Impurity in Pairwise Entanglement of Heisenberg XX Open Chain

We calculate the concurrence of all pairwise entanglement of Heisenberg XX open chain with single system impurity in three-qubit and four-qubit cases, and find that the impurity parameter J_i has great effect on pairwise entanglement. Choosing the proper parameter J_i, we can obtain the maximal pairwise entanglement of the nearest qubits and make the non-nearest qubits entangle.     

On the existence of a PBD(30,{4,5,7,8*})

In the present paper, we will prove by an exhaustive search method that a pairwise balanced design on 30 points with blocks of size 4,5,7 and exactly one block of size 8 does not exist. © 2004 Wiley Periodicals, Inc. J Combin Designs 12: 271–278, 2004.     

有序处理连续比较的置信区间

为有序均值的连续比较提出了一个新的检验过程.他们的过程对满足简单序的均值有重要的应用价值,例如在研究增长剂量对药物效用的影响. 与其它检验过程相比(例:Hayter\ucite{4}中的检验), 其优点在于产生了更短的连续比较的置信限,从而能够提供更多机会发现在何药剂量处有不同的效用.但作为有序均值的齐性检验, 它的势表现远劣于其它检验.本文的目的是提出一检验过程在尽量保持Lee andSpurrier\ucite{8}检验的优点的同时大大地提高其势表现.     

The enthalpies of dilution of pyridine and methylpyridine at 298.15 K

The enthalpies of dilution of aqueous solutions for pyridine and methylpyridine isomers have been determined with a 2277-Thermal Activity Monitor at 298.15 K. The results have been treated using the excess function concept and homotactic interaction coefficients have been obtained. The homotactic enthalpic pairwise interaction coefficients are discussed qualitatively in terms of substitution effects of methyl group introduced into the pyridine ring.     

肌醇在纯水和卤化钠水溶液中稀释过程的热力学性质

应用微量热法测定了298.15 K时肌醇在纯水和卤化钠水溶液中的稀释焓, 根据McMillan-Mayer理论, 计算了肌醇在溶液中的二到四阶焓相互作用系数. 结果表明, 肌醇在卤化钠溶液中的焓对相互作用系数h2均为负值, 并且随着卤素阴离子半径的增大, h2的绝对值呈增大趋势.     

Hydrotrope型两亲化合物的合成和自缔合研究

合成了一种hydrotrope型可聚合两亲化合物4-(2-(丙烯酰氧基)乙氧基)苯甲基三乙基溴化铵(AEBA),应用紫外吸收光谱和荧光探针技术研究了它的溶液性质和自缔合作用,实验结果表明,AEBA在水溶液中具有较高的自缔合能力、表面活性和增溶作用,它对油溶性染料荧光素二乙酸酯(fluorescein diacetate,FDA)的最小助溶浓度(minimum hydrotrope concentration,MHC)约为0.05 mol/L,AEBA分子间缔合形成不同于表面活性剂胶束结构的堆砌状(stack-type)聚集体结构。     

Dependence of enthalpic pairwise self-interactions on ionic strength: Some 2-deoxy and N-acetyl monosaccharides in aqueous NaCl solutions at T = 298.15 K

The dilution enthalpies of four derivatives of monosaccharides, namely 2-deoxy-d-glucose (2-DGlu), N-acetyl-d-glucosamine (GluNAc), 2-deoxy-d-galactose (2-DGal) and N-acetyl-d-galactosamine (GalNAc), in aqueous NaCl solutions of various molalities (b = 0–3.0 mol · kg⁻¹) have been determined respectively at T = 298.15 K by isothermal titration calorimetry (MicroCal ITC200). The corresponding values of enthalpic pairwise self-interaction coefficients (h₂) have been calculated according to the McMillan–Mayer theory. It was found that across the range studied of ionic strength (I) or molality (b = I), the h₂ coefficients are all positive, in the order h₂ (GluNAc) > h₂ (GalNAc) > h₂ (2-DGlu) > h₂ (2-DGal), and decrease gradually after increasing first up to a maximum at b ≈ 1.5 mol · kg⁻¹. The effects of ionic strength (I) on the trends of h₂ have been discussed from the point of view of complex (solute + solute) and (solute + solvent) interactions in solutions.     

Supramolecular Self-Associations of Amphiphilic Dendrons and Their Properties

This review presents precisely defined amphiphilic dendrons, their self-association properties, and their different uses. Dendrons, also named dendritic wedges, are composed of a core having two different types of functions, of which one type is used for growing or grafting branched arms, generally multiplied by 2 at each layer by using 1→2 branching motifs. A large diversity of structures has been already synthesized. In practically all cases, their synthesis is based on the synthesis of known dendrimers, such as poly(aryl ether), poly(amidoamine) (in particular PAMAM), poly(amide) (in particular poly(L-lysine)), 1→3 branching motifs (instead of 1→2), poly(alkyl ether) (poly(glycerol) and poly(ethylene glycol)), poly(ester), and those containing main group elements (poly(carbosilane) and poly(phosphorhydrazone)). In most cases, the hydrophilic functions are on the surface of the dendrons, whereas one or two hydrophobic tails are linked to the core. Depending on the structure of the dendrons, and on the experimental conditions used, the amphiphilic dendrons can self-associate at the air-water interface, or form micelles (eventually tubular, but most generally spherical), or form vesicles. These associated dendrons are suitable for the encapsulation of low-molecular or macromolecular bioactive entities to be delivered in cells. This review is organized depending on the nature of the internal structure of the amphiphilic dendrons (aryl ether, amidoamine, amide, quaternary carbon atom, alkyl ether, ester, main group element). The properties issued from their self-associations are described all along the review.     

Excess Molar Volumes of Binary Mixtures of 1-Heptanol or 1-Nonanol with n-Polyethers at 25°C

Excess molar volumes V ^E _m at 25°C and atmospheric pressure over the entirecomposition range for binary mixtures of 1-heptanol with 2,5-dioxahexane, 2,5,8-trioxanonane,5,8,11-trioxapentadecane, 2,5,8,11-tetraoxadodecane,or 2,5,8,11,14-pentaoxapentadecane, and mixtures of 1-nonanol with 2,5-dioxahexane,3,6-dioxaoctane, 2,5,8-trioxanonane, 3,6,9-trioxaundecane, 5,8,11-trioxapentadecane,2,5,8,11-tetraoxadodecane, or 2,5,8,11,14-pentaoxapentadecane are reportedfrom densities measured with a vibrating-tube densimeter.V ^E _m curves are nearlysymmetrical at about 0.5 mole fraction. Excess molar volumes are usually positive,indicating predominance of positive contributions to V ^E _m from the disruption ofH bonds of alcohols and from physical interactions. When chain lengths ofboth components of the mixture are increased, the contribution from interstitialaccommodation appears to be sufficiently negative, such that V ^E _m becomes negative(e.g., l-nonanol + 5,8,11-tetraoxapentadecane).     

Molecular Dynamics Study of Structural and Transport Properties of Silver Iodide Using Effective Charges

The superionic conductor, solid state, and body-centered cubic structure, silver iodide at room temperature, has been studied via molecular dynamics simulations. The calculated results using pairwise Coulomb-Buckingham potential, zero pressure on the sample, a semi-rigid model system of 1000 Ag and 1000 I ions, (NVE) as a statistical ensemble, and an effective charge of Z=0.63 for the pairs Ag-Ag and I-I, were found to be consistent with experimental data and one study using Z=0.60, different potential, and simulation software. For the pair Ag-I, there is a discrepancy due to the high silver ion diffusion. The calculated value of the diffusion constant of the silver ion is greater than iodide ion. The dynamic transport properties (mean square displacement, velocity autocorrelation function) results indicated typical behavior reported by other authors, using different potentials in their DM simulations for iodine and silver ions.