Transforming growth factor-beta 1(TGF-β1)has been extensively studied for its pleiotropic effects on central nervous system diseases.The neuroprotective or neurotoxic effects of TGF-β1 in specific brain areas may de...Transforming growth factor-beta 1(TGF-β1)has been extensively studied for its pleiotropic effects on central nervous system diseases.The neuroprotective or neurotoxic effects of TGF-β1 in specific brain areas may depend on the pathological process and cell types involved.Voltage-gated sodium channels(VGSCs)are essential ion channels for the generation of action potentials in neurons,and are involved in various neuroexcitation-related diseases.However,the effects of TGF-β1 on the functional properties of VGSCs and firing properties in cortical neurons remain unclear.In this study,we investigated the effects of TGF-β1 on VGSC function and firing properties in primary cortical neurons from mice.We found that TGF-β1 increased VGSC current density in a dose-and time-dependent manner,which was attributable to the upregulation of Nav1.3 expression.Increased VGSC current density and Nav1.3 expression were significantly abolished by preincubation with inhibitors of mitogen-activated protein kinase kinase(PD98059),p38 mitogen-activated protein kinase(SB203580),and Jun NH2-terminal kinase 1/2 inhibitor(SP600125).Interestingly,TGF-β1 significantly increased the firing threshold of action potentials but did not change their firing rate in cortical neurons.These findings suggest that TGF-β1 can increase Nav1.3 expression through activation of the ERK1/2-JNK-MAPK pathway,which leads to a decrease in the firing threshold of action potentials in cortical neurons under pathological conditions.Thus,this contributes to the occurrence and progression of neuroexcitatory-related diseases of the central nervous system.展开更多
Hydrogen-based mineral phase transformation(HMPT)technology has demonstrated its effectiveness in separating iron and enriching rare earths from Bayan Obo refractory ores.However,further research is needed to clarify ...Hydrogen-based mineral phase transformation(HMPT)technology has demonstrated its effectiveness in separating iron and enriching rare earths from Bayan Obo refractory ores.However,further research is needed to clarify the phase composition and floatability of rare earths obtained after HMPT owing to the associated phase transformations.This study explored the mineralogical characteristics and separation behavior of rare earths in HMPT-treated iron tailings.Process mineralogy studies conducted via BGRIMM process mineralogy analysis and X-ray diffraction revealed that the main valuable minerals in the tailings included rare-earth oxides(9.15wt%),monazite(5.31wt%),and fluorite(23.52wt%).The study also examined the impact of mineral liberation and gangue mineral intergrowth on flotation performance.Flotation tests achieved a rare-earth oxide(REO)grade of 74.12wt% with a recovery of 34.17% in open-circuit flotation,whereas closed-circuit flotation resulted in a REO grade of 60.27wt% with a recovery of 73%.Transmission electron microscopy and scanning electron microscopy coupled with energy-dispersive spectroscopy revealed that monazite remained stable during the HMPT process,while bastnaesite was transformed into Ce_(7)O_(12)and CeF_(3),leading to increased collector consumption.Nonetheless,the HMPT process did not significantly affect the flotation performance of rare earths.The enrichment of fluorite in the tailings highlighted its further recovery potential.The integration of HMPT with magnetic separation and flotation presents an efficient strategy for recovering rare earths,iron,and fluorite from Bayan Obo ores.展开更多
BACKGROUND Malignant transformation(MT)of mature cystic teratoma(MCT)has a poor prognosis,especially in advanced cases.Concurrent chemoradiotherapy(CCRT)has an inhibitory effect on MT.CASE SUMMARY Herein,we present a ...BACKGROUND Malignant transformation(MT)of mature cystic teratoma(MCT)has a poor prognosis,especially in advanced cases.Concurrent chemoradiotherapy(CCRT)has an inhibitory effect on MT.CASE SUMMARY Herein,we present a case in which CCRT had a reduction effect preoperatively.A 73-year-old woman with pyelonephritis was referred to our hospital.Computed tomography revealed right hydronephrosis and a 6-cm pelvic mass.Endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB)revealed squamous cell carci-noma.The patient was diagnosed with MT of MCT.Due to her poor general con-dition and renal malfunction,we selected CCRT,expecting fewer adverse effects.After CCRT,her performance status improved,and the tumor size was reduced;surgery was performed.Five months postoperatively,the patient developed dis-semination and lymph node metastases.Palliative chemotherapy was ineffective.She died 18 months after treatment initiation.CONCLUSION EUS-FNB was useful in the diagnosis of MT of MCT;CCRT suppressed the disea-se and improved quality of life.展开更多
Objective: To develop a best-evidence-based optimal nutrition management plan for patients with chronic heart failure, apply it in clinical practice, and evaluate its effectiveness. Methods: Use the KTA knowledge tran...Objective: To develop a best-evidence-based optimal nutrition management plan for patients with chronic heart failure, apply it in clinical practice, and evaluate its effectiveness. Methods: Use the KTA knowledge translation model to guide evidence-based practice in nutrition management, and compare the nutritional status, cardiac function status, quality of life, and quality review indicators of chronic heart failure patients before and after the application of evidence. Results: After the application of evidence, the nutritional status indicators (MNA-SF score, albumin, hemoglobin) of two groups of heart failure patients significantly increased compared to before the application of evidence, with statistically significant differences (p Conclusion: The KTA knowledge translation model provides methodological guidance for the implementation of evidence-based practice for heart failure patients. This evidence-based practice project is beneficial for improving the outcomes of malnutrition in chronic heart failure patients and is conducive to standardizing nursing pathways, thereby promoting the improvement of nursing quality.展开更多
Objective To predict the potential targets of Qingfu Juanbi Decoction(青附蠲痹汤,QFJBD)in treating rheumatoid arthritis(RA)using an improved Transformer model and investigate the network pharmacological mechanisms und...Objective To predict the potential targets of Qingfu Juanbi Decoction(青附蠲痹汤,QFJBD)in treating rheumatoid arthritis(RA)using an improved Transformer model and investigate the network pharmacological mechanisms underlying QFJBD’s therapeutic effects on RA.Methods First,a traditional Chinese medicine herb-target interaction(TCMHTI)model was constructed to predict herb-target interactions based on Transformer improvement.The per-formance of the TCMHTI model was evaluated against baseline models using three metrics:area under the receiver operating characteristic curve(AUC),precision-recall curve(PRC),and accuracy.Subsequently,a protein-protein interaction(PPI)network was built based on the predicted targets,with core targets identified as the top nine nodes ranked by degree val-ues.Gene Ontology(GO)functional and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analyses were performed using the targets predicted by TCMHTI and the targets identified through network pharmacology method for comparison.Then,the re-sults were compared.Finally,the core targets predicted by TCMHTI were validated through molecular docking and literature review.Results The TCMHTI model achieved an AUC of 0.883,PRC of 0.849,and accuracy of 0.818,predicting 49 potential targets for QFJBD in RA treatment.Nine core targets were identified:tumor necrosis factor(TNF)-α,interleukin(IL)-1β,IL-6,IL-10,IL-17A,cluster of differentia-tion 40(CD40),cytotoxic T-lymphocyte-associated protein 4(CTLA4),IL-4,and signal trans-ducer and activator of transcription 3(STAT3).The enrichment analysis demonstrated that the TCMHTI model predicted 49 targets and enriched more pathways directly associated with RA,whereas classical network pharmacology identified 64 targets but enriched pathways showing weaker relevance to RA.Molecular docking demonstrated that the active molecules in QFJBD exhibit favorable binding energy with RA targets,while literature research further revealed that QFJBD can treat RA through 9 core targets.Conclusion The TCMHTI model demonstrated greater accuracy than traditional network pharmacology methods,suggesting QFJBD exerts therapeutic effects on RA by regulating tar-gets like TNF-α,IL-1β,and IL-6,as well as multiple signaling pathways.This study provides a novel framework for bridging traditional herbal knowledge with precision medicine,offering actionable insights for developing targeted TCM therapies against diseases.展开更多
Thyroid nodules,a common disorder in the endocrine system,require accurate segmentation in ultrasound images for effective diagnosis and treatment.However,achieving precise segmentation remains a challenge due to vari...Thyroid nodules,a common disorder in the endocrine system,require accurate segmentation in ultrasound images for effective diagnosis and treatment.However,achieving precise segmentation remains a challenge due to various factors,including scattering noise,low contrast,and limited resolution in ultrasound images.Although existing segmentation models have made progress,they still suffer from several limitations,such as high error rates,low generalizability,overfitting,limited feature learning capability,etc.To address these challenges,this paper proposes a Multi-level Relation Transformer-based U-Net(MLRT-UNet)to improve thyroid nodule segmentation.The MLRTUNet leverages a novel Relation Transformer,which processes images at multiple scales,overcoming the limitations of traditional encoding methods.This transformer integrates both local and global features effectively through selfattention and cross-attention units,capturing intricate relationships within the data.The approach also introduces a Co-operative Transformer Fusion(CTF)module to combine multi-scale features from different encoding layers,enhancing the model’s ability to capture complex patterns in the data.Furthermore,the Relation Transformer block enhances long-distance dependencies during the decoding process,improving segmentation accuracy.Experimental results showthat the MLRT-UNet achieves high segmentation accuracy,reaching 98.2% on the Digital Database Thyroid Image(DDT)dataset,97.8% on the Thyroid Nodule 3493(TG3K)dataset,and 98.2% on the Thyroid Nodule3K(TN3K)dataset.These findings demonstrate that the proposed method significantly enhances the accuracy of thyroid nodule segmentation,addressing the limitations of existing models.展开更多
1.Introduction.Ni-Mn-X(X=Ga,In,Sn,or Sb)Heusler alloys have versatile properties[1-4],such as shape memory effect[1],superelastic-ity[5],magnetocaloric effect[3],elastocaloric effect[6],and even multicaloric effect[7]...1.Introduction.Ni-Mn-X(X=Ga,In,Sn,or Sb)Heusler alloys have versatile properties[1-4],such as shape memory effect[1],superelastic-ity[5],magnetocaloric effect[3],elastocaloric effect[6],and even multicaloric effect[7],that indicate their potential for use in actu-ators,sensors,micropumps,energy harvesters,and solid-state re-frigeration[8-10].Among the alloys,Ni-Mn-Sn-based alloys are environment-friendly and cost-effective[6,7,11],and hence,they have received widespread attention.展开更多
Large-scale damming has emerged as a prevalent global trend,significantly impacting nutrient transport and transformation,as well as the downstream ecological environment.Nitrogen and phosphorus are fundamental elemen...Large-scale damming has emerged as a prevalent global trend,significantly impacting nutrient transport and transformation,as well as the downstream ecological environment.Nitrogen and phosphorus are fundamental elements of primary productivity in aquatic ecosystems and serve as key limiting factors in reservoir eutrophication.This review focuses on the impact of damming on the transport and transformation of nitrogen and phosphorus,regarding changes in nutrient concentrations,fluxes,and proportions.Spatial changes in nitrogen and phosphorus concentrations primarily occur at the inlet and outlet of reservoirs,while temporal changes often exhibit seasonal patterns.At a global scale,phosphorus is preferentially removed from reservoirs compared to nitrogen.The factors influencing the transport and transformation processes of nitrogen and phosphorus in reservoirs include the physicochemical properties of water bodies and human activities.Additionally,nitrogen dynamics are affected by reservoir age,storage capacity,and water storage regulation modes,whereas phosphorus dynamics are also influenced by hydrodynamic conditions.Finally,this review summarizes the impact of damming on the downstream ecological environment and outlines future research directions,providing theoretical support for the management of river–reservoir ecosystems and promoting the green and sustainable development of hydropower in the context of carbon peaking and carbon neutrality goals.展开更多
BACKGROUND Acinar cystic transformation(ACT)of the pancreas is a rare non-neoplastic transformation of the pancreas.Adult women are the majority of patients with ACT,but few cases have been reported in pediatric patie...BACKGROUND Acinar cystic transformation(ACT)of the pancreas is a rare non-neoplastic transformation of the pancreas.Adult women are the majority of patients with ACT,but few cases have been reported in pediatric patients.Given that there are currently no guidelines for the treatment of ACT,current treatment is based primarily on expert opinions and clinical experiences.Here,we report the case of the youngest child with ACT to date.Additionally,a literature review on pediatric ACT cases was performed to summarize previous clinical experience and treatment methods.CASE SUMMARY A 1-year-old Chinese girl presented with progressive abdominal distension for 6 months.A detailed consultation revealed an uneventful history.The patient showed no signs of fever or abdominal pain and had a good appetite and normal feces.A mass of about 20 cm×10 cm×10 cm in size was detected in the abdomen.Both abdominal ultrasound and computed tomography examination revealed a multilocular cystic mass about 21.7 cm×16.8 cm×8.9 cm in size.At first,due to the large size and the possible retroperitoneal origin of the cyst,a total resection of the lesion was not possible.A single-port laparoscopic lymphangioma puncture and Pingyangmycin injection were performed in March 2023.One month after surgery,the abdominal cyst rapidly enlarged to its pre-operative size.After consulting with the experts in the angiology department and interventional department,sclerotherapy combined with oral sirolimus was performed in May 2023.After confirming that the tumor was not sensitive to sclerotherapy combined with oral sirolimus,our surgical team performed tumor reduction in August 2023.This surgery confirmed that the polycystic mass originated from the head of the pancreas,and pathological and immunohistochemical findings diagnosed pancreatic ACT.The patient showed no signs of cyst lesions after 6 months of follow-up and remains in good health up to the time of this report.CONCLUSION ACT is a rare non-neoplastic transformation of the pancreas,more rarely seen in children.Manifestation and examinations show no specificity for diagnosis,and final diagnosis is mainly based on histological findings.To reach a specific diagnosis and rule out malignancy is a priority in clinical practice,and repeated biopsy or radical surgery should be considered before malignancy is ruled out.However,once a diagnosis of ACT is made,a conser-vative treatment with consecutive follow-up is recommended until symptoms present or obvious enlargement occurs because ACT is considered a slow-growing and benign tumor.展开更多
In-situ high-resolution transmission electron microscopy(HRTEM)is performed to investigate the de-formation behavior of hexagonal close-packed rhenium(Re)which is compressed along the{1-100}di-rection.Atomistic simula...In-situ high-resolution transmission electron microscopy(HRTEM)is performed to investigate the de-formation behavior of hexagonal close-packed rhenium(Re)which is compressed along the{1-100}di-rection.Atomistic simulations are also conducted to better understand the deformation mechanisms.Two types of lattice reorientation are observed during compression.The first type involves the reori-entation of one lattice by∼90°around{11-20},which is accomplished by the formation of an interme-diate face-center-cubic(FCC)phase at the interface.This transformation sequence can be described as{1-100}matrix→{111}FCC→(0001)twin.In the second type,a new grain is formed but does not satisfy any known twin relationship with the matrix,and an intermediate FCC phase is also formed.The transfor-mation sequence can be described as{1¯101}matrix→{111}FCC→(0001)grain.Mechanisms responsible for the observed lattice reorientation and sequential phase transitions are analyzed by conducting lattice correspondence analyses on the simulation results.Strain accommodation is also analyzed to explain the mechanisms for lattice reorientation and the intermediate phase transformations.The results provide new insight into the deformation behavior of HCP metals.展开更多
The rapid advancement of Artificial Intelligence(AI)and automation has significantly transformed the accounting profession,shifting the role of accountants from routine data processors to strategic decision makers and...The rapid advancement of Artificial Intelligence(AI)and automation has significantly transformed the accounting profession,shifting the role of accountants from routine data processors to strategic decision makers and ethical stewards of technology.This conceptual study explores how AI and automation are reshaping accounting tasks,transforming required competencies,and redefining professional responsibilities.By analyzing relevant literature and theoretical frameworks,this paper identifies the evolving skill sets,both technical such as data analytics and AI literacy,and nontechnical such as critical thinking and ethical judgment,that are essential for modern accountants.The study also emphasizes the importance of continuous education,ethical integrity,and adaptive learning in navigating the digital transformation of accounting.Ultimately,this paper contributes to a deeper understanding of how accountants can maintain relevance and add value in an increasingly automated and data driven environment.展开更多
In sulfidic anoxic environments,iron sulfides are widespread solid phases that play an important role in the arsenic(As)biogeochemical cycle.This work investigated the transformation process of FeS-As coprecipitates,t...In sulfidic anoxic environments,iron sulfides are widespread solid phases that play an important role in the arsenic(As)biogeochemical cycle.This work investigated the transformation process of FeS-As coprecipitates,the concurrent behavior,and the speciation of associated As under anoxic conditions.The results showed that FeS-As coprecipitates could convert to greigite and pyrite.The transformation degree of the produced solid phases was dependent upon the pH conditions and initial As species.These results showed that the As mobilization was closely associated with the solid phase transformation.The solid phase transformationwent from disordered mackinawite to crystallinemackinawite,then greigite and finally pyrite.The As in the coprecipitates underwent a process of release,fixation,and release again.Both reduction of As(Ⅴ)and oxidation of As(Ⅲ)were observed in the aqueous and solid phases during reactions.Our study may have important implications for further understanding of As behavior and Fe/S cycling thatmay occur under an anoxic environment more comprehensively.展开更多
(Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4))_(100−x)Al_(x)(x=0,0.1,0.2,0.3,0.4 at.%)lightweight high-entropy alloys with different contents of Al were prepared via vacuum non-consumable arc melting method.Effects of adding varying...(Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4))_(100−x)Al_(x)(x=0,0.1,0.2,0.3,0.4 at.%)lightweight high-entropy alloys with different contents of Al were prepared via vacuum non-consumable arc melting method.Effects of adding varying Al contents on phase constitution,microstructure characteristics and mechanical properties of the lightweight alloys were studied.Results show that Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4)alloy is composed of body-centered cubic(BCC)phase and C15 Laves phase,while(Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4))_(100−x)Al_(x)lightweight high-entropy alloys by addition of Al are composed of BCC phase and C14 Laves phase.Addition of Al into Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4)lightweight high-entropy alloy can transform C15 Laves phase to C14 Laves phase.With further addition of Al,BCC phase of alloys is significantly refined,and the volume fraction of C14 Laves phase is raised obviously.Meanwhile,the dimension of BCC phase in the alloy by addition of 0.3 at.%Al is the most refined and that of Laves phase is also obviously refined.Adding Al to Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4)alloy can not only reduce the density of(Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4))_(100−x)Al_(x)alloy,but also improve strength of(Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4))_(100−x)Al_(x)alloy.As Al content increased from 0 to 0.4 at.%,the density of the alloy decreased from 6.22±0.875 to 5.79±0.679 g cm^(−3).Moreover,compressive strength of the alloy by 0.3 at.%Al addition is the highest to 1996.9 MPa,while fracture strain of the alloy is 16.82%.Strength improvement of alloys mainly results from microstructure refinement and precipitation of C14 Laves by Al addition into Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4)lightweight high-entropy alloy.展开更多
Purpose–This paper aims to provide a comprehensive analysis of the strategic adjustments in China’s transportation structure,with a particular focus on the pivotal role of railway freight and its integration into th...Purpose–This paper aims to provide a comprehensive analysis of the strategic adjustments in China’s transportation structure,with a particular focus on the pivotal role of railway freight and its integration into the modern logistics system.It seeks to address the need for a more nuanced understanding of the“road to rail”policy,emphasizing the importance of intermodal collaboration and service of fragmented market demands.Design/methodology/approach–The study employs a transport economics perspective to evaluate the achievements and shortcomings of China’s transportation structure optimization.It bases its assessment of the current state of railway freight logistics,multi-modal transportation and the broader implications for the transportation service market on data analysis.The methodology includes a review of existing policies,an examination of industry practices and a comparative analysis with global trends in railway logistics.Findings–The research underscores the importance of focusing on the development of non-bulk materials,noting the insufficiency in the development of China’s rail multi-modal transportation and highlighting the instructive value of successful cases in open-top container road-rail intermodal transportation.The study posits that the railway sector must enhance cooperation with other market entities,aligning with the lead enterprises in the logistics chain that are characterized by speed,high value and strong coordination capabilities,in order to better serve the transportation market.This approach moves away from a reliance on the railway’s own capabilities alone.Originality/value–This paper offers original insights into the transformation of railway freight in China,contributing to the body of knowledge on transportation economics and logistics.It provides valuable recommendations for policymakers and industry practitioners,emphasizing the strategic importance of railway logistics in the context of China’s economic development and intense competition in the supply chain.The value of the article lies in its comprehensive understanding of the complexities involved in the adjustment of transportation structures,providing direction for the market-oriented reform of China’s railway freight sector.展开更多
The aim of this paper is to study an extended modified Korteweg-de Vries-Calogero-Bogoyavlenskii-Schiff(mKdV-CBS)equation and present its Lax pair with a spectral parameter.Meanwhile,a Miura transformation is explored...The aim of this paper is to study an extended modified Korteweg-de Vries-Calogero-Bogoyavlenskii-Schiff(mKdV-CBS)equation and present its Lax pair with a spectral parameter.Meanwhile,a Miura transformation is explored,which reveals the relationship between solutions of the extended mKdV-CBS equation and the extended(2+1)-dimensional Korteweg-de Vries(KdV)equation.On the basis of the obtained Lax pair and the existing research results,the Darboux transformation is derived,which plays a crucial role in presenting soliton solutions.In addition,soliton molecules are given by the velocity resonance mechanism.展开更多
Maraging steels are known for their exceptional strength but suffer from limited work hardening and ductility.Here,we report an intermittent printing strategy to tailor the microstructure and mechanical properties of ...Maraging steels are known for their exceptional strength but suffer from limited work hardening and ductility.Here,we report an intermittent printing strategy to tailor the microstructure and mechanical properties of maraging 250 steel via tuning the thermal history during wire-arc directed energy deposition.By introducing a dwell time between adjacent layers,the maraging 250 steel is cooled below the martensite start temperature,triggering thermally-driven martensitic transformation during the printing process.Thermal cycling during subsequent layer deposition results in the formation of reverted austenite which shows a refined microstructure and induces elemental segregation between martensite and reverted austenite.The Ni enrichment in the austenite promotes stabilization of the reverted austenite upon cooling to room temperature.The reverted austenite is metastable during deformation,leading to strain-induced martensitic transformation under loading.Specifically,a 3 min interlayer dwell time produces a maraging 250 steel with approximately 8% reverted austenite,resulting in improved work hardening via martensitic transformation induced plasticity during deformation.Meanwhile,the higher cooling rate and refined prior austenite grains lead to substantially refined martensitic grains(by approximately fivefold)together with an increased dislocation density.With 3 min interlayer dwell time,the yield strength of the printed maraging 250 steel increases from 836 MPa to 990 MPa,and the uniform elongation is doubled from 3.2% to 6.5%.This intermittent deposition strategy demonstrates the potential to tune the microstructure of maraging steels for achieving strength-ductility synergy by engineering the thermal history during additive manufacturing.展开更多
In the present study,molecular dynamic simulation(MD)was used to investigate the plastic deformation process of the Fe-Mn alloys with different Mn contents.The influences of Mn contents ranging from 10%to 30%(at%)on t...In the present study,molecular dynamic simulation(MD)was used to investigate the plastic deformation process of the Fe-Mn alloys with different Mn contents.The influences of Mn contents ranging from 10%to 30%(at%)on the deformation behavior and the controlling mechanism of the Fe-base alloys were analyzed.The results show that phase transformations and{112}<111>_(BCC)deformation twinning occur in all Fe-Mn alloys but follow different deformation paths.In the Fe-10%Mn alloy the deformation twinning mechanism obeys the FCC-related path,the Fe-20%Mn alloy involves both the FCC-and HCP-related paths,and the deformation of the Fe-30%Mn alloy is dominated by the HCP-related twinning path.The addition of Mn can increase the stacking fault energy and retard the activation of slip systems as well as the formation of stacking faults.Thus,a higher content of Mn can delay the FCC®ε-martensite and the subsequentε-martensite®BCC phase transition at the intersection of twoε-martensitic bands.Therefore,the addition of Mn alloying element increases the yield strength and reduces the elastic modulus of the Fe-Mn alloys.The formation of deformation twins will contribute to the work-hardening effect and delay the necking and fracture of alloys.It is expected that the results in the present study will provide theoretical reference for the design and optimization of high-performance steels.展开更多
Liquefied natural gas storage and transportation as well as space propulsion systems have sparked inter-est in the martensitic transformation and behaviours of 316 L stainless steels(SS)under ultra-cryogenic deformati...Liquefied natural gas storage and transportation as well as space propulsion systems have sparked inter-est in the martensitic transformation and behaviours of 316 L stainless steels(SS)under ultra-cryogenic deformation.In this study,high-resolution transmission electron microscopy(HRTEM)and molecular dy-namics(MD)simulations were used to investigate the atomic arrangements and crystalline defects of deformation-induced γ-austenite→ε-martensite→α'-martensite and γ→α'martensitic transforma-tions in 316 L SS at 15 and 173 K.Theγ→εtransformation involves the glide of Shockley partial dislocations on(111)γplanes without a change in atomic spacing.The formation of anα'inclusion in a singleε-band is achieved by a continuous lattice distortion,accompanied by the formation of a tran-sition zone ofα'and the expansion of the average atomic spacings due to dislocation shuffling.Asα'grows further intoγ,the orientation relationship(OR)of theα'changes by lattice bending.This pro-cess follows the Bogers-Burgers-Olson-Cohen model despite it not occurring on intersecting shear bands.Stacking faults and twins can also serve as nucleation sites forα'at 173 K.We also found that direct transformation of γ→α'occurs by the glide of √6aγ[11(2)]/12 dislocations on every(111)γplane with misfit dislocations.Overall,this study provides,for the first time,insights into the atomic-scale mech-anisms of various two-step and one-step martensitic transformations induced by cryogenic deformation and corresponding local strain,enhancing our understanding of the role of martensitic transformation under ultra-cryogenic-temperature deformation in controlling the properties.展开更多
基金supported by the Natural Science Foundation of Guangdong Province,Nos.2019A1515010649(to WC),2022A1515012044(to JS)the China Postdoctoral Science Foundation,No.2018M633091(to JS).
文摘Transforming growth factor-beta 1(TGF-β1)has been extensively studied for its pleiotropic effects on central nervous system diseases.The neuroprotective or neurotoxic effects of TGF-β1 in specific brain areas may depend on the pathological process and cell types involved.Voltage-gated sodium channels(VGSCs)are essential ion channels for the generation of action potentials in neurons,and are involved in various neuroexcitation-related diseases.However,the effects of TGF-β1 on the functional properties of VGSCs and firing properties in cortical neurons remain unclear.In this study,we investigated the effects of TGF-β1 on VGSC function and firing properties in primary cortical neurons from mice.We found that TGF-β1 increased VGSC current density in a dose-and time-dependent manner,which was attributable to the upregulation of Nav1.3 expression.Increased VGSC current density and Nav1.3 expression were significantly abolished by preincubation with inhibitors of mitogen-activated protein kinase kinase(PD98059),p38 mitogen-activated protein kinase(SB203580),and Jun NH2-terminal kinase 1/2 inhibitor(SP600125).Interestingly,TGF-β1 significantly increased the firing threshold of action potentials but did not change their firing rate in cortical neurons.These findings suggest that TGF-β1 can increase Nav1.3 expression through activation of the ERK1/2-JNK-MAPK pathway,which leads to a decrease in the firing threshold of action potentials in cortical neurons under pathological conditions.Thus,this contributes to the occurrence and progression of neuroexcitatory-related diseases of the central nervous system.
基金the financial support received from the Key Program of National Natural Science Foundation of China(No.52130406)the National Key R&D Program of China(Nos.2021YFC2901000 and 2022YFC2905800)+1 种基金the General Program of National Natural Science Foundation of China(No.52274253)Natural Science Foundation Innovation Group Project of Hubei Province,China(No.2023AFA044)。
文摘Hydrogen-based mineral phase transformation(HMPT)technology has demonstrated its effectiveness in separating iron and enriching rare earths from Bayan Obo refractory ores.However,further research is needed to clarify the phase composition and floatability of rare earths obtained after HMPT owing to the associated phase transformations.This study explored the mineralogical characteristics and separation behavior of rare earths in HMPT-treated iron tailings.Process mineralogy studies conducted via BGRIMM process mineralogy analysis and X-ray diffraction revealed that the main valuable minerals in the tailings included rare-earth oxides(9.15wt%),monazite(5.31wt%),and fluorite(23.52wt%).The study also examined the impact of mineral liberation and gangue mineral intergrowth on flotation performance.Flotation tests achieved a rare-earth oxide(REO)grade of 74.12wt% with a recovery of 34.17% in open-circuit flotation,whereas closed-circuit flotation resulted in a REO grade of 60.27wt% with a recovery of 73%.Transmission electron microscopy and scanning electron microscopy coupled with energy-dispersive spectroscopy revealed that monazite remained stable during the HMPT process,while bastnaesite was transformed into Ce_(7)O_(12)and CeF_(3),leading to increased collector consumption.Nonetheless,the HMPT process did not significantly affect the flotation performance of rare earths.The enrichment of fluorite in the tailings highlighted its further recovery potential.The integration of HMPT with magnetic separation and flotation presents an efficient strategy for recovering rare earths,iron,and fluorite from Bayan Obo ores.
文摘BACKGROUND Malignant transformation(MT)of mature cystic teratoma(MCT)has a poor prognosis,especially in advanced cases.Concurrent chemoradiotherapy(CCRT)has an inhibitory effect on MT.CASE SUMMARY Herein,we present a case in which CCRT had a reduction effect preoperatively.A 73-year-old woman with pyelonephritis was referred to our hospital.Computed tomography revealed right hydronephrosis and a 6-cm pelvic mass.Endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB)revealed squamous cell carci-noma.The patient was diagnosed with MT of MCT.Due to her poor general con-dition and renal malfunction,we selected CCRT,expecting fewer adverse effects.After CCRT,her performance status improved,and the tumor size was reduced;surgery was performed.Five months postoperatively,the patient developed dis-semination and lymph node metastases.Palliative chemotherapy was ineffective.She died 18 months after treatment initiation.CONCLUSION EUS-FNB was useful in the diagnosis of MT of MCT;CCRT suppressed the disea-se and improved quality of life.
文摘Objective: To develop a best-evidence-based optimal nutrition management plan for patients with chronic heart failure, apply it in clinical practice, and evaluate its effectiveness. Methods: Use the KTA knowledge translation model to guide evidence-based practice in nutrition management, and compare the nutritional status, cardiac function status, quality of life, and quality review indicators of chronic heart failure patients before and after the application of evidence. Results: After the application of evidence, the nutritional status indicators (MNA-SF score, albumin, hemoglobin) of two groups of heart failure patients significantly increased compared to before the application of evidence, with statistically significant differences (p Conclusion: The KTA knowledge translation model provides methodological guidance for the implementation of evidence-based practice for heart failure patients. This evidence-based practice project is beneficial for improving the outcomes of malnutrition in chronic heart failure patients and is conducive to standardizing nursing pathways, thereby promoting the improvement of nursing quality.
基金General Program of the National Natural Science Foundation of China (82474352)Natural Science Foundation of Hunan Province (2023JJ60124)。
文摘Objective To predict the potential targets of Qingfu Juanbi Decoction(青附蠲痹汤,QFJBD)in treating rheumatoid arthritis(RA)using an improved Transformer model and investigate the network pharmacological mechanisms underlying QFJBD’s therapeutic effects on RA.Methods First,a traditional Chinese medicine herb-target interaction(TCMHTI)model was constructed to predict herb-target interactions based on Transformer improvement.The per-formance of the TCMHTI model was evaluated against baseline models using three metrics:area under the receiver operating characteristic curve(AUC),precision-recall curve(PRC),and accuracy.Subsequently,a protein-protein interaction(PPI)network was built based on the predicted targets,with core targets identified as the top nine nodes ranked by degree val-ues.Gene Ontology(GO)functional and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analyses were performed using the targets predicted by TCMHTI and the targets identified through network pharmacology method for comparison.Then,the re-sults were compared.Finally,the core targets predicted by TCMHTI were validated through molecular docking and literature review.Results The TCMHTI model achieved an AUC of 0.883,PRC of 0.849,and accuracy of 0.818,predicting 49 potential targets for QFJBD in RA treatment.Nine core targets were identified:tumor necrosis factor(TNF)-α,interleukin(IL)-1β,IL-6,IL-10,IL-17A,cluster of differentia-tion 40(CD40),cytotoxic T-lymphocyte-associated protein 4(CTLA4),IL-4,and signal trans-ducer and activator of transcription 3(STAT3).The enrichment analysis demonstrated that the TCMHTI model predicted 49 targets and enriched more pathways directly associated with RA,whereas classical network pharmacology identified 64 targets but enriched pathways showing weaker relevance to RA.Molecular docking demonstrated that the active molecules in QFJBD exhibit favorable binding energy with RA targets,while literature research further revealed that QFJBD can treat RA through 9 core targets.Conclusion The TCMHTI model demonstrated greater accuracy than traditional network pharmacology methods,suggesting QFJBD exerts therapeutic effects on RA by regulating tar-gets like TNF-α,IL-1β,and IL-6,as well as multiple signaling pathways.This study provides a novel framework for bridging traditional herbal knowledge with precision medicine,offering actionable insights for developing targeted TCM therapies against diseases.
文摘Thyroid nodules,a common disorder in the endocrine system,require accurate segmentation in ultrasound images for effective diagnosis and treatment.However,achieving precise segmentation remains a challenge due to various factors,including scattering noise,low contrast,and limited resolution in ultrasound images.Although existing segmentation models have made progress,they still suffer from several limitations,such as high error rates,low generalizability,overfitting,limited feature learning capability,etc.To address these challenges,this paper proposes a Multi-level Relation Transformer-based U-Net(MLRT-UNet)to improve thyroid nodule segmentation.The MLRTUNet leverages a novel Relation Transformer,which processes images at multiple scales,overcoming the limitations of traditional encoding methods.This transformer integrates both local and global features effectively through selfattention and cross-attention units,capturing intricate relationships within the data.The approach also introduces a Co-operative Transformer Fusion(CTF)module to combine multi-scale features from different encoding layers,enhancing the model’s ability to capture complex patterns in the data.Furthermore,the Relation Transformer block enhances long-distance dependencies during the decoding process,improving segmentation accuracy.Experimental results showthat the MLRT-UNet achieves high segmentation accuracy,reaching 98.2% on the Digital Database Thyroid Image(DDT)dataset,97.8% on the Thyroid Nodule 3493(TG3K)dataset,and 98.2% on the Thyroid Nodule3K(TN3K)dataset.These findings demonstrate that the proposed method significantly enhances the accuracy of thyroid nodule segmentation,addressing the limitations of existing models.
基金supported by the National Key R&D Pro-gram of China(No.2022YFB3805701)National Natural Science Foundation of China(NSFC)(No.52371182,51701052,52192592,52192593)+1 种基金Young Elite Scientists Sponsorship Program by CAST(No.2019QNRC001)the Heilongjiang Touyan Innovation Team Program.
文摘1.Introduction.Ni-Mn-X(X=Ga,In,Sn,or Sb)Heusler alloys have versatile properties[1-4],such as shape memory effect[1],superelastic-ity[5],magnetocaloric effect[3],elastocaloric effect[6],and even multicaloric effect[7],that indicate their potential for use in actu-ators,sensors,micropumps,energy harvesters,and solid-state re-frigeration[8-10].Among the alloys,Ni-Mn-Sn-based alloys are environment-friendly and cost-effective[6,7,11],and hence,they have received widespread attention.
基金supported by the General Project of the National Natural Science Foundation of China(Grant No.42377054)the National Natural Science Fund for Young Scholars(Grant No.42007149)the Key Project of the Major Research Plan of the National Natural Science Foundation of China(Grant No.92047201).
文摘Large-scale damming has emerged as a prevalent global trend,significantly impacting nutrient transport and transformation,as well as the downstream ecological environment.Nitrogen and phosphorus are fundamental elements of primary productivity in aquatic ecosystems and serve as key limiting factors in reservoir eutrophication.This review focuses on the impact of damming on the transport and transformation of nitrogen and phosphorus,regarding changes in nutrient concentrations,fluxes,and proportions.Spatial changes in nitrogen and phosphorus concentrations primarily occur at the inlet and outlet of reservoirs,while temporal changes often exhibit seasonal patterns.At a global scale,phosphorus is preferentially removed from reservoirs compared to nitrogen.The factors influencing the transport and transformation processes of nitrogen and phosphorus in reservoirs include the physicochemical properties of water bodies and human activities.Additionally,nitrogen dynamics are affected by reservoir age,storage capacity,and water storage regulation modes,whereas phosphorus dynamics are also influenced by hydrodynamic conditions.Finally,this review summarizes the impact of damming on the downstream ecological environment and outlines future research directions,providing theoretical support for the management of river–reservoir ecosystems and promoting the green and sustainable development of hydropower in the context of carbon peaking and carbon neutrality goals.
文摘BACKGROUND Acinar cystic transformation(ACT)of the pancreas is a rare non-neoplastic transformation of the pancreas.Adult women are the majority of patients with ACT,but few cases have been reported in pediatric patients.Given that there are currently no guidelines for the treatment of ACT,current treatment is based primarily on expert opinions and clinical experiences.Here,we report the case of the youngest child with ACT to date.Additionally,a literature review on pediatric ACT cases was performed to summarize previous clinical experience and treatment methods.CASE SUMMARY A 1-year-old Chinese girl presented with progressive abdominal distension for 6 months.A detailed consultation revealed an uneventful history.The patient showed no signs of fever or abdominal pain and had a good appetite and normal feces.A mass of about 20 cm×10 cm×10 cm in size was detected in the abdomen.Both abdominal ultrasound and computed tomography examination revealed a multilocular cystic mass about 21.7 cm×16.8 cm×8.9 cm in size.At first,due to the large size and the possible retroperitoneal origin of the cyst,a total resection of the lesion was not possible.A single-port laparoscopic lymphangioma puncture and Pingyangmycin injection were performed in March 2023.One month after surgery,the abdominal cyst rapidly enlarged to its pre-operative size.After consulting with the experts in the angiology department and interventional department,sclerotherapy combined with oral sirolimus was performed in May 2023.After confirming that the tumor was not sensitive to sclerotherapy combined with oral sirolimus,our surgical team performed tumor reduction in August 2023.This surgery confirmed that the polycystic mass originated from the head of the pancreas,and pathological and immunohistochemical findings diagnosed pancreatic ACT.The patient showed no signs of cyst lesions after 6 months of follow-up and remains in good health up to the time of this report.CONCLUSION ACT is a rare non-neoplastic transformation of the pancreas,more rarely seen in children.Manifestation and examinations show no specificity for diagnosis,and final diagnosis is mainly based on histological findings.To reach a specific diagnosis and rule out malignancy is a priority in clinical practice,and repeated biopsy or radical surgery should be considered before malignancy is ruled out.However,once a diagnosis of ACT is made,a conser-vative treatment with consecutive follow-up is recommended until symptoms present or obvious enlargement occurs because ACT is considered a slow-growing and benign tumor.
基金support from No.NSF CMMI 1536811 through the University of PittsburghC.M.W.was supported by the PNNL LDRD program.Bin Li thanks for the support from Nos.NSF CMMI 1635088,2016263,and 2032483+1 种基金This work was performed,in part,at the William R.Wiley Environmental Molecular Sciences Laboratory,a national scientific user facility sponsored by the U.S.Department of Energy,Office of Biological and Environmental Research,and located at PNNLPNNL is operated by Battelle for the U.S.Department of Energy under contract No.DE-AC05-76RLO1830.
文摘In-situ high-resolution transmission electron microscopy(HRTEM)is performed to investigate the de-formation behavior of hexagonal close-packed rhenium(Re)which is compressed along the{1-100}di-rection.Atomistic simulations are also conducted to better understand the deformation mechanisms.Two types of lattice reorientation are observed during compression.The first type involves the reori-entation of one lattice by∼90°around{11-20},which is accomplished by the formation of an interme-diate face-center-cubic(FCC)phase at the interface.This transformation sequence can be described as{1-100}matrix→{111}FCC→(0001)twin.In the second type,a new grain is formed but does not satisfy any known twin relationship with the matrix,and an intermediate FCC phase is also formed.The transfor-mation sequence can be described as{1¯101}matrix→{111}FCC→(0001)grain.Mechanisms responsible for the observed lattice reorientation and sequential phase transitions are analyzed by conducting lattice correspondence analyses on the simulation results.Strain accommodation is also analyzed to explain the mechanisms for lattice reorientation and the intermediate phase transformations.The results provide new insight into the deformation behavior of HCP metals.
文摘The rapid advancement of Artificial Intelligence(AI)and automation has significantly transformed the accounting profession,shifting the role of accountants from routine data processors to strategic decision makers and ethical stewards of technology.This conceptual study explores how AI and automation are reshaping accounting tasks,transforming required competencies,and redefining professional responsibilities.By analyzing relevant literature and theoretical frameworks,this paper identifies the evolving skill sets,both technical such as data analytics and AI literacy,and nontechnical such as critical thinking and ethical judgment,that are essential for modern accountants.The study also emphasizes the importance of continuous education,ethical integrity,and adaptive learning in navigating the digital transformation of accounting.Ultimately,this paper contributes to a deeper understanding of how accountants can maintain relevance and add value in an increasingly automated and data driven environment.
基金supported by the National Key Research and Development Program of China(No.2022YFC3701301)the National Natural Science Foundation of China(Nos.42173063 and 42377251)+1 种基金the Youth Innovation Promotion Association CAS(No.2020200)the Fundamental Research Funds for the Central Universities.
文摘In sulfidic anoxic environments,iron sulfides are widespread solid phases that play an important role in the arsenic(As)biogeochemical cycle.This work investigated the transformation process of FeS-As coprecipitates,the concurrent behavior,and the speciation of associated As under anoxic conditions.The results showed that FeS-As coprecipitates could convert to greigite and pyrite.The transformation degree of the produced solid phases was dependent upon the pH conditions and initial As species.These results showed that the As mobilization was closely associated with the solid phase transformation.The solid phase transformationwent from disordered mackinawite to crystallinemackinawite,then greigite and finally pyrite.The As in the coprecipitates underwent a process of release,fixation,and release again.Both reduction of As(Ⅴ)and oxidation of As(Ⅲ)were observed in the aqueous and solid phases during reactions.Our study may have important implications for further understanding of As behavior and Fe/S cycling thatmay occur under an anoxic environment more comprehensively.
基金supported by National Natural Science Foundation of China(Grant No.52001114)Program for Science and Technology Innovation Talents in Universities of Henan Province(No.23HASTIT022 and 2021GGJS064)Scientific Research Fund of State Key Laboratory of Materials Processing and Die and Mould Technology(Grant No.P2023-005).
文摘(Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4))_(100−x)Al_(x)(x=0,0.1,0.2,0.3,0.4 at.%)lightweight high-entropy alloys with different contents of Al were prepared via vacuum non-consumable arc melting method.Effects of adding varying Al contents on phase constitution,microstructure characteristics and mechanical properties of the lightweight alloys were studied.Results show that Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4)alloy is composed of body-centered cubic(BCC)phase and C15 Laves phase,while(Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4))_(100−x)Al_(x)lightweight high-entropy alloys by addition of Al are composed of BCC phase and C14 Laves phase.Addition of Al into Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4)lightweight high-entropy alloy can transform C15 Laves phase to C14 Laves phase.With further addition of Al,BCC phase of alloys is significantly refined,and the volume fraction of C14 Laves phase is raised obviously.Meanwhile,the dimension of BCC phase in the alloy by addition of 0.3 at.%Al is the most refined and that of Laves phase is also obviously refined.Adding Al to Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4)alloy can not only reduce the density of(Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4))_(100−x)Al_(x)alloy,but also improve strength of(Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4))_(100−x)Al_(x)alloy.As Al content increased from 0 to 0.4 at.%,the density of the alloy decreased from 6.22±0.875 to 5.79±0.679 g cm^(−3).Moreover,compressive strength of the alloy by 0.3 at.%Al addition is the highest to 1996.9 MPa,while fracture strain of the alloy is 16.82%.Strength improvement of alloys mainly results from microstructure refinement and precipitation of C14 Laves by Al addition into Ti_(8)Zr_(6)Nb_(4)V_(5)Cr_(4)lightweight high-entropy alloy.
基金supported by the Yuxiu Innovation Project of NCUT(Grant No.2024NCUTYXCX211).
文摘Purpose–This paper aims to provide a comprehensive analysis of the strategic adjustments in China’s transportation structure,with a particular focus on the pivotal role of railway freight and its integration into the modern logistics system.It seeks to address the need for a more nuanced understanding of the“road to rail”policy,emphasizing the importance of intermodal collaboration and service of fragmented market demands.Design/methodology/approach–The study employs a transport economics perspective to evaluate the achievements and shortcomings of China’s transportation structure optimization.It bases its assessment of the current state of railway freight logistics,multi-modal transportation and the broader implications for the transportation service market on data analysis.The methodology includes a review of existing policies,an examination of industry practices and a comparative analysis with global trends in railway logistics.Findings–The research underscores the importance of focusing on the development of non-bulk materials,noting the insufficiency in the development of China’s rail multi-modal transportation and highlighting the instructive value of successful cases in open-top container road-rail intermodal transportation.The study posits that the railway sector must enhance cooperation with other market entities,aligning with the lead enterprises in the logistics chain that are characterized by speed,high value and strong coordination capabilities,in order to better serve the transportation market.This approach moves away from a reliance on the railway’s own capabilities alone.Originality/value–This paper offers original insights into the transformation of railway freight in China,contributing to the body of knowledge on transportation economics and logistics.It provides valuable recommendations for policymakers and industry practitioners,emphasizing the strategic importance of railway logistics in the context of China’s economic development and intense competition in the supply chain.The value of the article lies in its comprehensive understanding of the complexities involved in the adjustment of transportation structures,providing direction for the market-oriented reform of China’s railway freight sector.
基金supported by the National Natural Science Foundation of China(Grant No.12271488)。
文摘The aim of this paper is to study an extended modified Korteweg-de Vries-Calogero-Bogoyavlenskii-Schiff(mKdV-CBS)equation and present its Lax pair with a spectral parameter.Meanwhile,a Miura transformation is explored,which reveals the relationship between solutions of the extended mKdV-CBS equation and the extended(2+1)-dimensional Korteweg-de Vries(KdV)equation.On the basis of the obtained Lax pair and the existing research results,the Darboux transformation is derived,which plays a crucial role in presenting soliton solutions.In addition,soliton molecules are given by the velocity resonance mechanism.
基金the U.S.Army Research Laboratory under Cooperative Agreement Award No.HQ0034-15-2-0007the U.S.National Science Foundation(DMR-2207965).
文摘Maraging steels are known for their exceptional strength but suffer from limited work hardening and ductility.Here,we report an intermittent printing strategy to tailor the microstructure and mechanical properties of maraging 250 steel via tuning the thermal history during wire-arc directed energy deposition.By introducing a dwell time between adjacent layers,the maraging 250 steel is cooled below the martensite start temperature,triggering thermally-driven martensitic transformation during the printing process.Thermal cycling during subsequent layer deposition results in the formation of reverted austenite which shows a refined microstructure and induces elemental segregation between martensite and reverted austenite.The Ni enrichment in the austenite promotes stabilization of the reverted austenite upon cooling to room temperature.The reverted austenite is metastable during deformation,leading to strain-induced martensitic transformation under loading.Specifically,a 3 min interlayer dwell time produces a maraging 250 steel with approximately 8% reverted austenite,resulting in improved work hardening via martensitic transformation induced plasticity during deformation.Meanwhile,the higher cooling rate and refined prior austenite grains lead to substantially refined martensitic grains(by approximately fivefold)together with an increased dislocation density.With 3 min interlayer dwell time,the yield strength of the printed maraging 250 steel increases from 836 MPa to 990 MPa,and the uniform elongation is doubled from 3.2% to 6.5%.This intermittent deposition strategy demonstrates the potential to tune the microstructure of maraging steels for achieving strength-ductility synergy by engineering the thermal history during additive manufacturing.
基金Project(51901248)supported by the National Natural Science Foundation of ChinaProject(2023JJ40742)supported by the Natural Science Foundation of Hunan Province,China。
文摘In the present study,molecular dynamic simulation(MD)was used to investigate the plastic deformation process of the Fe-Mn alloys with different Mn contents.The influences of Mn contents ranging from 10%to 30%(at%)on the deformation behavior and the controlling mechanism of the Fe-base alloys were analyzed.The results show that phase transformations and{112}<111>_(BCC)deformation twinning occur in all Fe-Mn alloys but follow different deformation paths.In the Fe-10%Mn alloy the deformation twinning mechanism obeys the FCC-related path,the Fe-20%Mn alloy involves both the FCC-and HCP-related paths,and the deformation of the Fe-30%Mn alloy is dominated by the HCP-related twinning path.The addition of Mn can increase the stacking fault energy and retard the activation of slip systems as well as the formation of stacking faults.Thus,a higher content of Mn can delay the FCC®ε-martensite and the subsequentε-martensite®BCC phase transition at the intersection of twoε-martensitic bands.Therefore,the addition of Mn alloying element increases the yield strength and reduces the elastic modulus of the Fe-Mn alloys.The formation of deformation twins will contribute to the work-hardening effect and delay the necking and fracture of alloys.It is expected that the results in the present study will provide theoretical reference for the design and optimization of high-performance steels.
基金supported by the Henry Royce Institute for Advanced Materials,funded through Engineering and Physical Sciences Research Council(EPSRC)grants EP/R00661X/1,EP/S019367/1,EP/P025021/1,and EP/P025498/1.
文摘Liquefied natural gas storage and transportation as well as space propulsion systems have sparked inter-est in the martensitic transformation and behaviours of 316 L stainless steels(SS)under ultra-cryogenic deformation.In this study,high-resolution transmission electron microscopy(HRTEM)and molecular dy-namics(MD)simulations were used to investigate the atomic arrangements and crystalline defects of deformation-induced γ-austenite→ε-martensite→α'-martensite and γ→α'martensitic transforma-tions in 316 L SS at 15 and 173 K.Theγ→εtransformation involves the glide of Shockley partial dislocations on(111)γplanes without a change in atomic spacing.The formation of anα'inclusion in a singleε-band is achieved by a continuous lattice distortion,accompanied by the formation of a tran-sition zone ofα'and the expansion of the average atomic spacings due to dislocation shuffling.Asα'grows further intoγ,the orientation relationship(OR)of theα'changes by lattice bending.This pro-cess follows the Bogers-Burgers-Olson-Cohen model despite it not occurring on intersecting shear bands.Stacking faults and twins can also serve as nucleation sites forα'at 173 K.We also found that direct transformation of γ→α'occurs by the glide of √6aγ[11(2)]/12 dislocations on every(111)γplane with misfit dislocations.Overall,this study provides,for the first time,insights into the atomic-scale mech-anisms of various two-step and one-step martensitic transformations induced by cryogenic deformation and corresponding local strain,enhancing our understanding of the role of martensitic transformation under ultra-cryogenic-temperature deformation in controlling the properties.
