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991.
He Lin Shun‐Guan Zhu Hong‐Zhen Li Xin‐Hua Peng 《Journal of Physical Organic Chemistry》2013,26(11):898-907
Intermolecular interactions and properties of octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐ tetrazocine (HMX) / 2,6‐diamino‐3,5‐dinitropyrazine‐1‐oxide (LLM‐105) cocrystal were studied by using the dispersion‐corrected density functionals (ωB97XD, B97D) and meta‐hybrid functional (M062x) methods. Binding energies, heats of formation, thermodynamic properties, atoms in molecules, and natural bond orbital analysis were performed to investigate HMX/LLM‐105 complexes. Results show that the main intermolecular interactions between HMX and LLM‐105 are CH…O, NH…O, N…O, and O…O interactions. In addition, Monte Carlo simulation was employed to predict the crystal structure of HMX/LLM‐105 cocrystal. The HMX/LLM‐105 cocrystal is most likely to crystallize in C2/c space group, and its corresponding cell parameters are Z = 8, a = 41.63 Å, b = 6.77 Å, c = 45.63 Å, ß = 164.55°, and ρ = 1.99 g/cm3. Detonation velocity and pressure of HMX/LLM‐105 cocrystal are 8.95 km/s, 37.69GPa, a little lower than those of HMX (9.10 km/s, 37.76GPa). However, according to the net charges of nitro group, HMX/LLM‐105 cocrystal exhibits less sensitive than HMX. Finally, bond dissociation energy calculation shows that HMX/LLM‐105 complexes are thermally stable. Considering thermal stability, sensitivity, and detonation performance, HMX/LLM‐105 cocrystal meets the requirements of insensitive high energy density materials. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
992.
993.
从模式保留和转换的角度, 过模波导器件可分为模式转换器、模式保留器和模式综合器. 传统方法只解决其中一种器件的设计或者对器件的某个指标进行改进. 本文在深入分析耦合波理论之后, 提出了过模波导器件的迭代设计方法, 从原理上解决了过模波导器件的设计问题. 该方法能够统一设计三类过模波导器件, 通过添加不同的结构控制方法, 可得到转换效率更高、带宽更宽、结构更紧凑、满足不同工程需求的器件, 而且还能有效设计一些新型器件. 给出了两个设计实例: 双频TM01–TE11模式变换器和光壁馈源喇叭. 双频TM01–TE11模式变换器的两个工作频点为8.75 GHz和10.3 GHz, 波导半径为16 mm, 在两个频点转换效率为99%以上. 光壁馈源喇叭实现TE11模式向高斯束的转换. CST仿真结果验证了这两个器件设计的正确性和有效性.
关键词:
耦合波理论
模式转换器
模式过渡器
迭代法 相似文献
994.
环境卫星HJlA超光谱成像仪在轨辐射定标及光谱响应函数敏感性分析 总被引:1,自引:0,他引:1
环境卫星HJIA搭载的超光谱成像仪HSI是我国第一个对地观测的星载高光谱传感器,针对超光谱成像仪缺乏各通道光谱响应函数这一问题,对传统的反射率基法予以改进,提出一种不使用光谱响应函数的场地定标方法.利用敦煌场地2009年8月定标实验数据,实现超光谱成像仪在轨辐射定标.通过构建不同形状的光谱响应函数,分析光谱响应函数形状对最终辐射定标结果产生的误差.结果表明,利用新提出的场地定标方法可以实现超光谱成像仪绝对辐射定标,除水汽和氧气吸收通道外,光谱响应函数对定标结果的影响小于3%,采用新定标方法得到的定标系数可以满足应用的需求. 相似文献
995.
Intermediate mass black holes may be formed through repeated coalescences of compact objects or through the direct collapse
of a hypermassive star formed through runaway collisions of main sequence stars. The gravitational wave signature of these
two formation scenarios will be different. Here we present an initial study of the waveform generated during the direct axisymmetric
collapse of a hypermassive star in order to facilitate searches for this source. We approximate the collapse of the core as
an axisymmetric Newtonian free-fall of a rotating relativistic degenerate iron core. The collapse waveform can be reasonably
well modeled by an exponential growth. 相似文献
996.
Brewster’s angle method was adopted to measure the absorption coefficient of a set of high-resistivity germanium samples at 2.52 THz in this paper. Numerical simulations were firstly carried out to evaluate the errors during measurement. The experimental setup was improved, and measurement was carried out based on a CW THz laser at 2.52 THz. 相似文献
997.
Disk-ring multiferroic heterostructures composed of Terfenol-D and Pb(Zr,Ti)O3 (PZT) were prepared and characterized, for which the ferromagnetic and ferroelectric phases were coupled through normal stresses
instead of the shear stresses that acted in most of the previous multiferroic heterostructures. High low-frequency magnetoelectric
coefficients of 0.10–0.75 V cm−1 Oe−1 were attained for the disk-ring heterostructures, which indicated the strong magnetoelectric coupling. Moreover, a symmetrical
resonant peak was observed for dE
3/dH
3 in the frequency range of 1–200 kHz, while another weak peak with asymmetrical shape also existed at a lower frequency for
dE
3/dH
1, which was due to the combination of two vibration modes. 相似文献
998.
Polarization entangled photon pairs are easily perturbed in noisy channels. We propose a polarization entanglement purification method using temporal degree of freedom, followed by the conventional iterative purification. The entanglement fidelity can be improved to any degree, and the steps needed are less than those using conventional iteration method. 相似文献
999.
The intrinsic transport properties of zigzag graphene nanoribbons (ZGNRs) are investigated using first-principles calculations. It is found that although all ZGNRs have similar metallic band structure, they show distinctly different transport behaviors under bias voltages, depending on whether they are mirror symmetric with respect to the midplane between two edges. Asymmetric ZGNRs behave as conventional conductors with linear current-voltage dependence, while symmetric ZGNRs exhibit unexpected very small currents with the presence of a conductance gap around the Fermi level. This difference is revealed to arise from different coupling between the conducting subbands around the Fermi level, which is dependent on the symmetry of the systems. 相似文献
1000.
Smalyuk VA Shvarts D Betti R Delettrez JA Edgell DH Glebov VY Goncharov VN McCrory RL Meyerhofer DD Radha PB Regan SP Sangster TC Seka W Skupsky S Stoeckl C Yaakobi B Frenje JA Li CK Petrasso RD Séguin FH 《Physical review letters》2008,100(18):185005
The compression of direct-drive, spherical implosions is studied using cryogenic D2 targets on the 60-beam, 351-nm OMEGA laser with intensities ranging from approximately 3x10(14) to approximately 1x10(15) W/cm2. The hard-x-ray signal from hot electrons generated by laser-plasma instabilities increases with laser intensity, while the areal density decreases. Mitigating hot-electron production, by reducing the laser intensity to approximately 3x10(14) W/cm2, results in areal density of the order of approximately 140 mg/cm2, in good agreement with 1D simulations. These results will be considered in future direct-drive-ignition designs. 相似文献