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71.
72.
Electron beam treatment of lignite-burning flue gas with high concentrations of sulfur dioxide and water 总被引:5,自引:0,他引:5
Hideki Namba Shoji Hashimoto Okihiro Tokunaga Ryoji Suzuki 《Radiation Physics and Chemistry》1998,53(6):673-681
Experiments were carried out to investigate the removals of SO2 and NOx from simulated lignite-burning flue gas containing SO2 (4800 ppm), NO (320 ppm) and H2O (22%) by electron beam irradiation. Removal efficiencies of SO2 and NOx were achieved to reach 97 and 88% at 70°C, and 74 and 85% at 80°C, respectively, with the dose of 10.3 kGy without NH3 leakage. The higher removal efficiencies of SO2 and NOx were observed in simulated lignite-burning flue gas than in coal-fired flue gas containing 800 ppm of SO2, 225 ppm of NO and 7.5% H2O at the same treatment condition. The higher removal efficiencies were attributed to the higher concentrations of SO2, H2O, and added NH3. Simulation calculations indicated that the higher concentrations of these components enhance the effective radical reactions to oxidize NO to form NO2 with HO2 radical, and to oxidize SO2 to form SO3 with OH radical and O2. The reactions of NOx with N and NH2 radicals to produce N2 and N2O also promote the NOx removal. By-product was determined to be the mixture of (NH4)2SO4 and NH4NO3 containing a small amount of H2SO4. 相似文献
73.
XPS measurement revealed that the original state of TiO2 was changed to Ti2O3 and TiO by ion bombardment. TiO2 decreased and Ti2O3 increased at the initial stage. TiO increased at a later stage than Ti2O3. Each of them saturated after enough sputtering time.A formulation was proposed in order to explain the change of XPS spectra for oxides as a function of ion sputtering time. This formulation was based on reaction equations that contain two reduction processes (from TiO2 to Ti2O3 and from Ti2O3 to TiO), and sputtering effects. Using four fitting parameters (two reduction coefficients, sputtering yield and information depth), the present formula was fitted to the experimental results. The fitting results agree satisfactorily with the experimental results. The calculation shows that the reduction coefficient from TiO2 to Ti2O3 is about ten times larger than that from Ti2O3 to TiO. This calculation predicts that surface composition of an oxide that is changed by ion bombardment will reach a different value depending on its bulk composition. Moreover, the present formulation can determine the chemical states of compounds changed by ion bombardment. 相似文献
74.
In two-flavor dense quark matter, we describe the dynamics in the single plane wave Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) state satisfying the color and electric neutrality conditions. We find that because the neutral LOFF state itself suffers from a chromomagnetic instability in the whole region where it coexists with the (gapped or gapless) two-flavor superconducting phases, it cannot cure this instability in those phases. This is unlike the recently revealed gluonic phase which seems to be able to resolve this problem. 相似文献
75.
Li ZhangYoshio Hashimoto Toshinori TaishiIsao Nakamura Qing-Qing Ni 《Applied Surface Science》2011,257(15):6577-6582
A novel flower-shaped Bi2O3 superstructure has been successfully synthesized by calcination of the precursor, which was prepared via a citric acid assisted hydrothermal process. The precursor and Bi2O3 were characterized with respect to morphology, crystal structure and elemental chemical state by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It was shown that both the precursor and Bi2O3 flower-shaped superstructure were constructed of numerous nanosheets while the nanosheets consisted of a great deal of nanoparticles. Furthermore, key factors for the formation of the superstructures have been proposed; a mechanism for the growth of the superstructure has been presented based on the FESEM investigation of different growth stages. 相似文献
76.
The effect of a geometrical relationship between a grain boundary (GB) plane and a tensile axis on intergranular fatigue cracking along 3(1 1 2) twin boundaries has been investigated in Fe-30%Cr alloy crystals. Fatigue experiments were carried out on the three kinds of the specimens containing the 3(1 1 2) twin boundary. It was found that the fatigue cracking behavior was sensitive to the geometry of the GB plane. In a specimen where both the GB plane and a slip vector lying in the GB plane in adjacent grains are inclined to the tensile axis at 45°, the fatigue cracks were nucleated preferentially along the twin boundary at a stress amplitude of 170 MPa. The specimen with the GB plane normal to the tensile axis showed that the fatigue crack was initiated from a slip band formed within a constituent grain at a stress amplitude of 300 MPa. When the GB plane was inclined to the tensile axis but the slip vector lying in the GB plane was normal to the tensile axis, development of additional slips formed perpendicular to the GB plane were observed at a specific site of the GB. Initiation of intergranular fatigue cracks at the site was recognized at a stress amplitude of 250 MPa. It can be suggested that the GB plane normal to the tensile axis provides the highest fatigue performance among them. The difference in the cracking property among these specimens could be understood in terms of the effective Schmid factor derived from elastically incompatible stress. 相似文献
77.
Tuong Lan Nguyen Masayuki Dokiya Shaorong Wang Hiroaki Tagawa Takuya Hashimoto 《Solid State Ionics》2000,130(3-4):229-241
The electrical property of (La1−xSrx)1−z(Al1−yMgy)O3−δ (LSAM; x≤0.3, y≤0.15 and z≤0.1) was measured using the DC four-probe method as a function of temperature (500–1000°C) and oxygen partial pressure (1–10−22 atm). Among LSAMs, (La0.9Sr0.1)AlO3−δ showed the highest ionic conductivity, σi=1.3×10−2 S cm−1 at 900°C. A simultaneous substitution at A and B sites or A site deficiency is expected to create larger oxygen vacancy and higher ionic conductivity. However, it showed a negative effect. The effect of the vacancy increase did not effect monotonously the ionic conductivity. It was found that the concentration of oxygen vacancy, [VO], influences not only the oxide ion conductivity, σi, but also the mobility, μv, of [VO]. These properties exhibit a maximum at around [VO]=0.05. With the increase in [VO], the activation energy, Ea, of the ionic conduction dropped from 1.8 to ca. 1.0 eV at [VO]=0.05 and became almost constant at [VO]>0.05. The dependency of the pre-exponential term, μ0v, and Ea on [VO] was analyzed and their effect on μv and σi was discussed with respect to crystal structure and defect association. It was estimated that the crystal structure mainly governs these properties. The effect of defect association could not be ignored but is considered to be a complicated correlation. 相似文献
78.
Y. Isshiki J. Shi H. Nakai M. Hashimoto 《Applied Physics A: Materials Science & Processing》2000,70(4):395-402
Laser surface alloying (LSA) with silicon was conducted on austenitic stainless steel 304. Silicon slurry composed of silicon
particle of 5 μm in average diameter was made and a uniform layer was supplied on the substrate stainless steel. The surface
was melted with beam-oscillated carbon dioxide laser and then LSA layers of 0.4–1.2 mm in thickness were obtained. When an
impinged energy density was adjusted to be equal to or lower than 100 W mm−2, LSA layers retained rapidly solidified microstructure with dispersed cracks. In these samples, Fe3Si was detected and the concentration of Si in LSA layer was estimated to be 10.5 wt.% maximum. When the energy density was
equal to or greater than 147 W mm−2, cellular grained structure with no crack was formed. No iron silicate was observed and alpha iron content in LSA layers
increased. Si concentration within LSA layers was estimated to be 5 to 9 wt.% on average. Crack-free as-deposited samples
exhibited no distinct corrosion resistance. The segregation of Si was confirmed along the grain boundaries and inside the
grains. The microstructure of these samples changed with solution-annealing and the corrosion resistance was fairly improved
with the time period of solution-annealing.
Received: 2 September 1999 / Accepted: 6 September 1999 / Published online: 1 March 2000 相似文献
79.
Widely tunable terahertz (THz)-wave generation using difference frequency generation (DFG) in an organic N-benzyl-2-methyl-4-nitroaniline (BNA) crystal was demonstrated. To our knowledge, this is the first report of THz-wave generation by BNA DFG. Large, high-quality single crystals of BNA (phi 8 mm x 30 mm) were grown using the vertical Bridgman method. The nonlinear optical (NLO) coefficient d(33) of the BNA crystal is approximately 234 pm/V, which is the largest value reported for any yellow NLO material. The collinear phase-matching condition of the type-0 configuration is satisfied using a 0.7-1 microm band pump wavelength. We generated THz waves using an organic BNA crystal; the generation range is 0.1-15 THz. 相似文献
80.
Takashi Yoshimoto Prof. Dr. Hisako Hashimoto Dr. Nozomi Takagi Prof. Dr. Shigeyoshi Sakaki Naoki Hayakawa Dr. Tsukasa Matsuo Prof. Dr. Hiromi Tobita 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(15):3795-3798
A tungsten silylyne complex having a W≡Si triple bond reacted with two molecules of aldehydes at room temperature to give W−Si−O−C four-membered metallacycles by [2+2] cycloaddition and subsequent formyl hydrogen transfer from one aldehyde molecule to another. Upon heating to 70 °C, the four-membered metallacycles underwent metathesis-like fragmentation cleanly to afford carbyne complexes and “silanoic esters,” in a manner similar to that of metallacyclobutadiene, an intermediate of alkyne metathesis reactions, and dimerization of the latter products gave 1,3-cyclodisiloxanes. The “silanoic ester” was also trapped by pivalaldehyde to give a [2+2] cycloaddition product in high yield. 相似文献