机器学习辅助的［5，6］稠环含能化合物高通量设计

与经验和计算指导的研发模式相比,机器学习辅助的含能分子高通量虚拟筛选技术,在分子设计效率及构效关系定量分析方面都展现出明显优势。鉴于富氮稠环含能化合物较好的能量-稳定平衡特性,研究利用机器学习辅助的高通量虚拟技术对［5,6］富氮稠环类含能分子的化学空间进行了探索研究,基于［5,6］全碳骨架,通过组合枚举和芳香性筛选得到142689个［5,6］稠环类化合物,同时采用核岭回归算法建立并优化了6个含能分子性能预测模型（密度,分解温度,爆速,爆压,撞感和生成焓）,分析了稠环上的氮氧原子以及分子上官能团对含能化合物性能的影响。结果发现,所生成稠环化合物的构效关系与含能化合物能量与稳定性相关性的一般规律相符,验证模型的合理性。以爆速和分解温度作为能量和热稳定性的标准,研究进而筛选获得了5个综合性质较为突出的分子,利用DFT等量子化学计算的结果与本研究模型预测结果符合良好,进一步验证了预测模型的精度。     

面向高通量含能分子设计筛选的三种生成焓计算方法评估

高通量含能分子设计需要兼顾准确性与效率的性能预测方法。结合原子化方案，对常见的3种不同水平的理论方法（半经验PM6方法、密度泛函理论方法B3LYP/6-31G（d，p）和高精度的完全基组CBS-4M方法）用于高通量含能分子设计筛选的生成焓（HOF）计算适宜性进行了评估。计算并比较了20种含能分子的固相HOF，发现不同理论水平预测结果存在较大差异；而基于10种常见含能分子的不同水平下的HOF，实验密度和Kamlet-Jacobs（K-J）、Becker-Kistiakowsky-Wilson（BKW）与Virial-Wu （VLW）3种模型预测的爆轰性能差别不大。其中B3LYP方法具有最佳适宜性，具有较高的计算效率且爆轰性能预测结果同CBS方法接近，如基于BKW模型计算的爆速和爆压的平均相对偏差仅为0.4%和1.2%。而低精度的PM6方法和高耗时的CBS方法难以满足兼顾高通量含能分子设计筛选中的精度和效率的要求。这表明，在高通量的含能分子设计筛选中，可考虑中等精度的方法进行快速的HOF预测。     

含氮桥头类含能稠环的合成和性能研究

稠环含能化合物由2个或2个以上的共用原子和1个化学键的环构成，具有较大π-π共轭结构，是一类热门的新型含能材料。含能稠环独特的多环共面结构和较大共轭体系，表现出良好的安定性，同时多个含氮杂环组成的共面结构还使得其具有较高的生成热、较大的环张力和优异的能量水平，能够在高性能和分子稳定性之间取得平衡。含氮桥头类稠环骨架以C—N键为共用键连接多个氮杂环，此类稠环大多具有良好的密度、稳定性和多个可修饰位点，是含能稠环领域中的一类新型含能骨架。本研究简要介绍了近年来报道的氮桥头型含能稠环化合物的合成、爆轰性能和稳定性研究，为该类化合物后续的研究和发展提供一定的参考。     

富氮稠环类氮氧化物的研究进展

富氮稠环类氮氧化物由于其平面共轭的分子骨架结构和共价氮氧键官能团,通常具有密度高、爆轰性能优异及感度适中等优点,因此,这类化合物已逐渐成为含能材料领域的研究热点.本研究综述了近十年来合成的20种富氮稠环类氮氧化物的分子结构、合成方法及理化性能等,比较了富氮稠环分子氮氧化前后的主要理化性能参数,为其合成及性能研究提供一定的参考.     

含能化合物量子化学数据库的设计及应用

高精度计算水平下的量子化学数据对于含能化合物的设计、合成以及表征具有重要意义。因此，建立含能化合物量子化学数据库，收集含能化合物在高精度计算水平下的量子化学数据，既能够避免重复性的计算研究与资源消耗，也保证了数据质量以便进行深入分析及知识挖掘，进而获得可靠的含能化合物结构与性质的分析预测模型。本文总结并梳理近年来量子化学计算所获得的含能化合物关键性结构和性质数据种类、数据库与高通量虚拟筛选相结合的含能化合物分子设计进展；并从量子化学计算标准与数据模型的选择、数据库以及数据库管理系统的开发等角度，对含能化合物量子化学计算数据库的设计与应用进行了展望，包括：（1）明确基准计算方法与性质预测模型以产生本领域专用性的数据；（2）建立开放共享的数据库以实现与高通量虚拟筛选相结合；（3）开发数据库管理系统以实现查询、获取与知识挖掘，以期为含能化合物量子化学数据库的设计及实际应用提供有益的参考。     

含能材料理论设计中的几个问题（英）

理论方法在新型含能材料的设计和研发中起到非常重要的作用。本研究介绍了含能材料理论设计中所遇到的问题,如从微观上估算含能化合物的密度、生成热、稳定性及爆轰性能等。并讨论了含能聚合物界观参数的计算方法:1) 基于优化的分子结构,求得含能金属配合物分子周围的电子云包覆体积,然后由公式求得包覆密度作为其晶体密度近似值; 2) 含能化合物的生成热根据原子化方案,进行数值计算; 3) 以五种小分子氮氢化合物和六种四嗪化合物的热分解机理为例,阐述采用将从头算分子动力学(ab initio MD)和从头算分子轨道理论(ab intio MO)结合起来研究含能化合物热分解机理的可靠性; 4) 含能材料的爆轰性能, 基于各个元素的Lennard-Jones势参数等,由反应物及产物的VLW状态方程,进行数值求解; 5) 采用DPD方法可用于研究含能聚合物的界面性质。上述性能的计算可为新型含能材料的探寻提供有价值的信息。      

富氮稠环含能化合物:平衡能量与稳定性的新一代含能材料

富氮稠环含能材料是指在富氮稠环化合物骨架上引入硝基和其他含能基团的含能化合物,由于该类化合物在拥有高爆轰性能的同时,兼具相对较低的机械感度和较高的热分解温度,近年来受到国内外含能材料学者的广泛研究和报道。研究显示,得益于富氮稠环骨架π电子的离域共振,稠环骨架结构的稳定性显著提高,从而使得富氮稠环含能化合物很好的平衡了含能材料能量与稳定性之间这一自然对立的矛盾,如4?氨基?3,7?二硝基三唑并[?5,1?c][1,2,4]三嗪4?氧(DPX?27),其爆速、爆压分别为8.97 km·s~(-1)和35.4 GPa,爆轰性能与RDX相当,撞击感度和摩擦感度分别为10 J和258 N,明显低于RDX;1,2,9,10?四硝基二并吡唑[1,5?d:5′,1′?f][1,2,3,4]四嗪(TNDPT)的爆速和爆压分别高达9.63 km·s~(-1)和44.0 GPa,与CL?20相当,机械感度(撞击感度:10 J;摩擦感度:240 N)却显著低于CL?20。可以看出,富氮稠环含能化合物作为新一代兼具高爆轰性能与良好稳定性的含能材料,正展现出巨大的研究价值和应用潜力。本文简要梳理了近年来发展的经典富氮稠环含能化合物的合成、含能性能、稳定性以及对富氮稠环含能化合物未来发展的展望,从而为从事富氮稠环含能材料研究工作者提供参考。     

含能晶体密度预测的研究进展

密度是决定含能材料爆轰性能的重要参数。为评估现有CHON类含能材料密度的计算方法,对等电子密度面法、分子表面静电势法、基团加和法、晶体堆积法、定量构效关系法、经验公式法等进行分析和归类。结果表明,基于分子体积预测方法的精度取决于分子间和分子内相互作用对密度影响描述的准确度。其中,准确描述氢键和van der Waals作用充满了挑战性。基于晶体体积计算密度的核心在于晶体结构的准确预测,结构搜索要面对巨大的状态空间和高度复杂的能量曲面的困难,预测效率是亟待解决的问题。体积加和法和经验公式法存在无法区分同分异构体和晶型的缺点,且对新发现的具有特殊结构的分子由于缺乏实验数据难以获得准确的经验参数,计算结果偏差较大。引入人工神经网络、遗传算法以及支持向量机等机器学习算法后,定量构效关系法在含能化合物性能与结构关系研究中取得很大成就,模型精度进一步提高将为基于材料基因组模式的含能材料设计研发奠定基础,这也是今后密度预测方法发展的主要方向。     

氟偕二硝基甲基类含能化合物的合成及性能研究进展

将氟偕二硝基甲基引入至含能化合物分子中,不但可以提高含能化合物的氧平衡、密度和爆轰性能,还可能提高化合物的热稳定性、降低机械感度。构建含氟偕二硝基甲基基团的含能化合物成为新型高能低感含能材料领域的研究热点。通过对近20年来含有氟偕二硝基甲基的含能化合物综述,总结氟偕二硝基甲基类含能化合物的合成方法,分析比较这类化合物的分子结构、理化性质和爆轰性能,为新颖氟偕二硝基甲基化合物的分子设计、合成研究提供参考。     

含吡啶/氨基苯环硝胺炸药的理论设计与合成

将含吡啶/氨基苯环炸药的钝感性与硝胺炸药的高能性相结合,同时在炸药分子中再引入含N—N键的硝酰胺基团。采用量子化学密度泛函理论计算,结合化学热力学和化学动力学研究,对此含吡啶/氨基苯环硝胺炸药进行了系统的理论计算,建立了分子和晶体结构与爆炸性能和安全性能之间的规律性联系。研究表明,含吡啶/氨基苯环炸药具有良好的爆轰性能,N—NO₂键为热解和起爆的引发键。通过理论设计和筛选,提供多个高能低感含吡啶/氨基苯环硝胺炸药目标物,并进行合成路线设计和合成实验研究,通过缩合反应、N-硝化反应、N-氧化反应、C-硝化反应等可获得含吡啶/氨基苯环硝胺化合物。      

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.     

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.     

Experimental Research on Output Performances of Giant Magnetostrictive Actuator

The paper introduces the performances of magnetostrictive actuators and its applications, discusses the design methods for the structure and internal magnetic circuit of a giant magnetostrictive actuator, and makes tests on the output displacement and force characteristics for an actuator using homemade magnetostrictive material. The experimental result shows that the actuator has satisfactory output precisions and ranges in transient and stable states, and can be used in lowfrequency vibration control system of precise equipment.     

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.