多普勒天气雷达探测中气旋分析

利用南京多普勒天气雷达资料,对南京地区2003年7月8日出现的一次雷雨大风和短时强降水过程进行了分析,结果表明:这次强天气过程与多普勒天气雷达观测到的中气旋相联系,文中结合环境风场分析了中气旋的特征,计算了中气旋的主要参数。     

一次暴雨过程多普勒天气雷达风场资料分析

通过对１９９御７月１４日的大－暴雨天气过程所获取的３８２４多普勒天气雷达平均径向风场资料的分析，发现边界层急流与较强的降水相伴。表明多普勒天气雷达对中小尺度天气系统和灾害性天气预报有预警作用。     

PSO-RBFNN模型及其在岩土工程非线性时间序列预测中的应用

岩土工程受力变形演化是一个典型的非线性问题,其演化的高度非线性和复杂性,很难用简单的力学、数学模型描述,但可用粒子群优化径向基神经网络对岩土工程应力、位移非线性时间序列进行动态实时预测。网络径向基层的单元数通过均值聚类法确定后,所有其它参数：中心位置、形状参数、网络权值,均通过粒子群优化算法在全局空间优化确定。工程实例应用表明,该模型预测结果准确、精度高,有良好的应用前景。     

Tensile stiffness analysis on ocean dynamic power umbilical

Tensile stiffness of ocean dynamic power umbilical is an important design parameter for functional implementation and structural safety. A column with radial stiffness which is wound by helical steel wires is constructed to predict the tensile stiffness value of umbilicals in the paper. The relationship between the tension and axial deformation is expressed analytically so the radial contraction of the column is achieved in the relationship by use of a simple finite element method. With an agreement between the theoretical prediction and the tension test results, the method is proved to be simple and efficient for the estimation of tensile stiffness of the ocean dynamic power umbilical.     

多普勒雷达资料在中尺度模式短时预报中的应用

将国内新一代多普勒雷达基数据Lev-Ⅱ的9个仰角的原始反射率和径向风资料应用于中尺度模式ARPS(the Advanced Regional Prediction System),通过对2007年7月18日济南短时特大暴雨过程的个例研究,分析了雷达资料对初始场的改进效果及其对模拟结果的影响。结果表明,同时利用雷达反射率和径向风资料改进过的初始场能明显改善中尺度数值模式短时定量降水预报。对比风场发现,雷达径向风调整后在初始场中出现明显的中小尺度特征,能减少模式的spin-up时间。随着积分的进行,对水汽场的调节也有一定作用,但相对于风场调节不够显著。雷达反射率主要是改进初始场中的湿度参数,增加初始场中云水等含量。积分开始后,对风场调整也很显著。此次模拟,控制试验较好地预报出雷达回波的分布和水汽中心,对应的降水落区与实况也较为接近,但对雷达回波中心强度的预报略大,相应地降水量的预报也偏大。     

Study on Recovering the Earth＇s Potential Field Based on GOCE Gradiometry

Given the second radial derivative Vrr（P） ｜δs of the Earth＇s gravitational potential V（P） on the surface δS corresponding to the satellite altitude, by using the fictitious compress recovery method, a fictitious regular harmonic field rrVrr（P）^＊ and a fictitious second radial gradient field V：（P） in the domain outside an inner sphere Ki can be determined, which coincides with the real field V（P） in the domain outside the Earth. Vrr^＊（P）could be further expressed as a uniformly convergent expansion series in the domain outside the inner sphere, because rrV（P）^＊ could be expressed as a uniformly convergent spherical harmonic expansion series due to its regularity and harmony in that domain. In another aspect, the fictitious field V^＊（P） defined in the domain outside the inner sphere, which coincides with the real field V（P） in the domain outside the Earth, could be also expressed as a spherical harmonic expansion series. Then, the harmonic coefficients contained in the series expressing V^＊（P） can be determined, and consequently the real field V（P） is recovered. Preliminary simulation calculations show that the second radial gradient field Vrr（P） could be recovered based only on the second radial derivative V（P）｜δs given on the satellite boundary. Concerning the final recovery of the potential field V（P） based only on the boundary value Vrr （P）｜δs, the simulation tests are still in process.     

非绝热加热对热带气旋径向非均匀结构的影响

利用平面极坐标系下无摩擦有外源(非绝热加热)的正压无辐散方程,将热带气旋的物理量分解成环境场和扰动,进而求出了热带气旋扰动的行波解,并分析了风场(切向、径向)和重力位势扰动场的径向非均匀松紧结构.表明:这种松紧结构与热带气旋所在纬度的科氏参数(f)、热带气旋的强度(Ω)、热带气旋扰动的圆频率(ω)、热带气旋扰动在θ方向的角波数(m)有关,且不同要素的松紧结构不尽相同;同时还受非绝热加热(Q₁)的影响,这种影响主要表现在使风场(切向、径向)呈内紧外松的非均匀分布.     

黄海辐射沙洲沉积物地球化学特征及其环境意义

对黄海辐射沙洲烂沙洋水道区域的3个钻孔共81个沉积物样品进行了微量、常量元素分析和^14C测年分析．化学元素质量分数的变化与当时沉积环境的变化相对应。突发事件(如风暴潮)的发生不但在沉积物的岩性上有所体现,而且在微量元素质量分数的变化上也有很明显的体现。微量元素Zr可作为沉积能量变化的地化指示剂,潮汐通道北部的西太阳沙区域的沉积动力环境在4000a以前是较弱的。潮流通道的上段沉积物是来自水深较浅的区域,由于潮流和波浪的作用使其能够保持稳定的水深。     

辐射沙洲南翼“水道-沙洲”系统与西太阳沙的稳定

通过对江苏岸外辐射沙洲动态和西太阳沙海域动力泥沙环境的分析,论述了西太阳沙演变的宏观背景;由实测固定断面资料、地形资料的对比得出近40年来西太阳沙表面形态和水下地形的变化;结合西太阳沙表面泥沙在波浪和波流共同作用下运动特性的水槽试验研究,分析了西太阳沙冲淤变化的动力机制。从“烂沙洋水道-西太阳沙-西太阳沙南水道”系统的角度研究了西太阳沙演变的控制因素和演变规律。     

The Subaru Telescope High Dispersion Spectrograph (HDS)

The High Dispersion Spectrograph (HDS) is the échelle spectrograph for an open‐use instrument of the Subaru Telescope. The current status of the instrument is reviewed. The new image slicers that significantly improve the efficiency of observations with very high resolving power have been installed in the past three years. Brief overview of recent science results is given on studies of early generations of stars and extra‐solar planets. An upgrade plan and future prospects of this instrument are discussed. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)