摘要:

Junction field-effect transistors (FET's) used as analog switching elements in laboratory instrumentation provide high performance, economy, and circuit simplicity. An error analysis and some criteria for selection of FET types are given. FET analog switches are particularly suitable for use in operational amplifier circuits. Several useful applications to laboratory instrumentation are discussed.

ISSN:1073-9149    

DOI:10.1080/10739147108543298

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

An electronic detection system specially developed for quasicontinuous Raman excitation with a 50 cps ruby laser is described. The linearity of Raman intensities is improved over an earlier system [1] including commercial components. In addition a reference signal channel was added to compensate for source fluctuations. Further advantages are: 1) reduction of the recorded dark current of the photomultiplier by a factor of 20, 2) suppression of ruby luminescence near the exciting line. Examples of the performance of the system are given. The Raman spectra of some absorbing substances are presented and discussed.

ISSN:1073-9149    

DOI:10.1080/10739147108543299

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

An analysis is presented of the accuracy obtainable in relaxation experiments with the temperature- or pressure-jump techniques. A procedure is proposed to determine the relaxation time of the main exponential in case of the superposition of two (or more) relaxing effects one of which has an amplitude considerably larger than the other(s). Furthermore, a technique is described for the objective determination of two relaxation processes which have comparable amplitude and a ratio of relaxation times larger than about five. Some effects likely to introduce errors in practical relaxation experiments and the means of eliminating or at least reducing their influence are discussed. Of course, the technique proposed is also applicable to other cases of superimposed exponential functions, e.g., to the determination of similar half-hfes of two simultaneously decaying radioactive elements.

ISSN:1073-9149    

DOI:10.1080/10739147108543300

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Magnetic titrations are performed by determining the changing overall magnetic susceptibility of a liquid system when a reactant solution is added stepwise to that of another reactant. A magnetic titration apparatus and procedure have been developed which are based upon the Quincke method for measuring susceptibility. It is believed to have marked advantages over the Gouy technique. Magnetic titrations have been found to have great utility in the study of complexation reactions in solutions of several transition-metal ions. A practical apparatus and its use are described. Sources of error are analyzed, and sample titration curves are presented. Limitations of the method are discussed.

ISSN:1073-9149    

DOI:10.1080/10739147108543301

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The general features of an instrument designed for the precise slicing and safe handling of radioactive polyacrylamide gels are presented. Gels are maintained frozen by circulating coolant and positioned under a moving slicing blade by an adjustable ratchet mechanism. The gel slices are automatically deposited in a scintillation vial by a blast of air directed over the surface of the cutting blade. The instrument is designed to accommodate gels of various diameters and is easily dismantled for cleaning.

ISSN:1073-9149    

DOI:10.1080/10739147108543302

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

ISSN:1073-9149    

DOI:10.1080/10739147108543303

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

ISSN:1073-9149    

DOI:10.1080/10739147108543297

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor