地外生命搜索和太阳系外的行星的发现

阐述地外生命搜索的意义，手段和现状，地外生命搜索的SETI计划及其发展，并着重介绍太阳系外的行星系统的发现，它的目的，成果以及未来。太阳系外的行星系统的发展是当代天文学最时髦的，也将是未来21世纪成果最丰富的研究领域之一，从1992年第一个确认了脉冲星PSR 1257＋12的行星系统以来，1995年确认主序星51Peg有一颗行星，至2001年5月，已经发现了60个太阳系外的行星系统，太阳系外的行星系统的发现与地外生命搜索研究是密不可分的，新的发现也提出了很多新的谜，这项研究近10年来发展很快，它的研究也促进了航天学，宇宙化学，天文生物学乃至哲学等其他学科的发展。     

Waveform Effect on Fatigue Properties of Intact Sandstone in Uniaxial Cyclical Loading

Summary. The effect of loading waveform and amplitude on the fatigue behaviour of intact sandstone was investigated using uniaxial cyclic loading conditions in the laboratory. In the first set of experiments sinusoidal, ramp and square waveforms were used at loading frequency of 5Hz and peak amplitude of 0.05mm. In another set of experiments, tests were conducted at a range of amplitudes varying from 0.05 to 0.3mm at 5Hz frequency using sinusoidal and ramp waveforms. It was found that loading waveform as well as amplitude is of great significance and affects the rock behaviour. It was found that fatigue behaviour is a function of the cyclic energy of the load and the shape of the waveform. Damage accumulated most rapidly under square waveforms with a high energy requirement. A ramp waveform was the least damaging of those considered. The loading waveforms strongly influenced the damage accumulation under cyclic loading conditions. Finally, it is concluded that machine behaviour in terms of amplitude affected the rock behaviour. This study has practical significance to the behaviour of rock and rock masses within the excavation systems subjected to cyclic loading.     

Seismic Performance of RC Frames Designed to Eurocode 8 or to the Greek Codes 2000

For the first time after the finalisation of the European Norm for seismic design of buildings (Eurocode 8 – EC8),the performance of RC buildings designed with this code is evaluated through systematic nonlinear analyses. Regular 4-, 8- or 12-storey RC frames are designed for a PGA of 0.2 or 0.4 g and to one of the three alternative ductility classes in EC8. As the Eurocodes are meant to replace soon existing national codes, design and performance is also compared to that of similar frames designed with the 2000 Greek national codes. The performance of alternative designs under the life-safety (475 years) and the damage limitation (95 years) earthquakes is evaluated through nonlinear seismic response analyses. The large difference in material quantities and detailing of the alternative designs does not translate into large differences in performance. Design for either Ductility Class High (H) or Medium (M) of EC8 is much more cost-effective than design for Ductility Class Low (L), even in moderate seismicity. It is also much more cost-effective than design to the 2000 Greek national codes.     

DISCOVERY OF ORGANIC MOLECULES IN DEEP-SEA IRON COSMIC DUST

A great quartity of cosmic dust(spherules) was found in deep-sea sediments during May to July,1983manganese nodule investigations by the R/V“XIANGYANGHONG 16”in the area 7°-11°N,167°-178°Win the Pacific.Comprehensive study of the cosmic dust and determination with Laser Raman MolecularMicroprobe(LRMM) of the molecules in it showed that besides Fe-Fe,Fe~(3+)-O,Fe-Ni,Al-O,Fe-Obr-Si and Si-Onb,it also contained the organic molecules C-H-O and C-H-S-O,various no fixed form molecules of C,CH_2,CH_3 and volatile molecules CO_2,H_2O,OH~- and H_2S,etc…The study result has very important applications for exploring the origin of interplanetary dust parti-cles and life material.     

BOOK REVIEWS

Book Reviewed in this article: The City in Cultural Context . John Agnew, John Mercer, David Sopher, eds. Soils and Geomorphology Peter W. Birkeland. Urbanization and Settlement Systems, International Perspectives . L. S. Bourne, R. Sinclair, and K. Dziewoński. eds. An Introduction to Urban Historical Geography . Harold Carter. Overshoot, The Ecological Basis of Revolutionary Change . William J. Catton, Jr. Rivers of the World . Eberhard Czaya. Jewish Communities in Frontier Societies: Argentina, Australia and South Africa . Daniel J. Elazar with Peter Medding. Color in Public Spaces: Toward a Communication-Based Theory of the Urban Built Environment. Kenneth E. Foote. Spatial Statistics and Models. Gary L. Gaile and Cort J. Willmott, eds. Mega-Geomorphology. Rita Gardner and Helen Scoging, eds. Technological Change and Regional Development. Gillespie, ed. The Arid Lands: Their Use and Abuse. R. L. Heathcote. The Location of Industry in Britain. A. G. Hoare. Groundwater as a Geomorphic Agent . R. G. LaFleur, ed. Rural Public Services: International Comparisons. Richard E. Lonsdale and Gyorgy Enyedi, eds. Saving Water in a Desert City. William E. Martin, Helen M. Ingram, Nancy K. Laney, and Adrian H. Griffin. Water Resources: Distribution, Use and Management. John R. Mather. Transnationals and the Third World: The Struggle for Culture. Armand Mattelart. South Hadley, MA: USGS Digital Cartographic Data Standards. R. B. McEwen, R. E. Witmer, and B. S. Ramey, eds. The Ecosystem Concept in Anthropology. Emilio F. Moran, ed. Boulder, CO: Women, Men, and the International Division of Labor. June Nash and Maria Patricia Fernandez-Kelly, eds. Nuclear Power: Assessing and Managing Hazardous Technology. Martin J. Pasqualetti and K. David Pijawka, eds. Mary Somerville and the Cultivation of Science 1815-1840. Elizabeth Chalmers Patterson. An Introduction to Coastal Geomorphology. John Pethick. Late Quaternary Environments of the United States , Vol. 1, The Late Pleistocene. Stephen C. Porter, ed. Planning and Ecology. R. D. Roberts and T. M. Roberts, eds. Regionalism and the Pacific Northwest. William G. Robbins, Robert J. Frank, and Richard E. Ross, eds. Environment and Health. Anthony J. Rowland and Paul Cooper. Sunbelt/Snowbelt: Urban Development and Regional Restructuring. Larry Sawers and William K. Tabb, eds. The Bad Earth. Environmental Degradation in China. Vaclav Smil. Armonk, NY: Voyage into Substance: Art, Science, Nature, and the Illustrated Travel Account, 1760–1840. Barbara Maria Stafford. The Institute of British Geographers: The First Fifty Years. Robert W. Steel. Visions of the Past. Christopher Taylor and Richard Muir. Glacial Lake Agassiz. J. T. Teller and Lee Clayton, eds. The Tule Breakers: The Story of the California Dredge. John Thompson and Edward A. Dutra. The Balkan City 1400–1900. Nikolai Todorov. Explanation, Prediction and Planning: the Lowry model. Michael J. Webber. Mercedes Reales: Hispanic Land Grants of the Upper Rio Grande Region. Victor Westphall. The World Atlas of Revolutions. Andrew J. M. Wheatcroft. The West European City, A Social Geography. Paul White. Urban Elites and Mass Transportation. J. Allen Whitt. Princeton, NJ: Urban Life In Contemporary China. Martin King Whyte and William L. Parish. The Demand for Energy in the Soviet Union. David Wilson. London and Canberra: Rethinking Geographical Inquiry. J. David Wood, ed.     

BOOK REVIEWS

Book Reviewed in this article: Latin America: Case Studies . Richard G. Boehm and Sent Visser Locality and Rurality: Economy and Society in Rural Regions . Tony Bradley And Philip Lowe The City and the Grassroots . Manuel Castells Geopolitics and Conflict in South America. Quarrels among Neighbors . Jack Child Post-Industrial America: A Geographical Perspective . David Clark Coastal Research: UK Perspectives . Malcolm W. Clark A Rural Policy for the EEC? Hugh Clout Peasant Agriculture in Assam: A Structural Analysis . M. M. Das . Environmental Change and Tropical Geomorphology . I. Douglas and T. Spencer Advances in Abandoned Settlement Analysis: Application to Prehistoric Anthrosols in Colombia, South America . Robert C. Eidt Measuring Culture . Jonathan L. Gross and Steve Rayner North America: A Human Geography . Paul Guinness and Michael Bradshaw A Geographical Bibliography for American Libraries . Chauncy D. Harris et al. Geography and the Urban Environment: Progress in Research and Applications, Vol. VI . D. T. Herbert and R. J. Johnston Changes in Global Climate: A Study of the Effect of Radiation and Other Factors During the Present Century . K. Ya . Kondrat'ev . Rural Development and the State: Contradictions and Dilemmas in Developing Countries . David A. M. Lea and D. P. Chaudhri The Martial Metropolis: U.S. Cities in War and Peace . Roger W. Lotchin The Climate of the Earth . Paul E. Lydolph . Weather and Climate . Paul E. Lydolph . Spatial Divisions of Labor: Social Structures and the Geography of Production . Doreen Massey . Panorama of the Soviet Union . N. Mikhailov . Soviet Armenia . K. S. Demirchian . USSR: Geography of the Eleventh Five-Year Plan Period . K. Spidchenko . Planung und Verwirklichung der Wiener Ringstrassenzone (Planning and Materialization of the Ringstrasse-Zone of Vienna). Kurt Mollik , Hermann Reining , Rudolf Wurzer . The American West Transformed: The Impact of the Second World War Gerald D. Nash . An Overview of the Survey of Income and Program Participation . Dawn Nelson , David Mc Millen, and Daniel Kasprzyk . Phenomenology, Science and Geography: Spatiality and the Human Sciences . John Pickles . Biological Diversification in the Tropics . Ghillean T. Prance Die Wanderviehwirtschaft im gebirgigen Westen der U.S.A. und ihre Auswirkungen im Naturraum . Gisbert Rinschede . Social and Economic Aspects of Radioactive Waste Disposal: Considerations for Institutional Management . World-Wide Weather . K. Takahashi Coastal Geomorphology in Australia . B. G. Thom Settlement System in Rural India: A Case Study of the Lower Ganga-Yamuna Doab . Ram Chandra Tiwari . Computer Programming for Geographers . David J. Unwin and John A. Dawson . Late Quaternary Environments of the Soviet Union . A. A. Velichko, ed . H. E. Wright , Jr. and C. W. Barnosky Ethics in Planning . Martin Wachs     

钢支撑及框架-中心支撑双重抗侧力体系研究现状、不足及改进

本文在总结钢支撑滞回性能及高层双重抗侧力体系研究现状的基础上，分析了现象学、物理学及有限元3种钢支撑模拟方法的优缺点，并针对现有支撑模拟方法及支撑疲劳累积损伤研究的不足提出了可行的改进方法。分析了框架一中心支撑双重体系研究中若干关键性问题之后，指出了我国《高层民用建筑钢结构技术规程》(JGJ99-98)等有关规范中关于双重体系设计相关条款存在的分歧及不足，并提出了通过双重结构体系在罕遇地震下的反应特性模拟分析来统一认识的建议。     

Research on Ecological Protection and Restoration Measures in Altay Region based on the Coupling Perspective of the Mountains-Rivers-Forests-Farmlands-Lakes-Grasslands System

The adoption of both Nature-based Solutions (NbS) and a system perspective is a hot issue and an area in which there is much room for improvement in ecological protection and restoration. The study takes Altay region as an example, an area located in Xinjiang, China, which is an important ecological corridor of the national key functional area and the core area of the Belt and Road but has a fragile ecological environment and needs much enhancement in ecological protection and restoration. Guided by the concept of “mountains-rivers-forests- farmlands-lakes-grasslands (MRFFLG) system is a life community”, the coupling relationship of the various MRFFLG elements, the main ecological environmental problems and the integrated countermeasures for protection and restoration in Altay region have been analyzed in this study. The study shows that Altay region has a typical meta-ecosystem of mountain, oasis, and desert, and the connections by rivers and lakes make the ecosystem links within the region much closer. The interweaving of resource-environmental-ecological issues of the aquatic ecosystem, degradation of the quality of terrestrial ecosystems such as forests, grasslands and farmlands, the increased ecosystem fragmentation and ecological risks are the major ecological environmental issues in this region. This study takes the improvement of the ecosystem health and function in Altay region as the core goal of regional ecological protection and restoration. First, we establish a zoning governance pattern from the perspective of ecosystem integrity; second, we design governance strategies for different zones with the goal of synergistic improvements in the ecosystem functions; and finally, we clarify the key engineering tasks in different zones from the perspective of ecosystem services. Ecological conservation and restoration of the MRFFLG system is a prime example of the application and development of NbS in China. This paper constructs an analytical framework for identifying regional life communities, diagnosing ecological protection and restoration of zoning problems, and proposing classified solutions for ecological protection tasks for the protection of the MRFFLG system. This research will enrich the theory and technology for the protection and restoration of MRFFLG systems, and provide guidance for the practice of ecological protection and restoration in Altay region.