By adopting sodium silicate as a major material,SiO_2 nanoparticles (size in 8-15nm) water-dispersiod was prepared by ion exchanging.The effects of sodium silicate concentration,surface-modifying time,temperature and ...By adopting sodium silicate as a major material,SiO_2 nanoparticles (size in 8-15nm) water-dispersiod was prepared by ion exchanging.The effects of sodium silicate concentration,surface-modifying time,temperature and technological conditions on their diameter,size distribution and dispersion stability were also studied.The result show that,the hydrophilic lipophlic and hydrophilic-lipophilic SiO_(2) nanoparticles water-dispersoid can be prepared through different kinds of surface-modifiers and the optimum reaction conditions have been determined as follows:sodium silicate solution concentration:8w%;silicone dosage:3% of the total mass of nano SiO_(2) water-dispersoid;adding way and time of surface-modifier:continual dropping for 2h;surface-modifying temperature:60-70℃.展开更多
In order to study synergism of the mixed surfactants system with molecular exchanging energy (E), the Lennard-Jones formula has been firstly introduced to evaluate the E of the mixed system, CH3(CH2)nOSO 3 /CH3(CH2)nN...In order to study synergism of the mixed surfactants system with molecular exchanging energy (E), the Lennard-Jones formula has been firstly introduced to evaluate the E of the mixed system, CH3(CH2)nOSO 3 /CH3(CH2)nN+(CH3)3 directly from their molecular structure. The comparison of the calculated and the observed results showed that this method is practical.展开更多
Cold metal transfer with polarity⁃exchanging is a new integrated welding technology based on MIG.Due to the alternation of the positive and negative polarities of the wire,favorable control upon the deposition rate an...Cold metal transfer with polarity⁃exchanging is a new integrated welding technology based on MIG.Due to the alternation of the positive and negative polarities of the wire,favorable control upon the deposition rate and the welding shape coefficient was obtained in order to meet the desired joint design,and the related controlling principles and joint characteristics were reported.Droplet transfer physical behavior exhibited strong dependability on the studied welding parameters,such as welding voltage,welding current,wire feeding speed,and polarity⁃exchanging.This welding technology provides a new way for the welding of body⁃in⁃white(BIW)thin sheet with special demands.Moreover,the typical quality defects of MIG were greatly improved.Our study provides important technical information from the perspective of industrial application of MIG and sheds light on the higher application level of MIG in BIW welding.展开更多
Laser plays an important role in synthesizing nanometer material. A three-dimensional mathematical model is established in this paper when single pulsed millisecond laser shocks the surface of the metal target at a li...Laser plays an important role in synthesizing nanometer material. A three-dimensional mathematical model is established in this paper when single pulsed millisecond laser shocks the surface of the metal target at a liquid-solid interface. By changing laser power density and target size, the temperature field variation of the metal target is investigated. Results show that the generation process of nanoparticles includes heating, melting and boiloff.展开更多
At present, electricity price to grid of domestic power plants is priced by the national administration based on the policy of "one power plant with one electricity price to grid," which is difficult to real...At present, electricity price to grid of domestic power plants is priced by the national administration based on the policy of "one power plant with one electricity price to grid," which is difficult to realize real bidding for access to grid in practice in a short term. This paper presents one kind of power-exchanging transaction model among price-varied power plants, which will be beneficial to price-varied power plants without any loss of profits of them and guarantee state-owned assets profits in minimum loss with no promotion of average price limit by power plants. Under ideal conditions, the computation results showed the sufficiency and necessity of power-exchanging transaction and maximum similarity with the requirements of optimized resources disposition in economics. The presented model is shown to be full of practicability and has been used in some part of power market.展开更多
By using the binary anionic/cationic surfactants system CH3(CH2)nOSO_3/CH3(CH2)nN+(CH3)3 as an ex-ample, the molecular exchanging energy (ε) of adsorption on the surface monolayer of aqueous solu-tion has been studie...By using the binary anionic/cationic surfactants system CH3(CH2)nOSO_3/CH3(CH2)nN+(CH3)3 as an ex-ample, the molecular exchanging energy (ε) of adsorption on the surface monolayer of aqueous solu-tion has been studied. ε can be obtained with two methods. One is from the relationship between ε and the molecule interaction parameter (β). This relationship is founded by considering that the adsorption of mixed surfactants on the surface monolayer of solution satisfies the dimensional crystal model condition under which β can be obtained by testing the surface tension of solution. The other is directly from the molecular structure of surfactants with the Lennard-Jones formula. The results for the studied system show that these two methods coincide well.展开更多
Benggang is a typical fragmented erosional landscape in southern and southeastern China,posing sig-nificant risk to the local residents and economic development.Therefore,an efficient and accurate fine-grained segment...Benggang is a typical fragmented erosional landscape in southern and southeastern China,posing sig-nificant risk to the local residents and economic development.Therefore,an efficient and accurate fine-grained segmentation method is crucial for monitoring the Benggang areas.In this paper,we propose a deep learning-based automatic segmentation method for Benggang by integrating high-resolution Digital Orthophoto Map(DOM)and Digital Surface Model(DSM)data.The DSM data is used to extract slope maps,aiming to capture primary morphological features.The proposed method consists of a dual-stream convolutional encoder-decoder network in which multiple cascaded convolutional layers and a skip connection scheme are used to extract morphological and visual features of the Benggang areas.The rich discriminative information in the DOM and slope data is fused by a channel exchanging mechanism that dynamically exchanges the most discriminative features from either the DOM or DSM stream ac-cording to their importance at the channel level.Evaluation experiments were conducted on a chal-lenging dataset collected from Guangdong Province,China,and the results show that the proposed channel exchanging network based deep fusion method achieves 84.62%IoU in Benggang segmentation,outperforming several existing unimodal or multimodal baselines.The proposed multimodal segmen-tation method greatly improves the efficiency of large-scale discovery of Benggang,and thus is important for the management and restoration of Benggang in southern and southeastern China,as well as the monitoring of other similar erosional landscapes.展开更多
A Tibetan art form bridges the past and present and connects cultures around the world.THANGKA,a unique form of Tibetan sacred painting,is gaining prominence globally due to its vibrant colors,exquisite craftsmanship,...A Tibetan art form bridges the past and present and connects cultures around the world.THANGKA,a unique form of Tibetan sacred painting,is gaining prominence globally due to its vibrant colors,exquisite craftsmanship,and profound religious and cultural significance.With the acceleration of globalization,this symbol of Tibetan culture that combines artistic expression with spirituality has become a bridge for cultural exchange between the East and the West.Recently,China Today spoke to Yixi Puncog,art collector and council member of the China Association for Preservation and Development of Tibetan Culture,to learn more about Thangka art,its role in international exchange,and how it is enhancing China’s cultural soft power.展开更多
Ambient-air,moisture-assisted annealing is widely used in fabricating perovskite solar cells(PSCs).However,the inherent sensitivity of perovskite intermediate-phase to moisture—due to fast and spontaneous intermolecu...Ambient-air,moisture-assisted annealing is widely used in fabricating perovskite solar cells(PSCs).However,the inherent sensitivity of perovskite intermediate-phase to moisture—due to fast and spontaneous intermolecular exchange reaction—requires strict control of ambient humidity and immediate thermal annealing treatment,raising manufacturing costs and causing fast nucleation of perovskite films.We report herein a self-buffered molecular migration strategy to slow down the intermolecular exchange reaction by introducing a n-butylammonium bromide shielding layer,which limits moisture diffusion into intermediate-phase film.This further endows the notably wide nucleation time and humidity windows for perovskite crystallization in ambient air.Consequently,the optimized 1.68 e V-bandgap n-i-p structured PSC reaches a record-high reverse-scan(RS)PCE of 22.09%.Furthermore,the versatility and applicability of as-proposed self-buffered molecular migration strategy are certified by employing various shielding materials and 1.53 eV-/1.77 eV-bandgap perovskite materials.The n-i-p structured PSCs based on 1.53 eV-and 1.77 eV-bandgap perovskite films achieve outstanding RS PCEs of 25.23%and 19.09%,respectively,both of which are beyond of the state-of-the-art ambient-air processed PSCs.展开更多
The Belt and Road Initiative and Xinjiang Editors:Foreign Affairs Office of the People’s Government of Xinjiang Uygur Autonomous Region&China Global Television Network of China Media Group Paperback,187 pages Pub...The Belt and Road Initiative and Xinjiang Editors:Foreign Affairs Office of the People’s Government of Xinjiang Uygur Autonomous Region&China Global Television Network of China Media Group Paperback,187 pages Published by Foreign Languages Press As a key junction along the ancient Silk Road,Xinjiang served as a vital crossroads for cultural exchanges between the Eastern and Western civilizations.Thanks to its unique geographic advantages,the region has been designated as a core area of the Belt and Road Initiative(BRI)and is playing a pivotal role in China’s westward opening-up.展开更多
3D printing,as a versatile additive manufacturing technique,offers high design flexibility,rapid prototyping,minimal material waste,and the capability to fabricate complex,customized geometries.These attributes make i...3D printing,as a versatile additive manufacturing technique,offers high design flexibility,rapid prototyping,minimal material waste,and the capability to fabricate complex,customized geometries.These attributes make it particularly well-suited for low-temperature hydrogen electrochemical conversion devices—specifically,proton exchange membrane fuel cells,proton exchange membrane electrolyzer cells,anion exchange membrane electrolyzer cells,and alkaline electrolyzers—which demand finely structured components such as catalyst layers,gas diffusion layers,electrodes,porous transport layers,and bipolar plates.This review provides a focused and critical summary of the current progress in applying 3D printing technologies to these key components.It begins with a concise introduction to the principles and classifications of mainstream 3D printing methods relevant to the hydrogen energy sector and proceeds to analyze their specific applications and performance impacts across different device architectures.Finally,the review identifies existing technical challenges and outlines future research directions to accelerate the integration of 3D printing in nextgeneration low-temperature hydrogen energy systems.展开更多
Chemical exchange saturation transfer magnetic resonance imaging is an advanced imaging technique that enables the detection of compounds at low concentrations with high sensitivity and spatial resolution and has been...Chemical exchange saturation transfer magnetic resonance imaging is an advanced imaging technique that enables the detection of compounds at low concentrations with high sensitivity and spatial resolution and has been extensively studied for diagnosing malignancy and stroke.In recent years,the emerging exploration of chemical exchange saturation transfer magnetic resonance imaging for detecting pathological changes in neurodegenerative diseases has opened up new possibilities for early detection and repetitive scans without ionizing radiation.This review serves as an overview of chemical exchange saturation transfer magnetic resonance imaging with detailed information on contrast mechanisms and processing methods and summarizes recent developments in both clinical and preclinical studies of chemical exchange saturation transfer magnetic resonance imaging for Alzheimer’s disease,Parkinson’s disease,multiple sclerosis,and Huntington’s disease.A comprehensive literature search was conducted using databases such as PubMed and Google Scholar,focusing on peer-reviewed articles from the past 15 years relevant to clinical and preclinical applications.The findings suggest that chemical exchange saturation transfer magnetic resonance imaging has the potential to detect molecular changes and altered metabolism,which may aid in early diagnosis and assessment of the severity of neurodegenerative diseases.Although promising results have been observed in selected clinical and preclinical trials,further validations are needed to evaluate their clinical value.When combined with other imaging modalities and advanced analytical methods,chemical exchange saturation transfer magnetic resonance imaging shows potential as an in vivo biomarker,enhancing the understanding of neuropathological mechanisms in neurodegenerative diseases.展开更多
The number of IoT(internet of things)connected devices increases rapidly.These devices have different operation systems and therefore cannot communicate with each other.As a result,the data they collected is limited w...The number of IoT(internet of things)connected devices increases rapidly.These devices have different operation systems and therefore cannot communicate with each other.As a result,the data they collected is limited within their own platform.Besides,IoT devices have very constrained resources like weak MCU(micro control unit)and limited storage.Therefore,they need direct communication method to cooperate with each other,or with the help of nearby devices with rich resources.In this paper,we propose a secure method to exchange resources(SMER)between heterogeneous IoT devices.In order to exchange resources among devices,SMER adopts a compensable mechanism for resource exchange and a series of security mechanisms to ensure the security of resource exchanges.Besides,SMER uses a smart contract based scheme to supervise resource exchange,which guarantees the safety and benefits of IoT devices.We also introduce a prototype system and make a comprehensive discussion.展开更多
High-resolution non-emissive displays based on electrochromic tungsten oxides(WOx)are crucial for future near-eye virtual/augmented reality interactions,given their impressive attributes such as high environmental sta...High-resolution non-emissive displays based on electrochromic tungsten oxides(WOx)are crucial for future near-eye virtual/augmented reality interactions,given their impressive attributes such as high environmental stability,ideal outdoor readability,and low energy consumption.However,the limited intrinsic structure of inorganic materials has presented a significant challenge in achieving precise patterning/pixelation at the micron scale.Here,we successfully developed the direct photolithography for WOx nanoparticles based on in situ photo-induced ligand exchange.This strategy enabled us to achieve ultra-high resolution efficiently(line width<4μm,the best resolution for reported inorganic electrochromic materials).Additionally,the resulting device exhibited impressive electrochromic performance,such as fast response(<1 s at 0 V),high coloration efficiency(119.5 cm^(2) C^(−1)),good optical modulation(55.9%),and durability(>3600 cycles),as well as promising applications in electronic logos,pixelated displays,flexible electronics,etc.The success and advancements presented here are expected to inspire and accelerate research and development(R&D)in high-resolution non-emissive displays and other ultra-fine micro-electronics.展开更多
Developing low-cost and high-performance nanofiber-based polyelectrolyte membranes for fuel cell applications is a promising solution to energy depletion.Due to the high specific surface area and one-dimensional longr...Developing low-cost and high-performance nanofiber-based polyelectrolyte membranes for fuel cell applications is a promising solution to energy depletion.Due to the high specific surface area and one-dimensional longrange continuous structure of the nanofiber,ion-charged groups can be induced to form long-range continuous ion transfer channels in the nanofiber composite membrane,significantly increasing the ion conductivity of the membrane.This review stands apart from previous endeavors by offering a comprehensive overview of the strategies employed over the past decade in utilizing both electrospun and natural nanofibers as key components of proton exchange membranes and anion exchange membranes for fuel cells.Electrospun nanofibers are categorized based on their material properties into two primary groups:(1)ionomer nanofibers,inherently endowed with the ability to conduct H+(such as perfluorosulfonic acid or sulfonated poly(ether ether ketone))or OH-(e.g.,FAA-3),and(2)nonionic polymer nanofibers,comprising inert polymers like polyvinylidene difluoride,polytetrafluoroethylene,and polyacrylonitrile.Notably,the latter often necessitates surface modifications to impart ion transport channels,given their inherent proton inertness.Furthermore,this review delves into the recent progress made with three natural nanofibers derived from biodegradable cellulose—cellulose nanocrystals,cellulose nanofibers,and bacterial nanofibers—as crucial elements in polyelectrolyte membranes.The effect of the physical structure of such nanofibers on polyelectrolyte membrane properties is also briefly discussed.Lastly,the review emphasizes the challenges and outlines potential solutions for future research in the field of nanofiber-based polyelectrolyte membranes,aiming to propel the development of high-performance polymer electrolyte fuel cells.展开更多
High-entropy materials have attracted considerable attention in recent years owing to their unique structural characteristics,tailorable chemical composition,and tunable functional properties.In this study,the concept...High-entropy materials have attracted considerable attention in recent years owing to their unique structural characteristics,tailorable chemical composition,and tunable functional properties.In this study,the concept of entropy-mediated phase stabilization was combined with strongly correlated electron systems to achieve directional property control in single-phase manganites.As Ca and Cr are sequentially doped into(Pr_(0.25)La_(0.25)Nd_(0.25)Sm_(0.25))MnO_(3) at specific contents,the original weak ferromagnetic(FM)state with a spin-canted antiferromagnetic(AFM)background transforms into the charge-ordered AFM state,and then further transitions to the intense FM-AFM competition state.Magnetic state evolution also causes significant changes in electrical properties,highlighting the complex magnetoelectronic phase diagram of this system.Under specific doping conditions,the system exhibits a temperature-induced metamagnetic transition and a significant magnetocaloric effect,demonstrating interesting properties brought about by magnetic phase transitions.The complex magnetoelectric behavior induced by the coexistence and competition of multiple interactions is discussed by combining microstructural characterization with a magnetic theory framework.This study explores a method for effectively manipulating the physical properties of manganites based on the high-entropy concept,which is conducive to the development of new functional materials with kaleidoscopic characteristics.展开更多
Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-po...Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-powered QD devices is still limited by their unfavorable charge carrier dynamics due to their intrinsically discrete charge carrier transport process. Herein, we strategically constructed semiconducting matrix in QD film to achieve efficient charge transfer and extraction.The p-type semiconducting CuSCN was selected as energy-aligned matrix to match the n-type colloidal PbS QDs that was used as proof-of-concept. Note that the PbS QD/CuSCN matrix not only enables efficient charge carrier separation and transfer at nano-interfaces but also provides continuous charge carrier transport pathways that are different from the hoping process in neat QD film, resulting in improved charge mobility and derived collection efficiency. As a result, the target structure delivers high specific detectivity of 4.38 × 10^(12)Jones and responsivity of 782 mA/W at 808 nm, which is superior than that of the PbS QD-only photodetector(4.66 × 10^(11)Jones and 338 mA/W). This work provides a new structure candidate for efficient colloidal QD based optoelectronic devices.展开更多
文摘By adopting sodium silicate as a major material,SiO_2 nanoparticles (size in 8-15nm) water-dispersiod was prepared by ion exchanging.The effects of sodium silicate concentration,surface-modifying time,temperature and technological conditions on their diameter,size distribution and dispersion stability were also studied.The result show that,the hydrophilic lipophlic and hydrophilic-lipophilic SiO_(2) nanoparticles water-dispersoid can be prepared through different kinds of surface-modifiers and the optimum reaction conditions have been determined as follows:sodium silicate solution concentration:8w%;silicone dosage:3% of the total mass of nano SiO_(2) water-dispersoid;adding way and time of surface-modifier:continual dropping for 2h;surface-modifying temperature:60-70℃.
基金the State Natural Science Foundation of China(No.30070178)the Governor Foundation of Guizhou Province for their financial supports.
文摘In order to study synergism of the mixed surfactants system with molecular exchanging energy (E), the Lennard-Jones formula has been firstly introduced to evaluate the E of the mixed system, CH3(CH2)nOSO 3 /CH3(CH2)nN+(CH3)3 directly from their molecular structure. The comparison of the calculated and the observed results showed that this method is practical.
文摘Cold metal transfer with polarity⁃exchanging is a new integrated welding technology based on MIG.Due to the alternation of the positive and negative polarities of the wire,favorable control upon the deposition rate and the welding shape coefficient was obtained in order to meet the desired joint design,and the related controlling principles and joint characteristics were reported.Droplet transfer physical behavior exhibited strong dependability on the studied welding parameters,such as welding voltage,welding current,wire feeding speed,and polarity⁃exchanging.This welding technology provides a new way for the welding of body⁃in⁃white(BIW)thin sheet with special demands.Moreover,the typical quality defects of MIG were greatly improved.Our study provides important technical information from the perspective of industrial application of MIG and sheds light on the higher application level of MIG in BIW welding.
基金Supported by National Natural Science Foundation of China(No.50902103)
文摘Laser plays an important role in synthesizing nanometer material. A three-dimensional mathematical model is established in this paper when single pulsed millisecond laser shocks the surface of the metal target at a liquid-solid interface. By changing laser power density and target size, the temperature field variation of the metal target is investigated. Results show that the generation process of nanoparticles includes heating, melting and boiloff.
基金This research is supported by Special Science Fund on University Doctor Science Point of the Department of Education of China (20020698027).
文摘At present, electricity price to grid of domestic power plants is priced by the national administration based on the policy of "one power plant with one electricity price to grid," which is difficult to realize real bidding for access to grid in practice in a short term. This paper presents one kind of power-exchanging transaction model among price-varied power plants, which will be beneficial to price-varied power plants without any loss of profits of them and guarantee state-owned assets profits in minimum loss with no promotion of average price limit by power plants. Under ideal conditions, the computation results showed the sufficiency and necessity of power-exchanging transaction and maximum similarity with the requirements of optimized resources disposition in economics. The presented model is shown to be full of practicability and has been used in some part of power market.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20676051 and 20573034)the Important Construction Project (Category A) of Shanghai Jiao Tong University (Grant No. AE 150085)
文摘By using the binary anionic/cationic surfactants system CH3(CH2)nOSO_3/CH3(CH2)nN+(CH3)3 as an ex-ample, the molecular exchanging energy (ε) of adsorption on the surface monolayer of aqueous solu-tion has been studied. ε can be obtained with two methods. One is from the relationship between ε and the molecule interaction parameter (β). This relationship is founded by considering that the adsorption of mixed surfactants on the surface monolayer of solution satisfies the dimensional crystal model condition under which β can be obtained by testing the surface tension of solution. The other is directly from the molecular structure of surfactants with the Lennard-Jones formula. The results for the studied system show that these two methods coincide well.
基金funded by Key Research and Development Program of Hubei Province,China under grant 2021BAA186the National Natural Science Foundation of China under grant number 41601298.
文摘Benggang is a typical fragmented erosional landscape in southern and southeastern China,posing sig-nificant risk to the local residents and economic development.Therefore,an efficient and accurate fine-grained segmentation method is crucial for monitoring the Benggang areas.In this paper,we propose a deep learning-based automatic segmentation method for Benggang by integrating high-resolution Digital Orthophoto Map(DOM)and Digital Surface Model(DSM)data.The DSM data is used to extract slope maps,aiming to capture primary morphological features.The proposed method consists of a dual-stream convolutional encoder-decoder network in which multiple cascaded convolutional layers and a skip connection scheme are used to extract morphological and visual features of the Benggang areas.The rich discriminative information in the DOM and slope data is fused by a channel exchanging mechanism that dynamically exchanges the most discriminative features from either the DOM or DSM stream ac-cording to their importance at the channel level.Evaluation experiments were conducted on a chal-lenging dataset collected from Guangdong Province,China,and the results show that the proposed channel exchanging network based deep fusion method achieves 84.62%IoU in Benggang segmentation,outperforming several existing unimodal or multimodal baselines.The proposed multimodal segmen-tation method greatly improves the efficiency of large-scale discovery of Benggang,and thus is important for the management and restoration of Benggang in southern and southeastern China,as well as the monitoring of other similar erosional landscapes.
文摘A Tibetan art form bridges the past and present and connects cultures around the world.THANGKA,a unique form of Tibetan sacred painting,is gaining prominence globally due to its vibrant colors,exquisite craftsmanship,and profound religious and cultural significance.With the acceleration of globalization,this symbol of Tibetan culture that combines artistic expression with spirituality has become a bridge for cultural exchange between the East and the West.Recently,China Today spoke to Yixi Puncog,art collector and council member of the China Association for Preservation and Development of Tibetan Culture,to learn more about Thangka art,its role in international exchange,and how it is enhancing China’s cultural soft power.
基金the financial support from the National Key R&D Program of China(2021YFF0500500)the National Natural Science Foundation of China(62474131,62274132,and 62204189)。
文摘Ambient-air,moisture-assisted annealing is widely used in fabricating perovskite solar cells(PSCs).However,the inherent sensitivity of perovskite intermediate-phase to moisture—due to fast and spontaneous intermolecular exchange reaction—requires strict control of ambient humidity and immediate thermal annealing treatment,raising manufacturing costs and causing fast nucleation of perovskite films.We report herein a self-buffered molecular migration strategy to slow down the intermolecular exchange reaction by introducing a n-butylammonium bromide shielding layer,which limits moisture diffusion into intermediate-phase film.This further endows the notably wide nucleation time and humidity windows for perovskite crystallization in ambient air.Consequently,the optimized 1.68 e V-bandgap n-i-p structured PSC reaches a record-high reverse-scan(RS)PCE of 22.09%.Furthermore,the versatility and applicability of as-proposed self-buffered molecular migration strategy are certified by employing various shielding materials and 1.53 eV-/1.77 eV-bandgap perovskite materials.The n-i-p structured PSCs based on 1.53 eV-and 1.77 eV-bandgap perovskite films achieve outstanding RS PCEs of 25.23%and 19.09%,respectively,both of which are beyond of the state-of-the-art ambient-air processed PSCs.
文摘The Belt and Road Initiative and Xinjiang Editors:Foreign Affairs Office of the People’s Government of Xinjiang Uygur Autonomous Region&China Global Television Network of China Media Group Paperback,187 pages Published by Foreign Languages Press As a key junction along the ancient Silk Road,Xinjiang served as a vital crossroads for cultural exchanges between the Eastern and Western civilizations.Thanks to its unique geographic advantages,the region has been designated as a core area of the Belt and Road Initiative(BRI)and is playing a pivotal role in China’s westward opening-up.
基金the support from the National Natural Science Foundation of China(Nos.22208376,UA22A20429)the Qingdao New Energy Shandong Laboratory Open Project(QNESL OP 202303)+3 种基金Shandong Provincial Natural Science Foundation(Nos.ZR2024QB175,ZR2023LFG005)Fundamental Research Funds for the Central Universities(No.25CX07002A)National Natural Science Foundation of China(Z202401390008)The Hunan Provincial Natural Science Foundation(2025JJ60301)。
文摘3D printing,as a versatile additive manufacturing technique,offers high design flexibility,rapid prototyping,minimal material waste,and the capability to fabricate complex,customized geometries.These attributes make it particularly well-suited for low-temperature hydrogen electrochemical conversion devices—specifically,proton exchange membrane fuel cells,proton exchange membrane electrolyzer cells,anion exchange membrane electrolyzer cells,and alkaline electrolyzers—which demand finely structured components such as catalyst layers,gas diffusion layers,electrodes,porous transport layers,and bipolar plates.This review provides a focused and critical summary of the current progress in applying 3D printing technologies to these key components.It begins with a concise introduction to the principles and classifications of mainstream 3D printing methods relevant to the hydrogen energy sector and proceeds to analyze their specific applications and performance impacts across different device architectures.Finally,the review identifies existing technical challenges and outlines future research directions to accelerate the integration of 3D printing in nextgeneration low-temperature hydrogen energy systems.
基金supported by The University of Hong Kong,China(109000487,109001694,204610401,and 204610519)National Natural Science Foundation of China(82402225)(to JH).
文摘Chemical exchange saturation transfer magnetic resonance imaging is an advanced imaging technique that enables the detection of compounds at low concentrations with high sensitivity and spatial resolution and has been extensively studied for diagnosing malignancy and stroke.In recent years,the emerging exploration of chemical exchange saturation transfer magnetic resonance imaging for detecting pathological changes in neurodegenerative diseases has opened up new possibilities for early detection and repetitive scans without ionizing radiation.This review serves as an overview of chemical exchange saturation transfer magnetic resonance imaging with detailed information on contrast mechanisms and processing methods and summarizes recent developments in both clinical and preclinical studies of chemical exchange saturation transfer magnetic resonance imaging for Alzheimer’s disease,Parkinson’s disease,multiple sclerosis,and Huntington’s disease.A comprehensive literature search was conducted using databases such as PubMed and Google Scholar,focusing on peer-reviewed articles from the past 15 years relevant to clinical and preclinical applications.The findings suggest that chemical exchange saturation transfer magnetic resonance imaging has the potential to detect molecular changes and altered metabolism,which may aid in early diagnosis and assessment of the severity of neurodegenerative diseases.Although promising results have been observed in selected clinical and preclinical trials,further validations are needed to evaluate their clinical value.When combined with other imaging modalities and advanced analytical methods,chemical exchange saturation transfer magnetic resonance imaging shows potential as an in vivo biomarker,enhancing the understanding of neuropathological mechanisms in neurodegenerative diseases.
文摘The number of IoT(internet of things)connected devices increases rapidly.These devices have different operation systems and therefore cannot communicate with each other.As a result,the data they collected is limited within their own platform.Besides,IoT devices have very constrained resources like weak MCU(micro control unit)and limited storage.Therefore,they need direct communication method to cooperate with each other,or with the help of nearby devices with rich resources.In this paper,we propose a secure method to exchange resources(SMER)between heterogeneous IoT devices.In order to exchange resources among devices,SMER adopts a compensable mechanism for resource exchange and a series of security mechanisms to ensure the security of resource exchanges.Besides,SMER uses a smart contract based scheme to supervise resource exchange,which guarantees the safety and benefits of IoT devices.We also introduce a prototype system and make a comprehensive discussion.
基金supported by the National Key R&D Program of China(2022YFB3606501,2022YFB3602902)the Key projects of National Natural Science Foundation of China(62234004)+8 种基金the National Natural Science Foundation of China(U23A2092)Pioneer and Leading Goose R&D Program of Zhejiang(2024C01191,2024C01092)Innovation and Entrepreneurship Team of Zhejiang Province(2021R01003)Ningbo Key Technologies R&D Program(2022Z085),Ningbo 3315 Programme(2020A-01-B)YONGJIANG Talent Introduction Programme(2021A-038-B,2021A-159-G)“Innovation Yongjiang 2035”Key R&D Programme(2024Z146)Ningbo JiangBei District public welfare science and technology project(2022C07)the China National Postdoctoral Program for Innovative Talents(grant no.BX20240391)the China Postdoctoral Science Foundation(grant no.2023M743623).
文摘High-resolution non-emissive displays based on electrochromic tungsten oxides(WOx)are crucial for future near-eye virtual/augmented reality interactions,given their impressive attributes such as high environmental stability,ideal outdoor readability,and low energy consumption.However,the limited intrinsic structure of inorganic materials has presented a significant challenge in achieving precise patterning/pixelation at the micron scale.Here,we successfully developed the direct photolithography for WOx nanoparticles based on in situ photo-induced ligand exchange.This strategy enabled us to achieve ultra-high resolution efficiently(line width<4μm,the best resolution for reported inorganic electrochromic materials).Additionally,the resulting device exhibited impressive electrochromic performance,such as fast response(<1 s at 0 V),high coloration efficiency(119.5 cm^(2) C^(−1)),good optical modulation(55.9%),and durability(>3600 cycles),as well as promising applications in electronic logos,pixelated displays,flexible electronics,etc.The success and advancements presented here are expected to inspire and accelerate research and development(R&D)in high-resolution non-emissive displays and other ultra-fine micro-electronics.
基金National Natural Science Foundation of China,Grant/Award Numbers:52173091,62101391。
文摘Developing low-cost and high-performance nanofiber-based polyelectrolyte membranes for fuel cell applications is a promising solution to energy depletion.Due to the high specific surface area and one-dimensional longrange continuous structure of the nanofiber,ion-charged groups can be induced to form long-range continuous ion transfer channels in the nanofiber composite membrane,significantly increasing the ion conductivity of the membrane.This review stands apart from previous endeavors by offering a comprehensive overview of the strategies employed over the past decade in utilizing both electrospun and natural nanofibers as key components of proton exchange membranes and anion exchange membranes for fuel cells.Electrospun nanofibers are categorized based on their material properties into two primary groups:(1)ionomer nanofibers,inherently endowed with the ability to conduct H+(such as perfluorosulfonic acid or sulfonated poly(ether ether ketone))or OH-(e.g.,FAA-3),and(2)nonionic polymer nanofibers,comprising inert polymers like polyvinylidene difluoride,polytetrafluoroethylene,and polyacrylonitrile.Notably,the latter often necessitates surface modifications to impart ion transport channels,given their inherent proton inertness.Furthermore,this review delves into the recent progress made with three natural nanofibers derived from biodegradable cellulose—cellulose nanocrystals,cellulose nanofibers,and bacterial nanofibers—as crucial elements in polyelectrolyte membranes.The effect of the physical structure of such nanofibers on polyelectrolyte membrane properties is also briefly discussed.Lastly,the review emphasizes the challenges and outlines potential solutions for future research in the field of nanofiber-based polyelectrolyte membranes,aiming to propel the development of high-performance polymer electrolyte fuel cells.
基金supported by the National Natural Science Foundation of China(Nos.12074204,12374258 and 12404326)the Natural Science Foundation of Inner Mongolia Autonomous Region of China(Nos.2022ZD06 and 2023QN01008)+3 种基金the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(No.NMGIRT2203)the Research Program of Science and Technology at Universities of Inner Mongolia Autonomous Region(No.NJZZ23024)the Fundamental Research Funds for the Inner Mongolia Normal University(No.2023JBYJ015)the Funds for Reform and Development of Local Universities Supported by the Central Government(Cultivation of First-Class Disciplines in Physics).
文摘High-entropy materials have attracted considerable attention in recent years owing to their unique structural characteristics,tailorable chemical composition,and tunable functional properties.In this study,the concept of entropy-mediated phase stabilization was combined with strongly correlated electron systems to achieve directional property control in single-phase manganites.As Ca and Cr are sequentially doped into(Pr_(0.25)La_(0.25)Nd_(0.25)Sm_(0.25))MnO_(3) at specific contents,the original weak ferromagnetic(FM)state with a spin-canted antiferromagnetic(AFM)background transforms into the charge-ordered AFM state,and then further transitions to the intense FM-AFM competition state.Magnetic state evolution also causes significant changes in electrical properties,highlighting the complex magnetoelectronic phase diagram of this system.Under specific doping conditions,the system exhibits a temperature-induced metamagnetic transition and a significant magnetocaloric effect,demonstrating interesting properties brought about by magnetic phase transitions.The complex magnetoelectric behavior induced by the coexistence and competition of multiple interactions is discussed by combining microstructural characterization with a magnetic theory framework.This study explores a method for effectively manipulating the physical properties of manganites based on the high-entropy concept,which is conducive to the development of new functional materials with kaleidoscopic characteristics.
基金supported by the National Natural Science Foundation of China (No. 62204079)the Science and Technology Development Project of Henan Province (Nos.202300410048, 202300410057)+2 种基金the China Postdoctoral Science Foundation (No. 2022M711037)the Intelligence Introduction Plan of Henan Province in 2021 (No. CXJD2021008)Henan University Fund。
文摘Quantum dot(QD)-based infrared photodetector is a promising technology that can implement current monitoring,imaging and optical communication in the infrared region. However, the photodetection performance of self-powered QD devices is still limited by their unfavorable charge carrier dynamics due to their intrinsically discrete charge carrier transport process. Herein, we strategically constructed semiconducting matrix in QD film to achieve efficient charge transfer and extraction.The p-type semiconducting CuSCN was selected as energy-aligned matrix to match the n-type colloidal PbS QDs that was used as proof-of-concept. Note that the PbS QD/CuSCN matrix not only enables efficient charge carrier separation and transfer at nano-interfaces but also provides continuous charge carrier transport pathways that are different from the hoping process in neat QD film, resulting in improved charge mobility and derived collection efficiency. As a result, the target structure delivers high specific detectivity of 4.38 × 10^(12)Jones and responsivity of 782 mA/W at 808 nm, which is superior than that of the PbS QD-only photodetector(4.66 × 10^(11)Jones and 338 mA/W). This work provides a new structure candidate for efficient colloidal QD based optoelectronic devices.
