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191.
192.
Laser ablation of C60 particles suspended in hexane or methanol solution has been studied using a Nd:YAG laser (266, 355, 532, and 1064 nm). Insoluble product analysis by Raman spectroscopy showed that C60 particles transformed to graphite-like ones. On the other hand, soluble product analysis by HPLC coupled with UV absorption spectroscopy and GC/MS demonstrated that linear hydrogen-capped polyynes (CnH2: n=8, 10, 12) were formed. The dominant CnH2 polyyne was C8H2 in all cases. The relative abundance of polyynes decreased with increasing wavelength of the Nd:YAG laser, except for 266-nm irradiation in hexane, where the relative abundance of polyynes at 355 nm was greater than that at 266 nm. It was therefore concluded that photochemical processes are more important than thermal ones for the formation of polyynes. The relative abundance of polyynes in hexane was greater than that in methanol. The dependence of relative abundance of polyynes on the particles concentration, laser irradiation time, and laser power was measured in order to obtain information on formation mechanism of polyynes. These results and reported laser photochemical processes of C60 molecules in the gas phase suggested that C2 radicals produced from C60 are polymerized and hydrogenated to form C8H2 and much smaller amounts of C10H2 and C12H2. 相似文献
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195.
Nishikino M Hasegawa N Kawachi T Yamatani H Sukegawa K Nagashima K 《Applied optics》2008,47(8):1129-1134
We have improved a highly coherent x-ray laser at 13.9 nm using an oscillator-amplifier configuration. To improve a high-brilliance x-ray laser, we adopted traveling wave pumping for the amplifier target and rotated the amplifier target 3-4 mrad in the counterclockwise direction. Thereby, a seed x-ray laser can be amplified by medium plasma of the amplifier target with a high gain coefficient. The amplified x-ray laser has the output energy of approximately 1.3 microJ, corresponding to a large photon flux of 6.5 x 10(10) photons/pulse and a high peak brilliance of 5 x 10(26) photons/(s x mm(2) x mrad(2) x 0.01% bandwidth). 相似文献
196.
Koichiro Okamoto Shigeru Inoue Takayuki Nakano Tae-Won Kim Masaharu Oshima Hiroshi Fujioka 《Thin solid films》2008,516(15):4809-4812
We have grown AlN films on single-crystalline Mo(110), (100), and (111) substrates using a low temperature pulsed laser deposition (PLD) growth technique and investigated their structural properties. Although c-axis oriented AlN films grow on Mo(100), the films contain 30° rotated domains due to the difference in the rotational symmetry between AlN(0001) and Mo(100). AlN films with only poor crystalline quality grow on Mo(111) substrates, probably due to the poor surface morphology and high reactivity of the substrates. On the other hand, single crystal AlN films grow epitaxially on Mo(110) substrates with an in-plane relationship of AlN[11-20] // Mo[001]. Reflection high-energy electron diffraction or electron backscattered diffraction analysis has revealed that neither in-plane 30° rotated domains nor cubic phase domains exist in the AlN films. X-ray reflectivity measurements have revealed that the heterointerface between AlN and Mo prepared by PLD at 450 °C is quite abrupt. These results indicate that PLD epitaxial growth of AlN on single crystal Mo substrates is quite promising for the fabrication of future high frequency filter devices. 相似文献
197.
Nazlina Haiza Mohd Yasin Masaharu Fukuzaki Toshinari Maeda Toshiki Miyazaki Che Mohd Hakiman Che Maail Hidayah Ariffin Thomas K. Wood 《International Journal of Hydrogen Energy》2013
Biohydrogen is considered a promising and environmentally friendly energy source. Escherichia coli BW25113 hyaB hybC hycA fdoG frdc ldhA aceE has been previously engineered for elevated biohydrogen production from glucose. In this study, we show that this strain can also use biomass from oil palm frond (OPF) juice and sewage sludge as substrates. Substrate improvement was accomplished when hydrogen productivity increased 8-fold after enzymatic treatment of the sludge with a mixture of amylase and cellulase. The OPF juice with sewage sludge provided an optimum carbon/nitrogen ratio since the yield of biohydrogen increased to 1.5 from 1.3 mol H2/mol glucose compared to our previous study. In this study, we also reveal that our engineered strain improved 200-fold biohydrogen productivity from biomass sources compared to the unmodified host. In conclusion, we determined that our engineered strain can use biomass as an alternative substrate for enhanced biohydrogen production. 相似文献
198.
Toto Sudiro Tomonori Sano Shoji Kyo Osamu Ishibashi Masaharu Nakamori Kazuya Kurokawa 《Oxidation of Metals》2013,80(5-6):589-597
The present paper is designed to provide a summary of our study on the high temperature corrosion of Al2O3, SiO2 and Al2O3–SiO2 forming alloys in the gas phase and liquid phase of Na2SO4–NaCl system by comparing their corrosion resistance at 1000 °C. The obtained results show that the alumina-forming alloy experiences severe internal corrosion in the gas phase compared to in the liquid phase due to oxide cracking. This results in an increase in the inward diffusion and/or penetration of constituents of the salts and oxygen to form internal Al-oxide and Cr-sulfides. In the liquid phase, however, the formation of yttrium sulfide beneath a continuous double oxides layer of Al5Y3O12 and Al2O3 may be related to the high affinity of yttrium for sulfur. On the other hand, it is apparent from the cross-sectional observations that a SiO2 and Al2O3–SiO2 forming alloys form a continuous and dense oxides layer, and demonstrate a high resistance against internal oxidation and corrosion in both corrosive environments. 相似文献
199.
When measuring multicarrier communication systems such as an orthogonal frequency division multiplexing (OFDM) or UWB wireless signal, there is a problem that the effective measuring dynamic range of the measuring instrument may be reduced, since the peak‐to‐average power ratio (PAPR) of the measured signal is significantly high. In order to solve this problem, we propose a technique that maintains the measuring dynamic range by dividing the measured signal into multiple bandwidths to decrease the measured signal power. We made a prototype of the measuring equipment, confirmed the operation of the algorithm, and verified the effectiveness of dynamic range improvement is 5 to 8 dB in relation to a conventional circuit. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(2): 28–35, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22367 相似文献
200.
Kei?AsadaEmail author Sadao?Eguchi Masaharu?Ikeba Taku?Kato Saeko?Yada Yasuhiro?Nakajima Sunao?Itahashi 《Nutrient Cycling in Agroecosystems》2018,110(2):307-326
Andosols, distributed widely around the Pacific basin, have unique soil–water and solute transport properties because of their stepwise water retention curves and high anion-adsorption capacity. The model modification and verification for these properties are crucial for evaluating the potential for improved agricultural management (e.g., using organic matter instead of inorganic fertilizer) to reduce N loss from the soils. Here, we improved an existing biogeochemical model, LEACHM, to predict long-term N leaching from Andosols amended with composted manure, without optimization to fit measured field data. The modified model was verified by observations from a 5.6-year lysimeter experiment with different rates of inorganic N fertilizer plus composted manure (100 + 0, 75 + 25, or 25 + 75%) of two different types (cattle, swine) on lettuce, sorghum (as a catch crop), and Chinese cabbage in rotation. Incorporation of Durner’s bimodal model dramatically improved predictions of drainage water volume and evapotranspiration. The non-linear Langmuir adsorption isotherms for soil NH4 + and NO3 ? improved model performance in simulating crop N uptake and N leaching loss. The RMSE, R2, and index of Agreement were evaluated as satisfactory in all lysimeters. Our model explained reasonably well that improved agricultural management decreased in current available N addition rates by 8.82–35.6% and reduced in the yearly averaged NO3 leaching by 8.70–41.8%. A modified model relating soil hydraulic properties and N adsorption properties could thus accurately predict N leaching under different long-term N application rates/types, and could be useful for supporting agricultural management decisions in cropped Andosols. 相似文献