Air pollution in China covers a large area with complex sources and formation mechanisms,making it a unique place to conduct air pollution and atmospheric chemistry research.The National Natural Science Foundation of ...Air pollution in China covers a large area with complex sources and formation mechanisms,making it a unique place to conduct air pollution and atmospheric chemistry research.The National Natural Science Foundation of China’s Major Research Plan entitled“Fundamental Researches on the Formation and Response Mechanism of the Air Pollution Complex in China”(or the Plan)has funded 76 research projects to explore the causes of air pollution in China,and the key processes of air pollution in atmospheric physics and atmospheric chemistry.In order to summarize the abundant data from the Plan and exhibit the long-term impacts domestically and internationally,an integration project is responsible for collecting the various types of data generated by the 76 projects of the Plan.This project has classified and integrated these data,forming eight categories containing 258 datasets and 15 technical reports in total.The integration project has led to the successful establishment of the China Air Pollution Data Center(CAPDC)platform,providing storage,retrieval,and download services for the eight categories.This platform has distinct features including data visualization,related project information querying,and bilingual services in both English and Chinese,which allows for rapid searching and downloading of data and provides a solid foundation of data and support for future related research.Air pollution control in China,especially in the past decade,is undeniably a global exemplar,and this data center is the first in China to focus on research into the country’s air pollution complex.展开更多
Nanocarbon-based materials, such as carbon nanotubes(CNTs) and graphene have been attached much attention by scientific and industrial community. As two representative nanocarbon materials, one-dimensional CNTs and tw...Nanocarbon-based materials, such as carbon nanotubes(CNTs) and graphene have been attached much attention by scientific and industrial community. As two representative nanocarbon materials, one-dimensional CNTs and twodimensional graphene both possess remarkable mechanical properties. In the past years, a large amount of work have been done by using CNTs or graphene as building blocks for constructing novel, macroscopic, mechanically strong fibrous materials. In this review, we summarize the assembly approaches of CNT-based fibers and graphene-based fibers in chronological order, respectively. The mechanical performances of these fibrous materials are compared, and the critical influences on the mechanical properties are discussed. Personal perspectives on the fabrication methods of CNT-and graphene-based fibers are further presented.展开更多
Graphene oxide(GO),an important chemical precursor of graphene,can stably disperse in aqueous surrounding and undergo aggregation as metal cations introduced.The usual instability of GO with ions is caused by the shie...Graphene oxide(GO),an important chemical precursor of graphene,can stably disperse in aqueous surrounding and undergo aggregation as metal cations introduced.The usual instability of GO with ions is caused by the shielding effect of ions and crosslinking between GO and ions.However,the dynamic stability of GO under ions exchange still remains unclear.Here,we investigated the dynamic dispersion stability of GO with metal ions and observed a redispersion behavior in concentrated Fe3+solution,other than permanent aggregation.The exchange with Fe3+ions drives the reversion of zeta(ζ)potential and enables the redispersion to individual GO-Fe3+complex sheets,following a dynamic electric double layer(EDL)mechanism.It is found that the specifically strong electrostatic shielding effect and coordination attraction between Fe3+and functional oxygen groups allows the selective redispersion of GO in concentrated Fe3+solution.The revealed dynamic dispersion stability complements our understanding on the dispersive stability of GO and can be utilized to fabricate graphene-metal hybrids for rich applications.展开更多
Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT...Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT aerogel structure shows nano-pore size(30-40 nm),high specific surface area(559 m^(2)g^(−1)),high void fraction(91.7%)and enhanced mechanical property:(1)the nano-pore size is beneficial for efficiently blocking thermal conduction and thermal convection via Knudsen effect(beneficial for infrared(IR)stealth);(2)the heterogeneous interface was beneficial for IR reflection(beneficial for IR stealth)and MWCNT polarization loss(beneficial for electromagnetic wave(EMW)attenuation);(3)the high void fraction was beneficial for enhancing thermal insulation(beneficial for IR stealth)and EMW impedance match(beneficial for EMW attenuation).Guided by the above theoretical design strategy,PVTMS@MWCNT nano-aerogel shows superior EMW absorption property(cover all Ku-band)and thermal IR stealth property(ΔT reached 60.7℃).Followed by a facial combination of the above nano-aerogel with graphene film of high electrical conductivity,an extremely high electromagnetic interference shielding material(66.5 dB,2.06 mm thickness)with superior absorption performance of an average absorption-to-reflection(A/R)coefficient ratio of 25.4 and a low reflection bandwidth of 4.1 GHz(A/R ratio more than 10)was experimentally obtained in this work.展开更多
Eliminating topological defects to achieve monodomain liquid crystals is highly significant for the fundamental studies of soft matter and building long-range ordered materials.However,liquid crystals are metastable a...Eliminating topological defects to achieve monodomain liquid crystals is highly significant for the fundamental studies of soft matter and building long-range ordered materials.However,liquid crystals are metastable and sensitive to external stimuli,such as flow,confinement,and electromagnetic fields,which cause their intrinsic polycrystallinity and topological defects.Here,we achieve the monodomain liquid crystals of graphene oxide over 30 cm through boundary-free sheargraphy.The obtained monodomain liquid crystals exhibit large-area uniform alignment of sheets,which has the same optical polarized angle and intensity.The monodomain liquid crystals provide bidirectionally ordered skeletons,which can be applied as lightweight thermal management materials with bidirectionally high thermal and electrical conductivity.Furthermore,we extend the controllable topology of two-dimensional colloids by introducing singularities and disclinations in monodomain liquid crystals.Topological structures with defect strength from−2 to+2 were realized.This work provides a facile methodology to study the structural order of soft matter at a macroscopic level,facilitating the fabrication of metamaterials with tunable and highly anisotropic architectures.展开更多
Highly thermally conductive graphitic film(GF)materials have become a competitive solution for the thermal management of high-power electronic devices.However,their catastrophic structural failure under extreme altern...Highly thermally conductive graphitic film(GF)materials have become a competitive solution for the thermal management of high-power electronic devices.However,their catastrophic structural failure under extreme alternating thermal/cold shock poses a significant challenge to reliability and safety.Here,we present the first investigation into the structural failure mechanism of GF during cyclic liquid nitrogen shocks(LNS),which reveals a bubbling process characterized by“permeation-diffusion-deformation”phenomenon.To overcome this long-standing structural weakness,a novel metal-nanoarmor strategy is proposed to construct a Cu-modified graphitic film(GF@Cu)with seamless heterointerface.This well-designed interface ensures superior structural stability for GF@Cu after hundreds of LNS cycles from 77 to 300 K.Moreover,GF@Cu maintains high thermal conductivity up to 1088 W m^(−1)K^(−1)with degradation of less than 5%even after 150 LNS cycles,superior to that of pure GF(50%degradation).Our work not only offers an opportunity to improve the robustness of graphitic films by the rational structural design but also facilitates the applications of thermally conductive carbon-based materials for future extreme thermal management in complex aerospace electronics.展开更多
The processing capability is vital for the wide applications of materials to forge structures as-demand.Graphene-based macroscopic materials have shown excellent mechanical and functional properties.However,different ...The processing capability is vital for the wide applications of materials to forge structures as-demand.Graphene-based macroscopic materials have shown excellent mechanical and functional properties.However,different from usual polymers and metals,graphene solids exhibit limited deformability and processibility for precise forming.Here,we present a precise thermoplastic forming of graphene materials by polymer intercalation from graphene oxide(GO)precursor.The intercalated polymer enables the thermoplasticity of GO solids by thermally activated motion of polymer chains.We detect a critical minimum containing of intercalated polymer that can expand the interlayer spacing exceeding 1.4 nm to activate thermoplasticity,which becomes the criteria for thermal plastic forming of GO solids.By thermoplastic forming,the flat GO-composite films are forged to Gaussian curved shapes and imprinted to have surface relief patterns with size precision down to 360 nm.The plastic-formed structures maintain the structural integration with outstanding electrical(3.07×10^(5) S m^(−1))and thermal conductivity(745.65 W m^(−1) K^(−1))after removal of polymers.The thermoplastic strategy greatly extends the forming capability of GO materials and other layered materials and promises versatile structural designs for more broad applications.展开更多
In this article Florian Puchtler at affiliation‘University of Bayreuth’,Josef Breu at affiliation‘University of Bayreuth’,and Ziliang Wu at affiliation‘Zhejiang University’was missing from the author Min Cao,Sen...In this article Florian Puchtler at affiliation‘University of Bayreuth’,Josef Breu at affiliation‘University of Bayreuth’,and Ziliang Wu at affiliation‘Zhejiang University’was missing from the author Min Cao,Senping Liu,Qingli Zhu,Ya Wang,Jingyu Ma,Zeshen Li,Dan Chang,Enhui Zhu,Xin Ming,Florian Puchtler,Josef Breu,Ziliang Wu,Yingjun Liu,Yanqiu Jiang,Zhen Xu,Chao Gao list.展开更多
The preparation of dense ZrB_(2)-based ceramics typically requires high temperatures and long sintering time,which often result in significant grain coarsening and thus deterioration of mechanical properties.Ultrafast...The preparation of dense ZrB_(2)-based ceramics typically requires high temperatures and long sintering time,which often result in significant grain coarsening and thus deterioration of mechanical properties.Ultrafast sintering techniques offer a solution to inhibit grain coarsening by reducing the processing time.However,the ultrafast preparation of dense ZrB_(2)-based ceramics remains a challenge.In this work,we successfully fabricated dense ZrB_(2)-based ceramics in just a few minutes using heavy continuous direct current(DC)Joule heating and pressing.Notably,the densification rate peaked at 1218℃,and the densification process was nearly complete at a relatively low temperature of 1500℃.The application of heavy continuous direct current not only promotes the densification of the ceramics but also enhances the texturization of ZrB_(2).This results in optimally aligned ZrB_(2) grains that form a three-dimensional bonded skeletal network.These unique microstructures can effectively induce multi-stage fracture surfaces during failure,which helps synergistic strengthening and toughening of the ceramics.The ceramics exhibit remarkable comprehensive mechanical properties,with flexural strength and fracture toughness values reaching 773±114 MPa and 5.88±0.08 MPa·m^(1/2),respectively,surpassing those of conventional hot pressed samples.This technique is expected to be applied to other ultra-high temperature ceramics,providing a promising approach for the development of thermal protection materials.展开更多
Enhancing the mechanical performance of synthetic fibers is pursued in aerospace,wearable devices,and protective textiles.However,current reinforcement methods rely on the chemical modification of polymer stock,introd...Enhancing the mechanical performance of synthetic fibers is pursued in aerospace,wearable devices,and protective textiles.However,current reinforcement methods rely on the chemical modification of polymer stock,introducing greater complexity and processing challenge.In this work,the mechanical properties of different aramid fibers and their composite fibers are improved through a cool spinning strategy.By reducing the coagulation temperature to -25℃,the interactions between polymer chains and solvent molecules are substantially enhanced,thereby improving the drawability of the polymer solution.The draw ratio markedly increases typically from 200% to 380%,leading to optimized oriented and crystalline structures.Consequently,the tensile strength,Young’s modulus and toughness of large-diameter heterocyclic para-aramid fibers increase by 112%,123% and 118%,respectively.The cool spinning proposal is further applied to 36-μm-thick heterocyclic paraaramid/graphene oxide composite fibers,realizing elevated tensile strength,Young’s modulus and toughness of 6.28 GPa,119.62 GPa and 172.7 MJ·m^(-3),respectively.This strategy is also applicable to meta-aramid fibers,where tensile strength increases up to 1.35 GPa.The simple and universal cool spinning approach opens an avenue towards the preparation of high-performance fibers and composite fibers for structural and functional applications.展开更多
石墨烯气凝胶(GAs)在解决下一代电子器件电磁屏蔽污染方面引起了广泛关注.但是,由于超轻石墨烯气凝胶在复杂环境中结构不稳定,其在电磁屏蔽的实际应用中仍面临巨大的挑战.在此,我们提出一类机械结构稳定的石墨烯气凝胶,其展示出优异可...石墨烯气凝胶(GAs)在解决下一代电子器件电磁屏蔽污染方面引起了广泛关注.但是,由于超轻石墨烯气凝胶在复杂环境中结构不稳定,其在电磁屏蔽的实际应用中仍面临巨大的挑战.在此,我们提出一类机械结构稳定的石墨烯气凝胶,其展示出优异可靠的电磁屏蔽性能.这类气凝胶呈现出面面堆叠的结构,在密度ρ=3.7 mg cm-3,高度1 m m时,电磁屏蔽效能可达到64.1 d B,比电磁屏蔽效能达到173,243 dB cm2g-1,远超现有报道的碳基材料.同时,石墨烯气凝胶具有优异的环境适应性,在机械形变、极端温度、燃烧及水下等环境中均可保持性能稳定.此外,制备的石墨烯气凝胶可通过真空袋装工艺进行包装运输,解决了超轻材料实际应用中低密度与大体积的矛盾,且在这一极端变形过程中材料结构和性能均未产生破坏.该研究为石墨烯气凝胶电磁屏蔽材料的实际应用铺平了道路,且拓展了其实际应用场景,比如航天、军事战机及海洋领域.展开更多
Parkinson’s disease(PD),the second most common age-associated neurodegenerative disorder,is characterized by the loss of dopaminergic(DA)neurons and the presence ofα-synuclein-containing aggregates in the substantia...Parkinson’s disease(PD),the second most common age-associated neurodegenerative disorder,is characterized by the loss of dopaminergic(DA)neurons and the presence ofα-synuclein-containing aggregates in the substantia nigra pars compacta(SNpc).Chronic neuroinflammation is one of the hallmarks of PD pathophysiology.Postmortem analyses of human PD patients and experimental animal studies indicate that activation of glial cells and increases in pro-inflammatory factor levels are common features of the PD brain.Chronic release of proinflammatory cytokines by activated astrocytes and microglia leads to the exacerbation of DA neuron degeneration in the SNpc.Besides,peripheral immune system is also implicated in the pathogenesis of PD.Infiltration and accumulation of immune cells from the periphery are detected in and around the affected brain regions of PD patients.Moreover,inflammatory processes have been suggested as promising interventional targets for PD and even other neurodegenerative diseases.A better understanding of the role of inflammation in PD will provide new insights into the pathological processes and help to establish effective therapeutic strategies.In this review,we will summarize recent progresses in the neuroimmune aspects of PD and highlight the potential therapeutic interventions targeting neuroinflammation.展开更多
Self-toughening ZrB2–SiC based composites are fabricated by in-situ reactive hot pressing.The effect of sintering additive content on the microstructure and mechanical properties of the composites is investigated.Mic...Self-toughening ZrB2–SiC based composites are fabricated by in-situ reactive hot pressing.The effect of sintering additive content on the microstructure and mechanical properties of the composites is investigated.Microstructure observation found that the in-situ reactive hot pressing could promote the anisotropic growth of ZrB2 grains and the formation of interlocking microstructure.Such microstructure could improve the mechanical properties,especially,for the fracture toughness.The improved mechanical properties could be attributed to the self-toughening structure related to the ZrB2 platelets and the formed interlocking microstructure,which could trigger various toughening mechanisms such as grain pull-out,crack bridging,crack deflection,and crack branching,providing the main contribution to the high fracture toughness.展开更多
Tribenuron-methyl （TM） is a powerful sulfonylurea herbicide that inhibits branched-chain amino acid （BCAA） biosynthesis by targeting the catalytic subunit （CSR1） of acetolactate synthase （ALS）. Selective in- d...Tribenuron-methyl （TM） is a powerful sulfonylurea herbicide that inhibits branched-chain amino acid （BCAA） biosynthesis by targeting the catalytic subunit （CSR1） of acetolactate synthase （ALS）. Selective in- duction of male sterility by foliar spraying of TM at low doses has been widely used for hybrid seed produc- tion in rapeseed （Brassica napus）; however, the underlying mechanism remains unknown. Here, we report greater TM accumulation and subsequent stronger ALS inhibition and BCAA starvation in anthers than in leaves and stems after TM application. Constitutive or anther-specific expression of csrl-lD （a CSR1 mutant） eliminated anther-selective ALS inhibition and reversed the TM-induced male sterile phenotype in both rapeseed and Arabidopsis. The results of TM daub-stem experiments, combined with the observations of little TM accumulation in anthers and reversion of TM-induced male sterility by targeted expression of the TM metabolism gene Bel in either the mesophyll or phloem, suggested that foliar-sprayed TM was polar-transported to anthers mainly through the mesophyll and phloem. Microscopy and immunoblotting revealed that autophagy, a bulk degradation process induced during cell death, was elevated in TM-induced male sterile anthers and by anther-specific knockdown of ALS. Moreover, TM-induced pollen abortion was significantly inhibited by the autophagy inhibitor 3-MA. These data suggested that TM was polar-transported to anthers, resulting in BCAA starvation via anther-specific ALS inhibition and, ulti- mately, autophagic cell death in anthers.展开更多
Graphene aerogel fibers(GAFs)combine the advantages of lightweight,high specific strength and conductivity of graphene,showing great potential in multifunctional wearable textiles.However,the fabrication and applicati...Graphene aerogel fibers(GAFs)combine the advantages of lightweight,high specific strength and conductivity of graphene,showing great potential in multifunctional wearable textiles.However,the fabrication and application of GAF textiles are considerably limited by the low structural robustness of GAF.Here,we report a plastic-swelling method to fabricate GAF textiles with high performance and multi-functionalities.GAF textiles were achieved by plastic-swelling,the prewoven graphene oxide fiber(GOF)tow textiles.This near-solid plastic-swelling process allows GAFs in textiles to maintain high structural order and controllable density,and exhibit record-high tensile strength up to 103 MPa and electrical conductivity up to 1.06.104 S m−1 at the density of 0.4 g cm−3.GAF textiles exhibit high strength of 113 MPa,multiple electrical and thermal functions,and high porosity to serve as host materials for more functional vips.The plastic-swelling provides a general strategy to fabricate diverse aerogel fiber textiles,paving the road for their realistic application.展开更多
The enhanced permeability retention(EPR)effect based nanomedicine has been widely used for tumor targeting during the past decades.Here we unexpectedly observed the similar"EPR effect"at the site of iniury.W...The enhanced permeability retention(EPR)effect based nanomedicine has been widely used for tumor targeting during the past decades.Here we unexpectedly observed the similar"EPR effect"at the site of iniury.We found that the temporary dilated and leaky blood vessels caused by the potent vasodilator histamine in response to injury allowed the injected nanoparticles to pass through the vasculature and reached the injured tissue.Our finding shows the potential underline mechanism of"EPR effect"at the injured site.By loading with antibiotics,we further demonstrated a new strategy for prevention of infection at the site of injury.展开更多
Graphene, a two-dimensional material with extraordinary electrical, thermal, and elastic performance, is a potential candidate for future technologies. However, the superior properties of graphene have not yet been re...Graphene, a two-dimensional material with extraordinary electrical, thermal, and elastic performance, is a potential candidate for future technologies. However, the superior properties of graphene have not yet been realized for graphenederived macroscopic structures such as graphene fibers. In this study, we systematically investigated the temperature （T ）-dependent transport and thermoelectric properties of graphene fiber, including the thermal conductivity （A）, electrical conductivity （o）, and Seebeck coefficient （S）. A increases from 45.8 to 149.7 W·m^-1·K^-1 and then decreases as T increases from 80 to 290 K, indicating the boundary-scattering and three-phonon Umklapp scattering processes. σ increases with T from 7.1 × 10^4 to 1.18 × 10^5 S·m^-1, which can be best explained by the hopping mechanism. S ranges from -3.9 to 0.8 μV·K^-1 and undergoes a sign transition at approximately 100 K.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.92044303)。
文摘Air pollution in China covers a large area with complex sources and formation mechanisms,making it a unique place to conduct air pollution and atmospheric chemistry research.The National Natural Science Foundation of China’s Major Research Plan entitled“Fundamental Researches on the Formation and Response Mechanism of the Air Pollution Complex in China”(or the Plan)has funded 76 research projects to explore the causes of air pollution in China,and the key processes of air pollution in atmospheric physics and atmospheric chemistry.In order to summarize the abundant data from the Plan and exhibit the long-term impacts domestically and internationally,an integration project is responsible for collecting the various types of data generated by the 76 projects of the Plan.This project has classified and integrated these data,forming eight categories containing 258 datasets and 15 technical reports in total.The integration project has led to the successful establishment of the China Air Pollution Data Center(CAPDC)platform,providing storage,retrieval,and download services for the eight categories.This platform has distinct features including data visualization,related project information querying,and bilingual services in both English and Chinese,which allows for rapid searching and downloading of data and provides a solid foundation of data and support for future related research.Air pollution control in China,especially in the past decade,is undeniably a global exemplar,and this data center is the first in China to focus on research into the country’s air pollution complex.
基金supported by the National Natural Science Foundation of China (Nos. 21325417, 51533008)the MOST National Key Research and Development Plan (2016YFA0200200)+1 种基金the National Postdoctoral Program for Innovative Talents (No. BX201700209)the State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University (No. LK1403)
文摘Nanocarbon-based materials, such as carbon nanotubes(CNTs) and graphene have been attached much attention by scientific and industrial community. As two representative nanocarbon materials, one-dimensional CNTs and twodimensional graphene both possess remarkable mechanical properties. In the past years, a large amount of work have been done by using CNTs or graphene as building blocks for constructing novel, macroscopic, mechanically strong fibrous materials. In this review, we summarize the assembly approaches of CNT-based fibers and graphene-based fibers in chronological order, respectively. The mechanical performances of these fibrous materials are compared, and the critical influences on the mechanical properties are discussed. Personal perspectives on the fabrication methods of CNT-and graphene-based fibers are further presented.
基金supported by the National Natural Science Foundation of China(Nos.51533008,51603183,51703194,51803177,21805242 and 5197030056)National Key R&D Program of China(No.2016YFA0200200)+4 种基金Fujian Provincial Science and Technology Major Projects(No.2018HZ0001-2)Hundred Talents Program of Zhejiang University(No.188020*194231701/113)Key Research and Development Plan of Zhejiang Province(No.2018C01049)the Fundamental Research Funds for the Central Universities(Nos.2017QNA4036,2017XZZX001-04)Foundation of National Key Laboratory on Electromagnetic Environment Effects(No.614220504030717)。
文摘Graphene oxide(GO),an important chemical precursor of graphene,can stably disperse in aqueous surrounding and undergo aggregation as metal cations introduced.The usual instability of GO with ions is caused by the shielding effect of ions and crosslinking between GO and ions.However,the dynamic stability of GO under ions exchange still remains unclear.Here,we investigated the dynamic dispersion stability of GO with metal ions and observed a redispersion behavior in concentrated Fe3+solution,other than permanent aggregation.The exchange with Fe3+ions drives the reversion of zeta(ζ)potential and enables the redispersion to individual GO-Fe3+complex sheets,following a dynamic electric double layer(EDL)mechanism.It is found that the specifically strong electrostatic shielding effect and coordination attraction between Fe3+and functional oxygen groups allows the selective redispersion of GO in concentrated Fe3+solution.The revealed dynamic dispersion stability complements our understanding on the dispersive stability of GO and can be utilized to fabricate graphene-metal hybrids for rich applications.
基金the National Natural Science Foundation(No.52073187)NSAF Foundation(No.U2230202)for their financial support of this project+3 种基金National Natural Science Foundation(No.51721091)Programme of Introducing Talents of Discipline to Universities(No.B13040)State Key Laboratory of Polymer Materials Engineering(No.sklpme2022-2-03)support of China Scholarship Council
文摘Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT aerogel structure shows nano-pore size(30-40 nm),high specific surface area(559 m^(2)g^(−1)),high void fraction(91.7%)and enhanced mechanical property:(1)the nano-pore size is beneficial for efficiently blocking thermal conduction and thermal convection via Knudsen effect(beneficial for infrared(IR)stealth);(2)the heterogeneous interface was beneficial for IR reflection(beneficial for IR stealth)and MWCNT polarization loss(beneficial for electromagnetic wave(EMW)attenuation);(3)the high void fraction was beneficial for enhancing thermal insulation(beneficial for IR stealth)and EMW impedance match(beneficial for EMW attenuation).Guided by the above theoretical design strategy,PVTMS@MWCNT nano-aerogel shows superior EMW absorption property(cover all Ku-band)and thermal IR stealth property(ΔT reached 60.7℃).Followed by a facial combination of the above nano-aerogel with graphene film of high electrical conductivity,an extremely high electromagnetic interference shielding material(66.5 dB,2.06 mm thickness)with superior absorption performance of an average absorption-to-reflection(A/R)coefficient ratio of 25.4 and a low reflection bandwidth of 4.1 GHz(A/R ratio more than 10)was experimentally obtained in this work.
基金The authors gratefully acknowledge the support of National Key Research and Development Program of China(2020YFE0204400)National Natural Science Foundation of China(Nos.52090030,52122301,51973191)+3 种基金Shanxi-Zheda Institute of New Materials and Chemical Engineering(2012SZ-FR004)Hundred Talents Program of Zhejiang University(188020*194231701/113)China Postdoctoral Science Foundation(2021M692772)supported by the Fundamental Research Funds for the Central Universities(Nos.2021FZZX001-17).
文摘Eliminating topological defects to achieve monodomain liquid crystals is highly significant for the fundamental studies of soft matter and building long-range ordered materials.However,liquid crystals are metastable and sensitive to external stimuli,such as flow,confinement,and electromagnetic fields,which cause their intrinsic polycrystallinity and topological defects.Here,we achieve the monodomain liquid crystals of graphene oxide over 30 cm through boundary-free sheargraphy.The obtained monodomain liquid crystals exhibit large-area uniform alignment of sheets,which has the same optical polarized angle and intensity.The monodomain liquid crystals provide bidirectionally ordered skeletons,which can be applied as lightweight thermal management materials with bidirectionally high thermal and electrical conductivity.Furthermore,we extend the controllable topology of two-dimensional colloids by introducing singularities and disclinations in monodomain liquid crystals.Topological structures with defect strength from−2 to+2 were realized.This work provides a facile methodology to study the structural order of soft matter at a macroscopic level,facilitating the fabrication of metamaterials with tunable and highly anisotropic architectures.
基金the National Natural Science Foundation of China(Nos.52272046,52090030,52090031,52122301,51973191)the Natural Science Foundation of Zhejiang Province(LR23E020003)+4 种基金Shanxi-Zheda Institute of New Materials and Chemical Engineering(2021SZ-FR004,2022SZ-TD011,2022SZ-TD012,2022SZ-TD014)Hundred Talents Program of Zhejiang University(188020*194231701/113,112300+1944223R3/003,112300+1944223R3/004)the Fundamental Research Funds for the Central Universities(Nos.226-2023-00023,226-2023-00082,2021FZZX001-17,K20200060)National Key R&D Program of China(NO.2022YFA1205300,NO.2022YFA1205301,NO.2020YFF0204400,NO.2022YFF0609801)“Pioneer”and“Leading Goose”R&D Program of Zhejiang 2023C01190.
文摘Highly thermally conductive graphitic film(GF)materials have become a competitive solution for the thermal management of high-power electronic devices.However,their catastrophic structural failure under extreme alternating thermal/cold shock poses a significant challenge to reliability and safety.Here,we present the first investigation into the structural failure mechanism of GF during cyclic liquid nitrogen shocks(LNS),which reveals a bubbling process characterized by“permeation-diffusion-deformation”phenomenon.To overcome this long-standing structural weakness,a novel metal-nanoarmor strategy is proposed to construct a Cu-modified graphitic film(GF@Cu)with seamless heterointerface.This well-designed interface ensures superior structural stability for GF@Cu after hundreds of LNS cycles from 77 to 300 K.Moreover,GF@Cu maintains high thermal conductivity up to 1088 W m^(−1)K^(−1)with degradation of less than 5%even after 150 LNS cycles,superior to that of pure GF(50%degradation).Our work not only offers an opportunity to improve the robustness of graphitic films by the rational structural design but also facilitates the applications of thermally conductive carbon-based materials for future extreme thermal management in complex aerospace electronics.
基金the support of the National Natural Science Foundation of China(Nos.51803177,51973191,51533008,and 51636002)National Key R&D Program of China(No.2016YFA0200200)+5 种基金the China Postdoctoral Science Foundation(No.2021M690134)Hundred Talents Program of Zhejiang University(188020*194231701/113)Key Research and Development Plan of Zhejiang Province(2018C01049)the National Postdoctoral Program for Innovative Talents(No.BX201700209)the Fundamental Research Funds for the Central Universities(2021FZZX001-17),the Natural Science Foundation of Jiangsu Province(BK20210353)the Fundamental Research Funds for the Central Universities(No.30920041106).
文摘The processing capability is vital for the wide applications of materials to forge structures as-demand.Graphene-based macroscopic materials have shown excellent mechanical and functional properties.However,different from usual polymers and metals,graphene solids exhibit limited deformability and processibility for precise forming.Here,we present a precise thermoplastic forming of graphene materials by polymer intercalation from graphene oxide(GO)precursor.The intercalated polymer enables the thermoplasticity of GO solids by thermally activated motion of polymer chains.We detect a critical minimum containing of intercalated polymer that can expand the interlayer spacing exceeding 1.4 nm to activate thermoplasticity,which becomes the criteria for thermal plastic forming of GO solids.By thermoplastic forming,the flat GO-composite films are forged to Gaussian curved shapes and imprinted to have surface relief patterns with size precision down to 360 nm.The plastic-formed structures maintain the structural integration with outstanding electrical(3.07×10^(5) S m^(−1))and thermal conductivity(745.65 W m^(−1) K^(−1))after removal of polymers.The thermoplastic strategy greatly extends the forming capability of GO materials and other layered materials and promises versatile structural designs for more broad applications.
文摘In this article Florian Puchtler at affiliation‘University of Bayreuth’,Josef Breu at affiliation‘University of Bayreuth’,and Ziliang Wu at affiliation‘Zhejiang University’was missing from the author Min Cao,Senping Liu,Qingli Zhu,Ya Wang,Jingyu Ma,Zeshen Li,Dan Chang,Enhui Zhu,Xin Ming,Florian Puchtler,Josef Breu,Ziliang Wu,Yingjun Liu,Yanqiu Jiang,Zhen Xu,Chao Gao list.
基金supported by the Natural Science Basic Research Program of Shaanxi(Nos.2024JC-YBQN-0580 and 2020JM-599)Shaanxi Province’s Key Research and Development Project(No.2023-YBGY-172)+1 种基金the Scientific Research Program Funded by Education Department of Shaanxi Provincial Government(No.24JK0360)the Graduate Scientific Research Foundation of Shaanxi Univerisity of Technology(No.SLGYCX2401).
文摘The preparation of dense ZrB_(2)-based ceramics typically requires high temperatures and long sintering time,which often result in significant grain coarsening and thus deterioration of mechanical properties.Ultrafast sintering techniques offer a solution to inhibit grain coarsening by reducing the processing time.However,the ultrafast preparation of dense ZrB_(2)-based ceramics remains a challenge.In this work,we successfully fabricated dense ZrB_(2)-based ceramics in just a few minutes using heavy continuous direct current(DC)Joule heating and pressing.Notably,the densification rate peaked at 1218℃,and the densification process was nearly complete at a relatively low temperature of 1500℃.The application of heavy continuous direct current not only promotes the densification of the ceramics but also enhances the texturization of ZrB_(2).This results in optimally aligned ZrB_(2) grains that form a three-dimensional bonded skeletal network.These unique microstructures can effectively induce multi-stage fracture surfaces during failure,which helps synergistic strengthening and toughening of the ceramics.The ceramics exhibit remarkable comprehensive mechanical properties,with flexural strength and fracture toughness values reaching 773±114 MPa and 5.88±0.08 MPa·m^(1/2),respectively,surpassing those of conventional hot pressed samples.This technique is expected to be applied to other ultra-high temperature ceramics,providing a promising approach for the development of thermal protection materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.52090031,52090030 and 52272046)National Key Research and Development Program of China(Grant Nos.2022YFA1205300 and 2022YFA1205301)+4 种基金"Pioneer"and"Leading Goose"R&D Program of Zhejiang(Grant No.2023C01190)Natural Science Foundation of Zhejiang Province(Grant No.LR23E020003)Fundamental Research Funds for the Central Universities(Grant Nos.226-2024-00074 and 226-2024-00172)Shanxi-Zheda Institute of New Materials and Chemical Engineering(Grant Nos.2022SZ-TD011,2022SZ-TD012 and 2022SZ-TD014)the fellowship of China National Postdoctoral Program for Innovative Talents(Grant No.BX20230309).
文摘Enhancing the mechanical performance of synthetic fibers is pursued in aerospace,wearable devices,and protective textiles.However,current reinforcement methods rely on the chemical modification of polymer stock,introducing greater complexity and processing challenge.In this work,the mechanical properties of different aramid fibers and their composite fibers are improved through a cool spinning strategy.By reducing the coagulation temperature to -25℃,the interactions between polymer chains and solvent molecules are substantially enhanced,thereby improving the drawability of the polymer solution.The draw ratio markedly increases typically from 200% to 380%,leading to optimized oriented and crystalline structures.Consequently,the tensile strength,Young’s modulus and toughness of large-diameter heterocyclic para-aramid fibers increase by 112%,123% and 118%,respectively.The cool spinning proposal is further applied to 36-μm-thick heterocyclic paraaramid/graphene oxide composite fibers,realizing elevated tensile strength,Young’s modulus and toughness of 6.28 GPa,119.62 GPa and 172.7 MJ·m^(-3),respectively.This strategy is also applicable to meta-aramid fibers,where tensile strength increases up to 1.35 GPa.The simple and universal cool spinning approach opens an avenue towards the preparation of high-performance fibers and composite fibers for structural and functional applications.
基金supported by the MOE Key Laboratory of Macromolecular Synthesis and Functionalization, the International Research Center for X Polymers, the National Natural Science Foundation of China (51973191, 52272046 and 52090030)Shanxi-Zheda Institute of New Materials and Chemical Engineering (2011SZ-FR004 and 2022SZ-TD011)+6 种基金the Hundred Talents Program of Zhejiang University (188020*194231701/ 113)Fujian Provincial Science and Technology Major Projects (2018HZ0001-2)the Fundamental Research Funds for the Central Universities (K20200060 and 2021FZZX001-17)the Key Laboratory of Novel Adsorption and Separation Materials and Application Technology of Zhejiang Province (512301-I21502)China Postdoctoral Science Foundation (2021M702788)the Postdoctoral Research Program of Zhejiang Province (ZJ2021145)the Devices of the Ministry of Education NJ2020003 (INMD-2021M06)。
文摘石墨烯气凝胶(GAs)在解决下一代电子器件电磁屏蔽污染方面引起了广泛关注.但是,由于超轻石墨烯气凝胶在复杂环境中结构不稳定,其在电磁屏蔽的实际应用中仍面临巨大的挑战.在此,我们提出一类机械结构稳定的石墨烯气凝胶,其展示出优异可靠的电磁屏蔽性能.这类气凝胶呈现出面面堆叠的结构,在密度ρ=3.7 mg cm-3,高度1 m m时,电磁屏蔽效能可达到64.1 d B,比电磁屏蔽效能达到173,243 dB cm2g-1,远超现有报道的碳基材料.同时,石墨烯气凝胶具有优异的环境适应性,在机械形变、极端温度、燃烧及水下等环境中均可保持性能稳定.此外,制备的石墨烯气凝胶可通过真空袋装工艺进行包装运输,解决了超轻材料实际应用中低密度与大体积的矛盾,且在这一极端变形过程中材料结构和性能均未产生破坏.该研究为石墨烯气凝胶电磁屏蔽材料的实际应用铺平了道路,且拓展了其实际应用场景,比如航天、军事战机及海洋领域.
基金by grants from the National Key Basic Research Program of China(2011CB504102)Natural Science Foundation of China(31430036,31123002,31321091).
文摘Parkinson’s disease(PD),the second most common age-associated neurodegenerative disorder,is characterized by the loss of dopaminergic(DA)neurons and the presence ofα-synuclein-containing aggregates in the substantia nigra pars compacta(SNpc).Chronic neuroinflammation is one of the hallmarks of PD pathophysiology.Postmortem analyses of human PD patients and experimental animal studies indicate that activation of glial cells and increases in pro-inflammatory factor levels are common features of the PD brain.Chronic release of proinflammatory cytokines by activated astrocytes and microglia leads to the exacerbation of DA neuron degeneration in the SNpc.Besides,peripheral immune system is also implicated in the pathogenesis of PD.Infiltration and accumulation of immune cells from the periphery are detected in and around the affected brain regions of PD patients.Moreover,inflammatory processes have been suggested as promising interventional targets for PD and even other neurodegenerative diseases.A better understanding of the role of inflammation in PD will provide new insights into the pathological processes and help to establish effective therapeutic strategies.In this review,we will summarize recent progresses in the neuroimmune aspects of PD and highlight the potential therapeutic interventions targeting neuroinflammation.
基金supported by research fund for the China Postdoctoral Science Foundation(2016M600201,2018T110214,2016M601304)National Natural Science Foundation of China(51805069)+1 种基金Natural Science Foundation of Liaoning Province,China(20170540154)Aviation Science Foundation of China(2016ZF63007).
文摘Self-toughening ZrB2–SiC based composites are fabricated by in-situ reactive hot pressing.The effect of sintering additive content on the microstructure and mechanical properties of the composites is investigated.Microstructure observation found that the in-situ reactive hot pressing could promote the anisotropic growth of ZrB2 grains and the formation of interlocking microstructure.Such microstructure could improve the mechanical properties,especially,for the fracture toughness.The improved mechanical properties could be attributed to the self-toughening structure related to the ZrB2 platelets and the formed interlocking microstructure,which could trigger various toughening mechanisms such as grain pull-out,crack bridging,crack deflection,and crack branching,providing the main contribution to the high fracture toughness.
文摘Tribenuron-methyl （TM） is a powerful sulfonylurea herbicide that inhibits branched-chain amino acid （BCAA） biosynthesis by targeting the catalytic subunit （CSR1） of acetolactate synthase （ALS）. Selective in- duction of male sterility by foliar spraying of TM at low doses has been widely used for hybrid seed produc- tion in rapeseed （Brassica napus）; however, the underlying mechanism remains unknown. Here, we report greater TM accumulation and subsequent stronger ALS inhibition and BCAA starvation in anthers than in leaves and stems after TM application. Constitutive or anther-specific expression of csrl-lD （a CSR1 mutant） eliminated anther-selective ALS inhibition and reversed the TM-induced male sterile phenotype in both rapeseed and Arabidopsis. The results of TM daub-stem experiments, combined with the observations of little TM accumulation in anthers and reversion of TM-induced male sterility by targeted expression of the TM metabolism gene Bel in either the mesophyll or phloem, suggested that foliar-sprayed TM was polar-transported to anthers mainly through the mesophyll and phloem. Microscopy and immunoblotting revealed that autophagy, a bulk degradation process induced during cell death, was elevated in TM-induced male sterile anthers and by anther-specific knockdown of ALS. Moreover, TM-induced pollen abortion was significantly inhibited by the autophagy inhibitor 3-MA. These data suggested that TM was polar-transported to anthers, resulting in BCAA starvation via anther-specific ALS inhibition and, ulti- mately, autophagic cell death in anthers.
基金the Shanghai Synchrotron Radiation Facility(SSRF)for assistance in SAXS characterizations.This work is supported by the National Natural Science Foundation of China(Nos.52090030,52122301,51973191,52272046 and 51533008)the Natural Science Foundation of Zhejiang Province(LR23E020003)+4 种基金the Fundamental Research Funds for the Central Universities(No.K20200060,2017QNA4036,2017XZZX001-04,226-2023-00023,2021FZZX001-17)Hundred Talents Program of Zhejiang University(188020*194231701/113)Postdoctoral Research Program of Zhejiang province(ZJ2022079)Shanxi-Zheda Institute of New Materials and Chemical Engineering(Nos.2022SZ-TD012,2022SZ-TD011 and 2021SZ-FR004)the International Research Center for X polymers.
文摘Graphene aerogel fibers(GAFs)combine the advantages of lightweight,high specific strength and conductivity of graphene,showing great potential in multifunctional wearable textiles.However,the fabrication and application of GAF textiles are considerably limited by the low structural robustness of GAF.Here,we report a plastic-swelling method to fabricate GAF textiles with high performance and multi-functionalities.GAF textiles were achieved by plastic-swelling,the prewoven graphene oxide fiber(GOF)tow textiles.This near-solid plastic-swelling process allows GAFs in textiles to maintain high structural order and controllable density,and exhibit record-high tensile strength up to 103 MPa and electrical conductivity up to 1.06.104 S m−1 at the density of 0.4 g cm−3.GAF textiles exhibit high strength of 113 MPa,multiple electrical and thermal functions,and high porosity to serve as host materials for more functional vips.The plastic-swelling provides a general strategy to fabricate diverse aerogel fiber textiles,paving the road for their realistic application.
基金This work was supported by grants from startup supports of Soochow University and the Program for Jiangsu Specially-Appointed Professors.This work was also supported by the National Natural Science Foundation of China(No.31900988)the Natural Science Foundation of Jiangsu Province(No.SBK2019040088).
文摘The enhanced permeability retention(EPR)effect based nanomedicine has been widely used for tumor targeting during the past decades.Here we unexpectedly observed the similar"EPR effect"at the site of iniury.We found that the temporary dilated and leaky blood vessels caused by the potent vasodilator histamine in response to injury allowed the injected nanoparticles to pass through the vasculature and reached the injured tissue.Our finding shows the potential underline mechanism of"EPR effect"at the injured site.By loading with antibiotics,we further demonstrated a new strategy for prevention of infection at the site of injury.
基金This work was supported by the National Natural Science Foundation of China （Nos. 51406236, 51576105, 51327001, 51336009, 51636002, 21325417 and 51533008）, the Science Foundation of China University of Petroleum, Beijing （Nos. 2462013YJRC027, and 2462015YQ0402）, the Science Fund for Creative Research Groups （No. 51321002）, and Tsinghua University Initiative Scientific Research Program.
文摘Graphene, a two-dimensional material with extraordinary electrical, thermal, and elastic performance, is a potential candidate for future technologies. However, the superior properties of graphene have not yet been realized for graphenederived macroscopic structures such as graphene fibers. In this study, we systematically investigated the temperature （T ）-dependent transport and thermoelectric properties of graphene fiber, including the thermal conductivity （A）, electrical conductivity （o）, and Seebeck coefficient （S）. A increases from 45.8 to 149.7 W·m^-1·K^-1 and then decreases as T increases from 80 to 290 K, indicating the boundary-scattering and three-phonon Umklapp scattering processes. σ increases with T from 7.1 × 10^4 to 1.18 × 10^5 S·m^-1, which can be best explained by the hopping mechanism. S ranges from -3.9 to 0.8 μV·K^-1 and undergoes a sign transition at approximately 100 K.
