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871.
872.
研究了激发态质子转移(ESPT)分子2-(2'-羟基苯基)苯并噻唑(HBT)在不同极性溶剂中的光开关行为,探讨了溶剂极性对HBT分子光开光效应的影响.揭示了光开关脉冲信号的形成原因,建立了基于光诱导HBT分子激发态非线性折射效应的皮秒全光开关的理论模型.根据对时间响应函数的理论计算和实验结果分析,确定了光开关脉冲信号下降前沿和上升后沿的形成机理以及影响因素,并提出了增强光开关信号下降前沿的关断深度,提升上升后沿的恢复速度的有效途径和方法.本文工作为制成皮秒量级关断,微秒甚至纳秒量级重新打开的快速全光开关器 相似文献
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Takafumi Hirata 《Journal of Oceanography》2008,64(4):561-566
An irradiance inversion model to estimate the in situ absorption coefficient of seawater has been developed for the Ultraviolet-A (UVA) wavelength domain. Input parameters are
sun angle and the up-and downward planar irradiances measured for at least two depths. The present method does not require
seawater to be sampled, and is a discrete wavelength method which returns the absorption coefficient at a given wavelength
from the irradiances measured at that wavelength without assuming a spectral shape of any optical properties a priori. Comparison between the model results and spectrophotometric measurements shows that the model is practically useful when
cloud cover in the atmosphere is ≤ 50%. According to the present method, measurements of the irradiances enable simultaneous
observation of the in situ underwater UVA radiation level and the absorption capacity of bulk seawater using a radiometer. 相似文献
879.
Numerical study of baroclinic tides in Luzon Strait 总被引:5,自引:1,他引:5
The spatial and temporal variations of baroclinic tides in the Luzon Strait (LS) are investigated using a three-dimensional
tide model driven by four principal constituents, O1, K1, M2 and S2, individually or together with seasonal mean summer or winter stratifications as the initial field. Barotropic tides propagate
predominantly westward from the Pacific Ocean, impinge on two prominent north-south running submarine ridges in LS, and generate
strong baroclinic tides propagating into both the South China Sea (SCS) and the Pacific Ocean. Strong baroclinic tides, ∼19
GW for diurnal tides and ∼11 GW for semidiurnal tides, are excited on both the east ridge (70%) and the west ridge (30%).
The barotropic to baroclinic energy conversion rate reaches 30% for diurnal tides and ∼20% for semidiurnal tides. Diurnal
(O1 and K1) and semidiurnal (M2) baroclinic tides have a comparable depth-integrated energy flux 10–20 kW m−1 emanating from the LS into the SCS and the Pacific basin. The spring-neap averaged, meridionally integrated baroclinic tidal
energy flux is ∼7 GW into the SCS and ∼6 GW into the Pacific Ocean, representing one of the strongest baroclinic tidal energy
flux regimes in the World Ocean. About 18 GW of baroclinic tidal energy, ∼50% of that generated in the LS, is lost locally,
which is more than five times that estimated in the vicinity of the Hawaiian ridge. The strong westward-propagating semidiurnal
baroclinic tidal energy flux is likely the energy source for the large-amplitude nonlinear internal waves found in the SCS.
The baroclinic tidal energy generation, energy fluxes, and energy dissipation rates in the spring tide are about five times
those in the neap tide; while there is no significant seasonal variation of energetics, but the propagation speed of baroclinic
tide is about 10% faster in summer than in winter. Within the LS, the average turbulence kinetic energy dissipation rate is
O(10−7) W kg− 1 and the turbulence diffusivity is O(10−3) m2s−1, a factor of 100 greater than those in the typical open ocean. This strong turbulence mixing induced by the baroclinic tidal
energy dissipation exists in the main path of the Kuroshio and is important in mixing the Pacific Ocean, Kuroshio, and the
SCS waters. 相似文献
880.
Review of recent findings on the water masses and circulation in the East Sea (Sea of Japan) 总被引:1,自引:0,他引:1
Kuh Kim Kyung-Il Chang Dong-Jin Kang Young Ho Kim Jae-Hak Lee 《Journal of Oceanography》2008,64(5):721-735
Recent findings on water masses, biogeochemical tracers, deep currents and basin-scale circulation in the East/Japan Sea,
and numerical modeling of its circulation are reviewed. Warming continues up to 2007 despite an episode of bottom water formation
in the winter of 2000–2001. Water masses have definitely changed since the 1970s and further changes are expected due to the
continuation of warming. Accumulation of current data in deep waters of the East/Japan Sea reveals that the circulation in
the East/Japan Sea is primarily cyclonic with sub-basin scale cyclonic and anticyclonic cells in the Ulleung Basin (Tsushima
Basin). Our understanding of the circulation of intermediate water masses has been deepened through high-resolution numerical
studies, and the implementation of data assimilation has had initial success. However, the East/Japan Sea is unique in terms
of the fine vertical structures of physical and biogeochemical properties of cold water mass measured at the highest precision
and their rapid change with the global warming, so that full understanding of the structures and their change requires in-depth
process studies with continuous monitoring programs. 相似文献