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1.
[目的]优化超声波辅助提取络石藤中总黄酮的工艺.[方法]以总黄酮含量为考察指标,采用正交试验设计研究超声波辅助提取络石藤总黄酮的最佳工艺条件.[结果]最佳提取工艺为乙醇浓度60%、反应温度70 ℃、超声时间30 min、料液比1:15;在此条件下,总黄酮的提取率为3.22%.[结论]优化后的工艺简便可行,可为络石藤总黄酮提取纯化工艺的产业化提供理论依据.  相似文献   

2.
[目的]探讨微波辅助法提取山楂中黄酮类化合物的工艺.[方法]采用单因素试验和正交试验,研究微波处理时间、微波功率、乙醇浓度和液固比4个因素对提取山楂黄酮类化合物的影响.[结果]最佳提取工艺条件为:液固比60:1、乙醇浓度80%、微波处理时间60 s、微波功率420 W.在此工艺条件下,提取率达到3.47%.[结论]该工艺条件适合于提取山楂中黄酮类化合物.  相似文献   

3.
[目的]建立并优化襄麦冬块根中总黄酮的提取方法.[方法]采用超声波辅助提取法,通过单因素试验和正交试验考察提取时间、料液比、乙醇体积分数和超声波功率对襄麦冬块根中黄酮提取的影响,优化提取工艺条件.[结果]正交试验结果表明,影响襄麦冬中总黄酮提取的主要因素为超声波功率,而最佳提取工艺为超声提取时间75 min,乙醇体积分教70%,料液比1:20,超声波功率90W.在此工艺条件下,寰麦冬总黄酮提取率为0.581 mg/g.[结论]研究结果为襄麦冬中总黄酮的开发利用提供了理论依捂.  相似文献   

4.
[目的]优化宁夏沙枣中总黄酮的提取工艺.[方法]采用乙醇回流法对沙枣中的总黄酮进行提取.在单因素试验的基础上,采用正交设计考察提取温度、乙醇浓度、提取时间和料液比对黄酮提取率的影响.[结果]最佳工艺条件如下:提取温度80℃,提取时间1h,提取剂为体积分数0.60的乙醇,料液比1:18.在此条件下,宁夏沙枣中总黄酮的提取率可达3.070 mg/g.[结论]该研究为提高宁夏沙枣的药用功效和进一步开发利用提供了试验依据.  相似文献   

5.
[目的]在微波辅助条件下寻找提取积雪草总黄酮的优化条件.[方法]选取单因素试验和正交试验,以微波功率、微波辅助提取时间、乙醇浓度、固液比为因素,每个因素3个水平,选择L9(34)正交表,用紫外分光光度法测定的总黄酮含量作为评价指标.[结果]最佳提取条件为微波功率406 W,微波时间90 s.乙醇浓度70%,固液比1:20,此时总黄酮含量为5.342%.[结论]该试验提取工艺操作简单、步骤简洁、方法稳定可行.  相似文献   

6.
[目的]研究利用索氏浸提法提取燕麦中皂苷的工艺条件.[方法]以乙醇–正丁醇为溶剂,以皂苷Re为标准品,采用分光光度法定量分析燕麦提取液中总皂苷含量,利用正交试验设计研究料液比、乙醇浓度、浸提温度对提取率的影响.[结果]各因素对皂苷提取率影响的主次顺序依次为:乙醇浓度>料液比>浸提温度;最佳提取条件:料液比为1∶7,乙醇浓度70%,浸提温度60 ℃;在此条件下,提取率为2.504%.[结论]该方法操作方便,简单易行,具有推广应用价值.  相似文献   

7.
[目的]优化微波直提法和微波-索氏提取法提取芦笋老茎中多糖的工艺.[方法]以多糖提取率为考察指标,通过正交试验优化2种提取方法的提取工艺.[结果] 微波直提法的最佳工艺条件为:料液比为1:30,提取时间为20 min,提取温度为60 ℃,微波功率为600 W,在此条件下多糖的提取率为4.35%;微波-索氏提取法的最佳工艺条件为:料液比为1:33,微波时间为10 min,微波功率为600 W,提取温度为70 ℃,在此条件下多糖的提取率为2.29%.[结论]微波直提法具有提取效率高,提取温度低,能量消耗小等特点,可用于实际生产中.  相似文献   

8.
[目的]优化柿叶(FOLIUM KAKI)总黄酮的提取工艺.[方法]在单因素试验基础上,采用响应面分析法对影响柿叶总黄酮提取率的主要因素(提取温度、料液比和乙醇体积分数)进行优化,建立了影响因素与响应值之间的函数关系.[结果]柿叶总黄酮最佳提取工艺为:提取温度74.05℃,料液比1:35.01,乙醇体积分数65.78%,在此条件下,提取率最高达4.041%.[结论]采用响应面法对柿叶总黄酮的提取条件进行优化合理可靠.  相似文献   

9.
[目的]优化甘草中总黄酮的提取工艺.[方法]以乙醇为提取剂,采用超声波法辅助提取甘草中的总黄酮,并采用正交设计试验优化甘草总黄酮的提取工艺.[结果]在提取液乙醇浓度75%、料液比1:25、超声功率350 W,超声时间25 min的条件下,甘草总黄酮提取得率最高达1.943%,各因素影响顺序为乙醇浓度>料液比>超声功率>超声时间.[结论]该试验为甘草的进一步开发利用提供了科学依据.  相似文献   

10.
[目的]优化荔枝壳中总黄酮的提取工艺.[方法]采用超声波辅助法提取荔枝壳中的总黄酮,以总黄酮得率为指标,在单因素试验的基础上,采用正交设计优化提取工艺.[结果]最佳工艺工艺如下:乙醇浓度60%,超声时间30 min,料液比1:50,超声提取次数2次,在此工艺条件下,荔枝壳总黄酮的提取得率可达28.18 mg/g.[结论]超声波辅助法提取荔枝壳总黄酮具有方便、高效的优点,该研究为荔枝壳总黄酮的进一步开发利用奠定了试验基础.  相似文献   

11.
转炉炉壳热应力分析   总被引:5,自引:1,他引:4  
任学平  郭志强  邹家祥 《炼钢》2001,17(6):47-49
根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。  相似文献   

12.
Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

13.
The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.  相似文献   

14.
鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".  相似文献   

15.
张兴强  叶运福 《冶金设备》2005,(6):71-72,47
针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。  相似文献   

16.
17.
Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.  相似文献   

18.
通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。  相似文献   

19.
20.
In this paper is treated the fundamental problematic of the fracture of the diaphysis of the tibia and the therapeutic results after the conservative and operative treatment are confronted. Among 518 patients with 433 open fractures and 35 with closed fractures of the diaphysis of the tibia, successful treatment of more 2/3 was obtained in the period from 1968 to 1972. Following our casuistics and literature, whose results are similar, we find out that the average total treatment of the osteosynthesis of the fracture of the diaphysis was shortened for 2,5 months depending upon the type and the localisation of the fracture. Apolied methods of the operative and conservative and conservative treatment in relation to the velocity of the medical cure as well as to the extreme anatomical-functional results are analised. We noticed that osteosynthesis, made by the intermedullary nail and the extension of the canals or by a small AO table, by the achieved stability makes conditions of immediate motions and an early rehabilitation. Because of that it gives the best functional results.  相似文献   

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