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Search Results: 1 - 10 of 50733 matches for " 段久芳 "
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松香基含氮杂环衍生物的研究进展
李娟,李保同,徐永霞,刘泽学,,韩春蕊,查显俊
化工进展 , 2015, DOI: 10.16085/j.issn.1000-6613.2015.10.034
Abstract: 在松香中引入杂环,可赋予松香特殊的生物和光学等活性,而松香基含氮杂环衍生物则是在松香中引入含氮的杂环,是松香基衍生物的重要组成部分。本文以羧基改性、菲环改性和综合改性为主线,根据羧基上的还原、胺化、酰基化、缩合、闭环等反应和菲环上的氧化、亲电取代反应(溴代、选择性硝化)、重氮化、缩合和闭环等反应类型,由18位羰基酰化改性、18位烷基碳原子成环改性、18位烷基相连氮原子成环改性、11,12位碳成环改性、12,13位碳成环改性、13,14位碳成环改性和综合成环改性分类,系统综述松香基咪唑啉、噻唑、唑、呋咱、喹啉、吲哚、吖啶等含氮杂环衍生物的研究现状,详细归纳了该类衍生物的生物活性、缓蚀活性、荧光活性和表面活性的性能应用,并对松香基含氮杂环衍生物的合成和应用研究趋势进行了展望。指出该类化合物在有机金属催化材料和染料敏化太阳能电池等功能性化合物开发中具有重要发展潜力。
罗望子多糖分级提取及其与黄原胶凝胶骨架材料缓释性能研究
刘彦涛,韩明会,,韩春蕊,张卫明,蒋建新
- , 2018, DOI: 10.13360/j.issn.2096-1359.2018.02.009
Abstract: 将罗望子多糖胶粉分别在50和100℃(TSP50和TSP100)条件下分级提取与纯化,其提取得率分别为28.71%和36.24%。X射线衍射图谱结果表明,在100℃下提取的罗望子多糖分级组分的结晶度明显高于50℃条件下提取的组分的结晶度。采用湿法造粒制备罗望子分级多糖与黄原胶不同质量配比的控释茶碱的缓释材料,并比较分析了其缓释性能。体外释药结果表明,在药物释放12 h时,仅含罗望子多糖骨架片的药物累积释放率最大,TSP50和TSP100分别达到载药量的93.4%和81.6%。当罗望子多糖和黄原胶的质量比例为40:60时,TSP50和TSP100的药物累积释放量最小,分别为67.2%和67.4%,表现出最为持续的药物释放性能。溶胀性能结果表明,罗望子多糖和黄原胶质量比例为40:60时,制备的骨架片均在溶胀6 h时表现出最高溶胀率,TSP50和TSP100溶胀率分别为285%和312%。
Tamarind seed polysaccharide(TSP)was fractional extracted from tamarind seed powder at 50℃ and 100℃, and the TSP yields were 28.71% and 36.24%, respectively. The main monosaccharide components in both two fraction TSPs(TSP50 and TSP100)were xylose, galactose and glucose with a ratio of 1.00:1.48:2.85 and 1.00:1.65:3.20, respectively. The FT-IR spectra of the TSP displayed peaks at 1 376 cm-1, 1 039 cm-1, 943 cm-1 and 899 cm-1, which were the characteristic absorption peaks of tamarind seed polysaccharide. Results from X-ray diffractograms(XRD)showed that the TSP samples extracted at 50℃ and 100℃ both presented a broad band centered at 2θ=19.4°. The crystallinity of the TSP100 was much higher than that of TSP50. The matrix tablets of theophylline were prepared by a wet granulation technique by using TSP and xanthan as raw materials. The ratios of tamarind seed polysaccharide(TSP50 and TSP100):xanthan in the matrix tablets were 20:80, 40:60, 60:40, 80:20, 100:0(TX20:80 to TX100:0). The in vitro drug release test showed that the cumulative drug release rate from the matrix tablets containing only TSP50 or TSP100 reached 93.4% and 81.6% of original drug within 12 h, respectively. While the most sustained drug release was found in the formulation of TX40:60 with both TSP50 and TSP100 matrices, which released 67.2% and 67.4% of original drug within 12 h, respectively. These results could be attributed to the viscosity and swelling properties of two polysaccharides. The results of swelling properties showed that the maximum swelling rate were 285% and 312% of the matrix tablets of TX40:60 and xanthan gum. We also found that the swelling index of the TSP100 was obviously higher than that of the TSP50, which might be due to a more difficult dissolution of the TSP100 with a higher molecular weight
不同品种葡萄籽培养基对平菇酚类物质及抗氧化性的影响

- , 2016, DOI: 10.13982/j.mfst.1673-9078.2016.5.017
Abstract: 为研究葡萄籽培养基对平菇抗氧化能力的影响,本实验采用葡萄籽培养基栽培平菇,对平菇多酚的组成以及含量进行了高效液相色谱-质谱法(high performance liquid chromatography-mass spectrometry,HPLC-MS)分析,并以总酚含量、总黄酮含量、ABTS自由基清除能力、FRAP还原能力为测试手段对其抗氧化活性进行了探讨。通过比较不同品种(赤霞珠和龙眼)、不同质量分数(39%和78%)的葡萄籽培养基对所培育平菇抗氧化能力的影响,结果发现,使用78%质量分数的赤霞珠葡萄籽培养基所栽种平菇的抗氧化能力较对照组有显著提高(其ABTS自由基清除率在平菇多酚提取物浓度为41 mg/mL时达到69.4%),并检测到了芦丁等10种多酚类物质。因此,葡萄籽可代替传统的棉籽壳培养基培育平菇,提高平菇的抗氧化性能,实现农产品加工副产物的综合利用。
Grape seeds are the major component of mushroom culture media. This study aimed to examine the effects of different grape seeds on the antioxidant activities of Pleurotus ostreatus polyphenols. Four different assays were employed to measure antioxidant activity, including the Folin–Ciocalteu assay, flavonoid content determination assay, 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) scavenging activity assay, and the ferric reducing ability of plasma assay. Polyphenol content was assessed using high performance liquid chromatography-mass spectrometry (HPLC-MS). Comparison of grape seeds from Cabernet Sauvignon and Longyan species, and different mass fractions (39% and 78%), showed that 78% of Cabernet Sauvignon grape seeds had positive effects on the antioxidant ability of mushroom (69.4% as determined by the ABTS radical scavenging assay) and 10 kinds of polyphenols were identified. Grape seeds can be used for cultivation of mushrooms.
不同处理葡萄籽粉与葡萄籽粉强化面包抗氧化活性研究

- , 2016, DOI: 10.13982/j.mfst.1673-9078.2016.7.030
Abstract: 本文采用普通粉碎技术、超微粉碎技术、超微粉碎结合超临界CO2萃取技术制备三种葡萄籽粉,即普通破碎葡萄籽粉(grape seeds powder, GSP)、葡萄籽超微粉(Ultrafine powder of grape seeds,UPGS),脱脂葡萄籽超微粉(Ultrafine powder of skimmed grape seeds,SUPGS),并通过粒度检测仪、扫描电镜检测其粒径大小并观察其内部结构。在此基础上,将UPGS、SUPGS添加至面包配方中,采用一定的加工工艺焙烤得到两种营养强化面包并采用三种抗氧化测定方法即ABTS、DPPH自由基清除能力和FRAP还原能力法考查UPGS、SUPGS及其强化面包在体外模拟胃肠消化前后的抗氧化性能。通过与无葡萄籽粉添加的空白组面包(CK)的比较,结果表明焙烤的SUPGS强化面包的抗氧化性能在三者中最强,在模拟消化后三种抗氧化能力测定结果比CK组分别提高了62.4%、43.93%、53.2%。因此,将SUPGS应用在强化面包生产中,可以有效提高强化面包的抗氧化性能。
Three groups of grape seeds powder were obtained by mechanical crushing method, ultrafine pulverization technology and ultrafine pulverization combined with upercritical fluid extraction technology. Specifically, they were abbreviated as GSP, UPGS, SUPGS to represent grape seeds powder, ultrafine powder of grape seeds and the ultrafine powder of skimmed grape seeds. Diameters of each sample were determined and their inside structure was evaluated under the scanning electron microscope. Then a proper bakery process was established to produce bread added with UPGS and SUPGS. The antioxidant activity of fortified bread enriched with UPGS and SUPGS before and after the process of in-vitro-digest were analysed. The results showed that fortified bread added with SUPGS still had strong antioxidant capacity after in-vitro-digest process and increased 62.4%, 43.93%, 53.2% in ABTS, DPPH scavenging activity as well as FRAP assays compared with common ones. Therefore, SUPGS-fortified bread can be applied in industrial production to enhance its antioxidant capability.
高校工程投资审计风险及其防范

财会月刊 , 2005,
Abstract: 随着《民法》、《审计法》、《招投标法》、《建筑法》、《行政诉讼法》等一系列法律法规的颁布实施,审计事业的迅猛发展和承包商法律意识的日益加强以及新的计价方法——工程量清单计价法的逐步实行,如何控制、规避、化解审计风险,提高审计质量,维护审计权威成为高校审计部门和审计人员需要面对的问题。一、内部审计及审计风险的特征  1.内部审计的定义。高校工程投资审计是内部审计,是内部控制的一个重要组成部分,是内部经济监督机构。它虽然没有直接参与各项经营管理活动,但其主要职能是评价各项经营管理活动是否达到预定目标、监督各项经营管理活动的开展是否严格遵循规章制度,目的是提高经营管理活动的效益与效率。
中国对上合组织国家直接投资特殊动因及政策建议

俄罗斯东欧中亚研究 , 2013,
Abstract: 上海合作组织国家丰富的能源资源与我国经济发展日益突出的资源瓶颈,使获得其资源为目的的资源导向型动因成为中国对上合组织国家直接投资的特殊动因;同时,上海合作组织国家特殊而重要的地缘政治地位,使我国对该地区的直接投资具有特殊的包括政治、安全、外交等在内的国家利益导向型动因。这与中国企业对外直接投资的一般动因依次是市场导向型、效率导向型和资源导向型动因有很大的不同。
基于因子分析的我国金融风险研究

中南民族大学学报(自然科学版) , 2005,
Abstract: 在建立金融风险监测指标体系的基础上,运用因子分析方法分析了20世纪90年代以来我国金融风险历程,评析了在历次的金融风险中,国家采取注资、剥离不良资产、转制、清产核资等化解措施,探索了在我国金融风险产生的根源,提出了从根本上解决金融风险的策略.
基于计量经济模型的最低工资水平测算

中南民族大学学报(自然科学版) , 2006,
Abstract: 论述了最低工资的构成要素,评析了政府制定最低工资标准的不同方法,提出了运用能考虑各种因素的计量经济模型制定适度的最低工资水平的方法.通过对武汉市2004年实施的最低工资水平的定量分析,得出政府制定的最低工资标准过低的结论.
单圈图的解析(英文)
王晓,
华东师范大学学报(自然科学版) , 2009,
Abstract: 得到了一些特殊图类的解析值.~利用数学归纳和分类讨论的方法,~%给出固定阶数的单圈图的解析的紧的界.~%证明了在所有阶数为~$n$~的单圈图中,~%图~$\Delta_{n-3}$~取得最小的~$a(G)$~和~$b(G)$;~图~$K_{1,n-1}^{+}$~%取得最大的~$a(G)$~和~$b(G)$.~%这里图~$\Delta_{n-3}$~是由联结~$K_{3}$~一个顶点和~$P_{n-3}$~的一个端点而得到,~%图~$K_{1,n-1}^{+}$~是由联结图~$K_{1,n-1}$~中两个度为~$1$~的顶点而得到.
慢性支气管炎冬病夏治穴位贴敷疗效观察

中国中医药信息杂志 , 2009,
Abstract:
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