离子色谱法测定五氧化二铌和五氧化二钽中痕量氟氯和硫酸根离子的前处理方法     

刘肖 滕曼蔡亚岐  牟世芬 《岩矿测试》2006,25(4):319-322

采用马弗炉将样品与NaOH混合进行熔融煅烧，热去离子水提取、离心、稀释后过OnGuard Ⅱ H柱和过滤膜进行前处理，抑制型电导离子色谱法检测，测定了Ta2O5和Nb2O5的氟离子、氯离子和硫酸根离子。该方法对三种被测阴离子的检测限（s／N=3）在0．15～0．70μg／g（以固体样品实际浓度计）或0．136～0．623μg／L（以溶液浓度计），标准曲线线性范围均在两个数量级以上，方法的精密度（RSD，n=7）小于5．46％，回收率为88％～106％，具有灵敏度高、选择性好、重现性佳、对环境友好等特点，用于实际样品的检测，结果令人满意。  相似文献   

Estimation of groundwater recharge using the chloride mass-balance method, Pingtung Plain, Taiwan   总被引：4，自引：0，他引：4  

Cheh-Shyh Ting  Tienfuan Kerh  Chiu-Jung Liao 《Hydrogeology Journal》1998,6(2):282-292

 Due to rapid economic growth in the Pingtung Plain of Taiwan, the use of groundwater resources has changed dramatically. Over-pumping of the groundwater reservoir, which lowers hydraulic heads in the aquifers, is not only affecting the coastal area negatively but has serious consequences for agriculture throughout the plain. In order to determine the safe yield of the aquifer underlying the plain, a reliable estimate of groundwater recharge is desirable. In the present study, for the first time, the chloride mass-balance method is adopted to estimate groundwater recharge in the plain. Four sites in the central part were chosen to facilitate the estimations using the ion-chromatograph and Thiessen polygon-weighting methods. Based on the measured and calculated results, in all sites, including the mountain and river boundaries, recharge to the groundwater is probably 15% of the annual rainfall, excluding recharge from additional irrigation water. This information can improve the accuracy of future groundwater-simulation and management models in the plain. Received, April 1996 Revised, March 1997, November 1997 Accepted, March 1998  相似文献   

Spatial and Temporal Characteristics of Horizontal Rolls and Cells in the Atmospheric Boundary Layer Based on Radar and in Situ Observations     

F. Lohou  A. Druilhet  B. Campistron 《Boundary-Layer Meteorology》1998,89(3):407-444

This paper is the second of a series devoted to the observation and analysis of coherent structures in the cloudy Atmospheric Boundary Layer (ABL) such as horizontal rolls or thermal cells. In the first paper, the TRAC (Turbulence Radar Aircraft Cells) experiment which is the observational support of this investigation based on coupled radar-aircraft measurements, was presented along with an overview of the main results of this campaign held in June 1993 in France. Here the analysis is focused on the spatial characteristics (length-scale, orientation ... ) of the coherent structures, their temporal evolution and vertical distribution deduced from the radar reflectivity fields acquired in clear air at several levels for five different ABLs. For that, an original and efficient image processing method able to extract the major mode of the organisation was developed. These characteristics are examined in relation to the dynamic and thermodynamic state of the ABL using mean and turbulent information as observed by the in-situ aircraft. These experimental results are the basis of a future Large Eddy Simulation modeling of an organised ABL which is in progress and will be the concern of the third paper in the series.  相似文献   

Modelling the chloride signal at Plynlimon,Wales, using a modified dynamic TOPMODEL incorporating conservative chemical mixing (with uncertainty)     

T. Page  K. J. Beven  Jim Freer  Colin Neal 《水文研究》2007,21(3):292-307

The application of a modified version of dynamic TOPMODEL for two subcatchments at Plynlimon, Wales is described. Conservative chemical mixing within mobile and immobile stores has been added to the hydrological model in an attempt to simulate observed stream chloride concentrations. The model was not fully able to simulate the observed behaviour, in particular the short‐ to medium‐term dynamics. One of the primary problems highlighted by the study was the representation of dry deposition and cloud‐droplet‐deposited chloride, which formed a significant part of the long‐term chloride mass budget. Equifinality of parameter sets inhibited the ability to determine the effective catchment mixing volumes and coefficients or the most likely partition between occult mass inputs and chloride mass inputs determined by catchment immobile‐store antecedent conditions. Some success was achieved, in as much as some aspects of the dynamic behaviour of the signal were satisfactorily simulated, although spectral analysis showed that the model could not fully reproduce the 1/f power spectra of observed stream chloride concentrations with its implications of a wide distribution of residence times for water in the catchment. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

姬松茸提取物组分体外抗病毒感染活性的研究     

樊廷俊  钱冠兰  杜玉堂  袁文鹏  吕雅萌 《中国海洋大学学报(自然科学版)》2008,38(5)

为了探明姬松茸提取物的体外抗病毒感染活性及其作用方式,进而为水产养殖鱼类高效抗淋巴囊肿病毒(lymphocystis disease virus,LCDV)感染活性物质的开发和鲆蝶类淋巴囊肿病的防治奠定基础,利用热水浸提和酒精沉淀法得到了5种姬松茸提取物组分(E1～5),并利用MTT、细胞病变程度观察等方法研究了5种组分对LCDV感染体外培养大菱鲆鳍细胞(turbot fin cells,TF细胞)的影响作用.细胞毒性实验结果显示,5种组分对体外培养TF细胞均无毒性.细胞病变程度结果表明,本文所得5种姬松茸提取物组分尤其是E5组分具有显著的抗LCDV感染TF细胞的活性.不同方式感染的实验结果进一步显示,5种姬松茸提取物组分抗LCDV感染TF细胞的作用可能主要是通过直接灭活病毒和/或阻断病毒吸附细胞来实现的.  相似文献   

Antiangiogenic activity of low-temperature lysozyme from a marine bacterium <Emphasis Type="Italic">in vivo</Emphasis> and <Emphasis Type="Italic">in vitro</Emphasis>     

王振华  刘金成  苏爱  孙谧  王春波 《中国海洋湖沼学报》2009,27(4):835-844

We extracted marine low-temperature lysozyme (MLTL), a novel lysozyme, from a marine microorganism through fermentation. Our previous study suggested that a low molecular weight (16 kDa) may exert anti-tumor activity through antiangiogenesis. In this study, we extracted a high weight (39 kDa) and investigated its antiangiogenic activity in vivo and in vitro. Using zebrafish embryos as an in vivo study model, we found that treatment with MLTL significantly inhibited the growth of subintestinal vessels (SIVs) in a dose-dependent manner and that 400 μg/ml MLTL was sufficient to block the growth of SIVs. An in vitro study conducted using human umbilical vein endothelial cells (HUVECs) revealed that MLTL suppressed the proliferation, migration and tube formation of HUVECs in a dose-dependent manner. Interestingly, assays by flow cytometry and DNA electrophoresis indicated that MLTL was able to induce apoptosis of HUVECs. Moreover, further study demonstrated that the disruption of intracellular Ca²⁺ homeostasis may play an important role in MLTL induced apoptosis of HUVECs. Taken together, the results of this study demonstrate for the first time that MLTL inhibits angiogenesis through its pleiotropic effects on vascular endothelial cells and induces apoptosis through regulation of cellular Ca²⁺ levels. The results of this study also revealed a possible mechanism underlying the antiangiogenic effect of MLTL and suggested that MLTL may be a promising new antiangiogenic agent for use in cancer therapy.  相似文献   

Effect of Fly Ash on Frost-Resistance and Chloride Ions Diffusion Properties of Marine Concrete     

杨文武  钱觉时  章一颖 《中国海洋工程》2009,23(2):367-377

It is necessary to pay more attention to the durability of concrete undergoing freeze-thaw cycles and seawater attack simultaneously.Investigated are the effects of water-binder ratio,fly ash (FA) contents and air-entraining agent on resistance to frost and chloride diffusion of marine concrete blended with FA in natural seawater.The results show that fly ash does not improve the frost resistance of concrete but can improve its resistance to chloride diffusion by addition of less than 30%.The resistance to frost and chloride diffusion of FA concrete can be improved with the decrease of water-binder ratio,and FA may improve both of them simultaneously only being mixed with air-entraining agent.A ratio (named as R) of the frost-resisting durability factor to chloride diffusion coefficient can be used to evaluate the durability of marine concrete.Scanning electron microscope (SEM) analyses are consistent with the evaluations by the value of R.  相似文献   

High chloride concentrations in the soil and groundwater under an oak hedge in the West of France: an indicator of evapotranspiration and water movement     

C. Grimaldi  Z. Thomas  M. Fossey  Y. Fauvel  P. Merot 《水文研究》2009,23(13):1865-1873

Chloride is a major anion in soil water and its concentration rises essentially as a function of evapotranspiration. Compared to herbaceous vegetation, high transpiration rates are measured for isolated trees, shelterbelts or hedgerows. This article deals with the influence of a tree hedge on the soil and groundwater Cl^? concentrations and the possibility of using Cl^? as an indicator of transpiration and water movements near the tree rows. Cl^? concentrations were measured over 1 year at different depths in the unsaturated zone and in the groundwater along a transect intersecting a bottomland oak hedge. We observed a strong spatial heterogeneity of Cl^? concentrations, with very high values up to 2 g l^?1 in the unsaturated zone and 1·2 g l^?1 in the upper part of the groundwater. This contrasts with the low and homogeneous concentrations (60–70 mg l^?1) in the deeper part of the groundwater. Cl^? accumulation in the unsaturated zone at the end of the vegetation season allows us to identify the active root zone extension of trees. In winter, upslope of the tree row, downwards leaching partly renews the soil solution in the root zone, while the slow water movement under the trees or farther downslope results in Cl^? accumulation and leads to a salinization of the soil and groundwater. This salinization is of the same order as experimental conditions produce negative effects on oak seedlings. The measurement of Cl^? concentrations in the unsaturated zone under tree rows at the end of the vegetation season would indicate whether certain topographic, pedological or climatic conditions are likely to favour a strong salinization of the soil, as observed in the present study. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

黑鱾血液的生理生化指标研究   总被引：2，自引：0，他引：2  

孙敏  徐善良  唐道军 《台湾海峡》2009,28(4):482-487

本文采用F-820半自动血细胞分析仪和全自动生化分析仪，对黑纪的血液常规指标及血清中的17项生化指标进行了分析测定，并用Wright’s染色法制作血涂片对白细胞进行分类计数．结果表明：（1）黑纪的血红细胞数量为（2．49±0．47）×10^12个／dm^3；白细胞数量为（1．08±0．21）×10^11个／dm^3；在白细胞中以嗜中性粒细胞数量最多，占52．42％±4．67％，其次为淋巴细胞，占25．72％±2．88％；单核细胞体积最大，占总数的3．27％±0．62％．（2）黑纪红细胞脆性大，抗性差，在0．65％～0．70％的NaCl溶液中开始溶血，在0．50％～0．55％的NaCl溶液中完全溶血．（3）黑纪的血红蛋白（HGB）为109．11±15．72g／dm^3，高于一般鱼类，与其较强的耐低氧生理能力相适应．（4）血清中血糖浓度为4．72±1．35mmol／dm^3，明显低于凶猛肉食性鱼类，与其岛礁性生态习性和杂食性相吻合．（5）雌雄鱼的乳酸脱氢酶分别为332．67±188．48U／dm^3和905．66±257．85U／dm^3，雌鱼显著高于雄鱼，可能与繁殖活动相关．  相似文献   

繁茂膜海绵清除大肠杆菌的过程     

张喜昌  张卫  褚亚东  赵宗宝  谭海东  梁玉波  许淑芬  冷晓飞  李丹 《海洋科学》2015,39(5):21-27

通过分析海绵清除大肠杆菌的过程,研究海绵净化细菌的机理。作者利用荧光显微镜和激光共聚焦显微镜观测等手段,监测和分析了绿色荧光大肠杆菌(Escherichia coli)在繁茂膜海绵(Hymeniacidon perlevis)体内、体外水环境中数量变化过程。在1 L含有3×107个/m L绿色荧光大肠杆菌的海水中放入鲜重(1.02±0.11)g的繁茂膜海绵24块,处理7 h,海水中的荧光大肠杆菌数量逐渐降低;而海绵体内荧光大肠杆菌数量在2 h时内逐渐增多,之后的2 h趋于稳定,4 h以后开始逐渐减少。水体中大肠杆菌不仅进入海绵体内,而且进入海绵细胞内。含有荧光大肠杆菌的海绵块转入无菌海水中后,海绵体内及细胞中大肠杆菌逐渐消失,而且大肠杆菌没有被释放到环境海水中。分析表明,繁茂膜海绵能够以摄食的方式净化水环境中的大肠杆菌。  相似文献