Heterointerfaces have been pivotal in unveiling extraordinary interfacial properties and enabling multifunctional material platforms.Despite extensive research on all-oxide interfaces,heterointerfaces between differen...Heterointerfaces have been pivotal in unveiling extraordinary interfacial properties and enabling multifunctional material platforms.Despite extensive research on all-oxide interfaces,heterointerfaces between different material classes,such as oxides and nitrides,remain underexplored.Here we present the fabrication of atomically sharp heterointerfaces between antiperovskite Ni_(3)InN and perovskite SrVO_(3).Leveraging layer-resolved scanning transmission electron microscopy and electron energy loss spectroscopy,we identified pronounced charge transfer across the well-ordered interface.First-principles calculations confirmed our experimental observations and further predicted an emergent magnetic moment within the Ni_(3)InN layer due to the charge transfer.These findings pave the way for novel electronic and spintronic applications by enabling tunable interfacial properties in nitride/oxide systems.展开更多
Mg alloy often undergoes shear deformation during industrial processing.While its anisotropy and tension-compression asymmetry have been thoroughly studied under uniaxial loading,the understanding for shear loading is...Mg alloy often undergoes shear deformation during industrial processing.While its anisotropy and tension-compression asymmetry have been thoroughly studied under uniaxial loading,the understanding for shear loading is still lacking.This study employed a rolled AZ31B plate with typical basal texture to investigate the shear behaviors.Positive and negative simple shear experiments were performed at different angles in the transverse plane,whereby the visco-plastic self-consistent model was calibrated to reveal the deformation mechanisms and predict the mechanical responses at various orientations.Positive-negative shear asymmetry is present because extension twinning preferentially operates in one shear direction but is suppressed in the opposite direction.Simple shear induces multiple twin variants,thus impedes twin growth and slows the consumption of matrix,as compared to in-plane compression.For slip dominated simple shear,the interaction between loading-induced rigid body rotation and slip-induced crystal rotation produces distinct hardening behaviors,namely orthogonally asymmetric mechanical responses at complementary loading angles,which is largely absent in uniaxial loading.Finally,simulation results verify that positive-negative shear asymmetry appears only when the deviatoric normal stress on the sheet plane is non-zero.Positive-negative shear asymmetry persists except for the conditions of shear plane parallel to sheet plane,or shear direction parallel or perpendicular to rolling direction.展开更多
The blocky LPSO particles were modulated by single-directional and multi-directional forging,and the effect of blocky LPSO particles on the anisotropy of mechanical properties of Mg-8.5Gd-2.5Y-1.5Zn-0.5Zr alloy forged...The blocky LPSO particles were modulated by single-directional and multi-directional forging,and the effect of blocky LPSO particles on the anisotropy of mechanical properties of Mg-8.5Gd-2.5Y-1.5Zn-0.5Zr alloy forged parts was investigated.In the present work,3D processing maps are established,and the forming domain that is both stable and power efficient is in the temperature range from 430 to 500℃ and strain rate range from 0.001 to 0.06 s^(-1),which is used to guide the single-directional forging(SDF)and multi-directional forging(MDF)experiments.The tensile mechanical properties reveal that the blocky LPSO particles have an influence on the mechanical anisotropy,especially in terms of the elongation anisotropy.The blocky LPSO particles after the MDF process have a more regular shape and smaller size and are homogeneously distributed,which is responsible for the low anisotropy of the elongation.In addition,the age-hardening capability of the MDF part is higher than that of the SDF part.展开更多
The crystallographic orientations are generally non-random in wrought Mg alloy,which will lead to their macroscopic physical properties to be anisotropic.Understanding the texture evolution in processing of Mg alloy b...The crystallographic orientations are generally non-random in wrought Mg alloy,which will lead to their macroscopic physical properties to be anisotropic.Understanding the texture evolution in processing of Mg alloy billets and its effect on mechanical properties is therefore an important project for all scientists and engineers in material area.This paper is concerned with the description of texture,with the mechanisms of texture evolution and with the interrelationships between texture and mechanical properties in Mg alloy.It is a full review of understanding of the basic mechanism on texture evolution,of texture altering by alloying or processing,and of the mechanism of texture weakening.Moreover,it provides theories necessary and available techniques to develop high-performance Mg wrought with optimized texture in the field.展开更多
3.0T magnetic resonance spectroscopic imaging brain function in Alzheimer＇s disease. However, is a commonly used method in the research ot the role of 7.0T high-field magnetic resonance spectroscopic imaging in brain...3.0T magnetic resonance spectroscopic imaging brain function in Alzheimer＇s disease. However, is a commonly used method in the research ot the role of 7.0T high-field magnetic resonance spectroscopic imaging in brain function of Alzheimer＇s disease remains unclear. In this study, 7.0T magnetic resonance spectroscopy showed that in the hippocampus of Alzheimer＇s disease rats, the N-acetylaspartate wave crest was reduced, and the creatine and choline wave crest was elevated. This finding was further supported by hematoxylin-eosin staining, which showed a loss of hippocampal neurons and more glial cells. Moreover, electron microscopy showed neuronal shrinkage and mitochondrial rupture, and scanning electron microscopy revealed small size hippocampal synaptic vesicles, incomplete synaptic structure, and reduced number. Overall, the results revealed that 7.0T high-field nuclear magnetic resonance spectroscopy detected the lesions and functional changes in hippocampal neurons of Alzheimer＇s disease rats in vivo, allowing the possibility for assessing the success rate and grading of the amyloid beta （1-40） animal model of Alzheimer＇s disease.展开更多
High reactivity and ease of ignition are the major obstacles for the application of Mg alloys in aerospace.Thus,the ignition mechanisms of Mg alloys should be investigated systematically,which can guide the ignition-p...High reactivity and ease of ignition are the major obstacles for the application of Mg alloys in aerospace.Thus,the ignition mechanisms of Mg alloys should be investigated systematically,which can guide the ignition-proof alloy design.This article concludes the factors influencing the ignition resistance of Mg alloys from oxide film and substrate microstructure,and also the mechanisms of alloying elements improving the ignition resistance.The low strength is another reason restricting the development of Mg alloys.Therefore,at the last section,Mg alloys with the combination of high strength and good ignition-proof performance are summarized,including Mg-Al-Ca based alloys,SEN(Mg-Al-Zn-Ca-Y)alloys as well as Mg-Y and Mg-Gd based alloys.Besides,the shortages and the future focus of theses alloys are also reviewed.The aim of this article is to promote the understanding of oxidation and ignition mechanisms of Mg alloys and to provide reference for the development of Mg alloys with high strength and excellent ignition-proof performance at the same time.展开更多
Double-pass hot compression tests were carried out over a wide range of holding time（0–180 s） and Zener-Hollomon parameter（1.6 E15–1.3 E20） to study the deformation behavior of cast Mg-8 Gd-3 Y alloy.The flow cu...Double-pass hot compression tests were carried out over a wide range of holding time（0–180 s） and Zener-Hollomon parameter（1.6 E15–1.3 E20） to study the deformation behavior of cast Mg-8 Gd-3 Y alloy.The flow curves show obvious work hardening and strain softening stages, leading to the peak stress of double-pass hot compression. Holding time and Zener-Hollomon parameter can significantly affect the second pass peak stress. It is found that increasing the holding time can cause a higher peak stress in the second pass deformation. The second pass stress reaches the peak stress of 71 MPa at ZenerHollomom parameter of 1.6 E15. When the parameter rises to 1.3 E20, the second pass peak goes up to237 MPa. In addition, the second pass peak stress is significantly higher than the unloading stress, which is opposite to the flow behavior of aluminum alloys. Residual stored deformation energy caused by the first pass deformation could be consumed by metadynamic recrystallization. Therefore, more strain energy is required for subsequent dynamic recrystallization, resulting in hardening behavior. A hardening fraction is defined to describe the deformation behavior quantitatively, which shows a positive correlation with the metadynamic recrystallization fraction. The metadynamic recrystallization leads to grain growth at the inter pass holding stage, diminishing dynamic recrystallization nucleation positions in the second pass deformation.展开更多
Hot shear spinning experiments with Mg–3.0 Al–1.0 Zn–0.5 Mn(AZ31 B, wt%) magnesium alloy sheets were conducted at various temperatures, spindle speeds and feed ratios to investigate the effects of these processing ...Hot shear spinning experiments with Mg–3.0 Al–1.0 Zn–0.5 Mn(AZ31 B, wt%) magnesium alloy sheets were conducted at various temperatures, spindle speeds and feed ratios to investigate the effects of these processing parameters on the microstructure, crystallographic texture and mechanical properties. The AZ31 B sheet displayed good shear formability at temperatures from 473 to 673 K, spindle speeds from 300 to 600 rev/min and feed ratios from 0.1 to 0.5 mm/rev. During the dynamic recrystallization process, the grain size and texture were affected by the deformation temperature of the hot shear spinning process. Each of the spun sheets presented a strong basal texture, and the c-axis of most of the grains was parallel to the normal direction. The optimal hot shear spinning parameters were determined to be a temperature of 473 K, a spindle speed of 300 rev/min and a feed ratio of 0.1 mm/rev. The yield strength, ultimate tensile strength and elongation in the rolled direction reached 221 MPa, 288 MPa and 14.1%, and those in the transverse direction reached 205 MPa, 280 MPa and 12.4%, respectively. The improved strength and decreased mechanical anisotropy resulted from the fine grain size and strong basal texture.展开更多
The laminate structure was applied to improve the mechanical properties of Mg-8.0 Gd-3.0 Y-0.5 Zr alloys.Two types of laminate structures only with different distribution positions of fine grains were produced by fric...The laminate structure was applied to improve the mechanical properties of Mg-8.0 Gd-3.0 Y-0.5 Zr alloys.Two types of laminate structures only with different distribution positions of fine grains were produced by friction-stir processing.Results show that the trilayer structure sample exhibits an excellent strengthductility synergy compared to the homogenous structure and bilayer structure.The enhanced mechanical properties are resulted from the hetero-deformation induced(HDI)stress strengthening and strain hardening which would be enhanced by increasing the quantity of interface.These observations suggest a crucial role of the number of interfaces in designing the laminate structure.展开更多
The utilization of non-noble metal catalysts with robust and highly efficient electrocatalytic activity for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)are extremely important for the large-scale...The utilization of non-noble metal catalysts with robust and highly efficient electrocatalytic activity for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)are extremely important for the large-scale implementation of renewable energy devices.Integration of bifunctional electrocatalysts on both anode and cathode electrodes remains a significant challenge.Herein,we report on a novel and facile strategy to construct the ordered and aligned MoS_(2)nanosheet-encapsulated metal–organic frameworks(MOFs)derived hollow CoS polyhedron,in-situ grown on a nickel foam(NF).The starfish-like MoS_(2)/CoS/NF heterojunctions were formed due to the ordered growth of the material caused by NF substrate.The optimized 2-MoS_(2)/CoS/NF heterojunction exhibits robust bifunctional electrocatalytic activity with a low overpotential of 67 and 207 m V toward the HER and OER at 10 mA cm^(-2),and the long-term stability,which exceeds most of the reported bifunctional electrocatalysts.Such high electrocatalytic performance arises due to the synergistic effect between the MoS_(2)and CoS phases across the interface,the abundant active sites,as well as the hierarchical pore framework,which collectively enhance the mass and electron transfer during the reactions.The work provides a promising approach to fabricating bifunctional catalysts with custom-designed heterojunctions and remarkable performance for applications in electrochemical energy devices and related areas.展开更多
In this paper, the torque tracking control problem for a class of series elastic actuators(SEAs) in the presence of unknown payload parameters and external disturbances is investigated. The uncertainties/disturbances ...In this paper, the torque tracking control problem for a class of series elastic actuators(SEAs) in the presence of unknown payload parameters and external disturbances is investigated. The uncertainties/disturbances rejection problem for SEAs is addressed from the view of a continuous nonlinear robust control development. Specifically, based on the analysis of a nonlinear SEA, the generic dynamics of SEA systems is described and a novel nonlinear control framework for SEAs is constructed. Then a RISE(robust integral of the sign of the error)-based second-order filter is introduced to synthesize the control law. Moreover, the control performance is theoretically ensured by Lyapunov analysis. Finally, some experimental results are included to demonstrate the superior performance of the proposed control method, in terms of transient response and robustness.展开更多
This paper introduces a self-sensing anthropomorphic robot hand driven by Twisted String Actuators(TSAs).The use of TSAs provides several advantages such as muscle-like structures,high transmission ratios,large output...This paper introduces a self-sensing anthropomorphic robot hand driven by Twisted String Actuators(TSAs).The use of TSAs provides several advantages such as muscle-like structures,high transmission ratios,large output forces,high efficiency,compactness,inherent compliance,and the ability to transmit power over distances.However,conventional sensors used in TSA-actuated robotic hands increase stiffness,mass,volume,and complexity,making feedback control challenging.To address this issue,a novel self-sensing approach is proposed using strain-sensing string based on Conductive Polymer Composite(CPC).By measuring the resistance changes in the strain-sensing string,the bending angle of the robot hand's fingers can be estimated,enabling closed-loop control without external sensors.The developed self-sensing anthropomorphic robot hand comprises a 3D-printed structure with five fingers,a palm,five self-sensing TSAs,and a 3D-printed forearm.Experimental studies validate the self-sensing properties of the TSA and the anthropomorphic robot hand.Additionally,a real-time Virtual Reality(VR)monitoring system is implemented for visualizing and monitoring the robot hand's movements using its self-sensing capabilities.This research contributes valuable insights and advancements to the field of intelligent prosthetics and robotic end grippers.展开更多
This paper provides a comprehensive review of research progress in particle-reinforced Mg matrix composites prepared via powder metallurgy.The article discusses different strategies,such as micro-sized,nano-sized part...This paper provides a comprehensive review of research progress in particle-reinforced Mg matrix composites prepared via powder metallurgy.The article discusses different strategies,such as micro-sized,nano-sized particles,and multi-particle hybridization,which has been employed to enhance the performance of the composites.In addition,a range of preparation techniques that optimize the dispersion of the reinforcing particles are summarized.The paper also highlights how the different configurations between the reinforcements and matrix alloy impact the composites’performance.Finally,the article outlines the prospects of particles reinforced Mg matrix composites fabricated via powder metallurgy and recommends modification methods that could be explored to further develop these materials for various applications.展开更多
A quantitative multi-phase-field model for non-isothermal and polycrystalline solidification was developed and applied to dilute multicomponent alloys with hexagonal close-packed structures.The effects of Lewis coeffi...A quantitative multi-phase-field model for non-isothermal and polycrystalline solidification was developed and applied to dilute multicomponent alloys with hexagonal close-packed structures.The effects of Lewis coefficient and undercooling on dendrite growth were investigated systematically.Results show that large Lewis coefficients facilitate the release of the latent heat,which can accelerate the dendrite growth while suppress the dendrite tip radius.The greater the initial undercooling,the stronger the driving force for dendrite growth,the faster the growth rate of dendrites,the higher the solid fraction,and the more serious the solute microsegregation.The simulated dendrite growth dynamics are consistent with predictions from the phenomenological theory but significantly deviate from the classical JMAK theory which neglects the soft collision effect and mutual blocking among dendrites.Finally,taking the Mg-6Gd-2Zn(wt.%)alloy as an example,the simulated dendrite morphology shows good agreement with experimental results.展开更多
Safflower(Carthamus tinctorius)is widely cultivated around the world for its seeds and flowers.The presence of linoleic acid(LA)in its seeds and hydroxysafflor yellow A(HSYA)in its flowers are the crucial traits that ...Safflower(Carthamus tinctorius)is widely cultivated around the world for its seeds and flowers.The presence of linoleic acid(LA)in its seeds and hydroxysafflor yellow A(HSYA)in its flowers are the crucial traits that enable safflower to be used for industrial and medicinal purposes.Understanding the genetic control of these traits is essential for optimizing the quality of safflower and its breeding.To further this research,we present a chromosome-scale assembly of the genome of the safflower variety‘Chuanhonghua 1’,which was achieved using an integrated strategy combining Illumina,Oxford Nanopore,and Hi-C sequencing.We obtained a 1.17-Gb assembly with a contig N50 of 1.08 Mb,and all assembled sequences were assigned to 12 pseudochromosomes.Safflower’s evolution involved the core eudicotγ-triplication event and a whole-genome duplication event,which led to large-scale genomic rearrangements.Extensive genomic shuffling has occurred since the divergence of the ancestor of dicotyledons.We conducted metabolite and transcriptome profiles with time-and part-dependent changes and screened candidate genes that significantly contribute to seed lipid biosynthesis.We also analyzed key gene families that participate in LA and HSYA biosynthesis.Additionally,we re-sequenced 220 safflower lines and carried out a genome-wide association study using high-quality SNP data for eight agronomic traits.We identified SNPs related to important traits in safflower.Besides,the candidate gene HH_034464(CtCGT1)was shown to be involved in the biosynthesis of HSYA.Overall,we provide a high-quality reference genome and elucidate the genetic basis of LA and HSYA biosynthesis in safflower.This vast amount of data will benefit further research for functional gene mining and breeding in safflower.展开更多
Firstly, the distribution of main biomass resources （like straw, livestock manure and forestry residue） in counties of Jilin Province, and then according to the annual output of biomass in each county, the energy re...Firstly, the distribution of main biomass resources （like straw, livestock manure and forestry residue） in counties of Jilin Province, and then according to the annual output of biomass in each county, the energy regeneration of biomass and project distribution of organic fertilizer were studied, finally the direct economic effect and environmental effect of biomass developed recently were calculated.展开更多
A theoretical model is proposed to calculate the internal contact distributions and contact forces of a 3×4×4×4 twisted NbSn cable under applied axial strain.The critical current density reduction of th...A theoretical model is proposed to calculate the internal contact distributions and contact forces of a 3×4×4×4 twisted NbSn cable under applied axial strain.The critical current density reduction of the whole cable can be calculated.The thin rod theory is employed to analyze the mechanical behavior of each strand.According to the regular helical structure,the contact distribution of each strand is obtained,and the contact force in the cable is analyzed.At last,a prediction about the critical current density of the twisted cable is made.The results show that decreasing the pitch length can reduce the contact forces between strands.展开更多
BACKGROUND Renal clear cell carcinoma(RCC)is a malignant tumor of the genitourinary system with a predilection for males.The most common metastatic sites are the lung,liver,lymph nodes,contralateral kidney or adrenal ...BACKGROUND Renal clear cell carcinoma(RCC)is a malignant tumor of the genitourinary system with a predilection for males.The most common metastatic sites are the lung,liver,lymph nodes,contralateral kidney or adrenal gland,however,skin metastasis has only been seen in 1.0%-3.3%of cases.The most common site of skin metastasis is the scalp,and metastasis to the nasal ala region is rare.CASE SUMMARY A 55-year-old man with clear cell carcinoma of the left kidney was treated with pembrolizumab and axitinib for half a year after surgery and was found to have a red mass on his right nasal ala for 3 mo.The skin lesion of the patient grew rapidly to the size of 2.0 cm×2.0 cm×1.2 cm after discontinuation of targeted drug therapy due to the coronavirus disease 2019 epidemic.The patient was finally diagnosed with skin metastasis of RCC in our hospital.The patient refused to undergo surgical resection and the tumor shrank rapidly after resuming target therapy for 2 wk.CONCLUSION It is rare for an RCC to metastasize to the skin of the nasal ala region.The tumor size change of this patient before and after treatment with targeted drugs shows the effectiveness of combination therapy for skin metastasis.展开更多
BACKGROUND Lichen planus(LP)with distribution of lesions along Blaschko’s lines is a rare entity,accounting for 0.24%-0.62%of all patients.Unilateral distribution of lesions in arm,leg,trunk,and waist is even less co...BACKGROUND Lichen planus(LP)with distribution of lesions along Blaschko’s lines is a rare entity,accounting for 0.24%-0.62%of all patients.Unilateral distribution of lesions in arm,leg,trunk,and waist is even less common.Approximately 10%of patients with LP manifest nail lesions.CASE SUMMARY A 20-year-old woman presented to our department with polygonal,purpuric,flattopped papules over the right arm,right leg,and right side of trunk and waist for the last 5 mo.The patient initially developed nail deformation in the left middle finger with no obvious cause,followed by development of blue-purple and red maculopapular rash with pruritus.During the disease course,the skin lesions aggravated and spread to several segments due to scratching.The lesions showed unilateral distribution along the Blaschko’s lines.The diagnosis of LP along Blaschko’s lines was established based on dermoscopy and skin biopsy.Her cutaneous lesions considerably improved after 4-wk treatment with intramuscular glucocorticoid,oral acitretin,topical glucocorticoid,and retinoids.CONCLUSION Cases of LP involving multiple segments of the body along the Blaschko’s lines with nail damage are rare.展开更多
基金supported by the Beijing Natural Science Foundation(Grant No.JQ24002)the National Key Basic Research Program of China(Grant No.2020YFA0309100)+3 种基金the National Natural Science Foundation of China(Grant Nos.U22A20263,52250308,12304158,12325401,12274069,12404102,and 12474096)the Chinese Academy of Sciences(CAS)Project for Young Scientists in Basic Research(Grant No.YSBR-084)the CAS Youth Interdisciplinary Team,the Guangdong Basic and Applied Basic Research Foundation(Grant No.2022B1515120014)the Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology,and the International Young Scientist Fellowship of Institute of Physics,CAS.
文摘Heterointerfaces have been pivotal in unveiling extraordinary interfacial properties and enabling multifunctional material platforms.Despite extensive research on all-oxide interfaces,heterointerfaces between different material classes,such as oxides and nitrides,remain underexplored.Here we present the fabrication of atomically sharp heterointerfaces between antiperovskite Ni_(3)InN and perovskite SrVO_(3).Leveraging layer-resolved scanning transmission electron microscopy and electron energy loss spectroscopy,we identified pronounced charge transfer across the well-ordered interface.First-principles calculations confirmed our experimental observations and further predicted an emergent magnetic moment within the Ni_(3)InN layer due to the charge transfer.These findings pave the way for novel electronic and spintronic applications by enabling tunable interfacial properties in nitride/oxide systems.
基金supports of the National Key Research and Development Program of China(Grant No.2023YFB3710900)the National Natural Science Foundation of China(Grant Nos.52071211 and 52071208)。
文摘Mg alloy often undergoes shear deformation during industrial processing.While its anisotropy and tension-compression asymmetry have been thoroughly studied under uniaxial loading,the understanding for shear loading is still lacking.This study employed a rolled AZ31B plate with typical basal texture to investigate the shear behaviors.Positive and negative simple shear experiments were performed at different angles in the transverse plane,whereby the visco-plastic self-consistent model was calibrated to reveal the deformation mechanisms and predict the mechanical responses at various orientations.Positive-negative shear asymmetry is present because extension twinning preferentially operates in one shear direction but is suppressed in the opposite direction.Simple shear induces multiple twin variants,thus impedes twin growth and slows the consumption of matrix,as compared to in-plane compression.For slip dominated simple shear,the interaction between loading-induced rigid body rotation and slip-induced crystal rotation produces distinct hardening behaviors,namely orthogonally asymmetric mechanical responses at complementary loading angles,which is largely absent in uniaxial loading.Finally,simulation results verify that positive-negative shear asymmetry appears only when the deviatoric normal stress on the sheet plane is non-zero.Positive-negative shear asymmetry persists except for the conditions of shear plane parallel to sheet plane,or shear direction parallel or perpendicular to rolling direction.
基金supports of the National Key Research and Development Program of China(Grant No.2021YFB3501005)the National Natural Science Foundation of China(Grant No.52071208)the Key R&D program of Shanxi Province(International Cooperation)(Grant No.201903D421036).
文摘The blocky LPSO particles were modulated by single-directional and multi-directional forging,and the effect of blocky LPSO particles on the anisotropy of mechanical properties of Mg-8.5Gd-2.5Y-1.5Zn-0.5Zr alloy forged parts was investigated.In the present work,3D processing maps are established,and the forming domain that is both stable and power efficient is in the temperature range from 430 to 500℃ and strain rate range from 0.001 to 0.06 s^(-1),which is used to guide the single-directional forging(SDF)and multi-directional forging(MDF)experiments.The tensile mechanical properties reveal that the blocky LPSO particles have an influence on the mechanical anisotropy,especially in terms of the elongation anisotropy.The blocky LPSO particles after the MDF process have a more regular shape and smaller size and are homogeneously distributed,which is responsible for the low anisotropy of the elongation.In addition,the age-hardening capability of the MDF part is higher than that of the SDF part.
基金The authors gratefully acknowledge the financial supports of the National Key Research and Development Plan(Grant No.2016YFB0701201,No.2016YFB0301103)the National Natural Science Foundation of China(Grant No.51771109,No.51631006).
文摘The crystallographic orientations are generally non-random in wrought Mg alloy,which will lead to their macroscopic physical properties to be anisotropic.Understanding the texture evolution in processing of Mg alloy billets and its effect on mechanical properties is therefore an important project for all scientists and engineers in material area.This paper is concerned with the description of texture,with the mechanisms of texture evolution and with the interrelationships between texture and mechanical properties in Mg alloy.It is a full review of understanding of the basic mechanism on texture evolution,of texture altering by alloying or processing,and of the mechanism of texture weakening.Moreover,it provides theories necessary and available techniques to develop high-performance Mg wrought with optimized texture in the field.
基金supported by the National Natural Science Foundation of China,No.81141013a grant for Talents in Beijing,No.2011D003034000019
文摘3.0T magnetic resonance spectroscopic imaging brain function in Alzheimer＇s disease. However, is a commonly used method in the research ot the role of 7.0T high-field magnetic resonance spectroscopic imaging in brain function of Alzheimer＇s disease remains unclear. In this study, 7.0T magnetic resonance spectroscopy showed that in the hippocampus of Alzheimer＇s disease rats, the N-acetylaspartate wave crest was reduced, and the creatine and choline wave crest was elevated. This finding was further supported by hematoxylin-eosin staining, which showed a loss of hippocampal neurons and more glial cells. Moreover, electron microscopy showed neuronal shrinkage and mitochondrial rupture, and scanning electron microscopy revealed small size hippocampal synaptic vesicles, incomplete synaptic structure, and reduced number. Overall, the results revealed that 7.0T high-field nuclear magnetic resonance spectroscopy detected the lesions and functional changes in hippocampal neurons of Alzheimer＇s disease rats in vivo, allowing the possibility for assessing the success rate and grading of the amyloid beta （1-40） animal model of Alzheimer＇s disease.
基金the financial supports from the National Key Research and Development Plan(Grant No.2021YFB3701100)the National Natural Science Foundation of China(Grant No.U2241231,No.52071206)。
文摘High reactivity and ease of ignition are the major obstacles for the application of Mg alloys in aerospace.Thus,the ignition mechanisms of Mg alloys should be investigated systematically,which can guide the ignition-proof alloy design.This article concludes the factors influencing the ignition resistance of Mg alloys from oxide film and substrate microstructure,and also the mechanisms of alloying elements improving the ignition resistance.The low strength is another reason restricting the development of Mg alloys.Therefore,at the last section,Mg alloys with the combination of high strength and good ignition-proof performance are summarized,including Mg-Al-Ca based alloys,SEN(Mg-Al-Zn-Ca-Y)alloys as well as Mg-Y and Mg-Gd based alloys.Besides,the shortages and the future focus of theses alloys are also reviewed.The aim of this article is to promote the understanding of oxidation and ignition mechanisms of Mg alloys and to provide reference for the development of Mg alloys with high strength and excellent ignition-proof performance at the same time.
基金support of the National Key Research and Development Program of China (Grant No. 2016YFB0301103 and No. 2016YFB0101604)the National Natural Science Foundation of China (Grant No. 51601112)the Shanghai Rising-Star Program (Grant No. 17QB1403000)
文摘Double-pass hot compression tests were carried out over a wide range of holding time（0–180 s） and Zener-Hollomon parameter（1.6 E15–1.3 E20） to study the deformation behavior of cast Mg-8 Gd-3 Y alloy.The flow curves show obvious work hardening and strain softening stages, leading to the peak stress of double-pass hot compression. Holding time and Zener-Hollomon parameter can significantly affect the second pass peak stress. It is found that increasing the holding time can cause a higher peak stress in the second pass deformation. The second pass stress reaches the peak stress of 71 MPa at ZenerHollomom parameter of 1.6 E15. When the parameter rises to 1.3 E20, the second pass peak goes up to237 MPa. In addition, the second pass peak stress is significantly higher than the unloading stress, which is opposite to the flow behavior of aluminum alloys. Residual stored deformation energy caused by the first pass deformation could be consumed by metadynamic recrystallization. Therefore, more strain energy is required for subsequent dynamic recrystallization, resulting in hardening behavior. A hardening fraction is defined to describe the deformation behavior quantitatively, which shows a positive correlation with the metadynamic recrystallization fraction. The metadynamic recrystallization leads to grain growth at the inter pass holding stage, diminishing dynamic recrystallization nucleation positions in the second pass deformation.
基金the National Natural Science Foundation of China(Nos.51601112,51701117)the Shanghai Rising-Star Program(No.17QB1403000)。
文摘Hot shear spinning experiments with Mg–3.0 Al–1.0 Zn–0.5 Mn(AZ31 B, wt%) magnesium alloy sheets were conducted at various temperatures, spindle speeds and feed ratios to investigate the effects of these processing parameters on the microstructure, crystallographic texture and mechanical properties. The AZ31 B sheet displayed good shear formability at temperatures from 473 to 673 K, spindle speeds from 300 to 600 rev/min and feed ratios from 0.1 to 0.5 mm/rev. During the dynamic recrystallization process, the grain size and texture were affected by the deformation temperature of the hot shear spinning process. Each of the spun sheets presented a strong basal texture, and the c-axis of most of the grains was parallel to the normal direction. The optimal hot shear spinning parameters were determined to be a temperature of 473 K, a spindle speed of 300 rev/min and a feed ratio of 0.1 mm/rev. The yield strength, ultimate tensile strength and elongation in the rolled direction reached 221 MPa, 288 MPa and 14.1%, and those in the transverse direction reached 205 MPa, 280 MPa and 12.4%, respectively. The improved strength and decreased mechanical anisotropy resulted from the fine grain size and strong basal texture.
基金financial supports of the National Key Research and Development Plan(Grant No.2016YFB0701201)the National Natural Science Foundation of China(Grant No.51771109,No.51631006)。
文摘The laminate structure was applied to improve the mechanical properties of Mg-8.0 Gd-3.0 Y-0.5 Zr alloys.Two types of laminate structures only with different distribution positions of fine grains were produced by friction-stir processing.Results show that the trilayer structure sample exhibits an excellent strengthductility synergy compared to the homogenous structure and bilayer structure.The enhanced mechanical properties are resulted from the hetero-deformation induced(HDI)stress strengthening and strain hardening which would be enhanced by increasing the quantity of interface.These observations suggest a crucial role of the number of interfaces in designing the laminate structure.
基金the financial support from the National Natural Science Foundation of China(22005273,21825106 and 21671175)the Natural Science Foundation of Henan Province(222300420258)+3 种基金the Scientific and Technological Research Project in Henan Province(222102240065 and 212102210647)the Key scientific research projects of colleges and universities in Henan Province(No.22A530006)the Natural Science Foundation of Jiangsu Province(BK20220598)the Program for Science&Technology Innovative Research Team in University of Henan Province(20IRTSTHN007)。
文摘The utilization of non-noble metal catalysts with robust and highly efficient electrocatalytic activity for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)are extremely important for the large-scale implementation of renewable energy devices.Integration of bifunctional electrocatalysts on both anode and cathode electrodes remains a significant challenge.Herein,we report on a novel and facile strategy to construct the ordered and aligned MoS_(2)nanosheet-encapsulated metal–organic frameworks(MOFs)derived hollow CoS polyhedron,in-situ grown on a nickel foam(NF).The starfish-like MoS_(2)/CoS/NF heterojunctions were formed due to the ordered growth of the material caused by NF substrate.The optimized 2-MoS_(2)/CoS/NF heterojunction exhibits robust bifunctional electrocatalytic activity with a low overpotential of 67 and 207 m V toward the HER and OER at 10 mA cm^(-2),and the long-term stability,which exceeds most of the reported bifunctional electrocatalysts.Such high electrocatalytic performance arises due to the synergistic effect between the MoS_(2)and CoS phases across the interface,the abundant active sites,as well as the hierarchical pore framework,which collectively enhance the mass and electron transfer during the reactions.The work provides a promising approach to fabricating bifunctional catalysts with custom-designed heterojunctions and remarkable performance for applications in electrochemical energy devices and related areas.
基金supported in part by the National Natural Science Foundation of China(61573198)in part by the National High-tech R&D Program of China(863 Program)(2012AA041403)
文摘In this paper, the torque tracking control problem for a class of series elastic actuators(SEAs) in the presence of unknown payload parameters and external disturbances is investigated. The uncertainties/disturbances rejection problem for SEAs is addressed from the view of a continuous nonlinear robust control development. Specifically, based on the analysis of a nonlinear SEA, the generic dynamics of SEA systems is described and a novel nonlinear control framework for SEAs is constructed. Then a RISE(robust integral of the sign of the error)-based second-order filter is introduced to synthesize the control law. Moreover, the control performance is theoretically ensured by Lyapunov analysis. Finally, some experimental results are included to demonstrate the superior performance of the proposed control method, in terms of transient response and robustness.
基金supported by the Anhui Provincial Key Research and Development Program No.2022f04020008National Natural Science Foundation of China No.62301522Anhui Provincial Nature Science Foundation No.1908085MF196.
文摘This paper introduces a self-sensing anthropomorphic robot hand driven by Twisted String Actuators(TSAs).The use of TSAs provides several advantages such as muscle-like structures,high transmission ratios,large output forces,high efficiency,compactness,inherent compliance,and the ability to transmit power over distances.However,conventional sensors used in TSA-actuated robotic hands increase stiffness,mass,volume,and complexity,making feedback control challenging.To address this issue,a novel self-sensing approach is proposed using strain-sensing string based on Conductive Polymer Composite(CPC).By measuring the resistance changes in the strain-sensing string,the bending angle of the robot hand's fingers can be estimated,enabling closed-loop control without external sensors.The developed self-sensing anthropomorphic robot hand comprises a 3D-printed structure with five fingers,a palm,five self-sensing TSAs,and a 3D-printed forearm.Experimental studies validate the self-sensing properties of the TSA and the anthropomorphic robot hand.Additionally,a real-time Virtual Reality(VR)monitoring system is implemented for visualizing and monitoring the robot hand's movements using its self-sensing capabilities.This research contributes valuable insights and advancements to the field of intelligent prosthetics and robotic end grippers.
基金supports of the National Natural Science Foundation of China (Nos.U2241231 and 51631006).
文摘This paper provides a comprehensive review of research progress in particle-reinforced Mg matrix composites prepared via powder metallurgy.The article discusses different strategies,such as micro-sized,nano-sized particles,and multi-particle hybridization,which has been employed to enhance the performance of the composites.In addition,a range of preparation techniques that optimize the dispersion of the reinforcing particles are summarized.The paper also highlights how the different configurations between the reinforcements and matrix alloy impact the composites’performance.Finally,the article outlines the prospects of particles reinforced Mg matrix composites fabricated via powder metallurgy and recommends modification methods that could be explored to further develop these materials for various applications.
基金the National Natural Science Foundation-Youth Science Foundation Project(No.51901208)the Henan University Key Scientific Research Project(No.20B430020)+1 种基金the Key Scientific and Technological Projects in Henan Province(Nos.202102210016,202102210272)the Major Innovation Project of Zhengzhou City(No.23101000010).
文摘A quantitative multi-phase-field model for non-isothermal and polycrystalline solidification was developed and applied to dilute multicomponent alloys with hexagonal close-packed structures.The effects of Lewis coefficient and undercooling on dendrite growth were investigated systematically.Results show that large Lewis coefficients facilitate the release of the latent heat,which can accelerate the dendrite growth while suppress the dendrite tip radius.The greater the initial undercooling,the stronger the driving force for dendrite growth,the faster the growth rate of dendrites,the higher the solid fraction,and the more serious the solute microsegregation.The simulated dendrite growth dynamics are consistent with predictions from the phenomenological theory but significantly deviate from the classical JMAK theory which neglects the soft collision effect and mutual blocking among dendrites.Finally,taking the Mg-6Gd-2Zn(wt.%)alloy as an example,the simulated dendrite morphology shows good agreement with experimental results.
基金supported by grants from the National Natural Science Foundation of China(82274039,U19A2010)the Key R&D Plan of Science and Technology Department of Sichuan Province(2021YFYZ0012-5,2020YFN0152)+2 种基金the Sichuan Provincial Central Guiding Local Science and Technology Development Special Project(2020ZYD058)the Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine(ZYYCXTD-D-202209)the Xinglin Talent Program of Chengdu University of TCM(0300510007).
文摘Safflower(Carthamus tinctorius)is widely cultivated around the world for its seeds and flowers.The presence of linoleic acid(LA)in its seeds and hydroxysafflor yellow A(HSYA)in its flowers are the crucial traits that enable safflower to be used for industrial and medicinal purposes.Understanding the genetic control of these traits is essential for optimizing the quality of safflower and its breeding.To further this research,we present a chromosome-scale assembly of the genome of the safflower variety‘Chuanhonghua 1’,which was achieved using an integrated strategy combining Illumina,Oxford Nanopore,and Hi-C sequencing.We obtained a 1.17-Gb assembly with a contig N50 of 1.08 Mb,and all assembled sequences were assigned to 12 pseudochromosomes.Safflower’s evolution involved the core eudicotγ-triplication event and a whole-genome duplication event,which led to large-scale genomic rearrangements.Extensive genomic shuffling has occurred since the divergence of the ancestor of dicotyledons.We conducted metabolite and transcriptome profiles with time-and part-dependent changes and screened candidate genes that significantly contribute to seed lipid biosynthesis.We also analyzed key gene families that participate in LA and HSYA biosynthesis.Additionally,we re-sequenced 220 safflower lines and carried out a genome-wide association study using high-quality SNP data for eight agronomic traits.We identified SNPs related to important traits in safflower.Besides,the candidate gene HH_034464(CtCGT1)was shown to be involved in the biosynthesis of HSYA.Overall,we provide a high-quality reference genome and elucidate the genetic basis of LA and HSYA biosynthesis in safflower.This vast amount of data will benefit further research for functional gene mining and breeding in safflower.
基金Supported by the Science and Technology Development Plan of Jilin Province,China (20100641)Doctor Foundation of Northeast Dianli University (BSJXM-201002)
文摘Firstly, the distribution of main biomass resources （like straw, livestock manure and forestry residue） in counties of Jilin Province, and then according to the annual output of biomass in each county, the energy regeneration of biomass and project distribution of organic fertilizer were studied, finally the direct economic effect and environmental effect of biomass developed recently were calculated.
基金Project supported by the National Natural Science Foundation of China(Nos.11202087,11472120 and 11421062)the National Key Project of Magneto-Constrained Fusion Energy Development Program(No.2013GB110002)+1 种基金the National Key Project of Scientific Instrument and Equipment Development(No.11327802)New Century Excellent Talents in University of Ministry of Education of China(NCET-13-0266)
文摘A theoretical model is proposed to calculate the internal contact distributions and contact forces of a 3×4×4×4 twisted NbSn cable under applied axial strain.The critical current density reduction of the whole cable can be calculated.The thin rod theory is employed to analyze the mechanical behavior of each strand.According to the regular helical structure,the contact distribution of each strand is obtained,and the contact force in the cable is analyzed.At last,a prediction about the critical current density of the twisted cable is made.The results show that decreasing the pitch length can reduce the contact forces between strands.
基金Supported by the National Natural Science Foundation of China,No.81803160.
文摘BACKGROUND Renal clear cell carcinoma(RCC)is a malignant tumor of the genitourinary system with a predilection for males.The most common metastatic sites are the lung,liver,lymph nodes,contralateral kidney or adrenal gland,however,skin metastasis has only been seen in 1.0%-3.3%of cases.The most common site of skin metastasis is the scalp,and metastasis to the nasal ala region is rare.CASE SUMMARY A 55-year-old man with clear cell carcinoma of the left kidney was treated with pembrolizumab and axitinib for half a year after surgery and was found to have a red mass on his right nasal ala for 3 mo.The skin lesion of the patient grew rapidly to the size of 2.0 cm×2.0 cm×1.2 cm after discontinuation of targeted drug therapy due to the coronavirus disease 2019 epidemic.The patient was finally diagnosed with skin metastasis of RCC in our hospital.The patient refused to undergo surgical resection and the tumor shrank rapidly after resuming target therapy for 2 wk.CONCLUSION It is rare for an RCC to metastasize to the skin of the nasal ala region.The tumor size change of this patient before and after treatment with targeted drugs shows the effectiveness of combination therapy for skin metastasis.
基金Supported by National Natural Science Foundation of China,No.81803160.
文摘BACKGROUND Lichen planus(LP)with distribution of lesions along Blaschko’s lines is a rare entity,accounting for 0.24%-0.62%of all patients.Unilateral distribution of lesions in arm,leg,trunk,and waist is even less common.Approximately 10%of patients with LP manifest nail lesions.CASE SUMMARY A 20-year-old woman presented to our department with polygonal,purpuric,flattopped papules over the right arm,right leg,and right side of trunk and waist for the last 5 mo.The patient initially developed nail deformation in the left middle finger with no obvious cause,followed by development of blue-purple and red maculopapular rash with pruritus.During the disease course,the skin lesions aggravated and spread to several segments due to scratching.The lesions showed unilateral distribution along the Blaschko’s lines.The diagnosis of LP along Blaschko’s lines was established based on dermoscopy and skin biopsy.Her cutaneous lesions considerably improved after 4-wk treatment with intramuscular glucocorticoid,oral acitretin,topical glucocorticoid,and retinoids.CONCLUSION Cases of LP involving multiple segments of the body along the Blaschko’s lines with nail damage are rare.
