The fifth species in the genus Lepidodens was reported from Wuyanling National Natural Reserve.Lepidodens taishunensis Lin,Wu&Pan sp.nov.is the second new species of this genus recorded from Zhejiang Province.This...The fifth species in the genus Lepidodens was reported from Wuyanling National Natural Reserve.Lepidodens taishunensis Lin,Wu&Pan sp.nov.is the second new species of this genus recorded from Zhejiang Province.This new species could be discriminated from others species in this genus by colour pattern,labial chaetae E and R ciliated,dorsal Abd.Ⅰ–Ⅲand centrodorsal Abd.Ⅳwith 2/4/7/8 macrochaetae.A detailed comparison among the five Lepidodens species,dorsal body chaetotaxy of larvae and key to species of the genus were provided.展开更多
Antimony(Sb)-ba sed anode materials are feasible candidates for sodium-ion batteries(SIBs) due to their high theoretical specific capacity and excellent electrical conductivity.However,they still suffer from volume di...Antimony(Sb)-ba sed anode materials are feasible candidates for sodium-ion batteries(SIBs) due to their high theoretical specific capacity and excellent electrical conductivity.However,they still suffer from volume distortion,structural collapse,and ionic conduction interruption upon cycling.Herein,a hierarchical array-like nanofiber structure was designed to address these limitations by combining architecture engineering and anion tuning strategy,in which SbPO_(4-x) with oxygen vacancy nanosheet arrays are anchored on the surface of interwoven carbon nanofibers(SbPO_(4-x)@CNFs).In particular,bulky PO_(4)^(3-) anions mitigate the large volume distortion and generate Na_(3)PO_(4) with high ionic conductivity,collectively improving cyclic stability and ionic transport efficiency.The abundant oxygen vacancies substantially boost the intrinsic electronic conductivity of SbPO_4,further accelerating the reaction dynamics.In addition,hierarchical fibrous structures provide abundant active sites,construct efficient conducting networks,and enhance the electron/ion transport capacity.Benefiting from the advanced structural design,the SbPO_(4-x)@CNFs electrodes exhibit outstanding cycling stability(1000 cycles at 1.0 A g^(-1) with capacity decay of 0.05% per cycle) and rapid sodium storage performance(293.8 mA h g^(-1) at 5.0 A g^(-1)).Importantly,systematic in-/ex-situ techniques have revealed the "multi-step conversion-alloying" reaction process and the "battery-capacitor dual-mode" sodium-storage mechanism.This work provides valuable insights into the design of anode materials for advanced SIBs with elevated stability and superior rate performance.展开更多
Dissociative adsorption of HCl on Au(111)has become one of unsolved puzzles in surface chemistry.Despite tremendous efforts in the past years,varioustheoretical models still greatly overestimate the zero-coverage init...Dissociative adsorption of HCl on Au(111)has become one of unsolved puzzles in surface chemistry.Despite tremendous efforts in the past years,varioustheoretical models still greatly overestimate the zero-coverage initial sticking probabilities(So).To find the origin of the large experiment-theory discrepancy,we have revisited the dissociative adsorption of HCl on Au(111)with a newly designed molecular beam-surface apparatus.The zero-coverage So derived from Cl-coverage measurements with varying HCl doses agree well with previous ones.However,we notice a sharp change of the coverage/dose slope with the HCl dosage at the low coverage regime,which may result in some uncertainties to the fitted So value.This seems consistent with a coverage-dependence of the dissociation barrier predicted by density functional theory at low Cl-coverages.Our results reveal the potential inconsistency of utilizing simulations with finite coverage to compare against experimental data with zero coverage in this system,and provide guidance for improving both experiment and theory in this regard.展开更多
The existing recycling and regeneration technologies have problems,such as poor regeneration effect and low added value of products for lithium(Li)-ion battery cathode materials with a low state of health.In this work...The existing recycling and regeneration technologies have problems,such as poor regeneration effect and low added value of products for lithium(Li)-ion battery cathode materials with a low state of health.In this work,a targeted Li replenishment repair technology is proposed to improve the discharge-specific capacity and cycling stability of the repaired LiCoO_(2) cathode materials.Compared with the spent cathode material with>50%Li deficiency,the Li/Co molar ratio of the regenerated LiCoO_(2) cathode is>0.9,which completely removes the Co_(3)O_(4) impurity phase formed by the decomposition of LixCoO_(2) in the failed cathode material after repair.The repaired LiCoO_(2) cathode mater-ials exhibit better cycling stability,lower electrochemical impedance,and faster Li^(+)diffusion than the commercial materials at both 1 and 10 C.Meanwhile,Li_(1.05)CoO_(2) cathodes have higher Li replenishment efficiency and cycling stability.The energy consumption and greenhouse gas emissions of LiCoO_(2) cathodes produced by this repair method are significantly reduced compared to those using pyrometallurgical and hydro-metallurgical recycling processes.展开更多
Tin selenide(SnSe)is considered as a potential anode for sodium-ion batteries(SIBs)owing to its high theoretical specific capacity.Unfortunately,it suffers from drastic volume expansion/contraction during sodium ions ...Tin selenide(SnSe)is considered as a potential anode for sodium-ion batteries(SIBs)owing to its high theoretical specific capacity.Unfortunately,it suffers from drastic volume expansion/contraction during sodium ions insertion/extraction,resulting in poor cycling stability.Herein,a pomegranate-inspired porous carbon shell wrapped heterogeneous SnSe/ZnSe composite(SnSe/ZnSe@C)is exquisitely designed and fabricated through electrostatic spraying followed by high-temperature selenization.The polyacrylonitrile-derived carbon shell acts as an adhesive to link the porous cubic SnSe/ZnSe and form highly interconnected microcircuits to improve the electron/ion transfer efficiency and inhibit the bulk volume change of internal metallic selenide nanoparticles and polyselenides dissolution during repeated cycling.Moreover,the abundant heterostructure interface of SnSe/ZnSe further significantly accelerates the electrons/ions transport.As a result,the as-prepared SnSe/ZnSe@C electrode exhibits a high specific capacity(508.3 m Ah g^(-1)at 0.05 A g^(-1)),excellent rate performance(177.8 m Ah g^(-1)at 10.0 A g^(-1)),and remarkable cycling stability(195.9 m Ah g^(-1)after 10,000 cycles at 5.0 A g^(-1)).Furthermore,in-situ Xray diffraction(XRD)/Raman,ex-situ transmission electron microscopy,and kinetic analysis clearly reveal a four-step electrochemical reaction process and battery-capacitor dual-mode sodium storage mechanism.This work provides a new perspective for developing commercial SIBs anode materials with high capacity and long lifespan.展开更多
The concurrent presence of different types of traffic in multimedia applications might aggravate a burden on the underlying data network, which is bound to affect the transmission quality of the specified traffic. Rec...The concurrent presence of different types of traffic in multimedia applications might aggravate a burden on the underlying data network, which is bound to affect the transmission quality of the specified traffic. Recently, several proposals for fulfilling the quality of service(QoS) guarantees have been presented. However, they can only support coarse-grained QoS with no guarantee of throughput, jitter, delay or loss rate for different applications. To address these more challenging problems, an adaptive scheduling algorithm for Parallel data Processing with Multiple Feedback(PPMF) queues based on software defined networks(SDN) is proposed in this paper, which can guarantee the quality of service of high priority traffic in multimedia applications. PPMF combines the queue bandwidth feedback mechanism to realise the automatic adjustment of the queue bandwidth according to the priority of the packet and network conditions, which can effectively solve the problem of network congestion that has been experienced by some queues for a long time. Experimental results show PPMF significantly outperforms other existing scheduling approaches in achieving 35--80% improvement on average time delay by adjusting the bandwidth adaptively, thus ensuring the transmission quality of the specified traffic and avoiding effectively network congestion.展开更多
As a layered inorganic material,MoS2 has recently attracted intensive attention as anode for sodium ion batteries(SIBs).However,this anode is plagued with low electronic conductivity,serious volume expansion and slugg...As a layered inorganic material,MoS2 has recently attracted intensive attention as anode for sodium ion batteries(SIBs).However,this anode is plagued with low electronic conductivity,serious volume expansion and sluggish kinetics,resulting in capacity fading and poor rate performance.Herein,we develop an interface engineering strategy to substantially enhance the sodium storage performance of MoS2 by incorporating layered MoS2 into three dimensional N-doped graphene scaffold.The strong coupling-interface between MoS2 and N-doped graphene scaffold can not only stabilize the MoS2 structure during sodium insertion/extraction processes,but also provide plenty of anchor sites for additional surface sodium storage.The 3D MoS2@N-doped graphene composite as anode for SIBs performs an outstanding specific capacity of 667.3 mA h g^-1 at 0.2 A g^-1,a prolonged stability with a capacity retention of 94.4%after 140cycles and excellent rate capability of 445 mA h g^-1 even at a high rate of 10 A g^-1.We combined experiment and theoretical simulation to further disclose the interaction between MoS2 and N-doped graphene,adsorption and diffusion of sodium on the composite and the corresponding sodium storage mechanism.This study opens a new door to develop high performance SIBs by introducing the interface engineering technique.展开更多
Power transmission across the sea is an important part of global energy interconnection(GEI).To support the construction of GEI and to serve the needs of future clean energy trans-sea transportation and offshore wind ...Power transmission across the sea is an important part of global energy interconnection(GEI).To support the construction of GEI and to serve the needs of future clean energy trans-sea transportation and offshore wind power development,this study a)analyzes the requirements of the GEI backbone network pertaining to direct current(DC)submarine cable technology,and b)defines the key technical and economic indices of ultrahigh-voltage direct current(UHVDC)submarine cable based on theoretical computations.The research is based on the thermoelectric coupling model and the finite element method.It is shown that the dielectric strength of the insulating materials of the±800 kV~±1100 kV/4000 MW^12000 MW UHVDC submarine cable(extrusion insulation)should be not less than 43~65 kV/mm,while the heat resistance is not less than 110°C.As the cost of submarine cable is 5~10 times higher than that of the overhead line,the project investment need to be decreased to a level within the economical carrying capacity to guarantee extensive applicability of the HVDC submarine cable technology.展开更多
For solid polymer electrolytes(SPEs),improving their mechanical and electrochemical properties is the key to obtaining batteries with higher safety and higher energy density.Herein,a novel synergistic strategy propose...For solid polymer electrolytes(SPEs),improving their mechanical and electrochemical properties is the key to obtaining batteries with higher safety and higher energy density.Herein,a novel synergistic strategy proposed is preparing a 3D flame-retardant skeleton(3DPA)and adding nano-multifunctional fillers(Li-ILs@ZIF-8).In addition to providing mechanical support for the polyethylene oxide(PEO)matrix,3DPA also has further contributed to the system’s flame retardancy and further improved the safety.Simultaneously,the electrochemical performance is fully guaranteed by rigid Li-ILs@ZIF-8,which provides fast migration channels forLi^(+),reduces the crystallinity of PEO and effectively inhibits lithium dendrites.The limiting oxygen index of the optimal sample(PL3Z/PA)is as high as 20.5%,and the ionic conductivity reaches 2.89×10^(-4) and 0.91×10^(-3) S cm^(-1) at 25 and 55°C,respectively.The assembled Li|PL3Z/PA|Li battery can be cycled stably for more than 1000 h at a current density of 0.1 m A cm^(-2) without short circuit being pierced by lithium dendrites.The specific capacity of the LFP|PL3Z/PA|Li battery was 160.5 m Ah g^(-1) under a current density of 0.5 C,and the capacity retention rate was 90.0%after 300 cycles.展开更多
With the increasing severity of environmental problems,many countries have set energy transition targets to promote the realization of the Paris Agreement.There has been a global consensus on utilizing solar energy re...With the increasing severity of environmental problems,many countries have set energy transition targets to promote the realization of the Paris Agreement.There has been a global consensus on utilizing solar energy resources as alternatives to conventional sources to support this energy transition.In this regard,analyzing the“location,”“quantity,”and“quality”of global solar energy resources will not only assist an individual country to efficiently utilize these resources but also promote the realization of large-scale intercontinental resource utilization and complementation.This study established the basic database,model methods,and platform tools for global solar energy assessment,Then,a global solar energy resource assessment was conducted,which included the theoretical reserves(TRs),technical installed potential capacity(TPIC),and average development cost(ADC).A comparative analysis of the assessment results for all continents was also performed.After that,based on big data analysis and geographic information system(GIS)calculations,the distribution characteristics of the global solar power TPIC were calculated with the two core indicators,namely the capacity factor and ADC.Furthermore,a data-driven quantitative evaluation of the refined development potential of solar energy resources was performed.Finally,the reasonableness and coincidence analysis of the resource assessment results were verified using data from global and specifically Chinese photovoltaic(PV)bases.展开更多
The front-row shading reduction coefficient is a key parameter used to calculate the system efficiency of a photovoltaic(PV)power station.Based on the Hay anisotropic sky scattering model,the variation rule of solar r...The front-row shading reduction coefficient is a key parameter used to calculate the system efficiency of a photovoltaic(PV)power station.Based on the Hay anisotropic sky scattering model,the variation rule of solar radiation intensity on the surface of the PV array during the shaded period is simulated,combined with the voltage-current characteristics of the PV modules,and the shadow occlusion operating mode of the PV array is modeled.A method for calculating the loss coefficient of front shadow occlusion based on the division of the PV cell string unit and Hay anisotropic sky scattering model is proposed.This algorithm can accurately evaluate the degree of influence of the PV array layout,wiring mode,array spacing,PV module specifications,and solar radiation on PV power station system efficiency.It provides a basis for optimizing the PV array layout,reducing system loss,and improving PV system efficiency.展开更多
Underwater shock waves generated by pulsed electrical discharges are an effective,economical,and environmentally friendly means of stimulating reservoirs,and this technology has received much attention and intensive r...Underwater shock waves generated by pulsed electrical discharges are an effective,economical,and environmentally friendly means of stimulating reservoirs,and this technology has received much attention and intensive research in the past few years.This paper reviews the main results of recent work on underwater electrical wire explosion(UEWE)for reservoir stimulation.Aplatform is developed for microsecond singlewire explosions in water,and diagnostics based on a voltage probe,current coil,pressure probe,photodiode,and spectrometer are used to characterize the UEWE process and accompanying shock waves.First,the UEWE characteristics under different discharge types are studied and general principles are clarified.Second,the shock-wave generation mechanism is investigated experimentally by interrupting the electrical energy injection into the wire at different stages of the wire-explosion process.It is found that the vaporization process is vital for the formation of shock waves,whereas the energy deposited after voltage collapse has only a limited effect.Furthermore,the relationships between the electrical-circuit and shock-wave parameters are investigated,and an empirical approach is developed for estimating the shock-wave parameters.Third,how the wire material and water state affect the wire-explosion process is studied.To adjust the shock-wave parameters,a promising method concerning energetic material load is proposed and tested.Finally,the fracturing effect of the pulsed-discharge shock waves is discussed,as briefly are some of the difficulties associated with UEWE-based reservoir stimulation.展开更多
Despite the promising prospects of nanoparticles in oral drug delivery,the process of oral administration involves a complex transportation pathway that includes cellular uptake,intracellular trafficking,and exocytosi...Despite the promising prospects of nanoparticles in oral drug delivery,the process of oral administration involves a complex transportation pathway that includes cellular uptake,intracellular trafficking,and exocytosis by intestinal epithelial cells,which are necessary steps for nanoparticles to enter the bloodstream and exert therapeutic effects.Current researchers have identified several crucial factors that regulate the interaction between nanoparticles and intestinal epithelial cells,including surface properties such as ligand modification,surface charge,hydrophilicity/hydrophobicity,intestinal protein corona formation,as well as holistic properties like particle size,shape,and rigidity.Understanding these properties is essential for enhancing transepithelial transport efficiency and designing effective oral drug delivery systems.Therefore,this review provides a comprehensive overview of the surface and holistic properties that influence the transepithelial transport of nanoparticles,elucidating the underlying principles governing their impact on transepithelial transport.The review also outlines the chosen of parameters to be considered for the subsequent design of oral drug delivery systems.展开更多
Advancing and deploying the Fe Ni-based catalyst,the state-of-the-art pre-electrocatalysts,for oxygen evolution reactions(OER)still suffer from unclear chemical state correlation to the catalytic ability,as evidenced ...Advancing and deploying the Fe Ni-based catalyst,the state-of-the-art pre-electrocatalysts,for oxygen evolution reactions(OER)still suffer from unclear chemical state correlation to the catalytic ability,as evidenced by the variedly reported performance for the different Fe Ni structures.Herein,we contributed the phase and redox chemical states tuning of Fe Ni oxides by the surface microenvironment regulation for the OER catalysis that was realized by the urea-assisted pyrolysis and molybdenum-doping technique by integrating molybdenum into the iron–nickel metal-organic precursor.Driven by the complicated and compromised atmosphere,namely,the oxidation state driven by the Mo doping and reduction ability induced by the urea-assisted pyrolysis,could transfer confined Fe Ni oxides to hybrid phases of Fe_(2)O_(3)and FeNi_(3)alloy,and the resultant compromised chemical states by the charge redistribution imparted very high electrocatalytic performance for OER compared with the control samples.The insitu Raman spectroscopy and post-XPS analysis confirmed the facile Fe/Ni oxyhydroxide active phase formation resulting from the proper phase and chemical states,and theoretical analysis disclosed the microenvironment regulation resulting in the charge redistribution forming the electron accumulation and depletion sites to accelerate the oxygen-species to oxyhydroxide-species transformation and enhance the electronic state density near the Fermi level by significantly reducing the energy barrier.The work not only showed the importance of surface chemical state tunning that can basically answer the varied performance of Fe Ni catalysts but also revealed an effective approach for fine-tuning their catalytic properties.展开更多
Fiber materials are highly desirable for wearable electronics that are expected to be flexible and stretchable.Compared with rigid and planar electronic devices,fiber-based wearable electronics provide significant adv...Fiber materials are highly desirable for wearable electronics that are expected to be flexible and stretchable.Compared with rigid and planar electronic devices,fiber-based wearable electronics provide significant advantages in terms of flexibility,stretchability and breathability,and they are considered as the pioneers in the new generation of soft wearables.The con-vergence of textile science,electronic engineering and nanotechnology has made it feasible to build electronic functions on fibers and maintain them during wear.Over the last few years,fiber-shaped wearable electronics with desired designability and integration features have been intensively explored and developed.As an indispensable part and cornerstone of flexible wearable devices,fibers are of great significance.Herein,the research progress of advanced fiber materials is reviewed,which mainly includes various material preparations,fabrication technologies and representative studies on different wearable applications.Finally,key challenges and future directions of fiber materials and wearable electronics are examined along with an analysis of possible solutions.展开更多
Protein corona(PC)has been identified to impede the transportation of intravenously injected nanoparticles(NPs)from blood circulation to their targeted sites.However,how intestinal PC(IPC)affects the delivery of orall...Protein corona(PC)has been identified to impede the transportation of intravenously injected nanoparticles(NPs)from blood circulation to their targeted sites.However,how intestinal PC(IPC)affects the delivery of orally administered NPs are still needed to be elucidated.Here,we found that IPC exerted“positive effect”or“negative effect”depending on different pathological conditions in the gastrointestinal tract.We prepared polystyrene nanoparticles(PS)adsorbed with different IPC derived from the intestinal tract of healthy,diabetic,and colitis rats(H-IPC@PS,D-IPC@PS,C-IPC@PS).Proteomics analysis revealed that,compared with healthy IPC,the two disease-specific IPC consisted of a higher proportion of proteins that were closely correlated with transepithelial transport across the intestine.Consequently,both D-IPC@PS and C-IPC@PS mainly exploited the recycling endosome and ER-Golgi mediated secretory routes for intracellular trafficking,which increased the transcytosis from the epithelium.Together,disease-specific IPC endowed NPs with higher intestinal absorption.D-IPC@PS posed“positive effect”on intestinal absorption into blood circulation for diabetic therapy.Conversely,CIPC@PS had“negative effect”on colitis treatment because of unfavorable absorption in the intestine before arriving colon.These results imply that different or even opposite strategies to modulate the disease-specific IPC need to be adopted for oral nanomedicine in the treatment of variable diseases.展开更多
Due to the advantages of large workspace,low cost and the integrated vision/force sensing,robotic milling has become an important way for machining of complex parts.In recent years,many scholars have studied the probl...Due to the advantages of large workspace,low cost and the integrated vision/force sensing,robotic milling has become an important way for machining of complex parts.In recent years,many scholars have studied the problems existing in the applications of robotic milling,and lots of results have been made in the dynamics,pose planning,deformation control etc.,which provides theoretical guidance for high precision and high efficiency of robotic milling.From the perspective of complex parts robotic milling,this paper focuses on machining process planning and control techniques including the analysis of the robot-workspace,robot trajectory planning,vibration monitoring and control,deformation monitoring and compensation.As well as the principles of these technologies such as robot stiffness characteristics,dynamic characteristics,chatter mechanisms,and deformation mechanisms.The methods and characteristics related to the theory and technology of robotic milling of complex parts are summarized systematically.The latest research progress and achievements in the relevant fields are reviewed.It is hoped that the challenges,strategies and development related to robotic milling could be clarified through the carding work in this paper,so as to promote the application of related theories and technologies in high efficiency and precision intelligent milling with robot for complex parts.展开更多
Disposable medical protective clothing for 2019-nCoV mainly consists of stacked layers with nanopore films,polymer coated nonwoven fabrics and melt-blown nonwoven fabrics against anti-microbial and anti-liquid penetra...Disposable medical protective clothing for 2019-nCoV mainly consists of stacked layers with nanopore films,polymer coated nonwoven fabrics and melt-blown nonwoven fabrics against anti-microbial and anti-liquid penetration.However,such structures lack moisture permeability and breathability leading to an uncomfortable,stuffy wearing experience.Here,we propose a novel medical protective clothing material with a superabsorbent layer to enhance moisture absorption.Poly(acrylic acid-co-acrylamide)/polyvinyl alcohol superabsorbent fibers(PAAAM/PVA fibers)were prepared via wet spinning.And the superabsorbent composite layer was stacked from PAAAM/PVA fibers,bamboo pulp fibers(BPF)and ethylene-propyl-ene side by side fibers(ESF).The novel disposable medical protective composite fabric was obtained through gluing the superabsorbent layer to the inner surface of strong antistatic polypropylene nonwoven fabric.The resultant composite fabric possesses excellent absorption and retention capacity for sweat,up to 12.3 g/g and 63.8%,and a maximum hygroscopic rate of 1.04 g/h,higher than that of the conventional material(only 0.53 g/h).The moisture permeability of the novel material reached 12,638.5 g/(m^(2) d),which was 307.6%of the conventional material.The novel material can effectively reduce the humidity inside the protective clothing and significantly improve the comfort of medical staff.展开更多
基金supported by Zhejiang Provincial Natural Science Foundation of China(LTY20C030001)the program on“Collembola species diversity of Wuyanling National Nature Reserve”。
文摘The fifth species in the genus Lepidodens was reported from Wuyanling National Natural Reserve.Lepidodens taishunensis Lin,Wu&Pan sp.nov.is the second new species of this genus recorded from Zhejiang Province.This new species could be discriminated from others species in this genus by colour pattern,labial chaetae E and R ciliated,dorsal Abd.Ⅰ–Ⅲand centrodorsal Abd.Ⅳwith 2/4/7/8 macrochaetae.A detailed comparison among the five Lepidodens species,dorsal body chaetotaxy of larvae and key to species of the genus were provided.
基金financially supported by the National Natural Science Foundation of China(52102223,51920105004)。
文摘Antimony(Sb)-ba sed anode materials are feasible candidates for sodium-ion batteries(SIBs) due to their high theoretical specific capacity and excellent electrical conductivity.However,they still suffer from volume distortion,structural collapse,and ionic conduction interruption upon cycling.Herein,a hierarchical array-like nanofiber structure was designed to address these limitations by combining architecture engineering and anion tuning strategy,in which SbPO_(4-x) with oxygen vacancy nanosheet arrays are anchored on the surface of interwoven carbon nanofibers(SbPO_(4-x)@CNFs).In particular,bulky PO_(4)^(3-) anions mitigate the large volume distortion and generate Na_(3)PO_(4) with high ionic conductivity,collectively improving cyclic stability and ionic transport efficiency.The abundant oxygen vacancies substantially boost the intrinsic electronic conductivity of SbPO_4,further accelerating the reaction dynamics.In addition,hierarchical fibrous structures provide abundant active sites,construct efficient conducting networks,and enhance the electron/ion transport capacity.Benefiting from the advanced structural design,the SbPO_(4-x)@CNFs electrodes exhibit outstanding cycling stability(1000 cycles at 1.0 A g^(-1) with capacity decay of 0.05% per cycle) and rapid sodium storage performance(293.8 mA h g^(-1) at 5.0 A g^(-1)).Importantly,systematic in-/ex-situ techniques have revealed the "multi-step conversion-alloying" reaction process and the "battery-capacitor dual-mode" sodium-storage mechanism.This work provides valuable insights into the design of anode materials for advanced SIBs with elevated stability and superior rate performance.
基金supported by the National Natural Science Foundation of China(No.22173042,No.21973037,No.22073089,and No.22327801)the In-novation program for Quantum Science and Technolo-gy(No.2021ZD0303304)+2 种基金the Guangdong Science and Technology Program(No.2019ZT08L455 and No.2019JC01X091)the Shenzhen Science and Technology Program(No.ZDSYS2020421111001787)Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450101).
文摘Dissociative adsorption of HCl on Au(111)has become one of unsolved puzzles in surface chemistry.Despite tremendous efforts in the past years,varioustheoretical models still greatly overestimate the zero-coverage initial sticking probabilities(So).To find the origin of the large experiment-theory discrepancy,we have revisited the dissociative adsorption of HCl on Au(111)with a newly designed molecular beam-surface apparatus.The zero-coverage So derived from Cl-coverage measurements with varying HCl doses agree well with previous ones.However,we notice a sharp change of the coverage/dose slope with the HCl dosage at the low coverage regime,which may result in some uncertainties to the fitted So value.This seems consistent with a coverage-dependence of the dissociation barrier predicted by density functional theory at low Cl-coverages.Our results reveal the potential inconsistency of utilizing simulations with finite coverage to compare against experimental data with zero coverage in this system,and provide guidance for improving both experiment and theory in this regard.
基金supported by the National Natural Science Foundation of China (Nos. 51972030 and 51772030)the S&T Major Project of Inner Mongolia Autonomous Region in China (No. 2020ZD0018)+1 种基金the Beijing Outstanding Young Scientists Program (No. BJJWZYJH01201910007023)the Guangdong Key Laboratory of Battery Safety (No. 2019B121203008)
文摘The existing recycling and regeneration technologies have problems,such as poor regeneration effect and low added value of products for lithium(Li)-ion battery cathode materials with a low state of health.In this work,a targeted Li replenishment repair technology is proposed to improve the discharge-specific capacity and cycling stability of the repaired LiCoO_(2) cathode materials.Compared with the spent cathode material with>50%Li deficiency,the Li/Co molar ratio of the regenerated LiCoO_(2) cathode is>0.9,which completely removes the Co_(3)O_(4) impurity phase formed by the decomposition of LixCoO_(2) in the failed cathode material after repair.The repaired LiCoO_(2) cathode mater-ials exhibit better cycling stability,lower electrochemical impedance,and faster Li^(+)diffusion than the commercial materials at both 1 and 10 C.Meanwhile,Li_(1.05)CoO_(2) cathodes have higher Li replenishment efficiency and cycling stability.The energy consumption and greenhouse gas emissions of LiCoO_(2) cathodes produced by this repair method are significantly reduced compared to those using pyrometallurgical and hydro-metallurgical recycling processes.
基金support from the National Natural Science Foundation of China(51920105004,52102223)the Basic and Applied Basic Research Fund Project of Guangdong Province(2020A1515110401)。
文摘Tin selenide(SnSe)is considered as a potential anode for sodium-ion batteries(SIBs)owing to its high theoretical specific capacity.Unfortunately,it suffers from drastic volume expansion/contraction during sodium ions insertion/extraction,resulting in poor cycling stability.Herein,a pomegranate-inspired porous carbon shell wrapped heterogeneous SnSe/ZnSe composite(SnSe/ZnSe@C)is exquisitely designed and fabricated through electrostatic spraying followed by high-temperature selenization.The polyacrylonitrile-derived carbon shell acts as an adhesive to link the porous cubic SnSe/ZnSe and form highly interconnected microcircuits to improve the electron/ion transfer efficiency and inhibit the bulk volume change of internal metallic selenide nanoparticles and polyselenides dissolution during repeated cycling.Moreover,the abundant heterostructure interface of SnSe/ZnSe further significantly accelerates the electrons/ions transport.As a result,the as-prepared SnSe/ZnSe@C electrode exhibits a high specific capacity(508.3 m Ah g^(-1)at 0.05 A g^(-1)),excellent rate performance(177.8 m Ah g^(-1)at 10.0 A g^(-1)),and remarkable cycling stability(195.9 m Ah g^(-1)after 10,000 cycles at 5.0 A g^(-1)).Furthermore,in-situ Xray diffraction(XRD)/Raman,ex-situ transmission electron microscopy,and kinetic analysis clearly reveal a four-step electrochemical reaction process and battery-capacitor dual-mode sodium storage mechanism.This work provides a new perspective for developing commercial SIBs anode materials with high capacity and long lifespan.
基金supported by National Key Basic Research Program of China(973 Program)under grant no.2012CB315802National Natural Science Foundation of China under grant no.61671081 and no.61132001Prospective Research on Future Networks of Jiangsu Future Networks Innovation Institute under grant no.BY2013095-4-01
文摘The concurrent presence of different types of traffic in multimedia applications might aggravate a burden on the underlying data network, which is bound to affect the transmission quality of the specified traffic. Recently, several proposals for fulfilling the quality of service(QoS) guarantees have been presented. However, they can only support coarse-grained QoS with no guarantee of throughput, jitter, delay or loss rate for different applications. To address these more challenging problems, an adaptive scheduling algorithm for Parallel data Processing with Multiple Feedback(PPMF) queues based on software defined networks(SDN) is proposed in this paper, which can guarantee the quality of service of high priority traffic in multimedia applications. PPMF combines the queue bandwidth feedback mechanism to realise the automatic adjustment of the queue bandwidth according to the priority of the packet and network conditions, which can effectively solve the problem of network congestion that has been experienced by some queues for a long time. Experimental results show PPMF significantly outperforms other existing scheduling approaches in achieving 35--80% improvement on average time delay by adjusting the bandwidth adaptively, thus ensuring the transmission quality of the specified traffic and avoiding effectively network congestion.
基金supported by the National Natural Science Foundation of China(Grant No.U1904187 and 21501049)the Fund of Key Scientific and Technological Project of Henan Province(No.182102410081)the High Performance Computing Center of Henan Normal University。
文摘As a layered inorganic material,MoS2 has recently attracted intensive attention as anode for sodium ion batteries(SIBs).However,this anode is plagued with low electronic conductivity,serious volume expansion and sluggish kinetics,resulting in capacity fading and poor rate performance.Herein,we develop an interface engineering strategy to substantially enhance the sodium storage performance of MoS2 by incorporating layered MoS2 into three dimensional N-doped graphene scaffold.The strong coupling-interface between MoS2 and N-doped graphene scaffold can not only stabilize the MoS2 structure during sodium insertion/extraction processes,but also provide plenty of anchor sites for additional surface sodium storage.The 3D MoS2@N-doped graphene composite as anode for SIBs performs an outstanding specific capacity of 667.3 mA h g^-1 at 0.2 A g^-1,a prolonged stability with a capacity retention of 94.4%after 140cycles and excellent rate capability of 445 mA h g^-1 even at a high rate of 10 A g^-1.We combined experiment and theoretical simulation to further disclose the interaction between MoS2 and N-doped graphene,adsorption and diffusion of sodium on the composite and the corresponding sodium storage mechanism.This study opens a new door to develop high performance SIBs by introducing the interface engineering technique.
基金supported by the Global Energy Interconnection Group Co.,Ltd.Science and Technology Project(Project No.101662224/Title:UHV large-capacity DC submarine cable key technology and roadmap research)the National Key R&D Program of China(2016YFB0900702)
文摘Power transmission across the sea is an important part of global energy interconnection(GEI).To support the construction of GEI and to serve the needs of future clean energy trans-sea transportation and offshore wind power development,this study a)analyzes the requirements of the GEI backbone network pertaining to direct current(DC)submarine cable technology,and b)defines the key technical and economic indices of ultrahigh-voltage direct current(UHVDC)submarine cable based on theoretical computations.The research is based on the thermoelectric coupling model and the finite element method.It is shown that the dielectric strength of the insulating materials of the±800 kV~±1100 kV/4000 MW^12000 MW UHVDC submarine cable(extrusion insulation)should be not less than 43~65 kV/mm,while the heat resistance is not less than 110°C.As the cost of submarine cable is 5~10 times higher than that of the overhead line,the project investment need to be decreased to a level within the economical carrying capacity to guarantee extensive applicability of the HVDC submarine cable technology.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFA0204600)the National Natural Science Foundation of China(Grant No.5210021666)the Key R&D and Promotion Projects of Henan Province(Grant No.212102310016)。
文摘For solid polymer electrolytes(SPEs),improving their mechanical and electrochemical properties is the key to obtaining batteries with higher safety and higher energy density.Herein,a novel synergistic strategy proposed is preparing a 3D flame-retardant skeleton(3DPA)and adding nano-multifunctional fillers(Li-ILs@ZIF-8).In addition to providing mechanical support for the polyethylene oxide(PEO)matrix,3DPA also has further contributed to the system’s flame retardancy and further improved the safety.Simultaneously,the electrochemical performance is fully guaranteed by rigid Li-ILs@ZIF-8,which provides fast migration channels forLi^(+),reduces the crystallinity of PEO and effectively inhibits lithium dendrites.The limiting oxygen index of the optimal sample(PL3Z/PA)is as high as 20.5%,and the ionic conductivity reaches 2.89×10^(-4) and 0.91×10^(-3) S cm^(-1) at 25 and 55°C,respectively.The assembled Li|PL3Z/PA|Li battery can be cycled stably for more than 1000 h at a current density of 0.1 m A cm^(-2) without short circuit being pierced by lithium dendrites.The specific capacity of the LFP|PL3Z/PA|Li battery was 160.5 m Ah g^(-1) under a current density of 0.5 C,and the capacity retention rate was 90.0%after 300 cycles.
基金supported by National Science and Technology Major Project(2018YFB0904000).
文摘With the increasing severity of environmental problems,many countries have set energy transition targets to promote the realization of the Paris Agreement.There has been a global consensus on utilizing solar energy resources as alternatives to conventional sources to support this energy transition.In this regard,analyzing the“location,”“quantity,”and“quality”of global solar energy resources will not only assist an individual country to efficiently utilize these resources but also promote the realization of large-scale intercontinental resource utilization and complementation.This study established the basic database,model methods,and platform tools for global solar energy assessment,Then,a global solar energy resource assessment was conducted,which included the theoretical reserves(TRs),technical installed potential capacity(TPIC),and average development cost(ADC).A comparative analysis of the assessment results for all continents was also performed.After that,based on big data analysis and geographic information system(GIS)calculations,the distribution characteristics of the global solar power TPIC were calculated with the two core indicators,namely the capacity factor and ADC.Furthermore,a data-driven quantitative evaluation of the refined development potential of solar energy resources was performed.Finally,the reasonableness and coincidence analysis of the resource assessment results were verified using data from global and specifically Chinese photovoltaic(PV)bases.
基金This work was supported by the Global Energy Interconnection Group Limited Science&Technology Project(Project No.:SGGEIG00JYJS1900046).
文摘The front-row shading reduction coefficient is a key parameter used to calculate the system efficiency of a photovoltaic(PV)power station.Based on the Hay anisotropic sky scattering model,the variation rule of solar radiation intensity on the surface of the PV array during the shaded period is simulated,combined with the voltage-current characteristics of the PV modules,and the shadow occlusion operating mode of the PV array is modeled.A method for calculating the loss coefficient of front shadow occlusion based on the division of the PV cell string unit and Hay anisotropic sky scattering model is proposed.This algorithm can accurately evaluate the degree of influence of the PV array layout,wiring mode,array spacing,PV module specifications,and solar radiation on PV power station system efficiency.It provides a basis for optimizing the PV array layout,reducing system loss,and improving PV system efficiency.
基金supported in part by the National High Technology Research and Development Program of China(Grant No.2013AA064502)the National Natural Science Foundation of China(Grant No.51907007)+1 种基金the State Key Laboratory of Intense Pulsed Radiation Simulation and Effect(Grant No.SKLIPR1906)the State Key Laboratory of Electrical Insulation and Power Equipment(Grant No.EIPE20204).
文摘Underwater shock waves generated by pulsed electrical discharges are an effective,economical,and environmentally friendly means of stimulating reservoirs,and this technology has received much attention and intensive research in the past few years.This paper reviews the main results of recent work on underwater electrical wire explosion(UEWE)for reservoir stimulation.Aplatform is developed for microsecond singlewire explosions in water,and diagnostics based on a voltage probe,current coil,pressure probe,photodiode,and spectrometer are used to characterize the UEWE process and accompanying shock waves.First,the UEWE characteristics under different discharge types are studied and general principles are clarified.Second,the shock-wave generation mechanism is investigated experimentally by interrupting the electrical energy injection into the wire at different stages of the wire-explosion process.It is found that the vaporization process is vital for the formation of shock waves,whereas the energy deposited after voltage collapse has only a limited effect.Furthermore,the relationships between the electrical-circuit and shock-wave parameters are investigated,and an empirical approach is developed for estimating the shock-wave parameters.Third,how the wire material and water state affect the wire-explosion process is studied.To adjust the shock-wave parameters,a promising method concerning energetic material load is proposed and tested.Finally,the fracturing effect of the pulsed-discharge shock waves is discussed,as briefly are some of the difficulties associated with UEWE-based reservoir stimulation.
基金the National Natural Science Foundation of China(82104069)the Regional Innovation and Development Joint Fund of the National Natural Science Foundation of China(U22A20356)+3 种基金the JapaneChina Sasakawa Medical Fellowship,Sichuan Science and Technology Department Project(2022089)Sichuan Medical Association Youth Innovation Research Project(Q20019)the Third People’s Hospital of Chengdu Scientific Research Project(2023PI16)Clinical Research Program(CSY-YN-01-2023-015).
文摘Despite the promising prospects of nanoparticles in oral drug delivery,the process of oral administration involves a complex transportation pathway that includes cellular uptake,intracellular trafficking,and exocytosis by intestinal epithelial cells,which are necessary steps for nanoparticles to enter the bloodstream and exert therapeutic effects.Current researchers have identified several crucial factors that regulate the interaction between nanoparticles and intestinal epithelial cells,including surface properties such as ligand modification,surface charge,hydrophilicity/hydrophobicity,intestinal protein corona formation,as well as holistic properties like particle size,shape,and rigidity.Understanding these properties is essential for enhancing transepithelial transport efficiency and designing effective oral drug delivery systems.Therefore,this review provides a comprehensive overview of the surface and holistic properties that influence the transepithelial transport of nanoparticles,elucidating the underlying principles governing their impact on transepithelial transport.The review also outlines the chosen of parameters to be considered for the subsequent design of oral drug delivery systems.
基金supported by the National Natural Science Foundation of China(21972124 and 22272148)。
文摘Advancing and deploying the Fe Ni-based catalyst,the state-of-the-art pre-electrocatalysts,for oxygen evolution reactions(OER)still suffer from unclear chemical state correlation to the catalytic ability,as evidenced by the variedly reported performance for the different Fe Ni structures.Herein,we contributed the phase and redox chemical states tuning of Fe Ni oxides by the surface microenvironment regulation for the OER catalysis that was realized by the urea-assisted pyrolysis and molybdenum-doping technique by integrating molybdenum into the iron–nickel metal-organic precursor.Driven by the complicated and compromised atmosphere,namely,the oxidation state driven by the Mo doping and reduction ability induced by the urea-assisted pyrolysis,could transfer confined Fe Ni oxides to hybrid phases of Fe_(2)O_(3)and FeNi_(3)alloy,and the resultant compromised chemical states by the charge redistribution imparted very high electrocatalytic performance for OER compared with the control samples.The insitu Raman spectroscopy and post-XPS analysis confirmed the facile Fe/Ni oxyhydroxide active phase formation resulting from the proper phase and chemical states,and theoretical analysis disclosed the microenvironment regulation resulting in the charge redistribution forming the electron accumulation and depletion sites to accelerate the oxygen-species to oxyhydroxide-species transformation and enhance the electronic state density near the Fermi level by significantly reducing the energy barrier.The work not only showed the importance of surface chemical state tunning that can basically answer the varied performance of Fe Ni catalysts but also revealed an effective approach for fine-tuning their catalytic properties.
基金supported by the Fundamental Research Funds for the Central Universities(2232022D-15).
文摘Fiber materials are highly desirable for wearable electronics that are expected to be flexible and stretchable.Compared with rigid and planar electronic devices,fiber-based wearable electronics provide significant advantages in terms of flexibility,stretchability and breathability,and they are considered as the pioneers in the new generation of soft wearables.The con-vergence of textile science,electronic engineering and nanotechnology has made it feasible to build electronic functions on fibers and maintain them during wear.Over the last few years,fiber-shaped wearable electronics with desired designability and integration features have been intensively explored and developed.As an indispensable part and cornerstone of flexible wearable devices,fibers are of great significance.Herein,the research progress of advanced fiber materials is reviewed,which mainly includes various material preparations,fabrication technologies and representative studies on different wearable applications.Finally,key challenges and future directions of fiber materials and wearable electronics are examined along with an analysis of possible solutions.
基金financial support from the National Natural Science Foundation of China(No.81872818)the National Key R&D Program of China(No.2021YFE0115200)。
文摘Protein corona(PC)has been identified to impede the transportation of intravenously injected nanoparticles(NPs)from blood circulation to their targeted sites.However,how intestinal PC(IPC)affects the delivery of orally administered NPs are still needed to be elucidated.Here,we found that IPC exerted“positive effect”or“negative effect”depending on different pathological conditions in the gastrointestinal tract.We prepared polystyrene nanoparticles(PS)adsorbed with different IPC derived from the intestinal tract of healthy,diabetic,and colitis rats(H-IPC@PS,D-IPC@PS,C-IPC@PS).Proteomics analysis revealed that,compared with healthy IPC,the two disease-specific IPC consisted of a higher proportion of proteins that were closely correlated with transepithelial transport across the intestine.Consequently,both D-IPC@PS and C-IPC@PS mainly exploited the recycling endosome and ER-Golgi mediated secretory routes for intracellular trafficking,which increased the transcytosis from the epithelium.Together,disease-specific IPC endowed NPs with higher intestinal absorption.D-IPC@PS posed“positive effect”on intestinal absorption into blood circulation for diabetic therapy.Conversely,CIPC@PS had“negative effect”on colitis treatment because of unfavorable absorption in the intestine before arriving colon.These results imply that different or even opposite strategies to modulate the disease-specific IPC need to be adopted for oral nanomedicine in the treatment of variable diseases.
基金supported by National Science Fund for Distinguished Young Scholars of China(No.51625502)Innovative Group Project of National Natural Science Foundation of China(No.51721092)Innovative Group Project of Hubei Province of China(No.2017CFA003)。
文摘Due to the advantages of large workspace,low cost and the integrated vision/force sensing,robotic milling has become an important way for machining of complex parts.In recent years,many scholars have studied the problems existing in the applications of robotic milling,and lots of results have been made in the dynamics,pose planning,deformation control etc.,which provides theoretical guidance for high precision and high efficiency of robotic milling.From the perspective of complex parts robotic milling,this paper focuses on machining process planning and control techniques including the analysis of the robot-workspace,robot trajectory planning,vibration monitoring and control,deformation monitoring and compensation.As well as the principles of these technologies such as robot stiffness characteristics,dynamic characteristics,chatter mechanisms,and deformation mechanisms.The methods and characteristics related to the theory and technology of robotic milling of complex parts are summarized systematically.The latest research progress and achievements in the relevant fields are reviewed.It is hoped that the challenges,strategies and development related to robotic milling could be clarified through the carding work in this paper,so as to promote the application of related theories and technologies in high efficiency and precision intelligent milling with robot for complex parts.
基金This work was supported by the Science and technology guidance project plan of China National Textile And Apparel Council(2017006)Natural Science Foundation of Shandong Province of China(ZR2018QEM004)+2 种基金Research and Development Program of Shandong Province of China(Grant Nos.2019GGXI02022,2019JZZY010340,and 2019JZZY010335)Anhui Province Special Science and Technology Project(201903a05020028)Shandong provincial universities youth innovation technology plan innovation team(2020KJA013).
文摘Disposable medical protective clothing for 2019-nCoV mainly consists of stacked layers with nanopore films,polymer coated nonwoven fabrics and melt-blown nonwoven fabrics against anti-microbial and anti-liquid penetration.However,such structures lack moisture permeability and breathability leading to an uncomfortable,stuffy wearing experience.Here,we propose a novel medical protective clothing material with a superabsorbent layer to enhance moisture absorption.Poly(acrylic acid-co-acrylamide)/polyvinyl alcohol superabsorbent fibers(PAAAM/PVA fibers)were prepared via wet spinning.And the superabsorbent composite layer was stacked from PAAAM/PVA fibers,bamboo pulp fibers(BPF)and ethylene-propyl-ene side by side fibers(ESF).The novel disposable medical protective composite fabric was obtained through gluing the superabsorbent layer to the inner surface of strong antistatic polypropylene nonwoven fabric.The resultant composite fabric possesses excellent absorption and retention capacity for sweat,up to 12.3 g/g and 63.8%,and a maximum hygroscopic rate of 1.04 g/h,higher than that of the conventional material(only 0.53 g/h).The moisture permeability of the novel material reached 12,638.5 g/(m^(2) d),which was 307.6%of the conventional material.The novel material can effectively reduce the humidity inside the protective clothing and significantly improve the comfort of medical staff.