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A SEMI-ANALYTICAL AND SEMI-NUMERICAL METHOD FOR SOLVING 2.D SOUND-STRUCTURE INTERACTION PROBLEMS

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Acta Mechanica Solida Sinica 2003年第2期16卷 116-126页

作者： Xiang Yu Huang Yuying (college of civil {2. and Mechanics,Huazhong university of Science and Technology,Wuhan 430074,china) collegeofcivil{2.andMechanics HuazhongUniversityofScienceandTechnologyWuhan430074China

Based on the transfer matrix method and the virtual source simulation technique, this paper proposes a novel semi-analytical and semi-numerical method for solving 2.D sound- structure interaction problems under a harmonic *** any integration segment, as long as its length is small enough,along the circumferential curvilinear coordinate,the non- homogeneous matrix differential equation of an elastic ring of complex geometrical shape can be rewritten in terms of the homogeneous one by the method of extended homogeneous capacity proposed in this *** the exterior fluid domain,the multi-circular virtual source simulation technique is *** source density distributed on each virtual circular curve may be ex- panded as the Fourier's *** with the inverse fast Fourier transformation,a higher accuracy and efficiency method for solving 2.D exterior Helmholtz's problems is presented in this *** the aspect of solution to the coupling equations,the state vectors of elastic ring induced by the given harmonic excitation and generalized forces of coefficients of the Fourier series can be obtained respectively by using a high precision integration scheme combined with the method of extended homogeneous capacity put forward in this *** to the superposition princi- ple and compatibility conditions at the interface between the elastic ring and fluid,the algebraic equation of system can be directly constructed by using the least square *** of acoustic radiation from two typical fluid-loaded elastic rings under a harmonic concentrated force are *** results show that the method proposed is more efficient than the mixed FE-BE method in common use.

关键词： sound-structure interaction acoustic radiatlon multi-circular virtual source simulation technique transfer matrix method inverse fast Fourier transformation semi-analytical and semi-numerical method

The sloshing of stratified liquid in a two-dimensional rectangular tank

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Science china(Physics,Mechanics & Astronomy) 2011年第1期54卷 2-9页

作者： WU GuoXiong1,2.1 State Key Laboratory of Ocean engineering,college of Naval Architecture,Ocean and {2. engineering,Shanghai Jiao Tong university,Shanghai 2.02.0,china 2.Department of Mechanical engineering,university college London,Torrington Place,London WC1E 7JE,UK 1. State Key Laboratory of Ocean engineering College of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 20024 China2. Department of Mechanical Engineering University College Londo Torrington Place London WC1E 7JE UK

The sloshing of inviscid liquid of stratified density in a rectangular tank is *** the flow is no longer irrotional,the governing equation is found to be quite different from the Laplace equation used for the liquid of constant *** particular it contains terms of mixed temporal and spatial *** problem is solved based on the variable separation method and Laplace transform for the constant Vaisala-Brunt *** is found that the stratification of density may have small effects on those natural frequencies associated with the constant density,but many new natural frequencies have appeared as a result of its effect.

关键词： sloshing density stratification resonance rectangular tank

Assessment of Curing Efficiency and Effect of Moist Curing on Performance of Fly Ash Concrete

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Journal of Wuhan university of Technology(Materials Science) 2011年第2期26卷 361-366页

作者：李美利钱觉时 college of Material Science and engineering Chongqing University Henan Building Research Institute Co. Ltd.

This study was conducted to evaluate the sensitivity of compressive strength,water permeability and electrical resistance of near-surface layer concrete with different fly ash contents to curing *** is shown that the sensitivity to curing condition and fly ash content descends in the following order：difference between internal and surface resistivity （ρ） at 2. days,water permeability and compressive strength;both of longer duration of moist curing and use of fly ash in concrete enhanced the water penetration *** is indicated that the resistivity difference ρ at 2. days can reflect accurately the curing history of fly ash concrete regardless of mix proportions;and use of fly ash in concrete requires longer moist curing duration.

关键词： concrete fly ash compressive strength water permeability resistivity

基于跨越连接与融合注意力机制的红外弱小目标检测方法

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光子学报 2024年第9期53卷 218-229页

作者：李慧李正周杨雨昕郝聪宇刘海涛重庆大学微电子与通信工程学院重庆401331

针对复杂背景红外小弱目标信号弱、特征不明显、干扰虚警多等检测性能低问题,提出基于跨越连接与融合注意力机制的单阶段红外弱小目标检测算法。该方法融合注意力机制与残差网络提取小目标多特征,减少复杂背景干扰;双向跨越连接结构融... 详细信息

针对复杂背景红外小弱目标信号弱、特征不明显、干扰虚警多等检测性能低问题,提出基于跨越连接与融合注意力机制的单阶段红外弱小目标检测算法。该方法融合注意力机制与残差网络提取小目标多特征,减少复杂背景干扰;双向跨越连接结构融合低层与高层各自的特征信息,凸显小弱目标特征表达能力;增加一个高分辨率检测层,重新聚类弱小目标先验框,增强目标与背景的特征差别学习能力;最后,建立真实目标和预测目标框的高斯分布模型,计算两者相似性,解决因IoU度量造成的目标损失回归偏差敏感问题,提升损失回归准确性。在公开红外小目标数据集上进行对比测试,实验结果表明该算法对多种复杂背景下红外小弱目标检测均取得了最佳性能,在平均精度和速度等方面都得到显著提升,模型最小,方便部署。

关键词：红外小目标目标检测跨越连接注意力机制多尺度融合

PROPERTY AND METALLOGENIC CHARACTERISTICS OF ALKALI-RICH PORPHYRY IN WESTERN MARGIN OF YANGTZE PLATFORM

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Journal of Central South university 1998年第2期10卷 57-60页

作者： Hu Xiangzhao (college of Resources, Environment and civil {2.,Central South university of Technology, Changsha 410083, china) college of Resources Environment and Civil Engineering Central South University of Technology Changsha 410083 China

The age of alkali rich porphyries in the western margin of Yangtze Platform is 30—50 Ma; the minerals mainly are orthoclase, quartz, plagioclase; the chemical composition is alkali rich [(K 2.+Na 2.)>8%],high potash[(K 2.+Na 2.)=5.09%-8.30%]; the content of  REE  is relatively low, LREE is concentrated, without anomaly of europium; the average initial ratio of 87 Sr/ 86 Sr is 0.7073; the value of δ 34 S similar to that of the meteoritic sulfur; the ratio of Pb isotope corresponds to that of upper mantle; metallogenic types belong to Cu, Mo, Au, Ag, Pb, Zn polymetal mineralization and rare, rare earth metal mineralization.

关键词： petrology geochemistry alkali rich porphyry metallogenic characteristics

Phylogeny of Ptychostomum (Bryaceae,Musci) inferred from sequences of nuclear ribosomal DNA internal transcribed spacer (ITS) and chloroplast rps4

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Journal of Systematics and Evolution 2009年第4期47卷 311-320页

作者： ~(1,2.Chen-Ying WANG ~1Jian-Cheng ZHAO~* 1(college of Life Science,Hebei Normal university,Shijiazhuang 050016,{2.) 2.Department of Life Science,zhengzhou Teachers college,zhengzhou 450044,{2.) ( Department of Life Science Zhengzhou Teachers College Zhengzhou 450044 China)

The phylogeny of Ptychostomum was first undertaken based on analysis of the internal transcribed spacer(ITS)region of the nuclear ribosomal(nr)DNA and by combining data from nrDNA ITS and chloroplast DNA rps4 *** parsimony,maximum likelihood,and Bayesian analyses all support the conclusion that the reinstated genus Ptychostomum is not *** funkii(Schw(a|¨)gr.)*** (≡Bryum funkii Schw(a|¨)gr.)is placed within a clade containing the type species of Bryum,*** Hedw. The remaining members of Ptychostomum investigated in the present study constitute another well-supported clade. The results are congruent with previous molecular *** the basis of phylogenetic evidence,we agree with transferring *** Mü***.(≡***(Brid.)Turton≡Bryum archangelicum Bruch & Schimp.), Bryum lonchocaulon Mü***.,Bryum pallescens *** Schw(a|¨)gr.,and Bryum pallens *** Ptychostomum.

关键词： Bryum molecular phylogeny nuclear ribosomal DNA internal transcribed spacer sequences Ptychostomum rps4 sequences.

An Analysis of Suburban Agricultural Land Allocation System and Sustainable Development Strategy──Taking Kaifeng Suburban as an example

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Journal of Systems Science and Systems engineering 2001年第4期13卷 409-417页

作者： QIN Ming-zhou1, ZHAO Shu-mao2.1. college of Environment and Planning, Henan university, Kadeng 475001, {2. 2. Planning Council of Henan Province, zhengzhou 450003, {2. college of Environment and Planning Henan UniversityKaifeng 475001 China Planning Council of Henan Province Zhengzhou 450003 China

Based on the system theory, this paper discusses the structure and efficiency of agricuItural land use in Kaifeng Suburban. Such present problems as benefit deviation from resource al1ocation, distinguished unemployment and four kinds of contribution of urban agriculture land use are revealed. Then, in the view of sustainab1e development, some resolution measures to the problems are advanced out. These suggestions include farmland protection, ecological agriculture, sustainable land use and input decrease of synthetic matter.

关键词： suburban agricultural land use resources allocation use efficiency farmland protection ecological agriculture

Dynamic subsidence prediction of ground surface above salt cavern gas storage considering the creep of rock salt

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Science china(Technological Sciences) 2010年第12期53卷 3197-3202页

作者： WANG TongTao1, YAN XiangZhen1, YANG XiuJuan1 & YANG HengLin2.1 college of Pipeline and civil {2., china university of Petroleum, Qingdao 2.6555, china 2.CNPC Drilling Research Institute, Beijing 100097, china 1. college of Pipeline and civil {2. China University of Petroleum Qingdao 266555 China2. CNPC Drilling Research Institute Beijing 100097 China

A new model is proposed to predict the dynamic subsidence of ground surface above salt cavern gas storage during the leaching and storage, which takes into account the creep of rock salt. In the model, the extended form of Gaussian curve is adopted to figure out the shape of subsidence areas. The corresponding theoretical formulas are derived. In addition, parameters are studied to investigate the surface subsidence as a function of the salt ejection rate, internal pressure, buried depth, diameter, height, running time, etc. Through an example, the subsidence of the salt cavern gas storage located at Jiangsu of china obtained by the new model was compared with those by Peter A F formula, Schober & Sroka formula and FLAC3D through simulation. The results showed the proposed model is precise and correct, and can meet the actual engineering demands. The surface subsidence is equidirectional with the increase of salt ejection rate, depth, diameter, height, and running time, but reverse to the increase of internal pressure. The depth, diameter, running time and internal pressure have great effects on the subsidence, whereas the salt ejection rate and height have little influences on it.

关键词： salt cavern gas storage dynamic subsidence creep of rock salt extended form of Gaussian curve calculation model

Evaporative Condensers in Comfortable Air Conditioning System

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湖南大学学报（自然科学版） 2009年第S1期36卷 136-140页

作者： YIN Ying-de1,ZHU Dong-sheng1,DU Gui-mei2.LI Yuan-xi1,SUN He-jing1,LIU Qing-ming1(1.Key Lab of Enhancement Heat Transfer and Energy Conservation,the Ministry of Education,South china university of Technology,Guangzhou,Guangdong 510641,china 2.college of civil engineering,Hunan university,Changsha,Hunan 410082.china) Key Lab. of Enhancement Heat Transfer and Energy Conservation South China University of Technology Guangzhou 510641 China college of civil {2. Hunan University Changsha 410082 China

The operating theory of an evaporative condenser was *** difference between an evaporative condensing refrigeration system and a general refrigeration system was *** with the air-cooled and the water-cooled,the virtues of energy-conservation and water-conservation of evaporative condensers were *** questions existing in the application of evaporative condensers were pointed out,the corresponding solving methods were analyzed accordingly,and the development trend of evaporative condensing technique in mechanical refrigeration system field and the applied foreground of evaporative condensers in comfortable air conditioning were prospected.

关键词： evaporative condensers evaporative condensing refrigeration system general refrigeration system comfortable air conditioning system