高功率激光装置打靶精度测试技术

 多路激光打靶精度在惯性约束聚变实验中起着至关重要的作用,提出了基于X光针孔相机的激光打靶精度测试方法。根据显微镜读取的靶平面坐标系的靶孔中心坐标及打多孔靶后X光针孔相机所记录的靶孔中心坐标,建立靶平面坐标系和X光针孔相机坐标系之间的转换关系;通过打焦斑靶,建立焦斑模板,采用套模板的方法,读取X光针孔相机坐标系中焦斑中心坐标;由靶平面坐标系和X光针孔相机坐标系之间的转换关系,求出靶平面坐标系中焦斑中心坐标,计算得到激光打靶精度,分析打靶精度测试结果的不确定度,从而给出多路激光打靶精度测量技术和方法。     

中法激光时间比对和探测基本物理的相关空间计划

激光时间比对T2L2(Time Transfer by Laser Link)是法国蔚蓝海岸天文台(OCA)和法国空间中心(CNES)进行的新一代的时间传递计划,将于2008年年中随Jason-2卫星发射上天,并开始观测。它利用激光脉冲在空间的传播来实现地面—卫星,地面—地面远距离时钟的同步,精度比现有的微波比对方式提高1~2个数量级。中国拥有5个固定激光测距站和2个流动激光测距站,基于良好的地理位置和中法双方比较成熟的激光测距技术,中法激光站之间的时间比对和中国内部激光站之间的时间比对是该计划的重要内容。本文系统描述了T2L2的主要内容和关键技术,初步估算了该计划的精度和稳定度,对中法之间的时间比对做出了初步的观测规划。同时,简单介绍了目前世界上精密时钟的发展现况、T2L2的应用前景及正在研究中的TIPO、ASTRODⅠ、ACES、EGE等探测基本物理的相关空间计划。     

基于磁光调制偏振光的空间方位失调角高精度测量新方法

调制偏振光可以作为方位信息的载体,实现方位角度信息的传递,在军事、航天和生物医药等领域有广泛的应用前景.阐述了基于磁光调制偏振光的方位失调角测量原理,分析了现有测量原理中的误差来源.为了从理论方法上提高测量精度,提出了直接计算的方法,将磁光调制后的光强信号直接进行取极值点处理,建立了失调角与极值点之间的方程,详细分析了...     

绩效度量的一致性、敏感性及准确性关系研究

将环境的波动性和度量噪音看作是影响绩效度量的两类不同的随机误差,在Linear-exponential-normal框架下,建立了以价值绩效度量和补偿绩效度量的线性组合为基础的收益激励模型,并分析了激励强度与绩效度量的一致性、敏感性和准确性之间的关系,以及环境波动性对上述关系的影响.研究发现,在确定性环境条件下,激励强度与绩效度量的"信号噪音比"成正比关系,但绩效度量的一致性的提高并不必然增加该度量指标在激励契约中的权重,而要视敏感性或噪音相对于一致性的变化幅度来定.特别地,在绩效度量的敏感性与一致性之间并不存在权衡取舍关系.研究还发现,波动性与激励强度之间存在负向关系,且波动性的存在降低了绩效度量的一致性和敏感性,但波动性对绩效度量的准确性的影响则呈非单调性变化.     

双参数十二参矩形板元的对称列式

1 引言 在位移有限元中,九参数三角形板元的研究取得了丰硕成果,根据不同方法已构造出众多收敛性能很好的单元（见[1]、[2]、[3]）。相比之下,矩形板元的研究却较少报道,ACM元及广义协调元RGC—12是其中比较成功的单元.但是ACM是C~0元。其位移形函数的外法向导数平均值在单元间不连续。广义协调元是基于势能原理建立单元协调的,其自由度(协调条件)不对称是其本身的一个弱点,陈万吉研究表明。这种不对称性会破坏单元的几何不变性。     

影响加工中心加工精度的因素

加工中心是高效自动化设备，为了充分利用机床的高效率、高精度、高自动化等特点，所以要考虑和了解影响加工中心加工精度的因素。     

Measurement of uncertainty in peptide molecular weight determination using size-exclusion chromatography with multi-angle laser light-scattering detection and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

The molecular weight of biopolymers such as peptides or proteins is vital information for understanding their physical/chemical properties. The matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and size-exclusion chromotography-multi-angle laser light scattering (SEC-MALLS) techniques each with its advantages and limitations were used for molecular weight determination of the SPf66 peptide. The precision of each method was studied using a two-factor fully-nested design with all the analyses performed by the same operator on a single instrument. The overall precision corresponded to the time-different intermediate precision (i.e. time and repeatability conditions). In the case of SEC-MALLS, all potential uncertainty components were carefully evaluated in an Ishikawa diagram, then included and mathematically combined with the uncertainty arising from the accuracy assessment to provide the overall uncertainty. In this case, the refractive-index increment with solute concentration value (dn/dc) provided the most significant contribution to the combined uncertainty. A method for its quantitation is proposed. The accuracy of method B (SEC-MALLS) against reference method A (MALDI-TOF-MS) was assessed using the interval testing hypothesis to limit the risk of unacceptable bias. The results indicate that the bias of B is higher than the limit established at 5%, and is therefore not traceable to A under the studied conditions.     

高精密运动工作台控制系统的设计与研究

设计并研制了用于母盘刻录机的高精密运动工作台及其控制系统。工作台控制系统采用线光栅作为工作台位移检测工具。采用数字位置环和模拟电流环组成双闭环随动系统,其中位置控制器是带有速度前馈和加速度前馈的数字PID伺服滤波器。实验结果表明,该系统可以满足母盘刻录机的要求。     

Improvements in Silo Design for Moist and Cohesive Bulk Solids by Using a Silo Centrifuge

The Jenike‐method is state of the art in silo design for trouble‐free flow, even for cohesive bulk solids. However, for some bulk solids, especially very cohesive and moist bulk solids, even the correct application of the Jenike‐method can lead to an over‐design of the silo outlet. If a reliable estimation of the critical outlet dimension is possible the dimension as well as the machinery costs can be reduced. Model testing can help to reduce the over‐design but reasonable test equipment and flexibility are only possible with silo centrifuge testing. Results, regarding the state of stress and the critical outlet dimensions, from experiments using a silo centrifuge with cohesive and moist bulk solids are presented. The influence of creeping effects on silo design is investigated using the silo centrifuge with moist gypsum.     

Estimation of the Common Mean of a Bivariate Normal Population

In this paper we discuss the problem of estimating the common mean of a bivariate normal population based on paired data as well as data on one of the marginals. Two double sampling schemes with the second stage sampling being either a simple random sampling (SRS) or a ranked set sampling (RSS) are considered. Two common mean estimators are proposed. It is found that under normality, the proposed RSS common mean estimator is always superior to the proposed SRS common mean estimator and other existing estimators such as the RSS regression estimator proposed by Yu and Lam (1997, Biometrics, 53, 1070–1080). The problem of estimating the mean Reid Vapor Pressure (RVP) of regular gasoline based on field and laboratory data is considered.