Antimony sulfide(Sb_(2)S_(3))is a promising material for photoelectrochemical(PEC)devices that generate green hydrogen from sunlight and water.In this study,we present a synthesis of high-performance Sb_(2)S_(3)photoa...Antimony sulfide(Sb_(2)S_(3))is a promising material for photoelectrochemical(PEC)devices that generate green hydrogen from sunlight and water.In this study,we present a synthesis of high-performance Sb_(2)S_(3)photoanodes via an interface-engineered hydrothermal growth followed by rapid thermal annealing(RTA).A TiO_(2)interfacial layer plays a crucial role in ensuring homogeneous precursor deposition,enhancing light absorption,and forming efficient heterojunctions with Sb_(2)S_(3),thereby significantly improving charge separation and transport.RTA further improves crystallinity and interfacial contact,resulting in dense and uniform Sb_(2)S_(3)films with enlarged grains and fewer defects.The optimized Sb_(2)S_(3)photoanode achieves a photocurrent density of 2.51 mA/cm^(2)at 1.23 V vs.the reversible hydrogen electrode(RHE),one of the highest reported for Sb_(2)S_(3)without additional catalysts or passivation layers.To overcome the limitations of oxygen evolution reaction(OER),we employ the iodide oxidation reaction(IOR)as an alternative,significantly lowering the overpotential and improving charge transfer kinetics.Consequently,it produces a record photocurrent density of 8.9 mA/cm^(2)at 0.54 V vs.RHE.This work highlights the synergy between TiO_(2)interfacial engineering,RTA-induced crystallization,and IOR-driven oxidation,offering a promising pathway for efficient and scalable PEC hydrogen production.展开更多
Preparation of hierarchically porous, heteroatom-rich nanostructured carbons through green and scalable routes plays a key role for practical energy storage applications. In this work, naturally abundant lignocellulos...Preparation of hierarchically porous, heteroatom-rich nanostructured carbons through green and scalable routes plays a key role for practical energy storage applications. In this work, naturally abundant lignocellulosic agricultural waste with high initial oxygen content, hazelnut shells, were hydrothermally carbonized and converted into nanostructured ‘hydrochar’. Environmentally benign ceramic/magnesium oxide（Mg O） templating was used to introduce porosity into the hydrochar. Electrochemical performance of the resulting material（HM700） was investigated in aqueous solutions of 1 M H;SO;, 6 M KOH and1 M Na;SO;, using a three-electrode cell. HM700 achieved a high specific capacitance of 323.2 F/g in 1 M H;SO;（at 1 A/g,-0.3 to 0.9 V vs. Ag/Ag Cl） due to the contributions of oxygen heteroatoms（13.5 wt%）to the total capacitance by pseudo-capacitive effect. Moreover, a maximum energy density of 11.1 Wh/kg and a maximum power density of 3686.2 W/kg were attained for the symmetric supercapacitor employing HM700 as electrode material（1 M Na;SO;, E = 2 V）, making the device promising for green supercapacitor applications.展开更多
Bi_2Se_3 was studied as a novel sodium-ion battery anode material because of its high theoretical capacity and high intrinsic conductivity. Integrated with carbon,Bi_2Se_3/C composite shows excellent cyclic performanc...Bi_2Se_3 was studied as a novel sodium-ion battery anode material because of its high theoretical capacity and high intrinsic conductivity. Integrated with carbon,Bi_2Se_3/C composite shows excellent cyclic performance and rate capability. For instance, the Bi_2Se_3/C anode delivers an initial capacity of 527 mAh g^(-10) at 0.1 A g^(-1) and maintains 89% of this capacity over 100 cycles. The phase change and sodium storage mechanism are also carefully investigated.展开更多
Energy storage and conversion technologies have attracted increasing attention from academic and industrial communities due to the large demands from wide-ranging applications.Designing and developing high-performance...Energy storage and conversion technologies have attracted increasing attention from academic and industrial communities due to the large demands from wide-ranging applications.Designing and developing high-performance electrode materials are cruciual to improve the performance of energy storage and conversion devices.At present,various energy storage and conversion devices,i.e.,potassium-ion batteries(PIBs).展开更多
With the rising demand for fast-charging technology in electric vehicles and portable devices,significant efforts have been devoted to the development of energy storage and conversion technologies.Nowadays,remarkable ...With the rising demand for fast-charging technology in electric vehicles and portable devices,significant efforts have been devoted to the development of energy storage and conversion technologies.Nowadays,remarkable progress has been made in the field of various energy storage and conversion devices,i.e.,lithium-ion batteries(LIBs),lithium-metal batteries(LMBs),lithium-sulfur batteries(LSBs),sodium-ion batteries(SIBs),sodium-metal batteries(SMBs),magnesium-ion batteries(MIBs),zinc-ion batteries(ZIBs),electrochemical capacitors(ECs),the corresponding electrode materials have always been the focus and difficulty to further improve the electrochemical performance of the devices.展开更多
Rechargeable Li-ion batteries were first commercialized in 1991 by Sony company,and the current portable electronic devices and electric vehicles powered by rechargeable batteries have significantly accelerated the de...Rechargeable Li-ion batteries were first commercialized in 1991 by Sony company,and the current portable electronic devices and electric vehicles powered by rechargeable batteries have significantly accelerated the development of social civilization.The Nobel Prize in Chemistry 2019 was also awarded jointly to John B.Goodenough,M.Stanley Whittingham,and Akira Yoshino for their outstanding contribution to rechargeable Li-ion batteries.展开更多
The cubic pyrochlore Dy2Pt2O7 was synthesized under 4 GPa and 1000℃ and its magnetic and thermodynamic properties were characterized by DC and AC magnetic susceptibility and specific heat down to 0.1 K.We found that ...The cubic pyrochlore Dy2Pt2O7 was synthesized under 4 GPa and 1000℃ and its magnetic and thermodynamic properties were characterized by DC and AC magnetic susceptibility and specific heat down to 0.1 K.We found that Dy2Pt2O7 does not form long-range magnetic order,but displays characteristics of canonical spin ice such as Dy2Pt2O7,including(1)a large effective moment 9.64μB close to the theoretical value and a small positive Curie-Weiss temperatureθCW=+0.77 K signaling a dominant ferromagnetic interaction among the Ising spins;(2)a saturation moment ~4.5μB being half of the total moment due to the local<111>Ising anisotropy;(3)thermally activated spin relaxation behaviors in the low(~1 K)and high(~20 K)temperature regions with different energy barriers and characteristic relaxation time;and most importantly,(4)the presence of a residual entropy close to Pauling’s estimation for water ice.展开更多
The corrosion behavior of bulk ultra-fine grained（UFG） Fe-Ni-Cr alloy prepared by equal-channel angular pressing technique was investigated in 0.25 mol/L Na2SO4＋0.05 mol/L H2SO4 solution by electrochemical measurem...The corrosion behavior of bulk ultra-fine grained（UFG） Fe-Ni-Cr alloy prepared by equal-channel angular pressing technique was investigated in 0.25 mol/L Na2SO4＋0.05 mol/L H2SO4 solution by electrochemical measurements.As compared to the coarse grained（CG） counterpart,the UFG alloy exhibits an acceleration of the active dissolution and a shrunk passive region with a higher passive current.The Mott-Schottky analysis in conjunction with the point defect model indicates mat the donor diffusion coefficient in the passive films of the UFG sample increases greatly to one magnitude order higher and the donor density is slightly lower than that of the CG sample.展开更多
The microstructural features of high-temperature sintered and CaO-MgO-Al_2O_3-SiO_2(CMAS) corroded air plasma sprayed Y_2O_3 stabilized ZrO_2(YSZ) thermal barrier coatings(TBCs) under the thermal gradient condition we...The microstructural features of high-temperature sintered and CaO-MgO-Al_2O_3-SiO_2(CMAS) corroded air plasma sprayed Y_2O_3 stabilized ZrO_2(YSZ) thermal barrier coatings(TBCs) under the thermal gradient condition were comparatively studied. As-sprayed YSZ has a lamellar structure and the lamellae are composed of closely aligned columnar crystals. The sintered and the CMAS corroded YSZ coatings maintain the t'-ZrO_2 phase as the as-sprayed YSZ coating. The sintered YSZ remains the lamellar structure with reduced interlamellar gaps and grains coarsening. After the CMAS corrosion, the top layer of the YSZ coating keeps its lamellar structure consisting of some columnar grains with the CMAS infiltration into the intergrain gaps and the formation of striped Zr_2Y_2 O_7. The typical lamellar structure transforms into more equiaxed grains in the middle and bottom layers of the ceramic coating along with significant infiltration of amorphous CMAS and anorthite formation in the bottom layer owing to the high contents of Ca and Al.展开更多
We fabricated sulfur and nitrogen codoped cyanoethyl cellulose-derived carbons(SNCCs)with state-of-the-art electrochemical performance for potassium ion battery(PIB)and potassium ion capacitor(PIC)anodes.At 0.2,0.5,1,...We fabricated sulfur and nitrogen codoped cyanoethyl cellulose-derived carbons(SNCCs)with state-of-the-art electrochemical performance for potassium ion battery(PIB)and potassium ion capacitor(PIC)anodes.At 0.2,0.5,1,2,5,and 10 A g−1,the SNCC shows reversible capacities of 369,328,249,208,150,and 121 mA h g−1,respectively.Due to a high packing density of 1.01 g cm^(−3),the volumetric capacities are also uniquely favorable,being 373,331,251,210,151,and 122 mA h cm^(−3)at these currents,respectively.SNCC also shows promising initial Coulombic efficiency of 69.0%and extended cycling stability with 99.8%capacity retention after 1000 cycles.As proof of principle,an SNCC-based PIC is fabricated and tested,achieving 94.3Wh kg^(−1)at 237.5Wkg^(−1)and sustaining over 6000 cycles at 30 A g−1 with 84.5%retention.The internal structure of S and N codoped SNCC is based on highly dilated and defective graphene sheets arranged into nanometer-scale walls.Using a baseline S-free carbon for comparison(termed NCC),the role of S doping and the resultant dilated structure was elucidated.According to galvanostatic intermittent titration technique and electrochemical impedance spectroscopy analyses,as well as COMSOL simulations,this structure promotes rapid solid-state diffusion of potassium ions and a solid electrolyte interphase that is stable during cycling.X-ray diffraction was used to probe the ion storage mechanisms in SNCC,establishing the role of reversible potassium intercalation and the presence of KC36,KC24,and KC8 phases at low voltages.展开更多
Aging precipitation and solid solution heat treatment were carried out on three steels which have chromium content of 18%, manganese content of 12%, 15%, 18%, and nitrogen content of 0.43%, 0.53%, 0.67%, respectively....Aging precipitation and solid solution heat treatment were carried out on three steels which have chromium content of 18%, manganese content of 12%, 15%, 18%, and nitrogen content of 0.43%, 0.53%, 0.67%, respectively. The mechanisms of precipitation and solid solution of high nitrogen anstenitic stainless steel were studied using the scanning electron microscopy, transmission electron microscopy, electron probe micro analysis and mechanical testing. The results show that, Cr2N is the primary precipitate in the tested stainless steels instead of Cr23C6. Cr2N nucleates at austenitic grain boundaries and grows towards inner grains with a lameUar morphology. By means of pre-precipitation of Cr2N at 800 ~C, the microstructure of the steels at solid solution state can be refined, thus improving the strength and plasticity. After the proposed treatment, the tensile strength, the proof strength and the elongation of the tested steel reach 881 MPa, 542 MPa and 54%, respectively.展开更多
In order to investigate the effects of solid solution atoms, precipitated particles and cold deformation on the microstructures and properties of Al-Sc-Zr alloys, the Al-Sc-Zr alloys prepared by continuous rheo-extrus...In order to investigate the effects of solid solution atoms, precipitated particles and cold deformation on the microstructures and properties of Al-Sc-Zr alloys, the Al-Sc-Zr alloys prepared by continuous rheo-extrusion were treated by thermomechanical treatment, analyzed for conductivity and mechanical properties by tensile and microhardness testing, and characterized using optical microscope, TEM and STEM. A mathematical model was established to quantitatively characterize the contribution of solid solution atoms, precipitates and cold deformation to the conductivity of the alloy. The results show that the strength of Al alloy can be significantly improved by solid solution, aging and cold deformation, and the quantitative impacts of solution atoms, precipitates and cold deformation on the conductivity of Al alloy are 10.5%(IACS), 2.3%(IACS) and 0.5%(IACS), respectively. Aging and cold deformation treatments are the keys to obtain high-strength and high-conductivity aluminum alloy wires.展开更多
A micro-nano structure CaF_(2)chemical conversion layer was prepared on fluoride-treated AZ31 alloy,then the composite fluoride conversion film(CaF_(2)/MgF_(2))was modified by stearic acid(SA)and fabricated a superhyd...A micro-nano structure CaF_(2)chemical conversion layer was prepared on fluoride-treated AZ31 alloy,then the composite fluoride conversion film(CaF_(2)/MgF_(2))was modified by stearic acid(SA)and fabricated a superhydrophobic surface.The fluoride-treated magnesium,fluoride conversion film and superhydrophobic coating were characterized by SEM,EDS,XRD and FTIR.The properties of coatings1 adhesion and corrosion resistance were evaluated via tape test and electrochemical measurement.The cytocompatibility of the MgF_(2),CaF_(2)and superhydrophobic CaF_(2)/SA surface was investigated with bone marrow-derived mesenchymal stem cells(BMSCs)by direct culture for 24 h.The results showed that the superhydrophobic fluoride conversion coating composed of inner MgF_(2)layer and the outer CaF_(2)/SA composite layer had an average water contact angle of 152°.SA infiltrated into the micro-nano structure CaF_(2)layer and formed a strong adhesion with CaF_(2)layer.Furthermore,the super-hydrophobic coating showed higher barrier properties and corrosion resistance compared with the fluoride conversion film and fluoride-treated AZ31 alloy.The BMSC adhesion test results demonstrated MgF_(2)CaF_(2)and CaF_(2)/SA coatings were all nontoxic to BMSC.At the condition of in direct contact with cells,MgF_(2)showed higher cell density and enhanced the BMSCs proliferation,while CaF_(2)and CaF_(2)/SA coating showed no statistically difference in cell density compared with glass reference but the CaF_(2)and CaF_(2)/SA coating were not conducive to BMSCs adhesion.展开更多
Five advanced high-strength transformation-induced plasticity(TRIP) steels with different chemical compositions were studied to correlate the retained austenite and nonmetallic inclusion content with their physical pr...Five advanced high-strength transformation-induced plasticity(TRIP) steels with different chemical compositions were studied to correlate the retained austenite and nonmetallic inclusion content with their physical properties and the characteristics of the resistance spot welding nuggets. Electrical and thermal properties and equilibrium phases of TRIP steels were predicted using the JMatPro? software. Retained austenite and nonmetallic inclusions were quantified by X-ray diffraction and saturation magnetization techniques. The nonmetallic inclusions were characterized by scanning electron microscopy. The results show that the contents of Si, C, Al, and Mn in TRIP steels increase both the retained austenite and the nonmetallic inclusion contents. We found that nonmetallic inclusions affect the thermal and electrical properties of the TRIP steels and that the differences between these properties tend to result in different cooling rates during the welding process. The results are discussed in terms of the electrical and thermal properties determined from the chemical composition and their impact on the resistance spot welding nuggets.展开更多
The three-dimensional (3D)bioprinting technology has progressed tremendously over the past decade.By controlling the size, shape,and architecture of the bioprinted constructs,3D bioprinting allows for the fabrication ...The three-dimensional (3D)bioprinting technology has progressed tremendously over the past decade.By controlling the size, shape,and architecture of the bioprinted constructs,3D bioprinting allows for the fabrication of tissue/organ-like constructs with strong structural-functional similarity with their in vivo counterparts at high fidelity.The bioink,a blend of biomaterials and living cells possessing both high biocompatibility and printability,is a critical component of bioprinting.In particular, gelatin methacryloyl (GelMA)has shown its potential as a viable bioink material due to its suitable biocompatibility and readily tunable physicochemical properties.Current GelMA-based bioinks and relevant bioprinting strategies for GelMA bioprinting are briefly reviewed.展开更多
Polycaprolactone/hydroxyapatite(PCL/HA)composite coating was fabricated by a combination of hydrothermal and dipping methods to delay the degradation of Mg alloy AZ31 as bioresorbable materials.The PCL/HA coating was ...Polycaprolactone/hydroxyapatite(PCL/HA)composite coating was fabricated by a combination of hydrothermal and dipping methods to delay the degradation of Mg alloy AZ31 as bioresorbable materials.The PCL/HA coating was composed of nano rod-shape HA crystals and PCL filled in the space of HA crystals.Compared with the single HA coating,the binding strength between the PCL/HA composite coating and Mg alloy was obviously improved and the PCL/HA coating still adhered to the surface of AZ31 substrate even after 38 days of immersion.The electrochemical corrosion rate of HA coated sample was reduced by ten times after being filled by PCL.The electrochemical impedance spectroscopy(EIS)and immersion test results showed that the PCL/HA composite coating could provide a more effective barrier for Mg substrate than the HA coating alone.The cytocompatibility and the antibacterial property of HA coating and PCL/HA coating were evaluated by culturing with bone marrow-derived mesenchymal stem cells(BMSCs)and methicillin-resistant staphylococcus aureus(MRSA)for 24 h under direct culture conditions,respectively.The PCL/HA composite coating showed better BMSC cell compatibility,more suitable for BMSC adhesion than HA coating alone and showed a potential application prospect as a biological materials.However,from the perspective of clinical applications,the antibacterial property of PCL/HA composite coating needs to be further improved.展开更多
In recent years, it has been shown that inflammatory biomarkers can be used as an effective signal for disease diagnoses. The early detection of these signals provides useful information that could prevent the occurre...In recent years, it has been shown that inflammatory biomarkers can be used as an effective signal for disease diagnoses. The early detection of these signals provides useful information that could prevent the occurrence of severe diseases. Here, we employed surface-enhanced Raman scattering(SERS) probe gold nanorods(GNRs) as a tool for the early detection of inflammatory molecules in inflamed cells. A murine macrophage cell line(Raw264.7) stimulated with lipopolysaccharide(LPS) was used as a model in this study. The prepared SERS probe GNRs containing 4-mercaptobenzoic acid as a Raman reporter to generate SERS signals were used for detection of intracellular adhesion molecule-1(ICAM-1) in macrophages after treatment with LPS for varying lengths of time. Our results show that SERS probe GNRs could detect significant differences in the expression of ICAM-1 molecules in LPS-treated macrophages compared to those in untreated macrophages after only 1 h of LPS treatment. In contrast, when using fluorescent labeling or enzyme-linked immunosorbent assays(ELISA) to detect ICAM-1, significant differences between inflamed and un-inflamed macrophages were not seen until the cells had been treated with LPS for 5 h. These results indicate that our SERS probe GNRs provide a higher sensitivity for detecting biomarker molecules in inflamed macrophages than the conventional fluorescence and ELISA techniques, and could therefore be useful as a potential diagnostic tool for managing disease risk.展开更多
Low-cost and flexible solid polymer electrolytes are promising in all-solid-state Li-metal batteries with high energy density and safety.However,both the low room-temperature ionic conductivities and the small Li^(+)t...Low-cost and flexible solid polymer electrolytes are promising in all-solid-state Li-metal batteries with high energy density and safety.However,both the low room-temperature ionic conductivities and the small Li^(+)transference number of these electrolytes significantly increase the internal resistance and overpotential of the battery.Here,we introduce Gd-doped CeO_(2) nanowires with large surface area and rich surface oxygen vacancies to the polymer electrolyte to increase the interaction between Gd-doped CeO_(2) nanowires and polymer electrolytes,which promotes the Li-salt dissociation and increases the concentration of mobile Li ions in the composite polymer electrolytes.The optimized composite polymer electrolyte has a high Li-ion conductivity of 5×10^(-4)4 S cm^(-1) at 30℃ and a large Li+transference number of 0.47.Moreover,the composite polymer electrolytes have excellent compatibility with the metallic lithium anode and high-voltage LiNi_(0.8)Mn _(0.1)Co_(0.1)O_(2)(NMC)cathode,providing the stable cycling of all-solid-state batteries at high current densities.展开更多
Powder charges of micron-size Ni and Al2O3were utilized to deposit nano-structured Ni-Al2O3composite coatings on analuminum plate fixed at the top end of a milling vial using a planetary ball mill.Composite coatings w...Powder charges of micron-size Ni and Al2O3were utilized to deposit nano-structured Ni-Al2O3composite coatings on analuminum plate fixed at the top end of a milling vial using a planetary ball mill.Composite coatings were fabricated using powdermixtures with a wide range of Ni/Al2O3mass ratio varying from1:1to plain Ni.XRD,SEM and TEM techniques were employed tostudy the structural characteristics of the coatings.It was found that the composition of the starting mixture strongly affects the Al2O3content and the microstructure of the final coating.Mixtures containing higher contents of Al2O3yield higher volume fractions of theAl2O3particles in the coating.Though Ni-Al2O3composite coatings with about50%of Al2O3particles were successfully deposited,well-compacted and free of cracks and/or voids coatings included less than20%(volume fraction)of Al2O3particles which weredeposited from powder mixtures with Ni/Al2O3mass ratios of4:1or higher.Moreover,mechanical and metallurgical bondings arethe main mechanisms of the adhesion of the coating to the Al substrate.Finally,functionally graded composite coatings withnoticeable compaction and integrity were produced by deposition of two separate layers under identical coating conditions.展开更多
In order to clarify the recrystallization mechanism of low-densityδ-ferrite steel Fe-4AI-2Ni,interrupted and single-pass compression tests were carried out.In this regard,five deformation temperatures(750-950 at an i...In order to clarify the recrystallization mechanism of low-densityδ-ferrite steel Fe-4AI-2Ni,interrupted and single-pass compression tests were carried out.In this regard,five deformation temperatures(750-950 at an interval of 50°C)and different hold time were selected.It was observed that the softening and recrystallization fraction was enhaneed with increased deformation temperature and hold time.The original grain bounclaries were the preferred nucleation sites for recrystallized grains,and recrystallization had an impact on obtaining homogeneous and fine-grained structure.Recrystallization in the ferritic alloy commenced after a significant degree of softening,and the softening associated with recovery was appreciably less.The optimum rolling deformation temperature was identified to be greater than 900°C.展开更多
基金supported by the National Research Foundation of Korea(NRF)grant fu nded by the Korean government(MSIT)(No.RS-2024-00335976)。
文摘Antimony sulfide(Sb_(2)S_(3))is a promising material for photoelectrochemical(PEC)devices that generate green hydrogen from sunlight and water.In this study,we present a synthesis of high-performance Sb_(2)S_(3)photoanodes via an interface-engineered hydrothermal growth followed by rapid thermal annealing(RTA).A TiO_(2)interfacial layer plays a crucial role in ensuring homogeneous precursor deposition,enhancing light absorption,and forming efficient heterojunctions with Sb_(2)S_(3),thereby significantly improving charge separation and transport.RTA further improves crystallinity and interfacial contact,resulting in dense and uniform Sb_(2)S_(3)films with enlarged grains and fewer defects.The optimized Sb_(2)S_(3)photoanode achieves a photocurrent density of 2.51 mA/cm^(2)at 1.23 V vs.the reversible hydrogen electrode(RHE),one of the highest reported for Sb_(2)S_(3)without additional catalysts or passivation layers.To overcome the limitations of oxygen evolution reaction(OER),we employ the iodide oxidation reaction(IOR)as an alternative,significantly lowering the overpotential and improving charge transfer kinetics.Consequently,it produces a record photocurrent density of 8.9 mA/cm^(2)at 0.54 V vs.RHE.This work highlights the synergy between TiO_(2)interfacial engineering,RTA-induced crystallization,and IOR-driven oxidation,offering a promising pathway for efficient and scalable PEC hydrogen production.
基金supported by the Scientific and Technological Research Council of Turkey(TüBTAK)under Grant 112T570
文摘Preparation of hierarchically porous, heteroatom-rich nanostructured carbons through green and scalable routes plays a key role for practical energy storage applications. In this work, naturally abundant lignocellulosic agricultural waste with high initial oxygen content, hazelnut shells, were hydrothermally carbonized and converted into nanostructured ‘hydrochar’. Environmentally benign ceramic/magnesium oxide（Mg O） templating was used to introduce porosity into the hydrochar. Electrochemical performance of the resulting material（HM700） was investigated in aqueous solutions of 1 M H;SO;, 6 M KOH and1 M Na;SO;, using a three-electrode cell. HM700 achieved a high specific capacitance of 323.2 F/g in 1 M H;SO;（at 1 A/g,-0.3 to 0.9 V vs. Ag/Ag Cl） due to the contributions of oxygen heteroatoms（13.5 wt%）to the total capacitance by pseudo-capacitive effect. Moreover, a maximum energy density of 11.1 Wh/kg and a maximum power density of 3686.2 W/kg were attained for the symmetric supercapacitor employing HM700 as electrode material（1 M Na;SO;, E = 2 V）, making the device promising for green supercapacitor applications.
基金the support from TcSUH as the TcSUH Robert A. Welch Professorships on High Temperature Superconducting (HTSg) and Chemical Materials (E-0001)the support from the National Science Foundation under grant number DMR-1410936
文摘Bi_2Se_3 was studied as a novel sodium-ion battery anode material because of its high theoretical capacity and high intrinsic conductivity. Integrated with carbon,Bi_2Se_3/C composite shows excellent cyclic performance and rate capability. For instance, the Bi_2Se_3/C anode delivers an initial capacity of 527 mAh g^(-10) at 0.1 A g^(-1) and maintains 89% of this capacity over 100 cycles. The phase change and sodium storage mechanism are also carefully investigated.
文摘Energy storage and conversion technologies have attracted increasing attention from academic and industrial communities due to the large demands from wide-ranging applications.Designing and developing high-performance electrode materials are cruciual to improve the performance of energy storage and conversion devices.At present,various energy storage and conversion devices,i.e.,potassium-ion batteries(PIBs).
文摘With the rising demand for fast-charging technology in electric vehicles and portable devices,significant efforts have been devoted to the development of energy storage and conversion technologies.Nowadays,remarkable progress has been made in the field of various energy storage and conversion devices,i.e.,lithium-ion batteries(LIBs),lithium-metal batteries(LMBs),lithium-sulfur batteries(LSBs),sodium-ion batteries(SIBs),sodium-metal batteries(SMBs),magnesium-ion batteries(MIBs),zinc-ion batteries(ZIBs),electrochemical capacitors(ECs),the corresponding electrode materials have always been the focus and difficulty to further improve the electrochemical performance of the devices.
文摘Rechargeable Li-ion batteries were first commercialized in 1991 by Sony company,and the current portable electronic devices and electric vehicles powered by rechargeable batteries have significantly accelerated the development of social civilization.The Nobel Prize in Chemistry 2019 was also awarded jointly to John B.Goodenough,M.Stanley Whittingham,and Akira Yoshino for their outstanding contribution to rechargeable Li-ion batteries.
基金Project supported by the National Key R&D Program of China(Grant No.2018YFA0305700)the National Natural Science Foundation of China(Grant Nos.11834016,11874400,and 11921004)+4 种基金the Beijing Natural Science Foundation,China(Grant No.Z190008)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(Grant No.QYZDB-SSW-SLH013)the CAS Interdisciplinary Innovation Teamsupport of Grant No.NSF-DMR-1350002support of NSF DMR Grant No.1729588。
文摘The cubic pyrochlore Dy2Pt2O7 was synthesized under 4 GPa and 1000℃ and its magnetic and thermodynamic properties were characterized by DC and AC magnetic susceptibility and specific heat down to 0.1 K.We found that Dy2Pt2O7 does not form long-range magnetic order,but displays characteristics of canonical spin ice such as Dy2Pt2O7,including(1)a large effective moment 9.64μB close to the theoretical value and a small positive Curie-Weiss temperatureθCW=+0.77 K signaling a dominant ferromagnetic interaction among the Ising spins;(2)a saturation moment ~4.5μB being half of the total moment due to the local<111>Ising anisotropy;(3)thermally activated spin relaxation behaviors in the low(~1 K)and high(~20 K)temperature regions with different energy barriers and characteristic relaxation time;and most importantly,(4)the presence of a residual entropy close to Pauling’s estimation for water ice.
基金Project (201202127) support by Liaoning Provincial Natural Science Foundation of China under GrantProject (LJQ2011033) support by Program for Liaoning Excellent Talents in University
文摘The corrosion behavior of bulk ultra-fine grained（UFG） Fe-Ni-Cr alloy prepared by equal-channel angular pressing technique was investigated in 0.25 mol/L Na2SO4＋0.05 mol/L H2SO4 solution by electrochemical measurements.As compared to the coarse grained（CG） counterpart,the UFG alloy exhibits an acceleration of the active dissolution and a shrunk passive region with a higher passive current.The Mott-Schottky analysis in conjunction with the point defect model indicates mat the donor diffusion coefficient in the passive films of the UFG sample increases greatly to one magnitude order higher and the donor density is slightly lower than that of the CG sample.
基金supported financially by the National Natural Science Foundation of China (Nos. 51590891 and 11772288)the opening project of State Key Laboratory of Explosion Science and Technology (Beijing Institute of Technology, the opening project No. KFJJ15-05M)"Hundred Talents Program" of Hunan Province, China
文摘The microstructural features of high-temperature sintered and CaO-MgO-Al_2O_3-SiO_2(CMAS) corroded air plasma sprayed Y_2O_3 stabilized ZrO_2(YSZ) thermal barrier coatings(TBCs) under the thermal gradient condition were comparatively studied. As-sprayed YSZ has a lamellar structure and the lamellae are composed of closely aligned columnar crystals. The sintered and the CMAS corroded YSZ coatings maintain the t'-ZrO_2 phase as the as-sprayed YSZ coating. The sintered YSZ remains the lamellar structure with reduced interlamellar gaps and grains coarsening. After the CMAS corrosion, the top layer of the YSZ coating keeps its lamellar structure consisting of some columnar grains with the CMAS infiltration into the intergrain gaps and the formation of striped Zr_2Y_2 O_7. The typical lamellar structure transforms into more equiaxed grains in the middle and bottom layers of the ceramic coating along with significant infiltration of amorphous CMAS and anorthite formation in the bottom layer owing to the high contents of Ca and Al.
基金Funding information National Natural Science Foundation of China,Grant/Award Numbers:22179123,21471139Natural Science Foundation of Shandong Province,Grant/Award Number:ZR2020ME038+1 种基金Fundamental Research Funds for the Central Universities,Grant/Award Number:201941010National Science Foundation,Division of Materials Research,Grant/Award Number:1938833。
文摘We fabricated sulfur and nitrogen codoped cyanoethyl cellulose-derived carbons(SNCCs)with state-of-the-art electrochemical performance for potassium ion battery(PIB)and potassium ion capacitor(PIC)anodes.At 0.2,0.5,1,2,5,and 10 A g−1,the SNCC shows reversible capacities of 369,328,249,208,150,and 121 mA h g−1,respectively.Due to a high packing density of 1.01 g cm^(−3),the volumetric capacities are also uniquely favorable,being 373,331,251,210,151,and 122 mA h cm^(−3)at these currents,respectively.SNCC also shows promising initial Coulombic efficiency of 69.0%and extended cycling stability with 99.8%capacity retention after 1000 cycles.As proof of principle,an SNCC-based PIC is fabricated and tested,achieving 94.3Wh kg^(−1)at 237.5Wkg^(−1)and sustaining over 6000 cycles at 30 A g−1 with 84.5%retention.The internal structure of S and N codoped SNCC is based on highly dilated and defective graphene sheets arranged into nanometer-scale walls.Using a baseline S-free carbon for comparison(termed NCC),the role of S doping and the resultant dilated structure was elucidated.According to galvanostatic intermittent titration technique and electrochemical impedance spectroscopy analyses,as well as COMSOL simulations,this structure promotes rapid solid-state diffusion of potassium ions and a solid electrolyte interphase that is stable during cycling.X-ray diffraction was used to probe the ion storage mechanisms in SNCC,establishing the role of reversible potassium intercalation and the presence of KC36,KC24,and KC8 phases at low voltages.
基金Project(50974014) supported by the National Natural Science Foundation of China
文摘Aging precipitation and solid solution heat treatment were carried out on three steels which have chromium content of 18%, manganese content of 12%, 15%, 18%, and nitrogen content of 0.43%, 0.53%, 0.67%, respectively. The mechanisms of precipitation and solid solution of high nitrogen anstenitic stainless steel were studied using the scanning electron microscopy, transmission electron microscopy, electron probe micro analysis and mechanical testing. The results show that, Cr2N is the primary precipitate in the tested stainless steels instead of Cr23C6. Cr2N nucleates at austenitic grain boundaries and grows towards inner grains with a lameUar morphology. By means of pre-precipitation of Cr2N at 800 ~C, the microstructure of the steels at solid solution state can be refined, thus improving the strength and plasticity. After the proposed treatment, the tensile strength, the proof strength and the elongation of the tested steel reach 881 MPa, 542 MPa and 54%, respectively.
基金Project(51674077) supported by the National Natural Science Foundation of ChinaProject(2018YFB2001800) supported by the National Research and Development Program of China
文摘In order to investigate the effects of solid solution atoms, precipitated particles and cold deformation on the microstructures and properties of Al-Sc-Zr alloys, the Al-Sc-Zr alloys prepared by continuous rheo-extrusion were treated by thermomechanical treatment, analyzed for conductivity and mechanical properties by tensile and microhardness testing, and characterized using optical microscope, TEM and STEM. A mathematical model was established to quantitatively characterize the contribution of solid solution atoms, precipitates and cold deformation to the conductivity of the alloy. The results show that the strength of Al alloy can be significantly improved by solid solution, aging and cold deformation, and the quantitative impacts of solution atoms, precipitates and cold deformation on the conductivity of Al alloy are 10.5%(IACS), 2.3%(IACS) and 0.5%(IACS), respectively. Aging and cold deformation treatments are the keys to obtain high-strength and high-conductivity aluminum alloy wires.
基金supported by the National Natural Science Foundation of China[Grant No.51201192]Natural Science Foundation of Chongqing[Grant No.cstc2018jcyj A2285]。
文摘A micro-nano structure CaF_(2)chemical conversion layer was prepared on fluoride-treated AZ31 alloy,then the composite fluoride conversion film(CaF_(2)/MgF_(2))was modified by stearic acid(SA)and fabricated a superhydrophobic surface.The fluoride-treated magnesium,fluoride conversion film and superhydrophobic coating were characterized by SEM,EDS,XRD and FTIR.The properties of coatings1 adhesion and corrosion resistance were evaluated via tape test and electrochemical measurement.The cytocompatibility of the MgF_(2),CaF_(2)and superhydrophobic CaF_(2)/SA surface was investigated with bone marrow-derived mesenchymal stem cells(BMSCs)by direct culture for 24 h.The results showed that the superhydrophobic fluoride conversion coating composed of inner MgF_(2)layer and the outer CaF_(2)/SA composite layer had an average water contact angle of 152°.SA infiltrated into the micro-nano structure CaF_(2)layer and formed a strong adhesion with CaF_(2)layer.Furthermore,the super-hydrophobic coating showed higher barrier properties and corrosion resistance compared with the fluoride conversion film and fluoride-treated AZ31 alloy.The BMSC adhesion test results demonstrated MgF_(2)CaF_(2)and CaF_(2)/SA coatings were all nontoxic to BMSC.At the condition of in direct contact with cells,MgF_(2)showed higher cell density and enhanced the BMSCs proliferation,while CaF_(2)and CaF_(2)/SA coating showed no statistically difference in cell density compared with glass reference but the CaF_(2)and CaF_(2)/SA coating were not conducive to BMSCs adhesion.
基金the Coordinación de la Investigación Científica(CIC)of the Universidad Michoacana de San Nicolás de Hidalgo(UMSNH-México)for the support during this project(CIC-UMSNH-1.8)sponsored by the National Council on Science and Technology(Consejo Nacional de Ciencia y Tecnología-México)and would like to thank for the support during this project N.B.254928
文摘Five advanced high-strength transformation-induced plasticity(TRIP) steels with different chemical compositions were studied to correlate the retained austenite and nonmetallic inclusion content with their physical properties and the characteristics of the resistance spot welding nuggets. Electrical and thermal properties and equilibrium phases of TRIP steels were predicted using the JMatPro? software. Retained austenite and nonmetallic inclusions were quantified by X-ray diffraction and saturation magnetization techniques. The nonmetallic inclusions were characterized by scanning electron microscopy. The results show that the contents of Si, C, Al, and Mn in TRIP steels increase both the retained austenite and the nonmetallic inclusion contents. We found that nonmetallic inclusions affect the thermal and electrical properties of the TRIP steels and that the differences between these properties tend to result in different cooling rates during the welding process. The results are discussed in terms of the electrical and thermal properties determined from the chemical composition and their impact on the resistance spot welding nuggets.
基金the National Institutes of Health (K99CA201603,R21EB025270, R21EB026175)Doctoral New Investigator Grant from American Chemical Society Petroleum Research Fund (56840-DNI7).G.L. Y.acknowledges Natural and Science Foundation of Hubei Province (2014CFB778).
文摘The three-dimensional (3D)bioprinting technology has progressed tremendously over the past decade.By controlling the size, shape,and architecture of the bioprinted constructs,3D bioprinting allows for the fabrication of tissue/organ-like constructs with strong structural-functional similarity with their in vivo counterparts at high fidelity.The bioink,a blend of biomaterials and living cells possessing both high biocompatibility and printability,is a critical component of bioprinting.In particular, gelatin methacryloyl (GelMA)has shown its potential as a viable bioink material due to its suitable biocompatibility and readily tunable physicochemical properties.Current GelMA-based bioinks and relevant bioprinting strategies for GelMA bioprinting are briefly reviewed.
基金supported by the National Natural Science Foundation of China[Grant No.51201192]Natural Science Foundation of Chongqing[Grant No.cstc2018jcyj A2285cstc2018jcyjA 2285]。
文摘Polycaprolactone/hydroxyapatite(PCL/HA)composite coating was fabricated by a combination of hydrothermal and dipping methods to delay the degradation of Mg alloy AZ31 as bioresorbable materials.The PCL/HA coating was composed of nano rod-shape HA crystals and PCL filled in the space of HA crystals.Compared with the single HA coating,the binding strength between the PCL/HA composite coating and Mg alloy was obviously improved and the PCL/HA coating still adhered to the surface of AZ31 substrate even after 38 days of immersion.The electrochemical corrosion rate of HA coated sample was reduced by ten times after being filled by PCL.The electrochemical impedance spectroscopy(EIS)and immersion test results showed that the PCL/HA composite coating could provide a more effective barrier for Mg substrate than the HA coating alone.The cytocompatibility and the antibacterial property of HA coating and PCL/HA coating were evaluated by culturing with bone marrow-derived mesenchymal stem cells(BMSCs)and methicillin-resistant staphylococcus aureus(MRSA)for 24 h under direct culture conditions,respectively.The PCL/HA composite coating showed better BMSC cell compatibility,more suitable for BMSC adhesion than HA coating alone and showed a potential application prospect as a biological materials.However,from the perspective of clinical applications,the antibacterial property of PCL/HA composite coating needs to be further improved.
基金the Japan Society for the Promotion of Science(JSPS)through a Grant-in-aid for Young Scientist B(No.24700481)
文摘In recent years, it has been shown that inflammatory biomarkers can be used as an effective signal for disease diagnoses. The early detection of these signals provides useful information that could prevent the occurrence of severe diseases. Here, we employed surface-enhanced Raman scattering(SERS) probe gold nanorods(GNRs) as a tool for the early detection of inflammatory molecules in inflamed cells. A murine macrophage cell line(Raw264.7) stimulated with lipopolysaccharide(LPS) was used as a model in this study. The prepared SERS probe GNRs containing 4-mercaptobenzoic acid as a Raman reporter to generate SERS signals were used for detection of intracellular adhesion molecule-1(ICAM-1) in macrophages after treatment with LPS for varying lengths of time. Our results show that SERS probe GNRs could detect significant differences in the expression of ICAM-1 molecules in LPS-treated macrophages compared to those in untreated macrophages after only 1 h of LPS treatment. In contrast, when using fluorescent labeling or enzyme-linked immunosorbent assays(ELISA) to detect ICAM-1, significant differences between inflamed and un-inflamed macrophages were not seen until the cells had been treated with LPS for 5 h. These results indicate that our SERS probe GNRs provide a higher sensitivity for detecting biomarker molecules in inflamed macrophages than the conventional fluorescence and ELISA techniques, and could therefore be useful as a potential diagnostic tool for managing disease risk.
基金This work was supported by the National Natural Science Foundation of China (51973157,61904123)the Tianjin Natural Science Foundation (18JCQNJC02900)+3 种基金the Special Grade of the Financial Support from the China Postdoctoral Science Foundation (2020T130469)the Sci-ence and Technology Plans of Tianjin (19PTSYJC00010)the Science&Technol-ogy Development Fund of Tianjin Education Commission for Higher Education (2018KJ196)State Key Laboratory of Membrane and Membrane Separation,Tiangong University.
文摘Low-cost and flexible solid polymer electrolytes are promising in all-solid-state Li-metal batteries with high energy density and safety.However,both the low room-temperature ionic conductivities and the small Li^(+)transference number of these electrolytes significantly increase the internal resistance and overpotential of the battery.Here,we introduce Gd-doped CeO_(2) nanowires with large surface area and rich surface oxygen vacancies to the polymer electrolyte to increase the interaction between Gd-doped CeO_(2) nanowires and polymer electrolytes,which promotes the Li-salt dissociation and increases the concentration of mobile Li ions in the composite polymer electrolytes.The optimized composite polymer electrolyte has a high Li-ion conductivity of 5×10^(-4)4 S cm^(-1) at 30℃ and a large Li+transference number of 0.47.Moreover,the composite polymer electrolytes have excellent compatibility with the metallic lithium anode and high-voltage LiNi_(0.8)Mn _(0.1)Co_(0.1)O_(2)(NMC)cathode,providing the stable cycling of all-solid-state batteries at high current densities.
文摘Powder charges of micron-size Ni and Al2O3were utilized to deposit nano-structured Ni-Al2O3composite coatings on analuminum plate fixed at the top end of a milling vial using a planetary ball mill.Composite coatings were fabricated using powdermixtures with a wide range of Ni/Al2O3mass ratio varying from1:1to plain Ni.XRD,SEM and TEM techniques were employed tostudy the structural characteristics of the coatings.It was found that the composition of the starting mixture strongly affects the Al2O3content and the microstructure of the final coating.Mixtures containing higher contents of Al2O3yield higher volume fractions of theAl2O3particles in the coating.Though Ni-Al2O3composite coatings with about50%of Al2O3particles were successfully deposited,well-compacted and free of cracks and/or voids coatings included less than20%(volume fraction)of Al2O3particles which weredeposited from powder mixtures with Ni/Al2O3mass ratios of4:1or higher.Moreover,mechanical and metallurgical bondings arethe main mechanisms of the adhesion of the coating to the Al substrate.Finally,functionally graded composite coatings withnoticeable compaction and integrity were produced by deposition of two separate layers under identical coating conditions.
文摘In order to clarify the recrystallization mechanism of low-densityδ-ferrite steel Fe-4AI-2Ni,interrupted and single-pass compression tests were carried out.In this regard,five deformation temperatures(750-950 at an interval of 50°C)and different hold time were selected.It was observed that the softening and recrystallization fraction was enhaneed with increased deformation temperature and hold time.The original grain bounclaries were the preferred nucleation sites for recrystallized grains,and recrystallization had an impact on obtaining homogeneous and fine-grained structure.Recrystallization in the ferritic alloy commenced after a significant degree of softening,and the softening associated with recovery was appreciably less.The optimum rolling deformation temperature was identified to be greater than 900°C.
