铁轨下采空区上覆地基稳定性分析

采空区上覆岩体在不能承受二次分布的应力时产生跨落塌陷,危及到地表,造成地表建筑物和设施的损坏。采空区上覆建筑物地基稳定性分析是预防灾害的前提和基础。应用采空区上覆建筑物临界安全加载深度法对某矿区上覆铁路地基稳定性进行分析,得出对研究区内H1巷道上覆地基稳定,不需要加固治理,采空区C1和C2上覆地基不稳定,需要加固治理,该结论为预防大规模灾害的发生和治理资源的分配提供了依据。     

Gravitational signature of rotationally distorted Jupiter caused by deep zonal winds

Both deep zonal winds, if they exist, and the basic rotational distortion of Jupiter contribute to its zonal gravity coefficients J_n for n ? 2. In order to capture the gravitational signature of Jupiter that is caused solely by its deep zonal winds, one must take into account the full effect of rotational distortion by computing the coefficients J_n in non-spherical geometry. This represents a difficult and challenging problem because the widely-used spherical-harmonic-expansion method becomes no longer suitable. Based on the model of a polytropic Jupiter with index unity, we compute Jupiter’s gravity coefficients J₂, J₄, J₆, … , J₁₂ taking into account the full effect of rotational distortion of the gaseous planet using a finite element method. For the model of deep zonal winds on cylinders parallel to the rotation axis, we also compute the variation of the gravity coefficients ΔJ₂, ΔJ₄, ΔJ₆, … , ΔJ₁₂ caused solely by the effect of the winds in non-spherical geometry. It is found that the effect of the zonal winds on lower-order coefficients is weak, ∣ΔJ_n/J_n∣ < 1%, for n = 2, 4, 6, but it is substantial for the high-degree coefficients with n ? 8.     

分布式水文模型全局敏感性高效分析方法研究(英文)

Sensitivity analysis of hydrological model is the key for model uncertainty quantification. However, how to effectively validate model and identify the dominant parameters for distributed hydrological models is a bottle-neck to achieve parameters optimization. For this reason, a new approach was proposed in this paper, in which the support vector machine was used to construct the response surface at first. Then it integrates the SVM-based response surface with the Sobol’ method, i.e. the RSMSobol’ method, to quantify the parameter sensitivities. In this work, the distributed time-variant gain model (DTVGM) was applied to the Huaihe River Basin, which was used as a case to verify its validity and feasibility. We selected three objective functions (i.e. water balance coefficient WB, Nash-Sutcliffe efficiency coefficient NS, and correlation coefficient RC) to assess the model performance as the output responses for sensitivity analysis. The results show that the parameters g1 and g2 are most important for all the objective functions, and they are almost the same to that of the classical approach. Furthermore, the RSMSobol method can not only achieve the quantification of the sensitivity, and also reduce the computational cost, with good accuracy compared to the classical approach. And this approach will be effective and reliable in the global sensitivity analysis for a complex modelling system.     

镇江２００９年盛夏极端异常气候分析 及ＥＣＭＷＦ模式检验

将2009年7月第5候至8月第2候作为研究时段,利用NCEP/NCAR再分析资料,对镇江地区2009年盛夏罕见的低温多雨寡照的极端异常气候作了诊断分析。在此基础上,对比分析了同期ECMWF的中期预报产品与实况,实现了对ECMWF模式的中期预报性能检验,由此加深了对此类天气过程中期预报的理解。结果表明：在研究时段内,西太平洋副热带高压异常偏东偏弱,110~120 °E上空850 hPa层上存在异常南北风的辐合区,受西南季风和热带系统的共同影响,整层具有良好的水汽输送条件。在此次极端异常气候发生过程中,ECMWF对西太平洋副热带高压减弱东退、维持海上和增强西进的中期预报精准。同时,其数值产品对西风指数和850 hPa温度也具有良好的中期预报指示意义,成为准确预报此次过程的重要依据。     

2008年12月2—6日寒潮天气过程分析

利用常规天气观测资料、美国NCEP/NCAR 1°×1°网格点逐6h再分析资料,采用天气学原理和天气动力学诊断分析方法,对2008年12月2-6日寒潮天气过程进行分析和总结.结果表明:此次寒潮天气过程出现在欧洲脊强烈发展并缓慢东移、北半球中高纬环流形势由纬向型向经向型转换过程中.西脊前强偏北风带南移、横槽涡度西部大于东部、横槽前东南方的负变高和横槽后部的暖平流正变高等促使横槽转竖;南掉极涡与转竖低槽合并后,低槽明显向南加深,冷空气势力显著加强并开始向南爆发;自西脊西北部入侵小槽压迫高脊向东南方向移动并逐渐崩溃,脊前偏北气流逆转为西北气流,引导冷空气大举向南爆发,造成了此次寒潮天气过程.强盛的冷平流是造成气温骤降的主要原因.强风的形成除与冷平流侵入有关外,还与高空动量下传的增加密切相关.山东半岛降雨和强降雪的环流成因和物理量特征存在明显差异,降雨为冷暖空气交汇所致;强降雪则是冷平流、海陆分布差异和地形抬升共同影响的结果.T639、ECMWF和日本等3种数值模式均对这次亚欧中高纬大气环流的演变和调整均做出了较准确的预报,尤以ECMWF模式预报性能最好.     

Two-dimensional properties of nearby galaxies

Research on two-dimensional (2-D) properties of galaxies is a significant component of the study of galaxy formation and evolution. Through the spatial distribution of physical properties (derived from integrated luminosity and spectroscopy) of galaxies, we are allowed to realize the inner environment and evolution history of each individual galaxy and finally answer how galaxies were assembled. In this paper, with reviewing previous work, we present a proposal for study on 2-D properties of nearby galaxies. In our prospective work, we will make use of multi-wavelength data covering a range from ultraviolet to far-infrared to determine the distributions of properties such as age, metallicity and dust-reddening in nearby galaxies, and try to remove the degeneracy among them. Combining with surface photometry and spectroscopy, we will also analyze the distribution of HII regions and star formation properties in galaxies. In our future plan, the World Space Observatory for Ultraviolet (WSO/UV) will be applied to our research and allow detail diagnosis of nearby galaxies at ultraviolet band.     

Measurements of electronic properties of the Miyun 50 m Radio Telescope

Measurement results of some properties of the Miyun 50 m radio telescope (MRT50) of the National Astronomical Observatories, such as pointing calibration, an-tenna beams, system noise temperature, gain and gain variations with elevation are intro-duced. By using a new de-convolution technique developed by our group, the broadening effect on measured beams caused by the width of an extended radio source has been re-moved so that we obtained higher accuracy on the measurements of MRT50 beams.     

The Influences of Shock Thickness and Alfven Waves on the Particle Acceleration by Diffusive Shocks

The influences of the shock thickness and Alfven waves on the particle acceleration by diffusive shock waves are numerically studied through solving one-dimensional diffusive equation including the second-order Fermi effect. It is shown that the spectral index of the energetic particles strongly depends on the shock thickness. For example, the spectral index increases from 2.1 to 3.7 in the low energy range of 3—10 MeV and from 2.5 to 5.0 in the high energy range of 20—60 MeV as the thickness increases. The spectral index decreases from 4.3 to 3.1 as the particle injection energy increases. The spectral index decreases from 4.0 to 1.8 at the quasi-steady stage with the enhancement of the compression ratio from 2 to 4. The results indicate that under the influence of Alfven waves, the energetic particle spectrum at lower energy becomes flat and the spectral index decreases from 2.5 to 0.6 in the low energy range of 3—10 MeV and from 11.6 to 5.0 in the high energy range of 20—60 MeV. At the same time, the turning point energy reaches 19.6 MeV. The spectral index decreases from 5.8 to 2.9 as the energy density of Alfven waves increases. All these results are basically consistent with the theoretical models, as well as the observations of typical energetic particle events.     

应用聚类和因子分析讨论猫岭金矿元素组合特征

猫岭金矿是一低品位、大型热液型金矿床。金矿体主要以脉状、似层状、透镜状产于下元古界辽河群盖县组二段的千枚岩中,受北北东向片理化带及低序次构造裂隙所控制。矿床原生晕样品的 R 型聚类分析和因子分析的结果表明,与金矿化关系最密切的元素为 Pb、Ag,其次为 As。即 Au、Pb、Ag 代表了主成矿阶段矿化元素组合特征,而 As 和 Co、Ni 元素组合分别反映了与 Au 矿化具成因联系的毒砂和磁黄铁矿化特点。(Au、Pb、Ag)因子与(As、Ag)因子紧密相关,与宏观上所见矿化阶段生成的矿物(自然金、方铅矿等)沿毒砂裂隙分布的特点相吻合,从而说明这两个因子的元素组合代表了最佳成矿地段的元素组合特征。