检索结果-南通市图书馆

A RAISED PANEL METHOD BASED ON NURBS FOR FREE-SURFACE POTENTIAL FLOWS WITH FORWARD SPEED

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2003年第2期15卷 112-120页

作者： Gao Gao, Ma Lingschool of Transportion, wuhan university of Technology, wuhan 430063, china school of Transportion Wuhan University of Technology Wuhan 430063 China

A raised panel method based on NURBS (Non-Uniform Rational B-Splines) forfree-surface flows with forward speed is presented. In this generalized panel method, NURBS areemployed to represent the body geometry, disturbed free surface, and to express the unknown sourcestrength distribution, on the body surface and above the free surface. Compared with commonhigher-order panel methods, it has no need of adopting local coordinates. NURBS make the geometryrepresentation of the body shape and the wave pattern more precise. Raised panels above the freesurface produce less numerical dispersion error, need less CPU consumption and are helpful andcombined with collocation-point shifting up-stream, can satisfy the radiation condition *** using continuous and discrete Fourier analysis, numerical errors of this method are discussedand a general expression for the errors of numerical damping and dispersion, including the effectsof the vertical distance of singularities to the free surface, the order of singularity distributionrepresented by B-splines in panels, and collocation-point shifting is derived.

关键词： NURBS free-surface flow raised panel method error analysis B-spline

A Software Pattern of the Genetic Algorithm ——a Study on Reusable Object Model of Genetic Algorithm

在线全文

学校读者我要写书评

暂无评论

wuhan university Journal of Natural Sciences 2001年第Z1期6卷 209-217页

作者： Zhuo Shi, Liu Chao, He Ke\|qing school of Computer,wuhan university, wuhan 430072, china school of Computer Wuhan University Wuhan 430072 China

The Genetic Algorithm (GA) has been a pop research field, but there is little concern on GA in view of Software Engineering and this result in a series of problems. In this paper, we extract a GA's software pattern, draw a model diagram of the reusable objects, analyze the advantages and disadvantages of the pattern, and give a sample code at the end. We are then able to improve the reusability and expansibility of GA. The results make it easier to program a new GA code by using some existing successful operators, thereby reducing the difficulties and workload of programming a GA's code, and facilitate the GA application.

关键词： genetic algorithm software pattern UML

Electron microscopy study of the sakhaite from endogenous borate deposit in Hunan, china

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2004年第3期47卷 232-238页

作者： LIU Xiangwen1,2, YANG Guangming2, ZOU Huamin3, QU Jing1 & ZHAO Wenxia4 1. Graduate school, china university of Geosciences, wuhan 430074, china 2. Test Center, china university of Geosciences, wuhan 430074, china 3. Physics and Technology College, wuhan university, wuhan 430072, china 4. Test Center, Zhongshan university, Guangzhou 510275, china china Univ Geosci Grad Sch Wuhan 430074 Peoples R China china Univ Geosci Test Ctr Wuhan 430074 Peoples R China wuhan Univ Phys & Technol Coll Wuhan 430072 Peoples R China Zhongshan Univ Test Ctr Guangzhou 510275 Peoples R China

Sakhaite specimens from an endogenous borate deposit in Hunan Province, china have been studied in detail by means of transmission electron microscopy (TEM). The selected area electron diffraction (SAED) patterns obtained with different crystal zone axes show that the crystal system is cubic, with a = 1.463 nm. The convergent beam electron diffraction (CBED) patterns indicate that the point group and space group of sakhaite is m3m and Fd3m, respec-tively. The space group of synthetic sakhaite determined by Chichagov (1974) is F4132. The possible reasons why the space groups of the natural and the synthetic sakhaites are different are discussed.

关键词： sakhaite, space group, convergent beam electron diffraction (CBED).

Integrating Audio-Visual Features and Text Information for Story Segmentation of News Video

在线全文

学校读者我要写书评

暂无评论

wuhan university Journal of Natural Sciences 2003年第4A期8卷 1070-1074页

作者： Liu Hua-yong, Zhou Dong-ru  school of Computer,wuhan university,wuhan 430072, Hubei, china wuhan university School of Computer Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

Video data are composed of multimodal information streams including visual, auditory and textual streams, so an approach of story segmentation for news video using multimodal analysis is described in this paper. The proposed approach detects the topic-caption frames, and integrates them with silence clips detection results, as well as shot segmentation results to locate the news story boundaries. The integration of audio-visual features and text information overcomes the weakness of the approach using only image analysis techniques. On test data with 135 400 frames, when the boundaries between news stories are detected, the accuracy rate 85.8% and the recall rate 97.5% are obtained. The experimental results show the approach is valid and robust.

关键词： news video story segmentation audio-visual features analysis text detection

Synthesis of Cr-Al_2O_3 Cermet Selective Surfaces Coated by SnO_2 Thin Film by Air Plasma Spraying

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2012年第S1期41卷 272-275页

作者： Zhu Zhenqi,Cheng Xudong,Li Guanglei school of Materials Science and Technology,wuhan university of Technology,wuhan 430070,china wuhan Univ Technol State Key Lab Adv Technol Mat Synth & Proc Sch Mat Sci & Technol Wuhan 430070 Peoples R China

High efficient Cr-Al2O3 cermet selective surfaces coated by sol-gel SnO2 thin film for high-temperature application were synthesized by air plasma spraying(APS),followed further heat and polish *** phase composition and micro morphology of coating samples were characterized by X-ray diffractions(XRD),scanning electron microscope(SEM)and roughmeter *** solar absorptance(α)and thermal emittance(ε)were determined by optical spectrum *** results show that Cr-Al2O3 cermet coating has a high absorptivity nearly *** unfortunately,the emissivity of these coatings is nearly 0.50 because of the big thickness and coarse surface prepared by APS ***,once coated SnO2 thin film,the composite coatings exhibit excellent selective absorbing property of α=0.89 and ε=***,SnO2 thin film plays a significant role in decreasing the emissivity of coatings as antireflection *** furthermore,the optical performance shows that more metal content and smooth surface are favorable for the selective absorbing ***,the coatings have excellent bond strength with stainless steel substrate and thermal shock resistance at high temperature.

关键词： selective surfaces SnO2 thin film air plasma spraying

COLLECTIVELY COMPACT COMPOSITION OPERATOR SEQUENCES BETWEEN BERGMAN AND HARDY SPACES

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2004年第2期24卷 206-212页

作者：王茂发刘培德 schoolofMathematicsandStatistics WuhanUniversityWuhan430072China

This paper studies the collective compactness of composition operator sequences between the Bergman and Hardy spaces. Some sufficient and necessary conditions involving the generalized Nevanlinna counting functions fo... 详细信息

关键词： Bergman space Hardy space composition operator collectively compact operator sequence

Exsolution of ilmenite and Cr-Ti magnetite from olivine of garnet-wehrlite

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第9期48卷 1368-1376页

作者： LIU Xiangwen1,2, JIN Zhenmin1,3, QU Jing2 & WANG Lu2 1. State Key Laboratory of Geological Processes and Mineral Resources, china university of Geosciences, wuhan 430074, china 2. Graduate school of china university of Geosciences, wuhan 430074, china 3. Faculty of Earth Sciences, china university of Geosciences, wuhan 430074, china 1. State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences 430074 Wuhan China 2. Graduate school of china university of Geosciences 430074 Wuhan China 3. Faculty of Earth Sciences China University of Geosciences 430074 Wuhan China

Exsolution of rod-like ilmenite (Ilm) and Cr-Ti magnetite (Mt) have been found in olivine of garnet-wehrlite from the core of Chinese Continental Sciences Drilling (CCSD). Their composition, morphology, crystal structure and their topotaxies with host olivine have been studied in detail by the transmission electron microscopy (TEM) and electron probe microanaly- sis (EPMA) technique. It shows that rod-like Ilm exsolution reported in this paper has similar characteristic with that of Alpe Arami olivine, while Cr-Ti magnetite exsolution mentioned in this paper has large discrepancy with chromite exsolution in Alpe Arami olivine. These observations suggest that both of the exsolutions found in this paper should be solid solution phases in β-olivine at their first period, then experiencing decomposition of solid solution and therefore forming Ilm and Cr-Ti magnetite exsolution with the pressure decreasing. So, this garnet-wehrlite perhaps had been ever located in mantle transition zone with a minimum depth of 300 km.

关键词： garnet-wehrlite, ilmenite, magnetite, exsolution, CCSD.

Comparison of Stress Distribution of Platform-switched and Non-platform Switched Abutment for Implant Supported Single Crown

在线全文

学校读者我要写书评

暂无评论

Journal of wuhan university of Technology(Materials Science) 2011年第2期26卷 247-250页

作者：夏海斌李智勇郭进新 school and Hospital of Stomatology Wuhan University Key Laboratory for Oral Biomedical Engineering of Ministry of Education School and Hospital of StomatologyWuhan University

The influence of platform-switched abutment on stress distribution within the surrounding bone,fixture,abutment,and screw under various loading conditions were *** 3-D finite element models representative of an implant-supported metal crown for the mandibular first molar and its surrounding bone were *** A simulated the implant with non-platform-switched abutment and model B was for platform-switched abutment.A load of 100 N was applied vertically and obliquely at the center fossa,the tip of the buccal cusp and the distal fossa,*** results show that the distribution of Von Mises stress in the two models is *** platform-switched abutment is used,the maximum Von Mises stress within the surrounding bone is lower;however,this value is higher within the fixture and screw.

关键词： dental implant platform-switched abutment stress finite element analysis

Research of Environment-friendly Low Emissivity Glass

在线全文

学校读者我要写书评

暂无评论

Journal of wuhan university of Technology(Materials Science) 2007年第2期22卷 385-387页

作者：余峰 school of Civil Engineering and Architecture Wuhan University of Technology

The environment-friendly glasses which integrate function and structure were introduced, among these glasses can save energy very efficiently due to its low infrared emissivity. The fundamental principle of the low emissivity glass and the research progress of this kind glass were analyzed. Meanwhile, high performance and low applied development trend of emissivity glass were reviewed.

关键词： low emissivity glass(Low-E) environment-friendly research progress development trend