摘要:

The generation of a second‐harmonic signal at a flat unbonded interface between two solids has been observed. This signal is caused by passage of a longitudinal acoustic wave across the interface. The harmonic amplitude depends upon the pressure applied normal to the interface and is largest close to zero pressure, as expected theoretically. The effect has also been used to detect the presence of microcracks on the surface of Al 2024, developed during fatigue.

ISSN:0003-6951    

DOI:10.1063/1.90399

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

In ferroelectric gadolinium molybdate a stable planar domain wall can be swept through the crystal by applying a voltage along the polar axis. The resulting polarization current can be used to read out analog information stored as a waveform pattern in the electrodes. Using a differential detection scheme, we have demonstrated the reproduction of 4 sec of typical speech stored with a density of 50 sec of speech per cm2.

ISSN:0003-6951    

DOI:10.1063/1.90400

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Applying a coaxial Marx generator with the rectangular pulse across a constant load for a study of double‐focusing diodes, an important difference of the behavior between the single‐ and the double‐focusing diode is found. In order to understand its behavior more precisely, the necessity will be pointed out to take into account the anode plasma effects.

ISSN:0003-6951    

DOI:10.1063/1.90401

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The magnetoresistance of bulk and epitaxial films of dopedn‐type yttrium iron garnet is reported for the first time. In (111) films a &Dgr;R/Rof −0.55% is observed as a saturating applied field H is rotated out of the (111) plane to the film normal. There is no observable change in &Dgr;R/Ras H is rotated in the (111) plane, with the current I in various directions in the (111) plane. This isotropy of &Dgr;R/Rin the (111) plane has not been observed in other ferromagnetic materials such as iron and nickel and is not understood as yet. The same isotropy in the (111) plane is also observed in bulk yttrium iron garnet. A possible use of this magnetoresistance for magnetoresistive detectors in magnetic bubble devices is discussed.

ISSN:0003-6951    

DOI:10.1063/1.90402

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

We have investigated an energy‐storage cycle in which CO2is electrochemically reduced to formic acid, HCOOH. The product can be used in several ways. By means of a catalyst, it can be converted to hydrgen for use as a fuel or raw material. We have obtained data on the efficiency of the process and analyzed the energetics.

ISSN:0003-6951    

DOI:10.1063/1.90403

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The first tests of the thermoelectronic laser energy converter (TELEC) concept are reported. This device has been devised as a means to convert high‐average‐power laser radiation into electrical energy, a crucial element in any space laser power transmission scheme using the available high power/efficiency infrared lasers. Theoretical calculations, based upon inverse bremsstrahlung absorption in a cesium plasma, indicate internal conversion efficiency up to 50% with an overall system efficiency of 42%. Experiments reported here were made with a test cell designed to confirm the theoretical model rather than demonstrate efficiency; 10.6‐&mgr;m laser‐beam absorption was limited to ∼10−3of the incident beam by the short absorption region. Nevertheless, confirmatory results were obtained and the conversion of absorbed radiation to electric power is estimated to be near 10%.

ISSN:0003-6951    

DOI:10.1063/1.90404

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Previous studies have indicated an increase in the adhesion of deposited metal films to commercial polymers when additional carbon‐oxygen bonds were present on the polymer surface. In this work, we report the changes taking place on an oxygen‐treated polystyrene surface following vapor deposition of copper. We first found that atomic oxygen produces a carbon‐oxygen single bond on the polystyrene surface, with the oxygen displacing a hydrogen and either forming an OH group or cross linking two chains. In addition, this bond is strongly perturbed after vapor deposition of copper. The deposition of copper results in the formation of a copper‐oxygen‐polymer complex on the surface, the exact nature of which is still to be determined. The formation of such a complex is consistent with an increased adhesive strength of copper on oxygen‐treated polystyrene.

ISSN:0003-6951    

DOI:10.1063/1.90405

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The use of a continuous scanned Kr ion laser as a tool for annealing of boron‐implanted silicon is described. Conditions were found that produce high electrical activity and crystallinity of the implanted layer without redistribution of the boron from the as‐implanted profile.

ISSN:0003-6951    

DOI:10.1063/1.90386

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

25‐nm‐wide lines and spaces have been fabricated in 22.5‐nm‐thick films of PdAu (40 : 60) using electron‐beam exposure and polymethylmethacrylate (PMMA) resist. A high‐resolution scanning transmission electron microscopy (STEM) was used to expose the resist and the samples were mounted on 60‐nm‐thick Si3N4membrane substrates. Previously, the smallest metal structures formed with a resist process were 60 nm wide with spaces between the lines several times larger than the lines. The results presented here show that 25‐nm lines can be fabricated with a center to center spacing of 50 nm.

ISSN:0003-6951    

DOI:10.1063/1.90387

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The irradiation effect of 0.45‐MeV protons on the solubility and diffusivity of interstitial impurities has been studied by annealing nitrogen‐implanted molybdenum samples in the temperature region 600–800 °C. The nondestructive (p,&ggr;) resonance‐broadening method was applied as a probe for the nitrogen. Even for the low proton irradiation doses, a remarkable increase in solubility and a decrease in diffusivity were observed.

ISSN:0003-6951    

DOI:10.1063/1.90388

出版商:AIP    

年代:1978

数据来源: AIP