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A new N* resonance as a hadronic molecular state

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Chinese Physics C 2009年第12期33卷 1312-1317页

作者： daisuke Jido Yoshiko Kanada-En’yo Yukawa Institute for Theoretical Physics Kyoto University Kyoto 606-8502 Japan

We report our recent work on a hadronic molecule state of the KKN system with I =1/2 and jR = 1/2＋. We assume that the A（1405） resonance and the scalar mesons, f0（980）, ao（980）, are reproduced as quasi-bound states of KN and KK, respectively. Performing non-relativistic three-body calculations with a variational method for this system, we find a quasibound state of the KIlN system around 1910 MeV below the three-body breakup threshold. This state corresponds to a new baryon resonance of N＊ with JP ： 1/2＋. We find also that this resonance has the cluster structure of the two-body bound states keeping their properties as in the isolated two-particle systems. We also briefly discuss another hadronic molecular state composed by two K and one N, which corresponds to a resonance.

关键词： three-body bound state ∧(1405) resonance kaon-nucleon intera^tion variational calculation

Seasonal change in sexual differences in nestling size and survival： a framework to evaluate sex-dependent environmental sensitivity in the wild

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Avian Research 2018年第2期9卷 136-143页

作者： daisuke Nomi Teru Yuta Itsuro Koizumi Graduate School of Environmental Science Hokkaido University Sapporo Hokkaido Japan Center for Toki and Ecological Restoration Niigata University Sado Niigata Japan Faculty of Environmental Earth Science Hokkaido University Sapporo Hokkaido Japan

Background: Sexual size dimorphism(SSD) occurs in a wide range of species in birds and other animals, but the magnitude of SSD often varies with environmental conditions. In general, in the developmental stages, the larger sex is more vulnerable to adverse environmental conditions because the larger sex requires more energy than the smaller sex. However, this may not hold true for birds with large brood sizes; the larger sex can acquire more food by suppressing the smaller sex. In addition, most previous studies have been experimental, such as by manipulating clutch size and ectoparasites, which may not reflect natural ***: In the present study, we propose a general framework to assess sexual differences in environmental sensitivity in natural populations. Because environmental conditions change throughout the breeding season, seasonal changes of nestling SSD and sex ratio should reflect sexual differences in environmental sensitivity. We applied this approach to a large dataset(1555 nestlings over 5 years) of Japanese Tits(Parus minor). In this population, the male nestling is generally larger than the female(5% SSD in body weight).Results: We found that the magnitude of SSD(weight, tarsus, wing) and fledgling sex ratio increased both in the beginning and the end of the breeding ***: Our study suggested that female nestlings are more valuable to poor environmental conditions in the relatively fecund species. This study underscores the importance of brood size on sexual differences in environmental stochasticity and our framework encourages comparative analysis among different bird species.

关键词： Brood size Japanese tit Parus minor Seasonal change Sexual size dimorphism

Numerical simulation of a possible origin of the positive radial metallicity gradient of the thick disk

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Research in Astronomy and Astrophysics 2014年第11期14卷 1406-1414页

作者： Awat Rahimi Kenneth Carrell daisuke Kawata National Astronomical Observatories Chinese Academy of Sciences Mullard Space Science Laboratory University College London Holmbury St.Mary DorkingSurrey RH5 6NT UK

We analyze the radial and vertical metallicity and [α/Fe] gradients of the disk stars of a disk galaxy simulated in a fully cosmological setting with the chemo- dynamical galaxy evolution code GCD＋. We study how the radial abundance gradients vary as a function of height above the plane and find that the metallicity （[α/Fe]） gra- dient becomes more positive （negative） with increasing height, changing sign around 1.5 kpc above the plane. At the largest vertical height （2 〈丨z丨〈 3 kpc）, our simulated galaxy shows a positive radial metallicity gradient. We find that the positive metallicity gradient is caused by the age-metallicity and age-velocity dispersion relation, where younger stars have higher metallicity and lower velocity dispersion. Due to the age- velocity dispersion relation, a greater fraction of younger stars reaches 丨z丨〉 2 kpc at the outer region, because of the lower gravitational restoring force of the disk, i.e. flaring. As a result, the fraction of younger stars with higher metallicity due to the age-metallicity relation becomes higher at the outer radii, which makes the median metallicity higher at the outer radii. Combining this result with the recently observed age-metallicity and age-velocity dispersion relation for the Milky Way thick disk stars suggested by Haywood et al., we argue that the observed （small） positive radial metal- licity gradient at large heights of the Milky Way disk stars can be explained by flaring of the younger thick and/or thin disk stars.

关键词： Galaxy disk -- Galaxy kinematics and dynamics -- galaxies interac-tions- galaxies formation- galaxies evolution- galaxies abundances

Driving force and structural strength evaluation of a flexible mechanical system with a hydrostatic skeleton

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第4期11卷 255-262页

作者： daisuke MARUYAMA Hitoshi KIMURA Michihiko KOSEKI Norio INOU Department of Mechanical and Control Engineering Tokyo Institute of Technology

The purpose of this study was to build a flexible mechanical system with a hydrostatic *** main components of this system are two type flexible *** is a structural bag with constant inner *** other is an actuator bag with controlled inner *** design the system,it was necessary to estimate both structural deformation and driving *** analysis of flexible bags,however,is difficult because of large nonlinear *** study analyzed structural strength and driving force of flexible bags with the nonlinear finite element analysis (FEA) software *** stress concentration dependency on the bag shape is described and the driving force is calculated to include the large *** the analytical results,this study derives an empirical equation of driving *** validity of the equation was confirmed by condition-changed analyses and experimental results.

关键词： Flexible mechanical system Hydrostatic skeleton Design method Nonlinear finite element analysis (FEA)

Direct Preparation of Styrene Carbonates from Styrene Using an Ionic-Liquid-Based One-pot Multistep Synthetic Process

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Direct Preparation of Styrene Carbonates from Styrene Using ...

Unsteady Flow Field under Surge and Rotating Stall in a Three-stage Axial Flow Compressor

The 4th Joint China/Japan Chemical Engineering Symposium

作者： Fumitaka ono daisuke Tomida Chiaki Yokoyama Institute of Multidisciplinary Research for Advanced Materials Tohoku University2-1-1KatahiraAoba-kuSendai980-8577Japan Institute of Multidisciplinary Research for Advanced Materials Tohoku University2-1-1KatahiraAoba-kuSendai980-8577Japan Institute of Multidisciplinary Research for Advanced Materials Tohoku University2-1-1KatahiraAoba-kuSendai980-8577Japan

Preparation of five member ring cyclic carbonates using CO2 as raw material represents one of the mostattractive routes for chemical fixation of CO2, as cyclic carbonates have a large market owing to their broad usageas solvents, intermediates, fuel additives and monomers for polymers. Usually, this route employs epoxide asstarting material and has been extensively investigated [1].

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Journal of Thermal Science 2011年第1期20卷 6-12页

作者： Takayuki HARA daisuke MORITA Yutaka OHTA Eisuke OUTA Graduate Student Graduate school of Science and EngineeringWaseda University3-4-1 OkuboShinjukuTokyo 169-8555Japan Department of Applied Mechanics and Aerospace Engineering Waseda University3-4-1 OkuboShinjukuTokyo 169-8555Japan

The unsteady flow structure between rotor blade-to-blade passages in a three-stage axial flow compressor is experimentally investigated by detailed measurements of unsteady performance characteristics,casing wall pressure fluctuations and their wavelet *** main feature of the test compressor is a capacity tank facility connected in series to the compressor outlet in order to supply compression and/or expansion waves from downstream of the *** attention is focused on the post-stall characteristics of the surge and rotating stall which occur *** influence of the compressor operating point on the unsteady performance curve shows that the surge cycle changes irregularly depending on the steady-state resistance characteristics,and the results of the wavelet analyses of the wall pressure fluctuations suggest that the surge cycle may selectively be determined by the rotating stall cell structure within the rotor cascade.

关键词： Axial flow compressor Surge Rotating stall Stall cell Wavelet analysis.

Optical and scintillation properties of Nd-doped SrAl2O4 crystals

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Journal of Rare Earths 2016年第8期34卷 757-762页

作者： daisuke Nakauchi Go Okada Masanori Koshimizu Takayuki Yanagida Graduate School of Materials Science.Nara Institute of Science and Technology(NAIST)8916-5 Takayama-cho lkoma-shiNara 630-0192Japan Department of Applied Chemistry Graduate School of EngineeringTohoku University 6-6-07 AobaAramakiAoba-ku.Sendai 980-8579.Japan

Nd-doped SrA1204 （Nd：SrA1204） crystals were prepared by a floating zone （FZ） method with different dopant concentra- tions. The photoluminescence （PL） measurements under visible light excitations confirmed strong near infrared （NIR） emissions around 890 nm, which is due to the 4f-4f transitions of Nd3＋, and the decay time constants were 300-400 μs. Furthermore, VUV ex- citations revealed two broad emissions around 250450 and 500-700 run, which were attributed to self-trapped excitons （STEs） perturbed by Nd3＋. Moreover, the X-ray induced scintillation spectra showed some small peaks at around 380 nm in addition to NIR emissions at 1064 nm similarly seen in PL. The former scintillation decay time constants were 30-40 Its. In the undoped sample, these emissions mentioned above were not present but a weak broad emission around 450 nm appeared. In thermally stimulated lu- minescence （TSL） after X-ray irradiation, strong TSL glow peaks were observed in the Nd-doped samples at around 100 and 250 ℃.

关键词： scintillation photoluminescence storage luminescence single crystal rare earths

Controlling the aggregation and assembly of boron-containing molecular and polymeric materials

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Aggregate

Aggregate 2022年第2期3卷 50-59页

作者： daisuke Shimoyama Frieder Jäkle Department of Chemistry Rutgers University-NewarkNewarkNew JerseyUSA

Boron-containing molecules and polymers are attractive as powerful tunable Lewis acids for small molecule activation and catalysis,as luminescent materials for organic electronic device and(bio)imaging applications,and as smart chemical *** the characteristics of the boron-containing building blocks are attractive in and of themselves,their assembly into higher order supramolecular materials offers access to unique properties and emerging ***,we highlight recent achievements in the field of aggregated organoboron *** discuss how supramolecular interactions can be exploited to precisely control the structure of the assemblies and impact their functions as luminescent materials,recyclable and smart catalyst systems,chemical sensors,stimuli-responsive and self-healing materials.

关键词： boron luminescent materials nanostructure self-assembly supramolecular polymers

Involvement of insulin receptor substrates in cognitive impairment and Alzheimer’s disease

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Neural Regeneration Research 2019年第8期14卷 1330-1334页

作者： daisuke Tanokashira Wataru Fukuokaya Akiko Taguchi Department of Integrative Aging Neuroscience National Center for Geriatrics and Gerontology Obu Aichi Japan Division of Neurology Endocrinology and Metabolism Faculty of Medicine University of Miyazaki Miyazaki Japan

Type 2 diabetes一associated with impaired insulin/insulin-like growth factor-1 (IGF1) signaling (IIS)一is a risk factor for cognitive impairment and dementia including Alzheimer's disease (AD). The insulin receptor substrate (IRS) proteins are major components of IIS, which transmit upstream signals via the insulin receptor and/or IGF1 receptor to multiple intracellular signaling pathways, including AKT/protein kinase B and extracellular-signal-regulated kinase cascades. Of the four IRS proteins in mammals, IRS1 and IRS2 play key roles in regulating growth and survival, metabolism, and aging. Meanwhile, the roles of IRS1 and IRS2 in the central nervous system with respect to cognitive abilities remain to be clarified. In contrast to IRS2 in peripheral tissues, inactivation of neural IRS2 exerts beneficial effects, resulting in the reduction of amyloid p accumulation and premature mortality in AD mouse models. On the other hand, the increased phosphorylation of IRS 1 at several serine sites is observed in the brains from patients with AD and animal models of AD or cognitive impairment induced by type 2 diabetes. However, these serine sites are also activated in a mouse model of type 2 diabetes, in which the diabetes drug metformin improves memory impairment. Because IRS1 and IRS2 signaling pathways are regulated through complex mechanisms including positive and negative feedback loops, whether the elevated phosphorylation of IRS1 at specific serine sites found in AD brains is a primary response to cognitive dysfunction remains unknown. Here, we examine the associations between IRS 1 /1 RS2-mediated signaling in the central nervous system and cognitive decline.

关键词： type 2 diabetes insulin/insulin^like growth factor-1 insulin receptor substrate Alzheimer's disease aging serine phosphorylation metformin neuroprotective effects high-fat-diet