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Bounded derived categories of very simple manifolds

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Science China Mathematics 2011年第8期54卷 1741-1750页

作者： OGUISO keiji Department of Mathematics Graduate School of ScienceOsaka University Korea Institute for Advanced Study

A non-representable cohomological functor of finite type of the bounded derived category of coherent sheaves of a compact complex manifold of dimension greater than one with no proper closed subvariety is given explic... 详细信息

关键词： derived category cohomological functor very simple manifold

A simple remark on a flat projective morphism with a Calabi-Yau fiber

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Science China Mathematics 2011年第8期54卷 1751-1756页

作者： OGUISO keiji Department of Mathematics Graduate School of ScienceOsaka University Korea Institute for Advanced Study

If a K3 surface is a fiber of a flat projective morphisms over a connected noetherian scheme over the complex number field,then any smooth connected fiber is also a K3 *** this,Professor Nam-Hoon Lee asked if the same is true for higher dimensional Calabi-Yau *** shall give an explicit negative answer to his question in each dimension greater than or equal to three as well as a proof of his initial observation.

关键词： flat projective morphism Hilbert scheme Calabi-Yau manifold

Krein Parameters of Fiber-Commutative Coherent Configurations

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Algebra Colloquium 2020年第1期27卷 1-10页

作者： keiji Ito Akihiro Munemasa Research Center for Pure and Applied Mathematics Graduate School of Information SciencesTohoku UniversitySendaiJapan

For fiber-commutative coherent configurations,we show that Krein parameters can be defined essentially *** a consequence,the general Krein condition reduces to positive semidefiniteness of finitely many matrices determined by the parameters of a coherent *** mention its implications in the coherent configuration defined by a generalized *** also simplify the absolute bound using the matrices of Krein parameters.

关键词： coherent configuration association scheme Krein parameter Krein condition generalized quadrangle absolute bound

STUDY ON THE CHARACTERISTICS OF LONG TERM DISCHARGE OF A CATCHMENT

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Journal of Hydrodynamics 2000年第2期12卷 31-41页

作者： Hong, Lin Takase, keiji Sato, Koichi Wuhan Univ of Hydraulic and Electric Engineering Wuhan China

The characteristics of the catchment discharge vary with land use. The characteristics of the long-term discharge of a terraced paddy field catchment were studied. Two kind of tank models for land use were proposed and used to simulate the discharge of the catchment: one is a forest type model used as the upper part of the catchment; the other is a paddy field type model used as the lower part of the catchment. The results of the model simulation were analyzed and compared with that of a forest catchment.

关键词： Discharge (fluid mechanics) Land use Models Tanks (containers)

Adult Congenital Lumbar Kyphosis Requiring Anteroposterior Correction and Fusion: A Case Report with 32-Year Follow-Up

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Open Journal of Orthopedics 2023年第9期13卷 397-404页

作者： Akihito wada Kazumasa Nakamura keiji Hasegawa Katsunori Fukutake Hiroshi Takahashi Department of Orthopedic Surgery Toho University School of Medicine Tokyo Japan

Congenital pure kyphosis due to failure of vertebral body segmentation is a relatively rare entity, and surgical intervention is infrequent compared to that for failure of vertebral body formation [1] [2]. There are very few reports of long-term follow-up of surgical treatment in patients with congenital pure kyphosis, and all the reported cases were diagnosed as failure of formation and had an age at the time of surgery of less than 18 years. It is important for orthopedic surgeons to follow the postoperative course of rare cases over 30 years. Here, we present a surgically treated case with ultra-long term follow-up of a 50-year-old patient with congenital pure kyphosis of the lumbar spine. Imaging of the lumbar spine showed six vertebrae and an unsegmented bar at L3-4 causing a pure kyphosis of 54°. The wedge-shaped block vertebra had 4 pedicles with the neural foramen between the pedicles without concomitant disc space, with compensatory thoracic hypokyphosis and lower lumbar hyperlordosis. One-stage correction and fusion surgery using anterior opening and posterior closing osteotomy was successfully performed. Both clinical and radiographic results were excellent and have been maintained for over 30 years postoperatively. The basic principle in the surgical treatment of adult spinal deformity is to achieve and maintain a good global sagittal balance over time. This case reaffirms the importance of spinopelvic harmony.

关键词： Adult Congenital Kyphosis Anterior Posterior Spinal Fusion Failure of Vertebral Body Segmentation Long-Term Follow-Up Spinopelvic Harmony

MICROSCOPIC HETEROGENEITY IN VISCOELASTIC PROPERTIES OF MOLECULAR ASSEMBLED SYSTEMS

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Chinese Journal of Polymer Science 2013年第1期31卷 1-1,2-11页

作者： Atsuomi Shundo David P. Penaloza keiji Tanaka Department of Applied Chemistry Kyushu University International Institute for Carbon-Neutral Energy Research (WPI-I2CNER) Kyushu University

An important step in understanding molecular assembled systems is to examine the structure and physical properties at various length scales and clarify the correlation between them. However, while the structures of these systems have been extensively studied from nanoscopic to macroscopic scales, their viscoelastic properties have been often limited to bulk rheological measurements. By using optical tweezers and particle tracking, we here show the local viscoelastic properties and their spatial distributions for the following systems： worm-like micelle solution, supramolecular hydrogel and lyotropic liquid crystal, which are formed by self-assembly of amphiphilic molecules in water. We found that all systems studied possessed a spatial heterogeneity in their viscoelastic properties and this was originated from the heterogeneous structures. It is interesting to note that there is the heterogeneity with the characteristic length scale of sub-micrometer or micrometer scale, thereby structures, although the systems are formed by molecules with nanometer size. The findings of these studies should lead to a better understanding of the dynamics of such systems.

关键词： Optical tweezers Soft materials Heterogeneity Hierarchical structure Rheological properties.

Effect of mechanical ball milling on the electrical and powder bed properties of gas-atomized Ti-48Al-2Cr-2Nb and elucidation of the smoke mechanism in the powder bed fusion electron b eam melting process

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Journal of Materials Science & Technology 2023年第6期137卷 36-55页

作者： Seungkyun Yim Kenta Aoyagi keiji Yanagihara Huakang Bian Akihiko Chiba Institute for Materials Research Tohoku University2-1-1 KatahiraSendaiMiyagi 980-8577Japan

Smoke is unexpected powder-splashing caused by electrostatic force and is one of the main problems hindering the process stability and applicability of the powder bed fusion electron beam(PBF-EB)*** this study,mechanical stimulation was suggested to suppress smoke of gas-atomized(GA)Ti-48Al-2Cr-2Nb powder using Al_(2)O_(3) and WC ball *** deformation mechanism of the GA powder depending on the ball milling media was discussed based on the developed particle morphology distribu-tion map and contact mechanics *** was revealed that the rapid decrement of flowability and packing density after WC ball milling owing to the formation of angular fragments by the brittle *** variation of surface and electrical properties by mechanical stimulation was investigated via XPS,TEM,and Impedance *** electrical resistivity of the ball-milled powders gradually decreased with increasing milling duration,despite the increased oxide film thickness,and the capacitive response disappeared in Al-60 and WC-30 via metal-insulator *** could be due to the accumulation of strain and defects on the oxide film via mechanical *** smoke mechanism of ball-milled powders was discussed based on the percolation *** the smoke experiment,smoke was more suppressed for WC-10 and WC-20 than that for Al-40 and Al-50,respectively,despite the longer charge dissipation *** could be due to the high probability of contact with conductive *** the Al-60 and WC-30 powders,smoke was further restricted by the formation of a percolation cluster with metal-like electrical *** believe that this study will contribute to a better understanding of the smoke mechanism and process optimization of the PBF-EB.

关键词： Metal-insulator transition Electron beam melting additive manufacturing Packing density Flowability Smoke mechanism Percolation theory

SURFACE RHEOLOGY OF POLYMERIC SOLIDS

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Chinese Journal of Polymer Science 2000年第3期18卷 239-248页

作者： Tisato Kajiyama keiji Tanaka Noriaki Satomi Atsushi Takahara Department of Materials Physics and Chemistry Graduate School of Engineering.Kyushu University6-10-1 HakozakiHigashi-kuFukuoka 812-8581Japan

Surface molecular motions of amorphous polymeric solids have been directly measured on the basis of scanningviscoelasticity microscopic(SVM)and lateral force microscopic(LFM)*** and LFM measurements werecarried out for films of conventional monodisperse polystyrene(PS)with sec-butyl and proton-terminated end groups atroom *** the case of the number-average molecular weight,M_(n),less than ca.4.0×10^(4),the surface was in a glass-rubber transition state even though the bulk glass transition temperature,T_(g)was far above room temperature,meaning thatthe surface molecular motion was fairly active compared with that in the *** measurements of the,monodisperse PSfilms at various scanning rates and temperatures revealed that the time-temperature superposition was applicable to thesurface mechanical relaxation behavior and also that the surface glass transition temperature,T_(g)^(σ),was depressed incomparison with the bulk one even though the magnitude of M_n was fairly high at 1.40×10~*** surface molecular motionof monodisperse PS with various chain end groups was investigated on the basis of temperature-dependent scanningviscoelasticity microscopy(TDSVM).The T_(g)^(σ)s for the PS films with M_n of 4.9×10^(6)to 1.45×10^(6)measured by TDSVMwere smaller than those for the bulk one,with corresponding M_ns,and the T_(g)^(σ)s for M_ns smaller than ca.4.0×10^(4)were lowerthan room temperature(293 K).The active thermal molecular motion at the polymeric solid surface can be interpreted interms of an excess free volume near the surface region induced by the surface localization of chain end *** the case ofM_n=ca.5.0×10^(4),the T_(g)^(σ)s for theα,ω-diamino-terminated PS(α,ω-PS(NH_2)_2)andα,ω-dicarboxy-terminated PS(α,ω-PS(COOH)_2)films were higher than that of the PS *** change of T_(g)^(σ)for the PS film with various chain end groups canbe explained in terms of the depth distribution of chain end groups at the surface region depending on

关键词： Surface rheology Chain end groups Scanning force microscope

Influence of comorbidity on outcomes of older patients with acute pancreatitis based on a national administrative database

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Hepatobiliary & Pancreatic Diseases International 2015年第4期14卷 422-428页

作者： Atsuhiko Murata Makoto Ohtani keiji Muramatsu Shinya Matsuda Department of Preventive Medicine and Community Health School of Medicine University of Occupational and Environmental Health

Little information is available on the influ- ence of comorbidities on outcomes of older patients with acute pancreatitis. This study aimed to investigate the influence of co- morbidities on outcomes of older patients with acute pancreati- tis using data from a national Iapanese administrative database. METHODS： A total of 14 322 older patients （〉70 years） with acute pancreatitis were referred to 1090 hospitals between 2010 and 2012 in Japan. We collected patients＇ data from the administrative database to compare the in-hospital mortal- ity and length of stay of older patients with acute pancreatitis. The patients were categorized into four groups according to comorbidity level using the Charlson Comorbidity Index （CCI）： none （CCI score=0; n=6890）; mild （1; n=3874）; moder- ate （2; n=2192） and severe （〉3; n=1366）. RESULTS： Multiple logistic and linear regression analyses revealed that severe comorbidity was significantly associated with higher in-hospital mortality and longer length of stay [odds ratio （OR）=2.26; 95% confidence interval （CI）： 1.75-2.92, P〈0.001 and coefficient 4.37 days; 95% CI： 2.89-5.85, P〈0.001, respectively]. In addition, cardiovascular and renal diseases were the most significant comorbidities affecting outcomes of the older patients. ORs of cardiovascular and renal diseases for mortality were 1.44 （95% CI： 1.13-1.85, P=0.003） and 2.69 （95% CI： 1.88-3.85, P〈0.001）, respectively, and coefficients forlength of stay were 3.01 days （95% CI： 1.34-4.67, P〈0.001） and 3.72 days （95% CI： 1.01-6.42, P=0.007）, respectively. CONCLUSION： This study demonstrated that comorbidities significantly influenced outcomes of older patients with acute pancreatitis and cardiovascular and renal comorbidities were significant factors affecting outcomes.

关键词： acute pancreatitis comorbidity length of stay databases