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Heat transfer model of two-phase flow across tube bundle in submerged combustion vaporizer
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作者 Jiajun Song Dongyan Han +2 位作者 Qinqin Xu Dan Zhou Jianzhong Yin 《中国化学工程学报:英文版》 SCIE EI CAS CSCD 2019年第3期613-619,共7页
In order to optimize the design of the submerged combustion vaporizer(SCV),an experimental apparatus was set up to investigate the heat transfer character outside the tube bundle in SCV.Several experiments were conduc... In order to optimize the design of the submerged combustion vaporizer(SCV),an experimental apparatus was set up to investigate the heat transfer character outside the tube bundle in SCV.Several experiments were conducted using water and CO2 as the heat transfer media in the tubes,respectively.The results indicated that hot air flux,the initial liquid level height and the tube pitch ratio had great influence on the heat transfer coefficient outside the tube bundle(ho).Finally,the air flux associated factorβand height associated factorγwere introduced to propose a new hocorrelation.After verified by experiments using cold water,high pressure CO2 and liquid N2 as heat transfer media,respectively,it was found that the biggest deviation between the predicted and the experimental values was less than 25%. 展开更多
关键词 SUBMERGED COMBUSTION VAPORIZER Fluid SWEEPING tube BUNDLE TWO-PHASE flow Heat transfer coefficient Modeling
Experimental investigation and optimization of weld bead characteristics during submerged arc welding of AISI 1023 steel 预览
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作者 Ankush Choudhary Manoj Kumar Deepak Rajendra Unune 《Defence Technology(防务技术)》 CAS CSCD 2019年第1期72-82,共11页
Submerged arc welding(SAW),owing to its high deposition rate and high welding quality,is widely used in the fabrication of pressure vessel,marine vessel,pipelines and offshore structures.However,selection of an optimu... Submerged arc welding(SAW),owing to its high deposition rate and high welding quality,is widely used in the fabrication of pressure vessel,marine vessel,pipelines and offshore structures.However,selection of an optimum combination of welding parameters is critical in achieving high weld quality and productivity.In this work,initially,the SAWexperiments were performed using fractional factorial design to analyze the effect of direct and indirect input parameters,namely,welding voltage,wire feed rate,welding speed,nozzle to plate distance,flux condition,and plate thickness on weld bead geometrical responses viz.bead width,reinforcement,and penetration.The bead on plate technique was used to deposit weld metal on AISI 1023 steel plates.The effect of SAW input parameters on response variables were analyzed using main and interaction effects.The linear regression was used to develop the mathematical models for the response variable.Then,the multi-objective optimization of input parameters was carried out using desirability approach,genetic algorithm and Jaya algorithm.The Jaya algorithm offered better optimization results as compared to desirability approach,genetic algorithm. 展开更多
关键词 SUBMERGED ARC welding Optimization Regression GENETIC ALGORITHM Jaya ALGORITHM
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Submerged flexible vegetation impact on open channel flow velocity distribution: An analytical modelling study on drag and friction 预览
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作者 Jaan H. Pu Awesar Hussain +3 位作者 Ya-kun Guo Nikolaos Vardakastanis Prashanth R. Hanmaiahgari Dennis Lam 《水科学与水工程:英文版》 EI CAS CSCD 2019年第2期121-128,共8页
In this paper,an analytical model that represents the streamwise velocity distribution for open channel flow with submerged flexible vegetation is studied.In the present vegetated flow modelling,the whole flow field h... In this paper,an analytical model that represents the streamwise velocity distribution for open channel flow with submerged flexible vegetation is studied.In the present vegetated flow modelling,the whole flow field has been separated into two layers vertically: a vegetated layer and a non-vegetated free-water layer.Within the vegetated layer,an analysis of the mechanisms affecting water flow through flexible vegetation has been conducted.In the non-vegetated layer,a modified log-law equation that represents the velocity profile varying with vegetation height has been investigated.Based on the studied analytical model,a sensitivity analysis has been conducted to assess the influences of the drag (CD) and friction (Cf ) coefficients on the flow velocity.The investigated ranges of CD and Cf have also been compared to published values.The findings suggest that the CD and Cf values are non-constant at different depths and vegetation densities,unlike the constant values commonly suggested in literature.This phenomenon is particularly clear for flows with flexible vegetation,which is characterised by large deflection. 展开更多
关键词 ANALYTICAL model FLEXIBLE VEGETATION Flow VELOCITY FRICTION Drag SUBMERGED VEGETATION
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Experimental and Numerical Study on the Hydrodynamic Characteristics of Solitary Waves Passing Over A Submerged Breakwater 预览
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作者 ZHAO Xi-zeng CHENG Du +1 位作者 ZHANG Yi-fei LI Meng-yu 《中国海洋工程:英文版》 SCIE EI CSCD 2019年第3期253-267,共15页
In this study, solitary waves passing over a submerged breakwater are investigated both experimentally and numerically. A total of 9 experimental conditions are carried out, including different incident wave heights a... In this study, solitary waves passing over a submerged breakwater are investigated both experimentally and numerically. A total of 9 experimental conditions are carried out, including different incident wave heights and water depths. Numerical simulations are performed using a high-order finite-difference model solving Navier–Stokes (N–S) equations. The predicted water wave elevation, velocity and pressure show good agreement with experimental data, verifying the accuracy and capacity of the numerical model. Furthermore, parametric studies are conducted by numerical modelling to examine the effects of the geometrical features of submerged dike on hydrodynamic characteristics around the breakwater. 展开更多
关键词 submerged BREAKWATER SOLITARY wave CIP METHOD NAVIER-STOKES model VOF METHOD
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Numerical investigation of filling transients in small-scale pipelines with submerged outlet 预览
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作者 Ling Wang Fu-jun Wang Jing Huang 《水动力学研究与进展:英文版》 SCIE EI CSCD 2019年第1期145-151,共7页
An elastic model that combines the dead-end and the orifice at the downstream end is proposed in order to study the hydraulic transients during the rapid filling in small-scale pipelines with submerged outlet.In this ... An elastic model that combines the dead-end and the orifice at the downstream end is proposed in order to study the hydraulic transients during the rapid filling in small-scale pipelines with submerged outlet.In this model,the unsteady water flow is solved by the method of characteristics,the water-air interface is traced by a shock fitting method,and the air phase is controlled by the polytropic law.The model is validated by a filling test in a pipeline with orifice.Then the proposed model is applied to the filling transient analysis in a small-scale pipeline with submerged outlet.Finally,the effects of the submerged depth of the downstream reservoir on the filling transients are analyzed.This model provides a reasonable approximation of the submerged outlet boundary condition in small-scale pipelines. 展开更多
关键词 SMALL-SCALE pipelines rapid FILLING SUBMERGED OUTLET ELASTIC model hydraulic transients
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Synthesis of Ag and Cd nanoparticles by nanosecond-pulsed discharge in liquid nitrogen
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作者 Mahmoud Trad Alexandre Nominé +4 位作者 Natalie Tarasenka Jaafar Ghanbaja Cédric Noel Malek Tabbal Thierry Belmonte 《化学科学与工程前沿:英文版》 EI CAS CSCD 2019年第2期360-368,共9页
The synthesis of CdO, Ag2O (5nm) and Ag (~20~30 nm) nano-objects is achieved simultaneously by nanosecond-pulsed discharges in liquid nitrogen between one cadmium electrode and one silver electrode. Oxidation occurs w... The synthesis of CdO, Ag2O (5nm) and Ag (~20~30 nm) nano-objects is achieved simultaneously by nanosecond-pulsed discharges in liquid nitrogen between one cadmium electrode and one silver electrode. Oxidation occurs when liquid nitrogen is fully evaporated and nanoparticles are in contact with the air. No alloy is formed, whatever the conditions, even though both elements are present simultaneously, as showed by timeresolved optical emission spectroscopy. This lack of reactivity between elements is attributed to the high pressure within the discharge that keeps each metallic vapor around the electrode it comes from. Each element exhibits a specific behavior. Cubic Cd particles, formed at 4 kV, get elongated with filamentary tips when the applied voltage reaches 7 and 10 kV. Cd wires are formed by assembly in liquid nitrogen of Cd nanoparticles driven by dipole assembly, and not by dielectrophoresis. On the contrary, silver spherical particles get assembled into 2D dendritic structures. The anisotropic growth of these structures is assumed to be due to the existence of pressure gradients. 展开更多
关键词 SPARK discharges SUBMERGED discharges timeresolved optical EMISSION SPECTROSCOPY liquid NITROGEN
Study of flow characteristics within randomly distributed submerged rigid vegetation 预览
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作者 Paromita Chakraborty Arindam Sarkar 《水动力学研究与进展:英文版》 SCIE EI CSCD 2019年第2期358-367,共10页
Flow through submerged rigid vegetation has been studied both analytically and experimentally.The Reynolds stress,present in the governing equation,has been modeled using one of the turbulent stress equations,adopted ... Flow through submerged rigid vegetation has been studied both analytically and experimentally.The Reynolds stress,present in the governing equation,has been modeled using one of the turbulent stress equations,adopted in numerous cases.The adva ntage of this turbulent stress model is to replace the mixing length non linear term of the stress with a linear relatio n between stress and the velocity gradient.The velocity field and shear stress are obtained by solving the governing force balance equation numerically.A correlation,validated with the experimental results,has been developed for the relevant non-dimensional numbers. 展开更多
关键词 SUBMERGED VEGETATION REYNOLDS stress drag force STREAM WISE velocity
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Experimental and numerical study of regular waves past a submerged breakwater 预览
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作者 Bi-jin Liu Du Cheng +3 位作者 Zhao-chen Sun Xi-zeng Zhao Yong Chen Wei-dong Lin 《水动力学研究与进展:英文版》 SCIE EI CSCD 2019年第4期641-653,共13页
Laboratory experiments are performed to investigate the hydrodynamics around a submerged breakwater due to regular incident waves. With an in-house code, a constrained interpolation profile (CIP)-based model is employ... Laboratory experiments are performed to investigate the hydrodynamics around a submerged breakwater due to regular incident waves. With an in-house code, a constrained interpolation profile (CIP)-based model is employed to simulate this process. The model is built on a Cartesian grid system with the Navier-Stokes equations using a CIP method for the flow solver and an immersed boundary method (IBM) is used for the treatment of the solid body boundary. A more accurate interface capturing scheme, the tangent of hyperbola for interface capturing/slope weighting (THINC/SW) scheme, is used to track the free surface. The numerical results are compared with experimental data. Reasonably good agreement is achieved in terms of the wave profiles at six measuring stations, the flow velocities at three different space locations and the pressures of eight points on the surface of the submerged breakwater. Moreover, the water mass transfer over the breakwater is discussed using a two-phase VOF model and the wave spectrum is also presented for analysis. It is indicated that the present model can accurately predict the hydrodynamic characteristics of the wave over a submerged bar. Furthermore, the experimental data in the present work can provide reliable basic data, including the wave transformations, the velocities and the dynamic pressures, for the validation of other CFD models. 展开更多
关键词 SUBMERGED BREAKWATER CIP METHOD wave TRANSFORM VOF METHOD immersed boundary METHOD
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Surface-to-bed heat transfer for high-density particles in conical spouted and spout–fluid beds
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作者 Onur Yaman Gorkem Kulaha Murat Koksalb 《中国颗粒学报:英文版》 SCIE EI CAS CSCD 2019年第1期35-47,共13页
Bed-to-surface heat transfer experiments from a vertically submerged cylindrical surface were conducted in laboratory-scale (Dc = 25 cm) conical spouted and spout–fluid beds at two different conical angles (31° ... Bed-to-surface heat transfer experiments from a vertically submerged cylindrical surface were conducted in laboratory-scale (Dc = 25 cm) conical spouted and spout–fluid beds at two different conical angles (31° and 66°) in the high particle density range (2500 kg/m3 ≤ρp ≤ 6000 kg/m3). The effects of the bed design parameters (conical angle and inlet diameter of spouting gas entrance) and operating conditions (static bed height, particle size, density, and spouting and fluidization gas flow rates) on the heat transfer characteristics were investigated in detail. The heat transfer coefficients were shown to be dependent on the density and size of the particles. The minimum stable spouting velocities of the denser and larger particles were higher, which led to higher operational spouting velocities and thereby resulted in higher heat transfer coefficients. The positive effect of increasing the particle diameter on heat transfer was more pronounced in the spout and at the spout–annulus interface, whereas this effect was diminished in the annulus region. The heat transfer coefficient increased with increasing spouting gas velocity up to 1.0Ums–1.1Ums, beyond which no significant change was observed regardless of the particle type. The heat transfer coefficient in the annulus decreased with increasing conical angle because of reduced particle circulation. The spout–fluid operation increased the heat transfer coefficient by a maximum of 10% at the expense of a significant increase of the total gas flow rate. This result was attributed to the inability of the fluidizing gas to penetrate the annulus. An empirical correlation for the average heat transfer coefficient in the annulus was also proposed based on the data obtained in this work. 展开更多
关键词 Conical spouted BED Spout–fluid BED Bed-to-surface HEAT TRANSFER Submerged HEAT TRANSFER SURFACE
Land submerged to carbonate platform by conodonts: paleoenvironment reconstruction of the western Gangdese in Tibet during Triassic 预览
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作者 Zhan-sheng Ji Jian-xin Yao +5 位作者 Gui-chun Wu Qian Sun Qiu-yuan Shi Hao Li Ji-fu He Shao-wen Zhang 《中国地质(英文)》 2018年第3期450-452,共3页
The western Gangdese in Tibet during Triassic was previously considered to be a part of the Gangdese Oldland (Zhao ZZ et al.,2001;Fig.1).If the Gangdese Oldland did exist,it means no prospect of petroleum exploration ... The western Gangdese in Tibet during Triassic was previously considered to be a part of the Gangdese Oldland (Zhao ZZ et al.,2001;Fig.1).If the Gangdese Oldland did exist,it means no prospect of petroleum exploration of the Triassic strata in western Gangdese area.Fortunately,the recent biostratigraphic progresses don’t support the existence of the Gangdese Oldland.This paper aims to briefly introduce the new paleogeographic interpretation and the reason that the western Gangdese in the Triassic was marine instead of terrigenous on the basis of the recent conodont data. 展开更多
关键词 LAND SUBMERGED western GANGDESE CARBONATE platform
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Global significance of the carbon cycle in the karst dynamic system:evidence from geological and ecological processes 预览
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作者 Jian-hua Cao Xia Wu +4 位作者 Fen Huang Bill Hu Chris Groves Hui Yang Chun-lai Zhang 《中国地质(英文)》 2018年第1期17-27,共11页
On the basis of proposing the existence of a karst carbon cycle and carbon sink at a watershed scale,this paper provides four pieces of evidence for;the integration of geology and ecology during the carbon cycle proce... On the basis of proposing the existence of a karst carbon cycle and carbon sink at a watershed scale,this paper provides four pieces of evidence for;the integration of geology and ecology during the carbon cycle processes m the karst dynamic system,and estxmated the karst carbon sink effect using the methods of comparative monitoring of paired watersheds and the carbon stable isotope tracer technique.The results of the soil carbon cycle in Maocun,Guilin,showed that the soil carbon cycle in the karst area,the weathering and dissolution of carbonate rocks under the soil,resulted in a lower soil respiration of 25% in the karstoarea than in a non-karst area (sandstone and shale),and the carbon isotope results indicated that 13.46% of the heavy carbon of the hmestone is involved in the soil carbon cycle.The comparative monitoring results m paxred watersheds,suggesting that the HCO3 concentration m a karst spring is 10 times that of a rivulet in a non-karst area,while the concentration of inorganic carbon flux is 23.8 times.With both chemical stoichiometry and carbon stable isotopes,the proportion of carbon in karst springs derived from carbonate rocks was found to be 58.52% and 37.65% respectively.The comparison on carbon exchange and isotopes at the water-gas interface between the granite and carbonate rock basins in the Li River showed that the CO2 emission of the karst water is 10.92 times that of the allogenic water from the non-karst area,while the carbon isotope of HCO3^- in karst water is lighter by 8.62%.However,this does not mean that the karst water body has a larger carbon source effect.On the contrary,it means the karst water body has a greater karst carbon sink effect.When the karst subterranean stream in Zhaidi,Guilin,is exposed at the surface,carbon-rich karst water stimulated the growth of aquatic plants.The values of carbon stable isotopes in the same species of submerged plants gradually becomes heavier and heavier,and the 512 m flow process has a maximum range of 15.46%.The calculation results showe 展开更多
关键词 KARST CARBON cycle CARBON stable isotope CARBON SINK effect SUBMERGED plants GUILIN
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Study on Hydrodynamic Coefficients of Double Submerged Inclined Plates 预览
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作者 WANG Ke ZHANG Zhi-qiang 《中国海洋工程:英文版》 SCIE EI CSCD 2018年第1期85-89,共5页
Added mass and damping coefficients are very important in hydrodynamic analysis of naval structures. In this paper,a double submerged inclined plates with ‘/ \’ configuration is firstly considered. By use of the bou... Added mass and damping coefficients are very important in hydrodynamic analysis of naval structures. In this paper,a double submerged inclined plates with ‘/ \’ configuration is firstly considered. By use of the boundary element method (BEM) based on Green function with the wave term, the radiation problem of this special type structure is investigated. The added mass and damping coefficients due to different plate lengths and inclined angles are obtained. The results show that: the added mass and damping coefficients for sway are the largest. Heave is the most sensitive mode to inclined angles. The wave frequencies of the maximal added mass and damping coefficients for sway and roll are the same. 展开更多
关键词 DOUBLE SUBMERGED inclined plates boundary element METHOD (BEM) added mass and damping coefficients GMRES METHOD
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Flow Separation and Vortex Dynamics in Waves Propagating over A Submerged Quartercircular Breakwater 预览
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作者 JIANG Xue-lian YANG Tian +1 位作者 ZOU Qing-ping GU Han-bin 《中国海洋工程:英文版》 SCIE EI CSCD 2018年第5期514-523,共10页
The interactions of cnoidal waves with a submerged quartercircular breakwater are investigated by a Reynolds-Averaged Navier–Stokes(RANS)flow solver with a Volume of Fluid(VOF)surface capturing scheme(RANSVOF)model.T... The interactions of cnoidal waves with a submerged quartercircular breakwater are investigated by a Reynolds-Averaged Navier–Stokes(RANS)flow solver with a Volume of Fluid(VOF)surface capturing scheme(RANSVOF)model.The vertical variation of the instantaneous velocity indicates that flow separation occurs at the boundary layer near the breakwater.The temporal evolution of the velocity and vorticity fields demonstrates vortex generation and shedding around the submerged quartercircular breakwater due to the flow separation.An empirical relationship between the vortex intensity and a few hydrodynamic parameters is proposed based on parametric analysis.In addition,the instantaneous and time-averaged vorticity fields reveal a pair of vortices of opposite signs at the breakwater which are expected to have significant effect on sediment entrainment,suspension,and transportation,therefore,scour on the leeside of the breakwater. 展开更多
关键词 SUBMERGED quartercircular BREAKWATER cnoidal wave flow separation VORTEX dynamics SCOUR
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三峡水库蓄水对消落带土壤Cu、Zn、Cr、Cd含量的影响
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作者 杨丹 谢宗强 +2 位作者 樊大勇 熊高明 张爱英 《自然资源学报》 CSSCI CSCD 北大核心 2018年第7期1283-1290,共8页
为揭示水位涨落形成系列淹水梯度对消落带土壤重金属含量的影响,论文采集三峡水库忠县消落带土壤,分析了不同淹水深度土壤Cu、Zn、Cr、Cd含量,并探讨了这些重金属元素物质来源及其与三峡水库水位涨落关系。结果表明:1)不同淹水深... 为揭示水位涨落形成系列淹水梯度对消落带土壤重金属含量的影响,论文采集三峡水库忠县消落带土壤,分析了不同淹水深度土壤Cu、Zn、Cr、Cd含量,并探讨了这些重金属元素物质来源及其与三峡水库水位涨落关系。结果表明:1)不同淹水深度下消落带土壤重金属含量差异较大,长期淹水土壤Cu、Zn、Cd含量远远高于短期淹水和未淹水土壤,Cr则在不同淹水深度略有变化;2)除CrSg对独立外,不同淹水深度下土壤SOM、pH与土壤cu、Zn、Cd含量密切相关,但pH、SOM间仅有微弱的相关关系;3)因子分析中因子1和因子2对Cu、Zn、Cr、Cd的累计贡献率为93.47%,Cu、Zn、Cd在第一轴载荷值为0.962、0.967、0.925,Cr在第二轴载荷值为0.998。研究发现:1)重金属输入来源和流向异质性是决定不同淹水深度Cu、zn、Cr、Cd含量差异的重要原因,长期淹水显著增加了土壤Cu、Zn、Cd含量,但对Cr效应并不明显;2)区域土壤内cr主要来源为自然源的土壤侵蚀和母岩风化,Cu、Zn、Cd来源于人为输入的库岸输入和长江上游来水悬浮颗粒沉积,应引起足够重视。 展开更多
关键词 因子分析-多元线性回归 地球化学行为 淹水 水位调度
中国洪湖沉水植物群落调查与分析 预览
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作者 李岚晶 封瑛 《世界生态学》 2018年第2期129-141,共13页
沉水植物是指植物体全部位于水层下面固着生存的大型水生植物,是湖泊生态系统的重要组成部分,具有净化水质、提供饵料、改善生境、营造景观的多重生态功能。洪湖是中国第七大、湖北省第一大淡水湖泊,水生植物十分丰富。按照水生植物调... 沉水植物是指植物体全部位于水层下面固着生存的大型水生植物,是湖泊生态系统的重要组成部分,具有净化水质、提供饵料、改善生境、营造景观的多重生态功能。洪湖是中国第七大、湖北省第一大淡水湖泊,水生植物十分丰富。按照水生植物调查规范,2017年7月对洪湖沉水植物群落调查,发现洪湖主要建群沉水植物有6科8属15种,包括金鱼藻(Ceratophyllum demersum)、五刺金鱼藻(C. oryzetorum)、黑藻(Hydrilla verticillata)、苦草(Vallisneria natans)、水车前(Ottelia alismoides)、荇菜(Nymphoidespeltata)、金银莲花(Nymphoides indica)、狐尾藻(Myriophyllum spicatum)、轮叶狐尾藻(M. verticillatum)、菹草(Potamogeton cristatus)、光叶眼子菜(P. lucens)、微齿眼子菜(P. maackianus)、竹叶眼子菜(P. malaianus)、蓖齿眼子菜(P. pectinatus)和小眼子菜(P. pusillus)。沉水植物组成了7个群丛48个群落,覆盖了洪湖49.14%的面积。分析表明,1960年代洪湖主要优势沉水植物是耐污能力差、饵料价值高的竹叶眼子菜、苦草和黑藻,表明那时的洪湖水质清洁,鱼类饵料丰富、生态系统优良;1980年代,耐污能力强的微齿眼子菜、菹草和金鱼藻占据优势,1990年代一直维持着这个格局,表明1980~2000期间,洪湖水质比较差;本次调查显示,虽然优势沉水植物还是耐污能力比较强的菹草和篦齿眼子菜,但苦草和竹叶眼子菜又重新回到优势种的位置,表明洪湖局部地区水质开始好转,生态健康程度有所回升。为提高生态系统稳定性,建议进一步取缔围网、绞草、拖螺等人为干扰,同时改善入湖水质,增加水体透明度,促进沉水植物的恢复。 展开更多
关键词 沉水植物 生态系统 植物群落 生物多样性 洪湖 SUBMERGED PLANT ECOSYSTEM PLANT Community BIODIVERSITY Honghu Lake
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百年一遇潮位淹没影响下山东沿海地区经济脆弱性评价 预览
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作者 李梦梦 罗新正 《海洋通报》 CSCD 北大核心 2018年第6期667-675,共9页
经济发达的山东沿海局部地区地势低平,海堤多为五十年一遇标准,一旦发生百年一遇风暴潮淹没事件,将会带来巨大的经济损失。因此,对山东沿海地区经济脆弱性进行评价,有助于减灾防灾措施的实施。本文借助DEM、遥感数据和GIS评价百年一遇... 经济发达的山东沿海局部地区地势低平,海堤多为五十年一遇标准,一旦发生百年一遇风暴潮淹没事件,将会带来巨大的经济损失。因此,对山东沿海地区经济脆弱性进行评价,有助于减灾防灾措施的实施。本文借助DEM、遥感数据和GIS评价百年一遇潮位淹没影响下山东沿海地区经济脆弱性。研究结果如下:百年一遇潮位淹没影响范围主要集中在潍坊、东营和滨州;龙口、福山、芝罘、莱山、威海四市、临胶州湾各区与日照沿海的东港区和岚山区GDP密度较高,滨州、东营、潍坊各市、区,莱州、招远、蓬莱、牟平、海阳、莱阳、即墨与平度的GDP密度较低;淹没深度较大地区集中在潍坊,东营部分地区,胶州湾及日照沿海地区;结果表明:(1)经济脆弱性极高地区分布在寒亭区,城阳区;经济脆弱性很高地区为黄岛区;经济脆弱性为高的地区有东港区、莱州市、寿光市、昌邑县、广饶县与东营区等地;(2)脆弱性成因:寒亭区、寿光市、昌邑县、广饶县、东营区、莱州市、县是淹没面积大,淹没深度大;黄岛区、东港区及城阳是GDP密度大,淹没深度大;(3)预防风暴潮灾害可通过加强预警预报与应急预案建设,调整经济分布,加强柽柳湿地保护与积极扩大柽柳湿地范围等方法。 展开更多
关键词 百年一遇潮位 山东沿海地区 GDP 脆弱性评价 淹没
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Determining the Scour Dimensions Around Submerged Vanes in a 180°Bend with the Gene Expression Programming Technique 预览
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作者 Saeid Shabanlou Hamed Azimi +1 位作者 Isa Ebtehaj Hossein Bonakdari 《船舶与海洋工程学报:英文版》 CSCD 2018年第2期233-240,共8页
Submerged vanes are installed on rivers and channel beds to protect the outer bank bends from scouring.Also,local scouring occurs around the submerged vanes over time,and identifying the effective factors on the scour... Submerged vanes are installed on rivers and channel beds to protect the outer bank bends from scouring.Also,local scouring occurs around the submerged vanes over time,and identifying the effective factors on the scouring phenomena around these submerged vanes is one of the important issues in river engineering.The most important aimof this study is investigation of scour pattern around submerged vanes located in 180°bend experimentally and numerically.Firstly,the effects of various parameters such as the Froude number(Fr),angle of submerged vanes to the flow(α),angle of submerged vane location in the bend(θ),distance between submerged vanes(d),height(H),and length(L)of the vanes on the dimensionless volume of the scour hole were experimentally studied.The submerged vanes were installed on a 180°bend whose central radius and channel width were 2.8 and 0.6 m,respectively.By reducing the Froude number,the scour hole volume decreased.For all Froude numbers,the biggest scour hole formed atθ=15°.In all models,by increasing the Froude number,the scour hole volume significantly increases.In addition,by increasing the submerged vanes’length and height,the scour hole dimensions also grow.Secondly,using gene expression programming(GEP),a relationship for determining the scour hole volume around the submerged vanes was provided.For this model,the determination coefficients(R2)for the training and test modes were computed as 0.91 and 0.9,respectively.In addition,this study performed partial derivative sensitivity analysis(PDSA).According to the results,the PDSA was calculated as positive for all input variables. 展开更多
关键词 180°bend SUBMERGED vanes SCOUR HOLE volume Gene expression PROGRAMMING Partial DERIVATIVE sensitivity analysis
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Viscous Effects on Wave Forces on A Submerged Horizontal Circular Cylinder 预览
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作者 TENG Bin MAO Hong-fei LU Lin 《中国海洋工程:英文版》 SCIE EI CSCD 2018年第3期245-255,共11页
Numerical simulations are carried out for wave action on a submerged horizontal circular cylinder by means of a viscous fluid model,and it is focused on the examination of the discrepancies between the viscous fluid r... Numerical simulations are carried out for wave action on a submerged horizontal circular cylinder by means of a viscous fluid model,and it is focused on the examination of the discrepancies between the viscous fluid results and the potential flow solutions.It is found that the lift force resulted from rotational flow on the circular cylinder is always in anti-phase with the inertia force and induces the discrepancies between the results.The influence factors on the magnitude of the lift force,especially the correlation between the stagnation-point position and the wave amplitude,and the effect of the vortex shedding are investigated by further examination on the flow fields around the cylinder.The viscous numerical calculations at different wave frequencies showed that the wave frequency has also significant influence on the wave forces.Under higher frequency and larger amplitude wave action,vortex shedding from the circular cylinder will appear and influence the wave forces on the cylinder substantially. 展开更多
关键词 SUBMERGED HORIZONTAL circular CYLINDER wave FORCE LIFT FORCE VORTEX effect
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浸水条件地震主动土压力的改进拟动力法 预览
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作者 黄睿 《绍兴文理学院学报》 2017年第8期1-7,共7页
基于极限平衡分析和拟动力法的计算思路,以无粘性填土的刚性挡土墙为研究对象,考虑填土处于无渗流的完全浸水条件,推导给出了浸水挡墙地震主动土压力的改进拟动力法的计算表达式.通过程序求解和参数分析表明:浸水条件下,拟动力法中的... 基于极限平衡分析和拟动力法的计算思路,以无粘性填土的刚性挡土墙为研究对象,考虑填土处于无渗流的完全浸水条件,推导给出了浸水挡墙地震主动土压力的改进拟动力法的计算表达式.通过程序求解和参数分析表明:浸水条件下,拟动力法中的剪切波参数对土压力系数的影响胜于压缩波参数,计算所得的土压力曲线为"类S型";主动土压力值随内摩擦角的增大而显著减小,随水平地震加速度的增大而明显增大,竖向地震加速度对土压力影响较小,可以忽略不计.与干土的地震主动土压力对比,浸水后土压力系数有一定增大,并且两者的差异随着地震作用的增大而扩大. 展开更多
关键词 土压力 地震 浸水 拟动力法
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浸没式喷水推进自航试验及数值模拟 预览
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作者 易文彬 王永生 +1 位作者 刘承江 彭云龙 《船舶力学》 EI CSCD 北大核心 2017年第4期407-412,共6页
浸没式喷水推进器与船体高度融合,难以通过试验的方法测量推进器各部件受力,因此文中采用船模水池试验和数值模拟相结合的方法来分析浸没式喷水推进的水动力特点。该文首先开展了船模拖曳阻力试验,测量了船模阻力、纵倾角及重心升沉。... 浸没式喷水推进器与船体高度融合,难以通过试验的方法测量推进器各部件受力,因此文中采用船模水池试验和数值模拟相结合的方法来分析浸没式喷水推进的水动力特点。该文首先开展了船模拖曳阻力试验,测量了船模阻力、纵倾角及重心升沉。然后开展船模自航试验,测量了船模纵倾角、升沉及轴的转速、力矩、推力等数据。基于CFX软件,对拖曳阻力试验及船模自航试验进行了数值模拟。在四个不同航速下的数值模拟中,阻力计算误差在3.7%以内,轴推力计算误差在2.7%以内,轴力矩计算误差在4.6%以内,试验测量值和CFD预报值吻合较好。通过数值模拟可以进一步得到浸没式喷水推进器上各部件的受力情况,泵的流量、扬程及其它流场信息,克服了浸没式喷水推进器推力测量和流场测量的困难。 展开更多
关键词 CFD 自航试验 浸没式 喷水推进
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