镀镍石墨烯制备及红外干扰性能

为了研究镀镍石墨烯的红外消光性能,探索消光较佳的工艺条件,采用氧化还原和化学镀的方法制备了镀镍石墨烯,通过正交试验设计,以红外衰减率为评价指标,分析了各因素对镀镍石墨烯消光性能的影响,确定了红外消光较佳的工艺条件。利用烟幕箱试验,测试了镀镍石墨烯的红外透过率。基于“Lambert-Beer”定律,通过线性拟合计算了镀镍石墨烯的平均质量消光系数,并与镀前进行了对比分析。结果表明：红外消光较佳的镀镍石墨烯的制备工艺参数为：六水合硫酸镍的浓度为20 g·L^-1,次磷酸钠的浓度为24 g·L^-1,柠檬酸钠的浓度为10 g·L^-1,施镀温度为65 ℃。该条件下制备的镀镍石墨烯在中远红外波段均表现出非常好的红外消光能力。对于3~5 μm和8~14 μm红外波段,镀镍石墨烯的平均质量消光系数分别为2.38 m²·g^-1和2.19 m²·g^-1。与改性前的石墨烯相比,镀镍石墨烯在中远红外波段的平均质量消光系数分别提高了30%和35%,具有更广阔的应用前景。     

疏水纳米SiO2改性鳞片石墨的流动性及红外干扰性能（英）

为研究疏水纳米SiO₂改性鳞片石墨的分散性能和红外干扰效能,采用粉体特性测试仪测定了改性前后鳞片石墨粒子的流动性。采用气流分散的方式将鳞片石墨粒子分散在烟幕箱中形成烟幕。测试了烟幕的质量浓度和红外光谱透过率。依据搅拌沉降模型,计算得到了烟幕的沉降速度。结果表明,用质量分数为4.0%的疏水纳米SiO₂改性鳞片石墨的Carr流动性指数最高,达到了61,同时鳞片石墨粒子的沉降速度也从改性前的2.288×10^-3m·s^-1降至改性后的1.125×10^-3m·s^-1,形成的烟幕在3~5 μm 和8~12 μm波段的平均红外光谱透过率也分别从0.3895%和 0.7288%降为0.072% 和 0.176%。疏水纳米SiO₂对鳞片石墨表面的物理修饰,有效改善了鳞片石墨粒子的流动性和分散性能,显著提高了鳞片石墨形成烟幕的留空持续时间和红外干扰性能。     

碳纳米管/石墨烯/碳复合材料烟幕的中远红外的干扰性能

为探索碳纳米管/石墨烯/碳复合材料在3～5μm和8～14μm中远红外波段烟幕干扰方面的应用,用液相法制备了碳纳米管/石墨烯/碳复合材料。采用扫描电子显微镜,对比分析了石墨烯、碳纳米管和复合材料的微观形貌。采用傅里叶红外光谱仪技术,对比分析了三种材料的静态红外吸收能力。基于烟箱实验,测试了石墨烯、碳纳米管和复合材料对3～5μm、8～14μm中远红外的透过率,并根据"朗伯?比尔"定律计算了烟幕的平均质量消光系数。结果表明,经过沥青碳化,以沥青碳为骨架,碳纳米管与石墨烯形成的复杂网状空间结构的烟幕干扰复合材料,抑制了碳纳米管的结团和石墨烯的堆叠现象,改善了悬浮性。针对3～5μm波段,计算得到碳纳米管、石墨烯及碳纳米管/石墨烯/碳复合材料平均红外透过率分别约为9%、10%和5%,复合材料的有效遮蔽时间相比碳纳米管、石墨烯分别增加了约13%和21%;对8～14μm红外波段的平均红外透过率分别约为3%、5%和4%,复合材料有效遮蔽时间相比碳纳米管、石墨烯增加了约28%和13%。碳纳米管/石墨烯/碳复合材料改善了单一碳材料的悬浮性能和红外光谱吸收性能,对中红外的干扰性能增强,对远红外的干扰性能有所下降,但有效干扰时间仍有所提高,其远红外干扰性能有待进一步改进。     

碳纳米材料红外图像遮蔽特性研究

碳纳米材料是一种新型材料,具有尺度小、重量轻、导电及吸波性能好等特点.为了探索碳纳米材料在干扰红外成像制导武器方面的应用,利用大型烟幕箱研究了碳纳米管、纳米碳纤维、纳米石墨几种碳纳米材料对8～12 μm波段红外图像的遮蔽特性.结果表明,碳纳米材料对红外辐射由于吸收和散射双重作用,具有很好的远红外消光作用,质量消光系数最小和最大值分别为0.8884 m2·g-1和2.6226 m2·g-1.     

几种纳米氧化铝的红外消光性能研究

利用傅里叶变换红外光谱仪在中型烟幕试验柜中,对八种α型和γ型纳米氧化铝粉体气溶胶在3~5μm与8~14μm波段的红外消光特性进行了测试对比。利用KBr压片法测试了样品的红外光谱,给出了样品的晶型、平均粒度和比表面积等特征数据。实验结果表明,纳米氧化铝对红外具有良好的消光作用。纳米氧化铝气溶胶在3~5μm和8~14μm波段的最大质量消光系数分别为1.798m2·g-1和1.940m2·g-1;γ型纳米氧化铝的红外平均透过率普遍小于α型;比表面积越大、纳米氧化铝粒子平均直径越小对红外的消光性能就越显著。     

膨胀石墨烟幕对1.06μm和10.6μm激光的消光特性研究

为测试膨胀石墨烟幕红外激光消光特性,在分析膨胀石墨烟幕消光机理的基础上,通过测量其在不同时段的烟幕平均质量浓度和平均激光透过率,得到了膨胀石墨烟幕对1.06μm近红外和10.6μm远红外激光的质量消光系数分别为1.149 8m<'2>/g和0.820 5m<'2>/g.结果表明,膨胀石墨烟幕对两个波长的红外激光具有良好的消光和干扰效果,在光电对抗领域具有广阔的应用前景.     

铝基微单元复合燃料在NEPE固体推进剂中的应用

为研究铝基微单元燃料在硝酸酯增塑聚醚（NEPE）固体推进剂中的应用性能,以自制的铝基微单元复合燃料（Al@AP）代替铝粉加入NEPE固体推进剂,以真空定容爆热试验、发动机试验、残渣活性铝测试、高速摄影、单向拉伸试验、工艺性能测试等手段研究了Al@AP对NEPE固体推进剂燃烧、力学、工艺等性能的影响;并对Al@AP在NEPE固体推进剂中的燃烧作用机理进行了分析。结果表明,以19.5%的Al@AP代替FLQT-3 Al后,NEPE固体推进剂的爆热由6039.4 J·g^-1提升至6924.8 J·g^-1,残渣量由28.91 g降至7.64 g,残渣活性铝含量由14.64%降至0.37%,残渣粒径d₅₀由94.12 μm降至24.21 μm,NEPE固体推进剂喷射效率提升,铝粉在燃面停留时间由55 ms缩短至40 ms,且无明显融联团聚现象,且Al@AP对推进剂的燃速、力学、工艺等性能基本无影响。     

红磷与纳米氧化铝组合烟幕对10.6μm激光的消光系数研究

为了提高红磷烟幕对10.6μm激光的消光性能,在中型烟幕试验柜中分别测试了纳米氧化铝气溶胶、红磷及其组合烟幕对10.6μm激光的质量消光系数。在空气相对湿度为40%的条件下,纳米氧化铝气溶胶、红磷及其组合烟幕对入射功率为1.0W的10.6μm激光的平均质量消光系数分别为0.222,0.298,0.449m2.g-1。根据试验结果,纳米氧化铝气溶胶和红磷烟幕组合使用后可以显著改善纳米氧化铝粉体的分散特性,并使得红磷烟幕对该波段激光的质量消光系数提高50.7%。     

2，6-二氨基-3，5-二硝基-1-氧吡嗪的高效液相色谱分析技术

为了快速检验单质炸药2,6-二氨基-3,5-二硝基-1-氧吡嗪（ANPZO）的质量,指导ANPZO合成工艺优化,建立了ANPZO和主杂质2,6-二氨基-3,5-二硝基吡嗪（ANPZ）含量分析的高效液相色谱法。采用C18色谱柱（250 mm×4.6 mm、5 μm）,以甲醇、水、三氟乙酸混合溶剂为流动相,用紫外-可见光检测器,在425 nm检测波长下,对ANPZO试样溶液进行色谱分离,结果发现,ANPZO与反应中间体ANPZ分离良好,分析时间仅为7.0 min。在0.1~0.6 mg·mL^-1的浓度范围内,ANPZO的线性相关系数为0.9996。ANPZO检出限为20 ng·g^-1,定量限为67 ng·g^-1,重复性测试结果的相对标准偏差为0.30%。     

光谱法研究膨胀石墨红外波段复折射率

具有良好消光性能的膨胀石墨可用作红外/毫米波复合无源干扰材料,复折射率是研究其消光性能的重要参数.采用压片法分别对膨胀石墨压片在0.24～2.6 μm和2.5～25μm波段的反射光谱进行了测试.结合所测光谱数据,利用Kramers-Kronig(K-K)关系和Bruggemen有效介质理论对膨胀石墨5～10μm波段的复...     

Stability of the Third Generation Intensifier under Illumination

The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased.     

Passive Acoustic Radar for Detecting Supersonic Cruise Missile

A Passive Acoustic Radar is presented as a necessary complement to electromagnetic wave radar, which will be expected to be an effective means for detecting cruise missiles. Acoustic characteristics of supersonic flying projectiles with diverse shapes are expounded via experiment. It is pointed out that simulation experiment could be implemented using bullet or shell instead of cruise missile. Based on theoretical analysis and experiment, the ““acoustic fingerprint““ character of cruise missile is illustrated to identify it in a strong noise environment. After establishing a locating mathematical model, the technique of acoustic embattling is utilized to resolve a problem of confirming the time of early-warning, considering the fact that velocity of sound is much slower than that of light. Thereby, a whole system of passive acoustic radar for detecting supersonic cruise missile is formed.     

Super-resolution Restoration of Remote-sensing Images

A novel image restoration scheme, which is super-resolution image restoration algorithm Poisson-maximum-afterword-probability based on Markvo constraint （MPMAP） combined with evaluating image detail parameter D, has been proposed. The advantage of super-resolution algorithm MPMAP incorporated with parameter D lies in the fact that superresolution algorithm MPMAP model is discrete, which is in accordance with remote-sensing imaging model, and the algorithm MPMAP is proved applicable to linear and non-linear imaging models with a unique solution when noise is not severe. According to simulation experiments for practical images, super-resolution algorithm MPMAP can retain image details better than most of traditional restoration methods; at the same time, the proposed parameter D can help to identify real point spread function （PSF） value of degradation process. Processing result of practical remote-sensing images by MPMAP combined with parameter D are given, it illustrates that MPMAP restoration scheme combined PSF estimation has a better restoration result than that of Photoshop processing, based on the same original images. It is proved that the proposed scheme is helpful to offset the lack of resolution of the original remote-sensing images and has its extensive application foreground.     

Design and Simulation of TF and TA Controller for Missile

A nonlinear terrain following(TF) and terrain avoidance(TA) controller is proposed for missile control systems. Based on classical TF algorithm (adaptive angle method), a new method for TF controller is proposed by using angle of attack. A method of obtaining terrain outline data from digital elevation map (DEM) for TF control is discussed in order to save store space. A TA algorithm is proposed by using bank-to-turn technique. The block control model, which is suitable for backstepping design, is given for nonlinear model of missile. Making full use of the characteristics of the system and combining block control principle and backstepping technique, a robust controller design method is proposed. Uncertainties in every sub-block are allowed, and can be canceled by using the idea of nonlinear damping. It is proved that the state tracking errors are converged to a neighborhood of the origin exponentially. Finally, nonlinear six-degree-of-freedom simulation results for the missile model are presented to demonstrate the effectiveness of the proposed control law.     

Design and Analysis of Test Schemes of Static Postponing Time on Shrapnels Used to Riot Control

The test scheme of static postponing time given in our actual national military test standard on shrapnels used to control riot is a nine-point test scheme on the combined action of three kinds of temperatures and three kinds of pressures,the consumed ammunitions are more excessive. Statistic analysis and tentative checkout about a lot of test data are done,feasibility gists are put forward for optimizing of the test design scheme. The optimizing design and data analysis of test scheme of the item are done by managing uniformity design theory, two scientific and reasonable six-point test schemes are confirmed. The feasibility and reliability of the optimizing design schemes put forward above are proved ulteriorly by test validating. The gained schemes not only have good design uniformity and little ammunition wastage and meet the test demand, but also have better forecast ability for the result data of other points using the mathematic models from the actual test points.     

Design of Non-fragile Satisfactory Estimator for Linear Continuous Perturbed Stochastic Systems

The design problem of non-fragile estimator is addressed for a class of perturbed linear continuous systems. The perturbations occur on the plant and estimator parameters. The estimator designed should force the error system to achieve the desired decay rate and force the steady error variance less than the specified upper bound irrdevancy of the admissible plant perturbations and estimator perturbations. Consistency problem of the decay rate with the variance upper bound is first considered via linear matrix inequality （LMI） approach. The solution of the estimator parameter under specifications to be consistent is then discussed. The consistency condition of specifications and estimator parameter solution are transformed to feasible or minimum problems subject to a set of LMI respectively. The method is illustrated by a numerical example.     

An Improved Scene-based Nonuniformity Correction Algorithm for Infrared Focal Plane Arrays Using Neural Networks

The improved scene-based adaptive nonuniformity correction （NUC） algorithms using a neural network （NNT） approach for infrared image sequences are presented and analyzed. The retlna-like neural networks using steepest descent model was the first proposed infrared focal plane arrays （IRFPA） nonuniformity compensation method, which can perform parameter estimation of the sensors over time on a frame by frame basis. To increase the strength and the robustness of the NNT algorithm and to avoid the presence of ghosting artifacts, some optimization techniques, including momentum term, regularization factor and adaptive learning rate, were executed in the parameter learning process. In this paper, the local median filtering result of Xij （ n ） is proposed as an alternative value of desired network output of neuron Xij （ n ）, denoted as Tij （ n ）, which is the local spatial average of Xij （ n ） in traditional NNT methods. Noticeably, the NUC algorithm is inter-frame adaptive in nature and does not rely on any statistical assumptions on the scene data in the image sequence. Applications of this algorithm to the simulated video sequences and real infrared data taken with PV320 show that the correction results of image sequence are better than that of using original NNT approach, especially for the short-time image sequences （several hundred frames） subjected to the dense impulse noises with a number of dead or saturated pixels.     

Piecewise Filter of Infrared Image Based on Moment Theory

The disadvantages of IR images mostly include high noise, blurry edge and so on. The characteristics make the existent smoothing methods ineffective in preserving edge, To solve this problem, a piecewise moment filter （PMF） is put forward. By using moment and piecewise linear theory, the filter can preserve edge. Based on the statistical model of random noise, a related-coefficient method is presented to estimate the variance of noise. The edge region and model are then detected by the estimated variance. The expectation of first-order derivatives is used in getting the reliable offset of edge. At last, a fast moment filter of double-stair edge model is used to gain the piecewise smoothing results and reduce the calculation. The experimental result shows that the new method has a better capability than other methods in suppressing noise and preserving edge.     

Bistatic Sonar Localization Based on Best Linear Unbiased Estimation

A best linear unbiased estimation （BLUE） algorithm for bistatic sonar localization is proposed. The Cramer-Rao bound for bistatic Sonar and the geometrical dilution of precision （GDOP） in different conditions are given. The simulation results show that the location accuracy of BLUE algorithm is higher than the weighted least square method.     

Research on Gear-broken Fault Diagnosis in a Tank Gearbox

A fault diagnosis method of working position gear in a tank gearbox is put forward based on simulating the fault of working position gear in an actual tank, extracting the envelope of vibration signal by Hilbert transformation amplitude demodulation method, and zooming the low-frequency band to envelope signal.