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Discrete dislocation plasticity analysis of dispersion strengthening in oxide dispersion strengthened(ODS) steels

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Journal of Central South University 2014年第4期21卷 1249-1255页

作者： Akiyuki takahashi Shota Sato Department of Mechanical Engineering Faculty of Science and TechnologyTokyo University of Science

A discrete dislocation plasticity analysis of dispersion strengthening in oxide dispersion strengthened(ODS) steels was described. Parametric dislocation dynamics(PDD) simulation of the interaction between an edge dislocation and randomly distributed spherical dispersoids(Y2O3) in bcc iron was performed for measuring the influence of the dispersoid distribution on the critical resolved shear stress(CRSS). The dispersoid distribution was made using a method mimicking the Ostwald growth mechanism. Then, an edge dislocation was introduced, and was moved under a constant shear stress condition. The CRSS was extracted from the result of dislocation velocity under constant shear stress using the mobility(linear) relationship between the shear stress and the dislocation velocity. The results suggest that the dispersoid distribution gives a significant influence to the CRSS, and the influence of dislocation dipole, which forms just before finishing up the Orowan looping mechanism, is substantial in determining the CRSS, especially for the interaction with small dispersoids. Therefore, the well-known Orowan equation for determining the CRSS cannot give an accurate estimation, because the influence of the dislocation dipole in the process of the Orowan looping mechanism is not accounted for in the equation.

关键词： parametric dislocation dynamics oxide dispersion strengthened steel Orowan mechanism critical resolved shear stress dislocation dipole

On a New Geometric Constant Related to the Modulus of Smoothness of a Banach Space

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Acta Mathematica Sinica,English Series 2014年第9期30卷 1526-1538页

作者： Yasuji takahashi Mikio KATO Department of System Engineering Okayama Prefectural University Department of Mathematics Faculty of EngineeringShinshu University

We shall introduce a new geometric constant A（X） of a Banach space X, which is closely related to the modulus of smoothness px （T）, and investigate it in relation with the constant As （X） by Baronti et al., the von Neumann-Jordan constant CNj（X） and the James constant J（X）. A sequence of recent results on these constants as well as some other geometric constants will be strengthened and improved.

关键词： Constant A(X) von Neumann-Jordan constant James constant modulus of smoothness modulus of convexity uniform non-squareness

Charge and Heat Transport in Polycrystalline Metallic Nanostructures

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Chinese Physics Letters 2008年第9期25卷 3360-3363页

作者：张兴 takahashi Koji FUJII Motoo Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering Mechanics Tsinghua University Beijing 100084 Graduate School of Engineering Kyushu University Fukuoka 819-0395 Japan Research Center for Hydrogen Industrial Use and Storage AIST Fhkuoka 819-0395 Japan

Metals are typically good conductors in which the abilities to transport charge and to transport heat can be related through the Wiedemann-Franz law. Here we report on an abnormal charge and heat transport in polycrystalline metallic nanostructures in which the ability to transport charge is weakened more obviously than that to transport heat. We attribute it to the influence of the internal grain boundaries and have formulated a novel relation to predict the thermal conductivity. The Wiedemann-Franz law is then modified to account for the influence of the grain boundaries on the charge and heat transport with the predictions now agreeing well with the measured results.

关键词： the power-law exponents precipitation durative abrupt precipitation change

interleukin 28B genetic polymorphism and hepatitis B virus infection

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World Journal of Gastroenterology 2014年第34期20卷 12026-12030页

作者： Toru takahashi Division of Gastroenterology and Hepatology Uonuma HospitalOjiyashiNiigata 947-0028Japan

Interleukin (IL) 28B genetic polymorphism is significantly associated with the sustained virological response rate in patients with chronic hepatitis C treated with pegylated interferon-α (PEG-IFN) plus ribavirin and with spontaneous hepatitis C virus clearance. However, a consensus on the relationship between IL28B genetic polymorphism and the favorable outcome of chronic hepatitis B virus infection defined by hepatitis B e antigen seroconversion, and/or hepatitis B surface antigen seroclearance in patients treated with interferon or PEG-IFN has not been reached. Several reports failed to show a positive association, while some studies demonstrated a positive association in certain subject settings. More prospective studies including large cohorts are needed to determine the possible association between IL28B genetic polymorphism and the outcome of interferon or PEG-IFN treatment for chronic hepatitis B.

关键词： interleukin 28B Polymorphism Hepatitis B virus interferon Pegylated interferon

Flow Electrification of Insulated Liquid in Metal Pipes

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Chinese Journal of Mechanical Engineering 2012年第6期25卷 1115-1120页

作者： ZHU Shouxin LIU Lin takahashi Satoshi School of Information and Engineering Huzhou Teachers College Huzhou 313000 China Graduate School of Natural Science and Technology Okayama University Okayama Japan

When relative motion occurs between a liquid and a solid, the two phases carry electric charge with opposite signs. The created charge easily accumulates in the liquid, and the amount of the charge carried in an insulated liquid refers to many factors, such as contact area with the solid surface, the contact time, and so forth. However, current theories agree that the amount of charge created during flow electrification is proportional to the contact surface. In this paper, the classical wall current theory is applied to establish an interfacial electrical double-layer model of flow electrification phenomena when an insulated liquid passes over metal pipe surface. Meanwhile, in conjunction with charge relaxation function, the relation between the charge density and flow velocity, the contact time and the contact area is obtained during the liquid flowing process. The experimental result demonstrates that the flowing charge carried in the insulated liquid is not simply proportional to the contact area, but has a non-linear dependence on the contact area and the contact time. Moreover, down flow experimental equipment pipes of different length and diameter, and dielectric hydraulic oil VG46 are used in an experimental study of laminar flow, in order to understand electrification phenomena in dielectric liquid flowing over metal pipes of different length and aperture. If they both increase linearly, charge relaxation will increase exponentially. As a result, the test result verifies related theoretical analysis, and the method given provides a theoretical basis to analyze interracial electrical phenomena.

关键词： flow electrification metal pipes contact time relaxation

Urban climate in the Tokyo metropolitan area in Japan

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Journal of Environmental Sciences 2017年第9期29卷 54-62页

作者： Jun Matsumoto Fumiaki Fujibe Hideo takahashi Research Center for Climatology Department of Geography Tokyo Metropolitan University Department of Coupled Ocean-Atmosphere-Land Processes Research JAMSTEC

Long-term climate changes related with urbanization in Tokyo, Japan, and recent temperature and heavy rainfall distribution in the Tokyo metropolitan area are reviewed. A relatively high temperature increase in annual mean temperature at the rate of 3.0°C/century was detected in Tokyo for the period 1901–2015. Some observational evidence showed the existence of both thermal and mechanical effects of urbanization on recent heavy rainfall occurrences, and modeling studies also support precipitation enhancement. Urban influences were recognized in other climatological elements, such as number of fog days, relative humidity, and wind circulation.

关键词： Heat island Cool island Heavy rainfall Fog Humidity Sea breeze

A sulfur–microporous carbon composite positive electrode for lithium/sulfur and silicon/sulfur rechargeble batteries

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Progress in Natural Science:Materials International 2015年第6期25卷 612-621页

作者： Takuya takahashi Masaki Yamagata Masashi Ishikawa Department of Chemistry and Materials Engineering Faculty of ChemistryMaterials and BioengineeringKansai University

Sulfur is an advantageous material as a promising next-generation positive electrode material for high-energy lithium batteries due to a high theoretical capacity of 1672 m A h g 1although its discharge potential is somewhat modest:ca.2 V vs Li/***,a sulfur positive electrode has some crucial problems for practical use,which are mainly attributed to the dissolution of its intermediate products in charge–discharge *** order to resolve the dissolution problem of lithium polysulfide,we attempted to synthesize a sulfur–microporous activated carbon(AC) composite positive ***,we have systematically researched the battery performance of sulfur–microporous AC positive electrode with variations of electrolytes as well as negative electrodes,and found its promising positive electrode performance for a nextgeneration rechargeable battery.

关键词： Sulfur Micropore Ionic liquid Silicon Lithium-ion battery

Who needs further evaluations to diagnose upper urinary tract urothelial cancers among patients with abnormal findings by enhanced CT?

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Asian Journal of Urology 2016年第1期3卷 44-48页

作者： Akio Takayanagi Atsushi takahashi Fumimasa Fukuta Manabu Okada masahiro Matsuki Shunsuke Sato Teruhisa Uehara Shuichi Kato Yoshio Takagi Department of Urology Hakodate Goryoukaku HospitalHakodateHokkaidoJapan Department of Urology Sapporo Medical University School of MedicineSapporoHokkaidoJapan

Objective:We evaluated who would need further evaluations such as retrograde pyelography(RP)and/or ureteroscopy to diagnose upper urinary tract urothelial cancers(UUTUCs)when abnormal findings for the upper urinary tract(UUT)were detected by enhanced computed tomography(CT).Methods:We retrospectively analyzed 125 patients who underwent enhanced CT for various reasons and had abnormal findings for the *** whose tumors were suspected to be of extraureteral origin were *** patients received RP and/or ureteroscopy to evaluate the ***:The median age of the 125 patients was 70 years and gross hematuria(26.4%)was the most frequently observed ***,ureteroscopy and both were performed for 121,59 and 55 patients,*** revealed tumor-like lesions in 58 patients and the other patients had non-tumor-like *** were found in 43(34.4%)of the 125 *** of them had tumor-like lesions on *** 58 patients who had tumor-like lesions on CT,univariate and multivariate analyses revealed that tumor diameter and tumor enhancement were significant predictive factors for *** curve analysis of enhanced CT to diagnose UUTUCs revealed that a tumor diameter of 18 mm was the best cutoff *** sensitivity,specificity and accuracy were 90.0%,98.8% and 92.7% for RP and 95.5%,100% and 97.1%for ureteroscopy,*** of them had high sensitivity,specificity and ***:We should decide to evaluate the UUT according to the tumor diameter on enhanced *** we evaluate the UUT in patients with tumor diameters of less than 20 mm,ureteroscopy is recommended.

关键词： Upper urinary tract urothelial cancers Enhanced CT Ureteroscopy Retrograde pyelography

Hand-holding and releasing between the anion and cation to change their macroscopic behavior in water

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Green Energy & Environment 2019年第2期4卷 127-130页

作者： Kosuke Kuroda Yumiko Shimada Kenji takahashi Faculty of Biological Science and Technology Institute of Science and Engineering Kanazawa University

Despite the similarity of ionic liquid and zwitterion, their some properties such as conductivity and hydrophobicity are different. Here we developed a novel phosphonium salt having a dynamic covalent bond between anion and cation, enabling reversible structural shift between free ion pair and zwitterion. With the phosphonium salt, control of the macroscopic phase behavior in aqueous solution, i.e. forming mono-or biphasic systems, upon exposure to an acid or base was reversibly achieved, based on the structural shift of the phosphonium salt. CO_2/N_2 bubbling reversibly changed the phase behavior as well as acid/base, leading to green separation systems.

关键词： Ionic liquid Zwitterion Phase separation Dynamic covalent bond