With the increasing demand for scalable and cost-effective electrochemical energy storage,aqueous zinc ion batteries(AZIBs)have a broad application prospect as an inexpensive,efficient,and naturally secure energy stor...With the increasing demand for scalable and cost-effective electrochemical energy storage,aqueous zinc ion batteries(AZIBs)have a broad application prospect as an inexpensive,efficient,and naturally secure energy storage device.However,the limitations suffered by AZIBs,including volume expansion and active materials dissolution of the cathode,electrochemical corrosion,irreversible side reactions,zinc dendrites of the anode,have seriously decelerated the civilianization process of AZIBs.Currently,polymers have tremendous superiority for application in AZIBs attributed to their exceptional chemical stability,tunable structure,high energy density and outstanding mechanical properties.Considering the expanding applications of AZIBs and the superiority of polymers,this comprehensive paper meticulously reviews the benefits of utilizing polymeric applied to cathodes and anodes,respectively.To begin with,with adjustable structure as an entry point,the correlation between polymer structure and the function of energy storage as well as optimization is deeply investigated in respect to the mechanism.Then,depending on the diversity of properties and structures,the development of polymers in AZIBs is summarized,including conductive polymers,redox polymers as well as carbon composite polymers for cathode and polyvinylidene fluoride-,carbonyl-,amino-,nitrile-based polymers for anode,and a comprehensive evaluation of the shortcomings of these strategies is provided.Finally,an outlook highlights some of the challenges posed by the application of polymers and offers insights into the potential future direction of polymers in AZIBs.It is designed to provide a thorough reference for researchers and developers working on polymer for AZIBs.展开更多
With the diversified development of big data,detection and precision guidance technologies,electromagnetic(EM)functional materials and devices serving multiple spectrums have become a hot topic.Exploring the multispec...With the diversified development of big data,detection and precision guidance technologies,electromagnetic(EM)functional materials and devices serving multiple spectrums have become a hot topic.Exploring the multispectral response of materials is a challenging and meaningful scientific question.In this study,MXene/TiO_(2)hybrids with tunable conduction loss and polarization relaxation are fabricated by in situ atomic reconstruction engineering.More importantly,MXene/TiO_(2)hybrids exhibit adjustable spectral responses in the GHz,infrared and visible spectrums,and several EM devices are constructed based on this.An antenna array provides excellent EM energy harvesting in multiple microwave bands,with|S11|up to−63.2 dB,and can be tuned by the degree of bending.An ultra-wideband bandpass filter realizes a passband of about 5.4 GHz and effectively suppresses the transmission of EM signals in the stopband.An infrared stealth device has an emissivity of less than 0.2 in the infrared spectrum at wavelengths of 6-14μm.This work can provide new inspiration for the design and development of multifunctional,multi-spectrum EM devices.展开更多
We proposed a vanadium dioxide(VO2)-integrated multi-functional metamaterial structure that consists of three metallic grating layers and two VO2 films separated by SiO2 dielectric spacers.The proposed structure can b...We proposed a vanadium dioxide(VO2)-integrated multi-functional metamaterial structure that consists of three metallic grating layers and two VO2 films separated by SiO2 dielectric spacers.The proposed structure can be flexibly switched among three states by adjusting temperature,incident direction,and polarization.In state 1,the incident wave is strongly transmitted and perfectly converted to its orthogonal polarization state.In state 2,the incident wave is perfectly absorbed.In state 3,incident wave is totally reflected back.The working frequency of the multi-functional metamaterial can be arbitrarily tuned within a broad pass band.We believe that our findings are beneficial in designing temperature-controlled metadevices.展开更多
We demonstrate a fiber-loop ring down multi-function sensors system, which can be used to measure refractive index and curvature simultaneously. Good agreement has been found between theoretical analyses and experimen...We demonstrate a fiber-loop ring down multi-function sensors system, which can be used to measure refractive index and curvature simultaneously. Good agreement has been found between theoretical analyses and experimental results. It has great potential for sensor applications.展开更多
With the development of medical level, specialized, refined and multidisciplinary collaborative therapy is the requirement and main development direction of neurosurgery. With the improvement of people’s medical awar...With the development of medical level, specialized, refined and multidisciplinary collaborative therapy is the requirement and main development direction of neurosurgery. With the improvement of people’s medical awareness, people cannot meet the simple surgical treatment, and there is a great demand for nursing treatment. At the same time, the demand for efficiency and convenience of medical nursing practice teaching continues to improve, and the multi-functional medical nursing training innovation platform has been paid more and more attention. The rapid development of material technology as well as digitalization has brought about a huge change, and we have created a multifunctional, spatially efficient and easy-to-transfer information platform for medical care training. A base box, placement drawer, platform board and display are used as the base module and the base module is filled with specific functional components. Lifting and lowering using motors and spiral base, moving using universal wheels. These devices together constitute the training platform. A survey of students and teachers was conducted through a questionnaire, and they all gave very good feedback that the multi-functional platform was very practical and useful. This platform effectively solves the drawbacks of the original training platform which is time-consuming, laborious and inconvenient, and is worthy of further promotion and research.展开更多
Population growth,loss of biodiversity,and climate change necessitate a new vision for the future of both agriculture and biodiversity.In order to safeguard and support the world's agricultural heritage systems,in 20...Population growth,loss of biodiversity,and climate change necessitate a new vision for the future of both agriculture and biodiversity.In order to safeguard and support the world's agricultural heritage systems,in 2002 the FAO started an initiative for the conservation and adaptive management called Globally Important Agricultural Heritage Systems (GIAHS).Tourism is suggested as part of the future as it is considered to be an alternative income source that will not only promote local economic development,but also provide the opportunity for tourists to learn about agriculture and ecology.However,inappropriate tourism in GIAHS sites will bring impacts on local culture and living styles,which not only threatens tourism's sustainable development,but also has the potential to damage these unique agricultural systems.This paper proposes that agriculture-based tourism is suitable for GIAHS and that Multi-functionality of Agriculture (MFA) can be the link between agriculture and tourism.This study constructs the framework for tourism development in GIAHS through MFA and applies it to the four GIAHS sites in China.Referring to the quantitative assessment for MFA and a qualitative analysis of the relationship between agriculture and tourism,we can give advice on agricultural tourism development in GIAHS sites.This framework also offers a universal methodology that allows stakeholders to communicate about the multiple functions of GIAHS across scales.展开更多
Eco-friendly electromagnetic wave absorbing materials with excellent thermal infrared stealth property,heat-insulating ability and compression resistance are highly attractive in practical applications.Meeting the afo...Eco-friendly electromagnetic wave absorbing materials with excellent thermal infrared stealth property,heat-insulating ability and compression resistance are highly attractive in practical applications.Meeting the aforesaid requirements simultaneously is a formidable challenge.Herein,ultra-light carbon aerogels were fabricated via fresh shaddock peel by facile freeze-drying method and calcination process,forming porous network architecture.With the heating platform temperature of 70℃,the upper surface temperatures of the as-prepared carbon aerogel present a slow upward trend.The color of the sample surface in thermal infrared images is similar to that of the surroundings.With the maximum compressive stress of 2.435 kPa,the carbon aerogels can provide favorable endurance.The shaddock peel-based carbon aerogels possess the minimum reflection loss value(RLmin)of−29.50 dB in X band.Meanwhile,the effective absorption bandwidth covers 5.80 GHz at a relatively thin thickness of only 1.7 mm.With the detection theta of 0°,the maximum radar cross-sectional(RCS)reduction values of 16.28 dB m^(2) can be achieved.Theoretical simulations of RCS have aroused extensive interest owing to their ingenious design and time-saving feature.This work paves the way for preparing multi-functional microwave absorbers derived from biomass raw materials under the guidance of RCS simulations.展开更多
With the rapid developments of the high-speed railway in China, a great number of long-span bridges have been constructed in order to cross rivers and gorges. At present, the longest main span of a constructed high-sp...With the rapid developments of the high-speed railway in China, a great number of long-span bridges have been constructed in order to cross rivers and gorges. At present, the longest main span of a constructed high-speed railway bridge is only 630 m. The main span of Hutong Yangtze River Bridge and of Wufengshan Yangtze River Bridge, which are under construction, will be much longer, at 1092 m each. In order to overcome the technical issues that originate from the extremely large dead loading and the relatively small structural stiffness of long-span high-speed railway bridges, many new technologies in bridge construction, design, materials, and so forth have been developed. This paper carefully reviews progress in the construction technologies of multi-function combined bridges in China, including com- bined highway and railway bridges and multi-track railway bridges. Innovations and practices regarding new types of bridge and composite bridge structures, such as bridges with three cable planes and three main trusses, inclined main trusses, slab-truss composite sections, and steel-concrete composite sections, are introduced. In addition, investigations into high-performance materials and integral fabrication and erection techniques for long-span railway bridges are summarized. At the end of the paper, prospects for the future development of long-span high-speed railwav bridges are provided.展开更多
The excessive expansion of urbanized areas has resulted in haphazard land utili- zation, immoderate consumption of superior agricultural land and water resources, significant fragmentation of agricultural landscape, a...The excessive expansion of urbanized areas has resulted in haphazard land utili- zation, immoderate consumption of superior agricultural land and water resources, significant fragmentation of agricultural landscape, and gradual deterioration of the agro-ecological en- vironment. Combined, these factors cause poor land use efficiency. Under these circum- stances, comprehensively assessing land use efficiency for urban agriculture is a key issue in land use research. Currently, evaluation methods for agricultural land use efficiency narrowly concentrate on aspects of economic input and output. However, urban agro-ecosystems can provide diverse economic, social, and ecological services and functions. In particular, the social and ecological services and functions originating from agricultural land, which have a higher value than economic services, play a significant role in ensuring regional social, eco- logical, and environmental security. However, recent research has rarely taken these benefits into consideration. Therefore, land use value has been greatly underestimated, which has resulted in mishandled and poor land use policies. In this study, we apply Landsat imagery and social and economic statistical data for the Xi'an metropolitan zone (XMZ) to investigate agricultural multi-functionality. We develop an evaluation framework for urban agricultural land use efficiency and identify agro-ecosystem services and functions as important outputs from agricultural land. The land use efficiency of urban agriculture is then evaluated using ecosystem services models, providing a mechanism for assessing spatial-temporal changes in land use efficiency in the XMZ from 1999 to 2015. Four important conclusions are reached from this analysis. First, the rapid urbanization and agricultural transformation from traditional cereal cultivation to modern urban agriculture has resulted in steadily increasing costs, out- puts, and land use efficiency of urban agriculture. The total output value increased 41% and land use efficiency per hectare increased by 33.13% on average. Second, the spatial patterns of comprehensive output and land use efficiency were dominated by economic outputs from agricultural land. Areas near cities, which are dominated by orchard and arable land, provide more economic functions. These areas support and regulate services due to the transforma- tion from extensive cereal production to intensive modern urban agriculture; therefore, they have higher output value and land use efficiency. In contrast, areas distant from cities, towns, and high traffic roads, namely, remote rural areas, provide more support and regulating ser- vices, but have relatively lower economic function due to inaccessibility tO urban markets and slow agricultural transformation. Therefore, these areas have lower output value and land use efficiency. The spatial change in agricultural output and land use efficiency in urban areas is strongly dependent on the degree of urbanization and agricultural transformation. Third, the total output value and land use efficiency of urban agriculture measured with our approach are much higher than evaluations using traditional methods. However, the spatial patterns measured using the two approaches are in agreement. The evaluation framework integrates ecological services and economic and social functions into a comprehensive output from agricultural land. This approach is more methodical and accurate for evaluating the compre- hensive efficiency of land use based on quantities and spatial scale because they are at the pixel scale. Finally, the evaluation results have important implications for enhancing current agricultural subsidies and even implementing ecological payment policies in China. Most importantly, they can be directly applied to agricultural transformation regulations, decision-making, and guidance for rational land utilization.展开更多
An ultra-wideband mixing component cascaded by a mixing multi-function chip and a frequency multiplier multi-function chip was demonstrated and implemented using 3D heterogeneous integration based on the silicon adapt...An ultra-wideband mixing component cascaded by a mixing multi-function chip and a frequency multiplier multi-function chip was demonstrated and implemented using 3D heterogeneous integration based on the silicon adapter board technology.Four layers of high-resistance silicon substrate stack packaging are implemented based on the wafer-level gold-gold bonding process.Each layer adopts though silicon via(TSV)technology to realize signal interconnection.A core monolithic integrated microwave chip(MMIC)is embedded in the silicon cavity,and the silicon-based filter is integrated with the high-resistance silicon substrate.The interconnect line,cavity and filter of the silicon-based adapter board are designed with AutoCAD,and HFSS is adopted for 3D electromagnetic field simulation.According to the measured results,the radio frequency(RF)of the mixing multi-function chip is 40-44 GHz and its intermediate frequency(IF)can cover the Ku band with a chip size of 10 mm×11 mm×1 mm.The multiplier multi-function chip operates at 16-20 GHz.The fundamental suppression is greater than 50 dB and the second harmonic suppression is better than 40 dB with a chip size of 8 mm×8 mm×1 mm.The cascaded fully assembled mixing component achieves a spur of better than-50 dBc and a gain of better than 15 dB.展开更多
CAD model retrieval based on functional semantics is more significant than content-based 3D model retrieval during the mechanical conceptual design phase. However, relevant research is still not fully discussed. There...CAD model retrieval based on functional semantics is more significant than content-based 3D model retrieval during the mechanical conceptual design phase. However, relevant research is still not fully discussed. Therefore, a functional semantic-based CAD model annotation and retrieval method is proposed to support mechanical conceptual design and design reuse, inspire designer creativity through existing CAD models, shorten design cycle, and reduce costs. Firstly, the CAD model functional semantic ontology is constructed to formally represent the functional semantics of CAD models and describe the mechanical conceptual design space comprehensively and consistently. Secondly, an approach to represent CAD models as attributed adjacency graphs(AAG) is proposed. In this method, the geometry and topology data are extracted from STEP models. On the basis of AAG, the functional semantics of CAD models are annotated semi-automatically by matching CAD models that contain the partial features of which functional semantics have been annotated manually, thereby constructing CAD Model Repository that supports model retrieval based on functional semantics. Thirdly, a CAD model retrieval algorithm that supports multi-function extended retrieval is proposed to explore more potential creative design knowledge in the semantic level. Finally, a prototype system, called Functional Semantic-based CAD Model Annotation and Retrieval System(FSMARS), is implemented. A case demonstrates that FSMARS can successfully botain multiple potential CAD models that conform to the desired function. The proposed research addresses actual needs and presents a new way to acquire CAD models in the mechanical conceptual design phase.展开更多
In most multi-function phased array radar applications, multiple missions, including airspace searching and target tracking, are usually performed simultaneously by the digital beam-forming technique and the time divi...In most multi-function phased array radar applications, multiple missions, including airspace searching and target tracking, are usually performed simultaneously by the digital beam-forming technique and the time dividing method. This paper presents a novel method to classify pulses of different missions from an interleaved pulse sequence emitted by the same radar, which is significant in radar electronic reconnaissance and electronic support measure. Firstly, two hypotheses, i.e., pulse relativity within the same mission and pulse independence among different missions, are proposed by analyzing the antenna pattern and the beam scheduling method of the phased array radar. Based on the above two hypotheses, an optimal model for pulse classification is exploited with pulse amplitude series, where the absolute-value sum of second order difference is taken as the optimal kernel to measure sequence smooth continuity. Finally, several pieces of sequences under different numbers of missions and tracking data rates are simulated for algorithm verification. The simulation results show that the long data length and the high data rate will increase classification efficiency due to the validity of the two hypotheses in sufficient pulse amplitude sequence.展开更多
Multifunctional ceramics of 0.825K_(0.5)Na_(0.5)NbO_(3)-0.175Sr(Yb_(0.5)Nb_(0.5))O_(3)-x%Er with ferroelectric,transparent and luminescent properties were obtained by doping Er.The effects of Er-doping on the structur...Multifunctional ceramics of 0.825K_(0.5)Na_(0.5)NbO_(3)-0.175Sr(Yb_(0.5)Nb_(0.5))O_(3)-x%Er with ferroelectric,transparent and luminescent properties were obtained by doping Er.The effects of Er-doping on the structure,luminescence and electrical properties of the ceramics were studied.After Er doping,the ceramics have luminescent properties and the luminescence intensity reaches the maximum when x=0.75.The ceramics still have good light transmission,but the transmittance decreases with the increase of Er-doping content due to the change of phase structure from pseudo-cubic phase to three-phase orthogonality.The energy storage properties is also greatly improved,and the W_(rec) and the η of the ceramics reach the maximum value of 0.31 J/cm^(3) and 94.6% when x=0.25,respectively.At the same time,the maximum electro-induced strain value is 0.031%.展开更多
The chronic problems of having a large population versus limited land resources and an urban-rural dual system are the premise for discussing China 's agricultural ontology. According to its natural properties, there...The chronic problems of having a large population versus limited land resources and an urban-rural dual system are the premise for discussing China 's agricultural ontology. According to its natural properties, there are three main types of agriculture systems: large-farm agriculture, small-farm agriculture and household-based agriculture. China cannot pursue agricultural modernization based on the developed countries'experiences with large-farm models regardless of its national conditions. Otherwise, it will suffer double negative externalities on the environment and food safety. In 2007, China made the policy shift towards modern agriculture. Current theoretical studies need to further explore new incentives and compensation mechanisms that are compatible with this new policy shift.展开更多
This paper briefly analyzes the present situation of textile mill's air-conditioning system. Since it is difficult to establish detailed math model to control a textile mill's airconditioning system because of the i...This paper briefly analyzes the present situation of textile mill's air-conditioning system. Since it is difficult to establish detailed math model to control a textile mill's airconditioning system because of the influence of various factors such as the differences in seasons, regions, etc., most air-conditioning equipment can not be controlled automatically. This paper suggests utilizing multi-function data acquisRion card to collect the data about the temperature and humidity of a workshop, processing the data on a PC, comparing them with the expert database, and then using the 485 serial port expanding module to output the parameters, which are used to control the inverter, so that the purpose of adjusting the temperature and humidity of the workshop is achieved.展开更多
Small-scale robots,ranging in size from micrometers to centimeters,have gained significant attention in the biomedical field.However,conventional small-scale robots made of rigid materials encounter challenges in adap...Small-scale robots,ranging in size from micrometers to centimeters,have gained significant attention in the biomedical field.However,conventional small-scale robots made of rigid materials encounter challenges in adapting themselves to the soft tissues and complicated environments of human body.Compared to the rigid counterpart,small-scale hydrogel-based robots hold great promises due to their tissue-like low modulus,outstanding biocompatibility and accessible stimuli-responsive capabilities.These attributes offer small-scale hydrogel-based robots with multimodal locomotion and reinforced functions,further enhancing the adaptability in manipulation and tasks execution for various biomedical applications.In this review,we present recent advances in small-scale hydrogel-based robots.We first summarize the design principles of small-scale hydrogel-based robots including materials,fabrication techniques and manipulation strategies,then highlighting their upgraded functions and adaptive biomedical applications.Finally,we discuss existing challenges and future perspectives for small-scale hydrogel-based robots.展开更多
The fabrication of light-weight,highly impact-resistant,and energy-absorbent materials is urgently demanded in many facets of the society from body armor to aerospace engineering,especially under an extreme environmen...The fabrication of light-weight,highly impact-resistant,and energy-absorbent materials is urgently demanded in many facets of the society from body armor to aerospace engineering,especially under an extreme environment.Carbon nanotubes(CNTs),one of the strongest and toughest materials ever found,also have good conductivity,chemical stability,and thermal stability,etc,making them a competitive candidate as building blocks to help achieve the above goal.In this work,a kind of CNT network was prepared by using chlorosulfonic acid(CSA)to release the internal stress of super-aligned carbon nanotube films(SA-CNTF)and dendritic polyamide amine(PAMAM)to further introduce multiple hydrogen bonds and interlocking structures.The fabricated bioinspired carbon nanotube network films(PAMAM@C-CNTF)have a high toughness of 45.97 MJ/m3,showing an increase of 420%compared to neat SA-CNTF.More importantly,the anti-impact performance of the films(e.g.,with a maximum specific energy absorption of 1.40 MJ/kg under 80-100 m/s projectile impact)is superior to that of conventional protective materials from steel and Kevlar fiber,and also exceeds that of any other reported carbon-based materials.The hierarchical energy dissipation mechanism was further revealed through experiment and simulation.Additional functions including intelligent heating/anti-icing,ultraviolet protection,as well as electromagnetic interference shielding properties make these network films have great potential in practical multi-protection applications,especially under an extreme environment.展开更多
Multi-functional Al-matrix composites with high volume fraction (55%-57%) of SiC particles are produced with the new pressureless infiltration fabrication technology. X-ray detection and microscopic observation disp...Multi-functional Al-matrix composites with high volume fraction (55%-57%) of SiC particles are produced with the new pressureless infiltration fabrication technology. X-ray detection and microscopic observation display the composites which are macroscopically homogeneous without porosity. The investigation further reveals that the SiC/Al composites possess low density (2.94 g/cm^3), high elastic modulus (220 GPa), prominent thermal management function as a result of low coefficient of thermal expansion (8 × 10^4 K^-1) and high thermal conductivity (235 W/(m.K)) as well as unique preventability of resonance vibration. By adopting a series of developed techniques, the multi-functional SiC/Al composites have managed to be made into near-net-shape parts. Many kinds of precision components of space-based optomechanical structures and airborne optoelectronic platform have been turned out. Of them, several typical products are being under test in practices.展开更多
To cope with the problem of emitter identification caused by the radar words' uncertainty of measured multi-function radar emitters, this paper proposes a new identification method based on stochastic syntax-directed...To cope with the problem of emitter identification caused by the radar words' uncertainty of measured multi-function radar emitters, this paper proposes a new identification method based on stochastic syntax-directed translation schema(SSDTS). This method, which is deduced from the syntactic modeling of multi-function radars, considers the probabilities of radar phrases appearance in different radar modes as well as the probabilities of radar word errors occurrence in different radar phrases. It concludes that the proposed method can not only correct the defective radar words by using the stochastic translation schema, but also identify the real radar phrases and working modes of measured emitters concurrently. Furthermore, a number of simulations are presented to demonstrate the identification capability and adaptability of the SSDTS algorithm.The results show that even under the condition of the defective radar words distorted by noise,the proposed algorithm can infer the phrases, work modes and types of measured emitters correctly.展开更多
The binary random in-chain silyl-hydride multi-functionalized poly(styrene/butadiene/isoprene and dimethyl[4-(1-phenylvinyl) phenyl]silane) (PS-DPESiH, PB-DPESiH, PI-DPESiH) copolymers were successfully synthesi...The binary random in-chain silyl-hydride multi-functionalized poly(styrene/butadiene/isoprene and dimethyl[4-(1-phenylvinyl) phenyl]silane) (PS-DPESiH, PB-DPESiH, PI-DPESiH) copolymers were successfully synthesized. These functionalized copo- lymers were prepared in hexane with n-BuLi as the initiator at 50℃ for 4 h. The silyl-hydride groups were introduced into polymer backbones quantitatively by living anionic polymerization. The copolymers were determined through 1H NMR, size exclusion chromatography (SEC) and differential scanning calorimetry (DSC) techniques, while the number of silyl-hych-ide groups was calculated and discussed.展开更多
基金financially supported by the National Natural Science Foundation of China(51872090,51772097,22304055)the Hebei Natural Science Fund for Distinguished Young Scholar(E2019209433)+4 种基金the Youth Talent Program of Hebei Provincial Education Department(BJ2018020)the Natural Science Foundation of Hebei Province(E2020209151,E2022209158,B2022209026,D2023209012)the Central Guiding Local Science and Technology Development Fund Project(236Z4409G)the Science and Technology Project of Hebei Education Department(SLRC2019028)the Science and Technology Planning Project of Tangshan City(22130227H)。
文摘With the increasing demand for scalable and cost-effective electrochemical energy storage,aqueous zinc ion batteries(AZIBs)have a broad application prospect as an inexpensive,efficient,and naturally secure energy storage device.However,the limitations suffered by AZIBs,including volume expansion and active materials dissolution of the cathode,electrochemical corrosion,irreversible side reactions,zinc dendrites of the anode,have seriously decelerated the civilianization process of AZIBs.Currently,polymers have tremendous superiority for application in AZIBs attributed to their exceptional chemical stability,tunable structure,high energy density and outstanding mechanical properties.Considering the expanding applications of AZIBs and the superiority of polymers,this comprehensive paper meticulously reviews the benefits of utilizing polymeric applied to cathodes and anodes,respectively.To begin with,with adjustable structure as an entry point,the correlation between polymer structure and the function of energy storage as well as optimization is deeply investigated in respect to the mechanism.Then,depending on the diversity of properties and structures,the development of polymers in AZIBs is summarized,including conductive polymers,redox polymers as well as carbon composite polymers for cathode and polyvinylidene fluoride-,carbonyl-,amino-,nitrile-based polymers for anode,and a comprehensive evaluation of the shortcomings of these strategies is provided.Finally,an outlook highlights some of the challenges posed by the application of polymers and offers insights into the potential future direction of polymers in AZIBs.It is designed to provide a thorough reference for researchers and developers working on polymer for AZIBs.
基金supported by the National Natural Science Foundation of China(Grant Nos.52373280,52177014,51977009,52273257).
文摘With the diversified development of big data,detection and precision guidance technologies,electromagnetic(EM)functional materials and devices serving multiple spectrums have become a hot topic.Exploring the multispectral response of materials is a challenging and meaningful scientific question.In this study,MXene/TiO_(2)hybrids with tunable conduction loss and polarization relaxation are fabricated by in situ atomic reconstruction engineering.More importantly,MXene/TiO_(2)hybrids exhibit adjustable spectral responses in the GHz,infrared and visible spectrums,and several EM devices are constructed based on this.An antenna array provides excellent EM energy harvesting in multiple microwave bands,with|S11|up to−63.2 dB,and can be tuned by the degree of bending.An ultra-wideband bandpass filter realizes a passband of about 5.4 GHz and effectively suppresses the transmission of EM signals in the stopband.An infrared stealth device has an emissivity of less than 0.2 in the infrared spectrum at wavelengths of 6-14μm.This work can provide new inspiration for the design and development of multifunctional,multi-spectrum EM devices.
基金Project supported by the Scientific and Technological Developing Scheme of Jilin Province,China(Grant No.20180101281JC)the"135"Research Project of Education Bureau of Jilin Province,China(Grant No.JJKH20190579KJ)the"111"Project of China(Grant No.D17017).
文摘We proposed a vanadium dioxide(VO2)-integrated multi-functional metamaterial structure that consists of three metallic grating layers and two VO2 films separated by SiO2 dielectric spacers.The proposed structure can be flexibly switched among three states by adjusting temperature,incident direction,and polarization.In state 1,the incident wave is strongly transmitted and perfectly converted to its orthogonal polarization state.In state 2,the incident wave is perfectly absorbed.In state 3,incident wave is totally reflected back.The working frequency of the multi-functional metamaterial can be arbitrarily tuned within a broad pass band.We believe that our findings are beneficial in designing temperature-controlled metadevices.
文摘We demonstrate a fiber-loop ring down multi-function sensors system, which can be used to measure refractive index and curvature simultaneously. Good agreement has been found between theoretical analyses and experimental results. It has great potential for sensor applications.
文摘With the development of medical level, specialized, refined and multidisciplinary collaborative therapy is the requirement and main development direction of neurosurgery. With the improvement of people’s medical awareness, people cannot meet the simple surgical treatment, and there is a great demand for nursing treatment. At the same time, the demand for efficiency and convenience of medical nursing practice teaching continues to improve, and the multi-functional medical nursing training innovation platform has been paid more and more attention. The rapid development of material technology as well as digitalization has brought about a huge change, and we have created a multifunctional, spatially efficient and easy-to-transfer information platform for medical care training. A base box, placement drawer, platform board and display are used as the base module and the base module is filled with specific functional components. Lifting and lowering using motors and spiral base, moving using universal wheels. These devices together constitute the training platform. A survey of students and teachers was conducted through a questionnaire, and they all gave very good feedback that the multi-functional platform was very practical and useful. This platform effectively solves the drawbacks of the original training platform which is time-consuming, laborious and inconvenient, and is worthy of further promotion and research.
基金financial support for this study by FAO/GEF project(GCP/GLO/212/GEF)project"rice-fish GIAHS dynamic conservation and adaptivemanagement"the National Public Benefit(Environmental)Research Foundation of China(201009020)
文摘Population growth,loss of biodiversity,and climate change necessitate a new vision for the future of both agriculture and biodiversity.In order to safeguard and support the world's agricultural heritage systems,in 2002 the FAO started an initiative for the conservation and adaptive management called Globally Important Agricultural Heritage Systems (GIAHS).Tourism is suggested as part of the future as it is considered to be an alternative income source that will not only promote local economic development,but also provide the opportunity for tourists to learn about agriculture and ecology.However,inappropriate tourism in GIAHS sites will bring impacts on local culture and living styles,which not only threatens tourism's sustainable development,but also has the potential to damage these unique agricultural systems.This paper proposes that agriculture-based tourism is suitable for GIAHS and that Multi-functionality of Agriculture (MFA) can be the link between agriculture and tourism.This study constructs the framework for tourism development in GIAHS through MFA and applies it to the four GIAHS sites in China.Referring to the quantitative assessment for MFA and a qualitative analysis of the relationship between agriculture and tourism,we can give advice on agricultural tourism development in GIAHS sites.This framework also offers a universal methodology that allows stakeholders to communicate about the multiple functions of GIAHS across scales.
基金National Nature Science Foundation of China(No.51971111)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX20_0190).
文摘Eco-friendly electromagnetic wave absorbing materials with excellent thermal infrared stealth property,heat-insulating ability and compression resistance are highly attractive in practical applications.Meeting the aforesaid requirements simultaneously is a formidable challenge.Herein,ultra-light carbon aerogels were fabricated via fresh shaddock peel by facile freeze-drying method and calcination process,forming porous network architecture.With the heating platform temperature of 70℃,the upper surface temperatures of the as-prepared carbon aerogel present a slow upward trend.The color of the sample surface in thermal infrared images is similar to that of the surroundings.With the maximum compressive stress of 2.435 kPa,the carbon aerogels can provide favorable endurance.The shaddock peel-based carbon aerogels possess the minimum reflection loss value(RLmin)of−29.50 dB in X band.Meanwhile,the effective absorption bandwidth covers 5.80 GHz at a relatively thin thickness of only 1.7 mm.With the detection theta of 0°,the maximum radar cross-sectional(RCS)reduction values of 16.28 dB m^(2) can be achieved.Theoretical simulations of RCS have aroused extensive interest owing to their ingenious design and time-saving feature.This work paves the way for preparing multi-functional microwave absorbers derived from biomass raw materials under the guidance of RCS simulations.
文摘With the rapid developments of the high-speed railway in China, a great number of long-span bridges have been constructed in order to cross rivers and gorges. At present, the longest main span of a constructed high-speed railway bridge is only 630 m. The main span of Hutong Yangtze River Bridge and of Wufengshan Yangtze River Bridge, which are under construction, will be much longer, at 1092 m each. In order to overcome the technical issues that originate from the extremely large dead loading and the relatively small structural stiffness of long-span high-speed railway bridges, many new technologies in bridge construction, design, materials, and so forth have been developed. This paper carefully reviews progress in the construction technologies of multi-function combined bridges in China, including com- bined highway and railway bridges and multi-track railway bridges. Innovations and practices regarding new types of bridge and composite bridge structures, such as bridges with three cable planes and three main trusses, inclined main trusses, slab-truss composite sections, and steel-concrete composite sections, are introduced. In addition, investigations into high-performance materials and integral fabrication and erection techniques for long-span railway bridges are summarized. At the end of the paper, prospects for the future development of long-span high-speed railwav bridges are provided.
基金National Natural Science Foundation of China, No.41271550 Humanities and Social Sciences Project of Ministry of Education in the West and the Frontier Areas, No. 12XJC790003
文摘The excessive expansion of urbanized areas has resulted in haphazard land utili- zation, immoderate consumption of superior agricultural land and water resources, significant fragmentation of agricultural landscape, and gradual deterioration of the agro-ecological en- vironment. Combined, these factors cause poor land use efficiency. Under these circum- stances, comprehensively assessing land use efficiency for urban agriculture is a key issue in land use research. Currently, evaluation methods for agricultural land use efficiency narrowly concentrate on aspects of economic input and output. However, urban agro-ecosystems can provide diverse economic, social, and ecological services and functions. In particular, the social and ecological services and functions originating from agricultural land, which have a higher value than economic services, play a significant role in ensuring regional social, eco- logical, and environmental security. However, recent research has rarely taken these benefits into consideration. Therefore, land use value has been greatly underestimated, which has resulted in mishandled and poor land use policies. In this study, we apply Landsat imagery and social and economic statistical data for the Xi'an metropolitan zone (XMZ) to investigate agricultural multi-functionality. We develop an evaluation framework for urban agricultural land use efficiency and identify agro-ecosystem services and functions as important outputs from agricultural land. The land use efficiency of urban agriculture is then evaluated using ecosystem services models, providing a mechanism for assessing spatial-temporal changes in land use efficiency in the XMZ from 1999 to 2015. Four important conclusions are reached from this analysis. First, the rapid urbanization and agricultural transformation from traditional cereal cultivation to modern urban agriculture has resulted in steadily increasing costs, out- puts, and land use efficiency of urban agriculture. The total output value increased 41% and land use efficiency per hectare increased by 33.13% on average. Second, the spatial patterns of comprehensive output and land use efficiency were dominated by economic outputs from agricultural land. Areas near cities, which are dominated by orchard and arable land, provide more economic functions. These areas support and regulate services due to the transforma- tion from extensive cereal production to intensive modern urban agriculture; therefore, they have higher output value and land use efficiency. In contrast, areas distant from cities, towns, and high traffic roads, namely, remote rural areas, provide more support and regulating ser- vices, but have relatively lower economic function due to inaccessibility tO urban markets and slow agricultural transformation. Therefore, these areas have lower output value and land use efficiency. The spatial change in agricultural output and land use efficiency in urban areas is strongly dependent on the degree of urbanization and agricultural transformation. Third, the total output value and land use efficiency of urban agriculture measured with our approach are much higher than evaluations using traditional methods. However, the spatial patterns measured using the two approaches are in agreement. The evaluation framework integrates ecological services and economic and social functions into a comprehensive output from agricultural land. This approach is more methodical and accurate for evaluating the compre- hensive efficiency of land use based on quantities and spatial scale because they are at the pixel scale. Finally, the evaluation results have important implications for enhancing current agricultural subsidies and even implementing ecological payment policies in China. Most importantly, they can be directly applied to agricultural transformation regulations, decision-making, and guidance for rational land utilization.
文摘An ultra-wideband mixing component cascaded by a mixing multi-function chip and a frequency multiplier multi-function chip was demonstrated and implemented using 3D heterogeneous integration based on the silicon adapter board technology.Four layers of high-resistance silicon substrate stack packaging are implemented based on the wafer-level gold-gold bonding process.Each layer adopts though silicon via(TSV)technology to realize signal interconnection.A core monolithic integrated microwave chip(MMIC)is embedded in the silicon cavity,and the silicon-based filter is integrated with the high-resistance silicon substrate.The interconnect line,cavity and filter of the silicon-based adapter board are designed with AutoCAD,and HFSS is adopted for 3D electromagnetic field simulation.According to the measured results,the radio frequency(RF)of the mixing multi-function chip is 40-44 GHz and its intermediate frequency(IF)can cover the Ku band with a chip size of 10 mm×11 mm×1 mm.The multiplier multi-function chip operates at 16-20 GHz.The fundamental suppression is greater than 50 dB and the second harmonic suppression is better than 40 dB with a chip size of 8 mm×8 mm×1 mm.The cascaded fully assembled mixing component achieves a spur of better than-50 dBc and a gain of better than 15 dB.
基金Supported by National Natural Science Foundation of China (Grant No.51175287)National Science and Technology Major Project of China (Grant No.2011ZX02403)
文摘CAD model retrieval based on functional semantics is more significant than content-based 3D model retrieval during the mechanical conceptual design phase. However, relevant research is still not fully discussed. Therefore, a functional semantic-based CAD model annotation and retrieval method is proposed to support mechanical conceptual design and design reuse, inspire designer creativity through existing CAD models, shorten design cycle, and reduce costs. Firstly, the CAD model functional semantic ontology is constructed to formally represent the functional semantics of CAD models and describe the mechanical conceptual design space comprehensively and consistently. Secondly, an approach to represent CAD models as attributed adjacency graphs(AAG) is proposed. In this method, the geometry and topology data are extracted from STEP models. On the basis of AAG, the functional semantics of CAD models are annotated semi-automatically by matching CAD models that contain the partial features of which functional semantics have been annotated manually, thereby constructing CAD Model Repository that supports model retrieval based on functional semantics. Thirdly, a CAD model retrieval algorithm that supports multi-function extended retrieval is proposed to explore more potential creative design knowledge in the semantic level. Finally, a prototype system, called Functional Semantic-based CAD Model Annotation and Retrieval System(FSMARS), is implemented. A case demonstrates that FSMARS can successfully botain multiple potential CAD models that conform to the desired function. The proposed research addresses actual needs and presents a new way to acquire CAD models in the mechanical conceptual design phase.
文摘In most multi-function phased array radar applications, multiple missions, including airspace searching and target tracking, are usually performed simultaneously by the digital beam-forming technique and the time dividing method. This paper presents a novel method to classify pulses of different missions from an interleaved pulse sequence emitted by the same radar, which is significant in radar electronic reconnaissance and electronic support measure. Firstly, two hypotheses, i.e., pulse relativity within the same mission and pulse independence among different missions, are proposed by analyzing the antenna pattern and the beam scheduling method of the phased array radar. Based on the above two hypotheses, an optimal model for pulse classification is exploited with pulse amplitude series, where the absolute-value sum of second order difference is taken as the optimal kernel to measure sequence smooth continuity. Finally, several pieces of sequences under different numbers of missions and tracking data rates are simulated for algorithm verification. The simulation results show that the long data length and the high data rate will increase classification efficiency due to the validity of the two hypotheses in sufficient pulse amplitude sequence.
基金Supported by the National Natural Science Foundation of China (No.61965007)Guangxi Natual Science Foundation (No.2018GXNSFDA281042)Guangxi Key Laboratory of Information Materials (No.201007-Z)。
文摘Multifunctional ceramics of 0.825K_(0.5)Na_(0.5)NbO_(3)-0.175Sr(Yb_(0.5)Nb_(0.5))O_(3)-x%Er with ferroelectric,transparent and luminescent properties were obtained by doping Er.The effects of Er-doping on the structure,luminescence and electrical properties of the ceramics were studied.After Er doping,the ceramics have luminescent properties and the luminescence intensity reaches the maximum when x=0.75.The ceramics still have good light transmission,but the transmittance decreases with the increase of Er-doping content due to the change of phase structure from pseudo-cubic phase to three-phase orthogonality.The energy storage properties is also greatly improved,and the W_(rec) and the η of the ceramics reach the maximum value of 0.31 J/cm^(3) and 94.6% when x=0.25,respectively.At the same time,the maximum electro-induced strain value is 0.031%.
文摘The chronic problems of having a large population versus limited land resources and an urban-rural dual system are the premise for discussing China 's agricultural ontology. According to its natural properties, there are three main types of agriculture systems: large-farm agriculture, small-farm agriculture and household-based agriculture. China cannot pursue agricultural modernization based on the developed countries'experiences with large-farm models regardless of its national conditions. Otherwise, it will suffer double negative externalities on the environment and food safety. In 2007, China made the policy shift towards modern agriculture. Current theoretical studies need to further explore new incentives and compensation mechanisms that are compatible with this new policy shift.
文摘This paper briefly analyzes the present situation of textile mill's air-conditioning system. Since it is difficult to establish detailed math model to control a textile mill's airconditioning system because of the influence of various factors such as the differences in seasons, regions, etc., most air-conditioning equipment can not be controlled automatically. This paper suggests utilizing multi-function data acquisRion card to collect the data about the temperature and humidity of a workshop, processing the data on a PC, comparing them with the expert database, and then using the 485 serial port expanding module to output the parameters, which are used to control the inverter, so that the purpose of adjusting the temperature and humidity of the workshop is achieved.
基金support provided by the National Natural Science Foundation of China(Nos.52022102,and 52261160380)National Key R&D Program of China(No.2017YFA0701303)+2 种基金the Youth Innovation Promotion Association of CAS(No.2019353)Guangdong Regional Joint Fund-Key Project(No.2021B1515120076)the Fundamental Research Program of Shenzhen(Nos.RCJC20221008092729033,and JCYJ20220818101800001).
文摘Small-scale robots,ranging in size from micrometers to centimeters,have gained significant attention in the biomedical field.However,conventional small-scale robots made of rigid materials encounter challenges in adapting themselves to the soft tissues and complicated environments of human body.Compared to the rigid counterpart,small-scale hydrogel-based robots hold great promises due to their tissue-like low modulus,outstanding biocompatibility and accessible stimuli-responsive capabilities.These attributes offer small-scale hydrogel-based robots with multimodal locomotion and reinforced functions,further enhancing the adaptability in manipulation and tasks execution for various biomedical applications.In this review,we present recent advances in small-scale hydrogel-based robots.We first summarize the design principles of small-scale hydrogel-based robots including materials,fabrication techniques and manipulation strategies,then highlighting their upgraded functions and adaptive biomedical applications.Finally,we discuss existing challenges and future perspectives for small-scale hydrogel-based robots.
基金supported by the National Key Basic Research Program of China(No.2022YFA1205400)the Chinese Postdoctoral Science Foundation(Nos.E1I41IR1 and E2911IR1).
文摘The fabrication of light-weight,highly impact-resistant,and energy-absorbent materials is urgently demanded in many facets of the society from body armor to aerospace engineering,especially under an extreme environment.Carbon nanotubes(CNTs),one of the strongest and toughest materials ever found,also have good conductivity,chemical stability,and thermal stability,etc,making them a competitive candidate as building blocks to help achieve the above goal.In this work,a kind of CNT network was prepared by using chlorosulfonic acid(CSA)to release the internal stress of super-aligned carbon nanotube films(SA-CNTF)and dendritic polyamide amine(PAMAM)to further introduce multiple hydrogen bonds and interlocking structures.The fabricated bioinspired carbon nanotube network films(PAMAM@C-CNTF)have a high toughness of 45.97 MJ/m3,showing an increase of 420%compared to neat SA-CNTF.More importantly,the anti-impact performance of the films(e.g.,with a maximum specific energy absorption of 1.40 MJ/kg under 80-100 m/s projectile impact)is superior to that of conventional protective materials from steel and Kevlar fiber,and also exceeds that of any other reported carbon-based materials.The hierarchical energy dissipation mechanism was further revealed through experiment and simulation.Additional functions including intelligent heating/anti-icing,ultraviolet protection,as well as electromagnetic interference shielding properties make these network films have great potential in practical multi-protection applications,especially under an extreme environment.
基金Foundation items: High-technology Research and Development Programme of China (2007AA03Z544) Aeronautical Science Foundation of China (20075221001)
文摘Multi-functional Al-matrix composites with high volume fraction (55%-57%) of SiC particles are produced with the new pressureless infiltration fabrication technology. X-ray detection and microscopic observation display the composites which are macroscopically homogeneous without porosity. The investigation further reveals that the SiC/Al composites possess low density (2.94 g/cm^3), high elastic modulus (220 GPa), prominent thermal management function as a result of low coefficient of thermal expansion (8 × 10^4 K^-1) and high thermal conductivity (235 W/(m.K)) as well as unique preventability of resonance vibration. By adopting a series of developed techniques, the multi-functional SiC/Al composites have managed to be made into near-net-shape parts. Many kinds of precision components of space-based optomechanical structures and airborne optoelectronic platform have been turned out. Of them, several typical products are being under test in practices.
基金supported by the National Natural Science Foundation of China (No. 61002026)
文摘To cope with the problem of emitter identification caused by the radar words' uncertainty of measured multi-function radar emitters, this paper proposes a new identification method based on stochastic syntax-directed translation schema(SSDTS). This method, which is deduced from the syntactic modeling of multi-function radars, considers the probabilities of radar phrases appearance in different radar modes as well as the probabilities of radar word errors occurrence in different radar phrases. It concludes that the proposed method can not only correct the defective radar words by using the stochastic translation schema, but also identify the real radar phrases and working modes of measured emitters concurrently. Furthermore, a number of simulations are presented to demonstrate the identification capability and adaptability of the SSDTS algorithm.The results show that even under the condition of the defective radar words distorted by noise,the proposed algorithm can infer the phrases, work modes and types of measured emitters correctly.
基金sponsored by the National Natural Science Foundation of China(Nos.21034001,21174021)
文摘The binary random in-chain silyl-hydride multi-functionalized poly(styrene/butadiene/isoprene and dimethyl[4-(1-phenylvinyl) phenyl]silane) (PS-DPESiH, PB-DPESiH, PI-DPESiH) copolymers were successfully synthesized. These functionalized copo- lymers were prepared in hexane with n-BuLi as the initiator at 50℃ for 4 h. The silyl-hydride groups were introduced into polymer backbones quantitatively by living anionic polymerization. The copolymers were determined through 1H NMR, size exclusion chromatography (SEC) and differential scanning calorimetry (DSC) techniques, while the number of silyl-hych-ide groups was calculated and discussed.