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1.
通过优化纳他霉素浸提和结晶工艺,提高提取收率,提升产品质量。结果表明:浸提最佳条件是浸提温度为20℃、溶媒的添加量为4倍量(v/m)、浸提的时间为2 h,浸提得率可达到92%;结晶的最佳条件是搅拌频率10 Hz,结晶温度30℃,加水倍数为1.5倍(v/v),加水的时间控制在1.5 h,结晶得率可达到87.7%。  相似文献   

2.
齿果酸模叶蛋白提取的初步研究   总被引:1,自引:0,他引:1  
采用热絮凝法提取齿果酸模的叶蛋白,对加水倍量、打浆时间、pH、加热时间和加热温度等5个影响叶蛋白提取得率的因素进行了研究.在单因素基础上,对加水倍量、打浆时间、pH值和加热温度进行4因素3水平正交试验.方差分析结果表明,影响粗蛋白提取得率的因素依次为加水倍量,打浆时间,pH,加热温度.最佳工艺条件组合为加水倍量3.5倍,打浆时间2 min,pH值4,加热温度70℃.  相似文献   

3.
红枣芦丁提取工艺的研究   总被引:8,自引:0,他引:8  
研究了从红枣中提取芦丁的工艺条件。实验结果表明,用热水提取芦丁,加水量为原料重量的17倍,提取温度为70℃,时间60min;用乙醇提取芦丁,75%的乙醇溶液的用量为原料重量的16倍,提取温度75℃,时间120min。  相似文献   

4.
裙带菜茎中硫酸多糖的提取工艺   总被引:1,自引:0,他引:1  
为了从裙带菜茎中优选提取硫酸多糖的最佳工艺,以多糖得率为指标,通过单因素分析获得正交表中各因素的最佳水平数,采用正交实验对裙带菜茎中硫酸多糖的提取工艺进行优选.结果表明,浸提温度是提取褐藻硫酸多糖的关键影响因素,加水量和提取时间影响不大.从而求得最佳水浸提工艺条件:温度100℃、加水量40或50倍、浸提时间4 h.  相似文献   

5.
牛血中血红素提取优选工艺的研究   总被引:1,自引:0,他引:1  
张东萍  张珍  赵文宝  孙婷 《甘肃科技纵横》2007,36(3):193-194,181
以肉牛新鲜血液为原料,研究肉牛血红素的提取方法和工艺.采用醋酸钠法,鞣酸法,蒸馏法,CMC法的四种方法提取血红素,通过对四种方法的比较,得出醋酸钠法是较好的提取方法.对醋酸钠法采用U8★(84)均匀试验设计,以醋酸钠添加量、氨仿添加量、丙酮添加量和加水量为试验因素进行试验.结果表明:醋酸钠添加量为0.7倍,氯仿添加量为0.1倍,丙酮添加量为4倍,加水量为1倍是醋酸钠法提取血红素的最佳工艺.  相似文献   

6.
为优化超声波法和酶解法提取菊花总黄酮的工艺,并比较其工艺条件,选择因素水平,采用L9(34)正交设计优化提取工艺,以芦丁为对照品,用紫外分光光度计分析其提取率.结果表明,酶解法最佳工艺条件为:25倍70%的乙醇溶液,酶添加量0.5%,于45℃水浴下酶解150min,得率为5.60%;超声波法最佳工艺条件为:10倍70%的乙醇溶液超声40min,提取3次,得率为4.61%.酶解法的得率比超声波法的高21.5%.  相似文献   

7.
以黄秋葵为原料,采用超声波辅助纤维素酶对黄秋葵果胶的提取进行研究.在单因素试验的基础上,采用响应面分析考察超声温度、超声时间、料液比、酶解时间四个因素对果胶得率的影响.得出最佳工艺条件为超声时间15 min、液料比35∶1(m L/g)、超声温度43℃、酶解时间25 min.在该工艺条件下果胶得率为8.84%.  相似文献   

8.
以莲心为原料,以总黄酮得率和提取物得率为指标,考察提取温度、乙醇体积分数、提取时间和料液比4个主要因素,通过单因素和正交试验,研究莲心中总黄酮的最佳提取工艺。研究结果表明,莲心中总黄酮的最佳提取工艺为:乙醇体积分数70%,提取温度90℃,料液比1∶30,提取时间2.5h;在此工艺条件下,总黄酮得率1.669%,提取物得率30.748%。  相似文献   

9.
橙皮果胶制备中提取和除杂的研究   总被引:9,自引:0,他引:9  
以干橙皮为原料,研究了离子交换树脂法提取果胶的多种影响因素、工艺条件以及除杂问题.结果表明,以离子交换树脂法提取橙皮果胶的最佳条件为水料比为30∶1,0.01×7阳离子交换树脂的用量为5%,在75℃、pH为2.0下处理90 min,其果胶得率高,果胶质量优于酸法提取所得果胶,产品质量指标达到或优于国家标准.  相似文献   

10.
任利  李强 《科技信息》2009,(29):33-33,393
本试验以红枣为主要原料,采用热水提取法提取其中的水溶性红枣多糖,其最适工艺条件为加水量4倍,浸提时间3h,浸提温度90℃,浸提2次,此条件下水溶性红枣多糖的提取率最大为3.91%。  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<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   

20.
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