Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bott...Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bottleneck in achieving high mechanical performance. Creating a large number of clean grain boundaries in refractory high-entropy alloys is a challenge. In this study, an ultrafine-grained (UFG) NbMoTaW alloy with high grain-boundary cohesion was prepared by powder metallurgy, taking advantages of rapid hot-pressing sintering and full-process inert atmosphere protection from powder synthesis to sintering. By oxygen control and an increase in the proportion of grain boundaries, the segregation of oxygen and formation of oxides at grain boundaries were strongly mitigated, thus the intrinsic high cohesion of the interfaces was preserved. Compared to the coarse-grained alloys prepared by arc-melting and those sintered by traditional powder metallurgy methods, the UFG NbMoTaW alloy demonstrated simultaneously increased strength and plasticity at ambient temperature. The highly cohesive grain boundaries not only reduce brittle fractures effectively but also promote intragranular deformation. Consequently, the UFG NbMoTaW alloy achieved a high yield strength even at elevated temperatures, with a remarkable performance of 1117 MPa at 1200 ℃. This work provides a feasible solution for producing refractory high-entropy alloys with low impurity content, refined microstructure, and excellent mechanical performance.展开更多
Immiscible bimetal systems,of which tungsten–copper(W–Cu)is a typical representative,have crucial applications in fields requiring both mechanical and physical properties.Nevertheless,it is a major challenge to dete...Immiscible bimetal systems,of which tungsten–copper(W–Cu)is a typical representative,have crucial applications in fields requiring both mechanical and physical properties.Nevertheless,it is a major challenge to determine how to give full play to the advantages of the two phases of the bimetal and achieve outstanding comprehensive properties.In this study,an ultrafine-grained W–Cu bimetal with spatially connected Cu and specific Wislands was fabricated through a designed powder-mixing process and subsequent rapid low-temperature sintering.The prepared bimetal concurrently has a high yield strength,large plastic strain,and high electrical conductivity.The stress distribution and strain response of individual phases in different types of W–Cu bimetals under loading were quantified by means of a simulation.The high yield strength of the reported bimetal results from the microstructure refinement and high contiguity of the grains in the W islands,which enhance the contribution of W to the total plastic deformation of the bimetal.The high electrical conductivity is attributed to the increased mean free path of the Cu and the reduced proportion of phase boundaries due to the specific phase combination of W islands and Cu.This work provides new insight into modulating phase configuration in immiscible metallic composites to achieve high-level multi-objective properties.展开更多
The harsh natural environment of Antarctica has led to a lack of research on the presence and transport mechanisms of organophosphate esters(OPEs) within its ecosystem.In this study,we analyzed levels of 11 OPEs in ai...The harsh natural environment of Antarctica has led to a lack of research on the presence and transport mechanisms of organophosphate esters(OPEs) within its ecosystem.In this study,we analyzed levels of 11 OPEs in air,soil,and vegetation samples collected during the 2018-2019 Chinese 35th Antarctic Scientific Expedition.Additionally,a level Ⅲ fugacity model was developed to simulate the movement and fate of detected OPEs in the air,soil,and vegetation of the Fildes Peninsula.Our model indicated that the primary OPEmigration pathway was from the atmosphere to the soil.OPE transportation primarily occurred through atmospheric wet deposition and rainwater dissolution.Among the 20 transport and transformation processes,atmospheric degradation was the most significant loss mechanism.The proposed model provides a method for continued investigation into the fate of OPEs in the Fildes Peninsula ecosystem.展开更多
To study the deterioration mechanisms of anhydrite rock under the freeze-thaw weathering process,the physico-mechanical characteristics and microstructure evolutions of anhydrite samples were determined by a series of...To study the deterioration mechanisms of anhydrite rock under the freeze-thaw weathering process,the physico-mechanical characteristics and microstructure evolutions of anhydrite samples were determined by a series of laboratory tests.Then,a descriptive-behavioral model was used to measure the integrity loss in anhydrite samples caused by cyclic freeze-thaw.Finally,the freeze-thaw damage mechanisms of anhydrite rock were revealed from the macro and micro aspects.The results show that the pore size of the anhydrite rock is mainly concentrated in the range of 0.001-10μm.As the number of freeze-thaw cycles increases,there is a growth in the proportion of macropores and mesopores.However,the proportion of micropores shows a declining trend.The relations of the uniaxial compressive strength,triaxial compressive strength,cohesion,and elastic modulus versus freeze-thaw cycles can be fitted by a decreasing exponential function,while the internal friction angle is basically unchanged with freezethaw cycles.With the increase of confining pressure,the disintegration rates of the compressive strength and the elastic modulus decrease,and the corresponding half-life values increase,which reveals that the increase of confining pressures could inhibit freeze-thaw damage to rocks.Moreover,it has been proven that the water chemical softening mechanism plays an essential role in the freeze-thaw damage to anhydrite rock.Furtherly,it is concluded that the freeze-thaw weathering process significantly influences the macroscopic and microscopic damages of anhydrite rock.展开更多
Flexible high-temperature electronics is a compliant form of high-temperature electronics to expand the application areas of conventional flexible one.In aerospace applications,electronic devices are not only required...Flexible high-temperature electronics is a compliant form of high-temperature electronics to expand the application areas of conventional flexible one.In aerospace applications,electronic devices are not only required to be deformable but also to be able to withstand extreme temperatures.The disadvantages of current flexible electronics,such as high cost,large differences between components,and even requiring independent debugging,are acceptable.展开更多
The WC-lOCo-4Cr composite powder was synthesized firstly. Then the composite powder was agglomerated to prepare thermal spraying feedstock. The ultrafine/nanostructured WC-lOCo-4Cr coating was prepared by high velocit...The WC-lOCo-4Cr composite powder was synthesized firstly. Then the composite powder was agglomerated to prepare thermal spraying feedstock. The ultrafine/nanostructured WC-lOCo-4Cr coating was prepared by high velocity oxygen fuel thermal spraying. The phase constitution, elemental distribution and microstructure of the coating were characterized by X-ray diffraction and transmission electron microscopy, respectively. The wear resistance and corrosion resistance of the prepared composite coating were tested. The results show that the main phases of the coating include WC, binding phase with partial amorphous structure, with a little WC and Co(Cr)coexisting. The distributions of Co and Cr elements from the phase boundary to the eutectic area then to Co zone were analyzed quantitatively. The mechanisms for the formation of the microstructure and effects of Cr on the performance of the composite coating are proposed.展开更多
BACKGROUND Digital intraoral scanning,although developing rapidly,is rarely used in occlusal reconstruction.To compensate for the technical drawbacks of current occlusal reconstruction techniques,such as time consumpt...BACKGROUND Digital intraoral scanning,although developing rapidly,is rarely used in occlusal reconstruction.To compensate for the technical drawbacks of current occlusal reconstruction techniques,such as time consumption and high technical requirements,digital intraoral scanning can be used in clinics.This report aims to provide a way of selecting the most suitable maxillo-mandibular relationship(MMR)during recovery.CASE SUMMARY A 68-year-old man with severely worn posterior teeth underwent occlusal reconstruction with fixed prosthesis using digital intraoral scanning.A series of digital models in different stages of treatment were obtained,subsequently compared,and selected using digital intraoral scanning together with traditional measurements,such as cone beam computed tomography,joint imaging,and clinical examination.Using digital intraoral scanning,the MMR in different stages of treatment was accurately recorded,which provided feasibility for deciding the best occlusal reconstruction treatment,made the treatment process easier,and improved patient satisfaction.CONCLUSION This case report highlights the clarity,recordability,repeatability,and selectivity of digital intraoral scanning to replicate and transfer the MMR during occlusal reconstruction,expanding new perspectives for its design,fabrication,and postoperative evaluation.展开更多
Eleven organophosphate esters(OPEs)in the air and seawater were investigated from the northwestern Pacific Ocean to the Southern Ocean during the 2018 Chinese 34th Antarctic Scientific Expedition.The concentration of ...Eleven organophosphate esters(OPEs)in the air and seawater were investigated from the northwestern Pacific Ocean to the Southern Ocean during the 2018 Chinese 34th Antarctic Scientific Expedition.The concentration of total OPEs ranged from 164.82 to 3501.79 pg/m~3in air and from 4.54 to 70.09 ng/L in seawater.Two halogenated OPEs,tri(chloropropyl)phosphate(TCPP)and tri(2-chloroethyl)phosphate(TCEP),were generally more abundant than the non-halogenated OPEs.A levelⅢfugacity model was developed to simulate the transfer and fate of seven OPEs in the air and seawater regions of the central Ross Sea.The model results indicate that OPEs are transferred from the air to the seawater in the central Ross Sea in summer,during which the Ross Sea acts as a final OPE sink.Dry and wet deposition dominated the processes involving OPE transfer to seawater.The OPE degradation process was also found to be more pervasive in the atmosphere than in the seawater region.These findings highlights the importance of long-range transport of OPEs and their air–seawater interface behavior in the Antarctic.展开更多
The challenge of fabricating nanostructured W–Cu composites by powder metallurgy has been solved by means of modulated phase separation.A hierarchically nanostructured(HN)W–Cu composite was prepared using intermedia...The challenge of fabricating nanostructured W–Cu composites by powder metallurgy has been solved by means of modulated phase separation.A hierarchically nanostructured(HN)W–Cu composite was prepared using intermediary Al through sluggish asynchronous phase separation.In addition to a dual network composed of a Cu phase and the W–Cu nanostructure,dense Al-containing nanoprecipitates with a body-centered cubic(bcc)structure are distributed in the W matrix.Compared with a pristine W/Cu interface,the newly formed W/Cu interfaces modulated by Al and the coherent W/Al-containing particle interfaces possess lower energy and enhanced bonding strength due to efficient electron transfer and strong coupling interactions.With a large number of stable heterogeneous interfaces and a“selflocking”geometry,the HN W–Cu composite exhibits excellent resistance against plastic deformation.The combination of the presented composite’s hardness and compressive strength outperforms all other sintered W–Cu composites with the same Cu content.Under a reciprocating sliding load,the reactive Al prevents excessive oxidation.The excellent synergy of the hardness and toughness of the friction-induced surface endows the HN composite with high abrasion resistance.This study provides a new strategy to modulate the structure and energy state of interfaces in metallic composites containing immiscible components in order to achieve high mechanical performance.展开更多
Characterizing immiscible metallic composites with electron microscopy and X-ray spectroscopy is the classic way of obtaining their structural and physical details.Nevertheless,such a combination lacks abil-ity to tel...Characterizing immiscible metallic composites with electron microscopy and X-ray spectroscopy is the classic way of obtaining their structural and physical details.Nevertheless,such a combination lacks abil-ity to tell the interfacial interactions at grain boundaries.Here we demonstrate a novel strategy to un-cover the mystery of interfacial interactions in such systems by spectroscopic microscopy.The morpho-logical and spectral data of samples were simultaneously recorded and analyzed,which reveals critical information regarding interfacial electronic modes.Taking W-Cu as a model,we experimentally quanti-fied its connectivity and unambiguously identified conditional bonding between W and Cu.Further,we chemically reconstructed the specific W-Cu boundary that possessed the strongest interactions and inves-tigated its atomic structure.The mechanism of W-Cu bonding was proposed and verified by first-principle calculations.The above methodology holds great promise to serve as a universal approach in achieving in-depth understanding of immiscible composites.展开更多
A model for describing solute segregation at grain boundaries has been developed for substitutional solid solution alloys,which integrates multiple factors from atomic to microstructural scales.A concept of mo-lar Gib...A model for describing solute segregation at grain boundaries has been developed for substitutional solid solution alloys,which integrates multiple factors from atomic to microstructural scales.A concept of mo-lar Gibbs free energy of segregation was introduced to evaluate the segregating capability of the solute elements in a closed system,through which the influences of grain boundary structure,grain size,ma-terial composition,and external conditions were described.Based on the evaluation of various energy forms related to solute segregation and grain growth processes,the nature of the thermal stabilization of nanograin structures by solute segregation was disclosed.A criterion for the destabilization of nanostruc-tures,which is determined by the competition of the change rates between the molar Gibbs free energy of segregation and the total energy of grain boundaries with grain size,has been proposed.This study provided guideline to achieve high-temperature stability of nanograin structures of solid solution alloys even for the weakly segregating nanocrystalline systems.展开更多
In the paper, the in vitro dissolution of borneol in 12 hours from 6 batches of optimized inhalant samples were investigated. As a new dosage form, the in vitro release apparatus of nasal inhalant was invented and a p...In the paper, the in vitro dissolution of borneol in 12 hours from 6 batches of optimized inhalant samples were investigated. As a new dosage form, the in vitro release apparatus of nasal inhalant was invented and a pushing bump was used according to the simulation of the nose expiration and inspiration. Based on the data of r2 in the profile and similar factor f2 from 6 linear release tendencies, a good controlled release and a zero order tendency were observed. It can be suggested that there is a good correlation between the in vitro controlled release and the nose steady self-controllable expiration and inspiration, which will contribute to the trend of insoluble volatile drug controlled release and the effect of quick absorption in nasal pulmonary delivery to cure severe or acute cardiovascular or lung diseases at patients' sleeping, such as angina or breathing obstruction. Also, it was concluded that the prescription composed of insoluble volatile drugs can be prepared to be nasal inhalant from which drugs can be absorbed through nose steady self-controllable inspiration to the lung then into the blood and have a great effectiveness improvement of bioavailability at night timing drug delivery system.展开更多
A new type of grain-interior planar defect in a ceramic phase in TiC doped cemented tungsten carbides was discovered.It is unique in that the monolayers of metal atoms exist stably in ceramic grains.The planar defects...A new type of grain-interior planar defect in a ceramic phase in TiC doped cemented tungsten carbides was discovered.It is unique in that the monolayers of metal atoms exist stably in ceramic grains.The planar defects were induced by the ordered heteroatoms distributing on certain crystal planes of the matrix,which are distinct from the known planar defects such as phase-,grain-,and twin-boundaries,stacking faults,and complexions.Detailed characterization on the atomic scale was performed for the composition,structure,and crystallography of the planar defects,and their energy state and stability were evaluated by modeling.It was found that the Ti monolayer assists nucleation of the new WC crystal along the normal direction to its basal plane.Due to the disturbance of the heteroatom layer,the deposition of W and C atoms deviates from the regular sites occupied in the perfect crystal lattice,resulting in variations of the W–C arrangement in the grain structure.Experiments confirmed that tailoring the distribution density of the planar defects could give the best comprehensive mechanical performance with simultaneously outstanding strength and fracture toughness in the materials containing the grain-interior planar defects.This study provides a new strategy to greatly enhance the mechanical properties of materials by introducing and tailoring planar defects in the grain interiors.展开更多
Artificial intelligence of things systems equipped with flexible sensors can autonomously and intelligently detect the condition of the surroundings.However,current intelligent monitoring systems always rely on an ext...Artificial intelligence of things systems equipped with flexible sensors can autonomously and intelligently detect the condition of the surroundings.However,current intelligent monitoring systems always rely on an external computer with the capability of machine learning rather than integrating it into the sensing device.The computer-assisted intelligent system is hampered by energy inefficiencies,privacy issues,and bandwidth restrictions.Here,a flexible,large-scale sensing array with the capability of low-power in-sensor intelligence based on a compression hypervector encoder is proposed for real-time recognition.The system with in-sensor intelligence can accommodate different individuals and learn new postures without additional computer processing.Both the communication bandwidth requirement and energy consumption of this system are significantly reduced by 1,024 and 500 times,respectively.The capability for in-sensor inference and learning eliminates the necessity to transmit raw data externally,thereby effectively addressing privacy concerns.Furthermore,the system possesses a rapid recognition speed(a few hundred milliseconds)and a high recognition accuracy(about 99%),comparing with support vector machine and other hyperdimensional computing methods.The research holds marked potential for applications in the integration of artificial intelligence of things and flexible electronics.展开更多
Biomacromolecules form membraneless organelles through liquid-liquid phase separation in order to regulate the efficiency of particular biochemical reactions.Dysregulation of phase separation might result in pathologi...Biomacromolecules form membraneless organelles through liquid-liquid phase separation in order to regulate the efficiency of particular biochemical reactions.Dysregulation of phase separation might result in pathological condensation or sequestration of biomolecules,leading to diseases.Thus,phase separation and phase separating factors may serve as drug targets for disease treatment.Nevertheless,such associations have not yet been integrated into phase separation-related databases.Therefore,based on MloDisDB,a database for membraneless organelle factor-disease associations previously developed by our lab,we constructed PhaSeDis,the phase separation-disease association database.We increased the number of phase separation entries from 52 to 185,and supplemented the evidence provided by the original articles verifying the phase separation nature of the factors.Moreover,we included the information of interacting small molecules with low-throughput or high-throughput evidence that might serve as potential drugs for phase separation entries.PhaSeDis strives to offer comprehensive descriptions of each entry,elucidating how phase separating factors induce pathological conditions via phase separation and the mechanisms by which small molecules intervene.We believe that PhaSeDis would be very important in the application of phase separation regulation in treating relateddiseases.PhaSeDis is availableathttp:/mlodis.phasep.pro.展开更多
The mesencephalic astrocyte-derived neurotrophic factor(MANF)has been recently identified as a neurotrophic factor,but its role in hepatic fibrosis is unknown.Here,we found that MANF was upregulated in the fibrotic li...The mesencephalic astrocyte-derived neurotrophic factor(MANF)has been recently identified as a neurotrophic factor,but its role in hepatic fibrosis is unknown.Here,we found that MANF was upregulated in the fibrotic liver tissues of the patients with chronic liver diseases and of mice treated with CCl4.MANF deficiency in either hepatocytes or hepatic mono-macrophages,particularly in hepatic mono-macrophages,clearly exacerbated hepatic fibrosis.Myeloid-specific MANF knockout increased the population of hepatic Ly6C^(high)macrophages and promoted HSCs activation.Furthermore,MANF-sufficient macrophages(from WT mice)transfusion ameliorated CCl4-induced hepatic fibrosis in myeloid cells-specific MANF knockout(MKO)mice.Mechanistically,MANF interacted with S100A8 to competitively block S100A8/A9 heterodimer formation and inhibited S100A8/A9-mediated TLR4-NF-κB signal activation.Pharmacologically,systemic administration of recombinant human MANF significantly alleviated CCl_(4)-induced hepatic fibrosis in both WT and hepatocytes-specific MANF knockout(HKO)mice.This study reveals a mechanism by which MANF targets S100A8/A9-TLR4 as a“brake”on the upstream of NF-κB pathway,which exerts an impact on macrophage differentiation and shed light on hepatic fibrosis treatment.展开更多
The Large High Altitude Air Shower Observatory(LHAASO)(Fig.1)is located at Mt.Haizi(4410 m a.s.l.,600 g/cm^(2),29°21'27.56"N,100°08'19.66"E)in Daocheng,Sichuan province,P.R.China.LHAASO con...The Large High Altitude Air Shower Observatory(LHAASO)(Fig.1)is located at Mt.Haizi(4410 m a.s.l.,600 g/cm^(2),29°21'27.56"N,100°08'19.66"E)in Daocheng,Sichuan province,P.R.China.LHAASO consists of 1.3 km^(2) array(KM2A)of electromagnetic particle detectors(ED)and muon detectors(MD),a water Cherenkov detector array(WCDA)with a total active area of 78,000 m^(2),18 wide field-of-view air Cherenkov telescopes(WFCTA)and a newly proposed electron-neutron detector array(ENDA)covering 10,000 m^(2).Each detector is synchronized with all the other through a clock synchronization network based on the White Rabbit protocol.The observatory includes an IT center which comprises the data acquisition system and trigger system,the data analysis facility.In this Chapter,all the above-mentioned components of LHAASO as well as infrastructure are described.展开更多
The facial expressions are a mirror of the elusive emotion hidden in the mind,and thus,capturing expressions is a crucial way of merging the inward world and virtual world.However,typical facial expression recognition...The facial expressions are a mirror of the elusive emotion hidden in the mind,and thus,capturing expressions is a crucial way of merging the inward world and virtual world.However,typical facial expression recognition(FER)systems are restricted by environments where faces must be clearly seen for computer vision,or rigid devices that are not suitable for the time-dynamic,curvilinear faces.Here,we present a robust,highly wearable FER system that is based on deep-learning-assisted,soft epidermal electronics.The epidermal electronics that can fully conform on faces enable high-fidelity biosignal acquisition without hindering spontaneous facial expressions,releasing the constraint of movement,space,and light.The deep learning method can significantly enhance the recognition accuracy of facial expression types and intensities based on a small sample.The proposed wearable FER system is superior for wide applicability and high accuracy.The FER system is suitable for the individual and shows essential robustness to different light,occlusion,and various face poses.It is totally different from but complementary to the computer vision technology that is merely suitable for simultaneous FER of multiple individuals in a specific place.This wearable FER system is successfully applied to human-avatar emotion interaction and verbal communication disambiguation in a real-life environment,enabling promising human-computer interaction applications.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52371128,52304378,52101031 and 92163107).
文摘Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bottleneck in achieving high mechanical performance. Creating a large number of clean grain boundaries in refractory high-entropy alloys is a challenge. In this study, an ultrafine-grained (UFG) NbMoTaW alloy with high grain-boundary cohesion was prepared by powder metallurgy, taking advantages of rapid hot-pressing sintering and full-process inert atmosphere protection from powder synthesis to sintering. By oxygen control and an increase in the proportion of grain boundaries, the segregation of oxygen and formation of oxides at grain boundaries were strongly mitigated, thus the intrinsic high cohesion of the interfaces was preserved. Compared to the coarse-grained alloys prepared by arc-melting and those sintered by traditional powder metallurgy methods, the UFG NbMoTaW alloy demonstrated simultaneously increased strength and plasticity at ambient temperature. The highly cohesive grain boundaries not only reduce brittle fractures effectively but also promote intragranular deformation. Consequently, the UFG NbMoTaW alloy achieved a high yield strength even at elevated temperatures, with a remarkable performance of 1117 MPa at 1200 ℃. This work provides a feasible solution for producing refractory high-entropy alloys with low impurity content, refined microstructure, and excellent mechanical performance.
基金supported by the National Natural Science Foundation of China(92163107,52171061,and 52371128)the National Key Research and Development Program of China(2022YFB3708800 and 2021YFB3501502).
文摘Immiscible bimetal systems,of which tungsten–copper(W–Cu)is a typical representative,have crucial applications in fields requiring both mechanical and physical properties.Nevertheless,it is a major challenge to determine how to give full play to the advantages of the two phases of the bimetal and achieve outstanding comprehensive properties.In this study,an ultrafine-grained W–Cu bimetal with spatially connected Cu and specific Wislands was fabricated through a designed powder-mixing process and subsequent rapid low-temperature sintering.The prepared bimetal concurrently has a high yield strength,large plastic strain,and high electrical conductivity.The stress distribution and strain response of individual phases in different types of W–Cu bimetals under loading were quantified by means of a simulation.The high yield strength of the reported bimetal results from the microstructure refinement and high contiguity of the grains in the W islands,which enhance the contribution of W to the total plastic deformation of the bimetal.The high electrical conductivity is attributed to the increased mean free path of the Cu and the reduced proportion of phase boundaries due to the specific phase combination of W islands and Cu.This work provides new insight into modulating phase configuration in immiscible metallic composites to achieve high-level multi-objective properties.
基金supported by the Joint Research Project of Hainan Province(No.ZDYF2024SHFZ085)Hainan Provincial Union Project of Sanya Yazhou Bay Science and Technology City(No.2021CXLH0009)+2 种基金the National Natural Science Foundation of China(Nos.42006195 and 42376234)the Science Technology Project of Yazhou Bay Innovation Institute of Hainan Tropical Ocean University(No.2022CXYZD002)the Scientific Research of Hainan Tropical Ocean University(No.RHDRC202201).
文摘The harsh natural environment of Antarctica has led to a lack of research on the presence and transport mechanisms of organophosphate esters(OPEs) within its ecosystem.In this study,we analyzed levels of 11 OPEs in air,soil,and vegetation samples collected during the 2018-2019 Chinese 35th Antarctic Scientific Expedition.Additionally,a level Ⅲ fugacity model was developed to simulate the movement and fate of detected OPEs in the air,soil,and vegetation of the Fildes Peninsula.Our model indicated that the primary OPEmigration pathway was from the atmosphere to the soil.OPE transportation primarily occurred through atmospheric wet deposition and rainwater dissolution.Among the 20 transport and transformation processes,atmospheric degradation was the most significant loss mechanism.The proposed model provides a method for continued investigation into the fate of OPEs in the Fildes Peninsula ecosystem.
基金the National Natural Science Foundation of China for financial support (Grant No. 51578091)
文摘To study the deterioration mechanisms of anhydrite rock under the freeze-thaw weathering process,the physico-mechanical characteristics and microstructure evolutions of anhydrite samples were determined by a series of laboratory tests.Then,a descriptive-behavioral model was used to measure the integrity loss in anhydrite samples caused by cyclic freeze-thaw.Finally,the freeze-thaw damage mechanisms of anhydrite rock were revealed from the macro and micro aspects.The results show that the pore size of the anhydrite rock is mainly concentrated in the range of 0.001-10μm.As the number of freeze-thaw cycles increases,there is a growth in the proportion of macropores and mesopores.However,the proportion of micropores shows a declining trend.The relations of the uniaxial compressive strength,triaxial compressive strength,cohesion,and elastic modulus versus freeze-thaw cycles can be fitted by a decreasing exponential function,while the internal friction angle is basically unchanged with freezethaw cycles.With the increase of confining pressure,the disintegration rates of the compressive strength and the elastic modulus decrease,and the corresponding half-life values increase,which reveals that the increase of confining pressures could inhibit freeze-thaw damage to rocks.Moreover,it has been proven that the water chemical softening mechanism plays an essential role in the freeze-thaw damage to anhydrite rock.Furtherly,it is concluded that the freeze-thaw weathering process significantly influences the macroscopic and microscopic damages of anhydrite rock.
基金financially supported by the National Key R&D Program of China (No.2021YFB3200700)the National Natural Science Foundation of China (Nos.52205593 and 51925503)Xplorer Prize (2020-1036)。
文摘Flexible high-temperature electronics is a compliant form of high-temperature electronics to expand the application areas of conventional flexible one.In aerospace applications,electronic devices are not only required to be deformable but also to be able to withstand extreme temperatures.The disadvantages of current flexible electronics,such as high cost,large differences between components,and even requiring independent debugging,are acceptable.
基金financially supported by the National Natural Science Foundation (No. 51601004)the Key Program of National Natural Science Foundation (No. 51631002)the National Science Fund for Distinguished Young Scholars (No. 51425101)
文摘The WC-lOCo-4Cr composite powder was synthesized firstly. Then the composite powder was agglomerated to prepare thermal spraying feedstock. The ultrafine/nanostructured WC-lOCo-4Cr coating was prepared by high velocity oxygen fuel thermal spraying. The phase constitution, elemental distribution and microstructure of the coating were characterized by X-ray diffraction and transmission electron microscopy, respectively. The wear resistance and corrosion resistance of the prepared composite coating were tested. The results show that the main phases of the coating include WC, binding phase with partial amorphous structure, with a little WC and Co(Cr)coexisting. The distributions of Co and Cr elements from the phase boundary to the eutectic area then to Co zone were analyzed quantitatively. The mechanisms for the formation of the microstructure and effects of Cr on the performance of the composite coating are proposed.
文摘BACKGROUND Digital intraoral scanning,although developing rapidly,is rarely used in occlusal reconstruction.To compensate for the technical drawbacks of current occlusal reconstruction techniques,such as time consumption and high technical requirements,digital intraoral scanning can be used in clinics.This report aims to provide a way of selecting the most suitable maxillo-mandibular relationship(MMR)during recovery.CASE SUMMARY A 68-year-old man with severely worn posterior teeth underwent occlusal reconstruction with fixed prosthesis using digital intraoral scanning.A series of digital models in different stages of treatment were obtained,subsequently compared,and selected using digital intraoral scanning together with traditional measurements,such as cone beam computed tomography,joint imaging,and clinical examination.Using digital intraoral scanning,the MMR in different stages of treatment was accurately recorded,which provided feasibility for deciding the best occlusal reconstruction treatment,made the treatment process easier,and improved patient satisfaction.CONCLUSION This case report highlights the clarity,recordability,repeatability,and selectivity of digital intraoral scanning to replicate and transfer the MMR during occlusal reconstruction,expanding new perspectives for its design,fabrication,and postoperative evaluation.
基金supported by the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City (No.2021CXLH0009)the National Natural Science Foundation of China (Nos.42006195 and 41976222)+1 种基金the Scientific Research Foundation of Hainan Tropical Ocean University (No.RHDRC202201)the Science and Technology Project of Yazhou Bay Innovation Institute of Hainan Tropical Ocean University (No.2022CXYZD002)。
文摘Eleven organophosphate esters(OPEs)in the air and seawater were investigated from the northwestern Pacific Ocean to the Southern Ocean during the 2018 Chinese 34th Antarctic Scientific Expedition.The concentration of total OPEs ranged from 164.82 to 3501.79 pg/m~3in air and from 4.54 to 70.09 ng/L in seawater.Two halogenated OPEs,tri(chloropropyl)phosphate(TCPP)and tri(2-chloroethyl)phosphate(TCEP),were generally more abundant than the non-halogenated OPEs.A levelⅢfugacity model was developed to simulate the transfer and fate of seven OPEs in the air and seawater regions of the central Ross Sea.The model results indicate that OPEs are transferred from the air to the seawater in the central Ross Sea in summer,during which the Ross Sea acts as a final OPE sink.Dry and wet deposition dominated the processes involving OPE transfer to seawater.The OPE degradation process was also found to be more pervasive in the atmosphere than in the seawater region.These findings highlights the importance of long-range transport of OPEs and their air–seawater interface behavior in the Antarctic.
基金supported by the National Natural Science Foundation of China(51621003,52101003,92163107,and 52101032)the National Key Research and Development Program of China(2021YFB3501502)the International Cooperation Seed Fund of Beijing University of Technology(2021B26).
文摘The challenge of fabricating nanostructured W–Cu composites by powder metallurgy has been solved by means of modulated phase separation.A hierarchically nanostructured(HN)W–Cu composite was prepared using intermediary Al through sluggish asynchronous phase separation.In addition to a dual network composed of a Cu phase and the W–Cu nanostructure,dense Al-containing nanoprecipitates with a body-centered cubic(bcc)structure are distributed in the W matrix.Compared with a pristine W/Cu interface,the newly formed W/Cu interfaces modulated by Al and the coherent W/Al-containing particle interfaces possess lower energy and enhanced bonding strength due to efficient electron transfer and strong coupling interactions.With a large number of stable heterogeneous interfaces and a“selflocking”geometry,the HN W–Cu composite exhibits excellent resistance against plastic deformation.The combination of the presented composite’s hardness and compressive strength outperforms all other sintered W–Cu composites with the same Cu content.Under a reciprocating sliding load,the reactive Al prevents excessive oxidation.The excellent synergy of the hardness and toughness of the friction-induced surface endows the HN composite with high abrasion resistance.This study provides a new strategy to modulate the structure and energy state of interfaces in metallic composites containing immiscible components in order to achieve high mechanical performance.
基金National Natural Science Foundation of China(No.52101032)to provide support for this work.F.T thanks the support from Beijing Natural Science Foun-dation(No.2214067).X.S.thanks the support from the National Natural Science Foundation of China(Nos.92163107,51621003).
文摘Characterizing immiscible metallic composites with electron microscopy and X-ray spectroscopy is the classic way of obtaining their structural and physical details.Nevertheless,such a combination lacks abil-ity to tell the interfacial interactions at grain boundaries.Here we demonstrate a novel strategy to un-cover the mystery of interfacial interactions in such systems by spectroscopic microscopy.The morpho-logical and spectral data of samples were simultaneously recorded and analyzed,which reveals critical information regarding interfacial electronic modes.Taking W-Cu as a model,we experimentally quanti-fied its connectivity and unambiguously identified conditional bonding between W and Cu.Further,we chemically reconstructed the specific W-Cu boundary that possessed the strongest interactions and inves-tigated its atomic structure.The mechanism of W-Cu bonding was proposed and verified by first-principle calculations.The above methodology holds great promise to serve as a universal approach in achieving in-depth understanding of immiscible composites.
基金supported by the Beijing Natural Science Foun-dation(No.2214067)the National Key R&D Program of China(Nos.2021YFB3501502 and 2021YFB3501504)the National Natural Science Foundation of China(No.92163107).
文摘A model for describing solute segregation at grain boundaries has been developed for substitutional solid solution alloys,which integrates multiple factors from atomic to microstructural scales.A concept of mo-lar Gibbs free energy of segregation was introduced to evaluate the segregating capability of the solute elements in a closed system,through which the influences of grain boundary structure,grain size,ma-terial composition,and external conditions were described.Based on the evaluation of various energy forms related to solute segregation and grain growth processes,the nature of the thermal stabilization of nanograin structures by solute segregation was disclosed.A criterion for the destabilization of nanostruc-tures,which is determined by the competition of the change rates between the molar Gibbs free energy of segregation and the total energy of grain boundaries with grain size,has been proposed.This study provided guideline to achieve high-temperature stability of nanograin structures of solid solution alloys even for the weakly segregating nanocrystalline systems.
文摘In the paper, the in vitro dissolution of borneol in 12 hours from 6 batches of optimized inhalant samples were investigated. As a new dosage form, the in vitro release apparatus of nasal inhalant was invented and a pushing bump was used according to the simulation of the nose expiration and inspiration. Based on the data of r2 in the profile and similar factor f2 from 6 linear release tendencies, a good controlled release and a zero order tendency were observed. It can be suggested that there is a good correlation between the in vitro controlled release and the nose steady self-controllable expiration and inspiration, which will contribute to the trend of insoluble volatile drug controlled release and the effect of quick absorption in nasal pulmonary delivery to cure severe or acute cardiovascular or lung diseases at patients' sleeping, such as angina or breathing obstruction. Also, it was concluded that the prescription composed of insoluble volatile drugs can be prepared to be nasal inhalant from which drugs can be absorbed through nose steady self-controllable inspiration to the lung then into the blood and have a great effectiveness improvement of bioavailability at night timing drug delivery system.
基金supported by the National Natural Science Foundation of China(92163107,52171061,52101003,52271085,and 52101032).
文摘A new type of grain-interior planar defect in a ceramic phase in TiC doped cemented tungsten carbides was discovered.It is unique in that the monolayers of metal atoms exist stably in ceramic grains.The planar defects were induced by the ordered heteroatoms distributing on certain crystal planes of the matrix,which are distinct from the known planar defects such as phase-,grain-,and twin-boundaries,stacking faults,and complexions.Detailed characterization on the atomic scale was performed for the composition,structure,and crystallography of the planar defects,and their energy state and stability were evaluated by modeling.It was found that the Ti monolayer assists nucleation of the new WC crystal along the normal direction to its basal plane.Due to the disturbance of the heteroatom layer,the deposition of W and C atoms deviates from the regular sites occupied in the perfect crystal lattice,resulting in variations of the W–C arrangement in the grain structure.Experiments confirmed that tailoring the distribution density of the planar defects could give the best comprehensive mechanical performance with simultaneously outstanding strength and fracture toughness in the materials containing the grain-interior planar defects.This study provides a new strategy to greatly enhance the mechanical properties of materials by introducing and tailoring planar defects in the grain interiors.
基金supported by the National Key R&D Program of China(grant no.2020YFA0405700)the NationalNatural Science Foundation of China(grant no.51925503 to Y.H.and grant no.52375568 to F.Z.)+1 种基金the Tencent Foundation(XPLORER Prize to Y.H.)the Science and Technology Innovation Team of Hubei Province.
文摘Artificial intelligence of things systems equipped with flexible sensors can autonomously and intelligently detect the condition of the surroundings.However,current intelligent monitoring systems always rely on an external computer with the capability of machine learning rather than integrating it into the sensing device.The computer-assisted intelligent system is hampered by energy inefficiencies,privacy issues,and bandwidth restrictions.Here,a flexible,large-scale sensing array with the capability of low-power in-sensor intelligence based on a compression hypervector encoder is proposed for real-time recognition.The system with in-sensor intelligence can accommodate different individuals and learn new postures without additional computer processing.Both the communication bandwidth requirement and energy consumption of this system are significantly reduced by 1,024 and 500 times,respectively.The capability for in-sensor inference and learning eliminates the necessity to transmit raw data externally,thereby effectively addressing privacy concerns.Furthermore,the system possesses a rapid recognition speed(a few hundred milliseconds)and a high recognition accuracy(about 99%),comparing with support vector machine and other hyperdimensional computing methods.The research holds marked potential for applications in the integration of artificial intelligence of things and flexible electronics.
基金supported by the National Key R&D Program of China(Grant No.2023YFF1204703)the Beijing Natural Science Foundation,China(Grant No.Z230014)the National Natural Science Foundation of China(Grant Nos.T2325003 and 31000609).
文摘Biomacromolecules form membraneless organelles through liquid-liquid phase separation in order to regulate the efficiency of particular biochemical reactions.Dysregulation of phase separation might result in pathological condensation or sequestration of biomolecules,leading to diseases.Thus,phase separation and phase separating factors may serve as drug targets for disease treatment.Nevertheless,such associations have not yet been integrated into phase separation-related databases.Therefore,based on MloDisDB,a database for membraneless organelle factor-disease associations previously developed by our lab,we constructed PhaSeDis,the phase separation-disease association database.We increased the number of phase separation entries from 52 to 185,and supplemented the evidence provided by the original articles verifying the phase separation nature of the factors.Moreover,we included the information of interacting small molecules with low-throughput or high-throughput evidence that might serve as potential drugs for phase separation entries.PhaSeDis strives to offer comprehensive descriptions of each entry,elucidating how phase separating factors induce pathological conditions via phase separation and the mechanisms by which small molecules intervene.We believe that PhaSeDis would be very important in the application of phase separation regulation in treating relateddiseases.PhaSeDis is availableathttp:/mlodis.phasep.pro.
基金supported by the National Natural Science Foundation of China(81973336)the Joint Fund of the National Natural Science Foundation of China(U21A20345)。
文摘The mesencephalic astrocyte-derived neurotrophic factor(MANF)has been recently identified as a neurotrophic factor,but its role in hepatic fibrosis is unknown.Here,we found that MANF was upregulated in the fibrotic liver tissues of the patients with chronic liver diseases and of mice treated with CCl4.MANF deficiency in either hepatocytes or hepatic mono-macrophages,particularly in hepatic mono-macrophages,clearly exacerbated hepatic fibrosis.Myeloid-specific MANF knockout increased the population of hepatic Ly6C^(high)macrophages and promoted HSCs activation.Furthermore,MANF-sufficient macrophages(from WT mice)transfusion ameliorated CCl4-induced hepatic fibrosis in myeloid cells-specific MANF knockout(MKO)mice.Mechanistically,MANF interacted with S100A8 to competitively block S100A8/A9 heterodimer formation and inhibited S100A8/A9-mediated TLR4-NF-κB signal activation.Pharmacologically,systemic administration of recombinant human MANF significantly alleviated CCl_(4)-induced hepatic fibrosis in both WT and hepatocytes-specific MANF knockout(HKO)mice.This study reveals a mechanism by which MANF targets S100A8/A9-TLR4 as a“brake”on the upstream of NF-κB pathway,which exerts an impact on macrophage differentiation and shed light on hepatic fibrosis treatment.
基金Supported by National Natural Science Foundation in China(NSFC)(U2031103,U1831208,11805209,11775233)NSFC for Distinguished Young Scholars(12025502)+1 种基金the Science and Technology Department of Sichuan Province(2021YFSY0031)the International Partnership Program of Chinese Academy of Sciences(113111KYSB20170055)。
文摘The Large High Altitude Air Shower Observatory(LHAASO)(Fig.1)is located at Mt.Haizi(4410 m a.s.l.,600 g/cm^(2),29°21'27.56"N,100°08'19.66"E)in Daocheng,Sichuan province,P.R.China.LHAASO consists of 1.3 km^(2) array(KM2A)of electromagnetic particle detectors(ED)and muon detectors(MD),a water Cherenkov detector array(WCDA)with a total active area of 78,000 m^(2),18 wide field-of-view air Cherenkov telescopes(WFCTA)and a newly proposed electron-neutron detector array(ENDA)covering 10,000 m^(2).Each detector is synchronized with all the other through a clock synchronization network based on the White Rabbit protocol.The observatory includes an IT center which comprises the data acquisition system and trigger system,the data analysis facility.In this Chapter,all the above-mentioned components of LHAASO as well as infrastructure are described.
基金supported by the National Natural Science Foundation of China(grant number 51925503)the Program for HUST Academic Frontier Youth Teamthe HUST“Qihang Fund.”。
文摘The facial expressions are a mirror of the elusive emotion hidden in the mind,and thus,capturing expressions is a crucial way of merging the inward world and virtual world.However,typical facial expression recognition(FER)systems are restricted by environments where faces must be clearly seen for computer vision,or rigid devices that are not suitable for the time-dynamic,curvilinear faces.Here,we present a robust,highly wearable FER system that is based on deep-learning-assisted,soft epidermal electronics.The epidermal electronics that can fully conform on faces enable high-fidelity biosignal acquisition without hindering spontaneous facial expressions,releasing the constraint of movement,space,and light.The deep learning method can significantly enhance the recognition accuracy of facial expression types and intensities based on a small sample.The proposed wearable FER system is superior for wide applicability and high accuracy.The FER system is suitable for the individual and shows essential robustness to different light,occlusion,and various face poses.It is totally different from but complementary to the computer vision technology that is merely suitable for simultaneous FER of multiple individuals in a specific place.This wearable FER system is successfully applied to human-avatar emotion interaction and verbal communication disambiguation in a real-life environment,enabling promising human-computer interaction applications.
