27 resultados para 1472


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IEECAS SKLLQG

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The branched copolymers prepared from ethylene and alpha-olefins using rac-Et(Ind)(2)ZrCl2/MMAO catalyst system were studied. Both the absolute molecular weight ((M) over bar (W)) and the molecular size (radius of glyration, R-g) of the polymers eluting from gel permeation chromatography (GPC) columns were obtained simultaneously via a high temperature GPC coupled with a two-angle laser light scattering (TALLS) detector. The branched structures and performances of the copolymers display approximate molecular weight and molecular sizes were investigated. Wide angle X-ray diffraction analyses indicate that 16-carbon side branch could co-crystallize effectively with backbone chain at low alpha-olefin incorporation. The melt behaviors of the copolymers were studied by dynamic rheological measurements. Both branch length and comonomer content affect considerably the loss modulus, storage modulus and complex viscosity of the copolymers. The relationship between the dynamic-mechanical behavior and the comonomer content of the copolymers was also examined by dynamic-mechanical experiments.

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The high-field nuclear magnetic resonance (NMR) spectra can be used for the rapid multicomponent analysis in small amounts of biological fluids. In this paper, the effect of La (NO3)(3) on the rats' metabolism in urine was investigated by H-1 NMR analysis. The experimental groups of wistar rats were injected intraperitoneally with La(NO3)(3) at doses of 0.2, 2.0, 10 and 20mg/kg body weight. The remarkable variation of low molecular weight metabolites in urine has been identified by H-1 NMR spectra, in which dimethylamine, N, N-dimethylglycine, urea, alpha -ketoglutarate, trimethylamine N-oxide, succinate, citrate and amino acids have been suggested as NMR markers for renal damage and ethanol, lactate, taurine as the markers for liver damage. This work may assess its possible use in the early detection of biochemical changes associated with Rare Earth induced kidney and liver dysfunction.

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以高场核磁共振技术为研究手段,通过分析腹腔注射0.2、2、10、20mg/kg体重剂量 的La(NO3)。后大鼠尿液中代谢物浓度、物种的变化,研究了稀土化合物在动物体内的作用 情况,结果表明稀土的引入使动物肾脏和肝脏都受到一定程度的损伤。并在代谢物中挑选出 了合适的NMR markers,其变化可以反映稀土离子作用后大鼠的异常代谢。

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沉积物可以提供连续的地磁场相对强度(RPI)记录,这些记录在全球范围内的对比具有一致性。目前RPI记录越来越多地在布容极性期内作为千年尺度高精度的地层对比手段,但由于构建RPI所需的岩石磁学标准较高,总体来说,RPI数据还相对缺乏,尤其是太平洋地区连续的RPI记录更是相对较少。本文以西太平洋特定海域沉积物为研究对象,进行了古地磁和岩石磁学方面等多个参数的综合测量,通过归一化天然剩磁得到了地磁场相对强度变化曲线,为RPI研究提供了新的记录,为研究区测年提供了新的手段。 西菲律宾海的Ph05孔沉积物的岩石磁学和古地磁研究表明,岩芯中的载磁矿物比较单一,以低矫顽力的磁铁矿为主,χ、ARM及SIRM等参数指示的磁性矿物的含量变化不大。磁性矿物的颗粒以准单畴为主,粒度指示参数χARM/χ具有冰期-间冰期旋回变化。通过交变退磁可得到稳定的特征剩磁,32-38 cm及108-110 cm处发现负倾角,并伴随着RPI的低值。谱分析检验后选择ARM作为归一化参数,通过ARM归一化天然剩磁获得了200 ka以来的地磁场相对强度记录。重建的RPI记录与综合曲线Sint-200有良好对比,可以反映全球性的信号。基于RPI建立的年代模型与氧碳同位素年代模型相似,可以作为独立的定年手段。 对东菲律宾海帕里西维拉海盆西侧F090102孔柱样沉积物进行了系统的古地磁和岩石磁学分析,结果表明样品适合进行相对强度研究。根据功率谱分析结果,选择非磁滞剩磁作为归一化的参数,得到约2 Ma以来的地球磁场相对强度变化曲线。该曲线与SINT-2000曲线可详细对比,比如呈比较典型的锯齿状特征,布容期内的记录与800 ka以来的SINT-800曲线相符。布容/松山极性转换期呈单强度降低的特征,在极性转换期和极性漂移期,相对强度曲线表现为显著低值。 对东海内陆架泥质区沉积物EC2005孔的磁学研究表明,岩芯在110 cm即受到还原成岩作用的影响;110-600 cm经历了铁氧化物还原阶段,样品中磁性矿物以PSD磁铁矿为主,随深度增加,其含量快速减少,其间随着硬磁矿物含量的波动,磁学参数也呈现出峰谷变化;600 cm向下岩芯经历硫酸盐还原阶段,各磁学参数都维持在很低的水平,顺磁性颗粒增加,并出现黄铁矿。早期成岩作用及重磁化作用使得古地磁信号被削弱和改造。

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【目的】验证饱和链烷技术测定家畜食性和食量的精确性,确定绵羊粪便中链烷的回收率。【方法】于2004年秋季在中国科学院内蒙古草原生态系统定位研究站用不同放牧演替阶段的优势植物羊草(Lcymus chincnsis)、糙隐子草(Cleistogenes squarrosa)和冷蒿(Artemisia frigide)按一定比例混合组成日粮,饲喂9只2岁羯羊,每只羊投喂一粒QSM胶囊,试验期内每天记录绵羊实际牧草采食量、采食成分和排粪量,利用气相色谱分析牧草和粪样的链烷含量,应用链烷技术测定绵羊的排粪量、不同牧草呆食比例和总干物质采食量,并与实际值进行比较。【结果】3种牧草链烷模式存在种间差异;绵羊粪便中链烷的回收率随链烷长度的增加而线性增加;绵羊排粪量测定值与实际值存在极显著的正相关(P〈0.01,r=0.9994);绵羊采食羊草、糙隐子草和冷蒿比例的测定值与实际值存在极显著(P〈0.01)正相关,相关系数分别为0.9913、0.9864和0.9999;绵羊干物质采食量用C33:C32和C31:C31比值测定的值分别比实际值低4%(±1.3%)和7%(±1.3%),但差异不显著(P〉0.05)。【结论】饱和链烷技术可以精确测定典型草原绵羊的排粪量、食物组成和采食量。

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本发明涉及一种降压消脂保健组合物,该组合物是由油菜花粉、决明子浸膏粉、山楂浸膏粉、黄芪浸膏粉、红花浸膏粉、山药浸膏粉制成,本发明具有调节血压,降低血脂,延缓高血压进展以及合并高脂血症,增强机体免疫力功能的作用,可达到预防和辅助治疗高血压症以及合并高脂血症的目的。

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The velocity field is important to investigate the motion and strain parameters of the block. It is also important to investigate the deformation of the fault, for example, the accumulation of strain and stress, at the boundary of the block. The dislocation model is a classic method to simulate the velocity field. In dislocation model, the aseismic crustal deformation is regarded as the sum of the rigid block motion and the effect of the locked fault. We modify the dislocation model in two aspects. Firstly, the block motion is assumed to be the sum of rotation and linear strain rather than the rigid motion. Secondly, the elastic layered-earth model rather than the homogenous half-space model is applied to calculate the effect of the locked part. The 1990~1995 annually Global Position System (GPS) velocity data of the Taiwan area are used in our dislocation model. The misfit of our modified model is smaller than that of the origin model clearly. Our simulation shows, in eastern Coastal Range, the velocity decreases northward rapidly from Chimei Fault, which may result from the high crustal compressive rate of about 30 mm•a-1 at Chimei Fault. The lock of fault in southern part is stronger than that in northern part generally. In western Taiwan, the most strongly locked faults appear in the southern Coastal Plain where many disaster earthquakes occur frequently. The calculated strain and rotation rates consist with previous results in most areas. The strain rate field reveals the nearly NW-SE compression in most parts of Taiwan with a fan-shaped distribution. The rotation rate field reveals anticlockwise rotation in eastern and southern Taiwan while clockwise rotation in western and northern Taiwan, generally.