Sensitivity analysis of a two-mode resonant gravitational-wave detector with arbitrary tuning

Summary We present a very general characterization of a resonant gravity wave detector and an explicit algorithm to evaluate its noise temperature when a passive transducer is used. This procedure also provides quantitative results for the sensitivity of such a detector in applications yet to be analysed, like insufficient or excessive tuning of the second resonator and use in detection of monochromatic radiation, both on and off resonance.

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Riassunto Si presenta una caratterizzazione del tutto generale di un'antenna gravitazionale risonante, ed un algoritmo esplicito per calcolarne la temperature di rumore nel caso in cui venga usato un trasduttore di vibrazioni passivo. Questo metodo fornisce risultati quantitativi per la sensibilità di un tale apparato anche in applicazioni non ancora analizzate completamente, quali un'imperfetta accordatura del secondo oscillatore e la rivelazione di radiazione monocromatica di frequenza coincidente o prossima alla risonanza dell'antenna.

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Резюме Приводятся характеристики общего типа резонансного детектора гравитационных волн. Предлагается явный алгоритм оценки температуры шума этого детектора в случае, когда используется пассивный преобразователь. Эта процедура также дает количественные результаты для чувствительности такого детектора при несовершенной настройке второго резонатора и при детектировании монохроматического излучения в резонансе и вне резонанса.

     

Development of an Automatic Electrochemical System for Differential Pulse Amperometry and Its Application for Se(IV) Determination

This work presents the development of an automatic system for differential pulse amperometry (DPA) with electrochemical deposition. The system consists of a microcomputer, running a home‐made software, connected to a commercial potentiostat through a data acquisition board. The system was applied for selenium determination using gold electrode and flow injection analysis (FIA). Analytical curves were obtained in the concentration range of 20 to 400 μg L^?1 for Se(IV), with a calculated detection limit of 6 μg L^?1. The analysis results for fish samples doped with Se(IV) and digested in a microwave oven showed recoveries above 93%.     

Analysis of biosensors by chemically specific optical techniques. Chemiluminescence-imaging and infrared spectroscopic mapping ellipsometry

The standard methods currently used to read out microarrays are fluorescent and chemiluminesent imaging techniques. These methods require labeling of a component with a marker and, usually, only the concentration of the marker molecule is detected. A label-free imaging method that also enables quantitative spectroscopic analysis of the composition and component interaction would be of great advantage. In this article it is shown for the first time that IR mapping ellipsometry enables label-free imaging of a biochip before and after incubation with peptide solution. The measurements prove that IR ellipsometry is a sensitive tool for laterally resolved identification of the different materials and determination of the composition of a biochip. The lateral resolution required was achieved by using radiation from an infrared synchrotron beamline.      

LC-MS analysis in the aquatic environment and in water treatment – a critical review

LC-MS has become an invaluable technique for trace analysis of polar compounds in aqueous samples of the environment and in water treatment. LC-MS is of particular importance due to the impetus it has provided for research into the occurrence and fate of polar contaminants, and of their even more polar transformation products. Mass spectrometric detection and identification is most widely used in combination with sample preconcentration, chromatographic separation and atmospheric pressure ionization (API). The focus of the first part of this review is directed particularly toward instruments and method development with respect to their applications for detecting emerging contaminants, microorganisms and humic substances (HS). The current status and future perspectives of 1) mass analyzers, 2) ionization techniques to interface liquid chromatography (LC) with mass spectrometry (MS), 3) methods for preconcentration and separation with respect to their application for water analysis are discussed and examples of applications are given. Quadrupole and ion trap mass analyzers with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) are already applied in routine analysis. Time-of-flight (TOF) mass spectrometers are of particular interest for accurate mass measurements for identification of unknowns. For non-polar compounds, different ionization approaches have been described, such as atmospheric pressure photoionization (APPI), electrochemistry with ESI, or electron capture ionization with APCI. In sample preconcentration and separation, solid phase extraction (SPE) with different non-selective sorbent materials and HPLC on reversed-phase materials (RP-HPLC) play the dominant role. In addition, various on-line and miniaturized approaches for sample extraction and sample introduction into the MS have been used. Ion chromatography (IC), size-exclusion chromatography (SEC), and capillary electrophoresis (CE) are alternative separation techniques. Furthermore, the issues of compound identification, matrix effects on quantitation, development of mass spectral libraries and the topic of connecting analysis and toxicity bioassays are addressed.     

Spherical neutron polarimetry applied to spin-echo and time-of-flight spectroscopy

The changes in direction of the neutron spin that take place on scattering by a magnetic interaction vector are highly dependent on their relative directions. In some circumstances, without zero-field polarimeter, it is impossible to distinguish between a simple depolarisation and a rotation of the polarisation vector.Motivated by the investigation of chiral magnetic fluctuations, we have implemented the third-generation zero-field polarimeter Cryopad on the neutron spin-echo spectrometer SPAN at the Helmholtz Centre Berlin (HCB). We present the method and the limitations of this novel technique that is now available on IN15 at the ILL.The huge progress accomplished with ³He neutron spin filters/flippers are going to facilitate the exploitation of polarised beams at spallation sources. Zero-field polarimeters like Cryopad are used routinely at several steady-state sources but their design would be inefficient at a pulse source. We have investigated the possibility to implement a zero-field polarimeter on a time-of-flight spectrometer. We propose a design that would lead to a better efficiency and present the finite element calculations.     

ICP—AES法测定玩具材料和涂料中的可溶性有害元素

本文报道用ＩＣＰ－ＡＥＳ法对玩具材料和涂料被吞咽在消化系统内停留４小时的模拟条件下溶出的Ｓｂ，Ａｓ，Ｂａ，Ｃｄ，Ｃｒ，Ｐｂ，Ｈｇ和Ｓｅ八种有害元素的量进行测定，以确保儿童玩具的安全性和促进玩具商品的顺利出口。     

Upgrade of a Raman Spectrometer

Abstract

Improvement of a conventional JEOL Raman spectrometer with a single channel photo multiplier detector is described. New optical components [fibers, mirror, lens, and charge coupled device detector (CCD)] have been chosen to design a high quality and easy‐to‐use instrument. Tests have shown that with this modified spectrometer, Raman spectra can be acquired of a quality comparable to the spectra obtained previously, but the time needed to obtain a spectrum is markedly reduced. Selected test spectra and a simple calibration procedure to obtain the wavenumber values from the band CCD pixel position are presented.     

激光光源条件对谷氨酸钠拉曼光谱的影响

采用多种激光和不同功率等,对谷氨酸钠晶体进行了激光拉曼光谱的影响研究。结果表明不同波长和功率的光源,对测定存在一定的影响,谱峰位移在6 cm-1以内。紫外激光由于光能量较大对样品有一定的破坏作用,造成拉曼光谱的减弱和泯灭,需采用光路衰减。拉曼谱峰的响应与光源的功率有着很好的线性关系,其相关系数r　0.999。首次提出单位光功率所产生的拉曼光强与所用的波长有关,与所用的光功率无关。     

Infrared band intensities: a comparative study of the transition moment matrix elements for fundamentals and overtones: Part I. General

A complete survey of the various expressions reported by different authors for transition moment matrix elements for infrared transitions of diatomic molecules has been made. The different expressions for fundamentals and overtones are presented in uniform coordinates. Although the expressions look different when compared in their original forms it is found that with the uniform coordinates, several of them are similar in the first few terms. Expressions obtained from the consideration of Morse potential as well as those obtained from inclusion of anharmonic potential are discussed. From the various expressions presented in uniform coordinates general remarks about the effects of inclusion of mechanical and electrical anharmonicity on the intensities of the fundamental and first two overtones are made. Since the effects of inclusion of mechanical and electrical anharmonicity are opposite in sign for the first overtone, it is further discussed that an increase in the intensity of the fundamental band on hydrogen bonding and a slight weakening of the intensity of the first overtone or no change in its intensity can be explained on the basis of an increase in the first and second derivatives of dipole moments on hydrogen bonding. Some general remarks are made regarding the dipole expansions and intensity expressions for polyatomic molecules.