High-entropy materials(HEMs)have attracted considerable research attention in battery applications due to exceptional properties such as remarkable structural stability,enhanced ionic conductivity,superior mechanical ...High-entropy materials(HEMs)have attracted considerable research attention in battery applications due to exceptional properties such as remarkable structural stability,enhanced ionic conductivity,superior mechanical strength,and outstanding catalytic activity.These distinctive characteristics render HEMs highly suitable for various battery components,such as electrodes,electrolytes,and catalysts.This review systematically examines recent advances in the application of HEMs for energy storage,beginning with fundamental concepts,historical development,and key definitions.Three principal categories of HEMs,namely high-entropy alloys,high-entropy oxides,and highentropy MXenes,are analyzed with a focus on electrochemical performance metrics such as specific capacity,energy density,cycling stability,and rate capability.The underlying mechanisms by which these materials enhance battery performance are elucidated in the discussion.Furthermore,the pivotal role of machine learning in accelerating the discovery and optimization of novel high-entropy battery materials is highlighted.The review concludes by outlining future research directions and potential breakthroughs in HEM-based battery technologies.展开更多
The ability to generate high pressures in a large-volume press(LVP)is crucial for the study of matter under extreme conditions.Here,we have achieved ultrahigh pressures of and 50 GPa,respectively,at room temperature a...The ability to generate high pressures in a large-volume press(LVP)is crucial for the study of matter under extreme conditions.Here,we have achieved ultrahigh pressures of and 50 GPa,respectively,at room temperature and a high temperature of 1900 K∼60within a millimeter-sized sample volume in a Kawai-type LVP(KLVP)using hard tungsten carbide(WC)and newly designed assem-blies.The introduction of electroconductive polycrystalline boron-doped diamond and dense alumina wrapped with Cu foils into a large conventional cell assembly enables the detection of resistance variations in the Fe_(2)O_(3) pressure standard upon compression.The efficiency of pressure generation in the newly developed cell assembly equipped with conventional ZK10F WC anvils is significantly higher than that of conventional assemblies with some ultrahard or tapered WC anvils.Our study has enabled the routine gener-ation of pressures exceeding 50 GPa within a millimeter-sized sample chamber that have been inaccessible with traditional KLVPs.This advance in high-pressure technology not only breaks a record for pressure generation in traditional KLVPs,but also opens up new avenues for exploration of the properties of the Earth’s deep interior and for the synthesis of novel materials at extreme high pressures.展开更多
Metal Additive Manufacturing(MAM) technology has become an important means of rapid prototyping precision manufacturing of special high dynamic heterogeneous complex parts. In response to the micromechanical defects s...Metal Additive Manufacturing(MAM) technology has become an important means of rapid prototyping precision manufacturing of special high dynamic heterogeneous complex parts. In response to the micromechanical defects such as porosity issues, significant deformation, surface cracks, and challenging control of surface morphology encountered during the selective laser melting(SLM) additive manufacturing(AM) process of specialized Micro Electromechanical System(MEMS) components, multiparameter optimization and micro powder melt pool/macro-scale mechanical properties control simulation of specialized components are conducted. The optimal parameters obtained through highprecision preparation and machining of components and static/high dynamic verification are: laser power of 110 W, laser speed of 600 mm/s, laser diameter of 75 μm, and scanning spacing of 50 μm. The density of the subordinate components under this reference can reach 99.15%, the surface hardness can reach 51.9 HRA, the yield strength can reach 550 MPa, the maximum machining error of the components is 4.73%, and the average surface roughness is 0.45 μm. Through dynamic hammering and high dynamic firing verification, SLM components meet the requirements for overload resistance. The results have proven that MEM technology can provide a new means for the processing of MEMS components applied in high dynamic environments. The parameters obtained in the conclusion can provide a design basis for the additive preparation of MEMS components.展开更多
Dual-ion batteries(DIBs)usually use carbon-based materials as electrodes,showing advantages in high operating volt-age,potential low cost,and environmental friendliness.Different from conventional“rocking chair”type...Dual-ion batteries(DIBs)usually use carbon-based materials as electrodes,showing advantages in high operating volt-age,potential low cost,and environmental friendliness.Different from conventional“rocking chair”type secondary batter-ies,DIBs perform a unique working mechanism,which employ both cation and anion taking part in capacity contribution at an anode and a cathode,respectively,during electrochemical reactions.Graphite has been identified as a suitable cathode material for anion intercalation at high voltages(>4.8 V)with fast reaction kinetics.However,the development of DIBs is being hindered by dynamic mismatch between a cathode and an anode due to sluggish Li+diffusion at a high rate.Herein,we prepared phyllostachys edulis derived carbon(PEC)through microstructure regulation strategy and investigated the carbonized temperature effect,which effectively tailored the rich short-range ordered graphite microdomains and disor-dered amorphous regions,as well as a unique nano-pore hierarchical structure.The pore size distribution of nano-pores was concentrated in 0.5-5 nm,providing suitable channels for rapid Li+transportation.It was found that PEC-500(carbon-ized at 500℃)achieved a high capacity of 436 mAh·g^(-1)at 300 mA·g^(-1)and excellent rate performance(maintaining a high capacity of 231 mAh·g^(-1)at 3 A·g^(-1)).The assembled dual-carbon PEC-500||graphite full battery delivered 114 mAh·g^(-1)at 10 C with 96%capacity retention after 3000 cycles and outstanding rate capability,providing 74 mAh·g^(-1)at 50 C.展开更多
LiNi_(0.5)Mn_(1.5)O_4(LNMO) was prepared by a high-temperature solid phase method,and then Al PO_(4)(AP) was coated on the polyhedral LNMO surface by the wet chemical method.The experimental results showed that the LN...LiNi_(0.5)Mn_(1.5)O_4(LNMO) was prepared by a high-temperature solid phase method,and then Al PO_(4)(AP) was coated on the polyhedral LNMO surface by the wet chemical method.The experimental results showed that the LNMO-1%AP|Li cell prepared with a 1%mass ratio of Al PO_(4and) LNMO had better electrochemical performance;after 450 cycles at 1C,its discharge specific capacity maintained 108.78 m Ah·g^(-1),while that of the LNMO|Li cell was only 86.04 m Ah·g^(-1).Especially at the high rates of 5C and 10C,the electrochemical properties of the former were far superior to the latter.This was attributed to the fact that the AP coating made the surface of LNMO in contact with the electrolyte more stable,effectively promoted the Li~+transport,and reduced the polarization voltage of the electrode.展开更多
This study begins with the fabrication and simulation of high-performance back-illuminated AlGaN-based solar-blind ultraviolet(UV)photodetectors.Based on the photodetectors,a low-noise,high-gain UV detection system ci...This study begins with the fabrication and simulation of high-performance back-illuminated AlGaN-based solar-blind ultraviolet(UV)photodetectors.Based on the photodetectors,a low-noise,high-gain UV detection system circuit is designed and fabricated,enabling the detection,acquisition,and calibration of weak solar-blind UV signals.Experimental results demonstrate that under zero bias conditions,with a UV light power density of 3.45μW/cm^(2) at 260 nm,the sample achieves a peak responsivity(R)of 0.085 A·W^(−1),an external quantum efficiency(EQE)of 40.7%,and a detectivity(D^(*))of 7.46×10^(12) cm·Hz^(1/2)·W^(−1).The system exhibits a bandpass characteristic within the 240–280 nm wavelength range,coupled with a high signal-to-noise ratio(SNR)of 39.74 dB.展开更多
MnCO_(3)represents a potentially high-capacity and low-cost anode candidate to replace graphite for enhancing energy density of commercial lithium-ion batteries,but it suffers from poor electrical conductivity and ser...MnCO_(3)represents a potentially high-capacity and low-cost anode candidate to replace graphite for enhancing energy density of commercial lithium-ion batteries,but it suffers from poor electrical conductivity and serious volumetric change,largely hindering its practical applications.展开更多
Thick and highly conductive poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate films with ideal porous structure are fulfilling as electrodes for supercapacitors.However,the homogeneous micro-structure without the...Thick and highly conductive poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate films with ideal porous structure are fulfilling as electrodes for supercapacitors.However,the homogeneous micro-structure without the aid of templates or composite presents a significant obstacle,due to the intrinsic softness of the dominant PSS component.In this study,we have successfully developed a porous configuration by employing a solvothermal approach with ethylene glycol(EG)as the solvent.The synergistic action of elevated pressure and temperature was crucial in prompting EG to tailor the microstructure of the PEDOT:PSS films by removing non-conductive PSS chains and improving PEDOT crystallinity,and the formation of a porous network.The resulting porous PEDOT:PSS films exhibited a high conductivity of 1644 S cm^(-1)and achieved a volumetric capacitance record of 270 F cm^(-3),markedly exceeding previous records.The flexible all-solid-state supercapacitor assembled by the films had an outstanding volumetric capacitance of 97.8 F cm^(-3)and an energy density of 8.7 mWh cm^(-3),which is best one for pure PEDOT:PSS-based supercapacitors.Grazing-incidence wide-angle X-ray scattering,X-ray photoelectron spectroscopy,and other characterizations were carried out to characterize the structure evolution.This work offers an effective novel method for conducting polymer morphology control and promotes PEDOT:PSS applications in energy storage field.展开更多
As an important grain and oil crop,soybean occupies an important position in China s agricultural production.High quality and stable yield of spring soybean is of great significance for ensuring food security and incr...As an important grain and oil crop,soybean occupies an important position in China s agricultural production.High quality and stable yield of spring soybean is of great significance for ensuring food security and increasing farmers income.Based on the planting experience and scientific research achievements in many regions,this paper systematically expounded a series of cultivation techniques of spring soybean with high quality and high yield from variety selection,preparation before sowing,sowing techniques,field management to disease and pest control and harvest and storage,aiming to provide scientific and comprehensive guidance for soybean growers and promote the development of soybean industry.展开更多
Energetic compounds bearing the trinitromethyl group are garnering broad attraction as potential candidates for a new generation of high energy dense oxidizers.In this work,an effective dual modulation strategy involv...Energetic compounds bearing the trinitromethyl group are garnering broad attraction as potential candidates for a new generation of high energy dense oxidizers.In this work,an effective dual modulation strategy involving both molecular isomerization and crystal morphology control was employed to design and optimize trinitromethyl-oxadiazole with improved comprehensive performance.Utilizing this dual strategy,3,5-bis(trinitromethyl)-1,2,4-oxadiazole(3)was synthesized,resulting in the formation of two distinct crystal morphologies(needle and sheet)corresponding to two crystal forms(3-a and3-b).Encouragingly,while maintaining ultra-high oxygen balance(21.73%),3 achieves impressive densities(1.97-1.98 g/cm^(3)).To our knowledge,the density of 1.98 g/cm^(3)for 3-a sets a new record among that of nitrogen-rich monocyclic compounds.Notably,practical crystal morphology prediction was creatively introduced to guide the experimental crystallization conditions of 3,increasing the impact sensitivity and friction sensitivity from 1 J to 80 N(3-a)to 10 J and 240 N(3-b),respectively.Additionally,the crystal structural analyses and theoretical calculations were conducted to elucidate the reasons of differences between 3-a and 3-b in density and stability.This work provides an efficient strategy to enhance performance of trinitromethyl derivatives,broadening the path and expanding the toolbox for energetic materials.展开更多
Oil and gas exploration studies have been increasingly moving deeper into the earth.The rocks in deep and ultra-deep reservoirs are exposed to a complex environment of high temperatures and large geo-stresses.The Tari...Oil and gas exploration studies have been increasingly moving deeper into the earth.The rocks in deep and ultra-deep reservoirs are exposed to a complex environment of high temperatures and large geo-stresses.The Tarim oilfield in the Xinjiang Uygur Autonomous Region(Xinjiang for short),China,has achieved a breakthrough in the exploration of deep hydrocarbon reservoirs at a depth of over 9000 m.The mechanical properties of deep rocks are significantly different from those of shallow rocks.In this study,triaxial compression tests were conducted on heat-treated carbonatite rocks to explore the evolution of the mechanical properties of carbonatite rocks under high confining pressure after thermal treatment.The rocks for the tests were collected from reservoirs in the Tarim oilfield,Xinjiang,China.The experiments were performed at confining pressures ranging from atmospheric to 120 MPa and temperatures ranging from25 to 500°C.The results show that the critical confining pressure of the brittle–ductile transition increases with increasing temperature.Young's modulus is negatively correlated with the temperature and positively correlated with the confining pressure.As the confining pressure increases,the failure mode of the specimens gradually transforms from shear fracture failure into“V”-type failure and finally into bulging failure(multiple shear fractures).With increasing temperature,the failure angle tends to decrease.In addition,an improved version of the Mohr-Coulomb strength criterion with a temperature-dependent power function was proposed to describe the failure strength of carbonatite rocks after exposure to high temperature and high confining pressure.The surface of the strength envelope of this criterion is temperature dependent,which could reflect the strength evolution of rock under high confining pressures after thermal treatment.Compared with other strength criteria,this criterion is more capable of replicating physical processes.展开更多
Anode active materials involving transition metal oxides and sulfides are of great significance for high energy density lithium-ion batteries(LIBs),but the huge volume expansion and inferior electronic conductivity up...Anode active materials involving transition metal oxides and sulfides are of great significance for high energy density lithium-ion batteries(LIBs),but the huge volume expansion and inferior electronic conductivity upon cycling critically constrain their further application.Herein,from a new perspective,a highly conductive and stable 3D flexible composite current collector is rationally designed by facilely electrodepositing metallic Ni thin layer onto the carbon cloth(CC/Ni),which endows the supported active materials with exceptional electronic conductivity and structural stability.In addition,the homogeneously distributed metallic Ni protrusions external CC can strongly bond with the active components,ensuring the structural integrity of electrodes upon cycling.More importantly,the 3D network structure with large specific surface area provides abundant space to alleviate the volume expansion and more active sites for electrochemical reactions.Therefore,taking Ni_(3)S_(2)nanosheet(Ni_(3)S_(2)NS)anode as an example,the prepared Ni_(3)S_(2)NS@CC/Ni electrode shows a high specific capacity of 2.32 mAh/cm^(2)at 1mA/cm^(2)and high capacity retention of 1.68 mAh/cm^(2)at a high rate of 8mA/cm^(2).This study provides a universal approach to obtain highly conductive and stable 3D flexible current collectors towards high performance metal-ion batteries beyond LIBs.展开更多
A team of researchers from the Beijing Normal University,the Institute of High Energy Physics(IHEP)under the Chinese Academy of Sciences(CAS),and the National Astronomical Observatories,CAS(NAOC),reported in Nature As...A team of researchers from the Beijing Normal University,the Institute of High Energy Physics(IHEP)under the Chinese Academy of Sciences(CAS),and the National Astronomical Observatories,CAS(NAOC),reported in Nature Astronomy on January 23,2025 their discovery of an X-ray flash about 12.5 billion lightyears away.The signals burst out only 1.2 billion years after the Big Bang,when our 13.8-billion-year-old universe was still in its infancy,and a science satellite swiftly recorded them.展开更多
Soybeans are rich in protein,fats,vitamins,and minerals,serving as an important source of plant-based protein for humans.Summer soybean is widely cultivated in China,and improving its yield and quality is of great sig...Soybeans are rich in protein,fats,vitamins,and minerals,serving as an important source of plant-based protein for humans.Summer soybean is widely cultivated in China,and improving its yield and quality is of great significance for ensuring food security and promoting agricultural economic development.This paper elaborated on the high-quality and high-yield cultivation techniques for summer soybean,including variety selection,seed treatment,field selection and land preparation,sowing techniques,field management,pest and disease control,and harvesting,aiming to provide scientific cultivation guidance for summer soybean growers to achieve both superior quality and high yield.展开更多
Although lithium-ion batteries are widely recognized as a new generation of energy storage devices,their large-scale application is severely hampered by their low energy density and restricted cyclic stability.Herein,...Although lithium-ion batteries are widely recognized as a new generation of energy storage devices,their large-scale application is severely hampered by their low energy density and restricted cyclic stability.Herein,an ingenious dual-modified interface,where the F-doping and fluorocarbon coating co-existed on Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)surface,is rationally constructed to elevate its energy density and structural stability attributed to F-grafting between the bulk material and the coating utilizing a robust super-conformal fluorocarbon coating structural framework and more stable F-doped system under high charge/discharge cut-off voltage.In comparison with a single carbon-coated modified Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2),the dual-modified sample overcomes the fatal disadvantage of carbon coating stripping during long-period cycles ascribed to the“TM-F-multifunctional coating”connector which firmly combines the bulk material with the coating with a strong interaction force,exhibiting a more stable-reversible structure and excellent comprehensive electrochemical performance under high cut-off voltage.Concomitantly,the F-transition metal bonds with stronger bond energies improve its structural reversibility during the processes of charge/discharge under high voltage.Furthermore,the fluorocarbon coating enhances its charge transfer ability and effectively restrains the interfacial side reactions.Additionally,the climbing nudged elastic band methodology is used to calculate the diffusion energy barrier of lithium-ions in the matrix material,which confirms the fundamental reason for its superior lithium-ion diffusion ability.The high pseudocapacitance contribution ratio is perfectly explained by calculating the adsorption capacity on the surface of the dual-modified sample.Consequently,experiments and theoretical calculations unequivocally confirm its distinguished electrochemical properties under high cut-off voltage.展开更多
AlCoCrFeNi and AlCoCrFeNiSi high entropy alloy(HEA)coatings have been prepared by high velocity oxygen fuel spraying,and the microstructure,mechanical properties as well as wear behaviors of the two HEA coatings were ...AlCoCrFeNi and AlCoCrFeNiSi high entropy alloy(HEA)coatings have been prepared by high velocity oxygen fuel spraying,and the microstructure,mechanical properties as well as wear behaviors of the two HEA coatings were studied.With Si element addition,the surface and cross-sectional microstructure of HEA coating are refined,and it was found that both HEA coatings have a body-centered cubic structure,and the X-ray diffraction peaks of AlCoCrFeNiSi HEA coating deviate to the right.The microhardness,bonding strength nanohardness and elastic modulus of AlCoCrFeNi HEA coating increased with addition of Si element due to the fact that Si promotes uniformly distribution of other elements.In terms of wear properties,coefficient of friction and the wear rate were reduced with Si element addition,and the two HEA coatings have similar wear mechanism at the same loads.And at lower loads,the wear mechanism is abrasive wear,adhesive and slight oxidative wear,it is turn to oxidative wear and severe abrasive wear while the load is increased.The AlCoCrFeNiSi HEA coating has a higher corrosion potential and a lower corrosion current density,indicating improved corrosion resistance.This enhancement is attributed to the presence of Si,which reduces interatomic spacing and results in a more compact atomic arrangement.Consequently,element migration and chemical reactions are reduced,leading to the formation of a denser and more uniform passivation film.展开更多
To fulfill the demands of applications under severe operational conditions,alloys should possess outstanding wear resistance at elevated temperatures.A Ti-Hf-Nb-V based refractory high entropy alloy(RHEA)was successfu...To fulfill the demands of applications under severe operational conditions,alloys should possess outstanding wear resistance at elevated temperatures.A Ti-Hf-Nb-V based refractory high entropy alloy(RHEA)was successfully produced using the directed energy deposition(DED)technique,which avoided the formation of fatal defects and showcased well-performed mechanical properties across a broad temperature spectrum.Strategic design of the oxidation sequence enabled the early formation of oxide nanolayers,which can form a polycrystalline oxide nanocoating under a complex stress condition to drastically reduce the wear rate from 2.69×10^(-4) mm^(3)·(N·m)^(−1) at room temperature to 6.90×10^(-7) mm^(3)·(N·m)^(−1) at 600℃.These results indicate that the application of additive manufacturing to fabricate RHEAs with superior wear resistance at high temperatures paves the way for the development of functional coatings designed to withstand extreme conditions.展开更多
We report the world-leading performance of a 1.3 GHz cryomodule equipped with eight 9-cell superconducting radio-frequency cavities that underwent a medium-temperature furnace baking process.During continuous wave hor...We report the world-leading performance of a 1.3 GHz cryomodule equipped with eight 9-cell superconducting radio-frequency cavities that underwent a medium-temperature furnace baking process.During continuous wave horizontal testing,these cavities achieved unprecedented average intrinsic quality factors of 4.0×10^(10)at 20 MV/m and 3.2×10^(10)at 29 MV/m,with no instances of field emission.The cryomodule demonstrates near-complete preservation of ultra-high quality factors and ultra-high accelerating gradients from vertical to horizontal testing,marking a significant milestone in continuous-wave superconducting radio-frequency accelerator technology.This letter presents the cryomodule development experience,includ-ing cavity preparation,cryomodule assembly,degaussing,fast cooldown,and performance testing.展开更多
Researches on plasma-facing materials/components(PFMs/PFCs)have become a focus in magnetic confinement fusion studies,particularly for advanced tokamak operation scenarios.Similarly,spacecraft surface materials must m...Researches on plasma-facing materials/components(PFMs/PFCs)have become a focus in magnetic confinement fusion studies,particularly for advanced tokamak operation scenarios.Similarly,spacecraft surface materials must maintain stable performance under relatively high temperatures and other harsh plasma conditions,making studies of their thermal and ablation resistance critical.Recently,a low-cost,low-energy-storage for superconducting magnets,and compact linear device,HIT-PSI,has been designed and constructed at Harbin Institute of Technology(HIT)to investigate the interaction between stable high heat flux plasma and PFMs/PFCs in scrape-off-layer(SOL)and divertor regions,as well as spacecraft surface materials.The parameters of the argon plasma beam of HIT-PSI are diagnosed using a water-cooled planar Langmuir probe and emission spectroscopy.As magnetic field rises to 2 T,the argon plasma beam generated by a cascaded arc source achieves high density exceeding 1.2×10^(21)m^(-3)at a distance of 25 cm from the source with electron temperature surpassing 4 eV,where the particle flux reaches 10^(24)m^(-2)s^(-1),and the heat flux loaded on the graphite target measured by infrared camera reaches 4 MW/m^(2).Combined with probe and emission spectroscopy data,the transport characteristics of the argon plasma beam are analyzed.展开更多
This study explores the molecular design of sulfur-containing polymers with high refractive indices(RI)and optimized Abbe numbers for advanced optical applications.The high molar refraction and low dispersion of sulfu...This study explores the molecular design of sulfur-containing polymers with high refractive indices(RI)and optimized Abbe numbers for advanced optical applications.The high molar refraction and low dispersion of sulfur make it an ideal component for enhancing the optical properties of polymers.Density functional theory(DFT)calculations were employed to predict the RI and Abbe numbers for a range of sulfurbased polymers.To improve the accuracy of the theoretical predictions,a correction function was developed by comparing the calculated values with experimental data.The key polymer families investigated included sulfur-containing polycarbonates,heterocyclic optical resins,and cycloolefins,all modified to balance RI enhancement with dispersion control.The results demonstrate that increasing the sulfur content and introducing specific heterocycles and bridged rings can effectively increase the RI while maintaining desirable Abbe numbers.Polymers incorporating 1,4-dithiane and sulfur-bridged rings exhibit excellent optical clarity and minimal visible light absorption,making them suitable for lens and coating applications.The study also calculated the UV-visible spectra for the most promising polymers,confirming their high transparency.This work establishes a predictive framework for developing high-performance optical polymers and offers a systematic approach for balancing the refractive index and dispersion,thereby providing valuable insights for the design of next-generation optical materials.展开更多
基金supported by the Fujian Provincial Science and Technology Planning Project(No.2022HZ027006,No.2024HZ021023)National Natural Science Foundation of China(No.U22A20118).
文摘High-entropy materials(HEMs)have attracted considerable research attention in battery applications due to exceptional properties such as remarkable structural stability,enhanced ionic conductivity,superior mechanical strength,and outstanding catalytic activity.These distinctive characteristics render HEMs highly suitable for various battery components,such as electrodes,electrolytes,and catalysts.This review systematically examines recent advances in the application of HEMs for energy storage,beginning with fundamental concepts,historical development,and key definitions.Three principal categories of HEMs,namely high-entropy alloys,high-entropy oxides,and highentropy MXenes,are analyzed with a focus on electrochemical performance metrics such as specific capacity,energy density,cycling stability,and rate capability.The underlying mechanisms by which these materials enhance battery performance are elucidated in the discussion.Furthermore,the pivotal role of machine learning in accelerating the discovery and optimization of novel high-entropy battery materials is highlighted.The review concludes by outlining future research directions and potential breakthroughs in HEM-based battery technologies.
基金supported by the National Key R&D Program of China(Grant No.2023YFA1406200)the National Natural Science Foundation of China(Grant Nos.42272041 and 52302043)+2 种基金the National Natural Science Foundation of China(Grant No.U23A20561)the Jilin University High-level Innovation Team Foundation(Grant No.2021TD–05)the Shanghai Synchrotron Radiation Facility(Grant Nos.2024-SSRF-PT-510031 and 505511).
文摘The ability to generate high pressures in a large-volume press(LVP)is crucial for the study of matter under extreme conditions.Here,we have achieved ultrahigh pressures of and 50 GPa,respectively,at room temperature and a high temperature of 1900 K∼60within a millimeter-sized sample volume in a Kawai-type LVP(KLVP)using hard tungsten carbide(WC)and newly designed assem-blies.The introduction of electroconductive polycrystalline boron-doped diamond and dense alumina wrapped with Cu foils into a large conventional cell assembly enables the detection of resistance variations in the Fe_(2)O_(3) pressure standard upon compression.The efficiency of pressure generation in the newly developed cell assembly equipped with conventional ZK10F WC anvils is significantly higher than that of conventional assemblies with some ultrahard or tapered WC anvils.Our study has enabled the routine gener-ation of pressures exceeding 50 GPa within a millimeter-sized sample chamber that have been inaccessible with traditional KLVPs.This advance in high-pressure technology not only breaks a record for pressure generation in traditional KLVPs,but also opens up new avenues for exploration of the properties of the Earth’s deep interior and for the synthesis of novel materials at extreme high pressures.
基金funded by the National Natural Science Foundation of China Youth Fund(Grant No.62304022)Science and Technology on Electromechanical Dynamic Control Laboratory(China,Grant No.6142601012304)the 2022e2024 China Association for Science and Technology Innovation Integration Association Youth Talent Support Project(Grant No.2022QNRC001).
文摘Metal Additive Manufacturing(MAM) technology has become an important means of rapid prototyping precision manufacturing of special high dynamic heterogeneous complex parts. In response to the micromechanical defects such as porosity issues, significant deformation, surface cracks, and challenging control of surface morphology encountered during the selective laser melting(SLM) additive manufacturing(AM) process of specialized Micro Electromechanical System(MEMS) components, multiparameter optimization and micro powder melt pool/macro-scale mechanical properties control simulation of specialized components are conducted. The optimal parameters obtained through highprecision preparation and machining of components and static/high dynamic verification are: laser power of 110 W, laser speed of 600 mm/s, laser diameter of 75 μm, and scanning spacing of 50 μm. The density of the subordinate components under this reference can reach 99.15%, the surface hardness can reach 51.9 HRA, the yield strength can reach 550 MPa, the maximum machining error of the components is 4.73%, and the average surface roughness is 0.45 μm. Through dynamic hammering and high dynamic firing verification, SLM components meet the requirements for overload resistance. The results have proven that MEM technology can provide a new means for the processing of MEMS components applied in high dynamic environments. The parameters obtained in the conclusion can provide a design basis for the additive preparation of MEMS components.
基金supported by the National Natural Science Foundation of China(Grant Nos.52272208,22309057)the Natural Science Foundation of Hubei Province(Grant No.2023AFB355)the Fundamental Research Funds for the Central Universities of China(Grant No.2662022LXQD001).
文摘Dual-ion batteries(DIBs)usually use carbon-based materials as electrodes,showing advantages in high operating volt-age,potential low cost,and environmental friendliness.Different from conventional“rocking chair”type secondary batter-ies,DIBs perform a unique working mechanism,which employ both cation and anion taking part in capacity contribution at an anode and a cathode,respectively,during electrochemical reactions.Graphite has been identified as a suitable cathode material for anion intercalation at high voltages(>4.8 V)with fast reaction kinetics.However,the development of DIBs is being hindered by dynamic mismatch between a cathode and an anode due to sluggish Li+diffusion at a high rate.Herein,we prepared phyllostachys edulis derived carbon(PEC)through microstructure regulation strategy and investigated the carbonized temperature effect,which effectively tailored the rich short-range ordered graphite microdomains and disor-dered amorphous regions,as well as a unique nano-pore hierarchical structure.The pore size distribution of nano-pores was concentrated in 0.5-5 nm,providing suitable channels for rapid Li+transportation.It was found that PEC-500(carbon-ized at 500℃)achieved a high capacity of 436 mAh·g^(-1)at 300 mA·g^(-1)and excellent rate performance(maintaining a high capacity of 231 mAh·g^(-1)at 3 A·g^(-1)).The assembled dual-carbon PEC-500||graphite full battery delivered 114 mAh·g^(-1)at 10 C with 96%capacity retention after 3000 cycles and outstanding rate capability,providing 74 mAh·g^(-1)at 50 C.
文摘LiNi_(0.5)Mn_(1.5)O_4(LNMO) was prepared by a high-temperature solid phase method,and then Al PO_(4)(AP) was coated on the polyhedral LNMO surface by the wet chemical method.The experimental results showed that the LNMO-1%AP|Li cell prepared with a 1%mass ratio of Al PO_(4and) LNMO had better electrochemical performance;after 450 cycles at 1C,its discharge specific capacity maintained 108.78 m Ah·g^(-1),while that of the LNMO|Li cell was only 86.04 m Ah·g^(-1).Especially at the high rates of 5C and 10C,the electrochemical properties of the former were far superior to the latter.This was attributed to the fact that the AP coating made the surface of LNMO in contact with the electrolyte more stable,effectively promoted the Li~+transport,and reduced the polarization voltage of the electrode.
基金supported by the Director’s Fund for the‘Climbing Plan’of the National Space Science Centre of the Chinese Academy of Sciences(No.E2PD10011S)the National Engineering Research Centre for Mobile Private Networks Project(No.BJTU20221102).
文摘This study begins with the fabrication and simulation of high-performance back-illuminated AlGaN-based solar-blind ultraviolet(UV)photodetectors.Based on the photodetectors,a low-noise,high-gain UV detection system circuit is designed and fabricated,enabling the detection,acquisition,and calibration of weak solar-blind UV signals.Experimental results demonstrate that under zero bias conditions,with a UV light power density of 3.45μW/cm^(2) at 260 nm,the sample achieves a peak responsivity(R)of 0.085 A·W^(−1),an external quantum efficiency(EQE)of 40.7%,and a detectivity(D^(*))of 7.46×10^(12) cm·Hz^(1/2)·W^(−1).The system exhibits a bandpass characteristic within the 240–280 nm wavelength range,coupled with a high signal-to-noise ratio(SNR)of 39.74 dB.
基金supported by the National Natural Science Foundation of China(Nos.52102088 and 22075026)support from Teli Fellowship,Beijing Institute of Technology,and facility support from Analysis&Testing Center,and Experimental Center of Materials Sciences&Engineering at Beijing Institute of Technology.
文摘MnCO_(3)represents a potentially high-capacity and low-cost anode candidate to replace graphite for enhancing energy density of commercial lithium-ion batteries,but it suffers from poor electrical conductivity and serious volumetric change,largely hindering its practical applications.
基金supported by the National Natural Science Foundation of China(No.51902134)Zhejiang Public Welfare Technology Application Research Program(No.LGJ22B040001)+1 种基金the Innovation Jiaxing Elite Leading Plan 2020,Jiaxing Public Welfare Technology Application Research Program(No.2023AY11051)the Fundamental Research Funds for the Jiaxing University(No.CD70519019,No.CDN70518005,No.CD70623018).
文摘Thick and highly conductive poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate films with ideal porous structure are fulfilling as electrodes for supercapacitors.However,the homogeneous micro-structure without the aid of templates or composite presents a significant obstacle,due to the intrinsic softness of the dominant PSS component.In this study,we have successfully developed a porous configuration by employing a solvothermal approach with ethylene glycol(EG)as the solvent.The synergistic action of elevated pressure and temperature was crucial in prompting EG to tailor the microstructure of the PEDOT:PSS films by removing non-conductive PSS chains and improving PEDOT crystallinity,and the formation of a porous network.The resulting porous PEDOT:PSS films exhibited a high conductivity of 1644 S cm^(-1)and achieved a volumetric capacitance record of 270 F cm^(-3),markedly exceeding previous records.The flexible all-solid-state supercapacitor assembled by the films had an outstanding volumetric capacitance of 97.8 F cm^(-3)and an energy density of 8.7 mWh cm^(-3),which is best one for pure PEDOT:PSS-based supercapacitors.Grazing-incidence wide-angle X-ray scattering,X-ray photoelectron spectroscopy,and other characterizations were carried out to characterize the structure evolution.This work offers an effective novel method for conducting polymer morphology control and promotes PEDOT:PSS applications in energy storage field.
基金Supported by Special Project for the Construction of the National Modern Agricultural Industry Technology System(CARS-04-CES16).
文摘As an important grain and oil crop,soybean occupies an important position in China s agricultural production.High quality and stable yield of spring soybean is of great significance for ensuring food security and increasing farmers income.Based on the planting experience and scientific research achievements in many regions,this paper systematically expounded a series of cultivation techniques of spring soybean with high quality and high yield from variety selection,preparation before sowing,sowing techniques,field management to disease and pest control and harvest and storage,aiming to provide scientific and comprehensive guidance for soybean growers and promote the development of soybean industry.
基金supported by the National Natural Science Foundation of China(No.22375021,22235003,22261132516&22205021)the BIT Research and Innovation 265 Promoting Project(Grant No.2023YCXZ017)。
文摘Energetic compounds bearing the trinitromethyl group are garnering broad attraction as potential candidates for a new generation of high energy dense oxidizers.In this work,an effective dual modulation strategy involving both molecular isomerization and crystal morphology control was employed to design and optimize trinitromethyl-oxadiazole with improved comprehensive performance.Utilizing this dual strategy,3,5-bis(trinitromethyl)-1,2,4-oxadiazole(3)was synthesized,resulting in the formation of two distinct crystal morphologies(needle and sheet)corresponding to two crystal forms(3-a and3-b).Encouragingly,while maintaining ultra-high oxygen balance(21.73%),3 achieves impressive densities(1.97-1.98 g/cm^(3)).To our knowledge,the density of 1.98 g/cm^(3)for 3-a sets a new record among that of nitrogen-rich monocyclic compounds.Notably,practical crystal morphology prediction was creatively introduced to guide the experimental crystallization conditions of 3,increasing the impact sensitivity and friction sensitivity from 1 J to 80 N(3-a)to 10 J and 240 N(3-b),respectively.Additionally,the crystal structural analyses and theoretical calculations were conducted to elucidate the reasons of differences between 3-a and 3-b in density and stability.This work provides an efficient strategy to enhance performance of trinitromethyl derivatives,broadening the path and expanding the toolbox for energetic materials.
基金National Natural Science Foundation of China,Grant/Award Number:52034010。
文摘Oil and gas exploration studies have been increasingly moving deeper into the earth.The rocks in deep and ultra-deep reservoirs are exposed to a complex environment of high temperatures and large geo-stresses.The Tarim oilfield in the Xinjiang Uygur Autonomous Region(Xinjiang for short),China,has achieved a breakthrough in the exploration of deep hydrocarbon reservoirs at a depth of over 9000 m.The mechanical properties of deep rocks are significantly different from those of shallow rocks.In this study,triaxial compression tests were conducted on heat-treated carbonatite rocks to explore the evolution of the mechanical properties of carbonatite rocks under high confining pressure after thermal treatment.The rocks for the tests were collected from reservoirs in the Tarim oilfield,Xinjiang,China.The experiments were performed at confining pressures ranging from atmospheric to 120 MPa and temperatures ranging from25 to 500°C.The results show that the critical confining pressure of the brittle–ductile transition increases with increasing temperature.Young's modulus is negatively correlated with the temperature and positively correlated with the confining pressure.As the confining pressure increases,the failure mode of the specimens gradually transforms from shear fracture failure into“V”-type failure and finally into bulging failure(multiple shear fractures).With increasing temperature,the failure angle tends to decrease.In addition,an improved version of the Mohr-Coulomb strength criterion with a temperature-dependent power function was proposed to describe the failure strength of carbonatite rocks after exposure to high temperature and high confining pressure.The surface of the strength envelope of this criterion is temperature dependent,which could reflect the strength evolution of rock under high confining pressures after thermal treatment.Compared with other strength criteria,this criterion is more capable of replicating physical processes.
基金financially supported by the National Natural Science Foundation of China(Nos.52075351,51604177)the National Key Research and Development Program of China(No.2019YFA0705701)+4 种基金the National Funded Postdoctoral Researcher Program(No.GZC20231762)the Major S&T Infrastructure Construction Project of Sichuan Province(No.2020-510000-73-01441847)the International S&T Innovation Cooperation Program of Sichuan Province(No.2020YFH0039)the Chengdu International S&T Cooperation Funded Project(Nos.2020-GH02-00006HZ,2022-GH02-00027-HZ)the“1000 Talents Plan”of Sichuan Province,and the Talent Introduction Program of Sichuan University(No.YJ201410)。
文摘Anode active materials involving transition metal oxides and sulfides are of great significance for high energy density lithium-ion batteries(LIBs),but the huge volume expansion and inferior electronic conductivity upon cycling critically constrain their further application.Herein,from a new perspective,a highly conductive and stable 3D flexible composite current collector is rationally designed by facilely electrodepositing metallic Ni thin layer onto the carbon cloth(CC/Ni),which endows the supported active materials with exceptional electronic conductivity and structural stability.In addition,the homogeneously distributed metallic Ni protrusions external CC can strongly bond with the active components,ensuring the structural integrity of electrodes upon cycling.More importantly,the 3D network structure with large specific surface area provides abundant space to alleviate the volume expansion and more active sites for electrochemical reactions.Therefore,taking Ni_(3)S_(2)nanosheet(Ni_(3)S_(2)NS)anode as an example,the prepared Ni_(3)S_(2)NS@CC/Ni electrode shows a high specific capacity of 2.32 mAh/cm^(2)at 1mA/cm^(2)and high capacity retention of 1.68 mAh/cm^(2)at a high rate of 8mA/cm^(2).This study provides a universal approach to obtain highly conductive and stable 3D flexible current collectors towards high performance metal-ion batteries beyond LIBs.
文摘A team of researchers from the Beijing Normal University,the Institute of High Energy Physics(IHEP)under the Chinese Academy of Sciences(CAS),and the National Astronomical Observatories,CAS(NAOC),reported in Nature Astronomy on January 23,2025 their discovery of an X-ray flash about 12.5 billion lightyears away.The signals burst out only 1.2 billion years after the Big Bang,when our 13.8-billion-year-old universe was still in its infancy,and a science satellite swiftly recorded them.
基金Supported by Special Project for the Construction of the National Modern Agricultural Industry Technology System(CARS-04-CES16).
文摘Soybeans are rich in protein,fats,vitamins,and minerals,serving as an important source of plant-based protein for humans.Summer soybean is widely cultivated in China,and improving its yield and quality is of great significance for ensuring food security and promoting agricultural economic development.This paper elaborated on the high-quality and high-yield cultivation techniques for summer soybean,including variety selection,seed treatment,field selection and land preparation,sowing techniques,field management,pest and disease control,and harvesting,aiming to provide scientific cultivation guidance for summer soybean growers to achieve both superior quality and high yield.
基金support from the Natural Science Foundation of Fujian Province,China(No.2021H0028)the Natural Science Foundation of China(No.21975212)+1 种基金Open Fund of Fujian Provincial Key Laboratory of Functional Materials and Applications(No.fma2023003)the Science and Technology Planning Project of Xiamen City(No.2022CXY0409).
文摘Although lithium-ion batteries are widely recognized as a new generation of energy storage devices,their large-scale application is severely hampered by their low energy density and restricted cyclic stability.Herein,an ingenious dual-modified interface,where the F-doping and fluorocarbon coating co-existed on Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)surface,is rationally constructed to elevate its energy density and structural stability attributed to F-grafting between the bulk material and the coating utilizing a robust super-conformal fluorocarbon coating structural framework and more stable F-doped system under high charge/discharge cut-off voltage.In comparison with a single carbon-coated modified Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2),the dual-modified sample overcomes the fatal disadvantage of carbon coating stripping during long-period cycles ascribed to the“TM-F-multifunctional coating”connector which firmly combines the bulk material with the coating with a strong interaction force,exhibiting a more stable-reversible structure and excellent comprehensive electrochemical performance under high cut-off voltage.Concomitantly,the F-transition metal bonds with stronger bond energies improve its structural reversibility during the processes of charge/discharge under high voltage.Furthermore,the fluorocarbon coating enhances its charge transfer ability and effectively restrains the interfacial side reactions.Additionally,the climbing nudged elastic band methodology is used to calculate the diffusion energy barrier of lithium-ions in the matrix material,which confirms the fundamental reason for its superior lithium-ion diffusion ability.The high pseudocapacitance contribution ratio is perfectly explained by calculating the adsorption capacity on the surface of the dual-modified sample.Consequently,experiments and theoretical calculations unequivocally confirm its distinguished electrochemical properties under high cut-off voltage.
基金supported by the National Natural Science Foundation of China(Nos.52175196 and 52275218)the National Key R&D Program of China(No.2022YFB3706600).
文摘AlCoCrFeNi and AlCoCrFeNiSi high entropy alloy(HEA)coatings have been prepared by high velocity oxygen fuel spraying,and the microstructure,mechanical properties as well as wear behaviors of the two HEA coatings were studied.With Si element addition,the surface and cross-sectional microstructure of HEA coating are refined,and it was found that both HEA coatings have a body-centered cubic structure,and the X-ray diffraction peaks of AlCoCrFeNiSi HEA coating deviate to the right.The microhardness,bonding strength nanohardness and elastic modulus of AlCoCrFeNi HEA coating increased with addition of Si element due to the fact that Si promotes uniformly distribution of other elements.In terms of wear properties,coefficient of friction and the wear rate were reduced with Si element addition,and the two HEA coatings have similar wear mechanism at the same loads.And at lower loads,the wear mechanism is abrasive wear,adhesive and slight oxidative wear,it is turn to oxidative wear and severe abrasive wear while the load is increased.The AlCoCrFeNiSi HEA coating has a higher corrosion potential and a lower corrosion current density,indicating improved corrosion resistance.This enhancement is attributed to the presence of Si,which reduces interatomic spacing and results in a more compact atomic arrangement.Consequently,element migration and chemical reactions are reduced,leading to the formation of a denser and more uniform passivation film.
基金supported by Guangdong Major Project of Basic and Applied Basic Research,China(No.2019B030302010)the Joint Research Scheme sponsored by the Research Grants Council of the Hong Kong Special Administrative Region,China and National Natural Science Foundation of China(Nos.N_PolyU523/20 and 52061160483)+4 种基金the National Natural Science Foundation of China(Nos.52104362,52071222,52471179,52471180 and 52001221)the National Key R&D Program of China(No.2022YFA1603800)the National Key Research and Development Program of China(No.2021YFA0716302)Guangdong Provincial Quantum Science Strategic Initiative(No.GDZX2301001)Guangdong Basic and Applied Basic Research,China(No.2020B1515130007).
文摘To fulfill the demands of applications under severe operational conditions,alloys should possess outstanding wear resistance at elevated temperatures.A Ti-Hf-Nb-V based refractory high entropy alloy(RHEA)was successfully produced using the directed energy deposition(DED)technique,which avoided the formation of fatal defects and showcased well-performed mechanical properties across a broad temperature spectrum.Strategic design of the oxidation sequence enabled the early formation of oxide nanolayers,which can form a polycrystalline oxide nanocoating under a complex stress condition to drastically reduce the wear rate from 2.69×10^(-4) mm^(3)·(N·m)^(−1) at room temperature to 6.90×10^(-7) mm^(3)·(N·m)^(−1) at 600℃.These results indicate that the application of additive manufacturing to fabricate RHEAs with superior wear resistance at high temperatures paves the way for the development of functional coatings designed to withstand extreme conditions.
基金supported by Zhangjiang Laboratory,the SHINE R&D project(No.2017SHZDZX02)the SHINE projectthe National Natural Science Foundation of China(No.12125508).
文摘We report the world-leading performance of a 1.3 GHz cryomodule equipped with eight 9-cell superconducting radio-frequency cavities that underwent a medium-temperature furnace baking process.During continuous wave horizontal testing,these cavities achieved unprecedented average intrinsic quality factors of 4.0×10^(10)at 20 MV/m and 3.2×10^(10)at 29 MV/m,with no instances of field emission.The cryomodule demonstrates near-complete preservation of ultra-high quality factors and ultra-high accelerating gradients from vertical to horizontal testing,marking a significant milestone in continuous-wave superconducting radio-frequency accelerator technology.This letter presents the cryomodule development experience,includ-ing cavity preparation,cryomodule assembly,degaussing,fast cooldown,and performance testing.
基金supported by National Natural Science Foundation of China(No.12105067)the ITER Organization and China Domestic Agency for the support of this work(No.ITER5.5.P01.CN.05)。
文摘Researches on plasma-facing materials/components(PFMs/PFCs)have become a focus in magnetic confinement fusion studies,particularly for advanced tokamak operation scenarios.Similarly,spacecraft surface materials must maintain stable performance under relatively high temperatures and other harsh plasma conditions,making studies of their thermal and ablation resistance critical.Recently,a low-cost,low-energy-storage for superconducting magnets,and compact linear device,HIT-PSI,has been designed and constructed at Harbin Institute of Technology(HIT)to investigate the interaction between stable high heat flux plasma and PFMs/PFCs in scrape-off-layer(SOL)and divertor regions,as well as spacecraft surface materials.The parameters of the argon plasma beam of HIT-PSI are diagnosed using a water-cooled planar Langmuir probe and emission spectroscopy.As magnetic field rises to 2 T,the argon plasma beam generated by a cascaded arc source achieves high density exceeding 1.2×10^(21)m^(-3)at a distance of 25 cm from the source with electron temperature surpassing 4 eV,where the particle flux reaches 10^(24)m^(-2)s^(-1),and the heat flux loaded on the graphite target measured by infrared camera reaches 4 MW/m^(2).Combined with probe and emission spectroscopy data,the transport characteristics of the argon plasma beam are analyzed.
基金supported by the Project of Shenzhen Science and Technology(Nos.JCYJ20210324095210028 and JSGGZD20220822095201003)the Shenzhen University 2035Program for Excellent Research(No.000003011002)the National Natural Science Foundation of China(No.U21A2087)。
文摘This study explores the molecular design of sulfur-containing polymers with high refractive indices(RI)and optimized Abbe numbers for advanced optical applications.The high molar refraction and low dispersion of sulfur make it an ideal component for enhancing the optical properties of polymers.Density functional theory(DFT)calculations were employed to predict the RI and Abbe numbers for a range of sulfurbased polymers.To improve the accuracy of the theoretical predictions,a correction function was developed by comparing the calculated values with experimental data.The key polymer families investigated included sulfur-containing polycarbonates,heterocyclic optical resins,and cycloolefins,all modified to balance RI enhancement with dispersion control.The results demonstrate that increasing the sulfur content and introducing specific heterocycles and bridged rings can effectively increase the RI while maintaining desirable Abbe numbers.Polymers incorporating 1,4-dithiane and sulfur-bridged rings exhibit excellent optical clarity and minimal visible light absorption,making them suitable for lens and coating applications.The study also calculated the UV-visible spectra for the most promising polymers,confirming their high transparency.This work establishes a predictive framework for developing high-performance optical polymers and offers a systematic approach for balancing the refractive index and dispersion,thereby providing valuable insights for the design of next-generation optical materials.
