回旋自谐振脉塞及其简化分析

利用Madey理论并结合天线阵理论,成功地进行了回旋自谐振脉塞(CARM)的简化分析。导出了CARM的增益公式和群聚参量,对其进行了讨论,并与传统回旋管和自由电子激光作了比较。     

改进型MVR-CORDIC算法研究

分析了CORDIC算法的基本原理和MVR-CODIC算法的特点。在此基础上,提出了一种改进型MVR-CODIC算法,利用查ROM表代替原算法中比例因子的计算方法,讨论了改进后算法的所需ROM表的容量,给出了实现框图。实验证明,改进型MVR-CODIC算法更适合于用大规模集成电路实现。     

Efficiency of projected score methods in rectangular array asymptotics

Summary. The paper considers a rectangular array asymptotic embedding for multistratum data sets, in which both the number of strata and the number of within-stratum replications increase, and at the same rate. It is shown that under this embedding the maximum likelihood estimator is consistent but not efficient owing to a non-zero mean in its asymptotic normal distribution. By using a projection operator on the score function, an adjusted maximum likelihood estimator can be obtained that is asymptotically unbiased and has a variance that attains the Cramér–Rao lower bound. The adjusted maximum likelihood estimator can be viewed as an approximation to the conditional maximum likelihood estimator.     

基于FPGA的超高速FFT硬件实现

介绍了频域抽取基二快速傅里叶运算的基本原理;讨论了基于FPGA达4 096点的大点数超高速FFT硬件系统设计与实现方法,当多组大点数进行FFT运算时,利用FPGA内部大容量存储资源,采用乒乓结构进行流型运算,提高FFT运算速度,同时保证结果的准确性;对实际硬件进行了FFT运算测试,测试结果证明了系统的可行性和正确性,并且利用该硬件系统成功完成了星载SAR实时成像处理。     

基于Fizeau干涉仪的直接探测多普勒测风激光雷达研究

回顾了基于Fizeau干涉仪的多普勒测风激光雷达的基本原理,在对测风雷达的主要参数说明的基础上,分析了多通道探测器的选择以及由于干涉仪圆形口径引起的通道间的能量修正系数问题,最后对基于Fizeau干涉仪多普勒测风激光雷达雷达系统的风速测量误差进行了数值模拟.结果显示,研制中的基于Fizeau干涉仪的多普勒测风激光雷达系统在5 km以下范围内,风速测量误差可以达到0.56 m/s(30s积分实际时间).     

基于半无穷维二次优化阵列方向图综合

提出一种综合具有任意需要方向图的包含非各向同性和非均匀间隔的线性阵列的新方法。该方法的基本思想在于将综合问题转变为一个半无穷维二次优化（ＳＩＱＯ）模型：在一组线性泛约束条件下使权矢量的范数最小。该约束条件保证瞄准方向为单位增益，并且在给定范围内旁瓣电平满足要求。该方法具有广泛的应用和实际意义。文中给出了设计例子以证明该方法的可行性和实用性。     

A class of Stein‐rules in multivariate regression model with structural changes

In this paper, we consider an estimation problem of the matrix of the regression coefficients in multivariate regression models with unknown change‐points. More precisely, we consider the case where the target parameter satisfies an uncertain linear restriction. Under general conditions, we propose a class of estimators that includes as special cases shrinkage estimators (SEs) and both the unrestricted and restricted estimator. We also derive a more general condition for the SEs to dominate the unrestricted estimator. To this end, we extend some results underlying the multidimensional version of the mixingale central limit theorem as well as some important identities for deriving the risk function of SEs. Finally, we present some simulation studies that corroborate the theoretical findings.     

利用弹性模量计算含气饱和度方法研究

利用弹性模量计算地层含气饱和度丰富了利用测井资料对储集层进行解释、 评价的手段， 提高了含气饱和度这一重要参数的解释精度。由阵列声波测井资料得到的纵、 横波速度信息以及密度信息可以计算出岩石弹性模量参数。根据 Gassmann 方程所描述的低频情况下岩石颗粒、 岩石骨架和流体体积模量与不同孔隙组分饱和度之间的关系， 建立了含气饱和度与地层饱含气、 饱含水时岩石骨架体积模量与剪切模量的关系方程， 从而得到基于弹性模量的地层含气饱和度计算模型。实际测井资料解释处理结果与试油资料符合， 验证了方法的可行性。     

Generalized minimum aberration two-level split-plot designs

Split-plot experiments may arise when it is impractical to completely randomize the treatment combinations of a designed experiment. To provide more flexible design choices in the nonregular split-plot setting, we describe an approach for constructing minimum aberration orthogonal two-level split-plot designs having 12, 16, 20 and 24 runs. We consider five design scenarios that may be of importance to practitioners, and then propose an approach for assigning word lengths under these five scenarios. We then use the extended word length patterns to rank both regular and nonregular orthogonal split-plot designs. While most existing papers concerning orthogonal split-plot designs focus on regular orthogonal designs, we find that many minimum aberration split-plot designs are nonregular orthogonal designs.     

不同花色映山红花中熊果酸和齐墩果酸的含量比较

结合超声技术提取不同花色映山红花中熊果酸和齐墩果酸,建立RP-HPLC法测定其含量。采用Kromasil C18色谱柱(250mm×4.6mm,5μm),流动相为甲醇-0.2%磷酸水溶液(88∶12),光电二极管阵列检测器,检测波长210nm,流速0.8mL/min,柱温30℃。以保留时间和紫外光谱对分离出的组分予以定性确证,用峰面积进行定量。组分的质量浓度与其峰面积在一定的范围内呈现良好的线性关系,相关系数均为0.9999,熊果酸进样量在0.443～7.088μg,齐墩果酸进样量在0.247～3.952μg时呈现良好的线性关系,平均加样回收率分别为98.53%和98.36%,RSD分别为1.3%和1.5%(n=5)。方法灵敏、准确,重现性好,可用于不同花色映山红花中熊果酸和齐墩果酸含量的测定。