LABORATORY OF RARE EARTH CHEMISTRY AND PHYSICS,CHANGCHUN INSTITUTE OF APPLIED CHEMISTRY,ACADEMIA SINICA

The Laboratory of Rare Earth Chemistry and Physics,Changchun Institute of Ap-plied Chemistry,Academia Sinica,has been opened to foreign scientists since October,1987.The first plenary session of the Academic Committee was held in March,1988,andthe first batch of research projects granted by the Scientific Funds of the Laboratory wereapproved at this meeting.

Construction and Properties of Structure-and Size-controlled Micro/Nano-energetic Materials

The recent research progress of structure- and size-controlled micro/nano-energetic materials is reviewed, which properties are fundamentally different from those of their corresponding bulk materials. The development of the construction strategies for achieving zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) micro/nanostructures from energetic molecules is introduced. Also, an overview of the unique properties induced by micro/nanostructures and size effects is provided. Special emphasis is focused on the size-dependent properties that are different from those of the conventional micro-sized energetic materials, such as thermal decomposition, sensitivity, combustion and detonation, and compaction behaviors. A conclusion and our view of the future development of micro/nano-energetic materials and devices are given.

Influence of Accelerated Aging on Detonation Performance of Explosives

To understand the aging effects on detonation performances of explosives,an accelerated aging mechanism and effect of explosives were analyzed.Based on the thermo-gravimetric(TG) curves of explosives under the heat rate of 5,10 and 20 K·min-1,the thermal decomposition activation energy,pre-exponential factor,mechanism function and kinetic equation of the explosives were calculated by Ozawa's equation and decomposition extents.Then,according to the derived kinetic equation,the density,composition and heat of formation of GI-1,PBX-1 and PBX-2 explosive in different decomposition extents were calculated at accelerated aging temperatures of 70 ℃ and 75 ℃,respectively.Furthermore,the detonation parameters of GI-1,PBX-1 and PBX-2 explosives were found out by means of VLWR code.The results show that after accelerated aging,the density are decrease,the detonation velocity and pressure are all decreased slightly.

Experimental research on influence of emulsifier on crystallization quantity of emulsion explosives under dynamic pressure

Dynamic pressure was applied on emulsion explosive by using an underwater explosion measuring apparatus, and the crystallization quantity was measured by dissolution method after emulsion explosive was pressed; the influence of emulsi- fier content and type was analyzed. The experimental results show that emulsifier content and type have an important effect on crystallization quantity of emulsion explosive. The crystallization quantity will reduce with Span-g0 content from 2% to 4%, so the demulsification and crystallization will decrease if the emulsifier content improves appropriately and the dynamic pressure resistance will increase. For emulsion explosive emulsified by T-152 and Span-g0, the crystallization quantity with T-152 is less than that of Span-g0 under the same dynamic pressure. This shows that the emulsifying effect ofT-152 is better than Soan-80.

Phonon relaxation and heat conduction in one-dimensional Fermi Pasta Ulam β lattices by molecular dynamics simulations

The phonon relaxation and heat conduction in one-dimensional Fermi Pasta-Ulam （FPU） β lattices are studied by using molecular dynamics simulations. The phonon relaxation rate, which dominates the length dependence of the FPU β lattice, is first calculated from the energy autoeorrelation function for different modes at various temperatures through equilibrium molecular dynamics simulations. We find that the relaxation rate as a function of wave number k is proportional to k^1.688, which leads to a N^0.41 divergence of the thermal conductivity in the framework of Green-Kubo relation. This is also in good agreement with the data obtained by non-equilibrium molecular dynamics simulations which estimate the length dependence exponent of the thermal conductivity as 0.415. Our results confirm the N^2/5 divergence in one-dimensional FPU β lattices. The effects of the heat flux on the thermal conductivity are also studied by imposing different temperature differences on the two ends of the lattices. We find that the thermal conductivity is insensitive to the heat flux under our simulation conditions. It implies that the linear response theory is applicable towards the heat conduction in one-dimensional FPU β lattices.

Bronsted acidic ionic liquid [C_3SO_3HDoim]HSO_4 catalyzed one-pot three-component Biginelli-type reaction: An efficient and solvent-free synthesis of pyrimidinone derivatives and its mechanistic study

A series of Bronsted acidic ionic liquids（ILs） were prepared and used for Biginelli-type condensation reaction among aromatic aldehydes, urea or thiourea and cyclopentanone. Through this reaction, the synthesis of various pyrimidinones could be achieved. Of interest, it was found that the reaction was efficiently catalyzed by a novel, eco-friendly functionalized IL [C3SO3HDoim]HSO4, which could be reused for at least 7 times without significantly loss of catalytic activity. The reaction proceeded efficiently at 80℃ to afford the desired products in good yield（up to 96%）. In addition, a possible mechanism that accounted for the IL [C3SO3HDoim]HSO4-catalyzed reaction was proposed.