温度对季节性冻土水分迁移的影响研究

寒区季节性冻土冻胀性质对工程实际影响很大。为了了解温度对水分迁移现象的影响,本文通过地温测试仪对野外不同深度处的土层温度进行测量,并在不同时间相应深度取土样,测其含水率,通过比较不同时间不同深度处的含水率的变化情况来分析温度变化对水分迁移现象的影响。在气温回升之前,当地表温度降低时,温度随深度的降低而升高;随着地表温度不断降低,各深度处的温度也不断下降,温度梯度增加,各深度处地层的含水率变化大,即温度梯度的增加促进了季节性冻土区水分迁移现象的发生。     

青龙铀矿田成矿地质特征及找矿方向初探

青龙铀矿田位于华北地台东北部,在山海关古隆起与燕辽沉降带接壤部位的建昌中生代盆地南部干沟EW向次级火山断陷盆地的南缘[1],是一个品位较高、储量大的矿田。通过对成矿地质背景、矿化特征和控矿因素的分析,提出了该矿田矿床类型为不整合型铀矿的新认识,指出了应重点在该矿田深部、外围找不整合型铀矿床的新的找矿思路。     

四川省代隆金矿区构造控矿因素分析

四川省代隆金矿位于壤塘金矿带内,该带总体呈北西西向,由一系列断层及褶皱组成,并伴有不同岩性的岩浆岩产出。区内构造整体呈北西西向,但也发育东西向及北东向次级断裂。区内金矿体主要富集在花岗斑岩与板岩之间的断裂破碎带内,在北西西向与东西向构造结合部位、北西西向构造产状变化部位,为下一步找矿有利部位。     

金平多衣梁钨多金属矿床地质特征及找矿方向

金平多衣梁钨多金属矿床大地构造位置处于青藏滇板块与扬子板块的交接拼合部位,挟持于北西向的阿墨江断裂和哀牢山深大断裂之间2的南东边缘。通过对矿床区域地质背景、矿床地质特征、控矿因素及矿床成因等初步研究,综合地质成矿信息总结出了找矿标志,并以此提出了有利找矿方向。     

High spectral resolution infrared studies of Titan: Winds, temperature, and composition

The Cassini Huygens mission provides a unique opportunity to combine ground-based and spacecraft investigations to increase our understanding of chemical and dynamical processes in Titan’s atmosphere. Spectroscopic measurements from both vantage points enable retrieving global wind structure, temperature structure, and atmospheric composition. An updated analysis of Titan data obtained with the NASA Goddard Space Flight Center’s Infrared Heterodyne Spectrometer (IRHS) and Heterodyne Instrument for Planetary Wind and Composition (HIPWAC) prior to and during the Cassini Huygens mission is compared to retrievals from measurements with the Cassini Composite Infrared Spectrometer (CIRS). IRHS/HIPWAC results include the first direct stratospheric wind measurements on Titan, constraints on stratospheric temperature, and the study of atmospheric molecular composition. These results are compared to CIRS retrievals of wind and temperature profile from thermal mapping data and ethane abundance at 10-15° South latitude, near the equatorial region. IRHS/HIPWAC wind results are combined with other direct techniques, stellar occultation measurements, and CIRS results to explore seasonal variability over nearly one Titan year and to provide an empirical altitude profile of stratospheric winds, varying from ∼50 to 210 m/s prograde. The advantage of fully resolved line spectra in species abundance measurements is illustrated by comparing the possible effect on retrieved ethane abundance by blended spectral features of other molecular constituents, e.g., acetylene (C₂H₂), ethylene (C₂H₄), allene (C₃H₄), and propane (C₃H₈), which overlap the ν₉ band of ethane, and are not resolved at lower spectral resolution. IR heterodyne spectral resolution can discriminate weak spectral features that overlap the ν₉ band of ethane, enabling ethane lines alone to be used to retrieve abundance. Titan’s stratospheric mean ethane mole fraction (8.6±3 ppmv) retrieved from IRHS/HIPWAC emission line profiles (resolving power λ?Δλ∼10⁶) is compared to past values obtained from lower resolution spectra and from CIRS measurements (resolving power λ?Δλ∼2×10³) and more compatible recent analysis. Results illustrate how high spectral resolution ground-based studies complement the spectral and spatial coverage and resolution of moderate spectral resolution space-borne spectrometers.     

大体积混凝土裂缝的分析及控制措施

随着高层建筑和工业建筑的发展,大型的筏式基础、箱形基础、桩基承台以及大型的设备基础,一般是大体积混凝土,在施工过程中都有一个温度控制和温度应力问题,这些问题如果解决不好,都会引起混凝土表面裂缝和收缩裂缝的发生。为了解决这个问题我们通过分析原因、现场实践得出一些实际有效的措施。     

Analyses of precipitation,temperature and evapotranspiration in a French Mediterranean region in the context of climate change

This study is focused on the western part of the French Mediterranean area, namely the Pyrénées-Orientales and Aude administrative departments. The water resources (surface and groundwater) in the region are sensitive to climate change. The study addresses the question of whether any trend in the annual and monthly series of temperature, rainfall and potential evapotranspiration (PET) already appears at the scale of this region. Two data sources have been used: (a) direct local measurements using the meteorological network; and (b) spatially interpolated data from the French weather service model SAFRAN for the period 1970–2006. The non-parametric Mann–Kendall test was applied to identify significant trends at the local scale and, because of the natural spatial variability of the Mediterranean climate, regional interpretation was also performed. The trends observed in the 13 catchments of interest are consistent with those observed at a larger scale. An increase in annual mean temperature and annual PET was observed throughout the study area, whereas annual precipitation has not exhibited any trend. The monthly scale has revealed strong seasonal variability in trend. The trend for an increase in monthly PET has been observed mainly in the spring, and has not been seen in the coastal areas. A trend for an increase in monthly temperature has been observed in June and in the spring throughout the entire area. Monthly rainfall has been found to decrease in June and increase in November throughout the area. The significant trends observed in rainfall and temperature seem to be consistent between the different data sources.     

大面积土体堆载地基变形一般规律分析

大面积土体堆载是典型的一维固结问题,但是大面积堆载的地基土变形规律与常规小范围堆载有显著差别。本文通过收集整理多项软土地区大面积土体堆载工程实测资料,结合工程地质情况,总结了大面积堆载的一般规律。从这些工程的实测结果看,大面积堆载与小范围堆载相比,其影响范围大、固结时间长、孔隙水压力消散缓慢、变形量大,这些规律对工程设计具有一定参考价值和指导意义。     

An Application of Close Range Photogrammetry In Dolphin Studies

Dolphins are agile animals and are very difficult to measure at sea. However, for the conservation of threatened or endangered species, measurement may be vital because it allows a demographic analysis of the population. Hector's dolphin (Cephalorhynchus hectori) is a rare species living only in coastal waters around New Zealand where it is studied from small boats. This paper describes a stereophotogrammetric technique developed to measure body length accurately at sea without having to capture the individual. Constant calibration with the use of a control frame allowed accurate body length measurements of dolphins to be made with this low cost system, with a measurement error of 4 per cent to 6 per cent of actual length.     

应用全站仪进行三角高程测量的新方法

一般在工程施工常用的传统测量方法比较局限,而应用全站仪进行三角高程测量,提高了每个点的高程测量精度,并且计算土方量时精确度增加,施测速度更快,符合测量精度要求。