AN INDIRECT METHOD FOR DETERMINATION OF PARAMETERS IN THE FORECAST MODEL

An indirect method for determining some parameters in a forecast model has been developed, by which the program of the original model with little modification can be used as a subroutine of the inversion system and the optimum estimate of the parameters can be obtained by calling the subroutine time after time. It is specially useful for the sophisticated numerical weather prediction model. It may also be utilized to improve the forecast timely in case of obvious differences between the recent observations and the forecasts. The effect of the method is verified by numerical simulation tests with simple models.     

THE APPLICATION OF EMPIRICAL ORTHOGONAL FUNCTIONS TO NUMERICAL SIMULATION OF CLIMATE

According to the nonlinear basic theory that a forced dissipative nonlinear system in a higher dimensional state space can be evolved into an attractor set of the descending dimension, a new method of reducing the degrees of freedom of the general circulation model (GCM) is given. The concrete way of it is: the time-dependent integral series of the model is decomposed through empirical orthogonal functions (EOFs), therefore the small number of the degrees of freedom supporting the attractor set of GCM can be formed, and then a simplified model can be derived when the EOFs are used as basis. The numerical simulation experiment has been done by using a theoretical model, and we are sure that the feasibility and effectiveness of the method can be proved.     

铁硅合金中立方织构的形成

铁硅合金(含硅3.25％)的样品,经过不同的冷轧和中间退火程序,在最后高温退火时,可以通过二次再结晶,或者一次再结晶形成集中的立方织构。通过二次再结晶形成立方织构时,并不包括重新形核的过程。(100)[001]取向的二次再结晶“晶核”,在一次再结晶完成后,就已经存在。通过一次再结晶形成的立方织构,由于样品在冷轧后,得到了较强的加工立方织构,退火时通过同位再结晶,就得到了再结晶立方织构。     

二元金属须的强度和形变特点

测量了直径20—300微米的大量的Fe鬚、Fe-Cu鬚、Fe-Co鬚、Cu鬚和Cu-Co鬚的室温和高温拉断强度,结果指出,弥散型的二元金属鬚如Fe-Cu鬚和Cu-Co鬚的强度较高于单元金属鬚,而固溶型的二元金属鬚如Fe-Co鬚则否。根据应力应变曲线的测量和金相观测的结果,认为弥散型的Fe-Cu鬚的强度所以较高,可能是由于高强度的铁铜弥散混合层的出现,而它的范性所以较好,可能是由于这种鬚具有范性较好的铜心轴。讨论了弥散型和固溶型二元金属鬚在变粗当中所包含的基本过程,以及与它们所表现的强度和形变特点的联系。并且指出,生长弥散型混合鬚的原理和方法给制备强度较高和范性较好的复合材料提供了一个值得参考的途径。 关键词：     

π介子核子碰撞产生π介子的色散关系

本文讨论了π介子核子碰撞产生π介子的色散关系,计算了束缚态的贡献。所用的方法是把核子场的算符由态矢量中提出来,对运动学和对称性作了较详细的分。     

冷轧铜板再结晶織构的形成

电解纯铜经88.7％冷轧后,所形成的轧制织构除稳定的(110)[112]舆(112)[111]外,还存在着一种(3,6,11)[533]织构。在较低温度下退火时,再结晶织构主要为(100)[001]、(358)[352]和舆(100)[001]成孪生取向的(122)[212]织构。随着退火温度的增加,(358)[352]织构逐渐减弱,立方织构(100)[001]则逐渐加强;当退火温度达到900℃时,开成了集中的(100)[001]织构。冷轧铜板在退火的过程中,具有(100)[001]再结晶晶粒首先形成,然后普遍地发生同位再结晶。其中具有(100)[001]取向的晶粒,继续发生选择性的生长,最后形成了集中的立方织构。本支中对轧制织构舆其再结晶织构取向间的关系也进行了分析,再结晶织构一般可认为是原有织构沿某一个[111]轴旋转45°,22°或38°的结果。同时,根据上述几何关系所绘出的理想极图舆实际测定的结果也是符合的。试验结果指出,不同加热速度和不同加热程序对形成最终的再结晶织构,不发生显著的影响,而退火温度对再结晶织构的形成起着主要的作用。     

双力程核子力的讨论

The binding energies of nuclei H³. He³, He⁴, the low energy n-p scattering length and effective range are calculated by using the standard variational methods. A two-range central Yukawa potential is considered in the first two sections. The longer range corresponds to the π meson mass. The smaller range corresponds either to the heavier meson or to the higher order field interactions. No repulsive core appears, when the force parameters are chosen to fit the low energy scattering and deuteron data. The calculated binding energies of nuclei H³, He³ and He⁴ are too high. This result is in agreement with most of the previous calculations. Tensor force of the Schwinger mixed type is considered in the third and fourth sections. The force parameters are chosen to fit the low energy two body data. They are not uniquely determined and are given for a set of possible D-percentage values. The adding of the tensor force reduces considerably the calculated binding energies of nuclei H³, He³, He⁴. But still, the calculated values increase too fast with the mass number. It does not fit the triton and helium binding energies simultaneously. The possibility of adding many body forces is discussed at the end of the paper.     

6.8MeV质子对Cr,Co,Ni,Cu,Zn的弹性散射

本实验测量了6.8MeV质子对Cr,Co,Ni,Cu和Zn的弹性散射角分布。在其微分截面σ_e(θ)与库仑散射微分截面σ_R(θ)之比对θ的作图中显示:这几种元素A相近,也有大体相似的角分布曲线;其极大极小位置可以用kR′sinθ_m/2=常数表之,显示出核的粗糙结构的特征。但在大角度处,这几种质量数A相近的核,其(σ_e(θ))/(σ_R(θ))值却有显著的差异,而且偶z核的(σ_e(     

一种4N阶幻方构造方法的论证

一种 4 N阶幻方构造方法被发现 .本文阐明了 4 N阶幻方构造方法 ,介绍了 12阶幻方构造过程 .