检索结果-南通市图书馆

Acta Metallurgica Sinica(English Letters) 2011年第3期24卷 195-204页

作者： Keijiro HIRAGA Byung-Nam KIM koji morita Hidehiro YOSHIDA Yoshio SAKKA Masaaki TABUCHI National Institute for Materials Science

From existing knowledge about high-temperature cavitation mechanisms, necessary conditions were discussed for the suppression of cavitation failure during superplastic deformation in ceramic materials. The discussion, where special attention was placed on the relaxation of stress concentrations during grain-boundary sliding and cavity nucleation and growth, leaded to a conclusion that cavitation failure could be retarded by the simultaneous controlling of the initial grain size, the number of residual defects, diffusivity, dynamic grain growth and the homogeneity of microstructure. On the basis of this conclusion, high-strain-rate superplasticity （defined as superplasticity at a strain rate higher than 0.01 s^-1） could be intentionally attained in some oxide ceramic materials. This was shown in tetragonal zirconia and composites consisting of zirconia, a-alumina and a spinel phase.

关键词： Grain-boundary sliding Accommodation Stress concentration Diffusional relaxation Cavity nucleation Cavity growth Dynamic grain growth

Empirical correlations for predicting the self-leveling behavior of debris bed

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2013年第1期24卷 43-52页

作者： CHENG Songbai YAMANO Hidemasa SUZUKI Tohru TOBITA Yoshiharu NAKAMURA Yuya ZHANG Bin MATSUMOTO Tatsuya morita koji Advanced Nuclear System R&D Directorate Japan Atomic Energy Agency (JAEA) Department of Applied Quantum Physics and Nuclear Engineering Kyushu University

Studies on the self-leveling behavior of debris bed are crucial for the assessment of core-disruptive accident (CDA) occurred in sodium-cooled fast reactors (SFR). To clarify this behavior over a comparatively wider range of gas velocities, a series of experiments were performed by injecting nitrogen gas uniformly from a pool bottom. Current experiments were conducted in a cylindrical tank, in which water, nitrogen gas and different kinds of solid particles, simulate the coolant, vapor (generated by coolant boiling) and fuel debris, respectively. Based on the quantitative data obtained (mainly the time variation of bed inclination angle), with the help of dimensional analysis technique, a set of empirical correlations to predict the self-leveling development depending on particle size, particle density and gas injection velocity was proposed and discussed. It was seen that good agreement could be obtained between the calculated and experimental values. Rationality of the correlations was further confirmed through detailed analyses of the effects of experimental parameters such as particle size, particle density, gas flow rate and boiling mode. In order to facilitate future analyses and simulations of CDAs in SFRs, the obtained results in this work will be utilized for the validations of an advanced fast reactor safety analysis code.

关键词：自流平行为模拟冷却水预测气体速度注入氮气粒子密度实验值

在线全文

学校读者我要写书评

暂无评论

亚洲液化天然气市场透析

天然气地球科学 1997年第5期8卷 37-43页

作者： morita koji 高峰日本

90年代末亚洲液化天然气市场出现变化:即日本的需求缓慢增长;韩国和台湾地区的需求快速增长,对中东依赖程度增加;中国和印度的需求存在较大的不确定因素。从各种指标因素如人均GDP、人均能源消费来看,中国进口液化天然气的时机尚未成熟... 详细信息

90年代末亚洲液化天然气市场出现变化:即日本的需求缓慢增长;韩国和台湾地区的需求快速增长,对中东依赖程度增加;中国和印度的需求存在较大的不确定因素。从各种指标因素如人均GDP、人均能源消费来看,中国进口液化天然气的时机尚未成熟,某些城市如上海、深圳等条件已成熟,但付诸行动尚需时日。印度由于受年生产天然气的能力限制,其2005年需求的40亿m^3液化天然需要靠进口。鉴于液化天然气供方市场的扩大,以及日、韩、台湾等需求的增长,2000年以后,这些远东国家和地区对中东液化天然气的依赖程度不会超过2000年的水平。

关键词：亚洲液化天然气市场分析需求量供应量

在线全文

学校读者我要写书评

暂无评论

严重事故中碎片床形成过程的数值模拟

核动力工程 2015年第5期36卷 184-186页

作者：张斌吴健 Shamsuzzaman M 守田幸路单建强陈耀东西安交通大学核科学与技术学院西安710049 中国核电工程有限公司北京100840 日本国立九州大学应用量子物理与核工程系福冈8190395 国核科学技术研究院北京100029

采用改进的离散要素法(DEM)对严重事故中碎片床的形成过程进行二维数值模拟。针对传统的DEM模型中计算系数选取困难的问题,围绕时间步长对计算参数重新进行推导和组合,改进后的DEM能大大提高应用的效率。通过与一系列的实验在颗粒扩散... 详细信息

采用改进的离散要素法(DEM)对严重事故中碎片床的形成过程进行二维数值模拟。针对传统的DEM模型中计算系数选取困难的问题,围绕时间步长对计算参数重新进行推导和组合,改进后的DEM能大大提高应用的效率。通过与一系列的实验在颗粒扩散角度、颗粒下落时间、形成碎片床的形状方面的系统对比,验证了模拟程序的有效性。

关键词：严重事故碎片床离散要素法(DEM)

Simple Kac-Moody groups with trivial Schur multipliers

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2018年第2期61卷 311-316页

作者： Jun morita Institute of Mathematics University of Tsukuba

We obtain new examples of simple Kac-Moody groups with trivial Schur multipliers.

关键词： Kac-Moody group simple group Schur multiplier

Experimental study on boundary lubricity of superficial area of articular cartilage and synovial fluid

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第5期12卷 981-996页

作者： Wenxiao LI Takehiro morita Yoshinori SAWAE Departure of Mechanical Engineering Kyushu UniversityFukuoka8190395Japan International Institute for Carton-Neutral Energy Research Kyushu UniversityFukuoka8190395Japan Advanced Research Center for Biomechanics Kyushu UniversityFukuoka8190395Japan

The boundary lubrication mechanism at the articulating surface of natural synovial joints has been the subject of much discussion in *** this study,to elucidate the lubricating function of the superficial area of articular cartilage and synovial fluid(SF),cartilage specimens were processed with four different treatments:gentle and severe washing with detergent,incubation in NaCl solution,and trypsin digestion to selectively remove certain constituents from the cartilage ***,the frictional characteristics were examined in phosphate-buffered saline(PBS)and SF against *** reciprocating sliding tests with a spherical glass probe and square articular cartilage specimens were performed at low contact loads in the mN range to extract the frictional behavior in the superficial area of the cartilage ***,the cartilage surface was observed to confirm the effects of treatments on the morphology of the cartilage surface using a fluorescence microscope and water-immersion *** coefficient of friction(COF)of the prepared cartilage specimens was varied from 0.05 to over 0.3 in ***,a certain group of cartilage specimens exhibited a low COF of less than 0.1 with limited *** the low COF group of specimens,all four treatments increased the COF in PBS to different extents,and fluorescence microscopy revealed that the integrity of the cartilage surface was deteriorated by *** means that the intact cartilage surface had lubricating constituents to maintain low friction,and the removal of such constituents resulted in the loss of the intrinsic boundary lubricity of the cartilage *** variation in the COF of the cartilage specimens was suppressed in SF because it had a clear boundary lubrication effect on the cartilage *** lubricating effect of SF could be confirmed even after degenerative treatment.

关键词： articular cartilage synovial fluid the uppermost superficial layer boundary lubrication

Numerical analysis of interaction between solute atom and extended dislocation using force multipoles

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Central South University 2014年第8期21卷 3000-3006页

作者： Hiroaki morita Akiyuki Takahashi Department of Mechanical Engineering Faculty of Science and TechnologyTokyo University of Science

The interaction between a solute atom and an extended dislocation was investigated using a continuum approximation method with force *** dislocation core structure of extended dislocation was modeled with the Peierls-Nabarro model discretized with a number of infinitesimal Volterra *** interaction energy and force between a nickel solute atom and perfect and extended dislocation in copper were successfully calculated using the force *** results clearly show that the core structure of extended dislocation weakens the interaction with solute *** interaction energy and force for extended dislocations are almost the half of those for perfect dislocations.

关键词： solution hardening force multipole solute atom extended dislocation Peierls-Nabarro model

Unsteady Behavior of Surge and Rotating Stall in an Axial Flow Compressor

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2012年第4期21卷 302-310页

作者： Yutaka OHTA Yutaka FUJITA Daisuke morita Department of Applied Mechanics and Aerospace Engineering Waseda University 3-4-1 Okubo Shinjuku Graduate Student Graduate School of Science and Engineering Waseda University 3-4-1 Okubo Shinjuku

Unsteady behaviors as well as unsteady cascade flow fields of a single-stage axial flow compressor were experi- mentally investigated by detail measurements of unsteady performance characteristics and casing wall pressure and internal flow velocity fluctuations. The main feature of the test compressor is a capacity tank connected di- rectly to the compressor outlet in series through slits and a concentric duplex pipe, and also jet nozzles in order to inject compressed air toward the rotor tip region. Research attention is focused on the post-stall characteristics of surge and rotating stall which occur simultaneously. When the compressor was connected to the capacity tank, surge was generated with rotating stall in accordance with the capacitance increment of whole compressor system The surge behavior changed irregularly with throttling valve installed behind the compressor, and several types of surge cycles were observed. In addition, the surge cycle changed by jet injection to the rotor tip region. The re- suits suggested that the blockages of the cascade flow which were generated by a stall cell play an important role in deciding the surge behaviors.

关键词： Axial flow compressor Surge Rotating stall Stall cell Jet injection

Novel aspects of extracellular adenosine dynamics revealed by adenosine sensor cells

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2017年第6期12卷 881-885页

作者： Kunihiko Yamashiro Mitsuhiro morita Department of Biochemistry and Cellular Biology National Institute of Neuroscience National Center of Neurology and Psychiatry (NCNP) Department of NCNP Brain Physiology and Pathology Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences Department of Biology Kobe University Graduate School of Sciences

Adenosine modulates diverse physiological and pathological processes in the brain, including neuronal activities, blood flow, and inflammation. However, the mechanisms underlying the dynamics of extracellular adenosine are not fully understood. We have recently developed a novel biosensor, called an adenosine sensor cell, and we have characterized the neuronal and astrocytic pathways for elevating extracellular adenosine. In this review, the physiological implications and therapeutic potential of the pathways revealed by the adenosine sensor cells are discussed. We propose that the multiple pathways regulating extracellular adenosine allow for the diverse functions of this neuromodulator, and their malfunctions cause various neurological and psychiatric disorders.

关键词： adenosine neuronal physiological understood astrocyte neurological Adenosine synaptic hippocampal psychiatric

The Study of Latent Heat Transport Characteristics by Solid Particles and Saccharide Solution Mixtures

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2011年第2期20卷 155-160页

作者： Shin-ichi morita Yasutaka HAYAMIZU Hideo INABA Department of Mechanical Engineering Yonago National College of Technology Tsuyama National College of Technology

The purpose of this study is the development of latent heat transport system by using the mixture of the minute latent heat storage materials and the saccharine solution as medium. The experimental studies are carried out by the evaluation of viscosity and pressure loss in a pipe. Polyethylene (P.E.) is selected as the dispersed minute material that has closeness density (920kg/m3) of ice (917kg/m3). D-sorbitol and D-xylose solutions are picked as continuum phase of the test mixture. The concentration of D-sorbitol solution is set 48mass% from measured results of saturation solubility and the melting point. 40mass% solution of D-xylose is selected as the other test continuum phase. The non-ion surfactant, EA157 Dai-ichiseiyaku CO. Ltd, is used in order to prevent of dispersed P.E. powder cohere. The pressure loss of test mixture is measured by the straight circular pipe that has smooth inner surface. The measuring length for pressure loss is 1000 mm, and the inner diameter of pipe is 15mm. The accuracy of experiment apparatus for measuring pressure loss is within ±5%. The pressure loss data is estimated by the relationship between the heat transport ratio and the required pump power. It is clarified that the optimum range of mixing ratio exists over 10mass% of latent heat storage material.

关键词： Latent heat transport Heat storage Multiphase flow