模拟移动床色谱提纯槲皮素

运用模拟移动床色谱分离技术,提取银杏叶水解物黄酮苷元中的槲皮素,在洗脱液配比为甲醇∶水=7∶3(体积),进样流速uF=0.1 mL/min,冲洗流速uP=3.0 mL/min时,去除前杂质的洗脱流速uD=1.0 mL/min,切换时间tS=9 min;去除后杂质的洗脱流速uD=0.8 ,L/min,切换时间tS=14 min.经HPLC检测,产品中槲皮素质量分数达90%以上.     

模拟移动床色谱法分离C_(60)的条件选择

用模拟移动床色谱对C60进行了分离。工作参数:直径1 cm长10 cm的半制备柱;固定相为ODS;残余液流速2.2 mL/min,萃取液流速2 mL/min,进样流速12 mL/h;室温;切除C60前杂质的流动相V(甲醇)∶V(甲苯)=60∶40,切换时间14.5-15.5 min;切除C60后杂质的流动相V(甲醇)∶V(甲苯)=50∶50,切换时间19.5-20.5 min;在上述条件下,对80?0固体粉末进行分离,C60的纯度可达95%,收率大于70%。结果表明,这种方法是可行的,易于实现工业化。     

反相高效液相色谱法测定三白草中槲皮素和芦丁的含量

采用反相高效液相色谱法 (RP -HPLC)在C1 8色谱柱上以甲醇 :0 .2 %磷酸溶液 (5 0∶5 0 )为流动相测定了三白草中槲皮素和芦丁的含量 .流动相的流速为 1mL min ,检测波长 370nm .结果表明槲皮素在 0 .0 0 8-0 0 84 μg、芦丁在 0 .0 5 4 - 0 .5 4 0 μg范围内呈良好的线性关系 ,相关系数分别为 0 .9988和 0 .9999.槲皮素回收率为 99% ,RSD为 2 .0 % (n =5 ) ,芦丁为 10 6 % ,RSD为 1.4 % (n =5 ) .     

模拟移动床色谱法分离C60的条件选择

用模拟移动床色谱对C60进行了分离.工作参数:直径1 cm长10 cm的半制备柱;固定相为ODS;残余液流速2.2 mL/min,萃取液流速2 mL/min,进样流速12 mL/h;室温;切除C60前杂质的流动相V(甲醇):V(甲苯)=60:40,切换时间14.5-15.5 min;切除C60后杂质的流动相V(甲醇):V(甲苯)=50:50,切换时间19.5-20.5 min;在上述条件下,对80?0固体粉末进行分离,C60的纯度可达95%,收率大于70%.结果表明,这种方法是可行的,易于实现工业化.     

模拟移动床色谱法分离C60的条件选择

用模拟移动床色谱对C60进行了分离。工作参数：直径1cm长10cm的半制备柱;固定相为ODS;残余液流速2．2mL/min,萃取液流速2mL／min,进样流速12mL/h;室温;切除C60前杂质的流动相V（甲醇）：V（甲苯）=60：40,切换时间14．5—15．5min;切除C60后杂质的流动相V（甲醇）：V（甲苯）=50：50,切换时间19．5—20．5min;在上述条件下,对80％C60固体粉末进行分离,C60的纯度可达95％,收率大于70％。结果表明,这种方法是可行的,易于实现工业化。     

模拟移动床色谱法分离C60的条件选择

用模拟移动床色谱对C60进行了分离.工作参数:直径1 cm长10 cm的半制备柱;固定相为ODS;残余液流速2.2 mL/min,萃取液流速2 mL/min,进样流速12 mL/h;室温;切除C60前杂质的流动相V(甲醇):V(甲苯)=60:40,切换时间14.5-15.5 min;切除C60后杂质的流动相V(甲醇):V(甲苯)=50:50,切换时间19.5-20.5 min;在上述条件下,对80%C60固体粉末进行分离,C60的纯度可达95%,收率大于70%.结果表明,这种方法是可行的,易于实现工业化.     

高效液相色谱法同时测定蒙药复方述达格-4中三种黄酮类成分的含量

采用反相高效液相色谱法,色谱柱为Diamosil C18(4.6mm×250mm,5μm),以甲醇(A)-0.5%磷酸水溶液为流动相,梯度洗脱(0～20min,43%A;20～30min,43%A→61%A;30～60min,61%A),流速1.0mL·min-1检测波长为350nm,柱温30℃,进样量20μL,建立同时测定蒙药复方述达格-4中高良姜素、槲皮素、芦丁的高效液相色谱含量测定方法.结果表明高良姜素、槲皮素、芦丁的线性范围分别为1.06～10.6μg(r =0.9999),0.0276～0.276μg(r = 0.9999),0.0264～0.264μg(r = 0.9999);平均加样回收率(n = 6)分别为98.71%,97.66%,98.13%.本法准确、简便,具有良好的重复性.     

HPLC法测定克糖片剂中的槲皮素

测定克糖片剂中槲皮素的质量比.采用高效液相色谱法,Hypersil C18柱,流动相为甲醇-0.3%磷酸(60∶40,V∶V),流速为1.0 mL/min,柱温为室温,柱长为250 mm,检测波长为360 nm.槲皮素的线性范围为0.2~1.0μg(r=0.999 9),槲皮素的平均加样回收率为99.57%(RSD为0.51%).最终计算得出平均含槲皮素0.052 7 mg/片,RSD为0.48%.本方法可简便快捷的测得克糖片剂中槲皮素的质量比.     

凝胶层析分离桔梗皂苷方法的研究

以桔梗为原料对桔梗总皂苷的分离方法进行了研究.采用超声波-水提法提取总皂苷,并采用凝胶层析法进行分离.通过单因素分析,确定了洗脱剂体积分数、上样量、流速、洗脱剂用量为影响凝胶层析的显著因素.通过凝胶层析分离实验确定了桔梗总皂苷的最佳分离工艺参数为:洗脱剂体积分数为70%,凝胶体积与上样量比为1∶4,流速为1 mL/min,洗脱剂用量与上样量为1∶1.     

RP-HPLC法同时测定三七安宫胶囊中人参皂苷和三七皂苷的含量

采用反相高效液相色谱法(RP-HPLC)同时测定了三七安宫胶囊中三七皂苷和人参皂苷的含量.实验中,用十八烷基硅烷键合硅胶作为填充剂,乙腈-0.2%磷酸梯度洗脱(0~30 min,V乙腈∶V磷酸=20∶80;31~80 min,V乙腈∶V磷酸=30∶70)作流动相,检测波长为203nm,流速为1.0 mL/min.结果表明:三七皂苷R1在0.42~2.10μg范围内线性关系良好(r=0.999 6),平均回收率(n=5)为96.4%;人参皂苷Rg1在1.59~10.6μg范围内线性关系良好(r=0.999 9),平均回收率(n=5)为97.7%;人参皂苷Rb1在1.497~9.98μg范围内线性关系良好(r=0.999 7),平均回收率(n=5)为98.1%.     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that