AIM:To investigate the impact of hsa_circ_0007482 on the proliferation and apoptosis of human pterygium fibroblasts(HPFs)and its correlation with the severity grades of pterygium.METHODS:Pterygium and normal conjuncti...AIM:To investigate the impact of hsa_circ_0007482 on the proliferation and apoptosis of human pterygium fibroblasts(HPFs)and its correlation with the severity grades of pterygium.METHODS:Pterygium and normal conjunctival tissues were collected from the superior area of the same patient’s eye(n=33).The correlation between pterygium severity and hsa_circ_0007482 expression using quantitative reversetranscription polymerase chain reaction(RT-qPCR)were analyzed.Three distinct siRNA sequences targeting hsa_circ_0007482,along with a negative control sequence,were transfected into HPFs.Cell proliferation was assessed using the cell counting kit-8.Expression levels of Ki67,proliferating cell nuclear antigen(PCNA),Cyclin D1,Bax,B-cell lymphoma-2(Bcl-2),and Caspase-3 were measured via RT-qPCR.Immunofluorescence staining was employed to detect Ki67 and vimentin expressions.Apoptosis was evaluated using flow cytometry.RESULTS:Hsa_circ_0007482 expression was significantly higher in pterygium tissues compared to normal conjunctival tissues(P<0.001).Positive correlations were observed between hsa_circ_0007482 expression and pterygium severity,thickness,and vascular density.Knockdown of hsa_circ_0007482 inhibited cell proliferation,reducing the mRNA expression of Ki67,PCNA,and Cyclin D1 in HPFs.Hsa_circ_0007482 knockdown induced apoptosis,increasing mRNA expression levels of Bax and Caspase-3,while decreasing Bcl-2 expression in HPFs.Additionally,hsa_circ_0007482 knockdown attenuated vimentin expression in HPFs.CONCLUSION:The downregulation of hsa_circ_0007482 effectively hampers cell proliferation and triggers apoptosis in HPFs.There are discernible positive correlations detected between the expression of hsa_circ_0007482 and the severity of pterygium.展开更多
This paper analyzes the current status,technological developments,academic exchange platforms,and future challenges and solutions in the field of intelligent ophthalmology(IO)in China.In terms of technology,significan...This paper analyzes the current status,technological developments,academic exchange platforms,and future challenges and solutions in the field of intelligent ophthalmology(IO)in China.In terms of technology,significant progress has been made in various areas,including diabetic retinopathy,fundus image analysis,quality assessment of medical artificial intelligence products,clinical research methods,technical evaluation,and industry standards.Researchers continually enhance the safety and standardization of IO technology by formulating a series of clinical application guidelines and standards.The establishment of domestic and international academic exchange platforms provides extensive collaboration opportunities for professionals in various fields,and various academic journals serve as publication platforms for IO research.However,challenges such as technological innovation,data privacy and security,lagging regulations,and talent shortages still pose obstacles to future development.To address these issues,future efforts should focus on strengthening technological research and development,regulatory framework construction,talent cultivation,and increasing patient awareness and acceptance of new technologies.By comprehensively addressing these challenges,IO in China is poised to further lead the industry’s development on a global scale,bringing more innovation and convenience to the field of ophthalmic healthcare.展开更多
AIM: To investigate the relationship between ARID1 A expression and clinicopathologic parameters, as well as its prognostic value, for patients with intrahepatic cholangiocarcinoma(IHCC).METHODS: We assessed ARID1 A p...AIM: To investigate the relationship between ARID1 A expression and clinicopathologic parameters, as well as its prognostic value, for patients with intrahepatic cholangiocarcinoma(IHCC).METHODS: We assessed ARID1 A protein and m RNA expression in IHCC tissues and paracarcinomatous(PC) tissues from 57 patients with IHCC using western blot and quantitative real-time reverse transcription polymerase chain reaction, respectively. We used Fisher's exact and χ2 tests to analyze relationships between clinicopathological parameters and ARID1 A expression. The Kaplan-Meier method and Cox regression were used to analyze survival.RESULTS: The mean ARID1 A protein level in IHCC tissues was 1.16 ± 0.36 relative units(RU), which was significantly lower than that in PC tissues(1.26 ± 0.21 RU, P < 0.01) and NL tissues(1.11 ± 0.31, P < 0.001).The mean ARID1 A m RNA level in IHCC tissues(1.20 ± 0.18) was also lower than that in PC tissues(1.27 ± 0.15, P < 0.001) and normal liver tissues(1.15 ± 0.34, P < 0.001). Low ARID1 A expression was significantly associated with tumor nodules, vein invasion, and recurrence. Median overall survival(OS) and disease-free survival(DFS) for the low ARID1 A expression group was 15.0 and 7.0 mo, respectively, which were significantly shorter than those for the high ARID1 A expression group at 25.0 and 22.0 mo(OS: P < 0.01; DFS: P < 0.001), respectively. Low ARID1 A expression was significantly associated with worse OS(HR = 3.967, 95%CI: 1.299-12.118, P = 0.016) in multivariate analyses.CONCLUSION: Low expression of ARID1 A is associated with poor prognosis in patients with IHCC, and thus may be a potential prognostic biomarker candidate in IHCC.展开更多
AIM: To compare kinesin family member 1B(KIF1B) expression with clinicopathologic parameters and prognosis in hepatocellular carcinoma(HCC) patients.METHODS: KIF1 B protein and m RNA expression was assessed in HCC and...AIM: To compare kinesin family member 1B(KIF1B) expression with clinicopathologic parameters and prognosis in hepatocellular carcinoma(HCC) patients.METHODS: KIF1 B protein and m RNA expression was assessed in HCC and paracarcinomatous(PC) tissues from 68 patients with HCC using Western blot and quantitative real-time reverse transcription-PCR, respectively. Student's t-tests were used to analyze relationships between clinicopathologic parameters and KIF1 B expression, the Kaplan-Meier method was used to analyze survival outcomes, and the log-rank test was used to compare survival differences between groups.RESULTS: Mean protein and m RNA levels of KIF1 B were similar between HCC and PC tissues. However, HCC tissues with vein invasions had significantly lower KIF1 B protein levels compared to those without vein invasions(2.30 ± 0.82 relative units vs 2.77 ± 0.84 relative units, P < 0.05). KIF1 B protein levels in HCC tissues from patients with recurrence during the followup period were significantly lower than those without recurrence(2.31 ± 0.92 relative units vs 2.80 ± 0.80 relative units, P < 0.05). However, KIF1 B protein and m RNA expression in HCC patients was not associated with other clinicopathologic parameters. Ratios of KIF1 B m RNA expression in HCC tissues to those in PC tissues were correlated with overall survival(13.5 mo vs 20.0 mo, P < 0.05) and disease-free survival(11.5 mo vs 19.5 mo, P < 0.05).CONCLUSION: Downregulation of KIF1 B in HCC tissues is associated with poor prognosis; additional clinical studies are needed to confirm whether KIF1 B can serve as a prognostic marker.展开更多
AIM: To measure the retinal vessels of primary open angle glaucoma(POAG) patients on spectral domain optical coherence tomography(SD-OCT) with a full-width at half-maximum(FWHM) algorithm to better explore their struc...AIM: To measure the retinal vessels of primary open angle glaucoma(POAG) patients on spectral domain optical coherence tomography(SD-OCT) with a full-width at half-maximum(FWHM) algorithm to better explore their structural changes in the pathogenesis of POAG.METHODS: In this retrospective case-control study, the right eyes of 32 patients with POAG and 30 healthy individuals were routinely selected.Images of the supratemporal and infratemporal retinal vessels in the B zones were obtained by SD-OCT, and the edges of the vessels were identified by the FWHM method.The internal and external diameters, wall thickness(WT), wall cross-sectional area(WCSA) and wall-to-lumen ratio(WLR) of the blood vessels were studied.RESULTS: Compared with the healthy control group, the POAG group showed a significantly reduced retinal arteriolar outer diameter(RAOD), retinal arteriolar lumen diameter(RALD) and WSCA in the supratemporal(124.22±12.42 vs 138.32±10.73 μm, 96.09±11.09 vs 108.53±9.89 μm,and 4762.02 ± 913.51 vs 5785.75 ± 114 8.28 μm^(2), respectively, all P<0.05) and infratemporal regions(125.01±15.55 vs 141.57±10.77 μm, 96.27±13.29 vs 110.83 ± 10.99 μm, and 4925.56 ± 1302.88 vs 6087.78±1061.55 μm^(2), all P<0.05).The arteriolar WT and WLR were not significantly different between the POAG and control groups, nor were the retinal venular outer diameter(RVOD), retinal venular lumen diameter(RVLD) or venular WT in the supratemporal or infratemporal region.There was a positive correlation between the arteriolar parameters and visual function.CONCLUSION: In POAG, narrowing of the supratemporal and infratemporal arterioles and a significant reduction in the WSCA is observed, while the arteriolar WT and WLR do not change.Among the venular parameters, the external diameter, internal diameter, WT, WLR, and WSCA of the venules are not affected.展开更多
Pterygium is a prevalent ocular disease that can cause discomfort and vision impairment.Early and accurate diagnosis is essential for effective management.Recently,artificial intelligence(AI)has shown promising potent...Pterygium is a prevalent ocular disease that can cause discomfort and vision impairment.Early and accurate diagnosis is essential for effective management.Recently,artificial intelligence(AI)has shown promising potential in assisting clinicians with pterygium diagnosis.This paper provides an overview of AI-assisted pterygium diagnosis,including the AI techniques used such as machine learning,deep learning,and computer vision.Furthermore,recent studies that have evaluated the diagnostic performance of AI-based systems for pterygium detection,classification and segmentation were summarized.The advantages and limitations of AI-assisted pterygium diagnosis and discuss potential future developments in this field were also analyzed.The review aims to provide insights into the current state-of-the-art of AI and its potential applications in pterygium diagnosis,which may facilitate the development of more efficient and accurate diagnostic tools for this common ocular disease.展开更多
The authors would like to make the following change to the above article:Co-first authors:Bang Chen and Xin-Wen Fang.The authors apologize for any inconvenience caused by this error.
Moirésuperlattices,arising from the controlled twisting of van der Waals homostructures at specific angles,have emerged as a promising platform for quantum emission applications.Concurrently,the manipulation of s...Moirésuperlattices,arising from the controlled twisting of van der Waals homostructures at specific angles,have emerged as a promising platform for quantum emission applications.Concurrently,the manipulation of strain provides a versatile strategy to finely adjust electronic band structures,enhance exciton luminescence efficiency,and establish a robust foundation for two-dimensional quantum light sources.However,the intricate interplay between strain and moirépotential remains partially unexplored.Here,we introduce a meticulously designed fusion of strain engineering and the twisted 2L-WSe_(2)/2L-WSe_(2) homobilayers,resulting in the precise localization of moiréexcitons.Employing low-temperature photoluminescence spectroscopy,we unveil the emergence of highly localized moiré-enhanced emission,characterized by the presence of multiple distinct emission lines.Furthermore,our investigation demonstrates the effective regulation of moirépotential depths through strain engineering,with the potential depths of strained and unstrained regions differing by 91%.By combining both experimental and theoretical approaches,our study elucidates the complex relationship between strain and moirépotential,thereby opening avenues for generating strain-induced moiréexciton single-photon sources.展开更多
Two-dimensional(2D)anisotropic materials have garnered significant attention in the realm of anisotropic optoelectronic devices due to their remarkable electrical,optical,thermal,and mechanical properties.While extens...Two-dimensional(2D)anisotropic materials have garnered significant attention in the realm of anisotropic optoelectronic devices due to their remarkable electrical,optical,thermal,and mechanical properties.While extensive research has delved into the optical and electrical characteristics of these materials,there remains a need for further exploration to identify novel materials and structures capable of fulfilling device requirements under various conditions.Here,we employ heterojunction interface engineering with black phosphorus(BP)to disrupt the C_(3) rotational symmetry of monolayer WS_(2).The resulting WS_(2)/BP heterostructure exhibits pronounced anisotropy in exciton emissions,with a measured anisotropic ratio of 1.84 for neutral excitons.Through a comprehensive analysis of magnetic-field-dependent and temperature-evolution photoluminescence spectra,we discern varying trends in the polarization ratio,notably observing a substantial anisotropy ratio of 1.94 at a temperature of 1.6 K and a magnetic field of 9 T.This dynamic behavior is attributed to the susceptibility of the WS_(2)/BP heterostructure interface strain to fluctuations in magnetic fields and temperatures.These findings provide valuable insights into the design of anisotropic optoelectronic devices capable of adaptation to a range of magnetic fields and temperatures,thereby advancing the frontier of material-driven device engineering.展开更多
Moiré superlattices based on twisted transition metal dichalcogenide (TMD) heterostructures have recently emerged as a promising platform for probing novel and distinctive electronic phenomena in two-dimensional ...Moiré superlattices based on twisted transition metal dichalcogenide (TMD) heterostructures have recently emerged as a promising platform for probing novel and distinctive electronic phenomena in two-dimensional (2D) materials. By stacking TMD monolayers with a small twist angle, these superlattices create a periodic modulation of the electronic density of states, leading to the formation of mini bands. These mini bands can exhibit intriguing properties such as flat bands, correlated electron behavior, and unconventional superconductivity. This review provides a comprehensive overview of recent progress in Moiré superlattices formed from twisted TMD heterostructures. It covers the theoretical principles and experimental techniques for creating and studying these superlattices, and explores their potential applications in optoelectronics, quantum computing, and energy harvesting. The review also addresses key challenges, such as improving the scalability and reproducibility of the fabrication process, emphasizing the exciting opportunities and ongoing hurdles in this rapidly evolving field.展开更多
Pressure exerts a profound influence on atomic configurations and interlayer interactions, thereby modulating the electronic and structural properties of materials. While high pressure has been observed to induce a st...Pressure exerts a profound influence on atomic configurations and interlayer interactions, thereby modulating the electronic and structural properties of materials. While high pressure has been observed to induce a structural phase transition in bulk PdSe_(2) crystals, leading to a transition from semiconductor to metal, the high-pressure behavior of few-layer PdSe_(2) remains elusive. Here, employing diamond anvil cell (DAC) techniques and high-pressure Raman spectroscopy, we investigate the structural evolution of layer-dependent PdSe_(2) under high pressure. We reveal that pressure significantly enhances interlayer coupling in PdSe_(2), driving structural phase transitions from an orthorhombic to a cubic phase. We demonstrate that PdSe_(2) crystals exhibit distinct layer-dependent pressure thresholds during the phase transition, with the decrease of transition pressure as the thickness of PdSe_(2) increases. Furthermore, our results of polarized Raman spectra confirm a reduction in material anisotropy with increasing pressure. This study offers crucial insights into the structural evolution of layer-dependent van der Waals materials under pressure, advancing our understanding of their pressure-induced behaviors.展开更多
Two-dimensional(2D)transition metal dichalcogenides(TMDs)have garnered considerable attention for their promising applications in sensors and optoelectronic devices,owing to their exceptional optical,electronic,and op...Two-dimensional(2D)transition metal dichalcogenides(TMDs)have garnered considerable attention for their promising applications in sensors and optoelectronic devices,owing to their exceptional optical,electronic,and optoelectronic properties.However,the inherent high symmetry of TMD lattices imposes limitations on their functional versatility.Here,we present a strategy to disrupt the C_(3)rotational symmetry of monolayer WSe_(2)by fabricating a heterostructure incorporating WSe_(2)and SiP flakes.Through comprehensive experimental investigations and first-principle calculations,we elucidate that in the WSe_(2)/SiP heterostructure,excitons-both neutral and charged-emanating from WSe_(2)exhibit pronounced anisotropy,which remains robust against temperature variations.Notably,we observe an anisotropic ratio reaching up to 1.5,indicating a substantial degree of anisotropy.Furthermore,we demonstrate the tunability of exciton anisotropy through the application of a magnetic field,resulting in a significant reduction in the anisotropic ratio with increasing field strength,from 1.57 to 1.18.Remarkably,the change in heterojunction anisotropy ratio reaches 24.8%as the magnetic field increases.Our findings elucidate that the perturbation of the C_(3)rotational symmetry of the WSe_(2)monolayer arises from a non-uniform charge density distribution within the layer,exhibiting mirror symmetry.These results underscore the potential of heterostructure engineering in tailoring the properties of isotropic materials and provide a promising avenue for advancing the application of anisotropic devices across various fields.展开更多
In this work, a scalable and cost-effective method including mechanical milling, centrifugation and spray drying was developed to fabricate Si nanoparticles.The synthesized Si nanoparticles show an average size of 62 ...In this work, a scalable and cost-effective method including mechanical milling, centrifugation and spray drying was developed to fabricate Si nanoparticles.The synthesized Si nanoparticles show an average size of 62 nm and exhibit a narrow particle size distribution. The influence of particle sizes on electrochemical performance of Si-based electrode was investigated, and it is found that as the particle size decreases in the studied range, the Si particles show a lower specific capacity and a higher irreversible capacity loss(ICL). Furthermore, an oxide layer with thickness of ~3 nm was detected on the surface of the as-received Si nanoparticles, and this layer can be effectively removed by hydrofluoric acid(HF) etching,resulting in much improved electrochemical performance over the as-received samples.展开更多
Purpose: To determine the effect of the posterior condylar offset (PCO) on clinical results after total knee arthroplasty (TKA) using a high-flex posterior-stabilized (PS) fixed-bearing prosthesis. Methods: We...Purpose: To determine the effect of the posterior condylar offset (PCO) on clinical results after total knee arthroplasty (TKA) using a high-flex posterior-stabilized (PS) fixed-bearing prosthesis. Methods: We prospectively studied the clinical and radiographic materials of 89 consecutive female patients (89 knees), who had undergone primary TKAs for end-stage osteoarthritis. All operations were performed by a single senior surgeon or under his supervision using the same operative technique. Based on the corrected PCO change, we divided all cases into two groups: group A (corrected PCO change _〉0 mm, 58 knees) and group B (corrected PCO change 〈0 ram, 31 knees). One-year postoperatively, clinical and radiographic variables from the two groups were compared by independent t-test. The as- sociations between the corrected PCO changes and the improvements of clinical variables in all patients were analyzed by Pearson linear correlation. Results: One-year postoperatively, the Knee Society Scores, the Western Ontario and McMaster Uni- versities Osteoarthritis Index, non-weight-bearing active and passive range of knee flexion, flexion contracture, extensor lag, and their improvements had no statistical differences between the two groups (all p 〉 0.05). The corrected PCO change was not significantly correlated with the improvement of any clinical variable (all p 〉 0.05). Group A demonstrated greater flexion than group B during active weight bearing (p 〈 0.05). Conclusions: Restoration of PCO plays an important role in the optimization of active knee flexion during weight-bearing conditions after posterior-stabilized TKA, while it has no benefit to non-weight-bearing knee flexion or any other clinical result.展开更多
A Si/Sn/SiOC/graphite(SSSG) composite with high efficiency and long-term cycling stability was synthesized by a cost-effective and scalable method, including the processes of mechanical milling and pyrolysis. The comp...A Si/Sn/SiOC/graphite(SSSG) composite with high efficiency and long-term cycling stability was synthesized by a cost-effective and scalable method, including the processes of mechanical milling and pyrolysis. The composite was characterized by X-ray diffraction(XRD),scanning electron microscope(SEM) and energy dispersive X-ray spectrometry(EDX). The electrochemical properties were investigated until the 25th cycle. As a result, the SSSG composite anode exhibits excellent long-term cycling stability and capacity. Such SSSG composite anode shows excellent cycling stability with a specific capacity of 568.2 mAh·g^(-1) and ~80% capacity retention over 25 cycles at 0.3C rate. The reasons for good electrochemical characteristics are considered that the SiOC net with favorable chemical stability acts as a skeleton to support and segregate Si/Sn nanostructures, and the graphitic mixing in the composite is used as conductive material to enhance the electrical conductivity in this composite. The results suggest that the design of this new structure has the potential to provide a way for the other functional composite materials.展开更多
Recently,the discovery of a variety of moiré-related properties in the twisted vertical stacking of two different monolayers has attracted considerable attention.The introduction of small twist angles in transiti...Recently,the discovery of a variety of moiré-related properties in the twisted vertical stacking of two different monolayers has attracted considerable attention.The introduction of small twist angles in transition metal dichalcogenide(TMD)heterostructures leads to the emergence of moirépotentials,which provide a fascinating platform for the study of strong interactions of electrons.While there has been extensive research on moiréexcitons in twisted bilayer superlattices,the capture and study of moiréexcitons in homostructure superlattices with layer-coupling effects remain elusive.Here,we present the observation of moiréexcitons in the twisted 1L-WSe_(2)/1L-WSe_(2)and 1L-WSe_(2)/2L-WSe_(2)homostructures with various layer-coupling interactions.The results reveal that the moirépotential increases(~260%)as the number of underlying layers decreases,indicating the effect of layer coupling on the modulation of the moirépotential.The effects of the temperature and laser power dependence as well as valley polarization on moiréexcitons were further demonstrated,and the crucial spectral features observed were explained.Our findings pave the way for exploring quantum phenomena and related applications of quantum information.展开更多
The stacking of twisted two-dimensional(2D)layered materials has led to the creation of moirésuperlattices,which have become a new platform for the study of quantum optics.The strong coupling of moirésuperla...The stacking of twisted two-dimensional(2D)layered materials has led to the creation of moirésuperlattices,which have become a new platform for the study of quantum optics.The strong coupling of moirésuperlattices can result in flat minibands that boost electronic interactions and generate interesting strongly correlated states,including unconventional superconductivity,Mott insulating states,and moiréexcitons.However,the impact of adjusting and localizing moiréexcitons in Van der Waals heterostructures has yet to be explored experimentally.Here,we present experimental evidence of the localization-enhanced moiréexcitons in the twisted WSe_(2)/WS_(2)/WSe_(2)heterotrilayer with type-II band alignments.At low temperatures,we observed multiple excitons splitting in the twisted WSe_(2)/WS_(2)/WSe_(2)heterotrilayer,which is manifested as multiple sharp emission lines,in stark contrast to the moiréexcitonic behavior of the twisted WSe_(2)/WS_(2)heterobilayer(which has a linewidth 4 times wider).This is due to the enhancement of the two moirépotentials in the twisted heterotrilayer,enabling highly localized moiréexcitons at the interface.The confinement effect of moirépotential on moiréexcitons is further demonstrated by changes in temperature,laser power,and valley polarization.Our findings offer a new approach for localizing moiréexcitons in twist-angle heterostructures,which has the potential for the development of coherent quantum light emitters.展开更多
Silicon nanowires(SiNWs)with diameter distributions ranging from 80 to 350 nm were prepared by electrochemical reduction of Ni/SiO2 in molten CaCl2.The effect of the content of nickel additives on the morphology of pr...Silicon nanowires(SiNWs)with diameter distributions ranging from 80 to 350 nm were prepared by electrochemical reduction of Ni/SiO2 in molten CaCl2.The effect of the content of nickel additives on the morphology of produced silicon was investigated.Large quantities of SiNWs are obtained by the electrochemical reduction of Ni/SiO2 blocks with SiO2 to Ni molar ratio of 20 and 10.Nickel additives repress the growth of irregular branches and promote longitudinal growth of SiNWs.Wire morphologies and surfaces are influenced by the electrolysis temperature.SiNWs become thicker with the increase of the electrolysis temperature.The optimum temperature to prepare single crystal SiNWs with high aspect ratio and extraordinary surface quality seems to be 1173 K.The amorphous layer of the silicon nanowire is thinner compared to the SiNWs obtained from the pure SiO2 pellets.The produced SiNWs show a photoluminescence emission peak at about 758 nm at room temperature.This work demonstrates the potentiality for the electrochemical reduction process to obtain large quantities of SiNWs with high quality.展开更多
Moirésuperlattices in van der Waals structures have emerged as a powerful platform for studying the novel quantum properties of two-dimensional materials.The periodic moirépatterns generated by these structu...Moirésuperlattices in van der Waals structures have emerged as a powerful platform for studying the novel quantum properties of two-dimensional materials.The periodic moirépatterns generated by these structures lead to the formation of flat mini-bands,which alter the electronic energy bands of the material.The resulting flat electronic bands can greatly enhance strong correlative interactions between electrons,leading to the emergence of exotic quantum phenomena,including moiréphonons and moiréexcitons.While extensive research has been conducted on the exotic quantum phenomena in twisted bilayers of transition metal dichalcogenides(TMDs),and the regulatory effect of stacked layers on moiréexcitons remains unexplored.In this study,we report the fabrication of a twisted WSe_(2)/WSe_(2)/WSe_(2) homotrilayer with two twist angles and investigate the influence of stacked layers on moiréexcitons.Our experiments reveal multiple moiréexciton splitting peaks in the twisted trilayer,with moirépotential depths of 78 and 112 meV in the bilayer and trilayer homostructures,respectively.We also observed the splitting of the moiréexcitons at 90 K,indicating the presence of a deeper moirépotential in the twisted trilayer.Moreover,we demonstrate that stacked layers can tune the moiréexcitons by manipulating temperature,laser power,and magnetic field.Our results provide a new physical model for studying moirésuperlattices and their quantum properties,which could potentially pave the way for the development of quantum optoelectronics.展开更多
The hot deformation behavior of homogenized Nia Al-based alloy MX246A has been characterized on the basis of its flow stress variation obtained by isothermal constant true strain rate compression testing on the MTS 81...The hot deformation behavior of homogenized Nia Al-based alloy MX246A has been characterized on the basis of its flow stress variation obtained by isothermal constant true strain rate compression testing on the MTS 810 machine in the temperature range of 1 150--1225 ℃ and strain rate range of 0. 001-0.1 s-1. Microstructural obser- vation revealed striped secondary γ' phase which was vertical to compression axis, and precipitation of fine ternary γ" phase. The amount of striped secondary γ' phase reduced and that of fine ternary γ' phase increased with increasing temperature and decreasing strain rate. The material exhibited peak stress followed by flow softening, but no obvious steady-state flow behavior. Microstructural investigations have shown no dynamic recrystallization happened. TEM studies indicated that the flow softening was controUed by dynamic recovery mechanism.展开更多
基金Supported by Guangdong Basic and Applied Basic Research Foundation (No.2021A1515111012).
文摘AIM:To investigate the impact of hsa_circ_0007482 on the proliferation and apoptosis of human pterygium fibroblasts(HPFs)and its correlation with the severity grades of pterygium.METHODS:Pterygium and normal conjunctival tissues were collected from the superior area of the same patient’s eye(n=33).The correlation between pterygium severity and hsa_circ_0007482 expression using quantitative reversetranscription polymerase chain reaction(RT-qPCR)were analyzed.Three distinct siRNA sequences targeting hsa_circ_0007482,along with a negative control sequence,were transfected into HPFs.Cell proliferation was assessed using the cell counting kit-8.Expression levels of Ki67,proliferating cell nuclear antigen(PCNA),Cyclin D1,Bax,B-cell lymphoma-2(Bcl-2),and Caspase-3 were measured via RT-qPCR.Immunofluorescence staining was employed to detect Ki67 and vimentin expressions.Apoptosis was evaluated using flow cytometry.RESULTS:Hsa_circ_0007482 expression was significantly higher in pterygium tissues compared to normal conjunctival tissues(P<0.001).Positive correlations were observed between hsa_circ_0007482 expression and pterygium severity,thickness,and vascular density.Knockdown of hsa_circ_0007482 inhibited cell proliferation,reducing the mRNA expression of Ki67,PCNA,and Cyclin D1 in HPFs.Hsa_circ_0007482 knockdown induced apoptosis,increasing mRNA expression levels of Bax and Caspase-3,while decreasing Bcl-2 expression in HPFs.Additionally,hsa_circ_0007482 knockdown attenuated vimentin expression in HPFs.CONCLUSION:The downregulation of hsa_circ_0007482 effectively hampers cell proliferation and triggers apoptosis in HPFs.There are discernible positive correlations detected between the expression of hsa_circ_0007482 and the severity of pterygium.
基金Supported by National Nature Science Foundation of China(No.62306254)SanMing Project of Medicine in Shenzhen(No.SZSM202311012)+1 种基金Shenzhen Fund for Guangdong Provincial High-level Clinical Key Specialties(No.SZGSP014)Shenzhen Science and Technology Program(No.KCXFZ20211020163813019).
文摘This paper analyzes the current status,technological developments,academic exchange platforms,and future challenges and solutions in the field of intelligent ophthalmology(IO)in China.In terms of technology,significant progress has been made in various areas,including diabetic retinopathy,fundus image analysis,quality assessment of medical artificial intelligence products,clinical research methods,technical evaluation,and industry standards.Researchers continually enhance the safety and standardization of IO technology by formulating a series of clinical application guidelines and standards.The establishment of domestic and international academic exchange platforms provides extensive collaboration opportunities for professionals in various fields,and various academic journals serve as publication platforms for IO research.However,challenges such as technological innovation,data privacy and security,lagging regulations,and talent shortages still pose obstacles to future development.To address these issues,future efforts should focus on strengthening technological research and development,regulatory framework construction,talent cultivation,and increasing patient awareness and acceptance of new technologies.By comprehensively addressing these challenges,IO in China is poised to further lead the industry’s development on a global scale,bringing more innovation and convenience to the field of ophthalmic healthcare.
文摘AIM: To investigate the relationship between ARID1 A expression and clinicopathologic parameters, as well as its prognostic value, for patients with intrahepatic cholangiocarcinoma(IHCC).METHODS: We assessed ARID1 A protein and m RNA expression in IHCC tissues and paracarcinomatous(PC) tissues from 57 patients with IHCC using western blot and quantitative real-time reverse transcription polymerase chain reaction, respectively. We used Fisher's exact and χ2 tests to analyze relationships between clinicopathological parameters and ARID1 A expression. The Kaplan-Meier method and Cox regression were used to analyze survival.RESULTS: The mean ARID1 A protein level in IHCC tissues was 1.16 ± 0.36 relative units(RU), which was significantly lower than that in PC tissues(1.26 ± 0.21 RU, P < 0.01) and NL tissues(1.11 ± 0.31, P < 0.001).The mean ARID1 A m RNA level in IHCC tissues(1.20 ± 0.18) was also lower than that in PC tissues(1.27 ± 0.15, P < 0.001) and normal liver tissues(1.15 ± 0.34, P < 0.001). Low ARID1 A expression was significantly associated with tumor nodules, vein invasion, and recurrence. Median overall survival(OS) and disease-free survival(DFS) for the low ARID1 A expression group was 15.0 and 7.0 mo, respectively, which were significantly shorter than those for the high ARID1 A expression group at 25.0 and 22.0 mo(OS: P < 0.01; DFS: P < 0.001), respectively. Low ARID1 A expression was significantly associated with worse OS(HR = 3.967, 95%CI: 1.299-12.118, P = 0.016) in multivariate analyses.CONCLUSION: Low expression of ARID1 A is associated with poor prognosis in patients with IHCC, and thus may be a potential prognostic biomarker candidate in IHCC.
文摘AIM: To compare kinesin family member 1B(KIF1B) expression with clinicopathologic parameters and prognosis in hepatocellular carcinoma(HCC) patients.METHODS: KIF1 B protein and m RNA expression was assessed in HCC and paracarcinomatous(PC) tissues from 68 patients with HCC using Western blot and quantitative real-time reverse transcription-PCR, respectively. Student's t-tests were used to analyze relationships between clinicopathologic parameters and KIF1 B expression, the Kaplan-Meier method was used to analyze survival outcomes, and the log-rank test was used to compare survival differences between groups.RESULTS: Mean protein and m RNA levels of KIF1 B were similar between HCC and PC tissues. However, HCC tissues with vein invasions had significantly lower KIF1 B protein levels compared to those without vein invasions(2.30 ± 0.82 relative units vs 2.77 ± 0.84 relative units, P < 0.05). KIF1 B protein levels in HCC tissues from patients with recurrence during the followup period were significantly lower than those without recurrence(2.31 ± 0.92 relative units vs 2.80 ± 0.80 relative units, P < 0.05). However, KIF1 B protein and m RNA expression in HCC patients was not associated with other clinicopathologic parameters. Ratios of KIF1 B m RNA expression in HCC tissues to those in PC tissues were correlated with overall survival(13.5 mo vs 20.0 mo, P < 0.05) and disease-free survival(11.5 mo vs 19.5 mo, P < 0.05).CONCLUSION: Downregulation of KIF1 B in HCC tissues is associated with poor prognosis; additional clinical studies are needed to confirm whether KIF1 B can serve as a prognostic marker.
基金Supported by Zhejiang Province Public Welfare Technology Application Research Project (No.LGF22H120017)Shenzhen Fund for Guangdong Provincial High-level Clinical Key Specialists (No.SZGSP014)+1 种基金Sanming Project of Medicine in Shenzhen (No.SZSM202011015)Shenzhen Fundamental Research Program (No.JCYJ20220818103207015)。
文摘AIM: To measure the retinal vessels of primary open angle glaucoma(POAG) patients on spectral domain optical coherence tomography(SD-OCT) with a full-width at half-maximum(FWHM) algorithm to better explore their structural changes in the pathogenesis of POAG.METHODS: In this retrospective case-control study, the right eyes of 32 patients with POAG and 30 healthy individuals were routinely selected.Images of the supratemporal and infratemporal retinal vessels in the B zones were obtained by SD-OCT, and the edges of the vessels were identified by the FWHM method.The internal and external diameters, wall thickness(WT), wall cross-sectional area(WCSA) and wall-to-lumen ratio(WLR) of the blood vessels were studied.RESULTS: Compared with the healthy control group, the POAG group showed a significantly reduced retinal arteriolar outer diameter(RAOD), retinal arteriolar lumen diameter(RALD) and WSCA in the supratemporal(124.22±12.42 vs 138.32±10.73 μm, 96.09±11.09 vs 108.53±9.89 μm,and 4762.02 ± 913.51 vs 5785.75 ± 114 8.28 μm^(2), respectively, all P<0.05) and infratemporal regions(125.01±15.55 vs 141.57±10.77 μm, 96.27±13.29 vs 110.83 ± 10.99 μm, and 4925.56 ± 1302.88 vs 6087.78±1061.55 μm^(2), all P<0.05).The arteriolar WT and WLR were not significantly different between the POAG and control groups, nor were the retinal venular outer diameter(RVOD), retinal venular lumen diameter(RVLD) or venular WT in the supratemporal or infratemporal region.There was a positive correlation between the arteriolar parameters and visual function.CONCLUSION: In POAG, narrowing of the supratemporal and infratemporal arterioles and a significant reduction in the WSCA is observed, while the arteriolar WT and WLR do not change.Among the venular parameters, the external diameter, internal diameter, WT, WLR, and WSCA of the venules are not affected.
基金Supported by National Natural Science Foundation of China(No.61906066)Scientific Research Fund of Zhejiang Provincial Education Department(No.Y202250196)+4 种基金Zhejiang Provincial Philosophy and Social Science Planning Project(No.21NDJC021Z)Natural Science Foundation of Ningbo City(No.202003N4072)Shenzhen Fund for Guangdong Provincial High-level Clinical Key Specialties(No.SZGSP014)Sanming Project of Medicine in Shenzhen(No.SZSM202011015)Shenzhen Fundamental Research Program(No.JCYJ20220818103207015).
文摘Pterygium is a prevalent ocular disease that can cause discomfort and vision impairment.Early and accurate diagnosis is essential for effective management.Recently,artificial intelligence(AI)has shown promising potential in assisting clinicians with pterygium diagnosis.This paper provides an overview of AI-assisted pterygium diagnosis,including the AI techniques used such as machine learning,deep learning,and computer vision.Furthermore,recent studies that have evaluated the diagnostic performance of AI-based systems for pterygium detection,classification and segmentation were summarized.The advantages and limitations of AI-assisted pterygium diagnosis and discuss potential future developments in this field were also analyzed.The review aims to provide insights into the current state-of-the-art of AI and its potential applications in pterygium diagnosis,which may facilitate the development of more efficient and accurate diagnostic tools for this common ocular disease.
文摘The authors would like to make the following change to the above article:Co-first authors:Bang Chen and Xin-Wen Fang.The authors apologize for any inconvenience caused by this error.
基金supported this research endeavor.Notably,the National Natural Science Foundation of China(No.52373311)the Science Talent Program of China,the Hunan Provincial Science Fund for Distinguished Young Scholars(No.2020JJ2059)+10 种基金the Hunan Province Key Research and Development Project(No.2019GK2233)the Youth Innovation Team(No.2019012)of Central South University(CSU)have played an essential role in facilitating the success of this study.Furthermore,the Science and Technology Innovation Basic Research Project of Shenzhen(No.JCYJ20190806144418859)the Key Program of the Science and Technology Department of Hunan Province(Nos.2019XK2001 and 2020XK2001)the National Natural Science Foundation of China(Nos.62090035 and U19A2090)have also made significant contributions to the advancement of this workThe support provided by the High-Performance Complex Manufacturing Key State Lab Project at CSU(No.ZZYJKT2020-12)has been of immeasurable value,greatly expediting the research processAcknowledgment is also extended to the Australian Research Council(ARC Discovery Project,DP180102976)for its pivotal role in driving forward this research agenda.AdditionallyJ.T.W.extends gratitude for the support received from the National Natural Science Foundation of China(Nos.92263202 and 11974387)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB33000000)the National Key Research and Development Program of China(No.2020YFA0711502)The authors also wish to convey their deep appreciation to the Beijing Super Cloud Computing Center(BSCC,http://www.blsc.cn)for granting access to high-performance computing(HPC)resources,which have been instrumental in yielding the research outcomes detailed in this paper.Finally,the authors hold profound gratitude for the support of the Postdoctoral Science Foundation of China(No.2022M713546)a vital contribution that has substantially propelled the advancement of this research endeavor.This work was supported in part by the High-Performance Computing Center of Central South University.
文摘Moirésuperlattices,arising from the controlled twisting of van der Waals homostructures at specific angles,have emerged as a promising platform for quantum emission applications.Concurrently,the manipulation of strain provides a versatile strategy to finely adjust electronic band structures,enhance exciton luminescence efficiency,and establish a robust foundation for two-dimensional quantum light sources.However,the intricate interplay between strain and moirépotential remains partially unexplored.Here,we introduce a meticulously designed fusion of strain engineering and the twisted 2L-WSe_(2)/2L-WSe_(2) homobilayers,resulting in the precise localization of moiréexcitons.Employing low-temperature photoluminescence spectroscopy,we unveil the emergence of highly localized moiré-enhanced emission,characterized by the presence of multiple distinct emission lines.Furthermore,our investigation demonstrates the effective regulation of moirépotential depths through strain engineering,with the potential depths of strained and unstrained regions differing by 91%.By combining both experimental and theoretical approaches,our study elucidates the complex relationship between strain and moirépotential,thereby opening avenues for generating strain-induced moiréexciton single-photon sources.
基金the National Natural Science Foundation of China(No.52373311)the High-Performance Complex Manufacturing Key State Lab Project at CSU(No.ZZYJKT2020-12)greatly expedited the research process.Gratitude is extended to the Australian Research Council(ARC Discovery Project,DP180102976)for its substantial contribution to advancing this research agenda.Moreover+2 种基金the National Natural Science Foundation of China(Nos.11974387 and 92263202)the National Key Research and Development Program of China(No.2020YFA0711502)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB33000000).
文摘Two-dimensional(2D)anisotropic materials have garnered significant attention in the realm of anisotropic optoelectronic devices due to their remarkable electrical,optical,thermal,and mechanical properties.While extensive research has delved into the optical and electrical characteristics of these materials,there remains a need for further exploration to identify novel materials and structures capable of fulfilling device requirements under various conditions.Here,we employ heterojunction interface engineering with black phosphorus(BP)to disrupt the C_(3) rotational symmetry of monolayer WS_(2).The resulting WS_(2)/BP heterostructure exhibits pronounced anisotropy in exciton emissions,with a measured anisotropic ratio of 1.84 for neutral excitons.Through a comprehensive analysis of magnetic-field-dependent and temperature-evolution photoluminescence spectra,we discern varying trends in the polarization ratio,notably observing a substantial anisotropy ratio of 1.94 at a temperature of 1.6 K and a magnetic field of 9 T.This dynamic behavior is attributed to the susceptibility of the WS_(2)/BP heterostructure interface strain to fluctuations in magnetic fields and temperatures.These findings provide valuable insights into the design of anisotropic optoelectronic devices capable of adaptation to a range of magnetic fields and temperatures,thereby advancing the frontier of material-driven device engineering.
基金the financial support received from various entities,including the National Natural Science Foundation of China(No.52373311)the Key Project of the Natural Science Program of Xinjiang Uygur Autonomous Region(No.2023D01D03)+4 种基金They also appreciate the support from the High-Performance Complex Manufacturing Key State Lab Project at Central South University(No.ZZYJKT2020-12)ZWL extends thanks to the Australian Research Council(ARC Discovery Project,DP180102976)for their supportJ.-T.W.acknowledges funding from the National Natural Science Foundation of China(Nos.92263202 and 12374020)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB33000000)the National Key Research and Development Program of China(No.2020YFA0711502)。
文摘Moiré superlattices based on twisted transition metal dichalcogenide (TMD) heterostructures have recently emerged as a promising platform for probing novel and distinctive electronic phenomena in two-dimensional (2D) materials. By stacking TMD monolayers with a small twist angle, these superlattices create a periodic modulation of the electronic density of states, leading to the formation of mini bands. These mini bands can exhibit intriguing properties such as flat bands, correlated electron behavior, and unconventional superconductivity. This review provides a comprehensive overview of recent progress in Moiré superlattices formed from twisted TMD heterostructures. It covers the theoretical principles and experimental techniques for creating and studying these superlattices, and explores their potential applications in optoelectronics, quantum computing, and energy harvesting. The review also addresses key challenges, such as improving the scalability and reproducibility of the fabrication process, emphasizing the exciting opportunities and ongoing hurdles in this rapidly evolving field.
基金the financial support received from various entities,including the National Natural Science Foundation of China(No.52373311)the Key Program of the Science and Technology Department of Hunan Province(Nos.2019XK2001 and 2020XK2001)+5 种基金the Key Project of the Natural Science Program of Xinjiang Uygur Autonomous Region(No.2023D01D03)They also appreciate the support from the High-Performance Complex Manufacturing Key State Lab Project at Central South University(No.ZZYJKT2020-12)Z.W.L.extends thanks to the Australian Research Council(ARC Discovery Project,DP180102976)for their supportJ.-T.W.acknowledges funding from the National Natural Science Foundation of China(Nos.92263202 and 12374020)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB33000000)the National Key Research and Development Program of China(No.2020YFA0711502)。
文摘Pressure exerts a profound influence on atomic configurations and interlayer interactions, thereby modulating the electronic and structural properties of materials. While high pressure has been observed to induce a structural phase transition in bulk PdSe_(2) crystals, leading to a transition from semiconductor to metal, the high-pressure behavior of few-layer PdSe_(2) remains elusive. Here, employing diamond anvil cell (DAC) techniques and high-pressure Raman spectroscopy, we investigate the structural evolution of layer-dependent PdSe_(2) under high pressure. We reveal that pressure significantly enhances interlayer coupling in PdSe_(2), driving structural phase transitions from an orthorhombic to a cubic phase. We demonstrate that PdSe_(2) crystals exhibit distinct layer-dependent pressure thresholds during the phase transition, with the decrease of transition pressure as the thickness of PdSe_(2) increases. Furthermore, our results of polarized Raman spectra confirm a reduction in material anisotropy with increasing pressure. This study offers crucial insights into the structural evolution of layer-dependent van der Waals materials under pressure, advancing our understanding of their pressure-induced behaviors.
基金the financial support from various sources.These include the National Natural Science Foundation of China(Nos.52373311,62090035,and U19A2090)the Youth Innovation Team of CSU(No.2019012)+8 种基金the Hunan Provincial Science Fund for Distinguished Young Scholars(No.2020JJ2059)the Hunan Province Key Research and Development Project(No.2019GK2233)the Key Program of Science and Technology Department of Hunan Province(Nos.2019XK2001 and 2020XK2001)the Science and Technology Innovation Basic Research Project of Shenzhen(No.JCYJ20190806144418859)the support of the High-Performance Complex Manufacturing Key State Lab Project,Central South University(No.ZZYJKT2020-12)the Australian Research Council(ARC Discovery Project,DP180102976)the support of the National Natural Science Foundation of China(Nos.92263202 and 12374020)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB33000000)the National Key Research and Development Program of China(No.2020YFA0711502).
文摘Two-dimensional(2D)transition metal dichalcogenides(TMDs)have garnered considerable attention for their promising applications in sensors and optoelectronic devices,owing to their exceptional optical,electronic,and optoelectronic properties.However,the inherent high symmetry of TMD lattices imposes limitations on their functional versatility.Here,we present a strategy to disrupt the C_(3)rotational symmetry of monolayer WSe_(2)by fabricating a heterostructure incorporating WSe_(2)and SiP flakes.Through comprehensive experimental investigations and first-principle calculations,we elucidate that in the WSe_(2)/SiP heterostructure,excitons-both neutral and charged-emanating from WSe_(2)exhibit pronounced anisotropy,which remains robust against temperature variations.Notably,we observe an anisotropic ratio reaching up to 1.5,indicating a substantial degree of anisotropy.Furthermore,we demonstrate the tunability of exciton anisotropy through the application of a magnetic field,resulting in a significant reduction in the anisotropic ratio with increasing field strength,from 1.57 to 1.18.Remarkably,the change in heterojunction anisotropy ratio reaches 24.8%as the magnetic field increases.Our findings elucidate that the perturbation of the C_(3)rotational symmetry of the WSe_(2)monolayer arises from a non-uniform charge density distribution within the layer,exhibiting mirror symmetry.These results underscore the potential of heterostructure engineering in tailoring the properties of isotropic materials and provide a promising avenue for advancing the application of anisotropic devices across various fields.
基金financially supported by the National Natural Science Foundation of China (No. 51404030)the National Key Technologies Research and Development Program (No. 2016YFB0100400)+2 种基金the Natural Science Foundation of Beijing Municipality (No. 3154043)the Beijing Science and Technology Plan (No. Z151100000115015)the Beijing Nova Program (No. Z161100004916096)
文摘In this work, a scalable and cost-effective method including mechanical milling, centrifugation and spray drying was developed to fabricate Si nanoparticles.The synthesized Si nanoparticles show an average size of 62 nm and exhibit a narrow particle size distribution. The influence of particle sizes on electrochemical performance of Si-based electrode was investigated, and it is found that as the particle size decreases in the studied range, the Si particles show a lower specific capacity and a higher irreversible capacity loss(ICL). Furthermore, an oxide layer with thickness of ~3 nm was detected on the surface of the as-received Si nanoparticles, and this layer can be effectively removed by hydrofluoric acid(HF) etching,resulting in much improved electrochemical performance over the as-received samples.
文摘Purpose: To determine the effect of the posterior condylar offset (PCO) on clinical results after total knee arthroplasty (TKA) using a high-flex posterior-stabilized (PS) fixed-bearing prosthesis. Methods: We prospectively studied the clinical and radiographic materials of 89 consecutive female patients (89 knees), who had undergone primary TKAs for end-stage osteoarthritis. All operations were performed by a single senior surgeon or under his supervision using the same operative technique. Based on the corrected PCO change, we divided all cases into two groups: group A (corrected PCO change _〉0 mm, 58 knees) and group B (corrected PCO change 〈0 ram, 31 knees). One-year postoperatively, clinical and radiographic variables from the two groups were compared by independent t-test. The as- sociations between the corrected PCO changes and the improvements of clinical variables in all patients were analyzed by Pearson linear correlation. Results: One-year postoperatively, the Knee Society Scores, the Western Ontario and McMaster Uni- versities Osteoarthritis Index, non-weight-bearing active and passive range of knee flexion, flexion contracture, extensor lag, and their improvements had no statistical differences between the two groups (all p 〉 0.05). The corrected PCO change was not significantly correlated with the improvement of any clinical variable (all p 〉 0.05). Group A demonstrated greater flexion than group B during active weight bearing (p 〈 0.05). Conclusions: Restoration of PCO plays an important role in the optimization of active knee flexion during weight-bearing conditions after posterior-stabilized TKA, while it has no benefit to non-weight-bearing knee flexion or any other clinical result.
基金the National High Technology Research and Development Program of China(Nos.2011AA11A256,2013AA050903,and 2013AA050906)。
文摘A Si/Sn/SiOC/graphite(SSSG) composite with high efficiency and long-term cycling stability was synthesized by a cost-effective and scalable method, including the processes of mechanical milling and pyrolysis. The composite was characterized by X-ray diffraction(XRD),scanning electron microscope(SEM) and energy dispersive X-ray spectrometry(EDX). The electrochemical properties were investigated until the 25th cycle. As a result, the SSSG composite anode exhibits excellent long-term cycling stability and capacity. Such SSSG composite anode shows excellent cycling stability with a specific capacity of 568.2 mAh·g^(-1) and ~80% capacity retention over 25 cycles at 0.3C rate. The reasons for good electrochemical characteristics are considered that the SiOC net with favorable chemical stability acts as a skeleton to support and segregate Si/Sn nanostructures, and the graphitic mixing in the composite is used as conductive material to enhance the electrical conductivity in this composite. The results suggest that the design of this new structure has the potential to provide a way for the other functional composite materials.
基金the National Natural Science Foundation of China(No.61775241)Hunan province key research and development project(No.2019GK2233)+9 种基金Hunan Provincial Science Fund for Distinguished Young Scholars(No.2020JJ2059)the Youth Innovation Team(No.2019012)of CSUthe Science and Technology Innovation Basic Research Project of Shenzhen(No.JCYJ20190806144418859)the National Natural Science Foundation of China(Nos.62090035 and U19A2090)the Key Program of Science and Technology Department of Hunan Province(Nos.2019XK2001 and 2020XK2001)support of the High-Performance Complex Manufacturing Key State Lab Project,Central South University(No.ZZYJKT2020-12)the Australian Research Council(ARC Discovery Project,No.DP180102976)the National Natural Science Foundation of China(No.11974387)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB33000000)the National Key Research and Development Program of China(No.2020YFA0711502).
文摘Recently,the discovery of a variety of moiré-related properties in the twisted vertical stacking of two different monolayers has attracted considerable attention.The introduction of small twist angles in transition metal dichalcogenide(TMD)heterostructures leads to the emergence of moirépotentials,which provide a fascinating platform for the study of strong interactions of electrons.While there has been extensive research on moiréexcitons in twisted bilayer superlattices,the capture and study of moiréexcitons in homostructure superlattices with layer-coupling effects remain elusive.Here,we present the observation of moiréexcitons in the twisted 1L-WSe_(2)/1L-WSe_(2)and 1L-WSe_(2)/2L-WSe_(2)homostructures with various layer-coupling interactions.The results reveal that the moirépotential increases(~260%)as the number of underlying layers decreases,indicating the effect of layer coupling on the modulation of the moirépotential.The effects of the temperature and laser power dependence as well as valley polarization on moiréexcitons were further demonstrated,and the crucial spectral features observed were explained.Our findings pave the way for exploring quantum phenomena and related applications of quantum information.
基金The authors express their gratitude to various organizations for their support in this research,including the National Natural Science Foundation of China(Grant No.61775241)the Hunan province key research and development project(Grant No.2019GK2233)+8 种基金the Hunan Provincial Science Fund for Distinguished Young Scholars(Grant No.2020JJ2059)the Youth Innovation Team(Grant No.2019012)of CSU.Additionally,they acknowledge the Science and Technology Innovation Basic Research Project of Shenzhen(Grant No.JCYJ20190806144418859)the National Natural Science Foundation of China(Nos.62090035 and U19A2090)the Key Program of Science and Technology Department of Hunan Province(2019XK2001,2020XK2001)The authors also thank the High-Performance Complex Manufacturing Key State Lab Project of Central South University(Grant No.ZZYJKT2020-12)for their support.Z.W.Lacknowledges the support from the Australian Research Council(ARC Discovery Project,DP180102976)C.T.W.is grateful for the support from the National Natural Science Foundation of China(Grant No.11974387)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB33000000)H.H.Z.acknowledges the support from the Postdoctoral Science Foundation of China(2022M713546).Finally,the authors recognize the Beijing Super Cloud Computing Center(BSCC)for providing HPC resources,which have greatly contributed to the results reported in this paper.
文摘The stacking of twisted two-dimensional(2D)layered materials has led to the creation of moirésuperlattices,which have become a new platform for the study of quantum optics.The strong coupling of moirésuperlattices can result in flat minibands that boost electronic interactions and generate interesting strongly correlated states,including unconventional superconductivity,Mott insulating states,and moiréexcitons.However,the impact of adjusting and localizing moiréexcitons in Van der Waals heterostructures has yet to be explored experimentally.Here,we present experimental evidence of the localization-enhanced moiréexcitons in the twisted WSe_(2)/WS_(2)/WSe_(2)heterotrilayer with type-II band alignments.At low temperatures,we observed multiple excitons splitting in the twisted WSe_(2)/WS_(2)/WSe_(2)heterotrilayer,which is manifested as multiple sharp emission lines,in stark contrast to the moiréexcitonic behavior of the twisted WSe_(2)/WS_(2)heterobilayer(which has a linewidth 4 times wider).This is due to the enhancement of the two moirépotentials in the twisted heterotrilayer,enabling highly localized moiréexcitons at the interface.The confinement effect of moirépotential on moiréexcitons is further demonstrated by changes in temperature,laser power,and valley polarization.Our findings offer a new approach for localizing moiréexcitons in twist-angle heterostructures,which has the potential for the development of coherent quantum light emitters.
基金financially supported by the National Natural Science Foundation of China(No.51404032 and No.51504032)the National High Technology Research and Development Program of China(No.2013AA050904)
文摘Silicon nanowires(SiNWs)with diameter distributions ranging from 80 to 350 nm were prepared by electrochemical reduction of Ni/SiO2 in molten CaCl2.The effect of the content of nickel additives on the morphology of produced silicon was investigated.Large quantities of SiNWs are obtained by the electrochemical reduction of Ni/SiO2 blocks with SiO2 to Ni molar ratio of 20 and 10.Nickel additives repress the growth of irregular branches and promote longitudinal growth of SiNWs.Wire morphologies and surfaces are influenced by the electrolysis temperature.SiNWs become thicker with the increase of the electrolysis temperature.The optimum temperature to prepare single crystal SiNWs with high aspect ratio and extraordinary surface quality seems to be 1173 K.The amorphous layer of the silicon nanowire is thinner compared to the SiNWs obtained from the pure SiO2 pellets.The produced SiNWs show a photoluminescence emission peak at about 758 nm at room temperature.This work demonstrates the potentiality for the electrochemical reduction process to obtain large quantities of SiNWs with high quality.
基金The study presented herein was generously supported by multiple funding agencies,including the National Natural Science Foundation of China(No.61775241)the Hunan Province Key Research and Development Project(No.2019GK2233)+9 种基金the Hunan Provincial Science Fund for Distinguished Young Scholars(No.2020JJ2059)the National Natural Science Foundation of China(Nos.62090035 and U19A2090)the Youth Innovation Team(No.2019012)of CSU,the Key Program of Science and Technology Department of Hunan Province(Nos.2019XK2001 and 2020XK2001)the Science and Technology Innovation Basic Research Project of Shenzhen(No.JCYJ20190806144418859)the Postdoctoral Science Foundation of China(No.2022M713546)The authors also express their gratitude to the High-Performance Complex Manufacturing Key State Lab Project,Central South University(No.ZZYJKT2020-12)the Australian Research Council(ARC Discovery Project,DP180102976)for their support of ZWLCTW is grateful for support from the National Natural Science Foundation of China(No.11974387)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB33000000)H.H.Z.acknowledges support from the Postdoctoral Science Foundation of China(No.2022M713546).
文摘Moirésuperlattices in van der Waals structures have emerged as a powerful platform for studying the novel quantum properties of two-dimensional materials.The periodic moirépatterns generated by these structures lead to the formation of flat mini-bands,which alter the electronic energy bands of the material.The resulting flat electronic bands can greatly enhance strong correlative interactions between electrons,leading to the emergence of exotic quantum phenomena,including moiréphonons and moiréexcitons.While extensive research has been conducted on the exotic quantum phenomena in twisted bilayers of transition metal dichalcogenides(TMDs),and the regulatory effect of stacked layers on moiréexcitons remains unexplored.In this study,we report the fabrication of a twisted WSe_(2)/WSe_(2)/WSe_(2) homotrilayer with two twist angles and investigate the influence of stacked layers on moiréexcitons.Our experiments reveal multiple moiréexciton splitting peaks in the twisted trilayer,with moirépotential depths of 78 and 112 meV in the bilayer and trilayer homostructures,respectively.We also observed the splitting of the moiréexcitons at 90 K,indicating the presence of a deeper moirépotential in the twisted trilayer.Moreover,we demonstrate that stacked layers can tune the moiréexcitons by manipulating temperature,laser power,and magnetic field.Our results provide a new physical model for studying moirésuperlattices and their quantum properties,which could potentially pave the way for the development of quantum optoelectronics.
文摘The hot deformation behavior of homogenized Nia Al-based alloy MX246A has been characterized on the basis of its flow stress variation obtained by isothermal constant true strain rate compression testing on the MTS 810 machine in the temperature range of 1 150--1225 ℃ and strain rate range of 0. 001-0.1 s-1. Microstructural obser- vation revealed striped secondary γ' phase which was vertical to compression axis, and precipitation of fine ternary γ" phase. The amount of striped secondary γ' phase reduced and that of fine ternary γ' phase increased with increasing temperature and decreasing strain rate. The material exhibited peak stress followed by flow softening, but no obvious steady-state flow behavior. Microstructural investigations have shown no dynamic recrystallization happened. TEM studies indicated that the flow softening was controUed by dynamic recovery mechanism.