The flow patterns of Euro-Atlantic blocking events in winter are investigated by dividing the sector into three sub- regions： 60°-30°W （Greenland region）; 20°W-30°E [eastern Atlantic-Europe （EA...The flow patterns of Euro-Atlantic blocking events in winter are investigated by dividing the sector into three sub- regions： 60°-30°W （Greenland region）; 20°W-30°E [eastern Atlantic-Europe （EAE） region]; and 50°-90°E （Ural region）. It is shown that blocking events in winter are extremely frequent in the three sub-regions. Composite 500-mb geopotential height fields for intense and long-lived blocking events demonstrate that the blocking fields over Greenland and Ural regions exhibit southwest-northeast （SW-NE） and southeast-northwest （SE-NW） oriented dipole-type patterns, respectively, while the composite field over the EAE region exhibits an Ω-type pattern. The type of composite blocking pattern seems to be related to the position of the blocking region relative to the positive center of the climatological stationary wave （CSW） anomaly existing near 10°W. The physical cause of why there are different composite blocking types in the three sub-regions is identified using a nonlinear multiscale interaction model. It is found that when the blocking event is in almost the same position as the positive CSW anomaly, the planetary-scale field can exhibit an Ω-type pattern due to the enhanced positive CSW anomaly. Neverthe- less, a SW-NE （SE-NW） oriented dipole-type block can occur due to the reduced positive CSW anomaly as it is farther in the west （east） of the positive CSW anomaly. The total fields of blocking in the three regions may exhibit a meandering flow comprised of several isolated anticyclonic and cyclonic vortices, which resembles the Berggren-Bolin-Rossby meandering jet type.展开更多
The task of vortex boundaries setting is one of the most complexes in examination of factors influencing on the vortex (circulation system) development and destruction. In this study a new approach of vortex analysis ...The task of vortex boundaries setting is one of the most complexes in examination of factors influencing on the vortex (circulation system) development and destruction. In this study a new approach of vortex analysis as a whole system is proposed. It is based on vorticity equation where vorticity (left part of the equation) is defined as time coefficients of EOF-decomposition, which is integrated indexes characterizing individual vortex dynamics. Right part of the vorticity equation depicts internal and external factors influencing on the vortex. It's approbation is done on the example of an arctic-subarctic circulation system including blocking anticyclone in winter 2012 which persisted for a long time over the Atlantic sector of the Arctic and led to the formation of the largest positive air temperature anomalies and the minimum ice cover area in the Barents and Kara seas in the entire history of regular observations. It is shown that the main factor in long-term maintenance of the blocking anticyclone over the Arctic was vorticity advection, which was stabilized by horizontal heat advection.展开更多
The diagnostic efficacy of contemporary bioimaging technologies remains constrained by inherent limitations of conventional imaging agents,including suboptimal sensitivity,off-target biodistribution,and inherent cytot...The diagnostic efficacy of contemporary bioimaging technologies remains constrained by inherent limitations of conventional imaging agents,including suboptimal sensitivity,off-target biodistribution,and inherent cytotoxicity.These limitations have catalyzed the development of intelligent stimuli-responsive block copolymers-based bioimaging agents,which was engineered to dynamically respond to endogenous biochemical cues(e.g.,p H gradients,redox potential,enzyme activity,hypoxia environment) or exogenous physical triggers(e.g.,photoirradiation,thermal gradients,ultrasound(US)/magnetic stimuli).Through spatiotemporally controlled structural transformations,stimuli-responsive block copolymers enable precise contrast targeting,activatable signal amplification,and theranostic integration,thereby substantially enhancing signal-to-noise ratios of bioimaging and diagnostic specificity.Hence,this mini-review systematically examines molecular engineering principles for designing p H-,redox-,enzyme-,light-,thermo-,and US/magnetic-responsive polymers,with emphasis on structure-property relationships governing imaging performance modulation.Furthermore,we critically analyze emerging strategies for optical imaging,US synergies,and magnetic resonance imaging(MRI).Multimodal bioimaging has also been elaborated,which could overcome the inherent trade-offs between resolution,penetration depth,and functional specificity in single-modal approaches.By elucidating mechanistic insights and translational challenges,this mini-review aims to establish a design framework of stimuli-responsive block copolymersbased for high fidelity bioimaging agents and accelerate their clinical translation in precise diagnosis and therapy.展开更多
Switchable polymerization is emerging as a powerful tool to construct block copolymers directly from mixtures of monomers.However,current achievements typically iterate between two polymerization cycles to afford prod...Switchable polymerization is emerging as a powerful tool to construct block copolymers directly from mixtures of monomers.However,current achievements typically iterate between two polymerization cycles to afford products with fixed sequences and compositions.Herein,we report the triethylborane/1,8-diazabicyclo[5.4.0]undec-7-ene(Et_3B/DBU)pair-mediated four-component switchable polymerization of propylene oxide(PO),CO_(2),phthalic anhydride(PA),and racemic lactide(rac-LA),which enables the on-demand synthesis of four different block copolymers,i.e.,poly(propylene phthalate)-b-polylactide(PPE-b-PLA),PPE-b-PLA-b-poly(propylene carbonate)(PPC),PPE-b-PPC-b-PLA,and PPE-b-PPCb-poly(propylene oxide)(PPO),through rationally modulating the Lewis pair(LP)ratio.Core to this protocol is that increasing the loading of Et_(3)B accelerates the ring-opening of PO while impeding the reactivity of rac-LA,thus allowing for fine-tuning of the thermodynamic and kinetic of the switchable polymerization.Therefore,the four polymerization cycles involving PO/PA ring-opening copolymerization(ROCOP),PO/CO_2 ROCOP,rac-LA ring-opening polymerization(ROP),and PO ROP can be connected and discriminated in precisely programmed manners.展开更多
Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphi...Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphite.This study utilizes the porous“defect advantage”of a cathode carbon block matrix to prepare silicon-doped and asphalt-coated detoxified and purified waste graphitization cathode carbon blocks for use as high-performance silicon/carbon composite anode materials.The results show that the uniformly silicondoped silicon/carbon composite material features a unique amorphous carbon-encapsulated“locked silicon”structure,which effectively addresses issues such as cathode volume expansion,excessive growth of the solid electrolyte interphase(SEI)film,and poor electrical contact between active materials.Consequently,electrochemical performance is enhanced.After assembly in a half-cell,the PSCC/10%Si@C(purified waste graphitization cathode carbon/10%Si@C)material exhibits optimal electrochemical stability,with an initial charging specific capacity of 514.5 mAh/g at 0.1 C(1 C=170 mA/g)and a capacity retention rate of 95.1%after 100 cycles.At a charge rate of 2.0 C,a specific capacity of 216.9 mAh/g is achieved.This technology provides a new pathway for the economical and high-value utilization of waste cathode carbon blocks and the development of low-cost,high-performance anode materials.展开更多
In this study,we examine the connectedness between the NASDAQ artificial intelligence index and sectoral cryptocurrency indices.Empirical analyses were conducted via the quantile‒quantile methodology and cross-multiqu...In this study,we examine the connectedness between the NASDAQ artificial intelligence index and sectoral cryptocurrency indices.Empirical analyses were conducted via the quantile‒quantile methodology and cross-multiquantilogram tests across 15 cryptocurrency sectors from June 1,2021,to May 28,2024.The results show that dynamic total spillovers primarily occur in extremely low and high quantiles,corresponding to the left and right tails of the return distributions.Net directional spillovers indicate the dominance of the AI sector over the cryptocurrency market,which intensifies during significant crashes or booms.The most substantial effect of AI is observed in the DeFi,NFT,and Smart Contracts sectors,highlighting the prominence of financial operation-based blockchain applications in their interaction with artificial intelligence.The cross-multiquantilogram results also suggest that developments in artificial intelligence dominate the cryptocurrency market and have high predictability in its price movements.On the basis of our findings,we recommend using the AI market as an early indicator for the cryptocurrency market and advise against combining these two asset groups in the same portfolio to maintain diversification benefits.展开更多
Climate change may have detrimental effects on different sectoral growth in global economy and according to the Intergovernmental Panel on Climate Change,the impacts of climate change will be more vigorous in the comi...Climate change may have detrimental effects on different sectoral growth in global economy and according to the Intergovernmental Panel on Climate Change,the impacts of climate change will be more vigorous in the coming years.The climatic and non-climatic driving forces behind the economic sectoral performances involve short-and long-run interconnections among variables.This study attempts to investigate the effect of climatic factors(temperature and precipitation)along with non-climatic factors,including foreign direct investment(FDI),human capital index(HCI),natural capital(NC),and information and communication technology(ICT)on three major sectors of the economy(agricultural sector,industrial sector,and service sector)through non-linear model framework by employing cross-sectionally augmented autoregressive distributed lag(CS-ARDL)estimation technique.It considers a panel of 56 selected countries from different income groups,including high-income countries,upper-middle-income countries,lower-middle-income countries,and low-income countries,covering the period 1985-2022.The confirmation of slope heterogeneity,cross-sectional dependence,stationarity,and cointegration among variables lends support to the robustness of results.The augmented mean group(AMG)robustness test was applied to check robustness and the results were found mostly consistent with estimation method.The results revealed that upper-middle-income countries are more vulnerable to extreme temperatures compared to high-income countries.The results also confirmed an inverted U-shaped relationship between each sector’s output and precipitation in upper-middle-income countries.In contrast,for upper-middle-income,lower-middle-income,and low-income countries,this relation exists in industrial sector only in long run.This indicates that precipitation is initially beneficial for production activities.However,beyond a certain threshold of precipitation,this trend reverses,i.e.,the output of the economic sectors tends to decline.Furthermore,there is no supporting evidence that confirms a short-run non-linear relation between precipitation and agricultural yields.In upper-middle-income countries,the results confirmed that FDI is a driving factor behind both agricultural sector and service sector in long run while short-run results indicated a negative association but insignificant.This study also showed that in long run,an increase in HCI contributes to improving the output of the three sectors for high-income countries.The empirical findings provide valuable insights for policy-makers and governments to formulate coherent adaptation and mitigation strategies,thereby accelerating the transition of sectoral productivity from low to high levels in the sample countries.展开更多
The identification and characterization of concealed in-situ rock blocks on high-steep slope exposures are critical in rock engineering,but remain challenging.This study employs advanced UAV-based photogrammetry to ca...The identification and characterization of concealed in-situ rock blocks on high-steep slope exposures are critical in rock engineering,but remain challenging.This study employs advanced UAV-based photogrammetry to capture high-resolution discontinuity data and develops a fully automated rock block extraction method consisting of three steps:(1)determination of free face and non-free fracture intersections,(2)surface search for rock blocks on free face.and(3)extraction and analysis of rock blocks.This approach simplifies the determination of discontinuity intersections while maintaining high accuracy.By incorporating all types of discontinuities contributing to rock block formation,the method enables precise in-situ rock block identification and extraction.Application to a rock slope in China,produced results consistent with the rock blocks observed in the 3D model,highlighting its accuracy and practical value.展开更多
Cryogenic block streams consist of a stream of rocks superficially resembling a stream deposit but lacking a matrix, usually occurring on a valley or gully floor or on slopes that are less steep than the maximum angle...Cryogenic block streams consist of a stream of rocks superficially resembling a stream deposit but lacking a matrix, usually occurring on a valley or gully floor or on slopes that are less steep than the maximum angle of repose of coarse sediments. They are usually formed on perennially frozen ground, but can also occur as relict landforms. There are three main active kinds forming today, viz., Siberian and Tibetan dynamic rock streams and lag block streams. During their formation, the blocks in the active Siberian and Tibetan dynamic block streams move downslope at up to 1 rn/a. They are forming today on the Tibetan Plateau and in the more arid parts of south-central Siberia, although the processes involved in the movement are different. In the case of the Tibetan type, individual blocks slide downslope over the substrate in winter on an icy coating in areas of minimal winter precipitation. The Siberian type develops in areas of 15-80 cm of winter snow cover and an MAAT （mean annual air temperature） of-4 ~C to -17 ~C. The movement is due to creep of snow and ice and collapse of the blocks downslope during thawing. Lag block streams are formed by meltwater flowing over the surface of sediment consisting primarily of larger blocks with a limited amount of interstitial sediment. The erosion of the matrix is primarily in the spring in areas of higher winter precipitation on 10^-30~ slopes. The blocks remain stationary, but the interstitial sediment is washed out by strong seasonal flows of meltwater or rain to form an alluvial fan. The boulders undergo weathering and become more rounded in the process. Lag block streams can also develop without the presence of permafrost in areas with cold climates or glaciers. Block streams also occur as relict deposits in older deposits under various climatic regimes that are unsuitable for their formation today. An example of relict lag block streams with subangular to subrounded blocks occurs in gullies on the forested mountainsides at Felsen in Germany, and is the original ＂felsenmeer＂. Similar examples occur near Vitosha Mountain in Bulgaria. The ＂stone runs＂ in the Falkland Islands are examples of the more angular relict lag block streams. In both Tasmania and the Falkland Islands, they mask a more complex history, the underlying soils indicating periods of tropical and temperate soil formation resulting from weathering during and since the Tertiary Period. Block streams have also been reported from beneath cold-based glaciers in Sweden, and below till in Canada, and when ex- humed, can continue to develop.展开更多
With the continuous development of artificial intelligence and machine learning techniques,there have been effective methods supporting the work of dermatologist in the field of skin cancer detection.However,object si...With the continuous development of artificial intelligence and machine learning techniques,there have been effective methods supporting the work of dermatologist in the field of skin cancer detection.However,object significant challenges have been presented in accurately segmenting melanomas in dermoscopic images due to the objects that could interfere human observations,such as bubbles and scales.To address these challenges,we propose a dual U-Net network framework for skin melanoma segmentation.In our proposed architecture,we introduce several innovative components that aim to enhance the performance and capabilities of the traditional U-Net.First,we establish a novel framework that links two simplified U-Nets,enabling more comprehensive information exchange and feature integration throughout the network.Second,after cascading the second U-Net,we introduce a skip connection between the decoder and encoder networks,and incorporate a modified receptive field block(MRFB),which is designed to capture multi-scale spatial information.Third,to further enhance the feature representation capabilities,we add a multi-path convolution block attention module(MCBAM)to the first two layers of the first U-Net encoding,and integrate a new squeeze-and-excitation(SE)mechanism with residual connections in the second U-Net.To illustrate the performance of our proposed model,we conducted comprehensive experiments on widely recognized skin datasets.On the ISIC-2017 dataset,the IoU value of our proposed model increased from 0.6406 to 0.6819 and the Dice coefficient increased from 0.7625 to 0.8023.On the ISIC-2018 dataset,the IoU value of proposed model also improved from 0.7138 to 0.7709,while the Dice coefficient increased from 0.8285 to 0.8665.Furthermore,the generalization experiments conducted on the jaw cyst dataset from Quzhou People’s Hospital further verified the outstanding segmentation performance of the proposed model.These findings collectively affirm the potential of our approach as a valuable tool in supporting clinical decision-making in the field of skin cancer detection,as well as advancing research in medical image analysis.展开更多
Accurate identification and effective support of key blocks are crucial for ensuring the stability and safety of rock slopes.The number of structural planes and rock blocks were reduced in previous studies.This impair...Accurate identification and effective support of key blocks are crucial for ensuring the stability and safety of rock slopes.The number of structural planes and rock blocks were reduced in previous studies.This impairs the ability to characterize complex rock slopes accurately and inhibits the identification of key blocks.In this paper,a knowledge-data dually driven paradigm for accurate identification of key blocks in complex rock slopes is proposed.Our basic idea is to integrate key block theory into data-driven models based on finely characterizing structural features to identify key blocks in complex rock slopes accurately.The proposed novel paradigm consists of(1)representing rock slopes as graph-structured data based on complex systems theory,(2)identifying key nodes in the graph-structured data using graph deep learning,and(3)mapping the key nodes of graph-structured data to corresponding key blocks in the rock slope.Verification experiments and real-case applications are conducted by the proposed method.The verification results demonstrate excellent model performance,strong generalization capability,and effective classification results.Moreover,the real case application is conducted on the northern slope of the Yanqianshan Iron Mine.The results show that the proposed method can accurately identify key blocks in complex rock slopes,which can provide a decision-making basis and rational recommendations for effective support and instability prevention of rock slopes,thereby ensuring the stability of rock engineering and the safety of life and property.展开更多
Dear Editor,The latest Visian implantable collamer lens(ICL)with a central port design(Aquaport;model V4c)obviates the necessity for preoperative laser iridotomy or intraoperative iridectomy by allowing the free flow ...Dear Editor,The latest Visian implantable collamer lens(ICL)with a central port design(Aquaport;model V4c)obviates the necessity for preoperative laser iridotomy or intraoperative iridectomy by allowing the free flow of the aqueous humor between the sides of the intraocular lens.The design of Aquaport can also eliminate the complications associated with iridotomy and iridectomy.Therefore,the V4c ICL has the potential to significantly reduce the risk of pupillary block compared to its predecessors.展开更多
针对传统硬件描述语言(Verilog/VHDL)实现密码算法时代码复杂性高、开发周期长且调试困难等问题,本文提出了一种基于Chisel语言的轻量级分组密码算法LBlock的硬件实现方案。利用Chisel的高级硬件构建能力,通过模块化设计和有限状态机控...针对传统硬件描述语言(Verilog/VHDL)实现密码算法时代码复杂性高、开发周期长且调试困难等问题,本文提出了一种基于Chisel语言的轻量级分组密码算法LBlock的硬件实现方案。利用Chisel的高级硬件构建能力,通过模块化设计和有限状态机控制,高效地实现了密钥扩展、加密和解密核心模块。通过在Xilinx ISE Design Suite 14.7上综合后,结果表明,基于Chisel的LBlock算法实现方案在逻辑资源消耗和工作频率上均表现出优势。最高工作频率达到250.197MHz,加密吞吐率为485.815 Mbps,与传统的Verilog实现相比,本设计在显著降低代码量的同时,吞吐率提升了55.7%,为资源受限环境下的密码硬件实现提供了一种更敏捷、高效的设计思路。展开更多
Dear Editor,In this case,we discuss a teenager who experienced severe eye pain and elevated intraocular pressure(IOP)caused by reverse pupillary block,which was successfully resolved using Neodymium-doped yttrium alum...Dear Editor,In this case,we discuss a teenager who experienced severe eye pain and elevated intraocular pressure(IOP)caused by reverse pupillary block,which was successfully resolved using Neodymium-doped yttrium aluminum garnet(Nd:YAG)laser peripheral iridotomy(LPI).展开更多
基金the support from the National Science Foundation of China(Grant No.41375067) "One-Hundred Talents Plan"of the Chinese Academy of Sciences(Grant No.Y163011)
文摘The flow patterns of Euro-Atlantic blocking events in winter are investigated by dividing the sector into three sub- regions： 60°-30°W （Greenland region）; 20°W-30°E [eastern Atlantic-Europe （EAE） region]; and 50°-90°E （Ural region）. It is shown that blocking events in winter are extremely frequent in the three sub-regions. Composite 500-mb geopotential height fields for intense and long-lived blocking events demonstrate that the blocking fields over Greenland and Ural regions exhibit southwest-northeast （SW-NE） and southeast-northwest （SE-NW） oriented dipole-type patterns, respectively, while the composite field over the EAE region exhibits an Ω-type pattern. The type of composite blocking pattern seems to be related to the position of the blocking region relative to the positive center of the climatological stationary wave （CSW） anomaly existing near 10°W. The physical cause of why there are different composite blocking types in the three sub-regions is identified using a nonlinear multiscale interaction model. It is found that when the blocking event is in almost the same position as the positive CSW anomaly, the planetary-scale field can exhibit an Ω-type pattern due to the enhanced positive CSW anomaly. Neverthe- less, a SW-NE （SE-NW） oriented dipole-type block can occur due to the reduced positive CSW anomaly as it is farther in the west （east） of the positive CSW anomaly. The total fields of blocking in the three regions may exhibit a meandering flow comprised of several isolated anticyclonic and cyclonic vortices, which resembles the Berggren-Bolin-Rossby meandering jet type.
文摘The task of vortex boundaries setting is one of the most complexes in examination of factors influencing on the vortex (circulation system) development and destruction. In this study a new approach of vortex analysis as a whole system is proposed. It is based on vorticity equation where vorticity (left part of the equation) is defined as time coefficients of EOF-decomposition, which is integrated indexes characterizing individual vortex dynamics. Right part of the vorticity equation depicts internal and external factors influencing on the vortex. It's approbation is done on the example of an arctic-subarctic circulation system including blocking anticyclone in winter 2012 which persisted for a long time over the Atlantic sector of the Arctic and led to the formation of the largest positive air temperature anomalies and the minimum ice cover area in the Barents and Kara seas in the entire history of regular observations. It is shown that the main factor in long-term maintenance of the blocking anticyclone over the Arctic was vorticity advection, which was stabilized by horizontal heat advection.
基金supported by the National Natural Science Foundation of China (Nos.22208218,22078196,and 22278268)the Natural Science Foundation of Shanghai (No.22ZR1460400)Collaborative Innovation Center of Fragrance Flavour and Cosmetics,and Collaborative Innovation Project of Shanghai Institute of Technology (No.XTCX2023-07)。
文摘The diagnostic efficacy of contemporary bioimaging technologies remains constrained by inherent limitations of conventional imaging agents,including suboptimal sensitivity,off-target biodistribution,and inherent cytotoxicity.These limitations have catalyzed the development of intelligent stimuli-responsive block copolymers-based bioimaging agents,which was engineered to dynamically respond to endogenous biochemical cues(e.g.,p H gradients,redox potential,enzyme activity,hypoxia environment) or exogenous physical triggers(e.g.,photoirradiation,thermal gradients,ultrasound(US)/magnetic stimuli).Through spatiotemporally controlled structural transformations,stimuli-responsive block copolymers enable precise contrast targeting,activatable signal amplification,and theranostic integration,thereby substantially enhancing signal-to-noise ratios of bioimaging and diagnostic specificity.Hence,this mini-review systematically examines molecular engineering principles for designing p H-,redox-,enzyme-,light-,thermo-,and US/magnetic-responsive polymers,with emphasis on structure-property relationships governing imaging performance modulation.Furthermore,we critically analyze emerging strategies for optical imaging,US synergies,and magnetic resonance imaging(MRI).Multimodal bioimaging has also been elaborated,which could overcome the inherent trade-offs between resolution,penetration depth,and functional specificity in single-modal approaches.By elucidating mechanistic insights and translational challenges,this mini-review aims to establish a design framework of stimuli-responsive block copolymersbased for high fidelity bioimaging agents and accelerate their clinical translation in precise diagnosis and therapy.
基金financially supported by National Key R&D Program Young Scientists Project(No.2023YFC3903100)the National Natural Science Foundation of China(No.22322503)analytical and testing assistance from the Analysis and Testing Center of HUST。
文摘Switchable polymerization is emerging as a powerful tool to construct block copolymers directly from mixtures of monomers.However,current achievements typically iterate between two polymerization cycles to afford products with fixed sequences and compositions.Herein,we report the triethylborane/1,8-diazabicyclo[5.4.0]undec-7-ene(Et_3B/DBU)pair-mediated four-component switchable polymerization of propylene oxide(PO),CO_(2),phthalic anhydride(PA),and racemic lactide(rac-LA),which enables the on-demand synthesis of four different block copolymers,i.e.,poly(propylene phthalate)-b-polylactide(PPE-b-PLA),PPE-b-PLA-b-poly(propylene carbonate)(PPC),PPE-b-PPC-b-PLA,and PPE-b-PPCb-poly(propylene oxide)(PPO),through rationally modulating the Lewis pair(LP)ratio.Core to this protocol is that increasing the loading of Et_(3)B accelerates the ring-opening of PO while impeding the reactivity of rac-LA,thus allowing for fine-tuning of the thermodynamic and kinetic of the switchable polymerization.Therefore,the four polymerization cycles involving PO/PA ring-opening copolymerization(ROCOP),PO/CO_2 ROCOP,rac-LA ring-opening polymerization(ROP),and PO ROP can be connected and discriminated in precisely programmed manners.
基金supported by the National Natural Science Foundation of China(No.52274346).
文摘Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphite.This study utilizes the porous“defect advantage”of a cathode carbon block matrix to prepare silicon-doped and asphalt-coated detoxified and purified waste graphitization cathode carbon blocks for use as high-performance silicon/carbon composite anode materials.The results show that the uniformly silicondoped silicon/carbon composite material features a unique amorphous carbon-encapsulated“locked silicon”structure,which effectively addresses issues such as cathode volume expansion,excessive growth of the solid electrolyte interphase(SEI)film,and poor electrical contact between active materials.Consequently,electrochemical performance is enhanced.After assembly in a half-cell,the PSCC/10%Si@C(purified waste graphitization cathode carbon/10%Si@C)material exhibits optimal electrochemical stability,with an initial charging specific capacity of 514.5 mAh/g at 0.1 C(1 C=170 mA/g)and a capacity retention rate of 95.1%after 100 cycles.At a charge rate of 2.0 C,a specific capacity of 216.9 mAh/g is achieved.This technology provides a new pathway for the economical and high-value utilization of waste cathode carbon blocks and the development of low-cost,high-performance anode materials.
文摘In this study,we examine the connectedness between the NASDAQ artificial intelligence index and sectoral cryptocurrency indices.Empirical analyses were conducted via the quantile‒quantile methodology and cross-multiquantilogram tests across 15 cryptocurrency sectors from June 1,2021,to May 28,2024.The results show that dynamic total spillovers primarily occur in extremely low and high quantiles,corresponding to the left and right tails of the return distributions.Net directional spillovers indicate the dominance of the AI sector over the cryptocurrency market,which intensifies during significant crashes or booms.The most substantial effect of AI is observed in the DeFi,NFT,and Smart Contracts sectors,highlighting the prominence of financial operation-based blockchain applications in their interaction with artificial intelligence.The cross-multiquantilogram results also suggest that developments in artificial intelligence dominate the cryptocurrency market and have high predictability in its price movements.On the basis of our findings,we recommend using the AI market as an early indicator for the cryptocurrency market and advise against combining these two asset groups in the same portfolio to maintain diversification benefits.
文摘Climate change may have detrimental effects on different sectoral growth in global economy and according to the Intergovernmental Panel on Climate Change,the impacts of climate change will be more vigorous in the coming years.The climatic and non-climatic driving forces behind the economic sectoral performances involve short-and long-run interconnections among variables.This study attempts to investigate the effect of climatic factors(temperature and precipitation)along with non-climatic factors,including foreign direct investment(FDI),human capital index(HCI),natural capital(NC),and information and communication technology(ICT)on three major sectors of the economy(agricultural sector,industrial sector,and service sector)through non-linear model framework by employing cross-sectionally augmented autoregressive distributed lag(CS-ARDL)estimation technique.It considers a panel of 56 selected countries from different income groups,including high-income countries,upper-middle-income countries,lower-middle-income countries,and low-income countries,covering the period 1985-2022.The confirmation of slope heterogeneity,cross-sectional dependence,stationarity,and cointegration among variables lends support to the robustness of results.The augmented mean group(AMG)robustness test was applied to check robustness and the results were found mostly consistent with estimation method.The results revealed that upper-middle-income countries are more vulnerable to extreme temperatures compared to high-income countries.The results also confirmed an inverted U-shaped relationship between each sector’s output and precipitation in upper-middle-income countries.In contrast,for upper-middle-income,lower-middle-income,and low-income countries,this relation exists in industrial sector only in long run.This indicates that precipitation is initially beneficial for production activities.However,beyond a certain threshold of precipitation,this trend reverses,i.e.,the output of the economic sectors tends to decline.Furthermore,there is no supporting evidence that confirms a short-run non-linear relation between precipitation and agricultural yields.In upper-middle-income countries,the results confirmed that FDI is a driving factor behind both agricultural sector and service sector in long run while short-run results indicated a negative association but insignificant.This study also showed that in long run,an increase in HCI contributes to improving the output of the three sectors for high-income countries.The empirical findings provide valuable insights for policy-makers and governments to formulate coherent adaptation and mitigation strategies,thereby accelerating the transition of sectoral productivity from low to high levels in the sample countries.
基金supported by the National Key R&D Program of China(Grant No.2022YFC3080200)。
文摘The identification and characterization of concealed in-situ rock blocks on high-steep slope exposures are critical in rock engineering,but remain challenging.This study employs advanced UAV-based photogrammetry to capture high-resolution discontinuity data and develops a fully automated rock block extraction method consisting of three steps:(1)determination of free face and non-free fracture intersections,(2)surface search for rock blocks on free face.and(3)extraction and analysis of rock blocks.This approach simplifies the determination of discontinuity intersections while maintaining high accuracy.By incorporating all types of discontinuities contributing to rock block formation,the method enables precise in-situ rock block identification and extraction.Application to a rock slope in China,produced results consistent with the rock blocks observed in the 3D model,highlighting its accuracy and practical value.
文摘Cryogenic block streams consist of a stream of rocks superficially resembling a stream deposit but lacking a matrix, usually occurring on a valley or gully floor or on slopes that are less steep than the maximum angle of repose of coarse sediments. They are usually formed on perennially frozen ground, but can also occur as relict landforms. There are three main active kinds forming today, viz., Siberian and Tibetan dynamic rock streams and lag block streams. During their formation, the blocks in the active Siberian and Tibetan dynamic block streams move downslope at up to 1 rn/a. They are forming today on the Tibetan Plateau and in the more arid parts of south-central Siberia, although the processes involved in the movement are different. In the case of the Tibetan type, individual blocks slide downslope over the substrate in winter on an icy coating in areas of minimal winter precipitation. The Siberian type develops in areas of 15-80 cm of winter snow cover and an MAAT （mean annual air temperature） of-4 ~C to -17 ~C. The movement is due to creep of snow and ice and collapse of the blocks downslope during thawing. Lag block streams are formed by meltwater flowing over the surface of sediment consisting primarily of larger blocks with a limited amount of interstitial sediment. The erosion of the matrix is primarily in the spring in areas of higher winter precipitation on 10^-30~ slopes. The blocks remain stationary, but the interstitial sediment is washed out by strong seasonal flows of meltwater or rain to form an alluvial fan. The boulders undergo weathering and become more rounded in the process. Lag block streams can also develop without the presence of permafrost in areas with cold climates or glaciers. Block streams also occur as relict deposits in older deposits under various climatic regimes that are unsuitable for their formation today. An example of relict lag block streams with subangular to subrounded blocks occurs in gullies on the forested mountainsides at Felsen in Germany, and is the original ＂felsenmeer＂. Similar examples occur near Vitosha Mountain in Bulgaria. The ＂stone runs＂ in the Falkland Islands are examples of the more angular relict lag block streams. In both Tasmania and the Falkland Islands, they mask a more complex history, the underlying soils indicating periods of tropical and temperate soil formation resulting from weathering during and since the Tertiary Period. Block streams have also been reported from beneath cold-based glaciers in Sweden, and below till in Canada, and when ex- humed, can continue to develop.
基金funded by Zhejiang Basic Public Welfare Research Project,grant number LZY24E060001supported by Guangzhou Development Zone Science and Technology(2021GH10,2020GH10,2023GH02)+1 种基金the University of Macao(MYRG2022-00271-FST)the Science and Technology Development Fund(FDCT)of Macao(0032/2022/A).
文摘With the continuous development of artificial intelligence and machine learning techniques,there have been effective methods supporting the work of dermatologist in the field of skin cancer detection.However,object significant challenges have been presented in accurately segmenting melanomas in dermoscopic images due to the objects that could interfere human observations,such as bubbles and scales.To address these challenges,we propose a dual U-Net network framework for skin melanoma segmentation.In our proposed architecture,we introduce several innovative components that aim to enhance the performance and capabilities of the traditional U-Net.First,we establish a novel framework that links two simplified U-Nets,enabling more comprehensive information exchange and feature integration throughout the network.Second,after cascading the second U-Net,we introduce a skip connection between the decoder and encoder networks,and incorporate a modified receptive field block(MRFB),which is designed to capture multi-scale spatial information.Third,to further enhance the feature representation capabilities,we add a multi-path convolution block attention module(MCBAM)to the first two layers of the first U-Net encoding,and integrate a new squeeze-and-excitation(SE)mechanism with residual connections in the second U-Net.To illustrate the performance of our proposed model,we conducted comprehensive experiments on widely recognized skin datasets.On the ISIC-2017 dataset,the IoU value of our proposed model increased from 0.6406 to 0.6819 and the Dice coefficient increased from 0.7625 to 0.8023.On the ISIC-2018 dataset,the IoU value of proposed model also improved from 0.7138 to 0.7709,while the Dice coefficient increased from 0.8285 to 0.8665.Furthermore,the generalization experiments conducted on the jaw cyst dataset from Quzhou People’s Hospital further verified the outstanding segmentation performance of the proposed model.These findings collectively affirm the potential of our approach as a valuable tool in supporting clinical decision-making in the field of skin cancer detection,as well as advancing research in medical image analysis.
基金supported by the National Natural Science Foundation of China(Grant Nos.42277161,42230709).
文摘Accurate identification and effective support of key blocks are crucial for ensuring the stability and safety of rock slopes.The number of structural planes and rock blocks were reduced in previous studies.This impairs the ability to characterize complex rock slopes accurately and inhibits the identification of key blocks.In this paper,a knowledge-data dually driven paradigm for accurate identification of key blocks in complex rock slopes is proposed.Our basic idea is to integrate key block theory into data-driven models based on finely characterizing structural features to identify key blocks in complex rock slopes accurately.The proposed novel paradigm consists of(1)representing rock slopes as graph-structured data based on complex systems theory,(2)identifying key nodes in the graph-structured data using graph deep learning,and(3)mapping the key nodes of graph-structured data to corresponding key blocks in the rock slope.Verification experiments and real-case applications are conducted by the proposed method.The verification results demonstrate excellent model performance,strong generalization capability,and effective classification results.Moreover,the real case application is conducted on the northern slope of the Yanqianshan Iron Mine.The results show that the proposed method can accurately identify key blocks in complex rock slopes,which can provide a decision-making basis and rational recommendations for effective support and instability prevention of rock slopes,thereby ensuring the stability of rock engineering and the safety of life and property.
基金Supported by the National Key Research and Development Program(No.2019YFC1710200)the Shandong Province Pharmaceutical Technology Development Project(No.202107020970).
文摘Dear Editor,The latest Visian implantable collamer lens(ICL)with a central port design(Aquaport;model V4c)obviates the necessity for preoperative laser iridotomy or intraoperative iridectomy by allowing the free flow of the aqueous humor between the sides of the intraocular lens.The design of Aquaport can also eliminate the complications associated with iridotomy and iridectomy.Therefore,the V4c ICL has the potential to significantly reduce the risk of pupillary block compared to its predecessors.
文摘针对传统硬件描述语言(Verilog/VHDL)实现密码算法时代码复杂性高、开发周期长且调试困难等问题,本文提出了一种基于Chisel语言的轻量级分组密码算法LBlock的硬件实现方案。利用Chisel的高级硬件构建能力,通过模块化设计和有限状态机控制,高效地实现了密钥扩展、加密和解密核心模块。通过在Xilinx ISE Design Suite 14.7上综合后,结果表明,基于Chisel的LBlock算法实现方案在逻辑资源消耗和工作频率上均表现出优势。最高工作频率达到250.197MHz,加密吞吐率为485.815 Mbps,与传统的Verilog实现相比,本设计在显著降低代码量的同时,吞吐率提升了55.7%,为资源受限环境下的密码硬件实现提供了一种更敏捷、高效的设计思路。
文摘Dear Editor,In this case,we discuss a teenager who experienced severe eye pain and elevated intraocular pressure(IOP)caused by reverse pupillary block,which was successfully resolved using Neodymium-doped yttrium aluminum garnet(Nd:YAG)laser peripheral iridotomy(LPI).
