M2钢离子氮化与离子镀TiN复合涂层的高温滑动磨损特性

研究了Ｍ２高速钢基体离子氮化和离子镀ＴｉＮ复合涂层在５００￣７００℃下的高温滑动磨损特性,利用ＸＲＤ分析了涂层的相结构,用划痕法测定了涂层的结合力,并用ＳＥＭ观察分析了涂层磨损表现形貌和磨损机离子氮化与离子镀ＴｉＮ复合涂层的结合力和硬度均高于ＴｉＮ涂层,其高温耐磨性优于ＴｉＮ涂层磨损随温度升高,各涂层的磨损率和摩擦系数均,离子氮化过渡层对ＴｉＮ涂层起到有力的支撑作用,涂层的主要磨损机制为粘着磨损、     

非线性振动方程周期解的存在性

构造了Ｐｏｉｎｃａｒｅ－Ｂｅｎｄｉｘｓｏｎ环域,证明了非线性振动方程ｘ＋ｆ（ｘ）ｘ＋ｇ（ｘ）＝０及ｘ＋（ｆ（ｘ）＋ｇ（ｘ）ｘ）ｘ＋ｈ（ｘ）＝０的极限环内的存在性,其中ｆ（ｘ）,ｇ（ｘ）,ｈ（ｘ）在（－∞,＋∞）上连续。     

APPLICATION OF THE MODIFIED METHOD OF MULTIPLE SCALES TO THE BENDING PROBLEMS FOR CIRCULAR THIN PLATE AT VERY LARGE DEFLECTION AND THE ASYMPTOTICS OF SOLUTIONS(Ⅱ)

This paper is a continuation of part (Ⅰ), on the asymptotics behaviors of the series solutions investigated in (Ⅰ). The remainder terms of the series solutions are estimated by the maximum norm.     

振荡边界层研究及其应用

综述了振荡边界展的研究现状,包括:层流边界层,转捩和湍流边界层的理论、数值和实验研究的最新进展．在自然界,最典型的例子是波浪、潮汐作用下的水底边界层．同时讨论了水底边界层的特点及其中物质输送的动力学过程,还给出了实际应用的例子．      

Some Asymptotic Behaviors on the K-S Function

ＴｈｅｃｏｎｃｅｐｔｏｆｔｈｅＫ－ＳｆｕｎｃｔｉｏｎｗａｓｔｈｅｆｉｒｓｔｔｉｍｅｐｒｅｓｅｎｔｅｄｂｙＧ．ＫｒｅｓｓｅｌｍｅｉｅｒａｎｄＲ．Ｓｔｅｉｎｈａｕｓｅｒｉｎ１９７９．ｗｈｅｎｔｈｅｙｓｔｕｄｉｅｄｎｏｎｓｍｏｏｔｈｏｐｔｉｍｉｚａｔｉｏｎｐｒｏｂｌｅｍｏｆｔｈｅｃｏｎｔｒｏｌｌｉｎｇｐａｒａｍｅｔｅｒｉｎｔｈｅｏｐｔｉｍａｌｄｅｓｉｇｎ［１］．Ｓｉｎｃｅｔｈｅｎｉｔｉｓｗｉｄｅｌｙａｐｐｌｉｅｄｔｏｔｈｅｓｔｒｕｃｔｕｒａｌｏｐｔｉｍｉｚａ－ｔｉｏｎｄｅｓｉｇｎｏｆｃｏｍｐｌｅｘｅｎ…     

Mixing process in estuaries

A theoretical expression for vertical profile of horizontal velocity in tenns of its depth-average is derived based on oscillatory boundary layer theory and estuarine flow characteristics. The derived theoretical profile is then incorporated into a vertical quasi-two-dimensional model, which is proved advantageous in more physical implications and less CPU time demand. To validate the proposed model, the calculated results are compared to the field data in the Yangtze River Estuary, exhibiting good agreement with observations. The proposed quasi-two-dimensional vertical model is used to study mixing process, especially dependence of salinity distribution and salt front strength on runoff and tides in estuaries. Project supported by the National Natural Science Foundation of China (Grant No. 59879025), the National Climbing Project of the Ministry of Science and Technology of China and the Director Foundation of Institute of Mechanics, Chinese Academy of Sciences.     

Rheology and Structure of Quenched Binary Mixtures Under Oscillatory Shear

We applied the D2Q9 BGK lattice Boltzmann method to study the rheology and structure of the phaseseparating binary fluids under oscillatory shear in the diffusive regime. The method is suitable for simulating systemswhose dynamicsis described by the Navier-Stokes equation and convection-diffusion equation. The shear oscillationinduces different rheological patterns from those under steady shear. With the increasing of the frequency of the shearthe system shows more isotropic behavior, while with the decreasing of the frequency we find more configurations similarto those under steady shear. By decreasing the frequency of the shear, the period of the applied flow becomes thesame order of the relaxation time of the shear velocity profile, which is inversely proportional to the viscosity, and moreanisotropic effects become observable. The structure factor and the velocity profile contribute to the understanding ofthe configurations and the kinetic process. Oscillatory shear induces nonlinear pattern of the horizontal velocity profile.Therefore, configurations are found where lamellar order close to the wall coexists with isotropic domains in the middleof the system. For very slow frequencies, the morphology of the domains is characterized by lamellar order everywherethat resembles what happens in the case of steady shear.     

肼及其衍生物在固体电极上的直接电化学行为研究

肼及其衍生物被广泛应用于医药,化工,军事,航天等领域,并被用作推进剂,水处理剂,农药,医药,燃料电池,光稳定剂以及化工生产助剂等诸多方面。因此对肼及其衍生物的研究和开发有着极其重要的理论意义和应用价值。本文研究了肼(Hydrzdine,DH),苯肼(Phenylhydrazine,PH),对硝基苯肼(p-Nitrophenykhzille,PNPH)和2,4-二硝基苯肼(2,4-DinitrophenyIhydrazine,DPH)在固体玻碳电极和铂电极上的不可逆电化学氧化行为,     

生漆与二异氰酸酯的反应及漆膜性能

本文用红外光谱（IR）、动态机械热分析（DMTA）、扫描电镜等仪器和物理、化学手段,研究生漆和2,4-甲苯二异氰酸酯（TDI）的反应特性、聚合成膜机理及漆膜性能等。结果表明,在漆酶和TDI共同作用下,生漆／TDI混合物的固化成膜速率比生漆快得多。当生漆与TDI混合后,生漆乳液的连续相中的漆酚迅速与TDI发生加成反应并生成聚氨酯化合物;在漆酶的催化作用下,该化合物的漆酚基上不饱和侧链双键进一步发生氧化聚合;所得的生漆／TDI涂膜具有优良的物理机械性能。