Extraction,isolation and structural characterization of polysaccharides from a red alga <Emphasis Type="Italic">Gloiopeltis furcata</Emphasis>     

Guangli Yu  Yannan Hu  Bo Yang  Xia Zhao  Peipei Wang  Guoli Ji  Jiandong Wu  Huashi Guan 《中国海洋大学学报(英文版)》2010,9(2):193-197

Three kinds of polysaccharides:GFW,GFH and GFA,were sequentially extracted from a red alga Gloiopeltis furcatawith 25℃and 85℃water,and 60℃ 4%NaOHwater solution.Based on the defatted alga,the yields of the polysaccharide were57.9%,2.5%and 2.6%,respectively.Their monosaccharide compositions,average molecular weights and structural characters weredetermined by gas chromatography(GC),high performance liquid chromatography(HPLC),fourier transform infrared spectroscopy(FTIR)or13C-NMR spectroscopy.The results show...  相似文献   

黄土覆盖区钼矿综合地球物理找矿技术组合:以沙坡岭钼矿为例   总被引：3，自引：0，他引：3       下载免费PDF全文

崔敏利  张宝林  梁光河  蔡新平  高浩中 《地球物理学进展》2010,25(2):602-611

覆盖区寻找隐伏矿成为当前找矿工作的热点问题,为了能在地表地质信息少的黄土覆盖区,寻找隐伏的有经济价值的矿床,本文以沙坡岭钼矿为例,综合应用r能谱、高精度磁法、高密度电法三种地球物理方法进行找矿勘探,辅以偏提取化探法对地球物理异常进行约束,结合地质资料进行解译,预测了有利的成矿区域,通过钻探得到了有效验证,初步建立了黄土覆盖区钼矿的综合地球物理找矿模式,为下一步的综合勘探打下了基础.  相似文献   

分层抽取法在泥沙沉积过程中的应用研究     

何洪涛  朱伟  张春雷  王亮 《岩土力学》2011,32(8):2371-2378

悬浮泥沙到沉积土的形成过程非常复杂,涉及到泥沙的沉降和土的自重固结。物理模型试验需要实测含水率、密度、颗粒分布、超孔隙水应力和总应力,但目前尚无简单可行的方法。提出了一种改进的室内试验方法,通过与国内外现有试验方法相对比,改进后的方法不仅可以得到泥沙在沉积过程中的泥面下沉变化、含水率（密度）分布、超孔压消散剖面,而且还能得到沉积物在不同高度和时间的颗粒分布变化等性质。通过多个试验实测及一致性测试表明,实测数据合理、可信,一致性检验误差较小,验证了此方法的可行性。  相似文献   

基于累积法理论的弹性阻抗参数提取   总被引：1，自引：0，他引：1  

崔旭冉  霍国栋  郑笑雪 《CT理论与应用研究》2015,24(2):177-189

弹性阻抗中蕴含着丰富的地下介质信息。从弹性阻抗中准确地提取地下介质信息用于储层预测是十分有意义的,传统的提取方法主要基于最小二乘理论的线性方法。本文引入累积法理论,将其用于弹性阻抗参数的提取,用层状模型和部分Marmousi2模型对该方法进行测试。从背景噪声分别为正态分布和均匀分布的弹性阻抗体中提取纵、横波速度和密度,并将其与最小二乘法提取的纵、横波速度和密度做定量对比分析。结果表明两种方法所得结果精度相当,但累积法具有计算量小、简洁直观的优势,因此,将其用于弹性参数的提取是有效可行的。   相似文献   

基于Landsat-8与ZY3多源遥感影像的城镇居民地识别与再分类研究     

李振敏  王晓青  窦爱霞  杨海霞  黄树松  崔丽萍 《地震》2015,35(3):123-135

精细的居民地数据对地震灾害风险分析具有重要意义。 为得到具有较高时效性与精细度的居民地数据, 充分发挥其对人口、 建筑物空间展布的指示作用, 本文综合利用多源遥感影像的优势, 基于分层分类思想开展城镇居民地识别与再分类研究。 以甘肃天水秦州区的主城区为例, 采用具有较高时效性的Landsat-8 OLI影像, 建立决策树分类模型识别出居民地轮廓; 在居民地轮廓内部, 进一步采用资源三号卫星(ZY3)高分影像, 利用面向对象方法进行居民地内部的建筑群再分类, 最后得到了具有不同精细程度的居民地数据。 实验结果中Landsat-8土地覆盖分类总体精度为92%(其中居民地识别率达86%), 城镇居民地再分类的总体精度为81%, 说明了本文研究方案的可行性。  相似文献   

Concentrations and Bioavailability of Heavy Metals in Sediments of Riverine Wetlands Located in the Huaihe River Watershed,China          下载免费PDF全文

Hezhong Yuan  Wei Pan  Zhengjie Zhu  Qifang Geng  Pengshan Li  Dong Xie  Yuhong Liu 《洁净——土壤、空气、水》2015,43(6):830-837

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引入地形校正的分区蚀变信息提取方法研究——以内蒙古帮帮乃别力切尔地区为例     

温静  谷雨 《地质力学学报》2015,21(2):252-259

选取我国重要矿集区内蒙古帮帮乃别力切尔地区作为研究区, 提出一种改进后的遥感蚀变信息提取方法, 即先分区提取蚀变信息, 后引入地形校正的提取方法。首先按照地貌、地形、岩性对研究区进行分区, 对提取的蚀变信息进行地形校正, 再综合地质资料以及物化探资料, 对研究区进行矿化蚀变信息综合提取, 并进行成矿预测。该方法较传统方法更好地显示了矿物蚀变信息, 消除了地形、岩性对异常信息提取的影响, 为今后的找矿勘查提供了更为准确的依据。   相似文献   

基于四阶累积量的同相轴自动拾取方法   总被引：1，自引：1，他引：0  

刘财  冯智慧  谢金娥  冯晅  王典 《吉林大学学报(地球科学版)》2010,40(5):1188-1193

针对强随机噪声干扰情况下地震勘探资料中同相轴无法正确拾取的问题,提出了基于四阶累积量的同相轴自动拾取方法。该方法利用四阶累积量进行时间延迟估计,避免了相关高斯噪声的影响;同时在参考道的选择上,以一定的间隔设置多个参考道,减少了同相轴拾取过程中的累积误差。理论模型计算表明:该方法相对于互相关方法,对相关高斯噪声有更强的抑制能力,信噪比达到-5 dB。在实际资料应用中,拾取了与同相轴有关的参数：同相轴位置,该参数为地震资料的属性分析和精确定量解释提供了依据。  相似文献   

Trace Elements in Sediments and Mussels – Spatial Distribution,Chemical Partitioning,and Risk Assessment     

Mohammed A. Khairy  Marit Kolb  Christiane Schmidt  Dieter W. Zachmann  Alaa R. Mostafa  Anwar A. EL‐Fiky  Müfit Bahadir 《洁净——土壤、空气、水》2010,38(12):1184-1193

Sediment samples were collected from 30 different locations in Abu Qir Bay (Mediterranean Sea), East Alexandria, Egypt and analyzed for trace elements. The highest concentrations of most of the elements were observed in the nearshore stations in the vicinity of the major anthropogenic activities as industrial settlements, wastewater discharges, and agricultural drainage. In addition, mussel samples of Mactra corallina and Tapes decussata were collected corresponding to the sediment samples. Concentrations of As, Cd, Cr, Mn, and Zn in the mussel tissues were higher than concentrations in sediments, thus indicating their relatively high bioavailability. Sequential extraction procedure was performed on selected sediment samples. Significant correlations were observed between the concentrations of Cu, Mn, Pb, and Zn in the exchangeable fraction of the sediments and the corresponding tissues of M. corallina. The output of the risk assessment applied on the sediments revealed that adverse ecological effects to benthic species could occur and that a higher level of risk is expected from the exposure to Cd, Cr, Hg, and Zn. No adverse carcinogenic or non‐carcinogenic human health effects are expected from the consumption of the two mussel species from Abu Qir Bay.  相似文献   

Detection of Pharmaceuticals and Personal Care Products in Agricultural Soils Receiving Biosolids Application     

Chenxi Wu  Alison L. Spongberg  Jason D. Witter  Min Fang  April Ames  Kevin P. Czajkowski 《洁净——土壤、空气、水》2010,38(3):230-237

Increasing research has suggested that biosolids generated from municipal wastewater treatment can be a major sink for many pharmaceuticals and personal care products (PPCPs) and their land application potentially introduces these contaminants into the terrestrial and aquatic environments. In this study, methods were developed for the analysis of 14 PPCPs in biosolids and soils using pressurized liquid extraction, solid phase extraction and liquid chromatography‐tandem mass spectrometry. Recoveries were over 50% for all analytes except diphenhydramine (?30%) in soils. Soil properties or type of biosolids showed minor effects on method recoveries. Estimated method limits of quantification (LOQ) range from 0.1–15 ng g^–1 for soil and 0.3–27 ng g^–1 for biosolids. A field study utilizing the methods revealed that other than carbamazepine‐10,11‐epoxide, all targeted compounds were detected in biosolids. Diphenhydramine, fluoxetine, triclosan and triclocarban were detected up to the μg g^–1 range with the highest concentration of 23 μg g^–1 for triclocarban. Seven of the PCCPs found in biosolids were also detected in agricultural soils amended with these biosolids and several (carbamazepine, diphenhydramine, and triclocarban) appeared to be persistent in soils. Triclocarban was also found most abundant in soils with the highest average concentration of 0.2 μg g^–1 while the rest of compounds were in the lower ng g^–1 range. Generally, the concentrations found on the fields were 2–3 degrees of magnitude lower than in the biosolids, which is likely to be due to dilution, degradation and leaching processes.  相似文献