基团定位连接性指数对脂肪醇的QSPR研究

引入基团定位参数,修正脂肪醇分子中侧链碳原子和氧原子的点价值βi,据以建构醇分子的新连接性指数mL:mL=∑(βi·βj·βk…)0.5,其中0L=∑(βi)0.5,1L=∑(βi·βj)0.5. 0L、1L与醇的-1gSw、1gKow的相关系数分别为0.9949和0.9971,均优于前人的方法.本方法对醇分子具有良好的结构性选择,是预测脂肪醇溶解度和辛醇/水分配系数的理想方法.     

热惯量成像研究

一、热惯量对经典的热传导方程给予一个简单的温度周期函数为边值条件,求解方程,可以得到一个简单的公式: Q=-2/ω~(1/2)T_0P (1)式中Q为热能,T_0为温度变化的振幅,ω为周日角频率,P是物体固有的常量,其表达式为: P=Kρc~(1/2) (2)其中K为热导率(焦耳/米·秒·开尔温),ρ为密度(千克/米~3),c为比热容(焦耳/(千克·开尔温)。从式(1)可见,当物体吸收或损失的热能相同时,物体温度变化的振幅T_0与物体固有的     

锂的电化学传感器的研制

用合成的新材料1,1,1—三[1′-(2′-氧杂-4′-氧代-5′-氮杂-5′-辛基)十三烷基]丙烷为中性载体,磷酸三[2-乙基己基]酯(TEHP)为增塑剂,制成了三种锂的电化学传感器:PVC 膜电极、涂碳电极和锂离子敏感场效应晶体管(Li ISFET),比较了它们的性能。PVC 膜电极的线性响应范围是5×10~(-5)～1mol·dm~(-3)(LiCl),涂碳电极和 Li ISFET 的线性响应范围分别为10~(-4)～1mol·dm~(-3)和10~(-3)～1mol·dm~(-3)。三种锂的电化学传感器中,PVC 膜电极的选择性较好,K_(Li,Na)~(Pot)为4×10~(-2),K_(Li,K)~(Pot)为8×10~(-3),Li ISFET 的选择性较差,K_(Li,N?)~(Pot)为9·6×10~(-2),K_(Li,K)~(Pot)为1.6×10~(-2)。     

中立型泛微分方程的一类混合方法

其中α<α,g(t)∈C_n~0(I_t)为已知的初值函数,f:I×C_n~0(I)×C_n~1(I)→R~n,满足下列条件: H_1:对于固定的X∈C_n~1(I),映射t→f(t,x(·),t’(·))在I上连续。 H_2:算子f满足Lipschitz条件 ||f(t,x_1(·),y_1(·))-f(t,x_2(·),y_2(·))||≤L_1||x_1-x_2||~[α,t]+L_2||y_1-y_2||~[α,t-δ],其中L_1,L_2≥0为常数,δ>0,t∈I,x_1,x_2∈C_n~0(I),y_1,y_2∈C_n~1(I)。     

直链聚合物的结构性质关系的人工神经网络建模

应用人工神经网络构造了2个直链聚合物的结构性质关系模型。一个是直链聚合物的基团均值法描述的结构参数与其12种性质间定量关系的模型(模型1A);一个是直链聚合物的连接性指数描述的结构参数与其12种性质间定量关系的模型(模型2A)。讨论了2个模型的参数设置,而2个模型绘出的聚合物的12种性质的拟合误差(拟合值与实验值间的标准偏差)分别是:V(298K)为18.9(模型1A)/40.5(模型2A)cc/mole,E_(coh)为8.019/11.122 KJ/mole,δ为0.74/2.17(J/cc)~(0.5) ,F_d为228/235 J~(0.5)cm~(1.5)/mole,T_g为27/52 K,P_s为25/37(cc/mole)(dyn/cm)~(1/4),n为0.0140/0.5191,ζ为7.45/5.36 10~(-6)cc/mole,U_R为727/593 cm~(10/3)/(sec~(1/3)mole),U_H为568/674 cm~(10/3)/(sec~(1/3)mole),H_(μsum)为649/719 gJ~(1/3)/mole~(4/3),Y_(d,1/2)为10.6/10.5 K*kg/mole。结果表明,所建立的模型可用于直链聚合物性质的预测,而人工神经网络确实是聚合物结构性质关系研究中的一个有利的数学工具。     

脂肪醛酮的沸点及色谱保留指数定量构效关系的研究

应用密度泛函理论(DFT),在6-31+G(d)水平上对脂肪醛酮的分子结构几何优化和量化计算.将量子化学计算的部分结果引入分子的拓扑结构中,构建新型分子量子拓扑指数(NQT),然后研究脂肪醛酮的沸点量子拓扑化学的变化规律,同时将Nqr与Gibbs自由能(G),恒容摩尔热容(Cv),配分函数(1gQ)结合起来建立脂肪醛酮色谱保留指数的定量模型.其沸点模型相关系数R>0.99,色谱保留指数模型相关系数R>0.98,并用随机抽样法、留一法(LOO)验证,证明所建模型稳健、合理、有效.本文将量子化学方法与拓扑学方法结合起来,使拓扑方法中某些经验数值上升为理论数值,从而推动拓扑化学的进步.该方法有望在物质的QSPR/QSAR研究中推广.     

碱金属卤化物晶格能的QSPR研究

采用密度泛函理论(DFT)的B3LYP法,对碱金属卤化物从头算.选取11个与晶格能相关的量化参数作为自变量,逐步回归分析碱金属卤化物的晶格能,建立的QSPR方程的相关系数R为0.999,剩余标准偏差s为4.731,F检验值为1927.597;留一法交叉验证结果为R=0.998,s=6.946,表明该模型预测可靠性高.讨论逐步回归引入QSPR方程中的4个量化参数表明,这4个变量物理意义明确,是影响碱金属卤化物晶格能的主要量化参数.此外,本文还以计算出来的量化参数作为自变量,用逐步回归分析方法分别以F心能带E(F)、标准熵S°m作为因变量构建QSPR方程,也均获得令人满意的结果.     

单片机在高精度光信号测量中的应用

<正> 一、引言许多光测仪器,如分光光度计,红外可见吸收光谱仪,散射光谱仪等,在测量过程中,光源强度对测量结果有很大影响。被测信号(如吸收、散射、发射等)的输出,可以用下式表征: Uout=K·X·I_0+U_0 式中K为光接收器和放大器总的增益。U_0为放大器零点漂移输出值。X为待测信息,它与被测物质的性质,光波长等因素有关。I_0为光源强度值。从上式可以看出,若得到理想的测量结果,必须使用理想的光源(I_0≡C为常数),且使放大器的增益稳定(K≡C为常数),无温漂(U_0≡0)。于是上式可     

单重态磷烯脱氢反应的热力学和动力学性质计算的研究

由于单重态磷烯价电子结构的特别,为了深入研究其反应的特性,本文报道利用计算程序研究单重态磷烯与极性分子硫化氢的脱氢反应在100～1 100 K温度范围和不同大气压条件下的热力学和动力学性质。结果表明反应在高温条件,同时具有热力学(K=6 747．55,1 atm,1 100 K)与动力学优势(k=0．29×10~7s~(-1),1 atm,1 100K),而在温度相同、低压条件下,则更具热力学优势(K=6747．55,1 atm,1 100 K;K=1 349．50,5 atm,1 100 K)。     

基于变差函数纹理和BP人工神经网络的QuickBird影像分类研究

通过对QuickBird影像的主成分分析,发现第一主成分信息量为67.09%,第二主成分信息量为31.73%,合计98.81%,因此选了第一、第二主成分进行纹理提取。纹理提取时采用绝对变差函数纹理,窗口大小为3×3,步长为1。地物类型分为4类即建筑物、水体、植被和裸地。BP人工神经网络的拓扑结构为4-4-1,隐层传递函数为S函数(logsig),输出层传递函数为线性(purelin),训练函数为Trainscg;应用该神经网络结构分别对QuickBird影像的多光谱影像和一二主成分及一二主成分纹理影像进行了分类,分别算出了前者的P=84.54%,Kappa系数K=78.50%;后者的P=89.46%,Kappa系数K=85.29%,同时发现加入纹理后分类结果显著提高。     

Controllability of quantum walks on graphs

In this paper, we consider discrete time quantum walks on graphs with coin, focusing on the decentralized model, where the coin operation is allowed to change with the vertex of the graph. When the coin operations can be modified at every time step, these systems can be looked at as control systems and techniques of geometric control theory can be applied. In particular, the set of states that one can achieve can be described by studying controllability. Extending previous results, we give a characterization of the set of reachable states in terms of an appropriate Lie algebra. Controllability is verified when any unitary operation between two states can be implemented as a result of the evolution of the quantum walk. We prove general results and criteria relating controllability to the combinatorial and topological properties of the walk. In particular, controllability is verified if and only if the underlying graph is not a bipartite graph and therefore it depends only on the graph and not on the particular quantum walk defined on it. We also provide explicit algorithms for control and quantify the number of steps needed for an arbitrary state transfer. The results of the paper are of interest in quantum information theory where quantum walks are used and analyzed in the development of quantum algorithms.     

New fusion operations for digitized binary images and their applications

This paper proposes a new class of fusion operations which are useful for binary image processing. To begin with, an algorithm for the classical fusion operations is presented. They are sequentially composed of two basic operations, that is, expansion and contraction. The strategy of the proposed algorithm is as follows: the first operation is performed with the distance transformation, and the second operation utilizes the distance information obtained in the first operation. Next, a topological contraction and a topological expansion are defined. The topological contraction preserves the Euler number of an input image except that some simply connected components of 1 pixels are erased. The topological expansion preserves the Euler number of an input image except that some simply connected holes are filled. Then, several new fusion operations are obtained by combining the classical contraction and the topological expansion (or, the classical expansion and the topological contraction) sequentially. The algorithms for them use the same strategy as the proposed algorithm for the classical fusion operations. Finally, experimental results show that the new fusion operations and their combinations are effectively used in the binary image processing, such as shape smoothing, merging and separating connected components, and structure analysis.     

Topological phenomena in quantum walks: elementary introduction to the physics of topological phases

Discrete quantum walks are dynamical protocols for controlling a single quantum particle. Despite of its simplicity, quantum walks display rich topological phenomena and provide one of the simplest systems to study and understand topological phases. In this article, we review the physics of discrete quantum walks in one and two dimensions in light of topological phenomena and provide elementary explanations of topological phases and their physical consequence, namely the existence of boundary states. We demonstrate that quantum walks are versatile systems that simulate many topological phases whose classifications are known for static Hamiltonians. Furthermore, topological phenomena appearing in quantum walks go beyond what has been known in static systems; there are phenomena unique to quantum walks, being an example of periodically driven systems, that do not exist in static systems. Thus the quantum walks not only provide a powerful tool as a quantum simulator for static topological phases but also give unique opportunity to study topological phenomena in driven systems.     

Photoalignment dynamics of azo dyes series with different coordination metals

There are many photoaligned azo dyes that can be used for orientation of liquid crystals in various display devices. However, the structure of these compounds needs to be optimized to increase the rate of the process of molecule photoalignment, as well as to spread the application of these compounds. The main coordination metal that presents in the molecules of azo dyes is sodium derivatives. The use of other alkali metals remains an open question. We used quantum‐chemical computation methods and reversible intermolecular bonding model to determine the effect of metal coordination on the velocity of photoalignment. The theoretical predictions were experimentally verified using sodium, potassium, lithium, and cesium salts of the model azo dye synthesized by us. We conclude that potassium azo derivatives are the fastest, ceteris paribus.     

并行量子进化算法的研究与实现

分析讨论并行进化模型理论及性能,提出了基于学习的多宇宙并行免疫量子进化算法,算法中将种群分成若干个独立的子群体,称为宇宙.并给出了多宇宙的并行拓扑结构,提出了宇宙内采用免疫量子进化算法,宇宙之间采用基于学习的移民和模拟量子纠缠的交互策略进行信息交换.这样能提高种群多样性,有效克服早熟收敛现象.算法综合了量子计算的天然并行性和免疫算法的充分自适应性,它比传统的进化算法具有更好的种群多样性,更快的收敛速度.通过并行实验验证了该算法的优越性.     

Quantum correlation and quantum phase transition in the one-dimensional extended Ising model

Quantum phase transitions can be understood in terms of Landau’s symmetry-breaking theory. Following the discovery of the quantum Hall effect, a new kind of quantum phase can be classified according to topological rather than local order parameters. Both phases coexist for a class of exactly solvable quantum Ising models, for which the ground state energy density corresponds to a loop in a two-dimensional auxiliary space. Motivated by this we study quantum correlations, measured by entanglement and quantum discord, and critical behavior seen in the one-dimensional extended Ising model with short-range interaction. We show that the quantum discord exhibits distinctive behaviors when the system experiences different topological quantum phases denoted by different topological numbers. Quantum discords capability to detect a topological quantum phase transition is more reliable than that of entanglement at both zero and finite temperatures. In addition, by analyzing the divergent behaviors of quantum discord at the critical points, we find that the quantum phase transitions driven by different parameters of the model can also display distinctive critical behaviors, which provides a scheme to detect the topological quantum phase transition in practice.     

Defining and Comparing Content Measures of Topological Relations

This work defines and compares three quantitative content measures of topological relations between spatial objects that consider metric refinements with respect to relative size, distance, and degree of overlapping. These content measures use minimum bounding rectangles (MBRs) as simplified views of spatial objects in order to create an efficient mechanism for characterizing the topological content of spatial configurations. A framework for comparing content measures is presented, which is based on the linear correlation between two similarity rankings: (1) a similarity ranking defined in terms of the distance of content-measure values and (2) a similarity ranking defined in terms of the error of the geometric adjustment between pairs of objects. The linear correlation between similarity rankings is used as indicator of how well the defined content measures characterize topological relations. Such kind of content measures can provide mechanisms for creating efficient methods to describe and access information on the basis of the topological content of spatial configurations.     

Controlled-topology filtering

Many applications require the extraction of isolines and isosurfaces from scalar functions defined on regular grids. These scalar functions may have many different origins: from MRI and CT scan data to terrain data or results of a simulation. As a result of noise and other artifacts, curves and surfaces obtained by standard extraction algorithms often suffer from topological irregularities and geometric noise.While it is possible to remove topological and geometric noise as a post-processing step, in the case when a large number of isolines are of interest there is a considerable advantage in filtering the scalar function directly. While most smoothing filters result in gradual simplification of the topological structure of contours, new topological features typically emerge and disappear during the smoothing process.In this paper, we describe an algorithm for filtering functions defined on regular 2D grids with controlled topology changes, which ensures that the topological structure of the set of contour lines of the function is progressively simplified.     

On Existence and Uniqueness Verification for Non-Smooth Functions

Given an approximate solution to a nonlinear system of equations at which the Jacobi matrix is nonsingular, and given that the Jacobi matrix is continuous in a region about this approximate solution, a small box can be constructed about the approximate solution in which interval Newton methods can verify existence and uniqueness of an actual solution. Recently, we have shown how to verify existence and uniqueness, up to multiplicity, for solutions at which the Jacobi matrix is singular. We do this by efficient computation of the topological index over a small box containing the approximate solution. Since the topological index is defined and computable when the Jacobi matrix is not even defined at the solution, one may speculate that efficient algorithms can be devised for verification in this case, too. In this note, however, we discuss, through examples, key techniques underlying our simplification of the calculations that cannot necessarily be used when the function is non-smooth. We also present those parts of the theory that are valid in the non-smooth case, and suggest when degree computations involving non-smooth functions may be practical.As a bonus, the examples lead to additional understanding of previously published work on verification involving the topological degree.     

Shape description by medial surface construction

The medial surface is a skeletal abstraction of a solid that provides useful shape information, which compliments existing model representation schemes. The medial surface and its associated topological entities are defined, and an algorithm for computing the medial surface of a large class of B-rep solids is then presented. The algorithm is based on the domain Delaunay triangulation of a relatively sparse distribution of points, which are generated on the boundary of the object. This strategy is adaptive in that the boundary point set is refined to guarantee a correct topological representation of the medial surface