摘要:

This paper describes in detail a freely vibrating reed apparatus which we have developed to study these low temperature dynamic mechanical properties of polymers (at approximately 5 cps). The apparatus is capable of measuring these properties from 4 up to 340 K. This method has the advantage over other methods of being relatively easy to set up and may be modified so more than one specimen can be investigated in a given temperature run. In addition measurements on the logarithmic decrement and Young's modulus of polystyrene are presented and compared with previous data.

ISSN:0034-6748    

DOI:10.1063/1.1684813

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A new apparatus is described which is used for bonding of metals in ultrahigh vacuum by the twist compression technique. It is shown that adhesion between hard metal specimens can be readily measured in ultrahigh vacuum after some initial mechanical abrasion of the surfaces, while adhesion tests in air at atmospheric pressure do not yield measurable adhesion coefficients. Experimental results are reported on the coefficients of adhesion and friction obtained for an atomically ordered platinum‐cobalt alloy.

ISSN:0034-6748    

DOI:10.1063/1.1684814

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A subnanosecond risetime, milliohm resistance Faraday cup was designed and tested for measuring fractional megampere electron beams from pulsed electron accelerators. The device has been typically operated at electron beam currents of 60 kA with an average electron kinetic energy of 4 MeV. Under short circuit conditions the device has measured currents exceeding 0.25 MA.

ISSN:0034-6748    

DOI:10.1063/1.1684815

出版商:AIP    

年代:1970

数据来源: AIP

摘要:

A multichannel monitor has been designed to shorten the effective scanning time of Auger electron spectroscopy. The circuitry of the multichannel monitor is described with specific reference to its application to the second derivative curve of a retarding potential analyzer. By adopting the monitor to a retarding potential analyzer of a LEED system, sufficiently fast response time has been obtained to permit various kinds of surface kinetics to be monitored. By way of illustrating the use of the monitor, results are given of surface composition changes on the Ni(110) surface that accompany heating subsequent to adsorption at room temperature. It was found, for example, that surface carbon may cover surface sulfur and, consequently, on heating the latter suddenly appears as a result of the removal of carbon. In this manner the nature of surface sites occupied by various surface species can be characterized. And by monitoring the kinetics specific activation energies may be determined.

ISSN:0034-6748    

DOI:10.1063/1.1684816

出版商:AIP    

年代:1970

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1684817

出版商:AIP    

年代:1970

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1684818

出版商:AIP    

年代:1970

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1684819

出版商:AIP    

年代:1970

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1684820

出版商:AIP    

年代:1970

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1684821

出版商:AIP    

年代:1970

数据来源: AIP

ISSN:0034-6748    

DOI:10.1063/1.1684822

出版商:AIP    

年代:1970

数据来源: AIP