基于HR-树扩展的时空索引机制研究

在HR-树基础上分别融入了HR^＋ -树、SEST时空索引与快照-增量索引结构思想，对共享指针与非共享指针进行了区分，增加了增量与事件的索引数据结构。提出了基于HR-树扩展的时空索引模型，为实现高效、统一的时空查询提供了理论依据。     

Social polarization and segregation in Beijing

I INTRODUCTIONIt is a popular belief that in socialist countries thereis less socio-spatial disparity than was present in the...past or in comparison with western countries(FRENCHet al., 1979) However, a new urban phenomenon social polarization and spatial segregation --has takenplace in Beijing since the implementation of the economic reforms and open-door policy in 1978, especiallywith the introduction of urban reforms in 1984 o. We.can summarize the urban reform in two points: the f…     

Anisotropy and Dissipation of Turbulence and Their Effects on Solar Models

1 INTRODUCTIONThe maing-length theory (MLT) is the most commonly used approach to calculate convective energy transport in stars and other astrophysical situations. Based on the original idea ofPrandtl (1952) that turbulent parcels trallsfer heat in a similar way as molecules of gas do inthermal conduction, the MLT assumes that convection cells, drived by buoyancy, move thlougha ~ng length 1 and release the heat they carry when they merge with their environment. Themost widely adopted f…     

相对论流体力学初步(为射电天文研究之用)

本文对相对论流体力学的基本理论及最近的进展作了统一的和连贯的叙述,以便为射电天文研 究提供一个简明扼要的基础材料。 在类星体和星系核的射电天文的观测研究中,已经揭示出那里存在着相对论运动效应(在0.1—10pc尺度范围内)。而在更大尺度上,例如最近在天鹅座A的西北射电瓣内测到了～60kpc长的射电喷流中,流动也可能是相对论性的。因此不论在小尺度还是大尺度的射电现象的研究中,都需要考虑相对论效应。这些年来,在河外射电天文学中经常要利用相对论流体力学的研究结果,有些工作直接是为射电天文而进行的。本文的目的就是根据这种需要(特别是什对射电喷流的研究的需要),对有关的相对论流体力学研究的基本结果,加以统一的和连贯的叙述,以便为射电天文的研究提供一个基础材料。     

辽宁南部全新世地质年代学研究的初步报导

全新世是地球发展历史的最近一页,距今约一万年,与人类的关系最为密切。通过全新世地质研究,有助于人们认识现代自然环境变化的规律,如气候波动、植被演化、水系发育、海陆变迁、沉积速率等,为利用和改造自然,如泥炭的开采和利用、地下水的寻找以及工农业建设等提供基础地质资料。     

PRELIMINARY STUDY ON SEDIMENTARY ENVIRONMENT OF XIHU LAKE IN THE GREAT WALL STATION AREA, ANTARCTICA

The first author of this paper made a drilling through the water 3.5--4m deep in the Xihu Lake by using a gravity corer during 1985--1986 investigation in the Great wall Station area. The drill hole was 2.6 m deep and total 102 samples were collected. The author wishes to express her warmest thanks to Gao Xinquan, Ren Jiawen, Yang Yibi, Liu Xiaohan, Lin Yunfang and others who gave me energetic support during the sampling process.     

斜长石双晶的鉴定—讨论

《辽西中生代火山岩斜长石双晶类型、分布及其岩石成因信息》一文包含有大量有趣的资料,其中的一些结论也值得引起人们的重视。遣憾的是它提出的鉴定斜长石双晶的方法不够确切,故以此短文作为补充。该文中认为,当 An<70时,相对于结合面的延性符号者为负延性,则该结合面为(010)。此结论并不确切。当 An<70时,(010)结合面的延性符号确实为负。但其逆定理并不成立,即并非所有延性符号为负的结合面都为(010)面。例如当切面垂直[010]对,此时 Nm 接近 c 的方向,Np 接近 a 的方向,这样(001)结合面的延性符号也为负。     

关于磁测资料处理的几点意见

地矿部物化探局于八四年十月十五日至九月十四日在北京办了磁测资料处理讲习班。参加讲习班的同志们对磁测处理成果,方法进行了交流,并展开了专题讨论;还聘请了五位老师对一些新的方法技术作了专题讲座。现将交流,讨论的概况摘记如下:     

A STUDY ON THE MECHANISM AND CHARACTEROF THE INDUSTRIALAND SPATIAL TRANSFERENCE OF FDI IN CHINA

1 BACKGROUND OF STUDYChina has begun to take part in the great practice ofinternational competition and opening-up in the last 1 /5 time of 20th century. In the last two decades, Chinahas become one of the areas that have the greatest potential in industrial production, thus it has rankedsecond only to USA in the flow of international capital.By the end of 1998, the real value of FDI China hasutilized has added up to $268. I billion. China has wonworld attention as a huge market for …     

A Possible Origin of 6.7 GHz Linear Methanol Maser Sources

LETTERS1 INTRODUCTIONNew1y formed massive stars are obscured by dust, and their clearest signature is oftenat radio frequencies from strong maser emission. Methanol maser emission arises from severaItransitions, the strongest being the 5o -- 61A line at 6.7 GHz, which is also the second strongestGalactic masers of any molecule, first reported by Meaten (1991) and recognized as typical ofClass II masers. CIass II methanol masers are always found in regions of receat massive starfOr…