首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
李思倩  王刚  张军  王浩 《中国科学(E辑)》2014,(12):1238-1246
采用磁控溅射(sputtering)、高温热分解(high-temp)H2Pt Cl6·6H2O溶液和低温化学还原(low-temp)H2Pt Cl6·6H2O溶液等方法在FTO导电基片上制备了三类不同的Pt对电极,通过改变磁控溅射时间或旋涂退火循环次数,对FTO上不同对电极的载Pt量进行了调节.分析了三种不同方法制备的对电极的晶相结构、表面形貌以及透光率等特性.基于纳米管阵列和不同条件制备的对电极组装了系列染料敏化太阳能电池.测量了正照射和背照射条件下的电池光电性能,并分析了制备方法对对电极微结构和形貌的影响,以及对组装电池光电性能的影响,并对其各自的适用性和优缺点进行了比较分析.  相似文献   

2.
Summary A method for the determination of wet and dry weight, has been developed which is adapted for small quantities of yeast. The wet yeast is prepared by a standardized suction filter method and titrated with Karl-Fischer solution. The dry matter content of yeast cells, harvested at daily intervals from growing cultures, changes in an increasing manner when the cultures becomes older. The values rise from about 20% to more than 30% dry matter from the second to the seventh day respectively.  相似文献   

3.
A combination of sister chromatid differential staining and giemsa banding.   总被引:2,自引:0,他引:2  
S Pathak  A D Stock  A Lusby 《Experientia》1975,31(8):916-918
We report a procedure for combining sister chromatid differential staining and G banding in the same metaphase plate. Mammalian cells in culture are grown in medium containing 5-bromodeoxyuridine for two cell cycles, and conventional air-dried preparations are made. The slides are treated with a trypsin or a urea solution the same way as for regular G banding. This method is simple and fast and provides additional information for cytogeneticists.  相似文献   

4.
Summary We describe a new rapid and simple method for collection and preparation of cell suspensions for electron microscopy; the cells are prefixed with glutaraldehyde in their culture medium, and are then compacted on a filter disc. Post-fixation in osmium, staining and dehydration are performed by transferring the filter disc and the cell pellet from one solution to the next. The pellet is easily separated from the filter disc just before treatment in propylene oxide. This method preserves the fine structure as well as the classical technique. Advantages are that numerous cells have the same orientation in the sections and that many samples can be taken in a very short time.Acknowledgments. The authors are indebted to Prof. H. Leclerc, Director of I.N.S.E.R.M. laboratory U 146 in which part of this work has been performed, and to Dr J.F. Dubremetz, Dr G. Prensier and Dr P.A. Trinel for their advices.  相似文献   

5.
Summary We report a procedure for combining sister chromatid differential staining and G banding in the same metaphase plate. Mammalian cells in culture are grown in medium containing 5-bromodeoxyuridine for two cell cycles, and conventional air-dried preparations are made. The slides are treated with a trypsin or a urea solution the same way as for regular G banding. This method is simple and fast and provides additional information for cytogeneticists.  相似文献   

6.
M J Pébusque  A Robaglia  R Se?te 《Experientia》1979,35(10):1370-1372
The superior cervical ganglia of the rat have been incubated in vitro for 1 h in basal medium Eagle (BME) with Hanks' salts, BME with Earle's salts, Kreb's solution and NCTC 109 medium. Comparison of the cell areas, established by a semi-automatic quantitative method, shows that the three former induce a 30--35% neuronal retraction, whereas NCTC 109 has no effect. Thus this latter medium seems the best one for studies using incubation of these cells.  相似文献   

7.
Substrates for studies of the interactions of attached cells with extracellular matrix components are often prepared by allowing a protein to adsorb from solution onto a glass or polystyrene substrate. This method is simple and effective for many studies, but it can fail in cases that require rigorous control over the structure and composition of adsorbed protein. Self-assembled monolayers formed by the spontaneous ordering of terminally functionalized alkanethiols onto a gold substrate are a class of well-ordered substrates and provide a convenient method for tailoring substrates with ligands, proteins and other groups. Methods that can pattern the monolayers provide a general strategy to create substrates that control the size, shape and spacing of attached cells. This review illustrates recent work that has used these methods of surface chemistry to create tailored substrates for studies in cell biology. Received 14 November 1997; received after revision 10 March 1998; accepted 10 March 1998  相似文献   

8.
悬索桥几何非线性及主缆受力分析   总被引:1,自引:1,他引:0  
利用离散、节点平衡求解、系统平衡协调迭代的方法求得具有确定长度的缆索在荷载作用下的曲线形式,详细分析了缆索在荷载作用下的挠度及变形。然后将悬索桥分为两大子结构,即主缆柔性结构,及加劲梁、塔柱等劲性结构。在两大子结构间的耦合点建立平衡方程,进行直接迭代求解。文中并对目前较为常用的结构几何非线性求解法进行了深入的探讨。通过算例证明本文方法不仅计算简单,迭代自由度少,而且计算结果完全可以与精确解媲美,完全克服了非线性方程求解中解的飘移现象。  相似文献   

9.
Summary The technique for testing lymphocytotoxicity by staining with Trypan-blue has been reevaluated. It was found that both cell suspension and aqueous stock solution (0.5%) of Trypan-blue must be adjusted to a pH of 7.3 prior to mixing in order to avoid a toxic effect of the dye itself, accounting for the lysis up to 35% of the cell population. This modification permitted a reproducibility of the results with a variation of less than 5%. This Trypan-blue test gives identical results as are obtained with the51Cr releasing method. The results may also be important for testing the viability of cells with Trypan-blue.  相似文献   

10.
Summary The superior cervical ganglia of the rat have been incubated in vitro for 1 h in basal medium Eagle (BME) with Hanks' salts, BME with Earle's salts, Krebs' solution and NCTC 109 medium. Comparison of the cell areas, established by a semi-automatic quantitative method, shows that the three former induce a 30–35% neuronal retraction, whereas NCTC 109 has no effect. Thus this latter medium seems the best one for studies using incubation of these cells.We are indebted to Miss M. Vio, Mrs J. Bottini, Mr C. Cataldo and Mr P. Cau for their helpful assistance.  相似文献   

11.
基于Matlab图像文字区域检测新方法对图文进行分离和显著性操作,并采用显著性度量对传统人脸文字区域检测的结果做进一步的显著性融合,实现了基于视觉显著性的人脸文字区域提取。实验结果表明,这种基于视觉显著性的人脸文字区域提取解决方案具有比较高的查全率和精确度。  相似文献   

12.
A Martin  M Richard  P Louisot 《Experientia》1976,32(7):844-846
One part of the microsomal galactosyl-transferase activity of splenic cells of rats can by solubilized by the action of Triton X-100 and Tween 20. Its purification on a Sephadex G-200 column and by electrophoresis on a polyacrylamide gel leads to a solution of high specific enzymic activity.  相似文献   

13.
针对一、二维椭圆方程构造了径向基无网格配置法;给出了解的存在唯一性;同时得到了基函数中自由参数c与求解精度的关系,以及节点均布时自由参数最佳取值的计算公式。将节点均布下得到的自由参数取值公式应用于节点任意排列的情况,其求解精度仍能得到保证,表明这种无网格方法对节点的位置不敏感。  相似文献   

14.
Summary Lectin-mediated stainings are widely used for the visualization of carbohydrate-carrying cellular components using the electron microscope. The use of glutarladehyde-fixed cells for these stainings introduces the possibility of low nonspecific lectin-trapping by the glutaraldehyde which coats the cells. This trapping was estimated by means of peroxidase-binding to human leukocytes,Tetrahymena pyriformis andEscherichia coli cells and was shown to be prevented by rinsing the glutaraldehyde-fixed cells in an amino acid solution before exposure to the lectin.  相似文献   

15.
Testing the existence of unit root and/or level change is necessary in order to understand the underlying processes of time series. In many studies carried out so far, the focus was only on a single aspect of unit root and level change, therefore limiting a full assessment of the given problems. Our study aims to find a solution to the given problems by testing the two hypotheses simultaneously. We derive the likelihood ratio test statistic based on the state space model, and their distributions are created by the simulation method. The performance of the proposed method is validated by simulated time series and also applied to two Korean macroeconomic time series to confirm its practical application. This analysis can provide a solution to determine the underlying structure of arguable time series. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

16.
钴及其化合物一维纳米材料的制备研究进展   总被引:1,自引:0,他引:1  
本文介绍了钴及其化合物一维纳米材料,如纳米线、纳米棒和纳米管的制备方法及其最新研究进展,包括热分解法、模板法、分子自组装、固相合成法和化学溶液法等。并预测了未来的可能的发展方向。  相似文献   

17.
三方硼镁石合成方法研究   总被引:1,自引:0,他引:1  
采用液-固转化法,研究了室温下水溶液中三方硼镁石的合成方法,并初步探讨了三方硼镁石的结晶机理.合成的三方硼镁石晶体,经化学分析法、X-ray粉晶衍射法、红外光谱法和热分析方法物相鉴定,发现合成晶体纯度高,可满足应用于该矿物的溶液化学性质研究.  相似文献   

18.
针对厚煤层采煤方法选择多目标非线性的问题,在影响因素分析的基础上,建立了预测仿真模型,利用神经网络改进算法训练网络,通过早停的方式解决网络过拟合问题。通过计算机仿真结合现场应用表明,该模型给出了最优方案,可为厚煤层采煤方法的合理选择和工作面主要经济技术指标的预测提供一种新的研究思路,在煤矿开采中具有广阔的应用前景。  相似文献   

19.
Summary Primary cell cultures from newborn rat brain hemispheres were exposed to different irrigation fluids used in neurosurgery. The cells died after incubation for 5 min with hydrogen peroxide, and the number of cells was drastically decreased after 10 sec of incubation. They shrank after incubation in Elliott's artificial cerebrospinal fluid for 3 h, but the viability as determined by trypan blue exclusion test was not affected. Physiological sodium chloride, Ringer's solution and the culture medium 199 with Hank's salt had no noticeable effect on the viability or morphology of the cells.Acknowledgments. This study was supported by grants from the Medical Faculty of Göteborg and from Statens Naturvetenskapliga Forskningsråd. We want to thank Dr Åke Sellström and Dr Hans-Arne Hansson for valuable discussions.  相似文献   

20.
Silica is the major component of the acid leaching residue of asbestos tailing.The waterglass solution can be prepared by the reaction of the residue with sodium hydroxide aqueous solution.Compared to the high temperature reaction method,this process is environmental friendly and low cost.In this paper,the reaction process of the residue and the sodium hydroxide aqueous solution is optimized.The optimum reaction process parameters are as follows:the usage of sodium hydroxide is 26.4 g/100 g acid leaching residue,the reaction temperature is 90℃,the reaction time is 1 h,and the ratio of the liquid/solid is 2.0.The significance sequence of the process parameters to the alkali leaching reaction effect is the usage of sodium hydroxidethe ratio of the liquid/solidthe reaction timethe reaction temperature.The significance sequence to the leaching ratio of SiO2 is the ratio of the liquid/solidthe usage of sodium hydroxidethe reaction timethe reaction temperature.The significance sequence to the modulus of the sodium silicate is the ratio of the liquid/solidthe usage of sodium hydroxidethe reaction timethe reaction temperature.Under the optimum conditions,the leaching ratio of the SiO2 is 77.5%,and the modulus of the sodium silicate is 3.15.The XRD analysis result indicates that the major components of the alkali leaching residue are serpentine,talc,quartz and some albite.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号