EXPERIMENTAL STUDY OF BEDLOAD TRANSPORT IN UNSTEADY OPEN-CHANNEL FLOW

I.INTRODUCTIONBedloadtransportinsteadyuniformopenchannelflowhasbeenextensiVelystudied.Manyoftheformulasdevelopedforthepredictionofbedloadtransportinuniformopen-channelflowcanbebroughtinthefollowingform(ChienandWan,1983);ac=f(O)(l)xvhereacisthedimensionlessparameterofbedloadtranSPortandOisthedimensionlessparameterofflowintensity.TheseparametersaredefinedasfwheregsisthebedloadtranspoftratePerunitwidthindryweight;disthesedimentdiameter,Sisthebedslopeofthechannel;Rbisthehydraulicradiusdue…     

Hercynian-Indosinian Sedimento-Tectonic Evolution of the Nanpanjiang Basin

Following the orogeny in the Early Palaeozoic, the tectonic evolution of the Nanpanjiang basin in the Hercynian-Indosinian stage constituted a complete Wilson Cycle, made up of the stages of early rifting (D-P1), late rifting and passive margin developement (P2-T1), and peripheral foreland basin developement (T2-T3). The REE data of the initial Early Triassic basalts from the southern part of the basin has verified the existence of the oceanic crust once in the basinal evolution. The basin developed into a foreland one in the Middle-Late Triassic, indicating that the Yangtze plate once collided with the Indo-Sinian plate along the Black River fracture zone.     

Experimentally validated numerical method for the hydrodynamic design of horizontal axis tidal turbines

Although a lot can be learnt from technology transfer from wind turbines and ship propellers, there have been a few experiments investigating marine current turbines. As a result, a study has been carried out on the power, thrust and cavitation characteristics of 1/20th scale model of a possible 16 m diameter horizontal axis tidal turbine. Cavitation tunnel experiments for different blade pitch settings have been compared with simulations based on a developed blade element-momentum theory. This theory has been shown to provide a satisfactory representation of the experimental turbine performance characteristics. As an example application, the developed theory has been used to design possible horizontal axis tidal turbines for the tidal flows around Portland Bill. The results show that there is a clear balance between design loads and optimisation of energy yields.     

Experimental and Theoretical Investigations of Mist Lift Cycle

A rectangular mist lift tube of 20 m effective height was constructed to investigate the mist generation and up flow processes with various temperatures, pressures and mass flow rates of the incoming hot water through two different mist generation plates. Parameters such as temperature, pressure and dryness of the two phase mixture at six different heights of the lift tube as well as the lift mass flow ratio were measured and analysed. A theoretical analysis was made based on simplified one dimensional model of two-velocity-two-phase flow. The calculated results were discussed regarding temperature, pressure and dryness variations along the lift tube height and compared with the experimental results.     

Numerical Simulation of Wave Height and Wave Set-Up in Nearshore Regions

Based on the time dependent mild slope equation including the effect of wave energy dissipation, an expression for the energy dissipation factor is derived in conjunction with the wave energy balance equation, and then a practical method for the simulation of wave height and wave set-up in nearshore regions is presented. The variation of the complex wave amplitude is numerically simulated by use of the parabolic mild slope equation including the effect of wave energy dissipation due to wave breaking. The components of wave radiation stress are calculated subsequently by new expressions for them according to the obtained complex wave amplitude, and then the depth-averaged equation is applied to the calculation of wave set-up due to wave breaking. Numerical results are in good agreement with experimental data, showing that the expression for the energy dissipation factor is reasonable and that the new method is effective for the simulation of wave set-up due to wave breaking in nearshore regions.     

Model Test and Design of the Wave Energy System on "Central Fairway No. 1" Light Ship

This paper presents the test of a ship model for the design of a backward-bent duct oscillating water column type wave energy conversion system, to supply electric power for a light ship. This system suggests a new way to produce electric power automatically for large light ships.     

含菱铁矿砂岩磁性的初步研究

作为煤田盖层产出的中国内蒙古平庄J₃砂岩,其平均磁化率为60×10^-5（SI）;平均剩磁为5×10^-3A/m.经热退磁后,在磁化率、剩余磁化、等温剩磁曲线、粘滞剩磁及磁组构等方面都发生了明显的变化,出现一系列奇异磁特征.岩石透射光与反射光鉴定、物相热红外分析、差热分析、X射线衍射分析表明,该砂岩的胶结物为弱磁性的菱铁矿,它在逐步热退磁过程中逐渐变为磁铁矿,部分变为赤铁矿.并大致确定,该砂岩胶结物含量近50％.此外,对这种砂岩样品仔细地进行了常规方法的退磁试验,得到其特征剩磁方向,确定其J₃古地磁极位置为198.8°E,84.6°N(α₉₅=4.8,k=94.5).     

南极磷虾的生长与复眼晶椎数目关系的研究

本文从自然种群现场取样和实验室内活体培养两个方面对南极磷虾复眼中的晶椎数目与磷虾体长之间的关系、在负生长状态下磷虾复眼中的晶椎数目的变化等进行了研究。实验结果表明：在正常情况下（磷虾身体不出现负生长），磷虾复眼中晶椎数目与体长之间存在指数函数关系。雌性磷虾的晶椎数目（ＮＯＣＣ）与体长（ＢＬ）之间的关系为ＮＯＣＣ＝４６３．６２ｅ０．０４８４ＢＬ（ｒ＝０．９６４２，ｎ＝２７３）。从活体培养的结果来看，当南极磷虾身体出现负生长时，磷虾复眼中的晶椎数目保持不变，即晶椎数目不受负生长的影响。晶椎数目与体长之间的比率可作为研究在自然环境中南极磷虾是否存在负生长的一种检测手段。     

薄层CT对肺内结节性病变的诊断价值

本文利用薄层CT扫描技术,对支气管微细结构和改变,对肺内结节性病变大小、边缘、钙化、CT值及定位进行观察,分析了炎性纵隔淋已结肿大的特点。对肺内不肯定结节行CT 导引下活检,可明确诊断。切凹征、胸膜牵拉征、小泡征、小蜘蛛状改变、血管聚集等对肺癌的定性诊断具有重要价值。     

矿产预测理论——区域成矿学向矿产勘查延伸的理论体系

矿产预测理论研究始于20世纪50年代,在近60年的预测实践中,始终是研究的热门课题。我国学者在全国第一、二轮区划实践和相关研究成果基础上,完善了矿产预测理论的基本内容,形成矿产预测的理论体系,推动了区域成矿学向矿产勘查延伸新领域的探索。矿产预测理论概括为矿床成矿作用“异相定位”预测理论;矿床成矿系列“缺位”预测理论;多元信息“类比-求同”预测理论和地质体“对等求异”预测理论。认为成矿作用的“异相定位和矿床成矿系列”缺位预测理论是矿产预测的地质理论依据,又是对成矿学理论的补充;多元信息“类比-求同”理论是传统的预测理论,本文赋以新的内含;地质体“对等求异”理论补充了“类比-求同”理论的不足,是前3项理论内容无可比拟的。矿产预测理论已受矿产勘查实践的检验,证明是有效的,在当前已成为提高矿产预测成果准确性和勘查效益的科学依据。