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Effect of total dissolved gas supersaturated water on early life of David's schizothoracin (Schizothorax davidi)

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2013年第7期14卷 632-639页

作者： Rui-feng LIANG Bo LI Ke-feng LI you-cai tuo State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Changjiang River Scientific Research Institute

The effect of total dissolved gas （TDG） supersaturation on fish living downstream of dams is one of the main ecological risks of high dam construction. A strategy for mitigating the negative effects is needed urgently since many high dams are under construction in the upper reaches of the Yangtze River in China. Experiments on the hatching process of David＇s schizothoracin were carried out and the results show that the hatching rate decreased with increasing TDG levels, and that most eggs hatched within a very short time in the higher TDG saturation groups. By using a stereomicroscope, damages to the head, yolk sac, body, anus, etc. were found in larvae which hatched in TDG supersaturated water. Results show that the lesion rate increased with increasing TDG levels. Furthermore, 7-d-old David＇s schizothoracin were exposed to TDG supersaturated water levels of 100%, 105%, 110%, 115%, 120%, 125%, 130%, 135%, and 140% for testing their tolerance to TDG supersaturation. We found that the median lethal concentrations （LC50） for 13, 14, 20, 35, 52, 73, and 96 h exposure were 138%, 138%, 134%, 130%, 129%, 128%, and 126%, respectively. The median lethal times （LTs0） were 7.49, 11.04, 19.25, and 35.38 h for exposure to water with TDG levels of 145%, 140%, 135%, and 130%, respectively.

关键词： Total dissolved gas (TDG) TDG supersaturation David's schizothoracin Hatch Larvae

Influence of total dissolved gas-supersaturated water on silver carp(Hypophthalmichthys molitrix)

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Water Science and Engineering 2016年第4期9卷 324-328页

作者： Lu Cao Rui-feng Liang you-cai tuo Yong Li Ke-feng Li State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University

Dam discharges over spillways are the main reason for the gas-supersaturated water generated in *** aquatic organisms,especially fish,readily develop gas bubble disease(GBD) in a river with total dissolved gas supersaturation(TDGS).Sometimes,fish will die after a specific exposure period,which negatively affects the biological *** this study,the influence of TDGS on silver carp was *** carp were exposed to gas-supersaturated water with TDGS levels of 140%,135%,130%,125%,120%,and 110%to test the impact of *** silver carp died when the TDGS level was 120%or higher,and all the silver carp exposed to a TDGS level of 140%died within10 *** comparison with the Chinese sucker,Prenant's schizothoracin,and rock carp,silver carp seem less sensitive to *** addition,we tested the catalase(CAT) activity in the muscles and gills of silver carp after they were exposed to gas-supersaturated water with a TDGS level of140%.The CAT activity changed with time;it increased first and then decreased until it was lower than the initial CAT *** results of this study can provide basic data for developing a standard for environmental evaluation.

关键词： Total dissolved gas supersaturation Silver carp CAT activity Gas bubble disease Median lethal time Median lethal concentration

Modeling of thermodynamics of ice and water in seasonal ice-covered reservoir

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Journal of Hydrodynamics 2018年第2期30卷 267-275页

作者： Nan Li you-cai tuo Yun Deng Rui-dong An Jia Li Rui-feng Liang State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Chengdu 610065China

A width-averaged 2-D numerical model for simulating vertical distributions of flow and water temperature in reservoirs with an ice cover is developed. In this model, the 2-D flow and water temperature distributions are solved by the finite volume method with the k-？ turbulent model. The heat conduction in the ice cover is modeled by the vertical heat transfer and the heat exchanges through the air-ice and ice-water interfaces. The model is applied to a 153 km long reservoir in Songhua River and the simulated results are in a good agreement with the field data of both the vertical water temperature and the ice thickness. The simulated results show that the ice cover thickness in the reservoir is not uniform, the maximum thickness appears in the middle reach, the outflow temperature has an obvious variation as compared with the natural temperature, and a buoyant flow occurs in the reservoir surface at the freeze-up and break-up periods. The model can effectively simulate the water temperature and the ice conditions of large reservoirs in cold regions.

关键词： Reservoir ice water temperature ice thickness heat conduction

Heat transfer at ice-water interface under conditions of low flow velocities

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Journal of Hydrodynamics 2016年第4期28卷 603-609页

作者：李楠脱友才邓云李嘉梁瑞峰安瑞冬 State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University

The heat transfer at the ice-water interface is closely related to the hydrodynamic and physical properties of the water *** affects the ice cover thickness and the water temperature underlying the ice *** paper studies the heat transfer from the water to the ice *** on the flume data,a linear relationship between the ice-water heat transfer coefficient and the flow velocity beneath the ice cover is established and the calculated dimensionless ice-water heat transfer coefficient is 1.1×*** empirical relationship can be applied to estimate the ice-water heat transfer of reservoirs,lakes and other freshwater bodies when the flow velocity under the ice cover is in the range of 0.024 m/s-0.110 m/s.

关键词： reservoirs beneath hydrodynamic dimensionless freshwater turbulence turbulent deviation affects thick

INFLUENCE OF STRUCTURE ON HYDRAULIC CHARACTERISTICS OF T SHAPE FISHWAY

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Journal of Hydrodynamics 2012年第5期24卷 684-691页

作者： MAO Xi FU Jing-jing tuo you-cai AN Rui-dong LI Jia State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Chengdu 610065China HydroChina Hua Dong Engineering Corp.9 Hangzhou 310014 China

While dams cut off the migratory route of fish, and affect their growth and breeding, fishways are built to restore the con- nectivity of rivers and facilitate the life cycle of these migratory fish. This paper proposes a new kind of fishway called the ＂T shape fishway＂, and studies it by using both numerical simulations and physical experimental methods with the aim to design a fishway in China for migratory fish with swimming and jumping capability much poorer, such as schizothorax davidi and schizothorax prenanti, as compared with migratory fish in other places of the world, like trout and salmon. It is indicated that the range of velocity in each regular pool of the T shape fishway is from 0.42 m/s to 1.22 m/s when the flow discharge Q is 350 L/s, and there are no large vortex zones found there. This study shows that the T shape fishway can meet the requirements of these migratory fish quite well in terms of velocity and flow patterns in China.

关键词： fishway migratory fish baffle drop sill numerical simulation experiment

Exploring the Possibility of Deformation Twinning in Pure Aluminum

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Acta Metallurgica Sinica(English Letters) 2016年第7期29卷 647-651页

作者： tuo cai Zhen-Jun Zhang Jin-Bo Yang Zhe-Feng Zhang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences

Can aluminum generate deformation twins？ Contradictories exist among the experimental results, theoretical predictions, and molecular dynamics simulations. Our first-principles calculations based on the full-potential linearly augmented plane wave method show that the bonding electron density of aluminum gathers at the tetrahedral interstices, and this specific electronic structure is in agreement with the experimental data from quantitative convergent-beam electron diffraction. In terms of this characteristic, the matching between the cohesive energy of local deformation twins with different thickness and global matrix can shed light on deformation twins in aluminum. This study may give a lane to insight into deformation twins in different metals.

关键词： Metals and alloys Deformation twinning First-principles Density functional theory

Simultaneously enhancing the strength and ductility of as-extruded AlN/AZ91 composites via nano-precipitation and pyramidal slip

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Journal of Materials Science & Technology 2024年第5期172卷 240-254页

作者： Bin Zhang Yunxia Sun tuo Liang Yunzhen Li Tian Li Jingchao Wang Ruiru cai Changlin Yang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

Age hardening is often used to optimize the mechanical properties of as-deformed Mg-based materials in industry,whereas the improvement of strength is usually accompanied by the significant loss of ductility,which hinders the application of Mg-based materials in structural *** the present work,high strength-ductility synergy(the yield strength of 263±9 MPa,ultimate tensile strength of 398±7 MPa and elongation to fracture of 34%±1%)was realized in as-extruded AlN/AZ91 composites after optimiz-ing aging *** characterization shows that AlN particles induced a large number of geometrically necessary dislocations around the AlN/Mg interface during extrusion,which decreased the nucleation barrier and provided more heterogeneous nucleation sites forγ-Mg 17 Al 12 continuous ***,95%of residual dislocations in as-extruded AlN/AZ91 composites were annihilated dur-ing peak-aging,suppressing the growth and coarsening of continuous ***,high density of nano-sizedγ-Mg 17 Al 12 continuous precipitates was produced in as-extruded AlN/AZ91 composites af-ter *** tension,gliding dislocations bypassed sphericalγ-Mg 17 Al 12 nano-precipitates by Orowan looping rather than cutting mechanism,which induced a strong block on dislocation *** high yield strength was mainly attributed to the high density of non-shearableγ-Mg 17 Al 12 nano-precipitates with spherical morphology,which was different from other Mg-Al-based *** results of texture evolution and slip trace analysis demonstrated that the suppression of extension twinning and less basal slip was due to the enhanced activity of pyramidalc+aslip in as-extruded AlN/AZ91 com-posites after peak-aging during the room temperature tension,meanwhile,the dislocation density of as-extruded AlN/AZ91 composites was significantly decreased during peak-aging,then higher elongation to fracture was achieved.

关键词： Magnesium matrix composites Mechanical properties Precipitation Deformation mechanisms Non-basal slip

Spin-Dependent Electron Transport in an Armchair Graphene Nanoribbon Subject to Charge and Spin Biases

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Chinese Physics Letters 2013年第1期30卷 158-160页

作者： ZHANG Xiao-Wei ZHAO Hua SANG Tian LIU Xiao-Chun cai tuo Qiannan Normal College for Nationalities Duyun 558000

We study the spin-dependent electron transport in an armchair graphene nanoribbon sample driven by both the charge and the spin biases within the tight-binding *** numerical calculations we give the spin-dependent currents for a fixed spin bias as a function of the charge *** is found that we can let only one type of spin current pass through the graphene nanoribbon for a wide range of charge bias,which is due to the difference of the bias voltage windows for different spin electrons when the charge and the spin biases ***,the pure spin current can be controlled via the charge *** results are suggestive for developing new kinds of spin filters.

关键词： graphene charge Electron

Global Governance and National Governance:Two Strategic Considerations by Contemporary China

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Peace 2016年第4期 19-26页

作者： cai tuo China Social Sciences

Preface Since the 1980s,governance has increasingly penetrated into the theory and practice of human activities,and has undoubtedly obtained the theoretical status as the concepts of globalization,global issues,public... 详细信息

关键词： Global Governance and National Governance