In the present research,we proposed a scheme to address the issues of severe heat damage,high energy consumption,low cooling system efficiency,and wastage of cold capacity in mines.To elucidate the seasonal variations...In the present research,we proposed a scheme to address the issues of severe heat damage,high energy consumption,low cooling system efficiency,and wastage of cold capacity in mines.To elucidate the seasonal variations of environmental temperature through field measurements,we selected a high-temperature working face in a deep mine as our engineering background.To enhance the heat damage control cability of the working face and minimize unnecessary cooling capac-ity loss,we introduced the multi-dimensional heat hazard prevention and control method called"Heat source barrier and cooling equipment".First,we utilize shotcrete and liquid nitrogen injection to eliminate the heat source and implemented pressure equalization ventilation to disrupt the heat transfer path,thereby creating a heat barrier.Second,we establish divi-sional prediction models for airflow temperature based on the variation patterns obtained through numerical simulation.Third,we devise the location and dynamic control strategy for the cooling equipment based on the prediction models.The results of field application show that the heat resistance and cooling linkage method comply with the safety requirement throughout the entire mining cycle while effectively reducing energy consumption.The ambient temperature is maintained below 30℃,resulting in the energy saving of 10%during the high-temperature period and over 50%during the low-temperature period.These findings serve as a valuable reference for managing heat damage in high-temperature working faces.展开更多
Objective:To characterize the effects of Qingwei San(QWS)on diabetic oral ulcer(OU)mice with stomach heat pattern through metabolomic analysis.Methods:A stomach heat pattern mouse model was established by treating C57...Objective:To characterize the effects of Qingwei San(QWS)on diabetic oral ulcer(OU)mice with stomach heat pattern through metabolomic analysis.Methods:A stomach heat pattern mouse model was established by treating C57BLKS/J Leprdb/db(db/db)mice with dried Zingiber officinale Rosc.rhizome(Z.officinale,Gan Jiang)decoction by gavage.All model mice had blood glucose levels of≥11.1 m M.Subsequently,OU was induced by Na OH cauterization.After 1 week of administration of QWS,non-targeted metabolomic analysis of serum was conducted using ultra high performance liquid chromatography coupled with mass spectrometry(UHPLC-MS/MS).Results:The non-targeted metabolomics results indicated that tryptophan metabolism,2-oxocarboxylic acid metabolism,serotonergic synapses,amino sugar and nucleotide sugar metabolism,and amino acid biosynthesis were involved in the therapeutic effects of QWS,with tryptophan metabolism playing a predominant role.Conclusion:QWS treatment can significantly improve the pathological status of diabetic OU mice with stomach heat pattern.QWS may regulate the release of inflammatory factors through the tryptophan metabolism pathway.展开更多
The rapid development of two-dimensional(2D)transition-metal dichalcogenides has been possible owing to their special structures and remarkable properties.In particular,palladium diselenide(PdSe_(2))with a novel penta...The rapid development of two-dimensional(2D)transition-metal dichalcogenides has been possible owing to their special structures and remarkable properties.In particular,palladium diselenide(PdSe_(2))with a novel pentagonal structure and unique physical characteristics have recently attracted extensive research inter-est.Consequently,tremendous research progress has been achieved regarding the physics,chemistry,and electronics of PdSe_(2).Accordingly,in this review,we recapitulate and summarize the most recent research on PdSe_(2),including its structure,properties,synthesis,and appli-cations.First,a mechanical exfoliation method to obtain PdSe_(2) nanosheets is introduced,and large-area synthesis strate-gies are explained with respect to chemical vapor deposition and metal selenization.Next,the electronic and optoelectronic properties of PdSe_(2) and related hetero-structures,such as field-effect transistors,photodetectors,sensors,and thermoelec-tric devices,are discussed.Subsequently,the integration of systems into infrared image sensors on the basis of PdSe_(2) van der Waals heterostructures is explored.Finally,future opportunities are highlighted to serve as a general guide for physicists,chemists,materials scientists,and engineers.Therefore,this com-prehensive review may shed light on the research conducted by the 2D material community.展开更多
Nano hierarchical mesoporous ZSM-5 catalysts were prepared with cationic dimethyldiallyl ammonium chloride acrylamide copolymer(PDDA) as a soft second template. Using ZSM-5 catalyst as a matrix,Zn/ZSM-5 catalysts we...Nano hierarchical mesoporous ZSM-5 catalysts were prepared with cationic dimethyldiallyl ammonium chloride acrylamide copolymer(PDDA) as a soft second template. Using ZSM-5 catalyst as a matrix,Zn/ZSM-5 catalysts were also obtained by the wet impregnation method. The effect of the PDDA amount and Zn loadings on the properties of the catalysts,including crystallinity,morphology,textural properties,acid nature and catalytic activity in MTG reaction,was investigated by XRD,FESEM,TEM,Nitrogen adsorption–desorption isotherms and NH3-TPD method,respectively. The MTG reaction was performed in a fixed bed reactor,and the result revealed that the nano hierarchical ZSM-5 catalyst prepared with a PDDA/Si molar ratio of 0.070 possesses longer stable phase of 70 h with a liquid hydrocarbon selectivity of 29.8%.Zn/ZSM-5 catalyst with a Zn/ZSM-5 ratio of 0.07 wt.% shows the highest liquid hydrocarbon selectivity,reaching 62.5%.展开更多
Zn-air batteries(ZABs),especially the secondary batteries,have engrossed a great interest because of its high specific energy,economical and high safety.However,due to the insufficient activity and stability of bifunc...Zn-air batteries(ZABs),especially the secondary batteries,have engrossed a great interest because of its high specific energy,economical and high safety.However,due to the insufficient activity and stability of bifunctional electrocatalysts for air-cathode oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)processes,the practical application of rechargeable ZABs is seriously hindered.In the effort of developing high active,stable and cost-effective electrocatalysts,transition metal nitrides(TMNs)have been regarded as the candidates due to their high conductivity,strong corrosion-resistance,and bifunctional catalytic performance.In this paper,the research progress in TMNs-based material as ORR and OER electrocatalysts for ZABs is discussed with respect to their synthesis,chemical/physical characterization,and performance validation/optimization.The surface/interface nanoengineering strategies such as defect engineering,support binding,heteroatom introduction,crystal plane orientation,interface construction and small size effect,the physical and chemical properties of TMNs-based electrocatalysts are emphasized with respect to their structures/morphologies,composition,electrical conductivity,specific surface area,chemical stability and corrosion resistance.The challenges of TMNs-based materials as bifunctional air-cathode electrocatalysts in practical application are evaluated,and numerous research guidelines to solve these problems are put forward for facilitating further research and development.展开更多
We established the thermodynamic analysis model by using the actual measurement parameters of 600 MW direct dry cooling power plant in Wuxiang, China. The performance, especially the exergy losses of the unit as well ...We established the thermodynamic analysis model by using the actual measurement parameters of 600 MW direct dry cooling power plant in Wuxiang, China. The performance, especially the exergy losses of the unit as well as its subsystems mainly including seven parts were obtained not only at one specific load but also at different loads. We have found that the exergy loss in the boiler is usually more than 70% of the total exergy loss of the system, while the exergy loss of the combustion occupies greater than 50% of that of the boiler. Therefore, it is crucial to reduce the losses in the boiler for energy saving potential improvement, especially that of the combustion and heat transfer. At the same time, the cold end optimization has relatively large potential for energy saving due to that the exergy efficiency of the air cooling system is quite low being about 5.7% or so. In addition, we have gotten the main changing trends of system performances along with the load change, including exergy loss, exergy efficiency and coal consumption, which were derived from the real-time system performance statistics according to a large amount of measured data in real time. In order to make the whole system run more efficiently, it is advised that the unit should run at the load better than 350 MW.展开更多
In this paper the SOFC-GT-Kalina (solid oxide fuel cell, gas turbine, and Kalina cycle) integrated system is proposed. The system uses Kalina cycle as the bottoming cycle to recovery the waste heat from the gas turbin...In this paper the SOFC-GT-Kalina (solid oxide fuel cell, gas turbine, and Kalina cycle) integrated system is proposed. The system uses Kalina cycle as the bottoming cycle to recovery the waste heat from the gas turbine to generate power. Kalina cycle uses ammonia-water mixture as the work fluid which has sliding-temperature boiling characteristics. By comparing with the SOFC-GT-ST (solid oxide fuel cell, gas turbine, and steam turbine cycle) system as the reference system, the systems are simulated by Aspen Plus through analyzing the overall system performance. Electrical and exergy efficiency of the proposed system are 74.41% and 71.93%, and electrical and exergy efficiency of the reference system are 71.45% and 69.07%, proving the superiority of Kalina cycle for waste heat recovery. In addition, the exergy losses of each component are studied, and the detail performance analysis of the proposed system is presented, consisting of thermal analysis, exergy analysis and EUD (Energy-utilization diagram) analysis, which intuitively disclosed the causes of exergy loss. Additionally, it was revealed that there exists an optimal current density at 350 mA/cm2 for power and power density.展开更多
Spatial Crowdsourcing(SC)is a transformative platform that engages a crowd of mobile users(i.e.,workers)in collecting and analyzing environmental,social and other spatio-temporal information.However,current solutions ...Spatial Crowdsourcing(SC)is a transformative platform that engages a crowd of mobile users(i.e.,workers)in collecting and analyzing environmental,social and other spatio-temporal information.However,current solutions ignore the preference of each worker’s remuneration and acceptable distance,and the lack of error analysis after privacy control lead to undesirable task recommendation.In this paper,we introduce an optimization framework for task recommendation while protecting participant privacy.We propose a Generalization mechanism based on Bisecting k-means and an efficient algorithm considering the generalization error to maximization the reward of SC server.Both numerical evaluations and performance analysis are conducted to show the effectiveness and efficiency of the propose framework.展开更多
Under the premise to protect the privacy of personal information,publishing valuable graph is a challenging issue in privacy research.Appling differential privacy in graph,most of the work focused on graph structure c...Under the premise to protect the privacy of personal information,publishing valuable graph is a challenging issue in privacy research.Appling differential privacy in graph,most of the work focused on graph structure characteristic values,because the basic of differential privacy is data distortion,it’s hard to get valuable composite graph if we add a large number of random noise into the raw data.In this article,we show the key that influence availability is whether the important data keep original value in a composite graph.We analysis the properties of important data of k triangle count,and provide a new method for synthesis graph publication.We show the application of this method in k triangle count,and the experimental results proved the accuracy of the method.展开更多
Flexible electronics has emerged as a continuously growing field of study.Two-dimensional(2D)materials often act as conductors and electrodes in elec-tronic devices,holding significant promise in the design of high-pe...Flexible electronics has emerged as a continuously growing field of study.Two-dimensional(2D)materials often act as conductors and electrodes in elec-tronic devices,holding significant promise in the design of high-performance,flexible electronics.Numerous studies have focused on harnessing the potential of these materials for the development of such devices.However,to date,the incorporation of 2D materials in flexible electronics has rarely been summa-rized or reviewed.Consequently,there is an urgent need to develop compre-hensive reviews for rapid updates on this evolving landscape.This review covers progress in complex material architectures based on 2D materials,including interfaces,heterostructures,and 2D/polymer composites.Addition-ally,it explores flexible and wearable energy storage and conversion,display and touch technologies,and biomedical applications,together with integrated design solutions.Although the pursuit of high-performance and high-sensitivity instruments remains a primary objective,the integrated design of flexible electronics with 2D materials also warrants consideration.By combin-ing multiple functionalities into a singular device,augmented by machine learning and algorithms,we can potentially surpass the performance of existing wearable technologies.Finally,we briefly discuss the future trajectory of this burgeoning field.This review discusses the recent advancements in flex-ible sensors made from 2D materials and their applications in integrated archi-tecture and device design.展开更多
Bone tissue engineering(BTE)has proven to be a promising strategy for bone defect repair.Due to its excellent biological properties,gelatin methacrylate(GelMA)hydrogels have been used as bioinks for 3D bioprinting in ...Bone tissue engineering(BTE)has proven to be a promising strategy for bone defect repair.Due to its excellent biological properties,gelatin methacrylate(GelMA)hydrogels have been used as bioinks for 3D bioprinting in some BTE studies to produce scaffolds for bone regeneration.However,applications for load-bearing defects are limited by poor mechanical properties and a lack of bioactivity.In this study,3D printing technology was used to create nano-attapulgite(nano-ATP)/GelMA composite hydrogels loaded into mouse bone mesenchymal stem cells(BMSCs)and mouse umbilical vein endothelial cells(MUVECs).The bioprintability,physicochemical properties,and mechanical properties were all thoroughly evaluated.Our findings showed that nano-ATP groups outperform the control group in terms of printability,indicating that nano-ATP is beneficial for printability.Additionally,after incorporation with nano-ATP,the mechanical strength of the composite hydrogels was significantly improved,resulting in adequate mechanical properties for bone regeneration.The presence of nano-ATP in the scaffolds has also been stud-ied for cell-material interactions.The findings show that cells within the scaffold not only have high viability but also a clear proclivity to promote osteogenic differentiation of BMSCs.Besides,the MUVECs-loaded composite hydrogels demonstrated increased angiogenic activity.A cranial defect model was also developed to evaluate the bone repair capability of scaffolds loaded with rat BMSCs.According to histo-logical analysis,cell-laden nano-ATP composite hydrogels can effectively im prove bone regeneration and promote angiogenesis.This study demonstrated the potential of nano-ATP for bone tissue engineering,which should also increase the clinical practicality of nano-ATP.展开更多
Controlling the size of fragranee microcapsules using designed agitator paddles was investigated and studied by CFD simulation. First, different fluid flows were established by varying stirring speeds, reactor scales,...Controlling the size of fragranee microcapsules using designed agitator paddles was investigated and studied by CFD simulation. First, different fluid flows were established by varying stirring speeds, reactor scales, and agitator paddle design, and the effects of each on particle size and distribution of prepared microcapsules were determined. The experimental results showed that the pattern design of orifices in the plate paddles control the flow field well. Narrow particle-size distributio ns of the microcapsules were obtained. The fluid flow characteristics including fluid velocity field, turbulent kinetic energy field, and shear stress distribution for thedifferent agitator paddle types in different reaction kettles were simulated using CFD tech no logy. The correlations between simulated data and experime ntal results were an alyzed. Significantly, the simulated average flow velocity was found to show good negative linear correlation w让h the average particle size of prepared microcapsules, with a correlation of y =-2.166x + 42.626.展开更多
The dry sliding wear behavior of Ti_2AlC reinforced AZ91 magnesium composites was investigated at sliding velocity of 0.5 m/s under loads of 10, 20, 40 and 80 N using pin-on-disk configuration against a Cr15 steel dis...The dry sliding wear behavior of Ti_2AlC reinforced AZ91 magnesium composites was investigated at sliding velocity of 0.5 m/s under loads of 10, 20, 40 and 80 N using pin-on-disk configuration against a Cr15 steel disc. Wear rates and friction coefficients were registered during wear tests. Worn tracks and wear debris were examined by scanning electron microscopy, energy dispersive X-ray spectrometry and transmission electron microscopy in order to obtain the wear mechanisms of the studied materials. The main mechanisms were characterized as the magnesium matrix oxidation and self-lubrication of Ti_2AlC MAX phase. In all conditions, the composites exhibit superior wear resistance and self-lubricated ability than the AZ91 Mg alloy. In addition, the anisotropic mechanisms in tribological properties of textured Ti_2AlC-Mg composites were confirmed and discussed.展开更多
Cu2O@Cu sub-microspheres composites with a narrow particle size distribution from 300 to 500 nm was successfully fabricated by one-step synthesis through the direct thermal decomposition of copper nitrate (Cu(NO3)2...Cu2O@Cu sub-microspheres composites with a narrow particle size distribution from 300 to 500 nm was successfully fabricated by one-step synthesis through the direct thermal decomposition of copper nitrate (Cu(NO3)2) in octadecylamine (ODA) solvent. As anode materials for lithium ion batteries, the Cu2O@Cu composites obviously possess high specific capacity, excellent cyclic stability and rate capability. The coulombic efficiency is about 84% in the 1 st cycle and increases significantly up to 97.8% during successive cycles at various current densities. Even under a high current density of 500 mA g^-l, the discharge capacity of Cu2O@Cu composites remains up to 200 mAh g^-1. The excellent electrochemical properties are ascribed to the synergistic effect between high electronic conductivity and volume-buffering capacity of metallic copper composited with Cu2O.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.展开更多
Porous polyaniline (PANI) was prepared through an efficient and costeffective method by polymerization of aniline in the NaCl solution at room temperature. The resulting PANI provided large surface area due to its hig...Porous polyaniline (PANI) was prepared through an efficient and costeffective method by polymerization of aniline in the NaCl solution at room temperature. The resulting PANI provided large surface area due to its highly porous structure and the intercrossed nanorod, resulting in good electrochemical performance. The porous PANI electrodes showed a high specific capacitance of 480 F·g^-1, 3 times greater than that of PANI without using the NaCl solution. We also make chemically crosslinked hydrogel film for hydrogel polymer electrolyte as well as the flexible supercapacitors (SCs) with PANI. The specific capacitance of the device was 234 F·g^-1 at the current density of 1 A·g^-1. The energy density of the device could reach as high as 75 W·h·kg^-1 while the power density was 0.5 kW·kg^-1, indicating that PANI be a promising material in flexible SCs.展开更多
Peony pollen is a cheap and readily available biomass material with a relatively high protein content.In this work,it was employed as an N-rich precursor to prepare the nitrogen-doped porous carbon for supercapacitor ...Peony pollen is a cheap and readily available biomass material with a relatively high protein content.In this work,it was employed as an N-rich precursor to prepare the nitrogen-doped porous carbon for supercapacitor application.The porous carbon microspheres were prepared through a hydrothermal method and subsequent carbonization process.Notably,ammonium borofruoride and potassium hydroxide were employed respectively as an etchant and an activator to modify the porosity of the materials.The as prepared ANPPCs-700 has a super high BET specific surface area of 824.69 m^2/g.The microstructure,chemical state and electrochemical properties of the product were investigated in detail.The prepared nitrogen-doped carbon microspheres exhibits excellent specific capacity of 209 F/g at a current density of lA/g and remained 92.5%of the initial capacitance after 5000 deep cycles at 5 A/g.展开更多
MXene-based hydrogels have drawn considerable attention as flexible and wearable sensors.However,the application of MXene-based hydrogels after sensing failure has rarely been investigated,which is of great significan...MXene-based hydrogels have drawn considerable attention as flexible and wearable sensors.However,the application of MXene-based hydrogels after sensing failure has rarely been investigated,which is of great significance for expanding their engineering application.In this work,multifunctional mineral MXene hydrogels(MMHs)were synthesized via a simple method inspired by biomineralization.The prepared MMHs were stretchable,self-healable and conductive,and can be used to fabricate wearable tensile strain sensors showing a super-wide sensing range with excellent sensitivity.MMHs-based strain sensors were designed to be directly attached to the skin surface to detect tiny and large human motions.In addition,with the advantages of a large specific area,excellent hydrophilicity and abundant active adsorption sites for MXene nanosheets and hydrogels,dehydrated MMHs were used as highly efficient adsorbents for the removal of strontium ions from aqueous solutions.This work shows the great potential of MXene in promoting the development of nextgeneration functional materials.展开更多
Recently,the development of new electrode materials for lithium-ion batteries(LIBs)has received intensive attention.As an important family of inorganic materials,mixed Mo-based transition metal oxides system is focuse...Recently,the development of new electrode materials for lithium-ion batteries(LIBs)has received intensive attention.As an important family of inorganic materials,mixed Mo-based transition metal oxides system is focused as anode materials.In the present work,a simple route has been adopted for the synthesis of layered-flake-likeβ-SnMo04 Nano-assemblies,which have been explored as potential anode materials for the first time in lithium-ion battery(LIB).Overall,the current reports on metal molybdate as anode materials are still rarely.As the anode material for LIBs,it was observed that the fabricated anode is capable of delivering a steady state capacity of almost 400 mAh/g up to 300 cycles under the influence of200 mA/g current density.Further,the anode material is suitable for use as a rated capacity anode because of its high current density tolerance.The present study can be further extended for the generation of a wide variety of other novel materials for multidisciplinary energy related applications.展开更多
基金supported by the National Natural Science Foundation of China (51874281)the Graduate Innovation Program of China University of Mining and Technology (2022WLKXJ006)the Postgraduate Research&Practice Innovation Program of Jiangsu Province (KYCX22_2612).
文摘In the present research,we proposed a scheme to address the issues of severe heat damage,high energy consumption,low cooling system efficiency,and wastage of cold capacity in mines.To elucidate the seasonal variations of environmental temperature through field measurements,we selected a high-temperature working face in a deep mine as our engineering background.To enhance the heat damage control cability of the working face and minimize unnecessary cooling capac-ity loss,we introduced the multi-dimensional heat hazard prevention and control method called"Heat source barrier and cooling equipment".First,we utilize shotcrete and liquid nitrogen injection to eliminate the heat source and implemented pressure equalization ventilation to disrupt the heat transfer path,thereby creating a heat barrier.Second,we establish divi-sional prediction models for airflow temperature based on the variation patterns obtained through numerical simulation.Third,we devise the location and dynamic control strategy for the cooling equipment based on the prediction models.The results of field application show that the heat resistance and cooling linkage method comply with the safety requirement throughout the entire mining cycle while effectively reducing energy consumption.The ambient temperature is maintained below 30℃,resulting in the energy saving of 10%during the high-temperature period and over 50%during the low-temperature period.These findings serve as a valuable reference for managing heat damage in high-temperature working faces.
基金funded by the Science and Technology Development Fund,Macao,China(007/2020/ALC)Major Basic and Applied Basic Research Projects of Guangdong Province of China(2019B030302005)the National Natural Science Foundation of China(81973535 and 81773960)。
文摘Objective:To characterize the effects of Qingwei San(QWS)on diabetic oral ulcer(OU)mice with stomach heat pattern through metabolomic analysis.Methods:A stomach heat pattern mouse model was established by treating C57BLKS/J Leprdb/db(db/db)mice with dried Zingiber officinale Rosc.rhizome(Z.officinale,Gan Jiang)decoction by gavage.All model mice had blood glucose levels of≥11.1 m M.Subsequently,OU was induced by Na OH cauterization.After 1 week of administration of QWS,non-targeted metabolomic analysis of serum was conducted using ultra high performance liquid chromatography coupled with mass spectrometry(UHPLC-MS/MS).Results:The non-targeted metabolomics results indicated that tryptophan metabolism,2-oxocarboxylic acid metabolism,serotonergic synapses,amino sugar and nucleotide sugar metabolism,and amino acid biosynthesis were involved in the therapeutic effects of QWS,with tryptophan metabolism playing a predominant role.Conclusion:QWS treatment can significantly improve the pathological status of diabetic OU mice with stomach heat pattern.QWS may regulate the release of inflammatory factors through the tryptophan metabolism pathway.
基金H.L.acknowledges the National Key Research and Development Program of China(2017YFB0405400)from the Ministry of Science and Technology(MOST)of Chinathe Natural Science Foundation for Distinguished Young Scientist of Shandong Province(Grant No.JQ201814)+6 种基金We thank the Project of“20 items of University”of Jinan(2018GXRC031)W.Z thanks Taishan Scholars Project Special Funds(tsqn201812083)and NSFC(No.52022037)The authors show their gratitude to the National Natural Science Foundation of China(NSFC grant No.51802113,51802116)the Natural Science Foundation of Shandong Province,China(grant No.ZR2019BEM040,ZR2018BEM015)M.H.R.thanks the National Science Foundation China(NSFC,Project 52071225)the National Science Center and the Czech Republic under the ERDF program“Institute of Environmental Technology-Excellent Research”(No.CZ.02.1.01/0.0/0.0/16_019/0000853)the Sino-German Research Institute for support(Project No.GZ 1400).
文摘The rapid development of two-dimensional(2D)transition-metal dichalcogenides has been possible owing to their special structures and remarkable properties.In particular,palladium diselenide(PdSe_(2))with a novel pentagonal structure and unique physical characteristics have recently attracted extensive research inter-est.Consequently,tremendous research progress has been achieved regarding the physics,chemistry,and electronics of PdSe_(2).Accordingly,in this review,we recapitulate and summarize the most recent research on PdSe_(2),including its structure,properties,synthesis,and appli-cations.First,a mechanical exfoliation method to obtain PdSe_(2) nanosheets is introduced,and large-area synthesis strate-gies are explained with respect to chemical vapor deposition and metal selenization.Next,the electronic and optoelectronic properties of PdSe_(2) and related hetero-structures,such as field-effect transistors,photodetectors,sensors,and thermoelec-tric devices,are discussed.Subsequently,the integration of systems into infrared image sensors on the basis of PdSe_(2) van der Waals heterostructures is explored.Finally,future opportunities are highlighted to serve as a general guide for physicists,chemists,materials scientists,and engineers.Therefore,this com-prehensive review may shed light on the research conducted by the 2D material community.
基金supported by the National Natural Science Foundation of China (grant no.21201130)Foundation of State Key Laboratory of Coal Conversion,China (J14-15-603)+1 种基金China Scholarship Council (CSC no.:201406895017)Shanghai Education Commission Innovation Project (14YZ016)
文摘Nano hierarchical mesoporous ZSM-5 catalysts were prepared with cationic dimethyldiallyl ammonium chloride acrylamide copolymer(PDDA) as a soft second template. Using ZSM-5 catalyst as a matrix,Zn/ZSM-5 catalysts were also obtained by the wet impregnation method. The effect of the PDDA amount and Zn loadings on the properties of the catalysts,including crystallinity,morphology,textural properties,acid nature and catalytic activity in MTG reaction,was investigated by XRD,FESEM,TEM,Nitrogen adsorption–desorption isotherms and NH3-TPD method,respectively. The MTG reaction was performed in a fixed bed reactor,and the result revealed that the nano hierarchical ZSM-5 catalyst prepared with a PDDA/Si molar ratio of 0.070 possesses longer stable phase of 70 h with a liquid hydrocarbon selectivity of 29.8%.Zn/ZSM-5 catalyst with a Zn/ZSM-5 ratio of 0.07 wt.% shows the highest liquid hydrocarbon selectivity,reaching 62.5%.
基金financial support from the National Key Research and Development Program of China(2017YFB0102900)
文摘Zn-air batteries(ZABs),especially the secondary batteries,have engrossed a great interest because of its high specific energy,economical and high safety.However,due to the insufficient activity and stability of bifunctional electrocatalysts for air-cathode oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)processes,the practical application of rechargeable ZABs is seriously hindered.In the effort of developing high active,stable and cost-effective electrocatalysts,transition metal nitrides(TMNs)have been regarded as the candidates due to their high conductivity,strong corrosion-resistance,and bifunctional catalytic performance.In this paper,the research progress in TMNs-based material as ORR and OER electrocatalysts for ZABs is discussed with respect to their synthesis,chemical/physical characterization,and performance validation/optimization.The surface/interface nanoengineering strategies such as defect engineering,support binding,heteroatom introduction,crystal plane orientation,interface construction and small size effect,the physical and chemical properties of TMNs-based electrocatalysts are emphasized with respect to their structures/morphologies,composition,electrical conductivity,specific surface area,chemical stability and corrosion resistance.The challenges of TMNs-based materials as bifunctional air-cathode electrocatalysts in practical application are evaluated,and numerous research guidelines to solve these problems are put forward for facilitating further research and development.
文摘We established the thermodynamic analysis model by using the actual measurement parameters of 600 MW direct dry cooling power plant in Wuxiang, China. The performance, especially the exergy losses of the unit as well as its subsystems mainly including seven parts were obtained not only at one specific load but also at different loads. We have found that the exergy loss in the boiler is usually more than 70% of the total exergy loss of the system, while the exergy loss of the combustion occupies greater than 50% of that of the boiler. Therefore, it is crucial to reduce the losses in the boiler for energy saving potential improvement, especially that of the combustion and heat transfer. At the same time, the cold end optimization has relatively large potential for energy saving due to that the exergy efficiency of the air cooling system is quite low being about 5.7% or so. In addition, we have gotten the main changing trends of system performances along with the load change, including exergy loss, exergy efficiency and coal consumption, which were derived from the real-time system performance statistics according to a large amount of measured data in real time. In order to make the whole system run more efficiently, it is advised that the unit should run at the load better than 350 MW.
文摘In this paper the SOFC-GT-Kalina (solid oxide fuel cell, gas turbine, and Kalina cycle) integrated system is proposed. The system uses Kalina cycle as the bottoming cycle to recovery the waste heat from the gas turbine to generate power. Kalina cycle uses ammonia-water mixture as the work fluid which has sliding-temperature boiling characteristics. By comparing with the SOFC-GT-ST (solid oxide fuel cell, gas turbine, and steam turbine cycle) system as the reference system, the systems are simulated by Aspen Plus through analyzing the overall system performance. Electrical and exergy efficiency of the proposed system are 74.41% and 71.93%, and electrical and exergy efficiency of the reference system are 71.45% and 69.07%, proving the superiority of Kalina cycle for waste heat recovery. In addition, the exergy losses of each component are studied, and the detail performance analysis of the proposed system is presented, consisting of thermal analysis, exergy analysis and EUD (Energy-utilization diagram) analysis, which intuitively disclosed the causes of exergy loss. Additionally, it was revealed that there exists an optimal current density at 350 mA/cm2 for power and power density.
文摘Spatial Crowdsourcing(SC)is a transformative platform that engages a crowd of mobile users(i.e.,workers)in collecting and analyzing environmental,social and other spatio-temporal information.However,current solutions ignore the preference of each worker’s remuneration and acceptable distance,and the lack of error analysis after privacy control lead to undesirable task recommendation.In this paper,we introduce an optimization framework for task recommendation while protecting participant privacy.We propose a Generalization mechanism based on Bisecting k-means and an efficient algorithm considering the generalization error to maximization the reward of SC server.Both numerical evaluations and performance analysis are conducted to show the effectiveness and efficiency of the propose framework.
文摘Under the premise to protect the privacy of personal information,publishing valuable graph is a challenging issue in privacy research.Appling differential privacy in graph,most of the work focused on graph structure characteristic values,because the basic of differential privacy is data distortion,it’s hard to get valuable composite graph if we add a large number of random noise into the raw data.In this article,we show the key that influence availability is whether the important data keep original value in a composite graph.We analysis the properties of important data of k triangle count,and provide a new method for synthesis graph publication.We show the application of this method in k triangle count,and the experimental results proved the accuracy of the method.
基金supported by National Key Research and Development Program(No.2022YFE0124200)National Natural Science Foundation of China(No.U2241221)+9 种基金J.P.thanks the Natural Science Foundation of Shandong Province for Excellent Young Scholars(YQ2022041)the fund(No.SKT2203)from the State Key Laboratories of Transducer TechnologyShanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences for support.W.Z.thanks the Major Scientific and Technological Innovation Project of Shandong Province(2021CXGC010603)NSFC(No.52022037)Taishan Scholars Project Special Funds(TSQN201812083)The Project was supported by the Foundation(No.GZKF202107)of State Key Laboratory of Biobased Material and Green PapermakingQilu University of Technology,Shandong Academy of Sciences.M.H.R.thanks NSFC(No.52071225)the National Science Center and the Czech Republic under the European Regional Development Fund(ERDF)“Institute of Environmental Technology-Excellent Research”(No.CZ.02.1.01/0.0/0.0/16_019/0000853)the SinoGerman Center for Research Promotion(SGC)for support(No.GZ 1400).
文摘Flexible electronics has emerged as a continuously growing field of study.Two-dimensional(2D)materials often act as conductors and electrodes in elec-tronic devices,holding significant promise in the design of high-performance,flexible electronics.Numerous studies have focused on harnessing the potential of these materials for the development of such devices.However,to date,the incorporation of 2D materials in flexible electronics has rarely been summa-rized or reviewed.Consequently,there is an urgent need to develop compre-hensive reviews for rapid updates on this evolving landscape.This review covers progress in complex material architectures based on 2D materials,including interfaces,heterostructures,and 2D/polymer composites.Addition-ally,it explores flexible and wearable energy storage and conversion,display and touch technologies,and biomedical applications,together with integrated design solutions.Although the pursuit of high-performance and high-sensitivity instruments remains a primary objective,the integrated design of flexible electronics with 2D materials also warrants consideration.By combin-ing multiple functionalities into a singular device,augmented by machine learning and algorithms,we can potentially surpass the performance of existing wearable technologies.Finally,we briefly discuss the future trajectory of this burgeoning field.This review discusses the recent advancements in flex-ible sensors made from 2D materials and their applications in integrated archi-tecture and device design.
基金This research was funded by Jiangsu Province’s Key Project of Science and Technology(Grant No.BE2018644)Changzhou Health Commission’s Young Talents Science and Technology project(Grant No.QN202029).
文摘Bone tissue engineering(BTE)has proven to be a promising strategy for bone defect repair.Due to its excellent biological properties,gelatin methacrylate(GelMA)hydrogels have been used as bioinks for 3D bioprinting in some BTE studies to produce scaffolds for bone regeneration.However,applications for load-bearing defects are limited by poor mechanical properties and a lack of bioactivity.In this study,3D printing technology was used to create nano-attapulgite(nano-ATP)/GelMA composite hydrogels loaded into mouse bone mesenchymal stem cells(BMSCs)and mouse umbilical vein endothelial cells(MUVECs).The bioprintability,physicochemical properties,and mechanical properties were all thoroughly evaluated.Our findings showed that nano-ATP groups outperform the control group in terms of printability,indicating that nano-ATP is beneficial for printability.Additionally,after incorporation with nano-ATP,the mechanical strength of the composite hydrogels was significantly improved,resulting in adequate mechanical properties for bone regeneration.The presence of nano-ATP in the scaffolds has also been stud-ied for cell-material interactions.The findings show that cells within the scaffold not only have high viability but also a clear proclivity to promote osteogenic differentiation of BMSCs.Besides,the MUVECs-loaded composite hydrogels demonstrated increased angiogenic activity.A cranial defect model was also developed to evaluate the bone repair capability of scaffolds loaded with rat BMSCs.According to histo-logical analysis,cell-laden nano-ATP composite hydrogels can effectively im prove bone regeneration and promote angiogenesis.This study demonstrated the potential of nano-ATP for bone tissue engineering,which should also increase the clinical practicality of nano-ATP.
文摘Controlling the size of fragranee microcapsules using designed agitator paddles was investigated and studied by CFD simulation. First, different fluid flows were established by varying stirring speeds, reactor scales, and agitator paddle design, and the effects of each on particle size and distribution of prepared microcapsules were determined. The experimental results showed that the pattern design of orifices in the plate paddles control the flow field well. Narrow particle-size distributio ns of the microcapsules were obtained. The fluid flow characteristics including fluid velocity field, turbulent kinetic energy field, and shear stress distribution for thedifferent agitator paddle types in different reaction kettles were simulated using CFD tech no logy. The correlations between simulated data and experime ntal results were an alyzed. Significantly, the simulated average flow velocity was found to show good negative linear correlation w让h the average particle size of prepared microcapsules, with a correlation of y =-2.166x + 42.626.
基金supported by the National Natural Science Foundation of China (No. 51701010)the Beijing Jiaotong University Foundation for youth scientists (No. No.2017RC013)+1 种基金the Project National United Engineering Laboratory for Advanced Bearing Tribology-Henan University of Science and Technology (No. 201805)the Beijing Government Funds for the Constructive Project of Central Universities (No. 353139535)
文摘The dry sliding wear behavior of Ti_2AlC reinforced AZ91 magnesium composites was investigated at sliding velocity of 0.5 m/s under loads of 10, 20, 40 and 80 N using pin-on-disk configuration against a Cr15 steel disc. Wear rates and friction coefficients were registered during wear tests. Worn tracks and wear debris were examined by scanning electron microscopy, energy dispersive X-ray spectrometry and transmission electron microscopy in order to obtain the wear mechanisms of the studied materials. The main mechanisms were characterized as the magnesium matrix oxidation and self-lubrication of Ti_2AlC MAX phase. In all conditions, the composites exhibit superior wear resistance and self-lubricated ability than the AZ91 Mg alloy. In addition, the anisotropic mechanisms in tribological properties of textured Ti_2AlC-Mg composites were confirmed and discussed.
基金financially supported by the National Program on Key Basic Research Project (2014CB643403)National Key Research and Development Program of China (2017YFB0102900)the Shanghai Pujiang Program (17PJD016)
文摘Cu2O@Cu sub-microspheres composites with a narrow particle size distribution from 300 to 500 nm was successfully fabricated by one-step synthesis through the direct thermal decomposition of copper nitrate (Cu(NO3)2) in octadecylamine (ODA) solvent. As anode materials for lithium ion batteries, the Cu2O@Cu composites obviously possess high specific capacity, excellent cyclic stability and rate capability. The coulombic efficiency is about 84% in the 1 st cycle and increases significantly up to 97.8% during successive cycles at various current densities. Even under a high current density of 500 mA g^-l, the discharge capacity of Cu2O@Cu composites remains up to 200 mAh g^-1. The excellent electrochemical properties are ascribed to the synergistic effect between high electronic conductivity and volume-buffering capacity of metallic copper composited with Cu2O.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.
文摘Porous polyaniline (PANI) was prepared through an efficient and costeffective method by polymerization of aniline in the NaCl solution at room temperature. The resulting PANI provided large surface area due to its highly porous structure and the intercrossed nanorod, resulting in good electrochemical performance. The porous PANI electrodes showed a high specific capacitance of 480 F·g^-1, 3 times greater than that of PANI without using the NaCl solution. We also make chemically crosslinked hydrogel film for hydrogel polymer electrolyte as well as the flexible supercapacitors (SCs) with PANI. The specific capacitance of the device was 234 F·g^-1 at the current density of 1 A·g^-1. The energy density of the device could reach as high as 75 W·h·kg^-1 while the power density was 0.5 kW·kg^-1, indicating that PANI be a promising material in flexible SCs.
基金financial supports from the National Key Research and Development Program of China(Nos.2017YFB0102200,2017YFB0102900)。
文摘Peony pollen is a cheap and readily available biomass material with a relatively high protein content.In this work,it was employed as an N-rich precursor to prepare the nitrogen-doped porous carbon for supercapacitor application.The porous carbon microspheres were prepared through a hydrothermal method and subsequent carbonization process.Notably,ammonium borofruoride and potassium hydroxide were employed respectively as an etchant and an activator to modify the porosity of the materials.The as prepared ANPPCs-700 has a super high BET specific surface area of 824.69 m^2/g.The microstructure,chemical state and electrochemical properties of the product were investigated in detail.The prepared nitrogen-doped carbon microspheres exhibits excellent specific capacity of 209 F/g at a current density of lA/g and remained 92.5%of the initial capacitance after 5000 deep cycles at 5 A/g.
基金supported by the Fundamental Research Funds for Central Universities and also supported by the National Key R&D Program of China(Grant No.2016YFC1402504).
文摘MXene-based hydrogels have drawn considerable attention as flexible and wearable sensors.However,the application of MXene-based hydrogels after sensing failure has rarely been investigated,which is of great significance for expanding their engineering application.In this work,multifunctional mineral MXene hydrogels(MMHs)were synthesized via a simple method inspired by biomineralization.The prepared MMHs were stretchable,self-healable and conductive,and can be used to fabricate wearable tensile strain sensors showing a super-wide sensing range with excellent sensitivity.MMHs-based strain sensors were designed to be directly attached to the skin surface to detect tiny and large human motions.In addition,with the advantages of a large specific area,excellent hydrophilicity and abundant active adsorption sites for MXene nanosheets and hydrogels,dehydrated MMHs were used as highly efficient adsorbents for the removal of strontium ions from aqueous solutions.This work shows the great potential of MXene in promoting the development of nextgeneration functional materials.
基金support of National Key ResearchDevelopment Program of China (No.2017YFB0102900)+2 种基金National Key Research and Development Plan (No.2017YFB0102200)the Shanghai Committee of Science and Technology,China (No. 17010500500)the Shanghai Municipal Education Commission (Peak Discipline Construction program)
文摘Recently,the development of new electrode materials for lithium-ion batteries(LIBs)has received intensive attention.As an important family of inorganic materials,mixed Mo-based transition metal oxides system is focused as anode materials.In the present work,a simple route has been adopted for the synthesis of layered-flake-likeβ-SnMo04 Nano-assemblies,which have been explored as potential anode materials for the first time in lithium-ion battery(LIB).Overall,the current reports on metal molybdate as anode materials are still rarely.As the anode material for LIBs,it was observed that the fabricated anode is capable of delivering a steady state capacity of almost 400 mAh/g up to 300 cycles under the influence of200 mA/g current density.Further,the anode material is suitable for use as a rated capacity anode because of its high current density tolerance.The present study can be further extended for the generation of a wide variety of other novel materials for multidisciplinary energy related applications.