气液螺旋环状流界面波失稳机理

为揭示气液螺旋环状流界面波失稳机理,基于经典的Kelvin-Helmholtz不稳定性理论,利用双流体模型,建立螺旋涡流作用下界面波的动力学模型。通过求解界面波色散方程,给出界面失稳的准则并进行理论验证。研究表明,界面波的增长特性决定于气动力、离心力和表面张力的相互作用。其中,不同气液动压相对大小条件下,离心力对界面波稳定性存在三重影响。基于此准则条件,系统分析气流速度、旋流强度及管径对界面波增长特性的影响规律。     

横向气流中环状流射流液膜的破碎与雾化

针对环状流射流液膜在横流中破碎与雾化过程开展实验研究。研究发现,从宏观雾化形态看,环状流射流在横流中可以实现稳定的雾化;实验给出横流作用下环状流射流轨迹无量纲关联式。采用高速摄影技术对横流中环状流射流液膜破碎与雾化瞬态过程进行捕捉,发现环状流射流液膜雾化过程具有周期性和不连续性;不同环状流状态下液膜在横流中雾化机制有较大差异;增大射流表观气速能有效提升雾化效果。     

全自动染片机的改进

在分析目前医院在用染缸或全自动染片机的结构和程序的基础上，提出了一种新的染片机结构及原理的设想，改进了软件控制流程并进行了试验，基本上解决了染缸式全自动染片机的弊端，取得了较理想的结果。     

田径旋转投掷项目的力偶和动量偶分析研究

就田径旋转投掷项目(铁饼、链球)特殊的用力原理，就运动员在投掷过程中所涉及的有关力学原理进行尝试性的研究，提出了旋转过程中的动量偶和动量偶矩的概念，并探讨了动量偶的性质，结果显示：1.动量偶矩相等的两动量偶等效；2．旋转时动量偶对于任一点的矩就等于动量偶矩，而与矩心位置无关；3．只要动量偶矩保持不变，动量偶可在其所在平面内及彼此平行的平面内采计算物体整体转动的物理效果；而且只要动量偶矩保持不变，可将动量偶的动量和动量偶臂做相应的改变而不会改变其对物体整体旋转效应；4．等效的动量偶虽然不一定能较为圆满地描述旋转投掷具体的运动状态，但它却是唯一可以描述旋转运动状态中的转动部分的物理参数。     

Growth of a Void in a Rubber Rectangular Plate under uniaxial Extension

The finite deformation and stress analyses for a rectangular plate with a center void and center void and made of rubber with the Yeoh elastic strain energy function under uniaxial extension were studied in this paper.An approximation solution was botained from the minimum potential energy principle.The num,erical results for the growth of the cavitation and stresses along the edge of the cavitation were discussed.In addition,the stress concentration phenomenon was considered.     

高纯碳酸锶纳米粉体制备的新工艺研究

以八水氢氧化锶和二氧化碳为原料，开发了在超重力旋转床反应器中直接碳化合成高纯纳米碳酸锶新工艺，对反应物浓度、旋转速度和表面活性剂添加量等影响因素进行了研究，结果表明，控制适当的工艺条件，可得到平均粒径小于80mm、主含量大于99％，比表面积大于14m^2／g的产品。     

复杂边界厚矩形板在静水压力作用下的弯曲

应用功的互等法（RTM）求解基于Reissner理论厚矩形板的弯曲问题,给出了对边简支另两边固定边界条件下厚矩形板在静水压力作用下弯曲的封闭解析解,并给出了该种情况下的曲线图.     

3D analytical solution for a rotating transversely isotropic annular plate of functionally graded materials

The analytical solution for an annular plate rotating at a constant angular velocity is derived by means of direct displacement method from the elasticity equations for axisymmetric problems of functionally graded transversely isotropic media. The displacement components are assumed as a linear combination of certain explicit functions of the radial coordinate, with seven undetermined coefficients being functions of the axial coordinate z. Seven equations governing these z-dependent functions are derived and solved by a progressive integrating scheme. The present solution can be degenerated into the solution of a rotating isotropic functionally graded annular plate. The solution also can be degenerated into that for transversely isotropic or isotropic homogeneous materials. Finally, a special case is considered and the effect of the material gradient index on the elastic field is illustrated numerically.     

碳含量对500 MPa级特厚钢板组织性能的影响

分别采用常规碳和低碳的成分设计开发出了屈服强度500 MPa级的特厚调质钢板,对比分析了其组织和性能的差异,结果表明:采用常规成分设计时,调质处理后获得回火索氏体,具有高的强韧性匹配,因此更适合高强度、大厚度产品的生产;采用低碳贝氏体的成分设计时,经较低温度回火能获得较高的低温韧性,但力学性能的热稳定性较差,因此更适用于较低强度级别的特厚板或薄规格的高强板的生产。     

Influence of graphite particle size and its shape on performance of carbon composite bipolar plate

INTRODUCTION The proton exchange membrane fuel cell(PEMFC)is a very promising power source for resi-dential and mobile applications due to its attractive features such as high power density,relatively low operating temperature,convenient fuel supply,long lifetime,etc.(Chalk et al.,2000;Lee and Mukergee,1998).Despite these advantages,commercialization of PEMFC is delayed mainly due to the high fabrica-tion cost.Bipolar plates,most commonly used among the PEMFC components,are the gra…