Forty nitramines by incorporating -C=O, -NH2, -N3, -NF2, -NHNO2, -NHNH2, -NO2, -ONO2, -C(NO2)3, and -CH(NO2)2 groups based on a 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) framework were designed. Their electronic structures, heats of formation (HOFs), detonation properties, thermal stabilities, electrostatic potential, and thermodynamic properties were systematically investigated by density functional theory. The comprehensive relationships between the structures and performance of different substituents were studied. Results indicate that -C(NO2)3 has the greatest effect on improvement of HOFs among the whole substituted groups. Thermodynamic parameters, such as standard molar heat capacity (Cp,mθ), standard molar entropy (Smθ), and standard molar enthalpy (Hmθ), of all designed compounds increase with the increasing number of energetic groups, and the volumes of energetic groups have a great influence on standard molar enthalpy. Except for -NH2(R1), -NHNH2(R5), and B3, all of the designed compounds have higher detonation velocities and pressures than HMX. Among them, E7 exhibits an extraordinarily high detonation performance (D = 10.89 km s-1, P = 57.3 GPa), E1 exhibits a relatively poor detonation performance (D = 8.93 km s-1, P = 35.5 GPa), and -NF2 and -C(NO2)3 are the best ones in increasing the density by more or less 12%.In this paper, a simple "one-step" route is introduced to prepare a kind of novel honeycomb-like hierarchical porous carbon (h-HPC) by carbonizing and activating garlic seeds. ISO-1 clinical trial Due to its special microstructure, h-HPC shows excellent electrochemical properties and high supercapacitor performances. The experimental results reveal the following (1) There exists an optimal condition for synthesizing h-HPC, i.e., 700 °C carbonization temperature and 11 mass ratio of KOH and garlic seeds. (2) h-HPC has a three-dimensional interconnected porous structure and exhibits a specific surface area as high as 1417 m2/g with a narrow pore size distribution. (3) When h-HPC is employed as an electrode material in supercapacitors, its specific capacitance reaches a value up to 268 F/g at a current density of 0.5 A/g and excellent rate capability. (4) The h-HPC-based symmetric supercapacitor shows a high energy density of 31.7 Wh/kg at a power density of 500 W/kg and retains 99.2% of the initial capacitance after 10,000 charge/discharge cycles at 200 mV/s. When compared with similar works, these data are competitive, which demonstrates that the garlic-derived h-HPC is a kind of promising electrode material for the next-generation high-energy-density supercapacitors.The reaction of magnesium or zinc amides with alkyl or benzyl halides is an attractive approach to make C-N bonds, especially for electron-poor organic halides. The magnesium-promoted preparation of hindered non-nucleophilic amine (N,N-diisopropylethylamine) from ethyl chloride and zinc diisopropylamide has been studied. In this paper, instead of the application scope of this method, we focused on the mechanisms of the catalytic processes and the associated electronic origins. According to the calculations, the C-N coupling process in all selected systems proceed preferably in an ethylium-transfer mode. Further, rather than undergoing the Grignard reaction route, the more pronounced electronic interactions within the transition structure as induced by the "innocent" magnesium atom should be responsible for the observed high catalytic activity of the Mg/ZnCl2 combination.Improving the electrochemical performance of biomass-derived carbon electrode-active materials for supercapacitor applications has recently attracted considerable attention. Herein, we develop hybrid electrode materials from rice-husk-derived porous carbon (RH-C) materials and β-Ni(OH)2 via a facile solid-state reaction strategy comprising two steps. The prepared RH-C/Ni(OH)2 (C-Ni) was investigated using scanning electron microscopy (SEM) (energy-dispersive X-ray spectrometer (EDS)), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) to acquire the physical and chemical information, which was used to demonstrate the successful fabrication of C-Ni. Thermogravimetric analysis (TGA) measurement results confirmed that the thermal stability of C-Ni changed due to the presence of Ni(OH)2. As expected, C-Ni possesses a high capacitance of ∼952 F/g at a current density of 1.0 A/g. This result is higher than that of pure biomass-based carbon materials under the three-electrode system. This facile preparation method, which was used to synthesize the electrode-active materials, can extend to the value-added utility of other waste biomass materials as high-performing supercapacitor electrodes for energy storage applications.In this work, the effect of coagulation bath temperature in different solvent systems [1,4-butyrolactone (GBL)/N,N-dimethylacetamide (DMAC)] on the structure and dielectric properties of polyimide (PI) films was investigated for the first time. The solubility parameter was introduced to explain the formation process of porous PI films. The results showed that the changed tendency of the dielectric constant versus temperature is opposite for the single-solvent system and cosolvent system. For a single DMAC and GBL solvent, the dielectric constants of the films decreased with increasing temperature. In contrast, the dielectric constants increased with the increase in temperature for the GBL/DMAC cosolvent system. Moreover, the measured porosities were applied to estimate the dielectric constants of the PI films. This showed that the porosity increased with increasing temperature for a single-solvent system, while it decreased for a cosolvent system. Scanning electron microscopy images suggested that the variation trends are derived from the different influences of the temperature on the structure and morphology. Thus, this study reveals the effect of coagulation bath temperature on the structure and dielectric properties of porous PI films and provides the guidance for the design and optimization of architectures for high-performance porous films.The geological structure and gas hydrate occurrence are stratification-dependent in the vertical direction. It is necessary to explore the formation processes and distribution characteristics of methane hydrate in layered porous media. The sand sample consists of two equal parts in a testing cylinder. The upper part is 0.5-1 mm sand in particle diameter, and the lower parts are 0.075∼0.5, 0.5∼1, and 1∼2 mm. The experimental results show that the formation rate of methane hydrate gradually decreases as the reaction goes on, and it is higher in layered sand than in nonlayered sand in the beginning. With the increase of the sand size in the lower part, saturation of methane hydrate gradually decreases in the upper part and increases in the lower part. In the layered sand, saturation of methane hydrate is higher in the sand layer whose particle size is bigger. The abovementioned results can be used to predict the favorable area where methane hydrate may appear in different stratigraphic structures in nature.