Recently,one of the main challenges facing the smart grid is insufficient computing resources and intermittent energy supply for various distributed components(such as monitoring systems for renewable energy power sta...Recently,one of the main challenges facing the smart grid is insufficient computing resources and intermittent energy supply for various distributed components(such as monitoring systems for renewable energy power stations).To solve the problem,we propose an energy harvesting based task scheduling and resource management framework to provide robust and low-cost edge computing services for smart grid.First,we formulate an energy consumption minimization problem with regard to task offloading,time switching,and resource allocation for mobile devices,which can be decoupled and transformed into a typical knapsack problem.Then,solutions are derived by two different algorithms.Furthermore,we deploy renewable energy and energy storage units at edge servers to tackle intermittency and instability problems.Finally,we design an energy management algorithm based on sampling average approximation for edge computing servers to derive the optimal charging/discharging strategies,number of energy storage units,and renewable energy utilization.The simulation results show the efficiency and superiority of our proposed framework.展开更多
In multi-infeed HVDC system, the interactions and influences between DC systems AC systems are complex as the electrical distances among DC converter stations which are relatively short. Multi-infeed interaction facto...In multi-infeed HVDC system, the interactions and influences between DC systems AC systems are complex as the electrical distances among DC converter stations which are relatively short. Multi-infeed interaction factor (MIIF) can effectively reflect the interaction among DC systems. The paper theoretically analyzes the impact factors of MIIF like the electrical distances between two DC converter stations and the equivalent impedance of the receiving end AC system. By applying the Kirchhoff’s current law on the inverter AC bus, the paper deduces the analytical expressions for MIIF. From the expression, it is clear how the equivalent impedance of AC system and coupling impedance can affect MIIF. PSCAD simulations validate the effectiveness and the correctness of the proposed expression and some useful conclusions are drawn.展开更多
Hydrogen energy,with its abundant reserves,green and low-carbon characteristic,high energy density,diverse sources,and wide applications,is gradually becoming an important carrier in the global energy transformation a...Hydrogen energy,with its abundant reserves,green and low-carbon characteristic,high energy density,diverse sources,and wide applications,is gradually becoming an important carrier in the global energy transformation and development.In this paper,the off-grid wind power hydrogen production system is considered as the research object,and the operating characteristics of a proton exchange membrane(PEM)electrolysis cell,including underload,overload,variable load,and start-stop are analyzed.On this basis,the characteristic extraction of wind power output data after noise reduction is carried out,and then the self-organizing mapping neural network algorithm is used for clustering to extract typical wind power output scenarios and perform weight distribution based on the statistical probability.The trend and fluctuation components are superimposed to generate the typical operating conditions of an off-grid PEM electrolytic hydrogen production system.The historical output data of an actual wind farm are used for the case study,and the results confirm the feasibility of the method proposed in this study for obtaining the typical conditions of off-grid wind power hydrogen production.The results provide a basis for studying the dynamic operation characteristics of PEM electrolytic hydrogen production systems,and the performance degradation mechanism of PEM electrolysis cells under fluctuating inputs.展开更多
Regard to the real-time dynamic digital twin modelling problem of a new-type distribution network that includes distributed resources such as distributed photovoltaic,energy storage,charging pile,and electric vehicle,...Regard to the real-time dynamic digital twin modelling problem of a new-type distribution network that includes distributed resources such as distributed photovoltaic,energy storage,charging pile,and electric vehicle,a new-type distribution network digital twin topology modeling method based on Common Information Model(CIM)specifications and spectral clustering is proposed.Firstly,according to the specifications of the CIM standard,the digital twin topology models of distributed resources are extended and established.Secondly,based on the digital twin topology models of distributed resources,a digital twin aggregation modelling method for new-type distribution network is proposed based on spectral clustering.Furthermore,an online linked update strategy for the digital twin model of new-type distribution network that integrates real-time topology states is proposed.Finally,a case study is conducted on a distribution network in a certain demonstration area in China,and the results verify the practicability and effectiveness of the method proposed in this paper.This lays the foundation for the application of electrical network twin analysis,such as power flow calculation,optimal power flow,economic dispatch,and safety check,in a new-type distribution network that includes diversified distributed resources.展开更多
This study explores a novel strategy to enhance the hydrogen evolution reaction(HER)activity of carbon-supported rock salt-type NiCo_(2)(O,F)_(3) nanorods through lattice modifications induced by fluorine and excess a...This study explores a novel strategy to enhance the hydrogen evolution reaction(HER)activity of carbon-supported rock salt-type NiCo_(2)(O,F)_(3) nanorods through lattice modifications induced by fluorine and excess amorphous carbon.X-ray absorption near-edge structure(XANES)analysis confirmed that Co and Ni predominantly exist in the+2 oxidation state,whereas extended X-ray absorption fine structure(EXAFS)analysis revealed shortened Co-O and Co-Co bond lengths,indicating lattice distortions.Rietveld refinement and electron microscopy confirmed the formation of a homogeneous solid solution(NixCo_(2-x)(O,F)_(3))rather than a simple CoO/NiO composite.The optimized material(AH-2)exhibited the lowest overpotential(145 mV at 10 mA cm^(-1))and the smallest Tafel slope(98 mV dec^(-1)),attributed to its balanced phase composition,enhanced electronic conductivity,and synergistic effects of carbon and fluorine incorporation.Electrochemical impedance spectroscopy(EIS)confirmed improved charge transfer efficiency,correlating with enhanced catalytic activity.These findings provide critical insights into the tunability of transition metal oxide catalysts via controlled lattice modifications,offering a promising avenue for developing cost-effective and efficient electrocatalysts for sustainable hydrogen production.展开更多
Objective:Triple-negative breast cancer(TNBC)remains a major therapeutic challenge with limited treatment options and poor prognosis.This study aimed to investigate the synergistic anticancer effects of doxorubicin(DO...Objective:Triple-negative breast cancer(TNBC)remains a major therapeutic challenge with limited treatment options and poor prognosis.This study aimed to investigate the synergistic anticancer effects of doxorubicin(DOX)combined with Viscum album L.var.coloratum agglutinin(VCA)and to elucidate the underlying molecular mechanisms in TNBC cells.Methods:This study evaluated the synergistic effects and mechanisms of doxorubicin(DOX)and Viscum album L.var.coloratum agglutinin(VCA)combination in MDA-MB231 TNBC cells.Cell viability,oxidative stress markers,apoptosis-related proteins,cell migration,and proliferative recovery were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay,superoxide dismutase(SOD)and nitric oxide(NO)assays,Western blotting,wound healing assay,and Muse^(TM)cell analyzer,respectively.Results:The DOXVCA combination demonstrated strong synergistic cytotoxicity with Bliss Independence scores of+8.9% to+33.4% at therapeutic concentrations(0.01-50 ng/mL,p=0.032)and remarkable dose reduction indices of>3000-fold for DOX and>16.7-fold for VCA.This synergistic effect was mediated through multiple mechanisms:enhanced oxidative stress modulation(48% increase in SOD-like activity,p=0.0003,and 94% increase in NO production,p=0.0002,at 50 ng/mL combination compared to control),augmented apoptotic responses(4.8-fold increase in cleaved caspase-3/caspase-3 ratio,p=0.0001,and 91% reduction in procaspase-9 levels,p=0.00008,at 48 h compared to control),significant inhibition of cell migration(85.8% remaining wound area at 48 h,p=0.0004 vs.control),and severely impaired proliferative recovery(98.9% reduction in cell viability at 72 h post-treatment,p=0.0001 vs.untreatedcontrol).Conclusion:The DOX-VCA combination demonstrates potent synergistic effects through multiple mechanisms,warranting further investigation as a potential dose-reducing strategy for TNBC treatment.展开更多
To predict the lithium-ion(Li-ion)battery degradation trajectory in the early phase,arranging the maintenance of battery energy storage systems is of great importance.However,under different operation conditions,Li-io...To predict the lithium-ion(Li-ion)battery degradation trajectory in the early phase,arranging the maintenance of battery energy storage systems is of great importance.However,under different operation conditions,Li-ion batteries present distinct degradation patterns,and it is challenging to capture negligible capacity fade in early cycles.Despite the data-driven method showing promising performance,insufficient data is still a big issue since the ageing experiments on the batteries are too slow and expensive.In this study,we proposed twin autoencoders integrated into a two-stage method to predict the early cycles'degradation trajectories.The two-stage method can properly predict the degradation from course to fine.The twin autoencoders serve as a feature extractor and a synthetic data generator,respectively.Ultimately,a learning procedure based on the long-short term memory(LSTM)network is designed to hybridize the learning process between the real and synthetic data.The performance of the proposed method is verified on three datasets,and the experimental results show that the proposed method can achieve accurate predictions compared to its competitors.展开更多
Current treatments for glioblastoma face challenges such as the blood-brain barrier and lack of targeted therapy,compounded by the aggressive nature,high invasiveness,and heterogeneity of the disease.Exosomes,a subtyp...Current treatments for glioblastoma face challenges such as the blood-brain barrier and lack of targeted therapy,compounded by the aggressive nature,high invasiveness,and heterogeneity of the disease.Exosomes,a subtype of extracellular vesicles are emerging as promising nanocarrier drug delivery systems to address these limitations.Exosomes released by all cell types can be easily obtained and modified as delivery vehicles or therapeutic agents.A systematic review was conducted to evaluate various methods for exosome isolation,characterization,engineering or modification,drug loading and delivery efficiency,including exosome biodistribution and treatment efficacy.A search of four databases for in vitro and in vivo studies(2000–,2023)identified 6165 records,of which 23 articles were found eligible and included for analyses.Most studies applied ultracentrifugation(UC)for exosomes isolation.Cancer cell lines being the most frequently used source of exosomes,followed by stem cells.The incubation approach was predominantly utilized to modify exosomes for drug loading.In vivo analysis showed that exosome biodistribution was primarily concentrated in the brain region,peaking in the first 6 h and remained moderately high.Compared to native exosomes and untreated control groups,utilizing modified native exosomes(cargo loaded)for treating glioblastoma disease models led to more pronounced suppression of tumor growth and proliferation,enhanced stimulation of immune response and apoptosis,effective restoration of drug chemosensitivity,increased anti-tumor effect and prolonged survival rates.Modified exosomes whether through incubation,sonication,transfection,freeze-thawing or their combination,improve targeted delivery and therapeutic efficacy against glioblastoma.展开更多
CRISPR-Cas system permanently deletes any harmful gene-of-interest to combat cancer growth.Chitosan(CS)is a potential cancer therapeutic that mediates via PI3K/Akt/mTOR,MAPK and NF-kβsignaling pathway modulation.CS a...CRISPR-Cas system permanently deletes any harmful gene-of-interest to combat cancer growth.Chitosan(CS)is a potential cancer therapeutic that mediates via PI3K/Akt/mTOR,MAPK and NF-kβsignaling pathway modulation.CS and its covalent derivatives have been designed as nanocarrier of CRISPR-Cas9 alone(plasmid or ribonucleoprotein)or in combination with chemical drug for cancer treatment.The nanocarrier was functionalized with polyethylene glycol(PEG),targeting ligand,cell penetrating ligand and its inherent positive zeta potential to mitigate premature clearance and particulate aggregation,and promote cancer cell/nucleus targeting and permeabilization to enable CRISPR-Cas9 acting on the host DNA.Different physicochemical attributes are required for the CS-based nanocarrier to survive from the administration site,through the systemic circulation-extracellular matrix-mucus-mucosa axis,to the nucleus target.CRISPR-Cas9 delivery is met with heterogeneous uptake by the cancer cells.Choice of excipients such as targeting ligand and PEG may be inappropriate due to lacking overexpressed cancer receptor or availability of excessive metabolizing enzyme and immunoglobulin that defies the survival and action of these excipients rendering nanocarrier fails to reach the target site.Cancer omics analysis should be implied to select excipients which meet the pathophysiological needs,and chitosan nanocarrier with a“transformative physicochemical behavior”is essential to succeed CRISPR-Cas9 delivery.展开更多
The Lao.67Mg0.33Ni2.5Co0.5 hydrogen storage alloy was prepared by the vacuum intermediate frequency induction furnace followed by annealing treatment. The pulverization degree of both the as-cast and annealed alloy po...The Lao.67Mg0.33Ni2.5Co0.5 hydrogen storage alloy was prepared by the vacuum intermediate frequency induction furnace followed by annealing treatment. The pulverization degree of both the as-cast and annealed alloy powders after gaseous hydriding and dehydriding cycle was investigated and the discovery was that annealing treatment could hardly ameliorate their anti-pulverization ability. The element content of La, Mg, Ni and Co existing in electrolyte before and after the electrochemical cycles by using ICP-AES technology was also analyzed and it showed that a large amount of La and Mg were dissolved in the electrolyte, but the amount of dissolution for La and Mg significantly declined when the alloy was annealed. The XRD analysis revealed that all the al- loys consisted of two main phases AB3 and AB2 and a residual phase AB5 while annealing treatment made the AB2 phase decrease slightly. Furthermore, the anti-corrosion abilities of various elements in different phases of the as-cast and annealed alloy samples were studied by analyzing the element （La, Mg, Ni, Co） change with the corrosion time in phases AB3 and AB2 by means of EDS. It turned out that the element of La was mainly corroded out from the phase AB2 while not easily from the phase AB3. However, the element of Mg was both easily corroded out from the phases AB2 and AB3, but the corrosion was more obvious in the phase AB3. Therefore, annealing improved the anti-corrosion performances of La and Mg in the phase AB2.展开更多
The significant occupancy of {411}〈148〉texture exists in the thin-gauge grain-oriented silicon steel(TGCRGO is defined that thickness of the sheet is〈0.25 mm and the reduction in cold rolling is more than 90%) whic...The significant occupancy of {411}〈148〉texture exists in the thin-gauge grain-oriented silicon steel(TGCRGO is defined that thickness of the sheet is〈0.25 mm and the reduction in cold rolling is more than 90%) which has been considered to have obviously effects on the abnormal growth of Goss-oriented grains during the secondary recrystallization process. The microstructures of the TG-CRGO were investigated by X-ray diffraction and electron back-scattered diffraction in this study. It was found that {411}〈148〉〉texture mainly exists in the center layer of hot-rolled as well as normalized plates.With the increase in cold rolling reduction, {411}〈148〉 orientation gradually rotates to a-fiber texture(〈110〉//RD).Finally, few {411}〈148〉would retain at the boundaries of deformed a-fiber grains(〈110〉//RD) as the reduction in cold rolling reaches 90%. After annealing treatment, a small amount of c-fiber textures(〈111〉//ND) preferably nucleates and recrystallizes between the DBs(deformation bands) at first; then, the {411}〈148〉 recrystallization texture occurs and mainly nucleates at the grains boundaries of the deformed a-fiber grains, and also quite a few {411}〈148〉orientation grains nucleate in the inner of {112}〈110〉grains. But this phenomenon was not observed in the {100}〈011〉deformation grains.With respect to the occurrence of {411}〈148〉recrystallization texture, it is mainly induced by strong a-fiber as well as weak c-fiber textures formed during cold rolling other than originating from {411}〈148〉 regions in hot bands.展开更多
Hydrogen energy,whether in generation plants or utilization facilities,plays a decisive role in the mission to achieve net-zero greenhouse gas emissions,all to minimize pollution.The growing demand for clean energy ca...Hydrogen energy,whether in generation plants or utilization facilities,plays a decisive role in the mission to achieve net-zero greenhouse gas emissions,all to minimize pollution.The growing demand for clean energy carrier steadily accelerates the development of hydrogen production processes,and therein proton exchange membrane(PEM)water electrolysis is deemed a promising long-term strategy for hydrogen preparation and collection.This review retrospects recent developments and applications of bipolar plates(BPs)as key components in PEM fuel cells and water electrolysers.The main content includes multifaceted challenges in the R&D or fabrication of BPs and potential future trends have also been proposed.Specific details cover the BPs matrix(metallic materials and carbon composites)and the surface coating types(metal and compound coatings,carbon-based coatings,and polymer coatings),as well as the influence of flow field design for mass transport.Long-term development and feasible researches of BPs are prospected.Especially in the following aspects:(1)Structural and functional integration of components,such as material fabrication and flow field geometry optimization using 3D printing technology;(2)Introduction of environment-friendly renewable energy for hydrogen production;(3)Research on hydrogen energy reversible systems;(4)Composition optimization of surface coatings based on computational materials science and(5)systematic design expected to evolve into the next generation of BPs.展开更多
Electrolysis is a promising technology to improve sludge dewaterability efficiently with negligible environmental impact. To intensify the electrolytic efficiency, the effect of electrolytes(NaCl, Na_2SO_4, NaNO_3, an...Electrolysis is a promising technology to improve sludge dewaterability efficiently with negligible environmental impact. To intensify the electrolytic efficiency, the effect of electrolytes(NaCl, Na_2SO_4, NaNO_3, and NaClO_4) on electrolysis pretreatment of municipal sludge and its mechanisms was investigated using Ti/PbO_2 electrodes. The electrolytes,which enhanced the production of oxidative radicals, showed a significant synergetic effect in reducing the capillary suction time(CST) of sludge. NaCl was distinguished from the other electrolytes since it formed a large amount of active chlorine species, which oxidized the sludge cells to improve the sludge dewaterability. The surface morphologies as well as the soluble proteins and polysaccharides were analyzed to unravel the underlying mechanisms of sludge dewaterability. Additionally, an economic assessment showed that NaCl addition in the electrolysis pretreatment can be a suitable technique for enhancing municipal sludge dewaterability.展开更多
At present,only a single modification method is adopted to improve the shortcomings of erythritol(ET)as a phase change material(PCM).Compared with a single modification method,the synergistic effect of multiple modifi...At present,only a single modification method is adopted to improve the shortcomings of erythritol(ET)as a phase change material(PCM).Compared with a single modification method,the synergistic effect of multiple modification methods can endow ET with comprehensive performance to meet the purpose of package,supercooling reduction,and enhancement of thermal conductivity.In this work,we innovatively combine graphene oxide(GO)nanosheet modified melamine foam(MF)and polyaniline(PANI)to construct a novel ET-based PCM by blending and porous material adsorption modification.PANI as the nucleation center can enhance the crystallization rate,thereby reducing the supercooling of ET.Meanwhile,GO@MF foam can not only be used as a porous support material to encapsulate ET but also as a heat conduction reinforcement to improve heat storage and release rate.As a result,the supercooling of GO@MF/PANI@ET(GMPET)composite PCM decreases from 91.2℃ of pure ET to 57.9℃ and its thermal conductivity(1.58 W·m^(-1)·K^(-1))is about three times higher than that of pure ET(0.57 W·m^(-1)·K^(-1)).Moreover,after being placed at 140℃ for 2 h,there is almost no ET leakage in the GMPET composite PCM,and the mass loss ratio is less than 0.75%.In addition,the GMPET composite PCM displays a high melting enthalpy of about 259 J·g^(-1) and a high initial mass loss temperature of about 198℃.Even after the 200th cycling test,the phase transition temperature and the latent heat storage capacity of the GMPET PCM all remain stable.This work offers an effective and promising strategy to design ET-based composite PCM for the field of energy storage.展开更多
Many MXenes are efficient catalysts for MgH_(2)hydrogen storage material.Nevertheless,the synthesis of MXenes should consume a large amount of corrosive HF to etch out the Al layers from the transition metal aluminum ...Many MXenes are efficient catalysts for MgH_(2)hydrogen storage material.Nevertheless,the synthesis of MXenes should consume a large amount of corrosive HF to etch out the Al layers from the transition metal aluminum carbides or nitrides(MAX) phases,which is environmentally unfriendly.In this work,Ti_(3)AlCN MAX without HFetching was employed directly to observably enhance the kinetics and the cycling stability of MgH_(2).With addition of10 wt% Ti_(3)AlCN,the onset dehydrogenation temperature of MgH2 was dropped from 320 to 205℃,and the rehydrogenation of MgH2 under 6 MPa H2 began at as low as50℃.Furthermore,at 300℃,it could provide 6.2 wt% of hydrogen in 10 min.Upon cycling,the composite underwent an activation process during the initial 40 cycles,with the reversible capacity increased from 4.7 wt% to 6.5 wt%.After that,the capacity showed almost no attenuation for up to 100 cycles.The enhancing effect of Ti_(3)AICN on MgH_(2) was comparable to many MXenes.It was demonstrated that Ti_(3)AICN did not destabilize MgH_(2) but acted as an efficient catalyst for MgH_(2).Ti_(3)AICN was observed to be the active sites for the nucleation and growth of MgH_(2)and might also help in dissociation and recombination of hydrogen molecules.Such two factors are believed to contribute to the improvement of MgH_(2).This study not only provides a promising strategy for improving the hydrogen storage performances of MgH_(2) by using noncorrosive MAX materials,but also adds evidence of nucleation and growth of MgH_(2) on a catalyst.展开更多
We investigate the triangular defects with different structural features on 4H-SiC epilayers by a Nomarski micro-scope,a Candela optical surface analyzer and ultraviolet photoluminescence(UV-PL)imaging.Both the foreig...We investigate the triangular defects with different structural features on 4H-SiC epilayers by a Nomarski micro-scope,a Candela optical surface analyzer and ultraviolet photoluminescence(UV-PL)imaging.Both the foreign particles and the substrate scratches can cause the formation of the obtuse triangular defects.The central area of some obtuse triangular defects can have the spatially confined core,in which the in-grown stacking faults can be observed under the UV-PL imaging.In contrast,the obtuse triangular defects induced by the scratches appear in the form of band-like defects,of which the width depends on the scratch direction and reaches the maximum when the scratch direction is parallel to the step flow direction.The formation mechanisms of these obtuse triangular defects are discussed.展开更多
Dear Editor,This letter proposes an unsupervised entity alignment method,which realizes integration of multiple multi-modal knowledge graphs adaptively.In recent years,Large-scale multi-modal knowledge graphs(LMKGs),c...Dear Editor,This letter proposes an unsupervised entity alignment method,which realizes integration of multiple multi-modal knowledge graphs adaptively.In recent years,Large-scale multi-modal knowledge graphs(LMKGs),containing text and image,have been widely applied in numerous knowledge-driven topics,such as question answering,entity linking,information extraction,reasoning and recommendation.展开更多
In response to the underutilization of energy and insufficient flexible operation capability of rural energy supply systems in China,this study proposes an optimal dispatch approach for a rural multi-energy supply sys...In response to the underutilization of energy and insufficient flexible operation capability of rural energy supply systems in China,this study proposes an optimal dispatch approach for a rural multi-energy supply system(RMESS)considering virtual energy storage(VES).First,to enable the flexible utilization of rural biomass resources and the thermal inertia of residential building envelopes,this study constructed VES-I and VES-II models that describe electrical-thermal and electrical-gas coupling from an electrical viewpoint.Subsequently,an RMESS model encompassing these two types of VES was formulated.This model delineates the intricate interplay of multi-energy components within the RMESS framework and facilitates the precise assessment of the adjustable potential for optimizing RMESS operations.Based on the above models,a day-ahead optimal dispatch model for an RMESS considering a VES is proposed to achieve optimal economic performance while ensuring efficient energy allocation.Comparative simulations validated the effectiveness of the VES modeling and the day-ahead optimal dispatch approach for the RMESS.展开更多
基金supported in part by the National Natural Science Foundation of China under Grant No.61473066in part by the Natural Science Foundation of Hebei Province under Grant No.F2021501020+2 种基金in part by the S&T Program of Qinhuangdao under Grant No.202401A195in part by the Science Research Project of Hebei Education Department under Grant No.QN2025008in part by the Innovation Capability Improvement Plan Project of Hebei Province under Grant No.22567637H
文摘Recently,one of the main challenges facing the smart grid is insufficient computing resources and intermittent energy supply for various distributed components(such as monitoring systems for renewable energy power stations).To solve the problem,we propose an energy harvesting based task scheduling and resource management framework to provide robust and low-cost edge computing services for smart grid.First,we formulate an energy consumption minimization problem with regard to task offloading,time switching,and resource allocation for mobile devices,which can be decoupled and transformed into a typical knapsack problem.Then,solutions are derived by two different algorithms.Furthermore,we deploy renewable energy and energy storage units at edge servers to tackle intermittency and instability problems.Finally,we design an energy management algorithm based on sampling average approximation for edge computing servers to derive the optimal charging/discharging strategies,number of energy storage units,and renewable energy utilization.The simulation results show the efficiency and superiority of our proposed framework.
文摘In multi-infeed HVDC system, the interactions and influences between DC systems AC systems are complex as the electrical distances among DC converter stations which are relatively short. Multi-infeed interaction factor (MIIF) can effectively reflect the interaction among DC systems. The paper theoretically analyzes the impact factors of MIIF like the electrical distances between two DC converter stations and the equivalent impedance of the receiving end AC system. By applying the Kirchhoff’s current law on the inverter AC bus, the paper deduces the analytical expressions for MIIF. From the expression, it is clear how the equivalent impedance of AC system and coupling impedance can affect MIIF. PSCAD simulations validate the effectiveness and the correctness of the proposed expression and some useful conclusions are drawn.
基金supported by the National Key Research and Development Program of China(Program Number 2021YFB4000100)the Beijing Postdoctoral Research Foundation(Grant Number 2023-ZZ-63).
文摘Hydrogen energy,with its abundant reserves,green and low-carbon characteristic,high energy density,diverse sources,and wide applications,is gradually becoming an important carrier in the global energy transformation and development.In this paper,the off-grid wind power hydrogen production system is considered as the research object,and the operating characteristics of a proton exchange membrane(PEM)electrolysis cell,including underload,overload,variable load,and start-stop are analyzed.On this basis,the characteristic extraction of wind power output data after noise reduction is carried out,and then the self-organizing mapping neural network algorithm is used for clustering to extract typical wind power output scenarios and perform weight distribution based on the statistical probability.The trend and fluctuation components are superimposed to generate the typical operating conditions of an off-grid PEM electrolytic hydrogen production system.The historical output data of an actual wind farm are used for the case study,and the results confirm the feasibility of the method proposed in this study for obtaining the typical conditions of off-grid wind power hydrogen production.The results provide a basis for studying the dynamic operation characteristics of PEM electrolytic hydrogen production systems,and the performance degradation mechanism of PEM electrolysis cells under fluctuating inputs.
基金Supported by Science and Technology Project of State Grid Corporation of China(5108-202218280A-2-396-XG).
文摘Regard to the real-time dynamic digital twin modelling problem of a new-type distribution network that includes distributed resources such as distributed photovoltaic,energy storage,charging pile,and electric vehicle,a new-type distribution network digital twin topology modeling method based on Common Information Model(CIM)specifications and spectral clustering is proposed.Firstly,according to the specifications of the CIM standard,the digital twin topology models of distributed resources are extended and established.Secondly,based on the digital twin topology models of distributed resources,a digital twin aggregation modelling method for new-type distribution network is proposed based on spectral clustering.Furthermore,an online linked update strategy for the digital twin model of new-type distribution network that integrates real-time topology states is proposed.Finally,a case study is conducted on a distribution network in a certain demonstration area in China,and the results verify the practicability and effectiveness of the method proposed in this paper.This lays the foundation for the application of electrical network twin analysis,such as power flow calculation,optimal power flow,economic dispatch,and safety check,in a new-type distribution network that includes diversified distributed resources.
基金supported by the Russian Science Foundation(project No.24-43-00215,http://rscf.ru/project/24-43-00215/).
文摘This study explores a novel strategy to enhance the hydrogen evolution reaction(HER)activity of carbon-supported rock salt-type NiCo_(2)(O,F)_(3) nanorods through lattice modifications induced by fluorine and excess amorphous carbon.X-ray absorption near-edge structure(XANES)analysis confirmed that Co and Ni predominantly exist in the+2 oxidation state,whereas extended X-ray absorption fine structure(EXAFS)analysis revealed shortened Co-O and Co-Co bond lengths,indicating lattice distortions.Rietveld refinement and electron microscopy confirmed the formation of a homogeneous solid solution(NixCo_(2-x)(O,F)_(3))rather than a simple CoO/NiO composite.The optimized material(AH-2)exhibited the lowest overpotential(145 mV at 10 mA cm^(-1))and the smallest Tafel slope(98 mV dec^(-1)),attributed to its balanced phase composition,enhanced electronic conductivity,and synergistic effects of carbon and fluorine incorporation.Electrochemical impedance spectroscopy(EIS)confirmed improved charge transfer efficiency,correlating with enhanced catalytic activity.These findings provide critical insights into the tunability of transition metal oxide catalysts via controlled lattice modifications,offering a promising avenue for developing cost-effective and efficient electrocatalysts for sustainable hydrogen production.
文摘Objective:Triple-negative breast cancer(TNBC)remains a major therapeutic challenge with limited treatment options and poor prognosis.This study aimed to investigate the synergistic anticancer effects of doxorubicin(DOX)combined with Viscum album L.var.coloratum agglutinin(VCA)and to elucidate the underlying molecular mechanisms in TNBC cells.Methods:This study evaluated the synergistic effects and mechanisms of doxorubicin(DOX)and Viscum album L.var.coloratum agglutinin(VCA)combination in MDA-MB231 TNBC cells.Cell viability,oxidative stress markers,apoptosis-related proteins,cell migration,and proliferative recovery were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay,superoxide dismutase(SOD)and nitric oxide(NO)assays,Western blotting,wound healing assay,and Muse^(TM)cell analyzer,respectively.Results:The DOXVCA combination demonstrated strong synergistic cytotoxicity with Bliss Independence scores of+8.9% to+33.4% at therapeutic concentrations(0.01-50 ng/mL,p=0.032)and remarkable dose reduction indices of>3000-fold for DOX and>16.7-fold for VCA.This synergistic effect was mediated through multiple mechanisms:enhanced oxidative stress modulation(48% increase in SOD-like activity,p=0.0003,and 94% increase in NO production,p=0.0002,at 50 ng/mL combination compared to control),augmented apoptotic responses(4.8-fold increase in cleaved caspase-3/caspase-3 ratio,p=0.0001,and 91% reduction in procaspase-9 levels,p=0.00008,at 48 h compared to control),significant inhibition of cell migration(85.8% remaining wound area at 48 h,p=0.0004 vs.control),and severely impaired proliferative recovery(98.9% reduction in cell viability at 72 h post-treatment,p=0.0001 vs.untreatedcontrol).Conclusion:The DOX-VCA combination demonstrates potent synergistic effects through multiple mechanisms,warranting further investigation as a potential dose-reducing strategy for TNBC treatment.
基金financially supported by the National Natural Science Foundation of China under Grant 62372369,52107229,62272383the Key Research and Development Program of Shaanxi Province(2024GX-YBXM-442)Natural Science Basic Research Program of Shaanxi Province(2024JC-YBMS-477)。
文摘To predict the lithium-ion(Li-ion)battery degradation trajectory in the early phase,arranging the maintenance of battery energy storage systems is of great importance.However,under different operation conditions,Li-ion batteries present distinct degradation patterns,and it is challenging to capture negligible capacity fade in early cycles.Despite the data-driven method showing promising performance,insufficient data is still a big issue since the ageing experiments on the batteries are too slow and expensive.In this study,we proposed twin autoencoders integrated into a two-stage method to predict the early cycles'degradation trajectories.The two-stage method can properly predict the degradation from course to fine.The twin autoencoders serve as a feature extractor and a synthetic data generator,respectively.Ultimately,a learning procedure based on the long-short term memory(LSTM)network is designed to hybridize the learning process between the real and synthetic data.The performance of the proposed method is verified on three datasets,and the experimental results show that the proposed method can achieve accurate predictions compared to its competitors.
基金supported by the Bridging Grant from Universiti Sains Malaysia (R501LR-RND003–0000001319–0000)funding through the Fundamental Research Grant Scheme (FRGS/1/2020/TK0/USM/02/32–6171275) awarded by the Ministry of Higher Education Malaysia
文摘Current treatments for glioblastoma face challenges such as the blood-brain barrier and lack of targeted therapy,compounded by the aggressive nature,high invasiveness,and heterogeneity of the disease.Exosomes,a subtype of extracellular vesicles are emerging as promising nanocarrier drug delivery systems to address these limitations.Exosomes released by all cell types can be easily obtained and modified as delivery vehicles or therapeutic agents.A systematic review was conducted to evaluate various methods for exosome isolation,characterization,engineering or modification,drug loading and delivery efficiency,including exosome biodistribution and treatment efficacy.A search of four databases for in vitro and in vivo studies(2000–,2023)identified 6165 records,of which 23 articles were found eligible and included for analyses.Most studies applied ultracentrifugation(UC)for exosomes isolation.Cancer cell lines being the most frequently used source of exosomes,followed by stem cells.The incubation approach was predominantly utilized to modify exosomes for drug loading.In vivo analysis showed that exosome biodistribution was primarily concentrated in the brain region,peaking in the first 6 h and remained moderately high.Compared to native exosomes and untreated control groups,utilizing modified native exosomes(cargo loaded)for treating glioblastoma disease models led to more pronounced suppression of tumor growth and proliferation,enhanced stimulation of immune response and apoptosis,effective restoration of drug chemosensitivity,increased anti-tumor effect and prolonged survival rates.Modified exosomes whether through incubation,sonication,transfection,freeze-thawing or their combination,improve targeted delivery and therapeutic efficacy against glioblastoma.
基金MOHE (FRGS/1/2023/STG05/UITM/01/3) for funding support
文摘CRISPR-Cas system permanently deletes any harmful gene-of-interest to combat cancer growth.Chitosan(CS)is a potential cancer therapeutic that mediates via PI3K/Akt/mTOR,MAPK and NF-kβsignaling pathway modulation.CS and its covalent derivatives have been designed as nanocarrier of CRISPR-Cas9 alone(plasmid or ribonucleoprotein)or in combination with chemical drug for cancer treatment.The nanocarrier was functionalized with polyethylene glycol(PEG),targeting ligand,cell penetrating ligand and its inherent positive zeta potential to mitigate premature clearance and particulate aggregation,and promote cancer cell/nucleus targeting and permeabilization to enable CRISPR-Cas9 acting on the host DNA.Different physicochemical attributes are required for the CS-based nanocarrier to survive from the administration site,through the systemic circulation-extracellular matrix-mucus-mucosa axis,to the nucleus target.CRISPR-Cas9 delivery is met with heterogeneous uptake by the cancer cells.Choice of excipients such as targeting ligand and PEG may be inappropriate due to lacking overexpressed cancer receptor or availability of excessive metabolizing enzyme and immunoglobulin that defies the survival and action of these excipients rendering nanocarrier fails to reach the target site.Cancer omics analysis should be implied to select excipients which meet the pathophysiological needs,and chitosan nanocarrier with a“transformative physicochemical behavior”is essential to succeed CRISPR-Cas9 delivery.
基金Project supported by the National Key Laboratory of New Metal(Z2011-11)the National Natural Science Foundation of China(51471054)
文摘The Lao.67Mg0.33Ni2.5Co0.5 hydrogen storage alloy was prepared by the vacuum intermediate frequency induction furnace followed by annealing treatment. The pulverization degree of both the as-cast and annealed alloy powders after gaseous hydriding and dehydriding cycle was investigated and the discovery was that annealing treatment could hardly ameliorate their anti-pulverization ability. The element content of La, Mg, Ni and Co existing in electrolyte before and after the electrochemical cycles by using ICP-AES technology was also analyzed and it showed that a large amount of La and Mg were dissolved in the electrolyte, but the amount of dissolution for La and Mg significantly declined when the alloy was annealed. The XRD analysis revealed that all the al- loys consisted of two main phases AB3 and AB2 and a residual phase AB5 while annealing treatment made the AB2 phase decrease slightly. Furthermore, the anti-corrosion abilities of various elements in different phases of the as-cast and annealed alloy samples were studied by analyzing the element （La, Mg, Ni, Co） change with the corrosion time in phases AB3 and AB2 by means of EDS. It turned out that the element of La was mainly corroded out from the phase AB2 while not easily from the phase AB3. However, the element of Mg was both easily corroded out from the phases AB2 and AB3, but the corrosion was more obvious in the phase AB3. Therefore, annealing improved the anti-corrosion performances of La and Mg in the phase AB2.
基金financially supported by the China’s State Grid Corporation of Science and Technology Projects (No. SGRI-WD-71-13-002)the National Natural Science Foundation of China (No. 51171019)
文摘The significant occupancy of {411}〈148〉texture exists in the thin-gauge grain-oriented silicon steel(TGCRGO is defined that thickness of the sheet is〈0.25 mm and the reduction in cold rolling is more than 90%) which has been considered to have obviously effects on the abnormal growth of Goss-oriented grains during the secondary recrystallization process. The microstructures of the TG-CRGO were investigated by X-ray diffraction and electron back-scattered diffraction in this study. It was found that {411}〈148〉〉texture mainly exists in the center layer of hot-rolled as well as normalized plates.With the increase in cold rolling reduction, {411}〈148〉 orientation gradually rotates to a-fiber texture(〈110〉//RD).Finally, few {411}〈148〉would retain at the boundaries of deformed a-fiber grains(〈110〉//RD) as the reduction in cold rolling reaches 90%. After annealing treatment, a small amount of c-fiber textures(〈111〉//ND) preferably nucleates and recrystallizes between the DBs(deformation bands) at first; then, the {411}〈148〉 recrystallization texture occurs and mainly nucleates at the grains boundaries of the deformed a-fiber grains, and also quite a few {411}〈148〉orientation grains nucleate in the inner of {112}〈110〉grains. But this phenomenon was not observed in the {100}〈011〉deformation grains.With respect to the occurrence of {411}〈148〉recrystallization texture, it is mainly induced by strong a-fiber as well as weak c-fiber textures formed during cold rolling other than originating from {411}〈148〉 regions in hot bands.
基金support by National Natural Science Foundation of China(61202354,51507084)Nanjing University of Post and Telecommunications Science Foundation(NUPTSF)(NT214203)
基金supported by the National Key Research and Development Program of China(No.2021YFB4000101)the National Natural Science Foundation of China(No.52125102)the Fundamental Research Funds for the Central Universities(No.FRF-TP-2021–02C2).
文摘Hydrogen energy,whether in generation plants or utilization facilities,plays a decisive role in the mission to achieve net-zero greenhouse gas emissions,all to minimize pollution.The growing demand for clean energy carrier steadily accelerates the development of hydrogen production processes,and therein proton exchange membrane(PEM)water electrolysis is deemed a promising long-term strategy for hydrogen preparation and collection.This review retrospects recent developments and applications of bipolar plates(BPs)as key components in PEM fuel cells and water electrolysers.The main content includes multifaceted challenges in the R&D or fabrication of BPs and potential future trends have also been proposed.Specific details cover the BPs matrix(metallic materials and carbon composites)and the surface coating types(metal and compound coatings,carbon-based coatings,and polymer coatings),as well as the influence of flow field design for mass transport.Long-term development and feasible researches of BPs are prospected.Especially in the following aspects:(1)Structural and functional integration of components,such as material fabrication and flow field geometry optimization using 3D printing technology;(2)Introduction of environment-friendly renewable energy for hydrogen production;(3)Research on hydrogen energy reversible systems;(4)Composition optimization of surface coatings based on computational materials science and(5)systematic design expected to evolve into the next generation of BPs.
基金supported by the National Nature Science Foundation of China (Nos.21547011,21307036,51708356)the Natural Science Foundation of Guangdong Province (No.2014A030313761)the Science and Technology Research Project of Shenzhen (Nos.ZDSYS201606061530079,JCYJ20150324141711622,JCYJ20150529164656097)
文摘Electrolysis is a promising technology to improve sludge dewaterability efficiently with negligible environmental impact. To intensify the electrolytic efficiency, the effect of electrolytes(NaCl, Na_2SO_4, NaNO_3, and NaClO_4) on electrolysis pretreatment of municipal sludge and its mechanisms was investigated using Ti/PbO_2 electrodes. The electrolytes,which enhanced the production of oxidative radicals, showed a significant synergetic effect in reducing the capillary suction time(CST) of sludge. NaCl was distinguished from the other electrolytes since it formed a large amount of active chlorine species, which oxidized the sludge cells to improve the sludge dewaterability. The surface morphologies as well as the soluble proteins and polysaccharides were analyzed to unravel the underlying mechanisms of sludge dewaterability. Additionally, an economic assessment showed that NaCl addition in the electrolysis pretreatment can be a suitable technique for enhancing municipal sludge dewaterability.
基金supported by the State Key Laboratory of Advanced Power Transmission Technology(GEIRI-SKL-2021-014)。
文摘At present,only a single modification method is adopted to improve the shortcomings of erythritol(ET)as a phase change material(PCM).Compared with a single modification method,the synergistic effect of multiple modification methods can endow ET with comprehensive performance to meet the purpose of package,supercooling reduction,and enhancement of thermal conductivity.In this work,we innovatively combine graphene oxide(GO)nanosheet modified melamine foam(MF)and polyaniline(PANI)to construct a novel ET-based PCM by blending and porous material adsorption modification.PANI as the nucleation center can enhance the crystallization rate,thereby reducing the supercooling of ET.Meanwhile,GO@MF foam can not only be used as a porous support material to encapsulate ET but also as a heat conduction reinforcement to improve heat storage and release rate.As a result,the supercooling of GO@MF/PANI@ET(GMPET)composite PCM decreases from 91.2℃ of pure ET to 57.9℃ and its thermal conductivity(1.58 W·m^(-1)·K^(-1))is about three times higher than that of pure ET(0.57 W·m^(-1)·K^(-1)).Moreover,after being placed at 140℃ for 2 h,there is almost no ET leakage in the GMPET composite PCM,and the mass loss ratio is less than 0.75%.In addition,the GMPET composite PCM displays a high melting enthalpy of about 259 J·g^(-1) and a high initial mass loss temperature of about 198℃.Even after the 200th cycling test,the phase transition temperature and the latent heat storage capacity of the GMPET PCM all remain stable.This work offers an effective and promising strategy to design ET-based composite PCM for the field of energy storage.
基金financially supported by the Science and Technology Department of Guangxi Zhuang Autonomous (No.GuiKeAD21238022)the Natural Science Foundation of Guangxi Province (No.2019GXNSFBA185004)National Natural Science Foundation of China (Nos.52001079,51961005 and 52261038)。
文摘Many MXenes are efficient catalysts for MgH_(2)hydrogen storage material.Nevertheless,the synthesis of MXenes should consume a large amount of corrosive HF to etch out the Al layers from the transition metal aluminum carbides or nitrides(MAX) phases,which is environmentally unfriendly.In this work,Ti_(3)AlCN MAX without HFetching was employed directly to observably enhance the kinetics and the cycling stability of MgH_(2).With addition of10 wt% Ti_(3)AlCN,the onset dehydrogenation temperature of MgH2 was dropped from 320 to 205℃,and the rehydrogenation of MgH2 under 6 MPa H2 began at as low as50℃.Furthermore,at 300℃,it could provide 6.2 wt% of hydrogen in 10 min.Upon cycling,the composite underwent an activation process during the initial 40 cycles,with the reversible capacity increased from 4.7 wt% to 6.5 wt%.After that,the capacity showed almost no attenuation for up to 100 cycles.The enhancing effect of Ti_(3)AICN on MgH_(2) was comparable to many MXenes.It was demonstrated that Ti_(3)AICN did not destabilize MgH_(2) but acted as an efficient catalyst for MgH_(2).Ti_(3)AICN was observed to be the active sites for the nucleation and growth of MgH_(2)and might also help in dissociation and recombination of hydrogen molecules.Such two factors are believed to contribute to the improvement of MgH_(2).This study not only provides a promising strategy for improving the hydrogen storage performances of MgH_(2) by using noncorrosive MAX materials,but also adds evidence of nucleation and growth of MgH_(2) on a catalyst.
基金Supported in part by the Program of 2011(2nd)Innovative Research Teams and Leading Talents in Guangdong Province of Chinathe Program of Strategical Boomindustry Key Technology of Guangdong Province+3 种基金the Major Science and Technology Program of Dongguanthe Program of State Grid Smart Grid Research Institute(SGRI-WD-71-13-004)the National Natural Science Foundation of China(Nos 51102225 and 61274007)the Natural Science Foundation of Beijing(No 4132074).
文摘We investigate the triangular defects with different structural features on 4H-SiC epilayers by a Nomarski micro-scope,a Candela optical surface analyzer and ultraviolet photoluminescence(UV-PL)imaging.Both the foreign particles and the substrate scratches can cause the formation of the obtuse triangular defects.The central area of some obtuse triangular defects can have the spatially confined core,in which the in-grown stacking faults can be observed under the UV-PL imaging.In contrast,the obtuse triangular defects induced by the scratches appear in the form of band-like defects,of which the width depends on the scratch direction and reaches the maximum when the scratch direction is parallel to the step flow direction.The formation mechanisms of these obtuse triangular defects are discussed.
基金supported by the National Key Research and Development Project(2019YFB2102500)the National Nature Science Foundations of China(U20B2052)。
文摘Dear Editor,This letter proposes an unsupervised entity alignment method,which realizes integration of multiple multi-modal knowledge graphs adaptively.In recent years,Large-scale multi-modal knowledge graphs(LMKGs),containing text and image,have been widely applied in numerous knowledge-driven topics,such as question answering,entity linking,information extraction,reasoning and recommendation.
基金supported by Science and Technology Project of SGCC(5108-202218280A-2-375-XG)。
文摘In response to the underutilization of energy and insufficient flexible operation capability of rural energy supply systems in China,this study proposes an optimal dispatch approach for a rural multi-energy supply system(RMESS)considering virtual energy storage(VES).First,to enable the flexible utilization of rural biomass resources and the thermal inertia of residential building envelopes,this study constructed VES-I and VES-II models that describe electrical-thermal and electrical-gas coupling from an electrical viewpoint.Subsequently,an RMESS model encompassing these two types of VES was formulated.This model delineates the intricate interplay of multi-energy components within the RMESS framework and facilitates the precise assessment of the adjustable potential for optimizing RMESS operations.Based on the above models,a day-ahead optimal dispatch model for an RMESS considering a VES is proposed to achieve optimal economic performance while ensuring efficient energy allocation.Comparative simulations validated the effectiveness of the VES modeling and the day-ahead optimal dispatch approach for the RMESS.
