According to the second law of thermodynamics,spontaneous chemical processes will ultimately reach the equilibrium state with the lowest energy.However,in biological systems,there are numerous highenergy states far fr...According to the second law of thermodynamics,spontaneous chemical processes will ultimately reach the equilibrium state with the lowest energy.However,in biological systems,there are numerous highenergy states far from equilibrium.One typical example is the transmembrane ion-concentration gradient,which plays crucial roles in maintaining homeostasis,regulating cell volume,and enabling cell signaling.Transmembrane ion-concentration gradient is achieved by an active transport process that requires the input of energy and the action of pump proteins.Replicating this process with synthetic supramolecular systems is particularly challenging,requiring both the input of energy and very specific,spatiotemporal control over ion uptake and release.In nature,pump proteins,such as protein-based ion channels,have evolved highly intricate architectures to perform this function.In contrast,Aprahamian and coworkers recently developed a much simpler smallmolecule system that functions as a molecular ion pump,utilizing light energy to pump chloride ions across a hydrophobic barrier against the concentration gradient[1].展开更多
Accelerating the development of lithium resources has attracted a great deal of attention with the explosive growth of new energy vehicles.As a new technology,electrochemical lithium ion pumping(ELIP)is featured by en...Accelerating the development of lithium resources has attracted a great deal of attention with the explosive growth of new energy vehicles.As a new technology,electrochemical lithium ion pumping(ELIP)is featured by environment-friendly,low energy consumption and high efficiency.This review summarizes the research progress in ELIP,and focuses on the evaluation methods,electrode materials and electrochemical systems of ELIP.It can be concluded that ELIP is expected to achieve an industrial application and has a promising prospect.In addition,challenges and perspective of electrochemical lithium extraction are also highlighted.展开更多
We study the absorption-dispersion process and group index of weak probe field in a four-level Er^3＋：YAG crystal.We find that the Er^3＋ion concentration and incoherent pumping field can influence the absorption-dis...We study the absorption-dispersion process and group index of weak probe field in a four-level Er^3＋：YAG crystal.We find that the Er^3＋ion concentration and incoherent pumping field can influence the absorption-dispersion process and group index of weak probe field. Moreover, our results show that Er^3＋ion concentration plays a major role in lasing without inversion and absorption with inversion.展开更多
During the analysis of benziamidazole-class irreversible proton pump inhibitors,an unusual mass spectral response with the mass-to-charge ratio at[Mt10]t intrigued us,as it couldn't be assigned to any literature k...During the analysis of benziamidazole-class irreversible proton pump inhibitors,an unusual mass spectral response with the mass-to-charge ratio at[Mt10]t intrigued us,as it couldn't be assigned to any literature known relevant structure,intermediate or adduct ion.Moreover,this mysterious mass pattern of[Mt10]t has been gradually observed by series of marketed proton pump inhibitors,viz.omeprazole,pantoprazole,lansoprazole and rabeprazole.All the previous attempts to isolate the corresponding component were unsuccessful.The investigation of present work addresses this kind of signal to a pyridinium thiocyanate mass spectral intermediate(10),which is the common fragment ion of series of labile aggregates.The origin of such aggregates can be traced to the reactive intermediates formed by acid-promoted degradation.These reactive intermediates tend to react with each other and give raise series of complicated aggregates systematically in a water/acetonitrile solution by electrospray ionization.The structure of the corresponding pyridinium thiocyanate species of omeprazole(10a)has been eventually characterized with the help of synthetic specimen(10a′).Our structural proposal as well as its origin was supported by in situ nuclear magnetic resonance,chemical derivatization and colorimetric experiments.展开更多
Resonance lines are extensively used to diagnose electronic temperature Te and ions distribution. However, the analysis of the x-ray spectroscopy emitted from plasmas produced by a ns laser Jsually needs the help of a...Resonance lines are extensively used to diagnose electronic temperature Te and ions distribution. However, the analysis of the x-ray spectroscopy emitted from plasmas produced by a ns laser Jsually needs the help of a code or some assumptions. In this paper, a diagnostic idea of using line-pairs emitted from a doubly-excited state is proposed. By using the method presented in this paper, Te and the fractional population ratio of bare nuclei and H-like ions are directly obtained from the emission intensity ratios.展开更多
A fundamental problem for cells with their fragile membranes is the control of their volume.The primordial solution to this problem is the active transport of ions across the cell membrane to modulate the intracellula...A fundamental problem for cells with their fragile membranes is the control of their volume.The primordial solution to this problem is the active transport of ions across the cell membrane to modulate the intracellular osmotic pressure.In this work,a theoretical model of the cellular pump-leak mechanism is proposed within the general framework of linear nonequilibrium thermodynamics.The model is expressed with phenomenological equations that describe passive and active ionic transport across cell membranes,supplemented by an equation for the membrane potential that accounts for the electrogenicity of the ionic pumps.For active ionic transport,the model predicts that the intracellular fluid pressure will be balanced by the osmotic pressure and a new pressure component that arises from the active ionic fluxes.A model for the pump-leak mechanism in an idealized human cell is introduced to demonstrate the applicability of the proposed theory.展开更多
A series of optical thin films for LD pumped all- solid- state laser are discussed. Because of the difference between the pumped wavelength and the output wavelength, various kinds of pumping ways, resonator structure...A series of optical thin films for LD pumped all- solid- state laser are discussed. Because of the difference between the pumped wavelength and the output wavelength, various kinds of pumping ways, resonator structures and laser crystals, there are so many new kinds of optical thin films, including novel edge filters ,high reflection and an- tireflection coatings. The key problems in designing and coating are analyzed, and the researches carried out world- wide in this field are also given.展开更多
Organic electrode materials(OEMs)have garnered great attention for aqueous Zn-ion batteries(AZIBs)owing to their flexible designability and sustainable resources.However,the sluggish reaction kinetics and low active s...Organic electrode materials(OEMs)have garnered great attention for aqueous Zn-ion batteries(AZIBs)owing to their flexible designability and sustainable resources.However,the sluggish reaction kinetics and low active site utilization have strongly restricted their development due to the competitive coordination of H^(+)and Zn^(2+)in weakly acidic zinc electrolytes.Herein,we design a symmetric naphthoquinone-based cathode,2,3-dimethoxynaphthalene-1,4-dione(DMeNQ),with rational functional groups to facilitate proton coordination chemistry and accomplish improved ability to capture with zinc ion.The carbonyl and methoxy groups on the DMeNQ construct hydrogen bond networks and serve as a“proton pump”to expedite proton conduction through the Grotthuss-type mechanism.Density functional theory calculations have visualized the formation of“ion traps,”while in situ Raman spectra have tracked the reversible evolution of the active sites.Accordingly,the DMeNQ delivers a high capacity of 245mAhg^(−1)(99.6%utilization of the active groups)and a long lifetime of 50,000 cycles at 40 C in AZIBs.In addition,the DMeNQ also possesses a superior rate capability of 85mAh g^(−1)and a satisfactory cycle life of over 150,000 cycles at 400 C in proton batteries.Our results provide an effective pathway for high-performance OEMs.展开更多
基金financial supports of National Natural Science Foundation of China(22171226)Natural Science Basic Research Program of Shaanxi(2022JC-06).
文摘According to the second law of thermodynamics,spontaneous chemical processes will ultimately reach the equilibrium state with the lowest energy.However,in biological systems,there are numerous highenergy states far from equilibrium.One typical example is the transmembrane ion-concentration gradient,which plays crucial roles in maintaining homeostasis,regulating cell volume,and enabling cell signaling.Transmembrane ion-concentration gradient is achieved by an active transport process that requires the input of energy and the action of pump proteins.Replicating this process with synthetic supramolecular systems is particularly challenging,requiring both the input of energy and very specific,spatiotemporal control over ion uptake and release.In nature,pump proteins,such as protein-based ion channels,have evolved highly intricate architectures to perform this function.In contrast,Aprahamian and coworkers recently developed a much simpler smallmolecule system that functions as a molecular ion pump,utilizing light energy to pump chloride ions across a hydrophobic barrier against the concentration gradient[1].
基金supported by the National Natural Science Foundation of China(grant numbers 21878133,21908082 and 21722604)the Natural Science Foundation of Jiangsu Province(BK20190854)+2 种基金the China Postdoctoral Science Foundation(2020M671364)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX191622)the Science&Technology Foundation of Zhenjiang(GY2020027)。
文摘Accelerating the development of lithium resources has attracted a great deal of attention with the explosive growth of new energy vehicles.As a new technology,electrochemical lithium ion pumping(ELIP)is featured by environment-friendly,low energy consumption and high efficiency.This review summarizes the research progress in ELIP,and focuses on the evaluation methods,electrode materials and electrochemical systems of ELIP.It can be concluded that ELIP is expected to achieve an industrial application and has a promising prospect.In addition,challenges and perspective of electrochemical lithium extraction are also highlighted.
文摘We study the absorption-dispersion process and group index of weak probe field in a four-level Er^3＋：YAG crystal.We find that the Er^3＋ion concentration and incoherent pumping field can influence the absorption-dispersion process and group index of weak probe field. Moreover, our results show that Er^3＋ion concentration plays a major role in lasing without inversion and absorption with inversion.
基金supported by the National Natural Science Foundation of China(Grant Nos.:82030107 and 81872831)the National Science and Technology Major Projects for significant new drugs creation of the 13th five-year plan(Grant Nos.:2017ZX09101001 and 2018ZX09721002007).
文摘During the analysis of benziamidazole-class irreversible proton pump inhibitors,an unusual mass spectral response with the mass-to-charge ratio at[Mt10]t intrigued us,as it couldn't be assigned to any literature known relevant structure,intermediate or adduct ion.Moreover,this mysterious mass pattern of[Mt10]t has been gradually observed by series of marketed proton pump inhibitors,viz.omeprazole,pantoprazole,lansoprazole and rabeprazole.All the previous attempts to isolate the corresponding component were unsuccessful.The investigation of present work addresses this kind of signal to a pyridinium thiocyanate mass spectral intermediate(10),which is the common fragment ion of series of labile aggregates.The origin of such aggregates can be traced to the reactive intermediates formed by acid-promoted degradation.These reactive intermediates tend to react with each other and give raise series of complicated aggregates systematically in a water/acetonitrile solution by electrospray ionization.The structure of the corresponding pyridinium thiocyanate species of omeprazole(10a)has been eventually characterized with the help of synthetic specimen(10a′).Our structural proposal as well as its origin was supported by in situ nuclear magnetic resonance,chemical derivatization and colorimetric experiments.
文摘Resonance lines are extensively used to diagnose electronic temperature Te and ions distribution. However, the analysis of the x-ray spectroscopy emitted from plasmas produced by a ns laser Jsually needs the help of a code or some assumptions. In this paper, a diagnostic idea of using line-pairs emitted from a doubly-excited state is proposed. By using the method presented in this paper, Te and the fractional population ratio of bare nuclei and H-like ions are directly obtained from the emission intensity ratios.
文摘A fundamental problem for cells with their fragile membranes is the control of their volume.The primordial solution to this problem is the active transport of ions across the cell membrane to modulate the intracellular osmotic pressure.In this work,a theoretical model of the cellular pump-leak mechanism is proposed within the general framework of linear nonequilibrium thermodynamics.The model is expressed with phenomenological equations that describe passive and active ionic transport across cell membranes,supplemented by an equation for the membrane potential that accounts for the electrogenicity of the ionic pumps.For active ionic transport,the model predicts that the intracellular fluid pressure will be balanced by the osmotic pressure and a new pressure component that arises from the active ionic fluxes.A model for the pump-leak mechanism in an idealized human cell is introduced to demonstrate the applicability of the proposed theory.
文摘A series of optical thin films for LD pumped all- solid- state laser are discussed. Because of the difference between the pumped wavelength and the output wavelength, various kinds of pumping ways, resonator structures and laser crystals, there are so many new kinds of optical thin films, including novel edge filters ,high reflection and an- tireflection coatings. The key problems in designing and coating are analyzed, and the researches carried out world- wide in this field are also given.
文摘Organic electrode materials(OEMs)have garnered great attention for aqueous Zn-ion batteries(AZIBs)owing to their flexible designability and sustainable resources.However,the sluggish reaction kinetics and low active site utilization have strongly restricted their development due to the competitive coordination of H^(+)and Zn^(2+)in weakly acidic zinc electrolytes.Herein,we design a symmetric naphthoquinone-based cathode,2,3-dimethoxynaphthalene-1,4-dione(DMeNQ),with rational functional groups to facilitate proton coordination chemistry and accomplish improved ability to capture with zinc ion.The carbonyl and methoxy groups on the DMeNQ construct hydrogen bond networks and serve as a“proton pump”to expedite proton conduction through the Grotthuss-type mechanism.Density functional theory calculations have visualized the formation of“ion traps,”while in situ Raman spectra have tracked the reversible evolution of the active sites.Accordingly,the DMeNQ delivers a high capacity of 245mAhg^(−1)(99.6%utilization of the active groups)and a long lifetime of 50,000 cycles at 40 C in AZIBs.In addition,the DMeNQ also possesses a superior rate capability of 85mAh g^(−1)and a satisfactory cycle life of over 150,000 cycles at 400 C in proton batteries.Our results provide an effective pathway for high-performance OEMs.
