观赏金银花中绿原酸的超声提取研究

以观赏金银花为原料,利用超声波强化提取绿原酸化合物.在单因素试验的基础上,采用正交试验法,考察了超声时间、料液比、乙醇浓度、超声温度对绿原酸提取率的影响,确定最佳的提取工艺.结果表明:超声波提取观赏金银花中绿原酸的最佳工艺条件为乙醇浓度60%,料液比1∶20,超声温度70℃,超声时间40 min.在上述最佳条件下,绿原酸的提取量为36.72 mg/g.     

葡萄中提取白藜芦醇的工艺研究

采用超声波法提取葡萄皮和葡萄籽中的白藜芦醇,由正交试验获得葡萄皮中提取白藜芦醇的最佳工艺为：乙醇提取剂浓度60%,料液比1∶12,超声时间12min,60℃水浴时间30min,白藜芦醇提取率为0.014 9%.葡萄籽中提取白藜芦醇的最佳工艺为：乙醇提取剂浓度60%,料液比1∶14,超声时间5min,60℃水浴时间30min,白藜芦醇提取率为0.005 7%.在此条件下的提取工艺稳定性好且简便易行,实验结果还显示葡萄皮中白藜芦醇的含量高于葡萄籽中的含量.     

超声波提取紫苏叶中黄酮工艺的研究

以干紫苏叶为原料采用超声提取法,提取紫苏叶中黄酮类化合物。通过超声时间、超声水浴温度、乙醇浓度以及料液比对提取率的影响因素进行单因素分析,择较优结果进行正交试验,确定超声波提取紫苏叶中黄酮类化合物的最优条件。结果表明:超声波提取紫苏叶中黄酮最佳提取工艺是料液比为1:50,乙醇浓度为60%,水浴温度在40℃,超声提取时间为40min。     

都匀楼梯草总黄酮提取工艺及其抗氧化性能研究

采用正交试验法优化都匀楼梯草中总黄酮的超声波提取工艺,考察超声波作用时间、乙醇浓度和液料比3个因素对都匀楼梯草总黄酮提取率的影响,确定都匀楼梯草总黄酮的优化超声波提取工艺条件为：提取溶剂80％乙醇,料液比1∶25,超声波作用时间40 min,最佳提取率为1.62％.乙醇提取物抑制DPPH自由基的能力IC50=125.25μg/mL,说明都匀楼梯草不同极性部位均具有一定的抗氧化活性.     

金银花中绿原酸提取及其在果蔬保鲜中的应用

以金银花的花、茎、叶为原料,乙醇为提取溶剂,通过单因子试验和正交试验,研究金银花绿原酸的最佳提取工艺;并用所得绿原酸对时令果蔬进行保鲜处理,以研究其对果蔬的保鲜效果．结果表明,从金银花的花和叶中提取其绿原酸的最佳浸提条件：浸提温度60℃,提取时间60min,料液比1：25,乙醇浓度60％．茎中绿原酸的提取最佳浸提条件：浸提温度60℃,提取时间45min,液料比1：25,乙醇浓度60％．保鲜实验结果表明：绿原酸对贡梨、红富士鲜切片都有保鲜效果．对圣女果的保鲜作用差．     

谈学生综合实验改进——超声波法提取绞股蓝中人参皂苷实验过程与分析

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。     

超声波辅助提取绿茶紫外线吸收剂工艺优化研究

为优化超声波辅助提取绿茶中紫外吸收剂的工艺参数,探讨提取时间、提取温度、料液比、乙醇浓度和提取次数对提取液吸光度的影响,采用RSA响应曲面法优化超声波提取时间、提取温度和料液比.结果表明,超声波辅助提取绿茶中紫外吸收剂的最佳工艺条件是：以60%的乙醇提取次1次,超声温度50℃,超声时间为50min,料液比为40 mL/g,紫外吸收剂的最大吸光度值为0.597.     

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%。     

商洛杜仲叶绿原酸含量测定及提取工艺研究

以商洛市所产杜仲叶为原料,乙醇为浸提溶剂,通过正交试验确定杜仲叶中绿原酸的最佳提取工艺。试验结果表明：杜仲叶中绿原酸的最佳提取条件为乙醇浓度60％,温度80℃,提取时间2．5h,料液比1：20。最佳工艺条件下绿原酸的提取率为2．114％。试验提取方法简便,结果准确可靠,可为商洛市杜仲叶中绿原酸的生产开发提供参考。     

超声波提取羊耳菊叶总黄酮优化工艺研究

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．     

汉字倒说

汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。     

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,     

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?     

钱生钱!

我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了     

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.     

Inequalities for inscribed simplexes

The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex.     

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.     

微薄的薪水,高尚的情操

现在,我们可以没有面包,没有钱,没有房子,没有车子……但我们唯独不能丢失的是高尚的情操,笃定的信念,还有,满满的希望!     

Virtual reality approach for 3D large model browsing on web site

Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator＇s Garden. Translating building data to the Virtual Reality Modeling Language （VRML） is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching.