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1.
通过对甘谷辣椒红色素进行提取,确定了其中的4种成分,研究了色素提取的最佳条件及色素的稳定性.结果表明:该色素含有辣椒红色素、辣椒玉红素、β-胡萝卜素、辣椒碱、二氢辣椒碱5种主要成分.色素在480 nm有最大吸收峰,该色素水溶性较差,油溶性较好,在pH值4~10时色调不变,具有良好的热稳定性.温度为90℃时,色素稳定.良好的耐酸碱性,耐光性较差,连续光照48 h,色素残存率为45%,1 mg/L Na+,Ca2+、Al3+溶液对色素最大吸收峰无明显影响,1 mg/L Cu2+,Fe2+溶液使色素最大吸收峰偏移.  相似文献   

2.
对黑甜玉米色素的提取试验结果表明,该色素提取的较优条件为:浸提剂为0.1mol/LHCl溶液,配料比为1:10,提取温度为70℃,提取时间为12h。水溶性色素,在酸性条件下稳定,最大吸收波长为445nm。该色素pH〈5时,热稳定、光稳定性较好。蔗糖、葡萄糖、抗坏血酸等对色素没有影响。除了Fe^3+,其他金属离子对色素无影响。  相似文献   

3.
宁夏枸杞子色素稳定性研究   总被引:2,自引:0,他引:2  
对宁夏枸杞子色素的提取条件及稳定性进行研究,结果表明:该色素在紫外光谱中有两个吸收峰,一个在240nm左右,一个在330nm左右 该色素在pH≥2时稳定,在pH=1~2间色素不稳定 该色素耐热性较差,温度>50℃,色素性质不稳定,光照对色素有较大的降解作用,4d后降解率达到17.25% 1mg/LNa+,Cu2+,Ca2+溶液对色素最大吸收峰无明显影响,1mg/LFe3+溶液使色素最大吸收峰偏移  相似文献   

4.
肉桂醛-苯甲醛双组分体系的紫外光谱特性研究   总被引:1,自引:0,他引:1  
研究了肉桂醛和苯甲醛的紫外吸收光谱,肉桂醛的最大吸收峰位于291nm,在该坡长下,肉桂醛在0.8~8 mg/L的浓度范围内,其浓度与吸光度符合朗伯—比耳定律;苯甲醛的最大吸收峰位于249nm,在1~12mg/L的浓度范围内,苯甲醛溶液浓度与其吸光度也符合朗伯—比耳定律.根据朗伯—比耳定律和吸光度的加和性推导出混合体系中苯甲醛和内桂醛含量的快速测定公式:c_(苯甲醛)=8.329×10~(-5)×A_(A~·_1)~总-9.627×10~(-6)×A_(A~·_1)~总,c_(桂醛)= 4.123×10~(-5)×A_(A~·_1)~总-4.375×10~(-6)×A_(A~·_1)~总.  相似文献   

5.
对陕南地产黄色桔皮进行了色素的提取及稳定性研究。结果表明:桔皮黄色素水溶性好,其最大吸收波长为280nm,对光、热耐受性强。当pH为2~10时,色素稳定;桔皮色素对于Na^ ,Mg^2 ,Mn^2 ,Ca^2 ,Cu^2 金属离子的作用不显著,但对Fe^3 较敏感;色素有较好的耐还原能力,耐氧化能力较差,加入食品添加剂,无变色反应。  相似文献   

6.
从酢浆草红花中提取一种酒红色色素,并对酢浆草红花色素的提取方法,提取剂的选择及其理化性质进行研究.实验结果表明,酢浆草红花色素提取的最佳工艺条件是以微酸性95﹪乙醇为浸取剂,浸取温度50℃,料液比1∶30,浸取时间4.5 h.酢浆草红花色素的最大吸收波长为530 nm,在酸性条件下都能稳定存在,有较好的耐热性,但不耐光照,Mg2 、Ca2 、Na 、Cu2 、Al3 、Zn2 等离子对该色素无不良影响,而Fe2 、Fe3 金属离子对色素影响较大,且耐氧化能力一般,耐还原能力较弱.苯甲酸﹑蔗糖﹑葡萄糖﹑食盐等食品添加剂的加入对色素影响较小.  相似文献   

7.
红花色素的分离提取及部分性质研究   总被引:3,自引:0,他引:3  
从干燥红花中分离提取一种水溶性黄色素,其最大吸收波长为402nm通过溶剂萃取的方法,提取红花色素的实验,确定了最佳萃取剂及最佳萃取时间,并研究了该色素的40%乙酸溶液在不同温度,酸碱环境,金属离子,光照条件下稳定性的变化。  相似文献   

8.
4种木本植物红色素最佳提取条件的研究   总被引:1,自引:0,他引:1  
以红花檵木、红叶李、红叶石楠、红叶鸡爪槭4种木本植物为原料,研究了叶片中红色素的提取工艺.结果表明,对4种植物色素提取效果较好的溶剂是蒸馏水,色素的最大吸收峰波长在325 nm左右;料液比、温度和时间3个提取条件中对色素提取影响最大的因素是温度,除红叶李外,温度越高色素的提取效果越好;红叶李在微波处理下浸提液的吸光度值随着时间的增加而减小,其余3种植物则呈现先上升后下降的趋势.  相似文献   

9.
分别考察了溶剂种类、浓度、酸度及提取时间、温度等单因素对提取紫黑高粱壳色素的影响,利用正交实验(L934)确定了紫黑高粱壳色素最佳提取条件.结果表明紫黑高粱壳色素最佳提取工艺为加热温度80℃、乙醇体积分数为85%、pH=0.5的乙醇溶液,固液比为1/100(g/mL)、加热时间2h.红、紫黑2种高粱壳色素溶液在可见光区的最大吸收峰波长分别是494nm和499nm.  相似文献   

10.
目的:研究pH,热,时间,光,金属离子,氧化剂等物质对菊花色素在可见光的稳定性的影响。方法:采用75%乙醇作为提取溶剂,对色素提取液在400~520nm范围内进行测其吸光度。结果:该色素最大吸收波长为400nm,在该波长的吸光度为0.580;该色素稳定的最佳pH条件为4~6;该色素对时间和热比较稳定,但对光不稳定;氧化剂及除铁和铜离子外,其他金属粒子对色素的影响不大;该色素对盐比较敏感;适合为酸性及弱酸性食品利用。  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
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.  相似文献   

14.
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。  相似文献   

15.
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.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
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-  相似文献   

20.
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-  相似文献   

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