负离子热表面电离质谱法测量铼的化学分离方法研究

Re-Os同位素定年中,丙酮萃取法分离Re比传统的阴离子交换法流程简单快速.用本实验室原有丙酮萃取流程纯化的Re溶液可用电感耦合等离子体质谱(ICP-MS)测定,但由于盐量较高(＞1 mg/mL)不能直接用于负离子热表面电离质谱(N-TIMS)测定.本文对Re-Os同位素定年方法中原有丙酮萃取分离Re的流程进行改进,将丙酮萃取和碱洗时的氢氧化钠浓度由5 mol/L提高到10 mol/L,有效降低了萃取后的Re溶液中的盐量,由此分离纯化的Re溶液经硝酸和过氧化氢处理,可直接点带用于N-TIMS测定.与阴离子交换分离Re方法相比,改进的丙酮萃取方法操作简单,缩减实验时间,同时有效降低全流程空白至3 ～7 pg,并且1 ng的Re测量信号可达到100 mV以上.经国家一级标准物质(GBW 04436)和实验室铜镍硫化物监控样品(JCBY)验证,利用改进的方法纯化,Re的测定值分别为(17.17±0.50)μg/g和(38.34±0.44) ng/g,与推荐值(17.39±0.32) μg/g和(38.61 ±0.86) ng/g在不确定度范围内完全吻合.目前改进的丙酮萃取方法已经应用于实际样品分析,并取得了长期稳定的良好效果.     

基于统计信息的低反差道路半自动提取方法

从实际应用的角度,采用基于统计信息的低反差半自动道路提取方法,提取了高分辨率遥感影像中道路特征分析时经常被忽略的、目标与背景反差较小的道路段;并在高层的知识处理后,将结果返回中层及底层进行了进一步验证。     

一种利用数学形态学提取地形轮廓的方法

提出了一种利用数学形态学提取图像中地形轮廓的方法。首先分析运用传统单一边缘检测算子提取地形轮廓的不足,然后着重介绍了数学形态学提取地形轮廓的原理,最后通过实验分析,采用开运算与闭运算相结合的方法提取地形轮廓,不仅有效地去除了各种噪声,而且极大地保持了地形轮廓的细节特征。     

基于分区和纹理特征的伊犁河谷遥感影像土地利用分类

利用新疆伊犁河谷的伊宁县SPOT5遥感影像,在ERDAS IMAGINE 9.2软件平台下,通过二次变异分析算法和三次非对称分析算法提取纹理信息。基于图像的光谱特征和纹理特征进行监督分类,然后根据地物的空间分布进行"分区分类处理"。结果表明,伊宁县的总体分类精度提高了19.34%,Kappa系数提高了0.247。利用霍城县遥感图像进行分类方法验证,同样取得了较好的效果,表明该方法可在伊犁河谷土地利用分类中进行推广应用。     

浅析基于Lecai DNA003水准仪在等级水准测量中的应用

介绍Lecai DNA003型电子水准仪在西煤东运煤炭基地三等水准测量项目中的实际应用情况,结合实际作业经验对仪器的不足之处讨论了解决办法,以提高工作效益。     

Steerable filtering in interactive tracing of archaeological linear features using digital true colour aerial images

In this study, a semi-automatic approach to support archaeological line tracing is proposed. The suggested procedure is based on colour and texture information derived from orthorectified RGB digital aerial data and consists of four steps: (1) line sketching; (2) steerable filtering; (3) objects selection; and (4) straight line fitting and vectorisation. Good results were observed by evaluating the algorithm according to trace visibility and integrity, global difficulty and level of feature extraction. Further reliability tests were performed to study poor data initialisation and different annual seasonal land use at the same site.     

An automatic extraction method for individual tree crowns based on self-adaptive mutual information and tile computing

Forest data acquisition, which is of crucial importance for modeling global biogeochemical cycles and climate, makes a contribution to building the ecological Digital Earth (DE). Due to the complex calculations and large volumes of data associated with high-resolution images of large areas, accurate and effective extraction of individual tree crowns remains challenging. In this study, two GeoEye-1 panchromatic images of Beihai and Ningbo in China with areas of 5 and 25 km², respectively, were used as experimental data to establish a novel method for the automatic extraction of individual tree crowns based on a self-adaptive mutual information (SMI) algorithm and tile computing technology (SMI-TCT). To evaluate the performance of the algorithm, four commonly used algorithms were also applied to extract the individual tree crowns. The overall accuracy of the proposed method for the two experimental areas was superior to that of the four other algorithms, with maximum extraction accuracies of 85.7% and 63.8%. Moreover, the results also indicated that the novel method was suitable for individual tree crowns extraction in sizeable areas because of the multithread parallel computing technology.     

Sample preparation methods for quantitative detection of DNA by molecular assays and marine biosensors

The need for quantitative molecular methods is growing in environmental, food, and medical fields but is hindered by low and variable DNA extraction and by co-extraction of PCR inhibitors. DNA extracts from Enterococcus faecium, seawater, and seawater spiked with E. faecium and Vibrio parahaemolyticus were tested by qPCR for target recovery and inhibition. Conventional and novel methods were tested, including Synchronous Coefficient of Drag Alteration (SCODA) and lysis and purification systems used on an automated genetic sensor (the Environmental Sample Processor, ESP). Variable qPCR target recovery and inhibition were measured, significantly affecting target quantification. An aggressive lysis method that utilized chemical, enzymatic, and mechanical disruption enhanced target recovery compared to commercial kit protocols. SCODA purification did not show marked improvement over commercial spin columns. Overall, data suggested a general need to improve sample preparation and to accurately assess and account for DNA recovery and inhibition in qPCR applications.     

基于主成分分析法对遥感蚀变异常提取——以内蒙古伊和诺尔地区1∶5万矿调为例

主成分分析法是遥感蚀变异常提取的有效方法之一.在开展伊合诺尔等两幅1∶5万矿调过程中采用该方法对遥感数据进行处理,并对其铁染、羟基蚀变异常提取,绘制1∶5万遥感蚀变异常图,圈定了7个成矿靶区.通过地质填图,与已知矿床(点)吻合,说明该方法在地质找矿过程中是行之有效的,同时也为下一步地质填图以及找矿提供依据,故此方法应值得进一步推广.     

New Extraction System for Lithium from Brine with High Magnesium Content

正Lithium is an important element with a wide variety of applications,especially in lithium ion batteries and in the exploration of nuclear energy.Salt lake brine is the most abundant lithium source available in world,comp-rising70%~80%of all known lithium deposits.Lithium can be abstracted from brines with low magnesium content and processed into kinds of lithium compound in Atacama and Hombre Muerto of South America(Nie et al.,2013).