检索结果-南通市图书馆

系统仿真学报 2023年第8期35卷 1635-1650页

作者： tanaka Satoshi College of Information Science and Engineering Ritsumeikan UniversityShiga 525-8577Japan

Three-dimensional(3D) scanning technology has undergone remarkable developments in recent *** acquired by 3D scanning have the form of 3D point *** 3D scanned point clouds have data sizes that can be considered big *** also contain measurement noise inherent in measurement *** properties of 3D scanned point clouds make many traditional CG/visualization techniques *** paper reviewed our recent achievements in developing varieties of high-quality visualizations suitable for the visual analysis of 3D scanned point *** demonstrated the effectiveness of the method by applying the visualizations to various cultural heritage *** main visualization targets used in this paper are the floats in the Gion Festival in Kyoto(the float parade is on the UNESCO Intangible Cultural Heritage List) and Borobudur Temple in Indonesia(a UNESCO World Heritage Site).

关键词： 3D scanning point cloud transparent visualization noise transparentization cultural heritage object

同方期刊数据库

Photosynthetic recovery of desiccated intertidal seaweeds after rehydration

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2005年第8期15卷 689-693页

作者： tanaka Jiro Japan Konan-4 Minato-ku Tokyo 108-8477 Tokyo University of Marine Science and Technology

Intertidal seaweeds experience periodical desiccation and rehydration to different extents due to the tidal cycles and their vertical distributions. Their photosynthetic recovery process during the rehydration may show different patterns among the seaweeds from different zonations or depths at intertidal zone. In this study 12 species of seaweeds collected from the upper, middle, lower and sublittoral zones were examined. The relationship of the photosynthetic recovery to vertical distribution was assessed by comparing their patterns of photosynthetic and respiratory performances after rehydration following desiccation. Both the photosynthesis and dark respiration declined during emersion, showing certain degrees of recovery after re-immersion into seawater for most species, but the extents were markedly different from one species to the other. The species from upper intertidal zone after being rehydrated for 1 hour, following 2 hours of desiccation, achieved 100% recovery of their initial physiological activity, while most of the lower or sublittoral species did not achieve full recovery. It is the ability to withstand desiccation stress (fast recovery during rehydration), but not that to avoid desiccation (water retaining ability) that determines the distribution of intertidal seaweeds. Such physiological behavior during rehydration after desiccation reflects the adaptive strategy of intertidal seaweeds against desiccation and their capability of primary production in the process of rehydration.

关键词： seaweeds desiccation emersion intertidal photosynthetic recovery.

Study of Spiral Flow Generated through an Annular Slit

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2005年第2期14卷 97-102页

作者： Tae Hun KIM Shigeru MATSUO toshiaki SETOGUCHI Heuy-Dong KIM Graduate school of Science and Technology Saga University 1Honjo-machiSaga shiSaga 840-8502JapanDepartment of Mechanical Engineering Saga University1Honjo-machiSaga shiSaga 840-8502JapanDepartment of Mechanical Engineering Saga University1Honjo-machiSaga shiSaga 840-8502JapanSchool of Mechanical Engineering College of Natural ScienceAndong National University388Song Cheon DongAndongKyung PookKorea

The effect of pressurized air inlets in the reservoir upstream of the annular slit on characteristics of the axial and tangential velocity components is investigated numerically, and the mechanism of occurrence of spiral nozzle flow is clarified. In simulations, Unified Platform for Aerospace Computational Simulation (UPACS) is used. The governing equations under consideration are the unsteady compressible Navier - Stokes. A second-order finite volume scheme with MUSCL (Roe scheme) is used to discretize the spatial derivatives, and a second order-central difference scheme for the viscous terms, and a MFGS (Matrix Free Gauss Seidel) is employed for time integration. Spalart-Allmaras model was used as a turbulence model. The results obtained are compared with velocity distributions in the experiment measured by the two-component fiber optic laser Doppler velocimeter system. The existence of discrete pressurized air inlets that leads to the occurrence of asymmetrical characteristics is a very important factor for the formation of spiral flow.

关键词： spiral nozzle flow Coanda effect convergent nozzle annular slit simulation.

Unsteady Operation of New Type Turbofan Engine with Aerodynamic Torque Converter Reducing Front Fan Speed

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2005年第3期14卷 206-210页

作者： toshiaki KANEMOTO Seita SEKI Kazunori IDENO Ahmed Mohamed GALAL Kyushu Institute of Technology Sensui 1-1 Tobata Kitakyushu 804-8550 Japan ProfessorKyushu Institute of Technology Sensui 1-1 Tobata Kitakyushu 804-8550 JapanKyushu Institute of Technology Sensui 1-1 Tobata Kitakyushu 804-8550 JapanKyushu Institute of Technology Sensui 1-1 Tobata Kitakyushu 804-8550 Japan

It is desired to increase the rotational speed of the core engine of the turbofan so as to get the best efficiency for the next leap of engine technology. The conventional mechanism in which the front fan is directly connected to the output shaft of a core engine, have a limit of increasing the spool speed, because the fan diameter is very large. The authors have proposed a new driving system in which the front fan is driven through the aerodynamic torque converter. The front fan can work at the best performance at slower speed while the core engine runs more efficiently at higher speed. Continuously, this paper discusses the response of the front fan in the unsteady operation of the core engine, accompanying with the internal flow. The system has the acceptable responsibility in the unsteady operation which is very important for the aircrafts.

关键词： turbofan engine front fan torque converter rotational speed

Petrology,geochemistry,and zircon U-Pb geochronology of the Zambezi Belt in Zimbabwe:Implications for terrane assembly in southern Africa

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2019年第6期10卷 2021-2044页

作者： Yusuke Kuribara toshiaki Tsunogae Yusuke Takamura Yukiyasu Tsutsumi Graduate School of Life and Environmental Sciences University of TsukubaIbaraki 305-8572Japan Department of Geology University of JohannesburgAuckland Park 2006South Africa Department of Geology and Paleontology National Museum of Nature and ScienceIbaraki 305-0005Japan

The Zambezi Belt in southern Africa has been regarded as a part of the 570-530 Ma Kuunga Orogen formed by a series of collision of Archean cratons and Proterozoic orogenic ***,we report new petrological,geochemical,and zircon U-Pb geochronological data of various metamorphic rocks(felsic to mafic orthogneiss,pelitic schist,and felsic paragneiss)from the Zambezi Belt in northeastern Zimbabwe,and evaluate the timing and P-T conditions of the collisional event as well as protolith *** data of felsic orthogneiss indicate within-plate granite signature,whereas those of mafic orthogneiss suggest MORB,ocean-island,or within-plate *** P-Testimates for orthogneisses indicate significant P-T variation within the study area(700-780 C/6.7-7.2 kbar to 800-875 C/10-11 kbar)suggesting that the Zambezi Belt might correspond to a suture zone with several discrete crustal *** cores from felsic orthogneisses yielded two magmatic ages:2655±21 Ma and 813士5 Ma,which suggests Neoarchean and Early Neoproterozoic crustal growth related to within-plate *** zircons from metasediments display various ages from Neoarchean to Neoproterozoic(ca.2700-750 Ma).The Neoarchean(ca.2700-2630 Ma)and Paleoproterozoic(ca.2200-1700 Ma)zircons could have been derived from the adjacent Kalahari Craton and the Magondi Belt in Zimbabwe,*** Choma-Kalomo Block and the Lufilian Belt in Zambia might be proximal sources of the Meso-to Neoproterozoic(ca.1500-950 Ma)and early Neoproterozoic(ca.900-750 Ma)detrital zircons,*** detrital zircons from adjacent terranes possibly deposited during late Neoproterozoic(744-670 Ma),and subsequently underwent highgrade metamorphism at 557-555 Ma possibly related to the collision of the Congo and Kalahari Cratons during the latest Neoproterozoic to *** contrast,670-627 Ma metamorphic ages obtained from metasediments are slightly older than previous reports,but consistent with^68

关键词： Geothermobarometry Detrital zircon Neoproterozoic Congo Craton Kalahari Craton Gondwana

DETERMINATION OF SOME PARAMETERS OF CRACK BASED ON FRASTA SIMULATION

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2005年第5期18卷 594-602页

作者： K. tanaka Department of Mechanical Systems Engineering Toyama Prefectural University Toyama 939-0398 Japan

A new method, using the fracture-surface topography analysis （FRASTA）, of determining the parameters of rotation factor and CTOA is provided. The fracture surfaces are scanned by laser microscope and the height data is recorded to analyze. By comparing the crack extension, plastic rotation factor and COA obtained by the method of double clip gauge and by this new method respectively, the validity of it is verified. It is then used to determine the CTOA. .The critical CTOA is well determined in this paper. Also by the new method, the variation of crack opening deformation （COA and CTOA） through specimen thickness can be obtained which can＇t be obtained by the usual methods. It also can provide much information of crack extension such as direction and ratio.

关键词： FRASTA COA CTOA rotation factor

Effect of Rotational Speed on the Stability of Two Rotating Side-by-side Circular Cylinders at Low Reynolds Number

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2018年第2期27卷 125-134页

作者： DOU Huashu ZHANG Shuo YANG Hui SETOGUCHI toshiaki KINOUE Yoichi Key Laboratory of Fluid Transmission Technology of Zhejiang Province Zhejiang Sci-Tech University Department of Mechanical Engineering Saga University

Flow around two rotating side-by-side circular cylinders of equal diameter D is numerically studied at the Rey- nolds number 40〈 Re 〈200 and various rotation rate 8i. The incoming flow is assumed to be two-dimensional laminar flow. The governing equations are the incompressible Navier-Stokes equations and solved by the finite volume method （FVM）. The ratio of the center-to-center spacing to the cylinder diameter is T/D=2. The objective of the present work is to investigate the effect of rotational speed and Reynolds number on the stability of the flow. The simulation results are compared with the experimental data and a good agreement is achieved. The stability of the flow is analyzed by using the energy gradient theory, which produces the energy gradient function K to identify the region where the flow is the most prone to be destabilized and the degree of the destabilization. Numerical results reveal that K is the most significant at the separated shear layers of the cylinder pair. With Re in- creases, the length of the wake is shorter and the vortex shedding generally exhibits a symmetrical distribution for θi〈θcrit. It is also shown that the unsteady vortex shedding can be suppressed by rotating the cylinders in the counter-rotating mode.

关键词： numerical simulation rotating circular cylinders stability vortex interactions energy gradient theory

Proton magnetic resonance spectroscopy of normal human brain and glioma: a quantitive in vivo study

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2005年第15期118卷 1251-1257页

作者： TONG Zhi-yong YAMAKI toshiaki WANG Yun-jie Department of Neurosurgery First Affiliated Hospital China Medical University Shenyang 110001 China Department of Neurosurgery School of Medicine Sapporo Medical University Sapporo 060-8543 Japan

Background In vivo proton magnetic resonance spectroscopy （MRS） provides a noninvasive method of examining a wide variety of cerebral metabolites in both healthy subjects and patients with various brain diseases. Absolute metabolite concentrations have been determined using external and internal standards with known concentrations. When an external standard is placed beside the head, variations in signal amplitudes due to B1 field inhomogeneity and static field inhomogeneity may occur. Hence an internal standard is preferable. The purpose of this study was to quantitatively analyze the metabolite concentrations in normal adult brains and gliomas by in vivo proton MRS using the fully relaxed water signal as an internal standard. Methods Between January 1998 and October 2001, 28 healthy volunteers and 16 patients with gliomas were examined by in vivo proton MRS. Single-voxel spectra were acquired using the point-resolved spectroscopic pulse sequence with a 1.5 T scanner （TR/TE/Ave = 3000 ms/30 ms/64）. Results The calculated concentrations of N-acetyl-asparatate （NAA）, creatine （Cre）, choline （Cho）, and water （H2O） in the normal hemispheric white matter were （23.59 ＋- 2.62） mmol/L, （ 13.06 ＋- 1.8） mmol/L, （4.28 ＋-0. 8） mmol/L, and （47 280.96 ＋-5414. 85） mmol/L, respectively. The metabolite concentrations were not necessarily uniform in different parts of the brain. The concentrations of NAA and Cre decreased in all gliomas （P 〈 0. 001 ）. The ratios of NAA/Cho and NAA/H2O showed a significant difference between the normal brain and gliomas, and also between the high and low grades （P 〈 0. 001 ）. Conclusions Quantitative analysis of in vivo proton MR spectra using the fully relaxed water signal as an internal standard is useful. The concentrations of NAA and the ratios of NAA/H2O and NAA/Cho conduce to discriminating between the glioma and normal brain, and also between the low-grade glioma and high-grade glioma.

关键词： human brain magnetic resonance spectroscopy· glioma

DEVELOPMENT OF FRASTA SIMULATION SOFTWARE

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2006年第3期19卷 165-170页

作者： K. tanaka Department of Mechanical Systems Engineering Toyama Prefectural University Toyama 939-0398 Japan

Fracture-surface topography analysis （FRASTA） was successfully used to simulate the process of crack and calculate parameters of crack such as the crack opening angle （COA） and crack-tip opening angle （CTOA）. But because the amount of calculation is large, errors are often made during the course of calculation. FRASTA simulation software, namely fracture surface analyst （FSA ） is developed and a series of center-cracked tension （CCT） and double edge notched （DEN） specimens of different materials with different sizes are tested, their fracture surfaces are scanned by non-contact 319 scanning system and the elevation data of the fracture surfaces is recorded. FSA used the recorded elevation data of fracture surfaces to simulate the process of crack based on the principle of FRASTA. Results show that FSA can accurately simulate the process and calculate the parameters of crack.

关键词： FRASTA (fracture-surface topography analysis) COA (crack opening angle) CTOA (crack-tip opening angle) CCT (center-cracked tension) DEN (double edge notched)

Effects of Vortex Generator on Cylindrical Protrusion Aerodynamics

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2016年第1期25卷 7-12页

作者： Vignesh Ram P.S. toshiaki Setoguchi Heuy Dong Kim School of Mechanical Engineering Andong National University Department of Mechanical Engineering Saga University

Experimental and numerical studies were carried out to evaluate the effect of vortex generator on a small cylindrical protrusion at Mach number 2.0. The experiments were performed using the supersonic blow down wind tunnel on different heights of cylindrical protrusion with vortex generator placed ahead of them. The upstream and downstream flow around the cylindrical protrusion is influenced by vortex generator as is observed using both visualization and pressure measurement techniques. Numerical studies using three dimensional steady implicit formulations with standard k-ω turbulence model was performed. Results obtained through the present computation are compared with the experimental results at Mach 2.0. Good agreements between computation and experimental results have been achieved. The results indicate that the aerodynamic drag acting on cylindrical protrusion can be reduced by adopting vortex generator.

关键词： Cylindrical protrusion Vortex generator Shock wave boundary layer interaction Drag control