摘要:

The design of a temperature‐controlled observation chamber is described, that allows light‐microscopic studies of the motile behavior of thermophilic bacteria at temperatures up to 100 °C. The chamber is built for use on an inverted light microscope. Heating and cooling is performed by Peltier elements, with a maximum rate of temperature change of 2 °C/s. The temperature is controlled via a personal computer with an accuracy of ±0.25 °C. ©1994 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1145182

出版商:AIP    

年代:1994

数据来源: AIP

摘要:

A General Valve Series 9 pulsed solenoid valve, when equipped with a 3.3 &OHgr; coil and driven by 400 &mgr;s low voltage (∼22–65 V) pulses, can stably produce gas pulses as little as 10 &mgr;s FWHM. This capability can enhance the performance of a skimmed supersonic molecular beam system. ©1994 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1145183

出版商:AIP    

年代:1994

数据来源: AIP

摘要:

A novel design is presented for a cryogenically cooled multisubstrate sample holder for thin film deposition in high vacuum. The cryogen flows through tubing soldered onto a fixed copper plate, while the substrates are mounted on a separate tray that is supported by a linear/rotary‐motion feedthrough. By lowering the substrate tray into firm contact with the copper plate, substrate temperatures as low as 120 K can be achieved. ©1994 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1145184

出版商:AIP    

年代:1994

数据来源: AIP

摘要:

We describe the use of an interference‐type optical bandpass filter matched to the output spectrum of the phosphor screen to selectively attenuate the light background coming from nearby radiant objects, such as evaporative sources or the (hot) sample under investigation itself in low‐energy electron diffraction. We find a dramatic improvement in signal‐to‐background intensity resulting in an enhanced signal‐to‐noise ratio over merely subtracting away the measured radiant background. ©1994 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1145185

出版商:AIP    

年代:1994

数据来源: AIP

摘要:

A simple method for the determination of coercive fields is described. It is based in the comparison between two signals; one proportional to the applied field which excites the sample, and the other proportional to the internal field that acts directly on the magnetization. Coercive fields as low as 0.14 A/m can be reliably measured and the error using this system does not exceed 0.02 A/m. ©1994 American Institute of Physics.

ISSN:0034-6748    

DOI:10.1063/1.1145186

出版商:AIP    

年代:1994

数据来源: AIP