Neon(Ne)seeding is used to cool the edge plasma by radiation to protect the divertor tungsten(W)target in the Experimental Advanced Superconducting Tokamak(EAST).The W sputtering in the outer divertor target with Ne s...Neon(Ne)seeding is used to cool the edge plasma by radiation to protect the divertor tungsten(W)target in the Experimental Advanced Superconducting Tokamak(EAST).The W sputtering in the outer divertor target with Ne seeding is assessed by the divertor visible spectroscopy system.It is observed that the W sputtering flux initially increases with Ne concentration in the divertor despite the decreasing plasma temperature.After reaching a maximum around 25 eV,the W sputtering rate starts to decrease,presenting a suppression effect.The effect on the divertor W sputtering flux and yield due to the competition between the increase of the Ne concentration and the decrease of the plasma temperature is discussed.The results show that enough Ne seeding is essential to effectively reduce the electron temperature and thus to suppress W sputtering.Moreover,ELM suppression is observed when Ne and W impurities enter the core plasma,which could be correlated to the enhanced turbulence transport in the pedestal.展开更多
In this study, magnesium and coconut shell carbon (CSC) were prepared by a ball milled process and used for water disinfection with adsorbing tiny amounts of copper(II). Dissolved oxygen (DO) was reduced to hydrogen p...In this study, magnesium and coconut shell carbon (CSC) were prepared by a ball milled process and used for water disinfection with adsorbing tiny amounts of copper(II). Dissolved oxygen (DO) was reduced to hydrogen peroxide (H_(2)O_(2)) via a two-electron pathway by Mg corrosion. Cu(II) in the wastewater will be enriched on the CSC surface and efficiently catalyzes H2O2 for inactivating E. coli. The results show that E. coli with an initial concentration of approximately 106 CFU/mL was under the detection limit (<4 CFU/mL) within 15 min. All of the Cu(II) could be adsorbed by the composite and catalyzed H2O2 to different active species. The quenching experiments, electron spin resonance (ESR) capture measurements and the UV-vis spectroscopy detection confirmed the present of the hydroxyl radicals (·OH), superoxide radicals (·O_(2)^(-)) and Cu(III). Different with tradition Fenton like process, Cu(III), rather than radicals, played the major role during the Mg-CSC/Cu(II) process. In addition to the cellular membrane damage, most of the bacterial genomic DNA was also be degraded and the bacterial reactivation was avoided. The Mg-CSC/Cu(II) process also showed a satisfied disinfection performance in real wastewater treatment. Overall, this study provides a new strategy for water disinfection.展开更多
This paper investigates the low earth orbit(LEO)satellite-enabled coded compressed sensing(CCS)unsourced random access(URA)in orthogonal frequency division multiple access(OFDMA)framework,where a massive uniform plana...This paper investigates the low earth orbit(LEO)satellite-enabled coded compressed sensing(CCS)unsourced random access(URA)in orthogonal frequency division multiple access(OFDMA)framework,where a massive uniform planar array(UPA)is equipped on the satellite.In LEO satellite communications,unavoidable timing and frequency offsets cause phase shifts in the transmitted signals,substantially diminishing the decoding performance of current terrestrial CCS URA receiver.To cope with this issue,we expand the inner codebook with predefined timing and frequency offsets and formulate the inner decoding as a tractable compressed sensing(CS)problem.Additionally,we leverage the inherent sparsity of the UPA-equipped LEO satellite angular domain channels,thereby enabling the outer decoder to support more active devices.Furthermore,the outputs of the outer decoder are used to reduce the search space of the inner decoder,which cuts down the computational complexity and accelerates the convergence of the inner decoding.Simulation results verify the effectiveness of the proposed scheme.展开更多
Platinum-based alloy nanoparticles are the most attractive catalysts for the oxygen reduction reaction at present,but an in-depth understanding of the relationship between their short-range structural information and ...Platinum-based alloy nanoparticles are the most attractive catalysts for the oxygen reduction reaction at present,but an in-depth understanding of the relationship between their short-range structural information and catalytic performance is still lacking.Herein,we present a synthetic strategy that uses transition-metal oxide-assisted thermal diffusion.PtCo/C catalysts with localized tetragonal distortion were obtained by controlling the thermal diffusion process of transition-metal elements.This localized structural distortion induced a significant strain effect on the nanoparticle surface,which further shortened the length of the Pt-Pt bond,improved the electronic state of the Pt surface,and enhanced the performance of the catalyst.PtCo/C catalysts with special short-range structures achieved excellent mass activity(2.27 Amg_(Pt)^(-1))and specific activity(3.34 A cm^(-2)).In addition,the localized tetragonal distortion-induced surface compression of the Pt skin improved the stability of the catalyst.The mass activity decreased by only 13% after 30,000 cycles.Enhanced catalyst activity and excellent durability have also been demonstrated in the proton exchange membrane fuel cell configuration.This study provides valuable insights into the development of advanced Pt-based nanocatalysts and paves the way for reducing noble-metal loading and increasing the catalytic activity and catalyst stability.展开更多
First mirror(FM)cleaning,using radio frequency(RF)plasma,has been proposed to recover FM reflectivity in nuclear fusion reactors such as the International Thermonuclear Experimental Reactor(ITER).To investigate the in...First mirror(FM)cleaning,using radio frequency(RF)plasma,has been proposed to recover FM reflectivity in nuclear fusion reactors such as the International Thermonuclear Experimental Reactor(ITER).To investigate the influence of simultaneous cleaning of two mirrors on mirror cleaning efficiency and uniformity,experiments involving single-mirror cleaning and dual-mirror cleaning were conducted using RF capacitively coupled plasma in the laboratory.For the test and simultaneous cleaning of two mirrors,the FM and second mirror(SM),both measuring 110 mm×80 mm,were placed inside the first mirror unit(FMU).They were composed of 16 mirror samples,each with a dimension of 27.5 mm×20 mm.These mirror samples consist of a titanium-zirconium-molybdenum alloy substrate,a 500 nm Mo intermediate layer and a 30 nm Al_(2)O_(3) surface coating as a proxy for Be impurities.The cleaning of a single first mirror(SFM)and the simultaneous cleaning of the FM and SM(DFM and DSM)lasted for 9 h using Ar plasma at a pressure of 1 Pa.The total reflectivity of mirror samples on the DSM did not fully recover and varied with location,with a self-bias of−140 V.With a self-bias of−300 V,the total reflectivity of mirror samples on the SFM and DFM was fully recovered.The energy dispersive spectrometer results demonstrated that the Al_(2)O_(3) coating had been completely removed from these mirror samples.However,the mass loss of each mirror sample on the SFM and DFM before and after cleaning varied depending on its location,with higher mass loss observed for mirror samples located in the corners and lower loss for those in the center.Compared with SM cleaning,the simultaneous cleaning of two mirrors reduced the difference between the highest and lowest mass loss.Furthermore,this mass loss for the mirror samples of the DFM facing the DSM was increased.This indicated that mirror samples cleaned face to face in the FMU simultaneously could influence each other,highlighting the need for special attention in future studies.展开更多
Polyetheretherketone(PEEK)has been recognized for its immense potential in hard tissue repair applications due to its mechanical properties resembling those of natural bones.However,the inherent bioinertness of pristi...Polyetheretherketone(PEEK)has been recognized for its immense potential in hard tissue repair applications due to its mechanical properties resembling those of natural bones.However,the inherent bioinertness of pristine PEEK results in insufficient osseointegration.Moreover,implant-associated infection(IAI)has become a serious threat in orthopedic surgery.These risks usually lead to implant loosening,delayed healing,and even the failure of implantation,hampering many clinical applications of PEEK.In this study,we present a facile strategy to endow PEEK implants with enhanced osseointegration and pH-responsive antibacterial activity.Briefly,pristine PEEK was first treated with mixed acids to obtain a porous structure(referred to as SNPEEK),and then the metal-phenolic networks(MPN)coating was prepared using layer-by-layer(LbL)assembly consisting of Sr^(2+) and tannin acid(TA)(referred to as ST coating).The results demonstrated that the dual-functional PEEK displayed enhanced antibacterial activity in pH-responsive manner.At pH 7.4,the antibacterial ratios were 71.72%and 66.79%against Staphylococcus aureus(MSSA,ATCC 25,923)and methicillin-resistant Staphylococcus aureus(MRSA,ATCC BAA-40),respectively.Remarkably,at pH 5.5,the antibacterial activities significantly increased,resulting in killing ratios of 99.98%and 100%,respectively.Furthermore,the dual-functional PEEK promoted osteogenic differentiation of pre-osteoblasts(MC3T3-E1)and migration of human umbilical vascular endothelial cells(HUVECs).In addition,the dual-functional PEEK demonstrated effective anti-infection ability and desirable new bone formation ability in vivo compared to both pristine PEEK and SNPEEK implants.Overall,this study provides a promising strategy to endow PEEK implants with effective osseointegration and anti-infective ability,representing a prospective solution to address current clinical challenges associated with PEEK implants.展开更多
Cellulose acetate(CA)is an important cellulose derivative that can undergo thermoplas-tic processing.Plasticizers can form stable hydrogen bonds with CA molecular chains,reducing intermolecular and intramolecular inte...Cellulose acetate(CA)is an important cellulose derivative that can undergo thermoplas-tic processing.Plasticizers can form stable hydrogen bonds with CA molecular chains,reducing intermolecular and intramolecular interactions,and play an important role in the melting processing of CA.In recent years,environmentally friendly plasticizers that are natural,non-toxic,odorless,low dissolution,and low migration have received increas-ing attention in plastic processing.This article reviews the research progress of environ-mentally friendly plasticizers such as natural plasticizers,ionic liquid plasticizers,citrate plasticizers,and polyethylene glycol plasticizers in the processing of cellulose acetate,and looks forward to the application prospects of environmentally friendly plasticizers.展开更多
Breast cancer is the most common malignant tumor in Chinese women,and its incidence is increasing.Regular screening is an effective method for early tumor detection and improving patient prognosis.In this review,we an...Breast cancer is the most common malignant tumor in Chinese women,and its incidence is increasing.Regular screening is an effective method for early tumor detection and improving patient prognosis.In this review,we analyze the epidemiological changes and risk factors associated with breast cancer in China and describe the establishment of a screening strategy suitable for Chinese women.Chinese patients with breast cancer tend to be younger than Western patients and to have denser breasts.Therefore,the age of initial screening in Chinese women should be earlier,and the importance of screening with a combination of ultrasound and mammography is stressed.Moreover,Chinese patients with breast cancers have several ancestry-specific genetic features,and aiding in the determination of genetic screening strategies for identifying high-risk populations.On the basis of current studies,we summarize the development of risk-stratified breast cancer screening guidelines for Chinese women and describe the significant improvement in the prognosis of patients with breast cancer in China.展开更多
Antibiotics are a category of chemical compounds used to treat bacterial infections and are widely applied in cultivation,animal husbandry,aquaculture,and pharmacy.Currently,residual antibiotics and their metabolites ...Antibiotics are a category of chemical compounds used to treat bacterial infections and are widely applied in cultivation,animal husbandry,aquaculture,and pharmacy.Currently,residual antibiotics and their metabolites pose a potential risk of allergic reactions,bacterial resistance,and increased cancer incidence.Residual antibiotics and the resulting bacterial antibiotic resistance have been recognized as a global challenge that has attracted increasing attention.Therefore,monitoring antibiotics is a critical way to limit the ecological risks from antibiotic pollution.Accordingly,it is desirable to devise new analytical platforms to achieve efficient antibiotic detection with excellent sensitivity and specificity.Quantum dots(QDs)are regarded as an ideal material for use in the development of antibiotic detection biosensors.In this review,we characterize different types of QDs,such as silicon,chalcogenide,carbon,and other doped QDs,and summarize the trends in QD-based antibiotic detection.QD-based sensing applications are classified according to their recognition strategies,including molecularly imprinted polymers(MIPs),aptamers,and immunosensors.We discuss the advantages of QD-derived antibiotic sensors,including low cost,good sensitivity,excellent stability,and fast response,and illustrate the current challenges in this field.展开更多
The radiation-induced degradation of 4-nitrophenol(4-NP) was performed in combination with a Fenton reagent, H_2O_2, and Ti O_2 nanoparticles to investigate the synergetic effects of radiolytical degradation combined ...The radiation-induced degradation of 4-nitrophenol(4-NP) was performed in combination with a Fenton reagent, H_2O_2, and Ti O_2 nanoparticles to investigate the synergetic effects of radiolytical degradation combined with other advanced oxidation processes. The experimental results indicated that the degradation efficiency of 4-NP was 87.5, 57.4, and 41.0 % at a dose of 20 k Gy when its initial concentration was 100, 200, and 350 mg/L, respectively. Radiation combined with H_2O_2, the Fenton method,and Ti O_2 remarkably increased the degradation efficiency of 4-NP, showing the synergetic effects. Radiation may enhance the biodegradability of 4-NP, suggesting that it has the potential to be used as a pretreatment method in combination with the biological method for the treatment of industrial wastewater containing toxic organic pollutants. Major intermediates during the 4-NP degradation process were identified and a possible degradation pathway was tentatively proposed.展开更多
In 2021,EAST realized a steady-state long pulse with a duration over 100 s and a core electron temperature over 10 keV.This is an integrated operation that resolves several key issues,including active control of wall ...In 2021,EAST realized a steady-state long pulse with a duration over 100 s and a core electron temperature over 10 keV.This is an integrated operation that resolves several key issues,including active control of wall conditioning,long-lasting fully noninductive current and divertor heat/particle flux.The fully noninductive current is driven by pure radio frequency(RF)waves with a lower hybrid current drive power of 2.5 MW and electron cyclotron resonance heating of 1.4 MW.This is an excellent experimental platform on the timescale of hundreds of seconds for studying multiscale instabilities,electron-dominant transport and particle recycling(plasma-wall interactions)under weak collisionality.展开更多
In the Experimental Advanced Superconducting Tokamak(EAST),the reflectivity of the charge exchange recombination spectroscopy(CXRS)first mirror(FM)was dramatically dropped down to 20%of the original value after the op...In the Experimental Advanced Superconducting Tokamak(EAST),the reflectivity of the charge exchange recombination spectroscopy(CXRS)first mirror(FM)was dramatically dropped down to 20%of the original value after the operation of two EAST experimental campaigns from 2014-2015,leading to degradation of the signal intensity of the CXRS diagnostic to an unacceptably low level.The radio frequency(RF)plasma cleaning of the CXRS FM with a dimension of 303×81×76 mm3 and a small curvature of 0.008 mm-1 was performed to remove deposits to recover the reflectivity.After 168 h cleaning by RF plasma,the maximum specular reflectivity of the FM could reach 92%of the original value at 532 nm,making the cleaned CXRS FM eligible to be reused for the CXRS diagnostic in the 2016 EAST campaign.Dedicated tests of sputtering polished mirror samples were performed to explore the cleaning uniformity and possible damage to the mirror surface.The specular reflectivity did not show obvious dependence on locations along the surface with the same cleaning time.The measured surface roughness gradually increased with sputtering time.The reflectivity remained almost unchanged regardless of different sputtering times and locations,indicating negligible damage to the FM surface even after 100 h sputtering.The recontaminated CXRS FM in the 2016 EAST campaign was firstly cleaned for 81 h,and the least reflectivity recovery for areas with relatively thick deposits was only 40%.After continuing cleaning to 147 h,redeposition of the sputtered residual deposits on the FM surface was observed.In the future for in situ cleaning of the FMs in EAST and ITER,deposits should be removed timely when they are very thin taking into account a very long cleaning time and presumable redeposition of thick and nonuniform deposits.展开更多
An innovative K+vacant ternary perovskite fluoride(K_(0.89)Ni_(0.02)Co_(0.03)Mn_(0.95)F_(3.0),KNCMF-3#)anode was designed for advanced Li-ion supercapattery(i.e.,Li-ion capacitors/batteries,LIC/Bs).Owing to the conver...An innovative K+vacant ternary perovskite fluoride(K_(0.89)Ni_(0.02)Co_(0.03)Mn_(0.95)F_(3.0),KNCMF-3#)anode was designed for advanced Li-ion supercapattery(i.e.,Li-ion capacitors/batteries,LIC/Bs).Owing to the conversion/insertion dual mechanisms and fast pseudocapacitive con-trol dynamics,the KNCMF-3#electrode exhibits superior electrochemical performance,especially the excellent cycle performance(467%(229 mAh·g^(-1))/1000 cycles/2 A·g^(-1)).Moreover,the hybrid KNCMF-3#/reduced gra-phene oxide(rGO)electrode can further increase the electrochemical performance(217-97 mAh·g^(-1)/0.1-3.2 A·g^(-1),150%(197 mAh·g^(-1))/1000 cycles/2 A·g^(-1)).Also,a novel capacitor/battery cathode,activated carbon(AC)+LiFePO_(4)+graphene(AC+LFP+G),exhibits impres-sive performance(128-82 mAh·g^(-1)/0.1-3.2 A·g^(-1),84%/1000 cycles/2 A·g^(-1)).By the synergistic optimization of anode and cathode,the Li-ion supercapattery KNCMF-3#@rGO//AC+LFP+G demonstrates remarkable per-formance,for example,111.9-23.8 Wh·kg^(-1)/0.4-8.0 kW·kg^(-1)/82%/2000 cycles/5 A·g^(-1)/0-4 V,which is superior to KNCMF-3#//AC LICs,KNCMF-3#@rGO//AC LICs,KNCMF-3#//AC+LFP+G LIC/Bs.In all,the novel Li-ion supercapattery idea adds a promising per-spective to develop advanced energy storage devices.展开更多
The blob properties in I-mode and ELM-free H-mode plasmas compared to L-mode have been investigated on the EAST tokamak,including the blob detection rate Nb,sizeδb,lifetimeτb and radial velocity vr,b.The blob proper...The blob properties in I-mode and ELM-free H-mode plasmas compared to L-mode have been investigated on the EAST tokamak,including the blob detection rate Nb,sizeδb,lifetimeτb and radial velocity vr,b.The blob properties in L-mode and I-mode are similar,and those in ELM-free H-mode are different to them.The blob Nbis smaller whileτbis larger in H-mode.The experimental blob sizeδband velocity scalings vr,b-δb show a good agreement with the theoretical models.The variation in blob properties during the L-I and H-L transitions,and their relations to the scrape-off layer(SOL)density,edge and SOL turbulence,and SOL collisionality are discussed.The suppression of the edge(inside the last closed flux surface)turbulence is not reflected in the blob behavior,while the blob detection rate shows a correlation with the SOL density and its low-frequency(3–50 kH z)fluctuations.In addition,the blob detection rate is found to increase with the divertor collisionalityΛdiv,indicating a dependence of blob behavior onΛdiv.The differences in blob detection rates among the three operating regimes might be due to their different SOL densities and collisionalities.The investigation contributes to understanding the influences of edge and SOL plasma parameters on the blob behavior.展开更多
Well-crystallized MgZnO alloy thin films with hexagonal wurtzite structure were fabricated by sol-gel method. With the band gap increases, the surface roughness and the grain size reduces. It is worth noting that the ...Well-crystallized MgZnO alloy thin films with hexagonal wurtzite structure were fabricated by sol-gel method. With the band gap increases, the surface roughness and the grain size reduces. It is worth noting that the intensity of the band-edge luminescence of Mg doped films enhances with the increase of the Mg content. The microstructure and photoluminescence mechanism have been discussed based on X-ray diffraction patterns, atomic force microscopy images, ultraviolet-visible absorption spectra, photoluminescence spectra and Fourier transform infrared spectra.展开更多
The generation of runaway electrons(REs)is observed during the low-density helium ohmic plasma discharge in the Experimental Advanced Superconducting Tokamak(EAST).The growth rate of hard x-ray(HXR)is inversely propor...The generation of runaway electrons(REs)is observed during the low-density helium ohmic plasma discharge in the Experimental Advanced Superconducting Tokamak(EAST).The growth rate of hard x-ray(HXR)is inversely proportional to the line-average density.Besides,the RE generation in helium plasma is higher than that in deuterium plasma at the same density,which is obtained by comparing the growth rate of HXR with the same discharge conditions.The potential reason is the higher electron temperature of helium plasma in the same current and electron density plateau.Furthermore,two Alfvén eigenmodes driven by REs have been observed.The frequency evolution of the mode is not fully satisfied with the Alfvén scaling and when extension of the Alfvén frequency is towards 0,the high frequency branch is~50 kHz.The different spatial position of the two modes and the evolution of the helium concentration could be used to understand deviation between theoretical and experimental observation.展开更多
Detachment in helium(He)discharges has been achieved in the EAST superconducting tokamak equipped with an ITER-like tungsten divertor.This paper presents the experimental observations of divertor detachment achieved b...Detachment in helium(He)discharges has been achieved in the EAST superconducting tokamak equipped with an ITER-like tungsten divertor.This paper presents the experimental observations of divertor detachment achieved by increasing the plasma density in He discharges.During density ramp-up,the particle flux shows a clear rollover,while the electron temperature around the outer strike point is decreasing simultaneously.The divertor detachment also exhibits a significant difference from that observed in comparable deuterium(D)discharges.The density threshold of detachment in the He plasma is higher than that in the D plasma for the same heating power,and increases with the heating power.Moreover,detachment assisted with neon(Ne)seeding was also performed in L-and H-mode plasmas,pointing to the direction for reducing the density threshold of detachment in He operation.However,excessive Ne seeding causes confinement degradation during the divertor detachment phase.The precise feedback control of impurity seeding will be performed in EAST to improve the compatibility of core plasma performance with divertor detachment for future high heating power operations.展开更多
基金supported by the National Key Research and Development Program of China(Grant Nos.2017YFE0301300,2017YFA0402500,and 2018YFE0303103)the National Natural Science Foundation of China(Grant Nos.12192283 and 12022511)+3 种基金the Users with Excellence Project of Hefei Science Center,CAS(Grant No.2018HSC-UE008)the CASHIPS Director’s Fund(Grant No.BJPY2019B01)the JSPS-CAS Bilateral Joint Research Project(Grant No.GJHZ201984)the Key Research Program of Frontier Sciences of CAS(Grant No.ZDBS-LY-SLH010)。
文摘Neon(Ne)seeding is used to cool the edge plasma by radiation to protect the divertor tungsten(W)target in the Experimental Advanced Superconducting Tokamak(EAST).The W sputtering in the outer divertor target with Ne seeding is assessed by the divertor visible spectroscopy system.It is observed that the W sputtering flux initially increases with Ne concentration in the divertor despite the decreasing plasma temperature.After reaching a maximum around 25 eV,the W sputtering rate starts to decrease,presenting a suppression effect.The effect on the divertor W sputtering flux and yield due to the competition between the increase of the Ne concentration and the decrease of the plasma temperature is discussed.The results show that enough Ne seeding is essential to effectively reduce the electron temperature and thus to suppress W sputtering.Moreover,ELM suppression is observed when Ne and W impurities enter the core plasma,which could be correlated to the enhanced turbulence transport in the pedestal.
基金the National Natural Science Foundation of China (No. 22006016)the Key Project of Fujian Provincial Department of Science and Technology (Nos. 2021Y0009 and 2019Y0010)the Natural Science Foundation of Fujian Province, China (No. 2021J011026).
文摘In this study, magnesium and coconut shell carbon (CSC) were prepared by a ball milled process and used for water disinfection with adsorbing tiny amounts of copper(II). Dissolved oxygen (DO) was reduced to hydrogen peroxide (H_(2)O_(2)) via a two-electron pathway by Mg corrosion. Cu(II) in the wastewater will be enriched on the CSC surface and efficiently catalyzes H2O2 for inactivating E. coli. The results show that E. coli with an initial concentration of approximately 106 CFU/mL was under the detection limit (<4 CFU/mL) within 15 min. All of the Cu(II) could be adsorbed by the composite and catalyzed H2O2 to different active species. The quenching experiments, electron spin resonance (ESR) capture measurements and the UV-vis spectroscopy detection confirmed the present of the hydroxyl radicals (·OH), superoxide radicals (·O_(2)^(-)) and Cu(III). Different with tradition Fenton like process, Cu(III), rather than radicals, played the major role during the Mg-CSC/Cu(II) process. In addition to the cellular membrane damage, most of the bacterial genomic DNA was also be degraded and the bacterial reactivation was avoided. The Mg-CSC/Cu(II) process also showed a satisfied disinfection performance in real wastewater treatment. Overall, this study provides a new strategy for water disinfection.
基金supported by the National Key R&D Program of China under Grant 2023YFB2904703the National Natural Science Foundation of China under Grant 62341110,62371122 and 62322104+1 种基金the Jiangsu Province Basic Research Project under Grant BK20192002the Fundamental Research Funds for the Central Universities under Grant 2242022k30005 and 2242023K5003。
文摘This paper investigates the low earth orbit(LEO)satellite-enabled coded compressed sensing(CCS)unsourced random access(URA)in orthogonal frequency division multiple access(OFDMA)framework,where a massive uniform planar array(UPA)is equipped on the satellite.In LEO satellite communications,unavoidable timing and frequency offsets cause phase shifts in the transmitted signals,substantially diminishing the decoding performance of current terrestrial CCS URA receiver.To cope with this issue,we expand the inner codebook with predefined timing and frequency offsets and formulate the inner decoding as a tractable compressed sensing(CS)problem.Additionally,we leverage the inherent sparsity of the UPA-equipped LEO satellite angular domain channels,thereby enabling the outer decoder to support more active devices.Furthermore,the outputs of the outer decoder are used to reduce the search space of the inner decoder,which cuts down the computational complexity and accelerates the convergence of the inner decoding.Simulation results verify the effectiveness of the proposed scheme.
基金supported by the National Natural Science Foundation of China (Grant No.22278123).
文摘Platinum-based alloy nanoparticles are the most attractive catalysts for the oxygen reduction reaction at present,but an in-depth understanding of the relationship between their short-range structural information and catalytic performance is still lacking.Herein,we present a synthetic strategy that uses transition-metal oxide-assisted thermal diffusion.PtCo/C catalysts with localized tetragonal distortion were obtained by controlling the thermal diffusion process of transition-metal elements.This localized structural distortion induced a significant strain effect on the nanoparticle surface,which further shortened the length of the Pt-Pt bond,improved the electronic state of the Pt surface,and enhanced the performance of the catalyst.PtCo/C catalysts with special short-range structures achieved excellent mass activity(2.27 Amg_(Pt)^(-1))and specific activity(3.34 A cm^(-2)).In addition,the localized tetragonal distortion-induced surface compression of the Pt skin improved the stability of the catalyst.The mass activity decreased by only 13% after 30,000 cycles.Enhanced catalyst activity and excellent durability have also been demonstrated in the proton exchange membrane fuel cell configuration.This study provides valuable insights into the development of advanced Pt-based nanocatalysts and paves the way for reducing noble-metal loading and increasing the catalytic activity and catalyst stability.
基金supported by the National Key R&D Project of China(No.2022YFE03030000)National Natural Science Foundation of China(Nos.11975269,12275306 and 12075279)+3 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2022452)the Anhui Provincial Natural Science Foundation(No.2208085J40)the CASHIPS Director’s Fund(Nos.YZJJQY202302 and BJPY2023B03)the Comprehensive Research Facility for Fusion Technology Program of China(No.2018-000052-73-01-001228).
文摘First mirror(FM)cleaning,using radio frequency(RF)plasma,has been proposed to recover FM reflectivity in nuclear fusion reactors such as the International Thermonuclear Experimental Reactor(ITER).To investigate the influence of simultaneous cleaning of two mirrors on mirror cleaning efficiency and uniformity,experiments involving single-mirror cleaning and dual-mirror cleaning were conducted using RF capacitively coupled plasma in the laboratory.For the test and simultaneous cleaning of two mirrors,the FM and second mirror(SM),both measuring 110 mm×80 mm,were placed inside the first mirror unit(FMU).They were composed of 16 mirror samples,each with a dimension of 27.5 mm×20 mm.These mirror samples consist of a titanium-zirconium-molybdenum alloy substrate,a 500 nm Mo intermediate layer and a 30 nm Al_(2)O_(3) surface coating as a proxy for Be impurities.The cleaning of a single first mirror(SFM)and the simultaneous cleaning of the FM and SM(DFM and DSM)lasted for 9 h using Ar plasma at a pressure of 1 Pa.The total reflectivity of mirror samples on the DSM did not fully recover and varied with location,with a self-bias of−140 V.With a self-bias of−300 V,the total reflectivity of mirror samples on the SFM and DFM was fully recovered.The energy dispersive spectrometer results demonstrated that the Al_(2)O_(3) coating had been completely removed from these mirror samples.However,the mass loss of each mirror sample on the SFM and DFM before and after cleaning varied depending on its location,with higher mass loss observed for mirror samples located in the corners and lower loss for those in the center.Compared with SM cleaning,the simultaneous cleaning of two mirrors reduced the difference between the highest and lowest mass loss.Furthermore,this mass loss for the mirror samples of the DFM facing the DSM was increased.This indicated that mirror samples cleaned face to face in the FMU simultaneously could influence each other,highlighting the need for special attention in future studies.
基金supported by the National Natu-ral Science Foundation of China(No.52073230)the Shaanxi Provincial Science Fund for Distinguished Young Scholars(No.2023-JC-JQ-32).
文摘Polyetheretherketone(PEEK)has been recognized for its immense potential in hard tissue repair applications due to its mechanical properties resembling those of natural bones.However,the inherent bioinertness of pristine PEEK results in insufficient osseointegration.Moreover,implant-associated infection(IAI)has become a serious threat in orthopedic surgery.These risks usually lead to implant loosening,delayed healing,and even the failure of implantation,hampering many clinical applications of PEEK.In this study,we present a facile strategy to endow PEEK implants with enhanced osseointegration and pH-responsive antibacterial activity.Briefly,pristine PEEK was first treated with mixed acids to obtain a porous structure(referred to as SNPEEK),and then the metal-phenolic networks(MPN)coating was prepared using layer-by-layer(LbL)assembly consisting of Sr^(2+) and tannin acid(TA)(referred to as ST coating).The results demonstrated that the dual-functional PEEK displayed enhanced antibacterial activity in pH-responsive manner.At pH 7.4,the antibacterial ratios were 71.72%and 66.79%against Staphylococcus aureus(MSSA,ATCC 25,923)and methicillin-resistant Staphylococcus aureus(MRSA,ATCC BAA-40),respectively.Remarkably,at pH 5.5,the antibacterial activities significantly increased,resulting in killing ratios of 99.98%and 100%,respectively.Furthermore,the dual-functional PEEK promoted osteogenic differentiation of pre-osteoblasts(MC3T3-E1)and migration of human umbilical vascular endothelial cells(HUVECs).In addition,the dual-functional PEEK demonstrated effective anti-infection ability and desirable new bone formation ability in vivo compared to both pristine PEEK and SNPEEK implants.Overall,this study provides a promising strategy to endow PEEK implants with effective osseointegration and anti-infective ability,representing a prospective solution to address current clinical challenges associated with PEEK implants.
文摘Cellulose acetate(CA)is an important cellulose derivative that can undergo thermoplas-tic processing.Plasticizers can form stable hydrogen bonds with CA molecular chains,reducing intermolecular and intramolecular interactions,and play an important role in the melting processing of CA.In recent years,environmentally friendly plasticizers that are natural,non-toxic,odorless,low dissolution,and low migration have received increas-ing attention in plastic processing.This article reviews the research progress of environ-mentally friendly plasticizers such as natural plasticizers,ionic liquid plasticizers,citrate plasticizers,and polyethylene glycol plasticizers in the processing of cellulose acetate,and looks forward to the application prospects of environmentally friendly plasticizers.
基金This work was supported by Grants from the National Key R&D Project of China(Grant No.2020YFA0112304)the National Natural Science Foundation of China(Grant Nos.91959207,92159301 and 82002792)+3 种基金the Shanghai Key Laboratory of Breast Cancer(Grant No.12DZ2260100)the Shanghai Key Clinical Specialty of Oncology(Grant No.shslczdzk02001)the Clinical Research Plan of SHDC(Grant Nos.SHDC2020CR4002 and SHDC2020CR5005)the Shanghai Sailing Program(Grant No.20YF1408600).
文摘Breast cancer is the most common malignant tumor in Chinese women,and its incidence is increasing.Regular screening is an effective method for early tumor detection and improving patient prognosis.In this review,we analyze the epidemiological changes and risk factors associated with breast cancer in China and describe the establishment of a screening strategy suitable for Chinese women.Chinese patients with breast cancer tend to be younger than Western patients and to have denser breasts.Therefore,the age of initial screening in Chinese women should be earlier,and the importance of screening with a combination of ultrasound and mammography is stressed.Moreover,Chinese patients with breast cancers have several ancestry-specific genetic features,and aiding in the determination of genetic screening strategies for identifying high-risk populations.On the basis of current studies,we summarize the development of risk-stratified breast cancer screening guidelines for Chinese women and describe the significant improvement in the prognosis of patients with breast cancer in China.
基金supported by grants from the National Key Research and Development Project(Project No.:2019YFC1605800)the National Natural Science Foundation of China(Grant Nos.:22006070 and 82103816)+2 种基金the Natural Science Foundation of Jiangsu Province(Grant Nos.:BK20200715,BK20200718,and BK20210538)the Natural Science Foundation of Jiangsu Higher Education Institutions,China(Grant No.:20KJB350010)the Natural Science Fund for Colleges and Universities in Jiangsu Province(Grant No.:19KJB530011).
文摘Antibiotics are a category of chemical compounds used to treat bacterial infections and are widely applied in cultivation,animal husbandry,aquaculture,and pharmacy.Currently,residual antibiotics and their metabolites pose a potential risk of allergic reactions,bacterial resistance,and increased cancer incidence.Residual antibiotics and the resulting bacterial antibiotic resistance have been recognized as a global challenge that has attracted increasing attention.Therefore,monitoring antibiotics is a critical way to limit the ecological risks from antibiotic pollution.Accordingly,it is desirable to devise new analytical platforms to achieve efficient antibiotic detection with excellent sensitivity and specificity.Quantum dots(QDs)are regarded as an ideal material for use in the development of antibiotic detection biosensors.In this review,we characterize different types of QDs,such as silicon,chalcogenide,carbon,and other doped QDs,and summarize the trends in QD-based antibiotic detection.QD-based sensing applications are classified according to their recognition strategies,including molecularly imprinted polymers(MIPs),aptamers,and immunosensors.We discuss the advantages of QD-derived antibiotic sensors,including low cost,good sensitivity,excellent stability,and fast response,and illustrate the current challenges in this field.
基金supported by the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT-13026)the National High Technology Research and Development Program (No. 2009AA063905)+1 种基金the International S&T Cooperation Program (ISTCP) of China (No. 2009DFB90600)the National Natural Science Foundation of China (No. 51338005)
文摘The radiation-induced degradation of 4-nitrophenol(4-NP) was performed in combination with a Fenton reagent, H_2O_2, and Ti O_2 nanoparticles to investigate the synergetic effects of radiolytical degradation combined with other advanced oxidation processes. The experimental results indicated that the degradation efficiency of 4-NP was 87.5, 57.4, and 41.0 % at a dose of 20 k Gy when its initial concentration was 100, 200, and 350 mg/L, respectively. Radiation combined with H_2O_2, the Fenton method,and Ti O_2 remarkably increased the degradation efficiency of 4-NP, showing the synergetic effects. Radiation may enhance the biodegradability of 4-NP, suggesting that it has the potential to be used as a pretreatment method in combination with the biological method for the treatment of industrial wastewater containing toxic organic pollutants. Major intermediates during the 4-NP degradation process were identified and a possible degradation pathway was tentatively proposed.
基金the National Key R&D Program of China(No.2022YFE03010003)National Natural Science Foundation of China(No.12275309).
文摘In 2021,EAST realized a steady-state long pulse with a duration over 100 s and a core electron temperature over 10 keV.This is an integrated operation that resolves several key issues,including active control of wall conditioning,long-lasting fully noninductive current and divertor heat/particle flux.The fully noninductive current is driven by pure radio frequency(RF)waves with a lower hybrid current drive power of 2.5 MW and electron cyclotron resonance heating of 1.4 MW.This is an excellent experimental platform on the timescale of hundreds of seconds for studying multiscale instabilities,electron-dominant transport and particle recycling(plasma-wall interactions)under weak collisionality.
基金National Natural Science Foundation of China(Nos.11975269,11905252,11675218,11675219,11775260,11861131010,11875230)the National Key R&D Program of China(Nos.2017YFA0402500 and 2017YFE0301300)。
文摘In the Experimental Advanced Superconducting Tokamak(EAST),the reflectivity of the charge exchange recombination spectroscopy(CXRS)first mirror(FM)was dramatically dropped down to 20%of the original value after the operation of two EAST experimental campaigns from 2014-2015,leading to degradation of the signal intensity of the CXRS diagnostic to an unacceptably low level.The radio frequency(RF)plasma cleaning of the CXRS FM with a dimension of 303×81×76 mm3 and a small curvature of 0.008 mm-1 was performed to remove deposits to recover the reflectivity.After 168 h cleaning by RF plasma,the maximum specular reflectivity of the FM could reach 92%of the original value at 532 nm,making the cleaned CXRS FM eligible to be reused for the CXRS diagnostic in the 2016 EAST campaign.Dedicated tests of sputtering polished mirror samples were performed to explore the cleaning uniformity and possible damage to the mirror surface.The specular reflectivity did not show obvious dependence on locations along the surface with the same cleaning time.The measured surface roughness gradually increased with sputtering time.The reflectivity remained almost unchanged regardless of different sputtering times and locations,indicating negligible damage to the FM surface even after 100 h sputtering.The recontaminated CXRS FM in the 2016 EAST campaign was firstly cleaned for 81 h,and the least reflectivity recovery for areas with relatively thick deposits was only 40%.After continuing cleaning to 147 h,redeposition of the sputtered residual deposits on the FM surface was observed.In the future for in situ cleaning of the FMs in EAST and ITER,deposits should be removed timely when they are very thin taking into account a very long cleaning time and presumable redeposition of thick and nonuniform deposits.
基金financially supported by the National Natural Science Foundation of China (No. 22078279)
文摘An innovative K+vacant ternary perovskite fluoride(K_(0.89)Ni_(0.02)Co_(0.03)Mn_(0.95)F_(3.0),KNCMF-3#)anode was designed for advanced Li-ion supercapattery(i.e.,Li-ion capacitors/batteries,LIC/Bs).Owing to the conversion/insertion dual mechanisms and fast pseudocapacitive con-trol dynamics,the KNCMF-3#electrode exhibits superior electrochemical performance,especially the excellent cycle performance(467%(229 mAh·g^(-1))/1000 cycles/2 A·g^(-1)).Moreover,the hybrid KNCMF-3#/reduced gra-phene oxide(rGO)electrode can further increase the electrochemical performance(217-97 mAh·g^(-1)/0.1-3.2 A·g^(-1),150%(197 mAh·g^(-1))/1000 cycles/2 A·g^(-1)).Also,a novel capacitor/battery cathode,activated carbon(AC)+LiFePO_(4)+graphene(AC+LFP+G),exhibits impres-sive performance(128-82 mAh·g^(-1)/0.1-3.2 A·g^(-1),84%/1000 cycles/2 A·g^(-1)).By the synergistic optimization of anode and cathode,the Li-ion supercapattery KNCMF-3#@rGO//AC+LFP+G demonstrates remarkable per-formance,for example,111.9-23.8 Wh·kg^(-1)/0.4-8.0 kW·kg^(-1)/82%/2000 cycles/5 A·g^(-1)/0-4 V,which is superior to KNCMF-3#//AC LICs,KNCMF-3#@rGO//AC LICs,KNCMF-3#//AC+LFP+G LIC/Bs.In all,the novel Li-ion supercapattery idea adds a promising per-spective to develop advanced energy storage devices.
基金supported by the National Key R&D Program of China(Nos.2022YFE03020004,2017YFE0301300,2018YFE0303104 and 2019YFE03030000)the Major Science and Technology Infrastructure Maintenance and Reconstruction Projects of the Chinese Academy of Sciences+3 种基金National Natural Science Foundation of China(Nos.12275313,11922513,12005004 and U19A20113)the Institute of Energy,Hefei Comprehensive National Science Center(No.GXXT-2020-004)the Anhui Provincial Natural Science Foundation(No.2008085QA38)the Users with Excellence Program of Hefei Science Center,Chinese Academy of Sciences(No.2020HSC-UE009)。
文摘The blob properties in I-mode and ELM-free H-mode plasmas compared to L-mode have been investigated on the EAST tokamak,including the blob detection rate Nb,sizeδb,lifetimeτb and radial velocity vr,b.The blob properties in L-mode and I-mode are similar,and those in ELM-free H-mode are different to them.The blob Nbis smaller whileτbis larger in H-mode.The experimental blob sizeδband velocity scalings vr,b-δb show a good agreement with the theoretical models.The variation in blob properties during the L-I and H-L transitions,and their relations to the scrape-off layer(SOL)density,edge and SOL turbulence,and SOL collisionality are discussed.The suppression of the edge(inside the last closed flux surface)turbulence is not reflected in the blob behavior,while the blob detection rate shows a correlation with the SOL density and its low-frequency(3–50 kH z)fluctuations.In addition,the blob detection rate is found to increase with the divertor collisionalityΛdiv,indicating a dependence of blob behavior onΛdiv.The differences in blob detection rates among the three operating regimes might be due to their different SOL densities and collisionalities.The investigation contributes to understanding the influences of edge and SOL plasma parameters on the blob behavior.
基金supported by the National Natural Science Foundation of China(Nos.10674023 and 60725413)863 Program(No.2006AA03Z313)+1 种基金973 Program(No.2007CB936300)the NSFJ(No.BK2006090)
文摘Well-crystallized MgZnO alloy thin films with hexagonal wurtzite structure were fabricated by sol-gel method. With the band gap increases, the surface roughness and the grain size reduces. It is worth noting that the intensity of the band-edge luminescence of Mg doped films enhances with the increase of the Mg content. The microstructure and photoluminescence mechanism have been discussed based on X-ray diffraction patterns, atomic force microscopy images, ultraviolet-visible absorption spectra, photoluminescence spectra and Fourier transform infrared spectra.
基金Project supported by the National Key R&D Program of China(Grant Nos.2017YFE0301205 and 2022YFE03050003)the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.Y2021116)+1 种基金the National Natural Science Foundation of China(Grant Nos.12005262,12105186,12175277,and 11975271)the Users of Excellence Program of Hefei Science Center CAS(Grant No.2021HSC-UE016).
文摘The generation of runaway electrons(REs)is observed during the low-density helium ohmic plasma discharge in the Experimental Advanced Superconducting Tokamak(EAST).The growth rate of hard x-ray(HXR)is inversely proportional to the line-average density.Besides,the RE generation in helium plasma is higher than that in deuterium plasma at the same density,which is obtained by comparing the growth rate of HXR with the same discharge conditions.The potential reason is the higher electron temperature of helium plasma in the same current and electron density plateau.Furthermore,two Alfvén eigenmodes driven by REs have been observed.The frequency evolution of the mode is not fully satisfied with the Alfvén scaling and when extension of the Alfvén frequency is towards 0,the high frequency branch is~50 kHz.The different spatial position of the two modes and the evolution of the helium concentration could be used to understand deviation between theoretical and experimental observation.
基金supported by the National Key Research and Development Program of China(Nos.2017YFA0301300,2017YFE0402500 and 2019YFE03030000)National Natural Science Foundation of China(Nos.11905255,12005004,12022511,U1867222 and U19A20113)+3 种基金the Institute of Energy,Hefei Comprehensive National Science Center(No.GXXT-2020-004)AHNSF(No.2008085QA38)the CASHIPS Director’s Fund(No.BJPY2019B01)the Key Research Program of Frontier Sciences of CAS(No.ZDBS-LY-SLH010)。
文摘Detachment in helium(He)discharges has been achieved in the EAST superconducting tokamak equipped with an ITER-like tungsten divertor.This paper presents the experimental observations of divertor detachment achieved by increasing the plasma density in He discharges.During density ramp-up,the particle flux shows a clear rollover,while the electron temperature around the outer strike point is decreasing simultaneously.The divertor detachment also exhibits a significant difference from that observed in comparable deuterium(D)discharges.The density threshold of detachment in the He plasma is higher than that in the D plasma for the same heating power,and increases with the heating power.Moreover,detachment assisted with neon(Ne)seeding was also performed in L-and H-mode plasmas,pointing to the direction for reducing the density threshold of detachment in He operation.However,excessive Ne seeding causes confinement degradation during the divertor detachment phase.The precise feedback control of impurity seeding will be performed in EAST to improve the compatibility of core plasma performance with divertor detachment for future high heating power operations.
