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SOME PROPERTIES OF COMMUTING AND ANTI-COMMUTING m-INVOLUTIONS

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Acta Mathematica Scientia 2012年第2期32卷 631-644页

作者： Mark yasuda 9525 Compass Point Drive South San DiegoCA 92126U.S.A.

We define an m-involution to be a matrix K ∈ Cn×n for which Km -= I. In this article, we investigate the class Sm （A） of m-involutions that commute with a diagonalizable matrix A E Cn×n. A number of basic properties of Sm （A） and its related subclass Sm （A, X） are given, where X is an eigenvector matrix of A. Among them, Sm （A） is shown to have a torsion group structure under matrix multiplication if A has distinct eigenvalues and has non-denumerable cardinality otherwise. The constructive definition of Sm （A, X） allows one to generate all m-involutions commuting with a matrix with distinct eigenvalues. Some related results are also given for the class S,, （A） of m-involutions that anti-commute with a matrix A ∈ Cnn×n.

关键词： Centrosymmetric skew-centrosymmetric bisymmetric involution eigenval-ues

The effect of the 18R-LPSO phase on the fatigue behavior of extruded Mg/LPSO two-phase alloy through a comparative experimental-numerical study

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Journal of Magnesium and Alloys 2021年第1期9卷 130-143页

作者： Fabien Briffod Takayuki Shiraiwa manabu Enoki Department of Materials Engineering The University of Tokyo7-3-1 HongoBunkyo-kuTokyo 113-8656Japan

The fatigue behavior of four extruded Mg-Y-Zn alloys containing different volume fractions of long-period stacking ordered(LPSO)grains was investigated through a comparative study combining experiments and crystal plasticity finite element *** controlled low-cycle fatigue experiments were conducted at different strain amplitudes and revealed a limited cyclic hardening in Mg_(89)Zn_(4)Y_(7)alloy or softening in Mg_(99.2)Zn_(0.2)Y_(0.6)and Mg_(97)Zn_(1)Y_(2)alloys.A decrease in the fatigue life against the plastic strain with the increase in LPSO phase volume fraction was observed and was related the limited ductility of extruded LPSO ***-strain hysteresis curves were used to calibrate and validate a crystal plasticity model taking into account twinning and *** interaction of the different phases on the distribution of local micro-mechanical fields at the grain scale was then analyzed on synthetic microstructures under strain-controlled *** twinning activity was predicted in coarse unrecrystallized grains and tended to disappear with the increase in the LPSO phase volume ***-like facets observed in LPSO grains were related to high tensile stress,especially at the Mg/LPSO interface,due to the limited number of deformation mechanisms in LPSO crystal to accommodate out-of-basal plane *** increase of the fatigue limit with the increase in LPSO phase volume fraction was finally associated with the decreasing presence of coarse unrecrystallizedα-Mg grains due to a higher dynamic recrystallization activity during the extrusion process.

关键词： Magnesium alloy Fatigue Long-period stacking ordered phase Crystal plasticity Finite element method

Effect of End Plates on the Performence of a Wells Turbine for Wave Energy Conversion

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Journal of Thermal Science 2006年第4期15卷 319-323页

作者： manabu Takao Toshiaki Setoguchi YoichiKinoue KenjiKaneko Department of Mechanical Engineering Matsue National College of Technology 14-4 Nishiikuma-choMatsue-shiShimane 690-8518Japan Institute of Ocean Energy Saga University1 Honjo-machiSaga-shiSaga 840-8502Japan Department of Mechanical Engineering Saga University1 Honjo-machiSaga-shiSaga 840-8502Japan

In order to improve the performance of the Wells turbine for wave energy conversion, the effect of end plates on the turbine characteristics has been investigated experimentally by model testing under steady flow conditions. The end plate attached to the tip of the original rotor blade is slightly larger than the original blade profile. The characteristics of the Wells turbine with end plates have been compared with those of the original Wells turbine, i.e., the turbine without end plate. As a result, it has been concluded that the characteristics of the Wells turbine with end plates are superior to those of the original Wells turbine and the characteristics are dependent on the size and position of end plate. Furthermore, the effect of annular plate on the turbine performance, which encircles the turbine and is attached to the tip, was investigated as an additional experiment. However, its device was not effective in improving the turbine characteristics.

关键词： fluid machinery natural energy Wells turbine end plate wave energy conversion ocean energy.

Effects of multimodal microstructure on fracture toughness and its anisotropy of LPSO-type extruded Mg-1Zn-2Y alloys

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Journal of Magnesium and Alloys 2024年第7期12卷 2952-2966页

作者： Soya Nishimoto Taiga yasuda Koji Hagihara Michiaki Yamasaki Department of Materials Science Graduate School of Science and TechnologyKumamoto University2-39-1 KurokamiChuo-kuKumamoto 860-8555Japan Magnesium Research Center Kumamoto University2-39-1 KurokamiChuo-kuKumamoto 860-8555Japan Department of Physical Science and Engineering Nagoya Institute of technologyGokiso-choShowa-kuNagoya 466-8555Japan

The fracture toughness of extruded Mg-1Zn-2Y(at.%)alloys,featuring a multimodal microstructure containing fine dynamically recrystallized(DRXed)grains with random crystallographic orientation and coarse-worked grains with a strong fiber texture,was *** DRXed grains comprised randomly oriented equiaxedα-Mg *** contrast,the worked grains includedα-Mg and long-period stacking ordered(LPSO)phases that extended in the extrusion direction(ED).Both types displayed a strong texture,aligning the(10.10)direction parallel to the *** volume fractions of the DRXed and worked grains were controlled by adjusting the extrusion *** the longitudinal-transverse(L-T)orientation,where the loading direction was aligned parallel to the ED,there was a tendency for the conditional fracture toughness,KQ,tended to increase as the volume fraction of the worked grains ***,the KQ values in the T-L orientation,where the loading direction was perpendicular to the ED,decreased with an increase in the volume fraction of the worked *** suggests strong anisotropy in the fracture toughness of the specimen with a high volume fraction of the worked grains,relative to the test *** worked grains,which included the LPSO phase and were elongated perpendicular to the initial crack plane,suppressed the straight crack extension,causing crack deflection,and generating secondary ***,these worked grains significantly contributed to the fracture toughness of the extruded Mg-1Zn-2Y alloys in the L-T orientation.

关键词： Magnesium alloy Magnesium-zinc-yttrium Long-period stacking ordered phase Multimodal microstructure Fracture toughness

Spatiotemporal changes in antlerless proportion of culled Sika deer in relation to deer density

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Journal of Forestry Research 2022年第3期33卷 1095-1101页

作者： Kei K.Suzuki Teruki Oka Masatoshi yasuda Kyushu Research Center Forestry and Forest Products Research InstituteKumamoto860-0862Japan Shikoku Research Center Forestry and Forest Products Research InstituteKochi780-8077Japan

Population management of herbivores is widely applied to decrease damage to forests in the northern hemisphere. Culling more antlerless deer, including females and fawns, is an effective means of reducing the population and helps to improve management efficiency. To increase the efficiency of antlerless-biased culling, we assessed the spatiotemporal distribution of the antlerless ratio in culled sika deer (Cervus nippon) in relation to population density. We hypothesized that the antlerless ratio is higher at the center of the distribution than at the margins of the deer’s range, because dispersal processes differ according to sex and age: Young male deer first disperse into an unoccupied area, and then males may become established in the new area for approximately 10–15 years before the number of females increases. A statistical model revealed spatiotemporal changes in the antlerless ratio of culled sika deer. The change in the ratio basically fit the density distribution of the deer, which was estimated independently on the basis of fecal pellet count surveys. The antlerless ratio estimated from the model increased asymptotically as deer density rose. The results support our hypothesis and suggest that antlerless sika deer will be more easily culled at the center rather than at the margins of the distribution range. These findings should help to increase the efficiency of managing the deer via antlerless-biased culling.

关键词： Antlerless Culling Density Distribution Large herbivore Wildlife management

Single-site surface-enhanced Raman scattering beyond spectroscopy

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Frontiers of physics 2016年第2期11卷 19-30页

作者： Mai Takas Satoshi yasuda Kei Murakoshi Department of Chemistry Faculty of Science Hokkaido University Sapporo Hokkaido 060-0810 Japan Graduate School of Engineering Muroran Institute of Technology Muroran 050-8585 Japan

Recent progress in the observation of surface-enhanced Raman scattering （SERS） is reviewed to examine the possibility of finding a novel route for the effective photoexcitation of materials. The importance of well-controlled SERS experiments on a single molecule at a single site is discussed based on the difference in the information obtained from ensemble SERS measurements using mul- tiple active sites with an uncontrolled number of molecules. A single-molecule SERS observation performed at a mechanically controllable breaking junction with a simultaneous conductivity mea- surement provides clear evidence of the drastic changes both in the intensity and in the Raman mode selectivity of the electromagnetic field generated by localized surface plasmon resonance. Careful con- trol of the field at a few-nanometer-wide gap of a metal nanodimer results in the modification of the selection rule of electronic excitation of an isolated single-walled carbon nanotube. The examples shown in this review suggest that a single-site SERS observation could be used as a novel tool to find, develop, and implement applications of plasmon-induced photoexcitation of materials.

关键词： surface-enhanced Raman scattering localized surface plasmon resonance metalnanostructure single-molecule observation single-walled carbon nanotube selection rule ofelectronic excitation

Steroid-sparing strategies in the management of ulcerative colitis:Efficacy of leukocytapheresis

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World Journal of Gastroenterology 2012年第41期18卷 5833-5838页

作者： manabu Shiraki Takayuki Yamamoto Inflammatory Bowel Disease Center Yokkaichi Social Insurance Hospital Yokkaichi Mie 510-0016 Japan

Active ulcerative colitis （UC） is frequently associated with infiltration of a large number of leukocytes into the bowel mucosa. Leukocytapheresis is a novel nonphar- macologic approach for active UC, in which leukocytes are mechanically removed from the circulatory system. Current data indicate that leukocytapheresis is effica- cious in improving response and remission rates with excellent tolerability and safety in patients with UC. Corticosteroid therapy remains a mainstay in the treat- ment of active UC, however, long-term, high doses of corticosteroids usually produce predictable and po- tentially serious side effects. If leukocytapheresis can spare patients from exposure to corticosteroids, the risk of steroid-induced adverse events should be mini- mized. This may be of great benefit to patients because severe side effects of steroids seriously impair health- related quality of life. In this article, we reviewed cur- rent evidence on whether leukocytapheresis can avoid or reduce the use of corticosteroids in the manage- ment of patients with UC. Several studies have shown that leukocytapheresis was effective for steroid-nafve patients with active UC. Furthermore, both short-term and long-term studies have demonstrated the steroid- sparing effects of leukocytapheresis therapy in patients with UC. Although the evidence level is not striking, theavailable data suggest that leukocytapheresis can avoid or reduce the use of corticosteroids in the management of UC. Large, well-designed clinical trials are necessary to more accurately evaluate the steroid-sparing effects of leukocytapheresis in the management of UC.

关键词： Corticosteroid Granulocyte and monocyteadsorptive apheresis Leukocytapheresis Steroid-naivepatients Steroid-sparing effect Ulcerative colitis

Cubic Spiral Transition Matching G^(2) Hermite End Conditions

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Numerical Mathematics(Theory,Methods and Applications) 2011年第4期4卷 525-536页

作者： Zulfiqar Habib manabu Sakai COMSATS Institute of Information Technology Department of Computer ScienceDefense RoadOff Raiwind RoadLahorePakistan Department of Mathematics&Computer Science Koorimoto 1-21-35Kagoshima 890-0065Japan

This paper explores the possibilities of very simple analysis on derivation of spiral regions for a single segment of cubic function matching positional,tangential,and curvature end *** are curves of monotone curvature with constant sign and have the potential advantage that the minimum and maximum curvature exists at their end ***,spirals are free from singularities,inflection points,and local curvature *** properties make the study of spiral segments an interesting problem both in practical and aesthetic applications,like highway or railway designing or the path planning of non-holonomic mobile *** main contribution is to simplify the procedure of existence methods while keeping it stable and providing flexile constraints for easy applications of spiral segments.

关键词： Path planning spiral cubic Bézier G2 Hermite Computer-Aided Design(CAD) computational geometry

Comparing salinity tolerance in embryonic and larval development of two species of water strider, Aquarius paludum and Gerris latiabdominis （Hemiptera： Gerridae）

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Insect Science 2013年第4期20卷 524-530页

作者： manabu Kishi Tetsuo Harada Kenji Fujisaki Laboratory of Insect Ecology Graduate School of Agriculture Kyoto University Laboratory of Environmental Physiology Faculty ofEducation Kochi University Kochi Japan

Water strider Aquarius paludum （Fabricius） is a cosmopolitan species colonizes mainly freshwater but occasionally brackish habitats throughout the Palearctic and Oriental regions. Water strider Gerris latiabdominis （Miyamoto） is a common species in Japan lives in temporary habitats as freshwater paddy fields. These two species often occur syntopically. We investigated differences in the developmental response to brackish water during embryonic and larval stages between the two species. Eggs were exposed to 0-1.8% NaC1 solutions within 24 h of oviposition. Larvae of G. latiabdominis were exposed to salinities of 0, 0.5%, and 0.9% from the first instar until adult emergence. Limits of NaC1 concentration for hatching were 1.3% and 1.0% for A. paludum and G. latiabdominis, respectively. The hatching rate of G. latiabdominis was lower than that ofA. paludum at salinities 〉0.9%. The period of embryonic development of G. latiabdominis was more prolonged than that ofA. paludum at a given salinity. Although the salinity tolerance of G. latiabdominis was lower than that ofA. paludum, our results suggest G. latiabdominis has the physiological capacity to expand into brackish waters. High and low salinity tolerances of A. paludum and G. latiabdominis, respectively, reflect the relatively wide range of habitat salinities utilized by A. paludum and the relatively restricted habitats preferred by G. latiabdominis. The high salinity tolerance ofA. paludum could be an important factor contributing to their cosmopolitan distribution because high tolerance to salinity means the possibility of them to be dispersed via ocean or sea to other continents and islands.

关键词： embryo larva salinity tolerance water strider