Radiation exposure and Mission Strategies for Interplanetary Manned Missions (REMSIM)   总被引：1，自引：0，他引：1  

C. Cougnet  N. B. Crosby  S. Eckersley  C. Foullon  V. Guarnieri  S. Guatelli  D. Heynderickx  A. Holmes-Siedle  C. Lobascio  S. Masiello  P. Nieminen  G. Parisi  P. Parodi  M. A. Perino  M. G. Pia  R. Rampini  P. Spillantini  V. Tamburini  E. Tracino 《Earth, Moon, and Planets》2004,94(3-4):279-285

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.  相似文献   

临沂市开展集体建设用地使用权流转的几点思考          下载免费PDF全文

冯连伟 《山东国土资源》2004,20(6):43-47

结合临沂市几年来开展集体建设用地使用权流转的实践和探索,对开展集体建设用地使用权流转的背景、概念及范围进行了论述。认为在计划经济条件下形成的农民集体所有建设用地使用权不能流转的制度已与当前农村经济,特别是小城镇的建设发展严重不适应,允许集体建设用地使用权流转已势在必行。开展集体建设用地使用权流转对保护土地所有者和失地农民的权益,推动小城镇建设健康发展,规范土地市场具有重要意义。  相似文献   

1999年8月11日日全食期间的重力吸引效应研究     

刘少明 《大地测量与地球动力学》2004,24(4):13-19

对1999年8月11日日全食阴影扫过欧洲期间,设在Annelles,Uccle,Walferdange和Bondy弹簧和超导重力仪的记录进行了分析.为了确定月亮对太阳万有引力可能的遮挡效应的极限,对超导和弹簧重力仪记录进行了比较.同时也对LCR和阿斯卡尼亚重力仪观测结果进行了讨论.结论是如果日食重力吸引效应存在,它应在超导重力仪±1 nm/s2(0.1×10-8ms-2)的观测精度范围之内.研究发现在以上情形下,弹簧和超导重力仪都在它们的精度范围内工作,并且日食引起的异常环境干扰可能使重力信号有重大的改变.  相似文献   

断层相关褶皱理论在准噶尔盆地南缘山前带构造研究的应用   总被引：8，自引：4，他引：4  

邵雨  陈伟  张伯友 《地球科学与环境学报》2005,27(1):26-29

利用断层相关褶皱的构造几何分析方法，对准噶尔盆地南缘山前复杂构造带内基于地震剖面进行了构造解析，搭建了中、东段的构造轮廓和构造组合样式，认为东段阜康断裂带主要表现为至地表的推覆逆掩。由于位移量大部分转移至地表，阜康断裂带的前陆部分无喜山期构造带；西段造山带内的挤压往前陆方向传递过程中以前列式不断释放其位移量，造成在纵向上呈现三排主要的断层相关褶皱带。根据正演平衡地质剖面制作技术对山前复杂构造区地震剖面反射波的构造识别进行了模拟与探讨。  相似文献   

Interpretation of aeromagnetic data across the central crystalline shield area of Nigeria     

D. E. Ajakaiye  D. H. Hall  T. W. Millar 《Geophysical Journal International》1985,83(2):503-517

Summary. A residual map of the total magnetic field (above 25 000 nT base) is presented for a portion of the central crystalline shield area of Nigeria and overlapping small portions of the Chad basin and the Benue rift (8°30'−12° 00'lat, and 7°−10°30' long). The map (based on a dataset digitized from recently released aeromagnetic sheets of Nigeria) leads to four results. (1) A magnetic boundary, evident on the map, separates the Younger Granite complexes into two groups. The groups are petrologically different, and the boundary may be a fault line with uplift to the south. (2) South of the boundary the map is dominated by a system of sub-parallel anomalies striking NE–SW, possibly representing major tectonic trends, and a set of fractures through which the Younger Granite complexes were intruded. The trend of the system parallels the Benue rift and lineaments in the oceanic crust off West Africa. (3) Negative magnetic anomalies lie over most of the known ring complexes, and over some suspected buried ring complexes and other intrusions. (4) 2½-and 3-D modelling shows that the larger complexes extend to 12 km depth, and the smaller ones to 6 km. They have nearly vertical sides, and magnetization contrasts range from 0.3 to 0.5 A m⁻¹.  相似文献   

AREAL DIFFERENTIATION AND CONSTRUCTION OF OASIS AGRICULTURAL ECOSYSTEM IN THE SHIYANG RIVER BASIN     

张维祥  梁智睿 《中国地理科学(英文版)》1993,3(4):357-364

On the basis of the study on areal differentiation of the natural environment of oasis agriculture ecosystems in the Shiyang River Basin, this paper comparatively analyzes the natural productivities, water economic benefits, production efficiency, ecological stabilities and developmental conditions of the Wuwei Oasis agricultural ecosystem in the middle reaches of the river basin and the Minqin Oasis agricultural ecosystem in the lower reaches. Under a same management level and investment of . material and energy, primary productiveness and economic benefits of the former are higher than those of the latter. Construction directions of Wuwei and Minqin oases should be different in order to alleviate the water- use contradiction between the middle and lower reaches. The construction objective of Wuwei Oasis should be efficient irrigated farming production system and Minqin Oasis should become a mixed forestry-pastoral-farming ecosystem taking ecological protection as its major function.  相似文献   

A 3D finite element simulation model for TBM tunnelling in soft ground     

Thomas Kasper  Günther Meschke 《国际地质力学数值与分析法杂志》2004,28(14):1441-1460

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THE CONSTRUCTION AND ITS DEVELOPMENT OFTHE OVERSEAS TRANSPORT SYSTEM IN NORTHEAST CHINA     

高莎丽  刘宁  孙丽华 《中国地理科学(英文版)》1994,4(1):19-30

ＴＨＥＣＯＮＳＴＲＵＣＴＩＯＮＡＮＤＩＴＳＤＥＶＥＬＯＰＭＥＮＴＯＦＴＨＥＯＶＥＲＳＥＡＳＴＲＡＮＳＰＯＲＴＳＹＳＴＥＭＩＮＮＯＲＴＨＥＡＳＴＣＨＩＮＡＧａｏＳｈａｌｉ（高莎丽）（ＤｅｐａｒｔｍｅｎｔｏｆＧｅｏｇｒａｐｈｙ，ＮｏｒｔｈｅａｓｔＮｏｒｍ...  相似文献   

Crustal and upper mantle structures of the brazilian coast     

Jorge Luis De Souza 《Pure and Applied Geophysics》1991,136(2-3):245-264

The Rayleigh wave phase and group velocities in the period range of 24–39 sec, obtained from two earthquakes which occurred in northeastern brazil and which were recorded by the Brazilian seismological station RDJ (Rio de Janeiro), have been used to study crustal and upper mantle structures of the Brazilian coastal region. Three crustal and upper mantle models have been tried out to explain crustal and upper mantle structures of the region. The upper crust has not been resolved, due basically to the narrow period range of the phase and group velocities data. The phase velocity inversions have exhibited good resolutions for both lower crust and upper mantle, with shear wave velocities characteristic of these regions. The group velocity data inversions for these models have showed good results only for the lower crust. The shear wave velocities of the lower crust (3.86 and 3.89 km/sec), obtained with phase velocity inversions, are similar to that (=3.89 km/sec) found byHwang (1985) to the eastern South American region, while group velocity inversions have presented shear velocity (=3.75 km/sec) similar to that (=3.78 km/sec) found byLazcano (1972) to the Brazilian shield. It was not possible to define sharply the crust-mantle transition, but an analysis of the phase and group velocity inversions results has indicated that the total thickness of the crust should be between 30 and 39 km. The crustal and upper mantle model, obtained with phase velocity inversion, can be used as a preliminary model for the Brazilian coast.  相似文献   

The largest karst cave discovered in a tunnel during motorway construction in Slovenia’s Classical Karst (Kras)   总被引：1，自引：0，他引：1  

Martin Knez  Tadej Slabe  Stanka Šebela  Franci Gabrovšek 《Environmental Geology》2008,54(4):711-718

Karst researchers of the Karst Research Institute ZRC SAZU are regularly consulted during the planning of Slovenia’s motorways and invited to observe and monitor construction in the karst areas. More than 350 caves have been discovered in the course of building 60 km of new motorways over the past decade. Access to the most important caves is preserved by concrete tubes closed with metal covers at the roadside. The largest cave system in a tunnel, named LC-S647, is almost entirely preserved. The protection of this cave will serve as a good example for the preservation of natural heritage in the future. Construction work for the motorway uncovered a high degree of karstification. In particular, the discovery of this cave in the Kastelec tunnel LC-S647 showed the existence of a major cave system in the geological and speleological past. A number of unconnected passages have also been found. Caves discovered during highway construction have brought new knowledge about the cavernosity and the geological history of this part of the karst.  相似文献