为研究山东省商贸流通业与城乡一体化间的耦合协调关系,从市场环境和业态规模2个维度构建商贸流通业的评价指标体系,从经济发展、社会发展和空间环境3个维度构建城乡一体化的评价指标体系,以山东省2012—2021年的指标数据为样本,分析山...为研究山东省商贸流通业与城乡一体化间的耦合协调关系,从市场环境和业态规模2个维度构建商贸流通业的评价指标体系,从经济发展、社会发展和空间环境3个维度构建城乡一体化的评价指标体系,以山东省2012—2021年的指标数据为样本,分析山东省商贸流通业与城乡一体化的关系。将熵权法与逼近理想解排序(technique for order preference by similarity to ideal solution,TOPSIS)法相结合计算指标权重,确定二者的发展指数,采用协整检验模型验证二者间的协整关系,以综合评价指数建立耦合协调度模型定量研究二者间的耦合协调关系,通过灰色关联度模型分析二者指标的关联度,确定影响二者耦合协调关系的关键因素。结果表明:城乡一体化水平每上升1个单位,商贸流通业的发展指数增大0.867个单位;2012—2021年山东省商贸流通业与城乡一体化间存在较强的耦合关系,耦合协调度从严重失调调整到优质协调;山东省商贸流通业和城乡一体化整体的灰色关联度较高。通过政策倾斜、资金扶持等措施加大资源要素投入,完善乡村基础设施,改善商贸流通业发展环境,搭建城乡商贸一体化发展体系,促进商贸流通业和城乡一体化的良性互动。展开更多
In natural water,microplastics(MPs)inevitably undergo microbial colonization to form biofilm,while the effect of biofilm formation on the photoaging of MPs remains unknown.This study systematically investigated the ph...In natural water,microplastics(MPs)inevitably undergo microbial colonization to form biofilm,while the effect of biofilm formation on the photoaging of MPs remains unknown.This study systematically investigated the photoaging behavior of disposable box-derived polypropylene(PPMPs)and polystyrene(PSMPs)mediated by formed biofilm in water.After incubating in Weihe water samples for 105 d,the biofilm was validated to form in PPMPs and PSMPs,with higher formation in PSMPs.In particular,biofilm formation inhibited the photoaging of PPMPs and PSMPs,with an 11.1%and 50.6%decrease in photooxidation compared to their virgin counterparts after 20 d of ultraviolet(UV)irradiation.Moreover,the photoaging route of MPs such as the reaction priority of functional groups(e.g.,C–H,C=O,and benzene ring)was altered,indicating the important role of biofilm formation in the photoaging process of MPs.The protective effect of the biofilm was mainly caused by the role of optical light filters that absorbed UV energy by sacrificing themselves.Also,as the main attacker on MPs,the production of reactive oxygen species(ROS,mainly^(1)O_(2)and·OH)was inhibited by biofilm,which was mainly responsible for the decreased photoaging of MPs.This study revealed the important role of biofilm in the photoaging process of MPs and suggested a higher resistance of(micro)plastics in natural water than that in the laboratory using pure MPs,which contributed to a deeper understanding of the environmental fate and pollution of MPs.展开更多
文摘为研究山东省商贸流通业与城乡一体化间的耦合协调关系,从市场环境和业态规模2个维度构建商贸流通业的评价指标体系,从经济发展、社会发展和空间环境3个维度构建城乡一体化的评价指标体系,以山东省2012—2021年的指标数据为样本,分析山东省商贸流通业与城乡一体化的关系。将熵权法与逼近理想解排序(technique for order preference by similarity to ideal solution,TOPSIS)法相结合计算指标权重,确定二者的发展指数,采用协整检验模型验证二者间的协整关系,以综合评价指数建立耦合协调度模型定量研究二者间的耦合协调关系,通过灰色关联度模型分析二者指标的关联度,确定影响二者耦合协调关系的关键因素。结果表明:城乡一体化水平每上升1个单位,商贸流通业的发展指数增大0.867个单位;2012—2021年山东省商贸流通业与城乡一体化间存在较强的耦合关系,耦合协调度从严重失调调整到优质协调;山东省商贸流通业和城乡一体化整体的灰色关联度较高。通过政策倾斜、资金扶持等措施加大资源要素投入,完善乡村基础设施,改善商贸流通业发展环境,搭建城乡商贸一体化发展体系,促进商贸流通业和城乡一体化的良性互动。
基金supported by the National Natural Science Foundation of China(Grant Nos.42107434 and 42077351)the Postdoctoral Science Foundation of China(Grant Nos.2020M680160 and 2022T150536).
文摘In natural water,microplastics(MPs)inevitably undergo microbial colonization to form biofilm,while the effect of biofilm formation on the photoaging of MPs remains unknown.This study systematically investigated the photoaging behavior of disposable box-derived polypropylene(PPMPs)and polystyrene(PSMPs)mediated by formed biofilm in water.After incubating in Weihe water samples for 105 d,the biofilm was validated to form in PPMPs and PSMPs,with higher formation in PSMPs.In particular,biofilm formation inhibited the photoaging of PPMPs and PSMPs,with an 11.1%and 50.6%decrease in photooxidation compared to their virgin counterparts after 20 d of ultraviolet(UV)irradiation.Moreover,the photoaging route of MPs such as the reaction priority of functional groups(e.g.,C–H,C=O,and benzene ring)was altered,indicating the important role of biofilm formation in the photoaging process of MPs.The protective effect of the biofilm was mainly caused by the role of optical light filters that absorbed UV energy by sacrificing themselves.Also,as the main attacker on MPs,the production of reactive oxygen species(ROS,mainly^(1)O_(2)and·OH)was inhibited by biofilm,which was mainly responsible for the decreased photoaging of MPs.This study revealed the important role of biofilm in the photoaging process of MPs and suggested a higher resistance of(micro)plastics in natural water than that in the laboratory using pure MPs,which contributed to a deeper understanding of the environmental fate and pollution of MPs.
