时域反射仪（TDR）测定土壤含水量标定曲线评价与方案推荐

时域反射仪（Time Domain Reflectometry）可用于室内和田间快速、 准确、 自动测定土壤含水量, 是目前应用最广泛的土壤含水量测定方法之一。适宜的土壤含水量标定曲线（即土壤表观介电常数和土壤含水量之间的关系）是TDR准确测定土壤含水量的关键。目前文献中存在大量的土壤含水量标定曲线, 但尚未有研究对这些标定曲线进行系统的验证和分析评价。因此, 它们的准确性和适用范围尚不明晰, 严重影响到与土壤含水量测定相关的研究。通过查阅大量国内外文献, 收集整理了一系列土壤含水量标定曲线的经验公式（19个）和半经验半物理模型（5个）, 并利用大量的文献实测数据对其进行综合评价。同时运用均方根差（RMSE）, 平均误差（AD）, 纳什效率系数（NSE）等三个指标对比分析和评价这些标定曲线的准确性和可靠性。研究结果表明： 经验公式中Topp、 Roth（1992）2、 Jacobosen、 Yoshikawa2、 Alharathi模型和半经验模型中Malicki1公式及其修订模型综合性能较好。研究成果可为利用TDR准确测定土壤含水量及土壤含水量标定曲线的选择提供参考和指导。     

北半球不同时域臭氧层遥相关结构的演变特征

分析了北半球不同时域Ｏ３层遥相关型的空间结构及其演变特征,探讨了太阳活动和极涡振荡对Ｏ３层遥相关型形成和演变的作用．结果发现：１．Ｏ３层对太阳活动响应具有显著的区域性,在不同季节里只存在一种Ｏ３层遥相关型与其相联系,随着季节的转换大气环流与太阳活动效应叠加将使Ｏ３层的响应区域及遥相关型的空间结构发生转移现象．２．极涡增强将导致Ｏ３层出现负异常,且在遥相关区域中Ｏ３含量的振幅变化最为显著．由于极涡的不对称性,各分区极涡强度对Ｏ３层遥相关型的影响存在着显著差异,表明极涡形变对Ｏ３层遥相关型的形成和演变具有重要作用．     

冰盖下水流速度分布的二维数值模拟分析

基于标准的κ-ε模型,利用有限体积法,对冰盖下水流速度分布进行了二维数值模拟和分析.结果表明:当冰盖和河床糙率比值变化时,水流速度剖面发生变化;冰盖下的最大流速值比速度对称分布时要大,且偏于光滑的一边;在相对光滑壁处近壁流速值大于相应对称分布时的流速值,该结果与实验室实测速度剖面情况吻合.数值试验表明,最大流速点位置的偏移量仅在有限的范围内,冰盖区、床面区及冰盖下水流平均速度相差较小,表明了工程应用中假定各区流速相等是可行的.     

Ore-forming Fluid Characteristics of the Saishitang Cu-polymetallic Deposit in Qinghai Province, China

Saishitang Cu-polymetallic deposit is located in the southeast section of Late Paleozoic arcfold in the southeastern margin of Qaidam platform. Accoring to the geological process of the deposit,four mineralization episodes were identified: melt/fluid coexisting period(O),skarn period(A),first sulfide period(B) and second sulfide period(C),and 10 stages were finally subdivided. Three types of inclusions were classified in seven stages,namely crystal bearing inclusions(type I),aqueous inclusions(type II) and pure liquid inclusions(type III). Type I and II inclusions were observed in stage O1,having homogenization temperature from 252 to 431°C,and salinities ranging from 24.3% to 48.0%. Type I inclusion was present in stage A1,having homogenization temperature from 506 to 548°C,and salinities ranging from 39.4% to 44.6%. In stage B1,type II and III inclusions were observed,with homogenization temperature concentrating between 300–400°C,and salinities from 0.4% to 4.3%. Type II inclusions were present in stage B2,with homogenization temperature varying from 403 to 550°C. In stage C1,type I and II inclusion commonly coexisted,and constituted a boiling inclusion group,having homogenization temperatures at 187–463°C,and salinities in a range of 29.4%–46.8% and 2.2%–11.0%. Type II and III inclusions were developed in stage C2,having homogenization temperature at 124–350°C,and salinities ranging between 1.6% and 15.4%. In stage C3,type II and III inclusions were presented,with a homogenization temperature range of 164–360°C,and salinities varying from 4.0% to 11.0%. The results of micro-thermal analysis show that fluids are characterized by high temperature and high salinity in stage O1 and A1,and experienced slight decrease in temperature and dramatic decrease in salinity in stage B1 and B2. In stage C1,the salinity of fluid increased greatly and a further decrease of temperature and salinity occurred in stage C2 and C3. Fluids boiled in stage C1. With calculated pressure of 22 MPa from the trapping temperature of 284–289°C,a mineralization depth of 2.2 km was inferred. Results of Laser Raman Spectroscopy show high density of H2 O,CH4 and CO2 were found as gas composition. H-O isotope study indicates the oreforming fluids were the mixture of magmatic water and meteoric water. Physicochemical parameters of fluids show oxygen and sulfur fugacity experienced a decrease,and redox state is weakly reducing. Along with fluid evolution,oxidation has increased slightly. Comprehensive analysis shows that melt exsolution occurred during the formation of quartz diorite and that metal elements existed and migrated in the form of chlorine complex. Immiscible fluid separation and boiling widely occurred after addition of new fluids,bringing about dissociation of chlorine-complex,resulting in a great deal of copper precipitation. In conclusion,Saishitang deposit,controlled by regional tectonics,is formed by metasomatism between highly fractionated mineralization rock body and wall rock,and belongs to banded skarn Cu-polymetallic deposit.     

蒙脱石提纯研究进展

总结了蒙脱石的各种提纯方法及其试验原理和提纯分离效果。主要涉及重力选矿、水力分析、絮凝法、离心分离和化学提纯。对电泳法提纯作了简介。研究证实，与蒙脱石粒度相近的方石英和石英微粒等杂质很难去除。氢氧化钠溶蚀法会对蒙脱石、石英和方石英同时产生溶蚀，引入新的物相杂质。     

西天山伊宁地块主褶皱幕鄯善运动的确立及地质意义

地层不整合接触是研究地质发展历史及鉴定地壳运动特征和运动时期的重要依据,主褶皱幕是一造山带多幕构造运动中起决定性作用和最为重要的一次构造运动。天山的构造运动幕次多且因地而异,前人认识多有分歧,也没有确立主褶皱幕。伊宁地块伊什基里克山一带上、下石炭统之间为角度不整合接触关系,在岩石组合、沉积环境、古生物地理区系、构造样式、区域大地构造背景等方面差异最为显著,凸显了鄯善运动对区内构造格架和盆山演化起到决定性的作用,因而是主褶皱幕。鄯善运动记录了西天山沟—弧—盆格局消亡,天山残余小洋盆终结,塔里木板块和准噶尔板块最终拼合在一起,形成了统一大陆的重要演化信息。     

全极化SAR图像中溢油极化特征研究

相比于单极化SAR图像,全极化SAR图像不仅能体现海面目标的几何特征、后向散射特征,还能体现目标的极化特征。因此,在溢油检测方面,极化SAR更具优势。特征提取作为溢油检测的关键步骤,直接影响到溢油检测的精度。在本文中,我们分析了全极化SAR图像中海面溢油的极化特征,如极化散射熵、平均散射角等。并提出了新的极化特征P,该特征参数能够反映海面目标电磁散射过程中布拉格散射机制和镜面散射机制的比例。为了研究极化特征溢油检测的能力,本文基于SIR-C/X-SAR和Radarsat-2全极化SAR图像开展了相关实验,并对比分析了溢油的多种极化特征。实验结果显示,在中低风速情况下,C波段溢油探测效果优于L波段;本文提出的极化特征P对海面散射机制敏感;基准高度和特征参数P在C波段比其他极化特征更适于溢油检测。     

基于图斑空间关系的遥感专家分类方法研究

以光谱均质单元——图斑作为空间对象粒度的基本单元，采用图斑邻域搜索算法，获取不同类别图斑间的空间关系。在ERDAS专家分类系统中，根据图斑相邻关系以及DEM信息对初始分类结果进行了修正，提高了湿地、草地和农业用地的分类精度。     

面向桉树和车桑子精准识别的高光谱特征变换方法比较分析

相对于遥感影像,高光谱遥感影像具有光谱信息,为精准识别植被提供了新的技术支持.对高分五号(GF-5)高光谱数据进行光谱变换,结合植被指数,分析各种光谱变换方法对植被的识别能力.首先提取研究区主要的两种植被端元光谱,对实验区进行分类,依据植被分布位置,确定这两种植被分别为桉树和车桑子;然后对植被的反射率光谱进行一阶、二阶...     

基于粒子群算法的高光谱影像端元提取技术

基于凸面几何学理论,由端元作为角点的单形体的体积应该是最大的.著名的N-FINDR和SGA算法正是基于以上理论,通过在数据云中寻找体积最大的单形体来实现端元的自动提取.本文利用粒子群优化(PS0)技术,基于凸面几何学理论,设计了一个新的端元提取算法.利用模拟和真实高光谱影像对其进行了实验,并将其结果与N-FINDR和S...