The lack of toolkits for assessing the shipping-related atmospheric impacts limits China's ability to formulate effective shipping emissions control policies to address coastal air pollution and mitigate related h...The lack of toolkits for assessing the shipping-related atmospheric impacts limits China's ability to formulate effective shipping emissions control policies to address coastal air pollution and mitigate related health burdens.Here,we developed a deep learning model,DeepShip,to efficiently predict shipping-related PM_(2.5)concentrations and further coupled it with a multi-task learning and generative-adversarial training strategy to enhance the sensitivity of the data-driven model to variations in small emission sources.Based on DeepShip,we comprehensively analyzed the response of shipping-related PM_(2.5)to changes in anthropogenic emissions based on 210 scenarios involving emission reductions of shipping and land-based sectors.Furthermore,sulfur and nitrogen emission control scenarios that China might implement in the future were established to assess their cost,air quality improvement,and health benefits.We found that shipping-related PM_(2.5)shows an almost linear relationship with shipping emissions,while exhibiting a nonlinear relationship with land-based emissions.Considering the cost and environmental-health benefits,future shipping emissions control should prioritize progressively enhancing the NOx emission standard while coordinating with land-based emission reductions.展开更多
Let ? be a bounded and connected open subset of R^N with a Lipschitzcontinuous boundary,the set ? being locally on the same side of ??.A vector version of a fundamental lemma of J.L.Lions,due to C.Amrouche,the first a...Let ? be a bounded and connected open subset of R^N with a Lipschitzcontinuous boundary,the set ? being locally on the same side of ??.A vector version of a fundamental lemma of J.L.Lions,due to C.Amrouche,the first author,L.Gratie and S.Kesavan,asserts that any vector field v =(vi) ∈(D′(?))~N,such that all the components 1/2(?_jv_i + ?_iv_j),1 ≤ i,j ≤ N,of its symmetrized gradient matrix field are in the space H^(-1)(?),is in effect in the space(L^2(?))~N.The objective of this paper is to show that this vector version of J.L.Lions lemma is equivalent to a certain number of other properties of interest by themselves.These include in particular a vector version of a well-known inequality due to J.Neˇcas,weak versions of the classical Donati and Saint-Venant compatibility conditions for a matrix field to be the symmetrized gradient matrix field of a vector field,or a natural vector version of a fundamental surjectivity property of the divergence operator.展开更多
基金supported by Jing-Jin-Ji Regional Integrated Environmental Improvement-National Science and Technology Major Project(2025ZD1202004)National Natural Science Foundation of China(42325505)+1 种基金the China National Postdoctoral Program for Innovative Talents(BX20250327)the Shuimu Tsinghua Scholar Program(2024SM028).
文摘The lack of toolkits for assessing the shipping-related atmospheric impacts limits China's ability to formulate effective shipping emissions control policies to address coastal air pollution and mitigate related health burdens.Here,we developed a deep learning model,DeepShip,to efficiently predict shipping-related PM_(2.5)concentrations and further coupled it with a multi-task learning and generative-adversarial training strategy to enhance the sensitivity of the data-driven model to variations in small emission sources.Based on DeepShip,we comprehensively analyzed the response of shipping-related PM_(2.5)to changes in anthropogenic emissions based on 210 scenarios involving emission reductions of shipping and land-based sectors.Furthermore,sulfur and nitrogen emission control scenarios that China might implement in the future were established to assess their cost,air quality improvement,and health benefits.We found that shipping-related PM_(2.5)shows an almost linear relationship with shipping emissions,while exhibiting a nonlinear relationship with land-based emissions.Considering the cost and environmental-health benefits,future shipping emissions control should prioritize progressively enhancing the NOx emission standard while coordinating with land-based emission reductions.
基金supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region,China(No.9041738-CityU 100612)
文摘Let ? be a bounded and connected open subset of R^N with a Lipschitzcontinuous boundary,the set ? being locally on the same side of ??.A vector version of a fundamental lemma of J.L.Lions,due to C.Amrouche,the first author,L.Gratie and S.Kesavan,asserts that any vector field v =(vi) ∈(D′(?))~N,such that all the components 1/2(?_jv_i + ?_iv_j),1 ≤ i,j ≤ N,of its symmetrized gradient matrix field are in the space H^(-1)(?),is in effect in the space(L^2(?))~N.The objective of this paper is to show that this vector version of J.L.Lions lemma is equivalent to a certain number of other properties of interest by themselves.These include in particular a vector version of a well-known inequality due to J.Neˇcas,weak versions of the classical Donati and Saint-Venant compatibility conditions for a matrix field to be the symmetrized gradient matrix field of a vector field,or a natural vector version of a fundamental surjectivity property of the divergence operator.
