共查询到20条相似文献,搜索用时 31 毫秒
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目的:分析鉴定实验室自制的功能红曲菌的固态发酵物中的主要莫纳可林类物质。方法:首先通过固态发酵制得功能红曲粉,然后分别使用极性不同的4种溶剂(蒸馏水、乙醇、乙酸乙酯和正己烷)超声提取提取功能红曲粉,再通过减压旋蒸及冷冻干燥制得提取物粉末。通过UPLC-Q-TOF-MS对功能红曲粉的不同溶剂提取物的化学成分进行定性分析与比较。采用Agilent Eclipse Plus-C18 RRHD色谱柱(2.1 mm x 100 mm,1.8μm),以乙腈-0.1%甲酸水为流动相进行梯度洗脱。质谱分析采用电喷雾正离子全扫描模式采集,扫描范围为m/z 100-1500Da。结论:本文通过UPLC-Q-TOF-MS对功能红曲粉的不同溶剂提取物的化学成分进行定性分析与比较。鉴定出17种主要的莫纳可林类物质。该方法快速、可靠、高效,能较全面地反映功能红曲粉的的提取物中的主要莫纳可林类物质,可为深入研究功能红曲粉中的药效物质提供参考。 相似文献
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采用高效液相色谱技术建立检测福建红曲醋中组胺、腐胺、尸胺、精胺、亚精胺、2-苯乙胺、酪胺、色胺共8种生物胺的分析方法。以色谱柱为C-18柱,柱温30℃,流速1.2ml/min,紫外检测波长为254nm,流动相A为超纯水,流动相B为乙腈,采用梯度洗脱方式,检测红曲醋中生物胺。检测限为组胺、尸胺、腐胺为0.05μg/kg;酪胺、亚精胺1.0μg/kg;苯乙胺、色胺为1.5μg/kg;精胺为0.02μg/kg,回收率在93.6%至99.0%之间,相对标准偏差(RSD)在0.14%~0.26%之间。结果表明:高效液相色谱法可以对红曲醋中生物胺进行准确的定性和定量。检测红曲醋样品中生物胺最高含量低于国际的发酵食品的建议限量要求。 相似文献
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目的 针对鲜榨米易氧化、吸潮的问题,使用红曲对鲜榨米进行发酵,制备红曲鲜榨米,开发鲜榨米新产品,分析不同培养条件对红曲鲜榨米色价的影响.方法 以鲜榨米为固态培养基质,利用传统固态发酵的方式,制备红曲鲜榨米,并分析培养温度、水添加量、pH值、外源氮含量和培养时间等培养条件对红曲鲜榨米色素色价的影响.结果 红曲鲜榨米醇溶性色素色价明显高于水溶性色素;水分含量对色素积累的影响较小;在30℃时,醇溶性橙、黄、红色素的色价分别高达298.34,186.35,230.09 U/g;当pH值为4.0时,水溶性色素色价最高,当pH值为7.0时,醇溶性色素色价最高;当醇、水溶性色素色价最高时,外源氮的质量分数分别为0.9%,0.5%;在培养6 d时红曲鲜榨米醇溶性色素色价最高,在培养7 d时水溶性色素色值最高.结论 外源氮含量、pH值和培养时间对红曲鲜榨米水溶性和醇溶性的影响较大. 相似文献
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施杰 《中国新技术新产品》2011,(12):6-6
啤酒花是一种重要的传统中药,也是酿造啤酒的重要原料,其中α-酸(α-acids)及β-酸(β-acids)是酒花苦味的主要来源,因其独特的使用价值而成为近年研究的热点。文章对国内外有关啤酒花中α-酸及β-酸的化学成分、测定方法、药理研究和临床应用进行了综述,为深入研究提供参考。 相似文献
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总结近年来对连翘的研究工作和文献,对有关连翘的研究现状进行概述,分别从化学成分和药理作用的研究进行综述。 相似文献
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山楂作为传统中药的一种重要材料,近年来得到广泛地应用与研究。山楂为药食同源植物,主要具有助消化、降压、降血脂、强心等药理学作用。通过对山楂化学成分及其药理性能的研究综述,旨在为山楂进一步的开发利用提供参考。 相似文献
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X射线荧光分析在区域地球化学勘查样品分析中的应用 总被引:1,自引:0,他引:1
详细论述了X-射线荧光光谱分析化探样品中24个元素的测试条件、方法及其精密度和准确度。采用粉末压片法,选用国家一级标准物质GBW07401~GBW07408、GBW07423~GBW07430和GBW07301~GBW07312为基准物质,使用经验系数法和康普顿散射线作内标校正基体效应。实验数据说明分析结果可靠,完全满足区域化探要求。 相似文献
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Yonghong Ni Guogen Wu Xiaolei Zhang Xiaofeng Cao Guangzhi Hu Ali Tao Zhousheng Yang Xianwen Wei 《Materials Research Bulletin》2008,43(11):2919-2928
In the present paper, flowerlike ZnO nanocrystals were successfully synthesized via a simple hydrothermal route in the presence of sodium dodecyl sulfate (SDS), employing Zn(CH3COO)2 and KOH as the starting reactants. The phase and morphology of the product were characterized by means of powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and select area electron diffraction (SAED). The optical properties of the product were studied. Some factors influencing the morphology of the final product including reaction time, temperature and amounts of the surfactant were discussed. Researches showed that the flowerlike ZnO nanocrystals had a good photo-catalytic activity for degradation of safranine T under 254 nm UV light irradiation. The electrochemical research of the product showed that flowerlike ZnO nanocrystals could promote electron transfers between catechol and the Au electrode. A possible formation mechanism was also suggested based on the results of the experiments. 相似文献
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目的:探讨直接数字化X线摄影(DR)在临床运用时的优点,针对实践总结DR影像的特点.方法:选取我科2009年6月~2012年6月期间经X射线检查的9900例患者为研究对象,在相应标准下,统计三片率.结果:统计三片率为甲级95.45%、乙级3.23%、废片1.31%.结论:DR数字化影像技术操作简便、曝光时间短、诊断准确率高,值得临床广泛应用. 相似文献
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膨润土是一种重要的非金属矿产,资源丰富,应用广泛。本文在查阅大量文献的基础上,并结合课题研究工作,对膨润土的改性技术、改性膨润土的应用与改性效果进行了系统的综述。 相似文献
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综述HIPS的改性应用研究。高抗冲聚苯乙烯由于聚丁二烯的加入在抗冲击强度及其他性能方面得到很大改善,广泛地用于家用电器壳体和家具制作。然而限于本性特点,在许多应用方面需要进行进一步的改性。本文介绍了通过采用不同原料以及方法对HIPS的导电性、抗紫外吸收性、可降解性、耐热性、力学性能、透明性、阻燃性等方面进行改性的方法。并提出结合环境、能源、原料来源因素等进行产品深度开发的发展方向。 相似文献
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In order to enhance the intensity of luminescent hybrid bimodal mesoporous silica (LHMS), the rare earth Eu3+ ion was employed as an enhancer to modify 1,8-naphthalic anhydride (NA) molecules. The modified LHMS were prepared with various anions of europium salts including Cl−, NO3−, and CH3COO−. The structure and photoluminescence properties of the obtained samples were characterized by XRD, TEM, N2-adsorption/desorption, FT-IR, TGA, ICP-OES, and PL measurements. The results showed that the bimodal mesoporous system of BMMs could be preserved after functionalization via grafted Eu3+-modified NA molecules onto mesoporous matrix. However, the structure parameters and textural properties of resultant LHMS series were obviously influenced by the anions volume. Meanwhile, the luminescent performances of LHMS series were seriously impacted by both of the binding force between Eu3+ and various anions and steric hindrance of the anions, resulting in the intensity of emission peak of obtained LHMS series declining as following order: LHMS-EN (NO3−) > LHMS-EA (CH3COO−) > LHMS-EC (Cl−). Finally, the related mechanism was discussed in-depth. 相似文献
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本文简单介绍了铂的物理化学性能,综述了铂及其合金在石油化工、电子电器、玻璃工业、医疗等各领域的应用状况,提出铂及其合金的发展方向。 相似文献
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Yu Liu Guangqiang Li Honghong Wang Kaiming Wu R. D. K. Misra 《Materials Science & Technology》2017,33(15):1750-1764
The effects of Cu and Al addition on the microstructure and fracture in the coarse-grained heat-affected zone (CGHAZ) of high-strength low-alloy steels with superior toughness were studied and compared with the X70 pipeline base steel counterpart. The microstructure in base steel was dominated by a small fraction of acicular ferrite and predominantly bainite. However, acicular ferrite microstructure was obtained in Cu-bearing steel, which nucleated on complex oxide with outer layer of MnS and CuS because of Cu addition. The microstructure in Al-bearing steel consisted of bainite with ultrafine martensite–austenite constituent, which was refined by Al addition. CGHAZ in Cu-bearing and Al-bearing steels had superior impact toughness and ductile fracture, which were attributed to acicular ferrite and ultrafine martensite–austenite constituent, respectively. 相似文献
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本文介绍了反射高能电子衍射的工作原理,并将其与低能电子衍射进行了比较,表明RHEED具有很多优越性。另外,综述了国内外有关利用RHEED进行表面科学及新材料研究方面的应用。 相似文献