On a simplified radiative-conductive heat transfer equation

Summary A simplified equation purported to represent the joint influence of radiative and turbulent transfers of heat in the atmosphere is derived by dividing the absorption spectrum of terrestrial radiation into strongly and weakly absorbed regions, classified according to the local scale of variation or to the local heating rate, and introducing two mean absorption coefficients for these two groups of regions. Assurning the validity of theK-theory of turbulent diffusion of heat, it is found that the temperature of the atmosphere is governed by a sixth-order partial differential equation in the heightz. This equation can be simplified to the second order if the mean absorption coefficient of the strongly absorbed regions is much larger while that of the weakly absorbed regions is much smaller than the local scale variation, and the influence of the former is equivalent to an added diffusion while that of the latter is a newtonian cooling, and these two influences are present simultaneously. The values of the two coefficients and their dependencies on the concentration of the absorbing material have been obtained. The equation has been applied to the problem of the thermal interaction between the atmosphere and the underlying earth, as related to the diurnal heat wave, and it was found that the temperature changes within the first few hundred meters from the earth can be predicted accurately by the model when the partition of the two groups is adjusted to the heating rate and the eddy transfer coefficient is allowed to increase very rapidly within the lowest 10 m.     

Similar single-difference model and its algorithm for solving GPS monitoring deformation directly at single epoch

A new similar singledifference mathematical model ( SS-DM) and its corresponding algorithm are advanced to solve the deformation of monitoring point directly in single epoch. The method for building the SSDM is introduced in detail, and the main error sources affecting the accuracy of deformation measurement are analyzed briefly, and the basic algorithm and steps of solving the deformation are discussed. In order to validate the correctness and the accuracy of the similar single-difference model, the test with five dual frequency receivers is carried out on a slideway which moved in plane in Feb. 2001. In the test, five sessions are observed. The numerical results of test data show that the advanced model is correct.     

GPS技术在三峡库区地质灾害专业监测中的应用

分析了GPS监测在三峡库区地质灾害专业监测中的作用,设计并构建了三峡库区三级GPS监测网,满足了国家对库区地质灾害体监测预警的要求。     

北京地区单双频地基GPS大气水汽遥测试验与研究

该文对北京地区单双频地基GPS大气水汽监测网布网依据、单频与双频地基GPS测量数据解算技术应用、GAMIT和Bernese地基GPS数据分析处理软件应用、远程遥控GPS数据采集与通讯系统、资料分析与数值同化应用等方面的工作进展进行简要介绍,重点讨论了单双频地基GPS大气水汽资料的解算技术及其应用效果。结果表明:在北京天气敏感区通过单双频地基GPS接收机合理组网布局,可构建并利用高分辨率电离层延迟订正技术将单频接收机的大气水汽监测精度提高到实用水平,为强降水天气预报提供有价值的产品。     

扫描电镜分析各类微体化石样品最佳镀膜的探讨

根据多年的工作经验和试验对比,总结出了非导电微体化石－放射虫,硅藻,竹节石,有孔虫,介形虫,轮藻,牙形石,海绵骨针等的最佳镀膜方法和最佳镀膜厚度。     

Planetary boundary layer of equatorial waves and critical latitude

The boundary-layer solutions for oscillatory interior flow in a neutral fluid show that, away from the critical latitude, the planetary boundary-layer flow is composed of two vertically propagating waves; one is of shorter vertical wavelength and attenuates faster with height while the other is of longer wavelength and attenuates slowly with height. At the critical latitude, the longer wave is of the nature of an inertial oscillation and penetrates the entire depth of the fluid and gives rise to a rather stronger (but finite) vertical motion than in the surroundings at great height, but below 2 km this difference is not very great. In general, the vertical velocity of the boundary-layer flow depends on both the vorticity and the divergence of the interior flow, and the influence of the former is to intensify while that of the latter is to diminish the existing vertical motion. The influence of the stable stratification above a mixed, neutral surface layer on the boundary-layer flow of the equatorial waves is analyzed in detail. It is shown that the boundary-layer flow is greatly impeded by the stable layer and the horizontal velocities of the boundary-layer flows are made to change their directions in the upper part of the mixed layer and above, so that the vertical velocity is greatly reduced. The effect of the critical latitude is almost absent in the antisymmetric Rossby waves under stable stratification.     

一种自适应的坡度阈值地面点云分割方法

针对城市道路斜坡地形场景中地面欠分割或过分割的问题,提出了一种自适应的激光雷达地面分割算法。首先将激光点云按照水平角度分辨率进行有序组织,然后求取同一水平角度下前后扫描圈间激光点云的距离和局部坡度,最后采用自适应水平距离、局部高度和全局高度阈值区分地面点和非地面点。结合40线激光雷达进行多场景实例分析,结果表明本文算法分割的准确率更高,处理每帧数据均用时约1ms,满足无人驾驶汽车的实时性需求。提出了一种自适应的激光雷达地面分割算法,实现了对激光雷达地面点云的准确分割。     

Estimation of aseismic crustal-strain using radon precursors of the 2003 <Emphasis Type="Italic">M</Emphasis> 6.8, 2006 <Emphasis Type="Italic">M</Emphasis> 6.1, and 2008 <Emphasis Type="Italic">M</Emphasis> 5.0 earthquakes in eastern Taiwan

Aseismic crustal-strain signals prior to the 2003 Mw 6.8 Chengkung, 2006 Mw 6.1 Taitung, and 2008 Mw 5.0 Antung earthquakes with epicenters located 20, 55 and 11 km, respectively, from the Antung radon-monitoring station have been calculated using the radon anomalies recorded. Specifically, radon decreased from background levels of 791 ± 46, 762 ± 57, and 735 ± 48 pCi/L to minima of 326 ± 9, 371 ± 9, and 480 ± 43 pCi/L prior to the 2003, 2006, and 2008 earthquakes, respectively. The estimated aseismic crustal-strain maxima at the Antung hot spring during the rock dilation stage were 3.6, 2.7, and 1.3 ppm, respectively. The v-shaped radon pattern recognized in all three anomalies is valuable for detecting the aseismic strain precursory to disastrous earthquakes in the Antung hot spring which is situated in a brittle fractured aquifer of limited recharge surrounded by ductile mudstone.     

Human capital requirements in Singapore's international financial centre

International financial centres (IFCs) are regarded as important nodes in governing global flows of money and capital. With increased globalization and rapid technological changes, the rivalry among IFCs has further intensified competition for financial labour—as a concentrated pool of highly skilled finance workers in an open and flexible labour market is crucial to sustaining the competitive dynamics of these urban financial hotspots. This study investigates the importance of different skills and tasks in financial work. Based on surveys and interviews conducted among Singapore's IFC workers, the findings show that cognitive, interpersonal communication and managerial-leadership skills and tasks are more important in financial work, whereas programming, mathematics and systems-based skills are perceived to be less important. Additionally, a network visualization of finance occupational skills obtained from Singapore's national skills database reinforces the importance of cognitive and relational skills in that sector. Higher-order cognitive and relational skills are expected to become even more critical as the financial sector undergoes rapid digital transformation, reinforcing the importance of IFCs as agglomerations of skilled finance talent.