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211.
A new computational system for the environmental noise measurement and analysis has been developed. The system consists of binaural microphones, a laptop PC, and analysing software. A target noise is recorded automatically depending on the specified background noise level, and the acoustical parameters are calculated simultaneously. These functions allow for precise field measurements. The system is equipped with a template-matching algorithm for the identification of noise source. This function was implemented to avoid the effect of an interrupting sound such as voice and wind blowing during a measurement. Noise analyses in this system are based on the model of human auditory system. In addition to the time-series data of sound level, the important acoustical parameters of noise source are extracted from the running autocorrelation function (ACF) and the inter-aural cross-correlation function (IACF). It has been found that those parameters are strongly related to the auditory primary sensations and spatial sensations. Evaluation of the environmental noise based on these functions is another feature of this system. This paper describes the effectiveness of the ACF and the IACF analysis for analysing acoustical properties of noise and for evaluating the subjective response to noise.  相似文献   
212.
用扫描隧道显微镜(STM)对Cu(111)-Au和Cu(111)-Pd表面的局域功函数进行了研究.通过 测量隧道电流对针尖样品间距的响应,得到了与STM形貌图一一对应的表面局域功函数图像. 实验发现,Au/Pd覆盖层和Cu衬底间的功函数有明显的不同.Pd薄膜的功函数甚至超过了其体 本征值,且功函数在台阶处变小.用偶极子的形成解释了台阶处功函数的降低.这一工作表明 ,用测量局域功函数的方法容易区分表面上不同的元素,并具有纳米尺度的空间分辨率. 关键词: 扫描隧道显微镜 局域功函数 台阶  相似文献   
213.
Scanning tunneling microscopy is applied for the first time to an atomic-resolution investigation of the 4×2 and 4×6 phases on a gallium-rich GaAs(001) surface obtained by molecular-beam epitaxy and migration-enhanced epitaxy. A unified structural model is proposed with consideration of the results of experiments and first-principles calculations of the total energy. In this model the 4×2 phase consists of two Ga dimers in the top layer and a Ga dimer in the third layer, and the 4×6 phase is matched to periodically arranged Ga clusters at the corners of a 4×6 unit cell on top of the 4×2 phase. Zh. éksp. Teor. Fiz. 111, 1858–1868 (May 1997)  相似文献   
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215.
The excitation of the neutron-rich nucleus 28Ne has been investigated via heavy-ion inelastic scattering in reversed kinematics. The value was determined to be , which is smaller than expected from the low excitation energy of the first state. A comparison with theoretical predictions suggests that the suppressed collectivity in 28Ne is characteristic of nuclei lying on the boundary of the ‘island of inversion’.  相似文献   
216.
Effect of intravenously (i.v.) or intraperitoneally (i.p.) administered (1----3)-beta-D-glucan, SSG, obtained from Sclerotinia sclerotiorum IFO 9395 on the murine peritoneal macrophage (PM) functions were examined. A single i.v. administration of SSG increased the number of PMs at a dose of 250 micrograms/mouse, and the peak appeared 4 d after administration. However, no special change was observed on peritoneal exude cell (PEC) populations. These PMs showed augmented lysosomal enzyme activity and the peaks appeared in 2 phases, on days 2 and 10. In contrast, SSG administered i.p. (250 micrograms/mouse) increased the number of PMs and enhanced the lysosomal enzyme activity of PMs from day 4, and a broad peak appeared until days 8--12. The populations of PECs were also changed by i.p. injection of SSG. Additionally, SSG administered i.v. enhanced phagocytic activity, H2O2 production and interleukin 1 (IL-1) production, and the kinetics of the activation differed depending on the activities. These data suggest that the effects of SSG on macrophage functions are different depending on administration routes, and there are some different mechanisms in the activation of macrophages in vivo by SSG.  相似文献   
217.
We have calculated the Einstein temperatures of the alloy surface as a function of composition employing the self-consistent Einstein model. The Einstein temperatures are found to vary almost linearly with surface and bulk compositions. Based upon these calculations,we have estimated the phonon contribution to the surface segregation of CuNi and NiPt alloys.  相似文献   
218.
The experiment was carried out to estimate the amount of residual ions after the etching of polyimide irradiated by heavy ions, where etching resulted in a channel of measurable depth in the polyimide. None of the analytical techniques presents each ion separately in etched polyimide containing heavy ions. Activation analysis was used for the irradiated polyimide to see how the injected ions were eluted into the solution by etching. When the irradiated polyimide was etched for only a little longer than the time needed to dissolve a selected range of incident ions, the bulk began subsequently to dissolve. The residual radioactivity in polyimide was found to fall below the limit of detection when the depth of the etched channel appeared 10% deeper than the expected value.  相似文献   
219.
220.
Alkaline sucrose density gradient and agarose gel electrophoresis methods were used to observe lambda deoxyribonucleic acid (DNA) strand breaks by the reaction system of reduced glutathione (GSH) with alloxan in the presence of Fe(3+)-ethylenediaminetetraacetic acid (EDTA). When DNA was incubated in the reaction system for 10 min, DNA strand breaks were easily induced. The increasing concentrations of GSH up to 1.0 mM in the reaction system in the presence of 1.0 mM alloxan caused DNA strand breaks in a concentration-dependent fashion and GSH beyond 2.0 mM caused in the strand breaks of DNA by which the fragments with multiple ranges of molecular weight were produced. The strand breaks of DNA in the reaction system containing low concentrations of GSH were protected by catalase and hydroxyl radical (HO.) scavengers but superoxide dismutase (SOD) did not, indicating that such breaks were induced by HO.generated from the Fenton reaction. On the other hand, the strand breaks of DNA at high concentrations of GSH were protected by ethanol and desferrioxamine, but not effectively by SOD and HO.scavengers, suggesting the possible participation of some oxidizing species of iron rather than HO.. These results indicate that HO.or oxidizing species of iron generated in the GSH-alloxan system depending on the concentration of GSH attacks DNA to produce strand breaks.  相似文献   
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