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Electron paramagnetic resonance (EPR) studies have been performed on the glass system (30–x) NaF-xNa2O-50B2O3-20Bi2O3 doped with CuO as a paramagnetic probe. The calculated g values indicate that Cu2+ is in a tetragonally elongated octahedral co-ordination, and the Jahn-Teller character gives rise to anisotropic hyperfine structure. The spin-Hamiltonian parameters and -bonding parameter, 2, are calculated. Varying the fluoride ion concentration and its effect on these parameters is also discussed.  相似文献   
2.
The effect of stone and vegetative covers was evaluated for soil and water conservation in a waterway on alfisols. Experiments were conducted on a hydraulic tilting flume under simulated flow (93 and 40 cm2?s?1) and slope (0.1, 1.0, 3.0, and 5.0%) conditions. The depth of soil was maintained at 0.35 m over a perforated bed to facilitate deep drainage. A comparative study of bare soil, stone cover (50%), and vegetative cover (50%) is made to evaluate soil loss, deep drainage, Manning’s roughness coefficient, and the Froude number. The study has revealed that stone cover is more effective than vegetative cover at lower discharge in reducing the flow velocity, and thereby soil erosion. Deep drainage has been reduced from lower to higher discharge for all the slopes with cover measures, including bare soil. It is found that cover measures are necessary beyond 3% slope in order to prevent rill erosion in alfisols.  相似文献   
3.
The temperature dependences of the d.c. electrical conductivity (σ) and thermoelectric power (TEP) of low-dimensional Cu(COOH)2 single crystal have been studied. The electrical conductivity is highly anisotropic (σ = 3.0 × 102) and the crystal undergoes a Peierls transition at 208 K and two polymorphous phase transitions, namely → β and β → at 327 and 377 K respectively. The conductivity in this crystal is found to be mainly due to a non-adiabatic hopping mechanism. TEP measurements carried out at various temperatures show that the conductivity is due to the mobility of holes.  相似文献   
4.
Journal of Materials Science: Materials in Electronics - The PFBBF-x glasses with the chemical structure...  相似文献   
5.
Small‐angle X‐ray scattering and spectroscopic (infrared and ultraviolet–visible) techniques were used to investigate the interactions between titanium dioxide (TiO2) and the semiconductor polymer poly[N‐(4‐sulfophenyl)aniline] (PSA) in a poly[N‐(4‐sulfophenyl)aniline]/TiO2 composite (TPSA). The radius of gyration of the cross section, the radius and length of the rodlike particle, the persistence length, the surface fractal dimension, and the PSA layer thickness on TiO2 in aqueous solutions and in powder form were calculated. The results indicated that the aggregation of TiO2 particles on drying was reduced by the formation of the composite with the semiconductor polymer. Only the particle length of the TPSA particle (which had a rodlike shape) increased on drying, probably because of increasing void sizes and the formation of aggregation. The persistence length of the TPSA particles decreased with respect to its individual components. The PSA layer thickness on TiO2 was about 3.6 nm and decreased (to 2.6 nm) on dehydration because of the expulsions of water molecules from the TiO2/PSA composite. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 3183–3187, 2003  相似文献   
6.
A study has been conducted to assess future climate change impacts on water resources of the Upper Sind River Basin using Soil Water Assessment Tool. Sequential uncertainty fitting (SUFI-2) algorithm has been applied for model calibration and uncertainty analysis. Monthly observed stream flows matched well with simulated flows with respect to p-factor, d-factor, Correlation coefficient and Nash-Sutcliffe coefficients with values of 0.73, 0.42, 0.82, 0.80 during calibration (1992–2000) and 0.42, 0.36, 0.96, 0.93 during validation (2001–2005) respectively. PRECIS generated outputs under IPCC A1B Scenarios for Indian conditions corresponding to the baseline (1961–1990), midcentury (2021–2050) and endcentury (2071–2098); extracted by Indian Institute of Tropical Meteorology, Pune (India) have been used for the study. It has been found from the model results that the average annual streamflow could increase by 16.4 % for the midcentury and a significant increase of 93.5 % by the endcentury. The results also indicate that streamflow may rise drastically in monsoon season, but will decrease in non-monsoon season due to the projected future climate change.  相似文献   
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