29 resultados para mini-PTA
Resumo:
本文以中国砂鼠利会曼原虫(Leishmanina grbilli)为材料,对动质体的细微结构及动质体碱性蛋白的细胞化学特性作了研究。已知真细菌类染色质体中有碱性的HU蛋白与DNA结合着,动质体中是否也有碱性蛋白与DNA相结合,一直是有争议的问题。de Souza等(1978-83)证明锥虫的动质体中确有碱性蛋白存在,但迄今止,国际上还没有关于利会曼原虫动质体碱性蛋白的报导。用热三氯醋酸-偶氮洋红G法、热三氯醋酸-固绿法、碱性比布列希猩法、碳酸氨银反应(AS反应)、经亚硝酸处理后作AS反应和经碱性蛋白不同成份抽提后作AS反应等光学显微细胞化学方法以及酒精钨酸染色(E-PTA)、用乙醇-醋酸固定、DNA酶处理后作E-PTA染色和碳酸氨银反应等电镜水平的细胞化学方法进行了研究。得到了如下的结果:(1)L.gerbilli的动质体中确实含有大量的酸溶性碱性蛋白。(2)对用E—PTA染色后,动质体只有周边着色的现象作了探讨,认为是假期象。动质体中碱性蛋白与DNA的分布是一致的。(3)动质体碱性蛋白对热三氯醋酸(TCA)处理的耐受性比HU蛋白的强比组慢白的弱;动质体碱性蛋白对亚硝酸处理的耐受性和与AS液的亲和力也比组蛋白弱。(4)可以抽提富含精氨酸的组蛋白的80%Alc-0.18NHCl,和可以抽抻富含赖氨酸的组蛋白的10%Alc-0.18NHCl,都不能把动质体碱性昼白全部抽提掉。(5)与真细菌类的HU蛋白相比较。L.gerbilli的动质体的碱性蛋白看来含有较多的精氨酸成份。作超薄切片,用电镜观察了L.gerbilli的质膜及质膜下微管、鞭毛、细胞核、动质体、线粒体、复片层结构等,发现:①与其它利会曼原虫和锥虫的鞭毛基部的结构不同,L.gerbilli的鞭毛基部没有基板存在。②L.gerbilli的复片层结构特别发达,是由膜组成的同心圆或同心椭圆结构。③L.gerbilli的动质体在通常情况下作“棒”状,但我们发现它实际上是一个环状结构。这在细胞膨胀时表现得非常突出。
Resumo:
Silicon crystal-facet-dependent nanostructures have been successfully fabricated on a (100)-oriented silicon-on-insulator wafer using electron-beam lithography and the silicon anisotropic wet etching technique. This technique takes ad-vantage of the large difference in etching properties for different crystallographic planes in alkaline solution. The mini-mum size of the trapezoidal top for those Si nanostructures can be reduced to less than 10nm. Scanning electron microscopy(SEM) and atomic force microscopy (AFM) observations indicate that the etched nanostructures have controllable shapes and smooth surfaces.
Resumo:
This paper presents an introduction to the application of ion traps and storage devices for cluster physics. Some experiments involving cluster ions in trapping devices such as Penning traps, Paul traps, quadrupole or multipole linear traps are briefly discussed. Electrostatic ion storage rings and traps which allow for the storage of fast ion beams without mass limitation are presented as well. We also report on the recently developed mini-ring, a compact electrostatic ion storage ring for cluster, molecular and biomolecular ion studies.
Resumo:
随着中科院近代物理研究所重离子束治癌技术和浅层治疗应用基础研究的不断开展,对束流入射深度分布的影像测试研究成为了重要的研究课题。本论文基于此背景,成功研制了小型符合影像探测系统,并进行了深入的影像测试应用研究。符合影像探测的基本原理为通过符合探测系统对正电子放射性核素引起的正负电子湮灭辐射进行符合测量,并利用相应的影像重建方法就可以得到影像体的影像结果。研制的符合影像探测系统由两个探测单元组成,单元的核心探测器件为具有64个通道的位置灵敏平板型光电倍增管H8500,其前端与性能优良的BGO闪烁晶体阵列耦合,输出信号采用电阻网络简化读出。通过比较蒙特卡罗模拟结果和实际测试结果,优化设计了符合探测单元,主要确定了闪烁晶体单元的大小和组成阵列的构形:探测阵列由19X19块晶体单元组成,每块晶体单元大小为2X2X10mm3,间距为0.3mm的Tefon薄膜隔离。基于这种单元构形,探测单元的本征位置分辨约为:1.37mm(FWHM),组成的符合影像探测系统空间位置分辨约为(对22Na源):1.87mm(FWHM)。上述指标接近于小型符合探测系统最佳本征和空间位置分辨。符合影像探测系统分别在22Na 正电子发射源和12C束流入射有机靶不同条件下进行测试研究。采用中心焦平面影像原理进行数据的影像重建,得到了符合探测系统的空间位置分辨能力、最大计数率和靶内深度分布的影像测试结果。分析束流入射PMMA靶60秒后的测量数据,成功分离了靶内10C、11C 和15O 三种主要正电子放射性核素产物,对不同产物的深度分布与测试布拉格峰位进行了比较,得到了一种如何实现浅层治疗在线监测的研究方法。实验研究结果表明,研制的这一套2D符合影像探测系统具有高的空间位置分辨率、较大的探测视野(约50X50mm3)和较好的影像能力。12C束流入射有机靶的影像测试研究结果表明,该方法和该探测系统可以应用于重离子浅层治疗,可以在治疗过程中实现快速地、准确地对布拉格峰位进行监测
Resumo:
采用田间试验研究了留茬少耕秸秆全程覆盖、免耕补充灌溉和传统保墒耕作 3种方法对旱地土壤水分及小麦产量的影响。结果表明 ,留茬少耕秸秆覆盖增加了夏闲期农田的蓄水量 ,为旱地小麦播种出苗提供了水分保证。小麦收获时的土壤水分含量 ,0~ 60 cm的土壤有效蓄水量传统保墒方法为 6.4mm,免耕补充灌水的为 6.7mm,留茬少耕秸秆全程覆盖方法为 1 5 .3 mm,留茬少耕秸秆全程覆盖方法的蓄水量多 ;60~ 1 0 0 cm的土壤有效蓄水量传统保墒方法为 3 0 .9mm,免耕补充灌水为 2 0 .3 mm,留茬少耕秸秆全程覆盖方法为 3 3 .5 mm,也是留茬少耕秸秆全程覆盖方法的蓄水量多。留茬少耕秸秆全程覆盖比传统耕作保墒技术增产 6.7%~ 5 4.8%。留茬少耕秸秆覆盖技术 ,提高了小麦播种时的底墒、灌浆时的土壤水含量 ,是一种有效的蓄水保墒、提高旱地小麦产量的方法
Resumo:
Quantum-chemistry methods were explored to investigate the electronic structures, injection and transport properties, absorption and phosphorescence mechanism of a series of blue-emitting Ir(III) complexes {[(F-2-ppy)(2)Ir(pta -X/pyN4)], where F-2-ppy = (2,4-difluoro)phenylpyridine; pta = pyridine-1,2,4-triazole; X = phenyl(1); p-tolyl (2); 2,6-difluororophenyl (3); -CF3 (4), and pyN4 = pyridine-1,2,4-tetrazolate (5)}, which are used as emitters in organic light-emitting diodes (OLEDs). The mobility of hole and electron were studied computationally based on the Marcus theory. Calculations of Ionization potentials (IPs) and electron affinities (EAs) were used to evaluate the injection abilities of holes and electrons into these complexes.
Resumo:
Layer-by-layer (LBL) self-assembly is a simple and elegant method of constructing organic-inorganic composite thin films from environmentally benign aqueous solutions. In this paper, we utilize this method to develop proton-exchange membranes for fuel cells. The multilayer film is constructed onto the surface of sulfonated poly(arylene ether ketone) (SPAEK-COOH) membrane by LBL self-assembly of polycation chitosan (CTS) and negatively charged inorganic particle phosphotungstic acid (VIA). The highly conductive inorganic nanoparticles ensure SPAEK-COOH-(CTS/PTA)(n) membranes to maintain high proton conductivity values up to 0.086 S cm(-1) at 25 degrees C and 0.24S cm(-1) at 80 degrees C, which are superior than previous LBL assembled electrolyte systems.
Resumo:
A novel and facile chemical synthesis of highly faceted multiply twinned gold nanocrystals is reported. The gold nanocrystals are hexagonal in transmission electron microscopy and icosahedral in scanning electron microscopy. Phosphotungstic acid (PTA), which was previously reduced, serves as a reductant and stabilizer for the synthesis of gold nanocrystals. The PTA-gold nanocomposites are quite stable in aqueous solutions, and electrochemically active towards the hydrogen evolution reaction.
Resumo:
Multilayers of anionic phosphotungstic acid (PTA) clusters and positively charged protonated poly(allylamine hydrochloride) (PAH) were assembled by layer-by-layer self-assembled method on Au electrode modified by 3-mercaptopropionic acid (3-MPA). The effect of the charge of the surface of the multilayer assembly on the kinetics of the charge transfer reaction was studied by using the redox probes [Fe(CN)(6)](3-)/(4-) [Ru(NH3)(6)](2+/3+). The cyclic voltammetry experiments showed that the peak currents and peak-to-peak potential differences changed after assembling different layers on the electrode surface indicating that the charge of the surface has a significant effect on the kinetics of the studied charge transfer reactions. These reactions were studied in more detail by electrochemical impedance spectroscopy. When [Fe(CN)(6)](3-/-) was used as the redox label, multilayers that terminated with negatively charged PTA showed a high charge transfer resistance but multilayers that terminated with positively charged PAH showed lower charge transfer resistance. With [Ru(NH3)(6)](2+/3+) as the redox label, the charge transfer resistance at multilayers that terminated with positively charged PAH was much higher than at the multilayer terminated by the negatively charged PTA.
Resumo:
Using a solid phase extraction mini-column home-made from a neutral extractant Cyanex 923, inorganic Hg could be on-line preconcentrated and simultaneously separated from methyl mercury. The preconcentrated Hg (11) was then eluted with 10% HNO3 and subsequently reduced by NaBH4 to form Hg vapor before determination by cold vapor atomic absorption spectrometry (CVAAS). Optimal conditions for and interferences on the Hg preconcentration and measurement were at 1% HCl, for a 25 mL sample uptake volume and a 10 mL min(-1) sample loading rate. The detection limit was 0.2 ng L-1 and much lower than that of conventional method (around 15.8 ng L-1). The relative standard deviation (RSD) is 1.8% for measurements of 40 ng L-1 of Hg and the linear working curve is from 20 to 2000 ng L-1 (with a correlation coefficient of 0.9996). The method was applied in determination of inorganic Hg in city lake and deep well water (from Changchun, Jilin, China), and recovery test results for both samples were satisfactory.
Resumo:
Two strains H-2-410 and H-2-419 were obtained from the chemically mutated survivors of wild Haematococcus pluvialis 2 by using ethyl methanesulphonate (EMS). Strains H2-410 and H2-419 showed a fast cell growth with 13% and 20% increase in biomass compared to wild type, respectively. Then H-2-419-4, a fast cell growth and high astaxanthin accumulation strain, was obtained by exposing the strain H2-419 to ultraviolet radiation (UV) further. The total biomass, the astaxanthin content per cell, astaxanthin production of H-2-4194 showed 68%, 28%, and 120% increase compared to wild H. pluvialis 2, respectively. HPLC (High Performance Liquid Chromatography) data showed also an obvious proportional variation of different carotenoid compositions in the extracts of H2-4194 and the wild type, although no peak of carotenoids appeared or disappeared. Therefore, the main compositions in strain H-2-419-4, like its wild one, were free of astaxanthin, monoester, and diester of astaxanthin. The asexual reproduction in survivors after exposed to UV was not synchronous, and different from the normal synchronous asexual reproduction as the mother cells were motile instead of non-motile. Interestingly, some survivors from UV irradiation produced many mini-spores (or gamete?), the spores moved away from the mother cell gradually 4 or 5 days later. This is quite similar to sexual reproduction described by Elliot in 1934. However, whether this was sexual reproduction remains questionable, as no mating process has been observed.
Resumo:
本文利用BP(Back-Propagation)人工神经网络对三维物体的姿态测定进行了研究。姿态测定一直缺少通用而实际的方法,人工神经网络由于具有强大的自组织、自适应学习能力,迅速的并行信息处理能力,可望解决这个问题。但现有BP算法存在训练慢和易陷入局部最小两个问题.本文提出的级联形式网络结构,使BP网络的训练速度大为提高,陷入局部最小的可能性大为降低。利用这种级联结构对飞机模型姿态测定,取得了较好的实验结果。
Resumo:
本文阐述了在小型计算机上建立的 GPSS-F/1000通用仿真软件包。该软件包不仅具有原 GPSS-F仿真软件的全部功能,并且使公用数组、系统参数的适配全部活化,通过子程序的形式参量传送赋给,从而,仿真时不必修改子程序的源程序。此外,增加了统计参数估计子程序集和图形绘制子程序集。
Resumo:
The reservoir of Zhongerbei region in Gudao Oilfield is a typical fluvial facies deposit, its serious heterogeneity of the reservoir caused the distribution of remaining oil in mature reservoirs is characterized by highly scattered in the whole field, and result to declination of production, tap potential and stabilize production is more difficult. Reservoir modeling based on lay scale can not fulfill requirement. How to further studied reservoir heterogeneity within the unit and establish the finer reservoir modeling is a valid approach to oil developing. The architectural structure elements analysis is the effectively method to study reservoir heterogeneity. Utilize this method, divide the reservoirs of Gudao Oilfield into ten hierarchies. The priority studying is sixth, seven hierarchies, ie single sand layers sand bodies By the identification of sixth, seven hierarchies, subdivide the reservoir to the single genetic unit. And to subdivide by many correlation means, such as isometry and phase transition, accomplish closure and correlation of 453 wells.Connectting fluvial deposit pattern, deposition characteristic with its log, build the inverting relation between “sedimentary facies” and “electrofacies” The process emphasize genetic communication and collocation structure of genetic body in space. By detailed architecture analyses sandbodies’ structure, this paper recognize seven structure elements, such as major channel, abandoned channel, natural levee, valley flat, crevasse splay, crevasse channel and floodplain fine grain.Combination identification of architectural structure elements with facieology and study of deposition characteristic, can further knowing genesis and development of abandoned channel. It boost the accuracy to separation in blanket channel bodies distribution, and provide reference to retrieving single channel boundary. Finally, establish fine plane and section construction. On basis architectural structure map, barrier beds and interbeds isopach map and mini-structure map, considering single thin layers to be construction unit, the main layer planimetric maps have drawn and the inner oil-water boundary have revealed. All account that architectural structure elements control remaining oil distribution in layer, and develop the study on architectural structure elements to direct horizontal well is succesful.