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以某型号导弹飞行试验为研制背景,设计出一款精度高、通用性强的新型弹载计算机。该弹载计算机以高性能DSP和FPGA为系统框架,通过其丰富的外围接口和强大的处理能力,结合AD5764转换模块、MAX3490通信模块、ADUM1401四通道数字隔离器和ULN2801达林顿管驱动器组成的离散量输出等模块,解决了弹载计算机与弹上飞控部件之间复杂的并行数据处理以及多种控制算法实时解算问题,具有体积小、重量轻、精度高、实时性好等特点。经过多次飞行试验表明,该弹载计算机具有较高的可靠性和稳定性,应用前景非常广泛。 相似文献
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Underwater asymmetric acoustic transmission structure using the medium with gradient change of impedance 下载免费PDF全文
We propose an underwater asymmetric acoustic transmission structure comprised of two media each with a gradient change of acoustic impedance. By gradually increasing the acoustic impedances of the media, the propagating direction of the acoustic wave can be continuously bent, resulting in allowing the acoustic wave to pass through along the positive direction and blocking acoustic waves from the negative one. The main advantages of this structure are that the asymmetric transmission effect of this structure can be realized and enhanced more easily in water. We investigate both numerically and experimentally the asymmetric transmission effect. The experimental results show that a highly efficient asymmetric acoustic transmission can be yielded within a remarkable broadband frequency range, which agrees well with the numerical prediction. It is of potential practical significance for various underwater applications such as reducing vibration and noise. 相似文献
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氨基葡萄糖及羧甲基氨基葡萄糖与铁(Ⅱ)、锌(Ⅱ)、钴(Ⅱ)、铜(Ⅱ)配合物的光谱特征 总被引:14,自引:1,他引:13
本文研究了氨基葡萄糖及羧甲基氨基葡萄糖分别与铁(Ⅱ)、锌(Ⅱ)、钴(Ⅱ)、铜(Ⅱ)形成配合物的UV,IR和^1H-NMR光谱特征。配合物紫外的λmax发生了明显紫移;在IR谱中,配合物的面外振动峰655cm^-1较未配位的氨基葡萄糖中的面外振动峰670cm^-1低,且在990cm^-1附近出现新的吸收峰;在^1H-NMR谱中,配合物C3上羟基中的质子化学位移较未配位的均移向高场,氨基上质子的化学位移较未配位的也移向高场,其他碳上羟基中的质子化学位移值不变,从而初步证实了配合物中的氨-金属(N-M)键的形成。本文还研究了羧甲基氨基葡萄糖及其与铁(Ⅱ)、钴(Ⅱ)、铜(Ⅱ)配合物的合成。其配合物的IR谱线较未配位的IR谱线并没增多,指出这种反常现象是糖环的刚性所致。它们的IR和UV光谱均证实了分子中不存在游离的羰基峰,并证实了它们分子中内盐的存在,配合物的IR谱中出现新的一组吸收峰:433.1和408.9cm^-1(O-Fe),507.1和495.0cm^-1(O-Co),403.1和389.0cm^-1(O-Cu),证实了配合物中的氧-金属键(O-M)的形成。 相似文献
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采用空气炮在6万g、8万g、10万g和12万g高过载环境下对制式桥丝式独角和双脚线电雷管进行实验,讨论了加速度峰值、加载方向和产品结构对损伤和性能的影响,获得了高过载下的损伤规律和损伤模式,结合产品结构用动力学理论进行了分析。研究表明:损伤模式有局部塑性变形、相对位移和结构脆性破坏,表现为撞击端变形、电极塞内陷、电极和脚线倾斜、电极塞裂纹、电阻增大、桥丝断裂、输出威力散布增大。输出端加载时长度变化率随加速度增加而增大,独角雷管长度减小由电极塞内陷引起,双脚线雷管长度减小由撞击端变形导致;独角雷管横向加载时电阻变化显著,发生断桥和爆炸;过载后输出威力散布增大。 相似文献
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A complete understanding of the bubble dynamics is deemed necessary in order to achieve their full potential applications in industry and medicine. For this purpose it is first needed to expand our knowledge of a single bubble behavior under different possible conditions including the frequency and pressure variations of the sound field. In addition, stimulated scattering of sound on a bubble is a special effect in sound field, and its characteristics are associated with bubble oscillation mode. A bubble in liquid can be considered as a representative example of nonlinear dynamical system theory with its resonance, and its dynamics characteristics can be described by the Keller–Miksis equation. The nonlinear dynamics of an acoustically excited gas bubble in water is investigated by using theoretical and numerical analysis methods. Our results show its strongly nonlinear behavior with respect to the pressure amplitude and excitation frequency as the control parameters, and give an intuitive insight into stimulated sound scattering on a bubble. It is seen that the stimulated sound scattering is different from common dynamical behaviors, such as bifurcation and chaos, which is the result of the nonlinear resonance of a bubble under the excitation of a high amplitude acoustic sound wave essentially. The numerical analysis results show that the threshold of stimulated sound scattering is smaller than those of bifurcation and chaos in the common condition. 相似文献
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叙述无光焦度补偿组与次镜重合时的全球面双反射系统的设计,给出利用PW法求解初始结构的基本理论,阐述应用无光焦度补偿组来平衡球面反射系统像差的方法。通过改变遮拦比K和焦点伸出量进行光线追迹,选择出该类系统K和的最佳组合。给出设计实例:系统工作波段=450 nm~700 nm、焦距f=1 600 mm、相对孔径A=1/8、视场角=05,遮拦比K=0.35、焦点伸出量=0.1,系统优化后的球差系数 SⅠ=-0.001 207,彗差系数SⅡ=0.000 192,波像差W=0.043 27。 相似文献
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