52 resultados para Travi reticolari miste (P.R.E.M), Ansys, Matlab, Stabilità
Resumo:
虾青素因其具有极强的抗氧化性及优越的着色作用,被广泛应用于营养保健和水产养殖中,备受国内外研究者的关注。红球藻是目前虾青素的生物来源中较有优势的一条途径。 我们选取雨生红球藻作为研究材料,收集其生长过程中四个不同的阶段,分别为绿色游动细胞阶段,绿色不动细胞阶段,绿褐色不动细胞阶段(开始积累虾青素),以及红色不动孢子阶段。本研究中提取了核酮糖-1,5-二磷酸羧化/加氧酶(Rubisco)的粗提液,并测定了酶活。其编码基因rbcL的mRNA表达量也被测定。另外,光合速率与呼吸速率的比值(P/R)通过测定与计算得出,各个阶段藻细胞中虾青素的含量由分析得出。本研究还应用了叶绿素荧光测定方法,确定了光系统II潜在最大活性(Fv / Fm),光系统II实际活性(ΦPSII),电子传递速率(ETR)和非光化学淬灭参数(NPQ)。 结果表明,绿色游动细胞的生长状态最佳,其P/R、Fv / Fm、ΦPSII均为最大,NPQ为最小。这说明在此状态的细胞中,光系统II的活性最强;但是其Rubisco活性与rbcL表达量均为最小。相比之下,在绿褐色不动细胞中,P/R和NPQ的值较低,Fv / Fm、ΦPSII和ETR值都最小,但Rubisco活性与rbcL表达量均为最高。 结合工业生产虾青素的方法,我们认为,Rubisco或许参与了虾青素的合成,而非Calvin循环为色素合成提供前体和能量。因此,在生产过程中适当加入碳源,比如CO2,可以有效增大虾青素的产量。
Resumo:
The Study carried out in Xueshan Township, Guoluo prefecture, Qinghai Province, P. R. China from 1997 to 1999 on 1) Growth regulation of yak from born to adult and 1/4 wild yak from born to one and half year; 2) The effect of nursing or not on the growth and development of dam; 3) Meat performance of local yak; 4)Milk productivity of female yak. It can be served as the theory basis from which crossbreed improvement of yak and government decision could be drawn.
Resumo:
Random amplified polymorphic DNA ( RAPD) markers were used to measure genetic diversity of Coelonema draboides ( Brassicaceae), a genus endemic to the Qilian Mountains of the Qinghai-Tibet Plateau. We sampled 90 individuals in 30 populations of Coelonema draboides from Datong and Huzhu counties of Qinghai Province in P. R. China. A total of 186 amplified bands were scored from the 14 RAPD primers, with a mean of 13.3 amplified bands per primer, and 87% ( 161 bands) polymorphic bands (PPB) was found. Analysis of molecular variance (AMOVA) shows that a large proportion of genetic variation (84.2%) resides among individuals within populations, while only 15.8% resides among populations. The species shows higher genetic diversity between individuals than other endemic and endangered plants. The RAPDs provide a useful tool for assessing genetic diversity of rare, endemic species and for resolving relationships among populations. The results show that the genetic diversity of this species is high, possibly allowing it to adapt more easily to environmental variations. The main factor responsible for the high level of differentiation within populations and the low level of diversity among populations is probably the outcrossing and long-lived nature of this species. Some long-distance dispersal, even among far separated populations, is also a crucial determinant for the pattern of genetic variation in the species. This distributive pattern of genetic variation of C. draboides populations provides important baseline data for conservation and collection strategies for the species. It is suggested that only populations in different habitats should be studied and protected, not all populations, so as to retain as much genetic diversity as possible.
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Constructing reservoir in mountain area, in order to avoid dangerous reservoir and ensure long-term stable reservoir storage, study on reservoir leakage has been one of research hotspots. How to accurately predict the capacity of leakage and the effect of anti-seepage after reservoir impoundment under different anti-seepage measures is one of the most difficult problems of study on reservoir leakage. The paper took Manghekou Reservoir as a case study, which is located in Jiyuan City, Henan Province, China. Based on the system analysis of the geological and hydrogeological characters in the research area, the hydrogeological conceptual model was established. Then, according to the triplex boundary nested grid model method, using three-dimensional numerical simulation technique, the 3-D groundwater seepage flow numerical model was established in the study area. Based on the model, the change of seepage flow field, the capacity of leakage and the effect of anti-seepage are predicted after Manghekou reservoir impoundment under different condition. The reasonable and reliable anti-seepage measure is selected according to the model. All these provides scientific basis for the design and assessment of anti-seepage measure for the reservoir in mountain area.
Resumo:
锡的分布和成矿作用通常与花岗岩浆作用具有十分密切的联系。以往研究表明锡矿化与高度分异的S型花岗岩或陆壳改造型花岗岩具有密切的成因联系,但近年来随着大量与A型花岗岩有关的锡矿床的发现,人们开始关注A型花岗岩与锡成矿关系的研究。相对于与S型花岗岩有关的锡矿床来说,与A型花岗岩有关的锡矿床成成矿机理的研究积累少,研究程度相对较低。 湘南地区位于南岭多金属成矿带中部,是我国华南地区重要的有色金属成矿带。近年来在该成矿带上新发现的芙蓉超大型锡多金属矿床为世界瞩目,该矿床的形成与骑田岭花岗岩具有密切的时空关系。近年来研究显示骑田岭花岗岩具有A型花岗岩的特征。本文以芙蓉超大型锡多金属矿床和相关的骑田岭岩体为研究对象,在前人研究的基础上,运用岩石学、矿物学、流体包裹体、微量元素和稳定同位素地球化学等理论和方法,对芙蓉锡矿成矿流体的地球化学特征及其演化机制进行了系统的研究,并在此基础上探讨了骑田岭花岗岩体与芙蓉锡矿间的成因联系和芙蓉锡矿的成因机制。论文取得的主要认识包括以下几个方面: 1. 运用矿物学、岩石化学、微量元素地球化学以及同位素地球化学方法,进一步证实了骑田岭花岗岩体具有A型花岗岩的特征,总体具有偏铝质-弱过铝质、高硅富碱高钾的地球化学特征,早晚两期花岗岩具有同源岩浆演化特征,属于A2型花岗岩。同位素地球化学数据显示花岗岩体具有EMII型富集地幔的特征,形成于华南大陆地壳拉张减薄的构造环境,成岩过程中有地幔物质加入。 2. 通过对矿石矿物组构和成分的岩矿鉴定、扫描电镜和电子探针分析,确定了芙蓉锡多金属矿床原生夕卡岩形成于较氧化的环境,成岩作用主要与早期侵入的角闪石黑云母花岗岩密切相关,锡主要以Sn(IV)进入夕卡岩的造岩矿物晶体内。退蚀变夕卡岩、云英岩和蚀变花岗岩矿化为锡成矿主阶段,三种矿化类型的成矿流体具有相似的地球化学性质,即富Cl、Ti和Sn的特征,而锡石硫化物型矿石形成于成矿晚阶段。 3. 运用流体包裹体地球化学理论和方法以及激光拉曼分析技术,揭示了芙蓉锡矿的成矿流体组成、形成的物理化学条件和演化特征。芙蓉锡多金属矿田成矿流体为CO2-CH4-CaCl2- NaCl-KCl不混溶体系,成矿过程中发生流体不混溶作用。芙蓉锡矿成矿流体盐度为0~50.63 wt%NaCl eq.,密度为0.31~1.12g/cm3,主成矿阶段热液流体的均一温度主要集中在300-450℃,流体压力为179-1800bar,成矿晚阶段锡石硫化物型矿石中均一温度主要集中在150~300℃,流体压力为400-600bar。成矿流体特别是主成矿阶段的流体成矿过程中普遍发生了沸腾现象。从主成矿阶段到成矿晚阶段、矿化期后,热液流体盐度呈降低的趋势,流体成分也从含CO2、CH4的CaCl2-NaCl-KCl-H2O水溶液体系转化为不含CO2的简单NaCl-KCl-H2O水溶液体系。 4. 通过分析主要矿化类型矿石中脉石矿物的稀土元素和稳定同位素特征,揭示了成矿流体来源。研究表明芙蓉矿床成矿期热液脉石矿物的稀土元素地球化学和稳定同位素地球化学显示了与本区花岗岩具明显的相似性,骑田岭黑云母花岗岩形成过程中分异出的岩浆期后热液应是芙蓉矿床成矿流体的主要来源,成矿过程中有少量经过深循环的大气降水加入。 5. 在总结前人研究成果的基础上,综合上述研究,探讨了骑田岭花岗岩体与芙蓉锡矿间的成因联系和芙蓉锡矿的成因机制。本文认为骑田岭岩体中黑云母花岗岩与Sn成矿具有密切的成因联系,芙蓉锡矿田的成矿流体主要来源于黑云母花岗岩岩浆结晶期后分异出的富Cl和Sn的热液流体。芙蓉锡矿成矿流体中锡主要呈Sn(II)与氯离子形成亚锡氯络合物进行迁移,低温的大气降水与高温的岩浆热液流体混合,导致流体体系温度、盐度、压力的降低和富CO2相流体的分离(CO2去气作用),流体的氧逸度升高,使得Sn(II)与氯离子形成亚锡氯络合物解体,Sn(II)被氧化成SnO2并发生沉淀作用。这种流体的混合作用是导致锡石沉淀的最有效的机制。
Resumo:
南岭地区是我国最重要的有色、稀有金属矿产资源产地,尤以钨、锡等金属的大规模爆发式成矿而闻名于世,已发现了一大批大型、超大型稀有和有色金属矿床。近年来的研究发现,这些矿床的形成很可能与华南地区中生代发生的大规模地壳拉张、岩石圈伸展减薄以及壳―幔相互作用的独特地质背景有关。本论文以与千里山花岗岩体密切相关的柿竹园钨锡钼铋铅锌矿田(以下简称柿竹园矿田)为研究对象,运用流体包裹体、稳定同位素和稀有气体同位素地球化学等方法,对其成矿流体的物理化学特征、来源及演化进行了研究,并在此基础上探讨了千里山花岗岩体与柿竹园矿田间的成因联系和矿田的成矿作用机制,获得以下主要研究成果: 1. 利用流体包裹体岩相学、显微测温学以及包裹体成分的激光拉曼分析技术,揭示了矿田中柿竹园钨锡钼铋矿床成矿流体的性质和演化特征。研究表明柿竹园钨锡钼铋矿床成矿流体为中高温、中高盐度H2O-NaCl-CaCl2-CO2-CH4-H2S-F体系。成矿流体的均一温度、盐度、密度和压力变化范围均较大,成矿早期夕卡岩阶段和云英岩阶段的流体具有较高的均一温度(239~477℃)和盐度(0~39.08 wt% NaCl eq.),云英岩网脉夕卡岩阶段和后期石英萤石脉阶段均一温度和盐度逐渐降低(分别为160~450℃,1.23~16.53 wt% NaCl eq.和156~340℃,1.23~4.49 wt% NaCl eq.)。夕卡岩阶段发生了流体沸腾作用。流体密度为0.37~1.12 g/cm3,主要集中在0.7~0.9 g/cm3;压力为10~820 bar,一般小于800 bar。野鸡尾锡铜矿床的成矿流体属于中高温度、中等盐度的H2O-NaCl-CaCl2-CO2-CH4-H2S-F型体系,柴山铅锌矿床属中温中等盐度H2O-NaCl-CaCl2-CO2-F体系,其均一温度和压力变化范围也较大。 2. 通过分析主要矿化类型矿石矿物及脉石矿物的C、H、O、S等稳定同位素特征,揭示了柿竹园矿田成矿流体的来源,并对C、O同位素的组成进行了CO2去气、流体混合和水―岩反应的理论模拟。研究表明矿田成矿流体主要来自千里山花岗岩浆,并有大气降水加入。水―岩反应在成矿过程中起着重要作用。 3. 对矿田不同矿化类型矿石矿物黄铁矿、黄铜矿、毒砂、方铅矿等进行了He、Ar同位素研究,其中3He/4He值为0.059~1.662 Ra(Ra为空气的3He/4He值,1 Ra=1.39×10-6),40Ar/36Ar值为289.8~1071.8,表明矿田成矿流体具有壳-幔两端员混合的特征。壳源组分为获得了大量地壳放射成因4He,但获得放射成因40Ar*较少的经过地下循环的低温饱和大气水。而幔源组分来自千里山花岗岩浆流体,表明千里山花岗岩并非传统的S型花岗岩。 4. 在总结前人研究成果的基础上,结合本次研究,建立了柿竹园矿田成矿作用模式:中生代华南岩石圈发生拉张、伸展作用,地幔物质上涌,发生壳幔相互作用,形成千里山花岗岩浆。花岗岩浆充分分异演化形成富含挥发分和成矿元素的成矿流体,与泥盆系碳酸盐岩发生反应而沉淀成矿。成矿过程有大气降水的加入,并发生了流体沸腾作用。
Resumo:
The capacity factors of a series of hydrophobic organic compounds (HOCs) were measured in soil leaching column chromatography (SLCC) on a soil column, and in reversed-phase liquid chromatography on a C-18 column with different volumetric fractions (phi) of methanol in methanol-water mixtures. A general equation of linear solvation energy relationships, log(XYZ) = XYZ(0) + mV(1)/100 + spi* + bbeta(m) + aalpha(m), was applied to analyze capacity factors (k'), soil organic partition coefficients (K-oc) and octanol-water partition coefficients (P). The analyses exhibited high accuracy. The chief solute factors that control log K-oc, log P, and log k' (on soil and on C-18) are the solute size (V-1/100) and hydrogen-bond basicity (beta(m)). Less important solute factors are the dipolarity/polarizability (pi*) and hydrogen-bond acidity (alpha(m)). Log k' on soil and log K-oc have similar signs in four fitting coefficients (m, s, b and a) and similar ratios (m:s:b:a), while log k' on C-18 and log P have similar signs in coefficients (m, s, b and a) and similar ratios (m:s:b:a). Consequently, log k' values on C-18 have good correlations with log P (r > 0.97), while log k' values on soil have good correlations with log K-oc (r > 0.98). Two K-oc estimation methods were developed, one through solute solvatochromic parameters, and the other through correlations with k' on soil. For HOCs, a linear relationship between logarithmic capacity factor and methanol composition in methanol-water mixtures could also be derived in SLCC. (C) 2002 Elsevier Science Ltd. All rights reserved.