Relation between Mass and Radius of Exoplanets Distinguished by their Density

The formation of the solar system has been studied since the 18th century and received a boost in 1995 with the discovery of the first exoplanet,51 Pegasi b.The investigations increased the number of confirmed planets to about5400 to date.The possible internal structure and composition of these planets can be inferred from the relationship between planet mass and radius,M-R.We have analyzed the M-R relation of a selected sample of iron-rock and ice-gas planets using a fractal approach to their d...     

Probing the Variation of Reverberation Lags along with X-Ray Flux in the AGN Mrk 704

Understanding the variation of lags with respect to the X-ray flux is important to explore the geometry of the inner region of the accretion disk in AGNs. We performed frequency-lag, energy–lag and spectral studies for two sets of observations, in order to investigate the variations in lags with respect to X-ray flux in the AGN source Mrk 704 using the XMM-Newton observatory. We divided one of the light curves into two sections which were noticed to exhibit a flux variation. The frequency-lag sp...     

Geochemistry and petrogenesis of the Paleoproterozoic orthogneisses and granitoids of the Banded Gneissic Complex,central Rajasthan,NW India: Implications for crustal reworking processes

Granitoids and orthogneisses(1.7 Ga) from the northern part of the Banded Gneissic Complex(BGC-II domain), Aravalli Craton(NW India) are geochemically analyzed to understand the geodynamic condition and crustal evolution processes. The samples are metaluminous to peraluminous(molar A/CNK: 0.74±2.12), and characterized by Eu-anomaly ranging from 0.17 to 1.06, Fe₂O₃^T/(Fe₂O₃^T+MgO) from 0.8 to 0.9 and high magmatic zircon saturation t...     

一个诊断极区平流层温度变化的近似方程的检验及应用

根据一个诊断极区平流层温度变化的近似方程及其滑动累加计算方案,采用1980—2000年的MERRA-2再分析日资料计算了北半球极区低平流层100 hPa逐月的温度增量项、动力加热项和非绝热加热项,以及各项的线性趋势。结果表明,各月温度增量项与累积的动力和非绝热加热之和在气候平均的年循环意义上接近平衡,而且它们的趋势也近似平衡。进一步通过多元回归,得到了动力和非绝热加热作用对当前月温度趋势的分别贡献,动力作用是北极低平流层冬季温度趋势的主导因素并且在冬季内不一致,而非绝热作用在其他季节是主导因素。     

Optical Spectroscopy of Classical Be Stars in Old Open Clusters

We performed the optical spectroscopy of 16 classical Be stars in 11 open clusters older than 100 Myr. Ours is the first spectroscopic study of classical Be stars in open clusters older than 100 Myr. We found that the Hα emission strength of most of the stars is less than 40 ?, in agreement with previous studies. Our analysis further suggests that one of the stars, [KW97] 35–12, might be a weak Hα emitter in nature, showing Hα equivalent width of-0.5 ?.Interestingly, we also found that the newly...     

PERFORMANCE EVALUATION OF SUBMERGENCE RATIO OF A RECTANGULAR SUBMERGED VANE WITH A COLLAR

1 INTRODUCTION Odgaard and Kennedy (1983) suggested that for values of angle of attack, α greater than or equal to approximately 20o, a persistent scour hole is produced near the upstream end of a vane. As α was reduced the number of vanes producing obj…     

北美水平定向钻进现状综述

本文概述了水平定向钻进的发展历史,对钻进承包商的工程类型、规模、设备、收入、前景以及施工中所关注的问题作了调查,指出水平定向钻进承包商和钻机生产商的数量在不断增加,水平定向钻进工业已成为非开挖领域革新和发展的领先技术。     

四川盆地南北缘志留纪生物礁成岩作用及储层特征

四川盆地南北缘志留纪生物礁发育、类型多样,有点礁、灰泥丘、层状礁等。它们曾经历了多种成岩作用,其中主要有胶结作用、溶蚀作用、硅化作用以及白云化作用。由于构造运动简单,本区生物礁的成岩作用演化过程是从早期的海底成岩作用,经短时的大气淡水作用就进入埋藏成岩作用阶段,最后达表生暴露阶段。生物礁的原生孔隙以格架孔、体腔孔为主,并发育有不规则窗格孔、粒间孔及晶间孔等,次生孔隙为后期溶孔及溶缝。由于胶结作用发育,使本区生物礁的储集意义减小。     

Machine learning-enhanced Monte Carlo and subset simulations for advanced risk assessment in transportation infrastructure

The maintenance of safety and dependability in rail and road embankments is of utmost importance in order to facilitate the smooth operation of transportation networks. This study introduces a comprehensive methodology for soil slope stability evaluation, employing Monte Carlo Simulation(MCS) and Subset Simulation(SS) with the "UPSS 3.0 Add-in" in MS-Excel. Focused on an 11.693-meter embankment with a soil slope(inclination ratio of 2H:1V), the investigation considers earthquake coefficients(k