A low resolution map of Europa from four occultations by Io

Analysis of three occultations of JII (Europa) by JI (Io) has resulted in a preliminary reflectivity map of JII for the hemisphere centered on longitude 324°, a measurement of 1483±20 km for the radius of JII, estimates of the event impact parameters, determination of the mid event times, and a visual geometric albedo, p_ν = 0.74, for JII. A fourth occultation light curve was used after derivation of the results to confirm their validity.     

C8051F330在地震观测系统中的应用

介绍基于C8051F330单片机的地震观测系统中故障报警子系统的工作原理,并对温度报警设计中的问题进行分析。     

Integration of Sequence Stratigraphic Analysis and 3D Geostatistical Modeling of Pliocene–Pleistocene Delta,F3 Block,Netherlands

This research is focused on the analysis of the sequence stratigraphic units of F3 Block, within a wave-dominated delta of Plio–Pleistocene age. Three wells of F3 block and a 3D seismic data, are utilized in this research. The conventional techniques of 3D seismic interpretation were utilized to mark the 11 surfaces on the seismic section. Integration of seismic sequence stratigraphic interpretation, using well logs, and subsequent 3D geostatistical modeling, using seismic data, aided to evaluat...     

Quantification of Cl,Br and I in Geological Materials by NH4F Digestion: Comparison with Rapid Acid Digestion

The lack of analytical techniques for halogens in geological materials is mainly due to the loss of analytes during sample preparation. This study describes a rapid bulk rock digestion method (NH₄F digestion) for determination of the abundances of Cl, Br and I in geological materials by SF-ICP-MS. During high temperature (200–240 °C) digestion, NH₃ released from the decomposition of molten NH₄F can effectively prevent the loss of halogens released from geological samples. Chlorine, Br and I were not lost during NH₄F digestion at 220 °C for 0.25–6 h. The limits of quantitation for NH₄F digestion were 2.8, 0.018 and 0.003 μg g^-1 Cl, Br and I, respectively. Most results for halogens in geological reference materials by NH₄F digestion were in agreement with their certified values, confirming that the high-performance rapid bulk rock NH₄F digestion has sufficient digestion capability to extract Cl, Br and I from rocks, sediments and soils. In comparison, results obtained following acid digestion showed that HNO₃ + HF digestion could effectively extract Br and I from soil and sediment samples, and that HNO₃ acid digestion is only suitable to use for the determination of Br and I in soil samples.