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971.
To investigate the characteristics of N2O concentration, we applied several types of time series analyses such as fast Fourier transform (FFT), auto-correlation, and cross-correlation, to 2.5-year time series data of trace N2O concentration continuously monitored by gas chromatography and meteorological data, measured in an urban area of Nagoya. It was found that there is a positive correlation between atmospheric N2O concentration (ppbv) and, both steam pressure (hPa) and temperature (°C). In addition, negative and positive correlations in atmospheric pressure and in solar flux were also found, respectively. These findings suggest an enrichment of N2O through environmental steam during the summer season, particularly in urban areas. On the other hand, the correlation to wind direction shows a variation with amplitude of 7 ppbv, from the north-west to the south-east, and a seasonal variation up to 12 ppbv, from winter to summer. These results support the hypothesis that atmospheric steam controls the N2O concentration in urban areas. In addition, the correlation with wind direction suggests the existence of an emission source in the direction of seaside areas. 相似文献
972.
Ken Sekimoto 《Physica A》1984,125(1):261-269
We construct the evolution equation of the size distribution function of the unswitched domains of a model of a 1-D system in a switching field, and solve it as an initial value problem. As the time goes on, the distribution approaches to the “fixed point”, which is the exponential distribution. This feature is unaffected by the finiteness of the critical radius of nucleation. 相似文献
973.
Trained choral tenors performed a series of vocal tasks before and after a “live” performance. Acoustic (perturbation, harmonic-to-noise ratio, pitch and amplitude ranges) and perceptual analyses (auditory and proprioceptive/kinesthetic) were undertaken to detect changes from pre- to postperformance. Individuality of response to the performance was revealed, with the majority of subjects showing vocal deterioration after performance. The most sensitive vocal tasks were the comfortably pitched notes, high soft notes, and the bottom notes in scale singing. The most sensitive acoustic measure in detecting change from pre- to postperformance was harmonic-to-noise ratio. In contrast to the demonstrated acoustic changes, no significant differences in perceptual ratings were evident after the performance. Perceptual ratings did not reflect the acoustic analysis results. The present study highlights the need to establish further normative data for the singing voice and to consider individual differences in vocal characteristics in future studies of the singing voice. 相似文献
974.
A Stroboscopic phase-shift interferometry has been developed to visualize surface acoustic wave (SAW) propagation on SAW devices quantitatively. The developed interferometry is a Fizeau-type one with a multi-mode semiconductor laser diode and an optical isolator. With the laser light illuminating stroboscopically, observed interference intensity gives information about average displacements of the vibrations. Fifty MHz SAW propagation on the surface of the SAW device has been measured with the interferometry. Distribution of the SAW along the propagation path has been observed, whose amplitude is 3 nm (p-p). Repetition accuracy evaluated with the root mean square method is 1/2500 of the laser wavelength. The system is useful for estimating and improving performances of micro-devices.Presented at 1996 International Workshop on Interferometry (IWI ‘96), August 27-29, Saitama, Japan. 相似文献
975.
Gary Stevens Bryan Read Giuseppe Della Gatta Ted Charsley Ken Mills 《Journal of Thermal Analysis and Calorimetry》2005,82(3):821-822
In memoriam Michael John Richardson. 相似文献
976.
Shigehiro Kagaya Yusaku Hosomori Hidekazu Arai Kiyoshi Hasegawa 《Analytical sciences》2003,19(7):1061-1064
Cadmium ranging from 1 - 8 ng could be coprecipitated quantitatively with lanthanum phosphate at pH 5 - 6 from up to 200 mL of river water samples spiked with 5 microg of indium as an internal standard. Cadmium and indium coprecipitated were measured by using electrothermal atomic absorption spectrometry. The cadmium content in the original sample solution could be determined by internal standardization with indium. Since complete collection of the precipitate and strict adjustment of the volume of the final solution after coprecipitation are not required in this method, the precipitate could be collected by using decantation and centrifugation, and then dissolved with 1 mL of about 2.4 mol L(-1) nitric acid. The proposed method is simple and rapid, and enrichment close to 200-times can be attained; the detection limit (3sigma, n = 6) was 0.63 ng L(-1) in 200 mL of the sample solution. 相似文献
977.
978.
979.
Properties of the shape memory alloy of 29 μm thick Ni-Ti foil are investigated as an actuator to align optical elements. Since the intrinsic properties of the Ni-Ti foil are not satisfactory in reproducibility and hysteresis, a simple feedback control is used. A pinhole integrated with a surrounding position sensor is proposed to realize a confocal optical system having an automatic alignment function. Large displacement (mm) and precision at the level of the optical wavelength are found to be possible.Present at 1996 International Workshop on Interferometry (IWI ‘96), August 27-29, Saitama, Japan. 相似文献
980.
Brillouin scattering is used as a sensitive probe of structural properties of gases adsorbed on porous glass. Evidence is seen for extensive supercooling behavior in both oxygen and nitrogen. 相似文献