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1.
作者采用超声波法改进了绞股蓝中人参皂苷的提取工艺。考察了乙醇浓度、提取时间和料液比对皂苷得率的影响,并通过正交设计优化超声提取工艺参数.得出最佳提取工艺为:料液比为1:15,乙醇浓度75%,提取时间60min.在此条件下皂苷得率可达到3.5674%。采用超声波法提取绞股蓝中人参皂苷比传统的回流提取法更简便快捷,且得率更高。  相似文献   

2.
以山竺果皮为原料,利用超声波提取天然食用红色素,正交法研究了影响超声波提取工艺的因素,并确定最佳工艺条件为:超声功率200W,超声温度45℃,超声时间30min,料液比1:5,收率为95.8%.  相似文献   

3.
优选返魂草颗粒中绿原酸的提取工艺,设计正交实验,采用水浴和超声波分别对返魂草颗粒中绿原酸的提取方法进行了研究,水浴法的最佳提取工艺条件为:70%乙醇,料液比24:1,40℃水浴回流90min;超声波法最佳提取工艺条件为:80%乙醇,料液比24:1,预浸渍30min超声40min,结果显示超声波提取法所得绿原酸含量较高,以本工艺提取返魂草颗粒绿原酸,绿原酸含熏达到3.63mg/g。  相似文献   

4.
冻干香蕉预处理条件优化的研究   总被引:1,自引:0,他引:1  
本文研究结果表明,不同蕉类香蕉,及在不同的季节成熟的香蕉加工的冻干品,其质量略有差别,同时香蕉的成熟度也影响冻干品的质量;采用“0.05%柠檬酸 0.5%氯化纳 0.6%氯化钙”的护色剂,对香蕉护色保脆有良好效果,其护色浸渍时间应以10min为宜。  相似文献   

5.
莲纤维及其制取   总被引:7,自引:0,他引:7  
以开发新型纺织服装原料为目的,研究了一种从农业废弃物(荷秆)中提取的新天然纤维——莲纤维.莲纤维的特征在于使用收取莲子或收获莲藕后的荷秆,或经手工分离或机械分离等物理方法提取茎秆内部的纤维。或经生物与化学法处理后再借助机械分离茎秆的纤维.所制取的莲纤维的平均长度40—300mm,细度为0.8—22dtex.这种纤维及其制品,具有清凉挺爽、透气舒适、吸湿快干、贴身抗皱,健康环保等穿着舒适性,为纺织等行业提供了绿色生态原料,同时叉为农业深加工开辟了新出路,具有较好的社会效益和经济价值.  相似文献   

6.
比较了有机溶剂提取法、酸热法和超声波提取法对于裂殖壶菌油脂的提取能力.酸热法和超声波提取法的提取得率高于有机溶剂提取法.当氯仿和甲醇以1:1的体积比混合时,油脂提取得率最高.当氯仿和甲醇以2:1的体积比混合时,提取所得油脂中的DHA含量最高.但总提取得率还是以氯仿和甲醇的体积混合比为1:1时为最佳.  相似文献   

7.
运用响应曲面优化法优化超声波辅助的茶粕中提取茶皂素工艺,建立以75%乙醇为提取剂的料液pH值、浸提温度、浸提时间、液固比和超声波功率等因素与茶皂素提取率间数学模型,据此确定最佳工艺条件为料液pH值8.0、浸提温度40℃、浸提时间4h、液固比8:1和超声波功率80W,此时实际茶皂素提取率8.041%(n=5),与模型预测接近。  相似文献   

8.
以香蕉茎纤维和丙烯酰胺为原料,过硫酸钾和亚硫酸钠为引发剂,制备了香蕉茎纤维-丙烯酰胺高吸水树脂.在单因素实验的基础上,以树脂吸水率为响应值,选取酰纤比、反应温度、引发剂用量和交联剂用量为自变量,利用Box-Behnken设计和响应面法对各自变量及其交互作用对树脂吸水率的影响进行了研究,得到了二次多项式回归方程模型.香蕉茎纤维-丙烯酰胺高吸水树脂的最佳制备工艺条件为:酰纤比9.9 g/g、反应温度48℃、引发剂用量1.9%和交联剂用量0.18%.在此条件下,测得所制备的吸水树脂吸水率为461.22 g/g,与预测值相对误差为0.68%,说明响应面优化香蕉茎纤维-丙烯酰胺高吸水树脂的制备工艺具有较高的准确性与可靠性,该方法可用于香蕉茎纤维-丙烯酰胺高吸水树脂制备工艺的优化.  相似文献   

9.
黑茶黄酮的光谱分析及抗氧化性能研究   总被引:3,自引:2,他引:1  
采用超声波法提取黑荼中的黄酮类化合物,通过光谱分析方法测定了黄酮含量.本法的回收率为97.5%-103.5%,相对标准偏差小于0.068%.通过流动注射化学发光法研究了黑茶的抗氧化性能。所得结果表明,黑茶具有较高的黄酮含量和较强的抗氧化性能.  相似文献   

10.
探讨超声波法提取羊耳菊叶总黄酮的主要影响因素,通过L^9(3^4)正交试验,研究了羊耳菊叶中黄酮类化合物提取的最佳工艺,结果表明,各试验因素时羊耳菊叶中黄酮类物质提取量的影响依次为乙醇浓度、提取时间、液料比,超声波法提取羊耳菊叶黄酮类化舍物的最佳工艺为:乙醇浓度为70%、液料比为25:1、超声波提取3h、提取1次.  相似文献   

11.
《海外英语》2007,(5):44-45
It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,  相似文献   

12.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.  相似文献   

13.
王菲 《华章》2007,(12):273-273
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.  相似文献   

14.
裴水妹 《华章》2007,(11):196
Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.  相似文献   

15.
16.
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…  相似文献   

17.
Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.  相似文献   

18.
STORIES     
正A One day a pig went to the stable(马棚)to see his good friend,an oldhorse,and was going to stay there forthenight.Night came and it was time forsleep.The pig went into the straw heap(稻草堆)and lay comfortably.A longtime passed,but the horse was stillstanding there and did not move.Thepig asked the horse why he did not go tosleep."Standing like this is the begin-ning ofsleeping,"answered the horse.  相似文献   

19.
正1.Any fool can count the seeds in an apple.Only God can count all the apples in one seed.2.Happy families are all alike;every unhappy family is unhappy in its own way.3.Memories are the key not to the past,but to the future.4.Sometimes in the dark you see what you want to see.5.There is a great difference between  相似文献   

20.
正Scope and Policy The Journal of Chongqing University-English Edition(JCQU-E)is a peerreviewed journal publishing research articles in multiple disciplines of science and technology,covering civil and environmental engineering,chemical engineering,biotechnology,mechanical and electrical engineering,computer and data processing,mining,metallurgy,materials science,and interdisciplines thereof.  相似文献   

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