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A Formal Model for Analyzing Fair Exchange Protocols Based on Event Logic
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作者 Ke Yang Meihua Xiao Zehuan Li 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2641-2663,共23页
Fair exchange protocols play a critical role in enabling two distrustful entities to conduct electronic data exchanges in a fair and secure manner.These protocols are widely used in electronic payment systems and elec... Fair exchange protocols play a critical role in enabling two distrustful entities to conduct electronic data exchanges in a fair and secure manner.These protocols are widely used in electronic payment systems and electronic contract signing,ensuring the reliability and security of network transactions.In order to address the limitations of current research methods and enhance the analytical capabilities for fair exchange protocols,this paper proposes a formal model for analyzing such protocols.The proposed model begins with a thorough analysis of fair exchange protocols,followed by the formal definition of fairness.This definition accurately captures the inherent requirements of fair exchange protocols.Building upon event logic,the model incorporates the time factor into predicates and introduces knowledge set axioms.This enhancement empowers the improved logic to effectively describe the state and knowledge of protocol participants at different time points,facilitating reasoning about their acquired knowledge.To maximize the intruder’s capabilities,channel errors are translated into the behaviors of the intruder.The participants are further categorized into honest participants and malicious participants,enabling a comprehensive evaluation of the intruder’s potential impact.By employing a typical fair exchange protocol as an illustrative example,this paper demonstrates the detailed steps of utilizing the proposed model for protocol analysis.The entire process of protocol execution under attack scenarios is presented,shedding light on the underlying reasons for the attacks and proposing corresponding countermeasures.The developedmodel enhances the ability to reason about and evaluate the security properties of fair exchange protocols,thereby contributing to the advancement of secure network transactions. 展开更多
关键词 Fair exchange protocols FAIRNESS formal analysis logic reasoning
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Durable poly(binaphthyl-co-p-terphenyl piperidinium)-based anion exchange membranes with dual side chains
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作者 Weiting Gao Xuelang Gao +2 位作者 Qiugen Zhang Aimei Zhu Qinglin Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期324-335,I0008,共13页
Building well-developed ion-conductive highways is highly desirable for anion exchange membranes(AEMs).Grafting side chain is a highly effective approach for constructing a well-defined phaseseparated morphological st... Building well-developed ion-conductive highways is highly desirable for anion exchange membranes(AEMs).Grafting side chain is a highly effective approach for constructing a well-defined phaseseparated morphological structure and forming unblocked ion pathways in AEMs for fast ion transport.Fluorination of side chains can further enhance phase separation due to the superhydrophobic nature of fluorine groups.However,their electronic effect on the alkaline stability of side chains and membranes is rarely reported.Here,fluorine-containing and fluorine-free side chains are introduced into the polyaromatic backbone in proper configuration to investigate the impact of the fluorine terminal group on the stability of the side chains and membrane properties.The poly(binaphthyl-co-p-terphenyl piperidinium)AEM(QBNp TP)has the highest molecular weight and most dimensional stability due to its favorable backbone arrangement among ortho-and meta-terphenyl based AEMs.Importantly,by introducing both a fluorinated piperidinium side chain and a hexane chain into the p-terphenyl-based backbone,the prepared AEM(QBNp TP-QFC)presents an enhanced conductivity(150.6 m S cm^(-1))and a constrained swelling at 80℃.The electronic effect of fluorinated side chains is contemplated by experiments and simulations.The results demonstrate that the presence of strong electro-withdrawing fluorine groups weakens the electronic cloud of adjacent C atoms,increasing OH^(-)attack on the C atom and improving the stability of piperidinium cations.Hence QBNp TP-QFC possesses a robust alkaline stability at 80℃(95.3%conductivity retention after testing in 2 M Na OH for 2160 h).An excellent peak power density of 1.44 W cm^(-2)and a remarkable durability at 80℃(4.5%voltage loss after 100 h)can be observed. 展开更多
关键词 Anion exchange membranes Backbone structure Fluorinated side chain Alkaline stability
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Performance Degradation Prediction of Proton Exchange Membrane Fuel Cell Based on CEEMDAN-KPCA and DA-GRU Networks 被引量:1
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作者 Tingwei Zhao Juan Wang +2 位作者 Jiangxuan Che Yingjie Bian Tianyu Chen 《Instrumentation》 2024年第1期51-61,共11页
In order to improve the performance degradation prediction accuracy of proton exchange membrane fuel cell(PEMFC),a fusion prediction method(CKDG)based on adaptive noise complete ensemble empirical mode decomposition(C... In order to improve the performance degradation prediction accuracy of proton exchange membrane fuel cell(PEMFC),a fusion prediction method(CKDG)based on adaptive noise complete ensemble empirical mode decomposition(CEEMDAN),kernel principal component analysis(KPCA)and dual attention mechanism gated recurrent unit neural network(DA-GRU)was proposed.CEEMDAN and KPCA were used to extract the input feature data sequence,reduce the influence of random factors,and capture essential feature components to reduce the model complexity.The DA-GRU network helps to learn the feature mapping relationship of data in long time series and predict the changing trend of performance degradation data more accurately.The actual aging experimental data verify the performance of the CKDG method.The results show that under the steady-state condition of 20%training data prediction,the CKDA method can reduce the root mean square error(RMSE)by 52.7%and 34.6%,respectively,compared with the traditional LSTM and GRU neural networks.Compared with the simple DA-GRU network,RMSE is reduced by 15%,and the degree of over-fitting is reduced,which has higher accuracy.It also shows excellent prediction performance under the dynamic condition data set and has good universality. 展开更多
关键词 proton exchange membrane fuel cell dual-attention gated recurrent unit data-driven model time series prediction
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Electrochemical reconstruction of non-noble metal-based heterostructure nanorod arrays electrodes for highly stable anion exchange membrane seawater electrolysis
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作者 Jingchen Na Hongmei Yu +7 位作者 Senyuan Jia Jun Chi Kaiqiu Lv Tongzhou Li Yun Zhao Yutong Zhao Haitao Zhang Zhigang Shao 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第4期370-382,共13页
Direct seawater electrolysis for hydrogen production has been regarded as a viable route to utilize surplus renewable energy and address the climate crisis.However,the harsh electrochemical environment of seawater,par... Direct seawater electrolysis for hydrogen production has been regarded as a viable route to utilize surplus renewable energy and address the climate crisis.However,the harsh electrochemical environment of seawater,particularly the presence of aggressive Cl^(-),has been proven to be prone to parasitic chloride ion oxidation and corrosion reactions,thus restricting seawater electrolyzer lifetime.Herein,hierarchical structure(Ni,Fe)O(OH)@NiCoS nanorod arrays(NAs)catalysts with heterointerfaces and localized oxygen vacancies were synthesized at nickel foam substrates via the combination of hydrothermal and annealing methods to boost seawater dissociation.The hiera rchical nanostructure of NiCoS NAs enhanced electrode charge transfer rate and active surface area to accelerate oxygen evolution reaction(OER)and generated sulfate gradient layers to repulsive aggressive Cl^(-).The fabricated heterostructure and vacancies of(Ni,Fe)O(OH)tuned catalyst electronic structure into an electrophilic state to enhance the binding affinity of hydroxyl intermediates and facilitate the structural transformation into amorphousγ-NiFeOOH for promoting OER.Furthermore,through operando electrochemistry techniques,we found that theγ-NiFeOOH possessing an unsaturated coordination environment and lattice-oxygen-participated OER mechanism can minimize electrode Cl^(-)corrosion enabled by stabilizing the adsorption of OH*intermediates,making it one of the best OER catalysts in the seawater medium reported to date.Consequently,these catalysts can deliver current densities of 100 and 500 mA cm-2for boosting OER at minimal overpotentials of 245and 316 mV,respectively,and thus prevent chloride ion oxidation simultaneously.Impressively,a highly stable anion exchange membrane(AEM)seawater electrolyzer based on the non-noble metal heterostructure electrodes reached a record low degradation rate under 100μV h-1at constant industrial current densities of 400 and 600 mA cm-2over 300 h,which exhibits a promising future for the nonprecious and stable AEMWE in the direct seawater electrolysis industry. 展开更多
关键词 Direct seawater electrolysis Anion exchange membrane water ELECTROLYSIS Oxygen evolution reaction Oxygen vacancies Operando electrochemistry techniques
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Intermolecular Acid-Base-Pairs Containing Poly(p-Terphenyl-co-lsatin Piperidinium)for High Temperature Proton Exchange Membrane Fuel Cells
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作者 Xiaofeng Hao Zhen Li +6 位作者 Min Xiao Zhiheng Huang Dongmei Han Sheng Huang Wei Liu Shuanjin Wang Yuezhong Meng 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第3期406-414,共9页
How to optimize and regulate the distribution of phosphoric acid in matrix,and pursuing the improved electrochemical performance and service lifetime of high temperature proton exchange membrane(HT-PEMs)fuel cell are ... How to optimize and regulate the distribution of phosphoric acid in matrix,and pursuing the improved electrochemical performance and service lifetime of high temperature proton exchange membrane(HT-PEMs)fuel cell are significant challenges.Herein,bifunctional poly(p-terphenyl-co-isatin piperidinium)copolymer with tethered phosphonic acid(t-PA)and intrinsic tertiary amine base groups are firstly prepared and investigated as HT-PEMs.The distinctive architecture of the copolymer provides a well-designed platform for rapid proton transport.Protons not only transports through the hydrogen bond network formed by the adsorbed free phosphoric acid(f-PA)anchored by the tertiary amine base groups,but also rely upon the proton channel constructed by the ionic cluster formed by the t-PA aggregation.Thorough the design of the structure,the bifunctional copolymers with lower PA uptake level(<100%)display prominent proton conductivities and peak power densities(99 mS cm^(-1),812 mW cm^(-2)at 160℃),along with lower PA leaching and higher voltage stability,which is a top leading result in disclosed literature.The results demonstrate that the design of intermolecular acid-base-pairs can improve the proton conductivity without sacrificing the intrinsic chemical stability or mechanical property of the thin membrane,realizing win-win demands between the mechanical robustness and electrochemical properties of HT-PEMs. 展开更多
关键词 bifunctional copolymer high temperature proton exchange membrane intermolecular acid-base-pairs phosphonic acid retention phosphonic acid uptake level
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Probing the Efficiency of PPMG-Based Composite Electrolytes for Applications of Proton Exchange Membrane Fuel Cell
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作者 Shakeel Ahmed Faizah Altaf +6 位作者 Safyan Akram Khan Sumaira Manzoor Aziz Ahmad Muhammad Mansha Shahid Ali Ata-ur-Rehman Karl Jacob 《Transactions of Tianjin University》 EI CAS 2024年第3期262-283,共22页
PPMG-based composite electrolytes were fabricated via the solution method using the polyvinyl alcohol and polyvinylpyrrolidone blend reinforced with various contents of sulfonated inorganic filler.Sulfuric acid was em... PPMG-based composite electrolytes were fabricated via the solution method using the polyvinyl alcohol and polyvinylpyrrolidone blend reinforced with various contents of sulfonated inorganic filler.Sulfuric acid was employed as the sulfonating agent to functionalize the external surface of the inorganic filler,i.e.,graphene oxide.The proton conductivities of the newly prepared proton exchange membranes(PEMs)were increased by increasing the temperature and content of sulfonated graphene oxide(SGO),i.e.,ranging from 0.025 S/cm to 0.060 S/cm.The induction of the optimum level of SGO is determined to be an excellent route to enhance ionic conductivity.The single-cell performance test was conducted by sandwiching the newly prepared PEMs between an anode(0.2 mg/cm^(2) Pt/Ru)and a cathode(0.2 mg/cm^(2) Pt)to prepare membrane electrode assemblies,followed by hot pressing under a pressure of approximately 100 kg/cm^(2) at 60℃for 5–10 min.The highest power densities achieved with PPMG PEMs were 14.9 and 35.60 mW/cm^(2) at 25℃and 70℃,respectively,at ambient pressure with 100%relative humidity.Results showed that the newly prepared PEMs exhibit good electrochemical performance.The results indicated that the prepared composite membrane with 6 wt%filler can be used as an alternative membrane for applications of high-performance proton exchange membrane fuel cell. 展开更多
关键词 Proton exchange membrane fuel cell Sulfonated graphene oxide POLYVINYLPYRROLIDONE Solution casting Membrane electrode assembly Fuel cell performance
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Analysis of influence of heat exchangerfouling on heat transfer performancebased on thermal fluid coupling 被引量:1
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作者 HUANG Si MURAD Tariq +2 位作者 NIU Qifeng LIN Guangtang CHEN Jianxun 《排灌机械工程学报》 CSCD 北大核心 2023年第7期695-700,共6页
A study on heat transfer performance by thermal fluid coupling simulation for the fouling in a shell-tube heat exchanger used in engineering was presented. The coupling simulation was performed in a fluid and solid do... A study on heat transfer performance by thermal fluid coupling simulation for the fouling in a shell-tube heat exchanger used in engineering was presented. The coupling simulation was performed in a fluid and solid domains under three different fouling conditions: fouling inside the tube, fouling outside the tube, and fouling inside the shell. The flow field, temperature, and pressure distributions in the heat exchanger were solved numerically to analyze the heat transfer performance parameters, such as thermal resistance. It is found that the pressure drop of the heat exchanger and the thermal resistance of the tube wall increase by nearly 30% and 20%, respectively, when the relative fouling thickness reaches 10%. The fouling inside the tube has more impact on the heat transfer performance of the heat exchanger, and the fouling inside the shell has less impact. 展开更多
关键词 shell-tube heat exchanger thermal fluid coupling fouling thermal resistance heat transfer analysis
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Pore-Scale Investigation of Coupled Two-Phase and Reactive Transport in the Cathode Electrode of Proton Exchange Membrane Fuel Cells 被引量:1
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作者 Shengjie Ye Yuze Hou +2 位作者 Xing Li Kui Jiao Qing Du 《Transactions of Tianjin University》 EI CAS 2023年第1期1-13,共13页
A three-dimensional multicomponent multiphase lattice Boltzmann model(LBM)is established to model the coupled two-phase and reactive transport phenomena in the cathode electrode of proton exchange membrane fuel cells.... A three-dimensional multicomponent multiphase lattice Boltzmann model(LBM)is established to model the coupled two-phase and reactive transport phenomena in the cathode electrode of proton exchange membrane fuel cells.The gas diff usion layer(GDL)and microporous layer(MPL)are stochastically reconstructed with the inside dynamic distribution of oxygen and liquid water resolved,and the catalyst layer is simplifi ed as a superthin layer to address the electrochemical reaction,which provides a clear description of the fl ooding eff ect on mass transport and performance.Diff erent kinds of electrodes are reconstructed to determine the optimum porosity and structure design of the GDL and MPL by comparing the transport resistance and per-formance under the fl ooding condition.The simulation results show that gradient porosity GDL helps to increase the reactive area and average concentration under fl ooding.The presence of the MPL ensures the oxygen transport space and reaction area because liquid water cannot transport through micropores.Moreover,the MPL helps in the uniform distribution of oxygen for an effi cient in-plane transport capacity.Crack and perforation structures can accelerate the water transport in the assembly.The systematic perforation design yields the best performance under fl ooding by separating the transport of liquid water and oxygen. 展开更多
关键词 Proton exchange membrane fuel cell Lattice Boltzmann model ELECTRODE Water management Two-phase fl ow Reactive transport
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Development of advanced anion exchange membrane from the view of the performance of water electrolysis cell 被引量:2
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作者 Chao Liu Zhen Geng +6 位作者 Xukang Wang Wendong Liu Yuwei Wang Qihan Xia Wenbo Li Liming Jin Cunman Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期348-369,I0009,共23页
Green hydrogen produced by water electrolysis combined with renewable energy is a promising alternative to fossil fuels due to its high energy density with zero-carbon emissions.Among water electrolysis technologies,t... Green hydrogen produced by water electrolysis combined with renewable energy is a promising alternative to fossil fuels due to its high energy density with zero-carbon emissions.Among water electrolysis technologies,the anion exchange membrane(AEM) water electrolysis has gained intensive attention and is considered as the next-generation emerging technology due to its potential advantages,such as the use of low-cost non-noble metal catalysts,the relatively mature stack assembly process,etc.However,the AEM water electrolyzer is still in the early development stage of the kW-level stack,which is mainly attributed to severe performance decay caused by the core component,i.e.,AEM.Here,the review comprehensively presents the recent progress of advanced AEM from the view of the performance of water electrolysis cells.Herein,fundamental principles and critical components of AEM water electrolyzers are introduced,and work conditions of AEM water electrolyzers and AEM performance improvement strategies are discussed.The challenges and perspectives are also analyzed. 展开更多
关键词 HYDROGEN Water electrolysis Anion exchange membrane Electrolysis cell
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Proton‑Prompted Ligand Exchange to Achieve High‑Efficiency CsPbI_(3) Quantum Dot Light‑Emitting Diodes 被引量:1
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作者 Yanming Li Ming Deng +2 位作者 Xuanyu Zhang Lei Qian Chaoyu Xiang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第6期53-62,共10页
CsPbI_(3)perovskite quantum dots(QDs)are ideal materials for the next generation of red light-emitting diodes.However,the low phase stability of CsPbI_(3)QDs and long-chain insulating capping ligands hinder the improv... CsPbI_(3)perovskite quantum dots(QDs)are ideal materials for the next generation of red light-emitting diodes.However,the low phase stability of CsPbI_(3)QDs and long-chain insulating capping ligands hinder the improvement of device performance.Traditional in-situ ligand replacement and ligand exchange after synthesis were often difficult to control.Here,we proposed a new ligand exchange strategy using a proton-prompted insitu exchange of short 5-aminopentanoic acid ligands with long-chain oleic acid and oleylamine ligands to obtain stable small-size CsPbI_(3)QDs.This exchange strategy maintained the size and morphology of CsPbI_(3)QDs and improved the optical properties and the conductivity of CsPbI_(3)QDs films.As a result,high-efficiency red QD-based light-emitting diodes with an emission wavelength of 645 nm demonstrated a record maximum external quantum efficiency of 24.45%and an operational half-life of 10.79 h. 展开更多
关键词 CsPbI_(3) perovskite quantum dots Light-emitting diodes Ligand exchange Proton-prompted in-situ exchange
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Solar wind ion charge state distributions and compound cross sections for solar wind charge exchange X-ray emission 被引量:1
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作者 Dimitra Koutroumpa 《Earth and Planetary Physics》 EI CSCD 2024年第1期105-118,共14页
Solar Wind Charge eXchange X-ray(SWCX) emission in the heliosphere and Ea rth’s exosphere is a hard to avoid signal in soft Xray obse rvations of astrophysical targets.On the other hand,the X-ray imaging possibilitie... Solar Wind Charge eXchange X-ray(SWCX) emission in the heliosphere and Ea rth’s exosphere is a hard to avoid signal in soft Xray obse rvations of astrophysical targets.On the other hand,the X-ray imaging possibilities offered by the SWCX process has led to an increasing number of future dedicated space missions for investigating the solar wind-terrestrial inte ractions and magnetospheric interfaces.In both cases,accurate modelling of the SWCX emission is key to correctly interpret its signal,and remove it from obse rvations,when needed.In this paper,we compile solar wind abundance measurements from ACE for different solar wind types,and atomic data from literature,including charge exchange cross-sections and emission probabilities,used fo r calculating the compound cross-section a for the SWCX X-ray emission.We calculate a values for charge-exchange with H and He,relevant to soft X-ray energy bands(0.1-2.0 keV)for various solar wind types and solar cycle conditions. 展开更多
关键词 solar wind charge exchange X-rays MAGNETOSPHERE HELIOSPHERE
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Two methods for separating the magnetospheric solar wind charge exchange soft X-ray emission from the diffuse X-ray background 被引量:2
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作者 YingJie Zhang TianRan Sun +5 位作者 JenniferACarter WenHao Liu Steve Sembay ShuiNai Zhang Li Ji Chi Wang 《Earth and Planetary Physics》 EI CSCD 2024年第1期119-132,共14页
Solar wind charge exchange(SWCX)is the process of solar wind high-valence ions exchanging charges with neutral components and generating soft X-rays.Recently,detecting the SWCX emission from the magnetosphere is propo... Solar wind charge exchange(SWCX)is the process of solar wind high-valence ions exchanging charges with neutral components and generating soft X-rays.Recently,detecting the SWCX emission from the magnetosphere is proposed as a new technique to study the magnetosphere using panoramic soft X-ray imaging.To better prepare for the data analysis of upcoming magnetospheric soft X-ray imaging missions,this paper compares the magnetospheric SWCX emission obtained by two methods in an XMM-Newton observation,during which the solar wind changed dramatically.The two methods differ in the data used to fit the diffuse X-ray background(DXB)parameters in spectral analysis.The method adding data from the ROSAT All-Sky Survey(RASS)is called the RASS method.The method using the quiet observation data is called the Quiet method,where quiet observations usually refer to observations made by the same satellite with the same target but under weaker solar wind conditions.Results show that the spectral compositions of magnetospheric SWCX emission obtained by the two methods are very similar,and the changes in intensity over time are highly consistent,although the intensity obtained by the RASS method is about 2.68±0.56 keV cm^(-2)s^(-1)sr^(-1)higher than that obtained by the Quiet method.Since the DXB intensity obtained by the RASS method is about 2.84±0.74 keV cm^(-2)s^(-1)sr^(-1)lower than that obtained by the Quiet method,and the linear correlation coefficient between the difference of SWCX and DXB obtained by the two methods in diffe rent energy band is close to-1,the diffe rences in magnetospheric SWCX can be fully attributed to the diffe rences in the fitted DXB.The difference between the two methods is most significant when the energy is less than 0.7 keV,which is also the main energy band of SWCX emission.In addition,the difference between the two methods is not related to the SWCX intensity and,to some extent,to solar wind conditions,because SWCX intensity typically va ries with the solar wind.In summary,both methods are robust and reliable,and should be considered based on the best available options. 展开更多
关键词 solar wind charge exchange(SWCX) ROSAT All-Sky Survey(RASS) soft X-ray X-ray imaging MAGNETOSPHERE
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Effects of drip and flood irrigation on carbon dioxide exchange and crop growth in the maize ecosystem in the Hetao Irrigation District,China 被引量:1
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作者 LI Chaoqun HAN Wenting PENG Manman 《Journal of Arid Land》 SCIE CSCD 2024年第2期282-297,共16页
Drip irrigation and flood irrigation are major irrigation methods for maize crops in the Hetao Irrigation District,Inner Mongolia Autonomous Region,China.This research delves into the effects of these irrigation metho... Drip irrigation and flood irrigation are major irrigation methods for maize crops in the Hetao Irrigation District,Inner Mongolia Autonomous Region,China.This research delves into the effects of these irrigation methods on carbon dioxide(CO_(2))exchange and crop growth in this region.The experimental site was divided into drip and flood irrigation zones.The irrigation schedules of this study aligned with the local commonly used irrigation schedule.We employed a developed chamber system to measure the diurnal CO_(2)exchange of maize plants during various growth stages under both drip and flood irrigation methods.From May to September in 2020 and 2021,two sets of repeated experiments were conducted.In each experiment,a total of nine measurements of CO_(2)exchange were performed to obtain carbon exchange data at different growth stages of maize crop.During each CO_(2)exchange measurement event,CO_(2)flux data were collected every two hours over a day-long period to capture the diurnal variations in CO_(2)exchange.During each CO_(2)exchange measurement event,the biological parameters(aboveground biomass and crop growth rate)of maize and environmental parameters(including air humidity,air temperature,precipitation,soil water content,and photosynthetically active radiation)were measured.The results indicated a V-shaped trend in net ecosystem CO_(2)exchange in daytime,reducing slowly at night,while the net assimilation rate(net primary productivity)exhibited a contrasting trend.Notably,compared with flood irrigation,drip irrigation demonstrated significantly higher average daily soil CO_(2)emission and greater average daily CO_(2)absorption by maize plants.Consequently,within the maize ecosystem,drip irrigation appeared more conducive to absorbing atmospheric CO_(2).Furthermore,drip irrigation demonstrated a faster crop growth rate and increased aboveground biomass compared with flood irrigation.A strong linear relationship existed between leaf area index and light utilization efficiency,irrespective of the irrigation method.Notably,drip irrigation displayed superior light use efficiency compared with flood irrigation.The final yield results corroborated these findings,indicating that drip irrigation yielded higher harvest index and overall yield than flood irrigation.The results of this study provide a basis for the selection of optimal irrigation methods commonly used in the Hetao Irrigation District.This research also serves as a reference for future irrigation studies that consider measurements of both carbon emissions and yield simultaneously. 展开更多
关键词 carbon dioxide exchange maize growth drip irrigation harvest index net primary productivity Hetao Irrigation District
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Defective layered Mn-based cathode materials with excellent performance via ion exchange for Li-ion batteries
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作者 Yongheng Si Kun Bai +4 位作者 Yaxin Wang Han Lu Litong Liu Ziyan Long Yujuan Zhao 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第7期537-546,I0012,共11页
Defective layered Mn-based materials were synthesized by Li/Na ion exchange to improve their electrochemical activity and Coulombic efficiency.The annealing temperature of the Na precursors was important to control th... Defective layered Mn-based materials were synthesized by Li/Na ion exchange to improve their electrochemical activity and Coulombic efficiency.The annealing temperature of the Na precursors was important to control the P3-P2 phase transition,which directly affected the structure and electrochemical characteristics of the final products obtained by ion exchange.The O3-Li_(0.78)[Li_(0.25)Fe_(0.075)Mn_(0.675)]O_(δ) cathode made from a P3-type precursor calcined at 700℃ was analyzed using X-ray photoelectron spectrometry and electron paramagnetic resonance.The results showed that the presence of abundant trivalent manganese and defects resulted in a discharge capacity of 230 mAh/g with an initial Coulombic efficiency of about 109%.Afterward,galvanostatic intermittent titration was performed to examine the Li^(+) ion diffusion coefficients,which affected the reversible capacity.First principles calculations suggested that the charge redistribution induced by oxygen vacancies(OV_(s))greatly affected the local Mn coordination environment and enhanced the structural activity.Moreover,the Li-deficient cathode was a perfect match for the pre-lithiation anode,providing a novel approach to improve the initial Coulombic efficiency and activity of Mn-based materials in the commercial application. 展开更多
关键词 Ion exchange Defective cathode materials Oxygen vacancies Initial coulombic efficiency DFT calculations
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CFD-Based Optimization of a Shell-and-Tube Heat Exchanger
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作者 Juanjuan Wang Jiangping Nan Yanan Wang 《Fluid Dynamics & Materials Processing》 EI 2023年第11期2761-2775,共15页
The main objective of this study is the technical optimization of a Shell-and-Tube Heat Exchanger(STHE).In order to do so,a simulation model is introduced that takes into account the related gas-phase circulation.Then... The main objective of this study is the technical optimization of a Shell-and-Tube Heat Exchanger(STHE).In order to do so,a simulation model is introduced that takes into account the related gas-phase circulation.Then,simulation verification experiments are designed in order to validate the model.The results show that the tem-peraturefield undergoes strong variations in time when an inlet wind speed of 6 m/s is considered,while the heat transfer error reaches a minimum of 5.1%.For an inlet velocity of 9 m/s,the heat transfer drops to the lowest point,while the heat transfer error reaches a maximum,i.e.,9.87%.The pressure drop increasesfirst and then decreases with an increase in the wind speed and reaches a maximum of 819 Pa under the 9 m/s wind speed con-dition.Moreover,the pressure drops,and the heat transfer coefficient increases with the Reynolds number. 展开更多
关键词 Heat exchanger AERODYNAMICS engineeringfluid mechanics TUBE heat transmission heat transfer model numerical simulation
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Influence of initial check, information exchange, final accuracy check, reaction information nursing on the psychology of elderly with lung cancer 被引量:2
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作者 Cui Jiang Jing Ma +1 位作者 Wen He Hai-Ying Zhang 《World Journal of Clinical Cases》 SCIE 2024年第4期737-745,共9页
BACKGROUND As one of the fatal diseases with high incidence,lung cancer has seriously endangered public health and safety.Elderly patients usually have poor self-care and are more likely to show a series of psychologi... BACKGROUND As one of the fatal diseases with high incidence,lung cancer has seriously endangered public health and safety.Elderly patients usually have poor self-care and are more likely to show a series of psychological problems.AIM To investigate the effectiveness of the initial check,information exchange,final accuracy check,reaction(IIFAR)information care model on the mental health status of elderly patients with lung cancer.METHODS This study is a single-centre study.We randomly recruited 60 elderly patients with lung cancer who attended our hospital from January 2021 to January 2022.These elderly patients with lung cancer were randomly divided into two groups,with the control group taking the conventional propaganda and education and the observation group taking the IIFAR information care model based on the conventional care protocol.The differences in psychological distress,anxiety and depression,life quality,fatigue,and the locus of control in psychology were compared between these two groups,and the causes of psychological distress were analyzed.RESULTS After the intervention,Distress Thermometer,Hospital Anxiety and Depression Scale(HADS)for anxiety and the HADS for depression,Revised Piper’s Fatigue Scale,and Chance Health Locus of Control scores were lower in the observation group compared to the pre-intervention period in the same group and were significantly lower in the observation group compared to those of the control group(P<0.05).After the intervention,Quality of Life Questionnaire Core 30(QLQ-C30),Internal Health Locus of Control,and Powerful Others Health Locus of Control scores were significantly higher in the observation and the control groups compared to the pre-intervention period in their same group,and QLQ-C30 scores were significantly higher in the observation group compared to those of the control group(P<0.05).CONCLUSION The IIFAR information care model can help elderly patients with lung cancer by reducing their anxiety and depression,psychological distress,and fatigue,improving their tendencies on the locus of control in psychology,and enhancing their life qualities. 展开更多
关键词 Initial check information exchange final accuracy check reaction information care model Lung cancer Mental health
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EBAKE-SE: A novel ECC-based authenticated key exchange between industrial IoT devices using secure element
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作者 Chintan Patel Ali Kashif Bashir +1 位作者 Ahmad Ali AlZubi Rutvij Jhaveri 《Digital Communications and Networks》 SCIE CSCD 2023年第2期358-366,共9页
Industrial IoT(IIoT)aims to enhance services provided by various industries,such as manufacturing and product processing.IIoT suffers from various challenges,and security is one of the key challenge among those challe... Industrial IoT(IIoT)aims to enhance services provided by various industries,such as manufacturing and product processing.IIoT suffers from various challenges,and security is one of the key challenge among those challenges.Authentication and access control are two notable challenges for any IIoT based industrial deployment.Any IoT based Industry 4.0 enterprise designs networks between hundreds of tiny devices such as sensors,actuators,fog devices and gateways.Thus,articulating a secure authentication protocol between sensing devices or a sensing device and user devices is an essential step in IoT security.In this paper,first,we present cryptanalysis for the certificate-based scheme proposed for a similar environment by Das et al.and prove that their scheme is vulnerable to various traditional attacks such as device anonymity,MITM,and DoS.We then put forward an interdevice authentication scheme using an ECC(Elliptic Curve Cryptography)that is highly secure and lightweight compared to other existing schemes for a similar environment.Furthermore,we set forth a formal security analysis using the random oracle-based ROR model and informal security analysis over the Doleve-Yao channel.In this paper,we present comparison of the proposed scheme with existing schemes based on communication cost,computation cost and security index to prove that the proposed EBAKE-SE is highly efficient,reliable,and trustworthy compared to other existing schemes for an inter-device authentication.At long last,we present an implementation for the proposed EBAKE-SE using MQTT protocol. 展开更多
关键词 Internet of things AUTHENTICATION Elliptic curve cryptography Secure key exchange Message Queuing telemetry transport
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铒镱共掺光纤放大器中ASE对激光线宽的影响研究
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作者 杜沅朋 王蓟 +1 位作者 宋华溢 夏敬华 《应用物理》 2024年第3期115-122,共8页
本文基于MOPA结构搭建了铒镱共掺光纤放大系统,通过对光纤放大器的线宽和光谱特性进行测量与分析,研究了光纤放大器中放大的自发辐射(ASE)对激光器线宽的影响。分析表明,在光纤放大器中,ASE作为噪声会引起激光线宽展宽,且呈现出正相关... 本文基于MOPA结构搭建了铒镱共掺光纤放大系统,通过对光纤放大器的线宽和光谱特性进行测量与分析,研究了光纤放大器中放大的自发辐射(ASE)对激光器线宽的影响。分析表明,在光纤放大器中,ASE作为噪声会引起激光线宽展宽,且呈现出正相关的特性。 展开更多
关键词 铒镱光纤放大器 窄线宽 ase 延时自外差法干涉仪
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A Machine Learning-Based Distributed Denial of Service Detection Approach for Early Warning in Internet Exchange Points
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作者 Salem Alhayani Diane R.Murphy 《Computers, Materials & Continua》 SCIE EI 2023年第8期2235-2259,共25页
The Internet service provider(ISP)is the heart of any country’s Internet infrastructure and plays an important role in connecting to theWorld WideWeb.Internet exchange point(IXP)allows the interconnection of two or m... The Internet service provider(ISP)is the heart of any country’s Internet infrastructure and plays an important role in connecting to theWorld WideWeb.Internet exchange point(IXP)allows the interconnection of two or more separate network infrastructures.All Internet traffic entering a country should pass through its IXP.Thus,it is an ideal location for performing malicious traffic analysis.Distributed denial of service(DDoS)attacks are becoming a more serious daily threat.Malicious actors in DDoS attacks control numerous infected machines known as botnets.Botnets are used to send numerous fake requests to overwhelm the resources of victims and make them unavailable for some periods.To date,such attacks present a major devastating security threat on the Internet.This paper proposes an effective and efficient machine learning(ML)-based DDoS detection approach for the early warning and protection of the Saudi Arabia Internet exchange point(SAIXP)platform.The effectiveness and efficiency of the proposed approach are verified by selecting an accurate ML method with a small number of input features.A chi-square method is used for feature selection because it is easier to compute than other methods,and it does not require any assumption about feature distribution values.Several ML methods are assessed using holdout and 10-fold tests on a public large-size dataset.The experiments showed that the performance of the decision tree(DT)classifier achieved a high accuracy result(99.98%)with a small number of features(10 features).The experimental results confirmthe applicability of using DT and chi-square for DDoS detection and early warning in SAIXP. 展开更多
关键词 Internet exchange point Saudi Arabia IXP(SAIXP) distributed denial of service CHI-SQUARE feature selection machine learning
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Spin wave resonance frequency in bilayer ferromagnetic films with the biquadratic exchange interaction
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作者 Xiaojie Zhang Yuting Wang +3 位作者 Yanqiu Chang Huan Wang Jianhong Rong Guohong Yun 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期607-613,共7页
The dependences of spin wave resonance(SWR)frequency on the surface anisotropy field,interface exchange coupling,symmetry,biquadratic exchange(BQE)interaction,film thickness,and the external magnetic field in bilayer ... The dependences of spin wave resonance(SWR)frequency on the surface anisotropy field,interface exchange coupling,symmetry,biquadratic exchange(BQE)interaction,film thickness,and the external magnetic field in bilayer ferromagnetic films are theoretically analyzed by employing the linear spin wave approximation and Green’s function method.A remarkable increase of SWR frequency,except for energetically lower two modes,can be obtained in our model that takes the BQE interaction into account.Again,the effect of the external magnetic field on SWR frequency can be increased by increasing the biquadratic to interlayer exchange ratio.It has been identified that the BQE interaction is of utmost importance in improving the SWR frequency of the bilayer ferromagnetic films.In addition,for bilayer ferromagnetic films,the frequency gap between the energetically highest mode and lowest mode is found to increase by increasing the biquadratic to interlayer exchange ratio and film thickness and destroying the symmetry of the system.These results can be used to improve the understanding of magnetic properties in bilayer ferromagnetic films and thus may have prominent implications for future magnetic devices. 展开更多
关键词 spin wave resonance frequency biquadratic exchange interaction interface exchange coupling surface anisotropy
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