超声波辅助提取沙田柚皮中柚皮苷工艺的研究

对沙田柚皮中柚皮苷提取工艺进行研究,通过单因素实验、正交实验等方法,确定了优化提取工艺:固液比为1∶10,乙醇浓度为70%,提取温度为40℃,提取时间为60min。本研究发现超声波辅助处理,不会显著增加柚皮苷提取率,但是可以在达到相同较高柚皮苷提取率的基础上,显著降低固液比,减少乙醇用量。     

柠檬皮中香精油提取工艺的研究

为了研究柠檬皮中香精油的提取工艺,利用石油醚索氏提取,采用单因素法分别考察了柠檬皮的投加量、石油醚的体积、萃取时间和萃取温度对香精油出油率的影响．结果表明当柠檬皮的投加量为25g、萃取温度为60℃、萃取时间为30min时香精油的出油率达到最大值;随着石油醚用量的增加,香精油的出油率不断增加,综合考虑提取率与经济性石油醚用量取400ml为宜．     

菊花脑花活性成分提取工艺及挥发油成分分析

以滁州本地菊花脑花作为实验材料,通过单因素和正交实验对常规水提法和超声波辅助提取菊花脑花中黄酮和总酚的工艺进行优化;并利用水蒸气蒸馏法提取菊花脑花中的挥发油,对其成分进行GC-MS分析.研究发现:常规水提取法对菊花脑花黄酮和总酚进行提取的最优的条件是料液比1:35、水浴温度80℃、提取时间100min,此时黄酮和总酚的得率分别为12.41mg/g和7.58mg/g;超声波辅助提取法对菊花脑花黄酮和总酚进行提取的最优条件是料液比1:35、提取剂浓度60%、超声功率200W、超声时间20min,此时黄酮和总酚的得率分别为20.34mg/g和7.97mg/g;蒸馏法所得挥发油的GC-MS分析出约50种成分,其中含量较高的有樟脑(9.92%)、β-倍半水芹烯(7.75%)、石竹烯(5.98%)和檀香醇(5.87%).     

发酵后山葡萄皮中花青素的提取工艺实验

本实验采用水浴法提取发酵后山葡萄皮中的花青素,在浸提时间、料液比、浸提温度和乙醇浓度4个单因素实验基础上,结合正交实验确定发酵后山葡萄皮中花青素的最佳提取工艺条件.正交结果显示4个单因素对发酵后山葡萄皮花青素提取的影响大小顺序为:浸提时间、料液比、浸提温度、乙醇浓度,得出发酵后山葡萄皮中花青素提取的最佳工艺参数为:浸提时间1 h,料液比为1:20,浸提温度65 ℃,乙醇浓度为50%.     

超声细胞粉碎法提取麦冬多糖的工艺条件研究

应用超声波技术对麦冬多糖的提取工艺条件进行了研究,在提取过程中,采用单因素法分析了几个主要因素：提取时间,超声波功率和液固质量比对麦冬多糖含量的影响.结果表明超声波提取麦冬的最佳工艺条件为：提取时间20 m in,功率700 W,水与麦冬液固质量比为1∶70,提取率83%.     

基于超声波辅助酶法提取茯苓多糖的工艺研究

目的:研究复合酶协同超声波法提取茯苓多糖的最佳工艺条件,方法:单因素试验和正交试验优化提取条件,确定最佳提取工艺。结果:复合酶最佳质量配比为:木瓜蛋白酶1.0%,果胶酶1.5%,纤维素酶1.5%;单因素试验及正交试验表明,影响多糖提取率顺序是:超声波功率>温度>提取时间>料液比,最佳提取工艺条件为超声波功率360W,料液比1:50,温度50℃,提取时间50min,此时茯苓多糖的得率为3.72%。结果表明,复合酶协同超声波法提取茯苓多糖,方便,有效。     

超声波辅助提取葛根总黄酮的工艺研究

以乙醇为提取溶剂,采用超声波辅助提取葛根总黄酮。通过单因素和正交试验研究了乙醇浓度、超声时间和料液比对葛根总黄酮浸出率的影响,确定其最佳提取工艺。结果表明,影响超声波辅助法提取葛根总黄酮因素的顺序为乙醇浓度>料液比>超声时间;最佳提取工艺为乙醇体积分数35%,超声时间24min,料液比1∶40(g/mL),黄酮浸出率最高,为2.76%。     

紫荆皮总黄酮提取工艺的优化研究

目的:利用超声波法研究紫荆皮中总黄酮的最佳提取工艺.方法:以总黄酮含量为考察指标,采用正交试验法,考察加醇量、提取次数、提取时问、乙醇浓度4个因素对提取工艺的影响.结果:最佳提取工艺为A3B1C3D2,即药材加乙醇12倍量,提取3次,提取时间15min,乙醇浓度60％.结论:正交试验法优选紫荆皮总黄酮的提取工艺简便、快速、准确.     

四种方法提取紫草乙酸乙酯溶解物的对比研究

以乙酸乙酯为溶剂,运用索氏提取、旋转蒸发、水蒸气蒸馏、超声波萃取等4种不同的提取方法提取紫草中的可溶性成分,对比提取率的差异并研究提取物中可溶性成分的紫外可见光谱性质.实验结果表明,4种方法的提取率及提取物成分依次为:索氏提取法(5种),旋转蒸发法(5种),超声波辅助萃取法(4种),水蒸气蒸馏法(3种);索氏提取法在提取时间、溶剂用量、产物产量等方面均优于其它3种提取方法.     

石南藤挥发油提取工艺研究

采用水蒸气蒸馏法对石南藤挥发油的提取工艺进行研究。以得油率为指标,以液料比、蒸馏时间、浸泡温度、浸泡时间为因素进行正交试验,得出最佳提取工艺为:液料比15:1,蒸馏时间1.5 h,浸泡温度30℃,浸泡时间1 h[1],得油率为0.324%。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

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.     

浅谈移民问题

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.     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.     

团图为数的图中的闭团贯数

Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F.     

Sister Carrie, an Adherent of Desires

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.