一种低频大功率调频声波束扫描发射系统

本文介绍一种中心工作频率在４．５ｋＨｚ发射电功率８ｋＷ的１６基元线列阵发射系统，并介绍了使用ＤＳＰ５６００１数字信号处理产生线性调频扫描波束发射信号及接收信号的频域处理和和一些测试结果。     

Simulation of X‐Ray Reflection Curves in Single Non‐Coplanar Geometry and Its Application

The reflection curves as measured by means of the “Ω‐Scan Method” have been simulated as exactly as possible and practicable. The contributions of the collimator function for different beam geometry and of the spectral distribution are considered. The influence of the dead time of the counting unit on the fluctuations of the used high intensities is described by computer modelling. By means of the simulated curves, the theoretical statistic errors of the method, employed to the orientation determination of quartz, can be estimated and compared to the measured ones. The statistic errors due to the intensity fluctuations were found to be dominating the measuring errors. From the simulated curves also the corrections to be applied to the measuring values of the peak positions are derived. Thus, the real physical values of the orientation coordinates can be determined.     

Electrocatalytic oxidation of formic acid on platinum particles dispersed in SWNT/PANI composite film

Single-walled carbon nanotube (SWNT)/Polyaniline (PANI) composite film with good dispersion was prepared by electropolymerization of aniline containing well-dissolved SWNTs. Platinum (Pt) particles were electrodeposited on the SWNT/PANI composite film subsequently. The presence of SWNTs and platinum in the composite film was confirmed by XRD analysis. Four-point probe investigation exhibits that the electrical conductivity of SWNT/PANI composite film is significantly higher than that of pure PANI film. Cyclic voltammogram and Chronoamperogram show that Pt-modified SWNT/PANI electrode performs higher electrocatalytic activity than Pt-modified pure PANI electrode toward formic acid oxidation.     

蔡司Axio Scan.Z1全自动数字玻片扫描系统的应用

全自动切片扫描技术优势大，应用范围广，已逐步成为形态学和病理学研究的一种变革性辅助手段。本文介绍了蔡司Axio Scan.Z1切片扫描系统的配置参数（光学系统、物镜、分辨率、扫描速度、相机等）和成像特点，阐述了蔡司Axio Scan.Z1在大批量全组织扫描、组织病理学、神经生物学等研究领域的重要应用。总结了仪器在使用过程中遇到的问题，分析了原因并提出解决方案，为科研工作提供更好的共享服务。     

On waiting time distributions associated with compound patterns in a sequence of multi-state trials

In this article, waiting time distributions of compound patterns are considered in terms of the generating function of the numbers of occurrences of the compound patterns. Formulae for the evaluation of the generating functions of waiting time are given, which are very effective computational tools. We provide several viewpoints on waiting time problems associated with compound patterns and develop a general workable framework for the study of the corresponding distributions. The general theory is employed for the investigation of some examples in order to illustrate how the distributions of waiting time can be derived through our theoretical results. This research was partially supported by the ISM Cooperative Research Program (2006-ISM·CRP-2007).     

A Simple Scan- and Display-Control for Magnetic Sector Mass Spectrometers

Abstract

Magnetically scanned sector mass spectrometers yield excellent spectra, covering a wide mass range. The spectral display is most reproducible if the magnet is cycled continuously in order to establish a constant hysteresis history.

We have adapted a single sweep spectrometer to continuous cycling. A simple and flexible control initiates and times the magnetic up- and down-sweep, erases and triggers a storage oscilloscope, advances and arrests the photographic recording chart and actuates an event marker on the recorder of the associated gas chromatograph.     

On the anomalous behaviour of a class of locality statistics

A scan statistic methodology for detecting anomalies has been developed for application to graphs, where “anomalies” are equated with vertices that exhibit distinctive local connectivity properties. We present an “anomaly graph” construction that illustrates the capabilities of these scan statistics via the behaviour of their associated locality statistics on our anomaly graphs.     

钢中残量元素As,Sn,Sb的X射线荧光光谱分析

本文介绍了用日本理学3530XRF光谱仪扫描道测定钢中痕量元素As、Sn、Sb。由于短波强大的背景破坏了检测线的线性,通过用DATAFLEX 181B背景扣除的数据处理,消除了这些影响,成功地校准了曲线。方法简单;快速;XRFS结果与化学分析一致,该法已用于炼钢的过程控制和原材料分析。     

A martingale approach to scan statistics

Scan statistics are commonly used in biology, medicine, engineering and other fields where interest is in the probability of observing clusters of events in a window at an unknown location. Due to the dependent nature of the number of events in a large number of overlapping window locations, even approximate solutions for the simplest scan statistics may require elaborate calculations. We propose a new martingale method which allows one to approximate the distribution for a wide variety of scan statistics, including some for which analytical results are computationally infeasible.     

Properties of residuals for spatial point processes

For any point process in that has a Papangelou conditional intensity λ, we define a random measure of ‘innovations’ which has mean zero. When the point process model parameters are estimated from data, there is an analogous random measure of ‘residuals’. We analyse properties of the innovations and residuals, including first and second moments, conditional independence, a martingale property, and lack of correlation. Some large sample asymptotics are studied. We derive the marginal distribution of smoothed residuals by solving a distributional equivalence.