还阳参化学成分研究

研究还阳参的化学成分。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,制得各层提取物。用柱层析、高效液相色谱等分离方法进行分离,得到5种单体化合物,经^1HNMR、^13CNMR确定单体化合物为叶绿素、蒲公英甾醇乙酸酯、葡萄糖、伪蒲公英甾醇乙酸酯、萨谷甾醇葡萄糖苷。     

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。     

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.     

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。     

"对叶大戟"正丁醇萃取物的化学成分研究

在超声辅助条件下,提取"对叶大戟"中的化学成分,经减压浓缩后得到浸膏,利用大孔树脂色谱法、凝胶色谱法对萃取物进行梯度洗脱,最后用1 H NMR、13 C NMR、ESI-MS对所得的产物进行结构鉴定.结果表明从"对叶大戟"萃取物中提取出了一种黄酮类化合物:山奈酚-3-O-β-D葡萄糖醛酸苷.     

苍耳子提取物的GC/MS分析

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。其中石油醚层提取物占总量的50%以上,采用GC/MS对石油醚层进行分析,其主要成分为:亚麻酸乙酯,硬脂酸,正十九烷,亚麻酸甲酯,棕榈酸。     

N-[甲氧(乙氧)羰基亚甲基] 5-取代苯基-2E,4E-戊二烯酰胺的合成与生物活性研究

通过芳醛与丙酮的羟醛缩合，经过还原，Vilsmeier-Haack反应，氧化四步反应制得脱落酸类似物，然后与α－氨基酸酯进行缩合反应，合成了6个未见报道的目标化合物，利用^1H NMR,IR,MS和元素分析表征了化合物结构，^1H NMR证实，目标分子中的2位和4位碳碳双键为反式构型。初步的生物活性测定表明，部分化合物具有一定的程度的植物生长抑制活性，如化合物Ⅶc，Ⅶc和Ⅶf在10mg/L浓度下对黄瓜子叶生根抑制率均为100％。     

日本苦苣菜Sonchus oleraceus L.的化学成分研究

将新采摘的日本苦苣菜（Sonchus oleraceus L．）粉碎后用甲醇浸泡，浸出液依次用正已烷、乙酸乙酯和氯仿萃取，制得相应的提取物。乙酸乙酯提取物被进一步采用柱层析及高效液相色谱分离，得到三种化合物。利用红外光谱、^1H—NMR、^13C-NMR方法对得到的化合物进行结构表征，证实其分别为β-谷甾醇、脱镁叶绿酸甲酯（Phaeophorbide—a methyl ester），和10-羟基脱镁叶绿酸甲酯Methyl（10s）-hydroxypheophorbide；其含量分别占乙酸乙酯提取物的0．0234％，0．115％和0．030％。     

南蛇藤中一种三萜成分的结构及其DSC研究

采用南蛇藤茎的氯仿提取浸膏，通过硅胶柱梯度淋洗法得到一种三萜化合物24－hydroxy-3-oxo-12,oleanen-28-oic-acid，通过MS和NMR等手段确定了其结构，并用DSC法研究了它的一些热力学性质。     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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-