首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 515 毫秒
1.
采用水浴法设计三因素三水平正交试验,对龙葵多糖提取工艺进行研究;采用乙醇沉淀法设计三因素三水平正交试验对其分离工艺进行探索.正交试验结果表明:水浴法提取中三因素对龙葵多糖提取的影响顺序为:提取温度>料液比>提取时间,最佳提取工艺为:料液比1∶10,提取时间30 m in,提取温度80℃;乙醇沉淀法分离龙葵多糖中三因素的影响顺序为:乙醇浓度>沉淀时间>乙醇加入量,最佳分离工艺为:乙醇浓度90%,沉淀时间8 h,乙醇加入量3倍体积,这些条件的确定为龙葵的大规模开发和应用奠定了基础.  相似文献   

2.
响应面法优化微波辅助提取桑叶多糖的工艺研究   总被引:1,自引:1,他引:0  
利用微波辅助技术进行桑叶多糖提取,通过单因素实验确定因素与水平,应用Box-Behnken设计3因素3水平的试验,依据回归分析确定最优的提取工艺条件.结果表明,微波辅助提取桑叶多糖的优化提取工艺条件为:温度88℃、时间11 min和液固比18∶1,提取的多糖含量为15.20 mg/g.微波辅助提取的多糖含量分别比传统水提法提取10 min和60 min高2.18倍和0.23倍.  相似文献   

3.
为了研究栀子多糖的最佳提取工艺,利用正交实验对栀子多糖的提取工艺进行优化。在单因素实验的基础上选取实验因素与水平,设计四因素三水平正交实验。以栀子多糖提取率为指标,优化最佳提取工艺。试验结果表明:各实验因素影响主次顺序为提取次数料液比提取时间。栀子多糖的最佳提取工艺条件为提取次数3次,料液比1∶30,提取时间3.5h,采用此工艺条件提取多糖提取率为3.12%。  相似文献   

4.
对广东清远地区种植的黄精多糖的提取工艺进行讨论,并对主要工艺参数进行优化。通过单因素试验,确定对黄精多糖热水提取影响较大主要因素温度、固液比、提取时间、提取次数的影响程度和变化范围,根据单因素试验结论选取主要影响因素及相应试验水平进行正交试验对提取主要参数进行筛选,最后确定热水提取黄精多糖的最佳工艺条件。  相似文献   

5.
对杏鲍菇粗多糖提取工艺条件进行了初步探讨.在单因子实验基础上,对影响多糖提取率的3个因素4水平进行正交试验,确定提取的最佳条件为提取时间3.5h、提取温度75℃、水料比35:1(V/W).在此条件下杏鲍菇粗多糖的提取率可达10.04%.  相似文献   

6.
以超声波辅助水提醇沉法提取桑叶多糖,采用正交实验法优化桑叶多糖的提取工艺;采用滤纸片法进行抑菌试验评价桑叶多糖体外抑菌作用。实验考察提取时间、液固比、提取温度等因素对桑叶多糖提取率的影响,观察桑叶醇提物和桑叶多糖对枯草芽孢杆菌、大肠杆菌抑制作用。实验结果证明:超声波提取时间50 min,液固比40:1(m L.g~(-1)),提取温度为70℃,其桑叶浸提液中的多糖得率达到5.50%,体外抑菌实验结果显示桑叶醇提物对枯草芽孢杆菌、大肠杆菌有明显的抑制作用,桑叶多糖对这两种菌则没有抑制作用。  相似文献   

7.
五味子多糖制备工艺的优化研究   总被引:3,自引:1,他引:2  
目的 研究提取五味子多糖的最佳工艺条件.方法 选用提取时间、提取次数、提取温度和料液比作为考察因素,以提取液中多糖含量为考察指标,通过正交试验筛选五味子多糖的最佳提取工艺条件.结果 五味子多糖提取最佳条件为煎煮4 h,加水25倍,温度100℃.结论 可以通过正交试验优化提取五味子多糖的最佳工艺条件.  相似文献   

8.
采用正交法研究了乙醇溶剂提取仙人掌中黄酮类物质的工艺条件.利用单因素试验,确定影响黄酮提取效果的4个因素:乙醇浓度、提取温度、提取时间和料液比的较优水平,用正交设计试验优化提取工艺条件.结果表明,最佳提取条件为乙醇浓度(V/V)90%、料液比20/1、温度55℃、时间1 h.  相似文献   

9.
对浒苔多糖的碱法提取工艺进行研究,为评价提取条件对浒苔多糖提取率的影响,首先选用固液比、浸提温度、浸提时间和碱溶液浓度4个因素进行单因素多水平实验,在此基础上进行正交试验,筛选出最佳提取工艺条件.实验结果表明,影响浒苔多糖提取率的各因素的主次关系依次为:浸提温度、浸提时间、固液比,碱溶液浓度;浒苔多糖碱法提取的最佳工艺条件为:提取温度90℃,提取时间2.5h,固液比1:40(g:mL),氢氧化钠溶液浓度0.3mol/L;最佳工艺条件下,浒苔多糖的提取率为3.1%.  相似文献   

10.
玉米须蚕茧多糖提取工艺条件优化研究   总被引:1,自引:1,他引:0  
目的 研究提取玉米须蚕茧多糖的最佳工艺条件.方法 选用提取时间、提取次数、提取温度和加水倍数作为考查因素,以提取液中多糖含量为考查指标,通过正交试验,筛选玉米须蚕茧多糖的提取工艺条件.结果 玉米须蚕茧多糖提取最佳条件为煎煮2次,每次2h,加水15倍,温度100℃.结论 可以通过正交试验优化提取玉米须蚕茧多糖的最佳工艺条件.  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.
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   

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 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   

15.
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   

16.
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.  相似文献   

17.
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.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
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   

20.
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.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号