Low-oxygen(O_(2))environments are essential in various research and application fields,yet traditional methods like nitrogen flushing or chemical O_(2) absorbers face challenges in high equipment cost and low controll...Low-oxygen(O_(2))environments are essential in various research and application fields,yet traditional methods like nitrogen flushing or chemical O_(2) absorbers face challenges in high equipment cost and low controllability.This study introduces a novel electrochemical oxygen removal(EOR)controller,offering a lightweight,low-cost,and precise low-O_(2) control solution.The self-powered EOR controller uses a sacrificial anode to drive the cathodic oxygen reduction reaction(ORR),efficiently consuming environmental O_(2) to reduce its level,thus eliminating the requirements of external gas or power sources.By integrating a single-atom ORR catalyst and flexible design,the device achieves a substantial reduction in weight and cost.The incorporation of electronic components for the EOR controller,including a switch for reaching targeted O_(2) concentration and a fixed resistor for O_(2) removal rate regulation,enables multi-dimensional O_(2) removal control.The system also realizes the O_(2) concentration estimation in real-time with±1%accuracy(within the 21%-1% range)by calculating electron transfers.The EOR controller's effectiveness is validated in plant hypoxia stress experiments,demonstrating precise O_(2) level adjustments and its potential across various applications requiring controlled hypoxic conditions.展开更多
Some structural factors to the design of polymer-supported Chiral Catalysts arediscussed, and some new approaches for designing of polymer-supported catalysts arereviewed in this paper
The fluorescence quenching of naphthalene (2)and 1, 3-di(α-naphthyl)propane (1) by RNA and bases in methanol-water (v:v=1:1) binary solvents in the presence or absence of cyclodex- trin (CD) has been investigated. Th...The fluorescence quenching of naphthalene (2)and 1, 3-di(α-naphthyl)propane (1) by RNA and bases in methanol-water (v:v=1:1) binary solvents in the presence or absence of cyclodex- trin (CD) has been investigated. The results show that both the monomer and excimer fluorescence of 1 can be quenched by these quenchers. The quenching and rates depend on the quencher and tem- perature. It is shown that there is a critical temperature (Tc) for each quencher. Below Tc, the excimer fluorescence spectra show vibrational structures and the Stern-Volmer plots are straight lines (for ura- cil and cytosine); while above the Tc, the vibrational structures disappear and the Stern-Volmer plots deviate from linearity and curve upward. The former is a static process; while the latter is a mixture of both static and dynamic processes. The addition of α-CD has no effect on the fine structure, whereas β-CD prevents the appearance of this structure efficiently. The quenching rates both for the monomer and excimer of 1 by bases except cytosine in the presence of β-CD at ambient temperature are not changed; the quenching of fluorescence of 1 by RNA in the presence of β-CD, however, is hindered. Time-resolved fluorescence study shows that the excimer fine structures appear from the zero time. The intensity of fine structures depend on the fraction of water (φ) in binary solvents, and it is independent of the pH value of the solvents. It is suggested that bases and RNA induced aggregates (perhaps microcrystal) are formed, in which the motion of molecules 1 is limited.展开更多
基金This work was supported by China Ministry of Science and Technology(No.2021YFA1600800)the National Natural Science Foundation of China(Nos.92261105,22221003,and 22401194)+6 种基金the Joint Funds of the National Natural Science Foundation of China(No.U23A2081)China Postdoctoral Science Foundation funded project(No.2022M712178)the Anhui Provincial Natural Science Foundation(Nos.2108085UD06 and 2208085UD04)the Anhui Provincial Key Research and Development Project(Nos.2023z04020010 and 2022a05020053)the Fundamental Research Funds for the Centre Universities(No.WK9990000155)the Joint Funds from Hefei National Synchrotron Radiation Laboratory(Nos.KY2060000180 and KY2060000195)the USTC Research Funds of the Double First-Class Initiative(No.YD2060006005).
文摘Low-oxygen(O_(2))environments are essential in various research and application fields,yet traditional methods like nitrogen flushing or chemical O_(2) absorbers face challenges in high equipment cost and low controllability.This study introduces a novel electrochemical oxygen removal(EOR)controller,offering a lightweight,low-cost,and precise low-O_(2) control solution.The self-powered EOR controller uses a sacrificial anode to drive the cathodic oxygen reduction reaction(ORR),efficiently consuming environmental O_(2) to reduce its level,thus eliminating the requirements of external gas or power sources.By integrating a single-atom ORR catalyst and flexible design,the device achieves a substantial reduction in weight and cost.The incorporation of electronic components for the EOR controller,including a switch for reaching targeted O_(2) concentration and a fixed resistor for O_(2) removal rate regulation,enables multi-dimensional O_(2) removal control.The system also realizes the O_(2) concentration estimation in real-time with±1%accuracy(within the 21%-1% range)by calculating electron transfers.The EOR controller's effectiveness is validated in plant hypoxia stress experiments,demonstrating precise O_(2) level adjustments and its potential across various applications requiring controlled hypoxic conditions.
文摘Some structural factors to the design of polymer-supported Chiral Catalysts arediscussed, and some new approaches for designing of polymer-supported catalysts arereviewed in this paper
基金This project was supported by the NationaI Natural Science Foundation of Chinathe National Education Commission Foundation of China.
文摘The fluorescence quenching of naphthalene (2)and 1, 3-di(α-naphthyl)propane (1) by RNA and bases in methanol-water (v:v=1:1) binary solvents in the presence or absence of cyclodex- trin (CD) has been investigated. The results show that both the monomer and excimer fluorescence of 1 can be quenched by these quenchers. The quenching and rates depend on the quencher and tem- perature. It is shown that there is a critical temperature (Tc) for each quencher. Below Tc, the excimer fluorescence spectra show vibrational structures and the Stern-Volmer plots are straight lines (for ura- cil and cytosine); while above the Tc, the vibrational structures disappear and the Stern-Volmer plots deviate from linearity and curve upward. The former is a static process; while the latter is a mixture of both static and dynamic processes. The addition of α-CD has no effect on the fine structure, whereas β-CD prevents the appearance of this structure efficiently. The quenching rates both for the monomer and excimer of 1 by bases except cytosine in the presence of β-CD at ambient temperature are not changed; the quenching of fluorescence of 1 by RNA in the presence of β-CD, however, is hindered. Time-resolved fluorescence study shows that the excimer fine structures appear from the zero time. The intensity of fine structures depend on the fraction of water (φ) in binary solvents, and it is independent of the pH value of the solvents. It is suggested that bases and RNA induced aggregates (perhaps microcrystal) are formed, in which the motion of molecules 1 is limited.
