Analysis of the light curves of the eclipsing system V548 Cygni     

A. Y. Ertan 《Astrophysics and Space Science》1981,77(2):391-408

The eclipsing binary V548 Cygni was observed photoelectrically in yellow and blue light at Ege University Observatory in 1975. A total of 857 observations were obtained of each colour. Three times of minima were obtained and new light elements were derived. The orbital analysis were made by the methods of Kitamura and Wood. The system has a third body whose total luminosity is greater than that of secondary companion.  相似文献   

Escape of atmospheric gases from the Moon     

Da Dao-an  Yang Ya-tian 《Journal of Earth System Science》2005,114(6):637-644

The escape rate of atmospheric molecules on the Moon is calculated. Based on the assumption that the rates of emission and escape of gases attain equilibrium, the ratio of molecular number densities during day and night, n_0d/n_0n, can be explained. The plausible emission rate of helium and radioactive elements present in the Moon has also been calculated.  相似文献   

Characterization of a profile of residual soil from granite combining geological, geophysical and mechanical testing techniques     

A. Viana Da Fonseca  J. Carvalho  C. Ferreira  J. A. Santos  F. Almeida  E. Pereira  J. Feliciano  J. Grade  A. Oliveira 《Geotechnical and Geological Engineering》2006,24(5):1307-1348

This paper summarizes the results of an experimental site investigation and characterization survey, on a residual (saprolitic) soil from granite, in the framework of a research project led by the Faculty of Engineering of the University of Porto (FEUP). This project aims at characterizing these unusual soils in the context of the development of an International Prediction Event (Class A) on the behaviour of different types of piles. A very extensive site characterization campaign, including a large variety of in-situ tests and field methods, has been held. These investigations comprised the application of several geophysical borehole and surface methods, namely P- and S-wave seismic refraction, reflection, cross-hole (CH), down-hole (DH), electrical resistivity imaging and ground probing radar (GPR), as well as mechanical tests, namely SPT, CPT and DMT, among others. The site is geologically formed by an upper layer of heterogeneous residual granitic soil, overlaying rather weathered granite contacting a gneissic migmatite. Direct and indirect results from some of the referred surveys were compared between them and with some of the available geological and geotechnical information, namely those obtained from seismic, electrical and GPR profiles, conducted adjacent to three boreholes in which undisturbed soil samples were collected previously to geophysical data acquisition. In addition, a comprehensive laboratory testing program was carried out using the collected undisturbed samples. A discussion of the obtained results is hereby presented, giving emphasis to the correlations encountered between the different tests, specific of saprolitic soils with weak relic structures.  相似文献   

Permeability and compression characteristics of municipal solid waste samples     

Ertan Durmusoglu  Itza M. Sanchez  M. Yavuz Corapcioglu 《Environmental Geology》2006,50(6):773-786

Four series of laboratory tests were conducted to evaluate the permeability and compression characteristics of municipal solid waste (MSW) samples. While the two series of tests were conducted using a conventional small-scale consolidometer, the two others were conducted in a large-scale consolidometer specially constructed for this study. In each consolidometer, the MSW samples were tested at two different moisture contents, i.e., original moisture content and field capacity. A scale effect between the two consolidometers with different sizes was investigated. The tests were carried out on samples reconsolidated to pressures of 123, 246, and 369 kPa. Time settlement data gathered from each load increment were employed to plot strain versus log-time graphs. The data acquired from the compression tests were used to back calculate primary and secondary compression indices. The consolidometers were later adapted for permeability experiments. The values of indices and the coefficient of compressibility for the MSW samples tested were within a relatively narrow range despite the size of the consolidometer and the different moisture contents of the specimens tested. The values of the coefficient of permeability were within a band of two orders of magnitude (10⁻⁶–10⁻⁴ m/s). The data presented in this paper agreed very well with the data reported by previous researchers. It was concluded that the scale effect in the compression behavior was significant. However, there was usually no linear relationship between the results obtained in the tests.  相似文献   

黄骅坳陷中生界砂岩地球化学特征及意义          下载免费PDF全文

李晨  陈世悦  楼达  付立新  鄢继华 《地球科学》2021,46(8):2903-2918

中生代黄骅坳陷位于华北克拉通汇聚与破坏的中心,为各物源的汇集地,记录了华北中生代盆地的构造及物源演化.对研究区中生界砂岩进行了主、微量元素测试分析,结果显示,样品SiO₂、Al₂O₃、Na₂O、K₂O和Fe₂O₃T平均含量分别为66.98%、13.65%、2.74%、3.03%和3.26%,砂岩为岩屑砂岩、长石砂岩和杂砂岩.砂岩CIA和ICV的平均值分别为56.12和0.94,均经历了一定的化学风化及再旋回作用.砂岩的母岩为长英质火成岩和再旋回沉积岩,并混杂少量基性火成岩.由三叠纪到白垩纪,中生界砂岩物源逐渐由华北北缘大陆弧演化为燕山造山带和黄骅坳陷内的岩浆作用及古隆起.   相似文献   

反倾层状岩质边坡倾倒变形机理与影响因素的离散元模拟     

黄达  马昊  石林 《吉林大学学报(地球科学版)》2021,51(6):1770-1782

为进一步研究层状反倾边坡的弯曲倾倒变形机制,以离心试验为原型,通过离散元数值模拟,研究了层状岩质反倾边坡的变形机理与影响因素。通过预置层内随机裂隙,实现了破裂面的形成和贯通。研究结果表明：模拟结果与试验吻合较好,边坡变形可分为起始蠕变、稳态变形和失稳破坏3个阶段;边坡破裂面在达到破坏荷载（G_f）后瞬间贯通,呈直线型,产状受岩层倾角控制,G_f值与坡角幂函数相关;反倾边坡的破坏需满足倾角和坡角启动条件,且变形破坏与岩层所受弯矩关系密切,当倾角为70°~80°、坡角大于60°时,最易破坏;典型破坏模式有倾倒-折断-块体式、倾倒-弯曲-折断式、倾倒-反折式3种,其受倾角、坡角组合控制;对材料参数的正交试验表明,各参数对G_f的敏感性从大到小依次为密度、层面内摩擦角、层厚、密度比、层面黏聚力,且G_f与层厚、层面内摩擦角及密度比具有良好的线性相关性;层面内摩擦角可影响破裂面产状,从而控制变形体规模,其他参数仅影响G_f的大小。  相似文献   

塔中地区晚奥陶世碳酸盐台缘与台内沉积差异--定性和定量的碳酸盐岩微相综合分析   总被引：2，自引：2，他引：0  

付坤荣  黄理力  祝怡  冯翔艺蓝  章巧  关小丽  高达 《沉积学报》2018,36(1):101-109

为揭示塔中地区东部的晚奥陶世镶边型碳酸盐台地边缘与台地内部的沉积差异,利用钻井岩芯及薄片资料,对良里塔格组开展了定性的和定量的碳酸盐岩微相分析研究。研究表明,台缘-台内沉积区发育9种微相类型（MF1~MF9）,不同颗粒岩类微相所代表的几种颗粒滩具有典型差别的粒度累积频率曲线样式。台地边缘主要发育各种高能颗粒滩的微相组合（MF1~MF4）,与台缘生物礁构成礁滩复合体;台地内部主要发育代表中-低能的潮坪-潟湖沉积的微相组合（MF5~MF9）。结合定量的粒度分析分析认为生屑砂屑颗粒灰岩微相（MF1）、生屑砾屑灰岩微相（MF2）和鲕粒颗粒灰岩微相（MF3）是冲流带（前滨）环境的产物,分别代表着台地边缘生屑滩、鲕粒滩和礁前砾屑滩沉积;球粒颗粒灰岩微相（MF5）为位于受障壁的台地内部、中等能量波浪控制的球粒滩;棘屑泥粒灰岩-漂浮岩微相（MF4）发育于台缘礁后的中-高能生屑滩。  相似文献   

商品住宅价格空间溢出效应测度及其影响因素分析——来自长三角地区的证据     

韦汝虹  金李  方达 《世界地理研究》2023,32(1):117-129

商品房价格的空间溢出效应是当前学界探讨的重要议题,但鲜有研究基于区域视角测度并对比不同商品房价格空间溢出效应的差异。本文以长三角地区为例,基于GIS的空间计量模型尝试测度商品房价格的空间溢出效应,并进一步对比分析三种商品住宅（新住宅、二手住宅和租赁住宅）价格的空间溢出效应及其影响因素。结果表明（：1）上海、杭州和南京三个城市的商品住宅价格明显高于其他城市,说明其价格与城市的经济（行政）等级密不可分（;2）三种住宅价格均表现为由上海向内陆区域依次降低的空间规律,具有明显的空间等级性（;3）新住宅、二手住宅和租赁住宅价格的空间溢出效应依次减弱,但新住宅和二手住宅价格的溢出效应差别不大（;4）上海、苏州、南通和嘉兴四个城市处于高房价集聚区,该区域商品房价格与周边城市的商品住宅价格存在显著的空间溢出关系（;5）经济基础、消费需求和社会资源对三种商品住宅价格的空间溢出均具有显著的促进作用。  相似文献   

2021年西北太平洋和南海台风活动概述          下载免费PDF全文

向纯怡  高拴柱  刘达 《海洋气象学报》2022,42(1):39-49

利用中央气象台台风实时业务资料、自动气象站观测资料以及卫星云图等对2021年西北太平洋及南海台风活动的主要特征和影响我国台风的路径、强度及风雨影响进行分析和回顾。结果表明:2021年西北太平洋及南海台风生成个数偏少,生成源地整体偏西;台风强度偏弱,但有多个台风出现了快速增强,其中台风“烟花”“灿都”的24 h强度增幅达40 m·s^-1,为近30 a少见;2021年先后有5个台风登陆我国,另有2个台风影响我国。在登陆台风中,4个登陆华南的台风强度均弱于历史平均值。所有登陆台风在登陆后的维持时间都明显高于历史均值,特别是台风“烟花”为历史上登陆华东后维持时间最长的台风,给我国带来了严重的灾害影响。  相似文献   

基于演化博弈的中国橡胶主产区目标价格补贴政策及其敏感性研究——以西双版纳为例     

李达  张绍文 《热带地理》2022,42(3):490-498

当前,橡胶收入不足于吸引农户继续种植橡胶,为保障国家橡胶战略安全,利用演化博弈模型分析了目标价格补贴政策的有效性边界,并对影响目标价格补贴政策的因素进行了敏感性分析。结果发现,依据2019年西双版纳18个样本村的947个截面数据及地区统计公报等测算得出,在橡胶价格为8元/kg时,应将目标补贴价格定位为12.8元/kg;橡胶树单产为影响目标价格补贴额度变量中敏感系数最大的因素;在当前其他因素不变的情况下,橡胶树单产提升10%可使目标补贴价格额度下降25%。建议采取积极稳健的财政补贴政策,利用浮动的目标价格补贴稳定橡胶产区的农户预期,同时辅以橡胶价格保险等配套政策激励农户提高橡胶树单产,在达到政策目标的同时降低财政成本。  相似文献