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1.
The development of Insensitive Munitions (IM) has been progressing for over three decades. Ever since the highly publicized US Navy aircraft carrier accidents in the 1960s to 1980s, there has been a growing recognition of the value of IM. Reminders of the need for IM have been provided all too often in the form of accidents, such as experienced by the US Army at Camp Doha and the prevalence of attacks on military installations around the world.
The process for developing IM has improved over the years as technology for mitigating the consequences of accidental initiation has emerged. Early IM developments were based upon replacement of the traditional TNT-based explosives, with their high vulnerability, with reduced vulnerability PBXs. This led to significant improvements, such as that observed with the replacement of H-6 with PBXN-109 in the US Navy Mk82 GP bomb. From the early 1990s, the use of a complete systems approach was highlighted as the optimum method to achieve IM compliance while maintaining or enhancing operational performance. The use of a systems approach has resulted in the fielding of a number of munition systems with significant IM properties. The challenge for the future is to continue the development and fielding of improved performance IM munitions with limited funding for research and the high cost of introducing new ingredients into energetic formulations. A key development to allow continued progress to occur is the introduction of improved versions of current explosive ingredients. The attention focused in the past few years on forms of RDX with reduced shock sensitivity has highlighted the possibility of improving well-known materials. In the near future, the application of materials technology may provide improved versions of other important crystalline energetic materials currently in production or advanced development, including HMX, NTO, CL-20 and ADN and help advance the development of further explosive ingredients such as FOX-7 and LLM-105. Advances in the development and application of computer modeling must be made if we are to move forward from our current reliance on a limited number of canonical tests that are held to be representative of the hazards likely to be encountered. The availability of verified and validated models describing the response of energetic materials to various thermal and mechanical threats will enable us to perform parametric studies on systems. This will allow us to estimate their response to hazards that are characteristic of the specific environment experienced by that system, and so to tailor the materials and packaging to minimize risk and maximize performance. 相似文献
2.
The technique of watermarking has been introduced into 2D vector maps for many potential applications such as protecting the copyright of important GIS (geographical information system) data and tracing the data source of military maps. In most previous works, although the validity of the map data could be preserved during the embedding procedure, the shape-distortions of the map elements are usually neglected which would tend to degrade the invisibility of the watermarking schemes. A shape-preserving algorithm for watermarking 2D vector maps is presented in this paper. A 1D distance sequence extracted from the original map is adopted as the cover data instead of 2D coordinates. A watermark bit is represented by changing the distributions of the cover data. The embedding procedure induces lower shape-distortions than in former works. Experimental results indicate better invisibility of the proposed scheme, as well as its robustness to certain attacks such as map simplification, interpolation, additive noise and most geometric transforms. 相似文献
3.
The vehicle system studied in this paper is a type of complex repairable system in which the subsystems follow various failure distributions and conform to arbitrary failure and repair distributions.The failure data of subsystems are sometimes lacking,and the reliability test sample sizes tend to be small.Monte-Carlo technique combined with Bayes method is used to evaluate its dependability(reliability and maintainability).Following the "first-in,first-out" queuing rule,the logic relation of dependability is established by means of repairing priority and event lists.Simulation outputs the entire history of a mission,statistics of reliability and maintainability parameters and provides the basic data for system reliability design and maintainability management. 相似文献
4.
The key technique of a kinetic energy rod(KER) warhead is to control the flight attitude of rods. The rods are usually designed to different shapes. A new conceptual KER named profiled rod which has large L/D ratio is described in this paper. The elastic dynamic equations of this profiled rod flying at high velocity after detonation are set up on the basis of Euler-Bernoulli beam, and the aeroelastic deformation of profiled rod is calculated by semi-analytical method for calculating the vibration characteristics of variable cross-section beam. In addition, the aeroelastic deformation of the undeformed profiled rod and the aeroelastic deformation of deformed profiled rod which is caused by the detonation of explosive are simulated by computational fluid dynamic and finite element method(CFD/FEM), respectively. A satisfactory agreement of these two methods is obtained by the comparison of two methods. The results show that the semi-analytical method for calculating the vibration characteristics of variable cross-section beam is applied to analyze the aeroelastic deformation of profiled rod flying at high velocity. 相似文献
5.
Active phased array antennas enhances the performance of modern radars by using multiple low power transmit/receive modules in place of a high power transmitter in conventional radars. Fully distributed phased array radars demand the distribution of various signals in radio frequency(RF) and digital domain for real time operation. This is normally achieved through complex and bulky coaxial distribution networks. In this work, we intend to tap the inherent advantages of fiber links with wavelength division multiplexed(WDM) technology and a feasibility study to adapt these links for radar applications is carried out. This is done by analysing various parameters like amplitude, delay, frequency and phase variation response of various radar waveforms over WDM links. This also includes performance evaluation of non-linear frequency modulation(NLFM) signals, known for better signal to noise ratio(SNR) to specific side lobe levels. NLFM waveforms are further analysed using pulse compression(PC) technique. Link evaluation is also carried out using a standard simulation environment and is then experimentally verified with other waveforms like RF continuous wave(CW), pulsed RF and digital signals. Synchronization signals are generated from this variable duty cycle digital signals during real time radar operation. During evaluation of digital signals, variable transient effects for different duty cycles are observed from an amplifier configuration. A suppression method is proposed to eliminate this transient effects. Further, the link delay response is investigated using different lengths of fiber spools. It can be inferred from the experimental results that WDM links are capable of handling various signals significant to radar applications. 相似文献
6.
The principle of rotor flux-orientation vector control on 100/150 kW three-phase AC induction motor for electric drive tracked vehicles is analyzed, and the mathematic model is deduced. The drive system of induction motor is modeled and simulated by Matlab/Simulink. The characteristics of motor and drive system are analyzed and evaluated by practical bench test. The simulation and bench test results show that the model is valid, and the driving control system has constant torque under rated speed, constant torque above rated speed, widely variable speed range and better dynamic characteris- tics. In order to evaluate the practical applications of high power induction motor driving system in electric drive tracked vehicles, a collaborative simulation based on interface technology of Matlab/Simulink and multi-body dynamic analysis software known as RecurDyn is done, the vehicle performances are predicted in the acceleration time (0 - 32 km/h) and turning characteristic (v = 10 km/h, R = B). 相似文献
7.
The automatic chain shell magazine is the primary subassembly of the automatic ammunition loading system of a big-caliber howitzer. Due to the change of the shell amount in the magazine during firing, its positioning control is a kind of control problem of systems with uncertain parameters. In order to realize accurate control of shell position, an optimal guaranteed cost control algorithm based on linear matrix inequality (LMI) theory was put forward. The motion equations of the magazine were built, and the motion equations for four special load situations were linearized; according to the basic theory of the guaranteed cost control, the motion equations were written as the standard forms for linear uncertain systems; the optimal guaranteed cost control law for the position control of the magazine was obtained by use of LMI toolbox in MATLAB package. Using this control law, the controlled dynamic simulation of the shell magazine was carried out. The simulation results indicate that the control algorithm has high control precision. 相似文献
8.
Unsymmetrical dimethylhydrazine (UDMH) is a main liquid rocket propellant. There are plenty of toxic and stable contaminations in its wastewater. The harmful influence has been considered. Nowadays the disposal technology of wastewater containing UDMH has plenty of disadvantages, such as high energy consuming, low safety factor, numerous secondary contaminations, strong toxicity, and so on. It is necessary to find a new way for wastewater disposal. Biodegradation technology is low innocuity and cleanliness, has great degradation capacity, and can almost degrade all kinds of organic substances. In this paper the aerobic active sludge is used to treat wastewater containing UDMH which is one kind of biodegradation technology. 相似文献
9.
Unsymmetrical dimethylhydrazine (UDMH) is a main liquid rocket propellant. There are plenty of toxic and stable contaminations in its wastewater. The harmful influence has been considered. Nowadays the disposal technology of wastewater containing UDMH has plenty of disadvantages, such as high energy consuming, low safety factor, numerous secondary contaminations, strong toxicity, and so on. It is necessary to find a new way for wastewater disposal. Biodegradation technology is low innocuity and cleanliness, has great degradation capacity, and can almost degrade all kinds of organic substances. In this paper the aerobic active sludge is used to treat wastewater containing UDMH which is one kind of biodegradation technology. 相似文献
10.
As weapon system effectiveness is affected by many factors,its evaluation is essentially a multi-criterion decision making problem for its complexity.The evaluation model of the effectiveness is established on the basis of metrics architecture of the effectiveness.The Bayesian network,which is used to evaluate the effectiveness,is established based on the metrics architecture and the evaluation models.For getting the weights of the metrics by Bayesian network,subjective initial values of the weights are given,gradient ascent algorithm is adopted,and the reasonable values of the weights are achieved.And then the effectiveness of every weapon system project is gained.The weapon system,whose effectiveness is relative maximum,is the optimization system.The research result shows that this method can solve the problem of AHP method which evaluation results are not compatible to the practice results and overcome the shortcoming of neural network in multilayer and multi-criterion decision.The method offers a new approach for evaluating the effectiveness. 相似文献
11.
介绍了3—硝基—1,2,4—三唑—5—酮(简称NTO)的爆轰性能以及国外研制的以NTO为基混合炸药的配方,并与HMX、TATB为基塑料粘结炸药的性能进行了比较.叙述了用来起爆以NTO为基混合炸药的传爆药和传爆序列. 相似文献
12.
通过动态差示扫描量热实验研究了3-硝基-1,2,4-三唑-5-酮(NTO)的热行为,得到其热分解反应曲线。利用中断回归法、瑞士方法研究了NTO的自催化热分解反应特性,并通过等温实验进行验证。基于NTO的热分解反应曲线数据,采用Friedman法求得其活化能Eα与ln\[Af(α)\]值随转化率α的变化曲线,并结合热平衡方程计算了其绝热诱导期TMRa. 结果表明:在升温速率分别为2 ℃/min、5 ℃/min、10 ℃/min、20 ℃/min条件下,NTO的起始分解温度为249.4~ 271.2 ℃, 其分解反应为自催化反应,热履历显著降低了其起始分解温度和峰值温度;在反应不同阶段,NTO具有不同的活化能,其绝热诱导期为8 h和24 h时对应的温度T8和T24分别为166.1 ℃和152.1 ℃. 相似文献
13.
14.
采用丙酮重结晶超细化NTO方法,将NTO溶于丙酮,通过快速真空蒸馏使NTO重结晶.研究了不同温度、真空度、溶液浓度等因素对重结晶NTO晶形和粒度的影响,并用热力学和动力学理论进行了分析.结果认为:温度、真空度和溶液浓度通过影响溶液过饱和度而影响NTO的粒径,同时温度是决定NTO晶形的主要因素.利用扫描电镜(SEM)和动态光散射法(SDP)对结果进行表征,其平均粒径小于1μm,粒度分布均匀,为立方型NTO晶体.撞击感度试验表明超细化后NTO的撞击感度明显降低.该细化过程简单、环境友好. 相似文献
15.
Based on the crystal engineering, six models of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX)/3-nitro-1,2,4-triazol-5-one(NTO) supramolecular explosive were designed. The probable formation of HMX/NTO supramolecular explosive was investigated by the molecular dynamic (MD) method. Interaction between oxygen atoms in HMX and hydrogen atoms in NTO or between hydrogen atoms in HMX and oxygen atoms in NTO were studied by the radial distribution function (RDF). It shows that there are strong hydrogen bonds and Van Der Waals forces between HMX and NTO, in which the hydrogen bonds between oxygen atoms in the NTO and hydrogen atoms in HMX are the main host-guest interactions. The distributions of bond length, bond angle and dihedral angle were simulated by MD. It shows that the structure of HMX is seriously distorted. The binding energies and X-ray powder diffraction (XRD) patterns were calculated on the basis of the final HMX/NTO supramolecular structures. The results show that the binding energies of six supramolecular models are E binding (1 1 1-) >E binding (1 0 0)>E binding (0 2 0)>E binding (random)>E binding (1 0 2-)>Ebinding (0 1 1), and the XRD patterns of six supramolecular models are quite different from pure HMX or NTO. Based on the investigation for growth morphology, binding energies and RDF, the model of HMX supercell substituted by NTO along the (1 1 1-) surface of HMX is easier to form. 相似文献
16.
用差示扫描量热仪(DSC)测定了含能化合物3-硝基-1,2,4-三唑-5-酮(NTO)和碳酰肼(CHZ)在340~410 K温度区间内、苦味酸(PA)和二硝基苯酚(DNP)在330~360 K温度区间内的比热容,对所测温度区间内物质的比热容随温度变化的曲线进行了拟合,NTO和CHZ的比热容在所测温度区间内比热随温度变化符合一次函数:Cp=a bT,而DNP和PA符合三次函数:Cp=a bT cT2 dT3。NTO、CHZ、DNP、PA拟合曲线的相关度分别是0.9591、0.9730、0.9968和0.9972。 相似文献
17.
用碱式碳酸镁与3 硝基 1,2,4 三唑 5 酮(NTO)在水中合成了[Mg(H2O)6](NTO)2·2H2O。用DSC,TG/DTG和IR研究了它的热分解机理。以晶体实验构型为初始值对配合物用6 31G基组在B3LYP水平下进行量子化学计算。结果表明Mg原子与配位水分子之间的配位键具有共价键性质。NTO环上的成环氮原子都带负电荷,而硝基上(—NO2)的氮原子带有正电荷,说明标题配合物在加热至一定温度时,—NO2将首先离去,这与热分解实验结果一致。 相似文献
18.
采用低感、钝感炸药NTO、NGU作为添加剂,获得了以RDX、HMX为基的低感高能炸药配方,研究了NTO、NUG对其撞击和摩擦感度的影响。实验表明NTO可降低撞击和摩擦感度,并对其他性能产生不大影响。这说明低感或钝感炸药的加人是降低塑性炸药感度的有效方法。 相似文献
19.
NTO铅铜衍生物对AP-CMDB推进剂燃烧性能和热分解的影响 总被引:5,自引:5,他引:0
研究了3-硝基-1,2,4-三唑-5-酮(NTO)的铅盐、铜盐和铜正盐对AP-CMDB推进剂燃烧性能和热分解特性的影响。结果表明,NTO铅铜衍生物均可促进AP-CMDB推进剂中双基粘合剂体系NC/NG的受热分解,使AP-CMDB推进剂较低压强(1~7MPa)下的燃速提高,较高压强(10~20MPa)下的燃速降低,并使推进剂的燃速压强指数降低。NTO铜正盐可同时促进AP-CMDB推进剂中粘合剂体系NC/NG和氧化剂AP的热分解,对该推进剂燃烧性能的催化效果最佳。 相似文献
20.
用X射线单晶衍射法测定了4-氨基-1,2,4-三唑(4-AT)与3-硝基-1,2,4-三唑-5-酮(NTO)制得的盐(AT)(NTO)的单晶结构。结果表明:该晶体为单斜晶系,属P21/c空间群,晶体学参数a=7.071(2),b=6.361(3),c=18.792(7);β=96.43(3)°;V=839.9(5)3;Z=4;Dc=1.694 g.cm-3;μ=0.145/mm;F(000)=440。在(AT)(NTO)晶体中,4-AT阳离子上所有的原子和NTO阴离子上所有的原子均在以各自三唑环为基础的一个平面上,两平面夹角为7.6°。由真空安定性(VST)、撞击感度、摩擦感度和静电火花感度试验所得的真空放气量、特性落高、爆炸概率、50%发火电压、50%发火能分别为0.28 mL.g-1(100℃/48 h),124.7 cm,0%,12.841 kV和2.515 J,表明,(AT)(NTO)对热是稳定的,对撞击、摩擦和静电火花是不敏感的。 相似文献