SC-CO_2辅助高固含量发射药代料挤出加工的流变行为(英文)

为了改善高固含量发射药挤出加工时流变性能,采用超临界二氧化碳(SC-CO_2)作为增塑剂辅助高固含量发射药代料醋酸纤维素/碳酸钙(CA/CaCO_3)挤出加工,通过狭缝流变仪和幂律方程研究了CA/CaCO_3和CA/CaCO_3/SC-CO_2溶液的在线流变行为,使用Polyflow软件模拟了CA/CaCO_3/SC-CO_2溶液的分散混合性能。结果表明,温度为50℃时,SC-CO_2使CA/CaCO_3溶液的稠度系数降低了26.00%,非牛顿指数增加了16.67%,降低了CA/CaCO_3溶液在挤出过程的粘度和压力;随着加工温度的升高,CA/CaCO_3/SC-CO_2溶液的粘度降低;在低剪切速率下,CA/CaCO_3/SC-CO_2溶液的剪切粘度对温度的敏感性较高;根据模拟结果,温度为50℃时,CA/CaCO_3/SC-CO_2溶液经受最大剪切应力的最大概率密度比CA/CaCO_3溶液增加了20.63%,SC-CO_2的注入有利于CA/CaCO_3溶液分散混合性能的提高。     

螺杆挤出过程中物料在线流变行为及其数值模拟

为研究发射药螺杆挤出成型工艺,采用硝化棉(NC)代料二醋酸纤维素(CDA)、通过狭缝流变仪研究了物料在螺杆挤出成型过程中的在线流变行为。结果表明,CDA溶液为一种非牛顿假塑性流体,提高加工温度有利于改善物料的流动性并降低机头压力。同时利用计算机辅助工程软件Polyflow对挤出机机头流道内物料的流变行为进行了数值模拟,选取Power模型,得到流道内物料的压力分布、剪切速率分布和剪切粘度分布,模拟结果与实验数据相近。模拟结果表明,螺杆转速增大,物料的剪切粘度降低,但同时增大了机头压力和压降速率,不利于发射药的质量和加工的安全性。CDA溶液挤出成型过程中在线流变行为及其数值模拟计算的研究,对发射药的连续挤出成型具有重要的指导意义。     

酸性和有机溶液对α-AlH3稳定改性的研究

为提高α-AlH₃的稳定性,采用酸性和有机溶液对其进行了处理,通过结构表征、稳定性测试和机械感度测试对比研究了处理前后的样品,探讨了改性对α-AlH₃释氢性能的影响及改性机理。结果表明,改性方法有效且对样品释氢性能影响微弱,改性后的α-AlH₃的释氢损失量不超过1%,起始释氢温度和释氢峰值温度变化不超过±3 ℃,最大释氢速率变化不超过20%,其中,氢溴酸处理增强α-AlH₃贮存稳定性的效果最好,样品贮存期间释氢量由0.87%降至0.02%。酸性和有机溶液处理能够使样品表面的杂质和缺陷减少,酸性溶液处理的α-AlH₃表面形成了无定形氧化铝或氢氧化铝,增强了α-AlH₃的稳定性。相较于有机溶液,酸性溶液在实际应用中更适于作为改性剂。     

预制刻槽增面燃烧发射药的原理与实验验证

为获得发射药能量释放渐增性及其多维度调节控制方法,根据内弹道学原理,提出预制刻槽增面燃烧发射药,建立了其燃烧过程的物理、数学模型,推导了气体生成猛度-已燃质量分数（Г-Ψ）关系,论述了其能量释放渐增性及多维度调节控制原理,提出了预制刻槽发射药的工艺实现方法。设计了一种中心开孔式预制刻槽发射药结构,制备了不同刻槽数、不同长径比的发射药试样。采用密闭爆发器试验对其燃烧性能进行测试与表征,并与七孔发射药、七孔包覆药进行对比分析。试验结果表明：制备的预制刻槽发射药具有理论设计的燃烧渐增性,对比七孔发射药其动态活度增量ΔL值提高了2倍,最大动态活度与起始动态活度的比值L_m/L₀提高了24.4%,最大动态活度对应的相对压力值B_m增加了32.4%,燃烧渐增性优于七孔发射药,可以达到七孔包覆药的渐增效果。     

叠氮硝胺发射药的燃烧性能调控技术

为改善叠氮硝胺发射药的燃烧性能,以小分子多炔基化合物(TPTM)作为钝感剂前驱体,采用转鼓喷涂工艺对其进行表面钝感处理,TPTM与发射药组份1,5-二叠氮基-3-硝基-3-氮杂戊烷(DIANP)在60 ℃反应,形成网状结构大分子钝感剂,并通过密闭爆发器试验、热加速老化试验和14.5 mm机枪试验表征了钝感效果,通过30 mm火炮试验考核了钝感发射药的内弹道性能。结果表明: 钝感叠氮硝胺发射药的初始燃速降低15%左右、渐增性燃烧特征量L_m/L₀大于1.5、长储稳定性好,在30 mm炮上具有良好的内弹道性能。     

某中小口径武器用梯度硝基发射装药效应

针对某中小口径武器发射烟焰大、刺激性气味强等问题，采用化学脱硝法，制备了不同脱硝程度的梯度硝基七孔发射药，对其理化性能、静态燃烧性能、内弹道性能、发射有害现象进行了研究，并基于最小自由能法，研究了樟脑钝感剂用量与脱硝程度对发射药可燃气体（CO、H₂）含量、未氧化碳值的影响规律。结果表明：随着脱硝程度的增加，发射药的爆热从4001 J·g^-1降低至3517 J·g^-1，弧厚从0.92 mm降低至0.89 mm、安定剂含量从2.60%降低至1.95%、安定性未发生变化，最大动态活度对应的相对压力B_m增加至0.66，燃烧渐增性逐渐提升；在相当膛压下，发射药燃烧渐增性越好，弹丸初速越高，并建立了装药量、膛压、初速之间的对映耦合关系，获得了梯度硝基发射药内弹道性能的数字表达与控制方法；当爆热值相当时，与樟脑钝感发射药相比，梯度硝基发射药燃气中可燃气体含量低、未氧化碳含量少；射击试验中发现，梯度硝基发射药火焰小、刺激性气味小，具有较少的发射有害现象。     

全氮苯N6的结构及合成可行性

用密度泛函理论(DFT)在B3LYP/6-311++G(d,p)水平上对氮气和全氮苯N₆分子进行了几何优化和振动分析,在此基础上求得不同温度下的热力学性质, 得到温度对热力学性能影响的关系式。运用Materials Studio程序包中Compass和Dreiding两种力场,在7种最可几空间群(P2₁/c, P-1, P2₁₂₁₂₁, P2₁, Pbca, C2/c和 Pna2₁)中分别进行分子力学全局搜索,获得最佳分子堆积方式。计算了反应3N₂(气)N₆(固)的标准摩尔吉布斯函数变,应用热力学方法分析反应的可行性,并对反应机理进行了预测。结果表明,全氮苯N₆属于C2/c空间群。温度低于61.6 K时,反应3N₂(气)N₆(固)具有热力学可行性,π键离域性对反应进行的难易具有决定作用。      

Cu(pn)2(FOX-7)2 的非等温分解动力学、比热容与绝热至爆时间（英）

通过K(FOX-7)·H₂O和Cu(NO₃)₂·3H₂O在1,3-丙二胺溶液中的反应制得含能配合物Cu(pn)₂(FOX-7)₂ (pn=1,3-丙二胺)。用差示扫描量热法(DSC)和热重/微商热重法(TG/DTG)研究了Cu(pn)₂(FOX-7)₂的热分解行为,采用微量热DSC法测定了比热容,也研究了绝热至爆时间和撞击感度。结果表明,第一放热分解过程的非等温动力学方程为: dα/dT=(10 17.83/β)3α 2/3exp(-1.635×10⁵/RT)。自加速分解温度和热爆炸临界温度分别为145.6 ℃和146.74 ℃。298.15 K时摩尔比热容为653.79 J·mol^-1·K^-1。绝热至爆时间约为77 s,Cu(pn)₂(FOX-7)₂的特性落高 (H₅₀) 是71 cm (>14 J)(RDX>7.5 J), Cu(pn)₂(FOX-7)₂是相对不敏感的。     

Al/Bi2O3-HNIW复合物的制备及其性能

为了探索纳米铝热剂-猛炸药复合物代替传统起爆药的可能性,以纳米Al粉、纳米Bi₂O₃、工业级六硝基六氮杂异伍兹烷（HNIW）以及纳米HNIW为原料,采用溶剂-非溶剂（Solvent-nonsolvent Method, SN）和物理混合（Physical Mixing Method,PM）两种方法分别制备了Al/Bi₂O₃-HNIW复合物,采用扫描电子显微镜（SEM）、X射线衍射仪（XRD）、X射线光电子能谱（XPS）、密闭爆发器试验、铅板试验等对制备的复合物性能进行表征和测试。结果表明,采用溶剂-非溶剂法制备的复合物中Al/Bi₂O₃均匀地包覆在HNIW表面,Al/Bi₂O₃与HNIW的质量比为3∶7时,结合压力-时间特性曲线,Al/Bi₂O₃-HNIW（SN）复合物的增压速率为2.914 GPa·s^-1,约为Al/Bi₂O₃-HNIW （PM） 的三倍,且升压时间短;其静电感度明显低于斯蒂芬酸铅（Lead Styphnate,LS）和叠氮化铅（Lead Azide,LA）,甚至低于猛炸药太安（PETN）; 采用太安（PETN）作为过渡药,Al/Bi₂O₃-HNIW（SN）能够可靠起爆黑索今（RDX）装药。采用溶剂-非溶剂法制备的Al/Bi₂O₃-HNIW因其优异的安全性和起爆性能,有望作为雷管起爆药替代物使用。     

高能硝胺发射药流变性能研究

为了提高高能硝胺发射药工艺稳定性并为成型模具设计提供依据,利用毛细管流变仪研究了溶剂比、温度、硝化棉含氮量对硝胺发射药胶化物料流变性能的影响规律。通过对数据进行线性回归分析,得到了物料的非牛顿性指数n、粘流活化能△E_η。实验结果表明:物料流变性能呈现典型假塑性流体特征,随着剪切速率的增大,n值减小非牛顿性增强;表观粘度随着溶剂比增大、温度升高或含氮量的降低而降低。     

Nitrosation and Nitration of Tetraacetyldibenzylhexaazaisowurtzitane

Tetraacetyldibenzylhitane (TADBIW) was subjected to debenzylation by nitrosating with inorganic materials available commercially to synthesize tetraacetyldinitrosohexaazaisowurtzitane (TADNSIW). TADNSIW was purified, and its structure was determined by FTIR, 1H NMR, MS and element analysis. The debenzylation reaction of TADBIW gave quantitative benzaldehyde as a by-product. This indicates that the reaction produces an imine cation as an intermediate. Hexanitrohexaazaisowurtzitane (HNIW) was prepared from unpurified TADNSIW with the yield over 96.0 % and the purity more than 98.0 %. And the mechanism of the reaction from TADNSIW to HNIW is proposed to be oxidation of nitroso and nitration of acetyl on the molecule of TADNSIW, This reaction system involved is simple, and the reaction can complete within a short time and under mild conditions. The product can be easily to separate and the waste disposed readily.     

A Robust Algorithm for Watermarking 2D Vector Maps with Low Shape-Distortions

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.     

Open Rule-setting System Applied to Conceptual Design of Engines

Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.     

Research on Linux Network Device Driver

By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux （kernel version 2.6.11 ） is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.     

Improvement and Experiment of the Reamer in Vibra Cutter Against Wave Edge of Titanium Sheet Alloy Parts

By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.     

Experimental Study on the Small Flyer Initiating Behavior of Fine-grained Explosives

The initiating behavior of fine-grained explosives by small flyer is studied. The diameter of small flyer in this device is 1 ram. The test results indicate that the granularity of explosives has great effect on its flyer initiating sensitivity.The flyer initiating sensitivity of the fine-grained explosives is higher and the critical initiating energy is lower than that of common explosives. For common explosive, the flyer initiating sensitivity increases as the density is reduced. But for the fine-grained explosive, the test results are exactly opposite.     

Algorithm for Multi-laser-target Tracking Based on Clustering Fusion

Multi-laser-target tracking is an important subject in the field of signal processing of laser warners. A clustering method is applied to the measurement of laser warner, and the space-time fusion for measurements in the same cluster is accomplished. Real-time tracking of multi-laser-target and real-time picking of multi-laser-signal are introduced using data fusion of the measurements. A prototype device of the algorithm is built up. The results of experiments show that the algorithm is very effective.     

Robust Graded Sliding Mode Tracking Control for Low Speed Spinning Ballistic Missiles

The nonlinear dynamic model of spinning ballistic missiles is established during the first boosting phase of the missile. Based on the conventional backstepping sliding mode control and the assumption of a two time-scale separation of missile dynamics, a graded sliding mode controller is designed with two sub-sliding surfaces which have invariability to external disturbances and parameter perturbations, and a matrix which comprises three first order low pass filters is introduced to prevent ＂explosion of terms＂. Owing to the upper bounds of the uncertainties are difficult to obtain in advance, adaptive laws are introduced to estimate the values of the uncertainties in real-time. Eventually, the numerical simulation results given to show the proposed controller can ensure the steady flight of missiles.     

A Study on the Estimation of Aeroheating upon the Warhead Nose at Supersonic Speed

An expression for estimating the aeroheating on a warhead nose at different supersonic speeds is proposed by incorporating CFD （computational fluid dynamics） and the least-square method. Compared with the traditional estimation formula, the expression is more accurate, convenient and can be used in the optimized design of warheads. The error from the result obtained in the test of a ball cartridge flight is less than 3 %. It satisfies the engineering requirements.     

Influence of Installing Error on the Surface Shape Precision of the Axial Symmetry Aspheric Workpiece in Lapping

A method to calculate the surface shape error, which is caused by the installing error between the workpiece and the lapping tool in the process of form lapping, is proposed. The mathematical model which the installing translation error influences on the workpiece surface shape error is established. The changing rule of the error is simulated through the calculating example of the paraboloid workpiece. The results indicate that the surface shape error of the workpiece is increasing with the increase of the installing translation error, it is also increasing gradually along the center point of the curve surface to the edge, and the influence is severer to the curve surface with great curvature than that of the small curvature when the translation error is the same.