SUSPENDED SEDIMENT TRANSPORT CAPACITY OF OPEN CHANNEL FLOW     

Zhixian Cao Prot. Dr.-Ing.. Director of Institute of Hydraulic Engineering  Tianjin University. Tianjin . China. Wensheng WangSenior Engineer  Associate Director of Lower Haihe River Administration Bureau. Ministry of Water Resources. Tianjin 《国际泥沙研究》1997,(3)

I.~ODUCTIONSuspendedsedimenttransportcapacity(SSTC)ofopenchannelflowisoneofthebasicsubjectsinsedimenttransportmechanicsandsedimentationengineeringpractice.Mostexistingformulationsareempiricalandsemiempiricalorrestheavilyonassumptionswhicharenotyetjustified.Thisarisesmostlybecauseofthecomplexityoftheproblem.Forafullydeveloped,in-equilibriumflowinawiderectangularchannel,theSSTCcanbbdeterminedasfollowsor=n:,ty)cab)-dy=Ca'I(l)1I=J4(D)'exp[--V,(n)]'da(2)unwhereCTIsSSTC,uistheaveragedflo…  相似文献   

SEDIMENT CONTROL MEASURES IN SERIOUS SOIL EROSION REGION IN CHINA     

CAO Wenhong  Senior Engineer  China Institute of Water Resources  Hydropower Research 《国际泥沙研究》1997,(3)

I.INTRODUCTIONSoilerosionareasinChinasearchto3.67millionkm'whichoccupies38.2%OfthewholeareainChina.Thesoilerosionregionisspreadingovertheti)holecountry.Amongthat,soilerosionbyrainfallistermedas"watererosion"whichisdistributedinmountainsandhillarea.soilerosionbywindistermedas"winderosion",mainlydistributedinareasalongtheGreatWall,soilerosionbyfreezeandmeltistermedas"freezeerosion",mainlydistributedinhighmountainarea.Inthepastfortyyears,manyintegrateharnessmeasureshavebeenaPPliedindiffer…  相似文献   

衡阳市清水塘矿区金,银成矿地质背景分析   总被引：1，自引：0，他引：1  

赖健清  罗贤昌 《湖南地质》1997,16(4):245-249

清水塘矿区主要含矿地层是下古生界浅变质岩，代表地槽构造层，受地洼阶段的岩浆侵入。由于构造岩浆多期活动的叠加和３，形成金银成矿的有利条件。地洼阶段的岩浆活动不仅提供了成矿的驱动力，而且提供了成矿物质来源。  相似文献   

A CASE STUDY ON POSSIBLE DEBRIS FLOW CAUSED BY WASTE SOLID IN JUNGAR COALFIELD AREA     

GAO Yitang Engineer  Soil  Water Conservation Bureau  Yellow River Conservancy Commission  Zhengzhou  P.R.China. QI Pu Senior Engineer  Institute of Hydraulic Research  Yellow River Conservancy Commission  Zhengzhou  P. R. China 《国际泥沙研究》1997,(3)

Debrisflow,definedasakindofhighlycondensedtit!o-phaseflowofsolidandfluid,iscomposedofslurryandrocksofdifferentsizeswithageneraldensity'ofI.2to2.3t/m3.Theactivityliesbetweenfloodandlandslide.Itflowslikenormalfloodandsholvsturbulentstateaswithlesssolidcontentsandlowerviscosity,itisplasticviscousflowwithunstablegUstmovementwhellitisofhighsolidcontainsandhighviscosity.Debrisflowisformedunderthreebasicconditionsfprecipitousslopeoflandform,solidwasteoflargevolume,andenoughwatersupply.Theoccurrence,…  相似文献   

On the contribution of local feedback mechanisms to the range of climate sensitivity in two GCM ensembles   总被引：3，自引：15，他引：3  

M. J. Webb  C. A. Senior  D. M. H. Sexton  W. J. Ingram  K. D. Williams  M. A. Ringer  B. J. McAvaney  R. Colman  B. J. Soden  R. Gudgel  T. Knutson  S. Emori  T. Ogura  Y. Tsushima  N. Andronova  B. Li  I. Musat  S. Bony  K. E. Taylor 《Climate Dynamics》2006,27(1):17-38

Global and local feedback analysis techniques have been applied to two ensembles of mixed layer equilibrium CO₂ doubling climate change experiments, from the CFMIP (Cloud Feedback Model Intercomparison Project) and QUMP (Quantifying Uncertainty in Model Predictions) projects. Neither of these new ensembles shows evidence of a statistically significant change in the ensemble mean or variance in global mean climate sensitivity when compared with the results from the mixed layer models quoted in the Third Assessment Report of the IPCC. Global mean feedback analysis of these two ensembles confirms the large contribution made by inter-model differences in cloud feedbacks to those in climate sensitivity in earlier studies; net cloud feedbacks are responsible for 66% of the inter-model variance in the total feedback in the CFMIP ensemble and 85% in the QUMP ensemble. The ensemble mean global feedback components are all statistically indistinguishable between the two ensembles, except for the clear-sky shortwave feedback which is stronger in the CFMIP ensemble. While ensemble variances of the shortwave cloud feedback and both clear-sky feedback terms are larger in CFMIP, there is considerable overlap in the cloud feedback ranges; QUMP spans 80% or more of the CFMIP ranges in longwave and shortwave cloud feedback. We introduce a local cloud feedback classification system which distinguishes different types of cloud feedbacks on the basis of the relative strengths of their longwave and shortwave components, and interpret these in terms of responses of different cloud types diagnosed by the International Satellite Cloud Climatology Project simulator. In the CFMIP ensemble, areas where low-top cloud changes constitute the largest cloud response are responsible for 59% of the contribution from cloud feedback to the variance in the total feedback. A similar figure is found for the QUMP ensemble. Areas of positive low cloud feedback (associated with reductions in low level cloud amount) contribute most to this figure in the CFMIP ensemble, while areas of negative cloud feedback (associated with increases in low level cloud amount and optical thickness) contribute most in QUMP. Classes associated with high-top cloud feedbacks are responsible for 33 and 20% of the cloud feedback contribution in CFMIP and QUMP, respectively, while classes where no particular cloud type stands out are responsible for 8 and 21%.  相似文献   

The selective flotation of enargite from other copper minerals — a single mineral study in relation to beneficiation of the Tampakan deposit in the Philippines     

G.D. Senior  P.J. Guy  W.J. Bruckard 《International Journal of Mineral Processing》2006

The floatability of enargite (3Cu₂S.As₂S₅) has been determined as a function of pulp potential to establish whether the flotation behaviour of the mineral differs sufficiently from that of other copper minerals thus offering the prospect of rejecting arsenic from the Tampakan ore by potential control during flotation.  相似文献   

Locational analysis of slums and the effects of slum dweller’s activities on the social,economic and ecological facets of the city: insights from Kumasi in Ghana     

Takyi  Stephen Appiah  Amponsah  Owusu  Yeboah  Ata Senior  Mantey  Emmanuel 《GeoJournal》2021,86(6):2467-2481

GeoJournal - Slum development has become a major urban planning and management problem due to the challenges they pose to the larger urban environment. Activities of slum dwellers are...  相似文献   

Simplified Method for Calculating Standing Wave Pressure on Vertical Breakwater     

Liu Liping Engineer  The Investigation  Design Institute of The Second Navigation Engineering Bureau  Ministry of Communications  P. R. of China  Wuhan 《中国海洋工程》1991,(4)

Through numerical modeling, a kind of simplified calculating method for standing wave pressure on vertical face breakwater have been put forward. Not only the formulas proposed in this paper are simple in form and very easy in use, but also they possess continuity on the full range of standing wave. And more, the precision requiremennts of calculation can be satisfied to a certain extent in engineering practice.  相似文献   

Stream Function Wave Derived by Unified Variational Principle of Water Gravity Wave     

Fu Yuhua Senior Engineer  China Offshore Oil Production Research Center  P.O.Box  Beijing 《中国海洋工程》1997,(2)

Based on the linear wave,solitary wave and fifth order stokes wave derived by use of the Uni-fied Variational Principle of Water Gravity Wave(UVPWGW),this paper derives stream function wavetheory by using UVPWGW.This paper will handle the Kinematic Free Surface Boundary Condition(KFSBC)and Dynamic Free Surface Boundary Condition(DFSBC)directly and give the optimum solu-tion,instead of the conditions ∑(Q_(av)-Q_i)~2=min,and the related equations of stational condition.When the wave height H,period T and water depth D are given,the original stream function wave willbe determined,and can not be adjusted if it does not agree with the real case;in the present method,the ad-justment can be done by adding several constraint conditions,for example,the wave profile can be ad-justed according to the condition of accurate peak position.The examples given in this paper show that forthe original stream function wave,the DFSBC can be fairly well satisfied,but the KFSBC can not;howev-er,the stream function wave derive  相似文献   

Effect of Wave Groups on Wave Run-up     

Zhou Jiabao  Zhang Jiachang Senior Engineer  River  Harbour Department  Nanjing Hydraulic Research Institute  Nanjing 《中国海洋工程》1992,(1)

-The effect of wave group on wave run-up on a slope dike is mainly discussed in this paper. Two simulating methods of wave group and their applications in laboratory are introduced. Synthesizing the research results of wave run-up on a slope dike, the effect of wave group on wave run-up on a slope dike in coastal protection engineering is studied as the main point.  相似文献