Analysis of Detectors and Transmission Curve Correction of Mobile Rayleigh Doppler Wind Lidar

A mobile molecular Doppler wind lidar （DWL） based on double-edge technique is presented for wind measurement at altitudes from 10 km to 40 km. A triple Fabry-Perot etalon is employed as a frequency discriminator to determine the Doppler shift proportional to the wind velocity. The lidar operates at 355 nm with a 45-cm aperture telescope and a matching azimuth-over-elevation scanner that can provide full hemispherical pointing. In order to guarantee the wind accuracy, different forms of calibration function of detectors in different count rates response range would be especially valuable. The accuracy of wind velocity iteration is improved greatly because of application of the calibration function of linearity at the ultra low light intensity especially at altitudes from 10 km to 40 km. The calibration functions of nonlinearity make the transmission of edge channel 1 and edge channel 2 increase 38.9% and 27.7% at about 1 M count rates, respectively. The dynamic range of wind field measurement may also be extended because of consideration of the response function of detectors in their all possible operating range.     

ENDF/B-VIII.β与ENDF/B-VII.1中水的热中子散射截面数据对比分析

以常见的慢化剂材料轻水为例,分析了ENDF/B评价库中两个版本ENDF/B-VⅢ.β与之前ENDF/BVⅡ.1中热中子散射截面数据的差异。由于ENDF/B-VⅢ.β与ENDF/B-VⅡ.1等两个版本中热中子散射截面的温度不尽相同,为定量分析同一温度下二者的差异,通过插值方法得到了任意温度下的热中子散射截面数据。对比发现,二者在同一温度下的热中子散射数据存在差异。相对于ENDF/B-VⅡ.1评价库版本而言,基于ENDF/B-VⅢ.β评价库版本加工得到的束缚在水中的氢的热中子散射截面与ENDF/B-VⅡ.1存在较为明显的差异,两个版本给出的低温情况下的中子与靶核碰撞后的平均散射角余弦在热区的低能段出现极小的负值。此外,当温度高于室温时,在热区的低能段ENDF/B-VⅢ.β给出的平均次级中子能量要稍大于ENDF/B-VⅡ.1给出平均次级中子能量。This work takes the traditional moderator material H₂O for example, the differences between ENDF/B-VⅢ.β and ENDF/B-VⅡ.1 versions from the ENDF/B nuclear evaluated library are analyzed. In order to compare the thermal neutron scattering data between ENDF/B-VⅢ.β and ENDF/B-VⅡ.1 versions under the same temperature, the interpolation method is used to obtain the thermal neutron scattering data under arbitrary temperatures. There are some differences between ENDF/B-VⅢ.β and ENDF/B-VⅡ.1 versions, the thermal neutron scattering cross sections of H bound in H₂O within ENDF/B-VⅢ.β is different with that of ENDF/B-VⅡ.1, the scattering angle cosines of the neutron and target nuclei from the two libraries are slightly smaller than zero in lower energy range within thermal range. Moreover, the second scattering energy spectrum from ENDF/B-VⅢ.β is slightly harder than that from the ENDF/B-VⅡ.1 in higher energy range within thermal range when the temperature is higher than room temperature.     

基于拟物方法的网络服务器选址问题的模型

带约束条件下的网络服务器的选址决策问题在信息服务中具有重要意义．本文从客户段的不确定性分析出发,建立一个基于拟物方法的服务器选址决策的改进模型．与原有模型相比,它能更合理描述信息服务中各种不同类型商品的供应者．并且它克服了原有模型不适用于已有多个供应者存在的情形．为带约束的网络服务决策提供科学依据．     

主次双波长新光度法测水体中的二硝基氯苯

本文通过对二硝基氯苯与吡啶生成的紫红色化合物光谱的研究,从而导出了主次双波长对二硝基氯苯进行定量测定的数学模型,二硝基氯苯在０～５０μｇ／２５ｍＬ范围内计算参数（Ｙ）与二硝基氯苯浓度（ｘ）呈良好的幂函数关系。由此对环境水体中微量二硝基氯苯进行了测定,方法的最低检出限为０．７μｇ,相对标准偏差ＲＳＤ≤２．７％,加标回收率９９．２％～１０１．０％。     

离子排斥色谱法分析有机酸和无机弱酸

用非抑制型电导检测的离子排斥色谱法,以对甲苯磺酸为淋洗液,研究了柠檬酸、苹果酸、抗坏血酸、乙醇酸、甲酸、乙酸、丙酸及氢氟酸和碳酸的色谱分离及定量检测条件。     

对流扩散方程的指数型摄动差分法

改进了作者所提出的对流扩散方程四阶指数型摄动差分格式,并阐明其在高Reynolds数适应性和节省计算量方面的显著优点。指数型摄动差分法经改进后具有较为简便的形式,克服了其他紧致高阶格式不能使用于高Reynolds数问题的致命弱点。文中针对计算流体力学的基本困难,作一至三维流动模型方程和自然对流传热问题的精细计算,且以双精制算法检验格式的四阶精度,表明摄动差分法能在较粗的网格下给出相当准确的结果,十分显著地节省计算机时,并对"激波"和"边界层"等高Reynolds数效应有极高的分辨能力。     

一种800MHz无线通信用高温超导滤波器的研究

本文设计了应用于800MHz无线通信系统基站的8节和14节高温超导滤波器,中心频率在800MHz附近,相对带宽为2.1%,并在以0.51mm厚度的MgO为衬底的双面YBCO薄膜上制作了14节滤波器.测试结果表明,该滤波器具有较好的性能,在60K温度下,其带内插损小于0.3dB,带边陡峭度大于25dB/MHz,带外抑制优于70dB.     

空气—乙炔火焰原子吸收法快速测定载金炭中银

样品经灰化，王水溶解后，直接用原子吸收法测定银，方法快捷、准确，经济，精密度小于等于3％，回收率为97．0％～101％，用于多种载金炭中银分析，结果令人满意。     

惯导设备用导电滑环瞬断故障分析研究

瞬断是表征精密导电滑环性能的主要性能指标,其具有出现概率低、时间短、难以检测的特点,但却又极易对系统造成不确定的影响,直接关系到系统信号传输的可靠性。对惯导设备转台调制过程中出现航姿跳变故障原因进行分析,通过搭建检测系统复现导电滑环的瞬断现象,指出外界微小异物进入环槽必定会导致具有刷丝对称双接触特点的导电滑环产生瞬断现象,从而导致航姿跳变故障的发生,且使导电滑环出现不可逆转的损伤。