Projectile fragment emission in the fragmentation of 56Fe on C,Al and CH2 targets at 471 A MeV

The emission angle and the transverse momentum distributions of projectile fragments produced in the fragmentation of 56Fe on CHs, C and A1 targets at 471 A MeV are measured. It is found that for the same target, the average value and width of the angular distribution decrease with an increase of the projectile fragment charge; for the same projectile fragment, the average value of the distribution increases and the width of the distribution decreases with increasing the target charge number. The transverse momentum distribution of a projectile fragment can be explained by a single Gaussian distribution and the averaged transverse momentum per nucleon decreases with the increase of the charge of projectile fragment. The cumulated squared transverse momentum distribution of a projectile fragment can be explained well by a single Rayleigh distribution. The temperature parameter of the emission source of the projectile fragment, calculated from the cumulated squared transverse momentum distribution, decreases with the increase of the size of the projectile fragment.     

几多欢乐几多愁－2009年BIRTV大展专业音频侃谈

一年一度的北京国际广播电视设备展如期举行，展馆仍然是国际展览中心。馆内分类设置基本延续前几届的约定，所以对于每届必到的专业广电人士来说就是“熟门熟路”了。我觉得这个传统很好．避免了不必要的找展位过程，提高了参观效率。从大门口领取入场卡的情况来看，明显人流比去年11月份时还稀疏些。没有入场券的只要出示名片即可获得入场卡。     

A nonlinear optical loop mirror-based linear cavity swit- chable multi-wavelength erbium-doped fiber laser

A nonlinear optical loop mirror (NOLM)-based linear cavity switchable multi-wavelength erbium-doped fiber (EDF) laser is proposed and experimentally demonstrated. Due to the characteristics of the intensity-dependent transmissivity, the NOLM can effectively mitigate the mode competition of the homogenous broadening gain medium, so that the multi-wavelength lasing can be achieved at room temperature. By adjusting the states of the polarization controllers (PCs), the number of the lasing wavelengths in the proposed laser can be adjusted flexibly from 11 to 13 with a wavelength spacing of 0.4 nm around the wavelength of 1 530 nm.     

基于HAM的短波相干信号DOA估计方法研究

文章研究分析了基于HAM的信号DOA估计方法的基本原理,并将其应用到短波相干信号的DOA估计中,通过计算机仿真验证了该方法的有效性。     

塑封铜引线集成电路开封方法

在集成电路高速发展的时代,内引线为铜的集成电路因为低廉的价格和性能方面的优势,将越来越多地被制造和改进,破坏性物理分析(DPA)中也将会遇到大量的塑封铜引线集成电路,这类器件开封容易引起铜引线、键合点的腐蚀等问题。对这类器件研究后的开封方法是：激光开封后一定比例的混酸腐蚀能使铜线和键合点完好保留,芯片表面无塑封料残留。本文提供了一种对塑封铜引线集成电路进行开封的可靠方法。     

高马赫飞行器迎风面与攻角对光学窗口周围流场的影响分析

为了提高高马赫飞行下光学窗口的光学性能,对比分析了基于气动光学效应三种飞行器模型不同攻角的马赫数场、密度场、温度场和压力场的流场结构及对光学性能的影响.首先, 根据飞行器与来流的迎风面,建立了三种飞行器典型模型;继而, 给出了0、5和10攻角飞行工况;然后,建立了基于Navier-Stokes方程和湍流模型的三种攻角流场分布;最后, 对比分析了宽平头体飞行器中三种攻角温度场作用下的光学系统传递函数.结果表明,马赫数场与密度场、温度场与压力场分别具有相似分布形式;相同飞行速度和攻角下,大迎风面的飞行器光学窗口周围温度与压力较小迎风面大;相同飞行器,较大攻角对应较大流场强度,攻角为0、5和10时传递函数分别为0.188,0.097和0.028.此分析结果可为高马赫飞行下光学窗口优化提供一定的理论依据.     

ICF激光装置靶场光束引导路径的优化研究

为了缩短惯性约束聚变(ICF)激光装置在靶场区光束引导的总时间为基于光束引导传感器固定子区划分的光束引导方法,提供了引导路径的一种优化方法。通过优化预备子区中心到目标子区中心的角度,最小化对引导总时间有贡献的投射镜的角位移量的总和。以终端光学组件的一种布置为研究对象,以引导目标点为靶室中心的情况为例,介绍了引导路径的优化过程。引导总时间的估计表明,与普通的串行光束引导方法相比,该方法可以很大程度上缩短光束引导的总时间。当预备子区中心与目标子区中心之间的距离为1 mm时,引导总时间可以缩短为采用普通串行引导方法时的0.518倍。     

多孔软硬磁Ni0.5Zn0.5Fe2O4/SrFe12O19复合纤维制备及吸波性能

通过静电纺丝技术制备了多孔软硬磁Ni_0.5Zn_0.5Fe₂O₄/SrFe₁₂O₁₉复合纤维,利用综合热重分析仪（TG-DSC）、X射线衍射仪（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、X射线能谱仪（EDS）和矢量网络分析仪（VNA）等对复合纤维的晶体结构、微观形貌和电磁性能进行了表征,研究了不同软硬磁质量比对纤维结构和性能的影响。结果表明：900℃下制备的复合纤维具有立体多孔结构,软硬磁质量比为1∶3时,复合纤维的比表面积达到55 m²·g^-1。吸波性能测试结果显示,当吸波剂涂层厚度为3.5 mm时,复合纤维在10.6 GHz处反射损失（R_L）值达到-31.9 dB,在2~18 GHz频率范围内,R_L值小于-10 dB的吸收带宽达到10.5 GHz,覆盖了整个X波段（8.2~12.4 GHz）和Ku波段（12.4~18 GHz）,显示出优异的宽波段吸收性能。     

高效液相色谱-质谱联用法测定烟草中茉莉酸

采用高效液相色谱-质谱(HPLC-MS)联用法检测烟草中茉莉酸(JA)含量。样品研磨均质后经丙酮和柠檬酸萃取,离心分离,取上清液,氮气吹去丙酮后用乙醚萃取。经氨丙基固相萃取柱净化,吹干后用色谱流动相溶解,过0.45μm有机滤膜。利用高效液相色谱-质谱联用电喷雾负离子,选择离子监测模式进行检测,内标法定量。结果表明,待测样品JA浓度范围在5～1 000ng/mL之间,标准曲线具有良好的线性关系。方法检出限(S/N≥3)是2.0ng/mL。平均回收率为80.6%～101.1%,相对标准偏差为3.5%～14.6%。应用该方法检测烟草打顶与不打顶植株之间JA含量的差异,结果比较理想。     

Effect of Plasma Treatment on the Structures and Properties of Konjac Glucomannan Film

To understand the effect of plasma treatment on the Konjac glucomannan film, the nitrogen plasma was injected into the film by ion beam injection machine in this study. The structures and properties of Konjac glucomannan film after plasma treatment were analyzed by Infrared spectroscopy, Raman spectrum, X-ray, ect. The result showed that nitrogen groups appeared in the KGM molecular chain and part of this chain fractured, and the number of hydrogen bonds increased after the treatment of plasma. The form of KGM molecule remained amorphous non-crystalline state, but the crystalline region was increased and became more ordered. The mechanical property of tensile strength and breaking elongation was improved, while the WVP was decreased. The nitrogen groups were grafted on the KGM molecular chain after plasma treatment, which led to the improvement of the properties of KGM film.