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1.
超声提取天冬多糖和总皂苷工艺研究   总被引:1,自引:0,他引:1  
目的:研究超声法在天冬多糖和总皂苷提取工艺中的应用。方法:采用单因素实验和正交实验考察不同因素对超声法提取天冬多糖和总皂苷的影响,优化最佳工艺参数。结果:天冬多糖最佳提取工艺为:料液比20∶1,提取温度70℃,提取时间30min,超声功率350 W;天冬总皂苷的最佳提取工艺为料液比20∶1,提取温度60℃,提取时间25min,超声功率350W。结论:超声法对天冬多糖和总皂苷的提取,具有提取率高、快速有效等优点。  相似文献   

2.
姬松茸多糖提取方法的研究   总被引:22,自引:0,他引:22  
探讨姬松茸子实体多糖和菌丝体我糖提取的条件,对子实体多糖和菌丝体多糖的提取率进行比较分析,得出了实体多糖提取的最佳条件为1:10的加水水量,100℃的提取温度,5h的提取时间,菌丝体提取的最佳条件为1:30的加水量,100℃的提取温度,5h的提取时间。在相同条件下,菌丝体提取到的多糖化实体的多。  相似文献   

3.
以多糖得率为指标,对影响多糖提取率的超声时间、温度、料液比进行单因素和正交试验;以清除自由基和抗猪油氧化作用探讨金荞麦多糖的抗氧化能力。结果表明,影响金荞麦多糖提取率的最主要因素是时间,最佳提取工艺条件为超声时间120 min、温度60℃、料液比1:20;金荞麦多糖可清除自由基,降低猪油过氧化值,具有体外抗氧化作用。  相似文献   

4.
为寻找金叶女贞果实多糖超声提取的最佳条件,采用以金叶女贞多糖含量为考察指标,用苯酚-硫酸法进行含量测定,通过单因素及正交实验,对提取时间、超声波频率、料液比、提取温度等提取因素进行研究.结果显示:影响金叶女贞多糖提取率的因素依次为:提取时间﹥超声频率>提取温度﹥料液比;最佳提取工艺为:提取温度100℃,料水比1∶30,提取时间80 min,超声频率为300 W.  相似文献   

5.
姬松茸胞内多糖提取工艺的研究   总被引:3,自引:0,他引:3  
采用单因子试验和正交试验组合优化,对姬松茸菌丝体胞内多糖提取工艺进行了研究,单因子试验表明姬松茸胞内多糖提取工艺为:组织捣碎、水提、提取3次,正交试验优化组合结果为温度90℃,时间4h,料水比1∶25,在此最佳提取工艺条件下,姬松茸胞内多糖提取得率为(2 1±0 1)mg/g湿菌体(含水量87%),具有一定的实际生产意义.  相似文献   

6.
为提高养心菜多糖的提取率,利用响应面法对养心菜多糖的超声辅助提取条件进行优化。研究了液料比、超声时间、超声温度和超声功率对养心菜多糖提取率的影响,并用响应面法对工艺条件进行了优化。结果表明养心菜多糖的最佳提取工艺条件为:液料比为34 mL/g,超声时间为24 min,超声温度为62℃和超声功率86 W。在该条件下,测得养心菜多糖提取率为75.48 mg/g,与预测值(76.25 mg/g)相比,其相对误差为1.05%,说明方程的预测值与实验值拟合性良好,可用于养心菜多糖提取工艺的优化,该研究为养心菜提取多糖类化合物提供理论依据和参考。  相似文献   

7.
为了简化刺梨多糖的提取工艺,达到节能、省时、方便的目的,用水提法提取刺梨多糖,探讨乙醇质量分数、提取温度、加热时间和料液比对多糖提取率的影响.采用正交实验优化工艺,以多糖提取率为评价指标,用蒽酮硫酸法测定多糖含量.水提法的最佳工艺条件为温度75℃,时间1h,料液比1∶40,乙醇质量分数0%.在此条件下刺梨多糖的得率为4.7%.  相似文献   

8.
超声波辅助提取桦褐孔菌多糖的工艺研究   总被引:1,自引:0,他引:1  
研究通过超声波振荡处理对桦褐孔菌多糖的提取工艺的优化。超声波振荡处理后,采用水提醇沉法提取桦褐孔菌粗多糖,并利用苯酚-硫酸显色法,以葡萄糖为标准液,测定桦褐孔菌粗多糖中多糖的提取率。通过单因素分析法考察超声时间、水提温度、料液比对桦褐孔菌多糖提取率的影响,以及应用正交实验法来获得超声辅助提取桦褐孔菌多糖的最佳工艺参数。桦褐孔菌多糖超声提取的最佳工艺条件为超声时间20 min,料液比1∶50,提取温度60℃。在最佳工艺条件下实验所得多糖的提取率为5.03%。与传统的水浴浸提法相比,超声波辅助提取法不仅能缩短提取时间,而且提高了桦褐孔菌多糖的提取率。  相似文献   

9.
翅果油树多糖提取工艺的优化   总被引:1,自引:0,他引:1  
本试验采用水提醇沉法提取翅果油树叶片中的多糖,探讨了浸提温度、浸提时间、固液比和浸提次数对多糖得率的影响.在单因素试验的基础上,通过正交试验确定最佳提取工艺条件.结果表明:在试验范围内,最佳提取温度为75 ℃,在此温度下提取次数对多糖提取率影响最大.翅果油树多糖提取的最优条件为提取温度75℃,固液比1∶ 10,浸提2次,每次浸提1.5 h,其水溶性多糖提取率达10.07%.  相似文献   

10.
超声法提取枸杞多糖工艺优化   总被引:1,自引:0,他引:1  
韩秋菊 《科学技术与工程》2013,13(13):3783-3785
采用超声法提取枸杞多糖,考察了料液比、超声功率、超声时间和提取温度四个因素对枸杞多糖提取率的影响。结果最佳提取工艺条件为:料液比1∶50、超声功率60 W、超声时间15 min,提取温度90℃。  相似文献   

11.
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.
何延凌 《科技信息》2008,(4):258-258
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.
王慧 《科技信息》2008,(10):240-240
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.
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.  相似文献   

16.
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.  相似文献   

17.
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   

18.
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   

19.
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.  相似文献   

20.
The non-orthogonal localized molecular orbital(NOLMO)is the most localized representation of electronic degrees of freedom.As such,NOLMOs are thus potentially the most efficient for linear scaling calculations of electronic structures for large systems.However,direct ab initio calculations with NOLMO have not been fully implemented and widely used,partly because of the slow convergence issue in the optimization of NOLMO.We devel-  相似文献   

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