CB chondrite is a class of meteorite rich in metal composition,and its characteristics are obviously different from other chondrite groups.These meteorites are distinguished by their content of up to 60% to 70%FeNi me...CB chondrite is a class of meteorite rich in metal composition,and its characteristics are obviously different from other chondrite groups.These meteorites are distinguished by their content of up to 60% to 70%FeNi metals and sulfides,in addition to their extreme lack of volatile and moderately volatile elements,less refractory inclusions,and almost no fine-grained matrix.Sierra Gorda 013(SG013)is a metal-rich chondritic meteorite of the CBa type.It has two different lithologies within SG 013:Lithology 1and Lithology 2.Lithology 1 is an anomalous CBa chondrite containing chromite-pyroxene complex assemblage,whereas Lithology 2 is featured by recrystallization with small chondrules and contains much less iron nickel metal than Lithology 1.Although the two lithologies have essentially the same oxygen isotope composition,their structures are different from each other,suggesting that they probably underwent distinct formation and evolution processes from common precursors.In this study,the mineralogy of SG013 chondrites is studied by means of petrographic observation,semi-quantitative analysis of chemical composition,fabric identification of minerals and integrated mineral phase analysis,while studying the mineralogy of SG 013,and the fabric characteristics of SG 013 are studied in detail.Different from previous studies,here we find that Lithology 1 of SG 013 contains non-porphyritic chondrules and metallic silicate globules,while Lithology 2 not only contains nonporphyritic chondrules and metallic-silicate globules,but also porphyritic chondrules.In this thesis,Electron backscatter diffraction(EBSD)analysis of magnesium olivine in metal-silicate globules and porphyritic chondrules in L2 of SG 013 shows that some magnesium olivine form under conditions of lower temperature and faster strain rate during uniaxial compression,where deformation of the olivine is dominated by dislocation glide.However,at higher temperatures and slower strain rates,the fabric of B-axis([100])is concentrated,indicating that the porphyritic chondrules may be dominated by the compaction of olivine particles,leading to dynamic recrystallization in the peripheral region or outer layer of the magnesium olivine crystal.New grains formed by dynamic recrystallization occur at the edges of residual grains and,their orientation is controlled by stress.It is found that the formation position of magnesium olivine in different chondrules of SG 013 from the inside out,with the gradual reduction of stress and the gradual increase of temperature,these local physicochemical changes reveal the complex thermal history and dynamic processes that chondrules undergo during their formation and evolution.展开更多
Gas sensors are valuable tools for human applications,and extensive research has been conducted in this field.However,practical implementation has yet to be fully realized.In response,efforts have been made to explore...Gas sensors are valuable tools for human applications,and extensive research has been conducted in this field.However,practical implementation has yet to be fully realized.In response,efforts have been made to explore metal-organic frameworks(MOFs),a novel class of porous materials,as potential solutions.MOFs exhibit exceptional porosity and highly tunable chemical compositions and structures,giving rise to a wide range of unique physical and chemical properties.Significant progress has been achieved in developing MOF-based gas sensors,improving sensing performance for various gases.This review aims to provide a comprehensive understanding of MOF-based gas sensors,even for readers unfamiliar with MOFs and gas sensors.It covers the working principles of these sensors,fundamental concepts of MOFs,strategies for tuning MOF properties,fabrication techniques for MOF films,and recent studies on MOF and MOF-derivative gas sensors.Finally,current challenges,overlooked aspects,and future directions for fully exploiting the potential of MOFs in gas sensor development are discussed.展开更多
Fabric defect detection plays a vital role in ensuring textile quality.However,traditional manual inspection methods are often inefficient and inaccurate.To overcome these limitations,we propose FD-YOLO,an enhanced li...Fabric defect detection plays a vital role in ensuring textile quality.However,traditional manual inspection methods are often inefficient and inaccurate.To overcome these limitations,we propose FD-YOLO,an enhanced lightweight detection model based on the YOLOv11n framework.The proposed model introduces the Bi-level Routing Attention(BRAttention)mechanism to enhance defect feature extraction,enabling more detailed feature representation.It proposes Deep Progressive Cross-Scale Fusion Neck(DPCSFNeck)to better capture smallscale defects and incorporates a Multi-Scale Dilated Residual(MSDR)module to strengthen multi-scale feature representation.Furthermore,a Shared Detail-Enhanced Lightweight Head(SDELHead)is employed to reduce the risk of gradient explosion during training.Experimental results demonstrate that FD-YOLO achieves superior detection accuracy and Lightweight performance compared to the baseline YOLOv11n.展开更多
From 2 to 4 February 2026,the 58th edition of the show will bring together more than 1,100 exhibitors from 33 countries at Paris–Le Bourget Exhibition Centre.As a true sourcing platform,the event stands out for its d...From 2 to 4 February 2026,the 58th edition of the show will bring together more than 1,100 exhibitors from 33 countries at Paris–Le Bourget Exhibition Centre.As a true sourcing platform,the event stands out for its diversity,clear structure and operational efficiency,giving international buyers direct access to an offer tailored to their needs.展开更多
Off-axis aspherical mirrors are widely used in optical systems and precision measuring instruments,whereas off-axis aspherical mirrors with large sizes and off-axis are used in large optical systems such as astronomic...Off-axis aspherical mirrors are widely used in optical systems and precision measuring instruments,whereas off-axis aspherical mirrors with large sizes and off-axis are used in large optical systems such as astronomical telescopes and radio telescopes.However,if the off-axis amount of an off-axis aspherical mirror exceeds the capability of the machine tool,traditional rotary-turning machining methods are not applicable,and advanced computerized numerical control(CNC)machining methods,such as the slow-tool-servo method,must be im-plemented.This article proposes a non-conventional offset(NCO)fabrication method based on slow-tool-servo single-point diamond turning for machining off-axis aspherical surfaces with large off-axis amounts.This method is theoretically applicable to the machining of off-axis aspherical surfaces with any off-axis amount.NCO fab-rication is a simpler and more efficient path-planning solution for machining individual off-axis parabolic sur-faces.In addition,corresponding solutions for other types of aspherical surfaces are proposed using the NCO method.The turning depths of workpieces with different off-axis amounts at the same machining position are analyzed and compared.A specific measurement scheme for the NCO method is presented,and the experimental results indicate that the PV and RMS form errors are 0.658μm and 60 nm,respectively.This work demonstrates that the NCO method can effectively deal with the machining challenges of off-axis aspherical structures with large off-axis amounts.展开更多
The accretion of the Panama-ChocóBlock to the South American Plate partially drove the geological setting of the northern Andes.This event occurred in different collisional stages that are recorded in Oligocene-m...The accretion of the Panama-ChocóBlock to the South American Plate partially drove the geological setting of the northern Andes.This event occurred in different collisional stages that are recorded in Oligocene-middle Miocene deformed rocks of the inter-Andean valley between the Western and Central Cordilleras of Colombia.However,uncertainty remains about the age of the latest accretionary phases of the Panama-ChocóBlock.Poorly studied late Miocene volcanic rocks within the northern inter-Andean valley may provide key information to constrain the temporality of that final collision.Here,we study the deformational features of the~12-6 Ma extrusive rocks of the Combia Volcanic Province located in the northwestern Andes(Colombia).We present anisotropy of magnetic susceptibility(AMS)data for pyroclastic and volcanic rocks within the AmagáBasin,an inter-Andean depression with Oligocene-middle Miocene sedimentary rocks that recorded NW-SE compression and NE-SW simple shear caused by the Panama-ChocóBlock collision.We identified that the magnetic fabrics of the extrusive rocks of the Combia Volcanic Province reveal flow directions that indicate the occurrence of ancient volcanoes in the central axis of the AmagáBasin.Some of these fabrics do not contain any deformational features,whereas others record the same structural regime as the Oligocene-middle Miocene sedimentary rocks.We infer that variations in the intensity of the deformation promoted late Miocene local fault reactivations that,in contrast to the Oligocene-middle Miocene deformational events,did not affect the entire AmagáBasin.Age differences among the studied sections can also explain the different deformational patterns identified in the basin.Both interpretations suggest that the most significant collisional events of the Panama-ChocóBlock occurred in the Oligocene-middle Miocene,whereas the formation of the Combia Volcanic Province may have either followed or coincided with the latest stages of the accretion.展开更多
The strength-ductility synergy in heterogeneous materials offers significant advantages,though their scalable and controlled fabrication remains challenging.This study introduces an in situ fabrication strategy for he...The strength-ductility synergy in heterogeneous materials offers significant advantages,though their scalable and controlled fabrication remains challenging.This study introduces an in situ fabrication strategy for heterogeneous lamellar titanium(HLT)alloy via laser powder bed fusion of a powder mixture consisting of Ti6Al4V(TC4)and 3 wt%Fe.By periodically varying the scanning velocity between layers,a heterogeneous lamellar microstructure is achieved due to the unique Fe distribution originating from the various volumetric energy densities(VEDs).Consequently,the HLT achieves high yield strength(1036 MPa)and ultimate tensile strength(1419 MPa)without compromising uniform elongation(UE),surpassing most TC4 alloys.The high strength may be attributed to precipitation strengthening originating from the nano-sizedαandωprecipitates,while the high UE and work hardening arise from the strain-induced martensite(SIM)and strong hetero-deformation induced(HDI)stress.The denser dual-phase interfaces and smaller grains in the low VED layers contribute to the higher sensitivity to the SIM.A strain gradient between soft and hard layers evolves during loading,and it further enhances the HDI strengthening and SIM behavior.Through this work,the in situ fabrication method and the deformation mechanism of lamellar heterostructure could offer valuable reference for the optimization and application of heterogeneous materials.展开更多
Hyperledger Fabric是一个主流的联盟链平台,当面临多笔并发执行且相互关联的交易时,现有架构容易生成大量无效交易,这严重降低了系统的有效交易处理能力。为了解决这一问题,提出一种融合映射与有向无环图(DAG)的冲突消除机制—FabricIM...Hyperledger Fabric是一个主流的联盟链平台,当面临多笔并发执行且相互关联的交易时,现有架构容易生成大量无效交易,这严重降低了系统的有效交易处理能力。为了解决这一问题,提出一种融合映射与有向无环图(DAG)的冲突消除机制—FabricIMD(Fabric integrated with map and DAG)。该机制在背书节点处通过映射识别交易间依赖关系,并使用有向无环图对此关系进行构建,以调整交易背书顺序,从而有效避免了交易冲突现象的出现。实验证明,当存在多笔相互关联的并发交易时,FabricIMD机制能显著减少因交易冲突导致的无效交易。随着交易间冲突程度的变化,系统有效交易吞吐量提升了15.68%~96.08%。此外,在处理无关联的并发交易时,引入该机制并未对系统性能造成显著影响。综上,FabricIMD机制在避免交易冲突现象出现的同时提高了系统有效交易吞吐量,减少了无效交易数量。展开更多
Electrolytic copper foil has gained significant attention as an essential component in lithium-ion batteries(LIBs),printed circuit boards(PCBs),and chip packaging substrates(CPSs)applications.With the advancement of L...Electrolytic copper foil has gained significant attention as an essential component in lithium-ion batteries(LIBs),printed circuit boards(PCBs),and chip packaging substrates(CPSs)applications.With the advancement of LIBs towards higher energy densities and the increasing density of electronic components on circuits,copper foil is required to have demanding properties,such as extremely thin thickness and extremely high tensile strength.This comprehensive review firstly summarizes recent progress on the fabrication of electrolytic copper foil,and the effects of process parameters,cathode substrate,and additives on the electrodeposition behavior,microstructure,and properties of copper foil are discussed in detail.Then the regulation strategies of mechanical properties of electrolytic copper foil are also summarized,including the formation of nanotwins and texture.Furthermore,the recent advances in novel electrolytic copper foils,such as composite foils and extra-thin copper foils,are also overviewed.Lastly,the remaining challenges and perspectives on the further development of electrolytic copper foils are presented.展开更多
Microneedle(MN)is a medical device containing an array of needles with a micrometer-scale.It can penetrate the human stratum corneum painlessly and efficiently for treatment and diagnosis purposes.Currently,the materi...Microneedle(MN)is a medical device containing an array of needles with a micrometer-scale.It can penetrate the human stratum corneum painlessly and efficiently for treatment and diagnosis purposes.Currently,the materials commonly used to manufacture MNs include silicon,polymers,ceramics and metals.Metallic MNs(MMNs)have drawn significant attention owing to its superior mechanical properties,machinability,and biocompatibility.This paper is a state-of-the-art review of the structure,fabrication technologies,and applications of MMNs.According to the relative position of the axis of MN and the plane of the substrate,MMNs can be divided into in-plane and out-of-plane.Solid,hollow,coated and porous MMNs are also employed to characterize their internal and surface structures.Until now,numerous fabrication technologies,including cutting tool machining,non-traditional machining,etching,hot-forming,and additive manufacturing,have been used to fabricate MMNs.The recent advances in the application of MMNs in drug delivery,disease diagnosis,and cosmetology are also discussed in-depth.Finally,the shortcomings in the fabrication and application of MMNs and future directions for development are highlighted.展开更多
Self-regulating heating and self-powered flexibility are pivotal for future wearable devices.However,the low energy-conversion rate of wearable devices at low temperatures limits their application in plateaus and othe...Self-regulating heating and self-powered flexibility are pivotal for future wearable devices.However,the low energy-conversion rate of wearable devices at low temperatures limits their application in plateaus and other environments.This study introduces an azopolymer with remarkable semicrystallinity and reversible photoinduced solid-liquid transition ability that is obtained through copolymerization of azoben-zene(Azo)monomers and styrene.A composite of one such copolymer with an Azo:styrene molar ratio of 9:1(copolymer is denoted as PAzo9:1-co-polystyrene(PS))and nylon fabrics(NFs)is prepared(composite is denoted as PAzo9:1-co-PS@NF).PAzo9:1-co-PS@NF exhibits hydrophobicity and high wear resistance.Moreover,it shows good responsiveness(0.624 s^(−1))during isomerization under solid ultraviolet(UV)light(365 nm)with an energy density of 70.6 kJ kg^(−1).In addition,the open-circuit voltage,short-circuit current and quantity values of PAzo9:1-co-PS@NF exhibit small variations in a temperature range of−20℃ to 25℃ and remain at 170 V,5 μA,and 62 nC,respectively.Notably,the involved NFs were cut and sewn into gloves to be worn on a human hand model.When the model was exposed to both UV radiation and friction,the temperature of the finger coated with PAzo9:1-co-PS was approximately 6.0°C higher than that of the other parts.Therefore,developing triboelectric nanogenerators based on the in situ photothermal cycles of Azo in wearable devices is important to develop low-temperature self-regulating heating and self-powered flexible devices for extreme environments.展开更多
Wearable thermoelectric devices hold significant promise in the realm of self-powered wearable electron-ics,offering applications in energy harvesting,movement tracking,and health monitoring.Nevertheless,developing th...Wearable thermoelectric devices hold significant promise in the realm of self-powered wearable electron-ics,offering applications in energy harvesting,movement tracking,and health monitoring.Nevertheless,developing thermoelectric devices with exceptional flexibility,enduring thermoelectric stability,multi-functional sensing,and comfortable wear remains a challenge.In this work,a stretchable MXene-based thermoelectric fabric is designed to accurately discern temperature and strain stimuli.This is achieved by constructing an adhesive polydopamine(PDA)layer on the nylon fabric surface,which facilitates the subsequent MXene attachment through hydrogen bonding.This fusion results in MXene-based thermo-electric fabric that excels in both temperature sensing and strain sensing.The resultant MXene-based thermoelectric fabric exhibits outstanding temperature detection capability and cyclic stability,while also delivering excellent sensitivity,rapid responsiveness(60 ms),and remarkable durability in strain sens-ing(3200 cycles).Moreover,when affixed to a mask,this MXene-based thermoelectric fabric utilizes the temperature difference between the body and the environment to harness body heat,converting it into electrical energy and accurately discerning the body’s respiratory rate.In addition,the MXene-based ther-moelectric fabric can monitor the state of the body’s joint through its own deformation.Furthermore,it possesses the capability to convert solar energy into heat.These findings indicate that MXene-based ther-moelectric fabric holds great promise for applications in power generation,motion tracking,and health monitoring.展开更多
The Janus fabrics designed for personal moisture/thermal regulation have garnered significant attention for their potential to enhance human comfort.However,the development of smart and dynamic fabrics capable of mana...The Janus fabrics designed for personal moisture/thermal regulation have garnered significant attention for their potential to enhance human comfort.However,the development of smart and dynamic fabrics capable of managing personal moisture/thermal comfort in response to changing external environments remains a challenge.Herein,a smart cellulose-based Janus fabric was designed to dynamically manage personal moisture/heat.The cotton fabric was grafted with N-isopropylacrylamide to construct a temperature-stimulated transport channel.Subsequently,hydrophobic ethyl cellulose and hydrophilic cellulose nanofiber were sprayed on the bottom and top sides of the fabric to obtain wettability gradient.The fabric exhibits anti-gravity directional liquid transportation from hydrophobic side to hydrophilic side,and can dynamically and continuously control the transportation time in a wide range of 3–66 s as the temperature increases from 10 to 40℃.This smart fabric can quickly dissipate heat at high temperatures,while at low temperatures,it can slow down the heat dissipation rate and prevent the human from becoming too cold.In addition,the fabric has UV shielding and photodynamic antibacterial properties through depositing graphitic carbon nitride nanosheets on the hydrophilic side.This smart fabric offers an innovative approach to maximizing personal comfort in environments with significant temperature variations.展开更多
Fueled by the increasing imperative for sustainable energy solutions and the burgeoning emphasis on health awareness,self-powered techniques have undergone notable strides in advancement.Triboelectric nanogenerators(T...Fueled by the increasing imperative for sustainable energy solutions and the burgeoning emphasis on health awareness,self-powered techniques have undergone notable strides in advancement.Triboelectric nanogenerators(TENGs)stand out as a prominent device capitalizing on the principles of triboelectrification and electrostatic induction to generate electricity or electrical signals.In efforts to augment the electrical output performance of TENGs and broaden their range of applications,researchers have endeavored to refine materials,surface morphology,and structural design.Among them,physical morphological modifications play a pivotal role in enhancing the electrical properties of TENGs by increasing the contact surface area,which can be achieved by building micro-/nano-structures on the surface or inside the friction material.In this review,we summarize the common morphologies of TENGs,categorize the morphologies into surface and internal structures,and elucidate their roles in enhancing the electric output performance of devices.Moreover,we systematically classify the methodologies employed for morphological preparation into physical and chemical approaches,thereby furnishing a comprehensive survey of the diverse techniques.Subsequently,typical applications of TENGs with special morphology divided by energy harvesting and self-powered sensors are presented.Finally,an overview of the challenges and future trajectories pertinent to TENGs is conducted.Through this endeavor,the aim of this article is to catalyze the evolution of further strategies for enhancing performance of TENGs.展开更多
This research study fabrics to ensure that they are free from carcinogenic dyes. It has been observed that there are poor-quality fabrics and consumers go to buy them without paying attention to the risks of using pro...This research study fabrics to ensure that they are free from carcinogenic dyes. It has been observed that there are poor-quality fabrics and consumers go to buy them without paying attention to the risks of using prohibited materials in the manufacture of these fabrics, and the use of unknown dyes has proven that some of them cause diseases to humans, especially children, that cause cancerous diseases. With the study sample consisting of (7), the study results indicate the presence of toxic formaldehyde in all sample dyes obtained from discount markets and online shopping.展开更多
基金Chinese Academy of Science,XDB 41000000,Chunhui Li。
文摘CB chondrite is a class of meteorite rich in metal composition,and its characteristics are obviously different from other chondrite groups.These meteorites are distinguished by their content of up to 60% to 70%FeNi metals and sulfides,in addition to their extreme lack of volatile and moderately volatile elements,less refractory inclusions,and almost no fine-grained matrix.Sierra Gorda 013(SG013)is a metal-rich chondritic meteorite of the CBa type.It has two different lithologies within SG 013:Lithology 1and Lithology 2.Lithology 1 is an anomalous CBa chondrite containing chromite-pyroxene complex assemblage,whereas Lithology 2 is featured by recrystallization with small chondrules and contains much less iron nickel metal than Lithology 1.Although the two lithologies have essentially the same oxygen isotope composition,their structures are different from each other,suggesting that they probably underwent distinct formation and evolution processes from common precursors.In this study,the mineralogy of SG013 chondrites is studied by means of petrographic observation,semi-quantitative analysis of chemical composition,fabric identification of minerals and integrated mineral phase analysis,while studying the mineralogy of SG 013,and the fabric characteristics of SG 013 are studied in detail.Different from previous studies,here we find that Lithology 1 of SG 013 contains non-porphyritic chondrules and metallic silicate globules,while Lithology 2 not only contains nonporphyritic chondrules and metallic-silicate globules,but also porphyritic chondrules.In this thesis,Electron backscatter diffraction(EBSD)analysis of magnesium olivine in metal-silicate globules and porphyritic chondrules in L2 of SG 013 shows that some magnesium olivine form under conditions of lower temperature and faster strain rate during uniaxial compression,where deformation of the olivine is dominated by dislocation glide.However,at higher temperatures and slower strain rates,the fabric of B-axis([100])is concentrated,indicating that the porphyritic chondrules may be dominated by the compaction of olivine particles,leading to dynamic recrystallization in the peripheral region or outer layer of the magnesium olivine crystal.New grains formed by dynamic recrystallization occur at the edges of residual grains and,their orientation is controlled by stress.It is found that the formation position of magnesium olivine in different chondrules of SG 013 from the inside out,with the gradual reduction of stress and the gradual increase of temperature,these local physicochemical changes reveal the complex thermal history and dynamic processes that chondrules undergo during their formation and evolution.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(RS-2024-00333650)supported by basic science research program through the National Research Foundation of Korea funded by the Ministry of Education(NRF-2019R1A6A1A11055660)+1 种基金supported by the Technology Innovation Program(“20013621”,Center for Super Critical Material Industrial Technology)funded By the Ministry of Trade,Industry&Energy(MOTIE,Korea)supported by Strategic Networking&Development Program funded by the Ministry of Science and ICT through the National Research Foundation of Korea(RS-2023-00268523)。
文摘Gas sensors are valuable tools for human applications,and extensive research has been conducted in this field.However,practical implementation has yet to be fully realized.In response,efforts have been made to explore metal-organic frameworks(MOFs),a novel class of porous materials,as potential solutions.MOFs exhibit exceptional porosity and highly tunable chemical compositions and structures,giving rise to a wide range of unique physical and chemical properties.Significant progress has been achieved in developing MOF-based gas sensors,improving sensing performance for various gases.This review aims to provide a comprehensive understanding of MOF-based gas sensors,even for readers unfamiliar with MOFs and gas sensors.It covers the working principles of these sensors,fundamental concepts of MOFs,strategies for tuning MOF properties,fabrication techniques for MOF films,and recent studies on MOF and MOF-derivative gas sensors.Finally,current challenges,overlooked aspects,and future directions for fully exploiting the potential of MOFs in gas sensor development are discussed.
基金financially supported by the Fujian Provincial Department of Science and Technology,the Collaborative Innovation Platform Project for Key Technologies of Smart Warehousing and Logistics Systems in the Fuzhou-Xiamen-Quanzhou National Independent Innovation Demonstration Zone(No.2025E3024).
文摘Fabric defect detection plays a vital role in ensuring textile quality.However,traditional manual inspection methods are often inefficient and inaccurate.To overcome these limitations,we propose FD-YOLO,an enhanced lightweight detection model based on the YOLOv11n framework.The proposed model introduces the Bi-level Routing Attention(BRAttention)mechanism to enhance defect feature extraction,enabling more detailed feature representation.It proposes Deep Progressive Cross-Scale Fusion Neck(DPCSFNeck)to better capture smallscale defects and incorporates a Multi-Scale Dilated Residual(MSDR)module to strengthen multi-scale feature representation.Furthermore,a Shared Detail-Enhanced Lightweight Head(SDELHead)is employed to reduce the risk of gradient explosion during training.Experimental results demonstrate that FD-YOLO achieves superior detection accuracy and Lightweight performance compared to the baseline YOLOv11n.
文摘From 2 to 4 February 2026,the 58th edition of the show will bring together more than 1,100 exhibitors from 33 countries at Paris–Le Bourget Exhibition Centre.As a true sourcing platform,the event stands out for its diversity,clear structure and operational efficiency,giving international buyers direct access to an offer tailored to their needs.
基金Supported by National Key R&D Program of China(Grant No.2023YFE0203800)the National Natural Science Foundation of China(Grant No.52105482).
文摘Off-axis aspherical mirrors are widely used in optical systems and precision measuring instruments,whereas off-axis aspherical mirrors with large sizes and off-axis are used in large optical systems such as astronomical telescopes and radio telescopes.However,if the off-axis amount of an off-axis aspherical mirror exceeds the capability of the machine tool,traditional rotary-turning machining methods are not applicable,and advanced computerized numerical control(CNC)machining methods,such as the slow-tool-servo method,must be im-plemented.This article proposes a non-conventional offset(NCO)fabrication method based on slow-tool-servo single-point diamond turning for machining off-axis aspherical surfaces with large off-axis amounts.This method is theoretically applicable to the machining of off-axis aspherical surfaces with any off-axis amount.NCO fab-rication is a simpler and more efficient path-planning solution for machining individual off-axis parabolic sur-faces.In addition,corresponding solutions for other types of aspherical surfaces are proposed using the NCO method.The turning depths of workpieces with different off-axis amounts at the same machining position are analyzed and compared.A specific measurement scheme for the NCO method is presented,and the experimental results indicate that the PV and RMS form errors are 0.658μm and 60 nm,respectively.This work demonstrates that the NCO method can effectively deal with the machining challenges of off-axis aspherical structures with large off-axis amounts.
基金supported financially by the National Natural Science Foundation of China (Grants W2433104 to V.A.P. and42225402 to J.L.)the China Postdoctoral Science Foundation(Grant 2024M753205 to V.A.P.)+4 种基金the Institute of Geology and Geophysics of the Chinese Academy of Sciences (International Fellowship for Postdoctoral Researchers, Grant 2025PD02 to V.A.P.)an association between ECOS-NORD (France)Colciencias/Icetex (Colombia)(Grant C12U01 to M.I.M.)a junior fellowship scheme of Colciencias (Colombia)(Grant 706-2015 to V.A.P.)supported the undergraduate final project of A.T
文摘The accretion of the Panama-ChocóBlock to the South American Plate partially drove the geological setting of the northern Andes.This event occurred in different collisional stages that are recorded in Oligocene-middle Miocene deformed rocks of the inter-Andean valley between the Western and Central Cordilleras of Colombia.However,uncertainty remains about the age of the latest accretionary phases of the Panama-ChocóBlock.Poorly studied late Miocene volcanic rocks within the northern inter-Andean valley may provide key information to constrain the temporality of that final collision.Here,we study the deformational features of the~12-6 Ma extrusive rocks of the Combia Volcanic Province located in the northwestern Andes(Colombia).We present anisotropy of magnetic susceptibility(AMS)data for pyroclastic and volcanic rocks within the AmagáBasin,an inter-Andean depression with Oligocene-middle Miocene sedimentary rocks that recorded NW-SE compression and NE-SW simple shear caused by the Panama-ChocóBlock collision.We identified that the magnetic fabrics of the extrusive rocks of the Combia Volcanic Province reveal flow directions that indicate the occurrence of ancient volcanoes in the central axis of the AmagáBasin.Some of these fabrics do not contain any deformational features,whereas others record the same structural regime as the Oligocene-middle Miocene sedimentary rocks.We infer that variations in the intensity of the deformation promoted late Miocene local fault reactivations that,in contrast to the Oligocene-middle Miocene deformational events,did not affect the entire AmagáBasin.Age differences among the studied sections can also explain the different deformational patterns identified in the basin.Both interpretations suggest that the most significant collisional events of the Panama-ChocóBlock occurred in the Oligocene-middle Miocene,whereas the formation of the Combia Volcanic Province may have either followed or coincided with the latest stages of the accretion.
基金financially supported by the National Natural Science Foundation of China(No.52375347)Shanghai Pujiang Programme(No.8003PJD023)Natural Science Foundation of Ningbo(Grant No.2023J008)。
文摘The strength-ductility synergy in heterogeneous materials offers significant advantages,though their scalable and controlled fabrication remains challenging.This study introduces an in situ fabrication strategy for heterogeneous lamellar titanium(HLT)alloy via laser powder bed fusion of a powder mixture consisting of Ti6Al4V(TC4)and 3 wt%Fe.By periodically varying the scanning velocity between layers,a heterogeneous lamellar microstructure is achieved due to the unique Fe distribution originating from the various volumetric energy densities(VEDs).Consequently,the HLT achieves high yield strength(1036 MPa)and ultimate tensile strength(1419 MPa)without compromising uniform elongation(UE),surpassing most TC4 alloys.The high strength may be attributed to precipitation strengthening originating from the nano-sizedαandωprecipitates,while the high UE and work hardening arise from the strain-induced martensite(SIM)and strong hetero-deformation induced(HDI)stress.The denser dual-phase interfaces and smaller grains in the low VED layers contribute to the higher sensitivity to the SIM.A strain gradient between soft and hard layers evolves during loading,and it further enhances the HDI strengthening and SIM behavior.Through this work,the in situ fabrication method and the deformation mechanism of lamellar heterostructure could offer valuable reference for the optimization and application of heterogeneous materials.
文摘Hyperledger Fabric是一个主流的联盟链平台,当面临多笔并发执行且相互关联的交易时,现有架构容易生成大量无效交易,这严重降低了系统的有效交易处理能力。为了解决这一问题,提出一种融合映射与有向无环图(DAG)的冲突消除机制—FabricIMD(Fabric integrated with map and DAG)。该机制在背书节点处通过映射识别交易间依赖关系,并使用有向无环图对此关系进行构建,以调整交易背书顺序,从而有效避免了交易冲突现象的出现。实验证明,当存在多笔相互关联的并发交易时,FabricIMD机制能显著减少因交易冲突导致的无效交易。随着交易间冲突程度的变化,系统有效交易吞吐量提升了15.68%~96.08%。此外,在处理无关联的并发交易时,引入该机制并未对系统性能造成显著影响。综上,FabricIMD机制在避免交易冲突现象出现的同时提高了系统有效交易吞吐量,减少了无效交易数量。
基金supported by the National Key R&D Plan Program of China(No.2021YFB3400800)Henan Key Research and Development Program(No.231111241000)+1 种基金the Joint Fund of Henan Province Science and Technology R&D Program(No.225200810026)Zhongyuan Scholar Workstation Funded Program(No.224400510025).
文摘Electrolytic copper foil has gained significant attention as an essential component in lithium-ion batteries(LIBs),printed circuit boards(PCBs),and chip packaging substrates(CPSs)applications.With the advancement of LIBs towards higher energy densities and the increasing density of electronic components on circuits,copper foil is required to have demanding properties,such as extremely thin thickness and extremely high tensile strength.This comprehensive review firstly summarizes recent progress on the fabrication of electrolytic copper foil,and the effects of process parameters,cathode substrate,and additives on the electrodeposition behavior,microstructure,and properties of copper foil are discussed in detail.Then the regulation strategies of mechanical properties of electrolytic copper foil are also summarized,including the formation of nanotwins and texture.Furthermore,the recent advances in novel electrolytic copper foils,such as composite foils and extra-thin copper foils,are also overviewed.Lastly,the remaining challenges and perspectives on the further development of electrolytic copper foils are presented.
基金Supported by Guangdong Provincial Key-Area Research and Development Program(Grant No.2023B0101200014)Guangdong Provincial Natural Science Foundation(Grant No.2024A1515010440).
文摘Microneedle(MN)is a medical device containing an array of needles with a micrometer-scale.It can penetrate the human stratum corneum painlessly and efficiently for treatment and diagnosis purposes.Currently,the materials commonly used to manufacture MNs include silicon,polymers,ceramics and metals.Metallic MNs(MMNs)have drawn significant attention owing to its superior mechanical properties,machinability,and biocompatibility.This paper is a state-of-the-art review of the structure,fabrication technologies,and applications of MMNs.According to the relative position of the axis of MN and the plane of the substrate,MMNs can be divided into in-plane and out-of-plane.Solid,hollow,coated and porous MMNs are also employed to characterize their internal and surface structures.Until now,numerous fabrication technologies,including cutting tool machining,non-traditional machining,etching,hot-forming,and additive manufacturing,have been used to fabricate MMNs.The recent advances in the application of MMNs in drug delivery,disease diagnosis,and cosmetology are also discussed in-depth.Finally,the shortcomings in the fabrication and application of MMNs and future directions for development are highlighted.
基金supported by the China Postdoctoral Science Foundation(No.2023M732344)the National Natural Science Foundation of China(Nos.51973119,52327802,52173078)+4 种基金Shenzhen Key Laboratory of Photonics and Biophotonics(ZDSYS20210623092006020)Shenzhen Key Laboratory for Low-carbon Natural Science Foundation of Guangdong Province(No.2024A1515010639)Construction Material and Technology(No.ZDSYS20220606100406016)National Key Laboratory of Green and Long-Life Road Engineering in Extreme Environment(Shenzhen)(No.868-000003010103)Joint Funds of Ministry of Education(No.8091B022225).
文摘Self-regulating heating and self-powered flexibility are pivotal for future wearable devices.However,the low energy-conversion rate of wearable devices at low temperatures limits their application in plateaus and other environments.This study introduces an azopolymer with remarkable semicrystallinity and reversible photoinduced solid-liquid transition ability that is obtained through copolymerization of azoben-zene(Azo)monomers and styrene.A composite of one such copolymer with an Azo:styrene molar ratio of 9:1(copolymer is denoted as PAzo9:1-co-polystyrene(PS))and nylon fabrics(NFs)is prepared(composite is denoted as PAzo9:1-co-PS@NF).PAzo9:1-co-PS@NF exhibits hydrophobicity and high wear resistance.Moreover,it shows good responsiveness(0.624 s^(−1))during isomerization under solid ultraviolet(UV)light(365 nm)with an energy density of 70.6 kJ kg^(−1).In addition,the open-circuit voltage,short-circuit current and quantity values of PAzo9:1-co-PS@NF exhibit small variations in a temperature range of−20℃ to 25℃ and remain at 170 V,5 μA,and 62 nC,respectively.Notably,the involved NFs were cut and sewn into gloves to be worn on a human hand model.When the model was exposed to both UV radiation and friction,the temperature of the finger coated with PAzo9:1-co-PS was approximately 6.0°C higher than that of the other parts.Therefore,developing triboelectric nanogenerators based on the in situ photothermal cycles of Azo in wearable devices is important to develop low-temperature self-regulating heating and self-powered flexible devices for extreme environments.
基金supported by the National Natural Science Foundation of China(No.21975107)the China Scholarship Council(No.202206790046).
文摘Wearable thermoelectric devices hold significant promise in the realm of self-powered wearable electron-ics,offering applications in energy harvesting,movement tracking,and health monitoring.Nevertheless,developing thermoelectric devices with exceptional flexibility,enduring thermoelectric stability,multi-functional sensing,and comfortable wear remains a challenge.In this work,a stretchable MXene-based thermoelectric fabric is designed to accurately discern temperature and strain stimuli.This is achieved by constructing an adhesive polydopamine(PDA)layer on the nylon fabric surface,which facilitates the subsequent MXene attachment through hydrogen bonding.This fusion results in MXene-based thermo-electric fabric that excels in both temperature sensing and strain sensing.The resultant MXene-based thermoelectric fabric exhibits outstanding temperature detection capability and cyclic stability,while also delivering excellent sensitivity,rapid responsiveness(60 ms),and remarkable durability in strain sens-ing(3200 cycles).Moreover,when affixed to a mask,this MXene-based thermoelectric fabric utilizes the temperature difference between the body and the environment to harness body heat,converting it into electrical energy and accurately discerning the body’s respiratory rate.In addition,the MXene-based ther-moelectric fabric can monitor the state of the body’s joint through its own deformation.Furthermore,it possesses the capability to convert solar energy into heat.These findings indicate that MXene-based ther-moelectric fabric holds great promise for applications in power generation,motion tracking,and health monitoring.
基金support of this work by National Key Research and Development Program of China(2019YFC19059003)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(23KJB430024)+1 种基金Jiangsu Funding Program for Excellent Postdoctoral Talent(2023ZB680)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)are gratefully acknowledged.
文摘The Janus fabrics designed for personal moisture/thermal regulation have garnered significant attention for their potential to enhance human comfort.However,the development of smart and dynamic fabrics capable of managing personal moisture/thermal comfort in response to changing external environments remains a challenge.Herein,a smart cellulose-based Janus fabric was designed to dynamically manage personal moisture/heat.The cotton fabric was grafted with N-isopropylacrylamide to construct a temperature-stimulated transport channel.Subsequently,hydrophobic ethyl cellulose and hydrophilic cellulose nanofiber were sprayed on the bottom and top sides of the fabric to obtain wettability gradient.The fabric exhibits anti-gravity directional liquid transportation from hydrophobic side to hydrophilic side,and can dynamically and continuously control the transportation time in a wide range of 3–66 s as the temperature increases from 10 to 40℃.This smart fabric can quickly dissipate heat at high temperatures,while at low temperatures,it can slow down the heat dissipation rate and prevent the human from becoming too cold.In addition,the fabric has UV shielding and photodynamic antibacterial properties through depositing graphitic carbon nitride nanosheets on the hydrophilic side.This smart fabric offers an innovative approach to maximizing personal comfort in environments with significant temperature variations.
基金financially supported by the Natural Science Foundation of Guangdong Province(No.2024A1515010639)PolyU Postdoc Matching Fund Scheme(No.1-W327),PolyU Grant(No.1-CE0H)+3 种基金Shenzhen Science and Technology Program(No.ZDSYS20220606100406016)Shenzhen Key Laboratory of Photonics and Biophotonics(No.ZDSYS20210623092006020)National Key Laboratory of Green and Long-Life Road Engineering in Extreme Environment(Shenzhen)(No.868-000003010103)National Natural Science Foundation of China(No.52208272)。
文摘Fueled by the increasing imperative for sustainable energy solutions and the burgeoning emphasis on health awareness,self-powered techniques have undergone notable strides in advancement.Triboelectric nanogenerators(TENGs)stand out as a prominent device capitalizing on the principles of triboelectrification and electrostatic induction to generate electricity or electrical signals.In efforts to augment the electrical output performance of TENGs and broaden their range of applications,researchers have endeavored to refine materials,surface morphology,and structural design.Among them,physical morphological modifications play a pivotal role in enhancing the electrical properties of TENGs by increasing the contact surface area,which can be achieved by building micro-/nano-structures on the surface or inside the friction material.In this review,we summarize the common morphologies of TENGs,categorize the morphologies into surface and internal structures,and elucidate their roles in enhancing the electric output performance of devices.Moreover,we systematically classify the methodologies employed for morphological preparation into physical and chemical approaches,thereby furnishing a comprehensive survey of the diverse techniques.Subsequently,typical applications of TENGs with special morphology divided by energy harvesting and self-powered sensors are presented.Finally,an overview of the challenges and future trajectories pertinent to TENGs is conducted.Through this endeavor,the aim of this article is to catalyze the evolution of further strategies for enhancing performance of TENGs.
文摘This research study fabrics to ensure that they are free from carcinogenic dyes. It has been observed that there are poor-quality fabrics and consumers go to buy them without paying attention to the risks of using prohibited materials in the manufacture of these fabrics, and the use of unknown dyes has proven that some of them cause diseases to humans, especially children, that cause cancerous diseases. With the study sample consisting of (7), the study results indicate the presence of toxic formaldehyde in all sample dyes obtained from discount markets and online shopping.
