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Prevention of 25% Azoxystrobin Suspending Agent to Cucumber Downy Mildew
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作者 石凤梅 《Agricultural Science & Technology》 CAS 2014年第7期1178-1179,1228,共3页
[Objective] The aim was to research prevention effects of 25% azoxys trobin suspending agent to cucumber downy mildew.[Method] The test,including control group and four treatment groups with 450,600,and 750 g/hm2 25... [Objective] The aim was to research prevention effects of 25% azoxys trobin suspending agent to cucumber downy mildew.[Method] The test,including control group and four treatment groups with 450,600,and 750 g/hm2 25% azoxystrobin suspending agents,and 80% mancozeb wettable powder,was carried out in 2012 and 2013 consecutively to test the prevention effects of 25% azoxystrobin suspending agent to cucumber downy mildew.[Result] The prevention effects were significant of 25% azoxystrobin suspending agent to cucumber downy mildew in the range of 70.0%-83.6%,and it is recommended 25% azoxystrobin suspending agent at 600 g/hm2 be spread before plants diseased or in initial stage.In the whole stage,it was spread once every 7 d,totaling 3 times.[Conclusion] The research provides references for wide application of 25% azoxystrobin suspending agent in production. 展开更多
关键词 25% azoxystrobin suspending agent Cucumber downy mildew Prevention effects
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Seismic Noise Suppression for Ground-Based Investigation of an Inertial Sensor by Suspending the Electrode Cage 被引量:5
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作者 谭定银 尹航 周泽兵 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第9期9-12,共4页
Performance test of a high precise accelerometer or an inertial sensor on the ground is inevitably limited by the seismic noise. A torsion pendulum has been used to investigate the performances of an electrostatic acc... Performance test of a high precise accelerometer or an inertial sensor on the ground is inevitably limited by the seismic noise. A torsion pendulum has been used to investigate the performances of an electrostatic accelerometer, where the test mass is suspended by a fiber to compensate for its weight, and this scheme demonstrates an advantage, compared with the high-voltage levitation scheme, in which the effect of the seismic noise can be suppressed for a few orders of magnitude in low frequencies. In this work, the capacitive electrode cage is proposed to be suspended by another pendulum, and theoretical analysis shows that the effects of the seismic noise can be further suppressed for more than one order by suspending the electrode cage. 展开更多
关键词 LENGTH Seismic Noise Suppression for Ground-Based Investigation of an Inertial Sensor by suspending the Electrode Cage
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Production and Properties of a Thickener with Ability of Suspending Sand 被引量:4
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作者 QIN Bo-tao WANG De-ming LI Zeng-hua CHEN jian-hua 《Journal of China University of Mining and Technology》 EI 2006年第2期115-118,122,共5页
To overcome the shortcomings of pouring sands, a thickener with the ability to suspend sands was developed. It is mixed with sands to form densified slurry, and can insure the sands against deposition, jamming pipelin... To overcome the shortcomings of pouring sands, a thickener with the ability to suspend sands was developed. It is mixed with sands to form densified slurry, and can insure the sands against deposition, jamming pipelines and de- hydration. The chemical structure of the thickener is introduced in this paper and the production process is studied. The main processes include immersion, decomposition, dilution and addition of additives. In order to produce a thickener with high viscosity to suspend sands, key factors must be controlled in each process: the immersion time is 2 h; the mass fraction of formaldehyde is 0.01% and mass of NaCO3 accounts for 15% of dry material; the water temperature is 65 ℃ in summer and 72 ℃ in winter and the decomposition time is 2 h in the reaction; the densified decomposition so- lution should be diluted to 1% mass fraction; the additives of calcium ions and pH indicators must be added to the di- luted liquid; the mass fraction of CaCl2 is 0.048% and the pH value of the solution is 7.5. The thickener is a gel with three-dimensional network structure, a liquid with non-Newtonian behaviour and the characteristics of pseudo-plastic material, a solution with little resistance and the ability to revive its oral primary viscosity. It has been successfully ap- plied in Shendong Mines and has great value and wide-spread prospective use. 展开更多
关键词 THICKENER ability of suspending sand spontaneous combustion of coal
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SUSPENDING VILLAGE" A MODEL OF NEW DEVELOPMENT AREA IN THE NINGXIA HUI AUTONOMOUS REGION OF CHINA
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作者 牛慧恩 汪一鸣 《Chinese Geographical Science》 SCIE CSCD 1993年第2期93-99,共7页
The southern part of the Ningxia Hui Autonomous Region in China was infamous for its poverty and serious soil erosion caused by over population. In order to alleviate poverty and backwardness, a plan was worked out: t... The southern part of the Ningxia Hui Autonomous Region in China was infamous for its poverty and serious soil erosion caused by over population. In order to alleviate poverty and backwardness, a plan was worked out: to remove 200,000 people to the north plain by developing newly irrigated land during the period of 1983-1992. The plan has been in operation for eight and half years to date. About 200,000 people have been removed from the poor southern part to the newly developed area, and 800,000 mu (1/ 15 ha) of desert land has been cultivated. Most of the migrants have been lifted out of poverty and the people’s life in the south is being improved. During the immigration process, a model, called 'Suspending Village', has been developed. In the article, the whole process of the development and the strategies are discussed. 展开更多
关键词 suspending VILLAGE REGIONAL DEVELOPMENT POPULATION RESETTLEMENT
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“SUSPENDING VILLAGE”——A MODEL OF NEW DEVELOPED AREA IN NINGXIA OF CHINA
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作者 Wang Yiming Niu Huien Ningxia Regional Management Office, Yinchuan, Ningxia,750001 P. R. China Dept. of Town and Country Planning, Univ. of Newcastle uponTyne, Newcastle NE1 7RU, UK 《干旱区资源与环境》 CSCD 1993年第Z1期441-444,共4页
Ningxia is located in the Northwest China. The Huanghe (Yellow River) flowsthrough from its middle--west to the north. It is a province in which the Chinese Muslim--Hui Nationality is concentrated, with about one thir... Ningxia is located in the Northwest China. The Huanghe (Yellow River) flowsthrough from its middle--west to the north. It is a province in which the Chinese Muslim--Hui Nationality is concentrated, with about one third of the total population, hence theNingxia Hui Autonomous Region. From 1983 to 1992, more than 200000 people 展开更多
关键词 suspending Village” POPULATION OVERLOAD PEOPLE MIGRATION Model
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Comprehensive Analysis of Suspending Force for Improved Bearingless Switched Reluctance Motor with Permanent Magnets in Stator Yoke
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作者 Fangxu Li Huijun Wang +1 位作者 Fengge Zhang He Zhang 《CES Transactions on Electrical Machines and Systems》 2018年第4期348-354,共7页
Different from conventional switched reluctance motor(SRM),bearingless SRM not only provides torque but also supplies levitation force for free-friction of rotor.In order to make sure that bearingless SRM can steadily... Different from conventional switched reluctance motor(SRM),bearingless SRM not only provides torque but also supplies levitation force for free-friction of rotor.In order to make sure that bearingless SRM can steadily levitates in static and dynamic rotating operation,it is necessary to analyze suspending force.Therefore,suspending force performance of an improved bearingless SRM with permanent magnets in stator yoke is comprehensively investigated in this paper.Basic structure and operation principle with permanent magnets in stator yoke are introduced firstly.Furthermore,mathematical model is built up for design of suspending force.In addition,parametric analysis for levitation performance is implemented.Finally,validity of proposed method is verified by experimental results. 展开更多
关键词 ANALYSIS BEARINGLESS switched reluctance suspending force
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Using Natural Radionuclides to Trace Sources of Suspended Particles in the Lower Reaches of the Yellow River
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作者 ZHANG Han BURNETT CWilliam +5 位作者 ZHANG Xiaojie ZHAO Shibin YANG Disong NAN Haiming YU Zhigang XU Bochao 《Journal of Ocean University of China》 CAS CSCD 2024年第1期99-108,共10页
Natural radionuclides are powerful tools for understanding the sources and fate of suspended particulate matter(SPM).Particulate matter with different particle sizes behaves differently with respect to adsorption and ... Natural radionuclides are powerful tools for understanding the sources and fate of suspended particulate matter(SPM).Particulate matter with different particle sizes behaves differently with respect to adsorption and desorption.We analyzed the activi-ties and distribution characteristics of multiple natural radionuclides(238U,226Ra,40K,228Ra,7Be and 210Pbex)on size-fractionated SPM at the Lijin Hydrographic Station(Huanghe or Yellow River)every month over a one-year period.Results showed that medium silt(16–32µm)was the main component.As expected,the activity of each radionuclide decreased with an increase of particle size.We examined the sources of SPM with different particle sizes using activity ratios of 226Ra/238U,228Ra/226Ra,40K/238U and 7Be/210Pbex,and concluded that SPM with different particle sizes originated from different sources.Our results indicate that fine SPM(<32µm)was mainly from the erosion of soil along the lower reaches of the Yellow River,while coarse SPM(>32µm)was mainly derived from resuspension of riverbed sediment.During high runoff periods,the concentration of SPM increased significantly,and the pro-portion of fine particles originating upstream increased.Naturally occurring radioactive isotopes,especially on size-fractionated par-ticles,are therefore seen as useful tracers to understand the sources and behaviors of riverine particles transported from land to sea. 展开更多
关键词 the Yellow River suspended particulate matter size-fractions radionuclides sediment sources water elutriator
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Electrically-driven ultrafast out-of-equilibrium light emission from hot electrons in suspended graphene/hBN heterostructures
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作者 Qiang Liu Wei Xu +7 位作者 Xiaoxi Li Tongyao Zhang Chengbing Qin Fang Luo Zhihong Zhu Shiqiao Qin Mengjian Zhu Kostya S Novoselov 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第1期328-338,共11页
Nanoscale light sources with high speed of electrical modulation and low energy consumption are key components for nanophotonics and optoelectronics.The record-high carrier mobility and ultrafast carrier dynamics of g... Nanoscale light sources with high speed of electrical modulation and low energy consumption are key components for nanophotonics and optoelectronics.The record-high carrier mobility and ultrafast carrier dynamics of graphene make it promising as an atomically thin light emitter which can be further integrated into arbitrary platforms by van der Waals forces.However,due to the zero bandgap,graphene is difficult to emit light through the interband recombination of carriers like conventional semiconductors.Here,we demonstrate ultrafast thermal light emitters based on suspended graphene/hexagonal boron nitride(Gr/hBN)heterostructures.Electrons in biased graphene are significantly heated up to 2800 K at modest electric fields,emitting bright photons from the near-infrared to the visible spectral range.By eliminating the heat dissipation channel of the substrate,the radiation efficiency of the suspended Gr/hBN device is about two orders of magnitude greater than that of graphene devices supported on SiO2or hBN.Wefurther demonstrate that hot electrons and low-energy acoustic phonons in graphene are weakly coupled to each other and are not in full thermal equilibrium.Direct cooling ofhigh-temperature hot electrons to low-temperature acoustic phonons is enabled by the significant near-field heat transfer at the highly localized Gr/hBN interface,resulting in ultrafast thermal emission with up to 1 GHz bandwidth under electrical excitation.It is found thatsuspending the Gr/hBN heterostructures on the SiO2trenches significantly modifies the light emission due to the formation of the optical cavity and showed a~440%enhancement inintensity at the peak wavelength of 940 nm compared to the black-body thermal radiation.The demonstration of electrically driven ultrafast light emission from suspended Gr/hBNheterostructures sheds the light on applications of graphene heterostructures in photonicintegrated circuits,such as broadband light sources and ultrafast thermo-optic phase modulators. 展开更多
关键词 suspended graphene ultrafast light emitter van der Waals heterostructures thermal radiation electron–phonon interaction
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Suspending Control Scheme of 8/10 Bearingless SRM Based on Adaptive Fuzzy PID Controller 被引量:2
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作者 Yingjie He Ying Tang +1 位作者 Dong-Hee Lee Jin-Woo Ahn 《Chinese Journal of Electrical Engineering》 2016年第2期60-67,共8页
As a nonlinear,strong coupling and multi-variable system,the drive performance of bearingless switched reluctance motor(BLSRM)is always limited by its complicated electromagnetic properties.Generally,conventional PID ... As a nonlinear,strong coupling and multi-variable system,the drive performance of bearingless switched reluctance motor(BLSRM)is always limited by its complicated electromagnetic properties.Generally,conventional PID methods are used to achieve the basic control requirement in wide industrial applications,however its inherent operating principle limits its use on suspending control of BLSRM.In this paper,the suspending force system,which is separately controlled from torque system,is built based on an adaptive fuzzy PID controller to limit the rotor eccentric displacement with proper generation of radial force.When compared with a system adopted using conventional PID method for suspending force control,the proposed adaptive fuzzy PID method has superior performance in shortening the response time,reducing the maximum eccentric displacement error and higher speed range of operation due to its online self-turning of controller parameters.Both in simulation and experimental cases,comparison of results of the above two methods validates the effectiveness of the adaptive fuzzy PID controller for BLSRM drive system. 展开更多
关键词 BLSRM suspending force control conventional PID controller adaptive fuzzy PID controlle
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Threshold friction velocity influenced by soil particle size within the Columbia Plateau, northwestern United States
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作者 MENG Ruibing MENG Zhongju +3 位作者 Brenton SHARRATT ZHANG Jianguo CAI Jiale CHEN Xiaoyan 《Journal of Arid Land》 SCIE CSCD 2024年第8期1147-1162,共16页
Wind erosion is a geomorphic process in arid and semi-arid areas and has substantial implications for regional climate and desertification.In the Columbia Plateau of northwestern United States,the emissions from fine ... Wind erosion is a geomorphic process in arid and semi-arid areas and has substantial implications for regional climate and desertification.In the Columbia Plateau of northwestern United States,the emissions from fine particles of loessial soils often contribute to the exceedance of inhalable particulate matter(PM)with an aerodynamic diameter of 10μm or less(PM10)according to the air quality standards.However,little is known about the threshold friction velocity(TFV)for particles of different sizes that comprise these soils.In this study,soil samples of two representative soil types(Warden sandy loam and Ritzville silt loam)collected from the Columbia Plateau were sieved to seven particle size fractions,and an experiment was then conducted to determine the relationship between TFV and particle size fraction.The results revealed that soil particle size significantly affected the initiation of soil movement and TFV;TFV ranged 0.304-0.844 and 0.249-0.739 m/s for different particle size fractions of Ritzville silt loam and Warden sandy loam,respectively.PM10 and total suspended particulates(TSP)emissions from a bed of 63-90μm soil particles were markedly higher for Warden sandy loam than for Ritzville silt loam.Together with the lower TFV of Warden sandy loam,dust emissions from fine particles(<100μm in diameter)of Warden sandy loam thus may be a main contributor to dust in the region's atmosphere,since the PM10 emissions from the soil erosion surfaces and its ensuing suspension within the atmosphere constitute an essential process of soil erosion in the Columbia Plateau.Developing and implementing strategic land management practices on sandy loam soils is therefore necessary to control dust emissions in the Columbia Plateau. 展开更多
关键词 particle size threshold friction velocity inhalable particulate matter total suspended particles Warden sandy loam Ritzville silt loam Columbia Plateau
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Fabrication of metal suspending nanostructures by nanoimprint lithography(NIL) and isotropic reactive ion etching(RIE)
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作者 XIE GuoYong ZHANG Jin +3 位作者 ZHANG YongYi ZHANG YingYing ZHU Tao LIU ZhongFan 《Science China(Technological Sciences)》 SCIE EI CAS 2009年第5期1181-1186,共6页
We report herein a rational approach for fabricating metal suspending nanostructures by nanoimprint lithography(NIL) and isotropic reactive ion etching(RIE).The approach comprises three principal steps:(1) mold fabric... We report herein a rational approach for fabricating metal suspending nanostructures by nanoimprint lithography(NIL) and isotropic reactive ion etching(RIE).The approach comprises three principal steps:(1) mold fabrication,(2) structure replication by NIL,and(3) suspending nanostructures creation by isotropic RIE.Using this approach,suspending nanostructures with Au,Au/Ti or Ti/Au bilayers,and Au/Ti/Au sandwiched structures are demonstrated.For Au nanostructures,straight suspending nanostructures can be obtained when the thickness of Au film is up to 50 nm for nano-bridge and 90 nm for nano-finger patterns.When the thickness of Au is below 50 nm for nano-bridge and 90 nm for nano-finger,the Au suspending nanostructures bend upward as a result of the mismatch of thermal expansion between the thin Au films and Si substrate.This leads to residual stresses in the thin Au films.For Au/Ti or Ti/Au bilayers nanostructures,the cantilevers bend toward Au film,since Au has a larger thermal expansion coefficient than that of Ti.While in the case of sandwich structures,straight suspending nanostructures are obtained,this may be due to the balance of residual stress between the thin films. 展开更多
关键词 suspending NANOSTRUCTURE FABRICATION NANOIMPRINT lithography(NIL) ISOTROPIC reactive ion etching(RIE)
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Numerical Modelling of Sediment Particle Transportation on a Navigation Inlet Using the Particle Tracking Model (PTM)
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作者 Lloyd Ndlovu Zaid Mustafa 《Open Journal of Civil Engineering》 2024年第3期374-390,共17页
This paper investigates particle transportation using a numerical model application approach to understand the final fate of suspended sediment particle masses due to a dredging operation in a navigational harbor inle... This paper investigates particle transportation using a numerical model application approach to understand the final fate of suspended sediment particle masses due to a dredging operation in a navigational harbor inlet using PTM (Particle Tracking Model). The investigation applied PTM and simulated particle transportation at a navigational harbor called St Jerome Creek Inlet in Chesapeake Bay in Maryland. The United States Army Corps of Engineers (USACE), Maryland District, designed jetties for the inlet, which, when constructed, would minimize dredging requirements from once in a two-year period to once in a ten-year period. In the meantime, due to the frequent dredging requirements of the inlet, there exists a need to understand the fate of the suspended sediments from the dredging operations to assess the environmental impact on the aquatic environment and the coastal community. This study used PTM to simulate the transportation of sediments in a 30-day period during a dredging operation. Ten sediment source locations were selected as possible sites from which dredged materials could be introduced into the flow system. The model output was analyzed to draw conclusions. Results showed that most suspended sediment particle masses moved from their initial site locations and settled along the shoreline, whilst the sediments that found their way out of the inlet system towards the ocean migrated southward and settled approximately 6 miles at the tip of the mainland. The objective of the study is to track sediment particles from a dredging operation. This would be significant in tracking possible contaminants in an aquatic environment for future environmental management decisions. 展开更多
关键词 PTM Suspended Sediments DREDGING Particle Tracking
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Models for Prediction and Assessment of Losses of Production Suspending and Cutting in Enterprises
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作者 Yu Qingdong Chi Kelian (Commerce College, Qingdao University, Qingdao 266071) 《Natural Disaster Reduction in China》 1999年第4期37-41,共5页
The reference paper 1 shows a primary approach to the assessment methods of disaster economic loss. In this paper, the prediction and assessment of indirect losses of disaster of production suspending and cutting in e... The reference paper 1 shows a primary approach to the assessment methods of disaster economic loss. In this paper, the prediction and assessment of indirect losses of disaster of production suspending and cutting in enterprises are studied and the prediction and assessment models are given. The methods can be applied not only to pre disaster prediction of losses caused by production suspending and cutting in enterprises, but also to after disaster losses assessment. 展开更多
关键词 LOSSES of PRODUCTION suspending and CUTTING DISASTER LOSS assessment DISASTER LOSS PREDICTION
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Study on the Sediment Transport Flux and Mechanism in the Bohai Strait at the Tidal and Monthly Scales in Summer 被引量:2
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作者 YUAN Xiaodong FENG Xiuli +2 位作者 HU Rijun JIANG Shenghui ZHONG Wei 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第1期75-87,共13页
Based on the data of tidal currents and suspended sediment concentrations observed synchronously at 11 stations in the Bohai Strait lasting for 25 hours,the temporal and spatial variations of currents and suspended se... Based on the data of tidal currents and suspended sediment concentrations observed synchronously at 11 stations in the Bohai Strait lasting for 25 hours,the temporal and spatial variations of currents and suspended sediment concentrations in the Bohai Strait in summer were analyzed.The Study preliminarily discussed the transport mechanism,transport trend and transport flux of suspended sediments in summer,using flux-mechanism decomposition method and numerical simulation.The suspended sediment transport was mainly controlled by advection and next influenced by vertical net circulation,while resuspension is relatively weak in Bohai Strait.The single-width fluxes of investigation stations varied from 3.8 to 89.1 gm^(−1) s^(−1),with the maximum value in Miaodao Strait.The suspended sediment transport trends in Laotieshan channel along the vertical section are obviously distinct.The waters mainly flow out of the Bohai Sea in surface layer,while into the Bohai Sea in bottom layer.However,the transport trends of other channels in the centre and south are consistent vertically.The sediments in the Bohai Strait follows the transport pattern of moving outward from the south and inward from the north in summer,i.e.,the sediments are carried out of the Bohai Sea through the Laotieshan channel,while into the Bohai Sea through other channels.And the outflow flux exceeds the inflow flux in August with the net water flux of 1.4×10^(10)m^(3),basically same as the deliveries of the rivers into the Bohai Sea.Moreover,the suspended sediment flux is 0.33 Mt under the action of tidal residual currents in the Yellow Sea in August. 展开更多
关键词 Bohai Strait suspended sediment transport numerical simulation SUMMER
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Modeling impact of culture facilities on hydrodynamics and solute transport in marine aquaculture waters of North Yellow Sea 被引量:1
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作者 Heng-zhi Jiang Yong-peng Ji Ming-liang Zhang 《Water Science and Engineering》 EI CAS CSCD 2023年第1期26-35,共10页
An increasing number of marine aquaculture facilities have been placed in shallow bays and open sea,which might significantly affect hydrodynamic and solute transport processes in marine aquaculture waters.In this stu... An increasing number of marine aquaculture facilities have been placed in shallow bays and open sea,which might significantly affect hydrodynamic and solute transport processes in marine aquaculture waters.In this study,a coupled hydrodynamic and solute transport model was developed with high-resolution schemes in marine aquaculture waters based on depth-averaged shallow water equations.A new expression of drag force was incorporated into the momentum equations to express the resistance of suspended culture cages.The coupled model was used to simulate the effect of suspended structures on tidal currents and the movement of a contaminant cloud in the marine aquaculture of the North Yellow Sea,China.The simulation results showed a low-velocity area appearing inside the aquaculture cage area,with a maximum reduction rate of velocity close to 45%under high-density culture.The results also showed that tidal currents were sensitive to the density of suspended cages,the length of cages,and the drag coefficients of cages.The transport processes of pollutants inside aquaculture facilities were inhibited away from the vicinity of the culture cage area because of the diminished tidal currents.Therefore,the suspended cages significantly affected the transport processes of pollutants in the coastal aquaculture waters.Furthermore,the reduced horizontal velocity significantly decreased the food supply for the aquaculture areas from the surrounding sea. 展开更多
关键词 Marine aquaculture Suspended cages Numerical simulation Current reduction Solute transport
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The dissolution of total suspended solids and treatment strategy of tailwater in a Litopenaeus vannamei recirculating aquaculture system
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作者 Yuhuan SUN Jian LU +3 位作者 Tianlong QIU Li ZHOU Jianming SUN Yishuai DU 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第3期1197-1205,共9页
In recirculating aquaculture systems(RASs),the effective treatment of aquaculture tailwater is essential to maintain the health of the RAS.This study investigated the optimal time and method for tailwater treatment du... In recirculating aquaculture systems(RASs),the effective treatment of aquaculture tailwater is essential to maintain the health of the RAS.This study investigated the optimal time and method for tailwater treatment during three periods of the aquaculture of the Litopenaeus vannamei:nursery(0–26 d),middle(27–57 d),and later(57–104 d).The variation of several water parameters during the dissolution of total suspended solid(TSS)in tailwater,applied with the effects of ozone on the microorganism and water quality parameters were investigated.Results showed that the TSS concentrations in tailwater decreased with time,although not significantly(P>0.05),whereas total ammonia nitrogen(TAN),nitrite(NO-2-N),and nitrate(NO_(3)^(-)-N)increased significantly(P<0.05).Therefore,TSS should be removed from the tailwater as early as possible,being most optimal within 4 h.Ozone removed 38.24%–48.95%of TSS,17.78%–90.14%of TAN,and 87.50%–98.90%of NO-2-N after 4 h of treatment.However,it resulted in the significant accumulation of NO_(3)^(-)-N.Moreover,the total number of Vibrio and bacterial counts in aquaculture tailwater was reduced completely by ozone within 4 h.Thus,these results provided technical details and data support for the effective treatment of tailwater from shrimp RAS. 展开更多
关键词 DISSOLUTION Litopenaeus vannamei OZONATION recirculating aquaculture system(RAS) tailwater treatment total suspended solid
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Random vortex induced vibration response of suspended flexible cable to fluctuating wind
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作者 Genjin MU Weiqiu ZHU Maolin DENG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第12期2207-2226,共20页
A popular dynamical model for the vortex induced vibration(VIV)of a suspended flexible cable consists of two coupled equations.The first equation is a partial differential equation governing the cable vibration.The se... A popular dynamical model for the vortex induced vibration(VIV)of a suspended flexible cable consists of two coupled equations.The first equation is a partial differential equation governing the cable vibration.The second equation is a wake oscillator that models the lift coefficient acting on the cable.The incoming wind acting on the cable is usually assumed as the uniform wind with a constant velocity,which makes the VIV model be a deterministic one.In the real world,however,the wind velocity is randomly fluctuant and makes the VIV of a suspended flexible cable be treated as a random vibration.In the present paper,the deterministic VIV model of a suspended flexible cable is modified to a random one by introducing the fluctuating wind.Using the normal mode approach,the random VIV system is transformed into an infinite-dimensional modal vibration system.Depending on whether a modal frequency is close to the aeolian frequency or not,the corresponding modal vibration is characterized as a resonant vibration or a non-resonant vibration.By applying the stochastic averaging method of quasi Hamiltonian systems,the response of modal vibrations in the case of resonance or non-resonance can be analytically predicted.Then,the random VIV response of the whole cable can be approximately calculated by superimposing the response of the most influential modal vibrations.Some numerical simulation results confirm the obtained analytical results.It is found that the intensity of the resonant modal vibration is much higher than that of the non-resonant modal vibration.Thus,the analytical results of the resonant modal vibration can be used as a rough estimation for the whole response of a cable. 展开更多
关键词 vortex induced vibration(VIV) wake oscillator random response suspended flexible cable fluctuating wind
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New algorithm of shape-finding of suspension bridge with spatial cables
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作者 Xiao-Kang Deng Zhuo Deng Xin Ren 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2023年第1期33-40,共8页
A new algorithm is proposed to solve the problems of shape-finding of suspension bridge with spatial cables what include tedious iteration,slow convergence speed and even no convergent under some circumstances.In this... A new algorithm is proposed to solve the problems of shape-finding of suspension bridge with spatial cables what include tedious iteration,slow convergence speed and even no convergent under some circumstances.In this paper,the stress analysis of the main cable is carried out,and the relationship between the slope change and the coordinate change is found.This paper also discussed how to find the minimum slope point of symmetrical or asymmetric main cable,and the deformation compatibility equation is established and solved to obtain the shape of main cable.The algorithm in this paper can ensure the convergence of the solution for the suspension bridge with spatial cables.The calculation accuracy is high through the demonstration of the calculation examples. 展开更多
关键词 Spatial cables Suspenders Shape-finding Slope of cable Coupling Unequal height main tower
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Numerical Simulation of Bed Load and Suspended Load Sediment Transport Using Well-Balanced Numerical Schemes
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作者 J.C.González-Aguirre J.A.González-Vázquez +2 位作者 J.Alavez-Ramírez R.Silva M.E.Vázquez-Cendón 《Communications on Applied Mathematics and Computation》 2023年第2期885-922,共38页
Sediment transport can be modelled using hydrodynamic models based on shallow water equations coupled with the sediment concentration conservation equation and the bed con-servation equation.The complete system of equ... Sediment transport can be modelled using hydrodynamic models based on shallow water equations coupled with the sediment concentration conservation equation and the bed con-servation equation.The complete system of equations is made up of the energy balance law and the Exner equations.The numerical solution for this complete system is done in a seg-regated manner.First,the hyperbolic part of the system of balance laws is solved using a finite volume scheme.Three ways to compute the numerical flux have been considered,the Q-scheme of van Leer,the HLLCS approximate Riemann solver,and the last one takes into account the presence of non-conservative products in the model.The discretisation of the source terms is carried out according to the numerical flux chosen.In the second stage,the bed conservation equation is solved by using the approximation computed for the system of balance laws.The numerical schemes have been validated making comparisons between the obtained numerical results and the experimental data for some physical experiments.The numerical results show a good agreement with the experimental data. 展开更多
关键词 Sediment transport Suspended load Bed load Finite volume method Numerical simulation Well-balanced schemes
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Simulation of Moving Bed Erosion Based on the Weakly Compressible Smoothed Particle Hydrodynamics-Discrete Element Coupling Method
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作者 Qingyun Zeng Mingxin Zheng Dan Huang 《Fluid Dynamics & Materials Processing》 EI 2023年第12期2981-3005,共25页
A complex interface exists between waterflow and solid particles during hydraulic soil erosion.In this study,the particle discrete element method(DEM)has been used to simulate the hydraulic erosion of a granular soil ... A complex interface exists between waterflow and solid particles during hydraulic soil erosion.In this study,the particle discrete element method(DEM)has been used to simulate the hydraulic erosion of a granular soil under moving bed conditions and surrounding terrain changes.Moreover,the weakly compressible smoothed particle hydrodynamics(WCSPH)approach has been exploited to simulate the instability process of the free surfacefluid and its propagation characteristics at the solid–liquid interface.The influence of a suspended medium on the waterflow dynamics has been characterized using the mixed viscosity concept accounting for the solid–liquid mixed particle volume ratio.Numerical simulations of wall-jet scouring and reservoir sedimentflushing on a mobile bed were performed and validated with experiments.The results show that the proposed WCSPH–DEM coupling model is highly suitable for determining parameters,such as the local maximum scour depth,the scour pit width,and the sand bed profile.The effects on the hydraulic erosion process of two important para-meters of the mixed viscosity coefficient(initial solid volume concentration and initial viscosity coefficient)are also discussed to a certain extent in this study. 展开更多
关键词 Hydraulic soil erosion WCSPH-DEM coupling model suspended medium mixed viscosity coefficient
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