The optimiz at ion operation of gas pipeline network is investigated in this paper. Based on th e theories of system optimization and the multi object decision, a mathematical model about the multi object optimization...The optimiz at ion operation of gas pipeline network is investigated in this paper. Based on th e theories of system optimization and the multi object decision, a mathematical model about the multi object optimization operation of gas pipeline network is established, in line with the demand of urban gas pipeline network operation. A t the same time, an effective solution of the mathematical model is presented. A calculating software about optimization operation is compiled, coupling the actual operation of gas pipeline network. It can be applied to the operation of the gas pipeline network. The software was examined by real examples. The resul ts indicated that 2.13% energy consumption and 3.12% gas supply cost can be reduced through optimization operation.展开更多
Changes in ozone(O_(3))can be evaluated to inform policy effectiveness and develop reasonable emissions reduction measures.This study investigated the causes of summertime maximum daily 8-h average(MDA8)O_(3) variatio...Changes in ozone(O_(3))can be evaluated to inform policy effectiveness and develop reasonable emissions reduction measures.This study investigated the causes of summertime maximum daily 8-h average(MDA8)O_(3) variation between 2015 and 2020 in Nanjing,China,a megacity in the Yangtze River Delta(YRD)region,from the perspective of meteorological conditions and anthropogenic emissions of O_(3) precursors(VOCs and NO_(x)).Compared with 2015,the observed MDA8 O_(3) decreased by 19.1μg/m^(3) in August 2020.The indirect and indirect impacts of meteorological conditions contributed 44%of the decline,with temperature,relative humidity,and wind playing important roles in the O_(3) variation.The O_(3) drop by 10.7μg/m^(3)(56%of the total decrease)may have been due to the decreases in anthropogenic emissions of VOCs and NO_(x) by 7.8%and 11.7%,respectively.The longer hydroxyl(OH)radical chain length and higher ozone production efficiency(OPE)indicated that the reduction of anthropogenic emissions accelerated the RO_(x)(RO_(x)=OH+HO_(2)+RO_(2))and NO_(x) cycles in O_(3) production,making O_(3) more sensitive to NO_(x).This corresponded to the O_(3) formation shifting from a VOC-limited regime in 2015 to a transition regime in 2020 and O_(3) decrease with anthropogenic emission reduction.Hence,the joint control of O_(3) precursor emissions can effectively mitigate O_(3) pollution in Nanjing.展开更多
文摘The optimiz at ion operation of gas pipeline network is investigated in this paper. Based on th e theories of system optimization and the multi object decision, a mathematical model about the multi object optimization operation of gas pipeline network is established, in line with the demand of urban gas pipeline network operation. A t the same time, an effective solution of the mathematical model is presented. A calculating software about optimization operation is compiled, coupling the actual operation of gas pipeline network. It can be applied to the operation of the gas pipeline network. The software was examined by real examples. The resul ts indicated that 2.13% energy consumption and 3.12% gas supply cost can be reduced through optimization operation.
基金supported by the National Natural Science Foundation of China(Grant Nos.42277095,42021004).
文摘Changes in ozone(O_(3))can be evaluated to inform policy effectiveness and develop reasonable emissions reduction measures.This study investigated the causes of summertime maximum daily 8-h average(MDA8)O_(3) variation between 2015 and 2020 in Nanjing,China,a megacity in the Yangtze River Delta(YRD)region,from the perspective of meteorological conditions and anthropogenic emissions of O_(3) precursors(VOCs and NO_(x)).Compared with 2015,the observed MDA8 O_(3) decreased by 19.1μg/m^(3) in August 2020.The indirect and indirect impacts of meteorological conditions contributed 44%of the decline,with temperature,relative humidity,and wind playing important roles in the O_(3) variation.The O_(3) drop by 10.7μg/m^(3)(56%of the total decrease)may have been due to the decreases in anthropogenic emissions of VOCs and NO_(x) by 7.8%and 11.7%,respectively.The longer hydroxyl(OH)radical chain length and higher ozone production efficiency(OPE)indicated that the reduction of anthropogenic emissions accelerated the RO_(x)(RO_(x)=OH+HO_(2)+RO_(2))and NO_(x) cycles in O_(3) production,making O_(3) more sensitive to NO_(x).This corresponded to the O_(3) formation shifting from a VOC-limited regime in 2015 to a transition regime in 2020 and O_(3) decrease with anthropogenic emission reduction.Hence,the joint control of O_(3) precursor emissions can effectively mitigate O_(3) pollution in Nanjing.