白花菜子不同溶剂提取物总多酚、总黄酮含量及抗氧化活性测定

测定了白花菜子四种不同溶剂提取物的总多酚含量、总黄酮含量和体外抗氧化活性。以没食子酸为对照品,采用福林-酚试剂法测定白花菜子提取物中总多酚的含量;以芦丁为对照品,采用可见-紫外分光光度法测定白花菜子提取物中总黄酮的含量。通过测定DPPH自由基清除率、氢氧基清除率和还原能力来评价白花菜子提取物的抗氧化活性。在四种白花菜子不同溶剂提取物中,总黄酮含量从高到低的顺序为乙酸乙酯提取物(CAEE)甲醇提取物(CME)石油醚提取物(CPEE)二氯甲烷提取物(CCE);总多酚含量从高到低的顺序为CMECAEECPEECCE。白花菜子提取物各种方法抗氧化活性从高到低的顺序为CMECAEECPEECCE,与总多酚含量顺序一致。结果表明白花菜子乙酸乙酯提取物总黄酮含量最高,白花菜子甲醇提取物总多酚含量最高,且甲醇提取物具有很强的抗氧化活性,可以用作抗氧化药物或食品添加剂,因此有必要对白花菜子的化学成分、体内抗氧化活性和机理进行深一步的研究。     

萌发青稞营养成分、多酚含量及抗氧化活性研究

以瓦蓝、14-946、昆仑15号青稞为原料,研究了不同萌发时间对青稞主要营养成分、多酚含量及抗氧化活性的影响。结果表明:在萌发期间,青稞中的总淀粉、β-葡聚糖、游离酚、结合酚、总酚及游离黄酮含量呈下降趋势,脂肪、蛋白、纤维及结合黄酮与总黄酮含量呈上升趋势。萌发处理显著提高了参试青稞游离态提取物清除DPPH自由基能力,降低了青稞游离态提取物的铁离子还原能力及ABTS自由基的清除能力;显著降低了参试青稞结合态提取物清除DPPH自由基、ABTS自由基能力及铁离子还原能力。蓝色青稞(瓦蓝)经萌发后其游离态提取物具有较强抗氧化活性,黑粒青稞(14-946)经萌发后其结合态提取物能保存较强的抗氧化活性。相关分析表明,青稞中主要营养成分(脂肪、总淀粉、纤维、β-葡聚糖)含量与多酚及抗氧化活性有显著的相关性,营养成分含量的高低可以用来评估其酚类物质含量与抗氧化活性;游离酚、结合酚与3种抗氧化能力均呈极显著正相关,说明酚酸类物质是青稞不同形态多酚提取物抗氧化活性的主要贡献者,这为选择专用型青稞品种提供了便捷的方法。萌发可以改变青稞中的营养成分、多酚含量及抗氧化活性,因此选择合适的青稞籽粒颜色与适宜的萌发时间能更好地保留青稞的生物活性物质,有益于青稞资源的开发利用。     

麻栎树皮多酚含量的测定及抗氧化活性的研究

采用分光光度法、DPPH法和连苯三酚红(PR)法对麻栎树皮提取物进行多酚化合物含量及抗氧化活性测定,讨论了用不同溶剂提取对多酚含量的影响.结果表明采用70%乙醇进行提取,提取物中多酚含量最高,为(6 589.91±43.32)mg/100 g.抗氧化活性测试中,麻栎树皮的不同溶剂提取物对DPPH自由基和羟自由基都表现出较高的清除率,其中麻栎树皮70%丙酮提取物的活性最好,在0.18 mg/m L质量浓度下,对DPPH自由基清除率为70%,在0.38 mg/m L质量浓度下,对羟自由基氧化率为75%.     

补血草不同部位多酚提取物的抗氧化能力

采用多种体外评价体系研究了补血草不同部位多酚提取物的抗氧化能力,结果表明:在4种不同的检测体系中,补血草根、根茎、叶和花的多酚提取物表现出不同的抗氧化能力水平.还原力从大至小依次为根>根茎>叶>花;FRAP值和TEAC值大小顺序依次分别为根>根茎≈叶>花,根≈根茎≈叶>花;而对β-胡萝卜素-亚油酸漂白的抑制作用大小为花>叶>根>根茎.光谱分析显示,根、根茎和叶提取物及花提取物的主要组分分别为原花色素类和黄酮类.在不同评价体系中,补血草不同部位多酚提取物的抗氧化能力与原花色素含量(R2=0.5450～0.9201),与黄酮含量(R2=0.7764～0.9993)均呈显著正相关.可见,补血草多酚提取物具有很强的体外抗氧化能力,且活性强弱与其原花色素和黄酮含量的高低密切相关.     

不同品种高粱甲醇提取物抗氧化活性研究

为评价六种不同产地品种高粱面粉甲醇提取物的抗氧化活性,测定了高粱面粉甲醇提取物的总酚含量、缩合单宁含量,以及还原能力;并分析了高粱面粉提取物抗氧化强弱与活性成分之间的相关性情况。结果表明,高粱面粉甲醇提取物均具有较强的抗氧化活性,其强弱与高粱的品种有关,并且与高粱提取物中总酚的含量相关,与缩合单宁的含量没有相关性。为筛选高抗氧化活性的高粱资源提供实验依据。     

海带抗氧化多酚的制备及活性研究

用1:1的氯仿:甲醇超声提取海带成分,并用石油醚、乙酸乙酯和正丁醇依次进行萃取,利用DPPH法、邻二氮菲-Fe2+氧化法、铁氰化钾还原法和邻苯三酚自氧化进行抗氧化实验,同时与抗氧化剂2,6-二叔丁基对甲酚(BHT)和没食子酸(GA)进行对照。结果显示海带提取物与各萃取组分均具有较强的抗氧化能力,其中乙酸乙酯提取物(EA)抗氧化活性最强。在50μg/mL浓度时,EA清除DPPH自由基、羟自由基、超氧阴离子自由基的能力和还原能力均高于抗氧化剂BHT,且清除超氧阴离子自由基的能力也高于GA;另外,Aqueous组分在所有测定浓度下清除羟自由基能力均高于GA,清除O2-的能力也高于BHT。海带各提取物总酚含量的分析表明总酚含量与抗氧化活性之间具有一定的相关性,总酚含量高其抗氧化能力也相应提高,表明多酚是提取物中重要的抗氧化成分。4种抗氧化方法的比较表明DPPH法的相关系数最高(R=0.987),是海带体外抗氧化实验最有效的方法。     

蓝莓籽不同组分抗氧化作用的比较

目的:为了加强蓝莓籽的综合利用开发,研究蓝莓籽不同组分的抗氧化能力。方法:对蓝莓籽的醇提取物、蓝莓籽多酚、蓝莓籽蛋白、蓝莓籽多糖进行提取分离,采用AAPH法、DPPH法对各组分进行抗氧化能力测定。结果:AAPH法测定的抗氧化能力由高到低的顺序为:蓝莓籽多糖﹥蓝莓籽蛋白≈α-VC﹥醇提取物﹥蓝莓籽多酚;DPPH法测定的清除自由基能力由高到低顺序为:蓝莓籽多酚﹥醇提取物≈α-VC﹥蓝莓籽蛋白﹥蓝莓籽多糖。结论:蓝莓籽不同组分均显示出一定的抗氧化能力,其中以蓝莓籽多糖、蓝莓籽蛋白的抗氧化能力最强,蓝莓籽多酚的清除自由基能力最强。     

昆明产银杏叶总黄酮含量测定及抗氧化活性研究

目的:测定昆明产银杏叶提取物中总黄酮的含量和研究其抗氧化活性.方法:采用AlCl3显色分光光法测定银杏叶提取物中总黄酮的含量,并利用DPPH自由基(DPPH.)捕获分光光度法和连苯三酚红褪色光度法对银杏叶提取物进行抗氧化活性测定.结果:银杏叶提取物中总黄酮含量为5.85%;提取物对DPPH.的捕获能力达59.11%,IC50=114.6μg/mL,对.OH的最大清除率为39.16%.结论:昆明产银杏叶提取物具有良好的抗氧化能力.     

壳斗科植物种子的多酚类含量及抗氧化能力

【目的】测定青冈栎Cyclobalanopsis glauca(Thunb.)Oerst.、饭甑青冈Cyclobalanopsis fleuryi(Hickel.et A.Camus)Chun ex Q.F.Zheng、大叶栎Quercus griffithii Hook.f.et Thoms ex Miq.、栲Castanopsis fargesii、椆木Lithocarpus thalassica(Hance)Rehd.种子中的多酚含量,评价其提取物的抗氧化能力,并分析多酚含量与抗氧化能力的关系。【方法】采用Folin-酚法测定多酚含量,通过DPPH·和ABTS·自由基清除法评价种子提取物的抗氧化能力。【结果】在选取的5种壳斗科植物种子中,饭甑青冈的多酚含量最高(14.16%),其次为大叶栎(10.89%),栲的含量最低(0.44%);各提取物均表现出良好的抗氧化能力,其中青冈栎的半清除率质量浓度IC50均优于抗坏血酸(Vc),饭甑青冈IC_(50)与Vc相当。【结论】青冈栎与饭甑青冈种子提取物可作为天然抗氧化剂应用于保健品、化妆品乃至药品等行业。     

几种茶叶中抗氧化性物质的比较研究

研究了几种茶叶的抗氧化性,为选择饮用茶叶品种和加工开发茶叶提供参考。采用了"蒸馏水熬制"和"乙醇浸取法",从不同茶叶中提取了抗氧化性物质,对其的还原能力、清除DPPH自由基能力及总酚含量进行了测定。三种测定方法测定结果:还原能力大小、清除DPPH自由基能力大小与提取物总酚含量高低相一致。结果表明,不发酵茶(炒青)、半发酵茶(乌龙茶和糯米小沱)和发酵茶(红茶)三类茶叶中,不发酵茶提取物的抗氧化性最强,可以为选择饮用茶叶品种和加工开发茶叶及天然抗氧化剂的开发应用提供参考。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-