Aluminum (Al) toxicity is a considerable factor limiting crop yield and biomass in acidic soil. Tartary buckwheatgrowing in acidic soil may suffer from Al poisoning. Here, we investigated the influence of Al stress on...Aluminum (Al) toxicity is a considerable factor limiting crop yield and biomass in acidic soil. Tartary buckwheatgrowing in acidic soil may suffer from Al poisoning. Here, we investigated the influence of Al stress on the growthof tartary buckwheat seedling roots, and the alleviation of Al stress by silicon (Si), as has been demonstrated inmany crops. Under Al stress, root growth (total root length, primary root length, root tips, root surface area, androot volume) was significantly inhibited, and Al and malondialdehyde (MDA) accumulated in the root tips. At thesame time, catalase (CAT) and ascorbate peroxidase activities, polyphenols, flavonoids, and 1,1-diphenyl-2-picrylhydrazyl(DPPH) and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free-radical scavenging abilitywere significantly decreased. After the application of Si, root growth, Al accumulation, and oxidative damage wereimproved. Compared to Al-treated seedlings, the contents of ·O2− and MDA decreased by 29.39% and 25.22%,respectively. This was associated with Si-induced increases in peroxidase and CAT enzyme activity, flavonoidcompounds, and free-radical scavenging (DPPH and ABTS). The application of Si therefore has positive effectson Al toxicity in tartary buckwheat roots by reducing Al accumulation in the roots and maintaining oxidationhomeostasis.展开更多
Tartary buckwheat(Fagopyrum tataricum)is an important pseudocereal feed crop with medicinal and nutritional value.Drought is one of the main causes of reduced growth and yield in these plants.We investigated the growt...Tartary buckwheat(Fagopyrum tataricum)is an important pseudocereal feed crop with medicinal and nutritional value.Drought is one of the main causes of reduced growth and yield in these plants.We investigated the growth,physiological,and metabolic responses of the widely promoted Tartary buckwheat variety Chuan Qiao No.1 to polyethylene glycol(PEG)-mediated drought stress.Drought significantly decreased shoot length,shoot biomass and relative water content.Root length,malondialdehyde content,electrolyte leakage,activities of superoxide dismutase,peroxidase,catalase and amylase,and contents of soluble sugar,soluble protein and proline were increased by PEG-mediated drought.Untargeted metabolomics analysis identified 32 core metabolites in seedlings subjected to PEG-mediated drought,16 of which increased—including quercetin,isovitexin,cyanidin 3-O-beta-D-glucoside,L-arginine,and glycerophosphocholine,while the other 16 decreased—including 3-methoxytyramine,2,6-diaminopimelic acid,citric acid,UDP-alpha-D-glucose,adenosine,keto-D-fructose.The 32 core metabolites were enriched in 29 metabolic pathways,including lysine biosynthesis,citrate(TCA)cycle,anthocyanin biosynthesis,and aminoacyl-tRNA biosynthesis.Among them,taurine and hypotaurine metabolism,flavor and flavor biosynthesis,indole alkaline biosynthesis,and alanine,aspartate and glutamate metabolism were the four main metabolic pathways affected by drought.Our findings provide new insights into the physiological and metabolic response mechanisms of Tartary buckwheat to drought stress.展开更多
In this work,a covalent organic framework(COF),which is constructed by the building blocks of[5,10,15,20-tetrakis(4-aminophenyl)porphinato]copper(Ⅱ)(CuTAPP)and p-benzaldehyde,is employed to integrate with TiO_(2) for...In this work,a covalent organic framework(COF),which is constructed by the building blocks of[5,10,15,20-tetrakis(4-aminophenyl)porphinato]copper(Ⅱ)(CuTAPP)and p-benzaldehyde,is employed to integrate with TiO_(2) for the purpose of establishing a Z-scheme hybrid.Within the system,isonicotinic acid performs the role of a bridge that connects the two components through a coordination bond.Further photocatalytic application reveals the hybrid framework is able to catalyze CO_(2) conversion under simulated solar light,resulting in CO production rate of 50.5 μmol g^(-1)·h^(-1),about 9.9 and 24.5 times that of COF and pristine TiO_(2),respectively.The ameliorated catalytic performance owes much to the por-phyrin block acting as photosensitizer that augments the light absorbance,and the establishment of Z-scheme system between the inorganic and orga nic comp on ents that enhances the separati on of the carriers.In addition,the chemical bridge also ensures a steady usage and stable charge delivery in the catalysis.Our study sheds light on the development of versatile approaches to covalently in corporate COFs with inorga nic semic on ductors.展开更多
Industrial Internet of Things(IoT)connecting society and industrial systems represents a tremendous and promising paradigm shift.With IoT,multimodal and heterogeneous data from industrial devices can be easily collect...Industrial Internet of Things(IoT)connecting society and industrial systems represents a tremendous and promising paradigm shift.With IoT,multimodal and heterogeneous data from industrial devices can be easily collected,and further analyzed to discover device maintenance and health related potential knowledge behind.IoT data-based fault diagnosis for industrial devices is very helpful to the sustainability and applicability of an IoT ecosystem.But how to efficiently use and fuse this multimodal heterogeneous data to realize intelligent fault diagnosis is still a challenge.In this paper,a novel Deep Multimodal Learning and Fusion(DMLF)based fault diagnosis method is proposed for addressing heterogeneous data from IoT environments where industrial devices coexist.First,a DMLF model is designed by combining a Convolution Neural Network(CNN)and Stacked Denoising Autoencoder(SDAE)together to capture more comprehensive fault knowledge and extract features from different modal data.Second,these multimodal features are seamlessly integrated at a fusion layer and the resulting fused features are further used to train a classifier for recognizing potential faults.Third,a two-stage training algorithm is proposed by combining supervised pre-training and fine-tuning to simplify the training process for deep structure models.A series of experiments are conducted over multimodal heterogeneous data from a gear device to verify our proposed fault diagnosis method.The experimental results show that our method outperforms the benchmarking ones in fault diagnosis accuracy.展开更多
In order to systematically explain the spreading mechanism of vertical fire,Pyrosim software with fire dynamic modules is used to simulate the fire spreading characteristics in a five-storey residential apartment buil...In order to systematically explain the spreading mechanism of vertical fire,Pyrosim software with fire dynamic modules is used to simulate the fire spreading characteristics in a five-storey residential apartment building.The vertical spread characteristics of fire,high-temperature smoke,and leap-frog behavior are analyzed by evaluating the distribution of pressure,temperature,and gas flow velocity in the studied numerical fire field.In addition,considering the possible cases of high-rise building fire in reality,the fire spreading characteristics of three different opening sequences of glass windows are given:(i)only the windows on the first floor are open;(ii)the windows are randomly opened by the high temperature of the glass;(iii)all glass windows from the first to the fifth floors are open.The simulation results show that an appropriate increase of turbulent flow in the low-level area can greatly reduce the fire temperature in the high-level area,which can provide a certain reference for the safety and design of building fire protection in the future.展开更多
Water splitting by photoelectrochemical(PEC)processes to convert solar energy into hydrogen energy using semiconductors is regarded as one of the most ideal methods to solve the current energy crisis and has attracted...Water splitting by photoelectrochemical(PEC)processes to convert solar energy into hydrogen energy using semiconductors is regarded as one of the most ideal methods to solve the current energy crisis and has attracted widespread attention.Herein,Co-based metal-organic framework(Co(bpdc)(H_(2)O)_(4)(CoMOF)nanosheets as passivation layers were in-situ constructed on the surface of Bi VO_(4)films through an uncomplicated hydrothermal method(Co-MOF/Bi VO_(4)).Under AM 1.5G illumination,synthesized CoMOF/BiVO_(4)electrode exhibited a 4-fold higher photocurrent than bare Bi VO_(4),measuring 6.0 m A/cm^(2)at 1.23 V vs.RHE in 1 mol/L potassium borate electrolyte(pH 9.5)solution.Moreover,the Co-MOF/BiVO_(4)film demonstrated a 96%charge separation efficiency,a result caused by an inhibited recombination rate of photogenerated electrons and holes by the addition of Co-MOF nanosheets.This work provides an idea for depositing inexpensive 2D Co-MOF nanosheets on the photoanode as an excellent passivation layer for solar fuel production.展开更多
Reaction kinetics of nanoparticles can be controlled by tuning the Peclet number(Pe)as it is an essential parameter in synthesis of multi-sized nanoparticles.Herein,we propose to implement a self-driven multi-dimensio...Reaction kinetics of nanoparticles can be controlled by tuning the Peclet number(Pe)as it is an essential parameter in synthesis of multi-sized nanoparticles.Herein,we propose to implement a self-driven multi-dimension microchannels reactor(MMR)for the one droplet synthesis of multi-sized nanoparticles.By carefully controlling the Pe at the gas-liquid interface,the newly formed seed crystals selectively accumulate and grow to a specific size.By the combination of microchannels of different widths and lengths,one droplet reaction in the same apparatus achieves the synchronous synthesis of diverse nanoparticles.MMR enables precise control of nanoparticle diameter at 5 nm precision in the range of 10-110 nm.The use of MMR can be extended to the synthesis of uniform Ag,Au,Pt,and Pd nanoparticles,opening towards the production and engineering of nanostructured materials.This approach gives the chance to regulate the accumulation probability for precise synthesis of nanoparticles with different diameters.展开更多
As one of the highly effective methods to prepare catalysts for photocatalytic reduction of CO2 into valueadded chemicals,using metalloporphyrin as light-harvesting mixed ligand to modify metal-organic framework(MOF)i...As one of the highly effective methods to prepare catalysts for photocatalytic reduction of CO2 into valueadded chemicals,using metalloporphyrin as light-harvesting mixed ligand to modify metal-organic framework(MOF)is very valuable since it can greatly improve the prophyrin dispersibility and consequently inhibit its potential agglomeration.Herein,we employed a one-pot synthetic strategy to chemically immobilize Cu(II)tetra(4-carboxylphenyl)porphyrin(CuTCPP)into UiO-66 MOF structure through coordination mode.Meanwhile,in-situ growth of TiO2 nanoparticles onto the MOF is actualized with the generation of CuTCPP c UiO-66/TiO2(CTU/TiO2)composites.Under Xe lamp irradiation(λ>300 nm),the catalytic result presents that an optimal value of 31.32 μmol g^-1 h^-1 CO evolution amount,about 7 times higher than that of pure TiO2 was obtained through the photocatalysis.It is supposed owning to a consistent augment of light absorption derived from chemically implanted porphyrin derivative,which is simultaneously functioning with an efficacious separation of photo-induced carries given by the newly engendered composites between MOF and TiO2,an effective catalytic activity and approving recyclability of CTU/TiO2 can be achieved in the photocatalytic reduction of CO2 into CO.展开更多
In this study,a graphitic carbon nitride(g-C_(3)N_(4))based ternary catalyst Cu O/Cu Fe_(2)O_(4)/gC_(3)N_(4)(CCCN)is successfully prepared thorough calcination method.After confirming the structure and composition of ...In this study,a graphitic carbon nitride(g-C_(3)N_(4))based ternary catalyst Cu O/Cu Fe_(2)O_(4)/gC_(3)N_(4)(CCCN)is successfully prepared thorough calcination method.After confirming the structure and composition of CCCN,the as-synthesized composites are utilized to activate persulfate(PS)for the degradation of organic contaminant.While using tetracycline hydrochloride(TC)as pollutant surrogate,the effects of initial p H,PS and catalyst concentration on the degradation rate are systematically studied.Under the optimized reaction condition,CCCN/PS is able to give 99%degradation extent and 74%chemical oxygen demand removal in assistance of simulated solar light,both of which are apparently greater than that of either Cu O/Cu Fe_(2)O_(4)and pristine g-C_(3)N_(4).The great improvement in degradation can be assignable to the effective separation of photoinduced carriers thanks to the integration between Cu O/Cu Fe_(2)O_(4)and g-C_(3)N_(4),as well as the increased reaction sites given by the g-C_(3)N_(4)substrate.Moreover,the scavenging trials imply that the major oxidative matters involved in the decomposition are hydroxyl radicals(·OH),superoxide radicals(·O_(2)^(-))and photo-induced holes(h^(+)).展开更多
Photoelectrochemical(PEC)water splitting is an effective strategy to convert solar energy into clean and renewable hydrogen energy.In order to carry out effective PEC conversion,researchers have conducted a lot of exp...Photoelectrochemical(PEC)water splitting is an effective strategy to convert solar energy into clean and renewable hydrogen energy.In order to carry out effective PEC conversion,researchers have conducted a lot of exploration and developed a variety of semiconductors suitable for PEC water splitting.Among them,metal oxides stand out due to their higher stability.Compared with traditional oxide semiconductors,ferrite-based photoelectrodes have the advantages of low cost,small band gap,and good stability.Interestingly,due to the unique characteristics of ferrite,most of them have various tunable features,which will be more conducive to the development of efficient PEC electrode.However,this complex metal oxide is also troubled by severe charge recombination and low carrier transport efficiency,resulting in lower conversion efficiency compared to theoretical value.Based on this,this article reviews the structure,preparation methods,characteristics and modification strategies of various common ferrites.In addition,we analyzed the future research direction of ferrite for PEC water splitting,and looked forward to the development of more efficient catalysts.展开更多
With the rapid development of indium tin oxide(ITO)in the electronic display industry,choosing which raw powders to prepare high-quality ITO targets has always been a controversial topic.In the work,in order to clearl...With the rapid development of indium tin oxide(ITO)in the electronic display industry,choosing which raw powders to prepare high-quality ITO targets has always been a controversial topic.In the work,in order to clearly understand the effect of the raw powders on the microstructure and properties of ITO targets and thin films,tin-doped indium oxide(dITO)and In_(2)O_3-SnO_(2)mixed(mITO)powders were chosen to prepare ITO targets for depositing the films and a comparative study on their microstructure and properties was conducted.It is found that,(1)dITO targets possess a higher solid solubility of tin in indium oxide and more uniform elemental distribution,while there are a higher density,a finer grain size and a higher mass ratio of In_(2)O_3 to SnO_(2)for the mITO targets;(2)dITO films with more coarser columnar grains and a rougher surface prefer to grow along the[100]direction in an Ar atmosphere;(3)the conductive property of ITO films only depends on the doping amount of tin and is independent of the raw powders and the preparation process of the target source;(4)dITO films possess the superior optical property and narrower optical band gap;(5)the etching property of mITO films is superior to that of dITO films due to the lower solid solubility of tin in indium oxide.展开更多
The construction of rich phase interfaces to increase active reaction area in hybrid materials is an excellent strategy to improve electrochemical performance.Under this guideline,MIL-101@OX-metal organic framework(MO...The construction of rich phase interfaces to increase active reaction area in hybrid materials is an excellent strategy to improve electrochemical performance.Under this guideline,MIL-101@OX-metal organic framework(MOF)is constructed by the"MOF on MOF"method,then converts to MIL-101@NiFe-layered double hydroxides(LDH)by in situ transformation in alkaline solution.MIL-101@NiFe-LDH shows excellent electrochemical water oxidation performance.It needs only an overpotential of 215 m V to drive10 m A/cm^(2)of oxygen evolution reaction(OER),which is less than that of NiFe-LDH,MIL-101.In addition,MIL-101@NiFe-LDH has the smallest Tafel slope(55.1 mV/dec)compared with Ni Fe-LDH(61.1 m V/dec),MIL-101(150.8 m V/dec).The excellent water oxidation activity is due to the high phase interfaces derived from high specific surface area of MOF.This work offers an alternative method for making MOF/LDH heterostructures with an optimized phase interfaces and provides new insights for OER.展开更多
Due to the involvement of four-electron transfer process at photoanode,water oxidation is the ratelimiting step in water splitting reaction.To settle this dilemma,ZnCo_(2)O_(4)nanoparticles are combined with BiVO_(4)t...Due to the involvement of four-electron transfer process at photoanode,water oxidation is the ratelimiting step in water splitting reaction.To settle this dilemma,ZnCo_(2)O_(4)nanoparticles are combined with BiVO_(4)to form a p-n ZnCo_(2)O_(4)/BiVO;heterojunction photoanode,which is proved by an input voltage-output current test.The built-in electric field formed within the heterojunction structure promotes the effective separation of electrons and holes.ZnCo_(2)O_(4)is also an effective water oxidation cocatalyst,since it could cause the holes entering the electrode/electrolyte interface rapidly for the subsequent water oxidation reaction.The photocurrent density of ZnCo_(2)O_(4)/BiVO_(4)composite photoanode reaches 3.0 mA/cm^(2) at 1.23 V vs.RHE in 0.5 mol/L sodium sulfate under AM 1.5 G simulated sunlight,about 2.1 times greater than that of BiVO_(4)(1.4 mA/cm^(2)).These results suggest the potential of ZnCo_(2)O_(4)nanoparticles for improving photoelectrochemical water splitting anode materials.展开更多
The serious surface charge recombination and fatigued photogenerated carriers transfer of the BiVO_(4)photoanode restrict its photoelectrochemical(PEC)water splitting performance.In this work,nickel fluoride(NiF_(2))i...The serious surface charge recombination and fatigued photogenerated carriers transfer of the BiVO_(4)photoanode restrict its photoelectrochemical(PEC)water splitting performance.In this work,nickel fluoride(NiF_(2))is applied to revamp pure BiVO_(4)photoanode by using a facile electrodeposition method.As a result,the asprepared NiF_(2)/BiVO_(4)photoanode increases the dramatic photocurrent density by approximately 180%compared with the pristine BiVO_(4)photoanode.Furthermore,the correlative photon-to-current conversion efficiency,the charge injection,and the separation efficiency,as well as the hydrogen generation of the composite photoanode have been memorably enhanced due to the synergy of NiF_(2)and BiVO_(4).This study may furnish a dependable guidance in fabricating the fluoride-based compound/semiconductor composite photoanode system.展开更多
基金Science&Technology Department of Sichuan Province(2022YFQ0041,2022NSFSC1725,2023NSFSC0214)China Agriculture Research System(CARS-07-B-1)+2 种基金The National Natural Science Foundation of China(32160428)Innovative Training Program for College Students(202311079040,S202311079112,CDUCX2023550)Undergraduate Education and Teaching Reform Project of Chengdu University(cdjgb2022186).
文摘Aluminum (Al) toxicity is a considerable factor limiting crop yield and biomass in acidic soil. Tartary buckwheatgrowing in acidic soil may suffer from Al poisoning. Here, we investigated the influence of Al stress on the growthof tartary buckwheat seedling roots, and the alleviation of Al stress by silicon (Si), as has been demonstrated inmany crops. Under Al stress, root growth (total root length, primary root length, root tips, root surface area, androot volume) was significantly inhibited, and Al and malondialdehyde (MDA) accumulated in the root tips. At thesame time, catalase (CAT) and ascorbate peroxidase activities, polyphenols, flavonoids, and 1,1-diphenyl-2-picrylhydrazyl(DPPH) and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free-radical scavenging abilitywere significantly decreased. After the application of Si, root growth, Al accumulation, and oxidative damage wereimproved. Compared to Al-treated seedlings, the contents of ·O2− and MDA decreased by 29.39% and 25.22%,respectively. This was associated with Si-induced increases in peroxidase and CAT enzyme activity, flavonoidcompounds, and free-radical scavenging (DPPH and ABTS). The application of Si therefore has positive effectson Al toxicity in tartary buckwheat roots by reducing Al accumulation in the roots and maintaining oxidationhomeostasis.
基金We acknowledge the Project of National Key Research and Development Program of China(2020YFD1001403)China Agriculture Research System(CARS-07-B-1)+3 种基金Science&Technology Department of Sichuan Province(2022YFQ0041)the National Natural Science Foundation of China(31601260,32160428)Innovative Training Program for College Students(S202111079058)Special Research Fund from Key Laboratory of Coarse Cereal Processing,Ministry of Agriculture and Rural Affairs(2020CC012)to facilitate the research.
文摘Tartary buckwheat(Fagopyrum tataricum)is an important pseudocereal feed crop with medicinal and nutritional value.Drought is one of the main causes of reduced growth and yield in these plants.We investigated the growth,physiological,and metabolic responses of the widely promoted Tartary buckwheat variety Chuan Qiao No.1 to polyethylene glycol(PEG)-mediated drought stress.Drought significantly decreased shoot length,shoot biomass and relative water content.Root length,malondialdehyde content,electrolyte leakage,activities of superoxide dismutase,peroxidase,catalase and amylase,and contents of soluble sugar,soluble protein and proline were increased by PEG-mediated drought.Untargeted metabolomics analysis identified 32 core metabolites in seedlings subjected to PEG-mediated drought,16 of which increased—including quercetin,isovitexin,cyanidin 3-O-beta-D-glucoside,L-arginine,and glycerophosphocholine,while the other 16 decreased—including 3-methoxytyramine,2,6-diaminopimelic acid,citric acid,UDP-alpha-D-glucose,adenosine,keto-D-fructose.The 32 core metabolites were enriched in 29 metabolic pathways,including lysine biosynthesis,citrate(TCA)cycle,anthocyanin biosynthesis,and aminoacyl-tRNA biosynthesis.Among them,taurine and hypotaurine metabolism,flavor and flavor biosynthesis,indole alkaline biosynthesis,and alanine,aspartate and glutamate metabolism were the four main metabolic pathways affected by drought.Our findings provide new insights into the physiological and metabolic response mechanisms of Tartary buckwheat to drought stress.
基金supported by the National Natural Science Foundation of China(21663027,51262028,21261021)the Science and Technology Support Project of Gansu Province(1504GKCA027)+2 种基金the Program for the Young Innovative Talents of Longyuanthe Program for Innovative Research Team(NWNULKQN-15-2)the Undergraduate Academic Innovative Research Team of Northwest Normal University~~
基金financially supported by the National Natural Science Foundation of China (21808189, 21663027)the Science and Technology Support Project of Gansu Province (1504GKCA027)+2 种基金the Program for Innovative Research Team (NWNULKQN-15-2)the Opening Project of Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control (GKLECPC-12)the Opening Project of Key Laboratory of Green Catalysis of Sichuan Institutes of High Education (LYJ18205)~~
基金financially supported by the National Natural Science Foundation of China (21663027 and 21808189)the Key Science and Technology Foundation of Gansu Province (20YF3GA021)+2 种基金the Innovation funding program of Universities of Gansu province (2020B-091)the Opening Project of Key Laboratory of Green Chemistry of Sichuan Institutes of Higher Education (LYJ18205)the Promotion Project of Young-Teacher Researchcapacity of Northwest Normal University (NWNU-LKQN-18-5).
文摘In this work,a covalent organic framework(COF),which is constructed by the building blocks of[5,10,15,20-tetrakis(4-aminophenyl)porphinato]copper(Ⅱ)(CuTAPP)and p-benzaldehyde,is employed to integrate with TiO_(2) for the purpose of establishing a Z-scheme hybrid.Within the system,isonicotinic acid performs the role of a bridge that connects the two components through a coordination bond.Further photocatalytic application reveals the hybrid framework is able to catalyze CO_(2) conversion under simulated solar light,resulting in CO production rate of 50.5 μmol g^(-1)·h^(-1),about 9.9 and 24.5 times that of COF and pristine TiO_(2),respectively.The ameliorated catalytic performance owes much to the por-phyrin block acting as photosensitizer that augments the light absorbance,and the establishment of Z-scheme system between the inorganic and orga nic comp on ents that enhances the separati on of the carriers.In addition,the chemical bridge also ensures a steady usage and stable charge delivery in the catalysis.Our study sheds light on the development of versatile approaches to covalently in corporate COFs with inorga nic semic on ductors.
基金supported in part by the National Key Research and Development Program of China(No.2018YFB1003700)in part by the National Natural Science Foundation of China(No.61836001)。
文摘Industrial Internet of Things(IoT)connecting society and industrial systems represents a tremendous and promising paradigm shift.With IoT,multimodal and heterogeneous data from industrial devices can be easily collected,and further analyzed to discover device maintenance and health related potential knowledge behind.IoT data-based fault diagnosis for industrial devices is very helpful to the sustainability and applicability of an IoT ecosystem.But how to efficiently use and fuse this multimodal heterogeneous data to realize intelligent fault diagnosis is still a challenge.In this paper,a novel Deep Multimodal Learning and Fusion(DMLF)based fault diagnosis method is proposed for addressing heterogeneous data from IoT environments where industrial devices coexist.First,a DMLF model is designed by combining a Convolution Neural Network(CNN)and Stacked Denoising Autoencoder(SDAE)together to capture more comprehensive fault knowledge and extract features from different modal data.Second,these multimodal features are seamlessly integrated at a fusion layer and the resulting fused features are further used to train a classifier for recognizing potential faults.Third,a two-stage training algorithm is proposed by combining supervised pre-training and fine-tuning to simplify the training process for deep structure models.A series of experiments are conducted over multimodal heterogeneous data from a gear device to verify our proposed fault diagnosis method.The experimental results show that our method outperforms the benchmarking ones in fault diagnosis accuracy.
基金the financial support from the National Science Foundation of China(Nos.51904311,52130409,52121003)China University of Mining and Technology(Beijing)Undergraduate Innovation training program(202112011)Beijing university students'innovative entrepreneurial training inter-school cooperation program(202198027).
文摘In order to systematically explain the spreading mechanism of vertical fire,Pyrosim software with fire dynamic modules is used to simulate the fire spreading characteristics in a five-storey residential apartment building.The vertical spread characteristics of fire,high-temperature smoke,and leap-frog behavior are analyzed by evaluating the distribution of pressure,temperature,and gas flow velocity in the studied numerical fire field.In addition,considering the possible cases of high-rise building fire in reality,the fire spreading characteristics of three different opening sequences of glass windows are given:(i)only the windows on the first floor are open;(ii)the windows are randomly opened by the high temperature of the glass;(iii)all glass windows from the first to the fifth floors are open.The simulation results show that an appropriate increase of turbulent flow in the low-level area can greatly reduce the fire temperature in the high-level area,which can provide a certain reference for the safety and design of building fire protection in the future.
基金financially supported by the National Natural Science Foundation of China(No.52173277)the Innovative Research Team for Science and Technology of Shaanxi Province(No.2022TD-04)+1 种基金the Fundamental Research Funds for the Central Universities of Chang’an University(Nos.300102299304,300102291403)the Natural Science Basic Research Fund of Shaanxi Province(No.2020JZ-20)。
文摘Water splitting by photoelectrochemical(PEC)processes to convert solar energy into hydrogen energy using semiconductors is regarded as one of the most ideal methods to solve the current energy crisis and has attracted widespread attention.Herein,Co-based metal-organic framework(Co(bpdc)(H_(2)O)_(4)(CoMOF)nanosheets as passivation layers were in-situ constructed on the surface of Bi VO_(4)films through an uncomplicated hydrothermal method(Co-MOF/Bi VO_(4)).Under AM 1.5G illumination,synthesized CoMOF/BiVO_(4)electrode exhibited a 4-fold higher photocurrent than bare Bi VO_(4),measuring 6.0 m A/cm^(2)at 1.23 V vs.RHE in 1 mol/L potassium borate electrolyte(pH 9.5)solution.Moreover,the Co-MOF/BiVO_(4)film demonstrated a 96%charge separation efficiency,a result caused by an inhibited recombination rate of photogenerated electrons and holes by the addition of Co-MOF nanosheets.This work provides an idea for depositing inexpensive 2D Co-MOF nanosheets on the photoanode as an excellent passivation layer for solar fuel production.
基金supported by the Beijing Nova Program from Beijing Municipal Science&Technology Commission(Nos.Z201100006820037 and Z211100002121001)the National Key R&D Program of China(No.2018YFA0208501)+3 种基金the National Natural Science Foundation of China(Nos.22075296,91963212,and 51961145102)the Youth Innovation Promotion Association,the Chinese Academy of Sciences(No.2020032)Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXXM-202005)F.F.Q.and J.C.acknowledge the Swiss National Super Computing Center(Project No.s1081)for providing the computing support.B.D.C.acknowledges Jiarong Yang for his support in graphing.
文摘Reaction kinetics of nanoparticles can be controlled by tuning the Peclet number(Pe)as it is an essential parameter in synthesis of multi-sized nanoparticles.Herein,we propose to implement a self-driven multi-dimension microchannels reactor(MMR)for the one droplet synthesis of multi-sized nanoparticles.By carefully controlling the Pe at the gas-liquid interface,the newly formed seed crystals selectively accumulate and grow to a specific size.By the combination of microchannels of different widths and lengths,one droplet reaction in the same apparatus achieves the synchronous synthesis of diverse nanoparticles.MMR enables precise control of nanoparticle diameter at 5 nm precision in the range of 10-110 nm.The use of MMR can be extended to the synthesis of uniform Ag,Au,Pt,and Pd nanoparticles,opening towards the production and engineering of nanostructured materials.This approach gives the chance to regulate the accumulation probability for precise synthesis of nanoparticles with different diameters.
基金financially supported by the National Natural Science Foundation of China (21663027, 21808189)the Science and Technology Support Project of Gansu Province (1504GKCA027)
文摘As one of the highly effective methods to prepare catalysts for photocatalytic reduction of CO2 into valueadded chemicals,using metalloporphyrin as light-harvesting mixed ligand to modify metal-organic framework(MOF)is very valuable since it can greatly improve the prophyrin dispersibility and consequently inhibit its potential agglomeration.Herein,we employed a one-pot synthetic strategy to chemically immobilize Cu(II)tetra(4-carboxylphenyl)porphyrin(CuTCPP)into UiO-66 MOF structure through coordination mode.Meanwhile,in-situ growth of TiO2 nanoparticles onto the MOF is actualized with the generation of CuTCPP c UiO-66/TiO2(CTU/TiO2)composites.Under Xe lamp irradiation(λ>300 nm),the catalytic result presents that an optimal value of 31.32 μmol g^-1 h^-1 CO evolution amount,about 7 times higher than that of pure TiO2 was obtained through the photocatalysis.It is supposed owning to a consistent augment of light absorption derived from chemically implanted porphyrin derivative,which is simultaneously functioning with an efficacious separation of photo-induced carries given by the newly engendered composites between MOF and TiO2,an effective catalytic activity and approving recyclability of CTU/TiO2 can be achieved in the photocatalytic reduction of CO2 into CO.
基金financially supported by the National Natural Science Foundation of China(Nos.21663027 and 21808189)the Key Science and Technology Foundation of Gansu Province(No.20YF3GA021)+2 种基金the Innovation funding program of Universities of Gansu province(No.2020B-091)the Opening Project of Key Laboratory of Green Chemistry of Sichuan Institutes of Higher Education(No.LYJ18205)the Promotion Project of Young-Teacher Research-capacity of Northwest Normal University(No.NWNU-LKQN-18-5)。
文摘In this study,a graphitic carbon nitride(g-C_(3)N_(4))based ternary catalyst Cu O/Cu Fe_(2)O_(4)/gC_(3)N_(4)(CCCN)is successfully prepared thorough calcination method.After confirming the structure and composition of CCCN,the as-synthesized composites are utilized to activate persulfate(PS)for the degradation of organic contaminant.While using tetracycline hydrochloride(TC)as pollutant surrogate,the effects of initial p H,PS and catalyst concentration on the degradation rate are systematically studied.Under the optimized reaction condition,CCCN/PS is able to give 99%degradation extent and 74%chemical oxygen demand removal in assistance of simulated solar light,both of which are apparently greater than that of either Cu O/Cu Fe_(2)O_(4)and pristine g-C_(3)N_(4).The great improvement in degradation can be assignable to the effective separation of photoinduced carriers thanks to the integration between Cu O/Cu Fe_(2)O_(4)and g-C_(3)N_(4),as well as the increased reaction sites given by the g-C_(3)N_(4)substrate.Moreover,the scavenging trials imply that the major oxidative matters involved in the decomposition are hydroxyl radicals(·OH),superoxide radicals(·O_(2)^(-))and photo-induced holes(h^(+)).
基金This work was financially supported by the National Natural Science Foundation of China(21808189,52173277)National Natural Science Foundation of Gansu province(No.20JR5RA523)the Young Teachers’Research Ability Improvement Project of Northwest Normal University(NWNULKQN2020-01).
文摘Photoelectrochemical(PEC)water splitting is an effective strategy to convert solar energy into clean and renewable hydrogen energy.In order to carry out effective PEC conversion,researchers have conducted a lot of exploration and developed a variety of semiconductors suitable for PEC water splitting.Among them,metal oxides stand out due to their higher stability.Compared with traditional oxide semiconductors,ferrite-based photoelectrodes have the advantages of low cost,small band gap,and good stability.Interestingly,due to the unique characteristics of ferrite,most of them have various tunable features,which will be more conducive to the development of efficient PEC electrode.However,this complex metal oxide is also troubled by severe charge recombination and low carrier transport efficiency,resulting in lower conversion efficiency compared to theoretical value.Based on this,this article reviews the structure,preparation methods,characteristics and modification strategies of various common ferrites.In addition,we analyzed the future research direction of ferrite for PEC water splitting,and looked forward to the development of more efficient catalysts.
基金financially supported by the National Key R&D Program of China(No.2017YFB0305401)the National Natural Science Foundation of China(Nos.51874369 and 51871249)the Huxiang Young Talents Plan(No.2018RS3007)。
文摘With the rapid development of indium tin oxide(ITO)in the electronic display industry,choosing which raw powders to prepare high-quality ITO targets has always been a controversial topic.In the work,in order to clearly understand the effect of the raw powders on the microstructure and properties of ITO targets and thin films,tin-doped indium oxide(dITO)and In_(2)O_3-SnO_(2)mixed(mITO)powders were chosen to prepare ITO targets for depositing the films and a comparative study on their microstructure and properties was conducted.It is found that,(1)dITO targets possess a higher solid solubility of tin in indium oxide and more uniform elemental distribution,while there are a higher density,a finer grain size and a higher mass ratio of In_(2)O_3 to SnO_(2)for the mITO targets;(2)dITO films with more coarser columnar grains and a rougher surface prefer to grow along the[100]direction in an Ar atmosphere;(3)the conductive property of ITO films only depends on the doping amount of tin and is independent of the raw powders and the preparation process of the target source;(4)dITO films possess the superior optical property and narrower optical band gap;(5)the etching property of mITO films is superior to that of dITO films due to the lower solid solubility of tin in indium oxide.
基金financially supported by the National Natural Science Foundation of China(No.21808189)the National Natural Science Foundation of Gansu(No.20JR5RA523)the Young Teachers’Research Ability Improvement Project of Northwest Normal University(NWNU-LKQN2020-01)。
文摘The construction of rich phase interfaces to increase active reaction area in hybrid materials is an excellent strategy to improve electrochemical performance.Under this guideline,MIL-101@OX-metal organic framework(MOF)is constructed by the"MOF on MOF"method,then converts to MIL-101@NiFe-layered double hydroxides(LDH)by in situ transformation in alkaline solution.MIL-101@NiFe-LDH shows excellent electrochemical water oxidation performance.It needs only an overpotential of 215 m V to drive10 m A/cm^(2)of oxygen evolution reaction(OER),which is less than that of NiFe-LDH,MIL-101.In addition,MIL-101@NiFe-LDH has the smallest Tafel slope(55.1 mV/dec)compared with Ni Fe-LDH(61.1 m V/dec),MIL-101(150.8 m V/dec).The excellent water oxidation activity is due to the high phase interfaces derived from high specific surface area of MOF.This work offers an alternative method for making MOF/LDH heterostructures with an optimized phase interfaces and provides new insights for OER.
基金financially supported by the National Natural Science Foundation of China (Nos. 21808189 and 21663027)Natural Science Basic Research Fund of Shaanxi Province (No.2020JZ20)Fundamental Research Funds for the Central Universities of Chang’an University (No. 300102299304)。
文摘Due to the involvement of four-electron transfer process at photoanode,water oxidation is the ratelimiting step in water splitting reaction.To settle this dilemma,ZnCo_(2)O_(4)nanoparticles are combined with BiVO_(4)to form a p-n ZnCo_(2)O_(4)/BiVO;heterojunction photoanode,which is proved by an input voltage-output current test.The built-in electric field formed within the heterojunction structure promotes the effective separation of electrons and holes.ZnCo_(2)O_(4)is also an effective water oxidation cocatalyst,since it could cause the holes entering the electrode/electrolyte interface rapidly for the subsequent water oxidation reaction.The photocurrent density of ZnCo_(2)O_(4)/BiVO_(4)composite photoanode reaches 3.0 mA/cm^(2) at 1.23 V vs.RHE in 0.5 mol/L sodium sulfate under AM 1.5 G simulated sunlight,about 2.1 times greater than that of BiVO_(4)(1.4 mA/cm^(2)).These results suggest the potential of ZnCo_(2)O_(4)nanoparticles for improving photoelectrochemical water splitting anode materials.
基金This work was financially supported by the National Key Research and Development Program of China(Grant No.2017YFC0602306)the National Natural Science Foundation of China(Grant No.21808189)National Natural Science Foundation of Gansu Province(Grant No.20JR5RA523).
文摘The serious surface charge recombination and fatigued photogenerated carriers transfer of the BiVO_(4)photoanode restrict its photoelectrochemical(PEC)water splitting performance.In this work,nickel fluoride(NiF_(2))is applied to revamp pure BiVO_(4)photoanode by using a facile electrodeposition method.As a result,the asprepared NiF_(2)/BiVO_(4)photoanode increases the dramatic photocurrent density by approximately 180%compared with the pristine BiVO_(4)photoanode.Furthermore,the correlative photon-to-current conversion efficiency,the charge injection,and the separation efficiency,as well as the hydrogen generation of the composite photoanode have been memorably enhanced due to the synergy of NiF_(2)and BiVO_(4).This study may furnish a dependable guidance in fabricating the fluoride-based compound/semiconductor composite photoanode system.
