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排序方式: 共有1177条查询结果,搜索用时 15 毫秒
981.
Manabu Iguchi Hiroshi Ueda Tomoyuki Chihara Zen-Ichiro Morita 《Metallurgical and Materials Transactions B》1996,27(5):765-772
Gas injection techniques are widely used in metals refining processes. Pressure on the bath surface of reactors is sometimes highly reduced to enhance the efficiency of refining. Many fundamental and practical investigations have been made to clarify the effects of reduced surface pressure on the mixing time and reaction rates of decarburization or desulfurization in the bath. However, details of these effects are not fully understood yet. Since the mixing time and chemical reaction rates are closely associated with fluid flow phenomena in the bath, information on, for example, the total surface area of bubbles rising in the bath and liquid flow induced by the buoyancy force of the bubbles should be accumulated as much as possible. In this study, the so-called water-model experiments were carried out to reveal the effects of reduced surface pressure on the bubble and liquidflow characteristics using a two-needle electroresistivity probe and a two-dimensional laser Doppler velocimeter. At an axial position near the nozzle, each bubble expanded to a volume corresponding to the hydrostatic pressure. The bubble and liquid-flow characteristics in the axial region located farther than this axial position were found to be approximately the same as those obtained under an atmospheric surface pressure. 相似文献
982.
T Saijo E Naito M Ito I Yokota J Matsuda Y Kuroda 《Canadian Metallurgical Quarterly》1996,228(2):446-451
In an attempt to restore pyruvate dehydrogenase complex (PDHC), expression vectors carrying wildtype E1 alpha cDNA (pRAWT) or 1162ins-mutant (pRA1162) were introduced into human lymphoblastoid cells which had a 4-bp insertion after nucleotide 1162 (1162ins) of E1 alpha cDNA, 28% of normal PDHC activity, and undetectable levels of both E1 alpha and E1 beta proteins. The amount of E1 alpha mRNA transcribed from the introduced cDNA was approximately 25 times greater than that transcribed from the endogenous gene. The PDHC activity of pRAWT-transformed cells increased to the normal level whereas this activity increased to 55% of the control in pRA1162-transformed cells. Mitochondria from pRAWT-transformed cells contained normal amounts of both the E1 alpha and the E1 beta subunits. These results suggest that the three C-terminal amino acids of E1 alpha, which were absent from 1162ins-mutant protein, may be important for the structural integrity of E1 and that a large amount of normal subunit, compared to the endogenous mutant enzyme, must be expressed to restore a multienzyme complex. 相似文献
983.
Yokota Y Mase A Kogi Y Bruskin LG Tokuzawa T Kawahata K 《The Review of scientific instruments》2008,79(5):056106
We report here on the application of an ultrashort-pulse reflectometer (USPR) to Large Helical Device in National Institute for Fusion Science. An impulse with picosecond pulse width is used as a source in an USPR. Since the bandwidth of a source is inversely related to the pulse width, we can utilize the frequency range of microwave to millimeter-wave by using wide band transmission lines. The density profiles can be reconstructed by collecting time-of-flight signal of each frequency component of an impulse reflected from each cutoff layer. Remote control system using super science information network has been introduced to the present USPR system. 相似文献
984.
Takashi Shinozaki Yutaka Udagawa Tomoyuki Sugiyama Masaki Amaya 《Journal of Nuclear Science and Technology》2016,53(9):1426-1434
In order to investigate the failure behavior of fuel cladding under a reactivity-initiated accident (RIA) condition, biaxial stress tests on unirradiated Zircaloy-4 cladding tube with an outer surface pre-crack were carried out under room temperature conditions by using an improved Expansion-Due-to-Compression (improved-EDC) test method which was developed by Japan Atomic Energy Agency. The specimens with an outer surface pre-crack were prepared by using Rolling-After-Grooving (RAG) method. In each test, a constant longitudinal tensile load of 0, 5.0 or 10.0 kN was applied along the axial direction of specimen, respectively. All specimens failed during the tests, and the morphology at the failure opening of the specimens was similar to that observed in the result of post-irradiation examinations of high burnup fuel which failed during a pulse irradiation experiment. The longitudinal strain (?tz) at failure clearly increased with increasing longitudinal tensile loads and the circumferential strain (?t?) at failure significantly decreased in the case of 5.0 and 10.0 kN tests, compared with the case of 0 kN tests. From these tests, the data of cladding failure were obtained in the range of strain ratio (?tz/?t?) between about ?0.6 and 0.7: this range of strain ratio covers the range between about 0.0 and 0.7 which is estimated in the case of RIA-simulated test. It is considered that the data obtained in this study can be used as a fundamental basis for quantifying the failure criteria of fuel cladding under a biaxial stress state. 相似文献
985.
Matsunaga T Hosokawa M Arakaki A Taguchi T Mori T Tanaka T Takeyama H 《Analytical chemistry》2008,80(13):5139-5145
Here, we report a high-efficiency single-cell entrapment system with a poly(dimethylsiloxane) (PDMS) microfluidic device integrated with a micromesh, and its application to single-cell fluorescence in situ hybridization (FISH) analysis. A micromesh comprising of 10 x 10 microcavities was fabricated on a black poly(ethylene terephthalate) (PET) substrate by laser ablation. The cavity was approximately 2 microm in diameter. Mammalian cells were driven and trapped onto the microcavities by applying negative pressure. Trapped cells were uniformly arrayed on the micromesh, enabling high-throughput microscopic analysis. Furthermore, we developed a method of PDMS surface modification by using air plasma and the copolymer Pluronic F-127 to prevent nonspecific adsorption on the PDMS microchannel. This method decreased the nonspecific adsorption of cells onto the microchannel to less than 1%. When cells were introduced into the microfluidic device integrated with the black PET micromesh, approximately 70-80% of the introduced cells were successfully trapped. Moreover, for mRNA expression analysis, on-chip fluorescence in situ hybridization (e.g., membrane permeabilization, hybridization, washing) can be performed in a microfluidic assay on an integrated device. This microfluidic device has been employed for the detection of beta-actin mRNA expression in individual Raji cells. Differences in the levels of beta-actin mRNA expression were observed in serum-supplied or serum-starved cell populations. 相似文献
986.
Physical and gas transport properties of hyperbranched polyimide-silica hybrid membranes were investigated. Hyperbranched polyamic acid as a precursor was prepared by polycondensation of a triamine, 1,3,5-tris(4-aminophenoxy) benzene (TAPOB), and a dianhydride, 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), and subsequently modified a part of end groups by 3-aminopropyltrimethoxysilane (APTrMOS). The hyperbranched polyimide-silica hybrid membranes were prepared by sol–gel reaction using the polyamic acid, water, and alkoxysilanes. 5% weight-loss temperature of the hybrid membranes increased with increasing silica content, indicating effective crosslinking at polymer-silica interface mediated by APTrMOS moiety. On the other hand, glass transition temperature of the hybrid membranes prepared with methyltrimethoxysilane (MTMS) showed a minimum value at low silica content region, suggesting insufficient formation of three-dimensional Si O Si network compared to the hybrid membranes prepared with tetramethoxysilane (TMOS). CO2, O2, N2, and CH4 permeability coefficients of the hybrid membranes increased with increasing silica content. Especially for TMOS/MTMS combined system, the hybrid membranes showed simultaneous enhancements of gas permeability and CO2/CH4 separation ability. It was concluded that the 6FDA-TAPOB hyperbranched polyimide-silica hybrid membranes have high thermal stability and excellent CO2/CH4 selectivity and are expected to apply to high-performance gas separation membranes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
987.
988.
In this paper, we describe the principle of the three-dimensional vector holograms formed in anisotropic recording medium. The polarization states of the interference light are three-dimensionally modulated due to both the polarization interference and optical anisotropy in the recording medium. The electric field of the polarized light reorients the director and forms the three-dimensional vector hologram in anisotropic photoreactive liquid-crystal composites. The theoretical consideration reveals the formation mechanism and optical characteristics of the resultant three-dimensional vector holograms. 相似文献
989.
Hideaki Ichiura Tatsuo Ohi Hiroshi Oyama Hiroshi Yokota Tetsunori Kunitake Shunpei Ohashi Masaaki Morikawa 《Journal of Materials Science》2008,43(4):1486-1491
Paper–paraffin composites were prepared by an interfacial polymerisation reaction on the paper surface and its function of
thermal energy storage was studied. Filter paper impregnated with O/W emulsion, which was composed of ethylenediamine, NaOH
and paraffin microcapsules prepared by methyl methacrylate polymer (PMMA), was left in a beaker containing a cyclohexane solution
of terephthaloyl chloride. The paraffin could fix on the treated paper surface and the encapsulation of the paraffin before
the interfacial polymerisation reaction on the paper surface was effective in the preparation of paper with the function of
heat storage. 相似文献
990.
Abstract: Phase‐shifting digital holography is applied to measure the shapes and positions of rough surfaces from the averaged conjugate product of the reconstructed complex amplitudes, named complex coherence factor, corresponding to dual wavelengths. The phase of the averaged product at the object plane provides the shape of the surface, whereas the peak position of the modulus with respect to reconstruction distance provides the position of the surface. The phase is almost free from speckle noise and easy to be unwrapped. The resultant resolution of surface shape amounts to a few tens of micrometres. The sensitivity of the position measurement that requires no marking on the object is several per cent of object distance from a charge‐coupled device (CCD). The method corresponds to the detection of the position of maximum contrast of the fringes to be observed in conventional holographic interferometry. It makes use of fringe phase for shape measurement and fringe contrast for position measurement. Both the theory explaining the principle and experimental results are presented. 相似文献