The sea fluxes of trace metals, POC, and settled material were studied in anoxic sea water, Saanich Inlet, B.C., Canada with sediment traps. This paper discusses the change of mass fluxes of sediment, trace metals and...The sea fluxes of trace metals, POC, and settled material were studied in anoxic sea water, Saanich Inlet, B.C., Canada with sediment traps. This paper discusses the change of mass fluxes of sediment, trace metals and POC for various seasons and depths. The annual mean of settled material is 1.56 g.m-2 .a-1, 84.6 mg. m-2. a-1 for POC, 60.0 mg.m-2. a-1 for Cu, 16.5 mg.m-2.a-1 for Pb, 189 mg.m-2. a-1 for Zn, 2.20mg.m-2.a-1 for Cd,699 mg.m-2.a-1 for Fe,38.8 mg.m-2.-1 for Co, and 84.6 mg.m-2.a-1 for Ni.The relations between the average fluxes of trace metals and POC, the fluxes of trace metals and settled matter, and the sea fluxes of trace metals and Fe are in linear progression. The resident times of elements as calculated from sea flux, are 1.1 a. for Cu, 0.014 a. for Pb, 0.50 a. for Zn, 3.8 a. for Cd, 0.16 a. for Fe, 0.39 a. for Co,and 1.14 a. for Ni.The order of resident times is as follows: Pb-Fe-Co-Zn-Cu-Ni-Cd. The metal resident times in Saanich Inlet are shorter than the values estimated for the展开更多
We report the femtosecond time-resolved studies of room temperature exciton recombination and ultrafast stimulated emission dynamics in ZnO microcrystallite thin films.A free exciton photoluminescence lifetime of a fe...We report the femtosecond time-resolved studies of room temperature exciton recombination and ultrafast stimulated emission dynamics in ZnO microcrystallite thin films.A free exciton photoluminescence lifetime of a few tens of picoseconds and a decay time of a few picoseconds for the stimulated emission were observed.The relatively slow rise time(3ps)for the P band as the result of exciton-exciton scattering compared with the 0.8ps rise time for the N band attributed to electron-hole plasma recombination clearly distinguished the two stimulated emission processes.展开更多
文摘The sea fluxes of trace metals, POC, and settled material were studied in anoxic sea water, Saanich Inlet, B.C., Canada with sediment traps. This paper discusses the change of mass fluxes of sediment, trace metals and POC for various seasons and depths. The annual mean of settled material is 1.56 g.m-2 .a-1, 84.6 mg. m-2. a-1 for POC, 60.0 mg.m-2. a-1 for Cu, 16.5 mg.m-2.a-1 for Pb, 189 mg.m-2. a-1 for Zn, 2.20mg.m-2.a-1 for Cd,699 mg.m-2.a-1 for Fe,38.8 mg.m-2.-1 for Co, and 84.6 mg.m-2.a-1 for Ni.The relations between the average fluxes of trace metals and POC, the fluxes of trace metals and settled matter, and the sea fluxes of trace metals and Fe are in linear progression. The resident times of elements as calculated from sea flux, are 1.1 a. for Cu, 0.014 a. for Pb, 0.50 a. for Zn, 3.8 a. for Cd, 0.16 a. for Fe, 0.39 a. for Co,and 1.14 a. for Ni.The order of resident times is as follows: Pb-Fe-Co-Zn-Cu-Ni-Cd. The metal resident times in Saanich Inlet are shorter than the values estimated for the
基金Supported by the National Natural Science Foundation of China under Grant No.69608002the Excellent Young Teacher's Foundation of the Minis try of Education.
文摘We report the femtosecond time-resolved studies of room temperature exciton recombination and ultrafast stimulated emission dynamics in ZnO microcrystallite thin films.A free exciton photoluminescence lifetime of a few tens of picoseconds and a decay time of a few picoseconds for the stimulated emission were observed.The relatively slow rise time(3ps)for the P band as the result of exciton-exciton scattering compared with the 0.8ps rise time for the N band attributed to electron-hole plasma recombination clearly distinguished the two stimulated emission processes.
