This study explores the impact of bismuth oxide(Bi_(2)O_(3))on the optical and radiation shielding properties of transparent,lead-free thulium-doped bismuth borotellurite radiation shielding glass.The investigated gla...This study explores the impact of bismuth oxide(Bi_(2)O_(3))on the optical and radiation shielding properties of transparent,lead-free thulium-doped bismuth borotellurite radiation shielding glass.The investigated glass composition follows the formula[(TeO_(2))_(75)(B_(2)O_(3))_(25)]_(98-x)(Bi_(2)O_(3))_x[Tm_(2)O_(3)]_(2),where x=0 mol%,5 mol%,10 mol%,15 mol%,20 mol%,25 mol%,and 30 mol%.All glass samples remain transparent,with an optical bandgap(E_(opt))exceeding 3.1 e V,ensuring visible light transmission.Radiation shielding data from Phy-X and XCom reveal interactions of the photoelectric effect,Compton scattering,and pair production,with minimal relative difference in mass attenuation coefficient(MAC)which is between0.05 and 0.56.At 0.662 Me V photon energy,the 20 mol%and 25 mol%Bi_(2)O_(3)glasses exhibit significantly higher Phy-X MAC values than other samples,except RS 520 glass,which contains 71%Pb O.Despite incorporating only up to 25 mol%Bi_(2)O_(3),these glasses outperform others in density,half-value layer(HVL),and mean free path(MFP).Correlating E_(opt)and MAC,the 20 mol%Bi_(2)O_(3)glass is the best candidate for transparent radiation shielding glass due to its wide optical bandgap which prevents ionization of trapped holes.Significantly,the linkage between MFP and molar refraction was also discovered based on the particle size influence on both parameters.展开更多
In recent years,Danyang in Jiangsu Province-one of China’s key eyewear manufacturing and distribution centers-has leveraged its“small glasses”to power a“big industry.”
Although the existence of glass–glass interfaces(GGIs)enables improved ductility of metallic nanoglasses(NGs),the excess free volumes at GGIs would cause the NGs to have a much-reduced mechanical strength.Herein,entr...Although the existence of glass–glass interfaces(GGIs)enables improved ductility of metallic nanoglasses(NGs),the excess free volumes at GGIs would cause the NGs to have a much-reduced mechanical strength.Herein,entropy-stabilized GGIs have been in-vestigated in Co–Fe–Ni–Zn–P NGs,which have a large entropy of mixing(1.32R,where R is the gas constant)and could be in a new glass phase,different from that of glassy grain interiors.Through quantitatively determining the activation energy of glass transition sep-arately for the GGIs and glassy grain interiors,the excess free volumes at GGIs are found to be reduced in comparison with those in the glassy grain interiors.The thermodynamically stable GGIs could be associated with increasing entropy of mixing in the GGI regions,which stabilizes the atomic structures of GGIs and enhances the glass forming ability of Co–Fe–Ni–Zn–P NGs.The influences of entropy-stabilized GGIs on the mechanical properties of Co–Fe–Ni–Zn–P NGs are further investigated by nanoindentation and creep tests under tensile deformation,demonstrating that there are notable enhancements in the ductility and mechanical strength for Co–Fe–Ni–Zn–P NGs.This work contributes to an in-depth understanding on the GGI phase in NGs and offers an alternative method for strengthening NGs through GGI engineering.展开更多
Agromyzid leafminers cause significant economic losses in both vegetable and horticultural crops,and precise assessments of pesticide needs must be based on the extent of leaf damage.Traditionally,surveyors estimate t...Agromyzid leafminers cause significant economic losses in both vegetable and horticultural crops,and precise assessments of pesticide needs must be based on the extent of leaf damage.Traditionally,surveyors estimate the damage by visually comparing the proportion of damaged to intact leaf area,a method that lacks objectivity,precision,and reliable data traceability.To address these issues,an advanced survey system that combines augmented reality(AR)glasses with a camera and an artificial intelligence(AI)algorithm was developed in this study to objectively and accurately assess leafminer damage in the feld.By wearing AR glasses equipped with a voice-controlled camera,surveyors can easily flatten damaged leaves by hand and capture images for analysis.This method can provide a precise and reliable diagnosis of leafminer damage levels,which in turn supports the implementation of scientifically grounded and targeted pest management strategies.To calculate the leafminer damage level,the DeepLab-Leafminer model was proposed to precisely segment the leafminer-damaged regions and the intact leaf region.The integration of an edge-aware module and a Canny loss function into the DeepLabv3+model enhanced the DeepLab-Leafminer model's capability to accurately segment the edges of leafminer-damaged regions,which often exhibit irregular shapes.Compared with state-of-the-art segmentation models,the DeepLabLeafminer model achieved superior segmentation performance with an Intersection over Union(IoU)of 81.23%and an F1score of 87.92%on leafminer-damaged leaves.The test results revealed a 92.38%diagnosis accuracy of leafminer damage levels based on the DeepLab-Leafminer model.A mobile application and a web platform were developed to assist surveyors in displaying the diagnostic results of leafminer damage levels.This system provides surveyors with an advanced,user-friendly,and accurate tool for assessing agromyzid leafminer damage in agricultural felds using wearable AR glasses and an AI model.This method can also be utilized to automatically diagnose pest and disease damage levels in other crops based on leaf images.展开更多
Bulk metallic glasses(BMGs)are typically characterized by high strength and elasticity.However,they generally demonstrate a deficiency in plastic deformation capability at room temperatures.In this work,Cu_(50-x)Zr_(4...Bulk metallic glasses(BMGs)are typically characterized by high strength and elasticity.However,they generally demonstrate a deficiency in plastic deformation capability at room temperatures.In this work,Cu_(50-x)Zr_(46)Al4Agx(x=0,1,2,3,4)alloys were prepared by arc melting and copper mold casting to investigate their structure,glass-forming ability,and mechanical properties.The results show that the addition of Ag can increase the parameter of DTx and g in Cu_(50)Zr_(46)Al_(4)alloy by 116%and 1.5%respectively,effectively enhancing its thermal stability and glass-forming ability.Compressive fracture tests reveal that the addition of Ag can significantly improve the yield strength,ultimate strength,and plasticity of the Cu_(50)Zr_(46)Al_(4)alloy.Specifically,with the Ag addition of 1 at.%,the alloy’s ultimate strength and plasticity increased by 71.8%and 21 times,respectively.Furthermore,the introduction of Ag can effectively control the free volume content in the Cu_(50)Zr_(46)Al_(4)alloy,thereby tuning the hardness of the material.This work provides valuable insights into improving the mechanical performance of BMGs through micro-alloying approaches.展开更多
Ti-based bulk metallic glasses(BMGs)have attracted increasing attention due to their high specific strength.However,a fundamental conflict exists between the specific strength and glass-forming ability(GFA)of Ti-based...Ti-based bulk metallic glasses(BMGs)have attracted increasing attention due to their high specific strength.However,a fundamental conflict exists between the specific strength and glass-forming ability(GFA)of Ti-based BMGs,restricting their commercial applications significantly.In this study,this challenge was addressed by introducing a two-step alloying strategy to mitigate the remarkable density increment effect associated with heavy alloying elements required for enhancing the GFA.Consequently,through two-step alloying with Al and Fe in sequence,simultaneous enhancements in specific strength and GFA were achieved based on a Ti-Zr-Be ternary metallic glass,resulting in the development of a series of centimeter-sized metallic glasses exhibiting ultrahigh-specific strength.Notably,the newly developed(Ti_(45)Zr_(20)Be_(31)A_(l4))_(94)Fe_(6)alloy established a new record for the specific strength of Ti-based BMGs.Along with a critical diameter(D_(c))of 10 mm,it offers the optimal scheme for balancing the specific strength and GFA of Ti-based BMGs.The present results further brighten the application prospects of Ti-based BMGs as lightweight materials.展开更多
We performed the coupled molecular-dynamics and spin dynamics simulations to investigate the magnetic annealing effect on the crystallization behavior of Fe metallic glasses(MGs). By calculating the local five-fold sy...We performed the coupled molecular-dynamics and spin dynamics simulations to investigate the magnetic annealing effect on the crystallization behavior of Fe metallic glasses(MGs). By calculating the local five-fold symmetry, Voronoi polyhedron, and bond orientational order parameters, we find a significant structural evolution at high-frequency magnetic annealing: the icosahedral order diminishes, and the crystalline-like order is enhanced, comparing to the case without magnetic field. The fraction of the body-centered cubic structures remarkably increases with the frequency of magnetic annealing, and the atoms of these order show a tendency of aggregating in space to form the crystalline nuclei. These findings unveil how the local structure evolves under magnetic annealing, and the accelerated crystallization process of MGs through alternating magnetic fields.展开更多
High-density germanate glasses doped with Tb^(3+)ions were synthesized via the melt-quenching meth-od.The physical and luminescent properties of these glasses were characterized through various techniques,in-cluding d...High-density germanate glasses doped with Tb^(3+)ions were synthesized via the melt-quenching meth-od.The physical and luminescent properties of these glasses were characterized through various techniques,in-cluding density measurement,differential scanning calorimetry(DSC),photoluminescence(PL)spectroscopy,X-ray excited luminescence(XEL)spectroscopy,and fluorescence decay analysis.The densities of the germanate glasses were greater than 6.1 g/cm^(3).Upon excitations of ultraviolet(UV)light and X-rays,the glasses emitted in-tense green emissions.The fluorescence lifetime of the strongest emission peak at 544 nm,measured under 377 nm excitation,ranged from 1.52 ms to 1.32 ms.In the glass specimens,the maximum XEL integral intensity reached roughly 26%of that of the commercially available Bi_(4)Ge_(3)O_(12)(BGO)crystal.These results indicate that Tb^(3+)-doped high-density germanate scintillating glasses hold potential as scintillation materials for X-ray imaging applications.展开更多
Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cr...Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cross-sections of Sm^(3+)result in low luminous efficiency,posing challenges for achieving high-quality solid-state lighting.Here,the excellent white emission of Sm^(3+)doped lithium aluminum silicate(LAS)glass was realized by introducing the Ag aggregates through Ag ion exchange.Under 395 nm excitation,the Ag-doped samples exhibit significant fluo⁃rescence enhancement with color coordinates close to the equal energy white point E(0.33,0.33)and a color ren⁃dering index(CRI)of 81.8.The study reveals that the surface plasmon resonance(SPR)effect of Ag nanoparticles enhances the luminescence of Sm^(3+),while the energy transfer mechanism between Ag^(+)and Sm^(3+)also promotes fluores⁃cence enhancement.By adjusting the concentration of AgNO_(3) and the exchange time,a series of high-quality full-spectrum white light emissions were obtained,indicating that the Ag ion-exchanged Sm^(3+)-doped LAS glass has good application potential in the development of solid-state lighting devices.Moreover,variations in the excitation wave⁃length can effectively tune the emission color,further demonstrating the tunability and practicality of this material in optoelectronic applications.展开更多
Annealing has been a popular method to improve the soft magnetism of metallic glasses (MGs), which however usually makes MGs brittle and difficult to process. Here, it is demonstrated that the embrittled Fe-based MG c...Annealing has been a popular method to improve the soft magnetism of metallic glasses (MGs), which however usually makes MGs brittle and difficult to process. Here, it is demonstrated that the embrittled Fe-based MG can be reductilized and the coercivity can be further lowered through the rejuvenation of memory effect. The synchronous improvement in the plasticity and soft magnetic properties is attributed to the combination effects of releasing much residual stress, decreasing the magnetic anisotropy, and homogenizing the glasses during the rejuvenation process. The current work opens a new perspective to improve the properties of MGs by utilizing the memory effect and holds promising commercial application potential.展开更多
Ag-doped alkali borosilicate glasses with different TiO_(2) contents were prepared by the melting method.The viscosity-temperature curves of the glass samples were fitted using the MYEGA equation,and it was found that...Ag-doped alkali borosilicate glasses with different TiO_(2) contents were prepared by the melting method.The viscosity-temperature curves of the glass samples were fitted using the MYEGA equation,and it was found that the viscosity of the glass showed a gradual decrease with the increase of TiO_(2) content in the interval of the crystallization temperature of the glass.The results of XPS analysis show that TiO_(2) mainly enters the glass network in the form of[TiO_(4)]before the heat treatment of the glass samples.In contrast,after the heat treatment,the contents of[TiO_(4)]and[TiO_(5)]in the glass decreased significantly,and the content of[TiO_(6)]increased,which led to the separation of TiO_(2) from the glass network.The microhardness of glass shows the same pattern.Raman spectral analysis shows that the introduction of TiO_(2) promotes phase separation in glass.The reduction of glass viscosity facilitates the movement of particles within the glass,while the creation of phase separation promotes heterogeneous nucleation of grains.FE-SEM analysis reveals that the silver halide grains in the heat-treated glass are dispersed in the matrix in a spherical shape,and the average size of the silver halide grains tends to increase with the increase of TiO_(2) content.展开更多
The effect of cryogenic treatment(CT)and relaxation annealing on the average nearest neighboring distance of atom(dm),ther-modynamic stability,soft magnetic properties,microhardness(Hv),and corrosion resistance of as-...The effect of cryogenic treatment(CT)and relaxation annealing on the average nearest neighboring distance of atom(dm),ther-modynamic stability,soft magnetic properties,microhardness(Hv),and corrosion resistance of as-spun(Fe_(0.5)Co_(0.5))_(75)B_(21)Nb_(4) metallic glasses(MGs)is studied.On the premise of maintaining a fully amorphous phase,appropriate CT and relaxation annealing are conducive to achieving the synergistic effect of increasing saturation magnetization(M_(s))and reducing coercivity(H_(c)).Shallow CT at 213 K optim-ally enhances the soft magnetic properties of MGs.Given its low activation energy of nucleation and increased activation energy of growth,appropriate CT is beneficial for achieving uniform annealed nanocrystals in amorphous phases.The correlation between free volumes(FVs)and potential energy suggests that the variation in Hc depends on the expansion and contraction behavior of amorphous phases after different CT processes.The fitting formulas of H_(c)–d_(m) and Ms–Hv correlations demonstrate that soft magnetic parameters have a solid linear relationship with the contents of FVs and degree of dense random packing.Moreover,pitting resistance is improved by ap-propriate CT and relaxation annealing.This improvement is characterized by the promotion of the stability of the Nb-rich passive film formed during electrochemical corrosion in 3.5wt%NaCl solution.展开更多
Lunar impact glasses have been identified as crucial indicators of geochemical information regarding their source regions. Impact glasses can be categorized as either local or exotic. Those preserving geochemical sign...Lunar impact glasses have been identified as crucial indicators of geochemical information regarding their source regions. Impact glasses can be categorized as either local or exotic. Those preserving geochemical signatures matching local lithologies (e.g., mare basalts or their single minerals) or regolith bulk soil compositions are classified as “local”. Otherwise, they could be defined as “exotic”. The analysis of exotic glasses provides the opportunity to explore previously unsampled lunar areas. This study focuses on the identification of exotic glasses within the Chang’e-5 (CE-5) soil sample by analyzing the trace elements of 28 impact glasses with distinct major element compositions in comparison with the CE-5 bulk soil. However, the results indicate that 18 of the analyzed glasses exhibit trace element compositions comparable to those of the local CE-5 materials. In particular, some of them could match the local single mineral component in major and trace elements, suggesting a local origin. Therefore, it is recommended that the investigation be expanded from using major elements to including nonvolatile trace elements, with a view to enhancing our understanding on the provenance of lunar impact glasses. To achieve a more accurate identification of exotic glasses within the CE-5 soil sample, a novel classification plot of Mg# versus La is proposed. The remaining 10 glasses, which exhibit diverse trace element variations, were identified as exotic. A comparative analysis of their chemical characteristics with remote sensing data indicates that they may have originated from the Aristarchus, Mairan, Sharp, or Pythagoras craters. This study elucidates the classification and possible provenance of exotic materials within the CE-5 soil sample, thereby providing constraints for the enhanced identification of local and exotic components at the CE-5 landing site.展开更多
The magnetic and magnetocaloric performances of the ternary Fe_(87)M_(10)B_(3)(M=Zr,Pr) amorphous alloys were systematically studied in the present work.By complete Pr substitution for Zr,the maximum magnetic entropy ...The magnetic and magnetocaloric performances of the ternary Fe_(87)M_(10)B_(3)(M=Zr,Pr) amorphous alloys were systematically studied in the present work.By complete Pr substitution for Zr,the maximum magnetic entropy change(-ΔS_(m)^(peak)) under 5 T is significantly enlarged from about 3.22 J/(kg·K) at 293 K to 4.66 J/(kg·K) at 337 K,with a simultaneous slight increase of magnetic hysteresis at 10 K.The mechanism involved was investigated with the help of first-principles simulation and magnetic force microscopy observation.The coercivity of the Fe_(87)Pr_(10)B_(3) amorphous ribbon at 10 K,which is induced by the strong random magnetic anisotropy that is related to the charge transfer from Pr atoms to Fe atoms,decreases to nearly zero at 200 K,indicating that the coercivity does not affect the magnetocaloric properties near room temperature.The enhanced Curie temperature(T_(c)) and the significantly enlarged-ΔS_(m)^(peak) are supposed to be closely related to a combination of the reinforced 3d-3d interaction and the introduction of 4f-4f interaction by complete Pr substitution for Zr.展开更多
We successfully prepared a series of rare-earth doped borosilicate glasses using the melt-quenching method,and carefully investigated the luminescent properties and the spectral modulation of Tb/Eucodoped borosilicate...We successfully prepared a series of rare-earth doped borosilicate glasses using the melt-quenching method,and carefully investigated the luminescent properties and the spectral modulation of Tb/Eucodoped borosilicate glasses under UV(200-400 nm)excitation.The results show that the prepared samples have the characteristics of broadband response,excellent transparency and tunable luminescence.By adjusting the excitation wavelength,the emissions of Tb^(3+),Eu^(2+)and Eu^(3+)ions are observed,which exhibit yellow-green,blue,red color and multi-color even white emissions,respectively.Moreover,the energy transfer between Tb^(3+)and Eu^(3+)ions in the codoped glasses is confirmed.Tb^(3+)absorbs a large number of solar-blind light,transfers to Eu^(3+)and results in intense visible emission in a wide waveband range.This makes the Tb/Eu co-doped glass a desirable candidate for solar-blind light detections.The photodetection system was built and shows a strong and stable response to the UV light of 210-400 nm.Due to broad detection range,high sensitivity and stability,our results offer strong implications for the development of photodetection device for diverse applications.展开更多
Focusing on the ultralow expansion functionality of the crystalized glass containing the cordierite crystal phase with the molar composition 20.7MgO·20.7Al_(2)O_(3)·51.6SiO_(2)·7.0TiO_(2),we systematica...Focusing on the ultralow expansion functionality of the crystalized glass containing the cordierite crystal phase with the molar composition 20.7MgO·20.7Al_(2)O_(3)·51.6SiO_(2)·7.0TiO_(2),we systematically investigated impacts of thermal treatment protocols on T dependence of coefficients of thermal expansion(CTE).Except for the phase compositions,morphology is identified as another important factor to control the T dependence of CTE.By using X-ray diffraction and scanning electron microscope,various modes of T dependence of CTE for crystallized glasses are ascribed to their different phase compositions and microstructure with finely dispersed nanoparticles.These understanding contributes to the further modification of CTE of the crystalized glass by altering their thermal treatment scenarios.展开更多
Transparent glass-ceramics containing MgSiO_(3)and/or Mg_(2)SiO_(4)nanocrystals were prepared.Effects of MgO/SiO_(2)ratio on crystallization properties of MgSiO_(3)and Mg_(2)SiO_(4)nanocrystals were investigated.When ...Transparent glass-ceramics containing MgSiO_(3)and/or Mg_(2)SiO_(4)nanocrystals were prepared.Effects of MgO/SiO_(2)ratio on crystallization properties of MgSiO_(3)and Mg_(2)SiO_(4)nanocrystals were investigated.When the MgO/SiO_(2)ratio is relatively low,crystallization of MgSiO_(3)is favored,whereas a higher MgO/SiO_(2)ratio tends to promote the crystallization of Mg_(2)SiO_(4).Glass-ceramics are transparent in the visible range due to the small size of the precipitated nanocrystals.Replacing SiO_(2)with MgO results in an increase in Vickers hardness,and the Vickers hardness can be further enhanced through the precipitation of MgSiO_(3)and Mg_(2)SiO_(4)nanocrystals.The findings presented herein are meaningful for the preparation of highly transparent glass-ceramics containing MgSiO_(3)and Mg_(2)SiO_(4)nanocrystals.展开更多
Metallic glasses (MGs) have been found to exhibit unexpected ultrasonic-vibration-induced plasticity (UVIP),which provides a promising way to realize room temperature processing and molding of MGs.However,whether all ...Metallic glasses (MGs) have been found to exhibit unexpected ultrasonic-vibration-induced plasticity (UVIP),which provides a promising way to realize room temperature processing and molding of MGs.However,whether all MGs possessing UVIP remains a mystery.展开更多
Lead-free low melting glasses,ZnO-CuO-Bi_(2)O_(3)-B_(2)O_(3)-SiO_(2)system,with fixed contents of 15 mol%CuO and 20 mol%Bi_(2)O_(3),were prepared by using melt cooling method.Structure and thermal properties of the gl...Lead-free low melting glasses,ZnO-CuO-Bi_(2)O_(3)-B_(2)O_(3)-SiO_(2)system,with fixed contents of 15 mol%CuO and 20 mol%Bi_(2)O_(3),were prepared by using melt cooling method.Structure and thermal properties of the glasses were studied by using X-ray diffractometer(XRD),infrared spectrometer(FIT-IR),thermal dilatometer and differential thermal analyzer(DTA).Chemical durability of the glasses was studied by using dissolution rate method.Wettability of glasses on substrate was tested by using button sintering experiment.It is found that alkaline resistance of the glass solders is lower than that of plate glass and the water resistance is comparable with that of plate glass.The sealing temperatures are Ts=445-490℃,while the average thermal expansion coefficient from room temperature to 300℃is in the range of(65-82)×10^(−7)℃^(−1).At sealing temperature,the glass solders have good wettability on plate glass or alumina substrate.They are not crystallized even sintered at the sealing temperature for 30 min.The solder glasses are suitable for sealing plate glass,alumina and other inorganic non-metallic materials.展开更多
Solidification cracking issues during additive manufacturing(AM)severely prevent the rapid development and broad application of this method.In this work,a representative Co_(34)Cr_(32)Ni_(27)Al_(4)Ti_(3) high-entropy ...Solidification cracking issues during additive manufacturing(AM)severely prevent the rapid development and broad application of this method.In this work,a representative Co_(34)Cr_(32)Ni_(27)Al_(4)Ti_(3) high-entropy al-loy(HEA)susceptible to crack formation was fabricated by selective laser melting(SLM).As expected,many macroscopic cracks appeared.The crack issues were successfully solved after introducing a certain amount of Fe-based metallic glass(MG)powder as a glue during SLM.The effect of MG addition on the formation and distribution of defects in the SLM-processed HEA was quantitatively investigated.With an increasing mass fraction of the MG,the dominant defects transformed from cracks to lack of fusion(LOF)defects and finally disappeared.Intriguingly,the MG preferred to be segregated to the boundaries of the molten pool.Moreover,the coarse columnar crystals gradually transformed into equiaxed crystals in the molten pool and fine-equiaxed crystals at the edge of the molten pool,inhibiting the initiation of cracks and providing extra grain boundary strengthening.Furthermore,multiple precipitates are formed at the boundaries of cellular structures,which contribute significantly to strengthening.Compared to the brit-tle SLM-processed Co_(34)Cr_(32)Ni_(27)Al_(4)Ti_(3) HEA,the SLM-processed HEA composite exhibited a high ultimate tensile strength greater than 1.4 Ga and enhanced elongation.This work demonstrates that adding Fe-based MG powders as glues into SLM-processed HEAs may be an attractive method to heal cracks and simultaneously enhance the mechanical properties of additively manufactured products.展开更多
基金funded by the National Defence University of Malaysia(Grant No.UPNM/2022/GPJP/SG/3)My Brain Sc Scholarship 2023。
文摘This study explores the impact of bismuth oxide(Bi_(2)O_(3))on the optical and radiation shielding properties of transparent,lead-free thulium-doped bismuth borotellurite radiation shielding glass.The investigated glass composition follows the formula[(TeO_(2))_(75)(B_(2)O_(3))_(25)]_(98-x)(Bi_(2)O_(3))_x[Tm_(2)O_(3)]_(2),where x=0 mol%,5 mol%,10 mol%,15 mol%,20 mol%,25 mol%,and 30 mol%.All glass samples remain transparent,with an optical bandgap(E_(opt))exceeding 3.1 e V,ensuring visible light transmission.Radiation shielding data from Phy-X and XCom reveal interactions of the photoelectric effect,Compton scattering,and pair production,with minimal relative difference in mass attenuation coefficient(MAC)which is between0.05 and 0.56.At 0.662 Me V photon energy,the 20 mol%and 25 mol%Bi_(2)O_(3)glasses exhibit significantly higher Phy-X MAC values than other samples,except RS 520 glass,which contains 71%Pb O.Despite incorporating only up to 25 mol%Bi_(2)O_(3),these glasses outperform others in density,half-value layer(HVL),and mean free path(MFP).Correlating E_(opt)and MAC,the 20 mol%Bi_(2)O_(3)glass is the best candidate for transparent radiation shielding glass due to its wide optical bandgap which prevents ionization of trapped holes.Significantly,the linkage between MFP and molar refraction was also discovered based on the particle size influence on both parameters.
文摘In recent years,Danyang in Jiangsu Province-one of China’s key eyewear manufacturing and distribution centers-has leveraged its“small glasses”to power a“big industry.”
基金This work has been endorsed by the Chengdu Guangming Paite Precious Metal Co.,Ltd.,the CDGM Glass Co.,Ltd.,China,and the Research Grants Council of Hong Kong Special Administrative Region,China(No.15233823).
文摘Although the existence of glass–glass interfaces(GGIs)enables improved ductility of metallic nanoglasses(NGs),the excess free volumes at GGIs would cause the NGs to have a much-reduced mechanical strength.Herein,entropy-stabilized GGIs have been in-vestigated in Co–Fe–Ni–Zn–P NGs,which have a large entropy of mixing(1.32R,where R is the gas constant)and could be in a new glass phase,different from that of glassy grain interiors.Through quantitatively determining the activation energy of glass transition sep-arately for the GGIs and glassy grain interiors,the excess free volumes at GGIs are found to be reduced in comparison with those in the glassy grain interiors.The thermodynamically stable GGIs could be associated with increasing entropy of mixing in the GGI regions,which stabilizes the atomic structures of GGIs and enhances the glass forming ability of Co–Fe–Ni–Zn–P NGs.The influences of entropy-stabilized GGIs on the mechanical properties of Co–Fe–Ni–Zn–P NGs are further investigated by nanoindentation and creep tests under tensile deformation,demonstrating that there are notable enhancements in the ductility and mechanical strength for Co–Fe–Ni–Zn–P NGs.This work contributes to an in-depth understanding on the GGI phase in NGs and offers an alternative method for strengthening NGs through GGI engineering.
基金supported by the National Key R&D Program of China(2021YFC2600400 and 2023YFC2605200)the National Key Research Program of China(2021YFD1401100)the“San Nong Jiu Fang”Sciences and Technologies Cooperation Project of Zhejiang Province,China(2024SNJF010)。
文摘Agromyzid leafminers cause significant economic losses in both vegetable and horticultural crops,and precise assessments of pesticide needs must be based on the extent of leaf damage.Traditionally,surveyors estimate the damage by visually comparing the proportion of damaged to intact leaf area,a method that lacks objectivity,precision,and reliable data traceability.To address these issues,an advanced survey system that combines augmented reality(AR)glasses with a camera and an artificial intelligence(AI)algorithm was developed in this study to objectively and accurately assess leafminer damage in the feld.By wearing AR glasses equipped with a voice-controlled camera,surveyors can easily flatten damaged leaves by hand and capture images for analysis.This method can provide a precise and reliable diagnosis of leafminer damage levels,which in turn supports the implementation of scientifically grounded and targeted pest management strategies.To calculate the leafminer damage level,the DeepLab-Leafminer model was proposed to precisely segment the leafminer-damaged regions and the intact leaf region.The integration of an edge-aware module and a Canny loss function into the DeepLabv3+model enhanced the DeepLab-Leafminer model's capability to accurately segment the edges of leafminer-damaged regions,which often exhibit irregular shapes.Compared with state-of-the-art segmentation models,the DeepLabLeafminer model achieved superior segmentation performance with an Intersection over Union(IoU)of 81.23%and an F1score of 87.92%on leafminer-damaged leaves.The test results revealed a 92.38%diagnosis accuracy of leafminer damage levels based on the DeepLab-Leafminer model.A mobile application and a web platform were developed to assist surveyors in displaying the diagnostic results of leafminer damage levels.This system provides surveyors with an advanced,user-friendly,and accurate tool for assessing agromyzid leafminer damage in agricultural felds using wearable AR glasses and an AI model.This method can also be utilized to automatically diagnose pest and disease damage levels in other crops based on leaf images.
基金supported by the National Natural Science Foun-dation of China(Grant Nos.12404228 and 52371148)the Science and Technology Research Program of Chongqing Ed-ucation Commission of China(Grant No.KJQN202200510).
文摘Bulk metallic glasses(BMGs)are typically characterized by high strength and elasticity.However,they generally demonstrate a deficiency in plastic deformation capability at room temperatures.In this work,Cu_(50-x)Zr_(46)Al4Agx(x=0,1,2,3,4)alloys were prepared by arc melting and copper mold casting to investigate their structure,glass-forming ability,and mechanical properties.The results show that the addition of Ag can increase the parameter of DTx and g in Cu_(50)Zr_(46)Al_(4)alloy by 116%and 1.5%respectively,effectively enhancing its thermal stability and glass-forming ability.Compressive fracture tests reveal that the addition of Ag can significantly improve the yield strength,ultimate strength,and plasticity of the Cu_(50)Zr_(46)Al_(4)alloy.Specifically,with the Ag addition of 1 at.%,the alloy’s ultimate strength and plasticity increased by 71.8%and 21 times,respectively.Furthermore,the introduction of Ag can effectively control the free volume content in the Cu_(50)Zr_(46)Al_(4)alloy,thereby tuning the hardness of the material.This work provides valuable insights into improving the mechanical performance of BMGs through micro-alloying approaches.
基金supported by the National Natural Science Foundation of China(Nos.52271148 and 51871129).
文摘Ti-based bulk metallic glasses(BMGs)have attracted increasing attention due to their high specific strength.However,a fundamental conflict exists between the specific strength and glass-forming ability(GFA)of Ti-based BMGs,restricting their commercial applications significantly.In this study,this challenge was addressed by introducing a two-step alloying strategy to mitigate the remarkable density increment effect associated with heavy alloying elements required for enhancing the GFA.Consequently,through two-step alloying with Al and Fe in sequence,simultaneous enhancements in specific strength and GFA were achieved based on a Ti-Zr-Be ternary metallic glass,resulting in the development of a series of centimeter-sized metallic glasses exhibiting ultrahigh-specific strength.Notably,the newly developed(Ti_(45)Zr_(20)Be_(31)A_(l4))_(94)Fe_(6)alloy established a new record for the specific strength of Ti-based BMGs.Along with a critical diameter(D_(c))of 10 mm,it offers the optimal scheme for balancing the specific strength and GFA of Ti-based BMGs.The present results further brighten the application prospects of Ti-based BMGs as lightweight materials.
基金Project supported by the Scientific Research Foundation of the Education Department of Hunan Province,China (Grant No. 24A0007)the National Natural Science Foundation of China (Grant No. 52371168)the Foundation of Science and Technology on Surface Physics and Chemistry Laboratory(Grant No. JCKYS2024120202)。
文摘We performed the coupled molecular-dynamics and spin dynamics simulations to investigate the magnetic annealing effect on the crystallization behavior of Fe metallic glasses(MGs). By calculating the local five-fold symmetry, Voronoi polyhedron, and bond orientational order parameters, we find a significant structural evolution at high-frequency magnetic annealing: the icosahedral order diminishes, and the crystalline-like order is enhanced, comparing to the case without magnetic field. The fraction of the body-centered cubic structures remarkably increases with the frequency of magnetic annealing, and the atoms of these order show a tendency of aggregating in space to form the crystalline nuclei. These findings unveil how the local structure evolves under magnetic annealing, and the accelerated crystallization process of MGs through alternating magnetic fields.
文摘High-density germanate glasses doped with Tb^(3+)ions were synthesized via the melt-quenching meth-od.The physical and luminescent properties of these glasses were characterized through various techniques,in-cluding density measurement,differential scanning calorimetry(DSC),photoluminescence(PL)spectroscopy,X-ray excited luminescence(XEL)spectroscopy,and fluorescence decay analysis.The densities of the germanate glasses were greater than 6.1 g/cm^(3).Upon excitations of ultraviolet(UV)light and X-rays,the glasses emitted in-tense green emissions.The fluorescence lifetime of the strongest emission peak at 544 nm,measured under 377 nm excitation,ranged from 1.52 ms to 1.32 ms.In the glass specimens,the maximum XEL integral intensity reached roughly 26%of that of the commercially available Bi_(4)Ge_(3)O_(12)(BGO)crystal.These results indicate that Tb^(3+)-doped high-density germanate scintillating glasses hold potential as scintillation materials for X-ray imaging applications.
文摘Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cross-sections of Sm^(3+)result in low luminous efficiency,posing challenges for achieving high-quality solid-state lighting.Here,the excellent white emission of Sm^(3+)doped lithium aluminum silicate(LAS)glass was realized by introducing the Ag aggregates through Ag ion exchange.Under 395 nm excitation,the Ag-doped samples exhibit significant fluo⁃rescence enhancement with color coordinates close to the equal energy white point E(0.33,0.33)and a color ren⁃dering index(CRI)of 81.8.The study reveals that the surface plasmon resonance(SPR)effect of Ag nanoparticles enhances the luminescence of Sm^(3+),while the energy transfer mechanism between Ag^(+)and Sm^(3+)also promotes fluores⁃cence enhancement.By adjusting the concentration of AgNO_(3) and the exchange time,a series of high-quality full-spectrum white light emissions were obtained,indicating that the Ag ion-exchanged Sm^(3+)-doped LAS glass has good application potential in the development of solid-state lighting devices.Moreover,variations in the excitation wave⁃length can effectively tune the emission color,further demonstrating the tunability and practicality of this material in optoelectronic applications.
基金support from the National Natural Science Foundation of China(No.52231006)Junqiang Wang acknowledges financial support from the National Key R&D Program of China(No.2018YFA0703600)the National Natural Science Foundation of China(Nos.92163108 and 52222105).
文摘Annealing has been a popular method to improve the soft magnetism of metallic glasses (MGs), which however usually makes MGs brittle and difficult to process. Here, it is demonstrated that the embrittled Fe-based MG can be reductilized and the coercivity can be further lowered through the rejuvenation of memory effect. The synchronous improvement in the plasticity and soft magnetic properties is attributed to the combination effects of releasing much residual stress, decreasing the magnetic anisotropy, and homogenizing the glasses during the rejuvenation process. The current work opens a new perspective to improve the properties of MGs by utilizing the memory effect and holds promising commercial application potential.
基金Funded by Key R&D Projects in Hubei Province of China(No.2020BAB061)。
文摘Ag-doped alkali borosilicate glasses with different TiO_(2) contents were prepared by the melting method.The viscosity-temperature curves of the glass samples were fitted using the MYEGA equation,and it was found that the viscosity of the glass showed a gradual decrease with the increase of TiO_(2) content in the interval of the crystallization temperature of the glass.The results of XPS analysis show that TiO_(2) mainly enters the glass network in the form of[TiO_(4)]before the heat treatment of the glass samples.In contrast,after the heat treatment,the contents of[TiO_(4)]and[TiO_(5)]in the glass decreased significantly,and the content of[TiO_(6)]increased,which led to the separation of TiO_(2) from the glass network.The microhardness of glass shows the same pattern.Raman spectral analysis shows that the introduction of TiO_(2) promotes phase separation in glass.The reduction of glass viscosity facilitates the movement of particles within the glass,while the creation of phase separation promotes heterogeneous nucleation of grains.FE-SEM analysis reveals that the silver halide grains in the heat-treated glass are dispersed in the matrix in a spherical shape,and the average size of the silver halide grains tends to increase with the increase of TiO_(2) content.
基金support from the National Natural Science Foundation of China(No.52271146)New 20 Items of Colleges and Universities in Jinan,China(No.202228111)University of Jinan Disciplinary Cross-Convergence Construction Project 2023,China(No.XKJC-202311).
文摘The effect of cryogenic treatment(CT)and relaxation annealing on the average nearest neighboring distance of atom(dm),ther-modynamic stability,soft magnetic properties,microhardness(Hv),and corrosion resistance of as-spun(Fe_(0.5)Co_(0.5))_(75)B_(21)Nb_(4) metallic glasses(MGs)is studied.On the premise of maintaining a fully amorphous phase,appropriate CT and relaxation annealing are conducive to achieving the synergistic effect of increasing saturation magnetization(M_(s))and reducing coercivity(H_(c)).Shallow CT at 213 K optim-ally enhances the soft magnetic properties of MGs.Given its low activation energy of nucleation and increased activation energy of growth,appropriate CT is beneficial for achieving uniform annealed nanocrystals in amorphous phases.The correlation between free volumes(FVs)and potential energy suggests that the variation in Hc depends on the expansion and contraction behavior of amorphous phases after different CT processes.The fitting formulas of H_(c)–d_(m) and Ms–Hv correlations demonstrate that soft magnetic parameters have a solid linear relationship with the contents of FVs and degree of dense random packing.Moreover,pitting resistance is improved by ap-propriate CT and relaxation annealing.This improvement is characterized by the promotion of the stability of the Nb-rich passive film formed during electrochemical corrosion in 3.5wt%NaCl solution.
基金funded by the National Natural Science Foundation of China (Grant Nos. 42241103 and 62227901)the Key Research Program of the Institute of Geology and Geophysics, Chinese Academy of Sciences (Grant Nos. IGGCAS-202101 and IGGCAS-202401)
文摘Lunar impact glasses have been identified as crucial indicators of geochemical information regarding their source regions. Impact glasses can be categorized as either local or exotic. Those preserving geochemical signatures matching local lithologies (e.g., mare basalts or their single minerals) or regolith bulk soil compositions are classified as “local”. Otherwise, they could be defined as “exotic”. The analysis of exotic glasses provides the opportunity to explore previously unsampled lunar areas. This study focuses on the identification of exotic glasses within the Chang’e-5 (CE-5) soil sample by analyzing the trace elements of 28 impact glasses with distinct major element compositions in comparison with the CE-5 bulk soil. However, the results indicate that 18 of the analyzed glasses exhibit trace element compositions comparable to those of the local CE-5 materials. In particular, some of them could match the local single mineral component in major and trace elements, suggesting a local origin. Therefore, it is recommended that the investigation be expanded from using major elements to including nonvolatile trace elements, with a view to enhancing our understanding on the provenance of lunar impact glasses. To achieve a more accurate identification of exotic glasses within the CE-5 soil sample, a novel classification plot of Mg# versus La is proposed. The remaining 10 glasses, which exhibit diverse trace element variations, were identified as exotic. A comparative analysis of their chemical characteristics with remote sensing data indicates that they may have originated from the Aristarchus, Mairan, Sharp, or Pythagoras craters. This study elucidates the classification and possible provenance of exotic materials within the CE-5 soil sample, thereby providing constraints for the enhanced identification of local and exotic components at the CE-5 landing site.
基金Project supported by the National Natural Science Foundation of China (51871139, 52071196, 52071043)。
文摘The magnetic and magnetocaloric performances of the ternary Fe_(87)M_(10)B_(3)(M=Zr,Pr) amorphous alloys were systematically studied in the present work.By complete Pr substitution for Zr,the maximum magnetic entropy change(-ΔS_(m)^(peak)) under 5 T is significantly enlarged from about 3.22 J/(kg·K) at 293 K to 4.66 J/(kg·K) at 337 K,with a simultaneous slight increase of magnetic hysteresis at 10 K.The mechanism involved was investigated with the help of first-principles simulation and magnetic force microscopy observation.The coercivity of the Fe_(87)Pr_(10)B_(3) amorphous ribbon at 10 K,which is induced by the strong random magnetic anisotropy that is related to the charge transfer from Pr atoms to Fe atoms,decreases to nearly zero at 200 K,indicating that the coercivity does not affect the magnetocaloric properties near room temperature.The enhanced Curie temperature(T_(c)) and the significantly enlarged-ΔS_(m)^(peak) are supposed to be closely related to a combination of the reinforced 3d-3d interaction and the introduction of 4f-4f interaction by complete Pr substitution for Zr.
基金Project supported by the Significant Science and Technology Projects of LongMen Laboratory in Henan Province(231100220100,231100221100)the Key Research and Development Program of Henan province(231111222200)+2 种基金the College Students Innovations Special Project(202410482008)the National Natural Science Foundation of China(62275105,12104163)Basic Scientific Research Operating Expenses of Henan Academy of Sciences(240607004)。
文摘We successfully prepared a series of rare-earth doped borosilicate glasses using the melt-quenching method,and carefully investigated the luminescent properties and the spectral modulation of Tb/Eucodoped borosilicate glasses under UV(200-400 nm)excitation.The results show that the prepared samples have the characteristics of broadband response,excellent transparency and tunable luminescence.By adjusting the excitation wavelength,the emissions of Tb^(3+),Eu^(2+)and Eu^(3+)ions are observed,which exhibit yellow-green,blue,red color and multi-color even white emissions,respectively.Moreover,the energy transfer between Tb^(3+)and Eu^(3+)ions in the codoped glasses is confirmed.Tb^(3+)absorbs a large number of solar-blind light,transfers to Eu^(3+)and results in intense visible emission in a wide waveband range.This makes the Tb/Eu co-doped glass a desirable candidate for solar-blind light detections.The photodetection system was built and shows a strong and stable response to the UV light of 210-400 nm.Due to broad detection range,high sensitivity and stability,our results offer strong implications for the development of photodetection device for diverse applications.
基金Funded by National Natural Science Foundation of China(No.52172007)Jiangsu Science and Technology Innovation Project for Carbon Peaking and Carbon Neutrality(No.BE2022035)。
文摘Focusing on the ultralow expansion functionality of the crystalized glass containing the cordierite crystal phase with the molar composition 20.7MgO·20.7Al_(2)O_(3)·51.6SiO_(2)·7.0TiO_(2),we systematically investigated impacts of thermal treatment protocols on T dependence of coefficients of thermal expansion(CTE).Except for the phase compositions,morphology is identified as another important factor to control the T dependence of CTE.By using X-ray diffraction and scanning electron microscope,various modes of T dependence of CTE for crystallized glasses are ascribed to their different phase compositions and microstructure with finely dispersed nanoparticles.These understanding contributes to the further modification of CTE of the crystalized glass by altering their thermal treatment scenarios.
基金Funded by the National Natural Science Foundation of China(Nos.52202026,and 62175192)the Natural Science Foundation of Hubei Province(No.2022CFB762)。
文摘Transparent glass-ceramics containing MgSiO_(3)and/or Mg_(2)SiO_(4)nanocrystals were prepared.Effects of MgO/SiO_(2)ratio on crystallization properties of MgSiO_(3)and Mg_(2)SiO_(4)nanocrystals were investigated.When the MgO/SiO_(2)ratio is relatively low,crystallization of MgSiO_(3)is favored,whereas a higher MgO/SiO_(2)ratio tends to promote the crystallization of Mg_(2)SiO_(4).Glass-ceramics are transparent in the visible range due to the small size of the precipitated nanocrystals.Replacing SiO_(2)with MgO results in an increase in Vickers hardness,and the Vickers hardness can be further enhanced through the precipitation of MgSiO_(3)and Mg_(2)SiO_(4)nanocrystals.The findings presented herein are meaningful for the preparation of highly transparent glass-ceramics containing MgSiO_(3)and Mg_(2)SiO_(4)nanocrystals.
基金financially supported by the Key Basic and Applied Research Program of Guangdong Province, China (No.2019B030302010)the National Natural Science Foundation of China (Nos.52371160,51901243,52122105 and 51971150)the National Key Research and Development Program of China (No.2018YFA0703604)。
文摘Metallic glasses (MGs) have been found to exhibit unexpected ultrasonic-vibration-induced plasticity (UVIP),which provides a promising way to realize room temperature processing and molding of MGs.However,whether all MGs possessing UVIP remains a mystery.
基金National Natural Science Foundation of China(52172070)Jiangxi Provincial Natural Science Foundation(20242BAB25222)Jiangxi Provincial Graduate Innovation Special Fund Project(YC2022-S882 and YC2023-S808).
文摘Lead-free low melting glasses,ZnO-CuO-Bi_(2)O_(3)-B_(2)O_(3)-SiO_(2)system,with fixed contents of 15 mol%CuO and 20 mol%Bi_(2)O_(3),were prepared by using melt cooling method.Structure and thermal properties of the glasses were studied by using X-ray diffractometer(XRD),infrared spectrometer(FIT-IR),thermal dilatometer and differential thermal analyzer(DTA).Chemical durability of the glasses was studied by using dissolution rate method.Wettability of glasses on substrate was tested by using button sintering experiment.It is found that alkaline resistance of the glass solders is lower than that of plate glass and the water resistance is comparable with that of plate glass.The sealing temperatures are Ts=445-490℃,while the average thermal expansion coefficient from room temperature to 300℃is in the range of(65-82)×10^(−7)℃^(−1).At sealing temperature,the glass solders have good wettability on plate glass or alumina substrate.They are not crystallized even sintered at the sealing temperature for 30 min.The solder glasses are suitable for sealing plate glass,alumina and other inorganic non-metallic materials.
基金National Natural Science Foundation of China(Nos.51971180,51871132,51971179 and 52271037)New R&D Institution Construction Program of Guangdong Province,China(No.2019B090905009)+2 种基金Shenzhen Fundamental Research Program,China(No.JCYJ20210324122203010)Shaanxi Provincial Science and Technology Program,China(No.2023-JC-ZD-23)Foreign Senior Talents Program of Guangdong Province,China and the Fundamental Research Funds for the Central Universities of China(No.D5000230131).
文摘Solidification cracking issues during additive manufacturing(AM)severely prevent the rapid development and broad application of this method.In this work,a representative Co_(34)Cr_(32)Ni_(27)Al_(4)Ti_(3) high-entropy al-loy(HEA)susceptible to crack formation was fabricated by selective laser melting(SLM).As expected,many macroscopic cracks appeared.The crack issues were successfully solved after introducing a certain amount of Fe-based metallic glass(MG)powder as a glue during SLM.The effect of MG addition on the formation and distribution of defects in the SLM-processed HEA was quantitatively investigated.With an increasing mass fraction of the MG,the dominant defects transformed from cracks to lack of fusion(LOF)defects and finally disappeared.Intriguingly,the MG preferred to be segregated to the boundaries of the molten pool.Moreover,the coarse columnar crystals gradually transformed into equiaxed crystals in the molten pool and fine-equiaxed crystals at the edge of the molten pool,inhibiting the initiation of cracks and providing extra grain boundary strengthening.Furthermore,multiple precipitates are formed at the boundaries of cellular structures,which contribute significantly to strengthening.Compared to the brit-tle SLM-processed Co_(34)Cr_(32)Ni_(27)Al_(4)Ti_(3) HEA,the SLM-processed HEA composite exhibited a high ultimate tensile strength greater than 1.4 Ga and enhanced elongation.This work demonstrates that adding Fe-based MG powders as glues into SLM-processed HEAs may be an attractive method to heal cracks and simultaneously enhance the mechanical properties of additively manufactured products.
