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991.
Implicit Large Eddy Simulation (ILES) with high-resolution and high-order computational modelling was applied to a turbulent mixing fuel injector flow. In the ILES calculation, the governing equations for three dimensional, non-reactive, multi-species compressible flows were solved using a finite volume Godunov-type method. Up to ninth-order spatial accurate reconstruction methods were examined with a second order explicit Runge–Kutta time integration. Mean and root mean square velocity and mixture fraction profiles showed good agreement with experimental data, which demonstrated that ILES using high-order methods successfully captured complex turbulent flow structure without using an explicit subgrid scale model. The effects of grid resolution and the influence of order of spatial accuracy on the resolution of the kinetic energy spectrum were investigated. An k−5/3 decay of energy could be seen in a certain range and the cut-off wavenumbers increased with grid resolution or order of spatial accuracy. The effective cut-off wavenumbers are shown to be larger than the maximum wavenumbers appearing on the given grid for all test cases, implying that the numerical dissipation represents sufficiently the energy transport between resolved and unresolved eddies. The fifth-order limiter with a 0.6 million grid points was found to be optimal in terms of the resolution of kinetic energy and reasonable computational time. 相似文献
992.
Si3N4 based ceramics such as hot isostatically pressed Si3N4, hot pressed Si3N4, hot pressed sialons containing 0, 30, 60 and 100% of phase were corroded by V2O5 melts at 700 to 1000C. These Si3N4-based ceramics were oxidized to SiO2 and dissolved into V2O5 melts. The surface chemical reaction controlled shrinking core model adequately described the relationship between the weight loss of the specimen and time for the corrosion reactions in V2O5 melts, and the apparent activation energies were 69 to 112kJ mor–1. phase Si3N4 and sialon showed higher corrosion resistance than phase sialons, but no clear relationship between the corrosion rate and the content of additives was found. The specimens corroded by V2O5 melts showed no significant degradation in the fracture strength up to 30wt% of weight loss. 相似文献
993.
Tadashi Endo Tetsuro Kobayashi Tsugio Sato Masahiko Shimada 《Journal of Materials Science》1990,25(1):619-623
The substitution of fluorine for oxygen in BaTiO3 was investigated by the reaction of BaO2, BaF2, TiO2 and Ti under the conditions of 3.0 GPa and 1300° C for 2 H. Batio3–x
F
x
solid solutions were obtained as a single phase in the region of 0 x0.1. The X-ray diffraction data showed that the symmetrical change from tetragonal to cubic form occurred atx=0.08 at room temperature. Also, the solid solutions were characterized by TG-DTA analysis, ESCA spectroscopy and diffusion reflectance spectroscopy. As a result, the existence of Ti3+ was verified. The electrical resistivities of BaTiO3–x
F
x
were in the range from 4cm for x=0.05 to 3Ocm forx=0.1 at 300 K and the relationship between In and 1000 T–1 was linear. The thermoelectric powers at 300 K were –250V K–1 forx=0.05 and –130VK–1 forx=0.1. The electrical property of the solid solution was discussed on the basis of a conventional band model which involved localized donor levels associated with oxygen vacancies. 相似文献
994.
Shoichi Hashiguchi Tsugio Sato Tadashi Endo Masahiko Shimada 《Journal of Materials Science》1990,25(11):4886-4891
A new phase of Tl2Ba2Ca3Cu4Oy withT
c = 100 K was prepared by the capillary synthetic method using Tl2O3, BaCuO2 and Ca2CuO3 as starting materials. The present capillary synthetic method was useful to obtain the single phase of Tl2Ba2CaCu2Oy Tl2Ba2Ca2Cu3Oy and Tl2Ba2Ca3Cu4Oy by solid state reactions using Tl2O3 BaCuO2, and Ca2CuO3 as starting materials. 相似文献
995.
We have carried out scanning tunneling microscopy (STM) observations of unreconstructed regions on quenched Si(1 1 1) surfaces at 380 degrees C at a scanning speed of 1.7 s per frame. In the regions, it is found that single faulted-halves of the dimer-adatom-stacking-fault (DAS) structure are formed isolatedly or at the edges of the surrounding DAS domains sharing one corner hole. In such "living" regions, we have succeeded to observe sudden structural changes of the faulted-halves during line scans in single frames of STM images. 相似文献
996.
Terano A Hiraishi H Shimada T Takahashi M Yoshiura K Horie-Sakata K 《Microscopy research and technique》2001,53(6):389-395
To elucidate the mechanisms of antiulcerogenic agents, we established the cell culture model derived from rat gastric epithelium. The cultured cells were identified as mucus-producing cells by using histological analysis. This culture model is useful for investigating the untiulcer effect of various agents and to reveal the mechanisms of the drug action. In particular, the ulcer-healing model using the cultured monolayer is promising and convenient for the study of several growth factors such as HGF as well as antiulcerogenic agents. The effect of polaporezinc in the cultured model is introduced. 相似文献
997.
Kline JL Shimada T Johnson RP Montgomery DS Hegelich BM Esquibel DM Flippo KA Gonzales RP Hurry TR Reid SL 《The Review of scientific instruments》2007,78(8):083501
A multiframe, high-time resolution pump-probe diagnostic consisting of a consecutive train of ultrashort laser pulses (approximately ps) has been developed for use with a chirped pulse amplification (CPA) system. A system of high quality windows is used to create a series of 1054 nm picosecond-laser pulses which are injected into the CPA system before the pulse stretcher and amplifiers. By adding or removing windows in the pulse train forming optics, the number of pulses can be varied. By varying the distance and thickness of the respective optical elements, the time in between the pulses, i.e., the time in between frames, can be set. In our example application, the CPA pulse train is converted to 527 nm using a KDP crystal and focused into a preformed plasma and the reflected laser light due to stimulated Raman scattering is measured. Each pulse samples different plasma conditions as the plasma evolves in time, producing more data on each laser shot than with a single short pulse probe. This novel technique could potentially be implemented to obtain multiple high-time resolution measurements of the dynamics of physical processes over hundreds of picoseconds or even nanoseconds with picosecond resolution on a single shot. 相似文献
998.
We investigated the distribution of radioactivity from (14)C-labeled gamma-aminobutyric acid (GABA) in the mouse by in vivo autoradiography to clarify the tissues that show GABA uptake and/or GABA binding. Male mice were injected intravenously with (14)C-GABA in both the absence and presence of an excess of unlabeled GABA, baclofen and isoguvacine. Whole-body autoradiography of (3)H-baclofen, a GABA(B) receptor agonist was also performed. At short intervals after (14)C-GABA injection ( 3 and 6 minutes), very high radioactivity was detected in the kidney cortex, liver, pineal gland, hypophysis, median eminence of the hypothalamus, and cervical ganglion. The hyaline cartilage and glandular part of the stomach showed moderate radioactivity. In the presence of an excess amount of unlabeled GABA, radioactivity in most of tissues decreased significantly, but no significant difference in radioactivity was observed in the presence of baclofen and isoguvacine, agonists of GABA(A) and GABA(B) receptors, respectively. Autoradiography of (3)H-baclofen showed that the kidney had high level of radioactivity, whereas the activity in other tissues and organs was similar or lower than in the blood except for the content of the urinary bladder and the pancreas at 15 minutes after injection. These data indicate that radioactivity from incorporated (14)C-GABA into a variety of cells is much higher than that from bound (14)C-GABA to the receptor sites. Our results suggest that GABA can be quickly localized in many organs of the mouse body after 3 minutes following injection, and GABA may serve multiple functions in those organs. 相似文献
999.
Bohao Cheng Dr. Hiromu Kashida Dr. Naohiko Shimada Prof. Dr. Atsushi Maruyama Prof. Dr. Hiroyuki Asanuma 《Chembiochem : a European journal of chemical biology》2017,18(16):1568-1572
Photodriven DNA strand displacement by using a 2′,6′‐dimethylazobenzene‐tethered strand and poly(l ‐lysine)‐graft‐dextran (PLL‐g‐Dex) as a chaperone is reported. Rapid strand displacement was reversibly induced by UV and visible‐light irradiation without any toehold portion. To further improve the method, the concentration of PLL‐g‐Dex and the number of equivalents of the photoresponsive strand were optimised. Optimally, 64 % strand displacement was reversibly induced by alternating UV and visible‐light irradiation. 相似文献
1000.
Fujii Y Shimada K Yokota M Hashimoto S Sugita Y Ito H 《The Review of scientific instruments》2008,79(5):056105
A prototype instrument for measuring astronaut body mass under microgravity conditions has been developed and its performance was evaluated by parabolic flight tests. The instrument, which is the space scale, is applied as follows. Connect the subject astronaut to the space scale with a rubber cord. Use a force transducer to measure the force acting on the subject and an optical interferometer to measure the velocity of the subject. The subject's mass is calculated as the impulse divided by the velocity change, i.e., M=integral Fdt/delta v. Parabolic flight by using a jet aircraft produces a zero-gravity condition lasting approximately 20 s. The performance of the prototype space scale was evaluated during such a flight by measuring the mass of a sample object. 相似文献