二色补血草花总黄酮化合物提取工艺研究

用L16(44)正交试验探讨从二色补血草花中提取黄酮类化合物,结果表明二色补血草花总黄酮类化合物的最佳提取工艺是以料液比为1g∶25mL,体积分数60%的乙醇为浸提剂,温度为50℃,浸提时间3.0h。     

微波辅助萃取-分光光度法测定加拿大一枝黄花中总黄酮

采用微波辅助萃取,以分光光度法测定加拿大一枝黄花中黄酮类化合物的含量。并通过单因素实验和正交试验优化溶剂浓度、液固比、微波功率和微波辐射时间等微波提取条件,确定了微波辅助萃取法提取加拿大一枝黄花中黄酮类化合物的最佳条件为:乙醇浓度50%,液固比40:1,微波功率700W,微波辐射时间20min。在上述最优条件下进行了精密度和回收率实验,相对标准偏差为1.68%(n=5),回收率在97.6%～101.0%之间。利用最佳提取工艺对加拿大一枝黄花根、茎、叶和花中总黄酮含量进行比较,结果表明叶中黄酮类化合物的含量最高;与传统的索式提取法和超声波提取法相比,微波辅助萃取法具有提取效率高、操作简便、经济可靠等优点。     

“逆流-超声-热压”技术在刺五加叶中提取黄酮类化合物的应用

刺五加是我国东北地区典型的药用植物,其中的黄酮类化合物具有广泛的药理活性,黄酮类化合物在叶中含量最高。利用"逆流-超声-热压"联用提取技术对刺五加叶中的黄酮类化合物进行提取,通过正交实验考察了该技术的提取条件,对刺五加中总黄酮提取率的影响,结果表明:溶剂为50%乙醇,提取时间为2h,提取次数为2次,投料比为1:20时,提取率最佳。     

大叶羊蹄甲中黄酮类化合物提取方法的初步研究

采用正交试验,分别用醇提法和超声波提取大叶羊蹄甲中的黄酮类化合物,比较2种方法的提取效果及黄酮类化合物的含量,从而得到最佳的工艺方案.实验结果表明:超声提取法效果较好,其最佳条件是:固液比1∶15,乙醇体积分数为90%,超声时间15 min,超声频率为500W,提取率为14.56%.     

融冻微波破壁法提取枣核中黄酮类化合物及纯化研究

本文将融冻微波破壁法和微波破壁法相结合技术用于枣核总黄酮类化合物的提取。详细研究了融冻微波破壁法和微波破壁法提取枣核中总黄酮类化合物最佳工艺,并对黄酮类化合物的纯化条件作以研究。结果表明:融冻微波破壁法是提取枣核黄酮类化合物的优选方法,游离黄酮类化合物最佳提取工艺为:以料液比为1g:20m l,体积分数40%的乙醇为浸提剂,在低火、微波提取2m in。具酚羟基和游离花色素类化合物的最佳提取工艺为:以料液比为1g:20m l,在中火、微波提取3m in。     

微波法提取柚皮中黄酮类化合物的工艺研究

应用微波萃取技术,以柚子皮为原料提取黄酮类化合物,用紫外分光光度法测定提取液中的黄酮类化合物的含量.在微波单因素浸提的基础上,采取正交优化试验,以探讨微波功率、料液比、微波处理时间、pH值、溶剂及溶剂的浓度对黄酮类化合物提取率的影响.正交实验表明,微波法提取黄酮类化合物的最佳条件是:微波功率是595W、微波处理时间20s、液料比为15:1、pH值为11、溶剂是浓度为80%的乙醇,在此条件下浸提,所得的黄酮类化合物含量为0.748%.在该工艺条件下,黄酮类化合物的得率比较高、所需要的时间短,是一种快速、高效、节能、环保的新型提取工艺.     

酸杨桃叶中总黄酮的提取工艺研究

利用甲醇浸提,通过单因素试验和正交试验探讨从酸杨桃叶中提取黄酮的最佳工艺条件,为酸杨桃叶中黄酮类化合物的提取提供实验数据。实验结果表明,酸杨桃叶中含有丰富的黄酮类化合物,酸杨桃叶中黄酮的最佳提取工艺条件为：提取时间3h,料液比1：80,提取温度70℃。在该最佳提取条件下,以芦丁为参照品,测量波长为359nm,所得的总黄酮平均回收率为98.84%,精密度为1.04%。     

超声波提取蕤核叶黄酮类化合物的工艺研究

研究超声波辅助提取蕤核叶中黄酮类化合物的工艺.通过单因素试验确定黄酮得率的主要因素和最佳范围,运用正交设计确定出最佳组合工艺条件.结果显示:利用超声波提取蕤核叶黄酮类化合物的最佳提取工艺条件是60%乙醇溶液,料液比为1∶30,在40℃提取70 min,该条件下的提取量为4.970 mg·g~(-1).     

密花翠雀中总黄酮含量的测定

研究了密花翠雀中黄酮类化合物的提取和含量测定方法,并通过正交实验优化了分离提取条件.以芦丁为标准品,采用NaNO_2-Al(NO_3)_3-NaOH显色-分光光度法,测得密花翠雀中总黄酮含量为8.957 7%,RSD值为1.37%(n=6),样品平均回收率99.35%.结果表明,最佳提取工艺:乙醇体积分数为80%,提取温度70℃,密花翠雀样品的质量浓度为0.03g/mL,提取时间4h.     

金银花花茎中黄酮的提取及抗氧化性的研究

目的对陕南地产金银花花茎中黄酮类化合物进行提取及抗氧化性研究。方法采用正交实验法并利用超声波确定黄酮类化合物的提取最佳条件;采用烘箱储藏法测定抗氧化性;采用H2O2/Fe2 体系法测定样品对.OH的清除作用;采用AP-TEMED体系法测定样品对O2-清除作用。结果花茎中黄酮类化合物的最佳提取条件为20℃,6 h,75%的乙醇,料液比为1∶30;花茎中黄酮类化合物对猪油的氧化具有明显的抑制作用;对.OH的清除达50.22%;对O2-清除达17.28%。结论超声波提取效果明显,提取率可达2.34%;花茎中黄酮类提取物有明显的抗氧化性,对O2-、.OH自由基的消除有明显效果。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-