IMU/DGPS辅助空三下几种布点方案的精度比较

主要介绍了在IMU/DGPS辅助空三的情况下,通过对不同的布点方案进行空三加密,对这些空三成果进行精度比较与分析,分析POS辅助空三在无地面控制点或少量的地面控制点的情况下能获得怎样的精度,能满足多大比例尺的成图要求。     

藏北红脊山地区角闪岩相变质地层的划分及时代

关于藏北羌塘中北部地区的变质地层的划分及其时代归属一直有不同的认识.红脊山地区出露的猫耳山岩组是一套由变质碎屑岩夹变质基性火山岩、大理岩和少量硅质岩组成,遭受了低角闪岩相变质作用改造的地层体,泥质变质岩中出现了十字石、蓝晶石、石榴石、角闪石等变质矿物,是羌塘中北部地区出露面积较大,变形强变质较深的构造岩石地层单位.其岩性组合、变质特征以及形成的构造环境均与上石炭统擦蒙组、展金组有明显的区别,二者之间为断层接触关系.根据岩性组合特征及岩石地球化学特征研究表明,猫耳山岩组是弧后盆地沉积的产物.获得角闪片岩全岩Sm-Nd等时线年龄值401±18Ma,可能代表了猫耳山岩组的沉积时代,也是红脊山地区早泥盆世或更早的地质时期发生了一次弧后盆地扩张作用与沉积演化的年代学记录.     

雅鲁藏布江蛇绿岩中超高压矿物硅尖晶石的研究

从西藏雅鲁藏布江蛇绿岩带的罗布莎蛇绿岩的铬铁矿中，发现一个由70-80种奇异矿物组成的地幔矿物群，其中包括一种成分特殊的尖晶石类矿物。该种尖晶石呈包裹体分布在毒砂中，28粒该矿物的平均化学成分：Na2O 1.58％，MgO7．52％，Al2O3 36．59％，SiO2 44．45％，FeO 8．72％，并含少量CaO和TiO2。经激光拉曼谱仪测试，一部分颗粒具有Franclinite（锌铁尖晶石ZnFe2O4）拉曼谱。根据尖晶石结构和化学成分，可以得出两种分子式：（Mg0．52Na0．14Fe0.32Al0.74）1.72（Si2.00Al1.20）3.20O8和（Mg0.52Na0.14Fe0.32Si0.50）1.48相（Si1.50Al1.94）3．44O8。两种分子式都表明阳离子Si呈六配位占据尖晶石八面体晶格位置。Si离子呈六配位的硅酸盐。实验证明具有超高压性质，来自相当于过渡带400-670km的深部。表明西藏雅鲁藏布江蛇绿岩（古大洋岩石圈）的岩浆活动达到过渡带。可能是地幔柱活动将硅尖晶石类等超高压矿物搬运到上地幔浅部的。     

Smectite formation in metalliferous sediments near the East Pacific Rise at 13°N

A 43 cm long E271 sediment core collected near the East Pacific Rise(EPR) at 13°N were studied to investigate the origin of smectite for understanding better the geochemical behavior of hydrothermal material after deposition.E271 sediments are typical metalliferous sediments. After removal of organic matter, carbonate, biogenic opal,and Fe-Mn oxide by a series of chemical procedures, clay minerals(2 μm) were investigated by X-ray diffraction,chemical analysis and Si isotope analysis. Due to the influence of seafloor hydrothermal activity and close to continent, the sources of clay minerals are complex. Illite, chlorite and kaolinite are suggested to be transported from either North or Central America by rivers or winds, but smectite is authigenic. It is enriched in iron, and its contents are highest in clay minerals. Data show that smectite is most likely formed by the reaction of hydrothermal Fe-oxyhydroxide with silica and seawater in metalliferous sediments. The Si that participates in this reaction may be derived from siliceous microfossils(diatoms or radiolarians), hydrothermal fluids, or detrital mineral phases. And their δ30 Si values are higher than those of authigenic smectites, which implies that a Si isotope fractionation occurs during the formation because of the selective absorption of light Si isotopes onto Feoxyhydroxides. Sm/Fe mass ratios(a proxy for overall REE/Fe ratio) in E271 clay minerals are lower than those in metalliferous sediments, as well as distal hydrothermal plume particles and terrigenous clay minerals. This result suggests that some REE are lost during the smectite formation, perhaps because their large ionic radii of REE scavenged by Fe-oxyhydroxides preclude substitution in either tetrahedral or octahedral lattice sites of this mineral structure, which decreases the value of metalliferous sediments as a potential resource for REE.     

新疆西准噶尔玛依勒山地区阔依塔斯杂岩体地球化学特征及锆石U-Pb年龄

新疆西准噶尔北部广泛发育中酸性侵入岩,其形成时代为晚石炭世—早二叠世,岩石类型为辉石闪长岩、石英闪长岩和花岗闪长岩。阔依塔斯杂岩体的形成年龄为(297±2)Ma,Si O2为52.40%~67.53%;高Al2O3,14.92%~17.85%;里特曼指数(δ)小于3.3,介于1.47~1.98;富钠贫钾,K2O/Na2O为0.15~0.49;铁高而镁低,Fe OT/Mg O为1.01~1.69。其稀土配分模式右倾,轻重稀土分馏明显,具有微弱铕正异常。地球化学和年代学特征表明:岩体形成于后碰撞演化的晚期阶段,这一时间早于东准噶尔后碰撞的时间(二叠纪末)。该杂岩体主体可能为幔源岩浆底侵镁铁质下地壳,导致发生部分熔融的产物。     

An Assessment of ENSO Stability in CAMS Climate System Model Simulations

We present an overview of the El Ni?o–Southern Oscillation(ENSO) stability simulation using the Chinese Academy of Meteorological Sciences climate system model(CAMS-CSM). The ENSO stability was quantified based on the Bjerknes(BJ) stability index. Generally speaking, CAMS-CSM has the capacity of reasonably representing the BJ index and ENSO-related air–sea feedback processes. The major simulation biases exist in the underestimated thermodynamic damping and thermocline feedbacks. Further diagnostic analysis reveals that the underestimated thermodynamic feedback is due to the underestimation of the shortwave radiation feedback, which arises from the cold bias in mean sea surface temperature(SST) over central–eastern equatorial Pacific(CEEP). The underestimated thermocline feedback is attributed to the weakened mean upwelling and weakened wind–SST feedback(μ_a) in the model simulation compared to observation. We found that the weakened μ_a is also due to the cold mean SST over the CEEP.The study highlights the essential role of reasonably representing the climatological mean state in ENSO simulations.     

规划管理中CAD与GIS集成方案的探讨

目前国内规划管理部门的地理信息系统多是基于ArcGIS平台开发的,而规划编制、设计单位主要是使用AutoCAD平台。探讨了ArcGIS与AutoCAD集成的适合于国内城市规划领域的较为有效的方法。该方法既可解决数据转换过程中的准确性问题,很好地集成ArcGIS、AutoCAD数据,又可包容规划编制、设计人员的工作习惯,提高工作效率,并尽量降低现有系统改造的工作量。     

不完整岩石样品的断裂与摩擦滑动

在单轴压力下对具有锯口面的岩石样品的破裂和摩擦滑动进行了实验室试验。当锯口面与轴应力方向垂直时（拼合样品）,研究了岩石的强度,破裂形态和前兆。对于锯口面与加载轴成65°和75°的样品,发现在宏观断裂发生之前有粘滑现象发生。粘滞时的应力降和轴向位移的变化比断裂时要小得多。实验发现,在锯口样品中的断裂往往从锯口一侧发生,穿过间断面而向另一侧发展。本文还简要地讨论了这些结果的意义。     

沧州地区地热资源开发利用探讨

沧州地区地热资源丰富,开采利用地热资源在该区的经济建设中占据着重要地位。介绍了该地区热储层概况及地热异常区划分、地热资源开发现状、地热井分布利用情况、存在的问题及发展前景。并在此基础上对利用地热资源的情况进行了探讨,提出遵循开发与保护并重的原则,制定科学的地热开发资源规划方案,优化地热井布局,并以市场为导向,大力发展供暖、洗浴、游泳、特色养殖、等区域地热资源合理开发的一些设想与建议。     

竖向地震下双塔连体建筑的分析和设计

首先输入多条实际竖向地震记录,用时程分析考察了塔楼高度和连体跨度不同的多个算例。然后将其抽象成塔楼和连体桁架组成的双自由度体系,运用频域分析方法,得到竖向地震作用的变化规律：11随着桁架对塔楼频率比增加,连体地震放大作用越明显;2）当连体对塔楼质量比较小且两者频率比相近1,连体地震反应进一步加强。现行抗震规范的重力系数法提出的大跨度结构竖向地震的实用计算公式对于本文研究结构并不完全适用。提出考虑塔楼和桁架协同地震作用的实用算式,并对一个超高层工程实例进行竖向地震作用分析,与时程分析结果吻合较好。