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排序方式: 共有134条查询结果,搜索用时 31 毫秒
31.
Tamada Tsutomu Ueda Yu Ueno Yoshiko Kojima Yuichi Kido Ayumu Yamamoto Akira 《Magma (New York, N.Y.)》2022,35(4):533-547
Magnetic Resonance Materials in Physics, Biology and Medicine - Diffusion-weighted imaging (DWI), a key component in multiparametric MRI (mpMRI), is useful for tumor detection and localization in... 相似文献
32.
Ando Y. Cappy A. Marubashi K. Onda K. Miyamoto H. Kuzuhara M. 《Electron Devices, IEEE Transactions on》1997,44(9):1367-1374
The effect of electron mobility (μn) on noise properties for InP-based pseudomorphic HEMTs has been analyzed based on the impedance field model. The analysis predicts that increasing μ n improves the minimum noise figure (Fmin) and associated gain not only because the unity current gain cut-off frequency increases but also because the source resistance is reduced. The analysis also predicts that increasing μn reduces the input noise resistance due to higher transconductance but hardly influences the noise-optimum impedance. Furthermore, it is predicted that the decrease in Fmin with increasing μn becomes less significant above 11000 cm2/Vs due to larger diffusion noise. Calculated results compare well with the measured scattering and noise parameters for InxGa1-xAs(x=0.53, 0.7, and 0.8) channel devices. Similar dependence of noise parameters on μn is shown in the theoretical and experimental results 相似文献
33.
Nineteen chronic schizophrenics (8 males and 11 females) showed at least one spike and wave complex (SpW) in their rested-awake EEGs during long-term neuroleptic treatment. The age at the first appearance of the SpW ranged from 16 to 60 years, and the duration of neuroleptic medication preceding its appearance was from 1 to 35 years. Two types of SpW waveform were discriminated; one was a diffuse high voltage isolated 3.5-4 Hz SpW complex, and the other a diffuse moderate voltage 5-6 Hz SpW burst. In EEG studies repeated over the long-term, the presence of SpW was transient in 11 cases, intermittent in 5 cases, and continuous in 3 cases. Three patients had generalized tonic-clonic clinical seizures; two of their EEGs did not show SpW until after the onset of seizures. All three responded well to adjunctive anticonvulsant therapy. The other 16 patients exhibited SpW but did not have clinical seizures with or without prophylactic use of anticonvulsants. The SpW in the EEG of chronic schizophrenics might be an indicator of predisposition for seizure, but it is not a good predictor of seizure. 相似文献
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In this work the absorptions of sulphur dioxide and hydrogen sulphide into jelly containing one of sodium chloride, sodium sulphite and sodium hydroxide aqueous solutions have been carried out. After a certain exposure time, the jelly was cut into slices in which the concentration of sodium ion was measured by a flame spectrometer. The concentration of sodium ion at the gas—jelly interface was considerably higher than that in the bulk except for the H2SNaCl system. Experimental results are compared with the analytical solution based on the molecular penetration theory in which the molecular diffusivity is replaced by the effective ionic diffusivity, and it is found that both dissociation and reaction effects influence the concentration profile of sodium ion in the liquid phase. 相似文献
37.
The process of characterizing polyacrylamide and its partially hydrolyzed materials by gel permeation chromatography was examined. The use of controlled-porosity glass and formamide as the stationary phase and the eluent, respectively, resulted in chromatographic behavior in accord with the hydrodynamic volume concept for polyacrylamide fractions. The addition of a salt (KCl) to the eluent was found to retard the elution of the hydrolyzed polyacrylamide. 相似文献
38.
Keiji Komatsu Takaaki Tsuchiya Yasuhiro Hasebe Tetsuo Sekiya Ayumu Toyama Atsushi Nakamura Hiroki Akasaka Hidetoshi Saitoh 《Journal of Thermal Spray Technology》2014,23(5):885-889
Highly dense, spherical yttria (Y2O3) and erbia (Er2O3) particles were synthesized from their corresponding metal-ethylenediaminetetraacetic (EDTA) complexes. The EDTA·Y·H and EDTA·Er·H complexes were prepared in powdered form. These complexes were used as the staring materials for synthesis of the Y2O3 and Er2O3 particles. The particles were synthesized using an H2-O2 flame produced with a commercial flame spray apparatus. Crystalline structure, surface and cross-sectional morphologies, and elemental distribution of the synthesized particles were investigated. It was confirmed that the crystalline phases of the Y2O3 and Er2O3 particles were homogeneous. In addition, the elemental distribution of the particles was uniform. These results indicate that dense, spherical particles of Y2O3 and Er2O3 have been synthesized with EDTA·Y·H and EDTA·Er·H complexes, respectively. 相似文献
39.
Prof. Takefumi Kuranaga Prof. Kenichi Matsuda Masachika Takaoka Chisato Tachikawa Ayae Sano Kosei Itoh Ayumu Enomoto Kei Fujita Prof. Ikuro Abe Prof. Toshiyuki Wakimoto 《Chembiochem : a European journal of chemical biology》2020,21(23):3329-3332
Kasumigamide is an antialgal hybrid peptide–polyketide isolated from the freshwater cyanobacterium Microcystis aeruginosa (NIES-87). The biosynthetic gene cluster was identified from not only the cyanobacterium but also Candidatus “Entotheonella”, associated with the Japanese marine sponge Discodermia calyx. Therefore, kasumigamide is considered to play a key role in microbial ecology, regardless of the terrestrial and marine habitats. We now report synthetic studies on this intriguing natural product that have led to a structural revision and the first total synthesis. During this study, a new analogue, deoxykasumigamide, was also isolated and structurally validated. This study confirmed the presence of the unusual pathway in the biosynthesis of a hybrid peptide–polyketide natural product. 相似文献
40.
Naotake Kamiura Shin-ya Umata Ayumu Saitoh Teijiro Isokawa Nobuyuki Matsui 《Artificial Life and Robotics》2011,16(2):258-261
In this article, self-organizing-map-based video object segmentation is proposed, assuming that either Y-quantification or
HSV-quantification can be systematically selected. Given a video sequence, the value of the probability density function for
each component value is calculated according to a kernel estimation at the first frame. Some areas randomly chosen from the
background are then examined, using each component value, to judge whether or not they include the target object. The quantification
is determined so that the frequency of occurrence of false extractions can be reduced. The data presented to the maps are
generated based on the selected quantification. Experimental results show that the proposed method recognizes the target object
well. 相似文献