26 resultados para Matthaei, Frederick C. Sr.
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
Ginseng is one of the most expensive Chinese herbal medicines and the effectiveness of ginseng depends strongly on its botanical sources and the use of different parts of the plants. In this study, a microchip electrophoresis method coupled with the polymerase chain reaction (PCR)-short tandem repeats (STR) technique was developed for rapid authentication of ginseng species. A low viscosity hydroxypropyl methylcellulose (HPMC) solution was used as the sieving matrix for separation of the amplified STR fragments. The allele sizing of the amplified PCR products could be detected within 240 s or less. Good reproducibility and accuracy of the fragment size were obtained with the relative standard deviation for the allele sizes less than 1.0% (n = 11). At two microsatellite loci (CT 12, CA 33), American ginseng had a different allele pattern on the electropherograms compared with that of the Oriental ginseng. Moreover, cultivated and wild American ginseng can be distinguished on the basis of allele sizing. This work establishes the feasibility of fast genetic authentication of ginseng species by use of microchip electrophoresis.
Resumo:
云南会泽铅锌矿田是我国著名的超大型特富铅锌矿田之一,由相距3公里的矿山厂和麒麟厂两个独立的矿床组成,Zn+Pb金属量超过五百万吨,矿石品位在25%至35%之间。为确定矿床成矿流体和成矿金属来源,本文系统研究了矿床的Ph、S、CO、H和Sr位素组成特征。矿石硫化物的铅N位素组成均一,^206Pb/^204Pb,^207Pb/^204Pb和。^206Pb/^204Pb的变化范围分别为18.251~18.530,15.663~15.855和38.487~39.433,与围岩碳酸盐岩中浸染状黄铁矿一致,与碳酸盐地层相近,在^208Pb/^204Pb-^206Pb/^204Pb图上显示明显的线性关系,表明铅N位素组成相近的碳酸盐围岩地层提供了成矿物质。矿石硫化物的δ^14S变化范围为10.9‰~17.4‰,多数集中于13‰~17‰,表明还原硫主要来自地层中海相硫酸盐的还原,还原方式为热化学还原,下伏页岩、碎屑岩和泥质岩中的有机质在硫酸盐还原过程中发挥了重要作用。三种不同产状的脉石矿物方解石的碳氧同位素组成均一且没有明显差别,δ^13C化范围为-2.1‰~-3.5‰, δ^18O为16.8‰~18.6‰。脉石矿物方解石中流体包裹体水的δDFI为-50‰~-60‰,取温度为200℃计算包裹体水的δ^18OH2O值为7.0‰~8.8‰。碳、氧和氢、氧同位素研究结果表明,成矿流体为来自下部上升的变质流体,由于下伏页岩、碎屑岩和泥质岩中有机质的参与,成矿流体具有低的δ^13Cδ^13DFI值,在上升过程中与围岩发生了同位素交换。矿石中黄铁矿、闪锌矿和方解石的初始锶同位素组成(^87Sr^86Sr.值的变化范围为0.714~0.717,赋矿围岩中未蚀变白云岩的初始锶同位素组成(^87Sr^86Sr.值为0.7083~0.7093,明显低于蚀变白云岩(0.7106),表明成矿流体具有高的(^87Sr^86Sr,比值。相对围岩碳酸盐岩而言,下伏地层中的页岩、碎屑岩和泥质岩往往具有高得多的^87Sr^86Sr因此,流经或者起源于这些地层的流体具有高的锶同位素比值.
Resumo:
对湖南香花岭锡多金属矿床成矿早、晚两期方解石进行了系统的CO、Sr位素研究。结果表明,成矿早期方解石具有相对较低的δ^13 CPDB(-5.4‰~-1.4‰)、δ^18 OSMOW(+6.1‰~+13.9‰)和较高的^87Sr^86Sr(0.7101~0.7230);而成矿晚期方解石则具有相对较高的δ^13 CPDB(+0.2‰~+0.6‰)、δ^18 OSMOW(+19.4‰~+21.5‰)和较低的^87Sr^86Sr(0.7101)。分析认为,成矿早期方解石为岩浆热液与海相碳酸盐岩相互作用的产物,成矿流体中的碳源于岩浆碳和海相碳酸盐岩;模拟计算结果显示,成矿早期方解石为成矿溶液发生0.05~0.1摩尔分数的CO2去气作用的产物。而成矿晚期方解石主要为矿区碳酸盐岩低温淋滤的产物,流体中的碳主要源于矿区碳酸盐岩围岩。成矿流体中的Sr于矿区花岗岩和碳酸盐岩,从成矿早期到晚期,岩浆来源的Sr渐减少,而碳酸盐岩围岩提供的Sr例不断增大。
Resumo:
湖北通山的徐家山锑矿床产在上震旦统陡山沱组和灯影组的海相碳酸盐岩中。对该矿床中成矿前和成矿期方解石进行了较系统的CO、Sr位素地球化学研究,结果表明,成矿前方解石具相对较高的δ^13CPDB(-0.7‰+2.0‰)、δ^18OSMOW(+18.6‰- +19.6‰)和Sr量(2645,8174μg/g,平均5656μg/g),及较低的87SrS6Sr值(0.7096—0.7097);而成矿期方解石具相对较低的δ^13 CPDB(-3.9‰~-2.1‰)、δ^18OSMOW(+11.5‰~+15.3‰)、Sr Rr含量(785~2563μg/g,平均1571μg/g),和较高的^87 Sr^85 Sr值(0.7109-0.7154,平均0.7141)。分析认为,成矿前方解石的CO和绝大部分Sr源于赋矿围岩——震旦系海相碳酸盐岩;而成矿流体为富H2CO3的溶液,它来自或流经富放射成因。^87 Sr下伏基底碎屑岩——中元古界冷家溪群浅变质岩;该流体与围岩发生水-岩反应导致成矿期方解石和辉锑矿的沉淀.
Resumo:
Er3+ doped multicomponent fluoride based glass was prepared. These precursor fluoride glass samples were then heated using different schedules. Crystalline phase particles were successfully precipitated in the multicomponent fluoride glass samples after heat treatment. The influence of heat treatment on the spectroscopic properties of Er3+ in multicomponent fluoride based glass samples were discussed. Small changes of the Judd-Ofelt parameters Omega(i) (i = 2,4,6) were found in multicomponent fluoride glass samples before and after heat treatment compared to oxyfluoride telluride glass. Preparation conditions used to produce transparent multicomponent fluoride glass ceramics doped with rare-earth ions are discussed. (c) 2007 Elsevier B.V. All rights reserved.
Resumo:
A new laser crystal Nd3+:(La, Sr)(Al, Ta)O-3 (abbreviated as Nd3+:LSAT) has been grown by the conventional Czochralski method. The absorption and luminescence spectra of trivalent neodymium in Nd3+:LSAT crystal were measured at room temperature. The value of absorption and emission cross-section was calculated. The Judd-Ofelt analysis was applied to the crystal to get the phenomenological parameters (Omega(i), i = 2,4,6), the line strengths, the radiative transition rates, the branching ratios and the radiative lifetime. (C) 2006 Elsevier B.V. All rights reserved.
Resumo:
采用气相传输平衡技术在掺Sr^2+的α-BBO(001)衬底上制备了β-BBO薄膜,研究了粉料配比、VTE处理温度以及恒温时间对薄膜质量的影响。结果表明,在适当的粉料配比、VTE处理温度以及恒温时间下,在Sr^2+:α-BBO晶片表层制备呈c高度择优取向的、没有第二相物质的β-BBO薄膜,其双晶摇摆曲线半峰宽值FWHM为1000",显示出β-BBO薄膜较好的结晶质量。并对气相传输平衡技术制备β-BBO薄膜的机理进行了初步的探讨。
Resumo:
A novel C-type lectin-like protein, dabocetin, was purified from Daboia russellii siamensis venom. On SDS-polyacrylamide gel electrophoresis, it showed a single band with an apparent molecular weight of 28 kDa and two distinct bands with the apparent mole
Resumo:
Two systems of mixed oxides, La2-xSrxCuO4 +/- lambda (0.0 less than or equal to x less than or equal to 1.0) and La(2-x)Tn(x)CuO(4 +/-) (lambda) (0.0 less than or equal to x less than or equal to 0.4), with K2NiF4 structure were prepared. The average valence of Cu ions and oxygen nonstoichiometry (lambda) were determined by means of chemical analysis. Meanwhile, the adsorption and activation of nitrogen monoxide (NO) and the mixture of NO + CO over the mixed oxide catalysts were studied by means of mass spectrometry temperature-programmed desorption (MS-TPD). The catalytic behaviors in the reactions of direct decomposition of NO and its reduction by CO were investigated, and were discussed in relation with average valence of Cu ions, A and the activation and adsorption of reactant molecules. It has been proposed that both reactions proceed by the redox mechanism, in which the oxygen vacancies and the lower-valent Cu ions play important roles in the individual step of the redox cycle. Oxygen vacancy is more significant for NO decomposition than for NO + CO reaction. For the NO + CO reaction, the stronger implication of the lower-valent Cu ions or oxygen vacancy depends on reaction temperature and the catalytic systems (Sr- or Th-substituted). (C) 2000 Elsevier Science B.V. All rights reserved.
Resumo:
With XRD, R-T, and ac chi measurements a comparative study on the doping effects of 3d elements in Bi(1.5)Pb(0.2)Sr(2)Ca(2)Cu(2.8)M(0.2)O(y) (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, or Zn) has been carried out. The effects of the former five members are significantly different, both on phase formed and on T-c, from the latter four. It seems that the effect on phase stabilization correlates with the valency of the doped cation. In connection with the instability of the 2223 phase, the correlation has been discussed.
Resumo:
Bi1-xLaxSrMn2O6 and BiSr1-xCaxMn2O6 are prepared by solid state reaction. They are n-type semiconductors with ferromagnetism at room temperture. When Bi is substituted partly by rare earth, a negative magnetoresistance effect is observed in the pellet of Bi1-xLaxSrMn2O6. There are semiconductor-metal transitions at 820 K in BiSrMn2O6. The transitions are attributed to the magnetic transition at high temperature. The substitution of Ca for Sr makes the transition temperature increase. However, when Bi is partly substituted by La, the solid solution does not change into metal. (C) 1996 Academic Press, Inc.