The reaction characteristics of calcium-based materials during calcium looping(CaL)process are pivotal in the efficiency of CaL thermochemical energy storage(TCES)and CO_(2)capture systems.Currently,metal oxide doping...The reaction characteristics of calcium-based materials during calcium looping(CaL)process are pivotal in the efficiency of CaL thermochemical energy storage(TCES)and CO_(2)capture systems.Currently,metal oxide doping is the primary method to enhance the reaction characteristics of calcium-based materials over multiple cycles.In particular,co-doping with variable-valence metal oxides(VVMOs)can effectively increase the oxygen vacancy content in calcium-based materials,significantly improving their cyclic reaction characteristics.However,there are so numerous VVMOs co-doping schemes that the experimental screening process is complex,consuming considerable time and economic costs.Density functional theory(DFT)calculations have been widely used to reveal the impact of metal oxide doping on the cyclic reaction characteristics of calcium-based materials,with calculation results showing good agreement with experimental conclusions.Nevertheless,there is still a lack of research on utilizing DFT to screen calcium-based materials,and a systematic research methodology has not yet been established.In this study,a systematic DFT-based screening methodology for calcium-based materials was proposed.A series of key parameters for DFT calculations including CO_(2)adsorption energy,oxygen vacancy formation energy,and sintering resistance were proposed.Furthermore,a preliminary mathematical model to predict the CaL TCES and CO_(2)capture performance of calcium-based materials was introduced.The aforementioned DFT method was employed to screen for VVMOs co-doped calcium-based materials.The results revealed that Mn and Ce co-doped calcium-based materials exhibited superior DFT-predicted reaction characteristics.These DFT predictions were validated through experimental assessments of cyclic thermochemical energy storage,CO_(2)capture,and relevant characterization.The outcomes demonstrate a high degree of consistency among DFT-based predictions,experimental results,and characterization.Hence,the DFT-based screening methodology for calcium-based materials proposed herein is a viable solution,poised to offer theoretical insights for the efficient design of calcium-based materials.展开更多
The globally increasing concentrations of greenhouse gases in atmosphere after combustion of coal-or petroleum-based fuels give rise to tremendous interest in searching for porous materials to efficiently capture carb...The globally increasing concentrations of greenhouse gases in atmosphere after combustion of coal-or petroleum-based fuels give rise to tremendous interest in searching for porous materials to efficiently capture carbon dioxide(CO_2) and store methane(CH4), where the latter is a kind of clean energy source with abundant reserves and lower CO_2 emission. Hundreds of thousands of porous materials can be enrolled on the candidate list, but how to quickly identify the really promising ones, or even evolve materials(namely, rational design high-performing candidates) based on the large database of present porous materials? In this context, high-throughput computational techniques, which have emerged in the past few years as powerful tools, make the targets of fast evaluation of adsorbents and evolving materials for CO_2 capture and CH_4 storage feasible. This review provides an overview of the recent computational efforts on such related topics and discusses the further development in this field.展开更多
The influences on the neutrino energy loss rates in iron group nuclei at the same density are investigated in the presence of strong electron screening and in the absence of electron screening. The results show that a...The influences on the neutrino energy loss rates in iron group nuclei at the same density are investigated in the presence of strong electron screening and in the absence of electron screening. The results show that at a temperature of 15 × 10^9 K, the neutrino energy loss rates which come from the electron capture process for most iron group nuclei decrease no more than 2 orders of magnitude but for the others （such as ^53,55,56,57,58,59,6o Co, ^56,59Ni） they can decrease about 3 orders of magnitude due to strong electron screening （SES）, whereas, at a temperature of 10^9K the neutrino energy loss rates of the most iron group nuclei can be diminished greatly due to the SES. For example, ^61Fe, ^60Fe, and ^62Ni the neutrino energy loss rates decrease about 4, 15 and 16 orders of magnitude and for ^57Cr, ^58Cr, and ^60Cr decrease about 18, 12, and 10 orders of magnitude respectively. According to our calculations the neutrino energy loss rates of nuclei ^58Mn, ^59Mn, ^60Mn, and ^62Mn may decrease about 13 orders of magnitude at a temperature of 10^9 K due to the SES.展开更多
Remote Sensing data, as an essential urban basic information in urban planning, has the characteristics of large information capacity, real time, high update speed and accuracy. Because of urban spatial information in...Remote Sensing data, as an essential urban basic information in urban planning, has the characteristics of large information capacity, real time, high update speed and accuracy. Because of urban spatial information involving multi-faceted public and public interests, its data security is very important. The use of digital watermarking technology can effectively protect the secu-rity of urban planning basic data. In practical applications, the “screen capture” poses a great threat to the security of remote sensing image. In order to resist the screen capture attacks, the QR code watermark information is encoded and converted, and combined with a circular angle template watermark, a digital watermarking algorithm for remote sensing images in urban planning information management is proposed. And the proposed algorithm is experimentally verified. Experiments show that the algorithm is robust against screen capture attacks, and provide security guarantee for urban construction and management.展开更多
Pinnacle studio 17下附带子程序Live Screen Capture的屏幕捕捉功能即可完成多媒体视频课件的制作,快速完成多媒体视频课件的制作方法以便教学应用,此软件操作方法简单易上手,能够快速完成多媒体视频课件的制作,是比较实用的医学多媒...Pinnacle studio 17下附带子程序Live Screen Capture的屏幕捕捉功能即可完成多媒体视频课件的制作,快速完成多媒体视频课件的制作方法以便教学应用,此软件操作方法简单易上手,能够快速完成多媒体视频课件的制作,是比较实用的医学多媒体视频课件制作方法.展开更多
The electron capture in N^(5+)-H collisions imbedded in a Debye plasma is studied by using the two-center atomic orbital close-coupling method in the energy range from 1 keV/u to 200 keV/u.The atomic orbitals and elec...The electron capture in N^(5+)-H collisions imbedded in a Debye plasma is studied by using the two-center atomic orbital close-coupling method in the energy range from 1 keV/u to 200 keV/u.The atomic orbitals and electron binding energies of atomic states are calculated within the Debye-Huckel approximation of the screened Coulomb potential and used in atomic orbital close-coupling dynamics formalism to calculate the electron capture cross sections.The electron capture cross sections and the charge transfer spectral lines of N^(4+)(1s^(2)nl)for a number of representative screening parameter values are presented and discussed.It is found that the screening of Coulomb interactions affects the entire collision dynamics and the magnitude and energy behavior of state-selective cross sections.The changes in electron binding energies and capture cross sections when the interaction screening varies introduce dramatic changes in the radiation spectrum of N^(4+)(1s^(2)nl)capture states with respect to the unscreened interaction case.展开更多
Since the mid-to-late 20th century,the scientific community has increasingly recognized that the rapid rise in atmospheric greenhouse gases,particularly CO_(2)from human activities,is the primary driver of global warm...Since the mid-to-late 20th century,the scientific community has increasingly recognized that the rapid rise in atmospheric greenhouse gases,particularly CO_(2)from human activities,is the primary driver of global warming.This escalation has led to pressing climate challenges,including sea-level rise and more frequent extreme weather events[1,2].Among the limited strategies available to mitigate CO_(2)emissions,carbon capture and storage have emerged as a key approach.To this end,various adsorbents—such as metalorganic frameworks(MOFs),zeolites,and carbon materials—have been developed for CO_(2)capture[3-6].展开更多
Ionic liquid(IL)can be inserted into metal organic framework(MOF)to form IL@MOF composite with enhanced properties.In this work,hypothetical IL@MOFs were computationally constructed and screened by integrating molecul...Ionic liquid(IL)can be inserted into metal organic framework(MOF)to form IL@MOF composite with enhanced properties.In this work,hypothetical IL@MOFs were computationally constructed and screened by integrating molecular simulation and convolutional neural network(CNN)for CO_(2)capture.First,the IL[BMIM][DCA]with a large CO_(2)solubility was inserted into 1631 pre-selected Computational-Ready Experimental(CoRE)MOFs to create hypothetical IL@MOFs.Then,given the temperature and pressure of adsorption and desorption,the CO_(2)/N_(2)selectivity and CO_(2)working capacity of 700 representative IL@MOFs were assessed via molecular simulations.Based on the results,two CNN models were trained and used to predict the performance of other IL@MOFs,which reduces the computational costs effectively.By combining the simulation results and CNN model predictions,22 IL@MOFs with top-ranked performance were identified.Three distinct ones IL@HABDAS,IL@GUBKUL,and IL@MARJAQ were chosen for explicit analysis.It was found that a desired balance between CO_(2)/N_(2)selectivity and CO_(2)working capacity can be obtained by inserting the optimal number of IL molecules.This helps guide a novel design of IL@MOF composites with advanced performance on carbon capture.展开更多
The influence of electron screening on electron capture rate in strong screening is investigated, in which the Gamow-Teller resonance transition is considered and the matrix elements for the resonance transition are c...The influence of electron screening on electron capture rate in strong screening is investigated, in which the Gamow-Teller resonance transition is considered and the matrix elements for the resonance transition are calculated on the basis of a shell model. The effect of electron screening on electron capture by 56Co is discussed. It is shown that the screening decreases evidently the capture rates in lower temperature and higher density. The effect of electron screening on other nuclear capture rates is estimated. The conclusion derived may influence the research for late stellar evolution and supernova explosion.展开更多
We performed large-scale molecular simulation to screen and identify metal-organic framework materials for gaseous iodine capture,as part of our ongoing effort in addressing management and handling issues of various r...We performed large-scale molecular simulation to screen and identify metal-organic framework materials for gaseous iodine capture,as part of our ongoing effort in addressing management and handling issues of various radionuclides in the grand scheme of spent nuclear fuel reprocessing.Starting from the computation-ready experimental(CoRE)metal-organic frameworks(MOFs)database,grand canonical Monte Carlo simulation was employed to predict the iodine uptake values of the MOFs.A ranking list of MOFs based on their iodine uptake capabilities was generated,with the Top 10 candidates identified and their respective adsorption sites visualized.Subsequently,machine learning was used to establish structure-property relationships to correlate MOFs’various structural and chemical features with their corresponding performances in iodine capture,yielding interpretable common features and design rules for viable MOF adsorbents.The research strategy and framework of the present study could aid the development of high-performing MOF adsorbents for capture and recovery of radioactive iodine,and moreover,other volatile environmentally hazardous species.展开更多
Adsorption-based carbon capture has been recognized as an attractive method for mitigating global warming.Metal–organic frameworks(MOFs)are promising candidate adsorbents for this purpose due to their high adsorption...Adsorption-based carbon capture has been recognized as an attractive method for mitigating global warming.Metal–organic frameworks(MOFs)are promising candidate adsorbents for this purpose due to their high adsorption uptake and selectivity for carbon dioxide.However,in real-world applications,such as direct air capture,the presence of moisture in the feed gas may pose a grand challenge for CO_(2)adsorption in MOFs.This paper aims to address the issue of water–CO_(2)co-adsorption in MOFs and present screening criteria for selecting MOFs that preferentially adsorb CO_(2)under humid conditions.First,we uncover a comprehensive overview of CO_(2)–water co-adsorption characteristics of various MOFs.Then,the high-throughput screening methods are summarized.Both computational and experimental efforts have been dedicated to identify the promising MOFs for humid CO_(2)capture.According to the screening results and adsorption mechanism,the optimal preparation strategies are proposed tomodulate the effect of water on CO_(2)uptake in MOFs.Finally,current MOF-based CO_(2)capture prototypes are presented to evaluate their practical feasibility and performance.This work could offer valuable guidance for the development and application of MOFs for CO_(2)capture in the presence of water and inspire further research in this field.展开更多
Gaussian modifications of the neutrino energy loss （NEL） by electron capture on the strongly screening nuclides 55Co and 56Ni are investigated. The results show that in strong electron screening （SES）, the NEL rat...Gaussian modifications of the neutrino energy loss （NEL） by electron capture on the strongly screening nuclides 55Co and 56Ni are investigated. The results show that in strong electron screening （SES）, the NEL rates decrease without modifying the Gamow-Teller （G-T） resonance transition. For instance, the NEL rates of 55Co and 56Ni decrease more than two and three orders of magnitude for ρ7 = 5.86, T9 5, Ye = 0.47, △ = 6.3, respectively. In contrast, due to Gaussian modification, the NEL rates increase about two orders of magnitude in SES. Due to SES, the maximum values of the C-factor （in %） on NEL of 55Co, 56Ni are of the order of 99.80%, 99.56% at ρ7 = 5.86 Ye = 0.47 and 99.60%, 99.65% at ρ7 = 106 Ye = 0.43, respectively.展开更多
基金supported by the National Natural Science Foundation of China(52276204 and U22A20435)。
文摘The reaction characteristics of calcium-based materials during calcium looping(CaL)process are pivotal in the efficiency of CaL thermochemical energy storage(TCES)and CO_(2)capture systems.Currently,metal oxide doping is the primary method to enhance the reaction characteristics of calcium-based materials over multiple cycles.In particular,co-doping with variable-valence metal oxides(VVMOs)can effectively increase the oxygen vacancy content in calcium-based materials,significantly improving their cyclic reaction characteristics.However,there are so numerous VVMOs co-doping schemes that the experimental screening process is complex,consuming considerable time and economic costs.Density functional theory(DFT)calculations have been widely used to reveal the impact of metal oxide doping on the cyclic reaction characteristics of calcium-based materials,with calculation results showing good agreement with experimental conclusions.Nevertheless,there is still a lack of research on utilizing DFT to screen calcium-based materials,and a systematic research methodology has not yet been established.In this study,a systematic DFT-based screening methodology for calcium-based materials was proposed.A series of key parameters for DFT calculations including CO_(2)adsorption energy,oxygen vacancy formation energy,and sintering resistance were proposed.Furthermore,a preliminary mathematical model to predict the CaL TCES and CO_(2)capture performance of calcium-based materials was introduced.The aforementioned DFT method was employed to screen for VVMOs co-doped calcium-based materials.The results revealed that Mn and Ce co-doped calcium-based materials exhibited superior DFT-predicted reaction characteristics.These DFT predictions were validated through experimental assessments of cyclic thermochemical energy storage,CO_(2)capture,and relevant characterization.The outcomes demonstrate a high degree of consistency among DFT-based predictions,experimental results,and characterization.Hence,the DFT-based screening methodology for calcium-based materials proposed herein is a viable solution,poised to offer theoretical insights for the efficient design of calcium-based materials.
基金supported by the Natural Science Foundation of China (Nos.21706106,21536001 and 21322603)the National Key Basic Research Program of China ("973") (No.2013CB733503)+1 种基金the Natural Science Foundation of Jiangsu Normal University(16XLR011)Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The globally increasing concentrations of greenhouse gases in atmosphere after combustion of coal-or petroleum-based fuels give rise to tremendous interest in searching for porous materials to efficiently capture carbon dioxide(CO_2) and store methane(CH4), where the latter is a kind of clean energy source with abundant reserves and lower CO_2 emission. Hundreds of thousands of porous materials can be enrolled on the candidate list, but how to quickly identify the really promising ones, or even evolve materials(namely, rational design high-performing candidates) based on the large database of present porous materials? In this context, high-throughput computational techniques, which have emerged in the past few years as powerful tools, make the targets of fast evaluation of adsorbents and evolving materials for CO_2 capture and CH_4 storage feasible. This review provides an overview of the recent computational efforts on such related topics and discusses the further development in this field.
基金Project supported by the National Natural Science Foundation of China （Grant No 10347008）.
文摘The influences on the neutrino energy loss rates in iron group nuclei at the same density are investigated in the presence of strong electron screening and in the absence of electron screening. The results show that at a temperature of 15 × 10^9 K, the neutrino energy loss rates which come from the electron capture process for most iron group nuclei decrease no more than 2 orders of magnitude but for the others （such as ^53,55,56,57,58,59,6o Co, ^56,59Ni） they can decrease about 3 orders of magnitude due to strong electron screening （SES）, whereas, at a temperature of 10^9K the neutrino energy loss rates of the most iron group nuclei can be diminished greatly due to the SES. For example, ^61Fe, ^60Fe, and ^62Ni the neutrino energy loss rates decrease about 4, 15 and 16 orders of magnitude and for ^57Cr, ^58Cr, and ^60Cr decrease about 18, 12, and 10 orders of magnitude respectively. According to our calculations the neutrino energy loss rates of nuclei ^58Mn, ^59Mn, ^60Mn, and ^62Mn may decrease about 13 orders of magnitude at a temperature of 10^9 K due to the SES.
文摘Remote Sensing data, as an essential urban basic information in urban planning, has the characteristics of large information capacity, real time, high update speed and accuracy. Because of urban spatial information involving multi-faceted public and public interests, its data security is very important. The use of digital watermarking technology can effectively protect the secu-rity of urban planning basic data. In practical applications, the “screen capture” poses a great threat to the security of remote sensing image. In order to resist the screen capture attacks, the QR code watermark information is encoded and converted, and combined with a circular angle template watermark, a digital watermarking algorithm for remote sensing images in urban planning information management is proposed. And the proposed algorithm is experimentally verified. Experiments show that the algorithm is robust against screen capture attacks, and provide security guarantee for urban construction and management.
基金supported by the National Basic Research Program of China(Grant No.2013CB922200)by the National Natural Science Foundation of China(Grant Nos.11204017,11474033 and 11474032)by the foundation for the development of Science and Technology of China Academy of Engineering Physics(Grant No.2013A0102005).
文摘The electron capture in N^(5+)-H collisions imbedded in a Debye plasma is studied by using the two-center atomic orbital close-coupling method in the energy range from 1 keV/u to 200 keV/u.The atomic orbitals and electron binding energies of atomic states are calculated within the Debye-Huckel approximation of the screened Coulomb potential and used in atomic orbital close-coupling dynamics formalism to calculate the electron capture cross sections.The electron capture cross sections and the charge transfer spectral lines of N^(4+)(1s^(2)nl)for a number of representative screening parameter values are presented and discussed.It is found that the screening of Coulomb interactions affects the entire collision dynamics and the magnitude and energy behavior of state-selective cross sections.The changes in electron binding energies and capture cross sections when the interaction screening varies introduce dramatic changes in the radiation spectrum of N^(4+)(1s^(2)nl)capture states with respect to the unscreened interaction case.
文摘Since the mid-to-late 20th century,the scientific community has increasingly recognized that the rapid rise in atmospheric greenhouse gases,particularly CO_(2)from human activities,is the primary driver of global warming.This escalation has led to pressing climate challenges,including sea-level rise and more frequent extreme weather events[1,2].Among the limited strategies available to mitigate CO_(2)emissions,carbon capture and storage have emerged as a key approach.To this end,various adsorbents—such as metalorganic frameworks(MOFs),zeolites,and carbon materials—have been developed for CO_(2)capture[3-6].
基金supported by the National Natural Science Foundation of China(NSFC)under grant 22278134.
文摘Ionic liquid(IL)can be inserted into metal organic framework(MOF)to form IL@MOF composite with enhanced properties.In this work,hypothetical IL@MOFs were computationally constructed and screened by integrating molecular simulation and convolutional neural network(CNN)for CO_(2)capture.First,the IL[BMIM][DCA]with a large CO_(2)solubility was inserted into 1631 pre-selected Computational-Ready Experimental(CoRE)MOFs to create hypothetical IL@MOFs.Then,given the temperature and pressure of adsorption and desorption,the CO_(2)/N_(2)selectivity and CO_(2)working capacity of 700 representative IL@MOFs were assessed via molecular simulations.Based on the results,two CNN models were trained and used to predict the performance of other IL@MOFs,which reduces the computational costs effectively.By combining the simulation results and CNN model predictions,22 IL@MOFs with top-ranked performance were identified.Three distinct ones IL@HABDAS,IL@GUBKUL,and IL@MARJAQ were chosen for explicit analysis.It was found that a desired balance between CO_(2)/N_(2)selectivity and CO_(2)working capacity can be obtained by inserting the optimal number of IL molecules.This helps guide a novel design of IL@MOF composites with advanced performance on carbon capture.
基金Climbing Program from the State and Technology CommissionNational Natural Science Foundation of China.
文摘The influence of electron screening on electron capture rate in strong screening is investigated, in which the Gamow-Teller resonance transition is considered and the matrix elements for the resonance transition are calculated on the basis of a shell model. The effect of electron screening on electron capture by 56Co is discussed. It is shown that the screening decreases evidently the capture rates in lower temperature and higher density. The effect of electron screening on other nuclear capture rates is estimated. The conclusion derived may influence the research for late stellar evolution and supernova explosion.
基金supported by the National Natural Science Foundation of China(No.22176135,C.L.)Additionally,this research was supported by the Fundamental Research Funds for the Central Universities in China(No.YJ201976,C.L.)start-up funds from the School of Chemical Engineering,Sichuan University(C.L.).
文摘We performed large-scale molecular simulation to screen and identify metal-organic framework materials for gaseous iodine capture,as part of our ongoing effort in addressing management and handling issues of various radionuclides in the grand scheme of spent nuclear fuel reprocessing.Starting from the computation-ready experimental(CoRE)metal-organic frameworks(MOFs)database,grand canonical Monte Carlo simulation was employed to predict the iodine uptake values of the MOFs.A ranking list of MOFs based on their iodine uptake capabilities was generated,with the Top 10 candidates identified and their respective adsorption sites visualized.Subsequently,machine learning was used to establish structure-property relationships to correlate MOFs’various structural and chemical features with their corresponding performances in iodine capture,yielding interpretable common features and design rules for viable MOF adsorbents.The research strategy and framework of the present study could aid the development of high-performing MOF adsorbents for capture and recovery of radioactive iodine,and moreover,other volatile environmentally hazardous species.
基金National Key Research and Development Program of China,Grant/Award Numbers:2022YFB4101700,2022YFE0128600National Natural Science Foundation of China,Grant/Award Numbers:52276022,22278365,22225802Basic Research Funds for the Central Government‘Innovative Team of Zhejiang University’,Grant/Award Number:2022FZZX01-09。
文摘Adsorption-based carbon capture has been recognized as an attractive method for mitigating global warming.Metal–organic frameworks(MOFs)are promising candidate adsorbents for this purpose due to their high adsorption uptake and selectivity for carbon dioxide.However,in real-world applications,such as direct air capture,the presence of moisture in the feed gas may pose a grand challenge for CO_(2)adsorption in MOFs.This paper aims to address the issue of water–CO_(2)co-adsorption in MOFs and present screening criteria for selecting MOFs that preferentially adsorb CO_(2)under humid conditions.First,we uncover a comprehensive overview of CO_(2)–water co-adsorption characteristics of various MOFs.Then,the high-throughput screening methods are summarized.Both computational and experimental efforts have been dedicated to identify the promising MOFs for humid CO_(2)capture.According to the screening results and adsorption mechanism,the optimal preparation strategies are proposed tomodulate the effect of water on CO_(2)uptake in MOFs.Finally,current MOF-based CO_(2)capture prototypes are presented to evaluate their practical feasibility and performance.This work could offer valuable guidance for the development and application of MOFs for CO_(2)capture in the presence of water and inspire further research in this field.
基金Supported by Natural Science Foundation of Hainan Province (109004)Institution of Higher Education Scientific Research and Foundation of Hainan Provincial Education Department (Hjkj 2010-42)Institution of Higher Education Special Foundation of Sanya (YD09047)
文摘Gaussian modifications of the neutrino energy loss （NEL） by electron capture on the strongly screening nuclides 55Co and 56Ni are investigated. The results show that in strong electron screening （SES）, the NEL rates decrease without modifying the Gamow-Teller （G-T） resonance transition. For instance, the NEL rates of 55Co and 56Ni decrease more than two and three orders of magnitude for ρ7 = 5.86, T9 5, Ye = 0.47, △ = 6.3, respectively. In contrast, due to Gaussian modification, the NEL rates increase about two orders of magnitude in SES. Due to SES, the maximum values of the C-factor （in %） on NEL of 55Co, 56Ni are of the order of 99.80%, 99.56% at ρ7 = 5.86 Ye = 0.47 and 99.60%, 99.65% at ρ7 = 106 Ye = 0.43, respectively.
