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Two-dimensional grating line parameter calibration based on biaxial phase mapping
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作者 TENG Hai-rui LIANG Xu +3 位作者 JIN Si-yu SUN Yu-jia LI Wen-hao LIU Zhao-wu 《中国光学(中英文)》 北大核心 2026年第2期407-420,共14页
The two-dimensional grating serves as a critical component in plane grating interferometers for achieving high-precision multidimensional displacement measurements.The calibration of grating groove density and orthogo... The two-dimensional grating serves as a critical component in plane grating interferometers for achieving high-precision multidimensional displacement measurements.The calibration of grating groove density and orthogonality error of grating grooves not only improves the positioning accuracy of grating interferometers but also provides essential feedback for optimizing two-dimensional grating fabrication.This study proposes a method for simultaneous calibration of these parameters using orthogonal heterodyne laser interferometry.A two-dimensional grating interferometer is built with the grating to be measured,and a biaxial laser interferometer provides a displacement reference for it.The phase mapping relationship between grating interference and laser interference is established.The interference phase information obtained by any two displacements can simultaneously solve the above three parameters and obtain the grating installation error.The feasibility of the proposed method is verified by using a 1200 gr/mm two-dimensional grating.The standard deviation of the grating groove density in the X and Y directions is 0.012 gr/mm and 0.014 gr/mm,respectively.The standard deviation of the orthogonality error of grating grooves is 0.004°,and the standard deviation of the installation error is 0.002°.Compared with the atomic force microscope method,the consistency of the grating groove density in the X and Y directions is better than 0.03 gr/mm and 0.06 gr/mm,and the orthogonality error of grating grooves is better than 0.008°.The experimental results show that the proposed method can be simply and efficiently applied to the calibration of the grating line parameters of the two-dimensional grating. 展开更多
关键词 two-dimensional grating grating line parameter calibration grating groove density orthogonality error of grating grooves
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Two-Dimensional MXene-Based Advanced Sensors for Neuromorphic Computing Intelligent Application
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作者 Lin Lu Bo Sun +2 位作者 Zheng Wang Jialin Meng Tianyu Wang 《Nano-Micro Letters》 2026年第2期664-691,共28页
As emerging two-dimensional(2D)materials,carbides and nitrides(MXenes)could be solid solutions or organized structures made up of multi-atomic layers.With remarkable and adjustable electrical,optical,mechanical,and el... As emerging two-dimensional(2D)materials,carbides and nitrides(MXenes)could be solid solutions or organized structures made up of multi-atomic layers.With remarkable and adjustable electrical,optical,mechanical,and electrochemical characteristics,MXenes have shown great potential in brain-inspired neuromorphic computing electronics,including neuromorphic gas sensors,pressure sensors and photodetectors.This paper provides a forward-looking review of the research progress regarding MXenes in the neuromorphic sensing domain and discussed the critical challenges that need to be resolved.Key bottlenecks such as insufficient long-term stability under environmental exposure,high costs,scalability limitations in large-scale production,and mechanical mismatch in wearable integration hinder their practical deployment.Furthermore,unresolved issues like interfacial compatibility in heterostructures and energy inefficiency in neu-romorphic signal conversion demand urgent attention.The review offers insights into future research directions enhance the fundamental understanding of MXene properties and promote further integration into neuromorphic computing applications through the convergence with various emerging technologies. 展开更多
关键词 two-dimensional MXenes SENSOR Neuromorphic computing Multimodal intelligent system Wearable electronics
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Within-plant variability in pod maturity and preharvest sprouting in peanut(Arachis hypogaea L.):Physiological drivers,agronomic impacts,and integrated mitigation strategies
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作者 Yohannes Gelaye Huaiyong Luo 《Oil Crop Science》 2026年第1期92-102,共11页
Peanut(Arachis hypogaea L.)exhibits an unusually asynchronous reproductive cycle,in which flowering,peg penetration,pod development,and seed filling occur over an extended period.This results in the simultaneous prese... Peanut(Arachis hypogaea L.)exhibits an unusually asynchronous reproductive cycle,in which flowering,peg penetration,pod development,and seed filling occur over an extended period.This results in the simultaneous presence of immature and preharvest sprouted(PHS)pods on the same plant a dual challenge that undermines yield,compromises seed quality,and complicates postharvest management.Immature pods reduce harvest efficiency,while PHS diminishes flavor,uniformity,and storage stability.Both genetic and environmental determinants ranging from temporal variation in peg initiation and hormonal gradients to microenvironmental heterogeneity and differential seed dormancy shape this variability.However,despite advances in pod biology,systematic field-based quantification of intra-plant temporal variation,genotype×environment interactions,and localized microclimatic influences remains limited.This review aims to synthesize current understanding of within-plant variability in pod maturation and PHS in peanut,to elucidate critical knowledge gaps at physiological and field scales,and to evaluate emerging strategies for mitigation.Particular emphasis is given for underexplored interface between physiological mechanisms and field-scale dynamics.Emerging innovations including hyperspectral imaging,soil and canopy moisture sensing,and molecular markers offer promising avenues for precise monitoring of pod maturity and early detection of PHS risk.Integrating these tools with targeted breeding strategies for synchronous flowering,enhanced dormancy,and late-season stress resilience,alongside adaptive agronomic practices such as optimized sowing,irrigation scheduling,nutrient management,and harvest timing,could substantially reduce yield and quality losses.Future progress will depend on bridging molecular insights with predictive models that capture mixed maturity and sprouting risk under variable environments. 展开更多
关键词 Genotype×environment interactions Pod maturity Preharvest sprouting Seed dormancy
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Two-dimensional kagome semiconductor Sc_(6)S_(5)X_(6)(X=Cl,Br,I)with trilayer kagome lattice
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作者 Jin-Ling Yan Xing-Yu Wang +5 位作者 Gen-Ping Wu Hao Wang Ya-Jiao Ke Jiafu Wang Zhi-Hong Liu Jun-Hui Yuan 《Chinese Physics B》 2026年第2期519-528,共10页
Two-dimensional(2D)multilayer kagome materials hold significant research value for regulating kagome-related physical properties and exploring quantum effects.However,their development is hindered by the scarcity of a... Two-dimensional(2D)multilayer kagome materials hold significant research value for regulating kagome-related physical properties and exploring quantum effects.However,their development is hindered by the scarcity of available material systems,making the identification of novel 2D multilayer kagome candidates particularly important.In this work,three types of 2D materials with trilayer kagome lattices,namely Sc_(6)S_(5)X_(6)(X=Cl,Br,I),are predicted based on first-principles calculations.These 2D materials feature two kagome lattices composed of Sc atoms and one kagome lattice composed of S atoms.Stability analysis indicates that these materials can exist as free-standing 2D materials.Electronic structure calculations reveal that Sc_(6)S_(5)X_(6)are narrow-bandgap semiconductors(0.76–0.95 e V),with their band structures exhibiting flat bands contributed by Sc-based kagome lattices and Dirac band gaps resulting from symmetry breaking.The sulfur-based kagome lattice in the central layer contributes an independent flat band below the Fermi level.Additionally,Sc_(6)S_(5)X_(6)exhibit high carrier mobility,with hole and electron mobilities reaching up to 10^(3)cm^(2)·V^(-1)·s^(-1),indicating potential applications in low-dimensional electronic devices.This work provides an excellent example for the development of novel multilayer 2D kagome materials. 展开更多
关键词 multilayer kagome lattice two-dimensional materials carrier mobility first-principles calculations
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Enrichment mechanism and optimal in-situ conversion recovery method of lacustrine low-to-medium maturity shale oil
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作者 ZHAO Wenzhi LIU Wei +11 位作者 BIAN Congsheng XU Ruina WANG Xiaomei LYU Weifeng JIN Jiafeng YAO Chuanjin XIONG Chi LI Ruirui LI Yongxin DONG Jin GUAN Ming BIAN Leibo 《Petroleum Exploration and Development》 2026年第1期1-15,共15页
In-situ heating conversion is the most practical recovery method for lacustrine low-to-medium maturity shale oil.However,the energy output-input ratio must exceed the economic threshold to achieve commercial developme... In-situ heating conversion is the most practical recovery method for lacustrine low-to-medium maturity shale oil.However,the energy output-input ratio must exceed the economic threshold to achieve commercial development.This paper systematically investigates the mechanism of super-rich accumulation of organic matter in continental shale,sweet spot evaluation,optimal heating windows,and appropriate well types and patterns from the perspectives of enhancing energy output and reducing energy input.(1)The super-rich accumulation of organic matter in lacustrine shale is primarily controlled by the intensity,frequency,and preservation of external material inputs,and is related to moderate volcanic and hydrothermal activities,marine transgressions,with total organic carbon content greater than or equal to 6%.(2)The quality of organic-rich intervals is related to the type of source material and hydrocarbon generation potential.The in-situ conversion-derived hydrocarbon quality index(HQI)is established,and the zones exhibiting HQI>450 are defined as sweet spots.(3)Considering the characteristics of the organic matter conversion material field and seepage field,the temperature interval 300-370℃is recommended as the optimal heating window for the Chang 7_(3)sub-member of the Triassic Yanchang Formation in the Ordos Basin.Based on the advantages of thermal conductivity,permeability,and hydrocarbon expulsion efficiency along the bedding direction during in-situ heating,the“horizontal well heating+vertical well development”scheme is proposed,which has demonstrated significant enhancement in both recovery factor and energy output-input ratio,making it the optimal in-situ conversion process.The research findings provide a theoretical and technical foundation for the economical and efficient development of low-to-medium maturity shale oil. 展开更多
关键词 lacustrine low-to-medium maturity shale oil in-situ conversion optimal heating window horizontal well+vertical well energy output-input ratio super-rich accumulation of organic matter renewable energy
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Inhibitory effect of the interlayer of two-dimensional vermiculite on the polysulfide shuttle in lithium-sulfur batteries 被引量:1
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作者 CHEN Xiaoli LUO Zhihong +3 位作者 XIONG Yuzhu WANG Aihua CHEN Xue SHAO Jiaojing 《无机化学学报》 北大核心 2025年第8期1661-1671,共11页
A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface... A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface area of 427 m^(2)·g^(-1)and rich surface active sites,which help restrain polysulfides(LiPSs)through good physi-cal and chemical adsorption,while simultaneously accelerating the nucleation and dissolution kinetics of Li_(2)S,effec-tively suppressing the shuttle effect.The assembled lithium-sulfur batteries(LSBs)employing the PVS-based inter-layer delivered a high initial discharge capacity of 1386 mAh·g^(-1)at 0.1C(167.5 mAh·g^(-1)),long-term cycling stabil-ity,and good rate property. 展开更多
关键词 vermiculite nanosheets two-dimensional materials INTERLAYER shuttle effect lithium-sulfur batteries
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Wearable Biodevices Based on Two-Dimensional Materials:From Flexible Sensors to Smart Integrated Systems 被引量:1
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作者 Yingzhi Sun Weiyi He +3 位作者 Can Jiang Jing Li Jianli Liu Mingjie Liu 《Nano-Micro Letters》 2025年第5期207-255,共49页
The proliferation of wearable biodevices has boosted the development of soft,innovative,and multifunctional materials for human health monitoring.The integration of wearable sensors with intelligent systems is an over... The proliferation of wearable biodevices has boosted the development of soft,innovative,and multifunctional materials for human health monitoring.The integration of wearable sensors with intelligent systems is an overwhelming tendency,providing powerful tools for remote health monitoring and personal health management.Among many candidates,two-dimensional(2D)materials stand out due to several exotic mechanical,electrical,optical,and chemical properties that can be efficiently integrated into atomic-thin films.While previous reviews on 2D materials for biodevices primarily focus on conventional configurations and materials like graphene,the rapid development of new 2D materials with exotic properties has opened up novel applications,particularly in smart interaction and integrated functionalities.This review aims to consolidate recent progress,highlight the unique advantages of 2D materials,and guide future research by discussing existing challenges and opportunities in applying 2D materials for smart wearable biodevices.We begin with an in-depth analysis of the advantages,sensing mechanisms,and potential applications of 2D materials in wearable biodevice fabrication.Following this,we systematically discuss state-of-the-art biodevices based on 2D materials for monitoring various physiological signals within the human body.Special attention is given to showcasing the integration of multi-functionality in 2D smart devices,mainly including self-power supply,integrated diagnosis/treatment,and human–machine interaction.Finally,the review concludes with a concise summary of existing challenges and prospective solutions concerning the utilization of2D materials for advanced biodevices. 展开更多
关键词 two-dimensional material Wearable biodevice Flexible sensor Smart integrated system Healthcare
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Origin of two-dimensional hole gas at the hydrogen-terminated diamond surfaces:Negative interface valence-induced upward band bending 被引量:1
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作者 Qingzhong Gui Wei Yu +9 位作者 Chunmin Cheng Hailing Guo Xiaoming Zha Ruyue Cao Hongxia Zhong John Robertson Sheng Liu Zhaofu Zhang Zhuo Jiang Yuzheng Guo 《Journal of Materials Science & Technology》 2025年第4期76-85,共10页
The surface transfer doping model has been extensively adopted as a mechanism to account for the generation of hole accumulation layers below hydrogen-terminated diamond(H-diamond)surfaces.To achieve effective surface... The surface transfer doping model has been extensively adopted as a mechanism to account for the generation of hole accumulation layers below hydrogen-terminated diamond(H-diamond)surfaces.To achieve effective surface transfer doping,surface electron acceptor materials with high electron affinity(EA)are required to produce a high density of two-dimensional hole gas(2DHG)on the H-diamond subsurface.We have established ingenious theoretical models to demonstrate that even if these solid materials do not have a high EA value,they remain capable of absorbing electrons from the H-diamond surface by forming a negatively charged interface to act as a surface electron acceptor in the surface transfer doping model.Our calculations,particularly for the local density of states,provide compelling evidence that the effect of an interface with negative charges induces an upward band bending on the H-diamond side.Furthermore,the valence band maximum of the diamond atoms at the interface crosses the Fermi level,giving rise to strong surface transfer p-type doping.These results give a strong theoretical interpretation of the origin of 2DHG on H-diamond surfaces.The proposed guidelines contribute to further improvements in the performance of 2DHG H-diamond field effect transistors. 展开更多
关键词 Hydrogen-terminated diamond Surface transfer doping two-dimensional hole gas First-principles calculations
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Designing a Comprehensive Data Governance Maturity Model for Kenya Ministry of Defence
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作者 Gilly Gitahi Gathogo Simon Maina Karume Josphat Karani 《Journal of Information Security》 2025年第1期44-69,共26页
The study aimed to develop a customized Data Governance Maturity Model (DGMM) for the Ministry of Defence (MoD) in Kenya to address data governance challenges in military settings. Current frameworks lack specific req... The study aimed to develop a customized Data Governance Maturity Model (DGMM) for the Ministry of Defence (MoD) in Kenya to address data governance challenges in military settings. Current frameworks lack specific requirements for the defence industry. The model uses Key Performance Indicators (KPIs) to enhance data governance procedures. Design Science Research guided the study, using qualitative and quantitative methods to gather data from MoD personnel. Major deficiencies were found in data integration, quality control, and adherence to data security regulations. The DGMM helps the MOD improve personnel, procedures, technology, and organizational elements related to data management. The model was tested against ISO/IEC 38500 and recommended for use in other government sectors with similar data governance issues. The DGMM has the potential to enhance data management efficiency, security, and compliance in the MOD and guide further research in military data governance. 展开更多
关键词 Data Governance maturity Model maturity Index Kenya Ministry of Defence Key Performance Indicators Data Security Regulations
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Finite-Time Expected Present Value of Operating Costs until Ruin in a Two-Dimensional Risk Model with Periodic Observation
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作者 TENG Ye XIE Jiayi ZHANG Zhimin 《应用概率统计》 北大核心 2025年第5期748-765,共18页
This paper investigates ruin,capital injection,and dividends for a two-dimensional risk model.The model posits that surplus levels of insurance companies are governed by a perturbed composite Poisson risk model.This m... This paper investigates ruin,capital injection,and dividends for a two-dimensional risk model.The model posits that surplus levels of insurance companies are governed by a perturbed composite Poisson risk model.This model introduces a dependence between the two surplus levels,present in both the associated perturbations and the claims resulting from common shocks.Critical levels of capital injection and dividends are established for each of the two risks.The surplus levels are observed discretely at fixed intervals,guiding decisions on capital injection,dividends,and ruin at these junctures.This study employs a two-dimensional Fourier cosine series expansion method to approximate the finite time expected discounted operating cost until ruin.The ensuing approximation error is also quantified.The validity and accuracy of the method are corroborated through numerical examples.Furthermore,the research delves into the optimal capital allocation problem. 展开更多
关键词 two-dimensional risk model Fourier cosine expansion capital injection DIVIDEND
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Role of preservation conditions on enrichment and fluidity maintenance of medium to high maturity lacustrine shale oil 被引量:2
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作者 ZHAO Wenzhi LIU Wei +9 位作者 BIAN Congsheng LIU Xianyang PU Xiugang LU Jiamin LI Yongxin LI Junhui LIU Shiju GUAN Ming FU Xiuli DONG Jin 《Petroleum Exploration and Development》 2025年第1期1-16,共16页
In addition to the organic matter type,abundance,thermal maturity,and shale reservoir space,the preservation conditions of source rocks play a key factor in affecting the quantity and quality of retained hydrocarbons ... In addition to the organic matter type,abundance,thermal maturity,and shale reservoir space,the preservation conditions of source rocks play a key factor in affecting the quantity and quality of retained hydrocarbons in source rocks of lacustrine shale,yet this aspect has received little attention.This paper,based on the case analysis,explores how preservation conditions influence the enrichment of mobile hydrocarbons in shale oil.Research showns that good preservation conditions play three key roles.(1)Ensure the retention of sufficient light hydrocarbons(C_(1)–C_(13)),medium hydrocarbons(C_(14)–C_(25))and small molecular aromatics(including 1–2 benzene rings)in the formation,which enhances the fluidity and flow of shale oil;(2)Maintain a high energy field(abnormally high pressure),thus facilitating the maximum outflow of shale oil;(3)Ensure that the retained hydrocarbons have the miscible flow condition of multi-component hydrocarbons(light hydrocarbons,medium hydrocarbons,heavy hydrocarbons,and heteroatomic compounds),so that the heavy hydrocarbons(C_(25+))and heavy components(non-hydrocarbons and asphaltenes)have improved fluidity and maximum flow capacity.In conclusion,in addition to the advantages of organic matter type,abundance,thermal maturity,and reservoir space,good preservation conditions of shale layers are essential for the formation of economically viable shale oil reservoirs,which should be incorporated into the evaluation criteria of shale oil-rich areas/segments and considered a necessary factor when selecting favorable exploration targets. 展开更多
关键词 medium-to-high maturity lacustrine shale oil mobile hydrocarbon enrichment preservation conditions stratum energy field miscible hydrocarbon component retained hydrocarbon fluidity Songliao Basin Ordos Basin Junggar Basin Bohai Bay Basin
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ESG disagreement and corporate debt maturity:evidence from China
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作者 Kangqi Jiang Jie Zhang +1 位作者 Mengling Zhou Zhongfei Chen 《Financial Innovation》 2025年第1期1013-1051,共39页
This study explores the relationship between corporate environmental,social,and governance(ESG)disagreements and corporate debt maturity.By examining panel samples from Chinese non-financial listed companies covering ... This study explores the relationship between corporate environmental,social,and governance(ESG)disagreements and corporate debt maturity.By examining panel samples from Chinese non-financial listed companies covering 2007 to 2020,we find that ESG disagreements negatively influence corporate debt maturity.Even after conducting a series of robustness tests and addressing endogeneity concerns,the adverse effects of ESG disagreements persisted.A heterogeneity analysis shows that this negative impact is more significant for non-state-owned enterprises,small enterprises,enterprises with high capital intensity,enterprises with low analyst attention,and enterprises in high-tech industries.Through a mechanism analysis,we discovered that ESG disagreements can lead to information asymmetry and heightened default risk,subsequently affecting the maturity of corporate debt.Further analysis confirms that the negative impact of ESG on the debt structure inhibits long-term investment and exacerbates the mismatch between investment and financing terms. 展开更多
关键词 ESG disagreement Debt maturity maturity mismatch China
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MXenes-based separators with nanoconfined two-dimensional channels for high-performance lithium-sulfur battery
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作者 Yi-Hui Zhao Shuai Li +6 位作者 Yu-Lu Huo Zhen Li Lan-Lan Hou Yong-Qiang Wen Xiao-Xian Zhao Jian-Jun Song Jing-Chong Liu 《Rare Metals》 2025年第5期2921-2944,共24页
Lithium-sulfur(Li-S)batteries with high energy density and capacity have garnered significant research attention among various energy storage devices.However,the shuttle effect of polysulfides(LiPSs)remains a major ch... Lithium-sulfur(Li-S)batteries with high energy density and capacity have garnered significant research attention among various energy storage devices.However,the shuttle effect of polysulfides(LiPSs)remains a major challenge for their practical application.The design of battery separators has become a key aspect in addressing the challenge.MXenes,a promising two-dimensional(2D)material,offer exceptional conductivity,large surface area,high mechanical strength,and active sites for surface reactions.When assembled into layered films,MXenes form highly tunable two-dimensional channels ranging from a few angstroms to over 1 nm.These nanoconfined channels are instrumental in facilitating lithium-ion transport while effectively impeding the shuttle effect of LiPSs,which are essential for improving the specific capacity and cyclic stability of Li-S batteries.Substantial progress has been made in developing MXenes-based separators for Li-S batteries,yet there remains a research gap in summarizing advancements from the perspective of interlayer engineering.This entails maintaining the 2D nanochannels of layered MXenes-based separators while modulating the physicochemical environment within the MXenes interlayers through targeted modifications.This review highlights advancements in in situ modification of MXenes and their integration with 0D,1D,and 2D materials to construct laminated nanocomposite separators for Li-S batteries.The future development directions of MXenes-based materials in Li-S energy storage devices are also outlined,to drive further advancements in MXenes for Li-S battery separators. 展开更多
关键词 Lithium-sulfur battery MXenes SEPARATOR two-dimensional materials two-dimensional nanochannels
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Two-Dimensional TiO_(2)Ultraviolet Filters for Sunscreens
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作者 Ling QiuHui-Ming Cheng Ruoning Yang +10 位作者 Jiefu Chen Xiang Li Yaxin Zhang Baofu Ding Yujiangsheng Xu Shaoqiang Luo Shaohua Ma Xingang Ren Gang Liu Ling Qiu Hui-Ming Cheng 《Nano-Micro Letters》 2025年第12期108-119,共12页
Titanium dioxide(TiO_(2))has been an important protective ingredient in mineral-based sunscreens since the 1990s.However,traditional TiO_(2)nanoparticle formulations have seen little improvement over the past decades ... Titanium dioxide(TiO_(2))has been an important protective ingredient in mineral-based sunscreens since the 1990s.However,traditional TiO_(2)nanoparticle formulations have seen little improvement over the past decades and continue to face persistent challenges related to light transmission,biosafety,and visual appearance.Here,we report the discovery of two-dimensional(2D)TiO_(2),characterized by a micro-sized lateral dimension(~1.6μm)and atomic-scale thickness,which fundamentally resolves these long-standing issues.The 2D structure enables exceptional light management,achieving 80%visible light transparency—rendering it nearly invisible on the skin—while maintaining UV-blocking performance comparable to unmodified rutile TiO_(2)nanoparticles.Its larger lateral size results in a two-orders-of-magnitude reduction in skin penetration(0.96 w/w%),significantly enhancing biosafety.Moreover,the unique layered architecture inherently suppresses the generation of reactive oxygen species(ROS)under sunlight exposure,reducing the ROS generation rate by 50-fold compared to traditional TiO_(2)nanoparticles.Through precise metal element modulation,we further developed the first customizable sunscreen material capable of tuning UV protection ranges and automatically matching diverse skin tones.The 2D TiO_(2)offers a potentially transformative approach to modern sunscreen formulation,combining superior UV protection,enhanced safety and a natural appearance. 展开更多
关键词 two-dimensional Titanium dioxide SUNSCREEN BIOSAFETY
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Stable carbon isotope compositions of individual light hydrocarbons in oils: New indicator of source facies and maturity
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作者 Donglin Zhang Meijun Li Rongzhen Qiao 《Geoscience Frontiers》 2025年第5期455-469,共15页
Light hydrocarbons(LHs)are key components of petroleum,and the carbon isotopes composition(δ^(13)C)of individual LHs contains a wealth of geochemical information.Forty-four oil samples from five different basins were... Light hydrocarbons(LHs)are key components of petroleum,and the carbon isotopes composition(δ^(13)C)of individual LHs contains a wealth of geochemical information.Forty-four oil samples from five different basins were analyzed using gas chromatography(GC),gas chromatography-mass spectrometry(GC–MS),and gas chromatography-isotope ratio mass spectrometry(GC-IRMS).Theδ^(13)C values of forty-three LHs were recognized and determined by comparing the GC and GC-IRMS methods.The results revealed significant differences inδ^(13)C distribution characteristics among different LH compounds.Theδ^(13)C variation of individual LHs in iso-paraffins showed the widest range,followed by cycloalkanes and aromatics,whereas theδ^(13)C variation in n-paraffins showed the narrowest range.Theδ^(13)C values of most individual LHs are primarily affected by the source facies and thermal evolution.Among them,c-1,3-dimethylcyclohexane(c-1,3DMCH)is mainly sourced from higher plants but may also form through abiotic mechanisms such as catalysis or cyclization.Theδ^(13)C values of c-1,3DMCH(δ^(13)Cc-1,3DMCH)primarily exhibit parental genetic characteristics,enabling effective distinction of oil from different source facies.Specifically,theδ^(13)Cc-1,3DMCH in marine oils,lacustrine oils,terrigenous oils,and coal-formed oils are<–22‰,from–22‰to−20.2‰,from−20.2‰to−18.4‰,and>−18.4‰,respectively.Moreover,maturity is the primary controlling factor forδ^(13)C values of 3MC7(δ^(13)C3MC7,3MC7:3-methylheptane),while the source facies serve as a secondary influence.The plot ofδ^(13)Cc-1,3DMCH andδ^(13)C3MC7 was introduced to classify source facies.Asδ^(13)Cc-1,3DMCH andδ^(13)C3MC7 increase,the source facies transits from marine to lacustrine,then terrigenous,and finally coal facies.Additionally,increasingδ^(13)C3MC7 indicates a relative increase in maturity.Therefore,theδ^(13)Cc-1,3DMCH vs.δ^(13)C3MC7 plot serves as an effective tool for distinguishing source facies and assessing relative maturity. 展开更多
关键词 Light hydrocarbons Individual carbon isotope Source facies maturity
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Toward Digital Technology Maturity:Empowering Small Medium Enterprise in Sleman Yogyakarta Indonesia Toward Sustainable Tourism and Creative Economy Development
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作者 Ayu Helena Cornellia Robertus Saptoto Kamila Salsabela 《Journalism and Mass Communication》 2025年第2期98-112,共15页
In the era of global tourism and creative economies,digital technology maturity has emerged as a critical factor for the sustainable development of small and medium enterprises(SMEs)in Indonesia.This research is imple... In the era of global tourism and creative economies,digital technology maturity has emerged as a critical factor for the sustainable development of small and medium enterprises(SMEs)in Indonesia.This research is implemented to find out current digital technology maturity levels among SMEs in the subdistrict of Cangkringan,district of Sleman,Yogyakarta,Indonesia,highlighting their role in fostering sustainable tourism and creative economic growth.Using a mixed-method approach,the research combines qualitative insights from in-depth interviews with three local government representatives and Focus Group Discussion with 15 SMEs in the area.Additionally,a quantitative analysis of SMEs across various sectors,including crafts and culinary services,supports the study’s conclusions.The finding reveals a significant gap between government’s training programs and the digital literacy of SMEs as well as a lack of affordable technological resources which could impede the full realization of digital benefits.Strengthening digital technology maturity among SMEs is essential for enhancing their competitiveness and long-term sustainability,yielding both financial and non-financial benefits.This also contributes to find out digital literacy gaps,impact on competitiveness and sustainability,policy and stakeholder recommendations,and government action.These insights offer valuable guidance for policymakers and stakeholders striving to support the digital transformation of SMEs in similar settings.The study also sheds light on digital literacy gaps,their impact on competitiveness and offers policy recommendations for government and stakeholders to address these challenges such as through government and community collaboration. 展开更多
关键词 digital technology maturity SMES sustainable tourism creative economy
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GULFSTREAM DELIVERS 50TH G700 Aircraft Continues to Demonstrate Unparalleled Program Maturity
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《今日民航》 2025年第1期108-109,共2页
Savannah,Ga.,May 20,2025-Gulfstream Aerospace Corp.today announced the 50th customer delivery of the Gulfstream G700.The aircraft was outfitted at Gulfstream's Savannah completions center.Since entering service in... Savannah,Ga.,May 20,2025-Gulfstream Aerospace Corp.today announced the 50th customer delivery of the Gulfstream G700.The aircraft was outfitted at Gulfstream's Savannah completions center.Since entering service in April 2024,the G700 operates globally,and the fleet has accumulated more than 11,700 flight hours. 展开更多
关键词 G Aircraft Delivery SAVANNAH Flight Hours Gulfstream gulfstream g Program maturity
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Analysis of Leakage Effects on Outlet Flow Characteristics of a Two-dimensional Piston Pump
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作者 Yu Huang Hanyu Xu +2 位作者 Wei Shao Chuan Ding Li Liu 《Chinese Journal of Mechanical Engineering》 2025年第3期545-557,共13页
Owing to their rolling friction,two-dimensional piston pumps are highly suitable as power components for electro-hydrostatic actuators(EHAs).These pumps are particularly advantageous for applications requiring high ef... Owing to their rolling friction,two-dimensional piston pumps are highly suitable as power components for electro-hydrostatic actuators(EHAs).These pumps are particularly advantageous for applications requiring high efficiency and reliability.However,the ambiguity surrounding the output flow characteristics of individual two-dimensional pumps poses a significant challenge in achieving precise closed-loop control of the EHA positions.To address this issue,this study established a comprehensive numerical model that included gap leakage to analyze the impact of leakage on the output flow characteristics of a two-dimensional piston pump.The validity of the numerical analysis was indirectly confirmed through meticulous measurements of the leakage and volumetric efficiency,ensuring robust results.The research findings indicated that,at lower pump speeds,leakage significantly affected the output flow rate,leading to potential inefficiencies in the system.Conversely,at higher rotational speeds,the impact of leakage was less pronounced,implying that the influence of leakage on the pump outlet flow must be carefully considered and managed for EHAs to perform position servo control.Additionally,the research demonstrates that two-dimensional motion does not have a unique or additional effect on pump leakage,thus simplifying the design considerations.Finally,the study concluded that maintaining an oil-filled leakage environment is beneficial because it helps reduce the impact of leakage and enhances the overall volumetric efficiency of the pump system. 展开更多
关键词 two-dimensional piston pump LEAKAGE Numerical simulation CLEARANCE
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Two-dimensional nanomaterials for environmental catalysis roadmap towards 2030
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作者 Jing Guo Jianzhong Ma +18 位作者 Junli Liu Guanjie Huang Xiaoting Zhou Francesco Parrino Riccardo Ceccato Leonardo Palmisano Boon-Junn Ng Lutfi Kurnianditia Putri Huaxing Li Rongjie Li Gang Liu Yang Wang Nikolay Kornienko Shan-Shan Zhu Zhenwei Zhang Xiaoming Liu Nur Atika Nikma Dahlan Siang-Piao Chai Jianmin Ma 《Chinese Chemical Letters》 2025年第9期223-235,共13页
Environmental catalysis has been considered one of the important research topics.Some technologies(e.g.,photocatalysis and electrocatalysis)have been intensively developed with the advance of synthetic technologies of... Environmental catalysis has been considered one of the important research topics.Some technologies(e.g.,photocatalysis and electrocatalysis)have been intensively developed with the advance of synthetic technologies of catalytical materials.In 2019,we discussed the development trend of this field,and wrote a roadmap on this topic in Chinese Chemical Letters(30(2019)2065-2088).Nowadays,we discuss it again from a new viewpoint along this road.In this paper,several subtopics are discussed,e.g.,photocatalysis based on titanium dioxide,violet phosphorus,graphitic carbon and covalent organic frameworks,electrocatalysts based on carbon,metal-and covalent-organic framework.Finally,we hope that this roadmap can enrich the development of two-dimensional materials in environmental catalysis with novel understanding,and give useful inspiration to explore new catalysts for practical applications. 展开更多
关键词 Environmental catalysis two-dimensional materials ELECTROCATALYSIS PHOTOCATALYSIS NANOMATERIALS
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Synthesis of two-dimensional diamond by phase transition from graphene at atmospheric pressure
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作者 Songyang Li Zhiguang Zhu +2 位作者 Youzhi Zhang Chengke Chen Xiaojun Hu 《Chinese Physics B》 2025年第5期596-607,共12页
It is a key challenge to prepare two-dimensional diamond(2D-diamond).Herein,we develop a method for synthesizing 2D-diamond by depositing monodisperse tantalum(Ta)atoms onto graphene substrates using a hot-filament ch... It is a key challenge to prepare two-dimensional diamond(2D-diamond).Herein,we develop a method for synthesizing 2D-diamond by depositing monodisperse tantalum(Ta)atoms onto graphene substrates using a hot-filament chemical vapor deposition setup,followed by annealing treatment under different temperatures at ambient pressure.The results indicate that when the annealing temperature increases from 700℃ to 1000℃,the size of the 2D-diamond found in the samples gradually increases from close to 20 nm to around 30 nm.Meanwhile,the size and number of amorphous carbon spheres and Ta-containing compounds between the graphene layers gradually increase.As the annealing temperature continues to rise to 1100℃,a significant aggregation of Ta-containing compounds is observed in the samples,with no diamond structure detected.This further confirms that monodisperse Ta atoms play a key role in graphene phase transition into 2D-diamond.This study provides a novel method for the ambient-pressure phase transition of graphene into 2D-diamond. 展开更多
关键词 GRAPHENE two-dimensional diamond vacuum annealing phase transition
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