With the progress of science and technology,China has gradually attached importance to research and exploration in chemistry,and the achievements in exploring mechanochemistry are also quite significant.Therefore,it i...With the progress of science and technology,China has gradually attached importance to research and exploration in chemistry,and the achievements in exploring mechanochemistry are also quite significant.Therefore,it is necessary to study and explore mechanochemistry.This article mainly discusses the application of mechanochemistry in powder and some silicate materials,as well as in special ceramics,and provides a brief introduction to provide reference for relevant researchers.展开更多
With the continuous demand of material performance,the development of materials is rapid,and the professional curriculum teaching of“new inorganic materials”as well as its teaching methods related to the internet ma...With the continuous demand of material performance,the development of materials is rapid,and the professional curriculum teaching of“new inorganic materials”as well as its teaching methods related to the internet mandate a reform,in order to meet the needs of innovative high-quality personnel training.The update and optimization of the teaching content and methods assisted by the internet meet the needs of modern teaching and research work.More than 90%of students believe that internet teaching is conducive to the understanding of classroom knowledge and the development of innovative projects.展开更多
Developing technologies that can be applied simultaneously in battery thermal management(BTM)and thermal runaway(TR)mitigation is significant to improving the safety of lithium-ion battery systems.Inorganic phase chan...Developing technologies that can be applied simultaneously in battery thermal management(BTM)and thermal runaway(TR)mitigation is significant to improving the safety of lithium-ion battery systems.Inorganic phase change material(PCM)with nonflammability has the potential to achieve this dual function.This study proposed an encapsulated inorganic phase change material(EPCM)with a heat transfer enhancement for battery systems,where Na_(2)HPO_(4)·12H_(2)O was used as the core PCM encapsulated by silica and the additive of carbon nanotube(CNT)was applied to enhance the thermal conductivity.The microstructure and thermal properties of the EPCM/CNT were analyzed by a series of characterization tests.Two different incorporating methods of CNT were compared and the proper CNT adding amount was also studied.After preparation,the battery thermal management performance and TR propagation mitigation effects of EPCM/CNT were further investigated on the battery modules.The experimental results of thermal management tests showed that EPCM/CNT not only slowed down the temperature rising of the module but also improved the temperature uniformity during normal operation.The peak battery temperature decreased from 76℃to 61.2℃at 2 C discharge rate and the temperature difference was controlled below 3℃.Moreover,the results of TR propagation tests demonstrated that nonflammable EPCM/CNT with good heat absorption could work as a TR barrier,which exhibited effective mitigation on TR and TR propagation.The trigger time of three cells was successfully delayed by 129,474 and 551 s,respectively and the propagation intervals were greatly extended as well.展开更多
The unity between physics and biology refers to that the inorganic systems： the Solar System, galaxies and artificial systems have the same structures and functions as the organisms. The development of science and te...The unity between physics and biology refers to that the inorganic systems： the Solar System, galaxies and artificial systems have the same structures and functions as the organisms. The development of science and technology is demonstrating the intense unification trends of physics and biology and a holistic science and technology era is about to start. The physics and biology unify on the basis of the four seasons＇ law, which is the most important rule of the universe. Life is defined as the four seasons＇ whole with the structure and process of four seasons. The organism is basically structured into a dual four-season body by state-varying, state-stabilizing and control organizations. Animals, the Solar System and the earth are all the dual four-season bodies. In the unity between physics and biology, the inorganic life materials and inorganic life body can be manufactured artificially.展开更多
hydroxy-4-nitro azobenzene (NHA) and 4-amino-4-nitro azobenzene (DO3) were prepared respectively from p-nitrophenylamine as a precursor compound. Two kinds of doped organic/inorganic hybrid nonlinear optical (NLO) mat...hydroxy-4-nitro azobenzene (NHA) and 4-amino-4-nitro azobenzene (DO3) were prepared respectively from p-nitrophenylamine as a precursor compound. Two kinds of doped organic/inorganic hybrid nonlinear optical (NLO) materials containing NHA and DO3 were synthesized by Sol-Gel process. The preparation and properties of two NLO materials were studied and characterized by FTIR, 1H-NMR, UV-VIS, SEM, DSC and SHG measurements. The results show that the maximum doping amounts of NHA and DO3 in two doped hybrid NLO materials are 7.2(wt)% and 11.3(wt)% respectively, and the corresponding second-order NLO coefficients (d33 values) are 2.91×10 8esu and 6.14×10 8esu. Two doped NLO materials have relatively good RT stability, after 90 days at RT the d33 values can maintain about 85% of their initial values, but after 10h at 100℃ can only maintain about 50% of their initial values. In this report, the reasons for high-temperature instability of doped materials were discussed, and the possible improvements were also suggested.展开更多
Rechargeable potassium-ion batteries(PIBs)have great potential in the application of electrochemical energy storage devices due to the low cost,the abundant resources and the low standard reduction potential of potass...Rechargeable potassium-ion batteries(PIBs)have great potential in the application of electrochemical energy storage devices due to the low cost,the abundant resources and the low standard reduction potential of potassium.As electrode materials are the key factors to determine the electrochemical performance of devices,relevant research is being carried out to build high-performance PIBs.In recent years,significant progress has been made in the study of the design of inorganic electrode materials.Herein,we review the cathode materials(Prussian blue and its analogues,layered oxides and poly anionic compounds)and the anode materials(antimony-based,selenium-based and bismuth-based compounds).On the basis of previous work,the structural design principles for improving the performance of electrode materials are reasonably summarized.At the same time,the problems that need to be solved in the preparation of electrode materials and the direction of future research and improvement are pointed out.展开更多
Long afterglow photoluminescent materials Sr2MgSi2O7 doped with Eu2+, Dy3+ were prepared by sol-gel method. The synthesized samples were characterized by X-ray diffraction. The excitation spectrum, emission spectrum a...Long afterglow photoluminescent materials Sr2MgSi2O7 doped with Eu2+, Dy3+ were prepared by sol-gel method. The synthesized samples were characterized by X-ray diffraction. The excitation spectrum, emission spectrum and long decay curve were measured and analyzed. XRD pattern indicates that phosphor is with Sr2MgSi2O7 crystal structure. The wide range of excitation wavelength indicates that luminescent material can be excited by light from ultraviolet ray to visible light. The main peak of emission spectrum is located at 466 nm. Sample excited by visible light can emit bright blue light, and the afterglow time lasts more than 8 h.展开更多
Mixed rare earth elements were incorporated into alumina ceramic materials. Hot-pressing was used to fabricate alumina matrix composites in nitrogen atmosphere protection. Microstructures and mechanical properties of ...Mixed rare earth elements were incorporated into alumina ceramic materials. Hot-pressing was used to fabricate alumina matrix composites in nitrogen atmosphere protection. Microstructures and mechanical properties of the composites were tested. It was indicated that the bending strength and fracture toughness of alumina matrix ceramic composites sintered at 1550 ℃ and 28 MPa for 30 min were improved evidently. Besides mixed rare earth elements acting as a toughening phase, AlTiC master alloys were also added in as sintering assistants, which could prompt the formation of transient liquid phase, and thus nitrides of rare earth elements were produced. All of the above were beneficial for improving the mechanical properties of alumina matrix ceramic composites.展开更多
Inorganic antibacterial materials consist of the antibacterial ions, the additives and the carrier. In this study, we synthesized a new inorganic antibacterialmaterial, of which Cu2+ and Ag+ were selected to be the bi...Inorganic antibacterial materials consist of the antibacterial ions, the additives and the carrier. In this study, we synthesized a new inorganic antibacterialmaterial, of which Cu2+ and Ag+ were selected to be the bi-component antibacterial ions, cerous nitrate served as the additives, and the white carbon black was chosen as the carrier, which was prepared by a sol-gel method. The as-synthesized antibacterial material was characterized by inductively coupled plasma, particle size measurement instrument, scanning electron microscope and enumeration tests. The result showed that the amount of antibacterial ions and bacteriostasis rate of this new material are higher than those for the single-ion inorganic antibacterial material. In addition, the particle size of this material can be extended down to 7 μm with a narrow size distribution. Other advantages of this material are its loose and dispersive structure, good thermal and light stability. From the antibacterial experiment in rubber and the coating surface of metal, this new material showed promising results. The possible antibacterial mechanism was also proposed through all the experimental data in this study.展开更多
In recent years, perovskite solar cells (PSCs) have become a much charming photovoltaic technology and have triggered enormous studies worldwide, owing to their high efficiency, low cost and ease of preparation. The p...In recent years, perovskite solar cells (PSCs) have become a much charming photovoltaic technology and have triggered enormous studies worldwide, owing to their high efficiency, low cost and ease of preparation. The power conversion efficiency has rapidly increased by more than 6 times to the current 25.5% in the past decade. Hole transport materials (HTMs) are an indispensable part of PSCs, which great affect the efficiency, the cost and the stability of PSCs. Inorganic Cu-based p-type semiconductors are a kind of representative inorganic HTMs in PSCs due to their unique advantages of rich variety, low cost, excellent hole mobility, adjustable energy levels, good stability, low temperature and scalable processing ability. In this review, the research progress in new materials and the control of photoelectric properties of Cu-based inorganic HTMs were first summarized systematically. And then, concerning different processing methods, advances of the interface engineering of Cu-based hole transport layers (HTLs) in PSCs were detailly discussed. Finally, the challenges and future trends of Cu-based inorganic HTMs and their interface engineering in PSCs were analyzed.展开更多
The LiMn2O4 thin film as a cathode material was prepared through solution deposition followed by rapid thermal annealing （RTA）. The phase identification and the study of surface morphology were carried out by X-my d...The LiMn2O4 thin film as a cathode material was prepared through solution deposition followed by rapid thermal annealing （RTA）. The phase identification and the study of surface morphology were carried out by X-my diffraction and scanning electron microscopy. Electrochemical properties were examined by cyclic voltammetry, galvanostatic charge-discharge experiments, and electrochemical impedance spectroscopy. The results show that the film prepared by this method is homogeneous, dense, and crack-free. The thin film has a capacity of 38 μtAh/（cm^2·μm） with the capacity loss of 0.037% per cycle after being cycled for 100 times. The average diffusion coefficient for lithium ions in the RTA-derived LiMn2O4 thin film is 1×10 ^-10 cm^2·s^-1.展开更多
The nanosized particle materials of doped-TiO_2 with Y_2O_3 were prepared by means of sol-gel technique for use in electrorheological (ER) fluids, and their crystal structures were measured by X-ray diffraction (XRD) ...The nanosized particle materials of doped-TiO_2 with Y_2O_3 were prepared by means of sol-gel technique for use in electrorheological (ER) fluids, and their crystal structures were measured by X-ray diffraction (XRD) analysis. To compare with the pure TiO_2, a distinct enhancement in the shear stress under dc electric field was found by using such materials. This can be explained by the increase of the dielectric loss and dielectric constant at low frequency. The effects of the crystal structure of the particles on the dielectric property and ER performance of materials were investigated.展开更多
Single crystal of lithium potassium sulphate, a nonlinear optical material, was grown from aqua solution by slow evapo- ration method at room temperature. The cell parameters were estimated by single crystal X-ray dif...Single crystal of lithium potassium sulphate, a nonlinear optical material, was grown from aqua solution by slow evapo- ration method at room temperature. The cell parameters were estimated by single crystal X-ray diffraction analysis. The optical transmittance of the crystal was recorded using the UV-Vis-NIR spectrophotometer and the optical band gap was calculated using this method. The second harmonic generation efficiency was measured by Kurtz and Perry powder technique and the phase-matching property was confirmed. The hardness of the material was measured by Vicker’s hardness test.展开更多
The microstructure and electrical properties of ZnO-based varistors with the SiO2 content in the range of 0-1.00mol% were prepared by a solid reaction route. The varistors were characterized by scanning electron micro...The microstructure and electrical properties of ZnO-based varistors with the SiO2 content in the range of 0-1.00mol% were prepared by a solid reaction route. The varistors were characterized by scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectrometry, inductively coupled plasma-atomic emission spectrometry, and X-ray photoelectron spectroscopy. The results indicate that the average grain size of ZnO decreases with the SiO2 content increasing. A new second phase （Zn2SiO4） and a glass phase （Bi2SiO5） are found. Element Si mainly exists in the grain boundary and plays an important role in controlling the Bi2O3 vaporization. The electric measurement shows that the incorporation of SiO2 can significantly improve the nonlinear properties of ZnO-based varistors, and the nonlinear coefficients of the varistors with SiO2 are in the range of 36.8-69.5. The varistor voltage reaches the maximum value of 463 V/mm and the leakage current reaches the minimum value of 0.11 μA at the SiO2 content of 0.75mol%.展开更多
Y2O3-doped ZnO-based varistor ceramics were prepared using high-energy ball milling （HEBM） and low-temperature sin- tering technique, with voltage-gradient of 1934-2197 V/mm, non-linear coefficients of 20.8-21.8, le...Y2O3-doped ZnO-based varistor ceramics were prepared using high-energy ball milling （HEBM） and low-temperature sin- tering technique, with voltage-gradient of 1934-2197 V/mm, non-linear coefficients of 20.8-21.8, leakage currents of 0.59-1.04 μA, and densities of 5.46-5.57 g/cm3. With increasing Y2O3 content, the voltage-gradient increases because of the decrease of ZnO grain size; the non-linear coefficient and the leakage current improve but the density decreases because of more porosity; the donor con- centration and density of interface states decrease, whereas the barrier height and width increase because of the acceptor effect of Y2O3 in varistor ceramics.展开更多
The homogeneously dispersed, less agglomerated YAG nanopowders are synthesized by the citrate-gel method followed by low-temperature self-propagating combustion reaction, using Y2O3, Al(NO3)3?9H2O and citric acid as s...The homogeneously dispersed, less agglomerated YAG nanopowders are synthesized by the citrate-gel method followed by low-temperature self-propagating combustion reaction, using Y2O3, Al(NO3)3?9H2O and citric acid as starting materials. This method effectively solves the problems caused by solid-state reaction at high temperature and the hard ag-glomerates brought by the chemical precipitation method. The powders are characterized by TG-DTA, XRD, FT-IR and TEM respectively. The experiments show that the forming temperature of YAG crystal phase is 850°C and the pseudo-YAG crystalline appears during the calcination and transforms to pure YAG at 1050°C. The powders with sizes less than 50 nm are observed by TEM micrography, which is consistent with the result calculated by Scherrer's formula. The powders consist of single grains.展开更多
The current study is directed to the rapidly developing field of inorganic material 3D object production at nano-/micro scale.The fabrication method includes laser lithography of hybrid organic-inorganic materials wit...The current study is directed to the rapidly developing field of inorganic material 3D object production at nano-/micro scale.The fabrication method includes laser lithography of hybrid organic-inorganic materials with subsequent heat treatment leading to a variety of crystalline phases in 3D structures.In this work,it was examined a series of organometallic polymer precursors with different silicon(Si)and zirconium(Zr)molar ratios,ranging from 9:1 to 5:5,prepared via sol-gel method.All mixtures were examined for perspective to be used in 3D laser manufacturing by fabricating nano-and micro-feature sized structures.Their spatial downscaling and surface morphology were evaluated depending on chemical composition and crystallographic phase.The appearance of a crystalline phase was proven using single-crystal X-ray diffraction analysis,which revealed a lower crystallization temperature for microstructures compared to bulk materials.Fabricated 3D objects retained a complex geometry without any distortion after heat treatment up to 1400℃.Under the proper conditions,a wide variety of crystalline phases as well as zircon(ZrSiO_(4)-a highly stable material)can be observed.In addition,the highest new record of achieved resolution below 60 nm has been reached.The proposed preparation protocol can be used to manufacture micro/nano-devices with high precision and resistance to high temperature and aggressive environment.展开更多
Transparent YAG (yttrium aluminum garnet) ceramics were fabricated by solid-state reaction method. Effect of additive (tetraethyl orthosilicate, TEOS) on microstructure of YAG ceramics was investigated. If the additio...Transparent YAG (yttrium aluminum garnet) ceramics were fabricated by solid-state reaction method. Effect of additive (tetraethyl orthosilicate, TEOS) on microstructure of YAG ceramics was investigated. If the addition of TEOS is more than 3% (mass fraction), large amount of liquid phase can be yielded at grain boundaries, resulting in the formation of second phase particles at grain boundaries. If the addition is less than 0.05% (mass fraction), pores are entrapped in the grains. The suitable amount is 0.5% (mass fraction). A fully transparent YAG ceramic was fabricated by vacuum sintering at 1700 ℃ for 5 h. Optical transmittance of the YAG ceramic is 63% in the visible light wavelengths and 70% in the infrared wavelengths.展开更多
Via a mild thermal precipitation and aging process, polycrystalline hydrated nickel oxalate nanofibers were synthesized using nickel chloride and ammonium oxalate as raw materials, with pH 8.0 and temperature 60 ？C. ...Via a mild thermal precipitation and aging process, polycrystalline hydrated nickel oxalate nanofibers were synthesized using nickel chloride and ammonium oxalate as raw materials, with pH 8.0 and temperature 60 ？C. Atomic absorption spectrometer （AAS）, organic elemental analyzer （OEA）, fourier transform infrared spectroscopy （FT-IR）, thermogravimetry-derivative thermogravimetry （TG-DTG）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM） were used to characterize the products properties. The results demonstrated that the product was hydrated nickel oxalate. The sizes of hydrated nickel oxalate nanofibers were 100-150 nm in diameter, and 0.5-5.0 μm in length. A rational mechanism based on coordination self-assembly was discussed for the selective formation of the polycrystalline hydrated nickel oxalate nanofibers.展开更多
The Cr^3＋：BeAl2O4 crystal, Cr^3＋：LiNbO3 crystal, and ZnO-Al2O3-SiO2 glass-ceramic were obtained by the Czochralski technique, Bridgman method, and melting processing, respectively. The optical absorption and emiss...The Cr^3＋：BeAl2O4 crystal, Cr^3＋：LiNbO3 crystal, and ZnO-Al2O3-SiO2 glass-ceramic were obtained by the Czochralski technique, Bridgman method, and melting processing, respectively. The optical absorption and emission spectra of the above Cr^3＋-incorporated solid-state materials were recorded. The technical parameters for growing high-quality Cr^3＋：BeAl2O4 and Cr^3＋：LINbO3 crystals were obtained. The results indicate that the optical absorption and fluorescence spectra of Cr^3＋ show quite a few differences in various matrixes. The sharp line emissions were observed in the Cr^3＋：BeAl2O4 and Cr^3＋：LiNbO3 crystals. The crystal-field parameters （Dq） for Cr^3＋. in different matrixes were calculated from their corresponding spectra. It is indicated that Cr^3＋：BeAl2O4 and Cr^3＋：LiNbO3 belong to the high-field site crystal, while the Cr^3＋ ZnO-Al2O3-SiO2 glass and glass-ceramic belong to the weak-field site crystal.展开更多
文摘With the progress of science and technology,China has gradually attached importance to research and exploration in chemistry,and the achievements in exploring mechanochemistry are also quite significant.Therefore,it is necessary to study and explore mechanochemistry.This article mainly discusses the application of mechanochemistry in powder and some silicate materials,as well as in special ceramics,and provides a brief introduction to provide reference for relevant researchers.
基金the National Natural Science Foundations of China(Grant Number:51772247).
文摘With the continuous demand of material performance,the development of materials is rapid,and the professional curriculum teaching of“new inorganic materials”as well as its teaching methods related to the internet mandate a reform,in order to meet the needs of innovative high-quality personnel training.The update and optimization of the teaching content and methods assisted by the internet meet the needs of modern teaching and research work.More than 90%of students believe that internet teaching is conducive to the understanding of classroom knowledge and the development of innovative projects.
基金financially supported by the National Key Research and Development Program(Grant No.2022YFE0207400)the National Natural Science Foundation of China(Grant No.U22A20168 and 52174225)。
文摘Developing technologies that can be applied simultaneously in battery thermal management(BTM)and thermal runaway(TR)mitigation is significant to improving the safety of lithium-ion battery systems.Inorganic phase change material(PCM)with nonflammability has the potential to achieve this dual function.This study proposed an encapsulated inorganic phase change material(EPCM)with a heat transfer enhancement for battery systems,where Na_(2)HPO_(4)·12H_(2)O was used as the core PCM encapsulated by silica and the additive of carbon nanotube(CNT)was applied to enhance the thermal conductivity.The microstructure and thermal properties of the EPCM/CNT were analyzed by a series of characterization tests.Two different incorporating methods of CNT were compared and the proper CNT adding amount was also studied.After preparation,the battery thermal management performance and TR propagation mitigation effects of EPCM/CNT were further investigated on the battery modules.The experimental results of thermal management tests showed that EPCM/CNT not only slowed down the temperature rising of the module but also improved the temperature uniformity during normal operation.The peak battery temperature decreased from 76℃to 61.2℃at 2 C discharge rate and the temperature difference was controlled below 3℃.Moreover,the results of TR propagation tests demonstrated that nonflammable EPCM/CNT with good heat absorption could work as a TR barrier,which exhibited effective mitigation on TR and TR propagation.The trigger time of three cells was successfully delayed by 129,474 and 551 s,respectively and the propagation intervals were greatly extended as well.
文摘The unity between physics and biology refers to that the inorganic systems： the Solar System, galaxies and artificial systems have the same structures and functions as the organisms. The development of science and technology is demonstrating the intense unification trends of physics and biology and a holistic science and technology era is about to start. The physics and biology unify on the basis of the four seasons＇ law, which is the most important rule of the universe. Life is defined as the four seasons＇ whole with the structure and process of four seasons. The organism is basically structured into a dual four-season body by state-varying, state-stabilizing and control organizations. Animals, the Solar System and the earth are all the dual four-season bodies. In the unity between physics and biology, the inorganic life materials and inorganic life body can be manufactured artificially.
基金Plan Project of Science and Technology of Guangzhou City (2002J1-C0061) The First Author: XI Hongxia(1968-)
文摘hydroxy-4-nitro azobenzene (NHA) and 4-amino-4-nitro azobenzene (DO3) were prepared respectively from p-nitrophenylamine as a precursor compound. Two kinds of doped organic/inorganic hybrid nonlinear optical (NLO) materials containing NHA and DO3 were synthesized by Sol-Gel process. The preparation and properties of two NLO materials were studied and characterized by FTIR, 1H-NMR, UV-VIS, SEM, DSC and SHG measurements. The results show that the maximum doping amounts of NHA and DO3 in two doped hybrid NLO materials are 7.2(wt)% and 11.3(wt)% respectively, and the corresponding second-order NLO coefficients (d33 values) are 2.91×10 8esu and 6.14×10 8esu. Two doped NLO materials have relatively good RT stability, after 90 days at RT the d33 values can maintain about 85% of their initial values, but after 10h at 100℃ can only maintain about 50% of their initial values. In this report, the reasons for high-temperature instability of doped materials were discussed, and the possible improvements were also suggested.
基金supported by the National Natural Science Foundation of China (21975283)the Natural Science Foundation of Jiangsu Province (Youth Fund,Nos.BK20220601)+1 种基金State Key Laboratory of Chemistry and Utilization of Carbon-based Energy Resource (KFKT2021007)CAS Key Laboratory of Carbon Materials (KLCMKFJJ2010)。
文摘Rechargeable potassium-ion batteries(PIBs)have great potential in the application of electrochemical energy storage devices due to the low cost,the abundant resources and the low standard reduction potential of potassium.As electrode materials are the key factors to determine the electrochemical performance of devices,relevant research is being carried out to build high-performance PIBs.In recent years,significant progress has been made in the study of the design of inorganic electrode materials.Herein,we review the cathode materials(Prussian blue and its analogues,layered oxides and poly anionic compounds)and the anode materials(antimony-based,selenium-based and bismuth-based compounds).On the basis of previous work,the structural design principles for improving the performance of electrode materials are reasonably summarized.At the same time,the problems that need to be solved in the preparation of electrode materials and the direction of future research and improvement are pointed out.
文摘Long afterglow photoluminescent materials Sr2MgSi2O7 doped with Eu2+, Dy3+ were prepared by sol-gel method. The synthesized samples were characterized by X-ray diffraction. The excitation spectrum, emission spectrum and long decay curve were measured and analyzed. XRD pattern indicates that phosphor is with Sr2MgSi2O7 crystal structure. The wide range of excitation wavelength indicates that luminescent material can be excited by light from ultraviolet ray to visible light. The main peak of emission spectrum is located at 466 nm. Sample excited by visible light can emit bright blue light, and the afterglow time lasts more than 8 h.
基金the Outstanding Young Scientist Rewards of Shandong Province (05BS04008)the Natural Science Fund of Shandong Province (Y2007F29)
文摘Mixed rare earth elements were incorporated into alumina ceramic materials. Hot-pressing was used to fabricate alumina matrix composites in nitrogen atmosphere protection. Microstructures and mechanical properties of the composites were tested. It was indicated that the bending strength and fracture toughness of alumina matrix ceramic composites sintered at 1550 ℃ and 28 MPa for 30 min were improved evidently. Besides mixed rare earth elements acting as a toughening phase, AlTiC master alloys were also added in as sintering assistants, which could prompt the formation of transient liquid phase, and thus nitrides of rare earth elements were produced. All of the above were beneficial for improving the mechanical properties of alumina matrix ceramic composites.
基金the National Nature Science Foundation of China (50574045)the Specialized Research Fundfor the Doctoral Program of Higher Education (20050674003)the Science Research Fund of Yunnan Provincial Department of Education(07Y41398)
文摘Inorganic antibacterial materials consist of the antibacterial ions, the additives and the carrier. In this study, we synthesized a new inorganic antibacterialmaterial, of which Cu2+ and Ag+ were selected to be the bi-component antibacterial ions, cerous nitrate served as the additives, and the white carbon black was chosen as the carrier, which was prepared by a sol-gel method. The as-synthesized antibacterial material was characterized by inductively coupled plasma, particle size measurement instrument, scanning electron microscope and enumeration tests. The result showed that the amount of antibacterial ions and bacteriostasis rate of this new material are higher than those for the single-ion inorganic antibacterial material. In addition, the particle size of this material can be extended down to 7 μm with a narrow size distribution. Other advantages of this material are its loose and dispersive structure, good thermal and light stability. From the antibacterial experiment in rubber and the coating surface of metal, this new material showed promising results. The possible antibacterial mechanism was also proposed through all the experimental data in this study.
基金This work was supported by Natural Science Foundation of Heilongjiang Province,China(Grant No.LH2019B007)the Heilongjiang Provincial Postdoctoral Science Foundation(Grant No.LBH-TZ0604)the Natural Scientific Research Innovation Foundation in Harbin Institute of Technology(Grant No.HIT.NSRIF2019042).
文摘In recent years, perovskite solar cells (PSCs) have become a much charming photovoltaic technology and have triggered enormous studies worldwide, owing to their high efficiency, low cost and ease of preparation. The power conversion efficiency has rapidly increased by more than 6 times to the current 25.5% in the past decade. Hole transport materials (HTMs) are an indispensable part of PSCs, which great affect the efficiency, the cost and the stability of PSCs. Inorganic Cu-based p-type semiconductors are a kind of representative inorganic HTMs in PSCs due to their unique advantages of rich variety, low cost, excellent hole mobility, adjustable energy levels, good stability, low temperature and scalable processing ability. In this review, the research progress in new materials and the control of photoelectric properties of Cu-based inorganic HTMs were first summarized systematically. And then, concerning different processing methods, advances of the interface engineering of Cu-based hole transport layers (HTLs) in PSCs were detailly discussed. Finally, the challenges and future trends of Cu-based inorganic HTMs and their interface engineering in PSCs were analyzed.
基金This project was financially supported by the Natural Science Foundation of Hunan Province, China (No. 04JJ40038) and the Education Department of Hunan Province, China (No. 04C 475).
文摘The LiMn2O4 thin film as a cathode material was prepared through solution deposition followed by rapid thermal annealing （RTA）. The phase identification and the study of surface morphology were carried out by X-my diffraction and scanning electron microscopy. Electrochemical properties were examined by cyclic voltammetry, galvanostatic charge-discharge experiments, and electrochemical impedance spectroscopy. The results show that the film prepared by this method is homogeneous, dense, and crack-free. The thin film has a capacity of 38 μtAh/（cm^2·μm） with the capacity loss of 0.037% per cycle after being cycled for 100 times. The average diffusion coefficient for lithium ions in the RTA-derived LiMn2O4 thin film is 1×10 ^-10 cm^2·s^-1.
文摘The nanosized particle materials of doped-TiO_2 with Y_2O_3 were prepared by means of sol-gel technique for use in electrorheological (ER) fluids, and their crystal structures were measured by X-ray diffraction (XRD) analysis. To compare with the pure TiO_2, a distinct enhancement in the shear stress under dc electric field was found by using such materials. This can be explained by the increase of the dielectric loss and dielectric constant at low frequency. The effects of the crystal structure of the particles on the dielectric property and ER performance of materials were investigated.
文摘Single crystal of lithium potassium sulphate, a nonlinear optical material, was grown from aqua solution by slow evapo- ration method at room temperature. The cell parameters were estimated by single crystal X-ray diffraction analysis. The optical transmittance of the crystal was recorded using the UV-Vis-NIR spectrophotometer and the optical band gap was calculated using this method. The second harmonic generation efficiency was measured by Kurtz and Perry powder technique and the phase-matching property was confirmed. The hardness of the material was measured by Vicker’s hardness test.
文摘The microstructure and electrical properties of ZnO-based varistors with the SiO2 content in the range of 0-1.00mol% were prepared by a solid reaction route. The varistors were characterized by scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectrometry, inductively coupled plasma-atomic emission spectrometry, and X-ray photoelectron spectroscopy. The results indicate that the average grain size of ZnO decreases with the SiO2 content increasing. A new second phase （Zn2SiO4） and a glass phase （Bi2SiO5） are found. Element Si mainly exists in the grain boundary and plays an important role in controlling the Bi2O3 vaporization. The electric measurement shows that the incorporation of SiO2 can significantly improve the nonlinear properties of ZnO-based varistors, and the nonlinear coefficients of the varistors with SiO2 are in the range of 36.8-69.5. The varistor voltage reaches the maximum value of 463 V/mm and the leakage current reaches the minimum value of 0.11 μA at the SiO2 content of 0.75mol%.
文摘Y2O3-doped ZnO-based varistor ceramics were prepared using high-energy ball milling （HEBM） and low-temperature sin- tering technique, with voltage-gradient of 1934-2197 V/mm, non-linear coefficients of 20.8-21.8, leakage currents of 0.59-1.04 μA, and densities of 5.46-5.57 g/cm3. With increasing Y2O3 content, the voltage-gradient increases because of the decrease of ZnO grain size; the non-linear coefficient and the leakage current improve but the density decreases because of more porosity; the donor con- centration and density of interface states decrease, whereas the barrier height and width increase because of the acceptor effect of Y2O3 in varistor ceramics.
基金This work is financially supported by the Excellent Teachers Fund by the Ministry of Education of China (No. KB200226).
文摘The homogeneously dispersed, less agglomerated YAG nanopowders are synthesized by the citrate-gel method followed by low-temperature self-propagating combustion reaction, using Y2O3, Al(NO3)3?9H2O and citric acid as starting materials. This method effectively solves the problems caused by solid-state reaction at high temperature and the hard ag-glomerates brought by the chemical precipitation method. The powders are characterized by TG-DTA, XRD, FT-IR and TEM respectively. The experiments show that the forming temperature of YAG crystal phase is 850°C and the pseudo-YAG crystalline appears during the calcination and transforms to pure YAG at 1050°C. The powders with sizes less than 50 nm are observed by TEM micrography, which is consistent with the result calculated by Scherrer's formula. The powders consist of single grains.
基金The US AMRDEC grant No.W911NF-16-2-0069“Enhanced Absorption in Stopped-Light Photonic Nanostructures:Applications to Efficient Sensing”EU LASERLAB-EUROPE(grant agreement No.871124Horizon 2020 research and innovation programme)projects are acknowleged for the financial support.D.G.acknowledges the financial support from the European Social Fund(project No 09.3.3-LMT-K712-17-0016)under grant agreement with the Research Council of Lithuania(LMTLT).
文摘The current study is directed to the rapidly developing field of inorganic material 3D object production at nano-/micro scale.The fabrication method includes laser lithography of hybrid organic-inorganic materials with subsequent heat treatment leading to a variety of crystalline phases in 3D structures.In this work,it was examined a series of organometallic polymer precursors with different silicon(Si)and zirconium(Zr)molar ratios,ranging from 9:1 to 5:5,prepared via sol-gel method.All mixtures were examined for perspective to be used in 3D laser manufacturing by fabricating nano-and micro-feature sized structures.Their spatial downscaling and surface morphology were evaluated depending on chemical composition and crystallographic phase.The appearance of a crystalline phase was proven using single-crystal X-ray diffraction analysis,which revealed a lower crystallization temperature for microstructures compared to bulk materials.Fabricated 3D objects retained a complex geometry without any distortion after heat treatment up to 1400℃.Under the proper conditions,a wide variety of crystalline phases as well as zircon(ZrSiO_(4)-a highly stable material)can be observed.In addition,the highest new record of achieved resolution below 60 nm has been reached.The proposed preparation protocol can be used to manufacture micro/nano-devices with high precision and resistance to high temperature and aggressive environment.
文摘Transparent YAG (yttrium aluminum garnet) ceramics were fabricated by solid-state reaction method. Effect of additive (tetraethyl orthosilicate, TEOS) on microstructure of YAG ceramics was investigated. If the addition of TEOS is more than 3% (mass fraction), large amount of liquid phase can be yielded at grain boundaries, resulting in the formation of second phase particles at grain boundaries. If the addition is less than 0.05% (mass fraction), pores are entrapped in the grains. The suitable amount is 0.5% (mass fraction). A fully transparent YAG ceramic was fabricated by vacuum sintering at 1700 ℃ for 5 h. Optical transmittance of the YAG ceramic is 63% in the visible light wavelengths and 70% in the infrared wavelengths.
基金Funded by the National Natural Science Foundation of China(51002126)the Open Project of State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials (10zxfk30)
文摘Via a mild thermal precipitation and aging process, polycrystalline hydrated nickel oxalate nanofibers were synthesized using nickel chloride and ammonium oxalate as raw materials, with pH 8.0 and temperature 60 ？C. Atomic absorption spectrometer （AAS）, organic elemental analyzer （OEA）, fourier transform infrared spectroscopy （FT-IR）, thermogravimetry-derivative thermogravimetry （TG-DTG）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM） were used to characterize the products properties. The results demonstrated that the product was hydrated nickel oxalate. The sizes of hydrated nickel oxalate nanofibers were 100-150 nm in diameter, and 0.5-5.0 μm in length. A rational mechanism based on coordination self-assembly was discussed for the selective formation of the polycrystalline hydrated nickel oxalate nanofibers.
基金This work is financially supported by the Project of Science and Technology of Zhejiang Province (No. 011066)Project of Education Committee of Zhejiang Province (No. 20010231)the Doctoral Science Foundation of Ningbo City (No. 02J20101-12)the Personal Bureau of Ningbo City, China (No. 2002182).
文摘The Cr^3＋：BeAl2O4 crystal, Cr^3＋：LiNbO3 crystal, and ZnO-Al2O3-SiO2 glass-ceramic were obtained by the Czochralski technique, Bridgman method, and melting processing, respectively. The optical absorption and emission spectra of the above Cr^3＋-incorporated solid-state materials were recorded. The technical parameters for growing high-quality Cr^3＋：BeAl2O4 and Cr^3＋：LINbO3 crystals were obtained. The results indicate that the optical absorption and fluorescence spectra of Cr^3＋ show quite a few differences in various matrixes. The sharp line emissions were observed in the Cr^3＋：BeAl2O4 and Cr^3＋：LiNbO3 crystals. The crystal-field parameters （Dq） for Cr^3＋. in different matrixes were calculated from their corresponding spectra. It is indicated that Cr^3＋：BeAl2O4 and Cr^3＋：LiNbO3 belong to the high-field site crystal, while the Cr^3＋ ZnO-Al2O3-SiO2 glass and glass-ceramic belong to the weak-field site crystal.
