To investigate the interactions of oppositely charged sites on the surfaces of variable-charge soil particles with cations and anions, and to evaluate the mean Gibbs free binding and adsorption energies of various cat...To investigate the interactions of oppositely charged sites on the surfaces of variable-charge soil particles with cations and anions, and to evaluate the mean Gibbs free binding and adsorption energies of various cations on particles of red soil and latosol, clay fractions smaller than 2 μm were separated from samples of the two variable-charge soils. Ferric oxides were removed from part of the clay fractions, which were then saturated with various chlorides （NaC1, KCl, CaCl2, CdCl2 or LaCl3）. Electrical conductivities （EC） of dilute suspensions of the original and of the iron oxides-free clay fractions in deionized water were measured with the SHP-2 short high-voltage pulse apparatus, which enables measurement of the Wien effect at field strengths （E） from 14 to 250 kV cm^-1. The Wien effect （EC-E） curves revealed EC increases of red soil suspensions between 14 and 200 kV cm^-1, of 8.3, 8.4, 12.1, 5.9, and 1.2 μS cm^-1 for NaCl, KCl, CaCl2, CdCl2, and LaCl3, respectively, reflecting the differing interactions with the various cations and chloride. The EC increments with the iron-free red soil suspensions were higher, being 29.7, 17.2, and 15.3 μS cm^-1 for NaCl, CaCl2, and CdCl2, respectively. In the natural latosol suspensions the EC increments were practically zero, whereas in the iron-free fractions there were significant EC increments of 10.3, 5.7, 5.0, and 1.6μS cm^-1 for NaCl, CaCl2, CdCl2, and LaCl3, respectively.展开更多
我国西北750 k V输电线路经过地区沙尘天气频发,沙尘天气的存在可能会对输电线路导线电晕特性产生影响。为此针对沙尘的粒径对导线的电晕特性影响展开仿真计算和试验研究,采用偏心偶极子法结合模拟电荷法对存在沙尘颗粒时导线周围空间...我国西北750 k V输电线路经过地区沙尘天气频发,沙尘天气的存在可能会对输电线路导线电晕特性产生影响。为此针对沙尘的粒径对导线的电晕特性影响展开仿真计算和试验研究,采用偏心偶极子法结合模拟电荷法对存在沙尘颗粒时导线周围空间电场分布进行计算,并在人工模拟沙尘条件下展开了导线电晕放电强度和电晕损失测量试验。研究结果表明:沙尘颗粒会使导线周围电场产生严重畸变,和导线距离相同时,大颗粒的沙粒对导线周围的空间电场影响更大,在沙粒接近导线时,沙尘颗粒表面场强约增加为无沙尘条件下原场强的2倍,沙粒-导线之间的平均场强可较无沙尘条件下最大增加11.8%;沙尘条件下导线电晕放电强度较无风沙时明显增强,且沙尘粒径越大则对电晕放电强度和电晕损失的影响越大,在该试验条件下,LGJ400-50导线在设计场强范围内无沙尘条件下的电晕损失最大不超过2 W/m,而在沙尘条件下的电晕损失最大可达60.76 W/m。仿真结果和试验结果都说明沙尘条件会对导线电晕放电产生影响,且粒径大的沙尘对电晕放电的影响程度更大。展开更多
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (No.ISSASIP 0718)the National Natural Science Foundation of China (Nos.40401030 and 40871114)
文摘To investigate the interactions of oppositely charged sites on the surfaces of variable-charge soil particles with cations and anions, and to evaluate the mean Gibbs free binding and adsorption energies of various cations on particles of red soil and latosol, clay fractions smaller than 2 μm were separated from samples of the two variable-charge soils. Ferric oxides were removed from part of the clay fractions, which were then saturated with various chlorides （NaC1, KCl, CaCl2, CdCl2 or LaCl3）. Electrical conductivities （EC） of dilute suspensions of the original and of the iron oxides-free clay fractions in deionized water were measured with the SHP-2 short high-voltage pulse apparatus, which enables measurement of the Wien effect at field strengths （E） from 14 to 250 kV cm^-1. The Wien effect （EC-E） curves revealed EC increases of red soil suspensions between 14 and 200 kV cm^-1, of 8.3, 8.4, 12.1, 5.9, and 1.2 μS cm^-1 for NaCl, KCl, CaCl2, CdCl2, and LaCl3, respectively, reflecting the differing interactions with the various cations and chloride. The EC increments with the iron-free red soil suspensions were higher, being 29.7, 17.2, and 15.3 μS cm^-1 for NaCl, CaCl2, and CdCl2, respectively. In the natural latosol suspensions the EC increments were practically zero, whereas in the iron-free fractions there were significant EC increments of 10.3, 5.7, 5.0, and 1.6μS cm^-1 for NaCl, CaCl2, CdCl2, and LaCl3, respectively.
文摘我国西北750 k V输电线路经过地区沙尘天气频发,沙尘天气的存在可能会对输电线路导线电晕特性产生影响。为此针对沙尘的粒径对导线的电晕特性影响展开仿真计算和试验研究,采用偏心偶极子法结合模拟电荷法对存在沙尘颗粒时导线周围空间电场分布进行计算,并在人工模拟沙尘条件下展开了导线电晕放电强度和电晕损失测量试验。研究结果表明:沙尘颗粒会使导线周围电场产生严重畸变,和导线距离相同时,大颗粒的沙粒对导线周围的空间电场影响更大,在沙粒接近导线时,沙尘颗粒表面场强约增加为无沙尘条件下原场强的2倍,沙粒-导线之间的平均场强可较无沙尘条件下最大增加11.8%;沙尘条件下导线电晕放电强度较无风沙时明显增强,且沙尘粒径越大则对电晕放电强度和电晕损失的影响越大,在该试验条件下,LGJ400-50导线在设计场强范围内无沙尘条件下的电晕损失最大不超过2 W/m,而在沙尘条件下的电晕损失最大可达60.76 W/m。仿真结果和试验结果都说明沙尘条件会对导线电晕放电产生影响,且粒径大的沙尘对电晕放电的影响程度更大。
