按顶点的经纬数确定一类图的a(H)值

本文定义了图的顶点的经数和纬数及图的宽，并应用它们确定了一类图Ｈ的ａ（Ｈ）值．

京纬数据:数据营销的痛点和转型之道(上)

京纬数据的起源最早来自于一家叫做威朋的移动广告平台。在2014年，这个项目—开始是威朋的一个SaaSBU，最早就是帮几家数字广告代理商搭建自己的广告平台以及数据平台。当时机缘巧合，有家代理商要求我们开放系统后台，我们开放给他们操作之后，他们觉得很先进，尤其是当时主打的LBS功能。

用经列和纬行造8k阶Franklin半幻方

给出一大类构造8k阶Franklin半幻方的方法:先作出满足一定条件的两列数(分别叫做经列和纬行),然后再在这个基础上造出8k阶Franklin半幻方.

基于分形理论的庆阳市A级景区空间结构研究

区域空间旅游结构研究自20世纪80年代以来,已经取得了较丰硕的成果,但实证研究多集中在经济发达地区和旅游业发达地区,对西部地县级城市的研究较少.随着全域旅游的发展,西部地县级小城市也开始大力发展旅游,对其进行研究并提出一定的建议具有重要的现实意义.以甘肃省庆阳市为例,运用分形理论中的聚集维数和关联维数,对该市的A级景区进行分析.研究表明庆阳市A级景区处于离散分布,关联性强,属于点状发展模式.

Zonal disintegration phenomenon in enclosing rock mass surrounding deep tunnels—mechanism and discussion of characteristic parameters

The mechanism of the zonal disintegration phenomenon(ZDP) was realized based on the analysis of the stressedstrained state of the rock mass in the vicinity of the maximum stress zone, which resides in the creep instability failure of rock mass due to the development of a plastic zone and transfer of the maximum stress zone within the rock mass.Some characteristic parameters of the ZDP are discussed theoretically.In first instance, the analytical critical depth condition for the occurrence of ZDP was obtained, which depends on the characteristics and stress concentration coefficient of the rock mass.Secondly, based on creep theory, the expression of the outer radius of the undisturbed zones in the deep rock mass was obtained with the use of an improved Burgers rheological model, which indicated that the radius depends on the characteristics of the rock mass and the depth of excavation and increases quasi-linearly with the rise of creep compliance of the rock mass.Finally, the formula for the distance of the most remote fissured zone away from the working periphery was derived, which increases logarithmically with the increase in the ratio of the in-situ stress and ultimate strength of rock mass.The distances between fissured zones are discussed in qualitative terms.

Three-dimensional transformation of magnetization direction and magnetic field component at low latitudes based on vertical relationship

The transformation of the magnetization direction and the magnetic fi eld component is one of the important methods in magnetic data processing and transformation,which can be conducted in both wavenumber and spatial domains.The transformation method in the wavenumber domain has simpler processing expression and higher processing effi ciency than in the spatial domain;however,they are unstable at low latitude.In this paper,the conclusion that the sum is 0 of two vertical magnetic fi eld components(magnetization inclinations are also perpendicular)in 2D is used for the 3D transformation of the magnetization direction and the magnetic field component.In addition,the transformation method at low latitudes based on vertical relationship(VMT)is proposed,which is an iterative algorithm that converts the transformation of the magnetization direction and the magnetic field component at the low latitude into the high latitude.This method restrains the instability of transformation of constant and variable magnetization direction and magnetic fi eld components in low latitudes.The accuracy,stability,and practicality are verifi ed from synthetic models and real data.

A Numerical Study of Vortex and Precipitating Cloud Merging in Middle Latitudes

We mainly focus on the study of precipitating cloud merging associated with vortex merging. The vortex and precipitating cloud merging are simulated by the cloud resolving model from 0000 21 to 1800 23 July 2003. The results show that the model well simulates vortex circulation associated with precipitating clouds. It is also proven that the vortex merging follows the precipitating cloud merging although vortices show the spatial and temporal differences. The convection vorticity vector is introduced to describe the merging processes. Two merging cases are identified during the 42-h simulation and are studied.

Numerical Simulation of Torrential Rainfall and Vortical Hot Towers in a Midlatitude Mesoscale Convective System

A cloud-resolving model simulation of a mesoscale convective system （MCS） producing torrential rainfall is performed with the finest horizontal resolution of 444 m. It is shown that the model reproduces the observed MCS, including its rainfall distribution and amounts, as well as the timing and location of leading rainbands and trailing stratiform clouds. Results show that discrete convective hot towers, shown in Vis5D at a scale of 2-5 kin, are triggered by evaporatively driven cold outflows converging with the high-θe air ahead. Then, they move rearward, with respect to the leading rainbands, to form stratiform clouds. These convective towers generate vortical tubes of opposite signs, with more intense cyclonic vorticity occurring in the leading convergence zone. The results appear to have important implications for the improvement of summertime quantitative precipitation forecasts and the understanding of vortical hot towers, as well midlevel mesoscale convective vortices.

Evaluation of the Earth＇s Magnetospheric Magnetic Field Models by Means of Cosmic Ray Data

At present, there are no reliable methods to evaluate uncertainty of model representation of magnetic field （MF） in the whole volume of the Earth＇s magnetosphere. Cosmic ray intensity distribution on the Earth surface contains information on the space distribution of magnetospheric MF through which charged particles propagate. Feasibility and limitations of cosmic ray data to be a tool for the validation of magnetospheric MF models have been analyzed. The authors＇ approach is based on the fact that time variations of magnetospheric cosmic ray are related to the changes in geomagnetic cutoff rigidities. The obtained cutoff rigidity changes by the trajectory tracing method in the MF model with those obtained on the base of experimental cosmic ray data have also been compared. The obtained results have shown that cosmic ray data can be successfully used for validation of models in presenting the dynamic structure of magnetospheric MF at mid latitudes.

Latitudinal variations of CPI values of long-chain n-alkanes in surface soils:Evidence for CPI as a proxy of aridity

Carbon preference index (CPI) of long-chain n-alkanes preserved in surface soil increases gradually from southeastern China to the north margin of Loess Plateau.Along this latitudinal transect,the CPI value correlates to relative humidity,precipitation,and temperature with a negative linear relationship,respectively,whereas the correlation of CPI to temperature is relatively weak.In the Wuyi,Shennongjia,and Tianshan Mountains,CPI values do not change systemically with altitude increasing (or temperature decreasing).However,mean value of CPI for the individual mountain increases in turn from the humid mountain to the arid.These results jointly suggest that aridity (or humidity) is a dominate climate factor in altering soil CPI value.High CPI values of geological records therefore indicate the arid paleoclimate.Though long-chain n-alkanes in soil are derived mainly from leaf wax of terrestrial vascular plants,the regular latitudinal variations of soil CPI might not be caused by the change of vegetation.We speculate that increased long-chain n-alkanes from microbes and/or enhanced biodegradation in the humid climate lead to the decrease of soil CPI.

The influence of Cretaceous paleolatitude variation of the Tethyan Himalaya on the India-Asia collision pattern

Identifying when, where, and how India and Asia collided is a prerequisite to better understand the evolution of the Himalayan-Tibetan Plateau. Whereas with essentially the same published paleomagnetic data, a large range of different India-Asia collision models have been proposed in the literature. Based upon the premise of a northwards-moving Indian plate during the Cretaceous times, we analyze the significant variations in relative paleolatitude produced by a nearly 90° counterclockwise(CCW)rotation of the plate itself during the Cretaceous. Interestingly, recent studies proposed a dual-collision process with a Greater India basin or post-Neo-Tethyan ocean for the India-Asia collision, mainly in the light of divergent Cretaceous paleolatitude differences of the Tethyan Himalaya between the observed values and expected ones computed from the apparent polar wander path of the Indian plate. However, we find that these varied paleolatitude differences are mainly resulted from a nearly 90° CCW rotation of a rigid/quasi-rigid Greater Indian plate during the Cretaceous. On the other hand, when the Indian craton and Tethyan Himalaya moved as two individual blocks rather than a united rigid/quasi-rigid Greater Indian plate before the India-Asia collision, current available Cretaceous paleomagnetic data permit only multiple paleogeographic solutions for the tectonic relationship between the Indian plate and the Tethyan Himalayan terrane. We therefore argue that the tectonic relationship between the Indian plate and the Tethyan Himalayan terrane cannot be uniquely constrained by current paleomagnetic data in the absence of sufficient geological evidence, and the so-called Greater India basin model is just one of the ideal scenarios.

The effects of vertical viscosity coefficients with different distribution characteristics on classical Ekman spiral structure

The classical Ekman theory tells us that the ocean surface current turns to the right(left) side of wind direction with 45° in the north(south) hemisphere,but the observation and research results show that the surface current deflexion angle is smaller than 45° in the Arctic and high latitude areas while larger than 45° in the low latitude areas.In order to explain these phenomena,a series of idealized numerical experiments are designed to investigate the influence of vertical viscosity coefficients with different vertical distribution characteristics on the classical and steady Ekman spiral structure.Results show that when the vertical viscosity coefficient decreases with water depth,the surface current deflexion angle is larger than 45°,whereas the angle is smaller than 45° when the vertical viscosity coefficient increases with water depth.So the different observed surface current deflexion angles in low latitude sea areas and the Arctic regions should be attributed to the different vertical distribution characteristics of vertical viscosity coefficients in the upper ocean.The flatness of the Ekman spiral is not equal to one and does not show regular behaviors for the numerical experiments with different distribution of vertical viscosity.However,the magnitudes and directions of volume transport of Ekman spirals are almost the same as the results of classical Ekman theory,i.e.,vertical viscosity coefficient distributions have no effect on the magnitudes and directions of volume transport.

Correction method for non-landing measuring of vehicle-mounted theodolite based on static datum conversion

During the non-landing measuring of vehicle mounted theodolite, especially under high-speed tracking measurement, the misalignment of theodolite's center of mass and spindle etc. will cause high-frequency vibration of theodolite platform, increase the observation error of targets and even unbelievable results. In this paper, a correction method of non-landing measuring of theodolite based on static datum conversion is presented, which can effectively improve the observation accuracy of theodolite. The CCD camera is fixed to the theodolite platform to calculate the gesture shaking quantity of theodolite platform in geodetic coordinate system through the real time imaging of static datum. The observation results of theodolite are corrected by using such shaking quantity. The experiment shows that the correction accuracy exceeds 10 s of arc. The intrinsic parameter calibration technology of camera based on stellar angular distance and absolute conic put forward in this paper can prevent the estimated error of extrinsic parameters influencing the intrinsic parameter calibration and improve the intrinsic parameter calibration accuracy; the static datum conversion technology can reduce the influence of installation error of camera and theodolite platform on gesture measuring of the platform. The simulation experiment shows that when the shaking range of the platform is less than 30 min of arc, the influence of the three-axis installation error of camera within 3deg on the accuracy of correction results is less than 8 s of arc. The method in this paper can be extended to and used in the field of gesture shaking measuring and micro-structure deformation of various unstable platforms, therefore it is of important theoretical research significance and has wide engineering application prospect.

Preliminary analysis of spatiotemporal pattern of global land surface water

Land surface water(LSW) is one of the most important resources for human survival and development, and it is also a main component of global water recycling. A full understanding of the spatial distribution of land surface water and a continuous measuring of its dynamics can support to diagnose the global ecosystem and environment. Based on the Global Land 30-water 2000 and Global Land 30-water 2010 products, this research analyzed the spatial distribution pattern and temporal fluctuation of land surface water under scale-levels of global, latitude and longitude, continents, and climate zones. The Global Land 30-water products were corrected the temporal inconsistency of original remotely sensed data using MODIS time-series data, and then calculated the indices such as water area, water ration and coefficient of spatial variation for further analysis. Results show that total water area of land surface is about 3.68 million km2(2010), and occupies 2.73% of land area. The spatial distribution of land surface water is extremely uneven and is gathered mainly in mid- to high-latitude area of the Northern Hemisphere and tropic area. The comparison of water ratio between 2000 and 2010 indicates the overall fluctuation is small but spatially differentiated. The Global Land 30-water products and the statistics provided the fundamental information for analyzing the spatial distribution pattern and temporal fluctuation of land surface water and diagnosing the global ecosystem and environment.