新型联苯酚双亚胺[ONS]三齿配体的合成

以2,2′-二羟基联苯为原料,经过羟基保护、羟基邻位甲酰化、去保护等反应,合成了2,2′-二羟基-[1,1′-联苯基]-3,3′-二醛,再与2-丙硫基苯胺通过希夫碱反应合成了一种新型的双水杨醛亚胺配体3,3′-双-[(2-丙硫基)-苯亚胺]-2,2′-二羟基联苯(5).所合成的化合物通过核磁氢谱、元素分析、红外光谱等手段进行了表征,目标产物5通过X射线单晶衍射进一步证实了其结构.双水杨醛亚胺配体5晶体结构表明两个相连的苯环不共平面,二面角为63.14°,且两个水杨醛亚胺中配位原子所在的键长、键角不同,说明与中心金属配位时产生了两个不同的活性中心.     

邻羟基化合物被高碘酸或四乙酸铅氧化产物的推断

分析了高碘酸和四乙酸铅对邻二醇氧化反应的机理;根据已有的反应结果,总结出用高碘酸和四乙酸铅对邻羟基化合物,特别是对于α-羟基醛、α-羟基酮、α-羟基酸、β-羟基胺等多种邻位含羟基结构的化合物进行氧化时所得产物的书写规律,并将这一规律应用于有关反应.     

邻羟基化合物被高碘酸或四乙酸铅氧化产物的推断

分析了高碘酸和四乙酸铅对邻二醇氧化反应的机理;根据已有的反应结果,总结出用高碘酸和四乙酸铅对邻羟基化合物,特别是对于α-羟基醛、α-羟基酮、α-羟基酸、β-羟基胺等多种邻位含羟基结构的化合物进行氧化时所得产物的书写规律,并将这一规律应用于有关反应.     

对甲氧苯炔基取代黄酮以及橙酮衍生物的合成

以2,4,6–三羟基苯乙酮为原料,通过保护、羟醛缩合、环化、碘代以及Sonogashira反应合成了2个新的8位对甲氧苯炔基取代黄酮化合物.同时,从4,6–二羟基橙酮和金鱼草素出发,通过保护、碘代以及Sonogashira反应合成了2个新的7位对甲氧苯炔基取代橙酮化合物.以常见黄酮和橙酮为母核,探讨8位对甲氧苯炔基取代黄酮和7位对甲氧苯炔基取代橙酮衍生物的合成方法.这些化合物的合成为进一步对黄酮化合物8位以及橙酮的7位进行化学修饰奠定了良好的基础.     

苯酚的一些衍生物电子结构的量子化学研究

采用MNDO法计算了苯酚和它的一些衍生物的最稳定的几何构型(用能量梯度法优化得到)的电荷分布,探讨了羟基、甲酰基等取代基对电荷分布的影响.计算结果表明,在这类化合物中绝对值最大的负的净电荷总是出现在羟基的邻位,适当配置羟基、甲酰基等取代基的位置可使苯环上的某些点(如羟基的邻位)上的净电荷变得更负.1个基团是“拉电子基团”或是“推电子基团”不能准确说明取代基对电荷分布的影响,必须从取代基在分子体系中的诱导、共轭效应等方面进行具体分析,并藉助量子化学计算,才能获得准确的定量结果.     

保护法提高超支化聚缩水甘油的羟基反应率

利用聚缩水甘油的大量末端羟基,将氟碳链接入聚缩水甘油中,得到全氟端基超支化聚合物．采用保护法对聚缩水甘油的外部羟基保护,使内部羟基接上氟端基;然后对外部羟基解保护,接上氟端基,得到最终产物．利用红外、核磁对各合成步骤和最终产物进行了表征．实验结果表明,外部羟基先保护后去保护的多步合成方法中的羟基转化率显著高于氟端基直接和聚缩水甘油反应的一步法．保护法将聚缩水甘油内外部羟基区别开,使其分剐参加反应,提高了羟基反应率．     

系列D-2-氨氧基酸的合成

通过天然氨基酸的重氮化、保护、以及与邻苯二甲酰亚胺的Mitsunobu反应、脱保护等步骤高效的合成一系列高立体选择性的氨氧基酸类化合物.其中,Mitsunobu反应是关键步骤,它构建分子中的N—O键,并翻转分子的手性中心.     

—取代联苯系电取代反应定位规则共振论观

—取代联苯发生亲电取代反应时,当取代基为产生-I-C效应的吸电基或供电基在联苯环上4-位或2-位时,第二个取代基主要进入,未有取代基的苯环的邻位和对位,以对位为主.若取代基为产生-I>+C效应的吸电基或供电基在联苯环上3-位时,第二个取代基主要进入有取代基的苯环的邻位和对位,以对位为主.     

苯并噁唑类化合物合成及光谱性质研究

在乙醇中以取代水杨醛与邻氨基酚反应合成希夫碱,以Mn(OAc)3氧化生成相应的羟基苯基苯并噁唑类化合物.测定了相应荧光化合物的荧光光谱图,发现化合物中羟基对位取代卤素随着分子量的增大,吸收和发射波长增长,荧光量子收率增大,Stokes位移减小.羟基邻位、对位都有溴原子取代时量子收率最大,吸收和发射波长也增大.     

天然岩藻糖苷酶的抑制剂L-deoxygulojirimycin关键中间体的不对称合成

报道一种合成天然氮杂糖L-deoxygulojirimycin关键中间体及全保护L-gulono-1,5-lactam的方法.其关键反应之一为二碘化钐(SmI2)促进下对硅基保护的3-羟基戊二酰亚胺10的C-2位的区域和立体选择性不对称羟甲基化,区域选择性为80:20,立体选择性为93:7;另一关键反应为采用OsO4-NMO体系对18进行不对称双羟基化反应,立体选择性单一,并通过NOE确定产物的立体化学.     

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.     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the