摘要:

The photoelectrolysis of water in cells with SrTiO3anodes has been confirmed. The maximum external quantum efficiency at zero bias voltage is 10% (ath&ngr;=3.8 eV), about an order of magnitude higher than the maximum value obtained with anodes of TiO2, the only other material so far known to catalyze photoelectrolysis. In agreement with the energy‐level model proposed previously, the efficiency is increased because the band bending at the anode surface is about 0.2 eV larger for SrTiO3than for TiO2, as a result of the smaller electron affinity of SrTiO3.

ISSN:0003-6951    

DOI:10.1063/1.88723

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

The compressive stress gradients induced by relatively energetic ion bombardment in sputtering, for surface analysis and cleaning, are shown to result in the possibility of atom migration and compositional changes. A solution to these problems is proposed.

ISSN:0003-6951    

DOI:10.1063/1.88724

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

The structural relaxation spectra of (Pd0.6Ni0.4)0.80P0.20and Pd0.775Cu0.06Si0.165metallic glasses have been obtained with a differential scanning calorimeter. The relaxation spectrum exhibits two distinguishable broad features: a low and high activation energy spectrum. The low activation energy spectrum peaks at activation energy &egr;≈22 kcal/mole. The intensity of the low activation energy spectrum relative to the total spectrum decreases with decreasing quenching rate. Implications of these phenomena are discussed. The observed heat of relaxation of the glasses is in fair agreement with the value calculated from viscosity data using the entropy model of viscous flow.

ISSN:0003-6951    

DOI:10.1063/1.88725

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Capacitance spectroscopy studies of lattice defects intentionally introduced into GaP diodes by 1‐MeV electron irradiation have shown a very large enhancement in the defect annealing rate under conditions of e‐h recombination. Six deep levels are observed and all exhibit recombination enhanced annealing. Four of the levels anneal athermally during recombination having the same rate at 100 K as at 300 K. Comparisons of the thermal annealing activation energy and the energy released during hole capture indicate that the observed athermal enhancement is a natural consequence of the wide GaP band gap.

ISSN:0003-6951    

DOI:10.1063/1.88726

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

At room temperature and below, a complete poling of polyvinylidene fluoride film can be produced in less than 1 sec by corona charging. Changes in pyroelectric coefficient and infrared spectra which accompany this poling are described. A transformation from &agr; to another form occurs; development of most of the pyroelectric property occurs at an early stage of this transformation.

ISSN:0003-6951    

DOI:10.1063/1.88727

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

General conditions are derived for achieving an inversion with respect to the ground level of an atom or ion by rapid cooling of a plasma. As an example, gain on the He+304‐A˚ resonance transition in a laser‐produced helium plasma is considered in detail.

ISSN:0003-6951    

DOI:10.1063/1.88728

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

A simple and rapid method is described for determining the refractive index profile of an optical fiber by observation of the near‐field intensity distribution. It is shown that in many cases the presence of tunnelling leaky modes is unavoidable and that these cause a length‐dependent error in the measurement. A correction factor is developed which may be applied to the measured intensity profile once the fiber length, core diameter, and numerical aperture are known. Examples are given of measurements made on both step and graded‐index fibers.

ISSN:0003-6951    

DOI:10.1063/1.88729

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

The possibility of mode locking of high‐powered laser oscillators by injection locking to a weak mode‐locked signal from a cw laser is proposed and demonstrated. The experiment was carried out using a flash‐lamp–pumped pulsed dye laser injection locked to a mode‐locked cw dye laser. Gains on the order of 3×104and nearly Fourier‐transform–limited mode‐locked pulses were obtained.

ISSN:0003-6951    

DOI:10.1063/1.88730

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Adaptive spatial filters based on the photodichroic property of anisotropic color centers in alkali halide crystals have been constructed for use in real‐time optical spectral analysis. Operating as change detectors in continuous spectrum surveillance, the photodichroic filter essentially sensitizes the monitoring system to detect only ’’new’’ signals. Long‐term background signals have been attenuated by factors as high as 30 000.

ISSN:0003-6951    

DOI:10.1063/1.88719

出版商:AIP    

年代:1976

数据来源: AIP

摘要:

Atomic fluorine is produced by dissociation of NF3in a fast‐pulsed electrical discharge in helium. High‐power laser action is observed, with 70 kW on five lines near 7100 A˚, all of which are assigned to electronic transitions in neutral atomic fluorine. Two of the laser lines are reported here for the first time. Some scalability appears possible for this laser, which already has proven to be an excellent pump source for infrared laser dyes.

ISSN:0003-6951    

DOI:10.1063/1.88720

出版商:AIP    

年代:1976

数据来源: AIP