双(2-甲氧乙氧基)铝氢化钠还原芳杂环酯的研究

双(2 甲氧乙氧基)铝氢化钠还原5 噻唑甲酸乙酯和3 吡啶甲酸乙酯,分别得到重要的医药中间体5 羟甲基噻唑和3 羟甲基吡啶.比较了反应温度,反应时间,还原剂当量比以及后处理方法等因素对反应的影响.5 噻唑甲酸乙酯还原收率为72%,3 吡啶甲酸乙酯还原收率为93.9%.     

电位法研究硝酸银-氨-吡啶甲酸体系络合物的组成

吡呵酸、烟酸镀银新工艺已取得实际应用,异烟酸也可用作镀银添加剂.这些镀液的主要成分是硝酸银、氨和吡啶甲酸(吡呵酸L_α、烟酸L_β、异烟酸L_γ).氨和吡啶甲酸均可与银(Ⅰ)形成单一配位型络合物.而在同时存在两种配位体的溶液中,在一定条件下,常可形成混合配位体络合物,或称混合型络合物.这类混合型络合物的形成往往对电极过程、槽液稳定性和镀层质量有一定影响.因此,研究硝酸银-氨-吡啶甲酸体系中的络合物组成,对进一步完善电镀工艺有一定意义.     

1-吡啶甲酰基-4-烯丙基氨基硫脲的合成与结构表征

报道了1-吡啶甲酰基-4-烯丙基氨基硫脲的合成.以3-溴丙烯和硫氰酸铵制得异硫氰酸烯丙酯(1);将2-吡啶甲酸,3-吡啶甲酸和4-吡啶甲酸酯化;由酯化反应所得(3a-3c)经肼解得吡啶甲酰肼(4a-4c);最后将化合物(1)分别和4a,4b,4c反应,合成了1-吡啶甲酰基-4-烯丙基氨基硫脲类化合物(5a-5c),其结构经红外光谱、氢核磁共振谱、元素分析表征.     

一株丛毛单胞菌对2-吡啶甲酸的好氧生物降解

在好氧条件下分离筛选到一株以2-吡啶甲酸为唯一碳、氮、能源的菌株,经16SrRNA基因序列分析鉴定为丛毛单胞菌(Comamonas sp.),并命名为ZD3。分别考察了培养液pH值和2-吡啶甲酸初始质量浓度对ZD3降解性能的影响,发现该菌株可在pH值为5.0~9.0的范围内降解2-吡啶甲酸,其中7.0为其最适pH值;当2-吡啶甲酸初始质量浓度分别为100、200、400、600和800mg·L~(-1)时,ZD3对其完全降解的时间相应为12、17、20、78和114h。零级动力学模型可比一级动力学模型更好地描述ZD3对2-吡啶甲酸的降解特性,当2-吡啶甲酸的初始质量浓度为100~400mg·L~(-1)时,降解速率常数k_0随着浓度的增加而增大,并在400mg·L~(-1)时达到最大值;当初始质量浓度为600~800mg·L~(-1)时,k_0开始下降,呈现抑制作用。紫外光谱和高效液相色谱-离子阱-飞行时间质谱表明,在2-吡啶甲酸的好氧生物降解过程中,第一步反应为α羟基化反应,产物为6-羟基吡啶甲酸。     

一维链状有机锡配合物三丁基锡4-吡啶甲酸酯的合成及晶体结构

用三丁基氯化锡与4-吡啶甲酸钠反应,合成了三丁基锡4-吡啶甲酸酯,并进行了红外光谱、核磁共振氢谱及质谱表征。X-射线单晶衍射表明,化合物属单斜晶系,空间群P2_1/c,α=9.667 3(14),b=23.845(4),c=9.707(14)A;β=112.463(3)°;V=2 067.9(5)A,Z=4,Dc=1.324 Mg m~(-3),μ=1.242 mm~(-1),F(000)=848,R_1=0.054 4,ωR_2=0.141 1.化合物通过4-吡啶甲酸配体的氮原子桥联,形成五配位三角双锥构型的一维无限链聚合物。     

硝基苯高效降解菌群对硝基苯好氧降解

硝基苯为环境有毒有害物质,好氧条件下硝基苯的生物降解主要通过部分还原途径.吡啶甲酸作为副产物出现在硝基苯的部分还原途径中.生物毒性大,阻碍了硝基苯的降解.本实验分离出3株在好氧条件下以硝基苯为惟一碳、氮、能源的菌株,分别鉴定为Streptomyces albidoflavus(微白黄链霉菌)、Rhodotorula mucilaginosa(胶红酵母)和Micrococcus luteus(藤黄微球菌),并借助其完整细胞考查了由上述3株菌混合而成的菌群对硝基苯的好氧降解.结果表明:硝基苯经部分还原生成2-氨基酚,2-氨基酚再进一步开环降解.在2-氨基酚开环过程中,有吡啶甲酸生成,毗啶甲酸被矿化成二氧化碳和水.     

三丁基锡氧化吡啶甲酸酯的合成和晶体结构

利用双三丁基氧化锡与氧化吡啶甲酸以1∶2摩尔比反应,合成有机金属锡配合物三丁基锡氧化吡啶甲酸酯。通过元素分析、红外光谱和核磁共振对其结构进行了表征。利用X-射线单晶衍射仪测定了三丁基氧化吡啶甲酸酯的晶体结构。结果表明,分子中的锡呈五配位的畸变的三角双锥构型。该配合物晶体属单斜晶系,空间群P2（1）/c,a=0.8996（4）nm,b=1.7824（8）nm,c=1.3255（6）nm,β=96.959（7）°,Z=4,V=2.1097（17）nm3,Dc=1.348g/cm3,μ（MoKα）=12.24cm-1,F（000）=880,R=0.0502,wR=0.1300.是由N-O中的O和邻近分子中的锡原子配合,形成一维链状有机锡配合物。     

吡啶甲酸铑阳离子催化甲醇羰基化反应IRC解析及催化剂结构与性能的理论计算

分别采用从头算HF方法和密度泛函(DFT) B3LYP方法,在LANL2DZ基组下,应用内禀反应坐标(IRC)理论分析吡啶甲酸铑阳离子催化甲醇羰基化决速步骤反应沿最小能量途径(MEP)上相互作用分子间化学键的变化,对比[Rh(CO)2I2)]-催化剂,从催化剂结构、分子轨道分布等方面,探讨吡啶甲酸铑阳离子催化剂具有较高...     

四氮杂大环铜(II)配合物催化羧酸酯水解研究

合成并表征了一种四氮杂大环配体及其铜(II)配合物.在Brij35胶束溶液中,试验了该配合物对羧酸酯(2-吡啶甲酸对硝基苯酚酯PNPP)水解的催化活性,研究了其催化PNPP水解的动力学,提出了可能的催化反应的机理.     

2'-(2-吡啶甲酰胺基)-苯甲酸苯酯的合成、表征及晶体结构

2-吡啶甲酸和邻氨基苯甲酸在亚磷酸三苯酯作用下合成了新型的标题化合物.产物经IR、UV、MS、元素分析、X-射线单晶衍射对其进行了表征.标题化合物的晶体由于C-H…O氢键弱相互作用的存在而稳定,继而形成沿a轴方向的R210二聚体.     

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.     

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