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941.
942.
Nel Caine 《地球表面变化过程与地形》1981,6(1):69-75
When estimated from measurements of introduced tracer particles, the rate of surface soil movement tends to be greater than the natural rate for equivalent particles on the same site. This consistent overestimation is greatest in the period following tracer introduction and leads to a measurement bias that may be as high as 300 per cent. The magnitude of the bias decreases with time, as the tracer is incorporated into the surface material, but remains detectable statistically for more than a year on some low-angle sites. 相似文献
943.
The authors conducted a Rn222 survey in wells of the Larderello geothermal field (Italy) and observed considerable variations in concentrations. Simple models show that flow-rate plays an important part in the Rn222 content of each well, as it directly affects the fluid transit time in the reservoirs. Rn222 has been sampled from two wells of the Serrazzano area during flow-rate drawdown tests. The apparent volume of the steam reservoir of each of these two wells has been estimated from the Rn222 concentration versus flow-rate curves.List of symbols
Q
Flow-rate (kg h–1)
-
Decay constant of Rn222 (=7.553×10–3 h–1)
-
Porosity of the reservoir (volume of fluid/volume of rock)
- 1
Density of the fluid in the reservoir (kg m–3)
- 2
Density of the rock in the reservoir (kg m–3)
-
M
Stationary mass of fluid filling the reservoir (kg).
-
E
Emanating power of the rock in the reservoir (nCi kg
rock
–1
h–1).
-
P
Production rate of Rn222 in the reservoir: number of atoms of Rn222 (divided by 1.764×107) transferred by the rock to the mass unit of fluid per unit time (nCi kg
fluid
–1
h–1).
-
N
Specific concentration of Rn222 in the fluid (nCi kg–1)
-
Characteristic time of the steam reservoir at maximum flow-rate (=M/Q) 相似文献
944.
Phase velocities of Rayleigh waves for the Adriatic Sea area are obtained in the period range 25–190 sec along the path (l'Aquila-Trieste) AQU-TRI and 20–167 sec along the path (Trieste-Bari) TRI-BAI.The phase velocities are systematically higher than the known values for the surrounding regions. The data inversion indicates the presence of a lithosphere typical of stable continental areas with clear high-velocity lid (V
s
4.6 km/sec) overlying a well developed low velocity zone (V
s
4.2 km/sec).P. F. Geodinamica C.N.R., Roma Pubbl. N. 189. 相似文献
945.
946.
This paper examines the effects of the mixing of dry air into a cloud top from the point of view of the droplet spectra. It is shown theoretically that the resulting cycling of the air up and down in the cloud, as seems to be the essential mechanism by which cumuli have been diluted to their observed liquid water mixing ratio, can double the largest drop radius and generate cloud parcels containing drops of all sizes up to this maximum. These changes in the droplet distribution with size occur by a process which is not greatly influenced by the cloud condensation nuclei or the details of droplet growth since maritime like spectra can develop in continental type cumuli. It shows that large numbers of cloud condensation nuclei should not have much effect in inhibiting the rainforming process by reducing coalescence growth. On the contrary, the controlling parameters which determine precipitation efficiency and times seem to be those which control the mixing. 相似文献
947.
S. K. Kao 《Pure and Applied Geophysics》1980,118(2):867-879
The equations of kinetic and available potential energy for the analysis of the growth and decay of atmospheric waves in wave-number-frequency space are derived. The effects of linear and nonlinear interactions of waves in the velocity and temperature fields, the conversions between the available potential and kinetic energies, and the Reynolds and molecular stresses on wave growth and decay are discussed. 相似文献
948.
949.
通过分析沂蒙山区东北部4县市冰雹天气特征,归纳出造成该区域冰雹天气的4种主要天气形势和5条主要冰雹路径以及雹灾多发时段为5 ̄6月份,据此分型建立了5 ̄6月份短期预报方程,依据雷达探测数据建立了雹云和雷雨云的短时判别指标。 相似文献
950.