基于沟里金矿集区线环构造与色调异常的找矿预测

青海沟里金矿集区内构造形迹复杂,岩浆作用强烈,变形变质广泛,具备形成大型—特大型金矿床的地质条件。通过对整个矿集区及外围区域的QuickBird、ASTER以及ETM等不同分辨率的影像进行了人机交互式线环构造解译和色调异常分析,分析区域内典型金矿床的影像特征,并找出有利的成矿线环构造。将色调异常区域与化探结果进行对比分析,得出其吻合度较高。最后,结合地质资料、遥感信息和化探信息,对靶区进行分级,圈定出有利的找矿区域。     

应用时变子波的盲反射系数反演

由于地震数据的非稳态和全盲特性,实际地震子波通常是未知的且其波形会随传播时间发生变化,故常规基于稳态子波假设的反射系数反演精度将难以保证。为此,利用广义S变换将非稳态地震数据变换到时频域,基于自相关理论逐点提取子波并重新构建时变子波矩阵,而不再是从一道地震记录中仅提取一个时不变子波,将其应用于反演模型以实现非稳态地震资料反射系数的盲反演。模型测试和实际资料处理结果表明,相较于传统时不变子波反演方法,所提方法考虑了地震信号的时变特征,且是数据驱动的,更适用于实际地震资料,能得到更精确的时变子波结果和较高分辨率的反射系数剖面。     

综合物探在罗布泊地下水勘查中的应用

地面核磁共振测深技术是目前唯一直接找水的物探新技术,而高分辨率浅层地震技术可为地下水勘查提供构造、地层划分、地层富水性和岩性对比等方面的资料。因而,上述两种方法在地下水勘查工作中起着重要作用。本文在简要介绍核磁共振技术和高分辨率浅层地震技术的基本原理和技术特点的基础上,以新疆罗布泊葫芦坝地下水勘查为例,对该两种方法的勘查成果进行了分析。地震勘探工作查明了工作区的地层情况和断裂带分布,同时为核磁共振测深圈定了工作靶区;核磁共振测深结果显示了测深点位置地层含水情况随深度的变化。经钻孔验证,勘测成果与实际地质情况基本吻合。     

Investigation of Laser-Assisted Microcrystalline SiGe Films Deposited at Low Temperature

SiGe films deposited by conventional plasma-enhanced chemical vapor deposition (PECVD) were compared with microcrystalline SiGe (μc-SiGe) films deposited at a low temperature using a laser-assisted plasma-enhanced chemical vapor deposition (LAPECVD). In the LAPECVD system, a CO₂ laser was used to assist the pyrolytic decomposition of SiH₄ and GeH₄ reactant gases. The μc-SiGe structure was identified using electron diffraction patterns from high-resolution transmission electron microscopy images. Microcrystalline SiGe films were analyzed using various measurements.     

利用极化方位角特征的高分辨极化SAR目标增强研究

针对高分辨极化SAR目标增强问题,提出一种利用极化方位角特征的增强方法.首先,利用圆极化法提取极化SAR图像像素点的极化方位角特征;其次,通过"方位角归零化"获得像素点在零度极化方位角下的散射矩阵值.对比归零化前、后目标及杂波区域内部像素点极化特性聚集程度的差异,阐述了利用极化方位角特征进行目标增强的原理;再次,统计获得目标及杂波区域的平均极化特性,采用非线性最优化方法实现了目标增强;最后,基于ADTS全极化SAR实测数据验证了本文方法具有优良的目标增强性能.     

超高效液相色谱-四极杆/静电场轨道阱高分辨质谱快速筛查测定几种食品中的8种碱性色素

本文研究了超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法快速测定面包、橙汁、卤豆干等食品中8种碱性色素的方法。样品用乙酸乙酯提取后,以C18(3.0 mm×100 mm,1.8μm)色谱柱分离,乙腈和10 mmol/L乙酸铵水溶液为流动相梯度洗脱,在正负离子切换模式下检测8种碱性色素。在全扫描模式下提取8种碱性色素的保留时间和一级母离子精确质量数以及同位素丰度比,实现对食品中8种碱性色素的快速测定;以自动触发采集的二级碎片离子精确质量数进行确证。8种碱性线性关系较好,相关系数(R2)大于0.99,回收率在82.2%～105.3%之间,相对标准偏差在6.0%～9.9%之间。该方法简单、快速、可靠,可定性筛查和定量分析食品中8种碱性色素。     

基于高分辨质谱的化妆品中防腐剂类致敏成分高通量检测方法的建立及应用

目的基于静电场轨道阱高分辨质谱,建立化妆品中异噻唑啉酮类、甲醛释放剂、对羟基苯甲酸酯类、酸类4大类防腐剂类致敏成分的高通量检测方法,幵应用于实际样品中致敏成分的筛查与定量分析。方法利用致敏成分标准品通过高分辨质谱正负离子切换FullMS/ddMS2扫描方式分析,获得多种致敏成分的保留时间、一级母离子和二级碎片离子精确质量数,构建致敏成分筛查谱库。样品经50%甲醇水溶液超声提取后,经ZORBAX Eclipse Plus C18 (3.0 mm×100 mm, 1.8μm)色谱柱分离,采用高分辨质谱分析,利用TraceFinder软件对化妆品中致敏成分与谱库相关信息匹配,实现目标物的高通量筛查确证,筛查确认后利用一级母离子外标法迚行致敏成分的定量分析。结果筛查方法既有一级母离子精确质量数和保留时间,又有二级碎片离子信息,其筛查确证结果可靠;目标化合物在相应的质量浓度范围内线性关系良好(r~20.99),检出限为0.2～20μg/g,回收率为85.6%～109.7%,相对标准偏差为3.2%～12.8%,能够满足检测需求。结论该方法简单、准确、快速,可用于化妆品中多种致敏成分的高通量快速筛查和定量分析。     

On the application of remote sensing towards the estimation of cultivated land lost to urbanization

In this research work, a 40-km² SPOT-5 High-Resolution Imagery (HRI) of the Warsak locality in district Peshawar, Pakistan, was utilized to approximate the quantity of cultivated land lost to urbanization, due to the construction of new homes and buildings. The imagery from a period of 2005 to 2015 for wheat crop was taken, specifically during the months of March and June when the crop is rich green and golden ripe respectively. eCognition ® program’s Object-Oriented Classification Method (OOCM) was employed for recognition of land versus buildings. Nearest Neighbour (NN), Support Vector Machine (SVM), Decision Trees (DT) and Random Forests (RF) were utilized for the classification process. The results demonstrated that the urbanized area had increased by approximately 28 per cent in the area considered. Moreover, the efficacy of the proposed method is depicted by an accuracy of 97.9 per cent and a Kappa Statistics of 0.975 for the SVM classifier.     

High-Resolution Chromosome Ideogram Representation of Currently Recognized Genes for Autism Spectrum Disorders

Recently, autism-related research has focused on the identification of various genes and disturbed pathways causing the genetically heterogeneous group of autism spectrum disorders (ASD). The list of autism-related genes has significantly increased due to better awareness with advances in genetic technology and expanding searchable genomic databases. We compiled a master list of known and clinically relevant autism spectrum disorder genes identified with supporting evidence from peer-reviewed medical literature sources by searching key words related to autism and genetics and from authoritative autism-related public access websites, such as the Simons Foundation Autism Research Institute autism genomic database dedicated to gene discovery and characterization. Our list consists of 792 genes arranged in alphabetical order in tabular form with gene symbols placed on high-resolution human chromosome ideograms, thereby enabling clinical and laboratory geneticists and genetic counsellors to access convenient visual images of the location and distribution of ASD genes. Meaningful correlations of the observed phenotype in patients with suspected/confirmed ASD gene(s) at the chromosome region or breakpoint band site can be made to inform diagnosis and gene-based personalized care and provide genetic counselling for families.     

ADVANCES IN HIGH-RESOLUTION MALDI MASS SPECTROMETRY FOR NEUROBIOLOGY

Research in the field of neurobiology and neurochemistry has seen a rapid expansion in the last several years due to advances in technologies and instrumentation, facilitating the detection of biomolecules critical to the complex signaling of neurons. Part of this growth has been due to the development and implementation of high-resolution Fourier transform (FT) mass spectrometry (MS), as is offered by FT ion cyclotron resonance (FTICR) and Orbitrap mass analyzers, which improves the accuracy of measurements and helps resolve the complex biological mixtures often analyzed in the nervous system. The coupling of matrix-assisted laser desorption/ionization (MALDI) with high-resolution MS has drastically expanded the information that can be obtained with these complex samples. This review discusses notable technical developments in MALDI-FTICR and MALDI-Orbitrap platforms and their applications toward molecules in the nervous system, including sequence elucidation and profiling with de novo sequencing, analysis of post-translational modifications, in situ analysis, key advances in sample preparation and handling, quantitation, and imaging. Notable novel applications are also discussed to highlight key developments critical to advancing our understanding of neurobiology and providing insight into the exciting future of this field. © 2020 John Wiley & Sons Ltd. Mass Spec Rev