Quasi-solid electrolytes(QSEs)based on nanoporous materials are promising candidates to construct high-performance Limetal batteries(LMBs).However,simultaneously boosting the ionic conductivity(σ)and lithium-ion tran...Quasi-solid electrolytes(QSEs)based on nanoporous materials are promising candidates to construct high-performance Limetal batteries(LMBs).However,simultaneously boosting the ionic conductivity(σ)and lithium-ion transference number(t^(+)) of liquid electrolyte confined in porous matrix remains challenging.Herein,we report a novel Janus MOFLi/MSLi QSEs with asymmetric porous structure to inherit the benefits of both mesoporous and microporous hosts.This Janus QSE composed of mesoporous silica and microporous MOF exhibits a neat Li^(+) conductivity of 1.5.10^(–4)S cm^(−1) with t^(+) of 0.71.A partially de-solvated structure and preference distribution of Li^(+)near the Lewis base O atoms were depicted by MD simulations.Meanwhile,the nanoporous structure enabled efficient ion flux regulation,promoting the homogenous deposition of Li^(+).When incorporated in Li||Cu cells,the MOFLi/MSLi QSEs demonstrated a high Coulombic efficiency of 98.1%,surpassing that of liquid electrolytes(96.3%).Additionally,NCM 622||Li batteries equipped with MOFLi/MSLi QSEs exhibited promising rate performance and could operate stably for over 200 cycles at 1 C.These results highlight the potential of Janus MOFLi/MSLi QSEs as promising candidates for next-generation LMBs.展开更多
The practical applications of zinc metal batteries are plagued by the dendritic propagation of its metal anodes due to the limited transfer rate of charge and mass at the electrode/electrolyte interphase.To enhance th...The practical applications of zinc metal batteries are plagued by the dendritic propagation of its metal anodes due to the limited transfer rate of charge and mass at the electrode/electrolyte interphase.To enhance the reversibility of Zn metal,a quasi-solid interphase composed by defective metal-organic framework(MOF)nanoparticles(D-UiO-66)and two kinds of zinc salts electrolytes is fabricated on the Zn surface served as a zinc ions reservoir.Particularly,anions in the aqueous electrolytes could be spontaneously anchored onto the Lewis acidic sites in defective MOF channels.With the synergistic effect between the MOF channels and the anchored anions,Zn^(2+)transport is prompted significantly.Simultaneously,such quasi-solid interphase boost charge and mass transfer of Zn^(2+),leading to a high zinc transference number,good ionic conductivity,and high Zn^(2+)concentration near the anode,which mitigates Zn dendrite growth obviously.Encouragingly,unprecedented average coulombic efficiency of 99.8%is achieved in the Zn||Cu cell with the proposed quasi-solid interphase.The cycling performance of D-UiO-66@Zn||MnO_(2)(~92.9%capacity retention after 2000 cycles)and D-UiO-66@Zn||NH_(4)V_(4)O_(10)(~84.0%capacity retention after 800 cycles)prove the feasibility of the quasi-solid interphase.展开更多
A robust solid-electrolyte interphase(SEI)enabled by electrolyte additive is a promising approach to stabilize Li anode and improve Li cycling efficiency.However,the self-sacrificial nature of SEI forming additives li...A robust solid-electrolyte interphase(SEI)enabled by electrolyte additive is a promising approach to stabilize Li anode and improve Li cycling efficiency.However,the self-sacrificial nature of SEI forming additives limits their capability to stabilize Li anode for long-term cycling.Herein,we demonstrate nanocapsules made from metal–organic frameworks for sustained release of LiNO3 as surface passivation additive in commercial carbonate-based electrolyte.The nanocapsules can offer over 10 times more LiNO3 than the solubility of LiNO3.Continuous supply of LiNO3 by nanocapsules forms a nitride-rich SEI layer on Li anode and persistently remedies SEI during prolonged cycling.As a result,lifespan of thin Li anode in 50μm,which experiences drastic volume change and repeated SEI formation during cycling,has been notably improved.By pairing with an industry-level thick LiCoO2 cathode,practical Li-metal full cell demonstrates a remarkable capacity retention of 90%after 240 cycles,in contrast to fast capacity drop after 60 cycles in LiNO3 saturated electrolyte.展开更多
High-energy Li-metal batteries (LMBs) suffer from short cycle life and safety issues due to severe parasitic reactions and dendrite growth of Li metal anode (LMA) in liquid electrolytes [1–3].It is generally believed...High-energy Li-metal batteries (LMBs) suffer from short cycle life and safety issues due to severe parasitic reactions and dendrite growth of Li metal anode (LMA) in liquid electrolytes [1–3].It is generally believed that replacing liquid electrolytes with solidstate electrolytes (SSEs) would be a feasible approach for practical LMBs [4,5]. Conventional SSEs including ceramic and polymer electrolytes have been studied for decades.展开更多
Electrochemical CO_(2)reduction reaction(CO_(2)RR)to multi-carbon products would simultaneously reduce CO_(2)emission and produce high-value chemicals.Herein,we report Cu electrodes modified by metal–organic framewor...Electrochemical CO_(2)reduction reaction(CO_(2)RR)to multi-carbon products would simultaneously reduce CO_(2)emission and produce high-value chemicals.Herein,we report Cu electrodes modified by metal–organic framework(MOF)exhibiting enhanced electrocatalytic performance to convert CO_(2) into ethylene and ethanol.The Zr-based MOF,UiO-66 would in situ transform into amorphous ZrOx nanoparticles(a-ZrO_(x)),constructing a-ZrOx/Cu hetero-interface as a dual-site catalyst.The Faradaic efficiency of multi-carbon(C2+)products for optimal UiO-66-coated Cu(0.5-UiO/Cu)electrode reaches a high value of 74%at−1.05 V versus RHE.The intrinsic activity for C2+products on 0.5-UiO/Cu electrode is about two times higher than that of Cu foil.In situ surface-enhanced Raman spectra demonstrate that UiO-66-derived a-ZrO_(x)coating can promote the stabilization of atop-bound CO^(*)intermediates on Cu surface during CO_(2)electrolysis,leading to increased CO^(*)coverage and facilitating the C–C coupling process.The present study gives new insights into tailoring the adsorption configurations of CO_(2)RR intermediate by designing dual-site electrocatalysts with hetero-interfaces.展开更多
We analyze continuous waveform data from 257 broadband stations of the portable seismic array deployed under the "China Seismic Array-northern part of NS seismic belt" project as well as data from a permanen...We analyze continuous waveform data from 257 broadband stations of the portable seismic array deployed under the "China Seismic Array-northern part of NS seismic belt" project as well as data from a permanent seismic network from January 2014 to December 2015. The phase velocity dispersion curve of 7,185 Rayleigh waves is obtained with a method based on the image analysis of phase velocity extraction, and the inversion is obtained. The period of Rayleigh wave phase velocity distribution has a range of 5–40 s, and minimum resolution close to 20 km. The results show that the phase velocity structure image well reflects the geological structural characteristics of the crust and uppermost mantle, and that the phase velocity distribution has obvious lateral heterogeneity. The phase velocity of the 5–15 s period is closely linked to the surface layer and sedimentary layer, the low-velocity anomalies correspond to loose sedimentary cover, and the high-velocity anomalies correspond to orogenic belts and uplifts and the boundary between high and low velocity anomalies is consistent with the block boundary. The phase velocity of the 5–15 s period is strongly affected by the crust layer thickness, the northeastern Tibetan plateau has low-velocity anomalies in the middle to lower crust, the west side of the Ordos block is consistent with the northeastern Tibetan plateau, which may imply the material exchange and fusion in this area. The velocity variation is inversely related to the Moho depth in the 40 s period of Swave, and the lateral velocity heterogeneity represents the lateral variation of the Moho depth. The Ordos block and the northern margin of Sichuan basin are located in the uppermost mantle at this depth, and the depth in the transition zone is still located in the lower crust.展开更多
Hyperthermal environments can harm workers’health and safety.However,it is difficult to include effective protection into standards because heat-related impacts vary significantly accord-ing to individual workers and...Hyperthermal environments can harm workers’health and safety.However,it is difficult to include effective protection into standards because heat-related impacts vary significantly accord-ing to individual workers and multiple factors.Studies suggested obvious relationship between en-vironment condition and bio-electricity signal,including electroencephalogram(EEG)signal.We used a detector with 64 electrodes to perform dedicated EEG measurements of nine individual sub-jects to analyze human cerebral activity under hyperthermal(35℃,80%RH)and standard condi-tions(25℃,30%RH).Amplitude changes of the frequency wavebands were analyzed using statist-ical analysis.Seven participants showed increasing beta activity due to high temperature and high humidity in the primary somatosensory cortex(electrode C3)and the temporopolar region(elec-trode FT 8).The amplitude value of alpha wave is increased from 0.194 to 0.213 while the amp-litude value of beta wave is increased from 0.144 to 0.160.Value is decreased due to hyperthermal environment for most people.The results of this study could be used to inform the development of wearable equipment to monitor the health of on-site workers,which is fundamental to improve worker safety and wellbeing.展开更多
Lithium-metal batteries(LMBs)based on high-voltage cathodes would deliver high specific energy density to meet the demand of future energy storage.However,developing liquid electrolytes with wide electrochemical windo...Lithium-metal batteries(LMBs)based on high-voltage cathodes would deliver high specific energy density to meet the demand of future energy storage.However,developing liquid electrolytes with wide electrochemical window for high-energy LMBs is intrinsically challenging.Herein,we demonstrate metal-organic framework-functionalized separators(PE@MOF)with solvent sieving capability that implement dual electrolyte for LMBs.The capability of PE@MOF separator to block the diffusion of liquid electrolytes has been investigated.The PE@MOF separator notably suppresses solvents shuttling,enabling the independent optimization of cathode-electrolyte and anode-electrolyte interfaces.By adapting commercial carbonate and ether electrolytes on cathode and anode sides,respectively,robust cathode-electrolyte interphase(CEI)and solid electrolyte interface(SEI)have been built on both electrodes.The lifespan of LiCoO_(2)(LCO)|Li full cell has been notably extended when using dual electrolyte and the solvent-sieving PE@MOF separator.This work demonstrates a new strategy to separately optimize the local environments at electrodes and to develop high-energy LMBs using low-cost and commercially available electrolytes.展开更多
Cu-based catalysts have attracted widespread attention for its capability in electrocatalytically reducing CO_(2)to a variety of products.Surface modification of Cu has become an interesting method for tuning the cata...Cu-based catalysts have attracted widespread attention for its capability in electrocatalytically reducing CO_(2)to a variety of products.Surface modification of Cu has become an interesting method for tuning the catalytic performance.Here,we use Zrbased metal-organic layers(MOLs)as the additive of the Cu surface,which enhanced the Faradaic efficiency of CH4 by two times as compared to the untreated polycrystalline Cu foil.Unexpectedly,the MOLs were found to induce in situ nano-structuring of the Cu foil surface within seconds in the electrolysis,as revealed by a combination of scanning electron microscopy(SEM),grazing incidence X-ray diffractometry(GIXRD),and linear sweep voltammetry(LSV)measurements.These surface changes are responsible for the shift of product selectivity.Control experiments suggest that negatively chargedμ3-O−on the Zr-cluster in the MOL might interact with CO-covered Cu surface and induce roughing and nano-structuring.This work reveals a potential role of additive on Cu to induce surface nano-structuring that tunes catalytic activity and selectivity.展开更多
Zhengzhou is a developing city in China, that is heavily polluted by high levels of particulate matter. In this study, fine particulate matter (PM2.5) was collected and analyzed for their chemical composition (solu...Zhengzhou is a developing city in China, that is heavily polluted by high levels of particulate matter. In this study, fine particulate matter (PM2.5) was collected and analyzed for their chemical composition (soluble ions, elements, elemental carbon (EC) and organic carbon (OC)) in an industrial district of Zhengzhou in 2010. The average concentrations of PM2.5 were 181, 122, 186 and 211 μg/m3 for spring, summer, autumn and winter, respectively, with an annual average of 175 μg/m3, far exceeding the PM2.5 regulation of USA National Air Quality Standards (15 μg/m3). The dominant components of PM2.5 in Zhengzhou were secondary ions (sulphate and nitrate) and carbon fractions. Soluble ions, total carbon and elements contributed 41%, 13% and 3% of PM2.5 mass, respectively. Soil dust, secondary aerosol and coal combustion, each contributing about 26%, 24% and 23% of total PM2.5 mass, were the major sources of PM2.5, according to the result of positive matrix factorization analysis. A mixed source of biomass burning, oil combustion and incineration contributed 13% of PM2.5. Fine particulate matter arising from vehicles and industry contributed about 10% and 4% of PM2.5, respectively.展开更多
Owing to their unique short-or medium-range ordered microstructures and excellent mechanical, physical, and chemical properties, amorphous alloys have attracted significant interest in recent years. For the applicatio...Owing to their unique short-or medium-range ordered microstructures and excellent mechanical, physical, and chemical properties, amorphous alloys have attracted significant interest in recent years. For the application of amorphous alloys, clarifying their oxidation processes and mechanisms is necessary since many of the surface-related properties of amorphous alloys largely depend on the surface oxide layer.The aim of this paper is to review the recent research on the thermal oxidation behaviors of amorphous alloys under pure oxygen or air condition. The contents are divided into three categories according to the number of components the research considers, i.e., the oxidation of binary, ternary, and multi-component(〉3) amorphous alloys. Each section discusses the thermal stability of the amorphous matrix, oxidation kinetics, and the oxide layer and amorphous substrate, which are strongly affected by internal factors(i.e., alloy elements and microstructure) and external factors(i.e., oxidation temperature, duration, and oxygen partial pressure, etc.). The general features of the oxidation of amorphous alloys – from simple binary to complex multi-component amorphous alloys – will be summarized. This overview of the current scientific understanding on the fundamentals of these materials may provide guidelines for the development of strongly corrosion-resistant amorphous alloys.展开更多
High silicon content Al-Si composites with a composition of Al-40 wt% Si were fabricated via a highenergy ball milling method. The microstructure evolution of Al-40 wt% Si milled powders and sintered composites has be...High silicon content Al-Si composites with a composition of Al-40 wt% Si were fabricated via a highenergy ball milling method. The microstructure evolution of Al-40 wt% Si milled powders and sintered composites has been thoroughly studied by scanning electron microscopy, X-ray diffraction, energydispersive spectrometry and high-resolution transmission electron microscopy. The mechanism of ball milling Al-40 wt% Si powders has been disclosed in detail: fracture mechanism dominating in the early stages, followed by the agglomeration mechanism, finally reaching the balance between the fragments and the agglomerates. It has been found that the average particle sizes of mixed Al-Si powders can be refined to the nanoscale, and the crystallite sizes of Al and Si have been reduced to 10nm and 62nm upon milling for 2h–50h, respectively. The finally formed Al-Si interfaces after ball milling for 50h are wellcohesive. A dense and homogenous Al-40 wt% Si composite have been achieved by solid-state sintering at550?C. The results thus provide an effective support for producing bulk nanostructured Al-Si composites.展开更多
The effect of structural order in the parent alloy substrate on the oxidation kinetics and oxide phase evolution was investigated for the thermal oxidation of amorphous Cu33at.%Zr67at.%and crystalline CuZr2 alloys of ...The effect of structural order in the parent alloy substrate on the oxidation kinetics and oxide phase evolution was investigated for the thermal oxidation of amorphous Cu33at.%Zr67at.%and crystalline CuZr2 alloys of identical compositions in the temperature range of 200–250?C.It was found that,besides the strong preferential oxidation of Zr in both alloys,the lack of structural order in the amorphous Cu33at.%Zr67at.%alloy results in much slower oxidation kinetics,as well as in distinctly different microstructures of the oxide overgrowth and its Zr-depletion zone in the wake of the ZrO2 overlayer growth front.The experimental findings can be rationalized on the basis of the strikingly different atomic mobilities of Cu,Zr and dissolved O in the amorphous and crystalline alloys,which also results in different nucleation barriers for crystalline oxide nucleation.The thus obtained knowledge on the underlying oxidation mechanisms provides new and profound insights into the surface engineering of metallic alloys.展开更多
The thermal oxidation of ZrAl2 in the temperature range of 550–750℃ in pure oxygen has been investigated by a combinational experimental approach using X-ray diffraction, scanning electron microscopy/energy dispersi...The thermal oxidation of ZrAl2 in the temperature range of 550–750℃ in pure oxygen has been investigated by a combinational experimental approach using X-ray diffraction, scanning electron microscopy/energy dispersive spectrometer, Auger electron spectroscopy and cross-sectional transmission electron microscopy. The thermal oxidation leads to the growth of anomalously thick(up to 4.5 μm)amorphous(Zr0.33 Al0.67)O1.66 surficial layers at temperatures as high as 750℃. The oxidation kinetics obeys a parabolic law with an activation energy of 143 kJ/mol. The underlying mechanism for the formation of such micrometer-thick amorphous oxide surficial layers has been discussed on the basis of interface thermodynamics and the occurrence of high interface stability associated with a synchronous oxidation of Al and Zr elements.展开更多
Dear Editor,Influenza A viruses(IAVs)are single-stranded,negative sense RNA viruses.IAV subtype is determined on the basis of the viral surface glycoproteins,hemagglutinin(HA),and neuraminidase(NA).To date,18 HA and 1...Dear Editor,Influenza A viruses(IAVs)are single-stranded,negative sense RNA viruses.IAV subtype is determined on the basis of the viral surface glycoproteins,hemagglutinin(HA),and neuraminidase(NA).To date,18 HA and 11NA subtypes have been reported(Tong et al.,2012).展开更多
Plant root hairs are essential for mineral and water absorption,which possess sophisticated sensory mechanisms to allow them to respond to different environmental signals.Ammonium(NH^(+))is a major form of nitrogen in...Plant root hairs are essential for mineral and water absorption,which possess sophisticated sensory mechanisms to allow them to respond to different environmental signals.Ammonium(NH^(+))is a major form of nitrogen in the soil.NH^(+)can influence the root system architecture,such as root hair growth(Liu and von Wir en,2017).展开更多
Human infection with Chlamydia psittaci is rare but difficult to recognize.We report an outbreak of psittacosis among poultry processing workers in China.We applied metagenomic next-generation sequencing and identifie...Human infection with Chlamydia psittaci is rare but difficult to recognize.We report an outbreak of psittacosis among poultry processing workers in China.We applied metagenomic next-generation sequencing and identified Chlamydia psittaci reads from samples of all seven patients,four of which were subsequently confirmed by PCR.Epidemiological results suggested that the poultry processed in the factory was the possible source of human infection.展开更多
基金supported by National Natural Science Foundation of China(Grant No.22005266)Zhejiang Provincial Natural Science Foundation(Grant No.LR21E020003)“the Fundamental Research Funds for the Central Universities”(2021FZZX001-09).
文摘Quasi-solid electrolytes(QSEs)based on nanoporous materials are promising candidates to construct high-performance Limetal batteries(LMBs).However,simultaneously boosting the ionic conductivity(σ)and lithium-ion transference number(t^(+)) of liquid electrolyte confined in porous matrix remains challenging.Herein,we report a novel Janus MOFLi/MSLi QSEs with asymmetric porous structure to inherit the benefits of both mesoporous and microporous hosts.This Janus QSE composed of mesoporous silica and microporous MOF exhibits a neat Li^(+) conductivity of 1.5.10^(–4)S cm^(−1) with t^(+) of 0.71.A partially de-solvated structure and preference distribution of Li^(+)near the Lewis base O atoms were depicted by MD simulations.Meanwhile,the nanoporous structure enabled efficient ion flux regulation,promoting the homogenous deposition of Li^(+).When incorporated in Li||Cu cells,the MOFLi/MSLi QSEs demonstrated a high Coulombic efficiency of 98.1%,surpassing that of liquid electrolytes(96.3%).Additionally,NCM 622||Li batteries equipped with MOFLi/MSLi QSEs exhibited promising rate performance and could operate stably for over 200 cycles at 1 C.These results highlight the potential of Janus MOFLi/MSLi QSEs as promising candidates for next-generation LMBs.
基金supported by Zhejiang University K.P.Chao’s High Technology Development Foundation.
文摘The practical applications of zinc metal batteries are plagued by the dendritic propagation of its metal anodes due to the limited transfer rate of charge and mass at the electrode/electrolyte interphase.To enhance the reversibility of Zn metal,a quasi-solid interphase composed by defective metal-organic framework(MOF)nanoparticles(D-UiO-66)and two kinds of zinc salts electrolytes is fabricated on the Zn surface served as a zinc ions reservoir.Particularly,anions in the aqueous electrolytes could be spontaneously anchored onto the Lewis acidic sites in defective MOF channels.With the synergistic effect between the MOF channels and the anchored anions,Zn^(2+)transport is prompted significantly.Simultaneously,such quasi-solid interphase boost charge and mass transfer of Zn^(2+),leading to a high zinc transference number,good ionic conductivity,and high Zn^(2+)concentration near the anode,which mitigates Zn dendrite growth obviously.Encouragingly,unprecedented average coulombic efficiency of 99.8%is achieved in the Zn||Cu cell with the proposed quasi-solid interphase.The cycling performance of D-UiO-66@Zn||MnO_(2)(~92.9%capacity retention after 2000 cycles)and D-UiO-66@Zn||NH_(4)V_(4)O_(10)(~84.0%capacity retention after 800 cycles)prove the feasibility of the quasi-solid interphase.
基金HBW acknowledges the funding support from“Hundred Talents Program”of Zhejiang University and International Joint Laboratory of Chinese Education Ministry on Resource Chemistry at Shanghai Normal University.
文摘A robust solid-electrolyte interphase(SEI)enabled by electrolyte additive is a promising approach to stabilize Li anode and improve Li cycling efficiency.However,the self-sacrificial nature of SEI forming additives limits their capability to stabilize Li anode for long-term cycling.Herein,we demonstrate nanocapsules made from metal–organic frameworks for sustained release of LiNO3 as surface passivation additive in commercial carbonate-based electrolyte.The nanocapsules can offer over 10 times more LiNO3 than the solubility of LiNO3.Continuous supply of LiNO3 by nanocapsules forms a nitride-rich SEI layer on Li anode and persistently remedies SEI during prolonged cycling.As a result,lifespan of thin Li anode in 50μm,which experiences drastic volume change and repeated SEI formation during cycling,has been notably improved.By pairing with an industry-level thick LiCoO2 cathode,practical Li-metal full cell demonstrates a remarkable capacity retention of 90%after 240 cycles,in contrast to fast capacity drop after 60 cycles in LiNO3 saturated electrolyte.
基金the funding support from “Hundred Talents Program” of Zhejiang University and International Joint Laboratory of Chinese Education Ministry on Resource Chemistry at Shanghai Normal Universitythe National Natural Science Foundation of China (No. 91961126) for funding this work。
文摘High-energy Li-metal batteries (LMBs) suffer from short cycle life and safety issues due to severe parasitic reactions and dendrite growth of Li metal anode (LMA) in liquid electrolytes [1–3].It is generally believed that replacing liquid electrolytes with solidstate electrolytes (SSEs) would be a feasible approach for practical LMBs [4,5]. Conventional SSEs including ceramic and polymer electrolytes have been studied for decades.
基金the funding support from Natural Science Foundation of Zhejiang Province (Grant No. LR21E020003)National Natural Science Foundation of China (Grant No. 22005266)“the Fundamental Research Funds for the Central Universities” (2021FZZX001-09)
文摘Electrochemical CO_(2)reduction reaction(CO_(2)RR)to multi-carbon products would simultaneously reduce CO_(2)emission and produce high-value chemicals.Herein,we report Cu electrodes modified by metal–organic framework(MOF)exhibiting enhanced electrocatalytic performance to convert CO_(2) into ethylene and ethanol.The Zr-based MOF,UiO-66 would in situ transform into amorphous ZrOx nanoparticles(a-ZrO_(x)),constructing a-ZrOx/Cu hetero-interface as a dual-site catalyst.The Faradaic efficiency of multi-carbon(C2+)products for optimal UiO-66-coated Cu(0.5-UiO/Cu)electrode reaches a high value of 74%at−1.05 V versus RHE.The intrinsic activity for C2+products on 0.5-UiO/Cu electrode is about two times higher than that of Cu foil.In situ surface-enhanced Raman spectra demonstrate that UiO-66-derived a-ZrO_(x)coating can promote the stabilization of atop-bound CO^(*)intermediates on Cu surface during CO_(2)electrolysis,leading to increased CO^(*)coverage and facilitating the C–C coupling process.The present study gives new insights into tailoring the adsorption configurations of CO_(2)RR intermediate by designing dual-site electrocatalysts with hetero-interfaces.
基金supported by the Science for Earthquake Resilience(Nos.XH17035YSX and XH19041Y)Navigation and Innovation Fund of Shaanxi Earthquake Agency of 2018(No.QC201805)
文摘We analyze continuous waveform data from 257 broadband stations of the portable seismic array deployed under the "China Seismic Array-northern part of NS seismic belt" project as well as data from a permanent seismic network from January 2014 to December 2015. The phase velocity dispersion curve of 7,185 Rayleigh waves is obtained with a method based on the image analysis of phase velocity extraction, and the inversion is obtained. The period of Rayleigh wave phase velocity distribution has a range of 5–40 s, and minimum resolution close to 20 km. The results show that the phase velocity structure image well reflects the geological structural characteristics of the crust and uppermost mantle, and that the phase velocity distribution has obvious lateral heterogeneity. The phase velocity of the 5–15 s period is closely linked to the surface layer and sedimentary layer, the low-velocity anomalies correspond to loose sedimentary cover, and the high-velocity anomalies correspond to orogenic belts and uplifts and the boundary between high and low velocity anomalies is consistent with the block boundary. The phase velocity of the 5–15 s period is strongly affected by the crust layer thickness, the northeastern Tibetan plateau has low-velocity anomalies in the middle to lower crust, the west side of the Ordos block is consistent with the northeastern Tibetan plateau, which may imply the material exchange and fusion in this area. The velocity variation is inversely related to the Moho depth in the 40 s period of Swave, and the lateral velocity heterogeneity represents the lateral variation of the Moho depth. The Ordos block and the northern margin of Sichuan basin are located in the uppermost mantle at this depth, and the depth in the transition zone is still located in the lower crust.
基金the Fundamental Research Funds for the Central Universities(Nos.FRF-IDRY-19-009,FRF-TP-19-038A1).
文摘Hyperthermal environments can harm workers’health and safety.However,it is difficult to include effective protection into standards because heat-related impacts vary significantly accord-ing to individual workers and multiple factors.Studies suggested obvious relationship between en-vironment condition and bio-electricity signal,including electroencephalogram(EEG)signal.We used a detector with 64 electrodes to perform dedicated EEG measurements of nine individual sub-jects to analyze human cerebral activity under hyperthermal(35℃,80%RH)and standard condi-tions(25℃,30%RH).Amplitude changes of the frequency wavebands were analyzed using statist-ical analysis.Seven participants showed increasing beta activity due to high temperature and high humidity in the primary somatosensory cortex(electrode C3)and the temporopolar region(elec-trode FT 8).The amplitude value of alpha wave is increased from 0.194 to 0.213 while the amp-litude value of beta wave is increased from 0.144 to 0.160.Value is decreased due to hyperthermal environment for most people.The results of this study could be used to inform the development of wearable equipment to monitor the health of on-site workers,which is fundamental to improve worker safety and wellbeing.
基金the funding support from“Hundred Talents Program”of Zhejiang University,the Fundamental Research Funds for the Central Universities(No.2021FZZX001-09)the National Natural Science Foundation of China(No.22005266)Zhejiang Provincial Natural Science Foundation(No.LR21E020003).
文摘Lithium-metal batteries(LMBs)based on high-voltage cathodes would deliver high specific energy density to meet the demand of future energy storage.However,developing liquid electrolytes with wide electrochemical window for high-energy LMBs is intrinsically challenging.Herein,we demonstrate metal-organic framework-functionalized separators(PE@MOF)with solvent sieving capability that implement dual electrolyte for LMBs.The capability of PE@MOF separator to block the diffusion of liquid electrolytes has been investigated.The PE@MOF separator notably suppresses solvents shuttling,enabling the independent optimization of cathode-electrolyte and anode-electrolyte interfaces.By adapting commercial carbonate and ether electrolytes on cathode and anode sides,respectively,robust cathode-electrolyte interphase(CEI)and solid electrolyte interface(SEI)have been built on both electrodes.The lifespan of LiCoO_(2)(LCO)|Li full cell has been notably extended when using dual electrolyte and the solvent-sieving PE@MOF separator.This work demonstrates a new strategy to separately optimize the local environments at electrodes and to develop high-energy LMBs using low-cost and commercially available electrolytes.
基金support from the National Natural Science Foundation of China(Nos.22125502,22071207,22121001,and 21721001)and NFFTBS(No.J1310024)。
文摘Cu-based catalysts have attracted widespread attention for its capability in electrocatalytically reducing CO_(2)to a variety of products.Surface modification of Cu has become an interesting method for tuning the catalytic performance.Here,we use Zrbased metal-organic layers(MOLs)as the additive of the Cu surface,which enhanced the Faradaic efficiency of CH4 by two times as compared to the untreated polycrystalline Cu foil.Unexpectedly,the MOLs were found to induce in situ nano-structuring of the Cu foil surface within seconds in the electrolysis,as revealed by a combination of scanning electron microscopy(SEM),grazing incidence X-ray diffractometry(GIXRD),and linear sweep voltammetry(LSV)measurements.These surface changes are responsible for the shift of product selectivity.Control experiments suggest that negatively chargedμ3-O−on the Zr-cluster in the MOL might interact with CO-covered Cu surface and induce roughing and nano-structuring.This work reveals a potential role of additive on Cu to induce surface nano-structuring that tunes catalytic activity and selectivity.
基金part of the Science and Technology Plan Project in Zhengzhou funded by Henan Administration of Foreign Experts Affairs and Science and Technology Bureau of Zhengzhou City (grant no.094SYJH36069)support from Peking University and Taiwan Yunlin University of Science and Technology
文摘Zhengzhou is a developing city in China, that is heavily polluted by high levels of particulate matter. In this study, fine particulate matter (PM2.5) was collected and analyzed for their chemical composition (soluble ions, elements, elemental carbon (EC) and organic carbon (OC)) in an industrial district of Zhengzhou in 2010. The average concentrations of PM2.5 were 181, 122, 186 and 211 μg/m3 for spring, summer, autumn and winter, respectively, with an annual average of 175 μg/m3, far exceeding the PM2.5 regulation of USA National Air Quality Standards (15 μg/m3). The dominant components of PM2.5 in Zhengzhou were secondary ions (sulphate and nitrate) and carbon fractions. Soluble ions, total carbon and elements contributed 41%, 13% and 3% of PM2.5 mass, respectively. Soil dust, secondary aerosol and coal combustion, each contributing about 26%, 24% and 23% of total PM2.5 mass, were the major sources of PM2.5, according to the result of positive matrix factorization analysis. A mixed source of biomass burning, oil combustion and incineration contributed 13% of PM2.5. Fine particulate matter arising from vehicles and industry contributed about 10% and 4% of PM2.5, respectively.
基金financially by the National Natural Science Foundation of China (No. 51571148)the National Key Research and Development Program of China (No. 2017YFB0701801)the Thousand Talents Program for Distinguished Young Scholars of China
文摘Owing to their unique short-or medium-range ordered microstructures and excellent mechanical, physical, and chemical properties, amorphous alloys have attracted significant interest in recent years. For the application of amorphous alloys, clarifying their oxidation processes and mechanisms is necessary since many of the surface-related properties of amorphous alloys largely depend on the surface oxide layer.The aim of this paper is to review the recent research on the thermal oxidation behaviors of amorphous alloys under pure oxygen or air condition. The contents are divided into three categories according to the number of components the research considers, i.e., the oxidation of binary, ternary, and multi-component(〉3) amorphous alloys. Each section discusses the thermal stability of the amorphous matrix, oxidation kinetics, and the oxide layer and amorphous substrate, which are strongly affected by internal factors(i.e., alloy elements and microstructure) and external factors(i.e., oxidation temperature, duration, and oxygen partial pressure, etc.). The general features of the oxidation of amorphous alloys – from simple binary to complex multi-component amorphous alloys – will be summarized. This overview of the current scientific understanding on the fundamentals of these materials may provide guidelines for the development of strongly corrosion-resistant amorphous alloys.
基金financially supported by the National Natural Science Foundation of China (No.51571148)the National Key Research and Development Program of China (No.2017YFE0302600 and No.2017YFB0701801)the Thousand Talents Program for Distinguished Young Scholars of China
文摘High silicon content Al-Si composites with a composition of Al-40 wt% Si were fabricated via a highenergy ball milling method. The microstructure evolution of Al-40 wt% Si milled powders and sintered composites has been thoroughly studied by scanning electron microscopy, X-ray diffraction, energydispersive spectrometry and high-resolution transmission electron microscopy. The mechanism of ball milling Al-40 wt% Si powders has been disclosed in detail: fracture mechanism dominating in the early stages, followed by the agglomeration mechanism, finally reaching the balance between the fragments and the agglomerates. It has been found that the average particle sizes of mixed Al-Si powders can be refined to the nanoscale, and the crystallite sizes of Al and Si have been reduced to 10nm and 62nm upon milling for 2h–50h, respectively. The finally formed Al-Si interfaces after ball milling for 50h are wellcohesive. A dense and homogenous Al-40 wt% Si composite have been achieved by solid-state sintering at550?C. The results thus provide an effective support for producing bulk nanostructured Al-Si composites.
基金supported by the National Natural Science Foundation of China(No.51571148)the National Key Research and Development Program of China(No.2017YFE0302600).
文摘The effect of structural order in the parent alloy substrate on the oxidation kinetics and oxide phase evolution was investigated for the thermal oxidation of amorphous Cu33at.%Zr67at.%and crystalline CuZr2 alloys of identical compositions in the temperature range of 200–250?C.It was found that,besides the strong preferential oxidation of Zr in both alloys,the lack of structural order in the amorphous Cu33at.%Zr67at.%alloy results in much slower oxidation kinetics,as well as in distinctly different microstructures of the oxide overgrowth and its Zr-depletion zone in the wake of the ZrO2 overlayer growth front.The experimental findings can be rationalized on the basis of the strikingly different atomic mobilities of Cu,Zr and dissolved O in the amorphous and crystalline alloys,which also results in different nucleation barriers for crystalline oxide nucleation.The thus obtained knowledge on the underlying oxidation mechanisms provides new and profound insights into the surface engineering of metallic alloys.
基金financially supported by the National Natural Science Foundation of China (No. 51571148)the National Key Research and Development Program of China (No. 2017YFE0302600 and No. 2017YFB0701801)the Thousand Talents Program for Distinguished Young Scholars of China
文摘The thermal oxidation of ZrAl2 in the temperature range of 550–750℃ in pure oxygen has been investigated by a combinational experimental approach using X-ray diffraction, scanning electron microscopy/energy dispersive spectrometer, Auger electron spectroscopy and cross-sectional transmission electron microscopy. The thermal oxidation leads to the growth of anomalously thick(up to 4.5 μm)amorphous(Zr0.33 Al0.67)O1.66 surficial layers at temperatures as high as 750℃. The oxidation kinetics obeys a parabolic law with an activation energy of 143 kJ/mol. The underlying mechanism for the formation of such micrometer-thick amorphous oxide surficial layers has been discussed on the basis of interface thermodynamics and the occurrence of high interface stability associated with a synchronous oxidation of Al and Zr elements.
基金partially supported by the National Institutes of Health(grant no.P20GM103646)the United States Department of Agriculture Animal and Plant Health Inspection Service(agreement 14-7428-1041-CA)
文摘Dear Editor,Influenza A viruses(IAVs)are single-stranded,negative sense RNA viruses.IAV subtype is determined on the basis of the viral surface glycoproteins,hemagglutinin(HA),and neuraminidase(NA).To date,18 HA and 11NA subtypes have been reported(Tong et al.,2012).
基金supported by the National Natural Science Foundation of China (31970198 and 31900239)the Natural Science Foundation of Henan Province (202300410230).
文摘Plant root hairs are essential for mineral and water absorption,which possess sophisticated sensory mechanisms to allow them to respond to different environmental signals.Ammonium(NH^(+))is a major form of nitrogen in the soil.NH^(+)can influence the root system architecture,such as root hair growth(Liu and von Wir en,2017).
文摘Human infection with Chlamydia psittaci is rare but difficult to recognize.We report an outbreak of psittacosis among poultry processing workers in China.We applied metagenomic next-generation sequencing and identified Chlamydia psittaci reads from samples of all seven patients,four of which were subsequently confirmed by PCR.Epidemiological results suggested that the poultry processed in the factory was the possible source of human infection.