阶梯式

The results shows that the flow characteristics of SiC-AlN granulated powder is obviously promoted after spray drying and a suitable particles grade match. With the increasing of pressure, the density of green body increases by the style of ladder at the pressure range of 4080 MPa, 80160 MPa and 160220 MPa, the green body is uniform and densification without hard pelleted particles above 160 MPa. The pressureless sintering SiC-AlN multiphase ceramic possesses superior sintering properties and mechanical properties. It is due to the rampart formation of AlN to SiC grain growth and the reaction of SiC and AlN to form 2H solid solution. It results in the grain fining, crack expansion producing bypass and deflection, fracture section producing tearing-open and pulling-out effects, which cooperatively improves the strength and fracture toughness of the multiphase ceramics.

结果表明：喷雾造粒后，复合粉体的流动特性显著提高，粒度级配合理；随着压强增加，坯体密度在40~80、80~160和160~220 MPa范围内呈现阶梯式增长，160 MPa以上成形后素坯均匀致密，无硬球颗粒存在；无压烧结SiC-AlN复相陶瓷具有优越的烧结性能和力学性能，这是由于AlN对SiC晶粒形成生长势垒，并反应生成2H型固溶体，从而细化晶粒，导致裂纹扩展产生了绕道与偏转效应，呈现晶粒撕裂与拨出现象，协同改善了复相陶瓷的强度及断裂韧性。

The concept of equivalent rotationally rigidity is offered and the formula of rotationally rigidity is obtained.

主要做了如下几个方面的工作：对伸臂位于顶部的单层框架—筒体模型进行分析，提出了等效转动约束的概念和转动约束刚度的表达式。

Male cats normally do not need aftercare with the exception of the night after the anesthetic.

男猫通常不需要善后除了晚上的麻醉。