土地分类方法

所有景观都能分成更小的单位。一些单位可能是独特的(如陨石坑),但大多数则是由一些重复的地形所组成,而这些地形本身则由更小的景观单位,如山顶、腰坡、谷底等锒嵌而成。本文,我们将探讨为不同目的而发展的、已应用于土地研究的各种方法,同时也将研究土地分类的一些哲理与方法论问题。方法澳大利亚联邦科学与工业研究组织土地研究处从事土地分类研究已二十多年了。调查目的是为了确定一个地区的主要类型,评价自然资源。     

高红移类星体吸收线光谱的研究

作者用英-澳四米望远镜的RGo卡焦摄谱仪及其附属的IPCS系统获得了分辨率为2的四个高红移类星体的光谱,并利用这些光谱讨论了:(Ⅰ)由PKS0805 046和PKS1442 101的L_α/L_β对及L_α/L_γ对的强相关证实了,大量存在于高红移类星体L_α发射短波区的吸收线是氢云吸收的结果;(Ⅱ)吸收线分布和L_α/L_β对相关函数的分析反映了PKS0528-250可能是一个例外,需要进一步的观测来证实这种特殊性;(Ⅲ)由类星体抛射出来的物质的吸收,或与类星体成协的星系团或插入星系的吸收都可造成含有金属线的吸收线红移系统;(Ⅳ)由L_α/L_β对的生长曲线定出的柱密度和弥散速度的随机性,支持了纯Lα的吸收来自大爆炸宇宙早期原始氢云的假说;(Ⅴ)单位红移的氢云密度随红移的分布取决于Z>3的类星体的吸收线资料。     

BOOK REVIEWS

P.H.Morgan,EllisHorwood,Ltd,Chiehester,U.K.,1989,ISBN0一85312一746一8. This book 15 about nunlerieal analysis withexamPles taken from(Physieal)ehemstry.APPlieations are deseribed in rhe flelds of EPR,Photoeleetron speetroscoPy,diffusion,ehemiealk inetles and other ehem一eal diseiPlines.Themathemat一eal style of the book 15 less terse than一5 tlsual in books on numerieal analysis beeause it15 written for ehemists,not for     

哈雷彗星的彗核分裂

彗核分裂是最重要的彗星性质之一。这是因为,不仅这一性质是支持P.L.Whipple的冰冻团块模型的强有力的证据,而且,对彗核分裂现象的理解亦将为研究彗星本质提供大量的信息。迄今为止,发现有彗核分裂的彗星总数已超过20。至于关于哈雷彗星的彗核分裂,上一次回归(1910年)提供的报告极少。国际天文界对此将信将疑,并无定论。     

Textural and geochemical characteristics of late Pleistocene to Holocene fine-grained deep-sea sediment cores(GM6 and GM7),recovered from southwestern Gulf of Mexico

Texture, mineralogy, geochemistry, and ~(14)C ages of two deep-sea sediment cores(GM6 and GM7) recovered in the southwestern Gulf of Mexico were investigated to infer their provenance and depositional condition. The sediments are enriched in fine-grained silt and clay and poor in sand content. Mineralogically, the sediments consist of quartz,calcite, smectite, and kaolinite. Based on the ~(14)C data, the age of the GM6 and GM7 sediment cores were calculated as23,615 cal yrs. BP and 19,007 cal yrs. BP, respectively. The weathering indices such as chemical index of alteration(CIA),chemical index of weathering(CIW), and plagioclase index of alteration(PIA) in GM6(56-69, 60-74, and 61-73,respectively) and GM7(54-69, 57-76, and 55-74, respectively) cores revealed a moderate-to-high intensity of weathering. The rare earth element(REE) patterns suggested that the sediments were derived mostly by the weathering of intermediate rocks, exposed along the coastal regions of the Gulf of Mexico. The trace elemental ratios like V/Cr(2),Ni/Co(2), and Cu/Zn(1), authigenic uranium content(1), and Ce anomaly(Ce/Ce~* ≤ 1) suggested that the sediments were deposited under an oxic condition, which was also revealed by the benthic foraminiferal assemblages throughout the GM6 and GM7 sediment cores.     

Mineralization of Indium in Northern Vietnam: A Study on Mineralogy and Geochemistry of the Na Bop and Lung Hoai Deposits in the Cho Don and Cho Dien Mining Area

Please?refer?to?the?attachment(s)?for?more?details.     

Photometric observations of three high mass X-ray binaries and a search for variations induced by orbital motion

We searched for long period variation in V-band,IC-band and RXTE X-ray light curves of the High Mass X-ray Binaries(HMXBs) LS 1698 /RX J1037.5-5647,HD 110432 /1H 1249-637 and HD 161103 /RX J1744.7-2713 in an attempt to discover orbitally induced variation. Data were obtained primarily from the ASAS database and were supplemented by shorter term observations made with the 24-and 40-inch ANU telescopes and one of the robotic PROMPT telescopes. Fourier periodograms suggested the existence of long period variat...