近相接双星室女座BF的轨道周期变化     

钱声邦  刘清耀  杨毓兰  袁礼礼 《天文学报》2000,41(1):36-43

收集了近相接双星ＢＦ Ｖｉｒ的光极小时刻,并对其轨道周期进行分析。结果表明该星的轨道周期在长期减小的财时也含有３０年的周期性变化,对引起轨道周期变化的各种物理机制的分析研究表明：一个质量为０．２８１Ｍ⊙、绕公共质心的轨道半径为１０．２ＵＡ的第３天体的存在能对轨道周期的周期性变化成份作出解释,如果轨道周期的周期性变化成份是由于次子星的周期性磁活动引起,那么系统总光度就应该有振幅０．０９７Ｌ⊙的周期性  相似文献   

Two-dimensional modeling of fine sediment transport with mixed sediment and consolidation: Application to the Gironde Estuary,France     

Sylvain Orseau  Nicolas Huybrechts  Pablo Tassi  Damien Pham Van Bang  Fabrice Klein 《国际泥沙研究》2021,36(6):736-746

In order to optimize ship navigation in the macrotidal Gironde Estuary, a recent project funded by the port of Bordeaux aims at better understand and forecast hydrodynamic and fine sediment transport within the estuary. In the framework of this project, a two-dimensional hydro-sedimentary model is built. The model includes hydrodynamic forcings, mixed-sediment transport, and consolidation processes. The harmonic analysis of the astronomical tides reveals a strong distortion of the tidal wave inducing the growth of overtide constituents and the non-significant effect of tide-surge interactions in annual-scale prediction. Depending on hydrological conditions, river discharge can considerably alter the model accuracy due to the migration of the turbidity maximum zone modifying the bottom roughness. Comparison with measurements shows the ability of the model to reproduce suspended-sediment concentrations in the central Estuary. Sensitivity of the model to sediment features has also been discussed in regard of suspended-sediment concentrations and fluid mud deposits. The model will be further coupled with ship squat predictions and a morphodynamic model.  相似文献   

Preliminary availability assessment to support single-frequency SBAS development in the Korean region     

Eugene Bang  Jinsil Lee  Todd Walter  Jiyun Lee 《GPS Solutions》2016,20(3):299-312

Satellite-Based Augmentation Systems (SBASs) enhance the global navigation satellite system (GNSS) to support all phases of flight by providing required accuracy, integrity, continuity, and availability. The Korean SBAS program was recently initiated to develop a single-frequency SBAS aiming to provide Approach Procedure with Vertical guidance (APV)-I Safety-of-Life (SoL) service to aviation users by 2022 within the Korean region. We assess the preliminary availability of the single-frequency SBAS which will be deployed in the Korean peninsula. The resulting system performance shall be used as a baseline to design system components and specifications. The fundamental components of SBAS architecture, SBAS monitor network, geostationary earth orbiting satellite parameters, and ionospheric grid point mask, are defined and their effects on system performance are investigated. Ionospheric correction and integrity algorithm parameters including an ionospheric irregularity threat model are determined using data collected from the Korean GNSS network. The coverage of 99.9 % availability for APV-I service increases from approximately 70 % for the baseline case to 100 % when SBAS monitor stations are expanded to overseas. Even with the expanded monitor network, however, 90 % and less than 95 % availability for LPV-200 service can be achieved only in a very limited region.  相似文献   

巨蛎属牡蛎DNA序列的比较及鉴定     

彭敏  罗邦  朱威霖  杨春玲  赵永贞  李强勇  刘青云  曾地刚  李旻  陈秀荔 《广东海洋大学学报》2020,(1):29-37

【目的】了解巨砺属牡蛎的系统关系和种类区分。【方法】对我国沿海分布的7种巨砺属牡蛎(香港牡蛎、有明牡蛎、熊本牡蛎、岩牡蛎、艾氏牡蛎、太平洋牡蛎、葡萄牙牡蛎)的线粒体DNA片段(COI、12S、16S和tRNAs),以及核糖体RNA基因转录间隔子序列(ITS-1、ITS-2和ITS)进行分子系统学研究。【结果】无论种间或种内,tRNAs序列差异最大,亚种内TS1序列差异最大;tRNAs和COI序列较其它序列变异更快,种间变异与种内变异之间有明显的条形码间隙;12S、16S、ITS和ITS2的种间变异与种内变异无重叠及条形码间隙;ITS1的种间变异与种内变异出现重叠。在亚种层面,12S、ITS、ITS1和ITS2的亚种间变异与亚种内变异出现重叠;16S的亚种间变异与亚种内变异无重叠及条形码间隙;tRNAs与COI序列亚种间变异与亚种内变异之间有明显的条形码间隙,有利于区分亚种。【结论】tRNAs和COI序列可用于种及亚种的鉴定。  相似文献   

Failure characteristics of brittle rock containing two rectangular holes under uniaxial compression and coupled static-dynamic loads     

Zhu  Quanqi  Li  Diyuan  Han  Zhenyu  Xiao  Peng  Li  Bang 《Acta Geotechnica》2022,17(1):131-152

Acta Geotechnica - To deeply understand the failure characteristics of defective rock under actual stress condition, impact tests were conducted on prismatic granite containing two rectangular...  相似文献   

钛矿石物相的快速分析   总被引：1，自引：1，他引：0  

郑民奇  李邦民  程秀花 《岩矿测试》2010,29(1):61-63

钛矿石的主要矿物有金红石(TiO2),其次钛铁矿(FeO.TiO2)、榍石(CaO.TiO2.SiO2)和钛磁铁矿(FeTiO3.nFe2O3)。样品经碱熔融,过氧化氢比色测定总钛;利用电感耦合等离子体质谱法测定,氟化氢铵和盐酸溶解钛铁矿、钛磁铁矿、榍石和硅酸盐中的钛;湿法磁选、盐酸溶解钛磁铁矿中的钛;磁选后的残渣经800℃灼烧,氟化氢铵和盐酸溶解榍石和硅酸盐中的钛。方法对12个钛矿石样品进行了4种钛矿物物相分析,结果与实际地质成矿组分符合。  相似文献   

大力开展直接找油找气技术研究     

陆邦干 《地球物理学进展》2002,17(2):277-280

提出了直接找渍气的必要性和可能性,回顾了以往失误的原因,推荐了百灵软件,并期望各石油公司经理层能使用该软件,化较小的代价对地震资料进一步解释利用而提高钻井成功率,并最终降低油气成本。  相似文献   

找矿信息量法在铜山铜矿成矿预测中的应用   总被引：4，自引：0，他引：4  

王勇  陈邦国 《地质与勘探》2002,38(3):49-51

在分析铜山矿田控矿条件，总结成矿规律的基础上，利用找矿信息量法对矿田进行综合成矿预测，提出了预测靶区。  相似文献   

Effect of self-weight consolidation on a hydro-sedimentological model for the Río de la Plata estuary     

Pablo Santoro  Mónica Fossati  Pablo Tassi  Nicolas Huybrechts  Damien Pham Van Bang  Ismael Piedra-Cueva 《国际泥沙研究》2019,34(5):444-454

The effect of the consolidation process on the morphodynamics and fine sediment dynamics of the Río de la Plata estuary is explored through a circulation-wave-sediment transport model. The consolidation model is calibrated based on settling column experimental data. Different simulations are done in order to initialize the mud layer distribution and to investigate the impact of different erosion parameter assumptions on the modeled sediment dynamics. Finally a two-year simulation is done with and without the consolidation process and realistic hydrodynamic forcings. Considering the consolidation process, the model correctly reproduces measured vertical density profiles in the Montevideo Bay access channel. The simulated suspended sediment dynamics behavior in Montevideo Bay with the consolidation process provides a more realistic deposition pattern in regard to the dredging activities.  相似文献   

中西非裂谷盆地白垩系两类优质烃源岩发育模式   总被引：1，自引：1，他引：0  

程顶胜  窦立荣  张光亚  刘邦  宋换新  刘计国  毛凤军  袁圣强  胡瑛 《地质学报》2020,94(11):3449-3460

中西非裂谷系位于非洲中部,主要为沿中非剪切断裂带分布的被动裂谷盆地,进一步划分为中非裂谷系和西非裂谷系。针对国内外对勘探程度极低的中西非裂谷盆地白垩系优质烃源岩展布、发育机理及油气成藏模式认识薄弱的现状,笔者在开展大量中西非裂谷盆地上、下白垩统两类烃源岩样品的主微量元素等地球化学分析的基础上,从含油气盆地构造、烃源岩发育古环境、古气候、古生产力和有机质保存条件等分析出发,剖析了不同类型含油气盆地优质烃源岩发育主控因素,分别建立了中、西非裂谷系低勘探程度含油气盆地下白垩统、上白垩统优质烃源岩的发育模式：中非裂谷盆地(Bongor、Muglad、Melut盆地)下白垩统裂陷期快速沉降、温暖湿润气候条件下,勃发的水生有机质(藻类)控制的深水湖相优质烃源岩“生产力”单因素发育模式;西非裂谷盆地(Termit盆地)上白垩统拗陷期海侵、炎热潮湿气候条件下,陆源有机质输入为主,优越的保存条件(偏咸水体)优质海相烃源岩 “生产力+保存条件”双因素控制的发育模式。从而进一步锁定富油气凹陷和主力成藏组合,有效指导含油气盆地内选区选带,助推油气规模储量发现。  相似文献