The success in compiling China's Civil Code benefits from factors such as China's complete system of civil law statutes,the methodology of the Pandekten System,and the private-law attributes of civil laws,etc....The success in compiling China's Civil Code benefits from factors such as China's complete system of civil law statutes,the methodology of the Pandekten System,and the private-law attributes of civil laws,etc.To construct the framework of China's environmental code,it is necessary to reference that success for theoretical and structural innovations.In addition,the fundamental features and inherent issues of China's existing environmental law system,such as its breadth,the extensiveness of origins of environmental law,the multiple implication of environmental legal relations,and the compound nature of the environmental legal liability system,should be taken into account.The layout structure of"General-Specifics"should be adopted for compiling China's environmental code,while moderate codification and extraction of the common factor(vor die Klammer zu ziehen)for connection with applicable rules of specific laws should serve as construction principles and methods for compiling the framework of China's environmental code.The environmental code should have five parts:"General";"Pollution Prevention and Control";"Nature Conservation";"Green and Low-Carbon Development";and"Ecological and Environmental Responsibility."展开更多
In this work,we reported an exceptionally high selectivity of a NaA zeolite(for which the framework type code of LTA was assigned by the Structure Commission of the International Zeolite Association)towards radioactiv...In this work,we reported an exceptionally high selectivity of a NaA zeolite(for which the framework type code of LTA was assigned by the Structure Commission of the International Zeolite Association)towards radioactive ^(90)Sr^(2+)and explained the origin of this high selectivity by combining structural Rietveld refinements and density functional theory(DFT)calculations.Nuclear wastewater with a ^(90)Sr^(2+)radioactive concentration of 400 Bq L^(-1)(7.75×10^(-2) ppt)and highly concentrated NaNO_(3) and NH_(4)NO_(3)(0.03 M Na^(+) and 0.4 M NH_(4)+,Na+/^(90)Sr^(2+)=3.48×10^(10),and NH_(4)^(+/90)Sr^(2+)=4.64×10^(11))was treated with NaA zeolite.The resultant ^(90)Sr^(2+)radioactive concentration was as low as 0.62±0.12 Bq L^(-1),close to the upper limit of 90Sr-induced radioactive activity in drinking water,and the distribution coefficient,Kd,was as high as 421.56±13.39 L g^(-1).The NaA zeolite showed fast adsorption kinetics(ca.5 min),high capture capacity(294.12 mg g^(-1)),a broad working pH range(4-12),and excellent radiation resistance.The crystallinity and performance of NaA zeolite were not affected by 1000 kGy 60Coγirradiation.Structural Rietveld refinements revealed that all Sr^(2+)ions are located at the center of the single 6-membered rings(s6rs)of the NaA zeolite.DFT calculations showed the free energy difference of exchanging different cations with Na+located in the 8-membered ring(s8r)of the NaA zeolite,and predicted the sequence of Sr^(2+)(-8.17 eV)>Ca^(2+)(-6.17 eV)>K^(+)(-2.13 eV)>Mg^(2+)(-1.94 eV)>NH_(4)+(-0.65 eV)>Cs+(-0.11 eV).The strong tendency of Sr^(2+)replacing Na+explains the exceptionally high selectivity of the NaA zeolite for ^(90)Sr^(2+)in high concentrations of Na^(+)and NH_(4)^(+).Along with the ion-exchange process,structural Rietveld refinements revealed that the Sr^(2+) ions at the s8rs center migrated to the s6rs center.展开更多
文摘The success in compiling China's Civil Code benefits from factors such as China's complete system of civil law statutes,the methodology of the Pandekten System,and the private-law attributes of civil laws,etc.To construct the framework of China's environmental code,it is necessary to reference that success for theoretical and structural innovations.In addition,the fundamental features and inherent issues of China's existing environmental law system,such as its breadth,the extensiveness of origins of environmental law,the multiple implication of environmental legal relations,and the compound nature of the environmental legal liability system,should be taken into account.The layout structure of"General-Specifics"should be adopted for compiling China's environmental code,while moderate codification and extraction of the common factor(vor die Klammer zu ziehen)for connection with applicable rules of specific laws should serve as construction principles and methods for compiling the framework of China's environmental code.The environmental code should have five parts:"General";"Pollution Prevention and Control";"Nature Conservation";"Green and Low-Carbon Development";and"Ecological and Environmental Responsibility."
基金financial support from the National Key Research and Development Program of China(2021YFA1500401,2021YFA1501202)the National Natural Science Foundation of China(U1967215,21835002,21621001,21903058,22173066)+9 种基金the 111 Project(B17020)Dr Peng Guo acknowledges financial support from the National Natural Science Foundation of China(No.21972136)the CAS Pioneer Hundred Talents Program(Y706071202)Dalian National Laboratory for Clean Energy,(DNL)Cooperation Fund,and the Chinese Academy of Sciences(DNL201908)Dr Nana Yan acknowledges financial support from the National Natural Science Foundation of China(No.22102177)the CAS Special Research Assistant Program and a scholarship from STOEDr Tao Cheng acknowledges support from Suzhou Key Laboratory of Functional Nano&Soft Materialsthe Collaborative Innovation Center of Suzhou Nano Science&Technologythe Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the 111 Project,and the Natural Science Foundation of Jiangsu Province(BK20190810).
文摘In this work,we reported an exceptionally high selectivity of a NaA zeolite(for which the framework type code of LTA was assigned by the Structure Commission of the International Zeolite Association)towards radioactive ^(90)Sr^(2+)and explained the origin of this high selectivity by combining structural Rietveld refinements and density functional theory(DFT)calculations.Nuclear wastewater with a ^(90)Sr^(2+)radioactive concentration of 400 Bq L^(-1)(7.75×10^(-2) ppt)and highly concentrated NaNO_(3) and NH_(4)NO_(3)(0.03 M Na^(+) and 0.4 M NH_(4)+,Na+/^(90)Sr^(2+)=3.48×10^(10),and NH_(4)^(+/90)Sr^(2+)=4.64×10^(11))was treated with NaA zeolite.The resultant ^(90)Sr^(2+)radioactive concentration was as low as 0.62±0.12 Bq L^(-1),close to the upper limit of 90Sr-induced radioactive activity in drinking water,and the distribution coefficient,Kd,was as high as 421.56±13.39 L g^(-1).The NaA zeolite showed fast adsorption kinetics(ca.5 min),high capture capacity(294.12 mg g^(-1)),a broad working pH range(4-12),and excellent radiation resistance.The crystallinity and performance of NaA zeolite were not affected by 1000 kGy 60Coγirradiation.Structural Rietveld refinements revealed that all Sr^(2+)ions are located at the center of the single 6-membered rings(s6rs)of the NaA zeolite.DFT calculations showed the free energy difference of exchanging different cations with Na+located in the 8-membered ring(s8r)of the NaA zeolite,and predicted the sequence of Sr^(2+)(-8.17 eV)>Ca^(2+)(-6.17 eV)>K^(+)(-2.13 eV)>Mg^(2+)(-1.94 eV)>NH_(4)+(-0.65 eV)>Cs+(-0.11 eV).The strong tendency of Sr^(2+)replacing Na+explains the exceptionally high selectivity of the NaA zeolite for ^(90)Sr^(2+)in high concentrations of Na^(+)and NH_(4)^(+).Along with the ion-exchange process,structural Rietveld refinements revealed that the Sr^(2+) ions at the s8rs center migrated to the s6rs center.
