The structures, relative stability and magnetic properties of pure Gen＋l, neutral cationic and anionic Sn- Gen （n = 1-17） clusters have been investigated by using the first principles density functional theory impl...The structures, relative stability and magnetic properties of pure Gen＋l, neutral cationic and anionic Sn- Gen （n = 1-17） clusters have been investigated by using the first principles density functional theory implemented in SIESTA packages. We find that with the increasing of cluster size, the Gen＋1 and SnGen（1, ±1） clusters tend to ad- opt compact structures. It has been also found that the Sn atom occupied a peripheral position for SnGen clusters when n 〈 12 and occupied a core position for n 〉 12. The structural and electronic properties such as optimized geometries, fragmentation energy, binding energy per atom, HOMO-LUMO gaps and second-order differences in energy of the pure G%＋1 and SnGen clusters in their ground state are calculated and analyzed. All isomers of neutral SnG% clusters are generally nonmagnetic except for n = 1 and 4, where the total spin magnetic moments is 2μb. The total （DOS） and partial density of states of these clusters have been calculated to understand the origin of peculiar magnetic properties. The cluster size dependence of vertical ionization potentials, vertical electronic affinities, chemical hardness, adiabatic electron affinities and adiabatic ionization potentials have been calculated and discussed.展开更多
This paper investigates the light propagation through several types of water by experimental and simulation.The Zemax-ray tracing software allowed to simulate the propagation of light in water and to observe the recei...This paper investigates the light propagation through several types of water by experimental and simulation.The Zemax-ray tracing software allowed to simulate the propagation of light in water and to observe the receiver response by reproducing the real conditions of propagation.The underwater environment has been reproduced by a 1.2 m long water tube and 20 cm in diameter with a glass window fitted on one side.The use of tap water with different amounts of sand leads toward three types of water with different attenuation coefficients(0.133,0.343,0.580 m^-1).The light transmission in the three types of water was experimentally evaluated using a doubled Nd:YAG laser with energy of 4.3 mJ and a pulse width of 20 ns.Comparisons were done between simulation and experimental results.展开更多
文摘The structures, relative stability and magnetic properties of pure Gen＋l, neutral cationic and anionic Sn- Gen （n = 1-17） clusters have been investigated by using the first principles density functional theory implemented in SIESTA packages. We find that with the increasing of cluster size, the Gen＋1 and SnGen（1, ±1） clusters tend to ad- opt compact structures. It has been also found that the Sn atom occupied a peripheral position for SnGen clusters when n 〈 12 and occupied a core position for n 〉 12. The structural and electronic properties such as optimized geometries, fragmentation energy, binding energy per atom, HOMO-LUMO gaps and second-order differences in energy of the pure G%＋1 and SnGen clusters in their ground state are calculated and analyzed. All isomers of neutral SnG% clusters are generally nonmagnetic except for n = 1 and 4, where the total spin magnetic moments is 2μb. The total （DOS） and partial density of states of these clusters have been calculated to understand the origin of peculiar magnetic properties. The cluster size dependence of vertical ionization potentials, vertical electronic affinities, chemical hardness, adiabatic electron affinities and adiabatic ionization potentials have been calculated and discussed.
文摘This paper investigates the light propagation through several types of water by experimental and simulation.The Zemax-ray tracing software allowed to simulate the propagation of light in water and to observe the receiver response by reproducing the real conditions of propagation.The underwater environment has been reproduced by a 1.2 m long water tube and 20 cm in diameter with a glass window fitted on one side.The use of tap water with different amounts of sand leads toward three types of water with different attenuation coefficients(0.133,0.343,0.580 m^-1).The light transmission in the three types of water was experimentally evaluated using a doubled Nd:YAG laser with energy of 4.3 mJ and a pulse width of 20 ns.Comparisons were done between simulation and experimental results.
