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161.
为提升排土场稳定性,以某露天煤矿排土场为例,结合正交试验和强度折减法,开展排土场稳定性影响因素显著性研究.通过分析资料与野外调研,厘定典型排土场稳定性诱发因素,构建排土场真三维地质模型,反演验证和分析排土场的岩土体参数和变形规律特征,得出排土场边坡内部应力和位移的变化特征以及塑性破坏区分布范围;以真三维网格模型中最危险... 相似文献
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The dissipation of chlorpyrifos in pakchoi-vegetated soil was investigated in the summer and autumn in a greenhouse and field, respectively. The dissipation of chlorpyrifos in pakchoi-grown soil was comparatively described by fitting the residue data to seven models (lst-order, 1.5th-order, 2nd-order, RF lst-order, RF 1.5th-order, RF 2nd-order, and bi-exponential or two-compartment models). Statistical analysis was performed using the SPSS 11.5 statistical package. The bi-exponential model was selected as the optimal model according to the coefficient of determination r^2. The dissipation half-lives (DT50) of chlorpyrifos in pakchoi-vegetated soil at the recommended dose in the summer and autumn, calculated by the bi-exponential model, were 0.6 and 1.2 d in a greenhouse, 0.4 and 1.0 d in a field, respectively; the corresponding values at double dose were 1.2 and 2.1 d in a greenhouse, 0.5 and 1.3 d in a field, respectively. The kinetic data indicate the dissipation of chlorpyrifos in pakchoi-grown soil in a greenhouse is slower than that in a field, and dissipates slower in the autumn than in the summer. 相似文献
165.
Characteristics of sewage sludge and distribution of heavy metal in plants with amendment of sewage sludge 总被引:15,自引:2,他引:13
In order to better understand land application of sewage sludge, the characterization of heavy metals and organic pollutants were investigated in three different sewage sludges in Shanghai City, China. It was found that the total concentrations of Cd in all of sewage sludge and total concentrations of Zn in Jinshan sewage sludge, as well as those ofZn, Cu, and Ni in Taopu sludge are higher than Chinese regulation limit of pollutants for sludge to be used in agriculture. Leachability of rig in all of studied samples and that of Cd in Taopu sewage sludge exceed the limit values of waste solid extraction standard in China legislation. Based on the characteristics for three kinds of sewage sludge, a pot experiment was conducted to investigate the effect of soil amended with Quyang sewage sludge on the accumulation of heavy metalo.by Begonia semperfloreas-hybr; Ophiopogon japonicas (L.F.) Ker-Gaw; Loropetalum chindense-var, rubrum; Dendranthema morifolium; Viola tricolor; A ntirrhinum majas; Buxas radicans Sieb; Viburnum macrocephalum; Osmanthas fragrans Lour; Cinnamomum camphora siebold and Ligustrum lucidum ait. Results showed that 8 species of plant survived in the amended soil, and moreover they flourished as well as those cultivated in the control soil. The heavy metal concentration in plants varied with species, As, Pb, Cd and Cr concentration being the highest in the four herbaceous species studied, particularly in the roots of D. morifolium. These plants, however, did not show accumulator of As, Pb, Cd and Cr. The highest concentration of Ni and Hg was found in the roots ofD. morifolium, followed by the leaves ofB. semperflorens-hybr. Levels of Zn and Cu were much higher in D. morifolium than in the other plant species. D. morifolium accumulated Ni, Hg, Cu and Zn, which may contribute to the decrease of heavy metal contents in the amended soil. Treatment with sewage sludge did not significantly affect the uptake of heavy metals by the L. chindense-var, rubrum, however, it significantly affected the uptake of heavy metals by D. morifolium. 相似文献
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五种重金属离子对黑褐新糠虾的急性毒性试验 总被引:11,自引:0,他引:11
通过Cu、Hg、Cd、Zn、Pb等5种重金属离子对黑褐新糠虾的急性毒性试验,分别得出了5种重金属离子对黑褐新糠虾的24、48、72、96 h半致死浓度及安全浓度,依次为:Cu2 0.625、0.161、0.161、0.125、0.013 mg/L;Zn2 4.028、1.083、0.917、0.583、0.058mg/L;Cd2 2.679、0.625、0.250、0.161、0.016mg/L;Pd2 13.750、13.750、9.583、1.917、0.192mg/L;Hg2 0.161、0.150、0.150、0.150、0.015 mg/L。研究结果表明:黑褐新糠虾对5种金属离子的敏感性为Cu2 >Hg2 >Cd2 >Zn2 >Pb2 ,黑褐新糠虾作为水域重金属离子的监测生物具有较明显的优势。 相似文献
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为研究燃料氢气泄漏、爆炸的特性和规律,预防高压储氢系统中氢气泄漏爆炸事故发生,以加氢站为背景,数值仿真45 MPa高压储罐氢气泄漏并引发爆炸事故,分析泄漏爆炸动力学性质以及爆炸波在非均匀氢气浓度中的传播机制。同时,基于泄漏爆炸事故演化的力学机理,开展氢气泄漏爆炸动态风险分析,针对氢气不同泄漏量,建立泄漏扩散形成的气云体积、气云爆炸产生的冲击波与空间x,z方向上危害距离之间关系。研究结果表明:氢气泄漏过程中,气云氢气浓度变化与流场雷诺数具有较好一致性;氢气扩散受到高压储氢罐周围装置影响,流场中氢气浓度分布不均匀;当发生燃烧爆炸事故时,冲击波参数和湍动能变化梯度大;得到复杂布局区域冲击波超压峰值与比例距离之间关系式,其相比于理论方法更精细、计算结果更准确。研究结果可为降低高压储氢系统泄漏爆炸事故后果、采取有效防护措施提供一定依据。 相似文献
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讨论了TA15钛合金与铝合金和结构钢接触后,在海南万宁大气试验站大气暴露的试验结果。3年的大气暴露试验显示,在海洋性大气环境下,2B06铝合金、16CrSiN i钢和30CrMnSiA钢无论与TA15钛合金接触与否,腐蚀都很严重,力学性能明显下降;对2B06铝合金进行阳极氧化,对16CrSiN i钢和30CrMnSiA钢进行氯化铵镀镉,可在一定程度上减缓腐蚀,但经过一定时间大气暴露,无论与TA15钛合金接触与否,都产生了严重腐蚀,力学性能明显下降;对2B06铝合金进行阳极氧化,对16CrSiN i钢和30CrMnSiA钢进行氯化铵镀镉,再喷涂1号航空底漆进行防护,可有效防止接触腐蚀。 相似文献
170.