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提出了一种用于高功率微波武器的等离子体通道天线(PCA),计算了该天线的辐射方向图。推导出了一般性天线的辐射方向函数;建立了PCA的近似电磁模型;给出了圆坐标系下PCA和周围空气中的电磁场,利用边界条件得出了PCA的色散方程,求出PCA的表面波波矢。重点讨论了PCA的辐射场随等离子体密度、天线长度、半径的变化,证实了PCA方向图的可控性。     

等离子体通道天线的辐射场计算

提出了一种用于高功率微波武器的等离子体通道天线(PCA),计算了该天线的辐射方向图。推导出了一般性天线的辐射方向函数;建立了PCA的近似电磁模型;给出了圆坐标系下PCA和周围空气中的电磁场,利用边界条件得出了PCA的色散方程,求出PCA的表面波波矢。重点讨论了PCA的辐射场随等离子体密度、天线长度、半径的变化,证实了PCA方向图的可控性。     

实时数字图像无损压缩的研究

针对实时数字图像的无损压缩方法进行了分析,采用三级5-3整数提升小波变换,小波变换的高频和低频系数分别采用不同的编码方法。进行了基于DSP和FPGA的压缩系统结构设计,提出了软、硬件并行的方法。进行三级小波变换时,硬件结构能够实现在对当前级小波变换的同时进行前一级小波变换的高频系数编码,提高了压缩系统的实时性。并对压缩系统的关键技术进行了研究。可以对80MB/s的数字图像进行无损压缩,压缩比可以达到1.68~1.8左右。     

CCD摄像系统镜头的畸变测量

从畸变定义出发,讨论了畸变数学模型,介绍了精密测角法与比长法综合测量畸变的原理。通过放大率法标定出CCD探测器的像素距离当量,通过质心法求出点目标的质心,质心与原点的像素距离乘以像素距离当量得到精确长度。利用正切函数求出绝对畸变值,用最小二乘法解多组数据超定方程,求出拟和公式的系数。实际计算和数据处理结果表明：畸变数学模型在中视场范围内拟合效果很好。     

超高速撞击充气压力容器二次碎片减速运动建模研究

 针对空间碎片超高速撞击充气压力容器的二次碎片减速运动问题,首先根据弹丸撞击容器前壁后的破碎程度,将二次碎片分为弹丸未破碎、未完全破碎及完全破碎3种模式,分别建立了二次碎片未受气体扰动时的初始模型;然后采用理论分析手段,应用流体动力学、气-固两相流理论,对弹丸不同破碎模式下的二次碎片在容器内的运动过程进行分析,建立了二次碎片减速运动的计算模型,通过与数值模拟结果的比较,验证了计算模型的有效性。     

Weyl Spinor and Solution of Massless Free Field Equations

The massless field equations for arbitrary spin in curved space-time arereconsidered. The general solution of the field equation in Robertson-Walkerspace-time that was previously determined is briefly discussed after explicitlyshowing that the Weyl spinor vanishes. The case of the Lemaître-Tolman-Bondispace-time is studied in detail. The general expression of the corresponding Weylspinor is obtained and some particular situations exploited. The spin-3/2 andspin-2 massless field equations are solved explicitly. The solutions are simplifiedby the existence of nontrivial algebraic constraints. The angular part of theequations is separated by the usual separation method and integrated directly.The other equations that are not separated in the radial and time dependence arereduced to a simple form. The results obtained are extended, as a consequenceof previous results, to the case of arbitrary spin. The solution of the general caseessentially reduces to the treatment of spin 3/2 and spin 2.     

丁二酮肟光度法直接测定镍铬烤瓷合金中镍的研究

探讨了丁二酮肟光度法直接测定镍铬烤瓷合金中镍的可行性。样品经酸完全溶解,镍在氨性介质且有氧化剂（碘）存在时与丁二酮肟显色,测定吸光度结合标准加入法绘制校准曲线,从而直接测定镍含量。样品镍含量的平均值为63.3%,相对标准差为3.6%,加标回收率为91.97%—109.5%。丁二酮肟光度法可直接测定镍铬烤瓷合金中的镍,该方法简便、快速、结果可靠。     

Mathematical modeling of a 50 MeV racetrack microtron

The mathematical model for a racetrack microtron with an output energy of 50 MeV is described. The number of orbits is five. The increment of energy beam increase is 10 MeV per turn. The frequency rate of acceleration is four. One feature of the accelerator is injection directly into the acceleration section with a rather low kinetic energy beam of 0.8–1 MeV. The parameters that affect the capture region in the acceleration mode are determined. The region of capture is calculated. The basic properties of the focusing system are studied. The conditions for the optimum passage of the beam are substantiated for all orbits.     

含散射闪光照相系统的布局优化

为了提高现有照相系统的图像品质,对使用CCD探测器的法国客体(FTO)照相布局进行了优化,获得最佳图像品质因子下的照相布局。研究结果为:在模糊实验测量结果和高斯分布近似下,系统放大倍率为2.0;后保护器件距离客体50 cm;系统布局总长与探测系统的噪声相关,噪声越大,布局总长越短,最优布局总长的范围为3~5 m;实验验证了这一结果。     

Electrical breakdown of microwave plasma in water

The electrical breakdown of microwave plasma in water was investigated between 1 and 30 kPa. The dependency of the ignition power for generating plasma on the size of coaxial electrode was measured. The ignition power decreases with a decrease of the diameter of the inner electrode. The behavior of microwave plasma in water was observed using a high-speed camera. The plasma ignites in a bubble generated by microwave heating. The model for calculating the electric field was created on the basis of the captured images of the bubble just before plasma ignition. The method presented can be used to visualize the electrical field distribution in the bubble. The electric field breakdown was calculated using the measured ignition power. The electric field breakdown of plasma in water is of the same order as gas phase plasma.     

Commissioning of electron cooling in CSRe

The 400 MeV/u 12C6+ion beam was successfully cooled by the intensive electron beam near 1 A in CSRe.The momentum cooling time was estimated near 15 s.The cooling force was measured in the cases of different electron beam profiles,and the different angles between the ion beam and electron beam.The lifetime of the ion beam in CSRe was over 80 h.The dispersion in the cooling section was confirmed as positive close to zero.The beam sizes before cooling and after cooling were measured by the moving screen.The beam diameter after cooling was about 1 mm.The bunch length was measured with the help of the signals from the beam position monitor.The diffusion was studied in the absence of the electron beam.     

4 MV激光触发多级多通道开关特性

 报道了4 MV激光触发多级多通道开关的结构设计和初步的实验结果及分析。该开关采用轴向聚焦触发方式，设计为匀场结构，采用场调整环与匀压环调整开关间隙电场分布，电极-绝缘子序列采用堆栈结构替代榫接结构，独立定位、紧固。实验结果表明：4 MV激光触发多级多通道开关的自击穿电压偏差小于5%，自击穿电压与工作气压呈良好的线性关系；触发延迟时间约25 ns，极差小于±2.5 ns，抖动1.5 ns；等工作电压-气压比条件下，随着气压和工作电压的上升触发延迟时间及其抖动趋向下降。     

Clausius-Mossotti-Type relation for planar monolayers

The dielectric properties of a quasi-two-dimensional molecular monolayer are analyzed. The dielectric function of the monolayer is expressed in terms of molecular polarizability and monolayer characteristics. The expression is analogous to the well-known Clausius-Mossotti equation for three-dimensional systems. The response of the monolayer to an external field is calculated. The case of a planar array of nanoparticles is also considered. The solution is obtained in the framework of a local-field theory.     

Stresses and strains in a deformable fractal medium and in its fractal continuum model

The model of fractal continuum accounting the topological, metric, and dynamic properties of deformable physical fractal medium is suggested. The kinematics of fractal continuum deformation is developed. The corresponding geometric interpretations are provided. The concept of stresses in the fractal continuum is defined. The conservation of linear and angular momentums is established. The mapping of mechanical problems for physical fractal media into the corresponding problems for fractal continuum is discussed.     

PrP5O14的晶体结构与铁弹畴

本文用X射线衍射方法研究了PrP₅O₁₄的晶体结构和铁弹相变。晶体空间群为P2₁/c,晶胞参数a=8.777(1)?,b=9.029(2)?,c=13.068(2)?,β=90.35°(1),z=4,最终R值为0.046。在130±5℃转变成正交晶系,空间群为P_ncm,a=8.813(7)?,b=9.075(2)?,c=13.119(10)?。高温相变使晶体产生了铁弹性孪晶,室温下晶体属mmmF2/m类铁弹体。 关键词：     

High-Breakdown-Voltage Submicron InGaAs/InP Double Heterojunction Bipolar Transistor with ft=170GHz and fmax=253GHz

The layer structure of InGaAs/InP double heterojunction bipolar transistor (DHBT) is designed to enhance the frequency performance and breakdown voltage. The composition-graded base structure is used to decrease the base transit time. The InGaAs setback layer and two highly doped InGaAsP layers are used to eliminate the conduction band spike of the collector. The submicron-emitter InGaAs/InP DHBT is fabricated successfully. The base contact resistance is greatly decreased by optimization of contact metals. The breakdown voltage is more than 6V. The current gain cutoff frequency is as high as 170GHz and the maximum oscillation frequency reached 253GHz. The DHBT with such high performances can be used to make W-band power amplifier.     

电感耦合等离子体-原子发射光谱法测定塑料中的铅的不确定度评价

对电感耦合等离子体-原子发射光谱法测定塑料中的铅含量的不确定度进行了评定.建立了该方法的定量数学模型并推导出不确定度计算公式,找出了该检测过程中的不确定度来源,并且计算了公式中各个变量的不确定度,最后计算出了检测结果的合成标准不确定度和扩展不确定度.     

超支化聚合物吸附金、铂和钯及化学光谱行为的研究

超支化聚合物在盐酸介质中分离富集金、铂和钯,具有吸附速度快、吸附容量大的特点。将吸附后的树脂灰化,用碳粉、硫酸锶和氧化锆作缓冲剂, 采用发射光谱法同时测定金、铂和钯,选择锆作内标线,直接压样于杯形的石墨电极中,测定简便、快速和准确。对测定条件、干扰因素进行了研究,以此建立测定金、铂和钯的新方法。金、铂和钯的分析线分别为312.3, 306.5和311.4 nm,内标线选择为310.7 nm的锆,金、铂和钯的线性范围分别为0～0.20%,0～0.40%和0～0.20%。金、铂和钯的检测限分别为0.010%,0.003%和0.003%。用于样品的测定获得了满意结果。     

不同季节的虎杖根茎中8种矿质元素的光谱测定

采用空气-乙炔火焰原子吸收法,测定虎杖根茎的K,Ca,Na,Mg,Fe,zn,Mn,Cu等8种矿质元素的含量。对测定条件进行了实验,选择了最佳电离抑制剂和酸性介质。实验以氯化铯为电离抑制剂,盐酸浓度控制在2％以内,用氯化锶消除磷对Ca的干扰,使吸光值稳定,用标准曲线法进行测定,获得了满意效果。该方法简单、快速、准确,加标回收率为90．5％～108．2％,相对偏差为0．3％～0．7％,适合于植物矿质元素的分析。实验结果表明：虎杖根茎中含有丰富的矿质元素,其中以K,Ca元素含量最高。这与虎杖的药用效果相符。同时,每种元素含量随季节变化而变化,与其生长发育密切相关。     

小位移条件下混沌隔振装置的设计与研究

本文根据混沌隔振原理, 设计出小位移下的混沌隔振装置, 该装置能够在小位移下产生强非线性, 并且其线性部分与非线性部分完全区分开, 实验中易于调节其整体刚度, 以及线性和非线性项比例, 大大增加了该装置在工程中的应用前景. 并利用数值计算方法对特定参数下的隔振装置在简谐激励力作用下的运动进行分析, 证实了该混沌隔振装置的可行性.