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61.
The results of the 9P/Tempel 1 CARA (Cometary Archive for Amateur Astronomers) observing campaign is presented. The main goal was to perform an extended survey of the comet as a support to the Deep Impact (DI) Mission. CCD R, I and narrowband aperture photometries were used to monitor the Afρ quantity. The observed behavior showed a peak of 310 cm 83 days before perihelion, but we argue that it can be distorted by the phase effect, too. The phase effect is roughly estimated around 0.0275 mag/degree, but we had no chance for direct determination because of the very similar geometry of the observed apparitions. The log-slope of Afρ was around −0.5 between about 180-100 days before the impact but evolved near the steady-state like 0 value by the impact time. The DI module impact caused about a 60% increase in the value of Afρ and a cloud feature in the coma profile which was observed just after the event. The expansion of the ejecta cloud was consistent with a fountain model with initial projected velocity of 0.2 km/s and β=0.73. Referring to a 25,000 km radius area centered on the nucleus, the total cross section of the ejected dust was 0.06 days after the impact, and 1.93 days after the impact (A is the dust albedo). Five days after the event no signs of the impact were detected, nor deviations from the expected activity referring both to the average pre-impact behavior and to the previous apparitions.  相似文献   
62.
Priabonian age is highlighted for the first time in Corsica in the Venaco Formation using the presence of specific microfauna (in particular some representatives of Turborotalia cerroazulensis lineage). This silicoclastic formation is mainly represented by coarse facies. It is composed of three members from south to north and from oldest towards youngest: member of Uboli, Cardo and Orsu. The sedimentologic analysis reveals a gravity depositional environment, involving different type of currents. Sedimentologic and chronologic characteristics make the Venaco Formation and the Annot Formation (p.p.) equivalent. Dating the Venaco Fm. brings confirmation that the green schist metamorphism of the Variscan batholith and the related deformation are from the pre-Priabonian period.  相似文献   
63.
64.
用层次分析法确定气象服务评价指标权重   总被引:5,自引:0,他引:5       下载免费PDF全文
在气象服务评价体系中,以气象服务总体评价为目标层,分层次确立一级和二级评价指标,利用2010年全国公众气象服务满意度调查中评价指标数据,应用层次分析法 (AHP) 中的9分位标度法和0.618标度法来构建判断矩阵,分析了各级评价指标的权重系数确定方法。分析发现,当评价指标少于5个时,可采用9分位标度法构建判断矩阵,以确定各评价指标的权重值;而当评价指标达到5个时,需采用0.618标度法来构建判断矩阵,计算出相应的权向量即为权重系数。将上述方法应用于2011年公众气象服务满意度调查数据中,前后两年主要评价指标对比显示,气象服务信息内容的权重在增加,而气象知识宣传普及的权重有所减小,即公众对于气象服务信息内容更为重视,同时气象部门对于公众的气象知识宣传普及工作也取得了成效。  相似文献   
65.
We report a measurement procedure to determine simultaneously the major cation concentrations (Na, Ca, K and Mg) of seawater‐derived solutions by inductively coupled plasma‐atomic emission spectrometry. The best results were obtained when the IAPSO (‘standard’) seawater reference material was diluted by thirty times with Milli‐Q® water. We obtained an average reference value rK (the ratio of the mass fraction of potassium to that of chlorine, i.e., (g kg?1)/(g kg?1)) for IAPSO seawater of 0.0205 ± 0.0006 (2.9% RSD), not significantly different from 0.0206 ± 0.0005 (2.4% RSD) for seawater composition reported in the literature. The measured Na, Ca and Mg concentrations correspond to rNa, rCa and rMg values of 0.5406 ± 0.0026 (0.5% RSD), 0.02192 ± 0.00048 (2.2% RSD) and 0.06830 ± 0.00047 (0.7% RSD), respectively, in line with previous values measured by wet‐chemistry and atomic absorption spectrophotometry or wet‐chemical titration. Our measurement procedure was used successfully on synthetic seawater solutions and high‐temperature hydrothermal fluids.  相似文献   
66.
With implications for the origin of ore deposits, redox state of the atmosphere, and effects of volcanic outgassing, understanding the sulfur cycle is vital to our investigation of Earth processes. However, the paucity of sulfur concentration measurements in silicate rocks and the lack of well‐calibrated reference materials with concentrations relevant to the rocks of interest have hindered such investigations. To aid in this endeavour, this study details a new method to determine sulfur concentration via high mass resolution solution inductively coupled plasma‐mass spectrometry (ICP‐MS). The method is based on an aqua regia leach, involving relatively rapid sample preparation and analysis, and uses small test portion masses (< 50 mg). We utilised two independently prepared standard solutions to calibrate the analyses, resulting in 4% accuracy, and applied the method to eight geochemical reference materials. Measurements were reproducible to within ~ 10%. Sulfur concentrations and isotopes of six reference materials were measured additionally by elemental analyser‐combustion‐isotope ratio mass spectrometry to independently evaluate the accuracy of the ICP‐MS method. Reference materials that yielded reproducible measurements identical to published values from other laboratories (JGb‐1, JGb‐2 and MAG‐1) are considered useful materials for the measurement of sulfur. Reference materials that varied between studies but were reproducible for a given test portion perhaps suffer from sample heterogeneity and are not recommended as sulfur reference materials.  相似文献   
67.
Lead isotope ratio data were obtained with good precision and accuracy using a 266 nm femtosecond laser ablation (fLA) system connected to a multi‐collector ICP‐MS (MC‐ICP‐MS) and through careful control of analytical procedures. The mass fractionation coefficient induced by 266 nm femtosecond laser ablation was approximately 28% lower than that by 193 nm excimer laser ablation (eLA) with helium carrier gas. The exponential law correction method for Tl normalisation with optimum adjusted Tl ratio was utilised to obtain Pb isotopic data with good precision and accuracy. The Pb isotopic ratios of the glass reference materials NIST SRM 610, 612, 614; USGS BHVO‐2G, BCR‐2G, GSD‐1G, BIR‐1G; and MPI‐DING GOR132‐G, KL2‐G, T1‐G, StHs60/80‐G, ATHO‐G and ML3B‐G were determined using fLA‐MC‐ICP‐MS. The measured Pb isotopic ratios were in good agreement with the reference or published values within 2s measurement uncertainties. We also present the first high‐precision Pb isotopic data for GSE‐1G, GSC‐1G, GSA‐1G and CGSG‐1, CGSG‐2, CGSG‐4 and CGSG‐5 glass reference materials obtained using the femtosecond laser ablation MC‐ICP‐MS analysis technique.  相似文献   
68.
在分析MapGIS自带的图框绘制功能存在的不足和航空物探图框构成的基础上,应用C#语言和MapGIS K9的二次开发接口,开发航空物探图框绘制软件。实际应用表明,该软件能快速、方便地绘制不同种类的图框,提高工作效率;图框要素样式库易维护、易扩展,用户可根据实际需要进行定制。  相似文献   
69.
Observed instances are given in this paper to show that sub-Alfvénic flow can be formed in the quiet and recurrent low-speed solar wind streams. This kind of flow appears in regions with abnormal enhancement of Alfvénic speed and is associated with a specific type of magnetic configuration.  相似文献   
70.
基于GIS的油田井位自动成图系统研究   总被引:1,自引:0,他引:1  
针对油田生产中油水井数据的特点和管理需求,设计并开发了油田井位自动成图系统:基于Oracle9i与ArcSDE9.0创建空间数据库;基于ASP.NET技术开发浏览器端更新与维护属性数据;基于C与MapObjects2.3开发客户端实现成图及应用功能;对自动成图原理、远程数据访问、图属互查等功能提供了实现方法。  相似文献   
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