Active rods propelled along their long axis align their velocities and orientations simultaneously in collision.However,as the propulsion is perpendicular to the long axis,velocity alignment becomes dynamically diffic...Active rods propelled along their long axis align their velocities and orientations simultaneously in collision.However,as the propulsion is perpendicular to the long axis,velocity alignment becomes dynamically difficult.Here,we show that ellipsoidal Quincke roller propelled along their short-axis(perpendicular to the long axis)can align their velocities by flipping and form flocking with nematic order.The flipping arises from the reversible transition between the static parallel spinless state and the spinning transversal state of ellipsoidal Quincke rollers.This is possible only near(above)the critical field where both the parallel spinless state and the spinning transversal spinning are metastable.The flipping-facilitated alignment offers an extra aligning mechanism for elongate active agents,and the resulting active liquid crystals serve a model system to explore the defect dynamics as the propulsion deviates from the local nematic orientation which has not been addressed yet.展开更多
Active matter is a non-equilibrium condensed system consisting of self-propelled particles capable of converting stored or ambient energy into collective motion.Typical active matter systems include cytoskeleton biopo...Active matter is a non-equilibrium condensed system consisting of self-propelled particles capable of converting stored or ambient energy into collective motion.Typical active matter systems include cytoskeleton biopolymers,swimming bacteria,artificial swimmers,and animal herds.In contrast to wet active matter,dry active matter is an active system characterized by the absence of significant hydrodynamic interactions and conserved momentum.In dry active matter,the role of surrounding fluids is providing viscous friction at low Reynolds numbers and can be neglected at high Reynolds numbers.This review offers a comprehensive overview of recent experimental,computational,and theoretical advances in understanding phase transitions and critical phenomena in dry aligning active matter,including polar particles,self-propelled rods,active nematics,and their chiral counterparts.Various ways of determining phase transition points as well as non-equilibrium phenomena,such as collective motion,cluster formation,and creation and annihilation of topological defects are reviewed.展开更多
Industrial data mining usually deals with data from different sources.These heterogeneous datasets describe the same object in different views.However,samples from some of the datasets may be lost.Then the remaining s...Industrial data mining usually deals with data from different sources.These heterogeneous datasets describe the same object in different views.However,samples from some of the datasets may be lost.Then the remaining samples do not correspond one-to-one correctly.Mismatched datasets caused by missing samples make the industrial data unavailable for further machine learning.In order to align the mismatched samples,this article presents a cooperative iteration matching method(CIMM)based on the modified dynamic time warping(DTW).The proposed method regards the sequentially accumulated industrial data as the time series.Mismatched samples are aligned by the DTW.In addition,dynamic constraints are applied to the warping distance of the DTW process to make the alignment more efficient.Then a series of models are trained with the cumulated samples iteratively.Several groups of numerical experiments on different missing patterns and missing locations are designed and analyzed to prove the effectiveness and the applicability of the proposed method.展开更多
The purpose of this study is to coordinate the alignment between the nursing curriculum and hospital clinical competencies,identify the reasons for the gaps,evaluate the impact of these gaps on the nursing profession,...The purpose of this study is to coordinate the alignment between the nursing curriculum and hospital clinical competencies,identify the reasons for the gaps,evaluate the impact of these gaps on the nursing profession,and propose strategies to bridge these gaps.This study will help strengthen nursing education,improve nursing students’skills,and help students adapt to complex clinical environments.展开更多
We investigated the effect of aligning crystal orientation in the microstructures containing sub micro-sized grains on the thermoelectric properties for polycrystalline Bi-Te materials.Bi-Te powder,prepared through th...We investigated the effect of aligning crystal orientation in the microstructures containing sub micro-sized grains on the thermoelectric properties for polycrystalline Bi-Te materials.Bi-Te powder,prepared through the conventional pulverization process,was sufficiently dispersed in an appropriate solvent,and then was formed into c-axis aligned green bodies under a designated high magnetic field.The green bodies were sintered with spark-plasma-sintering machine.The degree of crystal alignment of sintered bodies was examined with the electron-back-scatter-diffraction SEM and the X-ray diffraction patterns.It was observed that for both p and n type thermoelectric Bi-Te materials,aligning crystal orientation properly made electrical resistivity decreased with keeping Seebeck coefficient and thermal conductivity remained unchanged.As a typical result,the aligned Bi-Te material with the magnetic field of 10 tesla showed 30%enhancement of the thermoelectric performance.展开更多
Through theoretical analysis,we show how aligning pulse durations affect the degree and the time-rate slope of nitrogen field-free alignment at a fixed pulse intensity.It is found that both the degree and the slope fi...Through theoretical analysis,we show how aligning pulse durations affect the degree and the time-rate slope of nitrogen field-free alignment at a fixed pulse intensity.It is found that both the degree and the slope first increase,then saturate,and finally decrease with the increasing pump duration.The optimal durations for the maximum degree and the maximum slope of the alignment are found to be different.Additionally,they are found to mainly depend on the molecular rotational period,and are affected by the temperature and the aligning pump intensities.The mechanism of molecular alignment is also discussed.展开更多
With the increasing demand for beauty and health,clear aligners(CAs)have been widely applied among patients with malocclusion.However,patients treated with CAs also face some potential complications,such as deminerali...With the increasing demand for beauty and health,clear aligners(CAs)have been widely applied among patients with malocclusion.However,patients treated with CAs also face some potential complications,such as demineralization,dental caries,and periodontal diseases.In addition,some patients have additional needs to improve their quality of life,such as bleaching teeth.In order to prevent or solve these problems,the modification of CAs is a promising method because their extensive long-term contact with tooth surfaces makes them ideal devices for implementing adjuvant medical functions.In this review,we discuss various advanced CAs with medical functions based on the clinical needs of patients.As far as we know,the additional functions of CAs mainly include antibacterial,remineralization,whitening,and accelerating tooth movement.These functions are achieved by two major pathways,the combination of CAs with drugs/biomaterials and increasing the capacity or affinity of drugs.In addition,we discuss the current limitations of in vitro experiments which are designed to explore the effectiveness and properties of novel CAs,and the challenges of bringing a multifunctional appliance from proposal to clinical application.At the end of this review,we provide insights into the broader prospects for the improvement of CAs.展开更多
Autografting is the gold standard for surgical repair of nerve defects>5 mm in length;however,autografting is associated with potential complications at the nerve donor site.As an alternative,nerve guidance conduit...Autografting is the gold standard for surgical repair of nerve defects>5 mm in length;however,autografting is associated with potential complications at the nerve donor site.As an alternative,nerve guidance conduits may be used.The ideal conduit should be flexible,resistant to kinks and lumen collapse,and provide physical cues to guide nerve regeneration.We designed a novel flexible conduit using electrospinning technology to create fibers on the innermost surface of the nerve guidance conduit and employed melt spinning to align them.Subsequently,we prepared disordered electrospun fibers outside the aligned fibers and helical melt-spun fibers on the outer wall of the electrospun fiber lumen.The presence of aligned fibers on the inner surface can promote the extension of nerve cells along the fibers.The helical melt-spun fibers on the outer surface can enhance resistance to kinking and compression and provide stability.Our novel conduit promoted nerve regeneration and functional recovery in a rat sciatic nerve defect model,suggesting that it has potential for clinical use in human nerve injuries.展开更多
Clear aligner treatment is a novel technique in current orthodontic practice.Distinct from traditional fixed orthodontic appliances,clear aligners have different material features and biomechanical characteristics and...Clear aligner treatment is a novel technique in current orthodontic practice.Distinct from traditional fixed orthodontic appliances,clear aligners have different material features and biomechanical characteristics and treatment efficiencies,presenting new clinical challenges.Therefore,a comprehensive and systematic description of the key clinical aspects of clear aligner treatment is essential to enhance treatment efficacy and facilitate the advancement and wide adoption of this new technique.This expert consensus discusses case selection and grading of treatment difficulty,principle of clear aligner therapy,clinical procedures and potential complications,which are crucial to the clinical success of clear aligner treatment.展开更多
Through strategies such as process optimization,solvent selection,and component tuning,the crystallization of perovskite materials has been effectively controlled,enabling perovskite solar cells(PSCs)to achieve over 2...Through strategies such as process optimization,solvent selection,and component tuning,the crystallization of perovskite materials has been effectively controlled,enabling perovskite solar cells(PSCs)to achieve over 25%power conversion efficiency(PCE).However,as PCE continues to improve,interfacial issues within the devices have emerged as critical bottlenecks,hindering further performance enhancements.Recently,interfacial engineering has driven transformative progress,pushing PCEs to nearly 27%.Building upon these developments,this review first summarizes the pivotal role of interfacial modifications in elevating device performance and then,as a starting point,provides a comprehensive overview of recent advancements in normal,inverted,and tandem structure devices.Finally,based on the current progress of PSCs,preliminary perspectives on future directions are presented.展开更多
A polarization-sensitive and flexible photodetector was fabricated through the precise alignment of perovskite nanowires(NWs)using a brush coating technique.The alignment of the NWs was meticulously examined,consideri...A polarization-sensitive and flexible photodetector was fabricated through the precise alignment of perovskite nanowires(NWs)using a brush coating technique.The alignment of the NWs was meticulously examined,considering various chemical properties of the solvent,such as boiling point,viscosity,and surface tension.Notably,when the NWs were brush-coated with toluene dispersion,the NWs were aligned in higher order than those processed from octane dispersion.The degree of alignment was correlated with the photodetector property.Especially,the well-aligned NW photodetector exhibited a two-fold disparity in current response contingent on the polarization direction.Furthermore,even after enduring 500 bending cycles,the device retained 80%of its photodetector performance.This approach underscores the potential of solution-processed flexible photodetectors for advanced optical applications under dynamic operating conditions.展开更多
Nanocrystals have emerged as cutting-edge functional materials benefiting from the increased surface and enhanced coupling of electronic states.High-resolution imaging in transmission electron microscope can provide i...Nanocrystals have emerged as cutting-edge functional materials benefiting from the increased surface and enhanced coupling of electronic states.High-resolution imaging in transmission electron microscope can provide invaluable structural information of crystalline materials,albeit it remains greatly challenging to nanocrystals due to the arduousness of accurate zone axis adjustment.Herein,a homemade software package,called SmartAxis,is developed for rapid yet accurate zone axis alignment of nanocrystals.Incident electron beam tilt is employed as an eccentric goniometer to measure the angular deviation of a crystal to a zone axis,and then serves as a linkage to calculate theαandβtilts of goniometer based on an accurate quantitative relationship.In this way,high-resolution imaging of one identical small Au nanocrystal,as well as electron beam-sensitive MIL-101 metal-organic framework crystals,along multiple zone axes,was performed successfully by using this accurate,time-and electron dose-saving zone axis alignment software package.展开更多
Van der Waals(vdW)ferroelectric-semiconductor heterojunction provides reconfigurable band alignment based on optical/electrical-assisted polarization switching,which shows great potential to construct artificial visua...Van der Waals(vdW)ferroelectric-semiconductor heterojunction provides reconfigurable band alignment based on optical/electrical-assisted polarization switching,which shows great potential to construct artificial visual neural systems.However,the mechanical exfoliation fabrication scheme for proof-of-concept demonstrations and fundamental studies is cumbersome and not scalable for practical application.Here,we present a synthetic strategy for the large-scale and high crystallinity growth of planar/verticalα-In_(2)Se_(3)/MoS_(2)heterojunctions by dynamically tuning the growth temperature.Furthermore,based on theα-In_(2)Se_(3)/MoS_(2)heterostructures,photo-synapse devices are designed and fabricated to simulate visual neural systems functions,including multistate storage,optical logic operation,potentiation and depression,paired-pulse facilitation(PPF),short-term memory(STM),long-term memory(LTM),and Learning-Forgetting-Relearning.By coupling the spatiotemporally relevant optical and electric information,the device can mimic the superior biological visual system’s light adaptation and Pavlovian conditioning.This work provides a strategy for dynamically tuning the orientation of ferroelectric-semiconductor heterojunction stacks and will give impetus to applying all-in-one sensing and memory-computing artificial vision systems.展开更多
With the rapid expansion of social media,analyzing emotions and their causes in texts has gained significant importance.Emotion-cause pair extraction enables the identification of causal relationships between emotions...With the rapid expansion of social media,analyzing emotions and their causes in texts has gained significant importance.Emotion-cause pair extraction enables the identification of causal relationships between emotions and their triggers within a text,facilitating a deeper understanding of expressed sentiments and their underlying reasons.This comprehension is crucial for making informed strategic decisions in various business and societal contexts.However,recent research approaches employing multi-task learning frameworks for modeling often face challenges such as the inability to simultaneouslymodel extracted features and their interactions,or inconsistencies in label prediction between emotion-cause pair extraction and independent assistant tasks like emotion and cause extraction.To address these issues,this study proposes an emotion-cause pair extraction methodology that incorporates joint feature encoding and task alignment mechanisms.The model consists of two primary components:First,joint feature encoding simultaneously generates features for emotion-cause pairs and clauses,enhancing feature interactions between emotion clauses,cause clauses,and emotion-cause pairs.Second,the task alignment technique is applied to reduce the labeling distance between emotion-cause pair extraction and the two assistant tasks,capturing deep semantic information interactions among tasks.The proposed method is evaluated on a Chinese benchmark corpus using 10-fold cross-validation,assessing key performance metrics such as precision,recall,and F1 score.Experimental results demonstrate that the model achieves an F1 score of 76.05%,surpassing the state-of-the-art by 1.03%.The proposed model exhibits significant improvements in emotion-cause pair extraction(ECPE)and cause extraction(CE)compared to existing methods,validating its effectiveness.This research introduces a novel approach based on joint feature encoding and task alignment mechanisms,contributing to advancements in emotion-cause pair extraction.However,the study’s limitation lies in the data sources,potentially restricting the generalizability of the findings.展开更多
Few-layer nanosheets(NSs)of hexagonal boron nitride(h-BN)and molybdenum disulfide(MoS_(2))display notable piezoelectric properties.Yet,their integration into polymers typically yields non-piezoelectric composites due ...Few-layer nanosheets(NSs)of hexagonal boron nitride(h-BN)and molybdenum disulfide(MoS_(2))display notable piezoelectric properties.Yet,their integration into polymers typically yields non-piezoelectric composites due to NSs’random distribution.We introduce a facile method for fabricating intrinsic piezoelectric composites incorporated with NSs without electric poling.Our innovative process aligns NSs within polyvinyl alcohol polymer,leveraging ice-water interfacial tension,water crystallization thrust,and directional cross-linking during freezing.The resulting PE composites exhibit a maximum piezoelectric coefficient of up to 25.5-28.4 pC N^(-1),comparable to polyvinylidene difluoride(PVDF),with significant costefficiency,safety,and scalability advantages over conventional materials.Using this composite,we develop highly sensitive wearable pressure and strain sensors,and an ultrasound energy harvester.These sensors detect finger bending and differentiate between walking and running,while the harvester generates1.18 V/2.31μA under 1Wcm^(-2)ultrasound input underwater.This universal method offers a novel manufacturing technique for piezoelectric composites,demonstrating remarkable effectiveness in synthesizing intrinsic piezoelectric composites based on 2D materials.Moreover,its potential extends to applications in wearable electronics and energy harvesting,promising significant advancements in these fields.展开更多
Large language models(LLMs)represent significant advancements in artificial intelligence.However,their increasing capabilities come with a serious challenge:misalignment,which refers to the deviation of model behavior...Large language models(LLMs)represent significant advancements in artificial intelligence.However,their increasing capabilities come with a serious challenge:misalignment,which refers to the deviation of model behavior from the designers’intentions and human values.This review aims to synthesize the current understanding of the LLM misalignment issue and provide researchers and practitioners with a comprehensive overview.We define the concept of misalignment and elaborate on its various manifestations,including generating harmful content,factual errors(hallucinations),propagating biases,failing to follow instructions,emerging deceptive behaviors,and emergent misalignment.We explore the multifaceted causes of misalignment,systematically analyzing factors from surface-level technical issues(e.g.,training data,objective function design,model scaling)to deeper fundamental challenges(e.g.,difficulties formalizing values,discrepancies between training signals and real intentions).This review covers existing and emerging techniques for detecting and evaluating the degree of misalignment,such as benchmark tests,red-teaming,and formal safety assessments.Subsequently,we examine strategies to mitigate misalignment,focusing on mainstream alignment techniques such as RLHF,Constitutional AI(CAI),instruction fine-tuning,and novel approaches that address scalability and robustness.In particular,we analyze recent advances in misalignment attack research,including system prompt modifications,supervised fine-tuning,self-supervised representation attacks,and model editing,which challenge the robustness of model alignment.We categorize and analyze the surveyed literature,highlighting major findings,persistent limitations,and current contentious points.Finally,we identify key open questions and propose several promising future research directions,including constructing high-quality alignment datasets,exploring novel alignment methods,coordinating diverse values,and delving into the deep philosophical aspects of alignment.This work underscores the complexity and multidimensionality of LLM misalignment issues,calling for interdisciplinary approaches to reliably align LLMs with human values.展开更多
Bismuth oxyselenide(Bi_(2)O_(2)Se),a novel quasi-two-dimensional charge-carrying semiconductor,is recognized as one of the most promising emerging platforms for next-generation semiconductor devices.Recent advancement...Bismuth oxyselenide(Bi_(2)O_(2)Se),a novel quasi-two-dimensional charge-carrying semiconductor,is recognized as one of the most promising emerging platforms for next-generation semiconductor devices.Recent advancements in the development of diverse Bi_(2)O_(2)Se heterojunctions have unveiled extensive potential applications in both electronics and optoelectronics.However,achieving an in-depth understanding of band alignment and particularly interface dynamics remains a significant challenge.In this study,we conduct a comprehensive experimental investigation into band alignment utilizing high-resolution X-ray photoelectron spectroscopy(HRXPS),while also thoroughly discussing the properties of interface states.Our findings reveal that ultrathin films of Bi_(2)O_(2)Se grown on SrTiO_(3)(with TiO_(2)(001)termination)exhibit Type-I(straddling gap)band alignment characterized by a valence band offset(VBO)of approximately 1.77±0.04 eV and a conduction band offset(CBO)around 0.68±0.04 eV.Notably,when accounting for the influence of interface states,the bands at the interface display a herringbone configuration due to substantial built-in electric fields,which markedly deviate from conventional band alignments.Thus,our results provide valuable insights for advancing high-efficiency electronic and optoelectronic devices,particularly those where charge transfer is highly sensitive to interface states.展开更多
Metal halide perovskites,owing to their remarkable optoelectronic properties and broad application prospects,have emerged as a research hotspot in materials science and photovoltaics.In addressing challenges related t...Metal halide perovskites,owing to their remarkable optoelectronic properties and broad application prospects,have emerged as a research hotspot in materials science and photovoltaics.In addressing challenges related to energy loss,photoelectric conversion efficiency,and operational stability in perovskite solar cells(PSCs),various strategies have been proposed,such as improving perovskite crystallization,developing tandem architectures,and advancing interfacial engineering.However,the specific impact of these approaches on internal energy transfer and conversion mechanisms within PSCs remains insufficiently understood.This review systematically examines the relationship between energy and perovskite materials throughout the photon absorption to charge carrier transport process,with particular focus on key strategies for minimizing energy losses and their underlying influence on energy-level alignment-especially in the electron transport layer and hole transport layer.It summarizes optimal absorption conditions and contributing factors during energy transfer,alongside representative case studies of high-performing systems.By elucidating these mechanisms,this work offers valuable theoretical insights for optimizing energy-level alignment,reducing energy dissipation,and guiding experimental design in PSCs research.展开更多
基金financial support of the National Natural Science Foundation of China(Grant No.11974255)。
文摘Active rods propelled along their long axis align their velocities and orientations simultaneously in collision.However,as the propulsion is perpendicular to the long axis,velocity alignment becomes dynamically difficult.Here,we show that ellipsoidal Quincke roller propelled along their short-axis(perpendicular to the long axis)can align their velocities by flipping and form flocking with nematic order.The flipping arises from the reversible transition between the static parallel spinless state and the spinning transversal state of ellipsoidal Quincke rollers.This is possible only near(above)the critical field where both the parallel spinless state and the spinning transversal spinning are metastable.The flipping-facilitated alignment offers an extra aligning mechanism for elongate active agents,and the resulting active liquid crystals serve a model system to explore the defect dynamics as the propulsion deviates from the local nematic orientation which has not been addressed yet.
基金granted by the National Natural Science Foundation of China(No.12047503)Wenzhou Institute,University of Chinese Academy of Sciences(No.WIUCASQD2023009)。
文摘Active matter is a non-equilibrium condensed system consisting of self-propelled particles capable of converting stored or ambient energy into collective motion.Typical active matter systems include cytoskeleton biopolymers,swimming bacteria,artificial swimmers,and animal herds.In contrast to wet active matter,dry active matter is an active system characterized by the absence of significant hydrodynamic interactions and conserved momentum.In dry active matter,the role of surrounding fluids is providing viscous friction at low Reynolds numbers and can be neglected at high Reynolds numbers.This review offers a comprehensive overview of recent experimental,computational,and theoretical advances in understanding phase transitions and critical phenomena in dry aligning active matter,including polar particles,self-propelled rods,active nematics,and their chiral counterparts.Various ways of determining phase transition points as well as non-equilibrium phenomena,such as collective motion,cluster formation,and creation and annihilation of topological defects are reviewed.
基金the Key National Natural Science Foundation of China(No.U1864211)the National Natural Science Foundation of China(No.11772191)the Natural Science Foundation of Shanghai(No.21ZR1431500)。
文摘Industrial data mining usually deals with data from different sources.These heterogeneous datasets describe the same object in different views.However,samples from some of the datasets may be lost.Then the remaining samples do not correspond one-to-one correctly.Mismatched datasets caused by missing samples make the industrial data unavailable for further machine learning.In order to align the mismatched samples,this article presents a cooperative iteration matching method(CIMM)based on the modified dynamic time warping(DTW).The proposed method regards the sequentially accumulated industrial data as the time series.Mismatched samples are aligned by the DTW.In addition,dynamic constraints are applied to the warping distance of the DTW process to make the alignment more efficient.Then a series of models are trained with the cumulated samples iteratively.Several groups of numerical experiments on different missing patterns and missing locations are designed and analyzed to prove the effectiveness and the applicability of the proposed method.
文摘The purpose of this study is to coordinate the alignment between the nursing curriculum and hospital clinical competencies,identify the reasons for the gaps,evaluate the impact of these gaps on the nursing profession,and propose strategies to bridge these gaps.This study will help strengthen nursing education,improve nursing students’skills,and help students adapt to complex clinical environments.
基金Item Sponsored by Energy Efficiency&Resources of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Ministry of Knowledge Economy,Republic of Korea(2007EID11P050000)the DGIST Basic Research Program of the Ministry of Education,Science and Technology(MoEST),Republic of Korea(12-EN-01)
文摘We investigated the effect of aligning crystal orientation in the microstructures containing sub micro-sized grains on the thermoelectric properties for polycrystalline Bi-Te materials.Bi-Te powder,prepared through the conventional pulverization process,was sufficiently dispersed in an appropriate solvent,and then was formed into c-axis aligned green bodies under a designated high magnetic field.The green bodies were sintered with spark-plasma-sintering machine.The degree of crystal alignment of sintered bodies was examined with the electron-back-scatter-diffraction SEM and the X-ray diffraction patterns.It was observed that for both p and n type thermoelectric Bi-Te materials,aligning crystal orientation properly made electrical resistivity decreased with keeping Seebeck coefficient and thermal conductivity remained unchanged.As a typical result,the aligned Bi-Te material with the magnetic field of 10 tesla showed 30%enhancement of the thermoelectric performance.
基金Project supported by the National Natural Science Foundation of China (Grants Nos. 10634020,11074014 and 10821062)
文摘Through theoretical analysis,we show how aligning pulse durations affect the degree and the time-rate slope of nitrogen field-free alignment at a fixed pulse intensity.It is found that both the degree and the slope first increase,then saturate,and finally decrease with the increasing pump duration.The optimal durations for the maximum degree and the maximum slope of the alignment are found to be different.Additionally,they are found to mainly depend on the molecular rotational period,and are affected by the temperature and the aligning pump intensities.The mechanism of molecular alignment is also discussed.
基金supported by Postdoctoral Science Foundation of China(Nos.2018M630883 and 2019T120688)Hubei Province Chinese Medicine Research Project(No.ZY2023Q015)Natural Science Foundation of Hubei Province(No.2023AFB665)。
文摘With the increasing demand for beauty and health,clear aligners(CAs)have been widely applied among patients with malocclusion.However,patients treated with CAs also face some potential complications,such as demineralization,dental caries,and periodontal diseases.In addition,some patients have additional needs to improve their quality of life,such as bleaching teeth.In order to prevent or solve these problems,the modification of CAs is a promising method because their extensive long-term contact with tooth surfaces makes them ideal devices for implementing adjuvant medical functions.In this review,we discuss various advanced CAs with medical functions based on the clinical needs of patients.As far as we know,the additional functions of CAs mainly include antibacterial,remineralization,whitening,and accelerating tooth movement.These functions are achieved by two major pathways,the combination of CAs with drugs/biomaterials and increasing the capacity or affinity of drugs.In addition,we discuss the current limitations of in vitro experiments which are designed to explore the effectiveness and properties of novel CAs,and the challenges of bringing a multifunctional appliance from proposal to clinical application.At the end of this review,we provide insights into the broader prospects for the improvement of CAs.
基金supported by the National Natural Science Foundation of China,No.82202718the Natural Science Foundation of Beijing,No.L212050the China Postdoctoral Science Foundation,Nos.2019M664007,2021T140793(all to ZL)。
文摘Autografting is the gold standard for surgical repair of nerve defects>5 mm in length;however,autografting is associated with potential complications at the nerve donor site.As an alternative,nerve guidance conduits may be used.The ideal conduit should be flexible,resistant to kinks and lumen collapse,and provide physical cues to guide nerve regeneration.We designed a novel flexible conduit using electrospinning technology to create fibers on the innermost surface of the nerve guidance conduit and employed melt spinning to align them.Subsequently,we prepared disordered electrospun fibers outside the aligned fibers and helical melt-spun fibers on the outer wall of the electrospun fiber lumen.The presence of aligned fibers on the inner surface can promote the extension of nerve cells along the fibers.The helical melt-spun fibers on the outer surface can enhance resistance to kinking and compression and provide stability.Our novel conduit promoted nerve regeneration and functional recovery in a rat sciatic nerve defect model,suggesting that it has potential for clinical use in human nerve injuries.
文摘Clear aligner treatment is a novel technique in current orthodontic practice.Distinct from traditional fixed orthodontic appliances,clear aligners have different material features and biomechanical characteristics and treatment efficiencies,presenting new clinical challenges.Therefore,a comprehensive and systematic description of the key clinical aspects of clear aligner treatment is essential to enhance treatment efficacy and facilitate the advancement and wide adoption of this new technique.This expert consensus discusses case selection and grading of treatment difficulty,principle of clear aligner therapy,clinical procedures and potential complications,which are crucial to the clinical success of clear aligner treatment.
基金supported by National Natural Science Foundation of China(52302229,62404072)the Key Lab of Modern Optical Technologies of Education Ministry of China,Soochow University(KJS2425)+1 种基金Doctoral Foundation of Henan Polytech-nic University(B2024-72)Science and Technology Research Project of Jiangxi Provincial Department of Education(Grant No.GJJ2400702).
文摘Through strategies such as process optimization,solvent selection,and component tuning,the crystallization of perovskite materials has been effectively controlled,enabling perovskite solar cells(PSCs)to achieve over 25%power conversion efficiency(PCE).However,as PCE continues to improve,interfacial issues within the devices have emerged as critical bottlenecks,hindering further performance enhancements.Recently,interfacial engineering has driven transformative progress,pushing PCEs to nearly 27%.Building upon these developments,this review first summarizes the pivotal role of interfacial modifications in elevating device performance and then,as a starting point,provides a comprehensive overview of recent advancements in normal,inverted,and tandem structure devices.Finally,based on the current progress of PSCs,preliminary perspectives on future directions are presented.
基金supported by a Commercialization Promotion Agency for R&D Outcomes(COMPA)Grant funded by the Korean Government(Ministry of Science and ICT)(No.RS-2023-00304743)the National Research Foundation of Korea(NRF)Grant funded by the Korean Government(MSIT)(No.2022M3J7A1066428)"Regional Innovation Strategy(RIS)"through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(MOE)(No.2023RIS-008).
文摘A polarization-sensitive and flexible photodetector was fabricated through the precise alignment of perovskite nanowires(NWs)using a brush coating technique.The alignment of the NWs was meticulously examined,considering various chemical properties of the solvent,such as boiling point,viscosity,and surface tension.Notably,when the NWs were brush-coated with toluene dispersion,the NWs were aligned in higher order than those processed from octane dispersion.The degree of alignment was correlated with the photodetector property.Especially,the well-aligned NW photodetector exhibited a two-fold disparity in current response contingent on the polarization direction.Furthermore,even after enduring 500 bending cycles,the device retained 80%of its photodetector performance.This approach underscores the potential of solution-processed flexible photodetectors for advanced optical applications under dynamic operating conditions.
基金supported by the National Key R&D Program of China(No.2021YFA1501002)Thousand Talents Program for Distinguished Young Scholars.X.Li thanks the National Natural Science Foundation of China(No.22309021).
文摘Nanocrystals have emerged as cutting-edge functional materials benefiting from the increased surface and enhanced coupling of electronic states.High-resolution imaging in transmission electron microscope can provide invaluable structural information of crystalline materials,albeit it remains greatly challenging to nanocrystals due to the arduousness of accurate zone axis adjustment.Herein,a homemade software package,called SmartAxis,is developed for rapid yet accurate zone axis alignment of nanocrystals.Incident electron beam tilt is employed as an eccentric goniometer to measure the angular deviation of a crystal to a zone axis,and then serves as a linkage to calculate theαandβtilts of goniometer based on an accurate quantitative relationship.In this way,high-resolution imaging of one identical small Au nanocrystal,as well as electron beam-sensitive MIL-101 metal-organic framework crystals,along multiple zone axes,was performed successfully by using this accurate,time-and electron dose-saving zone axis alignment software package.
基金supported by the National Natural Science Foundation of China(Nos.52371245,12174237,12241403)the National Key Research and Development Program of China(No.2022YFB3505301).
文摘Van der Waals(vdW)ferroelectric-semiconductor heterojunction provides reconfigurable band alignment based on optical/electrical-assisted polarization switching,which shows great potential to construct artificial visual neural systems.However,the mechanical exfoliation fabrication scheme for proof-of-concept demonstrations and fundamental studies is cumbersome and not scalable for practical application.Here,we present a synthetic strategy for the large-scale and high crystallinity growth of planar/verticalα-In_(2)Se_(3)/MoS_(2)heterojunctions by dynamically tuning the growth temperature.Furthermore,based on theα-In_(2)Se_(3)/MoS_(2)heterostructures,photo-synapse devices are designed and fabricated to simulate visual neural systems functions,including multistate storage,optical logic operation,potentiation and depression,paired-pulse facilitation(PPF),short-term memory(STM),long-term memory(LTM),and Learning-Forgetting-Relearning.By coupling the spatiotemporally relevant optical and electric information,the device can mimic the superior biological visual system’s light adaptation and Pavlovian conditioning.This work provides a strategy for dynamically tuning the orientation of ferroelectric-semiconductor heterojunction stacks and will give impetus to applying all-in-one sensing and memory-computing artificial vision systems.
文摘With the rapid expansion of social media,analyzing emotions and their causes in texts has gained significant importance.Emotion-cause pair extraction enables the identification of causal relationships between emotions and their triggers within a text,facilitating a deeper understanding of expressed sentiments and their underlying reasons.This comprehension is crucial for making informed strategic decisions in various business and societal contexts.However,recent research approaches employing multi-task learning frameworks for modeling often face challenges such as the inability to simultaneouslymodel extracted features and their interactions,or inconsistencies in label prediction between emotion-cause pair extraction and independent assistant tasks like emotion and cause extraction.To address these issues,this study proposes an emotion-cause pair extraction methodology that incorporates joint feature encoding and task alignment mechanisms.The model consists of two primary components:First,joint feature encoding simultaneously generates features for emotion-cause pairs and clauses,enhancing feature interactions between emotion clauses,cause clauses,and emotion-cause pairs.Second,the task alignment technique is applied to reduce the labeling distance between emotion-cause pair extraction and the two assistant tasks,capturing deep semantic information interactions among tasks.The proposed method is evaluated on a Chinese benchmark corpus using 10-fold cross-validation,assessing key performance metrics such as precision,recall,and F1 score.Experimental results demonstrate that the model achieves an F1 score of 76.05%,surpassing the state-of-the-art by 1.03%.The proposed model exhibits significant improvements in emotion-cause pair extraction(ECPE)and cause extraction(CE)compared to existing methods,validating its effectiveness.This research introduces a novel approach based on joint feature encoding and task alignment mechanisms,contributing to advancements in emotion-cause pair extraction.However,the study’s limitation lies in the data sources,potentially restricting the generalizability of the findings.
基金funded by the Key Research Project of Zhejiang(LD22E030007)the“Leading Goose”R&D Program of Zhejiang Province(No.2022C01136)+2 种基金National Science Foundation of China(NSFC No.61974037,No.61904042,No.62274049)Zhejiang University Education Foundation Global Partnership Fund(No.100000-11320)the support of the Micro-nano Fabrication Center of International campus of Zhejiang University.
文摘Few-layer nanosheets(NSs)of hexagonal boron nitride(h-BN)and molybdenum disulfide(MoS_(2))display notable piezoelectric properties.Yet,their integration into polymers typically yields non-piezoelectric composites due to NSs’random distribution.We introduce a facile method for fabricating intrinsic piezoelectric composites incorporated with NSs without electric poling.Our innovative process aligns NSs within polyvinyl alcohol polymer,leveraging ice-water interfacial tension,water crystallization thrust,and directional cross-linking during freezing.The resulting PE composites exhibit a maximum piezoelectric coefficient of up to 25.5-28.4 pC N^(-1),comparable to polyvinylidene difluoride(PVDF),with significant costefficiency,safety,and scalability advantages over conventional materials.Using this composite,we develop highly sensitive wearable pressure and strain sensors,and an ultrasound energy harvester.These sensors detect finger bending and differentiate between walking and running,while the harvester generates1.18 V/2.31μA under 1Wcm^(-2)ultrasound input underwater.This universal method offers a novel manufacturing technique for piezoelectric composites,demonstrating remarkable effectiveness in synthesizing intrinsic piezoelectric composites based on 2D materials.Moreover,its potential extends to applications in wearable electronics and energy harvesting,promising significant advancements in these fields.
基金supported by National Natural Science Foundation of China(62462019,62172350)Guangdong Basic and Applied Basic Research Foundation(2023A1515012846)+6 种基金Guangxi Science and Technology Major Program(AA24263010)The Key Research and Development Program of Guangxi(AB24010085)Key Laboratory of Equipment Data Security and Guarantee Technology,Ministry of Education(GDZB2024060500)2024 Higher Education Scientific Research Planning Project(No.24NL0419)Nantong Science and Technology Project(No.JC2023070)the Open Fund of Advanced Cryptography and System Security Key Laboratory of Sichuan Province(GrantNo.SKLACSS-202407)sponsored by the Cultivation of Young andMiddle-aged Academic Leaders in the“Qing Lan Project”of Jiangsu Province and the 2025 Outstanding Teaching Team in the“Qing Lan Project”of Jiangsu Province.
文摘Large language models(LLMs)represent significant advancements in artificial intelligence.However,their increasing capabilities come with a serious challenge:misalignment,which refers to the deviation of model behavior from the designers’intentions and human values.This review aims to synthesize the current understanding of the LLM misalignment issue and provide researchers and practitioners with a comprehensive overview.We define the concept of misalignment and elaborate on its various manifestations,including generating harmful content,factual errors(hallucinations),propagating biases,failing to follow instructions,emerging deceptive behaviors,and emergent misalignment.We explore the multifaceted causes of misalignment,systematically analyzing factors from surface-level technical issues(e.g.,training data,objective function design,model scaling)to deeper fundamental challenges(e.g.,difficulties formalizing values,discrepancies between training signals and real intentions).This review covers existing and emerging techniques for detecting and evaluating the degree of misalignment,such as benchmark tests,red-teaming,and formal safety assessments.Subsequently,we examine strategies to mitigate misalignment,focusing on mainstream alignment techniques such as RLHF,Constitutional AI(CAI),instruction fine-tuning,and novel approaches that address scalability and robustness.In particular,we analyze recent advances in misalignment attack research,including system prompt modifications,supervised fine-tuning,self-supervised representation attacks,and model editing,which challenge the robustness of model alignment.We categorize and analyze the surveyed literature,highlighting major findings,persistent limitations,and current contentious points.Finally,we identify key open questions and propose several promising future research directions,including constructing high-quality alignment datasets,exploring novel alignment methods,coordinating diverse values,and delving into the deep philosophical aspects of alignment.This work underscores the complexity and multidimensionality of LLM misalignment issues,calling for interdisciplinary approaches to reliably align LLMs with human values.
基金supported by the National Natural Science Foundation of China(Nos.52072059,12304078,12274061 and 11774044)the Natural Science Foundation of Sichuan Province(No.2024NSFSC1384).
文摘Bismuth oxyselenide(Bi_(2)O_(2)Se),a novel quasi-two-dimensional charge-carrying semiconductor,is recognized as one of the most promising emerging platforms for next-generation semiconductor devices.Recent advancements in the development of diverse Bi_(2)O_(2)Se heterojunctions have unveiled extensive potential applications in both electronics and optoelectronics.However,achieving an in-depth understanding of band alignment and particularly interface dynamics remains a significant challenge.In this study,we conduct a comprehensive experimental investigation into band alignment utilizing high-resolution X-ray photoelectron spectroscopy(HRXPS),while also thoroughly discussing the properties of interface states.Our findings reveal that ultrathin films of Bi_(2)O_(2)Se grown on SrTiO_(3)(with TiO_(2)(001)termination)exhibit Type-I(straddling gap)band alignment characterized by a valence band offset(VBO)of approximately 1.77±0.04 eV and a conduction band offset(CBO)around 0.68±0.04 eV.Notably,when accounting for the influence of interface states,the bands at the interface display a herringbone configuration due to substantial built-in electric fields,which markedly deviate from conventional band alignments.Thus,our results provide valuable insights for advancing high-efficiency electronic and optoelectronic devices,particularly those where charge transfer is highly sensitive to interface states.
基金supported by the National Natural Science Foundation of China(22202102,62474194,22425903,U24A20568)the National Key R&D Program of China(2023YFB4204500)the Jiangsu Provincial Departments of Science and Technology(BE2022023,BK20220010,and BZ2023060)。
文摘Metal halide perovskites,owing to their remarkable optoelectronic properties and broad application prospects,have emerged as a research hotspot in materials science and photovoltaics.In addressing challenges related to energy loss,photoelectric conversion efficiency,and operational stability in perovskite solar cells(PSCs),various strategies have been proposed,such as improving perovskite crystallization,developing tandem architectures,and advancing interfacial engineering.However,the specific impact of these approaches on internal energy transfer and conversion mechanisms within PSCs remains insufficiently understood.This review systematically examines the relationship between energy and perovskite materials throughout the photon absorption to charge carrier transport process,with particular focus on key strategies for minimizing energy losses and their underlying influence on energy-level alignment-especially in the electron transport layer and hole transport layer.It summarizes optimal absorption conditions and contributing factors during energy transfer,alongside representative case studies of high-performing systems.By elucidating these mechanisms,this work offers valuable theoretical insights for optimizing energy-level alignment,reducing energy dissipation,and guiding experimental design in PSCs research.
