A New Model for Sediment Transport

The problem of predicting sediment transportation by water waves is treated analytically with the rate of wave energy dissipation or wave damping. With resorting to the theory of shallow water waves and the basis of Yamamoto’s Coulomb-damped poroelastic model, the Boussinesq-type equation has been derived over a variation depth bed. For convenience Cnoidal wave is just discussed, The Cnoidal wave with complex wave length and wave velocity, which are as a function of wave frequency, water depth, permeability, Poisson’s ratio and complex elastic moduli of bed soil, is applied to analyse the rate of sediment transportation. Considering the sediment transportation depended on the shear stress near-bed or the horizontal velocity, the conclusion of Yamamoto’s experiment in clay bed has been extended to general situation. It could be figured out that the model should provide a method to avoid the undistinguishable factors during sediment transport processes and relate mass transport with the sediment peculiarities

基于选择集成学习的表面增强拉曼光谱检波算法（英文）

文章提出了一种表面增强拉曼光谱的检波算法.该算法基于选择性学习和3种经典检波算法,构建了一个组合波峰检测器.结果表明,与传统算法相比,针对波峰提取,作者的算法有更好的正确率和检出...National Natural Science Foundation of China(Grant Nos.61472333,61772441,61472335);; Project of marine economic innovation and development in Xiamen(No.16PFW034SF02);; Natural Science Foundation of the Higher Education Institutions of Fujian Province(No...

Investigation of characteristics of fluid field over wavy beds under oscillatory flow

利用U型振荡水槽和粒子图像测速仪(PIV)对三种固定波状底床上的流场进行了测量，得到一系列不同振幅条件下的瞬时速度场和涡量场.通过分析不同时段涡强度以及涡轨迹，讨论了底床形状对其附近流场的影响.实验结果分析表明，底床形状决定着整个涡量场特征及涡轨迹，从而决定着泥沙的净输移.这些结果对于探讨浅海区沙波、沙纹和沙垄等波状底床上泥沙输移的力学机制是很有意义的

海底波状底床上的流场特征

波状底床是一种十分常见的海床形式,比如,沙纹、沙波、沙坝等等,其形成原因非常复杂,笼统地说波状底床的形成取决于加载波流场及海底沉积物的特性。在海水动力作用下波状底床处于不稳定状态,宏观上一般是以每年几米的速度迁移,然而在局部特别是近海区,极端波况又会使得波状底床时而消失时而产生。这些都会对海底管线的安全、海滩侵蚀、海岸带变迁以及污染物扩散等实际问题带来相当大的影响。随着近年来对海洋环境问题的日益关注,波状底床上的流场特性成为了诸多学者关心的主要问题之一

非对称波状底床上泥沙输移探究

通过非对称波状底床上振荡流场特征的实验,研究了两种典型的非对称形状下的速度场和涡量,得到了两种非对称底床上的涡强度随时间的变化特征以及缓坡段和陡坡段的涡心轨迹,探讨了非对称形状对泥沙输移带来的影响

浅海陆架泥沙运移模型研究

本文根据南海海域的特点提出了适合该海域的输沙模型。考虑了风浪流联合作用下从深海大陆架到岸边的海底泥沙输移，计算了准二维流场下的泥沙输移量及底床变形率，讨论了水深和砂粒粒径对推移质和悬移质泥沙输移的影响，并针对该模型提出了需进一步改进的地方

Estimating the Speed of Cross Shore Sand Waves

In a coastal environment, calculating the speed of sand waves is a challenge for engineers due to the complexity of the hydrodynamics and the variety of the governing phenomena. As the wave or wavecurrent propagates over wavy beds, the flow is fully complicated and involves regions of separation and advection of bubbles. Up to now, some formulae based on a certain flume experimental data and hypotheses are used to estimate the movement of sand waves. In this paper, with the method combined computational model and empirical formula, a simple model estimating the speed of sand waves movement is proposed. At last, comparing with the other formulae has certified the model

一氧化氮对人肝癌细胞SMMC-7721辐射敏感性的增强效应

目的:观察一氧化氮对肿瘤细胞SMMC-7721辐射敏感性的作用效果。方法:实验于2005-06/09在兰州大学生命科学学院和中科院近代物理研究辐射医学实验室进行。处于对数生长期的肝癌细胞SMMC-7721,在用X射线照射前4h,换入含有0.1mmol/L硝普钠(一氧化氮的前体)的培养液,与对照组(不加硝普钠)一起,在200cGy/min的剂量率下,分别照射0,1,2,4,6,8Gy,换为正常培养液培养。用集落形成法计算细胞的存活率,用吖啶橙/溴乙啶双染法检测细胞的死亡情况,用流式细胞仪检测细胞周期。结果:①存活曲线细胞存活率随照射剂量增加而减少,硝普钠组细胞的克隆形成率低于对照组(2Gy时,P<0.01)。②细胞死亡百分率(坏死细胞与凋亡细胞总数/总细胞数):与照射剂量呈正相关,硝普钠组高于对照组(P<0.05)。对照组从(9.95±3.53)%(0Gy)逐渐升至(58.74±3.46)%(6Gy),而硝普钠组则从(18.53±12.02)%(0Gy)迅速升至(61.57±9.53)%(2Gy)。③细胞周期检测结果:对照组细胞经过X射线照射后,出现了G2/M期阻滞[从0Gy时(12.50±5.76)%逐渐增加到8Gy(40.36±2.74)%],而硝普钠组细胞在低剂量时主要表现为G0/G1期阻滞[0Gy:(16.06±7.19)%;2Gy:(17.93±0.92)%],而G2/M期阻滞仅在高剂量时明显[8Gy时为(50.10±3.93)%,P<0.05]。结论:经硝普钠产生的一氧化氮,通过与X射线协同作用,减少了肝癌细胞SMMC-7721的细胞存活率,促进细胞死亡,阻止细胞被阻滞至G2/M期,是一种有效的辐射增敏剂

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel