Radiation exposure and Mission Strategies for Interplanetary Manned Missions (REMSIM)

Cosmic radiation is an important problem for human interplanetary missions. The “Radiation Exposure and Mission Strategies for Interplanetary Manned Missions–REMSIM” study is summarised here. They are related to current strategies and countermeasures to ensure the protection of astronauts from radiation during interplanetary missions, with specific reference to: radiation environment and its variability; radiation effects on the crew; transfer trajectories and associated fluences; vehicle and surface habitat concepts; passive and active shielding concepts; space weather monitoring and warning systems.     

Search For Correlations Between Batse Gamma-Ray Bursts and Supernovae

We report on our statistical research of space–time correlated supernovae and CGRO-BATSE gamma-ray bursts (GRBs). There exists a significantly higher abundance of core-collapse supernovae among the correlated supernovae, but the subset of all correlated objects does not seem to be physically different from the whole set.     

Nonlinear dynamic analysis of deep water risers

The paper presents a theoretical and numerical approach to the dynamical behaviour of risers in deep water which takes into account two types of nonlinearity; that due to viscous drag forces and that due to the large displacements of the riser when submitted to strong axial loads. As the second nonlinearity may have a significant influence upon the behaviour of risers in deep water, a method for automatically updating the structural geometry during the dynamic analysis is given. A computer programme has been written for this purpose.     

Submerged cylinder wave energy device: theory and experiment

Linearized water wave theory is used to show that a submerged long circular cylinder suitably constrained by springs and dampers to make small harmonic oscillations, can be extremely efficient in absorbing the energy in an incident regular wave whose crests are parallel to the axis of the cylinder. Experimental results are described which confirm the theory for small amplitude waves and which suggest that the device can still be fairly efficient in waves of moderate amplitude.     

The rapid variability of blazars at optical wavelengths

We monitored five active galactic nuclei in the R optical band with a CCD mounted on the 1-m Zeiss-1000 telescope of the Special Astrophysical Observatory from April 2001 to August 2003. Three sources displayed intraday variability on several nights. Stronger variability was detected on time scales from two days to a week. The two-year light curves are presented for four of the observed objects.     

ICESat-2水深提取方法及其反演应用

相比于传统水深测量方法, 结合主动激光卫星ICESat-2数据与被动光学遥感影像的主被动融合水深反演方法具有低成本、覆盖面积广、不受地域限制、无需地面实测数据等优点.研究选取澳大利亚大堡礁中部的John Brewer Reef和南部的Fitzroy Reef为实验区, 开展主被动融合水深反演实验.针对ICESat-2光子点群信噪比低、光子点水深信息提取和改正难的问题, 本文提出基于光子点群高斯分布特征的海面光子点群提取方法和基于深度自适应DBSCAN的海底光子点群提取方法, 并顾及海面倾斜引起的入射角偏移, 改进了Parrish水体折射改正几何模型.实验表明, 基于光子点群高斯分布特征的海面光子点群提取方法和基于深度自适应DBSCAN的海底光子点群提取方法可以高效准确地提取出有效的海面、海底光子点群; 经过地球物理改正和基于改进模型的水体折射改正后, 水深变浅, 且改正项与改正前水深呈线性关系, 线性系数约为-0.2550.实验将提取并改正后的ICESat-2光子点水深与经大气校正、耀斑校正、空间域滤波等预处理后的Sentinel-2影像进行空间匹配构建水深反演样本集, 并利用单波段模型(SB)、比值模型(BR)、Lyzenga多项式模型(LP)、二次多项式模型(QP)、三次多项式模型(CP)、支持向量回归模型(SVR)、多层感知器模型(MLP)、随机森林回归模型(RF)等水深反演模型对实验区全域水深进行反演.通过对比分析多种水深反演模型在不同地理区域和ICESat-2水深样本分布条件下的表现, 研究为不同场景下的主被动融合水深反演策略提供了一定的科学依据.

     

Variations in the near-ground electric field at high latitudes and the potential drop across the polar cap during morning polar substorms

This paper studies time variations in the near-ground atmospheric electric field (Ez) at the geomagnetic latitude of 74° (Hornsund observatory) during polar substorms. Ez variations are compared with those in the potential drop across the polar cap (Up), according to SuperDARN radar observations. It is found that in the morning sector, time variations in Ez are strongly driven by time variations in the electrojet and almost do not depend on time variations in Up, which is presumably due to the penetration of the electric field of the electrojet into tropospheric altitudes.     

DT—1016型阴离子交换树脂分离富集金铂钯

研究了DT－1016型阴离子交换树脂对超痕量Au,Pt,Pd的吸附性能及条件。在0.025mol/L HCl介质中，流出速度为0.5-1.0mL/min时，Au,Pt和Pd的富集效果最佳，吸附率分别为99.72％，99.06％和97.95％，共存离子无显著性影响。用等离子体质谱测定标准物质中Au，Pt和Pd，其结果与标准值基本相符。检出限Au为0.27μg/L，Pt为0.40μg/L，Pd为0.19μg／L。对GBW 07294铂族元素国家标准物质进行精密度试验，RSD（n=8）Au为19．2％，Pt为28.1％，Pd为15.6％。     

Hydrocarbons of bottom sediments at the Shtokman Field in the Barents Sea

Hydrocarbon samples taken from bottom sediments of the Barents Sea in summer 2010 in two grounds near the Shtokman Gas Condensate Field were studied. The concentration of hydrocarbons was found to increase with sampling depth along with a decrease in C_org concentration. The composition of alkanes had mixed genesis: autochthonous homologues (n-C₁₆-C₁₇) dominated in the low-molecular domain, while oil ones dominated in the high-molecular domain; light polyarenes dominated in the composition of polycyclic aromatic hydrocarbons. The seepage of hydrocarbons from the sedimentary stratum and their transformation in the surface layer of bottom sediments are considered as their major source. The relatively low hydrocarbon concentrations converted to dry mass and in the composition of C_org are supposed to be due to a decrease in the intensity of fluid flows, since the hydrocarbon reservoirs of the Shtokman Field are firmly capped by an impermeable stratum of mostly clay rocks.