复合酶法提取蕨麻多糖及其抗氧化活性研究

确定了复合酶(纤维素酶、果胶酶、中性蛋白酶)提取蕨麻多糖的最佳工艺,并对其体外抗氧化活性进行初步研究.在单因素试验的基础上,设计L9 (33)正交实验和L9(34)正交实验,分别得出复合酶的最佳配比和复合酶法提取蕨麻多糖的最佳提取工艺条件;采用清除·OH(羟基)自由基模型和O2-·(超氧阴离子)自由基模型评价了蕨麻多糖的抗氧化能力.结果表明:复合酶的最佳配比为:纤维素酶2.0％,木瓜蛋白酶1.0％,果胶酶2.0％;最佳工艺条件为∶料液比为1∶30、pH值为4.5,温度为45℃,酶解时间为60min,此时蕨麻多糖的提取率最大为8.12％,同时验证性实验也表明优化得到的提取工艺稳定可靠;蕨麻多糖对羟基自由基和超氧阴离子都具有较强的清除作用,并与浓度呈一定依赖关系,且对羟自由基的清除能力要比超氧阴离子自由基的清除能力强.     

响应面法优化白番红花球茎多糖提取工艺及其抗氧化活性研究

在单因素试验的基础上,以白番红花球茎多糖提取率为响应值,对超声功率、超声时间、液料比三因素进行响应面法优化试验,并通过白番红花球茎多糖对DPPH自由基、超氧阴离子自由基、羟基自由基、ABTS自由基的清除能力,来研究白番红花球茎多糖的抗氧化活性.白番红花球茎多糖的提取最佳工艺条件为：超声功率为428 W、超声时间为45 min、液料比为57.8∶1(mL·g^-1),多糖实际提取率为7.54%.白番红花球茎多糖对DPPH自由基、超氧阴离子自由基、羟基自由基、ABTS自由基均有清除作用,其清除率最高分别可达到78.5%、57.9%、45.3%、79.8%.响应面法优化超声波提取白番红花球茎多糖的工艺合理可行,并且白番红花球茎多糖具有较强的抗氧化活性.     

海西黑枸杞多糖酶法提取工艺研究及其体外抗氧化性分析

以青海海西黑枸杞为原料,用酶法辅助提取其中的多糖。对比果胶酶、木瓜蛋白酶和纤维素酶的辅助提取效果,以料液比、加酶量、酶解时间和酶解温度为因素进行单因素实验,考察其对黑枸杞多糖提取率的影响,利用响应面法进一步优化黑枸杞多糖提取工艺参数,并对提取的多糖进行体外抗氧化性分析。结果表明:(1)果胶酶辅助提取黑枸杞多糖的效果最好,最佳提取条件为料液比1∶35(g∶mL)、加酶量0.02 g、酶解时间60 min、酶解温度30℃,提取率达到最大值26.60%,与模型方程理论预测值26.90%相对误差为1.12%;(2)海西黑枸杞多糖对DPPH自由基和超氧阴离子自由基具有较强的清除作用。     

黄山石耳多糖的提取及其抗氧化性研究

文章研究了黄山石耳多糖的复合酶法辅助提取工艺及其抗氧化性。通过单因素和L9(33)正交实验确定复合酶的最佳添加量为每0.2g样品中添加240U纤维素酶、720U果胶酶和2 400U木瓜蛋白酶;通过单因素和L9(34)正交实验优化石耳多糖的提取工艺,得出最优条件,即提取温度为60℃,提取时间为1h,pH值为6和料液比1∶40,该工艺条件下多糖提取率为12.52%;通过单因素和L9(33)正交实验优化石耳多糖的醇沉工艺,得出最优醇沉时间为5h,醇沉温度为5℃,乙醇体积分数为80%,此时多糖最终提取率为10.52%。黄山石耳多糖的体外抗氧化性实验结果表明,石耳多糖具有较高的体外抗氧化活性,其对ABTS自由基、DPPH自由基和OH自由基的清除率分别达到82.95%、74.58%和70.87%。     

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.     

甘西鼠尾草水溶性多糖提取工艺的优化及体外抗氧化活性测定

本文利用超声波辅助水提醇沉法提取甘西鼠尾草粗多糖,应用单因素和Box-Behnken响应面法进行提取工艺优化.对甘西鼠尾草粗多糖进行脱色素、脱蛋白处理得到初步纯化多糖,并对粗多糖和初步纯化多糖进行体外抗氧化活性的测定.结果表明,甘西鼠尾草粗多糖的最佳提取条件为:液料比31:1 m L/g、提取时间2. 7 h、提取温度75℃、超声波功率300 W.在此条件下,甘西鼠尾草粗多糖的提取率为6. 568%,与预测值基本一致.清除自由基实验表明,在一定浓度范围内,对·OH自由基清除活性最高清除率达64. 34%;对DPPH清除活性最大清除率达83%.     

红景天多糖的提取及体外抗氧化活性研究

目的优化红景天多糖的制备工艺,并系统评价红景天多糖清除自由基的能力.方法采用正交设计方法优化红景天多糖提取工艺,以多糖提率为考察指标,比较不同固液比、提取温度、提取时间、提取次数对多糖提取效果的影响;通过反复冻融、透析及酶-sevag联合脱蛋白法,纯化制备红景天多糖(RSP);采用苯酚-硫酸法、红外色谱仪及紫外-可见分光光度计对红景天多糖的基本理化性质进行表征;利用体外抗氧化模型评价红景天多糖对1,1-二苯基-2-苦苯肼自由基(DPPH·)、羟基自由基(·OH)和超氧阴离子(O_2~-·)自由基的清除能力.结果红景天多糖的最佳提取条件固液比为1∶20,提取温度为90℃,提取时间为3 h,提取次数3次.此外,红景天多糖对DPPH·和·OH具有较好的清除能力.结论成功确立红景天多糖的最佳提取工艺,红景天多糖具有一定的抗氧化作用.     

复合酶法提取冬瓜多糖的研究

采用蛋白酶、果胶酶、纤维素酶复合处理冬瓜多糖溶液,通过对复合酶的作用温度、作用pH值、作用时间进行单因素实验,对复合酶配比、复合酶的提取工艺进行正交试验,确定了复合酶法提取冬瓜多糖的最佳工艺条件:复合酶按纤维素酶1.5%,果胶酶1.5%,蛋白酶1.5%配比,酶作用温度40℃,酶作用pH值为5.0,酶作用时间为40 min,多糖提取率最高.     

酶法提取甜玉米芯多糖的对比研究

采用酶法提取甜玉米芯多糖,分别选取纤维素酶、果胶酶和木瓜蛋白酶进行单因素试验.在此基础上,研究三种酶同时添加和分步添加对甜玉米芯多糖得率的影响.结果表明,分步添加法比同步添加法对甜玉米芯多糖提取的效果显著,即先加木瓜蛋白酶(添加量2.0%,p H=7,提取温度50℃,时间1.5 h);然后加果胶酶(添加量1.0%,p H=6,提取温度50℃,时间1.5 h);最后加纤维素酶(添加量1.5%,p H=7,提取温度50℃,时间1.5 h),该条件下多糖得率为42.37%.     

黄精多糖的提取优化及抗氧化活性研究

通过优化黄精多糖的提取工艺,研究多糖的抗氧化作用。正交试验结果表明:提取时间,提取次数,料液比对黄精多糖的提取均有明显影响,影响的主次顺序为提取时间提取次数料液比。确定最佳的提取黄精多糖的参数为:提取时间1. 5 h,提取次数为4次,料液比为1∶25,在此条件下,得到黄精多糖的提取率可达到(7. 96±0. 12)%。抗氧化试验表明,黄精多糖具有一定的抗氧化活性,并且对自由基的清除率均呈现浓度依赖性,多糖对这几种自由基的清除能力顺序为ABTS+··OH DPPH· O_2~-·。以Vc抗氧化活性研究作为对照,黄精多糖的抗氧化活性均小于Vc。     

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.