The microstructures of the Zn-27Al alloy after modification, solid-solution treatment, and natural aging were studied. It was clarified why the damping properties of Zn-27Al alloys, after treatment, had advanced most ...The microstructures of the Zn-27Al alloy after modification, solid-solution treatment, and natural aging were studied. It was clarified why the damping properties of Zn-27Al alloys, after treatment, had advanced most on the basis of analyzing the microstructures. Approximate expressions have been educed, which can be used to quantificationally work out the damping of the Zn-27Al alloy on the basis of the micro interface sliding model. By comparing the testing damping properties of the foundry Zn-27Al alloys and the Zn-27Al alloys after modification, solid solution, and natural aging, it was shown that the expressions were rational.展开更多
Active sites in proteins account for a small proportion but are crucial for their enhanced binding affinity and specificity,making related biomimetic structures a research hotspot.However,current structures greatly de...Active sites in proteins account for a small proportion but are crucial for their enhanced binding affinity and specificity,making related biomimetic structures a research hotspot.However,current structures greatly depended on rigid inorganic frameworks for high-certainty assembly,which introduced interfering inorganic groups and interactions not present in proteins.To address this,we utilized organic crystal rigidity to achieve high-certainty assembly conformations.Thus periodic active sites at crystal interface can be precisely assembled by pure organic units.Our three-step strategy for designing artificial super-receptors includes:(1)Learning active site model from proteins;(2)Imitating active sites in crystal cell unit;(3)Exceeding natural performance with periodic active sites at the crystal interface.Practically,by mimicking the human dopamine transporter(amphetamine drug receptor),our artificial super-receptor acted as super-sensor.It achieved a limit of detection down to 480 pM,64,580 times lower than the natural receptor.It also showed revolutionary broad-spectrum specificity for amphetamine drugs,including chiral methamphetamine,ecstasy,and even potential novel amphetamine derivative illicit drugs,allowing active preventing detection for the drug abuse problem.The customized designing strategy was also validated by high dopamine sensitivity(2.8 nM)and selectivity of d-DAT inspired PySO3 H artificial super-receptor.Such strategy can be further extended to other functional proteins for various super-performance,from sensor,catalyst,medicine,agriculture to therapeutic applications,etc.展开更多
Surface sediments are closely related to lake black blooms. The dissolved oxygen （DO） distribution and its penetration depth in surface sediments as well as the migration and transformation of redox sensitive elemen...Surface sediments are closely related to lake black blooms. The dissolved oxygen （DO） distribution and its penetration depth in surface sediments as well as the migration and transformation of redox sensitive elements such as Fe and S at the sediment-water interface are important factors that could influence the formation of the black bloom. In this study, dredged and undredged sediment cores with different surface properties were used to simulate black blooms in the laboratory. The Micro Profiling System was employed to explore features of the DO and ∑H2S distribution at the sediment-water interface. Physical and chemical characteristics in sediments and pore waters were also analyzed. The results showed that sediment dredging effectively suppressed the black blooms. In the undredged treatment, DO penetration depth was only 50 μm. Fe^2＋ concentrations, ∑H2S concentrations, and ∑H2S production rates were remarkably higher in surface sediments and pore waters compared to control and dredged treatments. Furthermore, depletion of DO and accumulation of Fe^2＋ and ∑H2S in surface sediments and pore waters provided favorable redox environments and necessary material sources for the blooms. The study results proved that physical and chemical characteristics in surface sediments are important factors in the formation of the black bloom, and could provide scientific guidance for emergency treatment and long-term pre-control of black blooms.展开更多
文摘The microstructures of the Zn-27Al alloy after modification, solid-solution treatment, and natural aging were studied. It was clarified why the damping properties of Zn-27Al alloys, after treatment, had advanced most on the basis of analyzing the microstructures. Approximate expressions have been educed, which can be used to quantificationally work out the damping of the Zn-27Al alloy on the basis of the micro interface sliding model. By comparing the testing damping properties of the foundry Zn-27Al alloys and the Zn-27Al alloys after modification, solid solution, and natural aging, it was shown that the expressions were rational.
基金supported by the National Key Research and Development Project(Grant 2022YFB3203501)the National Natural Science Foundation of China(Grants 62431026 and 62471460)+1 种基金the Key Research Project of Chinese Academy of Sciences(Grant KGFZD-145-25-21)the Science and Technology Commission of Shanghai Municipality(22QA1410800).
文摘Active sites in proteins account for a small proportion but are crucial for their enhanced binding affinity and specificity,making related biomimetic structures a research hotspot.However,current structures greatly depended on rigid inorganic frameworks for high-certainty assembly,which introduced interfering inorganic groups and interactions not present in proteins.To address this,we utilized organic crystal rigidity to achieve high-certainty assembly conformations.Thus periodic active sites at crystal interface can be precisely assembled by pure organic units.Our three-step strategy for designing artificial super-receptors includes:(1)Learning active site model from proteins;(2)Imitating active sites in crystal cell unit;(3)Exceeding natural performance with periodic active sites at the crystal interface.Practically,by mimicking the human dopamine transporter(amphetamine drug receptor),our artificial super-receptor acted as super-sensor.It achieved a limit of detection down to 480 pM,64,580 times lower than the natural receptor.It also showed revolutionary broad-spectrum specificity for amphetamine drugs,including chiral methamphetamine,ecstasy,and even potential novel amphetamine derivative illicit drugs,allowing active preventing detection for the drug abuse problem.The customized designing strategy was also validated by high dopamine sensitivity(2.8 nM)and selectivity of d-DAT inspired PySO3 H artificial super-receptor.Such strategy can be further extended to other functional proteins for various super-performance,from sensor,catalyst,medicine,agriculture to therapeutic applications,etc.
基金supported by the Major National Science and Technology Programs on Water Pollution Control and Treatment(No.2012X0713-005)the Natural Science Foundation of Jiangsu Province(No.BK20118790)+2 种基金the 135 Project of Nanjing Institute of Geography and Lim-nologyChinese Academy of Sciences(No.Y213518090)the Industry-University-Research Prosepective Joint Research Projects of Jiangsu Province(No.BY2011165)
文摘Surface sediments are closely related to lake black blooms. The dissolved oxygen （DO） distribution and its penetration depth in surface sediments as well as the migration and transformation of redox sensitive elements such as Fe and S at the sediment-water interface are important factors that could influence the formation of the black bloom. In this study, dredged and undredged sediment cores with different surface properties were used to simulate black blooms in the laboratory. The Micro Profiling System was employed to explore features of the DO and ∑H2S distribution at the sediment-water interface. Physical and chemical characteristics in sediments and pore waters were also analyzed. The results showed that sediment dredging effectively suppressed the black blooms. In the undredged treatment, DO penetration depth was only 50 μm. Fe^2＋ concentrations, ∑H2S concentrations, and ∑H2S production rates were remarkably higher in surface sediments and pore waters compared to control and dredged treatments. Furthermore, depletion of DO and accumulation of Fe^2＋ and ∑H2S in surface sediments and pore waters provided favorable redox environments and necessary material sources for the blooms. The study results proved that physical and chemical characteristics in surface sediments are important factors in the formation of the black bloom, and could provide scientific guidance for emergency treatment and long-term pre-control of black blooms.
