溶剂浸析法制备硝化棉基微孔球形药

为简化硝化棉基微孔球形药的制备工艺,使内部孔结构更加均匀,研究了一种新的制备工艺——溶剂浸析法。改变溶剂蒸馏工艺后期的溶剂驱除方式,由升温蒸馏方法改为水溶液常温浸析方法,并与溶剂蒸馏法工艺进行对比。探讨了两种工艺参数对球形药形貌、粒径、内部孔结构的影响。用扫描电镜及Hope Image软件表征了硝化棉基微孔球形药的结构。结果表明,用溶剂浸析法工艺制备的硝化棉基微孔球形药表面光滑,粒径主要集中在20μm左右,球形度为0.89,比溶剂蒸溶法提高约20%,孔隙率为92%,比溶剂蒸溶法提高约10%。溶剂浸析法工艺制备的硝化棉基微孔球形药内部孔结构分布更均匀。     

硝化棉基微孔球形药的结构控制研究

为了有效控制硝化棉(NC)基微孔球形药的结构,通过调节工艺参数及引入烷烃溶剂等方法,探索颗粒直径、颗粒表面孔隙率和颗粒球形度的变化规律。结果表明:提高溶剂用量可以降低硝化棉溶胶及乳液的粘度,微孔球形药的平均粒径显著减小。在乳化发泡环节引入烷烃作为致孔剂,可以制备出表面开孔的微孔球形药,随着烷烃用量的增加,表面孔隙率逐渐提高,样品的比表面积也相应增加。采用浸析法进行溶剂驱除时,降低加水速度可以显著提高微孔球形药颗粒的球形度。通过调节工艺参数及在乳液中加入烷烃溶剂,实现硝化棉基微孔球形药结构的定量控制是完全可行的。     

双乳液法制备微孔球形药的孔结构形成机制

为了揭示双乳液法制备微孔球形药孔结构的形成机制,分别在乳化、成球及溶剂蒸馏等过程中进行取样,并采用显微观察和图像分析方法探索了孔结构的形成和演变规律。结果表明：影响微孔球形药中孔结构形成的主要因素是乳化条件和溶剂蒸馏条件。硝化棉乳液中分散相水滴的形态及尺寸分布规律与成品微孔球形药中的孔结构及孔径分布规律基本一致。乳化条件决定球形药中孔的形貌特征;成球过程的工艺条件对孔径及孔的形貌无显著影响;溶剂蒸馏条件对孔径分布影响较大,溶剂蒸馏速度加快,孔隙发生聚集而导致孔径分布不均匀。通过降低溶剂蒸馏速度,成品颗粒中的孔结构均匀性可以得到有效改善。采用双乳液法制备的硝化棉基微孔球形药中的孔结构是由硝化棉乳液中的分散相液滴形态决定的。     

复合球形药对改性双基推进剂力学性能和燃烧性能的影响

将RDX、铝粉、催化剂等用硝化棉包覆,制成复合球形药,然后用这种复合球形药制备出改性双基推进剂,测试了这种推进剂的力学性能和燃烧性能。结果表明,采用复合球形药制备的改性双基推进剂比用双基球形药制备的改性双基推进剂的力学性能大幅度提高,低温断裂延伸率从7.84%提高到26.86%,高温最大拉伸强度提高了0.97倍,燃速压强指数从0.38降低到0.30。     

射流不稳定性对流动聚焦法制备硝化棉微球的影响

为通过微流控技术获得良好形貌特性的硝化棉微球，以硝化棉的乙酸乙酯溶液为研究对象，探究了流动聚焦微流控芯片中硝化棉/乙酸乙酯水包油液滴的生成机制，详细研究了在滴流、稳定射流、不稳定射流3种流动模式下，连续相、分散相流量以及界面张力等对微液滴生成的影响，并在3种流动模式下制备硝化棉微球。结果表明：滴流和稳定射流模式下制备的微球呈单分散、高度球形化、窄粒径分布特性；不稳定射流模式下制备的微球高度球形化，粒径分布较滴流和稳定射流下的宽。     

美军改进20毫米炮用制式发射药降低身管烧蚀的近况

美军在小口径武器弹药中广泛采用双基球形药为主要发射药已有二十多年历史。例如从五十年代初期起,在20毫米弹上采用了制式WC870型球形药,在7.62毫米弹上采用了WC846型球形药,与当时传统的用二硝基甲苯钝感的压伸单基药相比,采用球形药的优点之一,是延长了身管寿命,因为它的绝热火焰温度较低。六十年代上半期,生产小口径武器用火药的陆军弗兰克福兵工厂与湖域陆军弹药厂合作,开始发展一种后来定名为X2048型的球形药,即将20毫米弹用制式WC870型球形药(含约80％硝化棉、约10％硝化甘油、5-7％苯二甲酸二丁酯、约1％二苯胺、微量无机添加剂如除铜剂二氧化锡、消焰剂硝酸钾和中和     

微流控技术制备球形发射药及其表征

利用微流控技术,采用T型微通道装置,以水为连续相,以硝化棉的乙酸乙酯溶液为分散相,制备球形发射药。研究了连续相和分散相的流速比以及分散相的溶棉比对发射药成球效果的影响。结果表明:固定溶棉比(溶剂与硝化棉的质量比)为50∶2.5,连续相流速(Qc)为1000μL·min~(-1),分散相流速(Qd)在30~100μL·min~(-1)时,所得液滴均匀稳定,且随着分散相流速增大,所得球形药的粒径从270μm增大至306μm;固定水油两相流速比为1000μL·min~(-1):100μL·min~(-1),溶棉比在50∶2.0~50∶3.0,分散相溶棉比越小,所得球形药的粒径越大,其粒径从250μm增大到350μm。扫描电子显微镜(SEM)结果表明,利用微流控技术制得的硝化棉球形药表观形貌规整,粒径分布窄,单分散性好。     

美国海军发展无压延工艺制造小型火箭和大口径炮用无溶剂双基火药

近几年来美国马里兰州海军军械站正在发展一种无需辊筒压延工序的无溶剂双基火药制造工艺,生产小型火箭(例如2.75英寸尾翼折叠式航空火箭和阻尼人火箭)用药性和大口径炮用发射药(例如NOSOL318和363型)。采用这一新工艺时,只需将全部火药组份即硝化棉、硝酸酯、水溶性添加剂和其它组份放入到烃液(例如庚烷)之中混合成淤浆,然后将上部烃液潷析掉,並将药料干燥固化,最后放入压药机内压伸出所需形状的药管或药柱。整个过程中取消了压延工序和混合工序,故使工艺简化、劳动力和设备的需要量下降,並且安全性得到了提高。目前,已用这种工艺制造NOSOL型无溶剂炮药,其主要组份是46％硝化棉、38％三羟甲基乙烷三硝酸酯、3％三乙二醇二硝酸酯。这种工艺在经过进一步改进之后,也已经适用于加工含晶体氧化剂(例如高氯酸銨、RDX、     

基于真空热脱水工艺的硝化棉自动高效脱驱水生产线

针对目前国内普遍采用的离心机酒精置换离心驱水工艺已不能满足某些后续生产工序要求的问题,设计一种采用真空热脱水工艺的硝化棉自动高效脱驱水生产线。介绍了生产线工艺原理、工艺流程及设备组成,重点分析了真空热脱驱水工艺装备的3项关键技术:驱水棉含水量一致性控制、硝化棉浆管道输送和生产线安全保证技术,并采取了一系列措施保证硝化棉驱水质量、全线生产连续性和安全性。实践结果表明:该生产线驱水效率较高,劳动强度和环境污染降低,具备较高的安全性、可靠性和先进性,目前已投入到生产运行中。     

一种用于硝化棉粉碎的新技术与设备

研究设计了一种用于硝化棉粉碎的新技术与设备,介绍了其粉碎原理与结构组成,开展了初步的粉碎实验,简单分析了粉碎过程中的影响因素,并与锥形细断机制得的硝化棉进行了比较.结果表明,通过调整设备结构参数,控制工艺条件,可制得比表面大、质量均匀的超细硝化棉.     

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.     

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.     

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.