有机污染物臭氧氧化反应动力学研究

臭氧氧化是一种应用普遍的高效污水处理工艺。本文实验研究了硝基苯、苯胺、1,10-菲啰啉、邻氯苯酚、对二甲氨基苯甲醛、苯磺酸、对氨基苯磺酸、3-苯丙酸、亚甲基蓝、罗丹明B、间甲酚紫和苯酚等12种有机污染物化合物的臭氧氧化降解规律,探讨了有机物污染物臭氧（O₃）氧化降解的反应动力学特征。实验结果表明:在连续通入1 h24 mg·L^-1·min^-1的O₃之后,TOC去除率在碱性条件下明显优于酸性和中性条件,在酸性和中性条件下去除率介于10%～50%之间,而在碱性条件下,去除率基本介于35%～50%之间,初始反应过程符合一级动力学反应。12种有机物O₃氧化降解的平均动力学速率常数K_TOC在酸性、中性和碱性条件下分别为0.024±0.013、0.024±0.014和0.032±0.015,TOC降解速率在碱性条件下较酸性条件下和中性条件下提高了67%:在相同的pH条件下,不同物质的降解速率也有明显的差异,但是各种物质降解速率趋势变化不大,3个pH下,苯磺酸、3-苯丙酸和1,10-菲啰啉降解得最慢,总体降解趋势与pH和物质的本身结构呈现出很大的相关性。     

混凝土多步搅拌工艺自动控制的一种实现方法

本文简单介绍了混凝土多步搅拌工艺及自动控制．并介绍一种实现方法。     

聚合物线性降解计算机模拟及程序开发

分析了线性高分子的降解机理,确立了线性高分子降解的四种数学模型,采用Visual C 编制了模拟线性高分子降解的程序,并用该程序对聚二甲基硅氧烷的降解进行了模拟,得到了聚二甲基硅氧烷降解的分子量分布图,并对模拟结果进行了简要的分析。     

Coding coarse grained polymer model for LAMMPS and its application to polymer crystallization

We present a patch code for LAMMPS to implement a coarse grained (CG) model of poly(vinyl alcohol) (PVA). LAMMPS is a powerful molecular dynamics (MD) simulator developed at Sandia National Laboratories. Our patch code implements tabulated angular potential and Lennard-Jones-9-6 (LJ96) style interaction for PVA. Benefited from the excellent parallel efficiency of LAMMPS, our patch code is suitable for large-scale simulations.This CG-PVA code is used to study polymer crystallization, which is a long-standing unsolved problem in polymer physics. By using parallel computing, cooling and heating processes for long chains are simulated. The results show that chain-folded structures resembling the lamellae of polymer crystals are formed during the cooling process. The evolution of the static structure factor during the crystallization transition indicates that long-range density order appears before local crystalline packing. This is consistent with some experimental observations by small/wide angle X-ray scattering (SAXS/WAXS). During the heating process, it is found that the crystalline regions are still growing until they are fully melted, which can be confirmed by the evolution both of the static structure factor and average stem length formed by the chains. This two-stage behavior indicates that melting of polymer crystals is far from thermodynamic equilibrium. Our results concur with various experiments. It is the first time that such growth/reorganization behavior is clearly observed by MD simulations.Our code can be easily used to model other type of polymers by providing a file containing the tabulated angle potential data and a set of appropriate parameters.

Program summary

Program title: lammps-cgpvaCatalogue identifier: AEDE_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEDE_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: GNU's GPLNo. of lines in distributed program, including test data, etc.: 940 798No. of bytes in distributed program, including test data, etc.: 12 536 245Distribution format: tar.gzProgramming language: C++/MPIComputer: Tested on Intel-x86 and AMD64 architectures. Should run on any architecture providing a C++ compilerOperating system: Tested under Linux. Any other OS with C++ compiler and MPI library should sufficeHas the code been vectorized or parallelized?: YesRAM: Depends on system size and how many CPUs are usedClassification: 7.7External routines: LAMMPS (http://lammps.sandia.gov/), FFTW (http://www.fftw.org/)Nature of problem: Implementing special tabular angle potentials and Lennard-Jones-9-6 style interactions of a coarse grained polymer model for LAMMPS code.Solution method: Cubic spline interpolation of input tabulated angle potential data.Restrictions: The code is based on a former version of LAMMPS.Unusual features.: Any special angular potential can be used if it can be tabulated.Running time: Seconds to weeks, depending on system size, speed of CPU and how many CPUs are used. The test run provided with the package takes about 5 minutes on 4 AMD's opteron (2.6 GHz) CPUs.References:

[1]

D. Reith, H. Meyer, F. Müller-Plathe, Macromolecules 34 (2001) 2335-2345.

[2]

H. Meyer, F. Müller-Plathe, J. Chem. Phys. 115 (2001) 7807.

[3]

H. Meyer, F. Müller-Plathe, Macromolecules 35 (2002) 1241-1252.

     

线性离散随机系统输入和状态的多步估计方法及应用

具有未知输入的系统的状态估计问题已经在过去几十年里引起了相当的关注.本文对于线性离散随机系统提出了一种基于多步信息的输入和状态同步估计方法.首先,采用多步信息的最小方差方法来获得未知输入.由于引入了包含多个时间步骤的扩张状态和测量向量而计算多步信息,使估计结果与一步估计相比减少了对噪声的敏感性.其次,利用输入估计值和卡尔曼滤波估计过去和当前的状态.该方法在未知输入维数等于状态维数时仍然有良好的估计效果.数值仿真验证了提出的估计方法的有效性.最后,该方法应用于厌氧消化过程反应罐中的溶解甲烷和二氧化碳的浓度估计以验证方法的实用性.     

Thermodynamic modelling of vacancies as a constituent

The role of vacancies in thermodynamic models based on the compound energy formalism, CEF, is studied by application to a binary phase with two sublattices where the two components occupy one sublattice each. Vacancies were introduced in CEF by considering them as a chemical component. It is argued that this is not correct and their content is rather an internal variable. The variation in constitution is illustrated with a square-shaped diagram with corners representing the end-members. On two sides, the model degenerates to substitutional models of vacancies in either component. They meet in a corner representing only vacancies. For consistency, it may seem that all three models should represent the same physical state in that corner which is not true. The conflict was resolved by studying the molar Gibbs energy expressions of the models. The problem with multiple solutions is analyzed in terms of a critical state where the first, second and third derivative of the molar Gibbs energy vanish.     

An algorithm for Monte Carlo modeling of degradation of polymer networks

An algorithm for Monte Carlo simulation of polymer network degradation has been devised. The object was a random nearly regular molecular graph with almost all vertices of degree three. The vertices represented units of the polymer and edges were bonds or subchains of the network. The algorithm was particularly designed to study the effect of the substitution degree of units on the degradation process. The abrupt change of molecular parameters observed at a certain extent of degradation was referred to as the gel–sol transition. The position of the transition depended on the rate constants modeling the effect of units substitution.     

Optimization of a catalytic reactor subject to temperature constraints

The optimal design for maximum yield of SO₃ in the oxidation of SO₂ over a commercial vanadium pentoxide catalyst is considered. The control variables are the wall heat flux and the reactor radius, both as functions of axial distance. The volume and length of the reactor are both specified, as well as the maximum radial-average temperature. The problem is attacked by a partial averaging technique, whereby the full set of state partial differential equations are integrated forward, but a set of ordinary functional-differential adjoint equations are integrated on the backward pass in order to determine the new estimate of the optimal control. It is found that the optimal design consists of two approximately constant-radius adiabatic sections separated by a small intercooler, which is fairly close to existing commercial designs.     

Theoretical study on the degradation of ADP-ribose polymer catalyzed by poly(ADP-ribose) glycohydrolase

Poly(ADP-ribose) glycohydrolase (PARG) is the only enzyme responsible for the degradation of ADP-ribose polymers. Very recently, the first crystal structure of PARG was reported (Dea Slade, et al., Nature 477 (2011) 616), and a possible S_N1-type-like mechanism was proposed. In this work, we present a computational study on the hydrolysis of glycosidic ribose–ribose bond catalyzed by PARG using hybrid density functional theory (DFT) methods. Based on the crystal structure of PARG, three models of the active site were constructed. The calculation results suggest that the degradation of poly(ADP-ribose) follows an S_N2 mechanism, and the oxocarbenium expected by Dea Slade is a possible transition state but not an intermediate. The calculated reaction pathway agrees with the proposed mechanism. According to the computational models with different sizes, the roles of key residues are elucidated. Our results may provide useful information for the subsequent experimental and theoretical studies on the structure and functional relationships of PARG.     

Data-driven multi-step robust prediction of TBM attitude using a hybrid deep learning approach

A robust multi-step TBM attitude prediction approach named convolutional gated-recurrent-unit neural network (C-GRU) is proposed in this research and the random balance design Fourier amplitude sensitivity test method is used for sensitivity analysis to reveal the interaction between input and output of the C-GRU model. A tunnel construction project in Singapore is taken as an example to prove the robustness and effectiveness of the proposed approach. Results indicate that the length of the output sequence of the model can maintain high robustness and accuracy within 21 steps. In the 21-step prediction, the highest R² can reach 0.9652 while the mean R² is 0.9004 even though some attitude parameter is with large fluctuations. Each step in the 21-step prediction can maintain a stable accuracy. The data of the past 11 time steps of the TBM attitude parameters are the most sensitive. The proposed method has higher accuracy and robustness than state-of-art time-series based methods.     

Forecasting notebook computer price as a function of constituent features

This paper proposes a three-phase approach to forecast a competitive price for a notebook computer as a function of constituent features. Phase I uses regression analysis to relate computer price to constituent features in each of a series of time periods. Phase II involves a time series analysis of each regression coefficient to quantify how trends in market conditions (e.g., the evolution of component technology) affect the market value of each feature. Phase III uses the time series analysis to forecast future market values of each feature and combines these results to forecast a competitive selling price for a notebook model that is composed of a selected set of features. The approach can be used in support of management decisions related to prescribing when to upgrade a notebook model and what features to include in each upgrade. The approach can be used, for example, to forecast notebook model price at introduction, and the rate at which price will erode over the model’s life cycle. Computational results indicate that the approach can forecast the price of a notebook computer model up to four months in advance of its introduction to within 10%. It can also forecast the rate of price erosion to within 10% for up to seven months after introduction — the length of the life cycle of a typical notebook model. Since this approach uses only publicly available data, it can be used easily in industry.     

The application of ridge polynomial neural network to multi-step ahead financial time series prediction

Motivated by the slow learning properties of multilayer perceptrons (MLPs) which utilize computationally intensive training algorithms, such as the backpropagation learning algorithm, and can get trapped in local minima, this work deals with ridge polynomial neural networks (RPNN), which maintain fast learning properties and powerful mapping capabilities of single layer high order neural networks. The RPNN is constructed from a number of increasing orders of Pi–Sigma units, which are used to capture the underlying patterns in financial time series signals and to predict future trends in the financial market. In particular, this paper systematically investigates a method of pre-processing the financial signals in order to reduce the influence of their trends. The performance of the networks is benchmarked against the performance of MLPs, functional link neural networks (FLNN), and Pi–Sigma neural networks (PSNN). Simulation results clearly demonstrate that RPNNs generate higher profit returns with fast convergence on various noisy financial signals.     

Development of a novel emitting vinyl polymer and its application in organic electroluminescent devices

Abstract— A novel emitting vinyl polymer, poly[4‐(7‐{4‐[N,N‐bis(9,9‐dimethylfluoren‐2‐yl)amino]phenyl}‐2,1,3‐benzothiadiazol‐4‐yl)phenylethylene] (PVFABT), was designed and synthesized. The new vinyl polymer was found to form smooth amorphous films with a high glass‐transition temperature of 199°C. The polymer possesses bipolar character with both electron‐donating and accepting properties. It undergoes reversible anodic oxidation and cathodic reduction to give stable cation and anion radicals. It exhibits intense orange fluorescence in solution and as film. A multilayer organic electroluminescent device using PVFABT as an emitting material emitted orange light, exhibiting high performance.     

A spectral library for a semi-arid wetland and its application to studies of wetland degradation using hyperspectral and multispectral data

Semi-arid wetland areas in Central Spain are especially sensitive ecosystems and are considered to be one of the most important areas for the migration and wintering of waterfowl in Europe. Many of these wetland areas are saline or sub saline and are subjected to natural (seasonal) as well as human induced changes. Factors causing changes that significantly alter or modify the ecological function of these wetlands are considered to be degradation processes. The use of hyperspectral and multispectral data together with ground spectra and field studies has a great potential for monitoring wetland conditions. In this work spectral and analytical information concerning soil, vegetation and land use, contained in a site specific spectral library, is linked with the spectral characteristics of components from an anthropogenic influenced wetland area in La Mancha Alta. This information forms the basis for determining and selecting end members from hyperspectral data (DAIS 7915), which are then extrapolated to lower spatial and spectral resolution multispectral Landsat ETM+ and TM data. A spectral unmixing is carried out to obtain a multitemporal analysis for evaluating wetland degradation. Results show that the approach is successful in determining rapid surface change due to anthropogenic influences. Spectral unmixing results present an increase of salt-affected soil and a redistribution of saline pasture. This is further supported with a post classification change detection assessment and ground data confirm that principal causes are changes in wetland use together with water regulation of the Cigüela river.     

Study of a third grade non-Newtonian fluid flow between two parallel plates using the multi-step differential transform method

In this paper, the multi-step differential transform method (MDTM), one of the most effective method, is implemented to compute an approximate solution of the system of nonlinear differential equations governing the problem. It has been attempted to show the reliability and performance of the MDTM in comparison with the numerical method (fourth-order Runge–Kutta) and other analytical methods such as HPM, HAM and DTM in solving this problem. The first differential equation is the plane Couette flow equation which serves as a useful model for many interesting problems in engineering. The second one is the Fully-developed plane Poiseuille flow equation and finally the third one is the plane Couette–Poiseuille flow.     

A delay coupling method to reduce the dynamical degradation of digital chaotic maps and its application for image encryption

Multimedia Tools and Applications - In this study, a novel delayed coupled chaotic model to reduce the dynamical degradation of digital chaotic maps is firstly proposed. In this model, we introduce...     

3D Optical microstructure fabrication and its bonding to micro IR detector using elastomeric polymer

This paper describes polidimethylsiloxane(PDMS) based bonding for assembly of microstructure device, an UV lithography applications for fabricating a 3-dimensional (3D) feed-horn-shaped structure mold array, and obtaining parallel light by using a mirror-reflected parallel-beam illuminator (MRPBI) system. A 3D feed-horn-shaped micro-electro-mechanical systems (MEMS) antenna has some attractive features for array applications, which can be used to improve microbolometer performance and to enhance the optical efficiency for thin film transistor-liquid crystal display (TFT-LCD) and other display devices but currently, MEMS technology has faced many difficulties in the fabrication of a 3D feed-horn-shaped MEMS antenna array itself. The purpose of this paper is to propose a new fabrication method to realize a 3D feed-horn-shaped MEMS antenna array by using a mirror-reflected parallel-beam illuminator (MRPBI) System with a very slowly rotated, inclined x-y-z stage. With a conventional UV lithography apparatus, it is very difficult to fabricate high-aspect-ratio structures (HARS) because a typical UV lithography apparatus cannot produce perfectly parallel light. From a theoretical analysis, a columnar illuminator over 6 m in height is required to achieve parallel light, but generally a laboratory height is not 6 m. Also, a novel method of lithography was tried to make a 3D structure array by exposing a planar wafer to the generated parallel light and rotating an inclined x-y-z stage at an ultra-slow rate. An optimization of the 3D structure array can be achieved by simulating a 3D feed-horn MEMS antenna. The feasibility of fabricating both a 3D feed horn MEMS antenna and assembly of detector with 3D feed-horn MEMS antenna was demonstrated. As a result, it seems possible to use a 3D feed-horn-shaped MEMS antenna to improve microbolometer performance and to fabricate several optical microstructure applications.The authors wish to acknowledge that this paper is the result of research accomplished with the financial support of the Intelligent Microsystems Center, Seoul, Korea, which is carrying out one of the 21st centurys New Frontier R&D Projects sponsored by the Korea Ministry of Science & Technology.     

基于HYSYS的催化重整流程模拟及其应用

选取催化重整18集总31反应集总动力学模型,以流程模拟软件HYSYS为工具,建立了催化重整过程稳态模型。将模型参数估计问题转化为优化问题,在MATLAB中使用ActiveX技术调用HYSYS模型,利用Marquardt算法对模型进行参数估计,并利用工业数据对模型进行了验证。基于HYSYS稳态模型对催化重整过程进行了灵敏度分析,得出操作参数、进料性质和产品指标之间的关系,仿真结果与理论分析一致,从而能够对催化重整过程的监控和优化提供指导。     

A graph-theoretic method to identify candidate mechanisms for deriving the rate law of a catalytic reaction

Stoichiometrically, exact candidate pathways or mechanisms for deriving the rate law of a catalytic or complex reaction can be determined through the synthesis of networks of plausible elementary reactions constituting such pathways. A rigorous algorithmic method is proposed for executing this synthesis, which is exceedingly convoluted due to its combinatorial complexity. Such a method for synthesizing networks of reaction pathways follows the general framework of a highly exacting combinatorial method established by us for process-network synthesis. It is based on the unique graph-representation in terms of P-graphs, a set of axioms, and a group of combinatorial algorithms. In the method, the inclusion or exclusion of a step of each elementary reaction in the mechanism of concern hinges on the general combinatorial properties of feasible reaction networks. The decisions are facilitated by solving linear programming problems comprising a set of mass-balance constraints to determine the existence or absence of any feasible solution. The search is accelerated further by exploiting the inferences of preceding decisions, thereby eliminating redundancy. As a result, all feasible independent reaction networks, i.e. pathways, are generated only once; the pathways violating any first principle of either stoichiometry or thermodynamics are eliminated. The method is also capable of generating those combinations of independent pathways directly, which are not microscopically reversible. The efficiency and efficacy of the method are demonstrated with the identification of the feasible mechanisms of ammonia synthesis involving as many as 14 known elementary reactions.