外源添加物对海底沉积物微生物燃料电池性能的影响     

英明  柳昭慧  赵阳国  付玉彬 《海洋与湖沼》2015,46(3):489-496

以天然海泥(BMFC-0)、外添加葡萄糖的海泥(BMFC-1)和外添加丹皮酚的海泥(BMFC-2)作为底物构建海底沉积物微生物燃料电池(BMFCs),研究外源添加物对BMFCs电池性能及电极性能的影响。结果表明,丹皮酚对海泥中微生物具有明显抑制作用,葡萄糖提高海泥中微生物的产电性能。通路状态下,BMFC-1的阳极电位低于BMFC-0,BMFC-2的阳极电位高于BMFC-0。电化学研究结果表明,BMFC-1阳极生物膜中产电菌电化学活性高于BMFC-0,而BMFC-2产电菌的电化学活性受到抑制;BMFC-1和BMFC-2的阳极相对动力学活性分别是BMFC-0的1.91倍和0.67倍。BMFC-1的平均输出功率密度为7.294m W/m2,分别是BMFC-0(0.875m W/m2)和BMFC-2(0.106m W/m2)的8.3和68.8倍。根据添加物对阳极表面生物膜电容特性影响的分析,提出阳极表面电容性质对电极及电池性能影响的独特机理。  相似文献   

海藻胶低聚寡糖的酶法制备纯化技术及保水理化性质分析   总被引：1，自引：0，他引：1  

黄菊  丁晨  谢超  裘晓华  俞群娣  李桂芬 《海洋与湖沼》2015,46(3):595-602

海藻胶低聚寡糖是从马尾藻等藻类中提取出来的一种多糖类物质,具有良好的保水功能。本文采用酶解技术对海藻胶低聚寡糖的制备纯化工艺进行研究,通过对酶解过程中反应温度、酶解时间、加酶量、底物浓度和pH等进行研究,结果表明:酶解温度50°C、时间4h、加酶量45%、底物浓度0.4%、pH 6.0时,海藻胶降解成低聚寡糖的产率最高,达到75%左右。进一步对海藻胶低聚寡糖进行纯化,结果表明当温度控制在27°C,时间在2h时,分子量为6000—8000Da海藻胶低聚寡糖分离效率最高,达到70%以上,并对6000—8000Da海藻胶低聚糖的保水理化性能进行分析,结果表明6000—8000Da海藻胶低聚寡糖具有良好的保水性能。本研究可为开发一种安全、高效、节能、环保,适用于冷冻鱿鱼和虾仁等的生物保水剂提供理论基础。  相似文献   

Materials properties of barricade bricks for mining applications   总被引：1，自引：0，他引：1  

Christopher C. Berndt  Kirralee J. Rankine  Nagaratnam Sivakugan 《Geotechnical and Geological Engineering》2007,25(4):449-471

Barricade bricks are fundamental to the safe operation of a mining site. Past failures have lead to loss of life and reduced mine efficiency or even shut down. The fundamental material property that determines the operational characteristics of barricade bricks is their permeability, which must be tailored to suit the operational environment of the mine. The ability of the barricade to control the hydraulic pressure within a stope application is crucial for safety and economic returns. In the current work practical barricade bricks were tested for permeability. As well, the strength and modulus of bricks were measured after being soaked in water for either 7 or 90 days so that a measure of their engineering functionality could be determined. The primary conclusions of this work are as follows. There was substantial deviation in permeability between bricks; however, the average permeability of the barricade bricks was several orders of magnitude larger than the values obtained for the hydraulic fill. This difference indicates that modelling efforts can assume that the barricade does not contribute to the pore pressure development within the fill. Hence the drainage of the system is not related to the permeability of these bricks provided that the barricades are built from the bricks in such a way that the construction or future migration of fines from the fill does not impede the drainage performance.

Christopher C. BerndtEmail:

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Description and characterization of place properties using topic modeling on georeferenced tags     

Azam R. Bahrehdar  Ross S. Purves 《地球空间信息科学学报》2018,21(3):173-184

ABSTRACT

User-Generated Content (UGC) provides a potential data source which can help us to better describe and understand how places are conceptualized, and in turn better represent the places in Geographic Information Science (GIScience). In this article, we aim at aggregating the shared meanings associated with places and linking these to a conceptual model of place. Our focus is on the metadata of Flickr images, in the form of locations and tags. We use topic modeling to identify regions associated with shared meanings. We choose a grid approach and generate topics associated with one or more cells using Latent Dirichlet Allocation. We analyze the sensitivity of our results to both grid resolution and the chosen number of topics using a range of measures including corpus distance and the coherence value. Using a resolution of 500 m and with 40 topics, we are able to generate meaningful topics which characterize places in London based on 954 unique tags associated with around 300,000 images and more than 7000 individuals.  相似文献   

Magnetic properties of Jiaxian red clay sequences from northern Chinese Loess Plateau and its paleoclimatic significance     

QIANG Xiaoke  AN Zhisheng  LI Huamei  CHANG Hong & SONG Yougui . SKLLQG  Institute of Earth Environment  Chinese Academy of Sciences  Xi’an  China  . Guangzhou Institute of Geochemistry  Chinese Academy of Sciences  Guangzhou  China 《中国科学D辑(英文版)》2005,48(8):1234-1245

Rock magnetism research on eolian deposits from the Chinese Loess Plateau shows that magnetite, maghe- mite and hematite are the main magnetic minerals in loess-paleosol sequences and red clay se-quences[1―8], and finds that the magnetic susceptibility increase is positively correlated to the content of ultra-fine minerals and relatively strong pedogene- sis[7―15]. This offers significant information in studying the Late Cenozoic paleoclimatic history of Chinese Loess Plateau[1,5―8,10―22…  相似文献   

Space–Time Mathematical Framework for Sedimentary Geology     

Jean-Laurent Mallet 《Mathematical Geology》2004,36(1):1-32

Interpolating physical properties in the subsurface is a recurrent problem in geology. In sedimentary geology, the geometry of the layers is generally known with a precision much superior to that which one can reasonably expect for the properties. The geometry of the layers is affected by folding and faulting since the time of deposition, whereas the distribution of properties is, to a certain extent, determined at the time of deposition. As a consequence, it may be wise to model first the geometry of the layers and then, simplify the geologic equation by removing the influence of that geometry. Inspired from the work of H. E. Wheeler on Time-Stratigraphy, we define, mathematically, a new space where all horizons are horizontal planes and where faults, if any, have disappeared. We surmise that this new space, however approximative, is better to model physical properties of the subsurface whatever the subsequent interpolation method used. The proposed mathematical framework also provides solutions to complex problems such as determination of strains resulting from tectonic events and up-scaling of permeabilities on structured and unstructured 3D grids.  相似文献   

运动物体生成内波的一类非线性谱方程组     

徐肇廷  徐昊 《中国海洋大学学报(自然科学版)》2003,33(4):503-511

本文给出了由运动物体所生成内波的基本方程组和对应的谱方程组。该方程组的线性部分是一具有体积源 (其下简称为体源 )的 Sturm- Liouville本征值问题 ,而它的非线性部分是由体源与线性波场相互作用的谱表示。在这类强迫方程的源项中包含了 10类内波谱 ,这些谱最终均可利用内波的振幅谱表示。本文给出了线性波场波要素的谱表示和运动物体生成内波的非线性谱方程可解性的讨论。为了检验所得到的谱方程组 ,文中又进行了该谱方程组线性部分的数值计算。  相似文献   

南印度洋绕极深层水的性质和空间分布以及南极绕极流的作用   总被引：1，自引：0，他引：1  

蒲书箴  董兆乾  于卫东  卢燕  项宝强 《海洋科学进展》2007,25(1):1-8

利用世界大洋环流实验的南大洋观测温度、盐度和溶解氧资料,分析并说明了南印度洋绕极深层水的性质和空间分布特征,比较了30°E,90°E和145°E断面上温度、盐度和溶解氧的垂直分布及其异同,着重指出,在南印度洋的这3个不同经度断面上,绕极深层水和锋面的不同特征与南极绕极流越洋输运和南印度洋绕极深层水的经向运动有着密切的关系。实际上,绕极流的越洋输运是南大西洋与南印度洋之间以及南印度洋与南太平洋之间水交换的主要动力因素,对形成绕极深层水的物理性质的空间分布有着重要的作用。  相似文献   

Fisheries management and institutional reform: a European perspective   总被引：1，自引：0，他引：1  

Symes  David 《ICES Journal of Marine Science》2007,64(4):779-785

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一种来自海洋细菌的血纤维蛋白溶酶的分离纯化及性质研究   总被引：2，自引：0，他引：2  

魏香  刘晨光  刘万顺  刘成圣  韩宝芹 《海洋科学》2001,25(3):1-4

利用硫酸铵分级盐析、DEAE－纤维素阴离子交换层析、Sephadex G-75凝胶层析法对由海洋细菌FE92－8分泌的纤维蛋白溶酶进行了分离纯化，结果得到SDS－聚丙烯酰胺凝胶电泳单一区带。性质研究发现，该酶分子量为12.6kD，等电点为7.45，琼脂糖－纤维蛋白平板法测得该酶作用的最适温度为50℃，最适pH为8.0，在37℃，pH为8.0的情况下表现出很好的稳定性，温度起来50℃热稳定性较差，在碱性环境中稳定性较在酸性环境中稳定性强，阴性平板和阳性平板对比实验发现，该酶只有纤溶活性而无激酶活性，体外实验发现，该酶具有快速溶解血栓的能力。  相似文献