A new family of energetic ionic liquids 1-amino-3-alkyl-1,2,3-triazolium nitrates

A new class of energetic ionic liquids based upon 1-amino-3-alkyl-1,2,3-triazolium nitrates (alkyl = methyl, ethyl, n-propyl, 2-propenyl, and n-butyl) has been synthesized and characterized by vibrational spectra, multinuclear NMR, elemental as well as contaminant analyses, and DSC studies. A single crystal X-ray study was carried out for 1-amino-3-methyl-1,2,3-triazolium nitrate and the details will be presented.     

An approach to modeling the dependence of magnetization on magnetic field in the high field regime

The “law of approach to saturation” is a well-known mathematical model for describing the behavior of ferromagnets at high magnetic field strengths which has the additional advantage that it can be linked to anisotropy through one of the terms in the mathematical expression of the law. In this paper, two recent and more comprehensive models of the magnetization process are compared with the law of approach and with each other in terms of their capability to describe the dependence of the magnetization curve in the high field regime. The comparison leads to relations between these two models and the interpretation of certain aspects of the models in terms of anisotropy. It is shown that the effects of anisotropy can be incorporated directly into these models without any additional assumptions.     

高能离子的定向发射及其模拟研究

本文用二维粒子模拟方法研究了超强超短脉冲激光与圆形等离子体薄靶相互作用中产生的高能离子.模拟研究结果表明,在圆形等离子体薄靶后表面所产生的高能离子,角分布较小,定向性好,能获得很高的能量,并且等离子体薄靶的形状对高能离子的产生和会聚有一定地影响.     

New Energetic Copper(II) Complexes With Pyrazolyl Type Ligands

Nine Cu^II complexes ( I – IX ) containing the azide ion and bis‐2,6‐(pyrazol‐1‐yl)pyridine (pp), bis‐2,6‐(pyrazol‐1‐yl)pyridine (dmpp), and 2‐(pyrazol‐1‐yl)‐6‐(3,5‐dimethylpyrazol‐1‐yl)pyridine (mpp), which are derivatives of pyrazolylpyridine, were prepared in nonaqueous medium. These complexes were characterized by elemental analyses and IR spectroscopy. Crystals of one of these complexes [CumppClN₃ ( VII )] were prepared in suitable size, and a molecular structure of this complex was obtained with X‐ray diffraction method. Complexes were examined by thermogravimetry and differential scanning calorimetry methods. Thermal decomposition was observed in complexes including two azide groups similar to that seen in explosives. In the complexes containing one azide group, formation of the Cu^I complexes was observed after thermal decomposition of the azide group.     

JT-60U ��JT-60SA ���������¸��������Ӽ�������ɢ�����ұ���ģ

运用线性回旋动力学与磁流体力学的混合模拟程序,研究了JT-60U和JT-60SA装置中高能量粒子对离散阿尔芬本征模的共振激发.发现了丰富的αTAE动力学不稳定模式,研究了它的不稳定特性对高能量粒子速度的依赖关系.发现在JT-60U高βp ELMy H模运行中有grassy ELM的放电比有gaint ELM的放电更容易被高能量粒子激发成不稳定模式,在有边缘L模存在的负剪切运行下的各个势阱中都存在高能量粒子激发的αTAE不稳定模式.另外在JT-60SA中高βp全非感应电流驱动下的模拟实验放电下也发现了丰富的αTAE不稳定模式,观察了αTAE在该装置中沿磁场线和径向两个方向的二维广域本征模特性.     

Temperature measurements of Al containing nano-thermite reactions using multi-wavelength pyrometry

Thermite reactions with nano-scale particles have attracted much study due to their high flame temperatures and combustion velocities. The mechanism by which the reaction propagates is not well understood. The reaction temperature, the heating rate, and the reaction zone thickness are critical parameters to understanding the mechanism. Measurements of the reaction temperature for the Al/CuO, Al/MoO₃, and Al/Fe₂O₃ nano-thermite systems were made using multi-wavelength pyrometry for two experimental configurations. In one experiment, the radiative emission from the reaction of a small, unconfined pile (∼10 mg) of reacting nano-thermite is collected over a 50 ms integration time and the temperature is measured. In a second experiment, the radiative emission was collected from a single spot, with a diameter of 1.5 mm, on a transparent tube filled with the nano-thermite as the combustion wave passes and the spectrum is temporally resolved using a streak tube and detected using an intensified CCD camera. Temperature traces from these experiments show a temperature ramping period followed by a plateau in temperature. For Al/CuO, the average temperature from the unconfined pile experiment was 2390 ± 150 K, and the average plateau temperature for the temporally resolved measurements was approximately 2250 ± 100 K. For Al/MoO₃, the unconfined pile experiment yielded an average temperature of 2150 ± 100 K, and the average plateau temperature was the same. The temperature measured from the Al/Fe₂O₃ unconfined pile experiment was 1735 ± 50 K. The measured temperatures suggest that the gases generated during the reactions are primarily from the decomposition or vaporization of the various metal oxides. Furthermore, for Al/CuO and Al/MoO₃, which can be classified as ‘fast’ nano-thermites, it was shown that the length scale associated with the temperature rise is much longer than classical conduction driven reactions.     

A redox reaction model for self-heating and aging prediction of Al/CuO multilayers

Sputter-deposited Al/CuO multilayers capable of highly energetic reactions have been the subject of intense studies for tunable initiation and actuation. Designing high performance Al/CuO-based initiator devices definitively requires reliable prediction of their ignition and reaction kinetics including self-heating or ageing as a function of heating rate and environmental conditions. The paper proposes a heterogeneous reaction model integrating an ensemble of basic mechanisms (oxygen diffusion, structural transformations, polymorphic phase changes) that have been collected from recent experimental investigations. The reaction model assumes that the rate of reaction is limited by the transport of oxygen across the growing layer of Al₂O₃ separating Al and CuO. Importantly, we show that the model predicts reasonably all exotherms through a wide range of temperature (ambient – 1000°C), all resulting from a pure diffusion process as experimentally observed for such Al/CuO multilayers. The model shows how the temperature ramp affects the structure of the multilayer and especially the growth of alumina-based interfacial regions. It highlights the importance of the interfacial chemistry evolution such as the native mixture of Al_xCu_yO_z transformation into a thin amorphous alumina, and the polymorphic phase transformation of this latter. The first one occurring at ～350°C results in a loss of continuity of the interface leading to the accelerated redox reaction whereas the second one occurring between 500 and 600°C produces a denser barrier to oxygen diffusion leading to the stop of redox reaction. We finally use the model to simulate thermal annealing as usually performed in accelerated ageing experiments. We theoretically observe and experimentally validate that a two weeks exposure of the multilayers at 200°C starts degrading the multilayers thermal properties whereas when the temperature remains below 200°C, the material keeps its entire integrity.     

Energetic materials based on poly furazan and furoxan structures

Furazan and furoxan represent fascinating explosophoric units with intriguing structures and unique properties. Compared with other nitrogen-rich heterocycles, most poly furazan and furoxan-based heterocycles demonstrate superior energetic performances due to the higher enthalpy of formation and density levels. A large variety of advanced energetic materials have been achieved based on the combination of furazan and furoxan moieties with different kinds of linkers and this review provides an overview of the development of energetic poly furazan and furoxan structures during the past decades, with their physical properties and detonation characteristics summarized and compared with traditional energetic materials. Various synthetic strategies towards these compact energetic structures are highlighted by covering the most important cyclization methods for construction of the hetercyclic scaffolds and the following modifications such as nitrations and oxidations. Given the synthetic availabilities and outstanding properties, energetic materials based on poly furazan and furoxan structures are undoubtedly listed as a promising candidate for the development of new-generation explosives, propellants and pyrotechnics.     

Eco-friendly energetic complexes based on transition metal nitrates and 3,4-diamino-1,2,4-triazole (DATr)

Four eco-friendly energetic metal complexes of 3,4-diamino-1,2,4-triazole (DATr), including manganese (1), cobalt (2), nickel (3), and zinc (4), were synthesized by reacting DATr·HCl with the corresponding metal (Mn(II), Co(II), Ni(II), and Zn(II)) nitrate in aqueous solution and characterized by using Fourier transform-infrared spectroscopy and elemental analyses. The single crystals of 2, 3, and 4 were obtained and determined by X-ray single-crystal diffraction analysis. All three complexes crystallize in the monoclinic crystal system and belong to P2(1)/n space group. The thermal decomposition processes were investigated by differential scanning calorimeter (DSC) and thermogravimetry–derivative thermogravimetry analyses. The results show that the decomposition temperatures of 1–4 are above 260 °C, depending upon their onset DSC peaks. It can be predicted that these complexes based on 3,4-diamino-1,2,4-triazole have good thermal stability. The nonisothermal kinetic parameters of decomposition were calculated by using Kissinger and Ozawa–Doyle’s methods. Furthermore, the sensitivities of these complexes to impact, friction, and flame were determined. Sensitivity tests revealed that 2 was more sensitive to external stimuli compared to the other three complexes.     

多硝基尿酸衍生物含能性质的理论研究

为了寻找兼具优异爆轰性能和良好热力学及动力学稳定性的高能材料, 本文设计了15个硝基尿酸化合物, 运用密度泛函理论, 对其性质进行了研究. 通过半经验的K-J方程和比冲量预测了其爆炸性能, 结果表明, 所设计分子的爆热、 分子密度、 爆炸速率和爆炸压强同硝基取代基数目之间存在较强的线性关系. 三硝基尿酸和四硝基尿酸衍生物的爆炸速率超过了8.0 km/s, 爆炸压强超过了30 GPa, 并且大多数衍生物的比冲量要高于目前经常使用的炸药黑索金. 通过计算N—NO₂键的解离能、 特征落高、 分子的自由空间预判了衍生物的稳定性和撞击感度, 结果显示, 绝大多数分子有大于80 kJ/mol的键解离能. 本文的理论结果可以为实验上设计合成新的高能材料提供一些有用的信息.