分子印迹聚合物预组装体系计算机模拟

使用Gaussian 03软件研究了以苯丙氨酸为模板,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,三氟乙酸为助溶剂的分子印迹预组装体系。通过计算机模拟考察了功能单体浓度、交联剂浓度和助溶剂浓度对模板-功能单体复合物浓度的影响,从理论上计算了苯丙氨酸分子印迹聚合物的最佳合成条件。通过模拟,有助于解释实验现象以及合成高特异性和亲和性分子印迹聚合物。     

不同功能单体对分子印迹聚合物识别性能的模拟

以槲皮素为模板分子,以甲基丙烯酸(MAA)、三氟甲基丙烯酸(TFMAA)、丙烯酰胺(AM)、N-乙烯基吡咯烷酮(NVP)、2-乙烯基吡啶(2-VP)、4-乙烯基吡啶(4-VP)六种物质分别作为功能单体,运用量子化学方法模拟模板分子与不同功能单体的分子印迹聚合物预组装体系的构型、能量及复合反应的结合能△E,以讨论不同功能单体对分子印迹聚合物识别性能的影响,结果4-VP的印迹效应最好.通过模拟,有助于解释实验现象以及选择印迹效应更好的功能单体.     

采用量化计算和预实验的方法优化大黄酚印迹聚合物的合成

在研究大黄酚分子印迹聚合物制备过程中,为选择合适的功能单体,首先采用 PM3 量化计算方法,得出大黄酚与 4-乙烯吡啶、甲基丙烯酸之间的结合能分别为-768.91 kJ/mol 和-14.78 kJ/mol,表明4-乙烯吡啶与大黄酚的作用力更强,是较好的功能单体;又采用紫外预组装的实验方法优化选择功能单体,得出与上述一致的结论;同时实验确定大黄酚与4-乙烯吡啶最佳反应比为1:4.因此,以此单体和反应比去合成大黄酚印迹(MIP)和非印迹聚合物(NMIP),采用平衡吸附实验表征 MIP 的吸附性能和选择性,并推测其作用机理.结果表明:MIP 对大黄酚及结构相似物的分配系数均大于 NMIP;MIP 对大黄酚的结合容量大大高于 NMIP,对大黄酚的分配系数大于其结构类似物;由此说明:合成的 MIP 具有一定的印迹效果,4-乙烯吡啶与大黄酚(及其类似物)的作用可能产生于羟基蒽醌骨架上.研究表明:实验结果和量化计算具有一致性,量化计算方法对分子印迹聚合物合成时功能单体的选择具有很好的指导作用.     

氯霉素分子印迹聚合物预组装过程的分子动力学研究

以氯霉素(CAP)为模板分子,甲基丙烯酸(MAA)、丙烯酸(AA)、丙烯酰胺(AM)、甲基丙烯酸甲酯(MMA)为功能单体,采用分子动力学方法研究了不同预组装体系中CAP与功能单体的相互作用,考察了溶剂(氯仿、甲醇、乙腈)对预组装体系的影响,并采用试验方法验证模拟结果,最后研究了预组装体系中CAP与功能单体相互作用距离。结果表明:模拟结果与实验结果一致,在甲醇溶剂中,CAP与功能单体相互作用强弱顺序为MAA>AA>AM>MMA;乙腈溶剂中顺序为AM>MAA>AA>MMA。CAP与功能单体相互作用基团的距离在1.8~5.0,两者间可能存在较强的非共价结合作用。     

不同功能单体制备水杨酸分子印迹聚合物的分子模拟研究

采用分子模拟技术,研究水杨酸分子制备印迹聚合物过程中,水杨酸(SA)与不同功能单体之间的结合能.作者等先计算水杨酸与常用功能单体之间的结合能,再选出适合制备水杨酸分子印迹聚合物的功能单体.其次详细讨论丙烯酰胺(AM)和甲基丙烯酸(MAA)与SA的结合能以及聚合物与水杨酸分子之问的结合能.发现,(1)制备分子印迹聚合物过程中,水杨酸的作用功能基团是-COOH,AM、MAA的作用功能基团分别是-NH2、-COOH.(2)SA与AM形成的复合物结合能大于与MAA形成复合物的结合能.由此,推断以AM为功能单体的水杨酸分子印迹聚合物,比以MAA为功能单体的水杨酸分子印迹聚合物的吸附量大,与实验结果一致.     

分子印迹技术研究进展

分子印迹技术是一项新兴的分子识别技术,由于其卓越的分子识别功能,势必会形成一个崭新的技术群体.该文较系统地介绍和综述了分子印迹聚合物的制备、选择性结合特性及应用等方面的研究进展.     

酪胺分子印迹聚合物最佳功能单体筛选计算机模拟研究

酪胺广泛存在于发酵食品中,高浓度可引发偏头疼。用量子化学法,采用Gaussian软件中Hartre-Fock方法的6-31G(d)基组计算酪胺和甲基丙烯酸(MAA)、丙烯酸(AA)、甲基丙烯酸甲酯(MMA)和对乙烯基苯甲酸(P-VBA)4种功能单体的能量,模拟并探讨不同功能单体对酪胺的选择性。用模板分子和不同功能单体形成复合物的结合能(四大小来反映酪胺与不同功能单体之间的相互作用,比较模板分子与功能单体相互作用的强弱,选择最佳功能单体。计算机模拟结果表明MAA和P-VBA与模板分子的结合能(△E)最小,作用力较强,且最佳反应比为1:3,从而为合成高亲和性的酪胺分子印迹聚合物,实现酪胺快速检测提供理论基础。     

齐墩果酸分子印迹聚合物的计算机模拟、制备及吸附性能研究

在软件Hyperchem7.5中,采用分子力学MM与PM3半经验法优化齐墩果酸(OA)与甲基丙烯酸(MAA)、丙烯酰胺(AM)的分子最低能量构象,计算各自电荷分布;采用AmberMM与PM3半经验法,模拟OA-MAA、OA-AM的结合,计算OA-MAA、OA-AM的结合力大小。分别以MAA、AM作为功能单体,采用本体聚合法制备OA-MIP_1、OA-MIP_2。通过结合动力学实验和等温吸附实验对OA-MIP_1、OA-MIP_2进行吸附性能评价。从模拟结果可看出,OA-MAA较易形成氢键,使得OA-MIP_1对OA吸附较快,而OA-AM形成较稳定氢键,结合力较强,使得OA-MIP_2拥有更大的平衡吸附量。静态吸附结果表明,OA-MIP_1在0.5h即可达到吸附平衡,而OA-MIP_2则需要2h;OA-MIP_1的平衡吸附量为145μmol·g~(-1),远低OA-MIP_2平衡吸附量345μmol·g~(-1)。这与计算机模拟的结果一致。研究结果表明,计算机模拟能应用于OA-MIPs合成前的功能单体筛选,能有效地提高OA-MIPs的研发效率。     

分子模拟方法预测流体热力学性质

流体的热力学性质数据对化工过程设计具有重要意义,除实验测定外,也可采用分子模拟方法计算。为了考查分子模拟方法预测流体热力学性质的准确性和可靠性,本文以环氧乙烷为例,基于所开发的分子力学力场,综合采用分子动力学和蒙特卡罗等多种分子模拟方法,预测了环氧乙烷在较大温度范围内的气液相平衡、第二维里系数、热容、粘度系数等多种热力学性质。结果表明,采用分子模拟方法所预测的热力学性质与实验值吻合良好,所计算的环氧乙烷的液体密度、气相第二维里系数、热容和粘度系数的平均偏差分别在1%、5%、5%和10%以内。由此可见,分子模拟方法可以成为获取流体热力学性质的另1种可靠手段。     

分子自组装的应用与计算机模拟研究进展

分子自组装技术已经在纳米技术、膜技术和生命科学等领域有广泛的应用。计算机模拟又是研究分子自组装特性、超分子聚集体结构和特性的有效方法。本文综述了分子自组装技术的应用情况,从热力学和动力学角度对近年分子自组装特性计算机模拟的研究进展进行了评述,最后分析了存在的一些问题并对今后的发展前景进行了展望。     

Computer system simulation in Pascal

The programming language Pascal is considered as one of the most interesting computer system simulation tools. This paper discusses design facilities required in simulation languages, making use of a model described in Pascal. An important area is seen to be that of queues, lists or sets, and the facilities that are powerful yet simple to use are stressed. The problem of parallelism and synchronization in a simulator is solved. The structure of the simulator is considered.     

Computer simulation of a material flow system

This paper presents a computer simulation model of a material flow system. The flow system is a conveyor fed system for sorting and packing different types of bundles of cigarettes. Several bundle-types of cigarettes are produced at different rates by different machines and then released onto a common belt conveyor. The conveyor transports the bundles to a marshalling area. Because of the nature of the flow system different types of bundles get mixed up in the conveyor and several workers are stationed in the marshalling area to sort the different bundle-types and then pack into different crates. The model is used to answer questions relating to assignment of workers to particular bundle-types, whether workers should help each other in picking up bundles, and manpower levels in the marshalling area.This paper illustrates the application of computer simulation to a real world problem in a small factory.     

ms2: A molecular simulation tool for thermodynamic properties

This work presents the molecular simulation program ms2 that is designed for the calculation of thermodynamic properties of bulk fluids in equilibrium consisting of small electro-neutral molecules. ms2 features the two main molecular simulation techniques, molecular dynamics (MD) and Monte-Carlo. It supports the calculation of vapor–liquid equilibria of pure fluids and multi-component mixtures described by rigid molecular models on the basis of the grand equilibrium method. Furthermore, it is capable of sampling various classical ensembles and yields numerous thermodynamic properties. To evaluate the chemical potential, Widom?s test molecule method and gradual insertion are implemented. Transport properties are determined by equilibrium MD simulations following the Green–Kubo formalism. ms2 is designed to meet the requirements of academia and industry, particularly achieving short response times and straightforward handling. It is written in Fortran90 and optimized for a fast execution on a broad range of computer architectures, spanning from single processor PCs over PC-clusters and vector computers to high-end parallel machines. The standard Message Passing Interface (MPI) is used for parallelization and ms2 is therefore easily portable to different computing platforms. Feature tools facilitate the interaction with the code and the interpretation of input and output files. The accuracy and reliability of ms2 has been shown for a large variety of fluids in preceding work.

Program summary

Program title:ms2Catalogue identifier: AEJF_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJF_v1_0.htmlProgram obtainable from: CPC Program Library, Queen?s University, Belfast, N. IrelandLicensing provisions: Special Licence supplied by the authorsNo. of lines in distributed program, including test data, etc.: 82 794No. of bytes in distributed program, including test data, etc.: 793 705Distribution format: tar.gzProgramming language: Fortran90Computer: The simulation tool ms2 is usable on a wide variety of platforms, from single processor machines over PC-clusters and vector computers to vector-parallel architectures. (Tested with Fortran compilers: gfortran, Intel, PathScale, Portland Group and Sun Studio.)Operating system: Unix/Linux, WindowsHas the code been vectorized or parallelized?: Yes. Message Passing Interface (MPI) protocol Scalability. Excellent scalability up to 16 processors for molecular dynamics and >512 processors for Monte-Carlo simulations.RAM:ms2 runs on single processors with 512 MB RAM. The memory demand rises with increasing number of processors used per node and increasing number of molecules.Classification: 7.7, 7.9, 12External routines: Message Passing Interface (MPI)Nature of problem: Calculation of application oriented thermodynamic properties for rigid electro-neutral molecules: vapor–liquid equilibria, thermal and caloric data as well as transport properties of pure fluids and multi-component mixtures.Solution method: Molecular dynamics, Monte-Carlo, various classical ensembles, grand equilibrium method, Green–Kubo formalism.Restrictions: No. The system size is user-defined. Typical problems addressed by ms2 can be solved by simulating systems containing typically 2000 molecules or less.Unusual features: Feature tools are available for creating input files, analyzing simulation results and visualizing molecular trajectories.Additional comments: Sample makefiles for multiple operation platforms are provided. Documentation is provided with the installation package and is available at http://www.ms-2.de.Running time: The running time of ms2 depends on the problem set, the system size and the number of processes used in the simulation. Running four processes on a “Nehalem” processor, simulations calculating VLE data take between two and twelve hours, calculating transport properties between six and 24 hours.     

葫芦烙画的计算机系统仿真

为了获得葫芦烙画图像的计算机仿真效果,对Efros等人提出的以区块为基础的纹理传输算法进行改进,并对传输结果图像进行了有效的融合处理。该方法首先在YCbCr颜色空间中进行图像间亮度相似性匹配,通过纹理传输获得烙画图像,对传输结果图像根据Levin的最小二乘法原理,设计了一种基于动态权重控制的16点约束图像变形算法,实现了烙画图像的变形控制,然后在lαβ空间中实现了图像融合。最后将融合结果图像与泊松图像编辑方法的融合效果进行了对比分析。实验结果表明,该算法所获得的仿真结果图像接近真实葫芦烙画图像效果。