碳酸镧分离富集DNA的研究

通过紫外-可见分光光度法测定了碳酸镧吸附前后溶液中的DNA含量,并计算了DNA的吸附率.通过X射线光电子能谱(XPS)与X射线衍射(XRD)分析了吸附DNA前后固相的变化.结果表明,碳酸镧对DNA有较强的吸附作用,且该过程对碳酸镧晶型未产生明显影响.通过对吸附条件的考察,发现DNA的吸附率随pH值升高而降低.最后通过磷酸二氢钾作为洗脱液将吸附的DNA回收,洗脱液中镧离子含量低于0.1×10~(-6)mol/L,对DNA的后期使用无污染.     

基于Fourier变换的裂解价差期权定价

本文研究了期货期权和裂解价差期权的定价问题.利用Fourier变换方法,在ASub CIR模型的基础上,获得了单因素期货期权,两因素期货期权以及价差期权价格的表达式,最后用C++和MATLAB计算出期权的价格,解决了利用特征函数展开法计算期权价格时速度较慢且不稳定的问题.     

Solution for the oscillation of a newtonian fluid in a co-axial viscometer

When one cup of a co-axial viscometer oscillates,the measured moment on theother(stationary)cup shows a phase lag,partly due to the inertial effect of the fluidwithin the gap between the cups.In this paper such an effect is illustrated by a newexact solution of the Navier-Stokes equation,which is derived herein by a scheme ofreducing it to a two-point boundary value problem for ODEs,Our numerical resultsindicate that,as the Womersley number a or the dimensionless gap widthδincreases,the fluid velocity profile within the gap gradually deviates from the linear one andtransits to that of the boundary layer type,with the result that the moment decreasesin the magnitude and lags behind in the phase.With the advantage of high accuracyand excellent stability,the scheme proposed herein can readily be extended to solveother linear periodic problems.     

高效液相色谱法分析精对苯二甲酸中的微量杂质

应用高效液相色谱法,采用阴离子交换键合固定相,以磷酸盐缓冲溶液为流动相,ＵＶ２５４ｎｍ检测,外标法定量,同时测定了精对苯二甲酸（ＰＴＡ）中的主要杂质４－羧基苯甲醛（４－ＣＢＡ）和对甲基苯甲酸（ｐ－ＴＯＬ）的含量,４－ＣＢＡ和ｐ－ＴＯＬ的回收率分别为９８．３％～１０５．０％和９６．０％～１０３．８％,变异系数分别小于１．７％和３．３％。方法快速、准确,用于实际样品分析可得到满意的结果。     

TOMOGRAPHY FORMULA FOR BIOCHEMICAL IMAGING OF THIN TISSUE WITH DIFFUSE-PHOTON DENSITY WAVES

Using the transport theory to describe the near infrared light propagating in tissue with finite parallel-plane geometry, and taking the zero-boundary condition, we obtain the analytical expression of average photon density and Green's function incorporating the boundary effects in the homogeneous tissure. Making use of perturbation theory we also obtain the analytical expression of scattered wave induced by the heterogeneity, and present the 2-dimensional spatial transform of scattered wave with respect to transverse coordinate. If the information of heterogeneity on depth and thickness is available, diffraction tomography formula is presented to save the time of image reconstruction; if the information is unknown, we suggest to obtain the inhomogeneous function from the one-dimensional integral equation of 2-dimensional spatial transform of scattered wave applying the direct matrix method or iterative method for image reconstruction. This approach avoids directly solving three-dimensional integral equation of scattered wave. In our proposed approach the strong points of the direct matrix method, iterative method, and diffraction tomography are fully combined.     

1-癸烯光催化氢甲酯化反应中醋酸钠的促进作用

研究了以Ｃｏ（ａｃａｃ）２催化剂,通过光促进,在常温常压下１－癸烯的氢甲酯化反应,经实验证实,通过添加醋酸钠可提高反应的产率,而且还能有效地抑制反应中主要副产物正癸烷的生成,从而大大地提高了反应的选择性。     

广义a-stable过程局部时增量的H

该文证明了广义α-stable过程局部时增量的H     

用低温光谱方法揭示氢键的结构特征

本文提出了一种利用红外光谱方法揭示晶态物质中分子的氢键结构的新方法。用ＫＢｒ压片和氟油研磨法制备于红光谱测量的样品。测得的光谱有时基本相同,有时同明显的差别。对此现象一直没有一个十分满意的解释。我们用低温红外光谱法证明压力诱导晶格中氢键网络的微细变化是造成不同产法测得的光谱不同的原因。具有平面氢键结构的晶体不能有效地的御加于样品上的应力,易一城较低的外力作用下发生结构畸变,因此,用ＫＢｒ压片和氟油     

一种改进的分层剪切湍流亚格子尺度模型及其应用

提出了一种新型的分层剪切湍流应力和湍流热通量的动力学亚格子尺度(SGS)模型,并就热分层槽道湍流问题,计算验证了该模型的正确性.采用大涡模拟方法和该动力学亚格子尺度模型,数值研究了在浮力和剪切双重作用下的稳定分层和不稳定分层槽道热剪切湍流,探讨了某些湍流特性随Richardson数的变化规律,并分析了相关的流动物理机制.     

Ag纳米颗粒对有机小分子太阳能电池性能的改善

在有机小分子太阳能电池CuPc/C60和TiOPc/C60的阳极ITO表面分别制备了一层Ag纳米颗粒,并采用MoO3作为阳极缓冲层,器件的性能均得到有效改善.Ag纳米颗粒的引入所形成的表面等离子激元共振可显著提高有机光活性层的吸收效率和光生激子的分解效率;而MoO3有效抑制了光生激子在有机/金属界面处发生的猝灭,提高了...