选取1981—2020年海拉尔河流域及周边地区气象站点观测资料,结合水文数据,利用适用于植被稀疏下垫面的BTOP(Block-wise use of TOPMODEL)分布式水文模型估算区域蒸散发量,进而在不对称增温现象影响下,分析其对蒸散发的影响特征。结果表...选取1981—2020年海拉尔河流域及周边地区气象站点观测资料,结合水文数据,利用适用于植被稀疏下垫面的BTOP(Block-wise use of TOPMODEL)分布式水文模型估算区域蒸散发量,进而在不对称增温现象影响下,分析其对蒸散发的影响特征。结果表明:①流域内1981—2020年不对称增温现象显著,主要表现为因夜间温度升幅较大为主的昼夜不对称增温及地表温度升幅较大为主的地气不对称增温;②影响蒸散发的主要气象因子依次为相对湿度、风速、地气温差、地表温度和昼夜温差,且相对湿度、昼夜温差及地气温差与蒸散发量变化趋势相反,其中相对湿度及风速影响强度年际变化平稳,温度因子影响强度则逐年增强;③不对称增温对于流域蒸散发量的影响逐年增强,地表增温速率的增强是造成地气不对称增温的主要原因,在此影响下,区域蒸散发呈现减小趋势,故在探究蒸散发量变化原因时,温差变化不可忽视。展开更多
The main cause to the deactivation of ZSM-5 catalyst, used for oxidation of benzene to phenol (BTOP) by nitrous oxide, is that the carbon deposition on the catalyst surface blocks the mouth of pores of the catalyst.In...The main cause to the deactivation of ZSM-5 catalyst, used for oxidation of benzene to phenol (BTOP) by nitrous oxide, is that the carbon deposition on the catalyst surface blocks the mouth of pores of the catalyst.In the experiments, ZSM-5 catalyst was modified by chemical surface deposition of silicon, and then the effect of modification condition on the catalyst activation was studied. The catalyst samples were characterized by XRF,EPS, XRD, TEM, N2 adsorption at low temperature, pyridine adsorption-infrared technique and etc. All the above results show that the uniform SiO2 membrane can be formed on ZSM-5 crystal surface. The SiO2 membrane covers the acid centers on ZSM-5 surface to inhibit surface coking, to avoid or decrease the possibility of ZSM-5 pore blockage so that the catalyst activity and stability can be improved efficiently. The optimum siliconiting conditions determined by the experiments are as follows: 4% load of silanizing agent, volume (ml)/mass (g) ratio of hexane/ZSM-5=15/1, and 16 h of modification time. Compared with the samples without siliconiting treatment,the samples treated under the above optimum condition can increase the productivity of phenol by 14% for 3 h reaction time and by 41% for 6 h reaction time respectively.展开更多
文摘选取1981—2020年海拉尔河流域及周边地区气象站点观测资料,结合水文数据,利用适用于植被稀疏下垫面的BTOP(Block-wise use of TOPMODEL)分布式水文模型估算区域蒸散发量,进而在不对称增温现象影响下,分析其对蒸散发的影响特征。结果表明:①流域内1981—2020年不对称增温现象显著,主要表现为因夜间温度升幅较大为主的昼夜不对称增温及地表温度升幅较大为主的地气不对称增温;②影响蒸散发的主要气象因子依次为相对湿度、风速、地气温差、地表温度和昼夜温差,且相对湿度、昼夜温差及地气温差与蒸散发量变化趋势相反,其中相对湿度及风速影响强度年际变化平稳,温度因子影响强度则逐年增强;③不对称增温对于流域蒸散发量的影响逐年增强,地表增温速率的增强是造成地气不对称增温的主要原因,在此影响下,区域蒸散发呈现减小趋势,故在探究蒸散发量变化原因时,温差变化不可忽视。
文摘The main cause to the deactivation of ZSM-5 catalyst, used for oxidation of benzene to phenol (BTOP) by nitrous oxide, is that the carbon deposition on the catalyst surface blocks the mouth of pores of the catalyst.In the experiments, ZSM-5 catalyst was modified by chemical surface deposition of silicon, and then the effect of modification condition on the catalyst activation was studied. The catalyst samples were characterized by XRF,EPS, XRD, TEM, N2 adsorption at low temperature, pyridine adsorption-infrared technique and etc. All the above results show that the uniform SiO2 membrane can be formed on ZSM-5 crystal surface. The SiO2 membrane covers the acid centers on ZSM-5 surface to inhibit surface coking, to avoid or decrease the possibility of ZSM-5 pore blockage so that the catalyst activity and stability can be improved efficiently. The optimum siliconiting conditions determined by the experiments are as follows: 4% load of silanizing agent, volume (ml)/mass (g) ratio of hexane/ZSM-5=15/1, and 16 h of modification time. Compared with the samples without siliconiting treatment,the samples treated under the above optimum condition can increase the productivity of phenol by 14% for 3 h reaction time and by 41% for 6 h reaction time respectively.
