小波包分析用于重叠分析化学信号的处理

对小波包分析的算法进行了改进,并将此算法成功地应用于多组分重叠色谱信号的解析.结果表明,本文提出的算法解决了MRSD算法的不足,更适合处理分析化学信号,用于重叠信号的解析时不需重构(逆变换),简化了数据处理步骤,加快了数据解析速度,具有较强的解析能力.对于重叠色谱信号的解析,小波包分析比小波分析具有更强的解析能力.     

用DMF萃取蒸馏分离异戊二烯流程中解析塔的计算及验证

本文介绍DMF解析塔试验结果,提出适用于解析塔的逐板计算方法。并认为在减压解析塔计算中,必须考虑塔釜中dcpd热分反应的影响,文中还讨论了控制减压解析过程的主要因素。     

恒温条件下DAEM模型新型理论分析及其应用

本文给出了恒温条件下DAEM模型的最新理论阐述，得出了反应过程中活化能的解析表达式，并给出了得到反应过程中活化能变化曲线的具体步骤。对两种中国煤的气化行为进行的解析结果表明，该方法能够很好地反映气化过程中活化能的变化情况，解析结果能够与常规气化动力学的解析结果吻合。     

DMF中脱除环戊二烯、双环戊二烯的新方法

在用二甲基甲酰胺(DMF)抽提蒸馏分离异戊二烯(ip)时,控制溶剂中环戊二烯(cpd)、双环戊二烯(dcpd)的浓度是制取聚合级ip 的关键所在。目前工业化流程中,为控制循环溶剂中cpd、dcpd 含量,使用了常压解析、减压解析和共沸蒸馏等三个塔。从我们以前的工作得知,经解析后的DMF 中cpd 含量主要由解析塔釜温度、dcpd 浓度及停留时间所决定。也即降低DMF 中cpd 含量既可用降低解析塔釜温度的方法(即上述常、减压解析流程),也可以用降低dcpd 浓度     

动态分析解析解方法研究可逆吸附及不可逆吸附在多相催化反应中的作用

提出了一个多相催化反应中可逆吸附物种及不可逆吸附物种同时参与反应的动态分析解析解新模型。在同时考虑轴向扩散、不可逆物种吸附速率以及可逆物种和不可逆物种表面反应速率的情况下,通过解析解对实验曲线进行拟合计算,即可求出各反应的速率常数。在不同简化条件下,由解析解可自然得到稳态方程、不可逆物种表面反应流出曲线解析解以及迎头吸附流出曲线解析解等。通过理论计算,考察了各速率参数对流出曲线的影响。     

DSC 曲线解析

本文以作者发表的论文为基础阐述了解析DSC曲线应具备的理论知识和技能,并以作者解析抗癌药倍半氧化羧乙基锗、尼龙1010、标致汽车保险杆的DSC曲线为例,说明作者解析DSC曲线的思路和方法。     

液晶化合物分子结构的人工智能解析

液晶化合物分子结构的人工智能解析王丰彦（无锡环境科学研究所２１４０２３）宁永成（清华大学化学系北京１０００８４）近年来，随着计算机应用的日益广泛，计算机辅助分子结构解析的人工智能方法已引起人们的重视，已有文献从理论上对有机化合物人工智能解析作了一些探...     

电化学阻抗谱弛豫时间分布基础

电化学阻抗谱（EIS）是一种高效的原位/非原位电化学表征技术,已在电化学能源领域得到广泛应用,如用于锂离子电池、超级电容器、燃料电池等材料及器件性能的诊断和优化. 弛豫时间分布（DRT）是一种不依赖于研究对象先验知识的EIS解析技术,可用于分离和解析EIS中高度重叠的物理化学过程. 为了促进DRT解析技术的应用和推广,本文详细阐述了如下问题： 1） DRT解析原理、实现算法及重要扩展; 2） 典型电路基元的DRT解析分析; 3） DRT的具体实现及在电化学能源中的典型应用举例; 4）DRT解析技术研究进展、存在问题及发展趋势.     

遗传算法在色谱谱图解析中的应用

将遗传算法引入色谱峰解析程序 ,结合色谱峰EMG模型及峰形经验公式 ,实现了恒温色谱谱图的全自动解析。对模拟谱图和实验谱图进行了解析 ,取得了满意的结果。本文对遗传算法的运算控制及运算效率进行了研究和讨论     

一个用于含C, H, O的有机化合物结构解析专家系统

本文以1,3,3-三甲基-2-氧二环[2,2,2]辛烷为例, 介绍了结构解析专家系统ESESOC.I. 综合利用IR、13^C NMR进行结构解析的过程, 特别是对结构解析专家系统的核心部分, 即整体结构对接作了详细地描述。     

Energy contribution of the solvent to the charge migration in DNA

The authors have investigated the interactions of the reaction centers, participating in the charge transfer reaction within the DNA molecule with the phosphate backbones and the solvent molecules, and have estimated the contribution of these interactions into the charge migration in DNA. They have determined the unequal shift of the energy surfaces of the initial and final transition states of the transfer reaction along the energy axis and the dependence of the magnitude of the energy shift on the nature of the reaction centers and the surrounding environment. The nonuniform distribution of the negative charge in the DNA phosphate backbones results in an increase of the positive shift of the energy surface of the DNA base pairs in the center of the structure, where the maximum density of the negative charge is concentrated. Localization of the positive charge on the guanine and the adenine in the DNA base pairs in the oxidized state results in a dependence of the free energy of reaction in the solvent on the pair sequences and their arrangement in the DNA chain. As an example, for the G-C/A-T configuration the positive charges are localized on the same strand that results in a decrease of the free energy of reaction in the solvent for charge migration from G-C to A-T pair by 0.125 eV.     

Molecular dynamics simulation studies of the conformation and lateral mobility of a charged adsorbate biomolecule: implications for estimating the critical value of the radius of a pore in porous media

The conformations, the values of the lateral transport coefficient of a charged biomolecule (desmopressin) in the adsorbed layer and in the liquid layers above the adsorbed layer, the potential energies of the interaction between the biomolecules located in different liquid layers with the charged solid surface and with the biomolecules in the adsorbed layer, the potential energies of the interaction between water molecules in the hydration layers surrounding the conformations of the biomolecules in different layers, as well as the structure and number of hydration layers between the different conformations of desmopressin, were determined by molecular dynamics simulation studies. The results show that the lateral mobility of the adsorbed desmopressin is approximately equal to zero and the value of the lateral transport coefficient of the biomolecule in the liquid layers located above the adsorbed layer increases as the distance of the liquid layer from the charged solid surface increases. But the values of the lateral transport coefficient of the biomolecule in the liquid layers above the adsorbed layer are lower in magnitude than the value of the transport coefficient of desmopressin along the direction normal to the charged solid surface in the liquid phase located above the vacant charged sites of the solid surface, and these differences in the values of the transport coefficients have important implications with respect to the replenishment of the biomolecules in the inner parts of a channel (pore), the overall rate of adsorption, and the form of the constitutive equations that would have to be used in macroscopic models to describe the mechanisms of mass transfer and adsorption in the pores of adsorbent media. Furthermore, a novel method is presented in this work that utilizes the information about the sizes of the conformations of the biomolecule in the adsorbed layer and in the liquid layers above the adsorbed layer along the direction that is normal to the charged solid surface, as well as the number and size of the hydration layers along the same direction, and could be used to estimate the value of the lower bound of the linear characteristic dimension of a pore (i.e., pore radius) in porous adsorbent media (e.g., porous adsorbent particles; skeletons of porous monoliths) in order to realize effective transport and overall adsorption rate.     

Dynamics of electric field induced deformations in flexoelectric nematic layers

The dynamics of deformations induced by DC electrical fields in homeotropically aligned layers containing a flexoelectric nematic material with negative dielectric anisotropy has been studied numerically. The rise time constants, characterising the development of deformations after switching on the external voltage, and the decay time constants, describing the decay of deformation after switching off the voltage, were calculated as a function of the parameters essential for the behaviour of the layer. In particular, the influence of flexoelectricity was studied. It was found that the stronger the flexoelectric properties of the nematic, the lower is its viscosity, the higher is the bias voltage, the weaker is the surface anchoring, the thinner is the layer and the higher is the ion concentration, the more rapid was the onset of deformation. Similarly, the lower the viscosity, the thinner is the layer, the stronger the anchoring and the larger the ion content, the more rapid was the decay of deformation. Neither the voltage previously applied nor the flexoelectric properties were found to affect the decay time.     

Modeling of the trajectories of the hydrogen bubbles evolving from the cathode in a fluorine production cell

The fluid velocity and temperature fields and the trajectories of the hydrogen bubbles evolving from the cathode in a fluorine production cell were studied by using the finite element method. It was examined the effect of the configuration of the slits formed on the cathode on the escape of the hydrogen bubbles toward the backside of the cathode to reduce the ohmic voltage loss between the electrodes. The results showed that the cathode configuration has a profound effect on both of the flow pattern near the cathode and the bubble trajectories. It was found that the cathode with the slits only on the upper half of the electrode is more effective in removing the bubbles to the backside of the cathode than the one with the slits over the entire electrode.     

高分子链在球内表面上的吸附/排空转变

应用自洽场理论(SCFT)研究了受限于球内的高分子溶液的结构,重点关注高分子链在受限壁附近的行为.根据自洽场理论数值计算结果,讨论了球半径、高分子与球限制壁的相互作用、高分子平均浓度等因素对球内高分子浓度分布的影响.从高分子浓度分布和吸附/排空层厚度可以发现,在一定的条件下,受限的高分子在受限壁上会发生吸附/排空转变.吸附/排空转变与受限球大小、高分子链长和平均浓度,以及高分子链与受限壁之间相互作用都有关系.理论预测发生吸附/排空转变时的高分子与球限制壁的临界相互作用参数与链长的倒数成线性关系,且斜率与球半径有关.限制球越小,要发生吸附/排空转变,需要高分子与球之间有更大的临界吸引能.     

The effect of spacer length on the polymerization of diacetylenes in sams on gold surfaces

The influence of the molecular architecture of diacetylene disulfides on the structure and polymerizability of self assembled monolayers on gold was investigated. The position of the diacetylene group was varied systematically by adjusting the length of the tail and the spacer. For the structures studied, the longer the tail, the higher the akyl chain crystallinity as sensed by IR spectroscopy, and the higher the polymerization efficiency as probed by resonance Raman spectroscopy. The influence of the spacer on the polymerizability is more complicated. It is conjectured that the spacer reduces the lattice strain due to the misfit of the arrangement of the anchor groups and the arrangement of the diacetylene units and the polydiacetylene backbone, respectively. Simple modeling reveals that the number of the methylene units (odd or even) and the overall length both influence the arrangement. The highest polymerization efficiency is found for the longest, odd numbered spacer.     

启动工况下质子交换膜燃料电池动态性能仿真分析

本文以等效电路模型为基础模型,结合动态气体压力模型和动态热传输模型建立了集总参数模型,在SIMULINK环境下,利用建立的模型模拟了电池启动过程,发现了电压的下冲现象,且电压的响应时间与电池温度的响应时间基本一致,说明启停过程中电池温度对电池的动态性能影响很大. 进一步从温度角度对模型中决定电池输出电压大小的热力学电动势、活化过电势、欧姆过电势和浓差过电势的动态响应情况进行了分析,发现启动过程电压的下冲现象主要由电池活化过电势和欧姆过电势的过冲引起;当以阶跃信号形式输入温度时,启动过程电池输出电压响应很快且未发生下冲现象,说明提高电池温度的响应速度能够改善电池的动态性能.     

Electrically driven motion of an air bubble on hemispherical oil/water interface by three-phase boundary reactions

Our electrochemical cell consisted of a ferrocene-included hemispherical nitrobenzene (NB) droplet on the glassy carbon (GC) electrode which was immersed in the aqueous solution including sodium sulfate and sodium dodecyl sulfate (SDS). When an air bubble was injected near the boundary between the oil and the aqueous phase, it stayed at the top of the hemisphere on the boundary so that the lower half of the bubble was put in oil and the other half was in water. From the force balance of surface tension and buoyancy of the bubble, the bubble took an energetic minimum at the interface. It sank into the oil phase when ferrocene in the oil was electrochemically oxidized through the GC electrode by the three-phase boundary reaction. The electrochemical reduction caused the bubble to move back toward the aqueous phase. The motion of the bubble was synchronized with the redox reaction of ferrocene. The potential step oxidation showed such a rapid response that the motion could not be attributed to diffusion of ferricenium ion from the three-phase boundary to the bubble. Our idea of explaining the rapidity was the translational motion of the SDS layer along the boundary, which was driven by the difference in the surface concentration of SDS caused by the electrochemical generation of the ferricenium ion. The motion of the SDS layer was demonstrated by the shrinkage of the oil layer spread on the water surface when SDS solution was dropped on the oil layer. The spreading velocity was close to the velocity of propagating the oxidation of ferrocene to the bubble.     

Release of lysozyme from the branched polyelectrolyte-lysozyme complexation

On the basis of the discretely charged sphere model of lysozyme, the release behavior of lysozyme from the branched polyelectrolyte-lysozyme complexation is investigated by adding salt and changing the pH values of the solution. It is found that, with the increase of the salt ionic strength of the solution, the lysozymes are gradually released from the oppositely charged polyelectrolyte as a result of the screening of electrostatic attraction between the two ionic species by adding the salt. Interestingly, there exists a critical salt ionic strength at which all proteins are released from the branched polyelectrolyte, and the polyelectrolyte-protein complexation is broken completely. Beyond the critical value, the increase of the salt ionic strength causes self-association of the proteins released from the branched polyelectrolyte-protein complexation. The self-association of the protein is detrimental in biological systems. By calculating the second virial coefficient, we found that the optimal salt content for the dispersion of proteins coincides with the critical ionic strength, because the second virial coefficient reaches its maximum at the critical ionic strength. Similarly, increasing the pH value of the solution can also release the lysozymes from the polyelectrolyte, because the increase of pH value of the solution changes the charge distribution and net charge of the lysozyme, weakens the attraction between lysozymes mediated by polyelectrolyte, and finally leads to the dissolution of the complexation of branched polyelectrolyte with lysozymes in strong alkaline solution. In addition, by exploring the effect of architecture of the polyelectrolyte on the release behavior of proteins, we found that it is more difficult to release proteins from the branched polyelectrolyte than from the linear polyelectrolyte.     

高压离子交换排代法富集锂同位素(Ⅰ)——精馏型平衡塔板理论在富集同位素中的应用

本文根据精馏型平衡塔板理论推导出富集系数很小和有限带长时的同位素稳定谱带理论方程组,并对某些具体情况进行了分析。