The air quality model system RAMS （Regional Atmospheric Modeling System）-CMAQ （Models-3 Com- munity Multi-scale Air Quality） coupled with an aerosol optical/radiative module was applied to investigate the impact o...The air quality model system RAMS （Regional Atmospheric Modeling System）-CMAQ （Models-3 Com- munity Multi-scale Air Quality） coupled with an aerosol optical/radiative module was applied to investigate the impact of different aerosol mixing states （i.e., externally mixed, half externally and half internally mixed, and internally mixed） oil radiative forcing in East Asia. The simulation results show that the aerosol optical depth （AOD） generally increased when the aerosol mixing state changed from externally mixed to internally mixed, while the single scattering albedo （SSA） decreased. Therefore, the scattering and absorption proper- ties of aerosols can be significantly affected by the change of aerosol mixing states. Comparison of simulated and observed SSAs at five AERONET （Aerosol Robotic Network） sites suggests that SSA could be better estimated by considering aerosol particles to be internally mixed. Model analysis indicates that the impact of aerosol mixing state upon aerosol direct radiative forcing （DRF） is complex. Generally, the cooling effect of aerosols over East Asia are enhanced in the northern part of East Asia （Northern China, Korean peninsula, and the surrounding area of Japan） and are reduced in the southern part of East. Asia （Sichuan Basin and Southeast China） by internal mixing process, and the variation range can reach ＋5 W m 2. The analysis shows that the internal mixing between inorganic salt and dust is likely the main reason that the cooling effect strengthens. Conversely, the internal nfixture of anthropogenic aerosols, including sulfate, nitrate, ammonium, black carbon, and organic carbon, could obviously weaken the cooling effect.展开更多
Under environment with various water contents,the variations in the mixing state and particle size of coated black carbon(BC)aerosols cause changes in optical and radiative effects.In this study,fractal models for thi...Under environment with various water contents,the variations in the mixing state and particle size of coated black carbon(BC)aerosols cause changes in optical and radiative effects.In this study,fractal models for thinly,partially,and thickly coated BC under six relative humidities(RHs=0–95%)are constructed and optically simulated at 1064 and 532 nm.Differential scattering cross-sections are selected to retrieve the mixing state(D_(p)/D_(c))of BC to investigate the possible retrieval errors caused by the nonspherical morphology when using the single-particle soot photometer(SP2).Furthermore,the radiative forcing of BC aerosols at different RHs are analyzed.Results showed that the retrieval errors(REs)of D_(p)/D_(c) are negative for coated particles with BC volume fraction smaller than 0.10,indicating that the mixing states of coated fractal BC are underestimated during the hygroscopic growth.The partially-coated BC has the best retrieval accuracy of the mixing state,followed by the closed-cell and coated-aggregate model,judging from averaged REs.Radiative forcing enhancements for partially-coated aerosols with different BC volume fractions exponentially increase to opposite values,resulting in a warming or cooling effect.This study helps understand the uncertainties in Dp/Dc of BC aerosols retrieved by SP2 and their radiative forcing at different RHs.展开更多
Oxygenated organic molecules(OOMs)play an important role in the formation of secondary organic aerosols(SOAs),but the mixing states of OOMs are still unclear.This study investigates the mixing states of OOM-containing...Oxygenated organic molecules(OOMs)play an important role in the formation of secondary organic aerosols(SOAs),but the mixing states of OOMs are still unclear.This study investigates the mixing states of OOM-containing single particles from the measurements taken using a single particle aerosol mass spectrometer in Guangzhou,China in 2022.Generally,the particle counts of OOM particles and the mass concentration of secondary organic carbon(SOC)exhibited similar temporal trends throughout the entire year.The OOM particles were consistently enriched in secondary ions,including ^(16)O^(−),^(26)CN^(−),^(46)NO_(2)^(−),^(62)NO_(3)^(−),and ^(97)HSO_(4)^(−).In contrast,the number fractions and diurnal patterns of OOM particles among the total detected particles showed similar distributions in August and October;however,the SOC ratios in fine particulate matter were quite different,suggesting that there were different mixing states of single-particle oxygenated organics.In addition,further classification results indicated that the OOM particles were more aged in October than August,even though the SOC ratios were higher in August.Furthermore,the distribution of hydrocarbon fragments exhibited a notable decrease from January to October,emphasizing the more aged state of the organics in October.In addition,the sharp increase in elemental carbon(EC)-OOM particles in the afternoon in October suggests the potential role of EC in the aging process of organics.Overall,in contrast to the bulk analysis of SOC mass concentration,the mixing states of the OOM particles provide insights into the formation process of SOAs in field studies.展开更多
To investigate the volatility of atmospheric particulates and the evolution of other particulate properties(chemical composition,particle size distribution and mixing state)with temperature,a thermodenuder coupled wit...To investigate the volatility of atmospheric particulates and the evolution of other particulate properties(chemical composition,particle size distribution and mixing state)with temperature,a thermodenuder coupled with a single particle aerosol mass spectrometer was used to conduct continuous observations of atmospheric fine particles in Chengdu,southwest China.Because of their complex sources and secondary reaction processes,the average mass spectra of single particles contained a variety of chemical components(including organic,inorganic and metal species).When the temperature rose from room temperature to280℃,the relative areas of volatile and semi-volatile components decreased,while the relative areas of less or non-volatile components increased.Most(>80%)nitrate and sulfate existed in the form of NH_(4)NO_(3)and(NH_(4))_(2)SO_(4),and their volatilization temperatures were50–100℃and 150–280℃,respectively.The contribution of biomass burning(BB)and vehicle emission(VE)particles increased significantly at 280℃,which emphasized the important role of regional biomass burning and local motor vehicle emissions to the core of particles.With the increase in temperature,the particle size of the particles coated with volatile or semi-volatile components was reduced,and their mixing with secondary inorganic components was significantly weakened.The formation of K-nitrate(KNO_(3))and K-sulfate(KSO_(4))particles was dominated by liquid-phase processes and photochemical reactions,respectively.Reducing KNO_(3)and BB particles is the key to improving visibility.These new results are helpful towards better understanding the initial sources,pollution formation mechanisms and climatic effects of fine particulate matter in this megacity in southwest China.展开更多
Organic nitrogen(ON)compounds play a significant role in the light absorption of brown carbon and the formation of organic aerosols,however,the mixing state,secondary formation processes,and influencing factors of ON ...Organic nitrogen(ON)compounds play a significant role in the light absorption of brown carbon and the formation of organic aerosols,however,the mixing state,secondary formation processes,and influencing factors of ON compounds are still unclear.This paper reports on the mixing state of ON-containing particles based on measurements obtained using a highperformance single particle aerosol mass spectrometer in January 2020 in Guangzhou.The ON-containing particles accounted for 21% of the total detected single particles,and the particle count and number fraction of the ON-containing particles were two times higher at night than during the day.The prominent increase in the content of ON-containing particles with the enhancement of NO_xmainly occurred at night,and accompanied by high relative humidity and nitrate,which were associated with heterogeneous reactions between organics and gaseous NO_(x)and/or NO_(3)radical.The synchronous decreases in ON-containing particles and the mass absorption coefficient of water-soluble extracts at 365 nm in the afternoon may be associated with photo-bleaching of the ON species in the particles.In addition,the positive matrix factorization analysis found five factors dominated the formation processes of ON particles,and the nitrate factor(33%)mainly contributed to the production of ON particles at night.The results of this study provide unique insights into the mixing states and secondary formation processes of the ON-containing particles.展开更多
Oxalic acid(C_(2))is a significant tracer of secondary organic aerosols(SOA),yet its precursors,evolutionary processes,and formation mechanisms are not fully understood.This knowledge gap leads to uncertainties in eva...Oxalic acid(C_(2))is a significant tracer of secondary organic aerosols(SOA),yet its precursors,evolutionary processes,and formation mechanisms are not fully understood.This knowledge gap leads to uncertainties in evaluating the climate effect and global budget of SOA.Here we compared the size distribution,mixing fraction,and evolutionary mechanism of C_(2)-containing particles between summer and winter.In summer,the number of C_(2) particles and their homologs decreased compared to winter.However,the proportion of C_(2) relative to the total number of determined particles increased,indicating that the summertime particles are more aged.Higher relative aerosol acidity(Rra)and lower in-situ pH(pHis)in summer suggest that particles are more acidic during this season.Correlation analysis and temporal variation characteristics suggest that from 9:00 to 15:00 in summer,C_(2) particles mostly originate from the photochemical decomposition of larger dicarboxylic aids,driven by O3 concentration.Conversely,from 16:00 to 20:00,C_(2) particles are predominantly formed through aqueous-phase oxidation,influenced by higher relative humidity(RH),aerosol liquid water content(ALWC),and acidity.Additionally,heavy metal particles were the predominant type of C_(2) particles,and C_(2) particles exhibited an opposite diurnal variation to Fe in summer,suggesting that the photolysis of iron oxalate complexes is an important sink of C_(2) particles during this period.In winter,biomass burning(BB)particles were the most abundant,and a robust correlation between levoglucosan and C_(2) particles indicated a substantial influence of BB on C_(2) particles.The aqueous generation of C_(2) particles fromα-dicarbonyls driven by acidity was most effective when RH varied from 40%to 60%in the wintertime state of particles.These findings highlight the hourly and seasonal variations in the sources and evolutionary processes of SOA.Such variations must be considered in developing control measures and simulating the climate effect of SOA.展开更多
A heavy dust episode occurred from May 3 to 8,2017 in China,with an influenced area exceeding 1.63 million km2.In this work,the mixing state of aerosols and their spectral distributions were simultaneously observed in...A heavy dust episode occurred from May 3 to 8,2017 in China,with an influenced area exceeding 1.63 million km2.In this work,the mixing state of aerosols and their spectral distributions were simultaneously observed in the sand source region ofHohhot and the long-range dust transport regi on of Nanji ng by using a single-particle aerosol mass spectrometer(SPAMS).The duration time of this dust episode was 37-40 h in Hohhot and prolonged to 51-104 h in Nanjing.Totals of 336,135(Hohhot)and 235,840(Nanjing)particles in PM2.5 were successfully ionized to identify 10 main particle classes.During this episode,aerosol particles including OCEC(30.65%),K(22.42%),K-CN(17.03%),sodium(9.46%),heavy metal(8.96%),EC-sulfate(3.46%)and Al(3.22%)were prevailing in Hohhot and were dominated by EC-sulfate(22.26%),OCEC(15.21%),heavy metal(11.96%),K(13.68%),sodium(12.27%),Al(10.54%)and EC(9.02%)in Nanjing.The spectral distribution peaked at 0.66μm during the dust episode in Nanjing,0.12μm larger than the peak size in the non-dust episode.Strong signals at-62[NO3)and-61[HCO3]/-61[C5H]for aerosol particles were observed in Hohhot and Nanjing respectively.The proportions of K-CN,sodium,heavy mental,OCEC and EC-sulfate particles in the dust episode of Hohhot were 2.75,1.41,1.80,1.22 and 1.28 times as large as the values in the non-dust episode.For Nanjing,the fractions of EC-sulfate,EC,Al particles in the dust episode were 10.55,4.65 and 1.46 times higher than values in the non-dust episode.The proportions of EC-secondary and EC-nitate particles were found to decrease in the dust episode in the two regions.展开更多
Knowledge of haze particles in background areas of North China is limited, although they have been studied well in urban settings. Atmospheric aerosol particles were collected at a background site in the North China P...Knowledge of haze particles in background areas of North China is limited, although they have been studied well in urban settings. Atmospheric aerosol particles were collected at a background site in the North China Plain during 16–31 January, 2011. Water soluble inorganic ions of PM2.5 and physicochemical characteristics of individual particles on hazy and clean days were measured by Ion Chromatography(IC) and Transmission Electron Microscopy(TEM), respectively. Average PM2.5 mass concentration was 50.4±29.9 μg m?3 with 62.5±26.8 μg m?3 on hazy days and 19.9±11.5 μg m?3 on clean days. SO42?, NO3?, and NH4+ with a combined mass concentration of 19.0±11.5 μg m?3 accounted for 69.8%–89.4% of the total water soluble inorganic ions. Size distributions of SO42? and NH4+ showed one unimodal peak at 0.56–1.8 μm on hazy days, whereas NO3? appeared as bimodal peaks at 0.56–1.8 and 5.6–10 μm, respectively. Individual particle analyses showed that the dominant aerosols were a mixture of sulfate, nitrate, and carbonaceous species, which together determine their mixing states. 48-h air mass back trajectories on hazy days suggested that air masses crossed the polluted continental areas(such as Jing-jin-ji region and Shandong province) and entrained ground air pollutants 11–19 hours before reaching the background area. During long-range transport particles undergo ageing and tend to be internally mixed mainly due to condensation in the background atmosphere. Our results suggest that hygroscopic and optical properties of these aerosol particles in the background area differ substantially from those in urban areas.展开更多
Fresh straw burning （SB） particles were generated in the laboratory by the combustion of rice straw and corn straw. The chemical composition and mixing state of the fresh SB particles were investigated by an Aerosol...Fresh straw burning （SB） particles were generated in the laboratory by the combustion of rice straw and corn straw. The chemical composition and mixing state of the fresh SB particles were investigated by an Aerosol Time-of-Flight Mass Spectrometer （ATOFMS）. Based on the mass spectral patterns, the SB particles were clustered into four major types： Salt, Organic Carbon （OC）, Elemental Carbon （EC）, and internally mixed particles of EC and OC （EC-OC）. In addition, particles containing ash, polycyclic aromatic hydrocarbons, heavy metals or nicotine were also observed. Physical and chemical changes of the SB particles immediately after the emission were analyzed with highly time-resolved data. During the aging processes, the average particle size increased steadily. Freshly emitted organic compounds were gradu- ally oxidized to more oxygenated compounds in the OC- containing particles. Meanwhile, an important displace- ment reaction （2KCI＋ SO24- KzSO4 ＋ 2C1-） was observed. The marker ions for SB particles were optimized and applied to identify the SB particles in the ambient atmosphere. The fluctuation of the number fraction of ambient SB particles sorted by ATOFMS agrees well with that of water soluble K＋ measured by an online ion chromatography, demonstrating that the optimized marker ions could be good tracers for SB particles in field measurements.展开更多
Direct individual analysis using Scanning Electron Microscopy combined with online obscrv ation was conducted to examine the S-rich particles in PM2.5 of two typical polluted haze cpisodes in summer and winter from 20...Direct individual analysis using Scanning Electron Microscopy combined with online obscrv ation was conducted to examine the S-rich particles in PM2.5 of two typical polluted haze cpisodes in summer and winter from 2014 to 2015 in Beijing. Four major types of S-rich particles, including sccondary CaSO4 particles （mainly observed in summer）, S-rich mineral particles （SRM）, S-rich water droplets （SRW） and （C, O, S）-rich particles （COS） were identified. We lbund the differcnt typical morphologies and element distributions of S-rich particles and considered that （C, O, S）-rich parliclcs had two major mixing states in different seasons. On the basis of the S-rich particles＂ relative abundances. S concentrations and their relationships with PM2.5 as well as the seasonal comparison, wc revealed that the S-participated formation degrees of SRM and SRW would enhance with increasing PM2.5 concentration. Moreover, C-rich matter and sulfate had seasonally differcnt but significant impacts on the formation of COS.展开更多
To investigate the effect of covID-19 control measures on aerosol chemistry,the chemical compositions,mixing states,and formation mechanisms of carbonaceous particles in the urban atmosphere of Liao-cheng in the North...To investigate the effect of covID-19 control measures on aerosol chemistry,the chemical compositions,mixing states,and formation mechanisms of carbonaceous particles in the urban atmosphere of Liao-cheng in the North China Plain(NCP)were compared before and during the pandemic using a single particle aerosol mass spectrometry(SPAMS).The results showed that the concentrations of five air pollutants including PM2.5,PM1o,SO2,NO2,and cO decreased by 41.2%-71.5%during the pandemic compared to those before the pandemic,whereas O3 increased by 1.3 times during the pandemic because of the depressed titration of O3 and more favorable meteorological conditions.The count and percentage contribution of carbonaceous particles in the total detected particles were lower during the pandemic than those before the pandemic.The carbonaceous particles were dominated by elemental and organic carbon(ECOC,35.9%),followed by elemental carbon-aged(EC-aged,19.6%)and organic carbon-fresh(OC-fresh,13.5%)before the pandemic,while EC-aged(25.3%),ECOC(17.9%),and secondary ions-rich(SEC,17.8%)became the predominant species during the pandemic.The carbonaceous particle sizes during the pandemic showed a broader distribution than that before the pandemic,due to the condensation and coagulation of carbonaceous particles in the aging processes.The relative aerosol acidity(Rra)was smaller before the pandemic than that during the pandemic,indicating the more acidic particle aerosol during the pandemic closely related to the secondary species and relative humidity(RH).More than 95.0%and 86.0%of carbonaceous particles in the whole period were internally mixed with nitrate and sulfate,implying that most of the carbonaceous particles were associated with secondary oxidation during their formation processes.The diurnal variations of oxalate particles and correlation analyses suggested that oxalate particles before the pandemic were derived from aqueous oxidation driven by RH and liquid water content(LwC),while oxalate particles during the pandemic were originated from O3-dominatedphotochemical oxidation.展开更多
Black carbon(BC)plays an important role in air quality and climate change,which is closely associated with its mixing state and chemical compositions.In this work the mixing state of BC-containing single particles was...Black carbon(BC)plays an important role in air quality and climate change,which is closely associated with its mixing state and chemical compositions.In this work the mixing state of BC-containing single particles was investigated to explore the evolution process of ambient BC particles using a single particle aerosol mass spectrometer(SPAMS)in March 2018 in Zhengzhou,China.The BC-containing particles accounted for 61.4%of total detected ambient single particles and were classified into five types including BC-nitrate(BC-N,52.3%)as the most abundant species,followed by BC-nitrate-sulfate(BC-NS,22.4%),BCOC(16.8%),BC-fresh(BC-F,4.5%)and BC-sulfate particles(BC-S,4.0%).With enhancement of the ambient nitrate concentration,the relative peak area(RPA)of nitrate in BC-N and BC–NS particles both increased,yet only the number fraction(N_(f))of BC–N particles increased while the N_(f) of BC-NS particles decreased,suggesting that the enhanced mixing state of BC with nitrate was mainly due to the increase in the ambient nitrate mass concentration.In addition,the Nfof BC-N decreased from 65.3%to 28.4%as the absorbing Angstrom exponents(AAE)of e BC increased from 0.75 to 1.45,which indicated the reduction of light absorption ability of aged BC particles with the enhanced formation of BC-N particles.The results of this work indicated a change in the mixing state of BC particles due to the dominance of nitrate in PM_(2.5),which also influenced the optical properties of aged BC particles.展开更多
In this paper, we propose a protocol to deterministically teleport an unknown mixed state of qubit by utilizing a maximally bipartite entangled state of qubits as quantum channel. Ira non-maximally entangled bipartite...In this paper, we propose a protocol to deterministically teleport an unknown mixed state of qubit by utilizing a maximally bipartite entangled state of qubits as quantum channel. Ira non-maximally entangled bipartite pure state is employed as quantum channel, the unknown mixed quantum state of qubit can be teleported with 1 -√ 1- C^2 probability, where C is the concurrence of the quantum channel. The protocol can also be generalized to teleport a mixed state of qudit or a multipartite mixed state. More important purpose is that, on the basis of the protocol, the teleportation of an arbitrary multipartite （pure or mixed） quantum state can be decomposed into the teleportation of each subsystem by employing separate entangled states as quantum channels. In the case of deterministic teleportation, Bob only needs to perform unitary transformations on his single particles in order to recover the initial teleported multipartite quantum state.展开更多
Mixed symmetry states are studied in the framework of the neutron-proton interacting boson model. It is found that some of the mixed symmetry states with moderate high spins change very fast with respect to the Majora...Mixed symmetry states are studied in the framework of the neutron-proton interacting boson model. It is found that some of the mixed symmetry states with moderate high spins change very fast with respect to the Majorana interaction. Under certain conditions, they become the yrast state or yrare state. These states are difficult to decay and become very stable. This study suggests that a possible new mode of isomers may exist due to the special nature in their proton and neutron degrees of freedom.展开更多
Using the algebraic dynamical method, the entanglement dynamics of an atom-field bipartite system in a mixed state is investigated. The atomic center-of-mass motion and the field-mode structure are also included in th...Using the algebraic dynamical method, the entanglement dynamics of an atom-field bipartite system in a mixed state is investigated. The atomic center-of-mass motion and the field-mode structure are also included in this system. We find that the values of the detuning and the average photon number are larger, the amplitude of the entanglement is smaller, but its period does not increase accordingly. Moreover, with the increase of the field-mode structure parameter and the transition photon number, the amplitude of the entanglement varies slightly while the oscillation becomes more and more fast. Interestingly, a damping evolution of the entanglement appears when both the detuning and the atomic motion are considered simultaneously.展开更多
A continuous time and mixed state branching process is constructed by a scaling limit theorem of two-type Galton-Watson processes.The process can also be obtained by the pathwise unique solution to a stochastic equati...A continuous time and mixed state branching process is constructed by a scaling limit theorem of two-type Galton-Watson processes.The process can also be obtained by the pathwise unique solution to a stochastic equation system.From the stochastic equation system we derive the distribution of local jumps and give the exponential ergodicity in Wasserstein-type distances of the transition semigroup.Meanwhile,we study immigration structures associated with the process and prove the existence of the stationary distribution of the process with immigration.展开更多
Hardy＇s theorem on nonlocality has been verified by a series of experiments with two-qubit entangled pure states.However,in this paper we demonstrate the experimental test of the theorem by using the two-photon entan...Hardy＇s theorem on nonlocality has been verified by a series of experiments with two-qubit entangled pure states.However,in this paper we demonstrate the experimental test of the theorem by using the two-photon entangled mixed states.We first investigate the generic logic in Hardy＇s proof of nonlocality,which can be applied for arbitrary two-qubit mixed polarization entangled states and can be reduced naturally to the well-known logic tested successfully by the previous pure state experiments.Then,the optimized violations of locality for various experimental parameters are delivered by the numerical method.Finally,the logic argued above for testing Hardy＇s theorem on nonlocality is demonstrated experimentally by using the mixed entangled-photon pairs generated via pumping two type-I BBO crystals.Our experimental results shows that Hardy＇s proof of nonlocality can also be verified with two-qubit polarization entangled mixed states,with a violation of about 3.4 standard deviations.展开更多
We analyze the multipartite entanglement evolution of three-qubit mixed states composed of a GHZ state and a W state. For a composite system consisting of three cavities interacting with independent reservoirs, it is ...We analyze the multipartite entanglement evolution of three-qubit mixed states composed of a GHZ state and a W state. For a composite system consisting of three cavities interacting with independent reservoirs, it is shown that the entanglement evolution is restricted by a set of monogamy relations. Furthermore, as quantified by the negativity, the entanglement dynamical property of the mixed entangled state of cavity photons is investigated. It is found that the three cavity photons can exhibit the phenomenon of entanglement sudden death （ESD）. However, compared with the evolution of a generalized three-qubit GHZ state which has the equal initial entanglement, the ESD time of mixed states is later than that of the pure state. Finally, we discuss the entanglement distribution in the multipartite system, and point out the intrinsic relation between the ESD of cavity photons and the entanglement sudden birth of reservoirs.展开更多
To extend the PSRK (predictive Soave-Redlich-Kwong equation of state) model to vapor-liquid equilibria of polymer solutions, a new EOS-gE mixing rule is applied in which the term ∑ xi ln(b/bi) in the PSRK mixing rule...To extend the PSRK (predictive Soave-Redlich-Kwong equation of state) model to vapor-liquid equilibria of polymer solutions, a new EOS-gE mixing rule is applied in which the term ∑ xi ln(b/bi) in the PSRK mixing rule for the parameter a, and the combinatorial part in the original universal functional activity coefficient (UNIFAC) model are cancelled. To take into account the free volume contribution to the excess Gibbs energy in polymer solution, a quadratic mixing rule for the cross co-volume bij with an exponent equals to 1/2 is applied[bij1/2= 1/2(bi1/2+bj1/2)]. The literature reported Soave-Redlich-Kwong equation of state (SRK EOS) parameters ofpure polymer are employed. The PSRK model with the modified mixing rule is used to predict the vapor-liquid equilibrium (VLE) of 37 solvent-polymer systems over a large range of temperature and pressure with satisfactory results.展开更多
Weak formulation of mixed state equations including boundary conditions are presented in a cylindrical coordinate system by introducing Hellinger-Reissner variational principle. Analytical solutions are obtained for l...Weak formulation of mixed state equations including boundary conditions are presented in a cylindrical coordinate system by introducing Hellinger-Reissner variational principle. Analytical solutions are obtained for laminated cylindrical shell by means of state space method. The present study extends and unifies the solution of laminated shells.展开更多
基金supported by the "Strategic Priority Research Program (B)" of the Chinese Academy of Sciences (Grant Nos. XDB05030105, XDB05030102, and XDB05030103)"Strategic Priority Research Program (A)" of the Chinese Academy of Sciences (XDA05100502)+1 种基金the National Natural Science Foundation of China (Grant Nos. 20937001, 41105106, 41005064 and 41205123)the China Postdoctoral Science Foundation (Grant Nos. 200801498 and 20070420515)
文摘The air quality model system RAMS （Regional Atmospheric Modeling System）-CMAQ （Models-3 Com- munity Multi-scale Air Quality） coupled with an aerosol optical/radiative module was applied to investigate the impact of different aerosol mixing states （i.e., externally mixed, half externally and half internally mixed, and internally mixed） oil radiative forcing in East Asia. The simulation results show that the aerosol optical depth （AOD） generally increased when the aerosol mixing state changed from externally mixed to internally mixed, while the single scattering albedo （SSA） decreased. Therefore, the scattering and absorption proper- ties of aerosols can be significantly affected by the change of aerosol mixing states. Comparison of simulated and observed SSAs at five AERONET （Aerosol Robotic Network） sites suggests that SSA could be better estimated by considering aerosol particles to be internally mixed. Model analysis indicates that the impact of aerosol mixing state upon aerosol direct radiative forcing （DRF） is complex. Generally, the cooling effect of aerosols over East Asia are enhanced in the northern part of East Asia （Northern China, Korean peninsula, and the surrounding area of Japan） and are reduced in the southern part of East. Asia （Sichuan Basin and Southeast China） by internal mixing process, and the variation range can reach ＋5 W m 2. The analysis shows that the internal mixing between inorganic salt and dust is likely the main reason that the cooling effect strengthens. Conversely, the internal nfixture of anthropogenic aerosols, including sulfate, nitrate, ammonium, black carbon, and organic carbon, could obviously weaken the cooling effect.
基金This research was supported by the National Natural Science Foundation of China(grant No.42305082)the Hebei Natural Science Foundation(grant No.D2024201001)+3 种基金the Science Research Project of the Hebei Education Department(grant No.BJK2024179)the China Postdoctoral Science Foundation(grant No.2024M750493)the Innovation Team of Nondestructive Testing Technology and Instrument,Hebei University(grant No.IT2023C03)the Interdisciplinary Research Program of Natural Science of Hebei University(grant No.DXK201915).
文摘Under environment with various water contents,the variations in the mixing state and particle size of coated black carbon(BC)aerosols cause changes in optical and radiative effects.In this study,fractal models for thinly,partially,and thickly coated BC under six relative humidities(RHs=0–95%)are constructed and optically simulated at 1064 and 532 nm.Differential scattering cross-sections are selected to retrieve the mixing state(D_(p)/D_(c))of BC to investigate the possible retrieval errors caused by the nonspherical morphology when using the single-particle soot photometer(SP2).Furthermore,the radiative forcing of BC aerosols at different RHs are analyzed.Results showed that the retrieval errors(REs)of D_(p)/D_(c) are negative for coated particles with BC volume fraction smaller than 0.10,indicating that the mixing states of coated fractal BC are underestimated during the hygroscopic growth.The partially-coated BC has the best retrieval accuracy of the mixing state,followed by the closed-cell and coated-aggregate model,judging from averaged REs.Radiative forcing enhancements for partially-coated aerosols with different BC volume fractions exponentially increase to opposite values,resulting in a warming or cooling effect.This study helps understand the uncertainties in Dp/Dc of BC aerosols retrieved by SP2 and their radiative forcing at different RHs.
基金supported by the National Natural Science Foundation of China(Grant Nos.41827804 and 41805093)the Natural Science Foundation of Guangdong Province(China)(No.2021A1515011206)+1 种基金the State Key Laboratory of Marine Resource Utilization in the South China Sea,Hainan University(China)(No.MRUKF2023009)the State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,CAS(No.SKLLQG2218).
文摘Oxygenated organic molecules(OOMs)play an important role in the formation of secondary organic aerosols(SOAs),but the mixing states of OOMs are still unclear.This study investigates the mixing states of OOM-containing single particles from the measurements taken using a single particle aerosol mass spectrometer in Guangzhou,China in 2022.Generally,the particle counts of OOM particles and the mass concentration of secondary organic carbon(SOC)exhibited similar temporal trends throughout the entire year.The OOM particles were consistently enriched in secondary ions,including ^(16)O^(−),^(26)CN^(−),^(46)NO_(2)^(−),^(62)NO_(3)^(−),and ^(97)HSO_(4)^(−).In contrast,the number fractions and diurnal patterns of OOM particles among the total detected particles showed similar distributions in August and October;however,the SOC ratios in fine particulate matter were quite different,suggesting that there were different mixing states of single-particle oxygenated organics.In addition,further classification results indicated that the OOM particles were more aged in October than August,even though the SOC ratios were higher in August.Furthermore,the distribution of hydrocarbon fragments exhibited a notable decrease from January to October,emphasizing the more aged state of the organics in October.In addition,the sharp increase in elemental carbon(EC)-OOM particles in the afternoon in October suggests the potential role of EC in the aging process of organics.Overall,in contrast to the bulk analysis of SOC mass concentration,the mixing states of the OOM particles provide insights into the formation process of SOAs in field studies.
基金supported by the Sichuan Natural Science Foundation (No.2022NSFSC0982)the Sichuan Science and Technology Program (No.2019YFS0476)the National Natural Science Foundation of China (No.41805095)。
文摘To investigate the volatility of atmospheric particulates and the evolution of other particulate properties(chemical composition,particle size distribution and mixing state)with temperature,a thermodenuder coupled with a single particle aerosol mass spectrometer was used to conduct continuous observations of atmospheric fine particles in Chengdu,southwest China.Because of their complex sources and secondary reaction processes,the average mass spectra of single particles contained a variety of chemical components(including organic,inorganic and metal species).When the temperature rose from room temperature to280℃,the relative areas of volatile and semi-volatile components decreased,while the relative areas of less or non-volatile components increased.Most(>80%)nitrate and sulfate existed in the form of NH_(4)NO_(3)and(NH_(4))_(2)SO_(4),and their volatilization temperatures were50–100℃and 150–280℃,respectively.The contribution of biomass burning(BB)and vehicle emission(VE)particles increased significantly at 280℃,which emphasized the important role of regional biomass burning and local motor vehicle emissions to the core of particles.With the increase in temperature,the particle size of the particles coated with volatile or semi-volatile components was reduced,and their mixing with secondary inorganic components was significantly weakened.The formation of K-nitrate(KNO_(3))and K-sulfate(KSO_(4))particles was dominated by liquid-phase processes and photochemical reactions,respectively.Reducing KNO_(3)and BB particles is the key to improving visibility.These new results are helpful towards better understanding the initial sources,pollution formation mechanisms and climatic effects of fine particulate matter in this megacity in southwest China.
基金supported by the Key-Area Research and Development Program of Guangdong Province(No.2020B1111360001)the National Natural Science Foundation of China(Nos.41805093 and 41827804)+7 种基金the Natural Science Foundation of Guangdong Province(No.2021A1515011206)the GDAS’Project of Science and Technology Development(No.2021GDASYL-20210103058)the State Key Laboratory of Organic Geochemistry(No.SKLOG202105)Guangdong Foundation for Program of Science and Technology Research(No.2020B1212060053)the State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,CAS(No.SKLLQG2218)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515012165)Scientific research special project of Pudong new district Ecological and Environmental Bureau(No.PDHJ20210008)the Shanghai Municipal Science and Technology Commission Natural Fund(No.20ZR1449700)。
文摘Organic nitrogen(ON)compounds play a significant role in the light absorption of brown carbon and the formation of organic aerosols,however,the mixing state,secondary formation processes,and influencing factors of ON compounds are still unclear.This paper reports on the mixing state of ON-containing particles based on measurements obtained using a highperformance single particle aerosol mass spectrometer in January 2020 in Guangzhou.The ON-containing particles accounted for 21% of the total detected single particles,and the particle count and number fraction of the ON-containing particles were two times higher at night than during the day.The prominent increase in the content of ON-containing particles with the enhancement of NO_xmainly occurred at night,and accompanied by high relative humidity and nitrate,which were associated with heterogeneous reactions between organics and gaseous NO_(x)and/or NO_(3)radical.The synchronous decreases in ON-containing particles and the mass absorption coefficient of water-soluble extracts at 365 nm in the afternoon may be associated with photo-bleaching of the ON species in the particles.In addition,the positive matrix factorization analysis found five factors dominated the formation processes of ON particles,and the nitrate factor(33%)mainly contributed to the production of ON particles at night.The results of this study provide unique insights into the mixing states and secondary formation processes of the ON-containing particles.
基金supported by the National Natural Science Foundation of China (grant No.42177083)the Junior Faculty Support Program for Scientific and Technological Innovations in Shandong Provincial Higher Education Institutions (grant No.2021KJ085).
文摘Oxalic acid(C_(2))is a significant tracer of secondary organic aerosols(SOA),yet its precursors,evolutionary processes,and formation mechanisms are not fully understood.This knowledge gap leads to uncertainties in evaluating the climate effect and global budget of SOA.Here we compared the size distribution,mixing fraction,and evolutionary mechanism of C_(2)-containing particles between summer and winter.In summer,the number of C_(2) particles and their homologs decreased compared to winter.However,the proportion of C_(2) relative to the total number of determined particles increased,indicating that the summertime particles are more aged.Higher relative aerosol acidity(Rra)and lower in-situ pH(pHis)in summer suggest that particles are more acidic during this season.Correlation analysis and temporal variation characteristics suggest that from 9:00 to 15:00 in summer,C_(2) particles mostly originate from the photochemical decomposition of larger dicarboxylic aids,driven by O3 concentration.Conversely,from 16:00 to 20:00,C_(2) particles are predominantly formed through aqueous-phase oxidation,influenced by higher relative humidity(RH),aerosol liquid water content(ALWC),and acidity.Additionally,heavy metal particles were the predominant type of C_(2) particles,and C_(2) particles exhibited an opposite diurnal variation to Fe in summer,suggesting that the photolysis of iron oxalate complexes is an important sink of C_(2) particles during this period.In winter,biomass burning(BB)particles were the most abundant,and a robust correlation between levoglucosan and C_(2) particles indicated a substantial influence of BB on C_(2) particles.The aqueous generation of C_(2) particles fromα-dicarbonyls driven by acidity was most effective when RH varied from 40%to 60%in the wintertime state of particles.These findings highlight the hourly and seasonal variations in the sources and evolutionary processes of SOA.Such variations must be considered in developing control measures and simulating the climate effect of SOA.
基金the National Key Research and Development Program of China(2016YFA0602003)the Ministry of Science and Technology of China(2017YFC0210000)+3 种基金the National Natural Science Foundation of China(41805096 and 41830965)the Natural Science Foundation of Jiangsu Province(BK20180801)the Natural Science Research Project for Universities of Jiangsu Province,China(18KJB170011)the China Postdoctoral Science Foundation(2018M640169).
文摘A heavy dust episode occurred from May 3 to 8,2017 in China,with an influenced area exceeding 1.63 million km2.In this work,the mixing state of aerosols and their spectral distributions were simultaneously observed in the sand source region ofHohhot and the long-range dust transport regi on of Nanji ng by using a single-particle aerosol mass spectrometer(SPAMS).The duration time of this dust episode was 37-40 h in Hohhot and prolonged to 51-104 h in Nanjing.Totals of 336,135(Hohhot)and 235,840(Nanjing)particles in PM2.5 were successfully ionized to identify 10 main particle classes.During this episode,aerosol particles including OCEC(30.65%),K(22.42%),K-CN(17.03%),sodium(9.46%),heavy metal(8.96%),EC-sulfate(3.46%)and Al(3.22%)were prevailing in Hohhot and were dominated by EC-sulfate(22.26%),OCEC(15.21%),heavy metal(11.96%),K(13.68%),sodium(12.27%),Al(10.54%)and EC(9.02%)in Nanjing.The spectral distribution peaked at 0.66μm during the dust episode in Nanjing,0.12μm larger than the peak size in the non-dust episode.Strong signals at-62[NO3)and-61[HCO3]/-61[C5H]for aerosol particles were observed in Hohhot and Nanjing respectively.The proportions of K-CN,sodium,heavy mental,OCEC and EC-sulfate particles in the dust episode of Hohhot were 2.75,1.41,1.80,1.22 and 1.28 times as large as the values in the non-dust episode.For Nanjing,the fractions of EC-sulfate,EC,Al particles in the dust episode were 10.55,4.65 and 1.46 times higher than values in the non-dust episode.The proportions of EC-secondary and EC-nitate particles were found to decrease in the dust episode in the two regions.
基金supported by Distinguished Youth Foundation of Shandong Provin c e(Grant No.JQ20 1413)the Scientific Research Staring Foundation for the Institute of Arid Meteorology,China Meteorology Administration(Grant No.KYS2014SSKY05)+2 种基金the National Basic Research Program of China(Grant No.2011CB403401)Fundamental Research Funds of Shandong University(Grant No.2014QY001)State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry(Grant No.LAPC-KF-2014-03)
文摘Knowledge of haze particles in background areas of North China is limited, although they have been studied well in urban settings. Atmospheric aerosol particles were collected at a background site in the North China Plain during 16–31 January, 2011. Water soluble inorganic ions of PM2.5 and physicochemical characteristics of individual particles on hazy and clean days were measured by Ion Chromatography(IC) and Transmission Electron Microscopy(TEM), respectively. Average PM2.5 mass concentration was 50.4±29.9 μg m?3 with 62.5±26.8 μg m?3 on hazy days and 19.9±11.5 μg m?3 on clean days. SO42?, NO3?, and NH4+ with a combined mass concentration of 19.0±11.5 μg m?3 accounted for 69.8%–89.4% of the total water soluble inorganic ions. Size distributions of SO42? and NH4+ showed one unimodal peak at 0.56–1.8 μm on hazy days, whereas NO3? appeared as bimodal peaks at 0.56–1.8 and 5.6–10 μm, respectively. Individual particle analyses showed that the dominant aerosols were a mixture of sulfate, nitrate, and carbonaceous species, which together determine their mixing states. 48-h air mass back trajectories on hazy days suggested that air masses crossed the polluted continental areas(such as Jing-jin-ji region and Shandong province) and entrained ground air pollutants 11–19 hours before reaching the background area. During long-range transport particles undergo ageing and tend to be internally mixed mainly due to condensation in the background atmosphere. Our results suggest that hygroscopic and optical properties of these aerosol particles in the background area differ substantially from those in urban areas.
基金This work was supported by The National Natural Science Foundation of China （Grant Nos. 21177027 and 41275126）, Ministry of Science and Technology of China （2012YQ220113-4）, the Science ＆ Technology Commission of Shanghai Municipality （12DJ1400100, 14XD 1400600）, and the Jiangsu Provincial Collaborative Innovation Center of Climate Change.
文摘Fresh straw burning （SB） particles were generated in the laboratory by the combustion of rice straw and corn straw. The chemical composition and mixing state of the fresh SB particles were investigated by an Aerosol Time-of-Flight Mass Spectrometer （ATOFMS）. Based on the mass spectral patterns, the SB particles were clustered into four major types： Salt, Organic Carbon （OC）, Elemental Carbon （EC）, and internally mixed particles of EC and OC （EC-OC）. In addition, particles containing ash, polycyclic aromatic hydrocarbons, heavy metals or nicotine were also observed. Physical and chemical changes of the SB particles immediately after the emission were analyzed with highly time-resolved data. During the aging processes, the average particle size increased steadily. Freshly emitted organic compounds were gradu- ally oxidized to more oxygenated compounds in the OC- containing particles. Meanwhile, an important displace- ment reaction （2KCI＋ SO24- KzSO4 ＋ 2C1-） was observed. The marker ions for SB particles were optimized and applied to identify the SB particles in the ambient atmosphere. The fluctuation of the number fraction of ambient SB particles sorted by ATOFMS agrees well with that of water soluble K＋ measured by an online ion chromatography, demonstrating that the optimized marker ions could be good tracers for SB particles in field measurements.
基金This work was supported by the National Science and Technology Support Program of China （No. 2014BAC22B01）, the National Natural Science Foundation of China （Grant Nos. 21107061, 21190054, and 81571130090）, the Science-technology Program of State Grid Corporation of China （No. 521700140004） and the Development and Application of Field Emission Gun Scanning Electron Microscopy National Special Projects on Scientific Instrument Development （No. 2013YQ120353）. The authors also thank the Energy Saving and Pollution Control Association of East Asia （ESPA）, for their help in the management of the field observation program.
文摘Direct individual analysis using Scanning Electron Microscopy combined with online obscrv ation was conducted to examine the S-rich particles in PM2.5 of two typical polluted haze cpisodes in summer and winter from 2014 to 2015 in Beijing. Four major types of S-rich particles, including sccondary CaSO4 particles （mainly observed in summer）, S-rich mineral particles （SRM）, S-rich water droplets （SRW） and （C, O, S）-rich particles （COS） were identified. We lbund the differcnt typical morphologies and element distributions of S-rich particles and considered that （C, O, S）-rich parliclcs had two major mixing states in different seasons. On the basis of the S-rich particles＂ relative abundances. S concentrations and their relationships with PM2.5 as well as the seasonal comparison, wc revealed that the S-participated formation degrees of SRM and SRW would enhance with increasing PM2.5 concentration. Moreover, C-rich matter and sulfate had seasonally differcnt but significant impacts on the formation of COS.
基金supported by the National Natural Science Fund of China(grant number 42177083)Natural Science Foundation of Shandong Province(grant number ZR2020MD113)and Open Funds of State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences(grant number SKLLOG2020).
文摘To investigate the effect of covID-19 control measures on aerosol chemistry,the chemical compositions,mixing states,and formation mechanisms of carbonaceous particles in the urban atmosphere of Liao-cheng in the North China Plain(NCP)were compared before and during the pandemic using a single particle aerosol mass spectrometry(SPAMS).The results showed that the concentrations of five air pollutants including PM2.5,PM1o,SO2,NO2,and cO decreased by 41.2%-71.5%during the pandemic compared to those before the pandemic,whereas O3 increased by 1.3 times during the pandemic because of the depressed titration of O3 and more favorable meteorological conditions.The count and percentage contribution of carbonaceous particles in the total detected particles were lower during the pandemic than those before the pandemic.The carbonaceous particles were dominated by elemental and organic carbon(ECOC,35.9%),followed by elemental carbon-aged(EC-aged,19.6%)and organic carbon-fresh(OC-fresh,13.5%)before the pandemic,while EC-aged(25.3%),ECOC(17.9%),and secondary ions-rich(SEC,17.8%)became the predominant species during the pandemic.The carbonaceous particle sizes during the pandemic showed a broader distribution than that before the pandemic,due to the condensation and coagulation of carbonaceous particles in the aging processes.The relative aerosol acidity(Rra)was smaller before the pandemic than that during the pandemic,indicating the more acidic particle aerosol during the pandemic closely related to the secondary species and relative humidity(RH).More than 95.0%and 86.0%of carbonaceous particles in the whole period were internally mixed with nitrate and sulfate,implying that most of the carbonaceous particles were associated with secondary oxidation during their formation processes.The diurnal variations of oxalate particles and correlation analyses suggested that oxalate particles before the pandemic were derived from aqueous oxidation driven by RH and liquid water content(LwC),while oxalate particles during the pandemic were originated from O3-dominatedphotochemical oxidation.
基金financially supported by the National Natural Science Foundation of China(No.41827804,41805093)the Guangzhou Economic and Technological Development District International Science and Technology Cooperation Project(No.2018GH08)+1 种基金the International Science and Technology Cooperation Project of Guangdong Province(No.2018A050506020)the Pearl River Nova Program of Guangzhou(No.201806010064)。
文摘Black carbon(BC)plays an important role in air quality and climate change,which is closely associated with its mixing state and chemical compositions.In this work the mixing state of BC-containing single particles was investigated to explore the evolution process of ambient BC particles using a single particle aerosol mass spectrometer(SPAMS)in March 2018 in Zhengzhou,China.The BC-containing particles accounted for 61.4%of total detected ambient single particles and were classified into five types including BC-nitrate(BC-N,52.3%)as the most abundant species,followed by BC-nitrate-sulfate(BC-NS,22.4%),BCOC(16.8%),BC-fresh(BC-F,4.5%)and BC-sulfate particles(BC-S,4.0%).With enhancement of the ambient nitrate concentration,the relative peak area(RPA)of nitrate in BC-N and BC–NS particles both increased,yet only the number fraction(N_(f))of BC–N particles increased while the N_(f) of BC-NS particles decreased,suggesting that the enhanced mixing state of BC with nitrate was mainly due to the increase in the ambient nitrate mass concentration.In addition,the Nfof BC-N decreased from 65.3%to 28.4%as the absorbing Angstrom exponents(AAE)of e BC increased from 0.75 to 1.45,which indicated the reduction of light absorption ability of aged BC particles with the enhanced formation of BC-N particles.The results of this work indicated a change in the mixing state of BC particles due to the dominance of nitrate in PM_(2.5),which also influenced the optical properties of aged BC particles.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10575017 and 60472017
文摘In this paper, we propose a protocol to deterministically teleport an unknown mixed state of qubit by utilizing a maximally bipartite entangled state of qubits as quantum channel. Ira non-maximally entangled bipartite pure state is employed as quantum channel, the unknown mixed quantum state of qubit can be teleported with 1 -√ 1- C^2 probability, where C is the concurrence of the quantum channel. The protocol can also be generalized to teleport a mixed state of qudit or a multipartite mixed state. More important purpose is that, on the basis of the protocol, the teleportation of an arbitrary multipartite （pure or mixed） quantum state can be decomposed into the teleportation of each subsystem by employing separate entangled states as quantum channels. In the case of deterministic teleportation, Bob only needs to perform unitary transformations on his single particles in order to recover the initial teleported multipartite quantum state.
文摘Mixed symmetry states are studied in the framework of the neutron-proton interacting boson model. It is found that some of the mixed symmetry states with moderate high spins change very fast with respect to the Majorana interaction. Under certain conditions, they become the yrast state or yrare state. These states are difficult to decay and become very stable. This study suggests that a possible new mode of isomers may exist due to the special nature in their proton and neutron degrees of freedom.
基金Project supported by the National Natural Science Foundation of China (Grant No.10704031)the Fundamental Research Funds for the Central Universities of China (Grant No.lzujbky-2010-75)
文摘Using the algebraic dynamical method, the entanglement dynamics of an atom-field bipartite system in a mixed state is investigated. The atomic center-of-mass motion and the field-mode structure are also included in this system. We find that the values of the detuning and the average photon number are larger, the amplitude of the entanglement is smaller, but its period does not increase accordingly. Moreover, with the increase of the field-mode structure parameter and the transition photon number, the amplitude of the entanglement varies slightly while the oscillation becomes more and more fast. Interestingly, a damping evolution of the entanglement appears when both the detuning and the atomic motion are considered simultaneously.
基金supported by the National Key R&D Program of China(2020YFA0712900)the National Natural Science Foundation of China(11531001).
文摘A continuous time and mixed state branching process is constructed by a scaling limit theorem of two-type Galton-Watson processes.The process can also be obtained by the pathwise unique solution to a stochastic equation system.From the stochastic equation system we derive the distribution of local jumps and give the exponential ergodicity in Wasserstein-type distances of the transition semigroup.Meanwhile,we study immigration structures associated with the process and prove the existence of the stationary distribution of the process with immigration.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61308008 and U1330201)
文摘Hardy＇s theorem on nonlocality has been verified by a series of experiments with two-qubit entangled pure states.However,in this paper we demonstrate the experimental test of the theorem by using the two-photon entangled mixed states.We first investigate the generic logic in Hardy＇s proof of nonlocality,which can be applied for arbitrary two-qubit mixed polarization entangled states and can be reduced naturally to the well-known logic tested successfully by the previous pure state experiments.Then,the optimized violations of locality for various experimental parameters are delivered by the numerical method.Finally,the logic argued above for testing Hardy＇s theorem on nonlocality is demonstrated experimentally by using the mixed entangled-photon pairs generated via pumping two type-I BBO crystals.Our experimental results shows that Hardy＇s proof of nonlocality can also be verified with two-qubit polarization entangled mixed states,with a violation of about 3.4 standard deviations.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10905016 and 10971247)the Natural Science Foundation of Hebei Province of China (Grant Nos. A2012205062,A2012205013,and A2010000344)the Fund of Hebei Normal niversity
文摘We analyze the multipartite entanglement evolution of three-qubit mixed states composed of a GHZ state and a W state. For a composite system consisting of three cavities interacting with independent reservoirs, it is shown that the entanglement evolution is restricted by a set of monogamy relations. Furthermore, as quantified by the negativity, the entanglement dynamical property of the mixed entangled state of cavity photons is investigated. It is found that the three cavity photons can exhibit the phenomenon of entanglement sudden death （ESD）. However, compared with the evolution of a generalized three-qubit GHZ state which has the equal initial entanglement, the ESD time of mixed states is later than that of the pure state. Finally, we discuss the entanglement distribution in the multipartite system, and point out the intrinsic relation between the ESD of cavity photons and the entanglement sudden birth of reservoirs.
文摘To extend the PSRK (predictive Soave-Redlich-Kwong equation of state) model to vapor-liquid equilibria of polymer solutions, a new EOS-gE mixing rule is applied in which the term ∑ xi ln(b/bi) in the PSRK mixing rule for the parameter a, and the combinatorial part in the original universal functional activity coefficient (UNIFAC) model are cancelled. To take into account the free volume contribution to the excess Gibbs energy in polymer solution, a quadratic mixing rule for the cross co-volume bij with an exponent equals to 1/2 is applied[bij1/2= 1/2(bi1/2+bj1/2)]. The literature reported Soave-Redlich-Kwong equation of state (SRK EOS) parameters ofpure polymer are employed. The PSRK model with the modified mixing rule is used to predict the vapor-liquid equilibrium (VLE) of 37 solvent-polymer systems over a large range of temperature and pressure with satisfactory results.
文摘Weak formulation of mixed state equations including boundary conditions are presented in a cylindrical coordinate system by introducing Hellinger-Reissner variational principle. Analytical solutions are obtained for laminated cylindrical shell by means of state space method. The present study extends and unifies the solution of laminated shells.
