Stability of Rarefaction Waves to the 1D Compressible Navier–Stokes Equations with Density-Dependent Viscosity

In this paper, we study the asymptotic stability of rarefaction waves for the compressible isentropic Navier–Stokes equations with density-dependent viscosity. First, a weak solution around a rarefaction wave to the Cauchy problem is constructed by approximating the system and regularizing the initial values which may contain vacuum states. Then some global in time estimates on the weak solution are obtained. Based on these uniform estimates, the vacuum states are shown to vanish in finite time and the weak solution we constructed becomes a unique strong one. Consequently, the stability of the rarefaction wave is proved in a weak sense. The theory holds for large-amplitudes rarefaction waves and arbitrary initial perturbations.     

Global well‐posedness of the compressible Euler with damping in Besov spaces

In this paper, we consider the Cauchy problems for compressible Euler equations with damping. In terms of the Littlewood–Paley decomposition and Bony's para‐product formula, we prove the global existence, uniqueness and asymptotic behavior of the solution in the critical Besov space comparing with previous results. Copyright © 2012 John Wiley & Sons, Ltd.     

Local Well-posedness and Blow Up Criterion for the Inviscid Boussinesq System in Hölder Spaces

We prove the local in time existence and a blow up criterion of solution in the Hölder spaces for the inviscid Boussinesq system in R^N, N≥ 2, under the assumptions that the initial values θ_0, μ_0∈C^r, with 1< r≠ 2.     

CFD modeling using heterogeneous reaction kinetics for catalytic dehydrogenation syngas reactions in a fixed-bed reactor

A comprehensive 2D computational fluid dynamics （CFD） model was developed to simulate the flow behavior and catalytic dehydrogenation reaction of syngas in a heterogenous fixed-bed reactor （FBR）. The model combined the porous medium CFD model with a reaction kinetics model. To acquire an accu- rate reaction kinetics model, a comprehensive reaction mechanism was studied for the heterogeneous catalytic dehydrogenation reaction ofsyngas over a supported metal catalyst. Based on the reaction mech- anism and a statistical test, a reliable kinetics model was proposed. The CFD model combined with the above kinetics model was validated with one set of experimental data. The CFD model was also used to predict key reaction variable distributions such as the temperature and the component concentrations in the reactor.     

毕赤酵母表达的HIV-2外膜糖蛋白的纯化与活性测定

人免疫缺陷病毒(Human immunodeficiency virus,HIV)是艾滋病（AIDS）的病原体,其外膜蛋白是HIV侵入人体靶细胞的物质基础,对其结构与功能的深入研究不但能为彻底揭示HIV致病机理奠定基础,而且有助于抗感染免疫研究和治疗物的设计^[1,2],HIV－2ROD外膜蛋白gp105是一种高度糖基化的糖蛋白,近年来发展迅速的毕赤酵母（Pichia Pastoris）真核表达系统对分泌蛋白的糖基化修饰形式与天然的gp105相同^[3]。为实现大量制备有活性的gp105,我们用PCR法去除了gp105基因5′端28个密码子的非功能片段,以提高gp105的表达水平,并成功地在毕赤酵母中实现了gp105的高效分泌表达。本文对这一表面产物的纯化、性质及活性进行了研究,为尽快研制出有效的疫苗奠定基础。     

负载型纳米TiO2光催化降解活性艳红X-3B染料

光催化氧化;负载型纳米光催化剂;负载型纳米TiO2光催化降解活性艳红X-3B染料     

DMF溶液中导电玻璃上沉积类金刚石薄膜

液相法制备类金刚石膜设备简单,操作容易,能大面积成膜,越来越受到研究者们的关注．Ｎａｍｂａ［１］以乙醇为介质,在１２００Ｖ电压７０℃以下沉积膜,得到了类金刚石膜;Ｓｕｚｕｋｉ等［２］以水乙二醇溶液为介质制膜,只得到了石墨相的碳膜;以乙醇的水溶液为介质利用电解热沉积膜,得到了玻璃碳和石墨碳,同时阴极钨发生碳化有ＷＣ和Ｗ２Ｃ生成［３］;Ｎｏｖｉｋｏｖ等［４］在乙炔的液氨溶液中沉积膜,Ｒａｍａｎ谱表明他们得到了类金刚石（ＤＬＣ）膜;Ｋｗｉａｔｅｋ等［５］重复了Ｎａｍｂａ的实验,证明沉积膜主要为非晶态…     

Adiabatic population transfer in effective three-level systems driven by laser beams

The population transfer in effective three-state systems driven by laser beams has been studied based on the theory of Lewis－Riesenfeld Hermitian invariants in the full- and partial-adiabatic approximations. A strict formulation of adiabatic conditions is given, and a new adiabatic condition for inducing a complete population transfer is found.     

基于Mindlin解的盾构隧道地表沉降黏弹性分析

基于Mindlin解,采用三参数固体黏弹性模型,给出了盾构隧道黏弹性沉降的计算方法,通过退化验证,证明了所得出的黏弹性沉降计算方法的正确性。结合工程实例进行计算分析,分别得出了黏性系数、距开挖面距离以及开挖深度对刀盘正面摩擦、刀盘侧面摩擦、正面附加推力、盾壳与周围土体之间的摩擦力引起的地表变形的影响。计算表明:沉降稳定所需时间随黏性系数增大而延长,随开挖深度的不同而不同;不同的黏性系数,最终沉降值无明显差异;盾壳摩擦导致的沉降随距开挖面距离的增加而减小。     

The 3D incompressible magnetohydrodynamic equations with fractional partial dissipation

The magnetohydrodynamic (MHD) equations have played pivotal roles in the study of many phenomena in geophysics, astrophysics, cosmology and engineering. The fundamental problem of whether or not classical solutions of the 3D MHD equations can develop finite-time singularities remains an outstanding open problem. Mathematically this problem is supercritical in the sense that the 3D MHD equations do not have enough dissipation. If we replace the standard velocity dissipation Δu and the magnetic diffusion Δb by $?{(?\mathrm{\Delta })}^{\alpha }u$ and $?{(?\mathrm{\Delta })}^{\beta }b$, respectively, the resulting equations with $\alpha \ge \frac{5}{4}$ and $\alpha +\beta \ge \frac{5}{2}$ then always have global classical solutions. An immediate issue is whether or not the hyperdissipation can be further reduced. This paper shows that the global regularity still holds even if there is only directional velocity dissipation and horizontal magnetic diffusion $?{(?{\mathrm{\Delta }}_h)}^{\frac{5}{4}}b$, where ${\mathrm{\Delta }}_h={?}_1^2+{?}_2^2$.