斜入射弹丸着靶位置立靶测量原理

常规的立靶测量装置要求弹道垂直预定靶面,当弹道不垂直预定靶面时,得到的测量结果是错误的。在终点弹道,有时很难保证靶面垂直飞行弹道。提出了一种由多光幕阵列组成的光幕立靶,可以实现小于70°入射角的弹丸着靶坐标的测量,不要求飞行弹道垂直靶面。在X和Y方向分别采用四个成固定角度的光幕来实现入射角度的测量,一次射击可得到弹丸的速度、速度方向上的空间角和着靶位置坐标。     

斜入射弹丸速度测量系统研究

天幕靶是用于测量弹丸速度较为普遍的光学测量仪器。在测量弹丸速度时,要求弹道垂直于天幕靶的靶面,当弹道不垂直预定靶面时,弹丸飞越两个天幕靶靶面的实际距离与两靶靶距存在一定的误差,斜入射角度越大误差越大。提出了一种用6个天幕构成天幕阵的速度测量系统。当弹丸以任意方向穿越6个天幕时,测时仪记录弹丸穿越各个天幕的时间间隔,根据这些时间间隔便可以求出弹丸的速度值和速度的飞行方向。该方案解决了弹丸斜入射时速度测量不准的问题,特别适用于枪弹末速度的测量。     

声光信号融合的外弹道参数测量方法研究

分析了弹丸激波马赫角在超声速飞行物体研究中的意义,指出现代靶场测试中针对激波马赫角的测试手段的不足。给出了一种全新的激波马赫角、弹丸速度以及弹丸飞行距离的测量方法。通过分析激波声学压电传感器接收到激波的时间,以及高速目标探测器接收到超音速飞行弹丸遮光时间,结合两种探测器的位置空间信息,构建了一种基于声光双信号的外弹道参数测试系统的数学模型。建立仿真模型分析,基于声光双信号的弹丸马赫角的误差低于0.6%。实验结果表明,对于超音速飞行的弹丸,基于声光信号探测系统检测弹道参数测量系统具有较高的测量精度。为后续的多信号探测外弹道参数奠定了基础。     

弹丸激波在激光光幕靶测量中的影响分析

分析了弹丸在飞越激光光幕靶时弹丸激波对激光传播的影响。针对难于实际测量由激波形成的空气折射率分布问题,应用弹丸超音速绕流场的数值计算结果和折射定律,借助SolidWorks软件分析了激波内折射率为常数的情况下光线穿过激波时的折射和出射轨迹,并用模拟实验验证了其正确性。讨论了激波对激光光幕靶测量的影响,为光幕靶的设计与应用提供了依据。     

超高速碰撞天然白云石板产生闪光的实验研究

推导了碰撞产生闪光的射流起爆模型,并利用建立的光纤瞬态高温计测量系统和二级轻气炮加载系统,进行了碰撞速度相近、弹丸入射角度分别为45°和60°(与靶板平面的夹角)时球状铝丸超高速碰撞天然白云石板产生闪光现象的实验测试。实验结果表明:当弹丸为LY12铝、靶板为20mm厚的天然白云石板,碰撞速度分别为1.86km/s和1.96km/s时,弹丸入射角度为45°时的闪光强度峰值大于弹丸入射角度为60°时的闪光强度峰值。     

一种超声速运动目标的被动声定位算法

超声速运动目标在空气中飞行时产生激波，本文利用激波到达时间，提出了一种基于波前方向矢量的算法，确定目标的速度和位置。最后，通过对三站均匀圆阵的估计精度的分析计算，讨论了该算法的有效性．     

四光幕精度靶工程化模型及测量精度分析

针对现有四光幕精度靶理想化结构模型及测量精度分析无法满足其工程化设计及发展需求的问题,构建了通用的四光幕精度靶工程化结构模型,推导了相应的坐标测量及误差传播公式,仿真分析了着靶位置、靶距、幕面夹角、靶面大小、弹丸斜入射角度等多参量对系统坐标测量精度的影响,得到了系列坐标测量误差分析数据.最后给出了一实际四光幕精度靶的结构及理论坐标测量误差估计.实弹射击表明,该系统在1m×1m有效靶面内的X、Y坐标测量误差均小于2mm,与理论仿真分析结果接近,验证了所提工程化测量模型的正确性,测量精度分析有效.研究结果可为实用型四光幕精度靶的设计及测量精度评估提供可靠参考.     

弹丸超高速撞击铝靶成坑数值模拟

 低地球轨道的各类航天器易受到微流星体及空间碎片的超高速撞击,损伤航天器飞行关键系统,进而导致航天器发生灾难性的失效。微流星体及空间碎片防护结构设计,是航天器设计的一个重要问题。采用AUTODYN软件进行了弹丸超高速正撞击及斜撞击铝靶成坑的数值模拟,给出了二维及三维模拟结果。研究了弹丸密度、弹丸形状、板厚度、弹丸速度、弹丸直径和弹丸撞击入射角等对靶成坑的影响。模拟结果同实验结果进行了比较,模拟的成坑形状和特征尺寸同实验相吻合。验证了数值模拟方法的有效性。     

后效期火药燃气加速弹丸的数值研究

 弹丸出膛后受高压火药燃气作用将继续加速并达到最大速度,后效期内弹丸增速大小及增速规律对于武器系统的设计和射击精度等具有重要的影响。采用基于动网格的有限体积方法,对不同装药量、弹丸质量和口径等9种条件下的发射过程进行了数值模拟,讨论了弹丸出膛后的受力状况和运动过程,对最大速度出现的时间、位置和增速量及其变化特点、影响因素等进行了详细的分析。计算结果显示,后效期弹丸增速率最大可超过3%,且加速过程受弹丸质量和装药量的影响很小。     

超高速碰撞LY12铝靶产生闪光辐射的速度及角度效应

为了研究超高速碰撞产生闪光辐射的速度及角度效应,利用建立的瞬态光纤高温计测量系统结合二级轻气炮加载系统,进行了6种实验条件下的超高速碰撞实验。每组实验使用一组光纤探头,基于实验所获原始数据结合标定,通过Matlab编程处理得到了给定实验条件及光纤探头安装条件下,超高速碰撞LY12铝靶产生的闪光辐射与碰撞速度和弹丸入射角度的关系。实验结果表明,超高速碰撞LY12铝靶产生的闪光辐射在温度峰值出现前近似与碰撞速度和弹丸入射角度(弹道与靶板平面的夹角)正弦乘积的平方成正比;碰撞闪光辐射在温度峰值出现后近似与碰撞速度和弹丸入射角度正弦乘积的0.75次幂成正比,与理论推导结果基本吻合。     

Dynamics of coherence-induced state ordering under Markovian channels

We study the dynamics of coherence-induced state ordering under incoherent channels, particularly four specific Markovian channels: amplitude damping channel, phase damping channel, depolarizing channel and bit flit channel for single-qubit states. We show that the amplitude damping channel, phase damping channel, and depolarizing channel do not change the coherence-induced state ordering by l₁ norm of coherence, relative entropy of coherence, geometric measure of coherence, and Tsallis relative α-entropies, while the bit flit channel does change for some special cases.     

Optical Dimensional Phenomena in Thin Layers of Gold and Atomic Semiconductors

We have investigated optical dimensional phenomena which are manifested as the thickness dependences of the indices of refraction n and absorption k and of the magnitude of the quasiBrewster angle of thin layers of gold. In the range of thicknesses 20 < d > 180 , all these phenomena have an oscillating character. Based on the earlier published experimental data on the energy coefficients of transmission T and reflection R of thin layers of atomic semiconductors (Se, Te, Ge, and Si), new calculations of the thickness dependences of n and k have been carried out without the simplifying assumptions which lead to incorrect results. The errors in determining the optical constants of thin layers from photometric data have been analyzed in detail. The causes of the earlier errors in works devoted to this kind of investigation have been established.     

Impact of coupling geometry on thermoelectric properties of oligophenyl-base transistor

Thermal and electron transport through organic molecules attached to three-dimensional gold electrodes in two different configurations, namely para and meta with thiol-terminated junctions is studied theoretically in the linear response regime using Green's function formalism. We used thiol-terminated(–SH bond) benzene units and found a positive thermopower because the highest occupied molecular orbital(HOMO) is near the Fermi energy level. We investigated the influence of molecular length and molecular junction geometry on the thermoelectric properties. Our results show that the thermoelectric properties are highly sensitive to the coupling geometry and the molecular length. In addition, we observed that the interference effects and increasing molecular length can increase the thermoelectric efficiency of device in a specific configuration.     

Effect of icosahedral clusters on β-relaxations in metallic glasses

The most pronounced β-relaxation was found in the Y-based binary metallic glasses(MGs). The correlation betweenβ-relaxation and local atomic structure was studied. The dynamic mechanical measurements were performed for three chosen binary systems: Zr-, Ti-, and Y-based MGs. The experimental results show that, in each system,the larger negative enthalpy of mixing(?Hm) between the component elements makes β-relaxation become more pronounced. The less negative value of ?Hm facilitates the formation of icosahedral clusters, which have a pinning effect on the excitation of β-relaxations and correspondingly make the β-relaxation become less pronounced. These chemical effects on β-relaxations can only be compared in the same MG system, and it is not suitable for the comparison between different systems due to the different features of the major metallic elements.     

Coefficient of Performance at Maximum χ-Criterion for Feynman Ratchet as a Refrigerator

The χ-criterion is defined as the product of the energy conversion efficiency and the heat absorbed per unit time by the working substance [de Tomás et al., Phys. Rev. E 85 (2012) 010104(R)]. The χ-criterion for Feynman ratchet as a refrigerator operating between two heat baths is optimized. Asymptotic solutions of the coefficient of performance at maximum χ-criterion for Feynman ratchet are investigated at both large and small temperature difference. An interpolation formula, which fits the numerical solution very well, is proposed. Besides, the sufficient condition for the universality of the coefficient of performance at maximum χ is investigated.     

基于S1000D标准的技术插图制作过程规范研究

为了规范交互式电子技术手册中技术插图制作过程,解决因不同制作者完成图形的差异性及格式多样化等问题,通过将S1000D、GJB6600等标准与本单位实际工作情况相结合,从技术插图的制作过程进行了全方位的分析研究,对插图标注、图层分配、布局等作了规范性要求,形成了切合实际满足IETM标准的技术插图制作过程规范,该规范能有效指导IETM实施过程中的技术插图制作,提高IETM手册的编制效率和过程质量。本研究使技术插图的制作过程真正实现了规范化。     

Determining Energy Eigenvalues of Dynamic Systems by Finding ＇Eigen-operator＇ ofSquare of Schroedinger Operator

A newly transparent approach for determining energy eigenvalues is proposed, which is finding the ‘eigen-operator‘ of the square of the Schroedinger operator. As three examples, we discuss the energy level of a nondegenerate parametric amplifier, an angular momentum system and a ring shape of coupled oscillators.     

A Bounded Measure for Estimating the Benefit of Visualization (Part II): Case Studies and Empirical Evaluation

Many visual representations, such as volume-rendered images and metro maps, feature a noticeable amount of information loss due to a variety of many-to-one mappings. At a glance, there seem to be numerous opportunities for viewers to misinterpret the data being visualized, hence, undermining the benefits of these visual representations. In practice, there is little doubt that these visual representations are useful. The recently-proposed information-theoretic measure for analyzing the cost–benefit ratio of visualization processes can explain such usefulness experienced in practice and postulate that the viewers’ knowledge can reduce the potential distortion (e.g., misinterpretation) due to information loss. This suggests that viewers’ knowledge can be estimated by comparing the potential distortion without any knowledge and the actual distortion with some knowledge. However, the existing cost–benefit measure consists of an unbounded divergence term, making the numerical measurements difficult to interpret. This is the second part of a two-part paper, which aims to improve the existing cost–benefit measure. Part I of the paper provided a theoretical discourse about the problem of unboundedness, reported a conceptual analysis of nine candidate divergence measures for resolving the problem, and eliminated three from further consideration. In this Part II, we describe two groups of case studies for evaluating the remaining six candidate measures empirically. In particular, we obtained instance data for (i) supporting the evaluation of the remaining candidate measures and (ii) demonstrating their applicability in practical scenarios for estimating the cost–benefit of visualization processes as well as the impact of human knowledge in the processes. The real world data about visualization provides practical evidence for evaluating the usability and intuitiveness of the candidate measures. The combination of the conceptual analysis in Part I and the empirical evaluation in this part allows us to select the most appropriate bounded divergence measure for improving the existing cost–benefit measure.     

A Bounded Measure for Estimating the Benefit of Visualization (Part I): Theoretical Discourse and Conceptual Evaluation

Information theory can be used to analyze the cost–benefit of visualization processes. However, the current measure of benefit contains an unbounded term that is neither easy to estimate nor intuitive to interpret. In this work, we propose to revise the existing cost–benefit measure by replacing the unbounded term with a bounded one. We examine a number of bounded measures that include the Jenson–Shannon divergence, its square root, and a new divergence measure formulated as part of this work. We describe the rationale for proposing a new divergence measure. In the first part of this paper, we focus on the conceptual analysis of the mathematical properties of these candidate measures. We use visualization to support the multi-criteria comparison, narrowing the search down to several options with better mathematical properties. The theoretical discourse and conceptual evaluation in this part provides the basis for further data-driven evaluation based on synthetic and experimental case studies that are reported in the second part of this paper.