Wide area real time kinematic decimetre positioning with multiple carrier GNSS signals

This paper presents the technical basis for wide area real time decimetre positioning services using multiple carrier signals transmitted by future GNSS such as modernized GPS and Compass systems. The first step is to form two ionosphere-reduced extra-widelanes (EWL) that have the minimal total noise levels in cycles, considering the effects of the ionospheric and tropospheric delays, orbital error, and phase noise terms in various observational environments. The proposed three carrier ambiguity resolution ...     

The Linkage between Midwinter Suppression of the North Pacific Storm Track and Atmospheric Circulation Features in the Northern Hemisphere

The midwinter suppression(MWS) of the North Pacific storm track(NPST) has been an active research topic for decades. Based on the daily-mean NCEP/NCAR reanalysis from 1948 to 2018, this study investigates the MWS-related atmospheric circulation characteristics in the Northern Hemisphere by regression analysis with respect to a new MWS index, which may shed more light on this difficult issue. The occurrence frequency of the MWS of the upper-tropospheric NPST is more than 0.8 after the mid-1980 s. The MWS is accompanied by significantly positive sea-level pressure anomalies in Eurasia and negative anomalies over the North Pacific, which correspond to a strengthened East Asian winter monsoon. The intensified East Asian trough and atmospheric blocking in the North Pacific as well as the significantly negative low-level air temperature anomalies, lying upstream of the MNPST, are expected to be distinctly associated with the MWS. However, the relationship between the MWS and low-level atmospheric baroclinicity is somewhat puzzling.From the diagnostics of the eddy energy budget, it is identified that the inefficiency of the barotropic energy conversion related to the barotropic governor mechanism does not favor the occurrence of the MWS. In contrast, weakened baroclinic energy conversion, buoyancy conversion, and generation of eddy available potential energy by diabatic heating are conducive to the occurrence of the MWS. In addition, Ural blocking in the upstream region of the MNPST may be another candidate mechanism associated with the MWS.     

由空间直角坐标计算大地坐标的简便公式

对大地测量教科书中给出的空间三维直角坐标与大地坐标的转换公式进行了大量的计算与分析，总结得出一组由空间直角坐标计算大地坐标的简便公式。     

天陇铁路上倪滑坡工程地质特征分析及地质选线

在天陇铁路勘察设计工作中,发现上倪滑坡是新建天水至陇南铁路一处控制性不良地质体。本文在充分获取地质资料的基础上,从地形地貌角度出发,结合其地层岩性特征,分析了滑坡成因,认为上倪滑坡在北侧和南侧各存在一个软弱面,滑坡整体稳定性较差,尤其是滑坡北侧危险性较大。通过力学计算,显示该滑坡自然状态下能够保持相对稳定,但在地震或暴雨天气下发生滑动的可能性极大,对线路工程具有严重影响。经过对三种线路方案的综合比选,建议以深埋隧道形式从后壁通过上倪滑坡,保证工程安全性。     

W UMa型相接双星的理论研究

本文回顾了W UMa型相接双星观测和理论研究的历史。总结了W UMa型相接双星观测特性和理论研究的成果。最后讨论了W UMa型相接双星理论模型研究中存在的问题及其解决这些问题的一些可行方法。     

Methods and procedures to determine the outer limits of the continental shelf beyond 200 nautical miles

This paper establishes techniques and methods to determine a variety of boundaries associated with 200 nautical miles beyond the continental shelf. The methods, based on topography, slope and second-deriv- ative profile integrated analysis, are now able to identify automatically the foot of the continental slope （FOS）. By analyzing the sedimentary profile, the points of 1% sediment thickness are recognized. Through the intersection, cut, deletion and mergence calculation of the extrapolated data set of fLxed-point series, the method succeeds in generating automatically the extrapolated boundaries, including the FOS＋60 M line, the 350 M line, and the 2500 m＋100 M line. In addition, based on the automatic analysis of the topographic profile, it can be applied to determine rapidly the points of maximum water depth. Taking the northern Okinawa Trough （OT） as an example, these methods are used to calculate and examine the boundaries in- cluded in the Submission by the People＇s Republic of China Concerning the Outer Limits of the Continental Shelf beyond 200 Nautical miles in Part of the East China Sea （ECS）; the boundaries thus derived have a solid scientific and rational basis.     

Phase Equilibria Constraints on Relations of Ore-bearing Intrusionswith Flood Basalts in the Panxi Region, Southwestern China

There are two types of temporally and spatially associated intrusions within the Emeishan large igneous province (LIP); namely, small uitramafic subvolcanic sills that host magmatic Cu-Ni-Platinum Group Element (PGE)-bearing sulfide deposits and large mafic layered intrusions that host giant Ti-V magnetite deposits in the Panxi region. However, except for their coeval ages, the genetic relations between the ore-bearing intrusions and extrusive rocks are poorly understood. Phase equilibria analysis (Q-PI-OI-Opx-Cpx system) has been carried out to elucidate whether ore-bearing Panzhihua, Xinjie and Limahe intrusions are co-magmatic with the picrites and flood basalts (including high-Ti, low-Ti and alkali basalts), respectively. In this system, the parental magma can be classified as silica-undersaturated olivine basalt and silica-saturated tholeiite. The equivalents of the parental magma of the Xinjie and Limahe peridotites and picrites and iow-Ti basalts are silica-undersaturated, whereas the Limahe gabbro-diorites and high-Ti basalts are silica-saturated. In contrast, the Panzhihua intrusion appears to be alkali character. Phase equilibria relations clearly show that the magmas that formed the Panzhihua intrusion and high-Ti basalts cannot be co-magmatic as there is no way to derive one liquid from another by fractional crystallization. On the other hand, the Panzhihua intrusion appears to be related to Permian alkali intrusions in the region, but does not appear to be related to the alkali basalts recognized in the Longzhoushan lava stratigraphy. Comparably, the Limabe intrusion appears to be a genetic relation to the picrites, whereas the Xinjie intrusion may be genetically related to be low-Ti basaits. Additionally, the gabbro-diorites and peridotites of the Limahe intrusion are not co-magmatic, and the former appears to be derived liquid from high-Ti basalts.     

四氢呋喃水合物沉积物静动力学性质试验研究

利用研制的天然气水合物沉积物合成与力学性质测试一体化试验设备,以粉细砂土和蒙古砂土作为沉积物骨架,对四氢呋喃(THF)水合物沉积物进行了静动三轴试验,获得了水合物分解前后沉积物样品的应力-应变关系、强度和液化特性,对两种骨架的水合物沉积物的性质进行了对比,同时将水合物分解后的沉积物与对应的饱和土的动三轴试验结果进行了对比。结果表明：水合物沉积物均表现为塑性破坏;围压越大,水合物沉积物强度越高;水合物分解导致沉积物的强度大幅降低;水合物分解后沉积物液化所需的时间较饱和水沉积物缩短     

月壤及模拟月壤微观结构的研究

为了对比研究月壤与模拟月壤的微观结构,介绍了月壤的形成作用过程和5种基本颗粒类型;通过真实月壤照片,对月壤微观结构进行了分析;利用火山灰为模拟月壤主体材料,对其成分进行了检测;对模拟月壤的火山灰颗粒进行了显微图像分析试验。结果表明,月壤存在胶结物微观颗粒,胶结物颗粒具有分支的组织形态和封闭的气泡,并且有金属铁珠存在;火山灰所含的主要成分及含量与月壤相似,经过粉碎的火山灰试样棱角较为明显,其纵横比峰值略小,稍显长条状,但与月壤比较相近,而复杂度因子则略有欠缺,说明颗粒还不够粗糙和多棱     

重力勘探中近区地形改正数据测量方法的试验

针对重力勘探中近区地形改正的重要性以及至今没有效果较好的地形改正方法,笔者采用四种方法(目估、激光测距仪、森林罗盘仪、RTK)分别从人工、使用仪器、用时、精度及综合的台效方面进行了详细分析,总结了各种方法的优缺点,为近区地改提供了较好的应用和示范效果.