Differential non-destructive image current detection in a fourier transform quadrupole ion trap

Dual-detector differential non-destructive Fourier transform detection in a quadrupole ion trap is shown to improve signal intensity and reduce noise compared with spectra recorded using a single detector. A larger area detector in each end-cap electrode is machined to fit its hyperbolic shape and so minimize field imperfections on the z-axis. Argon, acetophenone and bromobenzene spectra were recorded to allow a comparison between single- and dual-detector (differential) modes of detection and to demonstrate the improvement achieved with differential detection. Copyright 1999 John Wiley & Sons, Ltd.     

Pseudo-steady-state solutions for solidification in a wedge

Polubarinova-Kochina's analytical differential equation methodis used to determine the pseudo-steady-state solution to problemsinvolving the freezing (solidification) of wedges of liquidwhich are initially at their fusion temperature. In particular,we consider four distinct problems for wedges which are: freezingwith the same constant boundary temperature, freezing with thesame constant boundary heat fluxes, freezing with distinct constantboundary temperatures and freezing with distinct constant fluxesat the boundaries. For the last two problems, a Heun's differentialequation with an unknown singularity is derived, which in bothcases admits a particularly elegant simple solution for thespecial case when the wedge angle is . The moving boundariesobtained are shown pictorially.     

用于高产量MEMS以及3D互联技术的低成本深层反应离子刻蚀系统

新兴的 3D 互联技术以及高产量的 MEMS 应用需要成本低廉以及高产量的深层反应离子刻蚀系统。最优化的 Alcatel 深层反应离子刻蚀系统可以同时满足工艺以及硬件生产性能的高要求。这些都已经在典型刻蚀工艺上进行了研究, 包括斜面刻蚀、堆叠时的 CMOS 刻蚀侧壁角度、3D 高精度惯性传感器的良好控制的形貌、大面积刻蚀的打印机喷头和硅麦克风应用。优化的工艺参数意味着在刻蚀率, 刻蚀的深宽比, notch free 的工艺, 光滑度以及高精度控制各方面的显著提高。Alcatel AMS 200 “I-Productivity”DRIE 机台用于高产量的工艺同时也确保了生产参数如整机效率的提高以及使用成本的降低, 这是通过机台的无可替代的硬件以及工艺方案实现的。     

Three-dimensional scattered-light stress analysis of discontinuous fiber-reinforced composites

This paper reports an investigation of three-dimensional stresses in models of composite materials with discontinuous fibers using the scattered-light photoelastic method. A special scattered-light polariscope with loading system was designed and constructed for this research. Two models were used in this investigation. The first was a cylindrical tension model with a single discontinuous axially aligned aluminum fiber surrounded by a polyester matrix. The second was a five-fiber cylindrical compression model with a central discontinuous fiber surrounded by four continuous ones and polyester matrix. The experimentally determined stress distribution from each model along chosen lines was presented. The stress distribution on the same lines in the single-fiber case was calculated using the finite-element method. The calculated result showed fair agreement with the experimentally determined results.