The origin of sulfur-bearing species on the surfaces of icy satellites

We present experimental results in order to understand the physico-chemical effects induced by fast ions irradiating sulfur bearing molecules. The experiments are relevant both to Solar System objects (icy satellites, comets, TNOs) and icy mantles on grains in the interstellar medium. Here we concentrate on the application to the Galilean moons that are exposed to high energetic particle fluxes in the jovian magnetosphere.     

我想有个家 俄黑海舰队的命运

俄罗斯濒临两大洋13个海，这一特殊的地缘环境客观上就需要拥有一支强大的海上武装力量。早在俄罗斯沙皇彼得大帝就提出，“没有一支强大的海军，就没有强大的俄罗斯。”始建于1696年彼得大帝时代的俄罗斯海军在历史上很长时间内都是全球最强大的海上力量之一。20世纪80年代是苏联海军的鼎盛时期，     

Production of oxidants by ion irradiation of water/carbon dioxide frozen mixtures

We present new experimental results on the formation of oxidants, such as hydrogen peroxide, ozone, and carbonic acid, under ion irradiation of icy mixtures of water/carbon dioxide at different ratios and temperatures (16 and 80 K). Pure water ice layers and mixtures with carbon dioxide were irradiated by 200 keV He+ ions. We found that the CO(2)/H(2)O ratio progressively decreased to a value of about 0.1, the H(2)O(2) production increased with increasing CO(2) abundance at both 16 and 80 K, and the CO and H(2)CO(3) production increased with increasing CO(2) abundance at 16 K. At 80 K, the synthesis of CO was less efficient because of the high volatility of the molecule that partially sublimed from the target. The production of carbonic acid was connected with the production of CO(3). O(3) was detected only after ion irradiation of CO(2)-rich mixtures. The experimental results are discussed with regard to the relevance they may have in the production of an energy source for a europan or a martian biosphere.     

一首歌曲 一个故事

"上海是我长大成人的所在,带着我所有的情怀;第一次干杯,头一回恋爱,在永远的纯真年代。追过港台同胞,迷上过老外,自己当明星感觉也不坏。成功的滋味,自己最明白,旧的不去新的不来。城市的高度,它越变越快,有人出去有人回来;身边的朋友越穿越新派,上海让我越看越爱。     

Multidimensional particle codes: Their capabilities and limitations

Increasing the number of dimensions calls for significant changes in simulation techniques. Demand on computer time and space increases by orders of magnitude and hardware development affects the feasibility. Gridless and Fokker-Planck codes are possible in ID, but one needs grids and PIC codes in 2D and 3D. This imposes limits on Debye lengths, particle size and spacing, and on resolution. Non-spectral (local) E-M codes also suffer a Courant restriction on δt, in addition to the usual ω_p δt restriction. Spectral methods therefore have an advantage; they also permit convenient filtering, particle shaping and control of resolution. 2D and codes are well advanced and documented (4,5). 3D codes are in their infancy. Data management, rather than physics or numerical analysis, becomes the major problem (10). Machine-independent 3D codes are too limited in resolution and speed. Parallelism helps greatly but makes the 3D codes machine-dependent. A present-day limit is attempted in a 2*128**3 grid code for CRAYs which process ∼ 5 million particles in ∼ 2 minutes per time step. Layering is employed to break up the 3D problem into many 2D problems. Fields and particles are packed and buffered in and out of core. Diagnostics are limited by the large volume of information accumulated in a run. Results of runs with 3D codes have tended to show that the third dimension, treated as “ignorable” in 2D simulations, should not have been ignored. With the next generation of highly parallel multiprocessors (which, however, call for the abandonment of spectral and implicit methods) one may hope to do very realistic 3D simulations.     

业报轮回 五年重现——第二艘“库尔斯克”？

2000年8月13日俄罗斯核动力潜艇“库尔斯克”号被困水下，118名艇员水下身亡。2005年8月4日，正值5周年纪念的前夕，又一艘俄罗斯潜艇被深深的困在海底…漆黑的舱室、刺骨的寒冷、焦急的等待……     

Traverses for the ISECG-GER design reference mission for humans on the lunar surface

This study explores the Design Reference Mission (DRM) architecture developed by Hufenbach et al. (2015) as a prelude to the release of the 2018 Global Exploration Roadmap (GER) developed by the International Space Exploration Coordination Group (ISECG). The focus of this study is the exploration of the south polar region of the Moon, a region that has not been visited by any human missions, yet exhibits a multitude of scientifically important locations – the investigation of which will address long standing questions in lunar research. This DRM architecture involves five landing sites (Malapert massif, South Pole/Shackleton crater, Schrödinger basin, Antoniadi crater, and the South Pole-Aitken basin center), to be visited in sequential years by crew, beginning in 2028. Two Lunar Electric Rovers (LER) are proposed to be tele-robotically operated between sites to rendez-vous with crew at the time of the next landing. With engineering parameters in mind we explore the feasibility of tele-robotic operation of these LERs between lunar landing sites, and identify potential high interest sampling locations en-route. Additionally, in-depth sample collection and return traverses are identified for each individual landing site across key geologic terrains that also detail crew Extra-Vehicular Activity (EVA). Exploration at and between landing sites is designed to address a suite of National Research Council (2007) scientific concepts.     

总统亲历俄军崛起——21世纪初俄军发展现状与特点

苏联解体后，俄罗斯面对经济上的不断衰退，被迫大幅裁减军队数量，大批作战飞机、舰艇和导弹因得不到及时维护而退役。2000年“库尔斯克”号核潜艇沉没表明，俄军实力已急剧下降。然而，面对美国和北约战略包围圈越来越近，美军新军事变革紧锣密鼓的推进，俄罗斯开始重新考虑加强自己的军事力量。