Influence of Misalignment on High-Order Aberration Correction for Normal Human Eyes

Although a compensation device can correct aberrations of human eyes, the effect will be degraded by its misalignment, especially for high-order aberration correction. We calculate the positioning tolerance of correction device for high-order aberrations, and within what degree the correcting effect is better than low-order aberration （defocus and astigmatism） correction. With fixed certain misalignment within the positioning tolerance, we calculate the residual wavefront rms aberration of the first-6 to first-35 terms along with the 3rd-Sth terms of aberrations corrected, and the combined first-13 terms of aberrations are also studied under the same quantity of misalignment. However, the correction effect of high-order aberrations does not meliorate along with the increase of the high-order terms under some misalignment, moreover, some simple combined terms correction can achieve similar result as complex combinations. These results suggest that it is unnecessary to correct too much the terms of high-order aberrations which are difficult to accomplish in practice, and gives confidence to correct high-order aberrations out of the laboratory.     

柠檬酸盐凝胶法制备La1.85Sr0.15CuO4超导样品工艺研究

采用溶胶凝胶法制备LSCO超导样品.凝胶中不同组元分布均匀,达到分子级的程度,有利于样品成相.通过我们的研究发现,仅在750℃就可以合成具有超导性的LSCO样品;处理过程中通氧,有利于有机物的分解,消除残余碳氮含量.     

最近邻密度估计强一致收敛性的必要条件问题

设x_1,…,X_n为取自具有分布密度f中的iid样本,1965年Loftsgarden等提出一个常称为“最近邻估计”的 f_n(x)=k_n/2na_n(x) x∈R~1去估计f(x),关于f_n的收敛性质已有不少的研究,到1977年Devroye等(见Ann.Statist.,5(1977),p.536)得到了最佳结果。 若i)f在R~1上一致连续,则 关于本结果之逆,即(1)成立的必要条件,柴根象,陈希孺(见中国科大学报83.4.407)分别证得:条件i)是必要的,条件及也是必要的。那末条件iii)是否也     

Data point selection for weighted least square fitting of cavity decay time constant

For the accurate extraction of cavity decay time, a selection of data points is supplemented to the weighted least square method. We derive the expected precision, accuracy and computation cost of this improved method, and examine these performances by simulation. By comparing this method with the nonlinear least square fitting(NLSF) method and the linear regression of the sum(LRS) method in derivations and simulations, we find that this method can achieve the same or even better precision, comparable accuracy, and lower computation cost. We test this method by experimental decay signals. The results are in agreement with the ones obtained from the nonlinear least square fitting method.     

删失数据非参数回归函数最近邻估计强收敛速度

建立了删失数据非参数回归函数最近邻估计强收敛速度,并得到主阶n的指数为1／(2 d)的最优速度．作为定理的推论,在完全数据情形时,本质地改善了赵林城等(1984,1986)所得的结果。     

双压电片变形镜像差校正能力

利用实测影响函数,通过数值仿真分析了有效孔径、光束入射角度对于20单元双压电片变形镜像差校正能力的影响。仿真结果表明:有效孔径为16 mm时,变形镜对于各阶像差的校正能力较好;而随着光束入射到变形镜角度的增大,变形镜对于像差的校正精度与校正幅度都会出现下降,但是如果能够将入射角控制在25以内,入射角度对变形镜的像差校正能力影响不大。     

环形光斑的波前传感器与波前校正器优化布局

针对自适应光学系统常遇到的环形光斑，仿真研究了波前传感器子孔径的六种环形布局，得出了环形布局的指导原则，并将环形布局与传统的方形布局进行了比较，认为环形布局更适合于环形光斑．     

环形光斑的波前传感器与波产校正器优化布局

针对自适应光学系统常遇到的环形光斑，仿真研究了波前传感器子孔径的六种环形布局，得出了环形布局的指导原则，并将环形布局与倾诉 方法布局进行了比较，认为环形布局更适合于环形光斑。     

强混合序列的联结构造与完全收敛性

对强混合随机变量序列,提出一种"联结构造”方法.作为它的应用,给出强混合序列的完全收敛性.这里的方法,也为处理其它相依随机变量序列,提供一种新的途径.