The accurate segmentation of deep gray matter nuclei is critical for neuropathological research,disease diagnosis and treatment.Existing methods employ the supervised learning training approach,which requires large la...The accurate segmentation of deep gray matter nuclei is critical for neuropathological research,disease diagnosis and treatment.Existing methods employ the supervised learning training approach,which requires large labeled datasets.It is challenging and time-consuming to obtain such datasets for medical image analysis.In addition,these methods based on convolutional neural networks(CNNs)only achieve suboptimal performance due to the locality of convolutional operations.Vision Transformers(ViTs)efficiently model long-range dependencies and thus have the potentiality to outperform these methods in segmentation tasks.To address these issues,we propose a novel hybrid network based on self-supervised pre-training for deep gray matter nuclei segmentation.Specifically,we present a CNN-Transformer hybrid network(CTNet),whose encoder consists of 3D CNN and ViT to learn local spatial-detailed features and global semantic information.A self-supervised learning(SSL)approach that integrates rotation prediction and masked feature reconstruction is proposed to pre-train the CTNet,enabling the model to learn valuable visual representations from unlabeled data.We evaluate the effectiveness of our method on 3T and 7T human brain MRI datasets.The results demonstrate that our CTNet achieves better performance than other comparison models and our pre-training strategy outperforms other advanced self-supervised methods.When the training set has only one sample,our pre-trained CTNet enhances segmentation performance,showing an 8.4%improvement in Dice similarity coefficient(DSC)compared to the randomly initialized CTNet.展开更多
The high-order deformation effects in even-even^(246,248)No are investigated by means of pairing self-consistent WoodsSaxon-Strutinsky calculations using the potential-energy-surface(PES)approach in an extended deform...The high-order deformation effects in even-even^(246,248)No are investigated by means of pairing self-consistent WoodsSaxon-Strutinsky calculations using the potential-energy-surface(PES)approach in an extended deformation space(β_(2),β_(3),β_(4),β_(5),β_(6),β_(7),β_(8)).Based on the calculated two-dimensional projected energy maps and different potential energy curves,we found that the highly even-order deformations have an important impact on both the fission trajectory and energy minima,while the odd-order deformations,accompanying the even-order ones,primarily affect the fission path beyond the second barrier.Relative to the light actinide nuclei,the nuclear ground state changes to the superdeformed configuration,but the normally deformed minimum,as the low-energy shape isomer,may still be primarily responsible for enhancing nuclear stability and ensuring experimental accessibility in^(246,248)No.Our present investigation indicates the nonnegligible impact of high-order deformation effects along the fission valley and will be helpful for deepening the understanding of different deformation effects and deformation couplings in nuclei,especially in this neutron-deficient heavy-mass region.展开更多
This study explores the dynamic contact response of a viscoelastic functionally graded material(FGM)-coated half-plane under a rigid flat punch subjected to a time-harmonic vertical force.The elastic modulus and mass ...This study explores the dynamic contact response of a viscoelastic functionally graded material(FGM)-coated half-plane under a rigid flat punch subjected to a time-harmonic vertical force.The elastic modulus and mass density of the FGM coating vary exponentially along the thickness direction.The FGM coating and the homogeneous half-plane possess viscoelastic properties,which are described by a linearly hysteretic damping model.By applying the asymptotic method and the Fourier integral transform technique,the contact problem is converted into a Cauchy singular integral equation.The effects of excitation frequency,gradient index,damping factor ratio,and punch width on the vertical impedance and dynamic contact stress are analyzed.The results indicate that adjusting the gradient index of the FGM coating can significantly affect the contact stress and vertical impedance.展开更多
The commercialization of solid oxide fuel cells depends on the cathode,which possesses both high catalytic activity and a thermal-expansion coefficient(TEC)that aligns with the electrolyte.Although the cobalt-based ca...The commercialization of solid oxide fuel cells depends on the cathode,which possesses both high catalytic activity and a thermal-expansion coefficient(TEC)that aligns with the electrolyte.Although the cobalt-based cathode La_(0.6)Sr_(0.4)CoO_(3)(LSC)offers excellent catalytic performance,its TEC is significantly larger than that of the electrolyte.In this study,we mechanically mix Sm_(0.2)Ce_(0.8)O_(2−δ)(SDC)with LSC to create a composite cathode.By incorporating 50wt%SDC,the TEC decreases significantly from 18.29×10^(−6) to 13.90×10^(−6) K^(−1).Under thermal-shock conditions ranging from room temperature to 800℃,the growth rate of polarization resistance is only 0.658%per cycle,i.e.,merely 49%that of pure LSC.The button cell comprising the LSC-SDC composite cathode operates stably for over 900 h without Sr segregation,with a voltage growth rate of 1.11%/kh.A commercial flat-tube cell(active area:70 cm^(2))compris-ing the LSC-SDC composite cathode delivers 54.8 W at 750℃.The distribution of relaxation-time shows that the non-electrode portion is the main rate-limiting step.This study demonstrates that the LSC-SDC mixture strategy effectively improves the compatibility with the electrolyte while maintaining a high output,thus rendering it a promising commercial cathode material.展开更多
Systems hosting flat bands offer a powerful platform for exploring strong correlation physics.Theoretically,topological degeneracy arising in systems with non-trivial topological orders on periodic manifolds of non-ze...Systems hosting flat bands offer a powerful platform for exploring strong correlation physics.Theoretically,topological degeneracy arising in systems with non-trivial topological orders on periodic manifolds of non-zero genus can generate ideal flat bands.However,experimental realization of such geometrically engineered systems is very difficult.In this work,we demonstrate that flat planes with strategically patterned hole defects can engineer ideal flat bands.We construct two families of models:singular flat band systems where degeneracy is stabilized by non-contractible loop excitations tied to hole defects and perfectly nested van Hove systems where degeneracy arises from line excitations in momentum space.These models circumvent the need for exotic manifolds while retaining the essential features of topological flat bands.By directly linking defect engineering to degeneracy mechanisms,our results establish a scalable framework for experimentally accessible flat band design.展开更多
With the most advanced and sophisticated technologies and equipment,NYBELT is one of the largest manufacturers of flat transmission belts in the world.Under the Certified Quality,Environment,Occupational Health&Sa...With the most advanced and sophisticated technologies and equipment,NYBELT is one of the largest manufacturers of flat transmission belts in the world.Under the Certified Quality,Environment,Occupational Health&Safety,and Energy Standardized ISO Management System,NYBELT can produce all kinds of flat transmission belts,roller coverings and conveyor belts applicable to textile,printing&packaging,electronics and other industries.Due to the superior quality and the reasonable prices,we have become well known in providing high quality belting products and excellent service to customers all over the world.Our success in the past gives us the confidence to look into the future with great expectations.展开更多
In a peach orchard in Lyuxiang Town,Jinshan District,Shanghai,youth delegates from 13 countries,officials from the Food and Agriculture Organization of the United Nations(FAO),and agricultural heritage experts were im...In a peach orchard in Lyuxiang Town,Jinshan District,Shanghai,youth delegates from 13 countries,officials from the Food and Agriculture Organization of the United Nations(FAO),and agricultural heritage experts were impressed by sweet and juicy Jinshan flat peaches.Jinshan has a history of flat peach cultivation that spans hundreds of years dating back to the Yuan Dynasty(1271-1368).展开更多
20-high mills often face various flatness problems in the production of cold-rolled stainless steel thin strips.The flatness prediction model is essential for flatness control techniques.A novel rapid prediction model...20-high mills often face various flatness problems in the production of cold-rolled stainless steel thin strips.The flatness prediction model is essential for flatness control techniques.A novel rapid prediction model for flatness in a 20-high mill is proposed based on a model coupling method capable of forecasting the flatness of cold-rolled stainless steel thin strips under symmetric and asymmetric rolling conditions.The model integrates deformation coordination equations between rolls,force and moment balance equations,strip exit transverse displacement equations,and no-load roll gap equations into a unified set of linear equations.This solution process avoids repeated iterations between the elastic deformation model of the roll system and the plastic deformation model of the strip,which is a limitation of the traditional method and significantly improves the calculation speed and stability.The accuracy of the model was verified via a ZR22B-52 Sendzimir 20-high mill.The measured and calculated flatness values highly coincided,confirming the model’s accuracy.Rolling calculations of 304 stainless steel thin strips demonstrate that the new model results are consistent with those of the traditional method.The calculation time of the new model is only approximately 0.04%-0.35%that of the traditional method.On this basis,the impact of common flatness control methods on the flatness has been analyzed.展开更多
The Lieb lattice, characterized by its distinctive Dirac cone and flat-band electronic structures, hosts a variety of exotic physical phenomena. However, its realization remains largely confined to artificial lattices...The Lieb lattice, characterized by its distinctive Dirac cone and flat-band electronic structures, hosts a variety of exotic physical phenomena. However, its realization remains largely confined to artificial lattices. In this work, we propose the concept of a Lieb electride, where the non-bound electrons gather at the middle edges,behaving as the quasi-atoms of a Lieb lattice, enabling the emergence of flat bands. Using crystal structure prediction method MAGUS and first-principles calculations, we predict a stable candidate, Ca_(2)I, at ambient pressure. Distinct from conventional electrides with localized electrons at cavity centers, Ca_(2)I features interstitial electrons situated at cavity edges. The resultant flat bands lie close to the Fermi level, giving rise to a pronounced peak in the density of states and leading to Stoner-type ferromagnetism. With increasing pressures, we observe quantum phase transitions from ferromagnetic to non-magnetic and finally to antiferromagnetic orders in Ca_(2)I.Intriguingly, superconductivity emerges in the antiferromagnetic region, suggesting potential competition between these correlated states. Our study not only extends the concepts of electrides but also provides a novel strategy for realizing Lieb lattices through non-bound electrons. This work establishes Ca_(2)I as a promising platform for exploring flat-band physics and correlated electronic states, opening avenues for novel quantum phenomena in electride-based materials.展开更多
Flat electronic bands in condensed matter provide a rich avenue for exploring novel quantum phenomena. Here, we report an optical spectroscopy study of a topological hourglass semimetal Nb_(3)SiTe_(6) with the electri...Flat electronic bands in condensed matter provide a rich avenue for exploring novel quantum phenomena. Here, we report an optical spectroscopy study of a topological hourglass semimetal Nb_(3)SiTe_(6) with the electric field of the incident light parallel to its crystalline ab-plane. The ab-plane optical conductivity spectra of Nb_(3)SiTe_(6) single crystals exhibit a remarkable peak-like feature around 1.20 eV, which is mainly contributed by the direct optical transitions between the two ab-initio-calculation-derived flat bands along the momentum direction Z–U. Our results pave the way for investigating exotic quantum phenomena based on the flat bands in topological hourglass semimetals.展开更多
In this study,the chemical freeze-out of hadrons,including light-and strange-flavor particles and light nuclei,produced in Au+Au collisions at the Relativistic Heavy Ion Collider(RHIC),was investigated.Using the Therm...In this study,the chemical freeze-out of hadrons,including light-and strange-flavor particles and light nuclei,produced in Au+Au collisions at the Relativistic Heavy Ion Collider(RHIC),was investigated.Using the Thermal-FIST thermodynamic statistical model,we analyzed various particle sets:those inclusive of light nuclei,those exclusive to light nuclei,and those solely comprising light nuclei.We determined the chemical freeze-out parameters at√^(S)NN=7.7–200 Ge V and four different centralities.A significant finding was the decrease in the chemical freeze-out temperature T_(ch)with light-nuclei inclusion,with an even more pronounced reduction when considering light-nuclei yields exclusively.This suggests that light-nuclei formation occurs at a later stage in the system’s evolution at RHIC energies.We present parameterized formulas that describe the energy dependence of T_(ch)and the baryon chemical potentialμ_(B) for three distinct particle sets in central Au+Au collisions at RHIC energies.Our results reveal at least three distinct T_(ch)at RHIC energies correspond to different freeze-out hypersurfaces:a light-flavor freeze-out temperature of T_L=150.2±6 Me V,a strange-flavor freeze-out temperature T_s=165.1±2.7 Me V,and a light-nuclei freeze-out temperature T_(ln)=141.7±1.4 Me V.Notably,at the Large Hadron Collider(LHC)Pb+Pb 2.76Te V,the expected lower freeze-out temperature for light nuclei was not observed;instead,the T_(ch)for light nuclei was found to be approximately 10 Me V higher than that for light-flavor hadrons.展开更多
This paper provides a comprehensive analysis of all stages of the heavy-ion fusion evaporation reaction,aiming to enhance the understanding of the entire process and identify the influencing factors in calculating the...This paper provides a comprehensive analysis of all stages of the heavy-ion fusion evaporation reaction,aiming to enhance the understanding of the entire process and identify the influencing factors in calculating the evaporation residue cross-section.By focusing on the synthesis of superheavy nuclei with Z=114,we discuss the capture cross-section,fusion probability,and survival probability of the ^(48)Ca+^(244)Pu reaction and compare them with those of the 40Ar+248Cm reaction.Moreover,a systematic study examined the evaporation residue cross-sections for the synthesis of superheavy nuclei with Z=112-116 using ^(40)Ar as the projectile nucleus.The results indicate that utilizing ^(40)Ar as the projectile nucleus for synthesizing isotopes with Z=114 offers advantages such as lower incident energy and reduced experimental costs.Furthermore,using ^(40)Ar as the projectile nucleus enables the synthesis of a new key isotope,285115,thereby facilitating its identification.展开更多
In this study,we explore the impact of state-of-the-art laser fields on theαdecay half-life of deformed ground-state odd-A nuclei within the proton number range of 52–107.The calculations show that the presence of a...In this study,we explore the impact of state-of-the-art laser fields on theαdecay half-life of deformed ground-state odd-A nuclei within the proton number range of 52–107.The calculations show that the presence of a laser field modulates theαdecay half-life by altering theαdecay penetration probability within a limited range.Moreover,the variance in the penetration probability rate of change between even–odd and odd–even nuclei is investigated.Furthermore,we investigate the rate of change of the penetration probability for the same parent nucleus with different neutron numbers,based on the characteristics of the odd-A nucleus.We found that the influence of the laser field on the penetration probability is determined by both the shell effect and odd–even staggering.This research contributes to the understanding of nuanced interactions between laser fields and nuclear decay processes.Therefore,valuable insights for future experiments in laser–nuclear physics are attainable using this study.展开更多
Nuclei segmentation is a challenging task in histopathology images.It is challenging due to the small size of objects,low contrast,touching boundaries,and complex structure of nuclei.Their segmentation and counting pl...Nuclei segmentation is a challenging task in histopathology images.It is challenging due to the small size of objects,low contrast,touching boundaries,and complex structure of nuclei.Their segmentation and counting play an important role in cancer identification and its grading.In this study,WaveSeg-UNet,a lightweight model,is introduced to segment cancerous nuclei having touching boundaries.Residual blocks are used for feature extraction.Only one feature extractor block is used in each level of the encoder and decoder.Normally,images degrade quality and lose important information during down-sampling.To overcome this loss,discrete wavelet transform(DWT)alongside maxpooling is used in the down-sampling process.Inverse DWT is used to regenerate original images during up-sampling.In the bottleneck of the proposed model,atrous spatial channel pyramid pooling(ASCPP)is used to extract effective high-level features.The ASCPP is the modified pyramid pooling having atrous layers to increase the area of the receptive field.Spatial and channel-based attention are used to focus on the location and class of the identified objects.Finally,watershed transform is used as a post processing technique to identify and refine touching boundaries of nuclei.Nuclei are identified and counted to facilitate pathologists.The same domain of transfer learning is used to retrain the model for domain adaptability.Results of the proposed model are compared with state-of-the-art models,and it outperformed the existing studies.展开更多
To investigate the structural configuration of^(6)He and^(6)Be in a three-cluster system and to highlight dinucleon correlations,we performed a two-cluster overlap amplitude(TCOA)calculation,which is an extension of t...To investigate the structural configuration of^(6)He and^(6)Be in a three-cluster system and to highlight dinucleon correlations,we performed a two-cluster overlap amplitude(TCOA)calculation,which is an extension of the RWA formalism.The total wave functions were obtained using the generator coordinate method with microscopic cluster wave functions.Based on these wave functions,we calculated the overlap amplitudes to extract the relative motion and spatial correlations between clusters.The computed energy spectra showed reasonable agreement with the experimental data,emphasizing the effectiveness of the present framework for investigating dinucleon correlations in light nuclei.Our results revealed the presence of both dinucleon-like and cigar-like configurations in the ground states of^(6)He and^(6)Be,indicating a coexistence of compact and extended cluster structures.Furthermore,the 2_(1)^(+)state of^(6)He revealed a pronounced dineutron structure,with strong spatial correlations between the two valence neutrons.We also performed calculations for the higher-lying 2_(1)^(+)state,which showed a more spatially extended structure and provided potential references for future experimental investigations.These findings demonstrated that the TCOA method served as a powerful tool to explore cluster dynamics and dinucleon features in light,weakly bound nuclear systems.展开更多
A new detector array with a large solid angle coverage for the coincidence measurement of charged fragments was developed to study the breakup reaction mechanisms of weakly bound nuclear systems at energies around the...A new detector array with a large solid angle coverage for the coincidence measurement of charged fragments was developed to study the breakup reaction mechanisms of weakly bound nuclear systems at energies around the Coulomb barrier.The array has been used to explore the breakup reaction mechanisms of^(6,7)Li+^(209)Bi systems at E_(beam)=30,40,47 MeV,showing good performance in particle identification and complete kinematic measurements.Based on this,different breakup modes and breakup components were clearly distinguished,and some new breakup modes were discovered,such as^(7)Li→α+t breakup mode in6Li+209Bi system and^(7)Li→^(6)He+p breakup mode in^(7)Li+^(209)Bi system.This array can also be used to explore other breakup reaction mechanisms induced by weakly bound nuclei.展开更多
We propose a method to measure the flatness of an object with a petal-like pattern generated by the interference of the measured orbital angular momentum(OAM)beam and the reference OAM beam which carries the opposite ...We propose a method to measure the flatness of an object with a petal-like pattern generated by the interference of the measured orbital angular momentum(OAM)beam and the reference OAM beam which carries the opposite OAM state.By calculating the difference between the petal rotation angle without/with the object,the thickness information of the object,and then the flatness information,can be evaluated.Furthermore,the direction of the object’s flatness can be determined by the petal’s clockwise/counterclockwise rotation.We theoretically analyze the relationship between the object’s thickness and petal rotation angle,and verify the proposed method by experiment.The experimental results show that the proposed method is a high precision flatness measurement and can obtain the convex/concave property of the flatness.For the 1.02 mm glass sample,the mean deviation of the flatness is 1.357×10^(-8) and the variance is 0.242×10^(-16).For the 0.50 mm glass sample,the mean deviation of the flatness is 1.931×10^(-8) and the variance is 2.405×10^(-16).Two different topological charges are adopted for the 2.00 mm glass sample,and their flatness deviations are 0.239×10^(-8)(ℓ=1)and 0.246×10^(-8)(ℓ=2),where their variances are 0.799×10^(-18)(ℓ=1)and 0.775×10^(-18)(ℓ=2),respectively.It is shown that the flatness measured by the proposed method is the same for the same sample when different topological charges are used.All results indicate that the proposed method may provide a high flatness measurement,and will be a promising way to measure the flatness.展开更多
With the increasing demand for higher-quality flatness in downstream industries,the optimization of rolling processes and parameters has become a critical area of research.The effects of rolling force and front tensio...With the increasing demand for higher-quality flatness in downstream industries,the optimization of rolling processes and parameters has become a critical area of research.The effects of rolling force and front tension adjustments on flatness were examined systematically under various rolling process conditions.By embedding the Johnson-Cook constitutive model into the ABAQUS simulation platform through a user-defined subroutine,a series of three-dimensional finite element models for different rolling scenarios were developed.Simulation results indicate that,under all four rolling process conditions,edge strain consistently exceeds center strain,with forward-driven rolling exhibiting greater edge strain than reverse-driven rolling.Along the strip thickness direction,reverse-driven rolling results in higher strain compared to forward-driven rolling.Moreover,in single roll driven rolling,the upper surface of the strip experiences higher strain than the lower surface,while the reverse trend is observed in double roll driven rolling.As the rolling force increases from 1000 to 5000 kN,the strain difference in the width and thickness directions of the strip varies significantly under double roll driven rolling and double roll reverse-driven rolling,with change slopes of 5.74×10^(-6) and-2.85×10^(-6),respectively.Double roll driven rolling effectively prevents the deterioration of flatness along the rolling direction.Furthermore,as the front tension increases from 60 to 100 MPa,double roll reverse-driven rolling significantly suppresses strain differentials in the width,thickness,and rolling directions,with change slopes of-6.73×10^(-4),1.22×10^(-5),and-1.29×10^(-5),respectively.Eventually,a predictive model is established,integrating rolling process,rolling force,and front tension,thereby providing a theoretical framework for advancing the precision and efficiency of strip rolling processes.展开更多
In this paper,we will discuss the almost global existence result for d-dimensional fractional nonlinear Schrodinger equation on flat torus,which is based on BNF technique,the tame property and the analysis of the spec...In this paper,we will discuss the almost global existence result for d-dimensional fractional nonlinear Schrodinger equation on flat torus,which is based on BNF technique,the tame property and the analysis of the spectrum of(-Δ)^(s).展开更多
基金supported in part by the National Natural Science Foundation of China under Grant 62071405the National Natural Science Foundation of China under Grant 12175189.
文摘The accurate segmentation of deep gray matter nuclei is critical for neuropathological research,disease diagnosis and treatment.Existing methods employ the supervised learning training approach,which requires large labeled datasets.It is challenging and time-consuming to obtain such datasets for medical image analysis.In addition,these methods based on convolutional neural networks(CNNs)only achieve suboptimal performance due to the locality of convolutional operations.Vision Transformers(ViTs)efficiently model long-range dependencies and thus have the potentiality to outperform these methods in segmentation tasks.To address these issues,we propose a novel hybrid network based on self-supervised pre-training for deep gray matter nuclei segmentation.Specifically,we present a CNN-Transformer hybrid network(CTNet),whose encoder consists of 3D CNN and ViT to learn local spatial-detailed features and global semantic information.A self-supervised learning(SSL)approach that integrates rotation prediction and masked feature reconstruction is proposed to pre-train the CTNet,enabling the model to learn valuable visual representations from unlabeled data.We evaluate the effectiveness of our method on 3T and 7T human brain MRI datasets.The results demonstrate that our CTNet achieves better performance than other comparison models and our pre-training strategy outperforms other advanced self-supervised methods.When the training set has only one sample,our pre-trained CTNet enhances segmentation performance,showing an 8.4%improvement in Dice similarity coefficient(DSC)compared to the randomly initialized CTNet.
基金supported by the Natural Science Foundation of Henan Province(No.252300421478)the National Natural Science Foundation of China(Nos.11975209,U2032211,12075287)。
文摘The high-order deformation effects in even-even^(246,248)No are investigated by means of pairing self-consistent WoodsSaxon-Strutinsky calculations using the potential-energy-surface(PES)approach in an extended deformation space(β_(2),β_(3),β_(4),β_(5),β_(6),β_(7),β_(8)).Based on the calculated two-dimensional projected energy maps and different potential energy curves,we found that the highly even-order deformations have an important impact on both the fission trajectory and energy minima,while the odd-order deformations,accompanying the even-order ones,primarily affect the fission path beyond the second barrier.Relative to the light actinide nuclei,the nuclear ground state changes to the superdeformed configuration,but the normally deformed minimum,as the low-energy shape isomer,may still be primarily responsible for enhancing nuclear stability and ensuring experimental accessibility in^(246,248)No.Our present investigation indicates the nonnegligible impact of high-order deformation effects along the fission valley and will be helpful for deepening the understanding of different deformation effects and deformation couplings in nuclei,especially in this neutron-deficient heavy-mass region.
基金Project supported by the National Natural Science Foundation of China(Nos.12021002,12192212,and 12462007)。
文摘This study explores the dynamic contact response of a viscoelastic functionally graded material(FGM)-coated half-plane under a rigid flat punch subjected to a time-harmonic vertical force.The elastic modulus and mass density of the FGM coating vary exponentially along the thickness direction.The FGM coating and the homogeneous half-plane possess viscoelastic properties,which are described by a linearly hysteretic damping model.By applying the asymptotic method and the Fourier integral transform technique,the contact problem is converted into a Cauchy singular integral equation.The effects of excitation frequency,gradient index,damping factor ratio,and punch width on the vertical impedance and dynamic contact stress are analyzed.The results indicate that adjusting the gradient index of the FGM coating can significantly affect the contact stress and vertical impedance.
基金the financial support from the National Natural Science Foundation of China(No.22209191)Ningbo Key R&D Project(No.2023Z155).
文摘The commercialization of solid oxide fuel cells depends on the cathode,which possesses both high catalytic activity and a thermal-expansion coefficient(TEC)that aligns with the electrolyte.Although the cobalt-based cathode La_(0.6)Sr_(0.4)CoO_(3)(LSC)offers excellent catalytic performance,its TEC is significantly larger than that of the electrolyte.In this study,we mechanically mix Sm_(0.2)Ce_(0.8)O_(2−δ)(SDC)with LSC to create a composite cathode.By incorporating 50wt%SDC,the TEC decreases significantly from 18.29×10^(−6) to 13.90×10^(−6) K^(−1).Under thermal-shock conditions ranging from room temperature to 800℃,the growth rate of polarization resistance is only 0.658%per cycle,i.e.,merely 49%that of pure LSC.The button cell comprising the LSC-SDC composite cathode operates stably for over 900 h without Sr segregation,with a voltage growth rate of 1.11%/kh.A commercial flat-tube cell(active area:70 cm^(2))compris-ing the LSC-SDC composite cathode delivers 54.8 W at 750℃.The distribution of relaxation-time shows that the non-electrode portion is the main rate-limiting step.This study demonstrates that the LSC-SDC mixture strategy effectively improves the compatibility with the electrolyte while maintaining a high output,thus rendering it a promising commercial cathode material.
基金supported by the Ministry of Science and Technology(Grant No.2022YFA1403901)the National Natural Science Foundation of China(Grant Nos.12494594,11888101,12174428,and 12504192)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB28000000)the New Cornerstone Investigator Program,the Chinese Academy of Sciences through the Youth Innovation Promotion Association(Grant No.2022YSBR-048)the Shanghai Science and Technology Innovation Action Plan(Grant No.24LZ1400800).
文摘Systems hosting flat bands offer a powerful platform for exploring strong correlation physics.Theoretically,topological degeneracy arising in systems with non-trivial topological orders on periodic manifolds of non-zero genus can generate ideal flat bands.However,experimental realization of such geometrically engineered systems is very difficult.In this work,we demonstrate that flat planes with strategically patterned hole defects can engineer ideal flat bands.We construct two families of models:singular flat band systems where degeneracy is stabilized by non-contractible loop excitations tied to hole defects and perfectly nested van Hove systems where degeneracy arises from line excitations in momentum space.These models circumvent the need for exotic manifolds while retaining the essential features of topological flat bands.By directly linking defect engineering to degeneracy mechanisms,our results establish a scalable framework for experimentally accessible flat band design.
文摘With the most advanced and sophisticated technologies and equipment,NYBELT is one of the largest manufacturers of flat transmission belts in the world.Under the Certified Quality,Environment,Occupational Health&Safety,and Energy Standardized ISO Management System,NYBELT can produce all kinds of flat transmission belts,roller coverings and conveyor belts applicable to textile,printing&packaging,electronics and other industries.Due to the superior quality and the reasonable prices,we have become well known in providing high quality belting products and excellent service to customers all over the world.Our success in the past gives us the confidence to look into the future with great expectations.
文摘In a peach orchard in Lyuxiang Town,Jinshan District,Shanghai,youth delegates from 13 countries,officials from the Food and Agriculture Organization of the United Nations(FAO),and agricultural heritage experts were impressed by sweet and juicy Jinshan flat peaches.Jinshan has a history of flat peach cultivation that spans hundreds of years dating back to the Yuan Dynasty(1271-1368).
基金supported by the National Natural Science Foundation of China(No.U21A20118)the Natural Science Foundation of Hebei Province(No.E2023203065)the National Key Laboratory of Metal Forming Technology and Heavy Equipment,China National Heavy Machinery Research Institute Co.,Ltd.(No.S2208100.W04).Author infor。
文摘20-high mills often face various flatness problems in the production of cold-rolled stainless steel thin strips.The flatness prediction model is essential for flatness control techniques.A novel rapid prediction model for flatness in a 20-high mill is proposed based on a model coupling method capable of forecasting the flatness of cold-rolled stainless steel thin strips under symmetric and asymmetric rolling conditions.The model integrates deformation coordination equations between rolls,force and moment balance equations,strip exit transverse displacement equations,and no-load roll gap equations into a unified set of linear equations.This solution process avoids repeated iterations between the elastic deformation model of the roll system and the plastic deformation model of the strip,which is a limitation of the traditional method and significantly improves the calculation speed and stability.The accuracy of the model was verified via a ZR22B-52 Sendzimir 20-high mill.The measured and calculated flatness values highly coincided,confirming the model’s accuracy.Rolling calculations of 304 stainless steel thin strips demonstrate that the new model results are consistent with those of the traditional method.The calculation time of the new model is only approximately 0.04%-0.35%that of the traditional method.On this basis,the impact of common flatness control methods on the flatness has been analyzed.
基金supported by the National Natural Science Foundation of China(Grant Nos.12125404,T2495231,123B2049,and 12204138)the National Key R&D Program of China(Grant No.2022YFA1403201)+7 种基金the Advanced MaterialsNational Science and Technology Major Project (Grant No.2024ZD0607000)the Basic Research Program of Jiangsu (Grant Nos.BK20233001 and BK20241253)the Jiangsu Funding Program for Excellent Postdoctoral Talent (Grant Nos.2024ZB002,2024ZB075,2025ZB440 and2025ZB852)the China Postdoctoral Science Foundation (Grant No.2025M773331)the Postdoctoral Fellowship Program of CPSF (Grant No.GZC20240695 and GZC20252202)the AI&AI for Science Program of Nanjing UniversityArtificial Intelligence and Quantum physics (AIQ) program of Nanjing Universitythe Fundamental Research Funds for the Central Universities。
文摘The Lieb lattice, characterized by its distinctive Dirac cone and flat-band electronic structures, hosts a variety of exotic physical phenomena. However, its realization remains largely confined to artificial lattices. In this work, we propose the concept of a Lieb electride, where the non-bound electrons gather at the middle edges,behaving as the quasi-atoms of a Lieb lattice, enabling the emergence of flat bands. Using crystal structure prediction method MAGUS and first-principles calculations, we predict a stable candidate, Ca_(2)I, at ambient pressure. Distinct from conventional electrides with localized electrons at cavity centers, Ca_(2)I features interstitial electrons situated at cavity edges. The resultant flat bands lie close to the Fermi level, giving rise to a pronounced peak in the density of states and leading to Stoner-type ferromagnetism. With increasing pressures, we observe quantum phase transitions from ferromagnetic to non-magnetic and finally to antiferromagnetic orders in Ca_(2)I.Intriguingly, superconductivity emerges in the antiferromagnetic region, suggesting potential competition between these correlated states. Our study not only extends the concepts of electrides but also provides a novel strategy for realizing Lieb lattices through non-bound electrons. This work establishes Ca_(2)I as a promising platform for exploring flat-band physics and correlated electronic states, opening avenues for novel quantum phenomena in electride-based materials.
基金Project supported by the Guangdong Basic and Applied Basic Research Foundation (Grant No. 2021B1515130007)the National Natural Science Foundation of China (Grant Nos. U21A20432 and 52273077)+1 种基金the National Key Research and Development Program of China (Grant No. 2022YFA1403800)the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB33000000)。
文摘Flat electronic bands in condensed matter provide a rich avenue for exploring novel quantum phenomena. Here, we report an optical spectroscopy study of a topological hourglass semimetal Nb_(3)SiTe_(6) with the electric field of the incident light parallel to its crystalline ab-plane. The ab-plane optical conductivity spectra of Nb_(3)SiTe_(6) single crystals exhibit a remarkable peak-like feature around 1.20 eV, which is mainly contributed by the direct optical transitions between the two ab-initio-calculation-derived flat bands along the momentum direction Z–U. Our results pave the way for investigating exotic quantum phenomena based on the flat bands in topological hourglass semimetals.
基金supported by the Scientific Research Foundation of Hubei University of Education for Talent Introduction(Nos.ESRC20230002 and ESRC20230007)the Research Project of Hubei Provincial Department of Education(Nos.D20233003 and B2023191)。
文摘In this study,the chemical freeze-out of hadrons,including light-and strange-flavor particles and light nuclei,produced in Au+Au collisions at the Relativistic Heavy Ion Collider(RHIC),was investigated.Using the Thermal-FIST thermodynamic statistical model,we analyzed various particle sets:those inclusive of light nuclei,those exclusive to light nuclei,and those solely comprising light nuclei.We determined the chemical freeze-out parameters at√^(S)NN=7.7–200 Ge V and four different centralities.A significant finding was the decrease in the chemical freeze-out temperature T_(ch)with light-nuclei inclusion,with an even more pronounced reduction when considering light-nuclei yields exclusively.This suggests that light-nuclei formation occurs at a later stage in the system’s evolution at RHIC energies.We present parameterized formulas that describe the energy dependence of T_(ch)and the baryon chemical potentialμ_(B) for three distinct particle sets in central Au+Au collisions at RHIC energies.Our results reveal at least three distinct T_(ch)at RHIC energies correspond to different freeze-out hypersurfaces:a light-flavor freeze-out temperature of T_L=150.2±6 Me V,a strange-flavor freeze-out temperature T_s=165.1±2.7 Me V,and a light-nuclei freeze-out temperature T_(ln)=141.7±1.4 Me V.Notably,at the Large Hadron Collider(LHC)Pb+Pb 2.76Te V,the expected lower freeze-out temperature for light nuclei was not observed;instead,the T_(ch)for light nuclei was found to be approximately 10 Me V higher than that for light-flavor hadrons.
基金supported by the National Natural Science Foundation of China(Nos.12175170 and 11675066).
文摘This paper provides a comprehensive analysis of all stages of the heavy-ion fusion evaporation reaction,aiming to enhance the understanding of the entire process and identify the influencing factors in calculating the evaporation residue cross-section.By focusing on the synthesis of superheavy nuclei with Z=114,we discuss the capture cross-section,fusion probability,and survival probability of the ^(48)Ca+^(244)Pu reaction and compare them with those of the 40Ar+248Cm reaction.Moreover,a systematic study examined the evaporation residue cross-sections for the synthesis of superheavy nuclei with Z=112-116 using ^(40)Ar as the projectile nucleus.The results indicate that utilizing ^(40)Ar as the projectile nucleus for synthesizing isotopes with Z=114 offers advantages such as lower incident energy and reduced experimental costs.Furthermore,using ^(40)Ar as the projectile nucleus enables the synthesis of a new key isotope,285115,thereby facilitating its identification.
基金supported by the National Natural Science Foundation of China(Nos.12375244 and 12135009)the Hunan Provincial Innovation Foundation for Postgraduate(Nos.CX20210007 and CX20230008)。
文摘In this study,we explore the impact of state-of-the-art laser fields on theαdecay half-life of deformed ground-state odd-A nuclei within the proton number range of 52–107.The calculations show that the presence of a laser field modulates theαdecay half-life by altering theαdecay penetration probability within a limited range.Moreover,the variance in the penetration probability rate of change between even–odd and odd–even nuclei is investigated.Furthermore,we investigate the rate of change of the penetration probability for the same parent nucleus with different neutron numbers,based on the characteristics of the odd-A nucleus.We found that the influence of the laser field on the penetration probability is determined by both the shell effect and odd–even staggering.This research contributes to the understanding of nuanced interactions between laser fields and nuclear decay processes.Therefore,valuable insights for future experiments in laser–nuclear physics are attainable using this study.
文摘Nuclei segmentation is a challenging task in histopathology images.It is challenging due to the small size of objects,low contrast,touching boundaries,and complex structure of nuclei.Their segmentation and counting play an important role in cancer identification and its grading.In this study,WaveSeg-UNet,a lightweight model,is introduced to segment cancerous nuclei having touching boundaries.Residual blocks are used for feature extraction.Only one feature extractor block is used in each level of the encoder and decoder.Normally,images degrade quality and lose important information during down-sampling.To overcome this loss,discrete wavelet transform(DWT)alongside maxpooling is used in the down-sampling process.Inverse DWT is used to regenerate original images during up-sampling.In the bottleneck of the proposed model,atrous spatial channel pyramid pooling(ASCPP)is used to extract effective high-level features.The ASCPP is the modified pyramid pooling having atrous layers to increase the area of the receptive field.Spatial and channel-based attention are used to focus on the location and class of the identified objects.Finally,watershed transform is used as a post processing technique to identify and refine touching boundaries of nuclei.Nuclei are identified and counted to facilitate pathologists.The same domain of transfer learning is used to retrain the model for domain adaptability.Results of the proposed model are compared with state-of-the-art models,and it outperformed the existing studies.
基金supported by the National Key R&D Program of China(Nos.2023YFA1606701 and 2022YFA1602402)the National Natural Science Foundation of China(Nos.12175042,11890710,11890714,12047514,12147101,and 12347106)+1 种基金Guangdong Major Project of Basic and Applied Basic Research(No.2020B0301030008)the 111 Project。
文摘To investigate the structural configuration of^(6)He and^(6)Be in a three-cluster system and to highlight dinucleon correlations,we performed a two-cluster overlap amplitude(TCOA)calculation,which is an extension of the RWA formalism.The total wave functions were obtained using the generator coordinate method with microscopic cluster wave functions.Based on these wave functions,we calculated the overlap amplitudes to extract the relative motion and spatial correlations between clusters.The computed energy spectra showed reasonable agreement with the experimental data,emphasizing the effectiveness of the present framework for investigating dinucleon correlations in light nuclei.Our results revealed the presence of both dinucleon-like and cigar-like configurations in the ground states of^(6)He and^(6)Be,indicating a coexistence of compact and extended cluster structures.Furthermore,the 2_(1)^(+)state of^(6)He revealed a pronounced dineutron structure,with strong spatial correlations between the two valence neutrons.We also performed calculations for the higher-lying 2_(1)^(+)state,which showed a more spatially extended structure and provided potential references for future experimental investigations.These findings demonstrated that the TCOA method served as a powerful tool to explore cluster dynamics and dinucleon features in light,weakly bound nuclear systems.
基金supported by the National Key R&D Program of China(Nos.2022YFA1602302 and 2023YFA1606402)the National Natural Science Foundation of China(Nos.U2167204,12175314,12235020 and 12275360)+2 种基金the Continuous-Support Basic Scientific Research Projectthe"111 Center"the China Scholarship Council(CSC)。
文摘A new detector array with a large solid angle coverage for the coincidence measurement of charged fragments was developed to study the breakup reaction mechanisms of weakly bound nuclear systems at energies around the Coulomb barrier.The array has been used to explore the breakup reaction mechanisms of^(6,7)Li+^(209)Bi systems at E_(beam)=30,40,47 MeV,showing good performance in particle identification and complete kinematic measurements.Based on this,different breakup modes and breakup components were clearly distinguished,and some new breakup modes were discovered,such as^(7)Li→α+t breakup mode in6Li+209Bi system and^(7)Li→^(6)He+p breakup mode in^(7)Li+^(209)Bi system.This array can also be used to explore other breakup reaction mechanisms induced by weakly bound nuclei.
基金supported by the National Natural Science Foundation of China(Grant No.62375140)the Open Research Fund of National Laboratory of Solid State Microstructures(Grant No.M36055).
文摘We propose a method to measure the flatness of an object with a petal-like pattern generated by the interference of the measured orbital angular momentum(OAM)beam and the reference OAM beam which carries the opposite OAM state.By calculating the difference between the petal rotation angle without/with the object,the thickness information of the object,and then the flatness information,can be evaluated.Furthermore,the direction of the object’s flatness can be determined by the petal’s clockwise/counterclockwise rotation.We theoretically analyze the relationship between the object’s thickness and petal rotation angle,and verify the proposed method by experiment.The experimental results show that the proposed method is a high precision flatness measurement and can obtain the convex/concave property of the flatness.For the 1.02 mm glass sample,the mean deviation of the flatness is 1.357×10^(-8) and the variance is 0.242×10^(-16).For the 0.50 mm glass sample,the mean deviation of the flatness is 1.931×10^(-8) and the variance is 2.405×10^(-16).Two different topological charges are adopted for the 2.00 mm glass sample,and their flatness deviations are 0.239×10^(-8)(ℓ=1)and 0.246×10^(-8)(ℓ=2),where their variances are 0.799×10^(-18)(ℓ=1)and 0.775×10^(-18)(ℓ=2),respectively.It is shown that the flatness measured by the proposed method is the same for the same sample when different topological charges are used.All results indicate that the proposed method may provide a high flatness measurement,and will be a promising way to measure the flatness.
基金supported by National Key R&D Program of China(No.2024YFB4007100).
文摘With the increasing demand for higher-quality flatness in downstream industries,the optimization of rolling processes and parameters has become a critical area of research.The effects of rolling force and front tension adjustments on flatness were examined systematically under various rolling process conditions.By embedding the Johnson-Cook constitutive model into the ABAQUS simulation platform through a user-defined subroutine,a series of three-dimensional finite element models for different rolling scenarios were developed.Simulation results indicate that,under all four rolling process conditions,edge strain consistently exceeds center strain,with forward-driven rolling exhibiting greater edge strain than reverse-driven rolling.Along the strip thickness direction,reverse-driven rolling results in higher strain compared to forward-driven rolling.Moreover,in single roll driven rolling,the upper surface of the strip experiences higher strain than the lower surface,while the reverse trend is observed in double roll driven rolling.As the rolling force increases from 1000 to 5000 kN,the strain difference in the width and thickness directions of the strip varies significantly under double roll driven rolling and double roll reverse-driven rolling,with change slopes of 5.74×10^(-6) and-2.85×10^(-6),respectively.Double roll driven rolling effectively prevents the deterioration of flatness along the rolling direction.Furthermore,as the front tension increases from 60 to 100 MPa,double roll reverse-driven rolling significantly suppresses strain differentials in the width,thickness,and rolling directions,with change slopes of-6.73×10^(-4),1.22×10^(-5),and-1.29×10^(-5),respectively.Eventually,a predictive model is established,integrating rolling process,rolling force,and front tension,thereby providing a theoretical framework for advancing the precision and efficiency of strip rolling processes.
基金Supported by the National Natural Science Foundation of China(12101542,12371189,12371241).
文摘In this paper,we will discuss the almost global existence result for d-dimensional fractional nonlinear Schrodinger equation on flat torus,which is based on BNF technique,the tame property and the analysis of the spectrum of(-Δ)^(s).
