白藓化学成分研究

采用无水乙醇浸泡提取制得浸膏,再将浸膏加水混悬后依次用石油醚、乙酸乙酯和正丁醇萃取,制得几种提取物。用柱层析、高效液相色谱等进行分离,得到3种单体化合物,经^1H NMR、^13C NMR确定化合物的结构为β-谷甾醇、叶绿素和秽酬。     

还阳参化学成分及生物活性研究

研究还阳参crepis tectorum linn.全草的化学成分。采用硅胶柱色谱、HPLC色谱等方法分离纯化,对还阳参浸膏进行化学成分的分离,根据理化性质和波谱数据进行结构鉴定。从还阳参提取物中分离得到了5个化合物,分别鉴定为:β-谷甾醇(β-sitosterol,1)、豆甾醇(stimastero,2)、羽扇豆酮(lupenone,3)、木栓酮(friedelin,4)、伪蒲公英甾醇乙酸酯(ω-taraxasteryl acetate,5)。化合物3为该植物中首次分离得到。正丁醇层提取物对玉米小斑病菌、玉米大斑病菌、草莓灰霉病菌有抑制作用。     

东北苍耳茎叶化学成分研究

本文采用乙醇浸泡提取制得浸膏,再将浸膏加水混悬后依次用石油醚、乙酸乙酯和正丁醇萃取,制得各种提取物。用柱层析、高效液相色谱等进行分离,得到两种单体化合物,经1HNMR鉴定并与文献对照,确定一种为苍耳亭,另一种为β-谷甾醇葡萄糖苷。     

东北苍耳子化学成分研究

本文采用无水乙醇浸泡提取制得浸膏,再将浸膏加水混悬后依次用石油醚、乙酸乙酯和正丁醇萃取,制得各种提取物。用柱层析、高效液相色谱等进行分离,得到两种单体化合物,经1HNMR鉴定并与文献对照,确定一种为xanthinosin,另一种为β—谷甾醇。     

还阳参化学成分的分离及结构鉴定

研究还阳参Crepis tectorum Linn.根的化学成分。采用柱层析、高效液相色谱等方法进行分离和纯化,通过理化、核磁共振等现代波谱技术鉴定化合物结构。从还阳参根石油醚部分分离得到3个化合物,分别鉴定为二十六烷醇(Ⅰ)、β-谷甾醇(Ⅱ)、蒲公英醋酸酯(Ⅲ);从其乙酸乙酯部分分离得到2个化合物,鉴定为咖啡酸(Ⅳ)和伪蒲公英甾醇乙酸酯(Ⅴ)。     

苍耳化学成分研究

研究苍耳Xanthium sibiricum Patrin ex Widder全草的化学成分。采用硅胶柱色谱、HPLC色谱等方法分离纯化,根据理化性质和波谱数据进行结构鉴定。从苍耳全草乙醇提取物中分离得到了7个化合物,分别鉴定为:羽扇豆醇乙酸酯(1),异香草酸(2),咖啡酸(3),β-谷甾醇(4),麦角甾醇(5),三十烷醇(6),蒲公英甾醇乙酸酯(7)。化合物2,5,7为首次从苍耳中分离得到。     

日本东北红豆杉枝化学成分研究

采用甲醇浸泡提取制得浸膏,再将浸膏加饱和食盐水溶解后依次用正己烷萃取除去油脂,再用二氯甲烷萃取浓缩萃取物。用柱层析、重结晶和高效液相色谱等进行分离,得到两种单体化合物,经1H-NMR,13C-NMR和IR鉴定并与文献对照,确定一种为紫杉吉酚,另一种为紫杉平F。     

黄牛奶树根茎的化学成分研究

采用硅胶柱层析法进行成分的分离纯化,以波谱分析法鉴定黄牛奶树的化合物的结构。从黄牛奶树根、茎部位的乙醇提取物中分离、鉴定了9个化合物,分别为:齐墩果酸-3-乙酸酯(1),高根二醇-3-乙酸酯(2),豆甾醇(3),α-菠甾醇(4),香草酸(5),蔗糖(6),麦芽糖(7),5,4'-二羟基-7-甲氧基二氢黄酮(8),肌醇(9)。全部化合物均为首次从该植物中分得。     

嘉祥白菊花中黄酮类化合物的分离纯化和结构鉴定

研究了嘉祥白菊花中黄酮类化合物的提取分离和结构鉴定.采用超声波提取法进行提取总黄酮,制得黄酮浸膏.样品经大孔树脂柱、硅胶柱分离,然后用TLC进行鉴定合并.最后经过减压蒸馏、冷冻干燥和多次重结晶后制得一种纯品,并通过红外和核磁等手段,对该纯品进行表征.     

狭基香茶菜化学成分的研究

从狭基香茶菜的叶和茎的乙醇提取物中分离得到７个化合物,应用波谱分析和元素分析等方法鉴定出３个化合物的化学结构,它们分别为金合欢烯、降胡萝卜素,羊毛甾醇乙酸酯．     

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.     

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.     

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     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has