Based on the dinuclear system model,the calculated evaporation residue cross sections matched well with the current experimental results.The synthesis of superheavy elements Z=121 was systematically studied through co...Based on the dinuclear system model,the calculated evaporation residue cross sections matched well with the current experimental results.The synthesis of superheavy elements Z=121 was systematically studied through combinations of stable projectiles with Z=21-30 and targets with half-lives exceeding 50 d.The influence of mass asymmetry and isotopic dependence on the projectile and target nuclei was investigated in detail.The reactions^(254)Es(^(46)Ti,3n)^(297)121 and^(252)Es(^(46)Ti,3n)^(295)121 were found to be experimentally feasible for synthesizing superheavy element Z=121,with maximal evaporation residue cross sections of 6.619 and 4.123 fb at 219.9 and 223.9 MeV,respectively.展开更多
Based on the dinuclear system model,the synthesis of the predicted double-magic nuclei^(298)Fl and 304120 was investigated via neutron-rich radioactive beam-induced fusion reactions.The reaction^(58)Ca+^(244)Pu is pre...Based on the dinuclear system model,the synthesis of the predicted double-magic nuclei^(298)Fl and 304120 was investigated via neutron-rich radioactive beam-induced fusion reactions.The reaction^(58)Ca+^(244)Pu is predicted to be favorable for producing^(298)Fl with a maximal ER cross section of 0.301 pb.Investigations of the entrance channel effect reveal that the^(244)Pu target is more promising for synthesizing^(298)Fl than the neutron-rich targets^(248)Cm and^(249)Bk,because of the influence of the Coulomb barrier.For the synthesis of 304120,the maximal ER cross section of 0.046 fb emerges in the reaction^(58)V+^(249)Bk,indicating the need for further advancements in both experimental facilities and reaction mechanisms.展开更多
In this work,plasma electrolytic oxidation(PEO)coatings were produced on magnesium alloy AZ31 in aluminate,silicate and phosphate-based electrolytes,and followed by hydrothermal treatments in order to synthesis layere...In this work,plasma electrolytic oxidation(PEO)coatings were produced on magnesium alloy AZ31 in aluminate,silicate and phosphate-based electrolytes,and followed by hydrothermal treatments in order to synthesis layered double hydroxides(LDHs)based nanocontainers.LDHs synthesis was done in three different growth solutions(deionized water,sodium nitrate and aluminum nitrate containing solution).In frame of this work it was shown,that it was difficult to form LDHs on Si-based PEO coating,due to more stable silicate phases in comparison with aluminate and phosphate phases in respective PEO coatings.The obtained hybrid LDH/PEO coatings were characterized using SEM,EDS and GDOES,and then the corrosion protection was further investigated by EIS.Based on the obtained results,it was confirmed that,the hydrothermal treatments in Al^(3+)containing solution played an important role on overall corrosion resistance for phosphate and silicate-based PEO coatings,but not for Al-based PEO coatings.展开更多
Previous studies on genetic diseases predominantly focused on protein-coding variations, overlooking the vast noncoding regions in the human genome. The development of high-throughput sequencing technologies and funct...Previous studies on genetic diseases predominantly focused on protein-coding variations, overlooking the vast noncoding regions in the human genome. The development of high-throughput sequencing technologies and functional genomics tools has enabled the systematic identification of functional noncoding variants. These variants can impact gene expression, regulation, and chromatin conformation, thereby contributing to disease pathogenesis. Understanding the mechanisms that underlie the impact of noncoding variants on genetic diseases is indispensable for the development of precisely targeted therapies and the implementation of personalized medicine strategies. The intricacies of noncoding regions introduce a multitude of challenges and research opportunities. In this review, we introduce a spectrum of noncoding variants involved in genetic diseases, along with research strategies and advanced technologies for their precise identification and in-depth understanding of the complexity of the noncoding genome. We will delve into the research challenges and propose potential solutions for unraveling the genetic basis of rare and complex diseases.展开更多
We numerically investigate the breathing dynamics induced by collision between bright solitons in a binary dipolar Bose–Einstein condensates, whose dipole–dipole interaction and contact interaction are attractive. W...We numerically investigate the breathing dynamics induced by collision between bright solitons in a binary dipolar Bose–Einstein condensates, whose dipole–dipole interaction and contact interaction are attractive. We identify three special breathing structures, such as snakelike special breathing structure, mixed breathing structure, and divide breathing structure.The characteristics of these breathing structures can be described by breathing frequency ?, maximum breathing amplitude A and lifetime τ, which can be manipulated by atomic number Ni and interspecies scattering length a12. Meanwhile, the above breathing structures can realize the process of quasi-transition with a reasonable Ni and a12. Additionally, the collision of two special breathing structures also can bring more abundant breathing dynamics. Our results provide a reference for the study of soliton interactions and deepen the understanding of soliton properties in a binary dipolar Bose–Einstein condensates.展开更多
The production mechanism of heavy neutronrich nuclei is investigated by using the multinucleon transfer reactions of ^(136;148)Xe+^(208)Pb and ^(238)U+^(208)Pb in the framework of a dinuclear system model. The evapora...The production mechanism of heavy neutronrich nuclei is investigated by using the multinucleon transfer reactions of ^(136;148)Xe+^(208)Pb and ^(238)U+^(208)Pb in the framework of a dinuclear system model. The evaporation residual cross sections of target-like fragments are studied with the reaction system ^(148)Xe+^(208)Pb at near barrier energies. The results show that the final isotopic production cross sections in the neutron-deficient side are very sensitive to incident energy while it is not sensitive in the neutron-rich side. Comparing the isotopic production cross sections for the reactions of ^(208)Pb bombarded with stable and radioactive projectiles, we find that neutron-rich radioactive beams can significantly increase the production cross sections of heavy neutron-rich nuclei.展开更多
BACKGROUND: The study aimed to investigate the clinical characteristics of acute renal failure(ARF) caused by oral acyclovir.METHODS: A 45-year-old Chinese male patient with acyclovir-induced ARF suffered fromabdo...BACKGROUND: The study aimed to investigate the clinical characteristics of acute renal failure(ARF) caused by oral acyclovir.METHODS: A 45-year-old Chinese male patient with acyclovir-induced ARF suffered fromabdominal pain for one day. The pain was extended to the epigastric area from the right lowerquadrant. Transient oliguria was seen in addition to microscopic hematuria and proteinuria. Theserum creatinine concentration was 304 !mol/L. Eight days before the occurrence of ARF, the patienttook oral acyclovir for facial neuritis.RESULTS: His renal function was restored completely following the discontinuation of acyclovir,with continuous renal replacement therapy for 54 hours and some symptomatic treatment.CONCLUSION: The presentation of acute renal failure caused by acyclovir can be diverse, butthe prognosis is good after active treatment.展开更多
East China(23.6°–38.4°N,113.6°–122.9°E)is the largest developed region in China.Based on CO2 products retrieved from the Greenhouse Gases Observing Satellite(GOSAT),the spatial and temporal distr...East China(23.6°–38.4°N,113.6°–122.9°E)is the largest developed region in China.Based on CO2 products retrieved from the Greenhouse Gases Observing Satellite(GOSAT),the spatial and temporal distributions of CO2 mixing ratios in East China during 2014–17 are discussed,and the retrieved CO2 from AIRS(Atmospheric Infrared Sounder)and OCO-2(Orbiting Carbon Observatory-2),as well as WLG(Waliguan)background station observations,are compared with those of GOSAT.The annual CO2 retrieved from GOSAT in East China ranged from 398.96±0.24 ppm in 2014 to 407.39±0.20 ppm in 2017,with a growth rate of 2.82±0.15 ppm yr^−1,which were higher than in other regions of China.The seasonal cycle presented a maximum in spring and a minimum in summer or autumn.Higher values were mainly concentrated in the coastal areas of Zhejiang Province,and lower values were concentrated in Jiangxi and the north of Fujian Province.CO2 observed in Fujian and parts of Jiangxi increased by less than 1.0 ppm during 2014–15,but enhanced significantly by more than 5.0 ppm during 2015–16,perhaps influenced by local emissions and global impacts.We calculated year-to-year CO2 enhancements in the Yangtze River Delta region during 2014–17 that were relatively low and stable,due to the region’s carbon emissions control and reduction policies.The annual and seasonal amplitudes of CO2 retrieved from AIRS were lower than those from GOSAT in East China,probably owing to the CO2 retrieved from AIRS better reflecting the characteristics of the mid-troposphere,while GOSAT is more representative of near-surface CO2.The spatial and temporal distribution characteristics of CO2 retrieved from OCO-2 were close to those from GOSAT in East China.展开更多
This work produced a Mg Al-layered double hydroxide by hydrothermal treatment of a plasma electrolytic oxidation(PEO) coating on magnesium alloy AZ31 in an phosphate electrolyte, followed by an ion-exchange reaction i...This work produced a Mg Al-layered double hydroxide by hydrothermal treatment of a plasma electrolytic oxidation(PEO) coating on magnesium alloy AZ31 in an phosphate electrolyte, followed by an ion-exchange reaction in 0.1 M phosphate solution. The coated specimens were scratched. Characterization, including utilization of the localized technique SIET, measured the pH and p Mg distributions and optical morphologies around the artificial defects during immersion in 0.05 M NaCl solution. In contrast with phosphate loaded PEO/LDHs, a stronger alkalinization area(with pH 11.4~12.3) appeared in the passive PEO specimens. Due to formation of insoluble Mg(OH)_(2) products, the p Mg map showed depletion of Mg^(2+) in this high p H area. Combined with optical morphologies and SEM images, the better self-healing ability toward defects for phosphate loaded PEO/LDHs was confirmed.展开更多
Retroperitoneal liposarcoma(RLPS)is the main subtype of retroperitoneal soft sarcoma(RSTS)and has a poor prognosis and few treatment options,except for surgery.The proteomic and metabolic profiles of RLPS have remaine...Retroperitoneal liposarcoma(RLPS)is the main subtype of retroperitoneal soft sarcoma(RSTS)and has a poor prognosis and few treatment options,except for surgery.The proteomic and metabolic profiles of RLPS have remained unclear.The aim of our study was to reveal the metabolic profile of RLPS.Here,we performed proteomic analysis(n=10),metabolomic analysis(n=51),and lipidomic analysis(n=50)of retroperitoneal dedifferentiated liposarcoma(RDDLPS)and retroperitoneal well-differentiated liposarcoma(RWDLPS)tissue and paired adjacent adipose tissue obtained during surgery.Data analysis mainly revealed that glycolysis,purine metabolism,pyrimidine metabolism and phospholipid formation were upregulated in both RDDLPS and RWDLPS tissue compared with the adjacent adipose tissue,whereas the tricarboxylic acid(TCA)cycle,lipid absorption and synthesis,fatty acid degradation and biosynthesis,as well as glycine,serine,and threonine metabolism were downregulated.Of particular importance,the glycolytic inhibitor 2-deoxy-D-glucose and pentose phosphate pathway(PPP)inhibitor RRX-001 significantly promoted the antitumor effects of the MDM2 inhibitor RG7112 and CDK4 inhibitor abemaciclib.Our study not only describes the metabolic profiles of RDDLPS and RWDLPS,but also offers potential therapeutic targets and strategies for RLPS.展开更多
Atmospheric carbonyl compounds play significant roles in the cycling of radicals and have exhibited surprisingly high levels in winter that were well correlated to particulate matter,for which the reason have not been...Atmospheric carbonyl compounds play significant roles in the cycling of radicals and have exhibited surprisingly high levels in winter that were well correlated to particulate matter,for which the reason have not been clearly elucidated.Here we measured carbonyl compounds and other trace gasses together with PM_(2.5)over urban Jinan in North China Plain during the winter.Markedly higher carbonyl concentrations(average:14.63±4.21 ppbv)were found during wintertime haze pollution,about one to three-times relative to those on nonhaze days,with slight difference in chemical composition except formaldehyde(HCHO).HCHO(3.68 ppbv),acetone(3.17 ppbv),and acetaldehyde(CH_3CHO)(2.83 ppbv)were the three most abundant species,accounting for~75% of the total carbonylson both haze and non-haze days.Results from observational-based model(OBM)with atmospheric oxidation capacity(AOC)indicated that AOC significantly increased with the increasing carbonyls during the winter haze events.Carbonyl photolysis have supplied key oxidants such as RO_(2) and HO_(2),and thereby enhancing the formation of fine particles and secondary organic aerosols,elucidating the observed haze-carbonyls inter-correlation.Diurnal variation with carbonyls exhibiting peak values at early-noon and night highlighted the combined contribution of both secondary formation and primary diesel-fuel sources.1-butene was further confirmed to be the major precursor for HCHO.This study confirms the great contribution of carbonyls to AOC,and also suggests that reducing the emissions of carbonyls would be an effective way to mitigate haze pollution in urban area of the NCP region.展开更多
Biomass burning(BB)is a very important emission source that significantly adversely impacts regional air quality.BB produces a large number of primary organic aerosol(POA)and black carbon(BC).Besides,BB also provides ...Biomass burning(BB)is a very important emission source that significantly adversely impacts regional air quality.BB produces a large number of primary organic aerosol(POA)and black carbon(BC).Besides,BB also provides many precursors for secondary organic aerosol(SOA)generation.In this work,the ratio of levoglucosan(LG)to organic carbon(OC)and the fire hotspots map was used to identify the open biomass burning(OBB)events,which occurred in two representative episodes,October 13 to November 30,2020,and April1 to April 30,2021.The ratio of organic aerosol(OA)to reconstructed PM_(2.5)concentration(PM_(2.5)^(*))increased with the increase of LG/OC.When LG/OC ratio is higher than 0.03,the highest OA/PM_(2.5)^(*)ratio can reach 80%,which means the contribution of OBB to OA is crucial.According to the ratio of LG to K^(+),LG to mannosan(MN)and the regional characteristics of Longfengshan,it can be determined that the crop residuals are the main fuel.The occurrence of OBB coincides with farmers’preferred choices,i.e.,burning biomass in“bright weather”.The“bright weather”refers to the meteorological conditions with high temperature,low humidity,and without rain.Meteorological factors indirectly affect regional biomass combustion pollution by influencing farmers’active choices.展开更多
Designing efficient proton-conductive materials is crucial in fuel cells.Yet,it remains a substantial challenge because of the issues in proton mobility,proton-carrier amount,and orientation of proton host materials.H...Designing efficient proton-conductive materials is crucial in fuel cells.Yet,it remains a substantial challenge because of the issues in proton mobility,proton-carrier amount,and orientation of proton host materials.Herein,we report an in-situ protonation strategy to produce a locally flexible porous coordination polymer(PCP)to enhance the proton-carrier loading and proton conductivity.The local dipole flipping of the ligand allows effective proton exchange with low activation energy,promoting interpore proton transport through the pore apertures and pore walls.The protonation induces substantial charges to the frameworks and enhances the interaction with proton carriers,thereby increasing the loading of the proton carriers.By this design strategy,the resulting PCP exhibits enhanced phosphoric acid loading and extraordinary proton conductivities under both aqueous and anhydrous conditions compared to its isoreticular analog that features rigidity without proton-exchange capability.Our work provides a new avenue for designing proton-conductive materials that combine structural dynamics with performance merits.展开更多
Owing to the large exciton binding energy(>100 meV)of most organic materials,the process of exciton dissociation into free electrons and holes is seriously hindered,which plays a key role in the photocatalytic syst...Owing to the large exciton binding energy(>100 meV)of most organic materials,the process of exciton dissociation into free electrons and holes is seriously hindered,which plays a key role in the photocatalytic system.In this study,a series of chalcogen(S,Se)-substituted mesoporous covalent organic frameworks(COFs)have been synthesized for enhanced photocatalytic organic transformations.Photoelectrochemical measurements indicate that the introduction of semi-metallic Se atom and the enlargement of conjugation degree can not only reduce the exciton binding energy accelerating the charge separation,but also reduce the band gap of COFs.As a result,the COF-NUST-36 with the lowest exciton binding energy(39.5 meV)shows the highest photocatalytic performance for selective oxidation of amines(up to 98%Conv.and 97.5%Sel.).This work provides a feasible method for designing COFs with high photocatalytic activity by adjusting exciton binding energy.展开更多
Atmospheric oxidizing capacity(AOC)is the fundamental driving factors of chemistry process(e.g.,the formation of ozone(O_(3))and secondary organic aerosols(SOA))in the troposphere.However,accurate quantification of AO...Atmospheric oxidizing capacity(AOC)is the fundamental driving factors of chemistry process(e.g.,the formation of ozone(O_(3))and secondary organic aerosols(SOA))in the troposphere.However,accurate quantification of AOC still remains uncertainty.In this study,a comprehensive field campaign was conducted during autumn 2019 in downtown of Beijing,where O_(3) and PM_(2.5) episodes had been experienced successively.The observation-based model(OBM)is used to quantify the AOC at O_(3) and PM_(2.5) episodes.The strong intensity of AOC is found at O_(3) and PM2.5 episodes,and hydroxyl radical(OH)is the dominating daytime oxidant for both episodes.The photolysis of O_(3) is main source of OH at O_(3) episode;the photolysis of nitrous acid(HONO)and formaldehyde(HCHO)plays important role in OH formation at PM_(2.5) episode.The radicals loss routines vary according to precursor pollutants,resulting in different types of air pollution.O_(3) budgets and sensitivity analysis indicates that O_(3) production is transition regime(both VOC and NOx-limited)at O3 episode.The heterogeneous reaction of hydroperoxy radicals(HO_(2))on aerosol surfaces has significant influence on OH and O_(3) production rates.The HO_(2) uptake coefficient(γHO_(2))is the determining factor and required accurate measurement in real atmospheric environment.Our findings could provide the important bases for coordinated control of PM_(2.5) and O_(3) pollution.展开更多
In situ-grown Mg-Al layered double hydroxide(LDH)films were obtained on an anodized AZ31 substrate,with the immersion of sample in different concentrations of Al^(3+)solution.The structure,composition and morphology o...In situ-grown Mg-Al layered double hydroxide(LDH)films were obtained on an anodized AZ31 substrate,with the immersion of sample in different concentrations of Al^(3+)solution.The structure,composition and morphology of LDH films were investigated by X-ray diffraction(XRD),Fourier transform infrared(FTIR)and scanning electronic microscopy(SEM),and the corrosion behavior of LDH films was further studied by electrochemical impedance spectroscopy(EIS).The influence of Al^(3+)concentration on the growth behavior of LDH was also discussed.The results indicated that the nest-like structure of MgAl-LDH film was composed of interconnected MgAl-LDH nanosheets.Besides,the LDH obtained in0.032 mol·L^(-1)Al^(3+)solution,possessing dense laminated structure,could effectively seal the porous surface of anodic oxide film.EIS results revealed that the samples coated with LDH films showed a higher electrochemical impedance,and thus,the corrosion resistance of samples coated with LDH films was signally improved compared with the anodized alloy.展开更多
Hydrogenation reactions play crucial roles on chemical synthesis and pollutant elimination.The improvement of the ability to activate reactants and increase of the contact probability between the catalysts and reactan...Hydrogenation reactions play crucial roles on chemical synthesis and pollutant elimination.The improvement of the ability to activate reactants and increase of the contact probability between the catalysts and reactants are positive to improve the catalytic performance.Herein,we have reported the design of two-dimensional porous Ni-Ni_(3)N-Ni Mo N heterojunction sheets(2D Mo-Ni based nanosheets)for efficient catalytic hydrogenation of the aromatic nitro-compounds.The heterojunction interfaces provide plentiful active sites to improve the activating ability of the catalyst on the reactants.Additionally,the 2D porous structure facilitates not only the contact of catalytic sites with reactants but also mass transfer and diffusion,both of which are favorable to accelerating the hydrogenation process.As a result,the optimized sample of 2D Mo-Ni sheet exhibits good activity for the hydrogenation of aromatic nitro-compounds by converting 0.2 mmol/L(30 mL)of p-nitrophenol to p-aminophenol within 45 s with good recyclability.The activation energy and the reaction rate at 25℃ is 31.11 k J/mol and 0.0796 s^(-1),respectively,both of which surpass most of reported non-noble metal catalysts and rivals with most noble metal-based catalysts.The combination of late and early transition metals provides an innovative way to obtain outstanding catalysts for the hydrogenation.展开更多
A doublely-doped layered double hydroxide(LDH)film was produced on an anodized magnesium alloy AZ31.The Ce-doped Mg-Al LDH film was prepared by in-situ hydrothermal treatment method,and the intercalation of vanadate w...A doublely-doped layered double hydroxide(LDH)film was produced on an anodized magnesium alloy AZ31.The Ce-doped Mg-Al LDH film was prepared by in-situ hydrothermal treatment method,and the intercalation of vanadate was realized by ion-exchange reaction.The structure,morphology and composition of as-prepared LDH film were investigated by X-ray diffractometer,field-emission scanning electronic microscope and energy dispersive spectrometry.Results indicated that a uniform and compact LDH film was formed and the intercalation of Ce^(3+)and vanadate would change the crystal structure of LDHs.The results of the potentiodynamic polarization,electrochemical impedance spectra,hydrogen evolution and corrosion weight loss tests showed the Ce^(3+)and vanadate anions significantly improve the impedance of LDH film,and the active double-doped LDH film could effectively protect the magnesium substrate from corrosion.展开更多
Anodic oxidation is a prevalent technique to introduce superior corrosion and wear resistance upon the surface of titanium(Ti)alloys,in which the selection of appropriate electrolytes and defect-sealing strategies is ...Anodic oxidation is a prevalent technique to introduce superior corrosion and wear resistance upon the surface of titanium(Ti)alloys,in which the selection of appropriate electrolytes and defect-sealing strategies is a key.This study aims to address such issues through anodizing Ti-10V-2Fe-3Al alloy in malic acid,followed by a post-sealing treatment with Mg-Al layered double hydroxides(LDHs).The characteristics of the samples were investigated using scanning electron microscopy(SEM),atomic force microscopy(AFM),glow discharge optical emission spectroscopy(GDOES),X-ray diffraction(XRD)and energy-dispersive X-ray spectroscopy(EDS).SEM micrographs reveals that the anodic coating had a surface full of bulges and cracks,and was almost sealed by the following LDHs treatment.XRD pattern indicate that the anodic coating was mainly consisted of amorphous TiO2 with a small fraction of anatase,but its crystallization degree was increased through the post-sealing.Moreover,electrochemical and tribological measurements demonstrate that corrosion current density was 2.8×10-6,2.0×10-7,5.9×10-9A cm-2,and wear rate was 1.45×10-3,1.30×10-4 and 6.90×10-5 mm3 N-1 m-1 for respective bare Ti-10V-2Fe-3Al alloy substrate,anodized specimens without and with the LDHs post treatment.Finally,a plausible wear mechanism was proposed.展开更多
Atmospheric peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), and carbon tetrachloride (CCl4) were measured from September 2010 to August 2011 in Beijing. PAN exhibited low values from mid-autumn to ear...Atmospheric peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), and carbon tetrachloride (CCl4) were measured from September 2010 to August 2011 in Beijing. PAN exhibited low values from mid-autumn to early spring (October to March) with monthly average concentrations ranging from 0.28 to 0.73 ppbV, and increased from early spring to summer (March to August), ranging from 1.37-3.79 ppbV. The monthly variation of PPN was similar to PAN, with low values (below detection limit to 0.18 ppbV) from mid-autumn to early spring, and a monthly maximum in September (1.14 ppbV). The monthly variation of CCl4 was tightly related to the variation of temperature, exhibiting a minimum in winter (69.3 pptV) and a maximum of 180.6 pptV in summer. Due to weak solar intensity and short duration, PAN and O3 showed no distinct diurnal patterns from morning to night during winter, whereas for other seasons, they both exhibited maximal values in the late afternoon (ca. 15:00 to 16:00 local time) and minimal values during early morning and midnight. Good linear correlations between PAN and PPN were found in autumn (R = 0.91), spring (R = 0.94), and summer (R = 0.81), with slopes of 0.130, 0.222, and 0.133, respectively, suggesting that anthropogenic hydrocarbons dominated the photochemical formation of PANs in Beijing. Positive correlation between PAN and O3 in summer with the low slopes (AO3/APAN) ranging from 9.92 to 18.0 indicated serious air pollution in Beijing, and strong negative correlation in winter reflected strong O3 consumption by NO titration and less thermal decompositin of PAN.展开更多
基金the National Key R&D Program of China(No.2023YFA1606401)the National Natural Science Foundation of China(Nos.12135004,11635003 and 11961141004).
文摘Based on the dinuclear system model,the calculated evaporation residue cross sections matched well with the current experimental results.The synthesis of superheavy elements Z=121 was systematically studied through combinations of stable projectiles with Z=21-30 and targets with half-lives exceeding 50 d.The influence of mass asymmetry and isotopic dependence on the projectile and target nuclei was investigated in detail.The reactions^(254)Es(^(46)Ti,3n)^(297)121 and^(252)Es(^(46)Ti,3n)^(295)121 were found to be experimentally feasible for synthesizing superheavy element Z=121,with maximal evaporation residue cross sections of 6.619 and 4.123 fb at 219.9 and 223.9 MeV,respectively.
基金supported by the National Key R&D Program of China(No.2023YFA1606401)the National Natural Science Foundation of China(Nos.12135004,11635003 and 11961141004)the Guangxi Natural Science Foundation(No.2022GXNSFBA035549).
文摘Based on the dinuclear system model,the synthesis of the predicted double-magic nuclei^(298)Fl and 304120 was investigated via neutron-rich radioactive beam-induced fusion reactions.The reaction^(58)Ca+^(244)Pu is predicted to be favorable for producing^(298)Fl with a maximal ER cross section of 0.301 pb.Investigations of the entrance channel effect reveal that the^(244)Pu target is more promising for synthesizing^(298)Fl than the neutron-rich targets^(248)Cm and^(249)Bk,because of the influence of the Coulomb barrier.For the synthesis of 304120,the maximal ER cross section of 0.046 fb emerges in the reaction^(58)V+^(249)Bk,indicating the need for further advancements in both experimental facilities and reaction mechanisms.
基金supported by the International Cooperation in Science and Technology Innovation between Governments,National Key Research and Development Program of China(No.2018YFE0116200)the National Natural Science Foundation of China(51971040,51701029)+4 种基金the Fundamental Research Funds for the Central Universities(2020CDJQY-A007)China Postdoctoral Science Foundation Funded Project(2017M620410,2018T110942)the Chongqing Postdoctoral Scientific Research Foundation(Xm2017010)G.Z.thanks also China Scholarship Council for the award of fellowship and funding(No.201806050047)M.S.and C.B.additionally thank the ACTICOAT project(Era.Net RUS Plus Call 2017,Project 477)for the financial support of this work.
文摘In this work,plasma electrolytic oxidation(PEO)coatings were produced on magnesium alloy AZ31 in aluminate,silicate and phosphate-based electrolytes,and followed by hydrothermal treatments in order to synthesis layered double hydroxides(LDHs)based nanocontainers.LDHs synthesis was done in three different growth solutions(deionized water,sodium nitrate and aluminum nitrate containing solution).In frame of this work it was shown,that it was difficult to form LDHs on Si-based PEO coating,due to more stable silicate phases in comparison with aluminate and phosphate phases in respective PEO coatings.The obtained hybrid LDH/PEO coatings were characterized using SEM,EDS and GDOES,and then the corrosion protection was further investigated by EIS.Based on the obtained results,it was confirmed that,the hydrothermal treatments in Al^(3+)containing solution played an important role on overall corrosion resistance for phosphate and silicate-based PEO coatings,but not for Al-based PEO coatings.
基金supported by the National Key Research and Development Program of China(82030030)the 1·3·5 Project for Disciplines of Excellence,West China Hospital+1 种基金Sichuan University(ZYJC20002)to H.YuanSichuan Science and Technology Program(2022YFS0211)to K.Wu.
文摘Previous studies on genetic diseases predominantly focused on protein-coding variations, overlooking the vast noncoding regions in the human genome. The development of high-throughput sequencing technologies and functional genomics tools has enabled the systematic identification of functional noncoding variants. These variants can impact gene expression, regulation, and chromatin conformation, thereby contributing to disease pathogenesis. Understanding the mechanisms that underlie the impact of noncoding variants on genetic diseases is indispensable for the development of precisely targeted therapies and the implementation of personalized medicine strategies. The intricacies of noncoding regions introduce a multitude of challenges and research opportunities. In this review, we introduce a spectrum of noncoding variants involved in genetic diseases, along with research strategies and advanced technologies for their precise identification and in-depth understanding of the complexity of the noncoding genome. We will delve into the research challenges and propose potential solutions for unraveling the genetic basis of rare and complex diseases.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12247103, 12275213, and 12247110)。
文摘We numerically investigate the breathing dynamics induced by collision between bright solitons in a binary dipolar Bose–Einstein condensates, whose dipole–dipole interaction and contact interaction are attractive. We identify three special breathing structures, such as snakelike special breathing structure, mixed breathing structure, and divide breathing structure.The characteristics of these breathing structures can be described by breathing frequency ?, maximum breathing amplitude A and lifetime τ, which can be manipulated by atomic number Ni and interspecies scattering length a12. Meanwhile, the above breathing structures can realize the process of quasi-transition with a reasonable Ni and a12. Additionally, the collision of two special breathing structures also can bring more abundant breathing dynamics. Our results provide a reference for the study of soliton interactions and deepen the understanding of soliton properties in a binary dipolar Bose–Einstein condensates.
基金supported by the National Natural Science Foundation of China under Grants Nos.11635003,11025524 and 11161130520the National Basic Research Program of China under Grant No.2010CB832903+1 种基金the European Commission’s 7th Framework Programme(Fp7-PEOPLE-2010-IRSES)under Grant Agreement Project No.269131the Project funded by China Postdoctoral Science Foundation(Grant No.2016M600956)
文摘The production mechanism of heavy neutronrich nuclei is investigated by using the multinucleon transfer reactions of ^(136;148)Xe+^(208)Pb and ^(238)U+^(208)Pb in the framework of a dinuclear system model. The evaporation residual cross sections of target-like fragments are studied with the reaction system ^(148)Xe+^(208)Pb at near barrier energies. The results show that the final isotopic production cross sections in the neutron-deficient side are very sensitive to incident energy while it is not sensitive in the neutron-rich side. Comparing the isotopic production cross sections for the reactions of ^(208)Pb bombarded with stable and radioactive projectiles, we find that neutron-rich radioactive beams can significantly increase the production cross sections of heavy neutron-rich nuclei.
文摘BACKGROUND: The study aimed to investigate the clinical characteristics of acute renal failure(ARF) caused by oral acyclovir.METHODS: A 45-year-old Chinese male patient with acyclovir-induced ARF suffered fromabdominal pain for one day. The pain was extended to the epigastric area from the right lowerquadrant. Transient oliguria was seen in addition to microscopic hematuria and proteinuria. Theserum creatinine concentration was 304 !mol/L. Eight days before the occurrence of ARF, the patienttook oral acyclovir for facial neuritis.RESULTS: His renal function was restored completely following the discontinuation of acyclovir,with continuous renal replacement therapy for 54 hours and some symptomatic treatment.CONCLUSION: The presentation of acute renal failure caused by acyclovir can be diverse, butthe prognosis is good after active treatment.
基金The authors thank the staff of WLG station in Qinghai Province for their data sampling and maintenance of the observation system.We are also grateful to NASA for providing the CO2 products retrieved from AIRS,OCO-2 and JAXA for providing the CO2 product retrieved from GOSAT.This research was supported by the China Meteorological Administration Climate Change Special Project(No.CCSF202035)the Jiangxi Meteorological Science and Technology Project(201805,201905).
文摘East China(23.6°–38.4°N,113.6°–122.9°E)is the largest developed region in China.Based on CO2 products retrieved from the Greenhouse Gases Observing Satellite(GOSAT),the spatial and temporal distributions of CO2 mixing ratios in East China during 2014–17 are discussed,and the retrieved CO2 from AIRS(Atmospheric Infrared Sounder)and OCO-2(Orbiting Carbon Observatory-2),as well as WLG(Waliguan)background station observations,are compared with those of GOSAT.The annual CO2 retrieved from GOSAT in East China ranged from 398.96±0.24 ppm in 2014 to 407.39±0.20 ppm in 2017,with a growth rate of 2.82±0.15 ppm yr^−1,which were higher than in other regions of China.The seasonal cycle presented a maximum in spring and a minimum in summer or autumn.Higher values were mainly concentrated in the coastal areas of Zhejiang Province,and lower values were concentrated in Jiangxi and the north of Fujian Province.CO2 observed in Fujian and parts of Jiangxi increased by less than 1.0 ppm during 2014–15,but enhanced significantly by more than 5.0 ppm during 2015–16,perhaps influenced by local emissions and global impacts.We calculated year-to-year CO2 enhancements in the Yangtze River Delta region during 2014–17 that were relatively low and stable,due to the region’s carbon emissions control and reduction policies.The annual and seasonal amplitudes of CO2 retrieved from AIRS were lower than those from GOSAT in East China,probably owing to the CO2 retrieved from AIRS better reflecting the characteristics of the mid-troposphere,while GOSAT is more representative of near-surface CO2.The spatial and temporal distribution characteristics of CO2 retrieved from OCO-2 were close to those from GOSAT in East China.
基金the International Cooperation in Science and Technology Innovation between Governments,National Key Research and Development Program of China(No.2018YFE0116200)the National Natural Science Foundation of China(51971040)the Fundamental Research Funds for the Central Universities(2020CDJQY-A007)。
文摘This work produced a Mg Al-layered double hydroxide by hydrothermal treatment of a plasma electrolytic oxidation(PEO) coating on magnesium alloy AZ31 in an phosphate electrolyte, followed by an ion-exchange reaction in 0.1 M phosphate solution. The coated specimens were scratched. Characterization, including utilization of the localized technique SIET, measured the pH and p Mg distributions and optical morphologies around the artificial defects during immersion in 0.05 M NaCl solution. In contrast with phosphate loaded PEO/LDHs, a stronger alkalinization area(with pH 11.4~12.3) appeared in the passive PEO specimens. Due to formation of insoluble Mg(OH)_(2) products, the p Mg map showed depletion of Mg^(2+) in this high p H area. Combined with optical morphologies and SEM images, the better self-healing ability toward defects for phosphate loaded PEO/LDHs was confirmed.
基金funded by grants from the National Natural Science Foundation of China(No.82272935 to Wengang Li.,Nos.91957120 and 21974114 to Shuhai Lin.)the Scientific Research Foundation for Advanced Talents,Xiang’an Hospital of Xiamen University(No.PM20180917008 to Wengang Li.)+3 种基金Joint laboratory of School of Medicine,Xiamen University-Shanghai Jiangxia Blood Technology Co.Ltd.(No.XDHT2020010C to Wengang Lin and Ye Shen.)the Fundamental Research Funds for the Central Universities(No.20720210001 to Shuhai Lin.)Major Science and Technology Special Project of Fujian Province(No.2022YZ036012 to Shuhai Lin)Natural Science Foundation of Fujian Province(No.2021J01123522 to Zhigang Zheng).
文摘Retroperitoneal liposarcoma(RLPS)is the main subtype of retroperitoneal soft sarcoma(RSTS)and has a poor prognosis and few treatment options,except for surgery.The proteomic and metabolic profiles of RLPS have remained unclear.The aim of our study was to reveal the metabolic profile of RLPS.Here,we performed proteomic analysis(n=10),metabolomic analysis(n=51),and lipidomic analysis(n=50)of retroperitoneal dedifferentiated liposarcoma(RDDLPS)and retroperitoneal well-differentiated liposarcoma(RWDLPS)tissue and paired adjacent adipose tissue obtained during surgery.Data analysis mainly revealed that glycolysis,purine metabolism,pyrimidine metabolism and phospholipid formation were upregulated in both RDDLPS and RWDLPS tissue compared with the adjacent adipose tissue,whereas the tricarboxylic acid(TCA)cycle,lipid absorption and synthesis,fatty acid degradation and biosynthesis,as well as glycine,serine,and threonine metabolism were downregulated.Of particular importance,the glycolytic inhibitor 2-deoxy-D-glucose and pentose phosphate pathway(PPP)inhibitor RRX-001 significantly promoted the antitumor effects of the MDM2 inhibitor RG7112 and CDK4 inhibitor abemaciclib.Our study not only describes the metabolic profiles of RDDLPS and RWDLPS,but also offers potential therapeutic targets and strategies for RLPS.
基金supported by the National Natural Science Foundation of China(Nos.42005092,42275127,42075112and 41775127)the Natural Science Foundation of Shandong Province(No.ZR2020QD058)。
文摘Atmospheric carbonyl compounds play significant roles in the cycling of radicals and have exhibited surprisingly high levels in winter that were well correlated to particulate matter,for which the reason have not been clearly elucidated.Here we measured carbonyl compounds and other trace gasses together with PM_(2.5)over urban Jinan in North China Plain during the winter.Markedly higher carbonyl concentrations(average:14.63±4.21 ppbv)were found during wintertime haze pollution,about one to three-times relative to those on nonhaze days,with slight difference in chemical composition except formaldehyde(HCHO).HCHO(3.68 ppbv),acetone(3.17 ppbv),and acetaldehyde(CH_3CHO)(2.83 ppbv)were the three most abundant species,accounting for~75% of the total carbonylson both haze and non-haze days.Results from observational-based model(OBM)with atmospheric oxidation capacity(AOC)indicated that AOC significantly increased with the increasing carbonyls during the winter haze events.Carbonyl photolysis have supplied key oxidants such as RO_(2) and HO_(2),and thereby enhancing the formation of fine particles and secondary organic aerosols,elucidating the observed haze-carbonyls inter-correlation.Diurnal variation with carbonyls exhibiting peak values at early-noon and night highlighted the combined contribution of both secondary formation and primary diesel-fuel sources.1-butene was further confirmed to be the major precursor for HCHO.This study confirms the great contribution of carbonyls to AOC,and also suggests that reducing the emissions of carbonyls would be an effective way to mitigate haze pollution in urban area of the NCP region.
基金supported by the Natural Science Foundation of Heilongjiang Province(No.LH2020D011)the S&T Development Fund of CAMS(No.2020KJ003)the Open Research Fund of State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research(No.201913)。
文摘Biomass burning(BB)is a very important emission source that significantly adversely impacts regional air quality.BB produces a large number of primary organic aerosol(POA)and black carbon(BC).Besides,BB also provides many precursors for secondary organic aerosol(SOA)generation.In this work,the ratio of levoglucosan(LG)to organic carbon(OC)and the fire hotspots map was used to identify the open biomass burning(OBB)events,which occurred in two representative episodes,October 13 to November 30,2020,and April1 to April 30,2021.The ratio of organic aerosol(OA)to reconstructed PM_(2.5)concentration(PM_(2.5)^(*))increased with the increase of LG/OC.When LG/OC ratio is higher than 0.03,the highest OA/PM_(2.5)^(*)ratio can reach 80%,which means the contribution of OBB to OA is crucial.According to the ratio of LG to K^(+),LG to mannosan(MN)and the regional characteristics of Longfengshan,it can be determined that the crop residuals are the main fuel.The occurrence of OBB coincides with farmers’preferred choices,i.e.,burning biomass in“bright weather”.The“bright weather”refers to the meteorological conditions with high temperature,low humidity,and without rain.Meteorological factors indirectly affect regional biomass combustion pollution by influencing farmers’active choices.
基金supported by the National Natural Science Foundation of China(21975078)the Fundamental Research Funds for the Central Universitiesthe start-up foundation of Sichuan University。
文摘Designing efficient proton-conductive materials is crucial in fuel cells.Yet,it remains a substantial challenge because of the issues in proton mobility,proton-carrier amount,and orientation of proton host materials.Herein,we report an in-situ protonation strategy to produce a locally flexible porous coordination polymer(PCP)to enhance the proton-carrier loading and proton conductivity.The local dipole flipping of the ligand allows effective proton exchange with low activation energy,promoting interpore proton transport through the pore apertures and pore walls.The protonation induces substantial charges to the frameworks and enhances the interaction with proton carriers,thereby increasing the loading of the proton carriers.By this design strategy,the resulting PCP exhibits enhanced phosphoric acid loading and extraordinary proton conductivities under both aqueous and anhydrous conditions compared to its isoreticular analog that features rigidity without proton-exchange capability.Our work provides a new avenue for designing proton-conductive materials that combine structural dynamics with performance merits.
基金financially supported by the National Natural Science Foundation of China(No.22171136)the Natural Science Foundation of Jiangsu Province(Nos.BK20220928,BK20220079)+4 种基金the Fundamental Research Funds for the Central Universities(Nos.30921011102,30922010902)the Medical Innovation and Development Project of Lanzhou University(No.lzuyxcx-2022-156)CAMS Innovation Fund for Medical Sciences(CIFMS,Nos.2019-I2M-5-074,2021-I2M-1-026,2021-I2M-3-001)the Startup Funding from Nanjing University of Science and Technology(Nos.AE89990,AE89991/376)G.Zhang acknowledges the support of the Thousand Young Talent Plan.
文摘Owing to the large exciton binding energy(>100 meV)of most organic materials,the process of exciton dissociation into free electrons and holes is seriously hindered,which plays a key role in the photocatalytic system.In this study,a series of chalcogen(S,Se)-substituted mesoporous covalent organic frameworks(COFs)have been synthesized for enhanced photocatalytic organic transformations.Photoelectrochemical measurements indicate that the introduction of semi-metallic Se atom and the enlargement of conjugation degree can not only reduce the exciton binding energy accelerating the charge separation,but also reduce the band gap of COFs.As a result,the COF-NUST-36 with the lowest exciton binding energy(39.5 meV)shows the highest photocatalytic performance for selective oxidation of amines(up to 98%Conv.and 97.5%Sel.).This work provides a feasible method for designing COFs with high photocatalytic activity by adjusting exciton binding energy.
基金supported by the National Key Research and Development Program of China (No. 2017YFC0210001)the National Natural Science Foundation of China (Nos. 41830106, 42022039)+1 种基金Beijing National Laboratory for Molecular Sciences (No. BNLMS-CXXM-202011)the Youth Innovation Promotion Association CAS (No. 2017042)
文摘Atmospheric oxidizing capacity(AOC)is the fundamental driving factors of chemistry process(e.g.,the formation of ozone(O_(3))and secondary organic aerosols(SOA))in the troposphere.However,accurate quantification of AOC still remains uncertainty.In this study,a comprehensive field campaign was conducted during autumn 2019 in downtown of Beijing,where O_(3) and PM_(2.5) episodes had been experienced successively.The observation-based model(OBM)is used to quantify the AOC at O_(3) and PM_(2.5) episodes.The strong intensity of AOC is found at O_(3) and PM2.5 episodes,and hydroxyl radical(OH)is the dominating daytime oxidant for both episodes.The photolysis of O_(3) is main source of OH at O_(3) episode;the photolysis of nitrous acid(HONO)and formaldehyde(HCHO)plays important role in OH formation at PM_(2.5) episode.The radicals loss routines vary according to precursor pollutants,resulting in different types of air pollution.O_(3) budgets and sensitivity analysis indicates that O_(3) production is transition regime(both VOC and NOx-limited)at O3 episode.The heterogeneous reaction of hydroperoxy radicals(HO_(2))on aerosol surfaces has significant influence on OH and O_(3) production rates.The HO_(2) uptake coefficient(γHO_(2))is the determining factor and required accurate measurement in real atmospheric environment.Our findings could provide the important bases for coordinated control of PM_(2.5) and O_(3) pollution.
基金supported by the National Key Research and Development Program of China(2016YFB0301100)the National Natural Science Foundation of China(51701029,51531002,51474043)+2 种基金China Postdoctoral Science Foundation Funded Project(2017M620410,2018T110942)the ChongqingPostdoctoral Scientific Research Foundation(Xm2017010)the Chongqing Research Program of Basic Research and Frontier Technology(cstc2016jcyjA0388,cstc2017jcyjBX0040)。
文摘In situ-grown Mg-Al layered double hydroxide(LDH)films were obtained on an anodized AZ31 substrate,with the immersion of sample in different concentrations of Al^(3+)solution.The structure,composition and morphology of LDH films were investigated by X-ray diffraction(XRD),Fourier transform infrared(FTIR)and scanning electronic microscopy(SEM),and the corrosion behavior of LDH films was further studied by electrochemical impedance spectroscopy(EIS).The influence of Al^(3+)concentration on the growth behavior of LDH was also discussed.The results indicated that the nest-like structure of MgAl-LDH film was composed of interconnected MgAl-LDH nanosheets.Besides,the LDH obtained in0.032 mol·L^(-1)Al^(3+)solution,possessing dense laminated structure,could effectively seal the porous surface of anodic oxide film.EIS results revealed that the samples coated with LDH films showed a higher electrochemical impedance,and thus,the corrosion resistance of samples coated with LDH films was signally improved compared with the anodized alloy.
基金the support of this research by the National Natural Science Foundation of China(No.91961111)the Natural Science Foundation of Heilongjiang Province(No.ZD2021B003)Fundamental Research Funds for the Central Universities(No.2572022BU05)。
文摘Hydrogenation reactions play crucial roles on chemical synthesis and pollutant elimination.The improvement of the ability to activate reactants and increase of the contact probability between the catalysts and reactants are positive to improve the catalytic performance.Herein,we have reported the design of two-dimensional porous Ni-Ni_(3)N-Ni Mo N heterojunction sheets(2D Mo-Ni based nanosheets)for efficient catalytic hydrogenation of the aromatic nitro-compounds.The heterojunction interfaces provide plentiful active sites to improve the activating ability of the catalyst on the reactants.Additionally,the 2D porous structure facilitates not only the contact of catalytic sites with reactants but also mass transfer and diffusion,both of which are favorable to accelerating the hydrogenation process.As a result,the optimized sample of 2D Mo-Ni sheet exhibits good activity for the hydrogenation of aromatic nitro-compounds by converting 0.2 mmol/L(30 mL)of p-nitrophenol to p-aminophenol within 45 s with good recyclability.The activation energy and the reaction rate at 25℃ is 31.11 k J/mol and 0.0796 s^(-1),respectively,both of which surpass most of reported non-noble metal catalysts and rivals with most noble metal-based catalysts.The combination of late and early transition metals provides an innovative way to obtain outstanding catalysts for the hydrogenation.
基金financially supported by the National Natural Science Foundation of China(No.51971040)the Graduate Research and Innovation Foundation of Chongqing,China(No.CYS19002)+4 种基金the National Natural Science Foundation of China(Nos.51701029 and 51531002)the National Key Research and Development Program of China(No.2016YFB0301100)the China Postdoctoral Science Foundation Funded Project(Nos.2017M620410 and 2018T110942)the Chongqing Postdoctoral Scientific Research Foundation(No.Xm2017010)the Fundamental Research Funds for the Central Universities(No.2018CDGFCL005)。
文摘A doublely-doped layered double hydroxide(LDH)film was produced on an anodized magnesium alloy AZ31.The Ce-doped Mg-Al LDH film was prepared by in-situ hydrothermal treatment method,and the intercalation of vanadate was realized by ion-exchange reaction.The structure,morphology and composition of as-prepared LDH film were investigated by X-ray diffractometer,field-emission scanning electronic microscope and energy dispersive spectrometry.Results indicated that a uniform and compact LDH film was formed and the intercalation of Ce^(3+)and vanadate would change the crystal structure of LDHs.The results of the potentiodynamic polarization,electrochemical impedance spectra,hydrogen evolution and corrosion weight loss tests showed the Ce^(3+)and vanadate anions significantly improve the impedance of LDH film,and the active double-doped LDH film could effectively protect the magnesium substrate from corrosion.
基金supported financially by the National Natural Science Foundation of China(Nos.51971040,51701029 and 51531002)the National Key Research and Development Program of China(No.2016YFB0301100)+3 种基金the Chongqing Research Program of Basic Research and Frontier Technology(No.cstc2016jcyjA0388)the China Postdoctoral Science Foundation Funded Project(Nos.2017M620410 and 2018T110942)the Chongqing Postdoctoral Scientific Research Foundation(No.Xm2017010)the Fundamental Research Funds for the Central Universities(No.2018CDGFCL005).
文摘Anodic oxidation is a prevalent technique to introduce superior corrosion and wear resistance upon the surface of titanium(Ti)alloys,in which the selection of appropriate electrolytes and defect-sealing strategies is a key.This study aims to address such issues through anodizing Ti-10V-2Fe-3Al alloy in malic acid,followed by a post-sealing treatment with Mg-Al layered double hydroxides(LDHs).The characteristics of the samples were investigated using scanning electron microscopy(SEM),atomic force microscopy(AFM),glow discharge optical emission spectroscopy(GDOES),X-ray diffraction(XRD)and energy-dispersive X-ray spectroscopy(EDS).SEM micrographs reveals that the anodic coating had a surface full of bulges and cracks,and was almost sealed by the following LDHs treatment.XRD pattern indicate that the anodic coating was mainly consisted of amorphous TiO2 with a small fraction of anatase,but its crystallization degree was increased through the post-sealing.Moreover,electrochemical and tribological measurements demonstrate that corrosion current density was 2.8×10-6,2.0×10-7,5.9×10-9A cm-2,and wear rate was 1.45×10-3,1.30×10-4 and 6.90×10-5 mm3 N-1 m-1 for respective bare Ti-10V-2Fe-3Al alloy substrate,anodized specimens without and with the LDHs post treatment.Finally,a plausible wear mechanism was proposed.
基金supported by the National Natural Science Foundation of China(No.41075094,21177140,20977097)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB05010100)the National Basic Research Program(973)of China(No.2010CB732304)
文摘Atmospheric peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), and carbon tetrachloride (CCl4) were measured from September 2010 to August 2011 in Beijing. PAN exhibited low values from mid-autumn to early spring (October to March) with monthly average concentrations ranging from 0.28 to 0.73 ppbV, and increased from early spring to summer (March to August), ranging from 1.37-3.79 ppbV. The monthly variation of PPN was similar to PAN, with low values (below detection limit to 0.18 ppbV) from mid-autumn to early spring, and a monthly maximum in September (1.14 ppbV). The monthly variation of CCl4 was tightly related to the variation of temperature, exhibiting a minimum in winter (69.3 pptV) and a maximum of 180.6 pptV in summer. Due to weak solar intensity and short duration, PAN and O3 showed no distinct diurnal patterns from morning to night during winter, whereas for other seasons, they both exhibited maximal values in the late afternoon (ca. 15:00 to 16:00 local time) and minimal values during early morning and midnight. Good linear correlations between PAN and PPN were found in autumn (R = 0.91), spring (R = 0.94), and summer (R = 0.81), with slopes of 0.130, 0.222, and 0.133, respectively, suggesting that anthropogenic hydrocarbons dominated the photochemical formation of PANs in Beijing. Positive correlation between PAN and O3 in summer with the low slopes (AO3/APAN) ranging from 9.92 to 18.0 indicated serious air pollution in Beijing, and strong negative correlation in winter reflected strong O3 consumption by NO titration and less thermal decompositin of PAN.