基于ArcGIS图解建模的水系自动提取研究   总被引：1，自引：0，他引：1  

贺丹  曹佳云  付晓婷  唐新庄 《地下水》2011,33(3):128-130

以DEM数据为基础,根据水系自动提取原理和过程,利用ArcGIS模型生成器构造水系自动提取的图解模型,依次实现洼地填充、水流方向计算、汇流累积量计算、矢量河网的生成,从而完成自然水系的一步提取.  相似文献   

正交实验法优化紫蛇尾皂苷提取工艺研究     

王荣镇  党永龙  冯建荣  王全会  代鹏  郭承华 《海洋科学》2012,36(2):46-49

以紫蛇尾(Ophiopholis mirabilis)皂苷溶液吸光度为指标,采用单因素实验法考察乙醇体积分数、料液比、提取时间、提取次数、提取温度等因素对紫蛇尾皂苷提取效果的影响,通过正交实验确定最佳工艺条件。结果表明,紫蛇尾皂苷的最佳提取工艺为60℃水浴,料液比1:40(W/V),每次3 h,提取4次。按照最佳工艺条件所得蛇尾皂苷平均产率为1.77‰,表明此最佳工艺可用于紫蛇尾皂苷的制备。  相似文献   

Ultrasound‐Assisted Emulsification‐Microextraction With In Situ Derivatization and Gas Chromatography‐Electron‐Capture Detection for Determination of Chlorophenols in Water          下载免费PDF全文

Senar Aydın  Ali Tor  Mehmet Emin Aydın  Fatma Beduk 《洁净——土壤、空气、水》2015,43(8):1143-1149

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Model tests on installation and extraction of suction caissons in dense sand     

Yukun Zhang  Yufeng Gao 《Marine Georesources & Geotechnology》2017,35(7):921-929

A series of model tests were performed on steel- and Perspex-made suction caissons in saturated dense marine sand to explore installation and extraction behaviors. The extractions of the caisson were conducted by applying monotonic loading or by pumping water into the caisson. Responses of suction caissons to pullout rates, aspect ratios, and extraction manners were examined. Test results show that a cone-shaped subsidence region occurs around the suction caisson during the suction-assisted installation. The pullout bearing capacity of the suction caisson in sand is dominated by the loading rate and the loading manner. For the suction caisson subjected to monotonic loading, the maximum bearing capacity is reached at the pullout rate of about 20.0?mm/s. The mobilized vertical displacement corresponding to the pullout capacity increases with increasing the pullout rate. The passive suction beneath the suction caisson lid reaches the maximum value when the pullout bearing capacity is mobilized. In addition, during the suction caisson extracted by pumping water into the caisson, the maximum pore water pressure in the caisson is obtained under the displacement of approximately 0.04 times the caisson diameter. The absolute values of the maximum pore water pressures for the suction caissons approximately equal those of the maximum vertical resistances at the monotonic pullout rate of 5 mm/s. When the vertical displacements of the suction caissons with the aspect ratio of 1.0 and 2.0 reach 0.92 and 1.77 times the caisson diameter, respectively, the seepage failure occurs around the caissons. Using a scaling method, the test results can be used to predict the time length required for the prototype suction caisson to be extracted from the seabed.  相似文献   

Metal Ion Extraction with Bipyridine Derivatives as Chelating Ligands in Supercritical Carbon Dioxide     

Hai‐Jian Yang  Hakwon Kim  Cun‐Yue Guo 《洁净——土壤、空气、水》2010,38(2):159-166

Three fluorinated bipyridine ligands have been designed and synthesized as chelating agents for the extraction of metal ions in supercritical CO₂ (sc‐CO₂). The ligand solubilities in sc‐CO₂ were investigated at different temperatures and pressures, and the measured data have been correlated using a semiempirical model. The calculated results showed satisfactory agreement with the experimental data. Based on these data, metal ion extraction with the three compounds as chelating agents in sc‐CO₂ was performed from spiked filter paper, whereby ligand 1 showed the highest extraction efficiency, especially for Ni²⁺ and Cu²⁺. The extraction constants, K_ex, of the three chelating ligands were seen to increase with increasing extraction efficiency for the same metal ion in the same extraction system.  相似文献   

余庆县小腮钒矿地质特征及工业利用性能评价     

杨光龙  孙青  黎海涛  李克庆  朱正坤  杨志书 《贵州地质》2014,31(3):195-200

余庆县小腮地区的钒矿赋存于下寒武统牛蹄塘组近底部,具有品位低、厚度大的特点,矿石类型属炭质泥岩型钒矿.钒在原矿中的价态主要以V^3＋形式存在,其次为V^4＋和V^5＋,其中V^3＋主要以类质同象形式取代Al^3＋、Fe^3＋等氧化矿物及硅酸盐矿物,而V^4＋、V^5＋则全部以吸附状态赋存于云母类矿物中.矿石通过“原矿—破碎—磨矿—浸出—固液分离—萃取—反萃—沉钒—脱铵—五氧化二钒成品”提钒工艺,其五氧化二钒浸出率达85％,五氧化二钒总回收率为79.20％,在环境保护上能得到较好的控制,所得产品质量达GB3283-87冶金用V20599牌号标准.  相似文献   

萃取分离—石墨炉原子吸收光谱法测定铅锌矿中的铟     

赵星  张代云  刘锐 《云南地质》2014,33(3):417-420

样品经硝酸、氢氟酸分解除硅,加热硫酸冒烟除尽硝酸、氢氟酸,利用铟与氢溴酸能生成稳定的络合物并被乙酸丁酯萃取的性质,将铟与其它干扰离子分离并富集.使用MOLAARM6（Thermo Electron Corporation）石墨炉原子吸收分光光度计,以钒为机体改进剂,测定铅锌矿中的铟.方法检出限为LD=0.012ug/ml.实验结果令人满意.  相似文献   

Analytical perspective on trace element species of interest in exploration   总被引：1，自引：0，他引：1  

Gwendy E. M. Hall 《Journal of Geochemical Exploration》1998,61(1-3)

Analysis of soil and sediment samples, using selective extraction methods to distinguish different phases, is of particular interest in exploration geochemistry to locate deeply buried mineral deposits. There are various mechanisms of binding labile elements in the secondary environment, including physical and chemical sorption, precipitation, chelation and complexation. Phases present in soils and sediments which are likely to scavenge ‘free' elements include amorphous Mn and Fe oxides, the humic and fulvic components of humus, and clays. This paper reviews these forms of trace elements and the methods in current use to quantify them. Examples of precision data, both for control and survey samples, are given with respect to trace elements dissolved from the ‘soluble organic' component of humus, Mn oxides and amorphous Fe oxides. The high sensitivity of inductively coupled plasma mass spectrometry (ICP–MS) is required to measure accurately and precisely a large suite of trace elements, especially where only small fractions of elements are dissolved by such leaches as the commercially available Enzyme and MMI (Mobile Metal Ion) extractions. The relative standard deviations (RSD) obtained for 33 elements (e.g. Ag, Cd, In, I) in the standard reference sample (SRM), TILL-2, are in the range 0.5–8% for the hydroxylamine hydrochloride (NH₂OH·HCl) leach designed to extract hydrous Fe and Mn oxides. The corresponding RSDs for elements in the reactive Mn oxide phase extracted by the Enzyme leach are in the range 3–19% except for some trace elements at levels close to detection limit (e.g. Cd, Bi). The RSDs obtained for field duplicates are inferior to those for analytical replicates (i.e. sample splits), probably a reflection of different concentrations of the host phase. In one soil survey, the Fe extracted by a 0.25 M NH₂OH·HCl leach ranged conservatively from 0.2 to 1.7% whereas the Mn extracted by the Enzyme leach varied extensively, from 0.3 to >999 ppm. In contrast, precision, at 1–7% RSD, for field duplicates was found to be comparable with that for both analytical duplicates and the SRM, LKSD-4, for elements associated with the humic and fulvic component of humus samples sieved to <177 μm.  相似文献   

裙带菜褐藻糖胶的分离及部分理化性质研究   总被引：1，自引：0，他引：1  

赖晓芳  沈善瑞  徐士军 《海洋技术学报》2006,25(4):58-60

以裙带菜为原材料,采用水提法从裙带菜中分离褐藻糖胶,Sevag法去蛋白,乙醇分步沉淀法进行初步纯化。结果表明裙带菜褐藻糖胶的最适提取温度为80℃,时间为8 h,加水量为1∶30,在最适条件下的提取率为1.72%,蛋白质含量为5.44%。同时本研究对部分理化性质进行了研究。结果是特性粘度为5 m pa.s,pH为8.50,含有硫酸基。  相似文献   

基于形状先验和图割的高分辨率遥感影像道路提取   总被引：2，自引：1，他引：1  

周绍光陈超  岳建平 《测绘学报》2014,43(1):60-65

给出一种从高分辨率遥感影像中提取道路的方法。先对遥感影像进行滤波预处理获取纹理特征;再以图割解算经典能量函数获取道路图斑,其中利用高斯混合模型构建T链;接着利用直线匹配法获得初始道路段;最后用图割解算融合了两种形状先验的能量函数,结合动态外推的思路连接道路段。对不同遥感影像的实验证明了算法的有效性。  相似文献