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1.
目的:提取云龙野生和人工培养两种黑木耳多糖并测定其含量。方法:采用乙醇浸提法提取多糖,紫外分光光度苯酚-硫酸显色法测定粗多糖含量。结果:在8.0-48.0μg/mL线性范围内,回收率为99.03%,RSD为0.66%(n=6),测到野生和人工培养黑木耳中多糖的收率分别为18.48%和18.29%;野生和人工培养黑木耳中多糖的含量分别为9.21%和8.20%。结论:野生黑木耳比人工培养黑木耳中多糖的含量高,生长环境对黑木耳多糖含量有影响。 相似文献
2.
野生及人工培养香菇和黑木耳中粗多糖含量测定 总被引:2,自引:1,他引:1
目的:测定野生及人工培养的香菇、黑木耳中多糖含量。方法:采用苯酚-硫酸法测定其多糖含量。结果:在10~60μg/ml线性范围内,相关系数r=0.9994,平均回收率为99.45%,RSD为0.47%(n=6)。野生香菇和黑木耳中多糖含量分别为9.52%和8.54%,人工培养的香菇和黑木耳中多糖含量分别为8.36%和7.77%。结论:此方法操作方便,结果准确,为香菇和黑木耳的进一步研究提供了可靠的依据。 相似文献
3.
野生与栽培云芝中多糖含量测定及提取的研究 总被引:3,自引:0,他引:3
利用苯酚硫酸法对野生和栽培云芝中的多糖含量进行测定,设计正交实验分别用水煮提取法和超声波提取法确定云芝多糖提取的最佳工艺,将脱脂后的云芝利用超声波提取法以质量分数2.0%的碳酸钠溶液做为介质,在90℃浸提二次,每次浸提1h,可使栽培云芝中多糖提取率高达7.74%,野生云芝多糖提取率高达6.04%.栽培云芝中多糖含量明显高于野生云芝. 相似文献
4.
微波辅助提取黑木耳多糖的工艺 总被引:1,自引:0,他引:1
以黑木耳为原料,选择微波间断加热方式提取黑木耳中的多糖。利用单因素试验和正交设计对黑木耳多糖的提取条件进行了优化研究。最终确定最佳的提取工艺。结果表明,黑木耳多糖的最佳提取条件为:微波辐射时间为40 min,固液质量比为1∶110,筛孔尺寸为0.250 mm。时间因素对黑木耳多糖的提取率影响最为显著,固液质量比因素的影响最小。在最佳提取条件下,木耳多糖的提取率为15.25%,呈灰白色丝状。 相似文献
5.
茚三酮比色法测定野生及人工培养香菇和黑木耳中氨基酸含量 总被引:1,自引:0,他引:1
目的:比较野生及人工培养香菇和黑木耳中氨基酸的含量,为高效、经济地开发利用资源提供依据。方法:采用茚三酮比色法测定氨基酸含量。结果:在60~100mg/L浓度范围内,浓度与吸光度呈良好线性关系。回归方程:A=0.0152C-0.7928,r=0.9987,平均回收率为99.5%,RSD为0.06%(n=9)。野生及人工培养香菇中氨基酸的含量分别为14.54%、12.57%,野生及人工培养黑木耳中氨基酸的含量分别为8.83%、7.43%。结论:该方法操作简便,结果准确,重现性好。野生与人工培养的香菇和黑木耳中氨基酸含量没有显著差别。 相似文献
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黑木耳多糖是一类具有重要生物活性作用的功能性成分,是目前最有开发前途的保健食品和药品新资源之一。本文综述了近年来国内外木耳多糖的提取方法、结构及生物活性的研究进展。 相似文献
7.
黑木耳多糖的研究进展 总被引:1,自引:0,他引:1
黑木耳多糖是一类具有重要生物活性作用的功能性成分,是目前最有开发前途的保健食品和药品新资源之一.本文综述了近年来国内外木耳多糖的提取方法、结构及生物活性的研究进展. 相似文献
8.
《南京师大学报(自然科学版)》2017,(2)
采用热水浸提法分别提取香菇(Lentinus edodes)、木耳(Auricularia polytricha)、银耳(Tremella)、猴头菇(Hericium erinaceus)、茶树菇(Agrocybe chaxinggu)5种食药用菌子实体中的水溶性多糖,子实体粉末在一定的料水比下热水浸提,胰蛋白酶法脱杂蛋白,乙醇沉淀得到精多糖.并采用苯酚-硫酸法测其糖含量,DPPH(1,1-二苯基-2-三硝基苯肼)法检测其抗氧化性.结果显示,茶树菇的精多糖得率最高,为4.81%,香菇其次,木耳最低;含糖量猴头菇最高,为53.9%,木耳最低;5种食药用菌子实体多糖均具抗氧化性、DPPH清除作用,茶树菇最强,浓度为1.13 mg/m L时清除率为50%,香菇次之,银耳最弱. 相似文献
9.
云南野生食用菌多糖含量测定及培养特性研究 总被引:1,自引:0,他引:1
对云南野生蘑菇青头菌和鸡枞菌中多糖含量进行测定.结果表明:野生青头菌中多糖含量高达31.0%,鸡枞次之为21.8%,比普通人工栽培的鸡腿菇分别高出3.0倍和1.8倍.因此,对研究如何增强人体的免役力,提高抗病毒和延缓衰老,开发天然资源有较大实用价值. 相似文献
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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. 相似文献
12.
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. 相似文献
13.
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. 相似文献
14.
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. 相似文献
15.
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。 相似文献
16.
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. 相似文献
17.
Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
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- 相似文献
18.
Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
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- 相似文献
19.
Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that 相似文献
20.
《上海师范大学学报(自然科学版)》2014,(5):550
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with 相似文献