Study of Mass Distribution of Carbon Cluster Anions by a Laser Vaporization/Pulsed Molecular Beam Method

By a laser vaporization/pulsed molecular beam method,the carbon anion clusters (n=1 to 45) are produced and analyzed. An evident odd-even abundance alternation pattern is observed,with the even-numbered (n=8,10,14,16,18,20,22,24,26,28 and 30) standing out. It can also be observed that the peaks at n=5 and n=13 are prominent. Compared with the results obtained by other authors,a discussion concerning cluster structures is made.     

1,1-二(2,4,6-三硝基苯甲酰胺基)-2,2-硝基乙烯的合成

以1,1-二氨基-2,2-二硝基乙烯(FOX-7)和2,4,6-三硝基苯甲酰氯(TNBC)为原料反应合成得到了1,1-二(2,4,6-三硝基苯甲酰胺基)-2,2-二硝基乙烯,并通过单因素试验和正交试验方法,分别探讨了反应介质、缚酸剂、反应温度和反应时间等对产物产率的影响,得到适宜的工艺条件为:FOX-7与TNBC物质的量的比1∶2.4,以四氢呋喃(THF)为反应介质,N,N-二甲基甲酰胺(DMF)为缚酸剂,反应温度0℃,反应时间48 h,产率可达94％.采用紫外可见光谱(UV-Vis)、核磁共振氢谱(1H NMR)、核磁共振碳谱(13C NMR)、红外光谱(FT-IR)、质谱(MS)及元素分析等对产物的结构进行了表征.利用差热分析仪对产物热稳定性进行了研究,结果表明,产物在空气中分解峰值温度为167℃,理论计算爆速为7.434km· s-1,爆压为23.67 GPa.     

电沉积富铁Fe-Ni合金箔工艺的研究

对硫酸盐-氯化物电解液中电沉积富铁Fe-Ni合金箔的工艺进行了研究,讨论了电解液组成、电流密度、温度及pH值等因素与合金箔组成之间的相互关系,得到了制备富铁合金箔的最佳镀液组成及工艺条件,并通过实验确定在阴阳极比为1:2时,镍铁联合阳极配比为1.5:1.通过扫描电镜,能谱和X-衍射对富铁Fe-Ni合金箔的形貌及结构进行分析表明合金箔晶粒细致,尺寸均匀,结构紧密,表面光滑平整,无孔洞和裂纹,晶粒结构为(111),(200),(311)及(222)织构,并表现为较强的(111)择优取向.     

Tin oxide nano-flower-anchored graphene composites as high-performance anode materials for lithium-ion batteries

The SnO₂ nano-flower/graphene (SnO₂-NF/GN) composites were synthesized by using graphene (GN) and SnO₂ nano-flower (SnO₂-NF). Among them, the SnO₂-NFs were prefabricated by using sodium hydroxide and stannic chloride pentahydrate (SnCl₄·5H₂O) as raw materials. The results of SEM show that the SnO₂-NFs are uniformly dispersed on the surface of GN. Furthermore, compared with the pure SnO₂, the as-prepared SnO₂-NF/GN composites displayed superior cycle performace and high rate capability. The SnO₂-NF/GN composite delivers a specific capacity of 650 mAh g^?1 after 60 cycles and an excellent rate capability of 480 mAh g^?1 at 2000 mA g^?1.     

ZnO three-dimensional hedgehog-like nanostructure: synthesis,growth mechanism and optical enhancement

The 3D hedgehog-like ZnO nanostructures were synthesized on Si substrate through chemical vapor deposition process. The morphology and structure of the products were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, as well as transmission electron microscopy. The ZnO 3D hedgehog-like architectures were found to consist of a central nucleus and multiple side-growing nanowires with diameter of 100–250 nm and length up to 10 µm. The growth mechanism of the hedgehog-like ZnO nanostructures was studied. It revealed a three-step process during the entire growth. Finally, room temperature photoluminescence spectra of ZnO 3D nanostructures showed that the center excitation would render much stronger PL emission intensity. Furthermore, simulation results indicated that the enhanced emission came from light-trapping-induced excitation light field enhancement.     

Facile Fabrication of Cu-doped Carbon Aerogels as Catalysts for the Thermal Decomposition of Ammonium Perchlorate

We report a simple and effective method to produce copper-doped carbon aerogel (Cu-CA) using sodium alginate as a carbon precursor through ion crosslinking and high-temperature carbonization. Results indicate that Cu-alginate has a 3D scaffold structure with pores. The effect of using different metal salt mass ratios of Cu-CA on the catalytic thermal decomposition of AP is also investigated. The thermal decomposition temperature of AP decreases by 94.24 °C, and the activation energy of the decomposition reaction is reduced by 45.7 kJ/mol. These results demonstrate that the composite exhibits superior catalytic performance compared with a single-component transition metal salt.     

On the shock sensitivity of explosive compounds with small-scale gap test

In this work an improved set of small-scale gap tests was applied to measure the shock sensitivity of 13 explosive compounds, and a Mn-Cu manometer was also employed to measure the output pressures of shock waves passed through aluminum gaps with different thicknesses to draw a standard curve. The critical initiation thicknesses of aluminum gaps of different explosive compounds (244 shots in total) were treated according to statistical method, and the Mulliken charges of nitro groups, bond dissociation energies of X-NO(2) (X = C, N), resonance energies, and ring strain energies of these explosive compounds were calculated with the means of DFT/BLYP/DNP calculations and homodesmotic reactions designs. Genetic function approximation was used to construct a relationship between the critical initiation thicknesses of aluminum gaps of different explosive compounds and their forementioned molecule structural parameters.