ART算法的改进及其应用—面波Q值反演

对地球物理学中常用的反演方法在算法上作了一些改进,使得计算速度大为提高,并使计算机占用的内存减少到改进前的几分之一,从而避免了原来由于身线或者反演的块数过多而不能计算的问题。     

河南一次沙尘天气过程干空气侵入的数值模拟及诊断分析

利用NCEP再分析资料(水平分辨率1°×1°)和同时间的探空、地面资料对2006年4月11—13日发生在河南省的沙尘天气进行了中尺度数值模拟,并应用干空气侵入的理论对这次过程进行了诊断和分析。结果表明,此次沙尘天气过程中存在明显的干空气侵入,且干空气侵入对沙尘天气产生重要作用:高位涡、低湿空气沿等相当位温线密集带向南下滑,在对流层中低层引起位涡和温度扰动,造成强冷平流南下,使低槽东移加深、冷锋南压,触发不稳定大气,同时配合低层辐合、高层辐散叠置的流场,引发了河南省沙尘天气的发生、发展。     

影响青藏高原植被生理过程与大气CO2浓度及气候变化的相互作用

利用一陆面过程模式,初步模拟研究了青藏高原夏季风盛行期植被生理过程与大气CO2浓度及气候变化的相互作用。结果表明,气候以及大气CO2浓度变化对青藏高原地区的植被生理过程有较明显的影响,高温、高温和高CO2浓度将加强高原植被的光合作用和呼吸作用,有利于植被生长。高原植被也可通过生理过程,产生净CO2呼收,降低大气CO2含量,起到调整温室效应的作用,从而影响全球气候变化;当气温升高、大气CO2增加时,这种作用更加有效。青藏高原地区大气CO2浓度加倍,对高原地区气候的直接影响不明显。植被的存在也会影响区域气候变化,并可通过改变高原热源,进而影响高原及其周边地区气候变化。文中还归纳出了植被生理与气候相互作用的简单概念模型。     

Information System for Ocean Wave Resources and Its Application to Wave Power Utilization

An information system for ocean wave resources and its application to wave power utilizationare indtroduced.It can manage,analyze and process the data in the monthly report of ocean wave observa-tion records of the State Ocean Administration,and can provide various kinds of curves and numericalcharacters of statistics.This system has been put into utility in Guangzhou Institute of Energy Conversion(GIEC),the Chinese Academy of Sciences since 1996.An application example is given of theinverstigation and analysis on ocean wave resource of the Nan Ao Island,Guangdong Province,where a100 kW onshore OWC(oscillating water column)wave power station will be built.The wave power distri-bution is obtained in different wave directions for different wave periods.It is found that 70 percent of thewave power comes from the direction of ENE,and more than 95 percent of the wave power is related withdirection E.The average wave power density is about 3 kW/m,and more than 80 percent of the wavepower is distributed in the     

Hybrid Element Method for Calculation of Harbor Resonance

This paper presents a hybrid element method for calculating harbor resonance in a coastal or offshore harbor under the effects of friction and boundary absorption. The friction term is assumed to be proportional to the flow velocity with a phase difference. The boundary absorption adopts a condition similar to the impedance condition in acoustics. In the near region a variational principle is established. In the far region the solution satisfies the Helmholtz equation. Computation results of harbor resonance by the model show good agreement with experimental data and theoretical result.     

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.     

海南岛存在类TTG岩系包体的证据及地质意义

海南岛西部中元古代花岗质片麻岩和海西—印支期似斑状花岗岩中发现了大量暗色包体。本对暗色包体进行了详细地研究，以确定其性质、来源和所揭示的地质意义。研究表明，暗色包体显示强烈剪切交形和糜棱岩化的特征，并可区分三期片理；包体为异源包体，具深源火成岩特征，成分与太古代TTG岩系类似，为高Al2O3大陆型英云闪长岩—花岗闪长岩岩石组合，产于大陆或大陆边缘俯冲带环境。结合Sr-Nd—Pb同位素结果，认为该暗色包体可能是海南岛存在太古宙最早陆核的标志，来源于亏损地幔、但可能含有地壳成分或受地壳强烈混染。海南岛西部类TTG岩系包体的发现，有可能为深入研究海南岛乃至华南古老结晶基底及地壳演化提供新的证据。     

Geological Evidence for the Presence of the Emperor Event in China

The presence of the reversals of the geomagnetic field within the Brunhes is indicated by paleomagnetic stuides on Cenozoic volcanic rocks in the Leizhou Peninsula, loess strata and Quaternary marine sediments in the Pearl River Mouth basin in China. These regional reversals occured at 0.58±0.13 Ma, 0.45 Ma and 0.47—0.48 Ma respectively according to the results of K-Ar isotopic dating and climatostratigraphic and biostratigraphic analyses. The reversals equivalent to the Emperor Event is suggested.The reversals revealed in different regions with various lithologic characters in China prove that the Emperor Event is a global reversal event rather than a geomagnetic excursion, and its confirmation will permit a precise definition of the Middle/Late Pleistocene boundary.     

十八烷的裂解动力学研究(I):气态烃组分及其碳同位素演化特征

本文通过对纯烃类化合物——正十八烷的动力学模拟实验,阐述了正十八烷裂解过程中气态烃组分及其同位素的演化特征,获得了产自正十八烷的甲烷生成动力学参数。运用动力学参数将模拟实验结果外推到地质条件下,表明由烷烃裂解形成的甲烷主要生成于150～200℃(Easy%Ro介于1.0%～2.0%)的范围,裂解产生的甲烷、乙烷、丙烷的碳同位素分馏效应与Easy%Ro的关系曲线受升温速率的影响,不能直接应用于地质条件。