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[目的]研究微波辅助提取啤酒酵母多糖的最佳提取工艺及其抗氧化作用.[方法]以多糖提取率作为考察指标,采用单因素分析和正交试验对啤酒酵母多糖的提取工艺条件进行优化,并通过比色法研究其体外清除自由基的能力.[结果]啤酒酵母多糖最佳提取工艺条件为:微波时间10 min,微波功率540 W,浸润时间1 h.多糖得率为13.27%;酵母多糖具有清除自由基和超氧阴离子的能力,且其清除能力与多糖浓度呈明显的剂量关系,清除的50%的羟自由基和超氧阴离子自由基的多糖浓度分别为0.32和0.08 mg/ml.[结论]与常规水提取法相比,微波辅助提取法具有提取时间短、效率高、节约能源的优点;酵母多糖具有明显的抗氧化活性. 相似文献
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[目的]为云南松低聚原花青素的进一步研究和应用提供依据.[方法]从还原能力、DPPH自由基和羟基自由基清除作用3个方面对云南松低聚原花青素抗氧化活性进行测定.[结果]云南松低聚原花青素的还原能力稍好于合成抗氧化剂BHT;DPPH自由基和羟基自由基的丰抑制浓度(IC50)分别为1.89和1.31 mg/ml,而BHT对二者的半抑制浓度分别为3.00和1.81 mg/ml,云南松低聚原花青素对DPPH自由基和羟基自由基的清除作用强于BHT,且该清除作用与样品浓度存在一定的量效关系.[结论]云南松低聚原花青素具有较强的抗氧化活性. 相似文献
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稀土在生物领域中应用研究进展 总被引:73,自引:2,他引:73
最近几年稀土在生物领域中的研究工作又有了新的重大突破和进展。纪云晶等从分子水平、细胞及亚细胞水平、整体动物实验和稀土接触人群肿瘤流调等方面进行了系统的研究,证明轻稀土确有抑癌作用。在环境研究方面解决了外源稀土的走向和回答了经多年施用稀土会不会污染地下水的问题。在机理研究方面提出了稀土可替换部分钙、铁等金属离子的“调节”论点和可消除机体内有害自由基的“清除”论点。 相似文献
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稀土元素有保护和提高Fe—Cr,Ni—Cr,Fe—Ni—Cr合金高温抗氧化的作用,已是公认的事实。但前人都是从合金氧化膜的形貌和形态进行观察和分析,得到一些结果,对稀土的作用提出了种种的解释,未能取得一致的看法。本研究中则发现氧化膜(Cr_2O_3)本身具有一种特有的择优取向。稀土Ce有改变这种取向,并且有增强和保持新的取向的作用,从而改善了合金的抗氧化性能。 相似文献
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由于稀土基材料具有独特的电子结构特性以及价态可变可调等优势,作为催化剂或助催化剂在活化过硫酸盐去除水中活性药物领域展现出优异的性能。本文概述了稀土基催化剂活化过硫酸盐去除水中活性药物的研究进展。介绍了稀土基催化剂常见的制备方法,讨论了作用于过硫酸盐的活化机制,以及对水中活性药物的降解性能,并基于前沿性、创新性的科研成果对未来稀土基催化剂应用于硫酸根自由基高级氧化技术去除水中活性药物领域的发展趋势进行了总结和展望。为后续稀土基新型催化剂的设计和制备提供参考和借鉴。 相似文献
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Advances on Rare Earth Application in Pollution Ecology 总被引:31,自引:6,他引:31
RE application in the agriculture was originatedfrom China and entitled to exclusive intellectual prop erty, which is the most advanced technology of thisfield in the world. Agriculture and RE industry of Chi na have been greatly benefited from t… 相似文献
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The reuse of RE and cobalt in Co-based magnetic scraps was studied.The optimized feat lixiviated condition was:200 mesh,sulfuric acid dosage was of 1.4 times theoretic dosage,temperature was 80 oC and leaching time 1 h.The optimum technology conditions was:Na2S2O8 dosage was of 8 times theoretic dosage,oxidation temperature 80 oC,oxidation time 2 h and pH=4.5.Rare earth was precipitated by saturated(NH4)2C2O4 solution,after roasting of rare earth oxalate,rare earth oxide was received.Cobalt-iron residue was soaked by hydrochloric acid,the Fe(OH)3 was preferential solution,pH was adjusted to 1.4 by hydrochloric acid,Co(OH)3 did not dissolve,cobalt and iron were separated,after roasting of Co(OH)3,cobalt oxide was received.The total recovery of cobalt was found to be 97% and rare earths was 96%. 相似文献
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复杂稀有金属矿稀土回收新工艺 总被引:2,自引:1,他引:1
研究一种从不能用物理选矿法有效富集稀土的复杂稀有金属矿中回收稀土的工艺。原矿在酸矿质量比为1.2时于400℃酸化90min,然后在液固比5∶1、90℃浸出120min,稀土浸出率可以达到85.64%。浸出液经氧化、中和除杂后,按稀土理论用量1.2倍添加草酸。得到的草酸稀土沉淀在950℃煅烧60min,可获得REO含量92.4%的氧化稀土产品,全流程稀土总回收率为71.32%。 相似文献
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综述了目前我国稀土在钢中加入方法和稀土添加剂的应用;稀土在钢中的机理研究;稀土处理钢的连铸结晶器保护渣的研制、稀土铝合金镀液热浸镀钢材表面抗高温氧化性能的研究。这些课题大都转入工业试制或生产,机理研究亦有所突破。 相似文献
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Rare earth and far-infrared mineral composite materials were added to ceramic glazes to prepare easy-cleaning ceramic. The morphology of easy-cleaning ceramic was observed by SEM. The influence of easy-cleaning ceramic on water surface tension and contact angles of water were investigated. Through calculation of ceramic surface free energy and observation of oil drop on ceramic surface in water, the easy-cleaning mechanism of rare earth composite ceramic was studied. It is found that the rare earth composite ceramic can make water surface tension decrease. The surface free energy and the polar component of rare earth composite ceramic are increased. The rare earth composite ceramics have the easy-cleaning property. 相似文献
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Olefinerubbercontainingunsaturatedcar bochainlikeNRetc .ismoreeasilyoxidative agedthanrubbercontainingsaturatedcar bochainis .Usually ,antioxidantsaredopedtopreventpolymermaterialfrombeingoxidized .Butitisalsoreportedthatrareearthcom pounds[1,2 ] ,metaloxidesa… 相似文献
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The co-operation action mechanism and model of photon-ion catalysis synergy material composed of thallium and valency-variable rare earth elements and semiconductor oxide were proposed. The radiation catalysis reactions of water and oxygen assisted by the synergy material that could largely increase electron, free radical and negative ion products were discussed. The applications of photon-ion catalysis synergy material in areas of air cleaning material, antibacterial material, healthy material and energy resource material were suggested. 相似文献
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Yoshikazu Nakamura 《Metallurgical and Materials Transactions A》1975,6(12):2217-2220
A study of oxidation of an iron-nickel alloy with and without yttrium or rare earth additions is made to provide information
over a range of temperature. The additions improve the oxidation resistance in air. The microfractograph features of oxide
scale are discussed. It is suggested that pores existing in the interface between oxide scale and substrate may be an important
factor for the good adherence which is obtained. In addition the pegging mechanism of rare earth element oxides may improve
the adherence of oxide scale to substrate. An incubation period of oxidation in the alloys containing yttrium or rare earth
elements is described and discussed in terms of net weight gain and weight loss due to gas evaporation. 相似文献
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稀土在热镀锌中的应用研究现状与发展趋势 总被引:1,自引:0,他引:1
介绍了稀土在热镀锌中体现的优异性能。综述了稀土在热镀锌行业中的发展过程与应用,以及稀土对镀层的作用,对镀层的耐腐蚀性和稀土添加量等方面的研究进展,指出了稀土在热镀锌行业中的发展趋势。 相似文献