329 resultados para 196-808
Resumo:
锂的两个稳定同位素(6Li 和7Li) 相对质量差较大,因此易产生明显的同位素分馏。业已查明,自然界中δ7Li值的变化在240 ‰和+ 50 ‰之间。其中较小的δ7Li 值见于海相生物碳酸盐样品,较大的δ7Li 值见于某些盐湖卤水以及有孔虫的样品。由于明显的同位素分馏和不同地质体中截然不同的δ7Li 值,锂同位素应用十分广泛,且在壳2幔演化、陆壳风化、卤水和污染水体示踪等研究领域取得显著成效。
Resumo:
本文从地屡舍矿性、同岩泉活动的关系厦同住素组成特扯等几十方面进行分析,以阐明湘中鹄矿山式锑矿成矿抽质来源于构造岩策活化作用形成的区域性深郜上升流体。虽煞赋矿层住相对集中,但不存在明显的锑矿源屡。铅同住素矸究表明矿石铅来源于深郜均化紊件下的铅同往素演化系统.与围岩地屡铅同住素明显车同。硫同住素显示矿石硫为均一化程度较高的混合漾源硫。包裹体水氢、氧同住素组成舟于太气降水与初生水之问,为混合水类型。
Resumo:
重庆城口地区从震旦统到下寒武统发育有丰富的黑色岩系,20世纪末期在该地区黑色岩系中开展了大量的铂族元素(PGE)的找矿工作,但是由于种种原因,关于该地区是否存在PGE矿化异常,还没有得到最终的结论。本次研究在PGE分析方法论证的基础上,进行了大量样品的PGE分析和微量元素分析。主要结论如下:①区域上上震旦统槽区和断块区两套黑色岩系在原始的沉积环境和物源供给上有较大的差异,虽然槽区上震旦统的黑色岩系具有和下寒武统黑色岩系相似但强度较低的V-Cu-Y-Mo—U异常,但基本上不具有明显的PGE-Au-Ag异常。②断块区水井沱组黑色岩系:和平剖面西段新发现的U-V-Mo-PGE异常可能是今后工作的重点,Pt+Pd最高达248.9×10^-9,局部U-V都达到了工业品位。③槽区巴山组硅质岩:四个剖面都揭示了在硅质岩中广泛存在连续的PGE异常,87个碳质硅质岩平均含Pt+Pd 57.2×10^-9,有10个样品Pt+Pd〉100×10^-9,最高达196.5×10^-9;大部分碳质硅质岩都具有不同程度的V-Cu-Y-Mo-Tl-U组合异常,V都达到了独立矿床的品位要求,其中猪草河、燕子河等剖面还存在厚度较大的富矿地段,特别是燕子河剖面,局部还存在REE+Y的高异常,值得深入研究。④城巴地区下寒武统黑色岩系存在广泛的PGE异常,但没有达到PGE的矿化要求,建议加强该地区的钒矿和铀矿勘探研究,PGE可以综合评价。
Resumo:
查干凹陷位于银额盆地东部查干德勒苏坳陷的中央,行政区划隶属内蒙古自治区乌拉特后旗,主体是在晚古生代褶皱基底上发育起来的中新生代断陷,面积约2000 km2.广泛分布的火山岩是查干凹陷的一个特色,火山岩作为沉积盆地特定演化阶段的产物,记录了凹陷沉积、构造、油气成藏等诸多方面的信息,而且钻井资料又显示孔缝发育的层段可以作为重要的储集层,致密火山岩可作为区域性的盖层,因而具有重要的研究意义.
Resumo:
在贵州牛角塘镉锌矿床中既有次生硫镉矿的存在,也发现了原生硫镉矿。硫镉矿的产状如下:①呈包裹 体形式产于硫化物中;② 以不规则晶粒赋存于硫化物粒间:③ 形成硫镉矿.方铅矿细脉或硫镉矿微脉穿插硫化 物:④分布在黄铁矿中方铅矿或闪锌矿周围;⑤被菱锌矿胶结并交代,形成硫镉矿残骸状角砾;⑥组成菱锌矿. 硫镉矿疏松集合体或菱锌矿.硫镉矿细脉;⑦呈皮壳状或薄膜状分布在氧化矿石表面或裂隙面上。前五种形式 产出的硫镉矿为原生硫镉矿,主要分布在原生矿石或弱氧化的矿石中。后两种产状的硫镉矿为次生硫镉矿, 分布于氧化矿石晶洞中或矿石表面和裂隙面上。并从Cd、zn地球化学特性、热力学和结晶化学性质探讨了原 生硫镉矿形成机制。
Resumo:
华南下寒武统保存着国际著名的生物群(如澄江生物群),同时蕴藏着磷块岩、重晶石、稀土及Ni-Mo-PGE等丰富的矿产资源,因此,它一直为地质科学家们持续关注的热点之一。关于华南下寒武统的研究,前人在古生物学方面已经取得了卓著的成就,主要表现在国际权威期刊上(如期刊《Science》和《Nature》)已发表大量的关于澄江生物群的研究成果,对早期生命演化研究具有重要而广泛的影响。然而,华南下寒武统年代学及国际对比研究方面已明显滞后,公开发表的华南下寒武统的高精度、可靠的锆石U-Pb年龄数据至本研究论文截稿时止仍然仅有唯一的一个,即Jenkins et al. (2002)报道的国际前寒武系-寒武系界线层型候选剖面―云南晋宁梅树村剖面的朱家菁组中谊村段中部(第5层)钾质斑脱岩锆石SHRIMP U-Pb年龄(538.2 ± 1.5 Ma)。因而,华南下寒武统中的重要生物群、矿床及具全球对比意义的C同位素漂移事件缺乏地层精确年龄的约束,进而制约了早期生命演化理论、矿床成因解释及地层国际对比等方面研究的发展。 近来,发现华南下寒武统赋存独特的钾质斑脱岩层,它们在横向上广泛分布于云南东部、四川峨眉麦地坪、贵州西部(如织金和金沙岩孔)及北部(如遵义松林)、湖北宜昌泰山庙和湖南张家界等地区,在地层序列垂向上主要产出于朱家菁组中谊村段中部、石岩头组底部以及它们的相当层位。这些钾质斑脱岩既是建立地层框架等时层潜在的物质基础,亦是获取地层精确锆石U-Pb年龄的具重要意义的研究对象之一。因此,对它们进行系统研究可望改观华南下寒武统年代学及国际对比研究方面的落后现状。 同时,华南下寒武统广泛产出的磷块岩既具有重要的资源价值,另一方面,任一磷块岩层代表着一次独立的成磷事件,因而将华南地区下寒武统磷块岩进行区域上的对比研究,从而以磷块岩层作为等时层,对构建华南下寒武统地层框架具有重要的地层学意义。 此外,华南下寒武统产出的Ni-Mo多元素富集层广泛分布于扬子地台范围,西起云南东部,东部延至浙江诸暨地区,在NE-SW向延伸近1600 km,它既代 表了重要的成矿事件,亦为关键的地球化学异常层位。因此,对Ni-Mo多元素富集层进行区域上的对比研究,明确它在华南下寒武统各重要剖面的产出位置,对于构建华南下寒武统层序框架具有重要意义。 遵义松林地区的下寒武统因赋存Ni-Mo-PGE矿床及与滇东地区澄江生物群相当的遵义生物群而日益受到国内外地质学家们的广泛关注。该区牛蹄塘组底部产出磷块岩、钾质斑脱岩及Ni-Mo多元素富集层,与滇东地区梅树村剖面出露的地层具有潜在的可对比性。因此,本研究选取近年来日益受科学家们关注的遵义松林地区下寒武统作为研究对象,重点对该区牛蹄塘组底部的钾质斑脱岩开展矿物学、地球化学和年代学研究。同时,将遵义松林地区下寒武统剖面上磷块岩、钾质斑脱岩、Ni-Mo多元素富集层主要与滇东地区梅树村剖面的相应岩层进行地球化学对比研究。研究的目的在于通过对华南地区上述两条代表性的下寒武统剖面进行地层对比研究,初步构建华南下寒武统具时间、空间涵义的层序框架,从而约束华南下寒武统中的重要生物群、矿床及具全球对比意义的C同位素漂移事件的时间,进一步促进华南下寒武统的划分和全球对比。论文获得以下主要结论性认识: (1)滇东地区朱家菁组中谊村段中部钾质斑脱岩及其邻近的磷块岩可构成华南下寒武统层序框架的第一个标志层。这一标志层在贵州大部分地区(或华南地区的多数下寒武统剖面)缺失。该标志层的磷块岩稀土元素总量和Y含量高于新元古代陡山沱期磷块岩,低于遵义松林地区牛蹄塘组底部及其华南其它地区相当层位(石岩头组底部及戈仲伍组)的磷块岩。第一个标志层的钾质斑脱岩的原始岩浆为亚碱性系列的酸性岩浆,其典型特征为具有较低的Zr(变化范围144×10-6~291×10-6,平均196.4×10-6)、Nb(变化范围10×10-6~13×10-6,平均11.86×10-6)含量和较高的Zr/Nb比值(变化范围为12.63~24.24,平均值为16.55)。这一层钾质斑脱岩的锆石U-Pb年龄为538.2±1.5 Ma(Jenkins et al., 2002)。 (2)遵义松林地区牛蹄塘组底部钾质斑脱岩和磷块岩分别相当于滇东地区石岩头组底部钾质斑脱岩和磷块岩,它们构成华南下寒武统层序框架的第二个标志层。该标志层中钾质斑脱岩的原始岩浆性质为中性岩浆,其碱性程度高于朱家菁组中谊村段中部钾质斑脱岩的原始岩浆。相对于中谊村段中部钾质斑脱岩,该层位的钾质斑脱岩具有高的Zr(变化范围187.0910-6~391.5710-6,平均值318.4010-6)、Nb(49.6910-6~140.0010-6,平均值90.6810-6)含量和低的Zr/Nb(2.60~4.32,平均值3.61)比值。该钾质斑脱岩的年龄为518 ± 5 Ma。该标志层的磷块岩以极其富REE和Y为特征,其稀土元素总量平均值为636.01×10-6,Y含量平均值262.43×10-6,明显高于滇东地区中谊村段磷块岩(∑REE平均值为195.45×10-6,Y含量平均值为91.2310-6),它们代表早寒武世时期一次特殊的以极其富REE和Y为特征的成磷事件。 (3)Ni-Mo多元素富集层可以作为构建华南下寒武统层序框架中的第三个等时标志层。滇东地区梅树村剖面的Ni-Mo多元素富集层被重新校正在玉案山组底部(即13层,Ni、Mo含量分别为135×10-6和583×10-6)。Ni-Mo多元素地球化学标志层的典型特征为在剖面上具Ni、Mo等多种微量元素及贵金属元素的最高异常。该标志层的Re-Os年龄为537~542 Ma,可能代表的不是地层层序的年龄。 (4)初步建立华南下寒武统时间框架。约束了华南地区下寒武统Ni-Mo-PGE矿床的下限年龄应为518 ± 5 Ma。同时,该时间框架亦约束了滇东地区澄江生物群及最古老三叶虫的下限年龄(518 ± 5 Ma),考虑到石岩头组底部钾质斑脱岩的产出位置与玉案山组中部澄江生物群的产出层位存在相当的距离(大于80 m),因此,前人对澄江生物群的推测年龄(525~530 Ma)可能有些偏老。此外,初步约束了华南地区具全球对比意义的C同位素正漂移事件的年龄(538~518 Ma)。该时间框架是建立在两个相互支持的地层高精度锆石SHRIMP U-Pb年龄的基础之上,而国际前寒武系-寒武系界线年龄的最新研究成果为542 Ma,因此,它支持将华南地区的前寒武系-寒武系界线置于朱家菁组中谊村段中部钾质斑脱岩层(第5层)的下伏地层的方案。结合华南地区最新的地层古生物学研究成果(朱茂炎等,2001;Zhu et al., 2003),将这一界线置于朱家菁组中谊村段底界可作为一种合理的选择。
Resumo:
There is an urgent need for thorough analysis of Radix astragali, a widely used Chinese herb, for quality control purposes. This paper describes the development of a total analytical method for Radix astragali extract, a multi-component complex mixture. Twenty-four components were separated step by step from the extract using a series of isocratic isopropanol-methanol elutions, and then 42 components were separated similarly using methanol-water elutions. Based on the log k(w) and -S of the 66 components obtained from the above procedure and the optimization software developed in our laboratory, an optimum elution program consisting of seven methanol-water segments and four isopropanol-methanol segments was developed to finish the task of analyzing the total components in a single run. Under optimized gradient conditions, the sample of Radix astragali extract was analyzed. As expected, most of the components were well separated and the experimental chromatogram was in a good agreement with the predicted one.
Resumo:
IQ Structure, Psycholinguistic and Visual-motor Abilities Study on Children Learning Disability TONG Fang Directed by professor Zhu Liqi (Developmental and educational psychology) ABSTRACT Objective To comprehensive analyze the IQ structures, and relationships among IQ, psychometric characteristics and visual-motor integration on children disability. At same time, to probe into the family factors that influenced IQ, psycholinguistic abilities and behavior of LD children. Method (1) Downloading the papers on children learning disability from www.cqvip.com and www.wanfangdata.com, in which, the articles were collected by key words from 1985 to 2005. To conduct meta-analysis on IQ construction, compare the case group and the control group, including full IQ, verbal and practice IQ. (2) Designed with model compared and self-compared, 59 diagnosed learning disability children, tested themes with WISC, ITPA and Berry’s VMI. WISC included 10 items, 5 of which subtotal to verbal and practice IQ respectively. IPTA included 10 items, too, 5 process of which subtotal to auditory and visual perception. The first 3 items shared representation level, the other 2 of that shared automatic level.VMI had one score. Analyzed factors and levels with description and Pearson Correlation. To probe to linguistic internal alternately functions of LD children, and compare the scores of groups in different IQ. (3) Analyzed the perspective questionnaire filled by parents. Early development facts compared with model groups. Factors relationships analyzed with Kendall correlation, KOM and Bartlett’s test of sphericity, Promax Rotation. Results: (1) There have been 319 papers related with LD, in which 36 with IQ and 14 valid reports have been analyzed by Meta. FIQ’s 95%CI (confidence interval) is 2.418 ~ 0.172, VIQ between the difficulty and non- difficulty group. C-WISC-R reports were 10 papers, of which, 95%CI of FIQ is 2.424 ~ 0.676, of VIQ is 2.314 ~ 1.196, of PIQ is 2.176 ~ 0.176. The VIQ comparing the PIQ, 95%CI is 1.1 ~ -0.07 in difficulty group and 0.5 ~ -0.0046 in non-difficult group. Nevertheless, in the other 4 tests, FIQ’s 95%CI is 2.00 ~ -0.818 between LD and NLD. (2) Children psycholinguistic abilities had strong relation with Berry’s VMI test excluding auditory reception, and with perceptive factor of intelligence excluding verbal expression. Auditory reception and visual closure had strong relation with FIQ and PIQ. Grammatic closure, visual association and manual expression had strong relation with concept factor. The representational and automatic levels are depended on integration of auditory and visual procession. Lower verbal expression (VE) let to lower expression process and low scores on representational level. Lower visual sequential memory (VSM) let to lower memory process and influenced automatic level. Groups compared by IQ 90 show that LD children with under IQ 90 had lower scores on items of IPTA than with up IQ 90 excluded verbal expression. It was proved that IQ administrated the linguistic ability. Nevertheless, general abilities deficiency didn’t show influencing on the types of the perceptive delay. There was mutual function among linguistic ability on LD children. Auditory and visual level are overlapped each other. Not only show higher Decoding and lower Encoding on Auditory perception, lower Decoding and higher Encoding on Visual perception, in representation, but also higher Sequential remember, lower Closure on Audition, and lower Sequential member, higher Closure on Vision, in Automation. Nevertheless, there was no different between Representational and Automatic level, which may be the relationship of parallel or evolution. (3) Major family factors were father’s education, occupation. Lower auditory perception related to unconcerned, lower visual perception related to premature delivery and written slowly. Threatened–abortion, childbirth-suffocated were known as influencing children’s IQ and later linguistic abilities. It wasn’t shown that dosage relationship with the types of perceptive delay. Conclusion: (1) The FIQ, VIQ and PIQ of Children with LD is lower than that of NLD group. There is no significantly different between VIQ and PIQ in LD and NLD groups. (2) The objectives of ITPA and WISC tests are differently. The psycholinguistic abilities had strong relation with perceptive factor and VMI. Some facts of IPTA related with FIQ. IQ had strong administration on linguistic abilities. There was mutual function among linguistic internal abilities. (3) Family facts on IQ and psycholinguistic abilities were Father’s education, abnormal pregnant and abortion. It would be pre-show development delay in early period.
Resumo:
Different mechanisms for the formation of acetaldehyde and ethanol on the Rh-based catalysts were investigated by the TPR (temperature programmed reaction) method, and the active sites were studied by CO-TPD, TPSR (temperature programmed surface reaction of preadsorbed CO by H-2) and XPS techniques. The TPR results indicated that ethanol and acetaldehyde might be formed through different intermediates, whereas ethanol and methanol might result from the same intermediate. Results of CO-TPD, TPSR, and XPS showed that on the Rh-based catalyst, the structure of the active sites for the formation of C-2-oxygenates is ((RhxRhy+)-Rh-0)-O-Mn+ (M=Mn or Zr, x>>y, 2 less than or equal ton less than or equal to4). The tilt-adsorbed CO species is the main precursor for CO dissociation and the precursor for the formation of ethanol and methanol. Most of the linear and geminal adsorbed CO species desorbed below 500 K. Based on the suggested model of the active sites, detailed mechanisms for the formation of acetaldehyde and ethanol are proposed. Ethanol is formed by direct hydrogenation of the tilt-adsorbed CO molecules, followed by CH2 insertion into the surface CH2-O species and the succeeding hydrogenation step. Acetaldehyde is formed through CO insertion into the surface CH3-Rh species followed by hydrogenation, and the role of the promoters was to stabilize the intermediate of the surface acetyl species. (C) 2000 Academic Press.
Resumo:
Molar heat capacities of ( S)-ibuprofen were precisely measured with a small sample precision automated adiabatic calorimeter over the temperature range from 80 to 370 K. Experimental heat capacities were fitted into a polynomial equation of heat capacities ( C-p,C- m) with reduced temperature ( X), [ X = f(T)]. The polynomial equations for ( S)-ibuprofen were C-p,C- m(s) = - 39.483 X-4 - 66. 649 X-3 + 95. 196 X-2 + 210. 84 X + 172. 98 in solid state and C-p,C- m(L) = 7. 191X(3) + 4. 2774 X-2 + 56. 365 X + 498. 5 in liquid state. The thermodynamic functions relative to the reference temperature of 298. 15 K, H-T - H-298.15 and S-T - S-298.15, were derived for the( S)-ibuprofen. A fusion transition at T-m = (324. 15 +/- 0. 02) K was found from the C-p - T curve. The molar enthalpy and entropy of the fusion transition were determined to be (18. 05 +/- 0. 31) kJ.mol(-1) and (55. 71 +/- 0. 95) J.mol(-1).K-1, respectively. The purity of the ( S)-ibuprofen was determined to be 99. 44% on the basis of the heat capacity measurement. Finally, the heat capacities of ( S)-ibuprofen and racemic ibuprofen were compared.