锻造余热淬火工艺及应用

对普通调质淬火和锻造余热淬火工艺的各方面进行比较，论述了锻造余热淬火工艺强韧化机理，介绍了确定造余热淬火工艺参数的方法，并分析其优点和经济效益。     

Planar deformation of amorphous poly(ethylene terephthalate) by stretching and forging

The planar deformation of amorphous poly(ethylene terephthalate) (PET) was performed by stretching and by forging under comparable conditions at a series of constant temperatures, 80, 90, 100, and 110°C. The highest planar draw ratios of 4.5 × 4.5 and 3.5 × 3.5 were obtained by forging and stretching, respectively. Samples were studied before and after deformation by wide angle x-ray scattering (WAXS), differential scanning calorimetry (DSC), density measurements, and elastic recovery at 100°C. A distinct difference in efficiency of draw between these two techniques is found, as judged mainly by the straininduced crystallization. The forging is more effective than stretching in achieving stabilized planar draw under comparable process conditions.     

Entrance flow in eccentric annular ducts

A control-volume-based solution of the complete set of Navier-Stokes equations for the laminar, three-dimensional developing flow in straight, eccentric, cylindrical annular ducts is described. Numerical results for velocity and pressure development, pressure defect and entrance lengths are presented for a wide range of duct parameters, i.e. relative eccentricity ? and radius ratio γ. The present results match very well with earlier numerical solutions for the limiting cases of developing flow in concentric ducts and fully developed flow in eccentric ducts. Comparison with earlier approximate results for developing flow in eccentric ducts indicates that the approximate model predicts the velocity and pressure development with an error of about 10%. However, the development length predicted by the approximate model is grossly in error. The pressure defect and development length in eccentric ducts are very high compared with their counterparts in concentric ducts. The pressure defect, development length and maximum velocity increase with the radius ratio for eccentric ducts, while the reverse is true for concentric ducts. Also, the apparent friction factor decreases as the eccentricity increases.     

锻造等温淬火对半钢的冲击韧性的影响

研究了含1.7%C,1.85%Cr和1.78%Mn的半钢径1150℃-900℃锻造后，采用不同方式进行等温淬火处理，对半钢材料冲击韧性的影响。结果表明，锻造等温淬工艺可以改善半钢材料的冲击韧性，从而达到了提高半钢冲击韧性的目的。     

热锻过程中工模具温度场的有限元迭代解法

热锻过程中温度对成形过程的影响是显著的，了解热锻过程中工模具内温度场的分布对控制锻件的成形是有益的，工模具的热传导问题，由于热性能参数随温度变化和／或存在辐射换热，所以是一个非线笥瞬态问题，本文提出求解此问题的有限迭代解法，用此算法分析了热锻过程中的对模阶段的工模具温度变化，并给出了它们的温度场分布。     

在大径高比环形透平叶栅中叶片弯曲对二次流影响的实验研究

1实验装置与模型叶片倾斜和弯曲的概念是针对小径高比环形叶栅提出来的。在短叶片环形叶栅中采用弯曲叶片的效果如何，本文作者对此进行了研究。同时也讨论了边界条件对静叶出口流场的影响。本实验是在哈尔滨工业大学的环形叶栅风洞上进行的。实验用的三套叶栅为：（1）常规径向叶片；（2）两端倾斜角为15”的弯曲叶片；（3）两端倾斜角为22“的弯曲叶片。其特性参数为：径高比为10．553，弦长b—31．Zmm，叶型安装角风一45．3“，进气角。0—90”，几何平均出气角。1—15”。出口马赫数M＝0．26左右。（1）（）（3）均为等截面叶栅，（2）…     

快速可靠的红外光安全装置

本文研制设计了适合冲压机械的红外光安全装置,此装置具有动作速度快、矩形光幕、故障异或逻辑自检等优点。文中给出了电路参数的选取原则和详细电路,并对其工作原理进行了分析。样机的实验结果证实了本装置是实用的。     

Hopf bifurcation in annular liquid jets with mass transfer

A numerical study of Hopf bifuractions in annular liquid jets with mass transfer is presented. The study is based on the asymptotic equations which govern the dynamics of inviscid, incompressible, thin, annular liquid jets and on equilibrium conditions for mass transfer at the jet's inner and outer interfaces. It is shown that the amplitude of the time-periodic motion that results from the Hopf bifurcation increases whereas its frequency decreases as the solubility ratio is increased.     

有机环形光纤中二次谐波产生的研究

本文从经典电磁理论出发，分析了有机环形光纤中二次谐波产生（ＳＨＧ）的转换效率，着重讨论利用环形光纤中模式的色散特性实现相位匹配等问题。报道了采用ＬＢ膜方法，制成半花菁环形光纤，由高灵敏度光检测计测出在强泵光（１．０６μｍ，ＹＡＧ激光）作用下该光纤中的二次谐波产生的实验结果。     

环型孔成像系统在部份相干光照明下对两个点物之分辨

在部份相干光照明下的环型孔成像系统，对两个点物之分辨，按照Ｓｐａｒｒｏｗ判据作了分析和研究，将两点之分辨作为两个参数的函数进行讨论－其一为照明光的空间相干条件，其二为环型孔的中心阻挡，在与圆型孔和完全相干照明的情况比较之后指出，环型孔和部份相干照明情况具有更高的两个点物的分辨本领。