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221.
B andV light curves for one epoch and radial velocity curves of three different epochs have been analyzed to revise the solution of TX UMa. The solution has been adjusted simultaneously in the light curves and radial velocity curves by the method of Wilson and Devinney's differential correction. The primary star's surface rotation rate to synchronous rate is determined as 1.768 from one of the radial velocity curves. The absolute dimension of the system has been deduced based on the simultaneous solution. The primary star is well fitted to the evolutionary track for a single star while the secondary star, while filling its Roche lobe, is fitted to the evolutionary track for a close binary system. 相似文献
222.
A preliminary application GIS in glaciological research along the traverse route from Zhongshan Station to Dome A, Antarctica 总被引:1,自引:0,他引:1
1 IntroductionGeographicalinformationsystem (GIS)isanefficientwayandimportanttechniquetomanage,displayandanalyzeAntarcticspatialdata.GIScanbeusedtomakeandre newmapproductsquickly ,evaluateenvironment,supportlogisticmanagementandfieldoperation,providechancetoextractnewknowledge,andtopromoteinformationex changeamongnationsunderthedemandoftheMadridProtocol(AADC 2 0 0 1 ;MAGIC1 998;1 999) .WorkingGroupofGeodesyandGeographicInformation (WG GGI)ofScientificCommitteeonAntarcticResearch (… 相似文献
223.
224.
测绘产品监督检验视角下城市测绘工程质量控制技术探讨 总被引:1,自引:0,他引:1
冉康 《测绘与空间地理信息》2012,(6):216-217
以测绘产品监督检验的视角,将城市测绘工程质量管理与质量控制思路为研究对象,探讨了质量管理的内涵及质量的系统化控制管理方法。全文以质量检查点为线索,探讨了整个流程中的数据检查方法。 相似文献
225.
CunDe Xiao ZhongQin Li Lin Zhao ShiChang Kang YuanQing He Xiang Qin XiaoBo He 《寒旱区科学》2012,4(1):0001-0012
In coordination with Global Cryosphere Watch (GCW) initiated by World Meteorology Administration (WMO), a regional observation
network is proposed based on existing stations/sites over High Asia and cryospheric elements required by GCW. Thus,
High Asian Cryosphere (HAC) network is preliminary designed, composing of seven "supersites", each containing several reference
sites. The network covers major mountain ranges in High Asia, such as East Tianshan, Qilian, Tanggula, Nyainqentanglha,
Himalayas as well as the central and eastern Qinghai-Xizang (Tibet) Plateau. Although multiple cryospheric elements were observed
at the existing HAC network, many others, which are required by Integrated Global Observation System-Cryosphere
Theme (IGOS-Cryosphere), are not yet included. More comprehensive observations are necessary to be included into "supersites"
of HAC, so that the basic requirements for validation of satellite data, assimilation and coupled regional models can be met. 相似文献
226.
Effects of Mesoscale Surface Thermal Heterogeneity on Low-Level Horizontal Wind Speeds 总被引:2,自引:2,他引:0
Using large-eddy simulation, we investigate characteristics of horizontal wind speed at 100 m above the ground, with surface
heat-flux variations that are sinusoidal with amplitudes of 0, 50, and 200 W m−2 and wavelengths of 16, 32, and 128 km, and no background flow. When the amplitude is 200 W m−2, wind speeds induced by the surface-flux variations on scales of 16 and/or 32 km have multiple temporal oscillations from
0600 to 1800 local standard time. The positive peaks first appear before noon. In contrast, for wind speeds induced by the
128-km surface heterogeneity, a single oscillation occurs in the late afternoon, which is much larger than those generated
by the 16- and 32-km surface heterogeneity. In addition, at the oscillation onset the kurtosis of the velocity increment over
a distance of 1 km significantly increases, which implies intermittency in the generation of 1-km scale eddies. The spatially
intermittent energy cascade generated by surface heterogeneity scaled down to 1-km eddies is analogous to the well-known intermittent
energy cascade in the inertial subrange. The kurtosis of the 1-km eddies is much larger with the 128-km surface heterogeneity
than with the 16- and 32-km heterogeneities. Thus we conclude that localized rapid changes of low-level horizontal wind speed
may be caused by significant local surface heterogeneity on scales between a few tens and a few hundreds of kilometres. 相似文献
227.
Tropical precipitation, SSTs and the surface energy budget: a zonally symmetric perspective 总被引:1,自引:1,他引:0
The relative importance of sea surface temperatures (SSTs) and the surface energy budget to tropical precipitation is examined by comparing models with zonally symmetric climates, both fixed SST and coupled to a slab mixed layer ocean. Two models are considered with differing surface flux formulations and in each case solutions that are symmetric about the equator are perturbed to create interhemispheric asymmetry. When SSTs are prescribed in the two models with different flux formulations, the magnitude of tropical precipitation response to identical SST anomalies is significantly different, but the differences can be understood in terms of the altered surface fluxes. In contrast, when the net surface energy fluxes are constrained to be identical in mixed layer simulations of the two different models, the response of tropical precipitation to perturbations in the surface energy balance is very similar. Both perspectives predict qualitatively the same precipitation response, but the energy budget better predicts the magnitude of the precipitation response. Thus, we argue that the atmospheric energy budget, controlled in these experiments primarily by the surface energy budget, is more fundamental to the control of tropical precipitation than the SSTs, in these simulations with axisymmetric climates. We touch briefly on a complication in the interpretation of the model results due to the fact that fixed SST and slab-ocean versions of the model can produce different Hadley cell strengths for the same SSTs. 相似文献
228.
229.
随着测绘技术的迅猛发展,内业处理已全面进入数字化阶段,但传统的外业调绘方式已经成为地理信息数据快速更新的“瓶颈”,不能完全满足现代测绘的需要。本文总结了数字调绘系统与传统调绘方法的各自优缺点,设计了一种数字调绘系统。该系统作为一个易操作的平台,降低了劳动强度,提高了数据精度,节约了生产成本。数字调绘为地理信息数据的快速更新提取提供了一种较好的技术手段,必将是今后航测外业的发展方向。 相似文献
230.
K. P. Sooraj Daehyun Kim Jong-Seong Kug Sang-Wook Yeh Fei-Fei Jin In-Sik Kang 《Climate Dynamics》2009,33(4):495-507
Recently, there is increasing evidence on the interaction of atmospheric high-frequency (HF) variability with climatic low-frequency
(LF) variability. In this study, we examine this relationship of HF variability with large scale circulation using idealized
experiments with an aqua-planet Atmospheric GCM (with zonally uniform SST), run in different zonal momentum forcing scenarios.
The effect of large scale circulation changes to the HF variability is demonstrated here. The HF atmospheric variability is
enhanced over the westerly forced region, through easterly vertical shear. Our study also manifests that apart from the vertical
wind shear, strong low-level convergence and horizontal zonal wind shear are also important for enhancing the HF variance.
This is clearly seen in the eastern part of the forcing, where the HF activity shows relatively maximum increase, in spite
of similar vertical shear over the forced regions. The possible implications for multi-scale interaction (e.g. MJO–ENSO interaction)
are also discussed. 相似文献