995 resultados para 49-410


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A method for the determination of Au, Pt and Pd in geological samples is described. Au, Pt and Pd can be separated and concentrated quantitatively by C-410 anion-exchange resin in the condition of 1.5 mol/L HCl with the adsorption rates of 91.2%, 100.0% and 95.7% respectively. No interference exists from coexisting elements except for Ge(IV), Cr(VI),Ti(IV) in inductively coupled plasma-mass spectrometry. The detection limits are 0.27 mug/L, 0.40 mug/L and 0.19 mug/L for Au, Pt and Pd respectively. The results of these elements in standard geological materials are in agreement with certified values with precision of 19.2% RSD for Au (n = 8), 28.1% RSD for Pt (n=8), and 15.6% RSD for Pd (n=8).

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研究了地质样品中超痕量Au、Pt和Pd的测定方法。采用C 4 1 0阴离子交换树脂在 1 .5mol LHCl条件下对Au、Pt、Pd的吸附率分别为 91 .2 %、1 0 0 .0 %、95 .7%。共存离子除Ge4+ 、Cr6 + 、Ti4+ 外 ,无显著性干扰。用ICP MS测定Au、Pt、Pd的检出限分别为 0 .2 7、0 .4 0和 0 .1 9μg L。当n =8时 ,Au的RSD为 1 9.2 % ;Pt的RSD为 2 8.1 % ;Pd的RSD为 1 5 .6%。

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A series of cardo polyaryletherketones and polyaryletersulfones containing alkyl substituents of a different kind, number and volume were synthesized from bis(4-nitrophenyl)ketone or bis(4-fluorophenyl)sulfone with various alkyl substituted phenolphthaleins by polycondensation using K2CO3 as catalyst. Their chemical and aggregation structures were confirmed by FT-IR, H-1-NMR and WAXD. The resulting polymers were soluble in a variety of common polar solvents and, transparent, colorless, and tough films could be easily cast from 1,1,2-trichluoroethane solution. Their tensile strength, elongation at break and tensile modulis were in the range of 70.5 similar to 97.1MPa, 4.49%similar to7.81%, and 1.69 similar to2.27GPa, respectively. The prepared polymers had reasonably high glass transition temperatures at 207 to 269 degreesC, and showed fairly good thermal stability with 5% thermal decomposition loss above 410 degreesC.

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In the title compound, catena-poly[dipotassium [[(oxalato-O,O')dioxomolybdate]-mu-oxo]monohydrate], oxalate acts as a bidentate ligand coordinating to each Mo atom through the two deprotonated carboxylate groups. The coordination polyhedron of molybdenum is distorted octahedral and there are infinite chains in the structure. Principal dimensions are: Mo-O(terminal) 1.560 (3) and 1.739 (3) Angstrom, Mo-O(bridging) 2.046 (4) and 2.410 (4) Angstrom, and Mo-O(carboxylate) 1.949 (3) and 2.113 (3) Angstrom.

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The morphology and structure of the syndiotactic polystyrene (sPS)/atactic polystyrene (aPS) blends with various compositions have been studied by means of DSC, optical microscopy, SAXS, and WAXD. The results show that aPS is miscible with amorphous region of sPS. There is no macroscopic evidence that aPS forms separated domains in the blends. The decrease in crystallinity of sPS in the blends implies segregation of the aPS to the interfibrillar regions of the spherulites of sPS. The constancy of interlamellar distance and melting points indicates that the fibrillar structural units of sPS is unchanged on addition of aPS to sPS, and the unchanging parameters of the sPS unit cells mean that aPS does not enter the unit cells of sPS.

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[Al(C15H9O3)(3)](2) . 2CHCl(3) . 8H(2)O was synthesized, and its crystal structure was determined. It belongs to trigonal system, R3, a=b=1. 655 8(3) nm, c=3. 646 5(20) nm, alpha = beta = 90 degrees, gamma = 120 degrees, V = 8. 656 08(0. 005 86) nm(3). D-c = 1.45 g/cm(3), mu(Mo K alpha) = 3. 20 cm(-1), F (000) = 3 924. The crystal structure was solved by Patterson and Fourier techniques, and refined by a block-diagonal least-squares method. A total of 3 737 independent intensity data were collected, of which 1 033 with I greater than or equal to 3 sigma(I-0) were observed, R = 0. 091 8, Rw=0. 091 8. Al3+ ion was 6-coordinated, bound to six oxygen atoms from three 3-hydroxyflavones to form a distortional coordination octahedron.

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Electrochemical behavior of the transfer of H+ across polypyrrole membrane (PPM) was studied. The transfer process was quasi-reversible and mainly diffusion-controlled. PPM electropolymerized in water solution has better reversibility than that in CH3CN solution for the transfer of H+. The transfer process of H+ across the two kinds of PPM indicated that the PPM electrochemically polymerized was of asymmetry.

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本论文研究了胶洲湾、东海和渤海的蓝细菌(Synechococcus)、生物量、异养细菌生物量和生产力的生态学特点。并在汇泉湾、渤海和东海用分极增减法对海洋蓝细菌在微型食物环(the microbial loop)中的作用进行了初步研究。在以上海区调查研究的时间如下:胶州湾:1993年2月、5月、9月11月,1996年5月、1999年3月、5月和12月。汇泉湾:1996年4月至1998年4月。东海:1997年2-3月,1998年7月。渤海1998年9-10月,1999年4-5月。研究结果如下:胶州湾:蓝细菌生物量的变化范围是11.4-0.03 mgC/m~3,季节变化是夏季>秋季和春季>冬季。其水平分布是除夏季蓝细菌生物量是沿岸浅水区向湾外递减外,其它三季(春、秋和冬季)是由湾外向湾内至沿岸浅水区递减。蓝细菌生物量与海水温度周年变化正相关,与季节海水温度的关系是秋、冬季分布变化一致,春、夏季分布变化相反。海水温度是影响胶州湾蓝细菌生物量分布变化的主要原因。异养细菌生物量和生产力的变化范围分别是29.8-1.62 mgC/m~3; 129.12-1.92 mgC/m~3.d。季节变化都是夏季>秋季、春季>冬季。夏季的异养细菌生物量和生产力水平分布趋势与蓝细菌生物量的分布变化相同。海水温度对异养细菌生产力的影响较对异养细菌生物量的影响大。异养细菌生产力相比(BP:PP)的变化在0.58-0.02之间,季节分布变化是夏季>秋季、春季>冬季。夏季表层的BP:PP由沿岸浅水区向湾心、湾口和湾外递减。东海:蓝细菌生物量的变化范围是46.72-0.011 mgC/m~3,夏季高平均是23.59 mgC/m~3,冬季低平均是3.61 mgC/m~3。冬季蓝细菌生物量的水平分布明显受黑潮的影响,在表面和20米层是由东南向西北方向递减。其垂直分布是冬季表层和20米层>底层,夏季是20米层>表层>底层;在连续站冬111站和410站变化都是中层>底层>表层。异养细菌生物量和生产力的变化范围分别是17.2-4.4 mgC/m~3(1997.2);376.8-7.2 mgC/m~3.d。异养细菌生产力夏季高平均是35.1 mgC/m~3.d。异养细菌生物量的水平分布是由沿岸向外海递增(1997.2),异养细菌生产力的水平分布是冬季异养细菌生产力在32度断面有由沿岸向外递减趋势,PN断面的变化与冬季相似。垂直分布,冬季和夏季的异养细菌生产力的垂直变化在2断面是底层大于表面,PN断面则是表层大于底层,32度断面大多断站是底层大于表层。在连续站冬季111站异养细菌生产力的变化是底层>中层>表层,409站的变化是中层>底层>表层,夏季111站和410站都是中>底层>表层。异养细菌生物量(1997.2)表层分布变化与海水温度分布变化相似,底层变化相反。异养细菌生产力与初级生产力相比(BP:PP),冬季在0.04-0.30之间,平均为0.17;夏季在0.20-0.43之间平均0.32。冬季在长江口附近BP:PP有一个高值区是0.30,夏季在111站附近有一个高值区是0.43。从连续站111站和409’站观测发现底层的BP:PP明显高于表层。渤海:蓝细菌生物量秋季(16.6-0.37 mgC/m~3)比春季(0.44-0.015 mgC/m~3)高。其秋季的水平分布与海水盐度水平分布相同,与海水温度水平分布相反。异养细菌生产力秋季(189-62.2 mgC/m~3.d)与春季(193.2-49.8 mgC/m~3.d)相当。但秋季捕层BP普遍小于底层,而春季是表层普遍大于底层。根据颗粒分级培养实验结果,海洋蓝图细菌在微型食物环中的作用如下:在汇泉湾的春季和秋季蓝细菌可能主要被小型浮游动物(microzooplankton 20-200 μm)捕食。在渤海的春季和秋季也是同样结果。但在东海夏季的111站和410站附近(东海大陆架中部)微型浮游动物(nanozooplankton 2-20 μm)对蓝细菌的捕食压力明显。

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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187.0910-6~391.5710-6,平均值318.4010-6)、Nb(49.6910-6~140.0010-6,平均值90.6810-6)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91.2310-6),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。

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1999

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A cultivar de trigo BRS 49, desenvolvida pela Embrapa Trigo, foi indicada para semeadura no Estado do Parana, a partir de 1999. Para a determinacao do seu valor de cultivo e uso, foram utilizados dados de 54 experimentos, instalados em nove locais das regioes 6, 7 e 8 do Parana, no periodo de 1996 a 1998. Apresenta como principais caracteristicas: ciclo intermediario, altura media a alta, moderada resistencia ao acamamento, tolerancia ao aluminio toxico no solo, moderada resistencia ao oidio (Blumeria graminis f. sp tritici) e a ferrugem da folha (Puccinia recondita f. sp. tritici), com percentuais de severidade em ensaios inferiores aos das testemunhas Trigo BR 23 e Trigo BR 35, suscetibilidade a giberela (Giberella zeae), cujas notas foram superiores as atribuidas as testemunhas, elevado potencial de rendimento e boa qualidade industrial. No trienio considerado, apresentou rendimento medio de 4.667 kg/ha na Regiao 6, 3.432 kg/ha, na Regiao 7, e 3.930 kg/ha, na regiao 8. Esses valores foram 11%, 11% e 28%, respectivamente, superiores a media das testemunhas (Trigo BR 2, Trigo BR 35 e CEP 24-Industrial). Os percentuais de resposta ao controle fitossanitario foram, em geral, inferiores aos observados nas referidas testemunhas, evidenciando o elevado potencial de rendimento da cultivar com aplicacoes reduzidas de fungicidas. A forca geral de gluten (W), na media de 14 amostras coletadas nas tres Regioes, foi de 260 e a relacao P/L foi de 0,685. Portanto, a cultivar se enquadra na classe Trigo Pao, de acordo com a Instrucao Normativa n.1, de 27 de janeiro de 1999 do MA. A cultivar apresenta caracteristicas de interesse agronomico, principalmente por possibilitar a obtencao de altos rendimentos, sem a necessidade de elevados investimentos com fungicidas.

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Practice Links is a free e-publication for practitioners working in Irish social services, voluntary and nongovernmental sectors. Practice Links was created to enable practitioners to keep up-to-date with new publications, electronic resources and conference opportunities. Issue 49 contains information regarding dance therapy for schizophrenia and the role mindfulness based stress reduction (MBSR) plays in improving the lives of adults. The issue also contains details of employment opportunities in Australia.