苯并三氮唑及其衍生物在菜籽油中的摩擦学性能研究

利用四球试验机考察了苯并三氮唑及其衍生物在菜籽油中的摩擦学性能,并用X射线光电子能谱和扫描电子显微镜分析观察磨斑表面的化学组成和形貌。结果表明,苯并三氮唑在菜籽油中有良好的抗磨作用,在其分子中引入长链烷基虽然提高了其在菜籽油中的溶解度,但却降低了其抗磨减摩性能,这主要是由于苯并三氮唑有效成分的减少以及添加剂和基础油之间的竞争吸附所致。     

Transparent electrodes fabricated via the self-assembly of silver nanowires using a bubble template

To shore up the demand of transparent electrodes for wide applications such as organic light emitting diodes and solar cells, transparent electrodes are required as an alternative for indium tin oxide electrodes. Herein the self-assembly method with a bubble template paves the way for cost-effective fabrication of transparent electrodes with high conductivity and transparency using self-assembly of silver nanowires (AgNWs) in a bubble template. AgNWs were first dispersed in water that was bubbled with a surfactant and a thickening agent. Furthermore, these AgNWs were assembled by lining along the bubble ridges. When the bubbles containing the AgNWs were sandwiched between two glass substrates, the bubble ridges including the AgNWs formed continuous polygonal structures. Mesh structures were formed on both glass substrates after air-drying. The mesh structures evolved into mesh transparent electrodes following heat-treatment. The AgNW mesh structure exhibited a low sheet resistance of 6.2 Ω/square with a transparency of 84% after heat treatment at 200 °C for 20 min. The performance is higher than that of transparent electrodes with random networks of AgNWs. Furthermore, the conductivity and transparency of the mesh transparent electrodes can be adjusted by changing the amount of the AgNW suspension and the space between the two glass substrates.     

Logic Bell state concentration with parity check measurement

Logic qubit plays an important role in current quantum communication. In this paper, we propose an efficient entanglement concentration protocol (ECP) for a new kind of logic Bell state, where the logic qubit is the concatenated Greenber–Horne–Zeilinger (C-GHZ) state. Our ECP relies on the nondemolition polarization parity check (PPC) gates constructed with cross-Kerr nonlinearity, and can distill one pair of maximally entangled logic Bell state from two same pairs of less-entangled logic Bell states. Benefit from the nondemolition PPC gates, the concentrated maximally entangled logic Bell state can be remained for further application. Moreover, our ECP can be repeated to further concentrate the less-entangled logic Bell state. By repeating the ECP, the total success probability can be effectively increased. Based on above features, this ECP may be useful in future long-distance quantum communication.     

A remark on free boundary problem of 1‐D compressible Navier–Stokes equations with density‐dependent viscosity

In this paper, we prove the existence and uniqueness of the weak solution of the one‐dimensional compressible Navier–Stokes equations with density‐dependent viscosity µ(ρ)=ρ^θ with θ∈(0, γ?2], γ>1. The initial data are a perturbation of a corresponding steady solution and continuously contact with vacuum on the free boundary. The obtained results apply for the one‐dimensional Siant–Venant model of shallow water and generalize ones in (Arch. Rational Mech. Anal. 2006; 182: 223–253). Copyright © 2009 John Wiley & Sons, Ltd.     

Global Weak Solutions to One-Dimensional Compressible Navier-Stokes Equations with Density-Dependent Viscosity Coefficients

We prove the global existence of weak solutions of the one-dimensional compressible Navier-stokes equations with density-dependent viscosity. In particular, we assume that the initial density belongs to L^1 and L^∞, module constant states at x = -∞ and x = ＋∞, which may be different. The initial vacuum is permitted in this paper and the results may apply to the one-dimensional Saint-Venant model for shallow water.     

Synthesis of a new aromatic diacid containing pyridine ring and related polybenzimidazole

<正>A new aromatic diacid monomer containing pyridine unit,4-phenyl-2,6-bis[4-(4-carboxyphenoxy) phenyl]pyridine 3,was successfully synthesized in three steps,starting from 4-hydroxyacetophenone.The corresponding pyridine-containing polybenzimidazole was prepared via polycondensation of 3 with tetraaminodiphenyl ether(TADE) in poly(phosphoric acid)(PPA).The resulting polybenzimidazole exhibits excellent solubility,good thermal stabilities and high thermal resistance.     

Preparation of polymer brushes on attapulgite surfaces via a combination of CROP and click reaction

<正>In this work,by a combination of controlled ring-opening polymerization(CROP) and click reaction,we reported a facile and useful method to synthesize linear poly(ε-caprolactone) at attapulgite nanocomposites with well-defined structures.For this,first, the chlorine terminated attapulgite was prepared by the self-assembly of 3-chloropropyltrimethoxysiIane from the surfaces of attapulgite.And then,the terminal chlorines of modified attapulgite were substituted with azido groups.As the second step,linear propargyl-terminated poly(ε-caprolactone)(PCLs) with different molecular weights were synthesized by the CROP ofε-CL monomer in toluene with Sn(Oct)_2 as a catalyst and propargyl alcohol as an initiator.Finally,the azido-terminated attapulgites were reacted with propargyl-terminated PCLs via the click reactions.     

Perturbation of systems of linear algebraic equations

A classical perturbation result for nonsingular systems of linear algebraic equations is extended to general consistent systems under any norm. An optimal perturbation result is also obtained for general linear least squares problems under a Euclidean norm.     

The arc length variational formula on the exponential manifold

In this paper, we mainly consider the first and second arc length variational problems on the exponential statistical manifold, and give the variational formulae.