摘要:

An x-ray fluorescence system has been designed to make elemental analyses of trace elements in low-Z matrices. It consists of radioisotope exciters, a Si(Li) detector, and a computer-based pulse height analyzer. Qualitative measurements of all elements heavier than phosphorus (Z = 15) and quantitative measurements of all elements heavier than potassium (Z = 19) can be made. For samples fluoresced for 1000 s on 9 mg/cm2filter paper, the three sigma detection limits range from 10 to 100 ng/cm2. Accuracy is within ±10% and reproducibility is better than 5%. The method often requires no sample preparation and is completely nondestructive. Quantitative information obtained with such a system is useful in monitoring trace element concentrations in air, water, or biological material.

ISSN:1073-9149    

DOI:10.1080/10739147508543381

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A phosphorimeter is described which is intended to be used for delayed fluorescence measurements in which the excitation light is introduced in a spatially nonhomogeneous manner. The excitation optics produce a reduced image of the space intermittency pattern at a 1 mm layer of the test solution. The delayed emission is isolated from prompt fluorescence by an adjustable phasing between excitation and emission choppers. Solutions of anthracene and 9, 10-diphenyl anthracene in ethanol both show changes in delayed fluorescence intensity with changing dimensions of the space intermittency pattern. The effects observed are in agreement with theoretical expectations.

ISSN:1073-9149    

DOI:10.1080/10739147508543382

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A digital readout system to obtain automatically the anodic or cathodic charges in electrochemical reactions by the multipulse potentiodynamic technique is presented. The cathodic charge of the hydrogen deposition is determined in 1N H2SO4in the absence and presence of 1M methanol on a platinum electrode to Illustrate the possibilities of the Instruments.

ISSN:1073-9149    

DOI:10.1080/10739147508543383

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

An electronic device for selection of 10 mass peaks from a quadrupole-mass spectrometer and for recording them on a single-pen recorder Is described.

ISSN:1073-9149    

DOI:10.1080/10739147508543384

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The Byron Model 233A air quality analyzer has been evaluated with respect to the manufacturer's performance specifications. Observations of operating characteristics, over a ten-month period, are noted. Some aspects of instrument performance, not normally included in specifications, are discussed. This evaluation is only concerned with the reliability of measurements made on atmospheric samples.

ISSN:1073-9149    

DOI:10.1080/10739147508543385

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

ISSN:1073-9149    

DOI:10.1080/10739147508543386

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

ISSN:1073-9149    

DOI:10.1080/10739147508543387

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

ISSN:1073-9149    

DOI:10.1080/10739147508543380

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor