Properties of proteolytic toxin of Vibrio anguilolarum from diseased flounder     

Mo Zhao-lan  Chen Shi-yong  Zhang Pei-jun 《中国海洋湖沼学报》2002,20(4):316-322

Extracellular products (ECP) produced byVibrio anguillarum strain M3 originally isolated from diseased flounder (Paralichthys olivaceus) were prepared. ECP of M3 showed gelatinase, casinase, amylase and haemolytic activity on agarose plates. High protease activity against azocasin was detected. Bacterium M2 showed highest growth and protease activity at 25°C. The protease present in ECP showed maximal activity at pH 8 and 55°C; was completely inactivated by application of 80°C heat for 30 min; was completely inhibited by EDTA and HgCl₂, and was partially inhibited by PMSF, SDS, MnCl₂ and iodoacetic acid; but not inhibited by CaCl₂ and MgCl₂. The ECP was toxic to flounder fish at LD₅₀ values of 3.1 μg protein/g body weight. The addition of HgCl₂ and application of heat at 50°C decreased the lethal toxicity of ECP. When heated at 100°C, ECP lethality to flounder was completely inhibited. After intramuscular injection of ECP into flounder, it showed evident histopathological changes including necrosis of muscle, extensive deposition of haemosiderin in the spleen, dilated blood vessels congested with numerious lymphocytes in the liver. These results showed that ECP protease was a lethal factor produced by the bacteriumV. anguillarum M3. Contribution No. 4213 from the Institute of Oceanology, Chinese Academy of Sciences. Funded by projects under the Major State Basic Research Development Program, Grant G1999012003.  相似文献   

“4D”数据在生态环境监测与评价中的应用     

姜莉莉齐清文  邹秀萍 《地球信息科学学报》2007,9(3):123-127,F0002,F0003

本文在阐述由DLG、DRG、DEM和DOM组成的4D产品的信息特征的基础上,深入分析了“4D”数据在生态环境监测与评价中的功能,包括生态环境的快速动态监测、三维生态景观的直观分析和表达、DLM与DCM相结合的生态模拟、多时空尺度的生态环境分析与评价等。并以云南省生态环境监测与评价为例,研究了其在生态环境监测与评价中的技术流程,并通过案例分析,生成了系列生态环境地图。  相似文献   

ECMWF细网格TP产品在北疆降雪天气中的预报性能检验     

李博渊  王小号  周鸿奎  庄晓翠 《沙漠与绿洲气象(新疆气象)》2016,10(6):41-48

基于升级后的EC细网格TP降水量预报产品,对北疆2015年17场降雪天气的12h累积降雪量,主要运用平均误差、平均绝对误差和均方根误差进行了检验。结果表明,该模式在北疆降雪天气预报中小雪的预报准确率最高,暴雪最小;预报准确率随时效的延长并非都是减小的;小雪空报率较高、暴雪漏报率较高,中雪和大雪空报率和漏报率都不容忽视;小雪和中雪的3种误差均较小,随时效的延长变化较小;强降雪(大雪及以上量级)的误差较大,随时效的延长有增大的趋势;模式对小雪的预报总体为系统性偏大,对强降雪预报则为明显的系统性偏小,对中雪的预报系统性偏向不稳定。  相似文献   

Alteration of nuclear glass in contact with iron and claystone at 90 °C under anoxic conditions: Characterization of the alteration products after two years of interaction     

《Applied Geochemistry》2016

The present study investigates the alteration of a fractured glass block in contact with iron and Callovo-Oxfordian claystone at 90 °C under anoxic and water-saturated conditions. The alteration rates and the nature of glass alteration products at the different compact interfaces (glass-clay, glass-iron) and in cracks were assessed by solution chemistry and microscopic-scale techniques (scanning electron microscopy coupled with energy-dispersive X-ray microscopy, microRaman spectroscopy, and X-ray absorption fine structure spectroscopy). A significant but modest (two-fold) increase in glass alteration in contact with steel was observed, leading to an average alteration rate over the experiment of about 0.007–0.014 g/m²/d. This rate is significantly lower than forward rate r₀ in clay-equilibrated groundwater (1.7 g/m²/d), indicating that a decrease of the alteration rate was not hindered by the steel presence. The corrosion–alteration interface was made up of successive layers of corrosion products in contact with iron, a layer of Fe silicates, and an altered glass layer enriched in Fe. Characterization of the glass block in direct contact with claystone revealed that the thickness of altered glass was much more important than at the glass-iron interface. The altered glass layer in contact with clay was slightly enriched in Fe and Mg, and depleted in alkali cations. Altered glass layers in cracks were usually limited to fringes thinner than 2 μm, with a thickness decreasing from the crack mouth, indicating that alteration is controlled by transport in the cracks. The fractures were partially filled with calcite and lanthanide hydroxocarbonate precipitates. These results contribute to the understanding of nuclear vitrified waste-iron-corrosion products interactions in a deep geological repository.  相似文献   

黑色岩系及相关矿产——以扬子地台为例     

王聚杰 《地质与勘探》2015,51(4):677-689

黑色岩系是指含有机碳及硫化物较多的深灰-黑色的硅质岩、碳酸盐岩、泥质岩及其变质岩石的组合体系,属于一种还原性岩石。黑色岩系中含铜、镍、锰、铀、磷、重晶石、铂族元素、铅-锌-银矿、油气等矿产,尤以铜、镍、钼、钒、钛最为典型,称为"五元素矿床"。近几年来,国内外关于黑色岩系中的非金属金属矿床的研究越来越多,黑色岩系的矿产经济意义也日益引起人们的重视。本文以扬子地台为例,研究震旦系-寒武系黑色岩系及其相关的矿产,为相似层位(如中晚泥盆统、石炭系、上二叠统、白垩系等)提供借鉴。通过对比云南晋宁梅树村震旦-寒武系界线的层型剖面与峡东地区震旦系剖面可以发现,两条剖面富磷层位具有可对比性,陡山沱组是扬子东部重要的含矿(磷)层位;而渔户村组是扬子西部最重要的含矿(磷)层位;过渡地段的贵州北部两个层位均重要;说明从陡山沱期到渔户村期,形成的磷矿活动中心逐渐从扬子东部向扬子西部迁移。  相似文献   

基于OpenStack Swift的雷达产品存储研究     

王丽玫  李莹  黄志  马军 《气象研究与应用》2019,40(1):75-79

简要介绍分布式对象存储系统OpenStack Swift,包括安装部署及其在雷达产品存储方面的应用,研究证明,OpenStack Swift能较好的支持雷达产品存储,也适用于其它气象资料存储管理。  相似文献   

三种气温预报产品黑龙江省预报效果检验     

孟莹莹  李树岭  赵玲  白雪梅  闫敏慧 《气象与环境学报》2022,38(2):21-30

利用T639模式预报产品和黑龙江省83个国家气象站气温实况观测资料,采用最优预报因子方法选取预报因子,应用多元回归方法建立逐站日最高气温和日最低气温的MOS预报方程; 对MOS、中央气象台指导预报（SCMOC）和T639三种气温预报产品的日最高气温和日最低气温预报效果进行对比检验分析,并用EOF方法检验预报与实况的时空变化特征一致性。结果表明: 与实况的时空变化一致性方面,MOS和SCMOC较好,T639略差; 预报效果方面,MOS和SCMOC对日最高气温和日最低气温的2 ℃预报准确率普遍高于T639,MOS的预报准确率在日最高气温方面高于SCMOC,在日最低气温方面低于SCMOC; MOS对T639气温预报产品改善效果明显,尤其对冬季日最低气温的预报改善效果十分显著; MOS较T639气温预报改善效果与T639模式预报效果呈负相关关系,主要表现为,MOS预报改善效果在T639预报准确率低的山区明显优于平原,在春、夏季,预报准确率较低的日最高气温明显优于日最低气温,在冬季,预报准确率较低的日最低气温优于日最高气温; MOS气温预报方法的预报性能较理想,SCMOC对黑龙江省预报难度较大的日最低气温预报效果较好。  相似文献   

地面站点观测数据代表性评价方法研究进展   总被引：1，自引：0，他引：1  

徐保东  李静  柳钦火  辛晓洲  曾也鲁  尹高飞 《遥感学报》2015,19(5):703-718

在遥感产品真实性检验中,地面站点网络的连续观测数据是进行算法及产品验证的重要数据来源。通常站点观测的空间范围有限,测量数据直接与产品像元值比较会存在尺度误差。因此,分析与评价站点观测在多大尺度上具有代表性,对有效利用观测数据进行算法与产品精度评价具有重要意义。目前全球地面观测站点类型繁多,虽有一定的代表性评价方法,但各类方法的优缺点及适用参数、适用条件各异。因此,为使站点观测代表性评价方法广泛的应用于地面站点观测,进而开展更加有效的遥感产品真实性检验,有必要对当前站点代表性评价方法进行系统的综述及梳理。本文首先阐述遥感产品真实性检验对站点连续观测数据的需求以及站点观测代表性评价的必要性。其次,分析站点观测代表性的评价指标特征,包含点面特征比较以及空间异质性两种评价指标。基于不同评价指标,综述了各种研究方法在站点观测数据代表性评价中的应用,即对点面特征比较评价的物理模型法、站点与区域分布图统计评价法和多站点多时相联合评价法,以及对空间异质性进行评价的一阶统计法和半方差函数法,总结不同代表性评价方法的原理及优缺点。然后,介绍了目前站点数据及代表性评价方法在蒸散、反照率和地表温度等遥感产品真实性检验中的应用,并且以黑河中游农田区观测LAI为例,分析了基于不同评价指标的不同评价方法的特点。最后,针对当前观测代表性评价方法面临的问题提出了下一步的研究方向。  相似文献   

海岛(礁)DEM成果的质量检查技术与方法     

赵有松  尹粟  张莉  毛文娟  郭婧  赵颖 《测绘科学》2015,40(7):127-130

针对海岛(礁)DEM成果的特殊性和质量检验方法研究不足的现状,该文在分析传统方法的基础上,提出了一套适用于大批量海岛(礁)DEM成果质量检验的流程及技术方法:根据海岛(礁)DEM成果特征,分析了需要检验的质量元素,确定了不同质量元素的检验方法;进一步区分出可以采用程序自动检查的质量元素,并通过建立检查规则库,实现了部分检查项的批量自动检查;然后,研究其余质量检查项的实现方法,明确了内外业分工,完善了质量检查项的人机交互检查。最后,对3000余幅海岛(礁)DEM成果质量检验的结果表明:本文提出的技术路线可行,质量评价结果客观可靠。  相似文献   

甘肃CGCS2000基础测绘成果转换方法研究     

李克恭 《测绘与空间地理信息》2015,(11):214-216

针对甘肃基础测绘成果数据类型多样、格式多样、存储方式多样、横跨六个三度带以及甘肃西部地区控制稀少和转换图幅多的特点,对数据成果和各种类型转换方法进行对比分析,形成了甘肃基础测绘成果转换的技术路线和实现方法,并成功地实现了甘肃省基础测绘成果的整体转换,该技术路线和方法对国家测绘地理信息局组织开展的全国CGCS2000基础测绘成果转换具有一定的借鉴意义。  相似文献