图形软件在编辑出版专题地图中的应用研究     

王大新 《地球信息科学学报》2001,3(2):25-28

计算机制图(CAC)和电子出版系统的普及和推广,从根本上改变了传统的地图生产工艺。本文结合制图实践,讨论了应用Coreldraw图形软件编辑出版专题地图的适应性、系统条件和工艺流程,并总结了一些制图经验和应该注意的若干问题。  相似文献   

A Chandra detection of the radio hotspot of 3C 123     

M. J. Hardcastle  M. Birkinshaw  D. M. Worrall 《Monthly notices of the Royal Astronomical Society》2001,323(2):L17-L22

Chandra X-ray Observatory observations of the powerful, peculiar radio galaxy 3C 123 have resulted in an X-ray detection of the bright eastern hotspot, with a 1-keV flux density of ∼5 nJy. The X-ray flux and spectrum of the hotspot are consistent with the X-rays being inverse-Compton scattering of radio synchrotron photons by the population of electrons responsible for the radio emission ('synchrotron self-Compton emission') if the magnetic fields in the hotspot are close to their equipartition values. 3C 123 is thus the third radio galaxy to show X-ray emission from a hotspot which is consistent with being in equipartition. Chandra also detects emission from a moderately rich cluster surrounding 3C 123, with L _X(2–10 keV)=2×10⁴⁴ erg s⁻¹ and kT ∼5 keV, and absorbed emission from the active nucleus, with an inferred intrinsic column density of 1.7×10²² cm⁻² and an intrinsic 2–10 keV luminosity of 10⁴⁴ erg s⁻¹.  相似文献   

CSCO_3 CYCLES IN SALAWUSU RIVER BASINSINCE 150KA B.P.     

LUO Kai-li    LI Bao-sheng    ZHU Yi-zhi  JIN He-ling  ZHANG David Dian  YAN Man-cun  LI Hou-xin  YAO Chun-xia  ZHANG Yu-hongf . Department of Geography  South China Normal University  Guangzhou  P. R. China  . State Key Labor 《中国地理科学(英文版)》2001,11(4):336-342

About 70years ago，Frenc卜卜alaeohdoglst回LL sc卜dars al卜ome and a卜road卜ave successively con－HARD de Chardin P．et al．Initiated the Quaternary ducted large amount ofwork on the Later Quaternarygeologlcal research In the ＞alawusu River Basin of strata（TEILHARD，1924； YUAN，1978； LI，1987；desert region of Northern China and established th，ZHENG，1989； SUN et al，1996； LI et al，1993），Salawusu Formation门EILHARD，1924）．Sine，then，palaeobiology…  相似文献   

Cygnus X-3 with ISO: investigating the wind     

R. N. Ogley  †  S. J. Bell Burnell  R. P. Fender 《Monthly notices of the Royal Astronomical Society》2001,322(1):177-186

We have observed the energetic binary Cygnus X-3 in both quiescent and flaring states between 4 and 16 μm using the ISO satellite. We find that the quiescent source shows the thermal free–free spectrum typical of a hot, fast stellar wind, such as from a massive helium star. The quiescent mass-loss rate arising from a spherically symmetric, non-accelerating wind is found to be in the range (0.4–2.9)×10⁻⁴ M_⊙ yr⁻¹, consistent with other infrared and radio observations, but considerably larger than the 10⁻⁵ M_⊙ yr⁻¹ deduced from both the orbital change and the X-ray column density. There is rapid, large-amplitude flaring at 4.5 and 11.5 μm at the same time as enhanced radio and X-ray activity, with the infrared spectrum apparently becoming flatter in the flaring state. We believe that non-thermal processes are operating, perhaps along with enhanced thermal emission.  相似文献   

Early warning research on salt-alkalization desertification in western Songnen Plain     

BIAN Jian-min  LIN Nian-feng  TANG Jie College of Environment  Resources  Jilin  University  Changchun  Jilin  China 《东北亚地学研究》2005,(Z1)

Desertification is an environmental issue in the world. The salt-alkalization desertification land area formed by both primary and secondary salt-alkalization has extended in a large scale, which has become a significant eco-environmental problem. Based on the characteristics of eco-environment and the situation of desertification in western Songnen plain, this paper reports the analyzes of its formation in background and cause. An early warning system on the salt-alkalization desertification is established and the GIS technology is used to abstract the information of desertification evaluation index. Supported by the integrated technology of the GIS and ANN, the orientation and quantitative result of desertification are gained, which is helpful to the eco-environment protection and resource development in western Songnen Plain.  相似文献   

Progress in Earthquake Science and Technology in China: Review and Prospects (Ⅰ)     

Chen Zhangli 《中国地震研究》2001,15(4):329-345

In the article the author looks back the hard development course and great progress in earth quake science and technology in China during the last near a half of century and expounds the following 3 aspects: (1) The strong desire of the whole society to mitigate seismic disasters and reduce the effect of earthquakes on social-economic live is a great driving force to push forward the development of earthquake science and technology in China; (2) To better ensure people‘ s life and property, sustainable economic development, and social stability is an essential purpose to drive the development of earthquake science and technology in China; and (3) To insist on the dialectical connection of setup of technical system for seismic monitoring with the scientific research of earthquakes and to better handle the relation between crucial task, current scientif ic level, and the feasibility are the important principles to advance the earthquake science and technology in China. Some success and many setbacks in earthquake disaster mitigation consistently enrich our knowledge regarding the complexity of the conditions for earthquake occurrence and the process of earthquake preparation, promote the reconstruction and modernization of technical system for earthquake monitoring, and deepen the scientific research of earthquakes. During the last 5 years, the improvement and modernization of technical system for earthquake monitoring have clearly provided the technical support to study and practice of earthquake prediction and pre caution, give prominence to key problems and broaden the field of scientific research of earth quakes. These have enabled us to get some new recognition of the conditions for earthquake oc currence and process of earthquake preparation, characteristics of seismic disaster, and mecha nism for earthquake generation in China‘s continent. The progress we have made not only en courages us to enhance the effectiveness of earthquake disaster mitigation, but also provides a basis for accelerating further development of earthquake science and technology in China in the new century, especially in the 10th five-year plan. Based on the history reviewed, the author sets forth a general requirement for develop ment of earthquake science and technology in China and brings out 10 aspects to be stressed and strengthened at present and in the future. These are: upgrade and setup of the network of digitized seismic observation; upgrade and setup of the network for observation of seismic pre cursors; setup of the network for observation of strong motion; setup of the laboratories for ex periment on seismic regime; establishment of technical system for seismic information, emer gency command and urgent rescue; research on short-term and imminent earthquake predic tion; research on intermediate- and long-term earthquake prediction; research on attenuation of seismic ground motion, mechanism for seismic disaster, and control on seismic disaster; ba sic research fields related to seismology and geoscience. We expect that these efforts will signifi cantly elevate the level of earthquake science and technology in China to the advanced interna tional level, improve theories, techniques, and methods for earthquake precaution and predic tion, and enhance the effectiveness of earthquake disaster mitigation.  相似文献   

Neutron background in large-scale xenon detectors for dark matter searches     

M. J. Carson  J. C. Davies  E. Daw  R. J. Hollingworth  V. A. Kudryavtsev  T. B. Lawson  P. K. Lightfoot  J. E. McMillan  B. Morgan  S. M. Paling  M. Robinson  N. J. C. Spooner  D. R. Tovey 《Astroparticle Physics》2004,21(6):667-687

Simulations of the neutron background for future large-scale particle dark matter detectors are presented. Neutrons were generated in rock and detector elements via spontaneous fission and (α,n) reactions, and by cosmic-ray muons. The simulation techniques and results are discussed in the context of the expected sensitivity of a generic liquid xenon dark matter detector. Methods of neutron background suppression are investigated. A sensitivity of 10⁻⁹–10⁻¹⁰ pb to WIMP-nucleon interactions can be achieved by a tonne-scale detector.  相似文献   

论现代航海技术与高等航海教育     

邓礼标 《广东海洋大学学报》2004,24(5):126-130

针对航海技术的现状和发展趋势 ,提出了高等航海教育应向国际化、高素质化、现代化、技能化、规范化发展 ,以培养高素质的国际航运人才。  相似文献   

REMOTE SENSING FOREST BIOMASS: AN EVALUATION USING HIGH RESOLUTION REMOTE SENSOR DATA AND LOBLOLLY PINE PLOTS     

John R. Jensen  Michael E. Hodgson 《The Professional geographer》1985,37(1):46-56

Eight-year-old Loblolly pine (Pinus taeda) plots located in South Carolina were evaluated using high resolution aircraft multispectral scanner data to determine if biomass could be accurately measured. Sixteen pine plots located on both sandy and clay soils were treated with 0, 180, or 360 kg. (approximately 0, 400, or 800 lb.) of nitrogen per plot. Indices of biomass from remote sensing data were significantly correlated with in situ biomass measurements made in each plot. A ratio of infrared (.9–1.1 μm) and red (.65–.70 μm) channels yielded the best correlation. The indices were not sensitive to differences in soil type (sandy or clay).  相似文献   

数字宜昌建设初探     

魏明果 《地理信息世界》2002,(3)

数字地球、数字城市是近几年刚提出来的一个全新的概念 ,但数字城市的建设却以空前的速度向前发展着 ,国务院总理朱熔基在视察宜昌时提出要把宜昌建设成世界级的城市 ,未来的城市数字化程度将是衡量一个城市发达程度的重要指标 ,启动数字宜昌建设是跻身世界级城市 ,提高宜昌市综合竞争力的重要举措  相似文献