New Approaches and Markers for Identifying Secondary Biogenic Coalbed Gas     

TAO Mingxin  LI Jing  LI Xiaobin  MA Yuzhen  LI Zhongping  WANG Zuodong  GAO Zhongliang  ZHANG Xiaojun  WANG Yanlong 《《地质学报》英文版》2012,86(1):199-208

According to the adsorption-desorption characteristics of coalbed gas and analysis of various experimental data, this paper proposes that the generation of secondary biogenic gas (SBG) and its mixing of with the residual thermogenic gas at an early stage inevitably lead to secondary changes of the thermogenic gas and various geochemical additive effects. Experimental results also show that the fractionation of the carbon isotope of methane of coal core desorption gas changes very little; the δ13C1 value of the mixed gas of biogenic and thermogenic gases is between the δ13C1 values of the two “original” gases, and the value is determined by the carbon isotopic compositions and mixing proportions of the two “original” methanes. Therefore this paper proposes that the study on the secondary changes of the thermogenic gas and various additive effects is a new effective way to study and identify SBG. Herein, a systematic example of research on the coalbed gas (Huainan coalbed gas) is further conducted, revealing a series of secondary changes and additive effects, the main characteristics and markers of which are: (1) the contents of CO2 and heavy-hydrocarbons decrease significantly; (2) the content of CH4 increases and the gas becomes drier; (3) the δ13C and δD values of methane decrease significantly and tend to have biogenetic characteristics; and (4) the values of δ13C2 and δ13CCO2 grow higher. These isotopic values also change with the degradation degrees by microbes and mixing proportions of the two kinds of gases in different locations. There exists a negative correlation between the δ13C1 vs δ13CCO2 values. The △δ13CC2–C1 values obviously become higher. The distributions of the △δ13CCO2–C1 values are within certain limits and show regularity. There exist a positive correlation between the N2 versus Ar contents, and a negative correlation between the N2 versus CH4 contents, indicating the down forward infiltration of the surface water containing air. These are important markers of the generation and existence of SBG.  相似文献   

Field hyperspectral data analysis for discriminating spectral behavior of tea plantations under various management practices     

《International Journal of Applied Earth Observation and Geoinformation》2013

The quality and yield of tea depends upon management of tea plantations, which takes into account the factors like type, age of plantation, growth stage, pruning status, light conditions, and disease incidence. Recognizing the importance of hyperspectral data in detecting minute spectral variations in vegetation, the present study was conducted to explore applicability of such data in evaluating these factors. Also stepwise discriminant analysis and principal component analysis were conducted to identify the appropriate bands for accessing the above mentioned factors. The Green region followed by NIR region was found as most appropriate best band for discriminating different types of tea plants, and the tea in sunlit and shade condition. For discriminating age of plantation, growth stage of tea, and diseased and healthy bush, Blue region was most appropriate. The Red and NIR regions were best bands to discriminate pruned and unpruned tea. The study concluded that field hyperspectral data can be efficiently used to know the plantation that need special care and may be an indicator of tea productivity. The spectral signature of these characteristics of tea plantations may also be used to classify the hyperspectral satellite data to derive these parameters at regional scale.  相似文献   

The potential of spectral mixture analysis to improve the estimation accuracy of tropical forest biomass     

Tyas Mutiara Basuki  Andrew K. Skidmore  Patrick E. van Laake  Iris van Duren  Yousif A. Hussin 《国际地球制图》2013,28(4):329-345

A main limitation of pixel-based vegetation indices or reflectance values for estimating above-ground biomass is that they do not consider the mixed spectral components on the earth's surface covered by a pixel. In this research, we decomposed mixed reflectance in each pixel before developing models to achieve higher accuracy in above-ground biomass estimation. Spectral mixture analysis was applied to decompose the mixed spectral components of Landsat-7 ETM+ imagery into fractional images. Afterwards, regression models were developed by integrating training data and fraction images. The results showed that the spectral mixture analysis improved the accuracy of biomass estimation of Dipterocarp forests. When applied to the independent validation data set, the model based on the vegetation fraction reduced 5–16% the root mean square error compared to the models using a single band 4 or 5, multiple bands 4, 5, 7 and all non-thermal bands of Landsat ETM+.  相似文献   

Technogenic hydrogeochemical anomalies of tungsten deposits in Kykylbey ore region     

LeonidV.Zamana LarisaP.Chechel 《东北亚地学研究》2004,7(1):52-57

Peculiarities of the tungsten deposits drainage flow chemical composition formation, the development of which was ceased almost 40 years ago, have been considered. Migration peculiarities of ore components have been covered, and forms of their migration have been calculated. Inertial characteristics of the surface flow contamination are shown.  相似文献   

Effect of watershed subdivision on simulation of water balance components     

M. P. Tripathi  N. S. Raghuwanshi  G. P. Rao 《水文研究》2006,20(5):1137-1156

The present effect of watershed subdivision on simulated water balance components using the thoroughly tested Soil and Water Assessment Tool (SWAT) model has been evaluated for the Nagwan watershed in eastern India. Observed meteorological and hydrological data (daily rainfall, temperature, relative humidity and runoff) for the years 1995 to 1998 were collected and used. The watershed and sub‐watershed boundaries, slope and soil texture maps were generated using a geographical information system. A supervised classification method was used for land‐use/cover classification from satellite imagery of 1996. In order to study the effect of watershed subdivision, the watershed was spatially defined into three decomposition schemes, namely a single watershed, and 12 and 22 sub‐watersheds. The simulation using the SWAT model was done for a period of 4 years (1995 to 1998). Results of the study showed a perfect water balance for the Nagwan watershed under all of the decomposition schemes. Results also revealed that the number and size of sub‐watersheds do not appreciably affect surface runoff. Except for runoff, there was a marked variation in the individual components of the water balance under the three decomposition schemes. Though the runoff component of the water balance showed negligible variation among the three cases, variations were noticed in the other components: evapotranspiration (5 to 48%), percolation (2 to 26%) and soil water content (0·30 to 22%). Thus, based on this study, it is concluded that watershed subdivision has a significant effect on the water balance components. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

X射线荧光光谱法同时测定石灰石中主次痕量组分   总被引：4，自引：2，他引：2  

刘江斌  曹成东  赵峰  陈月源  谈建安  党亮  余宇 《岩矿测试》2008,27(2):149-150

采用熔融玻璃片和粉末压片法制样,选用标准样品,以经验α系数和散射线内标法校正元素谱线重叠干扰和基体效应,用ZSX PrimusⅡX射线荧光光谱仪对石灰石样品中CaO、Na2O、MgO、Al2O3、SiO2、K2O、TFe2O3、P2O5、TiO2、MnO和S等主次痕量组分进行测定,分析结果与标准值和化学值相符,12次测定的相对标准偏差小于10%。  相似文献   

X射线荧光光谱法同时测定铁矿石中主次量组分   总被引：4，自引：1，他引：3  

普旭力  吴亚全  王鸿辉  董清木  蔡鹭欣  潘忠厚 《岩矿测试》2008,27(5):353-356

采用X射线荧光光谱法测定铁矿粉中的TFe(全铁量)、SiO2、Al2O3、P、S、CaO、MgO、MnO和TiO2等9个组分。以Li2B4O7和LiBO2(质量比67∶33)的混合熔剂熔融制样,将测量全铁量的内标Co2O3制备成均匀的Co玻璃粉,大大提高全铁量的测量准确度和精密度;加入LiNO3为氧化剂,解决了硫元素在制样过程中容易挥发的问题。与化学法相比,该法对铁矿石中主量和次量元素的测量结果满意,方法快速、简便、准确、精密度好。  相似文献   

MapX与PowerBuilder集成技术在交通事故信息系统中的应用     

杨斌  何政伟  刘小勇  蒋晓君 《测绘科学》2008,33(3):178-181

针对复杂的道路交通事故信息,利用MapInfo公司的组件式控件MapX5.0,在PowerBuilder8.0开发环境下,使用SQLServer2005作为系统后台属性数据库,研究路段采用高分辨率的遥感数据为地图背景,设计开发了城市道路交通事故信息系统。该系统具有城市道路交通信息与道路交通事故信息的查询、分析和统计功能,使道路交通事故信息查询更迅速、直观。实际开发表明,PowerBuilder与地图控件MapX结合开发GIS应用系统,不仅开发过程简单、开发速度快,而且能充分发挥PowerBuilder快速高效管理、访问MapX空间数据库的优势。  相似文献   

扩展的Helmert型方差分量估计的通用公式     

王杰龙  陈义 《大地测量与地球动力学》2020,40(12):1313-1316

摘 要： 基于概括函数模型,从Helmert型方差分量估计原理导出处理同类观测值包含多个方差分量的估计公式,即扩展的Helmert型方差分量通用公式,并给出其简化通用公式及特殊情况。  相似文献   

陇中黄土高原陆面辐射分量年际变化及其对气候波动的响应   总被引：1，自引：1，他引：0  

夏露  张强  岳平  刘君圣 《气象科学》2017,37(3):339-347

本文利用兰州大学半干旱气候与环境观测站(SACOL站)2006—2012年陆面过程观测资料以及榆中站气象资料,分析了陆面各辐射收支分量对于气候波动的响应,并且研究了地表反照率年际波动变化,讨论了各陆面过程参数对于黄土高原气候背景年际波动的反馈。并且根据黄土高原降水类型将全年分为冬夏半年讨论,以得到更为显著的年际变化特征和相关关系。结果显示,2006—2012年气温降水的趋势与近年来黄土高原暖干化总趋势相吻合。地表浅层土壤湿度和温度都与气温、降水呈现很好的响应。气候因素的综合影响是地表反照率变化波动的原因。通过冬夏半年资料区分探究得到,长波辐射分量与气候要素的相关较短波辐射分量与气候要素的相关性更强。但总体而言,陆面过程对于该地区气候背景波动的响应机制是较为复杂的。  相似文献