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丁爱玲 《广东微量元素科学》2003,10(2):20-22
给动物喂食高Se、高vitaminE、高Se高vitaminE合用饲料 ,探讨单独及合用高Se、高vitaminE对十二月龄动物血清中MDA和ALT的影响。结果显示 ,与对照组比较 ,单独及合用高Se、高vitaminE均可显著降低血清中MDA的含量 (P <0 0 1 ) ,高vitaminE尚能使血清中ALT水平升高 (P <0 0 5 ) ,而高Se高vitaminE合用则可纠正高vitaminE引起的血清中ALT水平的升高 相似文献
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高硒情况下维生素E对老龄大鼠血清中抗氧化作用的影响 总被引:3,自引:0,他引:3
研究了高Se或高维生素E下,老龄大鼠体内抗氧化活性的变化以及高Se下维生素E对其体内抗氧化水平的影响。将十二月龄Wistar大鼠32只随机分成4组:(1)正常饲料组;(2)高Se饲料组;(3)高维生素E饲料组;(4)高Se高维生素E饲料组。饲至十周末,处死大鼠,按试剂盒要求取其血液制成血清测GSH-Px,SOD活性,MDA含量。结果表明,高Se或高维生素E下饲养下的大鼠与对照组比较,血清中GSH-Px活性升高(P<0.05)。SOD活性未见改变,MDA含量分别减少50%和56%,有显著差异(P<0.01);维生素E与高Se合用与高Se组比较能进一步同GSH-Px,SOD活性(P<0.01)。结论:高Se会升高老龄大鼠的抗氧化活性,而与维生素E合用更加升高老龄大鼠血液中抗氧化活性。 相似文献
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高硒情况下维生素E对幼龄大鼠抗氧化作用的研究 总被引:3,自引:0,他引:3
研究了高Se或高维生系E下,幼龄大鼠体内抗氧化活性的变化以及高Se下,维生素E对其体内抗氧化水平的影响。将三月龄Wistar大鼠32只随机分成4组:正常饲料组、高Se高维生素E饲料组、高Se饲料组和高维生素E饲料组。饲至十周末,处死大鼠,按试剂盒要求分别取其血液、心、肝、肾制成标本测SOD、CAT活性及MDA、GSH含量。结果表明,高Se或高维生素E下饲养下的大鼠与对照组比较,血液中SOD活性明显下降;维生素E能明显抑制高Se大鼠血液中SOD活性的下降。结论:单独高Se或高维生素E会降低幼龄大鼠的抗氧化活性,而维生素E能明显提高高Se下幼龄大鼠体内抗氧化活性。 相似文献
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高纯材料是现代高新技术发展的基础,在电子、光学和光电子等尖端科学领域发挥着重要作用。采用固体样品直接分析的辉光放电质谱法(GDMS),在高纯金属、高纯半导体材料的痕量和超痕量杂质分析中有着非常广泛的应用。综述了GDMS法对高纯金属、高纯半导体材料进行的元素分析,并对分析过程中工作参数、溅射时间、干扰峰等因素的影响进行了阐述。同时,也详述了应用GDMS法对高纯金属钛、镉,高纯半导体硅,分别进行的痕量杂质元素分析,结果显示放电稳定性良好,典型元素含量的相对标准偏差均在较为理想范围内。GDMS应用前景广泛,未来,GDMS将在除固体样品之外的其他样品类型的分析领域中发挥重要作用。 相似文献
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Diets high in linoleate (safflower oil) or high in alpha-linolenate (perilla oil) were fed to rats for 11 months, and the effects of the diets on plasma and tissue lipids were compared. The plasma levels of total cholesterol (Cho), phospholipids (PL) and triacylglycerol (TG) were significantly lower in the high alpha-linolenate group than in the high linoleate group, the differences being more than 30% in the levels of total Cho and TG. The diets had differential effects on the lipid contents of major tissues: the TG level in muscle was higher but both the TG level in depot fat and the PL level in muscle were lower in the high alpha-linolenate group than in the high linoleate group. In order to clarify whether or not the hypolipidemic effect of the high alpha-linolenate diet was due to changes in the distribution of lipids among tissues, whole body lipids were estimated in mice fed these diets for 5 months. The whole body Cho content was significantly lower, by 28%, in the high alpha-linolenate group compared with the high linoleate group, but the total lipid content, PL and neutral lipids were similar between the groups. Our results indicate that the high alpha-linolenate diet has a more potent cholesterol lowering effect in plasma and body tissue than the high linoleate diet; interestingly, whole body TG levels are similar but tissue distributions of TG are different between the two dietary groups. 相似文献
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The effect of high molecular weight resin and multi-walled carbon nanotubes (MWCNTs) on the crystallization, rheological and dynamic mechanical properties of poly (vinylidene fluoride) (PVDF) composites was investigated. A synergetic effect of the high molecular weight resin and MWCNTs on the nucleation in the crystallization process of the matrix has been observed, and their contributions to the crystallization of the matrix are two-sided. The composites containing both the high molecular weight resin and MWCNTs have much higher crystallization peak temperatures but lower crystallinity, especially for samples with high MWCNT content. For the isothermal crystallization at relative high temperatures, higher Avrami exponent and shorter half-time of crystallization are observed for the composites containing both the high molecular weight resin and MWCNTs. The introduction of the high molecular weight resin not only reinforces the matrix, but also promotes the dispersion of MWCNTs. The reinforcement and synergetic nucleation effects of the high molecular weight resin and MWCNTs were also confirmed by dynamic mechanical analysis. 相似文献
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Electrochemical Synthesis of Tetrahexahedral Rhodium Nanocrystals with Extraordinarily High Surface Energy and High Electrocatalytic Activity 下载免费PDF全文
Neng‐Fei Yu Dr. Na Tian Dr. Zhi‐You Zhou Long Huang Jing Xiao Yu‐Hua Wen Prof. Shi‐Gang Sun 《Angewandte Chemie (International ed. in English)》2014,53(20):5097-5101
Noble metal nanocrystals (NCs) enclosed with high‐index facets hold a high catalytic activity thanks to the high density of low‐coordinated step atoms that they exposed on their surface. Shape‐control synthesis of the metal NCs with high‐index facets presents a big challenge owing to the high surface energy of the NCs, and the shape control for metal Rh is even more difficult because of its extraordinarily high surface energy in comparison with Pt, Pd, and Au. The successful synthesis is presented of tetrahexahedral Rh NCs (THH Rh NCs) enclosed by {830} high‐index facets through the dynamic oxygen adsorption/desorption mediated by square‐wave potential. The results demonstrate that the THH Rh NCs exhibit greatly enhanced catalytic activity over commercial Rh black catalyst for the electrooxidation of ethanol and CO. 相似文献
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《先进技术聚合物》2018,29(8):2245-2252
The encapsulation of high power light emitting diode (LED) needs the silicone resins to have relative high refractive index and thermal‐aging properties. Herein, high refractive index adamantane‐based phenyl epoxy‐silicone (APES) resins for LED encapsulation were synthesized by the sol‐gel condensation of 1‐adamantane methanol propyltrimethoxysilane‐3‐urethane, γ‐(2,3‐epoxypropoxy)propytrimethoxysilane and diphenylsilanediol. These adamantane‐based silicone resins have multifunctional groups including adamantyl group, phenyl group, and epoxy group in order to meet the various requirements for LED encapsulation. Importantly, the adamantane group in the silicone resins benefits for high refractive index and anti‐thermal properties. These APES resins were characterized by proton nuclear magnetic resonance and Fourier transform infrared spectroscopy. When APES resins were cured by methylhexahydrophthalic anhydride, they showed relatively high refractive index of 1.56, high hardness, and high thermal resistance. The encapsulated LED demonstrated high adhesion properties by red‐ink tests. These merits make adamantane‐based silicone resins promising candidates as LED encapsulation materials. 相似文献
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Chromatographia - A comparision between high resolution gas chromatography coupled with mass spectrometry (GC-MS) and an “on-line” high performance liquid chromatography, high... 相似文献
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聚酰胺6纤维具有良好的综合性能如力学性能、耐热性、耐磨损性和耐化学药品性等,同时具有很高的理论模量,如果开发制备出高强高模纤维,其在军用纤维和纺织上应用前景非常可观。但是聚酰胺分子间很强的氢键作用制约了分子的取向和纤维的高倍拉伸,从而限制了制备高强高模聚酰胺纤维技术的发展。所以要拉伸得到高取向聚酰胺纤维,需通过减少链间氢键的数量来实现。许多研究者已经通过各种工艺技术提高最大拉伸比,如增塑剂法、干法纺丝、冻胶纺丝、湿法纺丝、区域拉伸和退火等。鉴于已经通过冻胶纺丝法制备出了超高分子量聚乙烯纤维,因此目前冻胶纺丝法制备高强高模聚酰胺纤维具有较大的可行性。本文将介绍各种制备聚酰胺6纤维的工艺技术,主要突出冻胶法制备聚酰胺6纤维的技术。 相似文献
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聚合物在高压下的结构、形态和性能(下)张雄伟,黄锐(成都科技大学塑料工程系,成都,610065)在上篇中我们介绍了结晶性聚合物在高压下结晶的结构和形态。本篇将介绍聚合物在高压下的结晶动力学和热力学以及聚合物在高压下的退火等方面内容。2高压结晶动力学研... 相似文献
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Cellulose - The pressure retarded osmosis (PRO) process requires high performance, high flux, high rejection, and resistant membranes under harsh conditions. Since conventional phase-inversion... 相似文献
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Carmen Flosbach 《Macromolecular Symposia》2002,187(1):503-514
Target of development in the field of modern automotive clear coats is the combination of high etch and high scratch resistance. For high etch resistance the cross-linking chemistry is the key factor. The property scratch resistance is mainly influenced by the cross-linking density and the flexibility of chains between netpoints. By combining these parameters high etch and scratch resistant clear coats can be formulated. As a representative example an optimized clear coat based on epoxy/acid cross-linking chemistry is discussed. The ways to achieve high cross-linking density are shown. 相似文献