空间运输联系的分布与交流规律研究

空间运输联系是指在自然、社会、经济诸要素综合作用下，区域间通过交通运输设施进行旅客和货物交流产生的相互联系与作用。采用定量与定性相结合的实证分析方法，本文研究了客货运输的地域分布特征、地域间交流联系生成的内在机制、基本类型和增长演变的趋势，划分出客运联系“单中心”、“多中心”，货运联系“互补性交流”、“竞争性交流”、“递接性交流等类型，并提出了非均衡系数、集中度、首位联系量等评价指标。     

Metamorphism of the Bikou Group in the Shanxi-Gausu-Sichuan Border Region1

Abstract The Bikou Group on the Shaanxi-Gansu-Sichuan border is composed of Mid-Late Proterozoic metamorphosed bimodal volcanic rocks and flysch sediments. Its metamorphism may be divided into the blueschist and greenschist facies. Three metamorphic zones, i.e. zones A, B, and C, may be distinguished on the basis of the field distribution of metamorphic rocks and the variation of b₀ values of muscovite. Blueschists are characterized by coexistence of sodic amphiboles and epidote and occur as stripes or relict patches in extensive greenschists of zone A. Studies of metamorphic minerals such as amphiboles, chlorite, epidote and muscovite and their textural relationships indicate that blueschists and greenschists were not formed under the same metamorphic physico-chemical conditions. The blueschist facies was formed at temperatures of 300-400°C and pressures of 0.5–0.6 GPa. The greenschist facies in zones A and B has similar temperatures but its pressure is only 0.4 GPa or so. The transition from the blueschist to greenschist facies is a nearly isothermal uplift process. The rock and mineral assemblages of the Bikou Group indicate that the blueschist facies metamorphism of the group might be related to crustal thickening or A-subduction accompanying the closure of an intracontinental small ocean basin.     

作物叶面蒸腾与棵间蒸发分摊系数的计算方法

依据在冬小麦和玉米冠层表面及冠层内部下方土壤表面的净辐射观测资料,建立了一个能较准确地反映叶面蒸腾与棵间土壤蒸发分摊系数物理变化规律的较实用的计算模式,结果表明,分摊系数(α)随叶面积指数(LAI)增加而增加,且具有明显的日变化,α在中午最小、早、晚稍大,这种日变化受叶气孔调节的影响。     

全球月平均高度距平场正斜压性的分析(I)--相关系数分布

利用欧洲中心全球客观分析的7层月平均位势高度距平资料,分别计算了相同格点上12-2月和6-8月各层高度距平之间的同时相关分布。结果表明:全球月平均位势高度距平场的正压、斜压性随地理区域变化很大,并有较明显的季节变化。其中12-2月对流层下部大气环流距平场在海洋上空有较好的相当正压性,在大陆上空正压性较差;对流层上部大气环流异常的正、斜压性分布与下部不同,赤道附近地区是相关系数的高值区,副热带地区主要是低值区;在对流层下部与上部大气环流距平场的相关系数分布图上,海洋上空并不总是高值区,在热带东太平洋区域就出现最强的负相关中心。与6-8月的相关系数分布型比较发现:特别明显的季节变化在非洲大陆和热带印度洋区域,12-2月为强正压区,6-8月为强斜压区。     

Distribution coefficients of210Pb and210Po in laboratory and natural aquatic systems

We have measured the distribution coefficient (Kd) of²¹⁰Po and²¹⁰Pb in laboratory systems and in natural freshwater systems. In the laboratory systems, an inverse relationship was observed between the particle concentration of sand or lake sediment, and the distribution coefficients of²¹⁰Po and²¹⁰Pb. The slope of the log-linearK _d vs particle concentration relation is consistent with existingK _d-particle concentration theories. These laboratory observations are consistent with similar measurements in two lakes. TheK _d values of Po and Pb for the bottom sediment-pore water system with a high particle concentration were 10 to 100 times lower than those for dilute concentrations of particles suspended in the lake water. TheK _d of²¹⁰Pb in the sediments was >10⁴ so that the diffusive transport of²¹⁰Pb has only a small influence on the interpretation of²¹⁰Pb concentration-depth profiles and the²¹⁰Pb dating of these sediments.This is the second of a series of papers to be published by this journal following the 20^th anniversary of the first application of²¹⁰Pb dating of lake sediments. Dr P. G. Appleby is guest editing.     

彩色红外航空遥感技术在西藏农田非耕地系数测算中的应用研究与实践

西藏自治区的耕地多分布在藏东、藏南河谷地带,多数耕地地块破碎,形态各异,并且有大量的非耕地成分混杂其间,即使采用大比例尺图件,也难以测量准确的耕地面积。为准确查清耕地面积,在西藏土地资源调查工作中,独创地采用了彩色红外条带航空摄影,计算机图像处理系统求算彩色红外航空像片耕地样地中非耕地系数值和建立不同地貌、不同耕地类型非耕地系数检索表等系统的方法。该方法已在全藏调查工作中普遍推广,提高了调查精度,缩短了调查时间,大大减少了人力和经费投入。该项研究为我国山区耕地面积调查提供了有效的手段。     

变质岩构造置换与片层理概念的讨论

构造置换应分成形体置换和方位置换两类。形体置换是在一定尺度内新的透入性构造要素代替了旧的透入性构造要素,使后者不易识别或无法识别的置换作用;方位置换是在一定尺度内旧的透入性构造要素残存着,但其方位被改变,与新的透入性构造要素平行或近于平行的置换作用。片层理是受到不明显的形体置换和强的方位置换的层理,它具有片理的方位,层理的形体,是与片理产状一致的那一部分层理。     

孔隙水压力圆锥静力触探及其发展现状

介绍孔隙水压力圆锥静力触探这门新技术,着重评述近年来在探头优化设计方面的进展,以及在划分地层和鉴别土类、估计土的超固结比和固结系数方面应用的最新研究成果。     

对中国大陆区域地磁场提取的认识

本文从球谐函数理论的物理含义、中国地磁数据的分布情况及实际计算结果的分析,提出对当前用球谐函数拟合法提取中国大陆区域地磁异常的几点认识。