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961.
Kei-Ichi Kitahara Yuji Noguchi Satoshi Itoh Nobunao Chiba Tasuku Tohyama Kunio Nagashima Takako Hanada Isao Yoshihama Sadao Arai 《Journal of chromatography. A》2009,1216(44):7415-7421
Using an HPLC column packed with monodispersed vinylbenzeneboronic acid–divinylbenzene (V–D) copolymer resins, the elution behaviors of the mono- and disaccharides were studied under different pH mobile phases. The monodispersed V–D copolymer resins were prepared by the copolymerization of 4-vinylbenzeneboronic acid and divinylbenzene in the presence of template silica gel particles (particle size: 5 μm; pore size: 10 nm), followed by dissolution of the template silica gel using a NaOH solution. Similarly, styrene–divinylbenzene (S–D) copolymer resins as the control resins were also synthesized. The transmission electron micrographs of these polymer resins revealed a good monodispersity. The complexation behavior of the saccharides was evaluated by comparison of the peak area eluted through the V–D column for that through the S–D column. Four aldopentoses (d-ribose, d-arabinose, d-xylose, and d-lyxose) and four aldohexoses (d-glucose, d-mannose, d-galactose, and d-talose) were retained completely at pH 11.9. Especially, ribose and talose were totally retained even under acidic and neutral conditions. For the disaccharides, unlike sucrose and maltose, palatinose was completely retained in basic mobile phases. 相似文献
962.
Hiroki Sakurai Junji Noro Akira Kawase Masanori Fujinami Koichi Oguma 《Analytical sciences》2006,22(2):225-228
A rapid sample-digestion method for the determination of toxic metals, cadmium, chromium, and lead, in polyethylene and polyvinyl chloride has been developed by using a microwave oven for household use. An appropriate amount of the sample taken in a PTFE decomposition vessel was mixed with nitric acid or nitric and sulfuric acids. The vessel was heated in a microwave oven by a predetermined operating program. The digested sample was diluted to a definite volume with water after evaporating most of the nitric acid. The precipitate, if formed, was filtered off by a membrane filter. The metals were determined by ICP-AES. The sample digestion required 5 min (for 20-mg sample) to 25 min (for 60-mg sample). The analytical results obtained for cadmium, chromium, and lead in a polyethylene certified reference material, BCR-680, digested with nitric acid, were in good agreement with the certified values. 相似文献
963.
Learning performance of a neurocomputer for nonlinear dynamical system identification 总被引:1,自引:0,他引:1
This paper investigates the learning performance of a RICOH neurocomputer RN-2000 for the identification problem of input and output map of a discrete nonlinear dynamical system. The results obtained show capability of on-chip learning, which is essential for many neural applications such as machine learning and control where real-time adaptation is required. In this paper, the method to use a neurocomputer is briefly presented for a nonlinear identification problem. The main significance of this research is to obtain a further guideline for designing a primitive artificial brain for robotics. 相似文献
964.
A TTF-type coaxial higher order modes (HOM) coupler has been used in a TESLA 9 cell cavity. It is impossible to measure the stop band characteristics of the HOM coupler with the cavity. A measurement device for the coaxial transmission line type for the HOM coupler has been designed at Peking University. Experimentally it was shown that the average voltage standing wave ratio of the coaxial transmission line is smaller than 1.08. The experimental results of the stop band characteristics of the TTF-type HOM coupler have been fitted for the simulation. This paper describes the design of the measurement device and discusses the experimental and simulation results of stop band characteristics of the HOM coupler. 相似文献
965.
966.
Mamoru Kamikura Yu Tomimura Yutaro Sekimoto Shinichiro Asayama Wenlei Shan Naohisa Satou Yoshizou Iizuka Tetsuya Ito Toshiaki Kamba Yasutaka Serizawa Takashi Noguchi 《International Journal of Infrared and Millimeter Waves》2006,27(1):37-53
We have developed a 385–500 GHz sideband-separating (2SB) mixer, which is based on a waveguide split-block coupler at the
edge of the H-plane of the 508 μm × 254 μm (WR 2.0) waveguide, for the Atacama Large Millimeter/submillimeter Array (ALMA).
An RF/LO coupler, which contains an RF quadrature hybrid, two LO couplers, and an in-phase power divider, was designed with
the issue of mechanical tolerance taken into account. The RF/LO coupler was measured optically with a microscope and electrically
with a submillimeter vector network analyzer. The image rejection ratio (IRR) and the single-sideband (SSB) noise temperature
of the receiver using the RF/LO coupler have also been measured. The IRR was found to be larger than 8 dB and typically ∼
12 dB in the 385–500 GHz band. The SSB noise temperature of this receiver is 80 K at the band center, which corresponds to
4 times the quantum noise limit (hf/k) in SSB, and 250 K at the band edges.
An erratum to this article can be found at 相似文献
967.
968.
Taku Fukai Tatsuya Kobayashi Masahiro Sakaguchi Masanori Aoki Tsuyoshi Saito Eiji Fujimori Hiroki Haraguchi 《Analytical sciences》2007,23(2):207-213
The multielement determination of PM(10) (airborne particulate matter smaller than 10 microm) samples, which was collected by a high volume air sampler at the urban site of Nagoya City, was carried out by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). The present analytical method was validated by analyzing urban particulate matter standard reference material of NIST SRM 1648. The analytical data for ca. 30 elements in PM(10) samples collected during a period from 8 September to 9 October, 2003, were obtained in the concentration range from sub-microg g(-1) to several-10 mg g(-1), but the data for 18 elements among ca. 30 elements were available for the characterization of PM(10) samples in ambient air, because of problems caused by the filter blanks. Then, the trends concerning the distributions of diverse elements in PM(10) samples were analyzed based on the enrichment factors and size distribution factors. The lithophile and siderophile elements were distributed more than 50% in coarse particle fraction (>2.1 microm), which was derived mainly from natural sources, such as soils and crustal minerals. On the other hand, chalcophile elements were distributed more than 50% in fine particle fraction (<2.1 microm), which was derived mostly from anthropogenic emission sources. The large enrichment of chalcophile elements in PM(10) samples as well as their mining influence factors (MIFs) suggested their wide use in industrial productions. 相似文献
969.
We show analytically that addition of a quintic term to the positive Kerr-type nonlinearity offers a unique type of kink soliton-like solution with Fermi-Dirac profile. This type of optical kink allows, in contrast to other optical kinks discovered so far, stationary kink formation not only in the time domain but in the spatial domain. The latter could admit of a route for the first time to our knowledge to spatial kink solitons of intensified laser beams. The underlying principle of the optical kink propagation is described. 相似文献
970.
We have developed a subminiature gain flattening filter with the 90% volume reduced package compared with conventional ones. The excellent thermal stabilities for the transmission characteristics of 0.0002dB/℃ and 0.67pm/℃,and the high power durability up to 1 W were confirmed. 相似文献