According to international standard plant quarantine measures and principle risk analysis(ISPM No.11),a risk assessment was carried out for Passalora sequoiae through geographical distribution,possibility of colonizat...According to international standard plant quarantine measures and principle risk analysis(ISPM No.11),a risk assessment was carried out for Passalora sequoiae through geographical distribution,possibility of colonization,probability of diffusion,economic importance and difficulty in risk management.Results show that P.sequoiae has a greater risk of introduction and diffusion,and it has distributed in parts of China.It is suggested that P.sequoiae should be added to the list of forest dangerous pests in China.Besides,porting departments should focus on the pathogen on imported host seedlings like Cryptomeria.展开更多
With the advancement of the construction of emerging engineering education,the reform of practical teaching has become an important task of higher engineering education.This article takes the course“Linux Operating S...With the advancement of the construction of emerging engineering education,the reform of practical teaching has become an important task of higher engineering education.This article takes the course“Linux Operating System Fundamentals”as an example to explore practical teaching reform in the context of emerging engineering education.By analyzing the current situation and problems in course practical teaching,we proposed practical teaching reforms such as online experiments,practical content updates,project-based engineering practices,and diversified evaluation models,and designed corresponding implementation plans.Practice has proved that this reform can improve students’learning interest and engineering practical skills,and cultivate outstanding engineers with innovative spirit and practical skills.展开更多
To obtain high-performance lithium-sulfur(Li-S)batteries,it is necessary to rationally design electrocatalytic materials that can promote efficient sulfur electrochemical reactions.Herein,the robust heterostructured m...To obtain high-performance lithium-sulfur(Li-S)batteries,it is necessary to rationally design electrocatalytic materials that can promote efficient sulfur electrochemical reactions.Herein,the robust heterostructured material of nanoscale transition metal anchored on perovskite oxide was designed for efficient catalytic kinetics of the oxidation and reduction reactions of lithium polysulphide(Li PSs),and verified by density functional theory(DFT)calculations and experimental characterizations.Due to the strong interaction of nanoscale transition metals with Li PSs through chemical coupling,heterostructured materials(STO@M)(M=Fe,Ni,Cu)exhibit excellent catalytic activity for redox reactions of Li PSs.The bifunctional heterostructure material STO@Fe exhibits good rate performance and cycling stability as the cathode host,realizing a high-performance Li-S battery that can maintain stable cycling under rapid charge-discharge cycling.This study presents a novel approach to designing electrocatalytic materials for redox reactions of Li PSs,which promotes the development of fast charge-discharge Li-S batteries.展开更多
Carbon-fueled solid oxide fuel cells(CF-SOFCs)can electrochemically convert the chemical energy in carbon into electricity,which demonstrate both superior electrical efficiency and fuel utilisation compared to all oth...Carbon-fueled solid oxide fuel cells(CF-SOFCs)can electrochemically convert the chemical energy in carbon into electricity,which demonstrate both superior electrical efficiency and fuel utilisation compared to all other types of fuel cells.However,using solid carbon as the fuel of SOFCs also faces some challenges,the fluid mobility and reactive activity of carbon-based fuels are much lower than those of gaseous fuels.Therefore,the anode reaction kinetics plays a crucial role in determining the electrochemical performance of CF-SOFCs.Herein,the progress of various anodes in CF-SOFCs is reviewed from the perspective of material compositions,electrochemical performance and microstructures.Challenges faced in developing high performance anodes for CF-SOFCs are also discussed.展开更多
Variable gauge rolling is a new process to obtain a plate for which the thickness changes continuously by continuously and dynamically adjusting the roll gap upward and downward in the rolling process.This technology ...Variable gauge rolling is a new process to obtain a plate for which the thickness changes continuously by continuously and dynamically adjusting the roll gap upward and downward in the rolling process.This technology is an efective method for producing lightweight,low-cost,and economical plates.However,variable gauge rolling is an unsteady process,and the changes in the force and deformation parameters are complex.In this research,based on the minimum energy theory of the variational principle and considering the characteristics of the roll movement and workpiece deformation comprehensively,the internal plastic deformation,friction,shear and tension powers,and the minimum result of the total power functional in upward and downward rolling are obtained with the frst integral and then with a variation of adopting the specifc plastic power and strain rate vector inner product.The analytical results of the deformation and force parameters are also established using the variational method.Then the precision of this model is certifed using the measured values in a medium plate hot rolling plant and the experimental data for Tailor Rolled Blank rolling.Good agreement is found.Additionally,the variation rule of bite angle,neutral angle,and location neutral points are shown,and the change mechanism of the friction parameter on the stress state efect coefcient is given in variable gauge rolling.This research proposes a new mathematical model for rolling process control that provides a scientifc basis and technical support for obtaining an accurate section shape in variable gauge rolling production.展开更多
This paper studies the consensus problem for discrete-time multi-agent systems of first-order in the presence of constant communication delay. Provided that the agent dynamics is unstable and the network topology is u...This paper studies the consensus problem for discrete-time multi-agent systems of first-order in the presence of constant communication delay. Provided that the agent dynamics is unstable and the network topology is undirected, effects of two kinds of communication delays on consensus are investigated.When the relative information is affected by delay, we show that the effect of delay can be alleviated by using the historical input information in the protocol design. On the other hand, if the communication delay only influences the actually transmitted information, sufficient condition admitting any large yet bounded delay for consensus is obtained, and the delay in this case is allowed to be unknown and time-varying. Finally, simulation results are provided to demonstrate the effectiveness of the theoretical results.展开更多
The problem of the robust fault detection filter design for time-varying delays switched systems is considered in the framework of mixed H_-/H_∞. Firstly, the weighted H_∞ performance index is utilized as the robust...The problem of the robust fault detection filter design for time-varying delays switched systems is considered in the framework of mixed H_-/H_∞. Firstly, the weighted H_∞ performance index is utilized as the robustness performance, and the H_- index is used as the sensitivity performance for obtaining the robust fault detection filter. Then a novel multiple Lyapunov-Krasovskii function is proposed for deriving sufficient existence conditions of the robust fault detection filter based on the average dwell time technique. By introducing slack matrix variable, the coupling between the Lyapunov matrix and system matrix is removed, and the conservatism of results is reduced. Based on the robust fault detection filter, residual is generated and evaluated for detecting faults. In addition, the results of this paper are dependent on time delays,and represented in the form of linear matrix inequalities. Finally,the simulation example verifies the effectiveness of the proposed method.展开更多
Lithium(Li) metal,possessing ultrahigh theoretical capacity and the lowest electrode potential,is regarded as a promising new generation anode material.However,the uncontrollable growth of Li dendrites during cycling ...Lithium(Li) metal,possessing ultrahigh theoretical capacity and the lowest electrode potential,is regarded as a promising new generation anode material.However,the uncontrollable growth of Li dendrites during cycling process gives rise to problems as capacity decay and short circuit,suppressing the cycling and safety performances of Li metal battery.In this contribution,porous conductive interlayer(PCI),composed of carbon nanofibers(CNFs) and polyisophthaloyl metaphenylene diamine(PMIA),is developed to suppress Li dendrites and stabilize Li metal anode.PCI possesses the excellent conductive ability of CNFs and the preeminent mechanical properties of PMIA at the same time.When Li metal contacts with PCI during cycling process,an equipotential surface forms on their interface,which eliminates the tip effect on Li anode and homogenizes Li-ions flux in combination with the uniform porous structure of PCI.Employed PCI,the Li|Cu cell exhibits a remarkable cycling stability with a high average Coulombic efficiency of 97.5% for 100 cycles at 0.5 mA cm^(-2).And the Li|LiFePO_4 cell exhibits improved rate capability(114.7 mAh g^(-1) at 5.0 C) and enhanced cycling performance(78.9% capacity retention rate over 500 cycles at 1.0 C).This work provides a fresh and effective solving strategy for the problem of dendrites in Li metal battery.展开更多
Firstly,the distribution of main biomass resources(like straw,livestock manure and forestry residue) in counties of Jilin Province,and then according to the annual output of biomass in each county,the energy regenerat...Firstly,the distribution of main biomass resources(like straw,livestock manure and forestry residue) in counties of Jilin Province,and then according to the annual output of biomass in each county,the energy regeneration of biomass and project distribution of organic fertilizer were studied,finally the direct economic effect and environmental effect of biomass developed recently were calculated.展开更多
While lithium-sulfur(Li-S)battery has attracted remarkable attention owing to the high theoretical capacity,its practical application is still hindered by the shuttle and sluggish conversion kinetics of intermediate l...While lithium-sulfur(Li-S)battery has attracted remarkable attention owing to the high theoretical capacity,its practical application is still hindered by the shuttle and sluggish conversion kinetics of intermediate lithium polysulfides(Li PSs).Defect engineering,which can regulate the electronic structure and in turn influence the surface adsorption and catalytic capability,has been regarded as a feasible strategy to deal with the above challenges.However,few studies on nitrogen vacancies and their mechanisms are reported.Herein,cobalt nitride with nitrogen vacancies grown on multi-walled carbon nanotube(CNTCo N-VN)is designed and applied as the separator modification material to investigate the enhancing mechanism of nitrogen vacancies on Li-S batteries.The experimental evidence and theoretical calculation indicate that the introduction of nitrogen vacancies into cobalt nitride can enhance the chemical affinity to Li PSs and effectively hamper the shuttle effect.Meanwhile the reduced band gap of the d-band center of Co and p-band center of N for CNT-Co N-VNand the promoted diffusion of Li^(+) can expedite the solid-liquid and liquid-liquid conversions of sulfur species.Due to these superiorities,the cell with CNT-Co NVNmodified separator delivers a favorable initial capacity of 901 m Ah g^(-1)and a capacity of 660 m Ah g^(-1)can be achieved after 250 cycles at 2 C.This work explores the application of metal nitride with nitrogen vacancies and sheds light on the development of functional separators for high-efficient Li-S batteries.展开更多
[Objective] This study aimed to map quantitative tarit loci (QTLs) associated with salt tolerance of maize inbred line at seedling stage. [Method] The recombinant inbred line (RIL) F7 including 171 plants were develop...[Objective] This study aimed to map quantitative tarit loci (QTLs) associated with salt tolerance of maize inbred line at seedling stage. [Method] The recombinant inbred line (RIL) F7 including 171 plants were developed by single seed descent procedure from a combination, Huangzaosi×Mo17, and used to map QTLs associated with salt tolerance, based on the constructed genetic map of SSR markers. [Result]A linkage map consisting of 81 SSR markers loci from 10 chromosomes (1 428.3 cM in total length, with an average distance of 17.63 cM between two neighbouring loci) was constructed. Six QTLs associated significantly with salt tolerance were detected at chromosomes 1, 5 and 6. [Conclusion] This study is extremely significant for better understanding salt tolerance-related genes, the genes' location and cloning, salt tolerance mechanism and the marker-assisted selection of salt tolerant maize.展开更多
Proton conducting solid oxide fuel cell(H-SOFC)is an emerging energy conversion device,with lower activation energy and higher energy utilization efficiency.However,the deficiency of highly active cathode materials st...Proton conducting solid oxide fuel cell(H-SOFC)is an emerging energy conversion device,with lower activation energy and higher energy utilization efficiency.However,the deficiency of highly active cathode materials still remains a major challenge for the development of H-SOFC.Therefore,in this work,K_(2)NiF_(4)-type cathode materials Pr_(2-x)Ba_(x)Ni_(0.6)Cu_(0.4)O_(4+δ)(x=0,0.1,0.2,0.3),single-phase tripleconducting(e-/O^(2-)/H^(+))oxides,are prepared for intermediate temperature H-SOFCs and exhibit good oxygen reduction reaction activity.The investigation demonstrates that doping Ba into Pr_(2-x)BaxNi_(0.6)Cu_(0.4)O_(4+δ) can increase its electrochemical performance through enhancing electrical conductivity,oxygen vacancy concentration and proton conductivity.EIS tests are carried at 750℃ and the minimum polarization impedances are obtained when x=0.2,which are 0.068 Ω·cm^(2) in air and 1.336 Ω·cm^(2) in wet argon,respectively.The peak power density of the cell with Pr_(1.8)Ba_(0.2)Ni_(0.6)Cu_(0.4)O_(4+δ) cathode is 298 mW·cm^(-2) at 750℃ in air with humidified hydrogen as fuel.Based on the above results,Ba-doped Pr_(2-x)Ba_(x)Ni_(0.6)Cu_(0.4)O_(4+δ) can be a good candidate material for SOFC cathode applications.展开更多
OBJECTIVE There is a close correlation between interleukin-6 (IL-6) and malignant proliferation of gliomas. We investigated the effect of bradykinin on the expression of IL-6 in C6 glioma cells. METHODS Semi-quantitiv...OBJECTIVE There is a close correlation between interleukin-6 (IL-6) and malignant proliferation of gliomas. We investigated the effect of bradykinin on the expression of IL-6 in C6 glioma cells. METHODS Semi-quantitive RT-PCR and radioimmunoassay were used to examine the effect of bradykinin on the expression of IL-6 in C6 glioma cells and on the level of IL-6 in the culture medium. RESULTS Using semi-quantitive RT-PCR , the expression of IL-6 mRNA was examined in C6 glioma cells at 0, 5, 10,15, 30, 60 min following addition of 1 μmol/L bradykinin. There was no statistical difference in expression of IL-6 mRNA between the treatment and control groups (P>0.05) and IL-6 was not detected in the cell culture medium. CONCLUSION Within an hour, IL-6 expression in C6 glioma cells is not induced by bradykinin, suggesting that its clinical application may be useful as a potential therapeutic agent for tumors of the central nervous system.展开更多
The rapid development of information technology and the new economy is a challenge to the training of computer technology and engineering professionals. The cultivation of engineering talents in Computer Engineering u...The rapid development of information technology and the new economy is a challenge to the training of computer technology and engineering professionals. The cultivation of engineering talents in Computer Engineering under the new engineering is an important part of the construction and exploration of new engineering in universities. According to the teaching reform of computer specialty in the new engineering construction, starting from the practice of curriculum system of software, mainly discusses the basic ideas of practice teaching reform of the course of computer software, software engineering practice curriculum system and practice curriculum system implementation method. The basic ideas of teaching reform practice in the course of the software include: expanding computer professional students' knowledge, strengthening students' computer science and software engineering knowledge and engineering practice ability, strengthening the frontiers of computer science and technology guide. Software practice course system is divided into three levels, including basic language course, engineering basic professional practice course and the professional practice course of engineering application direction. The implementation method of engineering application practice curriculum system is discussed in detail, such as strengthening university-enterprise cooperation, introducing teachers of social training institutions and guiding students to participate in subject competition and innovation projects.展开更多
Big data are always processed repeatedly with small changes, which is a major form of big data processing. The feature of incremental change of big data shows that incremental computing mode can improve the performanc...Big data are always processed repeatedly with small changes, which is a major form of big data processing. The feature of incremental change of big data shows that incremental computing mode can improve the performance greatly. HDFS is a distributed file system on Hadoop which is the most popular platform for big data analytics. And HDFS adopts fixed-size chunking policy, which is inefficient facing incremental computing. Therefore, in this paper, we proposed iHDFS (incremental HDFS), a distributed file system, which can provide basic guarantee for big data parallel processing. The iHDFS is implemented as an extension to HDFS. In iHDFS, Rabin fingerprint algorithm is applied to achieve content defined chunking. This policy make data chunking has much higher stability, and the intermediate processing results can be reused efficiently, so the performance of incremental data processing can be improved significantly. The effectiveness and efficiency of iHDFS have been demonstrated by the experimental results.展开更多
Lithium-sulfur batteries as one of the most promising next-generation high-energy storage system, the shuttle effect, the expansion of cathode and the slow electrode redox kinetics limit its further development. Herei...Lithium-sulfur batteries as one of the most promising next-generation high-energy storage system, the shuttle effect, the expansion of cathode and the slow electrode redox kinetics limit its further development. Herein, we report a two-dimensional, ultrathin and ultra-light bimetal-Ni Co-organic framework as the interlayer for Li-S batteries. This kind of interlayer can effectively block polysulfides and accelerate the conversion with a thickness of only 1 μm and a load of 0.1 mg/cm^(2). Because the MOF nanosheets with a thickness of a few nanometers have a large specific surface and a large number of exposed accessible active sites. At the same time, the intrinsic activity of each site is enhanced and the catalytic performance is improved due to the synergistic effect of mixed metals and the unique coordination environment around the active sites. So, 2D NiCo MOF/CNT totally meets the requirements for the lightweight and effective interlayer. The initial discharge capacity of cell with 2D NiCo MOF/CNT interlayer can reach 1132.7 m Ah/g at 0.5 C. It remained 709.1 m Ah/g after 300 cycles, showing good cycling stability and rate performance.展开更多
The sluggish conversion kinetics and shuttle effect of lithium polysulfides(LiPSs)severely hamper the commercialization of lithium-sulfur batteries.Numerous electrocatalysts have been used to address these issues,amon...The sluggish conversion kinetics and shuttle effect of lithium polysulfides(LiPSs)severely hamper the commercialization of lithium-sulfur batteries.Numerous electrocatalysts have been used to address these issues,amongst which,transition metal dichalcogenides have shown excellent catalytic performance in the study of lithium-sulfur batteries.Note that dichalcogenides in different phases have different catalytic properties,and such catalytic materials in different phases have a prominent impact on the performance of lithium-sulfur batteries.Herein,1T-phase rich MoSe_(2)(T-MoSe_(2))nanosheets are synthesized and used to catalyze the conversion of LiPSs.Compared with the 2H-phase rich MoSe_(2)(H-MoSe_(2))nanosheets,the T-MoSe_(2) nanosheets significantly accelerate the liquid phase transformation of LiPSs and the nucleation process of Li2S.In-situ Raman and X-ray photoelectron spectroscopy(XPS)find that T-MoSe_(2) effectively captures LiPSs through the formation of Mo-S and Li-Se bonds,and simultaneously achieves fast catalytic conversion of LiPSs.The lithium-sulfur batteries with T-MoSe_(2) functionalized separators display a fantastic rate performance of 770.1 mAh/g at 3 C and wonderful cycling stability,with a capacity decay rate as low as 0.065%during 400 cycles at 1 C.This work offers a novel perspective for the rational design of selenide electrocatalysts in lithium-sulfur chemistry.展开更多
Reversible protonic ceramic cells(RPCCs) show great potential as new-generation energy conversion and storage devices. However, the mature development of RPCCs is seriously hindered by the inactivity and poor stabilit...Reversible protonic ceramic cells(RPCCs) show great potential as new-generation energy conversion and storage devices. However, the mature development of RPCCs is seriously hindered by the inactivity and poor stability of air electrodes exposed to concentrated vapor under operating conditions. Herein, we report a high-entropy air electrode with the composition BaCo_(0.2)Fe_(0.2)Zr_(0.2)Sn_(0.2)Pr_(0.2)O_(3-δ)(BCFZSP), which shows integrated electronic, protonic and oxygenic conduction in a single perovskite phase and excellent structural stability in concentrated steam. Such triple conduction can spread the electrochemically active sites of the air electrode to the overall electrode surface, thus optimizing the kinetics of the oxygen reduction and evolution reactions(0.448 Ω cm^(2) of polarization resistance at 550℃). As-prepared RPCCs with a BCFZSP air electrode at 600℃ achieved a peak power density of 0.68 W/cm^(2) in fuel-cell mode and a current density of 0.92 A/cm^(2) under a 1.3 V applied voltage in electrolysis mode. More importantly, the RPCCs demonstrate an encouragingly high stability during 120 h of reversible switching between the fuelcell and electrolysis modes. Given their excellent performance, high-entropy perovskites can be promising electrode materials for RPCCs.展开更多
基金Supported by Projects of General Administration of Customs(2020HK159)Nanjing Customs Research Projects(2023KJ20).
文摘According to international standard plant quarantine measures and principle risk analysis(ISPM No.11),a risk assessment was carried out for Passalora sequoiae through geographical distribution,possibility of colonization,probability of diffusion,economic importance and difficulty in risk management.Results show that P.sequoiae has a greater risk of introduction and diffusion,and it has distributed in parts of China.It is suggested that P.sequoiae should be added to the list of forest dangerous pests in China.Besides,porting departments should focus on the pathogen on imported host seedlings like Cryptomeria.
基金2023 China University of Geosciences(Beijing)Undergraduate Education Quality Improvement Plan Construction Project,including“Linux Operating System”Practical Teaching Reform(Project number:JG202215)“University Computer”Online Experiment Construction(Project number:JG202216)+1 种基金CUGB-Zhonggong Computer Science and Technology Off-Campus Practical Teaching Base(Project number:SSJJD202201)Ministry of Education Fund Project:Research and Development of Computer Vision Practical Courses Based on Deep Learning(Project number:2022BC003)。
文摘With the advancement of the construction of emerging engineering education,the reform of practical teaching has become an important task of higher engineering education.This article takes the course“Linux Operating System Fundamentals”as an example to explore practical teaching reform in the context of emerging engineering education.By analyzing the current situation and problems in course practical teaching,we proposed practical teaching reforms such as online experiments,practical content updates,project-based engineering practices,and diversified evaluation models,and designed corresponding implementation plans.Practice has proved that this reform can improve students’learning interest and engineering practical skills,and cultivate outstanding engineers with innovative spirit and practical skills.
基金supported by the National Natural Science Foundation of China (22179007)。
文摘To obtain high-performance lithium-sulfur(Li-S)batteries,it is necessary to rationally design electrocatalytic materials that can promote efficient sulfur electrochemical reactions.Herein,the robust heterostructured material of nanoscale transition metal anchored on perovskite oxide was designed for efficient catalytic kinetics of the oxidation and reduction reactions of lithium polysulphide(Li PSs),and verified by density functional theory(DFT)calculations and experimental characterizations.Due to the strong interaction of nanoscale transition metals with Li PSs through chemical coupling,heterostructured materials(STO@M)(M=Fe,Ni,Cu)exhibit excellent catalytic activity for redox reactions of Li PSs.The bifunctional heterostructure material STO@Fe exhibits good rate performance and cycling stability as the cathode host,realizing a high-performance Li-S battery that can maintain stable cycling under rapid charge-discharge cycling.This study presents a novel approach to designing electrocatalytic materials for redox reactions of Li PSs,which promotes the development of fast charge-discharge Li-S batteries.
基金financially supported by the National Natural Science Foundation of China(Grant nos.21376001,21576028 and 21506012)。
文摘Carbon-fueled solid oxide fuel cells(CF-SOFCs)can electrochemically convert the chemical energy in carbon into electricity,which demonstrate both superior electrical efficiency and fuel utilisation compared to all other types of fuel cells.However,using solid carbon as the fuel of SOFCs also faces some challenges,the fluid mobility and reactive activity of carbon-based fuels are much lower than those of gaseous fuels.Therefore,the anode reaction kinetics plays a crucial role in determining the electrochemical performance of CF-SOFCs.Herein,the progress of various anodes in CF-SOFCs is reviewed from the perspective of material compositions,electrochemical performance and microstructures.Challenges faced in developing high performance anodes for CF-SOFCs are also discussed.
基金Supported by National Natural Science Foundation of China(Grant Nos.51904206,52105390,51974196,51805359)Open Research Fund from the State Key Laboratory of Rolling and Automation,Northeastern University(Grant No.2020RALKFKT011)+1 种基金Shanxi Province Science and Technology Major Projects(Grant No.20181102015)China Postdoctoral Science Foundation(Grant No.2020M670705).
文摘Variable gauge rolling is a new process to obtain a plate for which the thickness changes continuously by continuously and dynamically adjusting the roll gap upward and downward in the rolling process.This technology is an efective method for producing lightweight,low-cost,and economical plates.However,variable gauge rolling is an unsteady process,and the changes in the force and deformation parameters are complex.In this research,based on the minimum energy theory of the variational principle and considering the characteristics of the roll movement and workpiece deformation comprehensively,the internal plastic deformation,friction,shear and tension powers,and the minimum result of the total power functional in upward and downward rolling are obtained with the frst integral and then with a variation of adopting the specifc plastic power and strain rate vector inner product.The analytical results of the deformation and force parameters are also established using the variational method.Then the precision of this model is certifed using the measured values in a medium plate hot rolling plant and the experimental data for Tailor Rolled Blank rolling.Good agreement is found.Additionally,the variation rule of bite angle,neutral angle,and location neutral points are shown,and the change mechanism of the friction parameter on the stress state efect coefcient is given in variable gauge rolling.This research proposes a new mathematical model for rolling process control that provides a scientifc basis and technical support for obtaining an accurate section shape in variable gauge rolling production.
基金supported by the Taishan Scholar Construction Engineering by Shandong Government,the National Natural Science Foundation of China(61034007,61120106011,61203029,61304045,61403235)
文摘This paper studies the consensus problem for discrete-time multi-agent systems of first-order in the presence of constant communication delay. Provided that the agent dynamics is unstable and the network topology is undirected, effects of two kinds of communication delays on consensus are investigated.When the relative information is affected by delay, we show that the effect of delay can be alleviated by using the historical input information in the protocol design. On the other hand, if the communication delay only influences the actually transmitted information, sufficient condition admitting any large yet bounded delay for consensus is obtained, and the delay in this case is allowed to be unknown and time-varying. Finally, simulation results are provided to demonstrate the effectiveness of the theoretical results.
基金supported by the National Natural Science Foundation of China(6127316261403104)
文摘The problem of the robust fault detection filter design for time-varying delays switched systems is considered in the framework of mixed H_-/H_∞. Firstly, the weighted H_∞ performance index is utilized as the robustness performance, and the H_- index is used as the sensitivity performance for obtaining the robust fault detection filter. Then a novel multiple Lyapunov-Krasovskii function is proposed for deriving sufficient existence conditions of the robust fault detection filter based on the average dwell time technique. By introducing slack matrix variable, the coupling between the Lyapunov matrix and system matrix is removed, and the conservatism of results is reduced. Based on the robust fault detection filter, residual is generated and evaluated for detecting faults. In addition, the results of this paper are dependent on time delays,and represented in the form of linear matrix inequalities. Finally,the simulation example verifies the effectiveness of the proposed method.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 21376001, 21576028 and 21506012)。
文摘Lithium(Li) metal,possessing ultrahigh theoretical capacity and the lowest electrode potential,is regarded as a promising new generation anode material.However,the uncontrollable growth of Li dendrites during cycling process gives rise to problems as capacity decay and short circuit,suppressing the cycling and safety performances of Li metal battery.In this contribution,porous conductive interlayer(PCI),composed of carbon nanofibers(CNFs) and polyisophthaloyl metaphenylene diamine(PMIA),is developed to suppress Li dendrites and stabilize Li metal anode.PCI possesses the excellent conductive ability of CNFs and the preeminent mechanical properties of PMIA at the same time.When Li metal contacts with PCI during cycling process,an equipotential surface forms on their interface,which eliminates the tip effect on Li anode and homogenizes Li-ions flux in combination with the uniform porous structure of PCI.Employed PCI,the Li|Cu cell exhibits a remarkable cycling stability with a high average Coulombic efficiency of 97.5% for 100 cycles at 0.5 mA cm^(-2).And the Li|LiFePO_4 cell exhibits improved rate capability(114.7 mAh g^(-1) at 5.0 C) and enhanced cycling performance(78.9% capacity retention rate over 500 cycles at 1.0 C).This work provides a fresh and effective solving strategy for the problem of dendrites in Li metal battery.
基金Supported by the Science and Technology Development Plan of Jilin Province,China (20100641)Doctor Foundation of Northeast Dianli University (BSJXM-201002)
文摘Firstly,the distribution of main biomass resources(like straw,livestock manure and forestry residue) in counties of Jilin Province,and then according to the annual output of biomass in each county,the energy regeneration of biomass and project distribution of organic fertilizer were studied,finally the direct economic effect and environmental effect of biomass developed recently were calculated.
基金supported by the Beijing Institute of Technology Research Fund Program for Young Scholars and the Analysis&Testing Center(Beijing Institute of Technology)the National Natural Science Foundation of China(22179007)。
文摘While lithium-sulfur(Li-S)battery has attracted remarkable attention owing to the high theoretical capacity,its practical application is still hindered by the shuttle and sluggish conversion kinetics of intermediate lithium polysulfides(Li PSs).Defect engineering,which can regulate the electronic structure and in turn influence the surface adsorption and catalytic capability,has been regarded as a feasible strategy to deal with the above challenges.However,few studies on nitrogen vacancies and their mechanisms are reported.Herein,cobalt nitride with nitrogen vacancies grown on multi-walled carbon nanotube(CNTCo N-VN)is designed and applied as the separator modification material to investigate the enhancing mechanism of nitrogen vacancies on Li-S batteries.The experimental evidence and theoretical calculation indicate that the introduction of nitrogen vacancies into cobalt nitride can enhance the chemical affinity to Li PSs and effectively hamper the shuttle effect.Meanwhile the reduced band gap of the d-band center of Co and p-band center of N for CNT-Co N-VNand the promoted diffusion of Li^(+) can expedite the solid-liquid and liquid-liquid conversions of sulfur species.Due to these superiorities,the cell with CNT-Co NVNmodified separator delivers a favorable initial capacity of 901 m Ah g^(-1)and a capacity of 660 m Ah g^(-1)can be achieved after 250 cycles at 2 C.This work explores the application of metal nitride with nitrogen vacancies and sheds light on the development of functional separators for high-efficient Li-S batteries.
基金Supported by Project of Key Opening Laboratory of Physiology and Ecology of Crop in Cold Terra of Agriculture MinistryProject of the Department of Education of Heilongjiang Province (11521196)
文摘[Objective] This study aimed to map quantitative tarit loci (QTLs) associated with salt tolerance of maize inbred line at seedling stage. [Method] The recombinant inbred line (RIL) F7 including 171 plants were developed by single seed descent procedure from a combination, Huangzaosi×Mo17, and used to map QTLs associated with salt tolerance, based on the constructed genetic map of SSR markers. [Result]A linkage map consisting of 81 SSR markers loci from 10 chromosomes (1 428.3 cM in total length, with an average distance of 17.63 cM between two neighbouring loci) was constructed. Six QTLs associated significantly with salt tolerance were detected at chromosomes 1, 5 and 6. [Conclusion] This study is extremely significant for better understanding salt tolerance-related genes, the genes' location and cloning, salt tolerance mechanism and the marker-assisted selection of salt tolerant maize.
基金the National Natural Science Foundation of China(Grant no.22078022).
文摘Proton conducting solid oxide fuel cell(H-SOFC)is an emerging energy conversion device,with lower activation energy and higher energy utilization efficiency.However,the deficiency of highly active cathode materials still remains a major challenge for the development of H-SOFC.Therefore,in this work,K_(2)NiF_(4)-type cathode materials Pr_(2-x)Ba_(x)Ni_(0.6)Cu_(0.4)O_(4+δ)(x=0,0.1,0.2,0.3),single-phase tripleconducting(e-/O^(2-)/H^(+))oxides,are prepared for intermediate temperature H-SOFCs and exhibit good oxygen reduction reaction activity.The investigation demonstrates that doping Ba into Pr_(2-x)BaxNi_(0.6)Cu_(0.4)O_(4+δ) can increase its electrochemical performance through enhancing electrical conductivity,oxygen vacancy concentration and proton conductivity.EIS tests are carried at 750℃ and the minimum polarization impedances are obtained when x=0.2,which are 0.068 Ω·cm^(2) in air and 1.336 Ω·cm^(2) in wet argon,respectively.The peak power density of the cell with Pr_(1.8)Ba_(0.2)Ni_(0.6)Cu_(0.4)O_(4+δ) cathode is 298 mW·cm^(-2) at 750℃ in air with humidified hydrogen as fuel.Based on the above results,Ba-doped Pr_(2-x)Ba_(x)Ni_(0.6)Cu_(0.4)O_(4+δ) can be a good candidate material for SOFC cathode applications.
基金supported by grants from the National Natural Science Foundation of China (No.30670723, No.30600060, No.30400145 and No.30570650)Natu-ral Science Foundation of Liaoning Province (No.20052102).
文摘OBJECTIVE There is a close correlation between interleukin-6 (IL-6) and malignant proliferation of gliomas. We investigated the effect of bradykinin on the expression of IL-6 in C6 glioma cells. METHODS Semi-quantitive RT-PCR and radioimmunoassay were used to examine the effect of bradykinin on the expression of IL-6 in C6 glioma cells and on the level of IL-6 in the culture medium. RESULTS Using semi-quantitive RT-PCR , the expression of IL-6 mRNA was examined in C6 glioma cells at 0, 5, 10,15, 30, 60 min following addition of 1 μmol/L bradykinin. There was no statistical difference in expression of IL-6 mRNA between the treatment and control groups (P>0.05) and IL-6 was not detected in the cell culture medium. CONCLUSION Within an hour, IL-6 expression in C6 glioma cells is not induced by bradykinin, suggesting that its clinical application may be useful as a potential therapeutic agent for tumors of the central nervous system.
文摘The rapid development of information technology and the new economy is a challenge to the training of computer technology and engineering professionals. The cultivation of engineering talents in Computer Engineering under the new engineering is an important part of the construction and exploration of new engineering in universities. According to the teaching reform of computer specialty in the new engineering construction, starting from the practice of curriculum system of software, mainly discusses the basic ideas of practice teaching reform of the course of computer software, software engineering practice curriculum system and practice curriculum system implementation method. The basic ideas of teaching reform practice in the course of the software include: expanding computer professional students' knowledge, strengthening students' computer science and software engineering knowledge and engineering practice ability, strengthening the frontiers of computer science and technology guide. Software practice course system is divided into three levels, including basic language course, engineering basic professional practice course and the professional practice course of engineering application direction. The implementation method of engineering application practice curriculum system is discussed in detail, such as strengthening university-enterprise cooperation, introducing teachers of social training institutions and guiding students to participate in subject competition and innovation projects.
文摘Big data are always processed repeatedly with small changes, which is a major form of big data processing. The feature of incremental change of big data shows that incremental computing mode can improve the performance greatly. HDFS is a distributed file system on Hadoop which is the most popular platform for big data analytics. And HDFS adopts fixed-size chunking policy, which is inefficient facing incremental computing. Therefore, in this paper, we proposed iHDFS (incremental HDFS), a distributed file system, which can provide basic guarantee for big data parallel processing. The iHDFS is implemented as an extension to HDFS. In iHDFS, Rabin fingerprint algorithm is applied to achieve content defined chunking. This policy make data chunking has much higher stability, and the intermediate processing results can be reused efficiently, so the performance of incremental data processing can be improved significantly. The effectiveness and efficiency of iHDFS have been demonstrated by the experimental results.
基金financially supported by the National Natural Science Foundation of China (No. 22179007)。
文摘Lithium-sulfur batteries as one of the most promising next-generation high-energy storage system, the shuttle effect, the expansion of cathode and the slow electrode redox kinetics limit its further development. Herein, we report a two-dimensional, ultrathin and ultra-light bimetal-Ni Co-organic framework as the interlayer for Li-S batteries. This kind of interlayer can effectively block polysulfides and accelerate the conversion with a thickness of only 1 μm and a load of 0.1 mg/cm^(2). Because the MOF nanosheets with a thickness of a few nanometers have a large specific surface and a large number of exposed accessible active sites. At the same time, the intrinsic activity of each site is enhanced and the catalytic performance is improved due to the synergistic effect of mixed metals and the unique coordination environment around the active sites. So, 2D NiCo MOF/CNT totally meets the requirements for the lightweight and effective interlayer. The initial discharge capacity of cell with 2D NiCo MOF/CNT interlayer can reach 1132.7 m Ah/g at 0.5 C. It remained 709.1 m Ah/g after 300 cycles, showing good cycling stability and rate performance.
基金supported by the National Natural Science Foundation of China(No.22179007).
文摘The sluggish conversion kinetics and shuttle effect of lithium polysulfides(LiPSs)severely hamper the commercialization of lithium-sulfur batteries.Numerous electrocatalysts have been used to address these issues,amongst which,transition metal dichalcogenides have shown excellent catalytic performance in the study of lithium-sulfur batteries.Note that dichalcogenides in different phases have different catalytic properties,and such catalytic materials in different phases have a prominent impact on the performance of lithium-sulfur batteries.Herein,1T-phase rich MoSe_(2)(T-MoSe_(2))nanosheets are synthesized and used to catalyze the conversion of LiPSs.Compared with the 2H-phase rich MoSe_(2)(H-MoSe_(2))nanosheets,the T-MoSe_(2) nanosheets significantly accelerate the liquid phase transformation of LiPSs and the nucleation process of Li2S.In-situ Raman and X-ray photoelectron spectroscopy(XPS)find that T-MoSe_(2) effectively captures LiPSs through the formation of Mo-S and Li-Se bonds,and simultaneously achieves fast catalytic conversion of LiPSs.The lithium-sulfur batteries with T-MoSe_(2) functionalized separators display a fantastic rate performance of 770.1 mAh/g at 3 C and wonderful cycling stability,with a capacity decay rate as low as 0.065%during 400 cycles at 1 C.This work offers a novel perspective for the rational design of selenide electrocatalysts in lithium-sulfur chemistry.
基金financially supported by the National Natural Science Foundation of China (Nos. 22078022, 22178023, 22179007)China Postdoctoral Science Foundation (No. 2021M690379)。
文摘Reversible protonic ceramic cells(RPCCs) show great potential as new-generation energy conversion and storage devices. However, the mature development of RPCCs is seriously hindered by the inactivity and poor stability of air electrodes exposed to concentrated vapor under operating conditions. Herein, we report a high-entropy air electrode with the composition BaCo_(0.2)Fe_(0.2)Zr_(0.2)Sn_(0.2)Pr_(0.2)O_(3-δ)(BCFZSP), which shows integrated electronic, protonic and oxygenic conduction in a single perovskite phase and excellent structural stability in concentrated steam. Such triple conduction can spread the electrochemically active sites of the air electrode to the overall electrode surface, thus optimizing the kinetics of the oxygen reduction and evolution reactions(0.448 Ω cm^(2) of polarization resistance at 550℃). As-prepared RPCCs with a BCFZSP air electrode at 600℃ achieved a peak power density of 0.68 W/cm^(2) in fuel-cell mode and a current density of 0.92 A/cm^(2) under a 1.3 V applied voltage in electrolysis mode. More importantly, the RPCCs demonstrate an encouragingly high stability during 120 h of reversible switching between the fuelcell and electrolysis modes. Given their excellent performance, high-entropy perovskites can be promising electrode materials for RPCCs.
