topics include the primeness of multivariate polynomial matrices, multivariate unimodular polynomial matrix completion, and prime factorization of multivariate polynomial matrices. A brief review is also presented on the wide-ranging applications of GrÖbner bases in multidimensional as well as one-dimensional circuits, networks, control, coding, signals, and systems and other related areas like robotics and applied mechanics. The impact and scope of GrÖbner bases in signals and systems are highlighted with respect to what has already been accomplished as a stepping stone to expanding future research.      

国产陶瓷膜清洗方法的探讨

本文结合生产实际 ,介绍陶膜的清洗工艺 ,并通过比较试验获得优化的清洗方案。     

15000 m^3／h制氧机组同步电动机起动技术研究

介绍液态软起动技术在济钢 15000 m3/h制氧机配套的 6000 kW同步电动机上的应用情况,阐述了系统的原理、特点、仿真计算及实际应用后达到的效果.     

Photoluminescence and X-ray Diffraction of Distributed Bragg Reflector

Spectral and structural characteristics of distributed Bragg reflector (DBR) in vertical-cavity surface-emitting lasers were studied with photoluminescence and double- crystal X- ray diffraction measurement. The expected high quality epitaxial DBR structure was verified. In the X- ray double- crystal rocking curves of DBR the zeroth- order peak, the first and second order satellite peaks were measured. Splitting of diffraction peak appeared in the rocking curves was analyzed. The effects of introduced deep energy levels on the structural perfection and optical properties were discussed.