期刊文献+
共找到2,372篇文章
< 1 2 119 >
每页显示 20 50 100
Determination of Moisture, Ash, Extract Content and TLC identification of Tibetan Medicinal Material Dracocephalum tanguticum Maxim. 被引量:1
1
作者 Pei QUN Risha WEIZE +3 位作者 Zhe LIU Haiyan XIANG Yunzhang XU Yuan LIU 《Medicinal Plant》 CAS 2019年第4期51-53,59,共4页
[Objectives] The moisture, ash and extract content of Dracocephalum tanguticum Maxim. were measured.[Methods] The moisture, total ash, acid-insoluble ash and extract content of D. tanguticum Maxim collected from 16 pr... [Objectives] The moisture, ash and extract content of Dracocephalum tanguticum Maxim. were measured.[Methods] The moisture, total ash, acid-insoluble ash and extract content of D. tanguticum Maxim collected from 16 producing areas were detected by using the methods in Chinese Pharmacopoeia (2015 edition, volume I), and D. tanguticum Maxim. was identified by thin layer chromatography in Chinese Pharmacopoeia (2015 edition, volume I).[Results] The moisture content of D. tanguticum Maxim collected from 16 producing areas ranged from 8.68% to 10.36%, averaging 9.28%. The content of total ash was between 7.21% and 11.60%, averaging 9.89%. The content of acid-insoluble ash was 0.21%-2.71%, averaging 1.51%. The extract content (water-soluble) was 26.67%-42.91%, averaging 32.65%. According to the results of TLC identification, the 16 samples and reference substance had the same characteristic spots at the corresponding positions.[Conclusions] It was recommended that the moisture, total ash and acid-insolue ash content of D. tanguticum Maxim were not be more than 11%, 12%, and 3% respectively, while the extract content was not less than 26%. It provides reference for filling the gaps in the quality standards of D. tanguticum Maxim. 展开更多
关键词 TIBETAN MEDICINAL MATERIAL Dracocephalum tanguticum MAXIM MOISTURE ASH extract content TLC
暂未订购
Evaluation of Wild Paeonia veitchii Lynch from Sichuan Based on Moisture, Ash and Extract Contents
2
作者 Fang XIAO Xuexue LI +3 位作者 Jixiu SHEN Xiaoxia CAI Zhengming YANG Yuan LIU 《Medicinal Plant》 CAS 2020年第1期76-79,共4页
[Objectives]The research aimed to determine the contents of moisture,ash and extract of wild Paeonia veitchii Lynch produced in Sichuan,so as to provide the basis for evaluating quality of wild P.veitchii Lynch from S... [Objectives]The research aimed to determine the contents of moisture,ash and extract of wild Paeonia veitchii Lynch produced in Sichuan,so as to provide the basis for evaluating quality of wild P.veitchii Lynch from Sichuan.[Methods]Moisture,ash and extract contents of wild P.veitchii Lynch were respectively determined according to the fourth part of the Chinese Pharmacopoeia of 2015 version,and correlation analysis and TOPSIS analysis were used for data processing.[Results]12 batches of samples all corresponded with the provision that moisture of P.veitchii Lynch should not exceed 14.0%in the Standard of Traditional Chinese Medicine in Sichuan Province of 2010 version;11 batches of samples all corresponded with the provisions that total ash and acid insoluble ash of P.veitchii Lynch should not exceed 7.0%and 1.0%in the Standard of Traditional Chinese Medicine in Sichuan Province of 2010 version;average content of alcohol-soluble extract by hot dipping from 12 batches of samples was 42.29%,which was not less than 30.0%.In P.veitchii Lynch,moisture and acid insoluble ash showed positive correlation with altitude,while total ash and extract content were negatively correlated with altitude.Taking moisture,ash and extract as evaluation indexes,No.9 P.veitchii Lynch sample was the best.[Conclusions]Moisture and ash of P.veitchii Lynch corresponded with the provisions of the Chinese Pharmacopoeia of 2015 version and the Standard of Traditional Chinese Medicine in Sichuan Province of 2010 version,while extract content was higher than provision of the standard.The research could provide reference basis for rational utilization and quality evaluation of P.veitchii Lynch resources. 展开更多
关键词 PAEONIA veitchii LYNCH MOISTURE ASH extract content determination
暂未订购
Quality Evaluation of Leontopodium franchetii Beauv. from Different Localities Based on Moisture,Ash and Extract Contents and Thin-layer Chromatography
3
作者 Pei QUN Yatao HAN +3 位作者 Fang XIAO Zhe LIU Yongxia KE Yuan LIU 《Medicinal Plant》 CAS 2018年第4期56-58,共3页
[Objectives] The aim was to determine the moisture,ash and extract contents in Leontopodium franchetii Beauv. from different localities. [Methods] The contents of moisture,total ash,acid-insoluble ash and extract in L... [Objectives] The aim was to determine the moisture,ash and extract contents in Leontopodium franchetii Beauv. from different localities. [Methods] The contents of moisture,total ash,acid-insoluble ash and extract in L. franchetii from different localities were determined according to the methods described in Chinese Pharmacopoeia( 2015 Edition). [Results] In the 10 samples,the contents of moisture were all less than or equal to 15. 0%; the contents of total ash were all below 12. 0%; and the contents of acid-insoluble ash were all less than 3. 0%. The contents of water-soluble extract( by cold-soaked extraction method) in the samples were all below 12. 0% except those from Hongyuan Prairie of Sichuan Province and Xinglong Mountain in Lanzhou City,Gansu Province. [Conclusions]The contents of the four indicators measured in this experiment varied by small margins,indicating that the quality was relatively stable. This study provides theoretical data for the revision of the quality standards for L. franchetii. 展开更多
关键词 Leontopodium franchetii Beauv. MOISTURE ASH extract content Thin-layer chromatography Quality evaluation
在线阅读 下载PDF
Extraction Process and Content Determination of Total Flavonoids in Ginkgo( Ginkgo biloba L. ) Leaves 被引量:2
4
作者 Dengfeng ZOU Hua ZHU +1 位作者 Binghua QIN Xiaohua WANG 《Agricultural Biotechnology》 CAS 2019年第1期171-175,共5页
[Objectives]This study was conducted to study the extraction process and the content determination of flavonoids in ginkgo( Ginkgo biloba L.) leaves.[Methods]Ethanol extraction and methanol extraction of total flavono... [Objectives]This study was conducted to study the extraction process and the content determination of flavonoids in ginkgo( Ginkgo biloba L.) leaves.[Methods]Ethanol extraction and methanol extraction of total flavonoids in ginkgo leaves were studied,and the optimal extraction conditions for flavonoids were determined by orthogonal test; and with quercetin as reference substance,total flavonoid content in ginkgo leaves was determined by UV spectrophotometry.[Results]The optimal extraction process was 4 h of Soxhlet extraction with methanol; and the total flavonoid contents had a good linear relation in the range of 0. 006 5-0. 039 mg/ml( R^2= 0. 999 9),the average content was stabilized at 1. 135%,and the average recovery of the method was 102. 0%. [Conclusions]This study selected the optimal extraction process for total flavonoids in ginkgo leaves. The test method is simple with high accuracy and precision,and is suitable for the extraction and determination of total flavonoids in ginkgo leaves. 展开更多
关键词 GINKGO biloba L. TOTAL FLAVONOIDS extractION process content determination
在线阅读 下载PDF
Basic density, extractive content and moisture sorption properties of Pinus pinaster wood infected with the pinewood nematode, Bursaphelenchus xylophilus 被引量:1
5
作者 Valeria Reva Luís Fonseca +3 位作者 José L.Lousada Isabel Abrantes António R.Figueiredo Domingos X.Viegas 《Journal of Forestry Research》 SCIE CAS CSCD 2015年第1期233-240,共8页
The pinewood nematode(PWN), Bursaphelenchus xylophilus, has become one of the most severe threats to pine forest worldwide. Nematodes, migrating through resin canals and feeding on the living cells, induce rapid met... The pinewood nematode(PWN), Bursaphelenchus xylophilus, has become one of the most severe threats to pine forest worldwide. Nematodes, migrating through resin canals and feeding on the living cells, induce rapid metabolic changes in ray parenchyma cells, create cavitation areas, decrease xylem water content and oleoresin exudation, and cause necrosis of parenchyma and cambial cells. This study focused on the impact of PWN infection on technological parameters of wood and evaluated the impact of anatomic and biochemical incidences of tree defense reactions on basic density, extractive content and moisture sorption properties of Pinus pinaster wood.Samples of infected and uninfected wood were studied.The presence of nematodes reduced wood basic density by2 % and decreased the total content of extractives in infected wood as compared with uninfected(5.98 and8.90 % of dry wood mass, respectively). Extractives in infected trees had inverse distribution along the trunk as compared with uninfected trees. The adsorption isotherms for infected and uninfected wood had similar positioning.We recorded differences(some statistically significant) in the equilibrium moisture content of infected and uninfected wood under varying environmental conditions. Despite the verified differences in wood basic density, extractive content and moisture sorption properties, the overall conclusion is that the PWN had a slight impact on these characteristics of wood. 展开更多
关键词 Pinewood nematode Wood density extractives Equilibrium moisture content Economic impact
在线阅读 下载PDF
Extraction Process and Content Determination of Caffeic Acid in Laggera alata from Different Production Areas of Guangxi 被引量:1
6
作者 Jiangcun WEI Yong CHEN +5 位作者 Zujie QIN Jiabao MA Shengbin CHEN Zuliang QUE Jinzhou LI Zijun CHEN 《Medicinal Plant》 CAS 2018年第4期73-76,共4页
[Objectives] To establish a method for determining the content of Laggera alata( D. Don) Sch. Bip. Ex Oliv. using caffeic acid the target component,and to compare the content of caffeic acid in the medicinal materials... [Objectives] To establish a method for determining the content of Laggera alata( D. Don) Sch. Bip. Ex Oliv. using caffeic acid the target component,and to compare the content of caffeic acid in the medicinal materials of L. alata in different production areas of Guangxi.[Methods]The content was determined by Inertsil~ODS-3 chromatographic column C_(18)( 4. 60 mm × 250 mm,5 μm,mobile phase: acetonitrile-0. 1% phosphoric acid( 22∶ 78),detection wavelength: 320 nm,flow rate: 1. 0 m L/min,column temperature: 30℃,and injection volume: 10 μL. [Results] The caffeic acid showed a good linear relationship in the range of injection volume of 0. 025 92-0. 259 2 μg( R =0. 999 5). The average recovery rate was 98. 33%( RSD = 1. 85%). L. alata in different production areas of Guangxi contained the caffeic acid,and there was a great difference in the caffeic acid. L. alata in Baise had the highest content of caffeic acid,while that in Guilin had the lowest content of caffeic acid. [Conclusions]This method can accurately determine the content of caffeic acid and is expected provide a scientific basis for the development and utilization of herbal medicine L. alata. 展开更多
关键词 Laggera alata(D.Don) Sch.Bip.Ex Oliv. HPLC Caffeic acid extraction process content Determination
在线阅读 下载PDF
Relevance-based content extraction of HTML documents
7
作者 吴麒 陈兴蜀 +1 位作者 朱锴 王春晖 《Journal of Central South University》 SCIE EI CAS 2012年第7期1921-1926,共6页
Content extraction of HTML pages is the basis of the web page clustering and information retrieval,so it is necessary to eliminate cluttered information and very important to extract content of pages accurately.A nove... Content extraction of HTML pages is the basis of the web page clustering and information retrieval,so it is necessary to eliminate cluttered information and very important to extract content of pages accurately.A novel and accurate solution for extracting content of HTML pages was proposed.First of all,the HTML page is parsed into DOM object and the IDs of all leaf nodes are generated.Secondly,the score of each leaf node is calculated and the score is adjusted according to the relationship with neighbors.Finally,the information blocks are found according to the definition,and a universal classification algorithm is used to identify the content blocks.The experimental results show that the algorithm can extract content effectively and accurately,and the recall rate and precision are 96.5% and 93.8%,respectively. 展开更多
关键词 content extraction DOM NODE RELEVANCE information block
在线阅读 下载PDF
Between-Tree and Within-Tree Variation in Specific Gravity and Extractive Content in the Wood of Stercufia setigera Del. Grown in Nigeria
8
作者 A. O. Oluwadare M. B. Ogunleye 《Journal of Agricultural Science and Technology(B)》 2011年第7期1075-1085,共11页
Variations of wood specific gravity and extractive contents from pith to bark and from base to the top of tree were investigated in a 14-year-old commercial pulpwood species Sterculia setigera Del. Growing in savanna ... Variations of wood specific gravity and extractive contents from pith to bark and from base to the top of tree were investigated in a 14-year-old commercial pulpwood species Sterculia setigera Del. Growing in savanna zone in Nigeria. Tree mean specific gravity averaged 0.37; wood at the base had significant higher specific gravity than those at the top while it increased from pith to bark. For extractive content mean value was 1.20% for wood and 1.72% for bark; i[t varied significantly between trees and from base of the tree to the top and from pith to the bark. Extractive content at the butt and breast height is more than double of the value at the top of the tree. The high extractive content at the base is similar to high specific gravity observed for wood samples from the base. Extractive content of the bast was significantly higher than that of the wood. The low specific gravity show possible suitability of the species for paper making in Nigerian paper mills. The wood of Sterculia setigera showed a significant variation between- and within-trees in the two properties considered, though the wood is light with low extractive content; it is however a potential raw material for large scale pulpwood production in Nigeria. 展开更多
关键词 Specific gravity extractive content patterns of variation Sterculia setigera.
在线阅读 下载PDF
Optimization of Extraction Process and Content Determination of Total Flavonoids from Sanguisorbae Radix and Carbonized Sanguisorba Root by Orthogonal Experimental Design 被引量:1
9
作者 Fenglin WANG Yunzhang XU +1 位作者 Jingxia WANG Yuan LIU 《Medicinal Plant》 2017年第6期5-9,共5页
[Objectives] To optimize the extraction process of total flavonoids from Sanguisorbae Radix and carbonized Sanguisorba root,compare quality of different batches of Sanguisorbae Radix,study the effects of processing on... [Objectives] To optimize the extraction process of total flavonoids from Sanguisorbae Radix and carbonized Sanguisorba root,compare quality of different batches of Sanguisorbae Radix,study the effects of processing on the content of flavonoids,and provide scientific basis for reasonable utilization of Sanguisorbae Radix. [Methods] Test samples were prepared by heating,refluxing,and extraction,the extraction process was optimized by orthogonal experiment design,color was developed by NaNO_2-Al( NO_3)3-NaOH,and total flavonoids were measured by UV method at the wavelength of 510 nm. [Results] The linear relationship of rutin was excellent in the concentration range of 0. 1248 mg/mL-0. 5712 mg/mL,R^2= 0. 9997; the average recovery was 99. 67% and the RSD was 0. 70%. The optimum extraction conditions were as follows: the volume fraction of ethanol was 50%,the extraction temperature was 90℃,the extraction time was 90 min,and the solid-to-liquid ratio was 1∶ 20( g/mL). [Conclusions] After optimization of the extraction process,the extraction rate of total flavonoids in samples of Sanguisorbae Radix was significantly increased; there was certain difference in the content of total flavonoids between different batches of Sanguisorbae Radix and processed products; the total flavonoids significantly declines in carbonized sanguisorba root,and the influence of processing on its curative effect was to be further studied. 展开更多
关键词 Sanguisorbae RADIX Carbonized sanguisorba ROOT TOTAL FLAVONOIDS extractION process content determination
暂未订购
Performance Analysis of Optimized Content Extraction for Cyrillic Mongolian Learning Text Materials in the Database
10
作者 Bat-Erdene Nyandag Ru Li G. Indruska 《Journal of Computer and Communications》 2016年第10期79-89,共12页
This paper had developed and tested optimized content extraction algorithm using NLP method, TFIDF method for word of weight, VSM for information search, cosine method for similar quality calculation from learning doc... This paper had developed and tested optimized content extraction algorithm using NLP method, TFIDF method for word of weight, VSM for information search, cosine method for similar quality calculation from learning document at the distance learning system database. This test covered following things: 1) to parse word structure at the distance learning system database documents and Cyrillic Mongolian language documents at the section, to form new documents by algorithm for identifying word stem;2) to test optimized content extraction from text material based on e-test results (key word, correct answer, base form with affix and new form formed by word stem without affix) at distance learning system, also to search key word by automatically selecting using word extraction algorithm;3) to test Boolean and probabilistic retrieval method through extended vector space retrieval method. This chapter covers: to process document content extraction retrieval algorithm, to propose recommendations query through word stem, not depending on word position based on Cyrillic Mongolian language documents distinction. 展开更多
关键词 Cyrillic Mongolian Language content extraction Formatting Learning Text Materials Style
在线阅读 下载PDF
Extraction Process and Content Determination of Caffeic Acid in Zhuang Medicine Cryptolepis buchananii
11
作者 Chenyan LIANG Lu ZHANG +2 位作者 Yunli TANG Liuyan HE Ganneng HUANG 《Medicinal Plant》 CAS 2019年第6期15-19,共5页
[Objectives]To establish a method for determining the content of caffeic acid in Zhuang Medicine Cryptolepis buchananii.[Methods]The content of caffeic acid in C.buchananii leaves was determined by high performance li... [Objectives]To establish a method for determining the content of caffeic acid in Zhuang Medicine Cryptolepis buchananii.[Methods]The content of caffeic acid in C.buchananii leaves was determined by high performance liquid chromatography(HPLC).[Results]The results of HPLC determination showed that the RSD values were less than 3%,and the content of caffeic acid in 10 batches of C.buchananii leaves was in the range of 0.0965%-0.4772%.[Conclusions]This method is accurate and reliable,has good linear relationship and high precision,and can be used for quality evaluation of C.buchananii. 展开更多
关键词 Cryptolepis buchananii Caffeic ACID High performance LIQUID chromatography(HPLC) extractION process content determination
暂未订购
Extraction Technology of Total Flavonoids from Pueraria lobata (Willd.) Ohwi and Content Determination of Pueraria lobata (Willd.) Ohwi at Different Altitudes 被引量:2
12
作者 Chunlin LIU Yingchen LI +1 位作者 Bochao LI Yuan LIU 《Medicinal Plant》 2017年第2期12-14,18,共4页
[Objectives]To optimize the extraction technology of total flavonoids from Pueraria lobata( Willd.) Ohwi. [Methods]The ultraviolet-visible spectrophotometry was used to determine the content of total flavonoids in Pue... [Objectives]To optimize the extraction technology of total flavonoids from Pueraria lobata( Willd.) Ohwi. [Methods]The ultraviolet-visible spectrophotometry was used to determine the content of total flavonoids in Pueraria lobata( Willd.) Ohwi. With the puerarin as index,the reflux extraction and single factor test were employed to investigate the effects of temperature,time,ethanol concentration and solid-liquid ratio on the content of total flavonoids in Pueraria lobata( Willd.) Ohwi,respectively. Under the optimal extraction technology,the content of total flavonoids in Pueraria lobata( Willd.) Ohwi at different altitudes was determined.[Results] The optimum extraction process was as follows: 70%ethanol; solid-liquid ratio of 1∶ 30; 1 h reflux extraction. Under these conditions,the extraction rate of flavonoids in Pueraria lobata( Willd.) Ohwi was 11. 48%,the total flavonoids content of different kudzu parts was in the order of roots > stems > leaves,and the total flavonoids content of the sample at about an altitude of 1000 m was significantly higher than at the altitudes of 1400 m and 1700 m.[Conclusions]It was suggested that the Pueraria lobata( Willd.) Ohwi should not be cultivated as medicinal plant in too high mountains,and the stems and leaves of Pueraria lobata( Willd.) Ohwi could be used as raw materials for extracting total flavonoids. 展开更多
关键词 PUERARIA lobata(Willd.) Ohwi TOTAL FLAVONOIDS extractION technology Different ALTITUDES content determination
暂未订购
Intelligent Web Robot for Content Extraction
13
作者 Wenxing HONG Jie LI +1 位作者 Weiwei WANG Yang WENG 《Instrumentation》 2019年第3期52-58,共7页
The main content of a news web page is a source of data for Natural Language Processing(NLP)and Information Retrieval(IR),which contains large quantities of valuable information.This paper proposes a method that formu... The main content of a news web page is a source of data for Natural Language Processing(NLP)and Information Retrieval(IR),which contains large quantities of valuable information.This paper proposes a method that formulates the main content extraction problem as a DOM tree node classification problem.In terms of feature extraction,we use the DOM tree node to represent HTML document and then develop multiple features by using the DOM tree node properties,such as text length,tag path,tag properties and so on.In consideration that the essence of the problem is the classification model,we use Xgboost to help select nodes.Experimental results show that the proposed approach is effective and efficient in extracting main content of new web pages,and achieves about 98%accuracy over 1083 news pages from 10 different new sites,and the average processing time per page is within 10 ms. 展开更多
关键词 content extraction DOM Machine Learning Xgboost
原文传递
Study of total phenol,flavonoids contents and phytochemical screening of various leaves crude extracts of locally grown Thymus vulgaris 被引量:3
14
作者 Mohammad Amzad Hossain Khulood Ahmed Salim AL-Raqmi +2 位作者 Zawan Hamood AL-Mijizy Afaf Mohammed Weli Qasim Al-Riyami 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2013年第9期705-710,共6页
Objective:To prepare various crude extracts using different polarities of solvent and to quantitatively evaluate their total phenol,flavonoids contents and phytochemical screening of Thymus vulgaris collected from Al ... Objective:To prepare various crude extracts using different polarities of solvent and to quantitatively evaluate their total phenol,flavonoids contents and phytochemical screening of Thymus vulgaris collected from Al Jabal Al Akhdar,Nizwa.Sultanate of Oman.Methods:The leave sample was extracted with methanol and evaporated.Then it was defatted with water and extracted with different polarities organic solvents with increasing polarities.The prepare hexane,chloroform,ethyl acetate,hutanol and methanol crude extracts were used for their evaluation of total phenol,flavonoids contents and phytochemical screening study.The established conventional metliods were used for quantitative determination of total phenol,flavonoids contents and phytochemical screening.Results:Phytochemical screening for various crude extracts were tested and shown positive result for flavonoids,saponins and steroids compounds.The result for total phenol content was the highest in hutanol and the lowest in methanol crude extract whereas the total flavonoids contents was the highest in methanol and the lowest hexane crude extract.Conclusions:The crude extracts from locally grown Thymus vulgaris showed high concentration of flavonoids and it could be used as antibiotics for different curable and uncurable diseases. 展开更多
关键词 THYMUS VULGARIS L. VARIOUS crude extracts PHYTOCHEMICAL screening SOXHLET extractOR Total phenol Flavonoids contents.
暂未订购
真空冷冻干燥对茶坯特性及窨制茉莉花茶品质的影响
15
作者 张芬 陈家献 +8 位作者 马进森 袁冬寅 于敬亚 欧淑琼 彭靖茹 张栩浩 谢大高 黄寿辉 温立香 《食品与发酵工业》 北大核心 2026年第1期291-299,共9页
为探究不同含水量茶坯真空冷冻干燥后对其特性及窨制茉莉花茶品质的影响,该文分析了不同含水量(25%、40%、55%)茶坯经真空冷冻干燥处理后其外观色泽、微观结构、复水比、水浸出物浸出规律的变化及窨制茉莉花茶品质差异。结果表明:随着... 为探究不同含水量茶坯真空冷冻干燥后对其特性及窨制茉莉花茶品质的影响,该文分析了不同含水量(25%、40%、55%)茶坯经真空冷冻干燥处理后其外观色泽、微观结构、复水比、水浸出物浸出规律的变化及窨制茉莉花茶品质差异。结果表明:随着含水量增加,茶坯外观的明度L^(*)、黄蓝色度b^(*)值增大,红绿色度a^(*)值减小,绿色变浅,黄色增加;茶叶表面褶皱、塌陷程度变小,孔隙变大。真空冷冻干燥能够增加茶坯的复水比、水浸率及冲泡初始阶段(沸水0~1 min、冷水0~0.5 h)的水浸出速度,且含水量越高,增加效果越明显;茶坯的水浸出率、水浸出速度与冲泡时间分别呈对数函数关系Y=A ln(X)+B、幂函数关系Y=aX^(b)。25%含水量茶坯真空冷冻干燥后窨制的茉莉花茶感官审评分数最高,为89.90,品质最优。综上所述,真空冷冻干燥可以显著改变茶坯外观色泽和微观结构,提高茶坯的复水比、水浸出率,适宜含水量的茶坯经真空冷冻干燥处理后可以其提高窨制茉莉花茶的品质。 展开更多
关键词 真空冷冻干燥 茶坯 含水量 微观结构 水浸出物 茉莉花茶
在线阅读 下载PDF
Technical Study on Extraction of Procyanidins in Lycium ruthenicum Murr. Using Sub-critical Fluid 1,1,1,2-Tetrafluoroethane( R134a)and Content Determination from Different Producing Areas
16
作者 Liang TAN Li ZHU Zhihao FENG 《Medicinal Plant》 CAS 2018年第5期36-40,44,共6页
[Objectives] To study the optimal conditions for extracting procyanidins fromLycium ruthenicum Murr. with sub-critical fluid R134 a( 1,1,1,2-tetrafluoroethane) in 1 L extraction kettle. [Methods]Taking the extraction ... [Objectives] To study the optimal conditions for extracting procyanidins fromLycium ruthenicum Murr. with sub-critical fluid R134 a( 1,1,1,2-tetrafluoroethane) in 1 L extraction kettle. [Methods]Taking the extraction rate of procyanidins as an indicator,the influence of pressure,temperature,and extraction time on extraction rate of procyanidins fromL. Ruthenicum Murr. was studied by single factor experimental methods and orthogonal array design. [Results]The order of factors affecting extraction rate of procyanidins was extraction temperature > extraction pressure > extraction time. The optimum extraction conditions were as follows: the extraction rate of procyanidins fromL. ruthenicum Murr. was the highest with extraction pressure of 1. 2 MPa,extraction temperature of 50℃ and extraction time of 90 min. The content of procyanidins in L. ruthenicum Murr. from different producing areas was determined by vanillin-HCl method under the optimal conditions. [Conclusions] The method has the advantages of easy operation,good selectivity,low extraction temperature and high extraction efficiency,which is suitable for extraction of procyanidins in L. ruthenicum Murr. 展开更多
关键词 Lycium ruthenicum Murr. PROCYANIDINS Sub-critical FLUID extractION technology R134A Vanillin-HCl method DIFFERENT producing areas content determination
暂未订购
不同干燥方法对羊胎盘品质的影响
17
作者 黄兰梅 周俊 杨林 《中国药业》 2026年第5期68-71,共4页
目的探讨不同干燥方法对羊胎盘品质的影响,为保障羊胎盘品质提供合适的干燥方法。方法以藏系绵羊胎盘为试验材料,分别采用冷冻干燥法、减压干燥法、热风干燥法3种干燥方法制备羊胎盘粉,考察并比较其感官评价、气味、水/醇溶性浸出物含... 目的探讨不同干燥方法对羊胎盘品质的影响,为保障羊胎盘品质提供合适的干燥方法。方法以藏系绵羊胎盘为试验材料,分别采用冷冻干燥法、减压干燥法、热风干燥法3种干燥方法制备羊胎盘粉,考察并比较其感官评价、气味、水/醇溶性浸出物含量、折干率、干燥时间、单位能耗。结果羊胎盘经3种干燥方法处理,其感官评价与气味均存在显著差异,热风干燥法处理样品的感官评价得分更高,腥膻气味更少,可接受度更高,水溶性浸出物含量和醇溶性浸出物含量分别为42.62%和33.38%,略低于减压干燥法处理样品的49.13%和37.83%,但仍高于冷冻干燥法处理样品的38.84%和27.72%;冷冻干燥法、减压干燥法、热风干燥法处理的羊胎盘的折干率分别为11.40%,11.11%,10.86%,无明显差异;热风干燥法和减压干燥法的平均干燥时间和单位能耗分别为14,28 h和216.72,282.24 kJ/g,远低于冷冻干燥法的72 h和2903.04 kJ/g。结论热风干燥法在改善羊胎盘腥膻味的同时,也能很好地保留其指标性成分,可作为羊胎盘饮片较理想的干燥方法。 展开更多
关键词 羊胎盘 冷冻干燥法 减压干燥法 热风干燥法 浸出物含量 折干率 单位能耗 品质评价
暂未订购
瑶药上山虎水提取工艺研究及3个成分含量测定
18
作者 秦丹 高洁 +2 位作者 曹家杰 唐清晨 傅鹏 《中国民族民间医药》 2026年第2期57-62,共6页
目的:建立瑶药上山虎总黄酮含量测定方法,系统研究上山虎水提物的提取工艺,筛选高效稳定的水提方法,并测定上山虎水提物中新绿原酸、绿原酸及丁香醛的含量。方法:采用单因素考察和L_(9)(3^(3))正交试验法,以干膏率和总黄酮含量为评价指... 目的:建立瑶药上山虎总黄酮含量测定方法,系统研究上山虎水提物的提取工艺,筛选高效稳定的水提方法,并测定上山虎水提物中新绿原酸、绿原酸及丁香醛的含量。方法:采用单因素考察和L_(9)(3^(3))正交试验法,以干膏率和总黄酮含量为评价指标,研究液料比、提取时间和提取次数对上山虎水提物总黄酮含量的影响;采用高效液相色谱法测定新绿原酸、绿原酸及丁香醛含量。结果:最佳水提工艺为水煮3次,每次40min,加12倍量水;上山虎水提物中新绿原酸、绿原酸及丁香醛含量分别为0.3789mg/g、1.7608mg/g、0.0646mg/g。结论:首次建立了瑶药上山虎的总黄酮含量测定方法,确定了稳定高效的水提工艺,同时测定了上山虎中绿原酸、绿原酸及丁香醛的含量。 展开更多
关键词 瑶药上山虎 总黄酮 提取工艺 HPLC含量测定
暂未订购
内容主题约束的无监督关键短语提取方法
19
作者 李伍任 黄于欣 《微电子学与计算机》 2026年第3期14-25,共12页
无监督关键短语提取能够自动识别概括文档核心内容与主题的关键短语,在信息检索、文本摘要和主题建模等任务中具有广泛应用。现有无监督方法通常依赖候选短语与文档在高维语义空间中的相似度计算来评估重要性,虽关注短语与文档整体语义... 无监督关键短语提取能够自动识别概括文档核心内容与主题的关键短语,在信息检索、文本摘要和主题建模等任务中具有广泛应用。现有无监督方法通常依赖候选短语与文档在高维语义空间中的相似度计算来评估重要性,虽关注短语与文档整体语义的相关性,却未能充分建模短语与文档主题之间的一致性,导致提取结果的准确性和语义一致性受限。为此,提出了一种结合内容和主题约束的无监督关键短语提取方法。该方法基于T5模型,通过编码器生成的自注意力得分捕捉候选短语与文档内容的关联性,并利用解码器提示模板计算生成概率,以衡量候选短语的语义相关性和主题一致性。通过自注意力机制和提示生成机制的协同作用,模型能够在无监督条件下提取出与文本语义和主题高度契合的关键短语。在SemEval2017、Inspec和SemEval2010公开数据集上的实验结果表明:所提方法在F1分数上显著优于当前主流无监督方法。 展开更多
关键词 关键短语提取 无监督 内容约束 主题约束
在线阅读 下载PDF
乌龙茶饮料加工工艺优化
20
作者 潘亭 卢莹 +4 位作者 马紫晨 王若懿 郎秀杰 孙敬明 郑程远 《食品研究与开发》 2026年第2期74-80,共7页
为优化乌龙茶饮料的加工工艺,该研究以感官评分与茶多酚含量为考察指标,在单因素和响应面法优化浸提工艺的基础上,进一步探讨糖酸添加量对产品品质的影响。结果表明,乌龙茶饮料的最佳工艺条件为浸提温度89℃、浸提时间4.4 min、浸提料液... 为优化乌龙茶饮料的加工工艺,该研究以感官评分与茶多酚含量为考察指标,在单因素和响应面法优化浸提工艺的基础上,进一步探讨糖酸添加量对产品品质的影响。结果表明,乌龙茶饮料的最佳工艺条件为浸提温度89℃、浸提时间4.4 min、浸提料液比1∶55(g/mL)、白砂糖添加量4%、柠檬酸添加量0.02%。在此条件下制得的乌龙茶饮料酸甜适宜,口感丰富,茶香突出。 展开更多
关键词 乌龙茶饮料 浸提工艺 茶多酚含量 糖酸添加量 感官品质
在线阅读 下载PDF
上一页 1 2 119 下一页 到第
使用帮助 返回顶部