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%.     

火龙果果皮总黄酮和多糖的提取工艺及抗氧化研究

考察提取时间、料液比、乙醇体积分数和提取温度对火龙果果皮总黄酮和多糖得率的影响. 并在单因素实验结果的基础上设计L₉(34)的正交实验,优化总黄酮和多糖的提取工艺. 此外,通过进行DPPH ·、ABTS自由基及·OH的清除实验,考察火龙果果皮提取物的抗氧化活性能力. 正交实验优化得出的提取时间3 h、料液比1 ∶ 30、乙醇体积分数70%、提取温度70 ℃为火龙果果皮总黄酮和多糖的最佳提取工艺. 该条件下提取到的火龙果果皮总黄酮和多糖的平均质量分数分别为7.87 mg/g和114.05 mg/g. 在373.44 μg/mL时,抗坏血酸对DPPH ·、ABTS自由基及·OH的最大清除率分别达到95.25%、99.57%、89.99%;而火龙果果皮提取物的最大清除率分别为88.64%、60.84%和61.77%,数据表明火龙果果皮提取物对自由基的清除率均达到对照品的2/3,证实火龙果果皮提取物具有良好的抗氧化活性能力,可作为天然抗氧化剂的提取原材料.     

金线莲多糖提取工艺优化及其体外抗氧化活性研究

以人工培育金线莲为原料，通过单因素试验考察液固比、提取温度、提取时间、超声波功率、提取次数5个因素对金线莲多糖得率的影响，并在此基础上选取液固比、提取时间及超声波功率3个因素为自变量，金线莲多糖得率为考察指标，采用响应面分析试验设计方法建立回归模型，以优化金线莲多糖提取工艺条件。结果表明，金线莲多糖最优提取工艺条件为：液固比30∶1(mL/g)、提取时间40 min、超声波功率240 W、提取温度60℃、提取次数2次，在此条件下金线莲多糖得率为8.14%，与预测值8.19%的相对偏差为0.61%。体外抗氧化实验结果表明，金线莲多糖对O_2-·自由基和DPPH自由基的清除作用与浓度呈正相关，其对O_2-·自由基和DPPH自由基清除率IC₅₀分别为0.744 mg/mL、0.665 mg/mL。金线莲多糖和VC还原力随着质量浓度增加而增大，但VC还原力增加的速度均高于金线莲多糖，表明金线莲多糖具有体外抗氧化活性，但抗氧化能力弱于VC。     

资木瓜乙醇提取物的体外抗氧化活性研究

目的:对资木瓜乙醇提取物进行体外抗氧化活性研究.方法:以65%乙醇为溶剂加热回流提取资木瓜,旋转蒸发浓缩得资木瓜乙醇提取物(CSF),通过猪油体系(POV)、DPPH*法和Fe3 还原力测定实验对其进行体外抗氧化活性评价.结果:与对照组比较,资木瓜乙醇提取物能使猪油的过氧化值(POV值)降低,且随提取物浓度升高其降低POV值的能力增强,所选取的药物浓度较Vc(0.8mg/mL)强,但量效关系不明显;乙醇提取物具明显清除DPPH*自由基作用,随提取物浓度增加其清除率增加,当浓度为6mg/mL时清除率达到近80%;同时提取物对铁离子的还原能力亦较强,与提取物浓度呈正相关性.结论:资木瓜乙醇提取物具有较强的抗氧化活性.     

不同提取方法对姬菇多糖抗氧化活性的影响

本研究采用传统水提法、超声波提取法、超声波辅助水提法、酸提法、碱提法、超声波辅助酸提法和超声波辅助碱提法7种方法提取姬菇多糖,测定还原力、羟自由基(·OH)清除率、超氧阴离子自由基(O_2~-·)清除能力、DPPH自由基清除力作为体外抗氧化作用的评价指标,并与Vc对照.结果表明酸法提取多糖得率最高,可达6.58%.总体来看,超声波辅助水提法所得姬菇多糖的抗氧化活性最好,多糖浓度为10 mg·m L~(-1)时其还原力达到2.18,·OH清除率为95.56%;多糖浓度为1 mg·m L~(-1)时,O_2~-·的清除率达到62.35%;多糖浓度为2 mg·m L~(-1)时,对DPPH自由基的清除率达到80.32%.超声波辅助碱提法所得多糖的抗氧化活性也较好,而超声波辅助酸提法所得多糖的抗氧化活性最差.由此可见,采用超声波辅助水提法所得多糖有利于姬菇多糖生物活性方面的研究.     

羊肚菌等9种食用菌抗氧化活性研究

通过对DPPH自由基清除能力、还原能力和清除羟基自由基能力的研究,比较羊肚菌、圆孢蘑菇、杏鲍菇、香菇、圆菇、白玉菇、平菇、金针菇和姬菇的甲醇提取物的抗氧化能力。结果显示:9种食用菌甲醇提取物具有不同程度的抗氧化活性,其中圆孢蘑菇甲醇提取物对DPPH自由基清除能力最强,其EC_(50)值为346.50μg/mL,羊肚菌甲醇提取物的铁氰化钾还原力最强,平菇甲醇提取物的羟基自由基清除能力最强,其EC_(50)为863.74μg/mL。     

苦荞芽多酚提取工艺优化及抗氧化活性研究

采用单因素实验结合正交试验优化苦荞芽多酚的提取工艺条件,并采用ABTS和DPPH自由基清除率法测定了苦荞芽多酚提取物的抗氧化活性.研究结果表明,苦荞芽多酚的最佳提取工艺参数为,甲醇体积分数60%、提取时间80 min、提取温度60℃、料液比1∶40 g/m L.在此条件下,苦荞芽多酚的提取量高达83.51 mg/g.抗氧化活性试验表明,苦荞芽多酚提取物具有较好的抗氧化能力,其对ABTS自由基和DPPH自由基清除的半抑制浓度(IC_(50))分别为93.36μg/m L和185.76μg/m L.     

傣药人面果根部清除DPPH自由基能力及实验方法比较

分别采用高效液相色谱法和可见分光光度法检测傣药人面果根部甲醇提取物清除DPPH自由基的能力.高效液相色谱法测得人面果根部甲醇提取物清除DPPH自由基的IC50为0.116 mg/m L,可见分光光度法测得人面果根部甲醇提取物清除DPPH自由基的IC50为0.108 mg/m L,且DPPH自由基清除率与人面果根部甲醇提取物质量浓度呈正相关.统计学分析结果表明,2种实验方法的实验结果之间无显著性差异,2种方法均可用于傣药人面果对DPPH自由基清除能力的研究.     

32株银杏内生真菌清除DPPH自由基活性的比较研究

采用液体摇瓶培养的方法,以DPPH自由基清除率为指标,对32株银杏内生真菌发酵液的甲醇提取物抗氧化活性进行初筛,不同菌株清除DPPH自由基活性差异较大,其中4株菌株DPPH自由基清除率显著高于其他菌株,分别为96.68%、96.09%、85.32%和84.48%.在此基础上,对8株DPPH自由基清除率较高菌株菌丝体的甲醇、乙酸乙酯、异丙醇、水4种溶剂提取物的DPPH自由基清除率进行比较,结果表明,甲醇和水提取效果较好,优于乙酸乙酯和异丙醇,其中GCZX015菌株菌丝体甲醇提取物DPPH自由基清除活性最强为93.97%,GCZX018菌株菌丝体异丙醇提取物DPPH自由基清除活性最低,仅为0.11%.     

脱脂沙苑子乙醇提取物的体外抗氧化活性研究

通过测定脱脂沙苑子乙醇提取物(ESA)对1,1-二苯基-2-苦苯肼自由基(DPPH·)、超氧阴离子自由基(O-·2)和羟基自由基(·OH)的清除能力、对Fe2 诱导的脂质过氧化反应的抑制作用、还原力和总抗氧化力,评价ESA的体外抗氧化活性,并与公认的抗氧化剂维生素C作了对照.结果表明,ESA有一定的DPPH·清除能力(IC50=419.1μg/mL)、较强的超氧阴离子清除能力(IC50=117.9μg/mL)和羟基自由基清除能力(IC50=224.4μg/mL),能有效的抑制脂质过氧化(IC50=1.70 mg/mL),有良好的总抗氧化力,说明沙苑子具有明显的抗氧化活性.     

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

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.