3,4-Dinitrofurazanfuroxan (DNTF) exhibited pronounced detonation properties and moderate sensitivity, but restricted on thermal decomposition investigation in melt-cast explosives owing to the volatility. Thereby, we employed pressurized experimental methods and density functional theory (DFT) simulation to comprehensively study the thermal decomposition mechanisms of DNTF, DNTF/CL-20 and DNTF/TKX-50 mixtures. The decomposition peak temperatures of DNTF/CL-20 and DNTF/TKX-50 systems shifted forward by 62 °C and 51 °C compared with DNTF, along with multi-step composite autocatalytic reactions. Through pressurized DSC/TG-FTIR-MS characterization and DFT calculations, the initial decomposition was triggered by (O)NO bond rupture on furoxan ring, NNO2 bond cleavage in liquefied CL-20 for DNTF/CL-20 mixture, and (O)NO bond dissociation of DNTF rings activated by NH3OH+ from TKX-50, respectively, originating from intermolecular π-π and O−H•••π interactions. We provided a feasible strategy combining experiments and DFT simulations to elucidate thermal decomposition mechanism of DNTF-based materials, holing great potential for optimizing DNTF-based melt-cast explosive formulations.

目的 探索实际贮存状态NEPE推进剂自重产生的诱发压力对其贮存寿命的影响,开展温度-压力双应力作用下NEPE推进剂的寿命预估研究.方法 对比分析NEPE推进剂在加速老化试验过程中的失效机理,确定其老化失效模式以及老化失效参量,采用加速老化试验及力学性能测试,分析NEPE推进剂加速老化过程中力学性能的变化规律.基于不同温度-压力应力条件下NEPE推进剂老化特性的变化规律,构建温度-压力双应力作用的贮存寿命预估模型,对25℃和2 MPa下NEPE推进剂的寿命进行评估.结果 温度、预紧压力升高均会促进NEPE推进剂力学性能的衰减.结论 相比于单温度应力下的加速老化特性,温度-压力双应力作用会提高NEPE推进剂试片力学性能的衰减速度,考虑推进剂的自重影响因素,采用温度-压力双应力条件下的NEPE推进剂寿命预估模型,可以更准确地预测NEPE推进剂的贮存寿命.

为探索新的特征参量来预估NEPE推进剂的贮存寿命,采用高温加速老化方法,通过老化样品性能测试,检测老化过程中爆热、力学性能、燃速、有效安定剂含量、热爆炸临界温度、交联密度等参量的变化,并利用Bethelot方程评估NEPE推进剂的贮存寿命.结果表明,NEPE推进剂在高温加速老化过程中爆热、燃速、热爆炸临界温度及有效安定剂含量随老化时间未出现显著变化,最大抗拉强度、交联密度随老化时间显著降低且具有规律性,表明力学性能、交联密度的下降是推进剂的主要失效模式,即力学性能和交联密度可作为特征参量;以交联密度性能下降至85％作为失效终点,评估NEPE推进剂在30℃下的贮存寿命为18.5 a,两种不同特征参量对NEPE推进剂贮存寿命的评估结果基本一致,可为NEPE推进剂贮存寿命研究提供指导.

In the synthesis process of N-nitrodihydroxyethyl dinitrate (DINA) with the HNO3-Mg(NO3)(2) method, the thermal stability of the nitration reaction liquid of the final state is poor, which leads to the thermal runaway of the entire reaction system easily. The research on the thermal runaway reaction under actual reaction conditions indicates high consumption and high risk. In this article, thermal decomposition behavior and isothermal thermal decomposition kinetics of the nitration reaction liquid of the final state in the synthesis process of DINA were investigated by differential scanning calorimetry (DSC) and microcalorimetry. The mechanism of the stability of the nitration reaction liquid was explored. The thermal safety of the material in a large-scale reactor was simulated and predicted by a thermal simulation software on the basis of kinetic parameters including activation energy, pre-exponential factors, and mechanistic functions. These findings not only avoid the risk and consumption of large-size materials but also guide their application in process optimization, inherent safety design, and handling.

采用落杆法,使用熔融指数测试仪和毛细管流变仪测试了一种高含量粉体填充树脂基复合材料在不同温度下的流动性,并对测试结果进行了分析比较.结果表明,3种测试方法均可用于该类材料的流动性测试;落杆法具有操作简单和可测试材料范围广的优势.

In the thermal analysis of many energetic compounds, there is a phenomenon of melting before decomposition, and the melting endothermic process is masked by the subsequent rapid exothermic decomposition, which has affected the research of separation in melting and thermal decomposition processes. 2-oximemalononitrile, an energetic intermediate whose melting and decomposition processes had the overlapping, was used as the research object in this paper, and the complete melting and decomposition processes were acquired by MATLAB software, separately. In addition, the kinetics and mechanism of thermal decomposition of 2-oximemalononitrile were investigated by Málek method, which was used as guidance for the safe application in handling, processing, and storage.

为了研究真空安定性法对新型高能量密度化合物的适用性,采用NBK型“拉瓦”量气测试系统研究了4种新型高能量密度化合物CL-20、ADN、TNAZ、DNTF及典型一代、二代含能材料NC+ NG(质量比50∶50)及RDX在恒温条件下的受热全分解过程,计算得到了其全分解放气量分别为653.53～662.38、613.80～619.82、624.04～636.23、601.52～629.82、594.52～617.25、和556.74～569.22mL/g,真空安定性判据2mL对应的反应深度都不超过0.4％,所对应的安全系数均大于2.5.通过对典型一代、二代含能材料及新型高能量密度化合物全分解过程的机理函数及动力学参数分析,由时温等效关系推算新型高能量密度化合物在100℃放气量达到判据2mL的时间分别为7341～8967、2091～2808、438～664和3955～3997h,所得结果均远大于真空安定性法规定的测试时长48h.典型一代、二代含能材料NC+ NG(质量比50∶50)及RDX在100℃受热分解放气量达到判据2mL的时间分别为5191～6316h和111～241h.通过对比验证,证明几种新型高能量密度化合物可以沿用真空安定性试验2mL判据.

以极限热流值为安全贮存寿命判据,用"温度系数"方程作为"时温等效"关系,改进了NATO STANAG 4582标准的外推方程,建立了一种用微量量热技术快速预估硝酸酯火药安全贮存寿命的新方法 ——"单温度定时热流量热法",即单一温度下,仅需短周期的一个试验就可以预估硝酸酯火药在特定贮存温度下特定年限的安全贮存寿命,或评估预定贮存期内的热安定性.结果表明,与以安定剂消耗50％ 为判据的热加速老化法相比,该方法是以模拟大尺寸装药体系在较苛刻环境下贮存不发生热爆炸的极限热流值为安全寿命判据,更符合实际,预估结果更可信,可广泛适用于单基、双基、三基和改性双基等硝酸酯火药安全贮存寿命的评估.该方法为在线检测,无需大药量、大规模的老化试验,相比热加速老化法既安全又更简单快速,可在4.01天内预估硝酸酯火药10年内能否安全贮存.

采用高能氧化剂ADN部分代替AP,分别设计了AP/RDX、AP/RDX/Al、ADN/AP/RDX、ADN/AP/RDX/Al四种组分体系,利用差示扫描量热技术,研究ADN与高能组分的相互作用,尤其是对组分体系放热量的影响.结果表明,ADN的加入使ADN/AP/RDX组分体系的放热量增加了1.6倍,使ADN/AP/RDX/Al组分体系的放热量增加了1.68倍.同时,采用热-红-质联用技术,通过对分解产物的结构鉴定及整个过程中红外光谱强度和质谱质子流强度变化规律的研究,发现ADN的加入导致组分体系热分解反应生成更多的标准摩尔生成焓小的生成物,使得热分解反应的焓值更小,放热量增加.

为研究NEPE推进剂在诱发压力载荷作用下的老化性能,在75℃、1 MPa下进行了双应力加速寿命试验,研究了温度和压力对NEPE推进剂燃烧性能、能量性能、力学性能和安全特性的影响;采用交联密度、动态力学性能及扫描电镜分析了NEPE推进剂力学性能的变化机理.结果表明,在75℃、1 MPa下,30 d加速老化过程中,在温度和压力的共同作用下,NEPE推进剂爆热为6007～6192 kJ/kg、燃速为10.36～10.64 mm/s、安定剂质量分数为0.43％～0.48％,均不随老化时间的增加而变化;抗拉强度随老化时间的增加而降低,老化30 d后,抗拉强度由0.612 MPa降至0.433 MPa,变化率29.2％,表明力学性能的变化是推进剂的主要失效模式;温度和压力双应力载荷作用下失效机理为温度使黏合剂降解,交联网络中结点受到破坏及固体颗粒分解引起脱湿,压力的存在强化了脱湿现象,导致力学强度快速下降.

To study the thermal decomposition of dihydroxylammonium 5,5′‑bistetrazole‑1,1'‑diolate (TKX‑50), thermal decomposition experiments such as thermogravimetry and differential scanning calorimetry were carried out, respectively. Meanwhile, MATLAB software was employed to decouple the overlapping parts and the Málek method was used to study the kinetics of the thermal decomposition of TKX‑50. The results show that the thermal decomposition process of TKX‑50 is divided into two stages. The complete thermal decomposition curves of the two stages are obtained by MATLAB software, and the basic parameters such as Tonset, Tp, and ΔH are acquired at different heating rates. The thermal decomposition of TKX‑50 follows the autocatalytic reaction model, and the kinetic parameters including activation energy, pre‑exponential factor and kinetic model are obtained, respectively. For the first stage,Ea=174.99 kJ∙mol-1,lnA=40.75,f(α)=α0.917(1-α)0.509， for the second stage,Ea=149.60 kJ∙mol-1,lnA=31.84,f(α)=α0.357(1-α)0.117.

A new approach to evaluate the stability period of propellant is presented to solve the problems of poor safety,fussy operation and time-consuming of the existing methods for evaluating the stability of propellants.The propellant samples with different stabilizer contents were prepared by thermal accelerated aging test,and the kinetic equation of propellant aging was studied.A quantitative model for the determination of stabilizer content in propellant is established using near-infrared spectroscopy and chemometrics algorithm.The best quantitative model is obtained by analyzing and optimizing the proposed model.Applied results show that the determination coefficient (R2) of the model is 0.999 6,and the maximum predicted error is no larger than 0.04％.It proves that the proposed model can be used for the nondestructive,rapid and real-time evaluation of the stability period of propellant.

The thermal behaviors and mechanism of nano-based fuel air explosive (FAE) were investigated by using DSC measurements in different situations and DSC/TG–FTIR–MS coupled technique. The thermal decomposition process of FAE under non-oxidizing environment was analyzed and described. The decomposition of FAE takes place in a multistage complex process. The first process is assigned to volatilization process of the volatile components. With an increase in temperature, isopropyl nitrate starts to break up into alkene and secondary alcohol. In the temperature range of 350–500 °C, the dominant volatile products are hydrocarbon fragments, CO2 and H2O. At the same time, the full formulation of FAE and formulation without nano-Al powder were studied and compared. The thermal decomposition of other components in FAE is significantly promoted by nano-Al powder.

This paper disscusses the importance of high-precision optical part blanks testing and describes the important indicators of blank quality. Also, testing indicators, testing principles and testing methods are introduced taking a certain kind of optical glass blank for example.

The enthalpies of dissolution for nitroglycerin in ethanol and ethyl acetate were measured successfully at 298.15 K under atmospheric pressure by designing a special mixing device and using microcalorimetry technology. Empirical formulae for the calculation of the molar enthalpies of dissolution (∆diss H), relative partial molar enthalpies (∆diss H partial), and relative apparent molar enthalpies (∆diss H apparent) were obtained by experimental data analysis and theoretical calculation. Furthermore, the corresponding kinetic equations describing the two dissolution processes are dα/dt = 10−3.21 (1 − α)1.01 in ethyl acetate and dα/dt = 10−3.43 (1 − α)1.02 in ethanol, respectively.

Under minus 40 degrees Celsius,Photoelectric conventional cable will happen Frozen stiff,cracking phenomenon when dynamic movement on the mast of the block and tackle,resulting in a decline in performance of torsion.Therefore,designed a set of low-temperature bending test device.By this device to simulate Photoelectric conventional cable to the mast by external force test environment,to test whether Photoelectric conventional cable oerformance meet the practical requirements.The designing of low temperature bending test device,analog Photoelectric conventional cable on the mast the movement characteristics of pulley block.Its operation is simple,save time and effort and high test efficiency.

The thermal behaviors in non-oxidizing environment and closed environment of isopropyl nitrate(IPN), high-density liquid fuels (HLF) and nanometer aluminum powder (nano-Al), as the main components in nano-based Fuel Air Explosive (FAE), were investigated by using DSC and DSC/TG-FTIR-MS coupled technique.The influence of nano-Al powder on the thermal behaviors of the main components in FAE was compared.The results show that the decomposition process of the main components in FAE is mainly divided into two stages: endothermic gasification and exothermic decomposition.IPN and HLF are the main energy source of FAE.The decomposition products of IPN can react with HLF and produce heat.

采用TG-DSC-FTIR-MS联用技术研究了Al-Li合金粉体燃料对高氯酸铵(AP)热分解特性的影响,探讨了其对AP的催化热分解机理.DSC,TG-DTG曲线表明,Al-Li的存在使得AP的低温分解及高温分解峰温分别降低7.7,11.2℃,分解热ΔH增加35.6%,说明Al-Li对AP的热分解过程有显著的促进作用.通过FTIR,MS对AP及Al-Li/AP的分解气体产物进行表征及对比,二者表现出明显不同.FTIR显示,低温分解过程中,Al-Li/AP相比于纯AP,出现了明显的NH3红外特征吸收;MS显示,高温分解过程中,Al-Li/AP比纯AP明显少了m/z=35(Cl)的离子流.更多还原

The light source emits parallel light through a self collimation parallel light tube,the beam is irradiated to the reflector mounted on the front of the stabilized platform,after self collimation collimator,forming a converging spot on the detection device PSD,control shaking table to start work, the stabilizing system can overcome the disturbance caused by the shaking table,by subsequent processing circuit and calculation,stability accuracy of airborne electro-optical stabilized sight system can be measured.

In orderto meet the needs of photoelectric tracking system dynamic performance testing, to solve the problems existing in the process of test,put forward will PowerPC processor for dynamic characteristics of integrated test equipment to achieve moving target data efficiently and accurately capture and display.The introduction of the dynamic characteristics of PowerPC processor integrated test equipment data acquisition and display system has the characteristics of strong data processing ability, strong expansibility,stable and reliable target motion state, and has broad application prospects.