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Dissipation and Adsorption Behavior of the Insecticide Ethiprole on Various Cultivated Soils in China 被引量:2
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作者 LIU Xin-gang DONG Feng-shou +2 位作者 XU Jun YUAN Shan-kui ZHENG Yong-quan 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第11期2471-2478,共8页
In this study, the hydrolysis of the insecticide ethiprole in buffered solutions at pH 4.0, 7.0 and 9.0, respectively, and the degradation and adsorption-desorption behaviors of ethiprole in ifve agricultural soil sam... In this study, the hydrolysis of the insecticide ethiprole in buffered solutions at pH 4.0, 7.0 and 9.0, respectively, and the degradation and adsorption-desorption behaviors of ethiprole in ifve agricultural soil samples from China were investigated. The half-lives under anaerobic conditions were faster than that in the aerobic experiment. Ethiprole was relatively stable under both acidic and neutral conditions while it was readily hydrolyzed under alkaling condition. The sorption of ethiprole on ifve soils was well described by the linear and Freundlich equation and mainly governed by soil organic matter. The exothermic process of ethiprole adsorption can also be well explained by physical adsorption. A weak adsorption capacity was observed in all soils, which could readily lead to leaching problems. 展开更多
关键词 ethiprole ADSORPTION DESORPTION HYDROLYSIS soil dissipatio
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Wave propagation and energy dissipation in viscoelastic granular media 被引量:2
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作者 SUN Ye-zhi 1, WU Ai-xiang 1, LI Jian-hua 1,2 (1. College of Resources, Environment and Civil Engineering, Central South Unive rsity, Changsha 410083, China 2. The 5th Building Company in Guangdong Province, Shaoguan 512026, China) 《Journal of Central South University》 SCIE EI CAS 2001年第3期185-188,共4页
In terms of viscoelasticity, the relevant theory of wave i n granular media is analyzed in this paper. Under the conditions of slight deforma tion of granules, wave equation, complex number expressions of propagation ... In terms of viscoelasticity, the relevant theory of wave i n granular media is analyzed in this paper. Under the conditions of slight deforma tion of granules, wave equation, complex number expressions of propagation vecto r and attenuation vector, attenuation coefficient expressions of longitudinal wa ve and transverse wave, etc, are analyzed and deduced. The expressions of attenu ation coefficients of viscoelastic longitudinal wave and transverse wave show th a t the attenuation of wave is related to frequency. The higher the frequency is, the more the attenuation is, which is tested by the laboratory experiment. In a ddi tion, the energy dissipation is related to the higher frequency wave that is abs orbed by granular media. The friction amongst granular media also increase the e nergy dissipation. During the flowing situation the expression of transmission f actor of energy shows that the granular density difference is the key factor whi ch leads to the attenuation of vibrating energy. This has been proved by the exp eriment results. 展开更多
关键词 viscoelastic granular media wave motion energy dissipation flowing situation
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岩弹冲击破岩规律试验研究 被引量:5
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作者 刘勇 郭鑫辉 +1 位作者 魏建平 张宏图 《振动与冲击》 EI CSCD 北大核心 2023年第4期270-278,305,共10页
针对深部岩层掘进过程中钻具磨损快、掘进效率低等问题,基于粒子冲击破岩技术,提出采用高压气体驱动加速岩弹冲击预裂掘进面岩体,减少钻具磨损。通过SHPB试验和三维扫描试验,测试岩石破坏吸收能和新增表面积,构建岩石冲击破坏吸收能理... 针对深部岩层掘进过程中钻具磨损快、掘进效率低等问题,基于粒子冲击破岩技术,提出采用高压气体驱动加速岩弹冲击预裂掘进面岩体,减少钻具磨损。通过SHPB试验和三维扫描试验,测试岩石破坏吸收能和新增表面积,构建岩石冲击破坏吸收能理论模型;采用自主研制的岩弹冲击破岩试验装置研究了气体压力、岩弹质量及岩性对破岩效果的影响。形成了以下结论:基于实测岩石破坏吸收能和新增表面积,得出试验花岗岩岩样比表面自由能γs为6.34 mJ/mm^(2);增大气体压力能够有效提高岩弹冲击动能,使花岗岩吸收能和新增表面积增大,同时岩弹破碎和弹射耗散能随之提高,岩弹冲击动能转化为花岗岩破坏吸收能效率降低;吸收能与岩弹质量和动能乘积成幂次方关系,保持气压不变,增大岩弹质量可在一定范围内提高岩弹冲击动能和花岗岩破坏吸收能,提升破坏效果。但过多提高岩弹质量,导致其动能降低,从而使吸收能转化效率降低。不同岩性的岩石比表面自由能不同,但气体压力、岩弹质量对不同岩性岩石冲击破坏效果的影响基本一致。研究结论为硬岩辅助掘进提供理论和技术支撑。 展开更多
关键词 辅助掘进 粒子射流 冲击破岩 硬岩破碎 能量耗散
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电涡流缓速器转子盘风道散热结构参数影响分析 被引量:6
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作者 刘成晔 沈建明 +1 位作者 何仁 蒋科军 《兵工学报》 EI CAS CSCD 北大核心 2011年第2期236-241,共6页
电涡流缓速器(ECR)实施缓速制动时将车辆行驶动能转化为热能,使得转子盘产生较大温升,导致其制动性能不稳定。针对这一现象本文提出在转子盘风道内安装圆柱扰流强化散热装置。为合理选择扰流圆柱结构尺寸,建立不同直径圆柱扰流强制散热... 电涡流缓速器(ECR)实施缓速制动时将车辆行驶动能转化为热能,使得转子盘产生较大温升,导致其制动性能不稳定。针对这一现象本文提出在转子盘风道内安装圆柱扰流强化散热装置。为合理选择扰流圆柱结构尺寸,建立不同直径圆柱扰流强制散热结构转子盘单风道物理模型,采用K-ε标准双方程和能量方程分析各模型不同进口气流速度条件下热交换改进机理及性能,并与未装该结构时风道散热特性进行对比。结果表明:扰流圆柱直径越大,压力损失系数越大;风道内前排扰流柱平均换热系数大于后排;安装圆柱扰流件对叶片背流面和工作面均有较高的换热强化效果,且对工作面传热强化优于背流面。 展开更多
关键词 汽车工程 辅助制动 电涡流缓速器 强化散热 结构优化
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