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戴吾蛟  赵岩 《大地测量与地球动力学》2013,33(2):72-76

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高晓  戴吾蛟 《大地测量与地球动力学》2013,33(2):136-138

????GPS??????????BD2????????????????????????λ?????????????????????????????????Helmert????????????????????????α?????????λ??????α????λ????λ????λ????????з??????????????Helmert????????????????GPS/BD2????λ????????????α?????????????21????λ????????11??  相似文献   

皖西南地区中强地震前后地磁资料变化特征     

戴苗  李军辉  刘坚  李明  蒋玲霞 《大地测量与地球动力学》2013,(Z1):143-146,151

计算并分析了2011年1月19日安庆M4.8地震和2011年9月10日瑞昌-阳新M4.6地震前后震中周边主要地磁台站地磁转换函数参数的变化特征,总结了安庆地震前华东片主要地磁台站地磁资料垂直分量的变化特征。结果表明:在两次中强地震前,武汉、泾县、金寨三个地磁台的转换函数的部分参数出现了不同程度的异常变化;安庆地震前,中国大陆东部地磁低点时间出现位移,地磁日变形态亦发生了明显的畸变。  相似文献   

交互式地震广播会商系统的应用     

刘坚  李盛乐  戴苗  董兴朋  彭愿 《大地测量与地球动力学》2013,(Z1):110-113

针对目前地震会商现场缺乏交互性与数据分析的动态性,提出地震会商会议发起人-参与者的应用模式。会商期间,通过在广播端实时广播操作消息、运用网络实时推送技术,使各地参与的信息节点会商资料内容一致,同时接收端实时接收并执行操作消息,从而同步显示广播计算机的操作画面,最终达到模拟广播视频的效果。该系统增强了地震会商在线动态数据分析的真实性与实时交互性。  相似文献   

Orbital period analysis of eclipsing post-novae T Aurigae: Evidence of magnetic braking and an unseen companion     

Zhibin Dai  Shengbang Qian 《New Astronomy》2010,15(4):380-384

Four new CCD times of light minimum of T Aurigae are presented. The orbital period variation is analyzed by means of the standard O–C technique. The new times of light minimum indicate that a ～24 yr sine-like period variation superimposed on a secular orbital period decrease is obviously seen in the O–C diagram. However, the orbital period should increase because of mass transfer between components. In order to solve this apparent paradox, three possibilities including magnetic braking mechanism, which plays an important role in angular moment loss of binary, are proposed. The mass loss rate $\dot{M}={10}^{-10.4}{M}_{\odot }{\text{yr}}^{-1}$ is derived by assuming that the Alfvén radius of secondary is the same as that of the sun (i.e. $R_A?15R_{\odot }$). Using the observational relationship of ${\dot{M}}_{\mathit{mb}}-P_{\mathit{orb}}(h)$ (McDermott and Taam, 1989, Rappaport et al., 1983), the Alfvén radius of secondary is estimated as $R_A?1.9R_{\odot }$, which only requires a weak magnetic field in secondary. Since the brightness variations of T Aurigae caused by Applegate’s mechanism need large energy beyond the total radiant energy in the time interval of 24 yr, the third body light travel-time effect is the most likely explanation for the 24-yr variation. The third body may be a brown-dwarf star in case of the high orbital inclination.  相似文献   

山东省GNSS基准站的建设     

冯志军  王强  崔居全  王伟  陈安方  刘作华  申健  潘双进 《大地测量与地球动力学》2012,32(Z1):76-80

介绍山东省GNSS基准站土建、供电避雷、通讯以及仪器设备安装调试的技术工艺.  相似文献   

陆地沉积物对大洋缺氧事件的响应：六盘山群黑色页岩地球化学特征及其意义     

戴霜  刘学  赵杰  张明震  刘俊伟  孔立  朱强  黄永波 《地学前缘》2012,19(4):255-259

通过对六盘山群中上部湖相沉积中一层黑色页岩年代（113.45~112.98 Ma）及其下部泥灰岩的元素地球化学特征研究发现,黑色页岩形成于干热而相对湿润气候背景下的缺氧还原环境中,与典型缺氧事件黑色页岩的地球化学特征基本一致,说明该黑色页岩记录了六盘山地区对全球白垩纪大洋缺氧事件OAE1b (约113～111 Ma)的响应,可能指示该期大洋缺氧事件是一次全球性的气候变化事件。  相似文献   

南极格罗夫山100块陨石的矿物-岩石学特征   总被引：2，自引：2，他引：0       下载免费PDF全文

戴德求  王道德  王桂琴 《极地研究》2008,20(2):153-166

本文主要报道了南极格罗夫山新回收的100块陨石的岩石学和矿物化学特征。并根据矿物-岩石学特征,划分了它们的化学-岩石类型:6块属于非平衡型普通球粒陨石(H3和L3群各3块);92块属于平衡型普通球粒陨石,包括:H群24块(13块H4,10块H5,1块H6),L群64块(2块L4,44块L5,18块L6),LL群4块(3块LL4,1块LL5);另外两块属于石-铁陨石。6块非平衡型普通球粒陨石保存了原始的岩石学和矿物化学特征,包括:清晰的球粒结构、橄榄石和低钙辉石具有明显的成分环带以及极不均一的化学组成等。92块平衡型普通球粒陨石中的橄榄石和低钙辉石显示出均一的化学组成,表明它们达到了一定的热力学平衡。这些普通球粒陨石受到的风化作用以W1和W2为主,所占比例高于90%,表明南极陨石受到的风化作用不强烈。有约40%的陨石样品受到了强烈的冲击作用,并产生冲击脉或者冲击囊,它们是研究高压冲击矿物和冲击作用的理想样品。  相似文献   

南极威德尔海冬季海冰叶绿素及其生态意义          下载免费PDF全文

戴芳芳  王自磐  E.Allhusen  G.Dieckmann 《极地研究》2008,20(3):248-257

2006年8-10月南极威德尔海冬季海冰考察,对海冰生物地球化学特征,包括叶绿素a、POC、C/N等的含量与垂直分布及其生态意义进行分析研究。结果表明,海冰叶绿素a含量普遍较高,平均总量233.8μg·l-1,范围14.7-1519.2μg·l-1,其中有57%以上的冰芯平均总量超过100μg·l-1。冰芯叶绿素a平均值为16.6μg·l-1,范围2.1-84.4μg·l-1,高出威德尔海区初冬海冰叶绿素a平均值的2.2倍,高出深冬时的7.5倍。海冰不同层次叶绿素垂直分布不均匀,底部有色层多位高值区。本文海冰R值83%,表明冬季冰藻具有较强活性,并处于初春旺发前期的活跃状态,不仅有利于暖季大量冰藻释放促成海域浮游植物水华与初级生产的迅速增长,并为浮游动物幼体的生长发育提供丰富饵料,确保海域生态系统的修复和可持续发展。  相似文献   

Impacts of an improved low-level cloud scheme on the eastern Pacific ITCZ-cold tongue complex   总被引：1，自引：0，他引：1  

DAI Fushan  YU Rucong  ZHANG Xuehong  YU Yongqiang  LI Jianglong 《大气科学进展》2005,22(4):559-574

A statistically-based low-level cloud parameterization scheme is introduced, modified, and applied in the Flexible coupled General Circulation Model (FGCM-0). It is found that the low-level cloud scheme makes improved simulations of low-level cloud fractions and net surface shortwave radiation fluxes in the subtropical eastern oceans off western coasts in the model. Accompanying the improvement in the net surface shortwave radiation fluxes, the simulated distribution of SSTs is more reasonably asymmetrical about the equator in the tropical eastern Pacific, which suppresses, to some extent, the development of the double ITCZ in the model. Warm SST biases in the ITCZ north of the equator are more realistically reduced, too. But the equatorial cold tongue is strengthened and extends further westward, which reduces the precipitation rate in the western equatorial Pacific but increases it in the ITCZ north of the equator in the far eastern Pacific. It is demonstrated that the low-level cloud-radiation feedback would enhance the cooperative feedback between the equatorial cold tongue and the ITCZ. Based on surface layer heat budget analyses, it is demonstrated that the reduction of SSTs is attributed to both the thermodynamic cooling process modified by the increase of cloud fractions and the oceanic dynamical cooling processes associated with the strengthened surface wind in the eastern equatorial Pacific, but it is mainly attributed to oceanic dynamical cooling processes associated with the strengthening of surface wind in the central and western equatorial Pacific.  相似文献