土洞型岩溶塌陷发育过程气体示踪试验研究——以广州金沙洲为例

运用气体示踪进行土洞型岩溶塌陷监测预警是一种比较新的技术方法,其原理是通过气体在不同形状、规模的土体孔隙、裂缝和土洞中的运移规律研究,分析气体特征值与土体变形破坏的关系,进而间接判断土洞的发育情况,实现岩溶塌陷监测预警.本文以广州市金沙洲岩溶塌陷区为例,通过室内物理模型试验再现了土洞发育、形成到地面塌陷的全过程.运用气...     

汞矿区稻田土壤汞形态分布特征及对甲基化的影响

汞污染区稻米甲基汞超标现象普遍存在,汞在土壤中的形态分布被认为是影响甲基化过程的重要因素之一.本研究选取贵州省万山废弃汞矿区和土法炼汞区为研究区域,在水稻生长期间对稻田土壤剖面中总汞、甲基汞及形态汞进行测定,结合土壤环境因子指标,讨论土壤汞形态分布特征对甲基化的影响.研究表明,汞矿区稻田土壤中总汞和甲基汞均表现出随土壤...     

扬子板块西缘攀西地区白草矿区黄铁矿标型元素特征及其指示意义

黄铁矿是重要的金属硫化物矿物,在多种矿床中均有产出,其标型特征对矿床成因、矿体空间分布等具有重要的指示意义.以扬子板块西缘攀西地区白草矿区黄铁矿为研究对象,利用矿相学、电子探针等分析方法来对比研究浸染状、致密块状、斑杂状、网脉状矿石中黄铁矿的标型元素特征.结果表明:白草矿区黄铁矿Fe、S平均含量(质量分数,下同)分别为...     

山东省菏泽凸起地热田岩溶地热水水化学水平演化特征

在前人研究成果的基础上,选择A-A'和B-B'两条路径,采用Piper三线图解、Schoeller图解、Na-K-Mg平衡图解、饱和指数计算评价等方法,研究山东菏泽凸起地热田地热水沿路径上的循环演化特征.结果表明:沿A-A'、B-B'剖面岩溶冷水→岩溶热水,水化学类型由SO4?HCO3-Ca?Mg?Na或SO4?HCO...     

Correlation Between Total Lightning Activity and Precipitation Particle Characteristics Observed from 34 Thunderstorms

A total of 34 thunderstorms around Shanghai and Wuhan of China are analyzed in order to determine the relationship between total lightning activity and precipitation particle characteristics.Precipitation particle concentration data are obtained from the 2A12 product of TRMM/TMI(Tropical Rainfall Measuring Mission/TRMM Microwave Image) and lightning activity data are from the TRMM/LIS(Lightning Imaging Sensor) and SAFIR3000(Surveillance et Alerte Founder par Interferometric Radioelectirque).On a spatial ...     

ANALYSIS OF THE CHARACTERISTICS OF WEST-PACIFIC TYPHOONS AFFECTING THE SEA AREA AROUND THE ISLAND OF TAIWAN

1 INTRODUCTION Inflicting hundreds of millions yuan (RMB) worth of economic losses annually, strong winds and torrential rains caused by tropical cyclones are two of the major meteorological disasters exposed in the southeastern coast of China. Much effort has been devoted to the research on the patterns of TC genesis, evolution and variation.     

山西宁武地区全新世以来气候与环境变化

根据野外实测剖面、室内测试分析,笔者通过对山西宁武地区全新世以来的湖相沉积地层的孢粉、易溶盐、pH值、磁化率、碳酸盐和粒度分析,探讨了该区全新世以来的气候与环境变化过程。结果表明该区全新世以来的气候变化可划分为4个阶段112400~10000aB.P.期间,显示气候干冷,但有逐渐变暖的趋势;210000~8000aB.P.期间,气候较温湿;38000~3000aB.P.期间,气候温暖;4距今3000aB.P.~现代,气候出现3次波动,整个气候向干凉方向发展。对山西宁武地区湖相沉积地层的进一步深入调查与研究,将会确定华北地区的全新世以来环境与气候变化的基本规律。     

Research on runoff variations based on wavelet analysis and wavelet neural network model: A case study of the Heihe River drainage basin (1944?2005)

The Heihe River drainage basin is one of the endangered ecological regions of China. The shortage of water resources is the bottleneck, which constrains the sustainable development of the region. Many scholars in China have done researches concerning this problem. Based on previous researches, this paper analyzed characteristics, tendencies, and causes of annual runoff variations in the Yingluo Gorge (1944–2005) and the Zhengyi Gorge (1954–2005), which are the boundaries of the upper reaches, the middle reaches, and the lower reaches of the Heihe River drainage basin, by wavelet analysis, wavelet neural network model, and GIS spatial analysis. The results show that: (1) annual runoff variations of the Yingluo Gorge have principal periods of 7 years and 25 years, and its increasing rate is 1.04 m3/s·10y; (2) annual runoff variations of the Zhengyi Gorge have principal periods of 6 years and 27 years, and its decreasing rate is 2.25 m3/s·10y; (3) prediction results show that: during 2006–2015, annual runoff variations of the Yingluo and Zhengyi gorges have ascending tendencies, and the increasing rates are respectively 2.04 m3/s·10y and 1.61 m3/s·10y; (4) the increase of annual runoff in the Yingluo Gorge has causal relationship with increased temperature and precipitation in the upper reaches, and the decrease of annual runoff in the Zhengyi Gorge in the past decades was mainly caused by the increased human consumption of water resources in the middle researches. The study results will provide scientific basis for making rational use and allocation schemes of water resources in the Heihe River drainage basin.     

青藏高原北部成矿带划分

青藏高原北部地质构造复杂,成矿条件优越,金属矿产资源成群成带分布特征明显,研究程度相对较低。通过对1999年以来,在青藏高原北部空白区相继完成的1∶25万区域地质调查、1∶5万区域地质调查和一批1∶50万、1∶20万区域化探成果资料的综合研究,根据青藏高原北部金属矿产资源的时、空分布特征,结合区域物、化探资料和区域成矿地质背景,将青藏高原北部地区初步划分为3个级成矿带(域),5个级成矿带,9个级成矿带,对以后青藏高原北部地区地质矿产勘查评价工作具有十分重要的意义。     

科尔沁沙地30种植物叶凋落物CO2释放量及释放速率的研究

 采用可以有效控制环境因子的室内土壤培养试验，初步研究了科尔沁沙地30种植物叶凋落物的CO₂释放量及释放速率。结果表明：①在28 d培养期内，不同植物叶凋落物释放的CO₂量差异很大，其中，多年生植物叶凋落物CO₂释放量平均值大于一年生植物，但二者之间的差异不显著；禾本科植物叶凋落物CO₂释放量平均值明显小于其他植物，二者之间呈显著差异。②在28 d培养期内，不同植物叶凋落物每四天CO₂释放速率差异很大。一年生与多年生植物叶凋落物28 d内每四天释放CO₂的速率无显著差异；禾本科与其他植物叶凋落物每四天释放CO₂的速率在培养的前16 d差异呈显著，而后差异消失。③植物叶凋落物的全碳含量，氮含量，C／N，灰分/N及灰分含量不同造成CO₂释放量及释放速率的差异。叶凋落物28 d释放CO₂的量与叶凋落物初始碳含量及灰分含量均无相关关系，与叶凋落物初始氮含量呈显著正相关，与叶凋落物C／N及灰分／N呈显著负相关。叶凋落物培养期内每四天释放CO₂的速率与叶凋落物初始碳含量无相关关系；叶凋落物0\_20天释放CO₂的速率与叶凋落物初始氮含量呈显著正相关，与叶凋落物C／N呈显著负相关；叶凋落物9\_28天CO₂释放速率与灰分／N呈显著负相关；培养后期（17\_28天）的CO₂释放速率与灰分含量呈显著负相关。