新型双萘酰亚胺类化合物与DNA作用研究

运用紫外吸收光谱、荧光光谱和圆二色光谱等技术方法,研究了5种不同长短烷基异硫脲阳离子作为连接臂的新型双萘酰亚胺类化合物(DN2～DN6)与DNA的作用.紫外吸收光谱结果表明,该类化合物能使DNA发生明显的减色效应并伴有微弱的红移现象,其减色效应随化合物烷基链的延长而增强;化合物的荧光可被DNA强烈猝灭,室温下DN3～DN6与DNA的结合常数随烷基链的延长而增大,分别为1.18×105、1.36×105、1.67×105、2.32×105 L/mol;化合物能够将嵌入在DNA中的吖啶橙游离出来,烷基链越长的化合物该作用力也越强;圆二色光谱表明,DNA的双螺旋结构发生了碱基堆积和局部解旋,碱基堆积程度与化合物烷基链的长度成正相关.实验结果表明,DN2～DN6均以嵌入方式与DNA发生作用,其作用强度顺序为DN6>DN5>DN4>DN3>DN2.     

基于光电技术的圆度测量及最小二乘评定

提出了一种基于光电技术测量圆度误差的新方法.该方法将圆度误差转化为轴上物点的移动,利用理想光组轴向放大率理论来实现微位移的放大,并通过采用位置敏感探测器将光斑像点的位移转化为电信号的输出,从而实现位移与电信号的转化;在测量圆度的同时,采用圆光栅来测量工件转角,实现整周的圆轮廓实时记录;对于圆度误差的评定采用最小二乘法,并经过对比实验,证实该方法的测量原理可行,实现了圆度误差的整周连续测量,其测量精度可以达到1 μm.     

Al-Zr二元合金的第一原理计算

采用基于密度泛函理论的第一原理方法,计算了Al-Zr二元合金系金属间化合物的晶格常数、体弹性模量和形成焓,计算结果与已有的实验值和其他理论结果符合得很好.     

数码相机参数的靶圆切点标定法

数码相机定位是计算机图形学中的一个重要课题,在图像处理等方面有着广泛的应用,其中数码相机参数的标定是定位的关键．文章结合数码相机成像原理、坐标的旋转变换与平移变换,利用两靶圆切点的像仍为切点的原理,提出了数码相机参数标定的靶圆切点法,并利用最小二乘法将数据拟合,得到数码相机的内外部参数．实验结果证明了这种方法的可行性与实用性．     

圆二色谱电化学研究进展

从圆二色谱的基本概念出发,简述了圆二色谱电化学的工作原理、仪器设备和研究领域,评述了圆二色谱电化学的研究进展,并展望了其应用前景.     

水杨醛缩乙二胺希夫碱与牛血清白蛋白的相互作用及抑菌活性研究

合成了水杨醛缩乙二胺希夫碱化合物.利用紫外可见吸收光谱、荧光光谱和圆二色光谱法研究了水杨醛缩乙二胺希夫碱与牛血清白蛋白(BSA)的相互作用.结果表明,该希夫碱化合物与BSA形成了复合物,导致BSA的构象发生变化,使BSA的内源性荧光发生静态猝灭,计算得到了希夫碱化合物与BSA相互作用的热力学参数.体外抑菌实验表明该希夫碱对大肠杆菌具有一定的抑菌活性.     

三个天然产物绝对构型的研究

为了研究三个来源于高等真菌的化合物的绝对构型,采用理论计算与实验数据相结合的方法.运用时间依赖密度泛函理论(TDDFT)计算了这三个新化合物的电子圆二色谱(ECD)并与实验所测ECD谱图作比较,最终确定了它们的绝对构型.     

透明质酸酶和四氧化三铁纳米粒子相互作用研究

用荧光光谱、紫外吸收光谱及圆二色光谱技术研究Fe3O4磁性纳米粒子与透明质酸酶(Hyaluronidase)的相互作用,结果表明Fe3O4磁性纳米粒子对透明质酸酶的荧光猝灭机理为静态猝灭;二者结合常数K在104数量级,说明Fe3O4磁性纳米粒子与透明质酸酶有较强的结合;二者相互作用过程中各热力学常数的变化表明Fe3O4与透明质酸酶的作用过程是一个自发过程,而且他们之间的结合力为疏水作用力;紫外吸收光谱研究发现Fe3O4能改变透明质酸酶的空间结构;圆二色谱数据表明Fe3O4磁性纳米粒子能够引起透明质酸酶的二级结构发生变化。     

自旋标记鬼臼2位立体异构体酯类分析及生物活性

合成了四对自旋标记的鬼臼2位立体异构体酯类衍生物,通过比较圆二色谱中第一偶合谱(270～290 nm),应用Hulbert规则可区分鬼臼2位酯类立体异构体.薄层色谱研究中,四对化合物的R_f值具有一定的规律性,为区分这些化合物提供了一种简便、快捷的方法.进行了四对自旋标记酯类衍生物对人体三种肿瘤细胞株(肺癌细胞A-549、肝癌细胞Bel-7402和结肠癌细胞HCT-8)的抗肿瘤活性实验,并对Sprague Dawley(SD)大鼠的肝、肾组织做了抗脂质过氧化实验,结果显示该类化合物的抗癌活性与抗氧化活性有一定的相关性.     

圆度误差测量数据处理的数学模型

介绍了在没有圆度仪的条件下利用计算机对圆度误差测量数据进行处理的方法。讨论了数据处理的设计原理，给出了最小二乘圆法、最小外接圆法和最大内切圆法三种不同评定方法的数学模型。     

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