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Numerical Study of Shock Waves Propagating through Right Angled Multiple Elbows

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Journal of Thermal Science 2005年第3期14卷 254-257页

作者： kazuyuki KAGE Mihoko SHIROYAMA Katsuya ISHIMATSU Department of Mechanical and Energy Systems Engineering Oita University 700 Dannoharu Oita 870-1192 Japan ProfessorDepartment of Mechanical and Energy Systems Engineering Oita University 700 Dannoharu Oita 870-1192 JapanDepartment of Mechanical and Energy Systems Engineering Oita University 700 Dannoharu Oita 870-1192 Japan

The details of the shock propagated through the right angled multiple elbows (mainly double elbow and fourfold elbow) are investigated by the numerical study. Computations were carried out by solving the two-dimensional compressible Navier-Stokes equations by using the total variation diminishing (TVD) scheme. Computations were performed for six types of elbow (two types of double elbow and four types of fourfold elbow) and two incident shock Mach numbers (Ms=1.5, 2.3). The effects of the direction and number of the bends in the stabilizing, merging and attenuating processes of the shock are numerically explored by various diagrams such as pressure contours, pressure distributions on the walls and time histories of the pressure contours, and the strength of the shock front at the location of about 20 times the length for each type of elbows was displayed.

关键词：震动波衍射现象二维空间 Navier-Stokes方程

Measurement of ethylene and methane production in a temperate forest soil using inhibition of acetylene and carbon monoxide

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Chinese Science Bulletin 2008年第7期53卷 1087-1093页

作者： XU XingKai INUBUSHI kazuyuki State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate School of Horticulture Chiba University Matsudo Chiba 271-8510 Japan

We studied in the laboratory the effects of acetylene (C2H2) concentrations on the accumulation and consumption of ethylene and methane in a temperate pine forest soil, and in situ ethylene and methane production and flush effects of nitrogen sources on both productions in the pine forest stand (Pinus sylvestris L.). The addition of C2H2 at concentrations more than 50 Pa C2H2 in the headspace caused a more than 95% reduction in rates of ethylene and methane consumption in forest soil compared to those with no C2H2. Furthermore, addition of acetylene within a range of 50 to 10, 000 Pa C2H2 induced a similar rate of methane accumulation in forest soil. Hence, it can be concluded that presence of more than 50 Pa C2H2 in the headspace is an effective method to measure methane production in forest soil. The addition of C2H2 at concentrations more than 50 Pa C2H2 induced an increasing concentration of ethylene in the headspace (P≤0.05), indicating the reduction of acetylene to ethylene in forest soil. Using inhibition of 0.5 kPa C2H2 in combination with 5 kPa carbon monoxide that inhibits the reduction of acetylene in a short term, it was observed that there was a larger in situ methane production rate (218 ± 26 μg C m-2 h-1 (μg C per square meter per hour, the same below)) than in situ ethylene produc-tion rate (92 ± 6 μg C m-2 h-1) in the pine forest soil. The addition of nitrogen sources such as urea, urea plus a nitrification inhibitor dicyandiamide, and potassium nitrate, could induce a 5-fold greater in-crease in rates of in situ ethylene and methane production compared to those in the control, particu-larly in the latter (P≤0.05). The results can promote in situ measurement of ethylene and methane production in forest soils at different sites.

关键词：乙烯甲烷温度森林土壤一氧化碳

Temperature effects on ethylene and methane production from temperate forest soils

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Chinese Science Bulletin 2009年第8期54卷 1426-1433页

作者： XU XingKai INUBUSHI kazuyuki State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chi- nese Academy of Sciences Beijing 100029 China Graduate School of Horticulture C~hiba University Matsudo Chiba 271-8510 Japan

Change in temperature affects the activity of soil ***,there is limited knowledge about temperature effects on ethylene(C2H4) and methane(CH4) production from forest *** samples(0―5 cm) collected from different temperate forest stands(e.g.,Pinus sylvestris L.,Cryptomeria japonica,and Quercus serrata) were used to compare C2H4 and CH4 production from soils at temperature from 5 to 35℃ under oxic and anoxic *** rates of C2H4 and CH4 production from soils under oxic conditions were measured by using inhibition of acetylene(C2H2) and carbon monoxide(CO).The consumption of C2H2 by soils at an initial concentration of c.250 Pa C2H2 was negligible at 5 and 15℃,but it was significantly increased at 25 and 35℃.The presence of 2 kPa CO in the headspace gases tended to decrease the consumption of C2H2 by soils at high *** Q10 values for the soil C2H2 consumption ranged from 2.3 to 3.8,and there were no significant differences in Q10 values between these topsoil *** rate of CH4 production from each sample under oxic conditions was larger than the soil C2H4 production at 5―35℃,particularly at low temperature,and presented a smaller Q10 *** production from soil after 1 week of anoxic incubation at 5―35℃ was larger than the soil CH4 production,and presented a larger Q10 ***,CH4 produc-tion from Quercus serrata forest soil and its response to temperature increased significantly with in-cubation ***-term anoxic conditions of in situ upland forest soils are normally not prevalent,so it can be reasonably concluded that there is a larger C2H4 production rather than CH4 production under temperate forest stands due to heavy rainfall in summer.

关键词：土壤微生物活性甲烷产量土壤温度温带森林乙烯好氧条件二氧化碳气体缺氧条件

Effects of nitrogen sources and glucose on the con- sumption of ethylene and methane by temperate volcanic forest surface soils

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Chinese Science Bulletin 2007年第23期52卷 3281-3291页

There is limited knowledge with regard to the consumption of ethylene (C2H4) and methane (CH4) in volcanic forest soils containing low microbial carbon-to-organic carbon ratio, and to the responses of both consumptions to nitrogen and carbon additions. Temperate volcanic forest surface soils under three forest stands (e.g. Pinus sylvestris L., Cryptomeria japonica and Quercus serrata) were used to compare CH4 and C2H4 consumption by forest soils, and to study the effects of nitrogen sources and glucose on both consumptions. There was a good parallel between CH4 and C2H4 consumption by for- est soils, but mineralization reduced CH4 consumption rather than C2H4 consumption in forest soils, particularly in a Pinus forest soil. The stimulatory effect of glucose addition on both CH4 and C2H4 consumption by forest soils was increased by increasing the pre-incubation period after glucose addi- tion, and a largest stimulation occurred in the Pinus forest soil. The addition of KNO3-N at the rate of 100 μg·g1 significantly reduced the consumptions of both C2H4 and CH4 by forest soils (P≤0.05). In the presence of urea plus dicyandiamide, the consumption rates of C2H4 and CH4 by forest soils were higher than those in the KNO3-N and urea-N treated soils at the same N rate (P≤0.05), but were similar to those of the control. Hence, under experimental conditions, there was a strong inhibitory effect of NO3 rather than NH4+ addition on the CH4 and C2H4 consumption in these forest soils. When amount of the added NO3-N increased up to more than 2―3 times the soil initial NO3-N concentrations, both C2H4 and CH4 consumption rates were reduced to 10%―20% of the rates in soils without nitrate addition. By comparing the three forest stands, it was shown that there was a smallest effective concentration of the added nitrate that could inhibit C2H4 and CH4 consumption in the Pinus forest soil, which indicated that C2H4 and CH4 consumption of the soil was more sensitive to NO3-N addition.

关键词：乙烯森林土壤甲烷硝化作用

Dysfunction of axonal transport in normal-tension glaucoma:a biomarker of disease progression and a potential therapeutic target

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Neural Regeneration Research 2021年第3期16卷 506-507页

作者： kazuyuki Hirooka Tohru Yamamoto Yoshiaki Kiuchi Department of Ophthalmology and Visual Science Graduate School of Biomedical SciencesHiroshima UniversityHiroshimaJapan Department of Molecular Neurobiology Kagawa University Faculty of MedicineKagawaJapan

Glaucoma and dysfunction of axonal transport:One of the leading causes of irreversible blindness worldwide is glaucoma,with increased intraocula r pressu re(IOP)being the most common risk ***,in some glaucoma patients it has been shown that the IOP does not differ from that of the normal *** Japan,normal-tension glaucoma(NTG),which accounts for 92%of primary open-angle glaucoma,has been shown to be more frequent in the population.

关键词： glaucoma axonal transport

Dynamics-based data science in biology

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National Science Review 2021年第5期8卷 16-18页

作者： Jifan Shi kazuyuki Aihara Luonan Chen International Research Center for Neurointelligence The University of Tokyo Institutes for Advanced StudyThe University of Tokyo Shanghai Institute of Biochemistry and Cell Biology Center for Excellence in Molecular Cell ScienceChinese Academy of Sciences Center for Excellence in Animal Evolution and Genetics Chinese Academy of Sciences School of Life Science and Technology Shanghai Tech University Key Laboratory of Systems Biology Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesChinese Academy of Sciences

Life science has long been a rich subject for research, and continues to develop at high speed. One of the major aims of life science is to study the mechanisms of various biological processes on the basis of biological big-data. Many statistics-based methods have been proposed to catch the essence by mining such data, including the popular category classification,variables regression, group clustering,statistical comparison, dimensionality reduction, and component analysis.

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Numerical Study of Interaction of Propagated Shock with Boundary Layer Behind Contact Surface in Ducts

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Journal of Thermal Science 2003年第1期12卷 16-19页

作者： kazuyuki Kage Katsuya Ishimatsu Toyoyasu Okubayashi Department of Production Systems Engineering Oita University 700 DannoharuDepartment of Production Systems Engineering Oita University 700 Dannoharu OitaDepartment of Production Systems Engineering Oita University 700 Dannoharu Oita Oita 870-1192 Japan 870-1192 Japan870-1192 Japan

The interactions of the shock with the boundary layer of the cold gas behind the contact in many different conditions.i.e. three kinds of test gases and three kinds of sound speed ratios across the contact,were explored by numerical *** trajectories of the transmitted shock in cold gas flow and the development of shock bifurcation in the process of interaction with boundary layer are illustrated by many kinds of figures(*** time-distance diagrams of the acoustic impedance contours on the axis,the pressure and density contours and the static pressure distributions on the axis.).

关键词：冲击波边界层互作用实验

Fabrication of Micro -Optical Devices by a Femtosecond Laser

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光学学报 2003年第S1期23卷 825-826页

作者： kazuyuki Hirao Graduate School of Engineering Kyoto University Japan

Femtosecond laser is a perfect laser source for materials processing when high accuracy and small structure size are required. Due to the ultra short interaction time and the high peak power, the process is generally characterized by the absence of heat diffusion and, consequently molten layers. Various induced structures have been observed in materials after the femtosecond laser irradiation. Here, we report on fabrication of micro-optical devices by the femtosecond laser. 1) formation of optical waveg...

关键词： by on in as of Optical Devices by a Femtosecond Laser Fabrication of Micro

R&D Activities of Manufacturing Multinationals in China:Structure,Motivations and Regional Differences

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China & World Economy 2010年第6期18卷 56-72页

作者： kazuyuki Motohashi Department of Technology Management for Innovation School of EngineeringUniversity of Tokyo Faculty Fellow at Research Institute of Economy Trade and Industry (RIETI)

This paper investigates the R＆D motivations of various multinationals operating in China, drawing on a large-scale, firm-level dataset of official Chinese statistics on science and technology activities. The present study shows that R＆D efforts in China have intensified for bothJbreign-owned and domestic firms, but less so for foreign-owned firms, perhaps because foreign-owned firms tend to operate on a foundation of technological capabilities developed within their home countries. Statistical analysis confirms that the major motivations for foreign R＆D in China are production-driven, not market-driven or technology-driven. Nevertheless, one sees significant variations in foreign R＆D strategies from region to region. Guangdong is characterized by production-driven R＆D. In Beijing, R＆D strategies tend to take a technology-driven approach, drawing on the clusters of scienl（fic institutions. In Shanghai, the R＆D efforts of multinationals tend to focus on support for market-driven R＆D,

关键词： China multinational R&D management