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1.
依据正交实验研究各种影响因素,建立RBF人工神经网络模型,应用于RSM实验优化,得到最佳实验条件是料液比为1:20 g/mL,浸液时间为1.5h,温度为60℃,提取时间为20 min,提取次数为4,红景天苷提取率理论值可达到2.966%。  相似文献   

2.
采用热水浸提法提取菊芋中的菊糖,并用磷酸水解为还原糖(大部分为果糖)。从固液比、提取时间、温度、水解时间、温度和菊糖液pH值等方面试验了对还原糖得率的影响,通过正交实验确定了最佳条件为:固液比1∶30,浸提温度80℃,浸提时间30min,水解温度80℃,水解时间30min,pH值为2,可以得到较令人满意的结果。  相似文献   

3.
脐橙皮中黄酮类化合物与果胶的分离和提取研究   总被引:5,自引:0,他引:5  
黄酮类化合物是具备主要生物活性的天然产物,果胶是人体7大营养素中膳食纤维的主要成分.实验就黄酮和果胶提取分别作L9(34)和L16(44)正交化实验.工艺条件表明,提取黄酮的较佳工艺条件是:固液比1∶30,超声处理时间55 min,处理温度50℃,浸提液浓缩得到粗黄酮.提取黄酮后的脐橙皮渣中提取果胶的较佳工艺条件是:70℃的温度,提取时间为55 min,pH=2.0,固液提取比为1∶25.  相似文献   

4.
以总姜黄素含量为考察指标,采用正交设计优化乙醇法提取姜黄中姜黄素,用分光光度法对姜黄素提取液总姜黄素含量进行检测。考察了料液比、浸提时间、温度、乙醇浓度等因素对提取量的影响。结果表明:在30℃时,乙醇浓度70%、料液比1∶28、浸提时间2 h提取率最高,该提取条件下提取工艺合理、科学。  相似文献   

5.
柿皮黄色素主要成分的鉴别及提取工艺条件的选择   总被引:1,自引:0,他引:1  
用显色反应检测及UV-VIS-分光光度法确定了柿皮黄色素的主要成分为类胡萝卜色素。探讨了从柿子皮中提取天然黄色素的工艺。研究了提取剂的类型、料液比、浸提温度、时间、次数等因素对柿皮黄色素提取的影响。通过正交试验,确定了最佳提取工艺:浸提料液比为1g:20mL,浸提温度60℃,浸提时间2.5h,浸提次数为2次,此条件下提取率为80.74mg/100g。  相似文献   

6.
正交设计优化木贼多糖的超声提取工艺(英文)   总被引:1,自引:0,他引:1  
以蒸馏水为溶剂提取,通过单因素实验和正交实验,研究料液比、超声功率、超声提取温度和超声作用时间对木贼多糖提取效果的影响。超声提取法的优化工艺条件为:料液比(g/mL)1∶20,提取温度70℃,超声功率100 W,作用时间50 min。在此条件下,木贼多糖的平均提取率为12.33%,RSD为0.16%。超声波强化提取木贼多糖省时高效。  相似文献   

7.
用超声波强化提取地骨皮中有机酸,采用单因素和正交试验方法研究了提取温度、提取时间、料液比、超声波功率对地骨皮中有机酸提取量的影响规律。结果表明超声波提取法的最佳工艺条件为提取温度65℃、提取时间35 min、料液比1∶16、超声波功率135 W,在此条件下地骨皮中总有机酸提取率为2.73%。  相似文献   

8.
选取微波功率、提取温度、提取时间和料液比作为因素,以毛细管电泳-紫外检测测定龙须藤多糖水解产物中的单糖峰面积总和为指标,通过单因素和正交试验,对提取条件进行了优化.结果表明,最大影响因素为微波功率,其次为提取温度,再次为提取时间,最后为料液比.最优提取条件为微波功率600 W,提取温度70 ℃,提取时间25 min,料液比1:35.  相似文献   

9.
采用微波和超声波提取技术,实现了川佛手中多酚类物质的有效提取.在微波功率800 W和微波提取时间40 min的条件下,通过单因素实验条件优化,考察了超声功率、乙醇浓度、提取温度、超声时间和提取料液比对提取效率的影响;通过正交试验设计,确定了最佳提取工艺条件参数,即超声功率800 W、乙醇体积分数60%、提取温度55℃、超声时间1.0 h和提取料液比1∶20 g/m L;通过验证实验,得到川佛手多酚的提取率约为20.79 mg/g.  相似文献   

10.
以油茶饼粕为原材料,采用微波预处理复合酶法,通过单因素试验研究了液固比、温度、时间、pH值和复合酶用量对油茶饼粕中茶皂素提取率的影响,采用正交试验确定最佳提取工艺条件。结果表明在时间为1.5 h、液固比为9∶1、pH值为6、浸提温度为55℃、复合酶用量为0.45%的条件下,茶皂素的提取率为13.35%,产品纯度为58.47%。  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

16.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.
19.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

20.
设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。  相似文献   

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