Abstract:The sub-micron ultra-fine particles of nitroamine explosives (HMX and RDX) were prepared by using high-speed impinging stream. The fundamental principle and characteristic of this method were analyzed. The granularity and shape of the ultra-fine explosive particles obtained were tested with laser-sedimentograph and scanning electronic microscope.

Abstract:The impact sensitivity,friction sensitivity,thermal sensitivity (explosion point) and sensitivity to electrostatic spark of HNIW were measured according to the Chinese National Military Standard (GJB). The obtained results are as follows： H₅₀=20～27cm (5kg hammer); friction sensitivity 100% (90±1°，3.92±0.07MPa) or 92% (80±1°，2.45±0.07MPa)，explosion point 283.9℃(5s delay time); V₅₀=4.61kV，E₅₀=0.106J.

Abstract:The geometries of 55 organic azides were fully optimized by using the semiempirical molecular orbi- tal (MO) methods of AM1,PM3,MNDO and MINDO/3. Compared with the available experimental geometry parameters in gaseous phase,it is found that the calculation error from AM1 is the smallest and the next are those from PM3 and MNDO.Among four MO methods used, the heat of formation computed with AM1 is the closest to the results obtained from group additivity method. The results from MINDO/3 are the worst.

Abstract:The semiempirical AM1 method is used to optimize the geometry of hexanitrohexaazaisowurtzitane (HNIW),compute and analyze the vibration frequency. Furthermore a discussion of the strong absorption characteristic peaks of -NO₂ is presented as well as its comparison with the experimental IR spectra. According to the population and analysis the molecular structural stability is discussed. The bondshaping characteristics of N-NO₂ are analyzed by the NBO and BO methods.

Abstract:The physicochemical nature of pressure dependence of the dark zone is analyzed based on the common existence of dark zone in the combustion wave of high energy nitroamine propellants. The mathematics relationship between dark zone thickness and pressure is deduced in the light of the overall chemical reaction therein. It is found that the thickness of dark zone is inversely proportional to the cube of pressure,well agreeable to Kubota's experimental results and verifying the reasonableness of the deducing method and hypothesis.

Abstract:By consideration of the combustion characteristics of the fuelrich propellant at low pressure,the various techniques to measure the combustion properties of the fuelrich propellant,such as, the strand burner method,thermocouple method,ultrasonic method,firing test and highspeed photography method are evaluated. The difference between the recorded pressure and absolute pressure should be noticed in the low pressure experiment data process as well as the selection of the burningrate and pressure correlations.

Abstract:介绍了过氯酰胺盐的一些性质，指出过氯酰胺盐是激光起爆阈值低的光敏炸药。用10%光学透明的聚合物分别粘结50mg/cm²的过氯酰胺钾(Ⅱ)和过氯酰胺钡(Ⅳ)制成了1cm²的光敏炸药薄板并进行了实验。Ⅱ的起爆阈值约0.1J/cm²，Ⅳ的起爆阈值为5～7mJ/cm²,皆低于压装的叠氮化铅药柱。全都实现了平面起爆。

Abstract:In order to initiate detonation of fuelair explosive (FAE) chemically,some formulations (abbr.as FAE-Ⅲ) were made by using different forms of aluminum powder mixed with fuels,such as epoxy propane,nitromethane and isoprene,and with azidoalkane or triethylaluminum (TEA). It is found that after 40 days storage at 50℃ the activity of both spherical and flake aluminum powder,sealed in the mixture of epoxy propane,isoprene and nitromethane,decreased 37.0% and 59.4%,while the activity of the said aluminum powder in the mixture with azidoalkane or TEA only little reduced at the same conditions. These results indicate that the later two compounds are promising to be used as ingredients of FAE-Ⅲ to increase their performance.

Abstract:The electric spark sensitivity of 32 polynitro arenes was determined as the spark energy, E_ES,required for 50 per cent initiation probability. A relationship between the E_ES values and the squares of detonation velocities of the polynitro arenes was established. This relationship represents a certain form of Evans-Polanyi-Semenov equation and,therefore,it signalises an identity of chemical mechanisms of the primary fragmentation processes in the molecules of polynitro compounds during their detonation and in the initiation of their decomposition and/or explosive transformation by the action of electric spark. However,the way of energy transfer from the spark to reaction centre of molecule of the said compounds is not yet clear.

Abstract:The processes of melting,initiation and explosion of the sample of Alcontaining PETN are observed directly by a high speed photograph during impact, and the solid products of the sample after impact from the gas gun are studied by SEM analysis. The results show that the aluminum powder is oxidized and burns during detonation. After conducting the related numerical modeling by the DYTRAN code,the process of the hot spot formation in the sample around the aluminum grain is described theoretically.

Abstract:The influence factors on the burning rate characteristics of GAP/AN propellants including binder,plasticizing ratio,AN content,particle size of AN,content of AP,HMX and Al were studied. The experimental results indicate that plasticizing ratio and AN content show a strong effect on the burning rate characteristics of GAP/AN propellants. Lowered the plasticizing ratio and AN content,the higher burning rate and lower burning rate pressure exponent were achieved.

Abstract:An improved crosslink density measuring apparatus is introduced. The equilibrium compression modulus of a swollen elastomer at very small deformation can be measured by this apparatus. The precision and sensitivity of the improved apparatus are increased obviously. The apparatus is suitable to determine the crosslink density of all kinds of thermosetting elastomers including composite solid propellant.

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