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排序方式: 共有528条查询结果,搜索用时 15 毫秒
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Voltage noise in Limulus visual cells 总被引:26,自引:0,他引:26
Intracellular recordings from Limulus eccentric cells suggest that the generator potential arises from the superposition of numerous discrete fluctuations in membrane conductance. If this is so, a relation between frequency response to flickering light and noise characteristics under steady light may be predicted. This prediction is verified experimentally. If a discrete fluctuation model is assumed, the data indicate that increased light has two major effects: (i) the discrete events are strongly light-adapted to smaller size, and (ii) the time course of each event becomes briefer. 相似文献
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The development of a coupled model (PCPF-SWMS) to simulate water flow and pollutant transport in Japanese paddy fields 总被引:1,自引:0,他引:1
Julien Tournebize Hirozumi Watanabe Kazuhiro Takagi Taku Nishimura 《Paddy and Water Environment》2006,4(1):39-51
A new coupled model (PCPF–SWMS) was developed for simulating fate and behavior of pollutant in paddy water and paddy soil.
The model coupled the PCPF-1, a lumped model simulating pesticide concentrations in paddy water and 1 cm-surface sediment
compartment, and the SWMS-2D, a finite element numerical model solving Richard's and advection-dispersion equations for solute
transport in soil compartment. The coupling involved improvements on interactions of the water flow and the concentration
the pollutant of at the soil interface between both compartments. The monitoring data collected from experimental plots in
Tsukuba, Japan in 1998 and 1999 were used to parameterise and calibrate hydraulic functioning, hydrodynamic and hydrodispersive
parameters of the paddy soil. The analysis on the hydraulic functioning of paddy soil revealed that the hard pan layer was
the key factor controlling percolation rate and tracer transport. Matric potential and tracer monitoring highlighted the evolution
of saturated hydraulic conductivity (K
S) of hard pan layer during the crop season. K
S slightly decreased after puddling by clay clogging and strongly increased after mid term drainage by drying cracks. The model
was able to calculate residential time in every soil layers. Residential time of tracer in top saturated layers was evaluated
to be less than 40 days. It took 60 days to reach the unsaturated layers below hardpan layer. 相似文献
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Kazuhiro Aoki Toshihiro Yamamoto Nobuto Fukuda Kazuki Yokouchi Hiroaki Kurogi Takashi Setou Hiroshi Kuroda Takahiko Kameda Kazuhiro Takafuji Tsutomu Tokeshi 《Fisheries Science》2018,84(5):777-785
To examine the environmental factors controlling the inshore recruitment dynamics of Anguilla japonica in the Oyodo River, Miyazaki Prefecture, Kyushu, glass eel samplings were carried out using fyke nets during winter (November–March) of 1994–2014. The peak CPUEs (catch per unit effort) were observed between November and February, but differed from year to year. The yearly CPUE was extremely high in 2002, when the sea surface temperature (SST) in the offshore area of the Oyodo River was the lowest in winter of all the sampling years. The negative SST anomaly of less than ? 0.5 °C was sustained in the offshore area during the recruitment season in 2002, which was caused by two combined factors; low air temperature and the Kuroshio path. The oceanographic data showed that the dominant path of the Kuroshio was displaced eastward at 31°N in 2002, which was different from the average Kuroshio path. The eastward displacement of the Kuroshio induced a cyclonic mesoscale eddy in the offshore area of the Oyodo River, resulting in the entrainment of the cold seawater into coastal waters from deep water. The oceanographic condition in relation to the continuous low SST could be favorable for local recruitment of glass eels. 相似文献
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