TWO POSSIBLE ACCELERATION MECHANISMS IN COMET TAIL

The large accelerations of plasma were observed early in type-Ⅰ comet tail. The accelerations can reach 300 cm/S^2. Recently, the direct measurements for comet G-Z show that the energy of particles reaches 2×10~5 eV. It is much higher than the initial

A PRELIMINARY STUDY OF THE TAIL OF COMET HALLEY AND THE GEOMAGNETIC STORM

Ⅰ. INTRODUCTION The famous Comet Halley (whose period P=76.1 years, orbital eccentricity e=0.9673, inclination of orbit i=16202) threw men into a great panic and nervous state on May 18, 1910 before its flying past the earth. When the comet’s tail swept over

2014年美国加州纳帕M_W6.1地震断层参数的Sentinel-1A InSAR反演

2014年8月24日,在美国加州旧金山海湾北部的纳帕地区发生了MW6.1地震.发震断层是西纳帕断裂系统中的一部分,但是该断层之前并未被足够重视.本文利用欧洲空间局最近发射成功并刚刚投入使用的Sentinel-1A卫星获取的第一对同震干涉像对(20140807-20140831),得到了该地震的地表同震形变场,结合震后24h内区域GPS同震形变资料作为约束条件,反演了纳帕地震的断层几何参数以及滑动分布.Sentinel-1A干涉结果表明,此次地震造成了明显的地面形变,视线向最大抬升和最大沉降量均达到了10cm.联合反演结果表明,该发震断层的走向为344°,倾角为80°.主要破裂以右旋走滑为主,平均倾滑角为-146.5°,最大倾滑量达到了1.1m,位于地表下约4km,存在明显的滑动亏损现象.此次地震,累计释放地震矩达1.5×1018 N·m,约合矩震级MW6.1.该结果略小于InSAR单独约束结果,可能与Sentinel-1A像对中包含的快速震后形变分量有关.

以解决全球问题为导向的地学类专业“遥感原理与应用”课程教学改革研究

本文从全球背景与国家战略层面、学生就业需求与深造层面、国内外主要高校教学现状等方面探讨了“遥感原理与应用”课程教学改革的必要性,分析了教学改革关键问题、目标与内容,提出了教学改革应以陆海统筹为原则,以解决全球性问题为导向,并在实际课程教学过程开展了教学方法的改革,主要体现在教学内容的持续更新、灵活的课程教学形式、加强学科交叉应用等方面。

基于Hadoop技术的科研大数据存储系统设计

针对高校科研海量数据存储问题,为提高大数据存储系统的存储能力和效率,降低硬件搭建成本,本文提出了一种基于Hadoop技术的分布式存储系统设计方案。该系统以Hadoop技术为核心和基础,设计Hadoop分布式数据存储模型,结合科研数据存储结构的特征,考虑存储数据类型的多样性,以及低成本高可靠性的存储需求,设计了三层结构的Hadoop分布式存储系统结构,并对系统中的文件块存储策略、科研资源网结构、数据库访问层三个子模块进行了具体设计。该存储系统结构简洁、构建成本低、存储安全可靠且便于扩展,与科研数据的存储需求相适应。

海潮负荷对沿海地区宽幅InSAR形变监测的影响

海岸带地区是全球自然生态环境最为复杂和脆弱的地域之一,合成孔径雷达干涉测量(InSAR)技术可以为全球人类活动、气候变暖和俯冲带剧烈构造运动等背景下的大范围海岸带地理环境变化研究提供重要观测资料.海洋潮汐导致固体地球长周期形变,波长尺度为102~103km的海潮负荷引入mm级至cm级的形变梯度,此类非构造信号对海岸带InSAR精密形变分析(如:大范围、微小、缓慢且非稳态构造过程等)造成显著影响.本文以宽幅模式SAR数据为例,基于多种海潮模型研究了全球典型海岸带地区(福建、智利和阿拉斯加湾)海潮负荷效应对宽幅InSAR形变监测的影响,给出了宽幅InSAR海潮负荷三维分量估计与差分相位提取方法,并进一步讨论了基于不同海潮模型估计海潮负荷位移的差异.海潮负荷影响不仅与研究范围大小有关,其形变梯度变化与研究区域地形特征存在强相关,对于长波长形变分析而言,传统平面或者曲面拟合方法难以有效分离海潮负荷位移.

Resolving co- and early post-seismic slip variations of the 2021 MW 7.4 Madoi earthquake in east Bayan Har block with a block-wide distributed deformation mode from satellite synthetic aperture radar data

On 21 May 2021(UTC),an MW 7.4 earthquake jolted the east Bayan Har block in the Tibetan Plateau.The earthquake received widespread attention as it is the largest event in the Tibetan Plateau and its surroundings since the 2008 Wenchuan earthquake,and especially in proximity to the seismic gaps on the east Kunlun fault.Here we use satellite interferometric synthetic aperture radar data and subpixel offset observations along the range directions to characterize the coseismic deformation of the earthquake.Range offset displacements depict clear surface ruptures with a total length of~170 km involving two possible activated fault segments in the earthquake.Coseismic modeling results indicate that the earthquake was dominated by left-lateral strike-slip motions of up to 7 m within the top 12 km of the crust.The well-resolved slip variations are characterized by five major slip patches along strike and 64%of shallow slip deficit,suggesting a young seismogenic structure.Spatial-temporal changes of the postseismic deformation are mapped from early 6-day and 24-day InSAR observations,and are well explained by time-dependent afterslip models.Analysis of Global Navigation Satellite System(GNSS)velocity profiles and strain rates suggests that the eastward extrusion of plateau is diffusely distributed across the east Bayan Har block,but exhibits significant lateral heterogeneities,as evidenced by magnetotelluric observations.The block-wide distributed deformation of the east Bayan Har block along with the significant co-and post-seismic stress loadings from the Madoi earthquake imply high seismic risks along regional faults,especially the Tuosuo Lake and Maqên-Maqu segments of the Kunlun fault that are known as seismic gaps.

Locating the Small 1999 Frenchman Flat, Nevada Earthquake with InSAR Stacking

Due to high interferometric coherence in the Nevada region,Interferometric Synthetic Aperture Radar(InSAR)phase stacking is capable of mapping coseismic signals from the 27 January 1999,M w 4.8 Frenchman Flat earthquake.This is one of the smallest earthquakes yet studied using InSAR with line-of-sight displacements as small as~1.5 cm.Modelling the event as dislocation in an elastic half space suggests that the fault centroid was located at(115.96°W,36.81°N)with a precision of 0.2~0.3 km(1σ)at a depth of 3.4±0.2 km.Despite the dense local seismic network in southern Nevada,differences as large as 2~5 km were observed between our InSAR earthquake location and those estimated from seismic data.The InSAR-derived magnitude appeared to be greater than that from seismic data,which is consistent with other studies,and believed to be due to the relatively long time interval of InSAR data.

Sigma稳健性分析在冲压模具调试中的应用

在汽车冲压模具的成形分析过程中,往往一些参数无法精确给定具体数值,如材料参数、摩擦系数、拉伸筋强度、板料形状等都存在不确定性,导致现场调试时与CAE仿真结果不吻合,不能及时生产出合格的制件,影响模具调试周期。基于AutoForm-Sigma模块,阐述稳健性分析在汽车覆盖件车门内板冲压模具制造调试过程中的成功应用,快速找到导致制件缺陷的主要因素,及时解决拉伸制件开裂问题,为汽车覆盖件冲压模具制造调试提供参考。

遥感地质学教学改革3W原则及支撑创新创业训练的探索

在地球大数据与空间对地观测技术飞速发展的时代背景下,遥感地质学课程需要紧密围绕培养创新型人才、服务全球可持续发展开展教学改革与评估。本文以中国海洋大学为例,提出可具推广性的教学改革与评估3W原则,即为什么要开课(Why)、讲什么内容(What)、时间如何安排(When),并探讨了近年来遥感地质学课程建设与毕业设计选题在支撑大学生创新创业训练方面的作用与成效。

交易商在铁矿石和其他工业矿物销售中的作用和贡献

叙述随着商业的全球化和竞争压力的加剧,交易商的作用和他参与活动的收益完全没有过时或被取代,相反则要求不断地增加服务和拓展其业务范围。

Successful Applications of Generic Atmospheric Correction Online Service for InSAR (GACOS) to the Reduction of Atmospheric Effects on InSAR Observations

The tremendous development of Synthetic Aperture Radar(SAR)missions in recent years facilitates the study of smaller amplitude ground deformation over greater spatial scales using longer time series.However,this poses greater challenges for correcting atmospheric effects due to the wider coverage of SAR imagery than ever.Previous attempts have used observations from Global Positioning System(GPS)and Numerical Weather Models(NWMs)to separate atmospheric delays,but they are limited by(1)The availability(and distribution)of GPS stations;(2)The low spatial resolution of NWM;And(3)The difficulties in quantifying their performance.To overcome these limitations,we have developed the Generic Atmospheric Correction Online Service for InSAR(GACOS)which utilizes the high-resolution European Centre for Medium-Range Weather Forecasts(ECMWF)products using an Iterative Tropospheric Decomposition(ITD)model.This enables the reduction of the coupling effects of the troposphere turbulence and stratification and hence achieves equivalent performances over flat and mountainous terrains.GACOS comprises a range of notable features:(1)Global coverage;(2)All-weather,all-time usability;(3)Available with a maximum of two-day latency;And(4)Indicators available to assess the model’s performance and feasibility.In this paper,we demonstrate some successful applications of the GACOS online service to a variety of geophysical studies.

Acceleration of Glacier Mass Loss after 2013 at the Mt.Everest(Qomolangma)

Satellite geodesy is capable of observing glacier height changes and most recent studies focus on the decadal scale due to limitations of data acquisition and precision.Glaciers at the Mt.Everest(Qomolangma),locating at the central Himalaya,have been studied from the 1970s to 2015.Here we obtained TerraSAR-X/TanDEM-X images observed in two epochs,a group around 2013 and another in 2017.Together with SRTM observed in 2000,we derived geodetic glacier mass balance between 2000 and 2013 and 2013 and 2017.We proposed two InSAR procedures for deriving the second period,which yields with basically identical results of geodetic glacier mass balance.The differencing between DEMs derived by TerraSAR-X/TanDEM-X shows better precision than that between TerraSAR-X/TanDEM-X formed DEM and SRTM,and it can capable of providing geodetic glacier mass balance at a sub-decadal scale.Glaciers at the Mt.Everest(Qomolangma)and its surroundings present obvious speeding up in mass loss rates before and after 2013 for both the Chinese and the Nepalese sides.The previous obtained spatial heterogeneous pattern for glacier downwasting between 2000 and 2013 generally kept the same after 2013.Glaciers with lacustrine terminus present the most rapid lost rates.

A Neural Network Algorithm to Detect Sulphur Dioxide Using IASI Measurements

The remote sensing of volcanic sulphur dioxide (SO2) is important because it is used as a proxy for volcanic ash, which is dangerous to aviation and is generally more difficult to discriminate. This paper presents an Artificial Neural Network (ANN) algorithm that recognizes volcanic SO2 in the atmosphere using hyperspectral remotely sensed data from the IASI instrument aboard the Metop-A satellite. The importance of this approach lies in exploiting all thermal infrared spectral information of IASI and its application to near real-time volcanic monitoring in a fast manner. In this paper, the ANN algorithm is demonstrated on data of the Eyjafjallajokull volcanic eruption (Iceland) during the months of April and May 2010, and on the Grímsvotn eruption occurring during May 2011. The algorithm consists of a two output neural network classifier trained with a time series consisting of some hyperspectral eruption datasets collected during 14 April to 14 May 2010 and a few from 22 to 26 May 2011. The inputs were all channels (441) in the IASI v3 band and the target outputs (truth) were the corresponding retrievals of SO2 amount obtained with an optimal estimation method. The validation results for the Eyjafjallajokull independent data-sets had an overall accuracy of 100% and no commission errors, therefore demonstrating the feasibility of estimating the presence of SO2 using a neural network approach also a in cloudy sky conditions. Although the validation of the neural network classifier on datasets from the Grímsvotn eruption had no commission errors, the overall accuracies were lower due to the presence of omission errors. Statistical analysis revealed that those false negatives lie near the detection threshold for discriminating pixels affected by SO2. This demonstrated that the accuracy in classification is strictly related to the sensitivity of the model. The lower accuracy obtained in detecting SO2 for Grímsvotn validation dates might also be caused by less statistical knowledge of such an eruption during the training phase.

Effect and Influence of Aryl Mercaptanes with Various Chain Lengths on DNA/RNA and Cadmium Oxide (CdO) Nanoparticles Sandwiched Complex

CdO(cadmium oxide)nanoparticles show a strong peak of Plasmon absorption in ultraviolet-visible zone.A strong interaction exists between the surface of CdO nanoparticles and aryl mercaptan compounds.Aryl mercaptan compounds cause aggregation of CdO nanoparticles linked to DNA/RNA(eoxyribonucleic acid/ribonucleic acid)and hence,lead to widening of peak Plasmon of CdO nanoparticles surface at 550 nm and emerge a new peak at higher wavelength.In the current project,this optical characteristic of CdO nanoparticles is used to investigate interaction time between different aryl mercaptanes and CdO nanoparticles.The results showed that aryl mercaptan compounds with shorter chain length interact faster with CdO nanoparticles.Therefore,a simple and fast method for identification of aryl mercaptanes with various chain lengths using red shift in surficial Plasmon absorption is presented.

Infrastructure of Synchrotronic Biosensor Based on Semiconductor Device Fabrication for Tracking, Monitoring, Imaging, Measuring, Diagnosing and Detecting Cancer Cells

Copper Zinc Antimony Sulfide(CZAS)is derived from Copper Antimony Sulfide(CAS),a famatinite class of compound.In the current paper,the first step for using Copper,Zinc,Antimony and Sulfide as materials in manufacturing synchrotronic biosensor-namely increasing the sensitivity of biosensor through creating Copper Zinc Antimony Sulfide,CZAS(Cu1.18Zn0.40Sb1.90S7.2)semiconductor and using it instead of Copper Tin Sulfide,CTS(Cu2SnS3)for tracking,monitoring,imaging,measuring,diagnosing and detecting cancer cells,is evaluated.Further,optimization of tris(2,2'-bipyridyl)ruthenium(II)(Ru(bpy)32+)concentrations and Copper Zinc Antimony Sulfide,CZAS(Cu1.18Zn0.40Sb1.90S7.2)semiconductor as two main and effective materials in the intensity of synchrotron for tracking,monitoring,imaging,measuring,diagnosing and detecting cancer cells are considered so that the highest sensitivity obtains.In this regard,various concentrations of two materials were prepared and photon emission was investigated in the absence of cancer cells.On the other hand,ccancer diagnosis requires the analysis of images and attributes as well as collecting many clinical and mammography variables.In diagnosis of cancer,it is important to determine whether a tumor is benign or malignant.The information about cancer risk prediction along with the type of tumor are crucial for patients and effective medical decision making.An ideal diagnostic system could effectively distinguish between benign and malignant cells;however,such a system has not been created yet.In this study,a model is developed to improve the prediction probability of cancer.It is necessary to have such a prediction model as the survival probability of cancer is high when patients are diagnosed at early stages.

Cyclone Bomb Hits Southern Brazil in 2020

An“explosive extratropical cyclone”is an atmospheric phenomenon that occurs when there is a very rapid drop in central atmospheric pressure.This phenomenon,with its characteristic of rapidly lowering the pressure in its interior,generates very intense winds and for this reason it is called explosive cyclone,bomb cyclone.With gusts recorded of 116 km/h,atmospheric phenomenon-“cyclone bomb”(CB)hit southern Brazil on June 30,the beginning of winter 2020,causing destruction in its influence over.One of the cities most affected was Chapecó,west of the state of Santa Catarina.The satellite images show that the CB generated a low pressure(976 mbar)inside it,generating two atmospheric currents that moved at high speed.In a northwest-southeast direction,Bolivia and Paraguay,crossing the states of Parana and Santa Catarina,and this draft that hit the south of Brazil,which caused the destruction of the affected states.Another moving to Argentina,southwest-northeast direction,due to high area of high pressure(1022 mbar).Both enhanced the phenomenon.

Focal mechanism inversion of the 2018 M_(W)7.1 Anchorage earthquake based on high-rate GPS observation

The M_(W)7.1 Anchorage earthquake is the most destructive earthquake since the 1964 M_(W)9.2 great Alaska earthquake in the United States.In this study,high-rate GPS data and near-field broadband seismograms are used in separate and joint inversions by the generalized Cut-and-Paste(gCAP)method to estimate the focal mechanism.In order to investigate the influence of crustal velocity structure on the focal mechanism inversion results,two velocity models(Crustl.0 and Alaska Earthquake Center(AEC))are used for detailed comparison and analysis.The results show that:(1)The two nodal planes of the optimal double-couple solution are nearly north-south striking,with dip angles of about 30°and 60°respectively,and the centroid focal depth is 54-55 km,which is an intraplate normal fault event.(2)The inversion results for the two types of data and the two velocity models are consistent with some previous studies,which indicates that the results are stable and reliable.The more accurate velocity structure model is helpful for focal mechanism inversion of the complex earthquake.(3)The inclusion of high-rate GPS data in joint inversion provides a more effective constraint on centroid depth.

ebeam Technologies:以电子束固化改变数字印刷

2017年9月,在比利时布鲁塞尔举办的Labelexpo Europe 2017展会同期,隶属于瑞士上市公司COMET集团公司的ebeam Technologies事业部出品的紧凑型固化单元荣获了'2017标签工业全球大奖'4个重量级奖项之一的'可持续发展大奖',该奖项表彰了ebeam在研发适用于窄幅轮转印刷机的紧凑型电子束固化系统方面的努力。

宽幅InSAR大地测量学与大尺度形变监测方法

随着人们对大尺度地形信息与地表环境变化监测需求的提升,以及哨兵1号(Sentinel-1A)、大地2号(ALOS-2)等合成孔径雷达(synthetic aperture radar,SAR)卫星的宽幅模式数据不断获取,宽幅雷达干涉测量(SAR interferometry,InSAR)技术已成为大尺度地形测绘、地球动力学(地震、火山、滑坡等)与人工地物结构健康监测等领域的研究热点。分析了两类宽幅SAR数据,即扫描(ScanningSAR,ScanSAR)模式与逐行扫描地形观测(terrain observation by progressive scans SAR,TOPSAR)模式开展干涉测量的主要限制条件与解决方法,探讨了宽幅InSAR形变监测关键误差估计与改正方法、时间序列分析技术与方位向位移观测技术,并给出2008年矩震级Mw 7.1新疆于田地震同震、震后形变监测应用。随着宽幅SAR数据的不断积累,宽幅InSAR大地测量学有望得到深入发展与应用。