On-line chemical characterization of atmospheric particulate matter(PM)with soft ionization technique and ultrahigh-resolution Mass Spectrometry(UHRMS)provides molecular information of organic constituents in real tim...On-line chemical characterization of atmospheric particulate matter(PM)with soft ionization technique and ultrahigh-resolution Mass Spectrometry(UHRMS)provides molecular information of organic constituents in real time.Here we describe the development and application of an automatic measurement system that incorporates PM_(2.5)sampling,thermal desorption,atmospheric pressure photoionization,and UHRMS analysis.Molecular formulas of detected organic compounds were deducted from the accurate(±10 ppm)molecular weights obtained at a mass resolution of 100,000,allowing the identification of small organic compounds in PM_(2.5).Detection efficiencies of 28 standard compounds were determined and we found a high sensitivity and selectivity towards organic amines with limits of detection below 10 pg.As a proof of principle,PM_(2.5)samples collected off-line in winter in the urban area of Beijing were analyzed using the Ionization Module and HRMS of the system.The automatic system was then applied to conduct on-line measurements during the summer time at a time resolution of 2 hr.The detected organic compounds comprised mainly CHON and CHN compounds below 350 m/z.Pronounced seasonal variations in elemental composition were observed with shorter carbon backbones and higher O/C ratios in summer than that in winter.This result is consistent with stronger photochemical reactions and thus a higher oxidation state of organics in summer.Diurnal variation in signal intensity of each formula provides crucial information to reveal its source and formation pathway.In summary,the automatic measurement system serves as an important tool for the on-line characterization and identification of organic species in PM_(2.5).展开更多
Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress magnitude.To investigate the correlation between the rock mass properties and maximum horizontal stre...Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress magnitude.To investigate the correlation between the rock mass properties and maximum horizontal stress,the three-dimensional(3D)stress tensors at 89 measuring points determined using an improved overcoring technique in nine mines in China were adopted,a newly defined characteristic parameter C_(ERP)was proposed as an indicator for evaluating the structural properties of rock masses,and a fuzzy relation matrix was established using the information distribution method.The results indicate that both the vertical stress and horizontal stress exhibit a good linear growth relationship with depth.There is no remarkable correlation between the elastic modulus,Poisson's ratio and depth,and the distribution of data points is scattered and messy.Moreover,there is no obvious relationship between the rock quality designation(RQD)and depth.The maximum horizontal stress σ_(H) is a function of rock properties,showing a certain linear relationship with the C_(ERP)at the same depth.In addition,the overall change trend of σ_(H) determined by the established fuzzy identification method is to increase with the increase of C_(ERP).The fuzzy identification method also demonstrates a relatively detailed local relationship betweenσ_H and C_(ERP),and the predicted curve rises in a fluctuating way,which is in accord well with the measured stress data.展开更多
The accurate characterization of thermoelectric properties at low temperatures is crucial for the development of high-performance thermoelectric cooling devices. While measurement errors of thermoelectric properties a...The accurate characterization of thermoelectric properties at low temperatures is crucial for the development of high-performance thermoelectric cooling devices. While measurement errors of thermoelectric properties at temperatures above room temperature have been extensively discussed, there is a lack of standard measurement protocols and error analyses for low-temperature transport properties. In this study, we present a measurement system capable of characterizing all three key thermoelectric parameters, i.e., Seebeck coefficient, electrical conductivity, and thermal conductivity, for a single sample across a temperature range of 10 K to 300 K. We investigated six representative commercial Bi_(2)Te_(3)-based samples(three N-type and three P-type). Using an error propagation model, we systematically analyzed the measurement uncertainties of the three intrinsic parameters and the resulting thermoelectric figure of merit. Our findings reveal that measurement uncertainties for both N-type and P-type Bi_(2)Te_(3)-based materials can be effectively maintained below 5% in the temperature range of 40 K to 300 K. However, the uncertainties increase to over 10% at lower temperatures, primarily due to the relatively smaller values of electrical resistivity and Seebeck coefficients in this regime. This work establishes foundational data for Bi_(2)Te_(3)-based thermoelectric materials and provides a framework for broader investigations of advanced low-temperature thermoelectrics.展开更多
Noise is inevitable in electrical capacitance tomography(ECT)measurements.This paper describes the influence of noise on ECT performance for measuring gas-solids fluidized bed characteristics.The noise distribution is...Noise is inevitable in electrical capacitance tomography(ECT)measurements.This paper describes the influence of noise on ECT performance for measuring gas-solids fluidized bed characteristics.The noise distribution is approximated by the Gaussian distribution and added to experimental capacitance data with various intensities.The equivalent signal strength(Ф)that equals the signal-to-noise ratio of packed beds is used to evaluate noise levels.Results show that the Pearson correlation coefficient,which indicates the similarity of solids fraction distributions over pixels,increases with Ф,and reconstructed images are more deteriorated at lower Ф.Nevertheless,relative errors for average solids fraction and bubble size in each frame are less sensitive to noise,attributed to noise compromise caused by the process of pixel values.These findings provide useful guidance for assessing the accuracy of ECT measurements of multiphase flows.展开更多
Ensuring highway safety relies heavily on pavement friction resistance.To enable network-level pavement skid resistance monitoring and management,this study proposes a non-contact three-dimensional laser surface testi...Ensuring highway safety relies heavily on pavement friction resistance.To enable network-level pavement skid resistance monitoring and management,this study proposes a non-contact three-dimensional laser surface testing method to obtain detailed aggregate surface data.The existing contact-based skid resistance measurement methods suffer from poor reproducibility and repeatability,hindering their application for network-level management.In this research,traditional multiple linear regression and four machine learning methods,support vector machine(SVM),random forest(RF),gradient boosting decision tree(GBDT),and convolutional neural network(CNN),are utilized to evaluate and predict pavement frictional performance.To assess the proposed methods,data from 45 pavement sites in Oklahoma,including 6 major preventive maintenance(PM)treatments and 7 typical types of aggregates,are collected.Parallel data acquisition is conducted at highway speeds using a grip tester and a high-speed texture profiler to measure pavement skid resistance and surface macro-texture,respectively.Aggregate properties are captured in 3D using a portable ultra-high-resolution 3D laser imaging scanner,leading to the calculation of four types of 3D aggregate parameters characterizing the micro-texture of aggregate surfaces.The relationship between pavement surface friction and texture is explored using machine learning models.The results reveal that the random forest and gradient boosting decision tree models exhibit the highest accuracy,SVM and CNN perform moderately,while the traditional linear regression method fares the worst.By assessing the importance of the 38 parameter variables,the most critical 21 variables were selected for model development.Test results demonstrate that the GBDT model exhibits the best predictive performance,with an explanatory capability of 87.4%for road friction performance.The findings demonstrate the feasibility of replacing contact-based pavement friction evaluation with non-contact texture measurements,offering promising prospects for a network-level pavement skid resistance monitoring and management system.展开更多
Aviation kerosene RP-3 is extensively used in China.This paper details the measurement of the density of Chinese aviation kerosene RP-3 employing the flow method under high-pressure and high-temperature conditions.The...Aviation kerosene RP-3 is extensively used in China.This paper details the measurement of the density of Chinese aviation kerosene RP-3 employing the flow method under high-pressure and high-temperature conditions.The methodology utilizes circular tubes with two different diameters.The density of aviation kerosene RP-3 was experimentally measured for the first time within a pressure range from 6 MPa to 8 MPa and a temperature range from 323 K to 783 K,with a maximum relative uncertainty of 0.35%.The experimental setup used n-decane for calibration,achieving an average calibration error of 0.91%.The data indicate that the density of RP-3 ranges from 764 kg/m^(3)to 247 kg/m^(3)under the tested conditions.The results show that the density of kerosene RP-3 decreases with an increase in temperature at a constant pressure,and at a given temperature,a higher pressure results in a higher density.Polynomial fitting was applied to the data,resulting in the average absolute deviation of 1.09%,0.80%,and 0.76%at different pressures of 6,7,and 8 MPa,respectively.展开更多
The distance distributions between two site-specifically anchored spin labels in a protein,measured by pulsed electron-electron double resonance(PELDOR or DEER),provide rich sources of structural and conformational re...The distance distributions between two site-specifically anchored spin labels in a protein,measured by pulsed electron-electron double resonance(PELDOR or DEER),provide rich sources of structural and conformational restraints on the proteins or their complexes.The rigid connection of the nitroxide spin label to the protein improves the accuracy and precision of distance measurement.We report a new spin labelling approach by formation of thioester bond between nitroxide(NO)spin label,NOAI(NO spin labels activated by acetylimidazole),and a protein thiol,and this spin labeling method has demonstrated high performance in DEER distance measurement on proteins.The results showed that NOAI has shorter connection to the protein ligation site than 2,2,5,5-tetramethyl-pyrroline-1-oxyl methanethiosulfonate(MTSL)and 3-maleimido-proxyl(M-Prox)in the respective protein conjugate and produces narrower distance distributions for the tested proteins including ubiquitin(Ub),immunoglobulin-binding b1 domain of streptococcal protein G(GB1),and second mitochondria-derived activator of caspases(Smac).The NOAI protein conjugate connected by a thioester bond is resistant to reducing reagent and offers highfidelity DEER distance measurements in cell lysates.展开更多
Using nine ice-tethered buoys deployed across the marginal ice zone(MIZ)and pack ice zone(PIZ)north of the Laptev Sea during the expedition of the Multidisciplinary drifting Observatory for the Study of Arctic Climate...Using nine ice-tethered buoys deployed across the marginal ice zone(MIZ)and pack ice zone(PIZ)north of the Laptev Sea during the expedition of the Multidisciplinary drifting Observatory for the Study of Arctic Climate(MOSAiC)in 2019-2020,we characterized the spatiotemporal variations in sea ice kinematics and deformation between October 2019 and July 2020 in the Transpolar Drift(TPD).From October to November,the buoys were in the upstream area of the TPD;spatial variations of deformation rates were significantly correlated with initial ice thickness(R=−0.84,P<0.05).From December 2019 to March 2020,the buoys were in the high Arctic and the ice cover was consolidated;heterogeneity in ice kinematics as measured across the buoys reduced by 65%.From April to May 2020,the buoys were in the downstream TPD;amplified spatial variations in ice kinematics were observed.This is because two buoys had drifted over the shallow waters north of Svalbard earlier;trajectory-stretching exponents derived from the data from these two buoys indicate deformation rates(10.6 d^(−1))that were about twice those in the deep basin(4.2 d^(−1)).By June 2020,a less consolidated ice pack and enhanced tidal forcing in the Fram Strait MIZ resulted in ice deformation with a semi-diurnal power spectral density of>0.25 d^(−1),which is about 1.5 times that in PIZ.Therefore,in both the upstream and downstream regions of the TPD,the transition between the MIZ and the PIZ contributes to the spatial and seasonal variations of sea ice motion and deformation.The results from this study can be used to support the characterization of the momentum balance and influencing factors during the ice advection along the TPD,which is a crucial corridor for Arctic sea ice outflow to the north Atlantic Ocean.展开更多
Branch angles are an important plant morphological trait affecting light interception within forest canopies.However,studies on branch angles have been limited due to the time-consuming nature of manual measurements u...Branch angles are an important plant morphological trait affecting light interception within forest canopies.However,studies on branch angles have been limited due to the time-consuming nature of manual measurements using a protractor.Terrestrial laser scanning(TLS),however,provides new opportunities to measure branch angles more efficiently.Despite this potential,studies validating branch angle measurements from TLS have been limited.Here,our aim is to evaluate both manual and automatic branch angle measurements of European beech from TLS data using traditional field-measurements with a protractor as a reference.We evaluated the accuracy of branch angle measurements based on four automated algorithms(aRchiQSM,TreeQSM,Laplacian,SemanticLaplacian)from TLS data.Additionally,we assessed different ways of manual branch angle measurements in the field.Our study was based on a dataset comprising 124 branch angles measured from six European beech in a European deciduous forest.Our results show that manual branch angle measurements from TLS data are in high agreement with the reference(root-mean-squared error,RMSE:[3.57°-4.18°],concordance correlation coefficient,CCC:[0.950.97])across different branch length positions.Automated algorithms also are in high agreement with the reference although RMSE is approximately twice as large compared to manual branch angle measurements from TLS(RMSE:[9.29°-10.55°],CCC:[0.830.86])with manual leaf points removal.When applying the automatic wood-leaf separation algorithm,the performance of the four methods declined significantly,with only approximately 20 branch angles successfully identified.Moreover,it is important to note that there is no influence of the measurement position(branch surface versus center)for branch angle measurements.However,for curved branches,the selection of branch measurement length significantly impacts the branch angle measurement.This study provides a comprehensive understanding of branch angle measurements in forests.We show that automated measurement methods based on TLS data of branch angles are a valuable tool to quantify branch angles at larger scales.展开更多
Schottky mass spectrometry utilizing heavy-ion storage rings is a powerful technique for the precise mass and decay half-life measurements of highly charged ions.Owing to the nondestructive ion detection features of S...Schottky mass spectrometry utilizing heavy-ion storage rings is a powerful technique for the precise mass and decay half-life measurements of highly charged ions.Owing to the nondestructive ion detection features of Schottky noise detectors,the number of stored ions in the ring is determined by the peak area in the measured revolution frequency spectrum.Because of their intrinsic amplitude-frequency characteristic(AFC),Schottky detector systems exhibit varying sensitivities at different frequencies.Using low-energy electron-cooled stored ions,a new method is developed to calibrate the AFC curve of the Schottky detector system of the Experimental Cooler Storage Ring(CSRe)storage ring located in Lanzhou,China.Using the amplitude-calibrated frequency spectrum,a notable refinement was observed in the precision of both the peak position and peak area.As a result,the storage lifetimes of the electron-cooled fully ionized^(56)Fe^(26+)ions were determined with high precision at beam energies of 13.7 and 116.4 MeV/u,despite of frequency drifts during the experiment.When electron cooling was turned off,the effective vacuum condition experienced by the 116.4 MeV/u^(56)Fe^(26+)ions was determined using amplitude-calibrated spectra,revealing a value of 2×10^(−10)mbar,which is consistent with vacuum gauge readings along the CSRe ring.The method reported herein will be adapted for the next-generation storage ring of the HIAF facility under construction in Huizhou,China.It can also be adapted to other storage ring facilities worldwide to improve precision and enhance lifetime measurements using many ions in the ring.展开更多
Metabolic dysfunction-associated steatotic liver disease(MASLD)is the most widespread chronic liver disease signified by serious life-threatening conditions.The prevalence of MASLD increases along the growing prevalen...Metabolic dysfunction-associated steatotic liver disease(MASLD)is the most widespread chronic liver disease signified by serious life-threatening conditions.The prevalence of MASLD increases along the growing prevalence in obesity and metabolic syndrome.To minimize costs and complications,non-invasive diagnostic tools,including transient elastography(TE),were introduced for assessment of MASLD.TE measures liver stiffness(LS),a clinical marker for the diagnosis of liver fibrosis and cirrhosis.LS measurements are based on ultrasound wave imaging and quantification.Vibration-controlled TE,including FibroScan®,is commonly used TE methods which can accurately identify the degree of liver fibrosis and cirrhosis progression.TE was reported to predict the progression towards hepatocellular carcinoma,portal hypertension,and varices.However,the accuracy of LS diagnostics alone in patients with MASLD remains controversial.TE measurements have several limitations,including inadequate precision due to focal liver lesions,cholestasis,inflammation,and other pathological and anatomical factors which can lead to the stiffness variability.Overestimations of TE readings were reported in obese patients with body mass index(BMI)over 30 kg/m2,and older patients with ascites,diabetes,or hypertension.Not all MASLD patients have high BMI.The prevalence of obesity among MASLD patients varies worldwide,indicating the urgent need for comprehensive diagnostic tools.In patients with MASLD,improved diagnostic accuracy has been demonstrated by combining LS measurements with other blood test-based scores and simple clinical parameters(agile scores based on age,sex,platelet count,aminotransferases,and diabetes).This study reviews the limitations of TE-based diagnostics and discusses the combined scoring algorithm.In conclusion,the sequence of LS measurements along assessment of other important clinical markers is an effective,low-cost,reliable tool to identify and monitor fibrosis progression in MASLD.展开更多
Water-soluble organic matter（WSOM） represents a critical fraction of fine particles（PM2.5）in the air, but its changing behaviors and formation mechanisms are not well understood yet, partly due to the lack of fast...Water-soluble organic matter（WSOM） represents a critical fraction of fine particles（PM2.5）in the air, but its changing behaviors and formation mechanisms are not well understood yet, partly due to the lack of fast techniques for the ambient measurements. In this study,a novel system for the on-line measurement of water-soluble components in PM2.5, the particle-into-liquid sampler（PILS）–Nebulizer–aerosol chemical speciation monitor（ACSM）, was developed by combining a PILS, a nebulizer, and an ACSM. High time resolution concentrations of WSOM, sulfate, nitrate, ammonium, and chloride, as well as mass spectra, can be obtained with satisfied quality control results. The system was firstly applied in China for field measurement of WSOM. The mass spectrum of WSOM was found to resemble that of oxygenated organic aerosol, and WSOM agreed well with secondary inorganic ions. All evidence collected in the field campaign demonstrated that WSOM could be a good surrogate of secondary organic aerosol（SOA）. The PILS–Nebulizer–ACSM system can thus be a useful tool for intensive study of WSOM and SOA in PM2.5.展开更多
Fireworks(FW)could significantly worsen air quality in short term during celebrations.Due to similar tracers with biomass burning(BB),the fast and precise qualification of FW and BB is still challenging.In this study,...Fireworks(FW)could significantly worsen air quality in short term during celebrations.Due to similar tracers with biomass burning(BB),the fast and precise qualification of FW and BB is still challenging.In this study,online bulk and single-particle measurements were combined to investigate the contributions of FW and BB to the overall mass concentrations of PM_(2.5)and specific chemical species by positive matrix factorization(PMF)during the Chinese New Year in Hong Kong in February 2013.With combined information,fresh/aged FW(abundant ^(140)K_(2)NO_(3)^(+)and ^(213)K_(3)SO_(4)^(+)formed from ^(113)K_(2)Cl^(+)discharged by fresh FW)can be extracted from the fresh/aged BB sources,in addition to the Second Aerosol,Vehicles+Road Dust,and Sea Salt factors.The contributions of FW and BB were investigated during three high particle matter episodes influenced by the pollution transported from the Pearl River Delta region.The fresh BB/FW contributed 39.2%and 19.6%to PM_(2.5)during the Lunar Chinese New Year case.However,the contributions of aged FW/BB enhanced in the last two episodes due to the aging process,evidenced by high contributions from secondary aerosols.Generally,the fresh BB/FW showed more significant contributions to nitrate(35.1%and15.0%,respectively)compared with sulfate(25.1%and 5.9%,respectively)and OC(14.8%and11.1%,respectively)on average.In comparison,the aged FW contributed more to sulfate(13.4%).Overall,combining online bulk and single-particle measurement data can combine both instruments’advantages and provide a new perspective for applying source apportionment of aerosols using PMF.展开更多
Visible light communication(VLC)has attracted much attention in the research of sixthgeneration(6G)systems.Furthermore,channel modeling is the foundation for designing efficient and robust VLC systems.In this paper,we...Visible light communication(VLC)has attracted much attention in the research of sixthgeneration(6G)systems.Furthermore,channel modeling is the foundation for designing efficient and robust VLC systems.In this paper,we present extensive VLC channel measurement campaigns in indoor environments,i.e.,an office and a corridor.Based on the measured data,the large-scale fading characteristics and multipath-related characteristics,including omnidirectional optical path loss(OPL),K-factor,power angular spectrum(PAS),angle spread(AS),and clustering characteristics,are analyzed and modeled through a statistical method.Based on the extracted statistics of the above-mentioned channel characteristics,we propose a statistical spatial channel model(SSCM)capable of modeling multipath in the spatial domain.Furthermore,the simulated statistics of the proposed model are compared with the measured statistics.For instance,in the office,the simulated path loss exponent(PLE)and the measured PLE are 1.96and 1.97,respectively.And,the simulated medians of AS and measured medians of AS are 25.94°and 24.84°,respectively.Generally,the fact that the simulated results fit well with measured results has demonstrated the accuracy of our SSCM.展开更多
In this paper,to study the mechanical responses of a solid propellant subjected to ultrahigh acceleration overload during the gun-launch process,specifically designed projectile flight tests with an onboard measuremen...In this paper,to study the mechanical responses of a solid propellant subjected to ultrahigh acceleration overload during the gun-launch process,specifically designed projectile flight tests with an onboard measurement system were performed.Two projectiles containing dummy HTPB propellant grains were successfully recovered after the flight tests with an ultrahigh acceleration overload value of 8100 g.The onboard-measured time-resolved axial displacement,contact stress and overload values were successfully obtained and analysed.Uniaxial compression tests of the dummy HTPB propellant used in the gunlaunched tests were carried out at low and intermediate strain rates to characterize the propellant's dynamic properties.A linear viscoelastic constitutive model was employed and applied in finite-element simulations of the projectile-launching process.During the launch process,the dummy propellant grain exhibited large deformation due to the high acceleration overload,possibly leading to friction between the motor case and propellant grain.The calculated contact stress showed good agreement with the experimental results,though discrepancies in the overall displacement of the dummy propellant grain were observed.The dynamic mechanical response process of the dummy propellant grain was analysed in detail.The results can be used to estimate the structural integrity of the analysed dummy propellant grain during the gun-launch process.展开更多
Based on the theory of multi-body system (MBS), bine’s and huston’s methods are applied to an on-line measuring system of machining center in this paper. Through the study on modeling technique, the comprehensive mo...Based on the theory of multi-body system (MBS), bine’s and huston’s methods are applied to an on-line measuring system of machining center in this paper. Through the study on modeling technique, the comprehensive model for errors calculation in an on-line measuring System of machining center have been built for the first time. Using this model, the errors can be compensated by soft.ware and the measuring accuracy can be enhanced without any more inveSt. This model can be used in all kinds of machining center.展开更多
Although near infrared (NIR) spectroscopy has been evaluated for numerous applications, the number of actual on-line or even on-site industrial applications seems to be very limited. In the present paper, the attempts...Although near infrared (NIR) spectroscopy has been evaluated for numerous applications, the number of actual on-line or even on-site industrial applications seems to be very limited. In the present paper, the attempts to produce online predictions of the chemical oxygen demand (COD) in wastewater from a pulp and paper mill using NIR spectroscopy are described. The task was perceived as very challenging, but with a root mean square error of prediction of 149 mg/l, roughly corresponding to 1/10 of the studied concentration interval, this attempt was deemed as successful. This result was obtained by using partial least squares model regression, interpolated reference values for calibration purposes, and by evenly distributing the calibration data in the concentration space. This work may also represent the first industrial application of online COD measurements in wastewater using NIR spectroscopy.展开更多
Combining the system of rapid collection of ambient particles and ion chromatography, the system of rapid collection of fine particles and ion chromatography （RCFP-IC） was established to automatically analyze on-lin...Combining the system of rapid collection of ambient particles and ion chromatography, the system of rapid collection of fine particles and ion chromatography （RCFP-IC） was established to automatically analyze on-line the concentrations of water-soluble ions in ambient particles. Here, the general scheme of RCFP-IC is described and its basic performance is tested. The detection limit of RCFP-IC for SO4^2-, NO3^-, NO2^-, Cl^- and F- is below 0.3μg m^-3. The collection efficiency of RCFP-IC increases rapidly with increasing sized particles. For particles larger than 300 nm, the collection efficiency approaches 100%. The precision of RCFP-IC is more than 90% over 28 repetitions. The response of RCFP-IC is very sensitive and no obvious cross-pollution is found during measurement. A comparison of RCFP-IC with an integrated filter measurement indicates that the measurement of RCFP-IC is comparable in both laboratory experiments and field observations. The results of the field experiment prove that RCFP-IC is an effective on-line monitoring system and is helpful in source apportionment and pollution episode monitoring.展开更多
This paper studies a strongly convergent inertial forward-backward-forward algorithm for the variational inequality problem in Hilbert spaces.In our convergence analysis,we do not assume the on-line rule of the inerti...This paper studies a strongly convergent inertial forward-backward-forward algorithm for the variational inequality problem in Hilbert spaces.In our convergence analysis,we do not assume the on-line rule of the inertial parameters and the iterates,which have been assumed by several authors whenever a strongly convergent algorithm with an inertial extrapolation step is proposed for a variational inequality problem.Consequently,our proof arguments are different from what is obtainable in the relevant literature.Finally,we give numerical tests to confirm the theoretical analysis and show that our proposed algorithm is superior to related ones in the literature.展开更多
In our study of super quantum discord between two excitonic qubits inside a coupled semiconductor quantum dots system,our primary focus is to uncover the impact of weak measurement on its quantum characteristics.To ac...In our study of super quantum discord between two excitonic qubits inside a coupled semiconductor quantum dots system,our primary focus is to uncover the impact of weak measurement on its quantum characteristics.To achieve this,we analyze how varying the measurement strength x,affects this super quantum correlation in the presence of thermal effects.Additionally,we assess the effect of this variation on the system's evolution against its associated quantum parameters;external electric fields,exciton-exciton dipole interaction energy and F?rster interaction.Our findings indicate that adjusting x to smaller values effectively enhances the super quantum correlation,making weak measurements act as a catalyst.This adjustment ensures its robustness against thermal effects while preserving the non-classical attributes of the system.Furthermore,our study unveils that the effect of weak measurements on this latter surpasses the quantum effects associated with the system.Indeed,manipulating the parameter x allows the weak measurement to function as a versatile tool for modulating quantum characteristics and controlling exciton-exciton interactions within the coupled semiconductor quantum dots system.展开更多
基金supported by the National Natural Science Foundation of China(No.41805105)。
文摘On-line chemical characterization of atmospheric particulate matter(PM)with soft ionization technique and ultrahigh-resolution Mass Spectrometry(UHRMS)provides molecular information of organic constituents in real time.Here we describe the development and application of an automatic measurement system that incorporates PM_(2.5)sampling,thermal desorption,atmospheric pressure photoionization,and UHRMS analysis.Molecular formulas of detected organic compounds were deducted from the accurate(±10 ppm)molecular weights obtained at a mass resolution of 100,000,allowing the identification of small organic compounds in PM_(2.5).Detection efficiencies of 28 standard compounds were determined and we found a high sensitivity and selectivity towards organic amines with limits of detection below 10 pg.As a proof of principle,PM_(2.5)samples collected off-line in winter in the urban area of Beijing were analyzed using the Ionization Module and HRMS of the system.The automatic system was then applied to conduct on-line measurements during the summer time at a time resolution of 2 hr.The detected organic compounds comprised mainly CHON and CHN compounds below 350 m/z.Pronounced seasonal variations in elemental composition were observed with shorter carbon backbones and higher O/C ratios in summer than that in winter.This result is consistent with stronger photochemical reactions and thus a higher oxidation state of organics in summer.Diurnal variation in signal intensity of each formula provides crucial information to reveal its source and formation pathway.In summary,the automatic measurement system serves as an important tool for the on-line characterization and identification of organic species in PM_(2.5).
基金financially supported by the National Natural Science Foundation of China(No.52204084)the Open Research Fund of the State Key Laboratory of Coal Resources and safe Mining,CUMT,China(No.SKLCRSM 23KF004)+3 种基金the Interdisciplinary Research Project for Young Teachers of USTB(Fundamental Research Funds for the Central Universities),China(No.FRF-IDRY-GD22-002)the Fundamental Research Funds for the Central Universities and the Youth Teacher International Exchange and Growth Program,China(No.QNXM20220009)the National Key R&D Program of China(Nos.2022YFC2905600 and 2022 YFC3004601)the Science,Technology&Innovation Project of Xiongan New Area,China(No.2023XAGG0061)。
文摘Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress magnitude.To investigate the correlation between the rock mass properties and maximum horizontal stress,the three-dimensional(3D)stress tensors at 89 measuring points determined using an improved overcoring technique in nine mines in China were adopted,a newly defined characteristic parameter C_(ERP)was proposed as an indicator for evaluating the structural properties of rock masses,and a fuzzy relation matrix was established using the information distribution method.The results indicate that both the vertical stress and horizontal stress exhibit a good linear growth relationship with depth.There is no remarkable correlation between the elastic modulus,Poisson's ratio and depth,and the distribution of data points is scattered and messy.Moreover,there is no obvious relationship between the rock quality designation(RQD)and depth.The maximum horizontal stress σ_(H) is a function of rock properties,showing a certain linear relationship with the C_(ERP)at the same depth.In addition,the overall change trend of σ_(H) determined by the established fuzzy identification method is to increase with the increase of C_(ERP).The fuzzy identification method also demonstrates a relatively detailed local relationship betweenσ_H and C_(ERP),and the predicted curve rises in a fluctuating way,which is in accord well with the measured stress data.
基金supported by the National Natural Science Foundation of China (Grant No. 52172259)the National Key Research and Development Program of China (Grant Nos. 2021YFA0718700 and 2022YFB3803900)the Fundamental Research Funds for the Inner Mongolia Normal University (Grant No. 2022JBTD008)。
文摘The accurate characterization of thermoelectric properties at low temperatures is crucial for the development of high-performance thermoelectric cooling devices. While measurement errors of thermoelectric properties at temperatures above room temperature have been extensively discussed, there is a lack of standard measurement protocols and error analyses for low-temperature transport properties. In this study, we present a measurement system capable of characterizing all three key thermoelectric parameters, i.e., Seebeck coefficient, electrical conductivity, and thermal conductivity, for a single sample across a temperature range of 10 K to 300 K. We investigated six representative commercial Bi_(2)Te_(3)-based samples(three N-type and three P-type). Using an error propagation model, we systematically analyzed the measurement uncertainties of the three intrinsic parameters and the resulting thermoelectric figure of merit. Our findings reveal that measurement uncertainties for both N-type and P-type Bi_(2)Te_(3)-based materials can be effectively maintained below 5% in the temperature range of 40 K to 300 K. However, the uncertainties increase to over 10% at lower temperatures, primarily due to the relatively smaller values of electrical resistivity and Seebeck coefficients in this regime. This work establishes foundational data for Bi_(2)Te_(3)-based thermoelectric materials and provides a framework for broader investigations of advanced low-temperature thermoelectrics.
基金National Key Research and Development Program of China(2021YFA1501302)the National Natural Science Foundation of China(22121004,22122808)+1 种基金the Haihe Laboratory of Sustainable Chemical Transformations and the Program of Introducing Talents of Discipline to Universities(BP0618007)for financial supportsupported by the XPLORER PRIZE.
文摘Noise is inevitable in electrical capacitance tomography(ECT)measurements.This paper describes the influence of noise on ECT performance for measuring gas-solids fluidized bed characteristics.The noise distribution is approximated by the Gaussian distribution and added to experimental capacitance data with various intensities.The equivalent signal strength(Ф)that equals the signal-to-noise ratio of packed beds is used to evaluate noise levels.Results show that the Pearson correlation coefficient,which indicates the similarity of solids fraction distributions over pixels,increases with Ф,and reconstructed images are more deteriorated at lower Ф.Nevertheless,relative errors for average solids fraction and bubble size in each frame are less sensitive to noise,attributed to noise compromise caused by the process of pixel values.These findings provide useful guidance for assessing the accuracy of ECT measurements of multiphase flows.
基金study is under the research project“development of aggregate characteristics-based preventive maintenance treatments using 3D laser imaging and aggregate imaging technology for optimized skid resistance of pavements”sponsored by the Oklahoma Department of Transportation(ODOT SPR 2275).
文摘Ensuring highway safety relies heavily on pavement friction resistance.To enable network-level pavement skid resistance monitoring and management,this study proposes a non-contact three-dimensional laser surface testing method to obtain detailed aggregate surface data.The existing contact-based skid resistance measurement methods suffer from poor reproducibility and repeatability,hindering their application for network-level management.In this research,traditional multiple linear regression and four machine learning methods,support vector machine(SVM),random forest(RF),gradient boosting decision tree(GBDT),and convolutional neural network(CNN),are utilized to evaluate and predict pavement frictional performance.To assess the proposed methods,data from 45 pavement sites in Oklahoma,including 6 major preventive maintenance(PM)treatments and 7 typical types of aggregates,are collected.Parallel data acquisition is conducted at highway speeds using a grip tester and a high-speed texture profiler to measure pavement skid resistance and surface macro-texture,respectively.Aggregate properties are captured in 3D using a portable ultra-high-resolution 3D laser imaging scanner,leading to the calculation of four types of 3D aggregate parameters characterizing the micro-texture of aggregate surfaces.The relationship between pavement surface friction and texture is explored using machine learning models.The results reveal that the random forest and gradient boosting decision tree models exhibit the highest accuracy,SVM and CNN perform moderately,while the traditional linear regression method fares the worst.By assessing the importance of the 38 parameter variables,the most critical 21 variables were selected for model development.Test results demonstrate that the GBDT model exhibits the best predictive performance,with an explanatory capability of 87.4%for road friction performance.The findings demonstrate the feasibility of replacing contact-based pavement friction evaluation with non-contact texture measurements,offering promising prospects for a network-level pavement skid resistance monitoring and management system.
基金supported by the Science Center for Gas Turbine Project,China(No.P2022-C-II-005-001)。
文摘Aviation kerosene RP-3 is extensively used in China.This paper details the measurement of the density of Chinese aviation kerosene RP-3 employing the flow method under high-pressure and high-temperature conditions.The methodology utilizes circular tubes with two different diameters.The density of aviation kerosene RP-3 was experimentally measured for the first time within a pressure range from 6 MPa to 8 MPa and a temperature range from 323 K to 783 K,with a maximum relative uncertainty of 0.35%.The experimental setup used n-decane for calibration,achieving an average calibration error of 0.91%.The data indicate that the density of RP-3 ranges from 764 kg/m^(3)to 247 kg/m^(3)under the tested conditions.The results show that the density of kerosene RP-3 decreases with an increase in temperature at a constant pressure,and at a given temperature,a higher pressure results in a higher density.Polynomial fitting was applied to the data,resulting in the average absolute deviation of 1.09%,0.80%,and 0.76%at different pressures of 6,7,and 8 MPa,respectively.
基金supported by National Natural Science Foundation of China(22161142018,21991081,22177056,and 22174074)the Ministry of Science and Technology of China(2021YFA1600304).
文摘The distance distributions between two site-specifically anchored spin labels in a protein,measured by pulsed electron-electron double resonance(PELDOR or DEER),provide rich sources of structural and conformational restraints on the proteins or their complexes.The rigid connection of the nitroxide spin label to the protein improves the accuracy and precision of distance measurement.We report a new spin labelling approach by formation of thioester bond between nitroxide(NO)spin label,NOAI(NO spin labels activated by acetylimidazole),and a protein thiol,and this spin labeling method has demonstrated high performance in DEER distance measurement on proteins.The results showed that NOAI has shorter connection to the protein ligation site than 2,2,5,5-tetramethyl-pyrroline-1-oxyl methanethiosulfonate(MTSL)and 3-maleimido-proxyl(M-Prox)in the respective protein conjugate and produces narrower distance distributions for the tested proteins including ubiquitin(Ub),immunoglobulin-binding b1 domain of streptococcal protein G(GB1),and second mitochondria-derived activator of caspases(Smac).The NOAI protein conjugate connected by a thioester bond is resistant to reducing reagent and offers highfidelity DEER distance measurements in cell lysates.
基金supported by the National Key Research and Development Program of China(Grant no.2021YFC2803304)the National Natural Science Foundation of China(Grant nos.52192691 and 52192690)the Program of Shanghai Academic/Technology Research Leader(Grant no.22XD1403600).
文摘Using nine ice-tethered buoys deployed across the marginal ice zone(MIZ)and pack ice zone(PIZ)north of the Laptev Sea during the expedition of the Multidisciplinary drifting Observatory for the Study of Arctic Climate(MOSAiC)in 2019-2020,we characterized the spatiotemporal variations in sea ice kinematics and deformation between October 2019 and July 2020 in the Transpolar Drift(TPD).From October to November,the buoys were in the upstream area of the TPD;spatial variations of deformation rates were significantly correlated with initial ice thickness(R=−0.84,P<0.05).From December 2019 to March 2020,the buoys were in the high Arctic and the ice cover was consolidated;heterogeneity in ice kinematics as measured across the buoys reduced by 65%.From April to May 2020,the buoys were in the downstream TPD;amplified spatial variations in ice kinematics were observed.This is because two buoys had drifted over the shallow waters north of Svalbard earlier;trajectory-stretching exponents derived from the data from these two buoys indicate deformation rates(10.6 d^(−1))that were about twice those in the deep basin(4.2 d^(−1)).By June 2020,a less consolidated ice pack and enhanced tidal forcing in the Fram Strait MIZ resulted in ice deformation with a semi-diurnal power spectral density of>0.25 d^(−1),which is about 1.5 times that in PIZ.Therefore,in both the upstream and downstream regions of the TPD,the transition between the MIZ and the PIZ contributes to the spatial and seasonal variations of sea ice motion and deformation.The results from this study can be used to support the characterization of the momentum balance and influencing factors during the ice advection along the TPD,which is a crucial corridor for Arctic sea ice outflow to the north Atlantic Ocean.
基金supported by the Chinese Scholarship Council under Grant 202106910006.
文摘Branch angles are an important plant morphological trait affecting light interception within forest canopies.However,studies on branch angles have been limited due to the time-consuming nature of manual measurements using a protractor.Terrestrial laser scanning(TLS),however,provides new opportunities to measure branch angles more efficiently.Despite this potential,studies validating branch angle measurements from TLS have been limited.Here,our aim is to evaluate both manual and automatic branch angle measurements of European beech from TLS data using traditional field-measurements with a protractor as a reference.We evaluated the accuracy of branch angle measurements based on four automated algorithms(aRchiQSM,TreeQSM,Laplacian,SemanticLaplacian)from TLS data.Additionally,we assessed different ways of manual branch angle measurements in the field.Our study was based on a dataset comprising 124 branch angles measured from six European beech in a European deciduous forest.Our results show that manual branch angle measurements from TLS data are in high agreement with the reference(root-mean-squared error,RMSE:[3.57°-4.18°],concordance correlation coefficient,CCC:[0.950.97])across different branch length positions.Automated algorithms also are in high agreement with the reference although RMSE is approximately twice as large compared to manual branch angle measurements from TLS(RMSE:[9.29°-10.55°],CCC:[0.830.86])with manual leaf points removal.When applying the automatic wood-leaf separation algorithm,the performance of the four methods declined significantly,with only approximately 20 branch angles successfully identified.Moreover,it is important to note that there is no influence of the measurement position(branch surface versus center)for branch angle measurements.However,for curved branches,the selection of branch measurement length significantly impacts the branch angle measurement.This study provides a comprehensive understanding of branch angle measurements in forests.We show that automated measurement methods based on TLS data of branch angles are a valuable tool to quantify branch angles at larger scales.
基金supported by the National Key R&D Program of China (No. 2023YFA1606401 and 2018YFA0404401)the Young Scholar of Regional Development,CAS ([2023] 15)+1 种基金Chinese Academy of Sciences Stable Support for Young Teams in Basic Research (No. YSBR-002)Special Fund for Strategic Pilot Technology of Chinese Academy of Sciences (No. XDB34000000)
文摘Schottky mass spectrometry utilizing heavy-ion storage rings is a powerful technique for the precise mass and decay half-life measurements of highly charged ions.Owing to the nondestructive ion detection features of Schottky noise detectors,the number of stored ions in the ring is determined by the peak area in the measured revolution frequency spectrum.Because of their intrinsic amplitude-frequency characteristic(AFC),Schottky detector systems exhibit varying sensitivities at different frequencies.Using low-energy electron-cooled stored ions,a new method is developed to calibrate the AFC curve of the Schottky detector system of the Experimental Cooler Storage Ring(CSRe)storage ring located in Lanzhou,China.Using the amplitude-calibrated frequency spectrum,a notable refinement was observed in the precision of both the peak position and peak area.As a result,the storage lifetimes of the electron-cooled fully ionized^(56)Fe^(26+)ions were determined with high precision at beam energies of 13.7 and 116.4 MeV/u,despite of frequency drifts during the experiment.When electron cooling was turned off,the effective vacuum condition experienced by the 116.4 MeV/u^(56)Fe^(26+)ions was determined using amplitude-calibrated spectra,revealing a value of 2×10^(−10)mbar,which is consistent with vacuum gauge readings along the CSRe ring.The method reported herein will be adapted for the next-generation storage ring of the HIAF facility under construction in Huizhou,China.It can also be adapted to other storage ring facilities worldwide to improve precision and enhance lifetime measurements using many ions in the ring.
文摘Metabolic dysfunction-associated steatotic liver disease(MASLD)is the most widespread chronic liver disease signified by serious life-threatening conditions.The prevalence of MASLD increases along the growing prevalence in obesity and metabolic syndrome.To minimize costs and complications,non-invasive diagnostic tools,including transient elastography(TE),were introduced for assessment of MASLD.TE measures liver stiffness(LS),a clinical marker for the diagnosis of liver fibrosis and cirrhosis.LS measurements are based on ultrasound wave imaging and quantification.Vibration-controlled TE,including FibroScan®,is commonly used TE methods which can accurately identify the degree of liver fibrosis and cirrhosis progression.TE was reported to predict the progression towards hepatocellular carcinoma,portal hypertension,and varices.However,the accuracy of LS diagnostics alone in patients with MASLD remains controversial.TE measurements have several limitations,including inadequate precision due to focal liver lesions,cholestasis,inflammation,and other pathological and anatomical factors which can lead to the stiffness variability.Overestimations of TE readings were reported in obese patients with body mass index(BMI)over 30 kg/m2,and older patients with ascites,diabetes,or hypertension.Not all MASLD patients have high BMI.The prevalence of obesity among MASLD patients varies worldwide,indicating the urgent need for comprehensive diagnostic tools.In patients with MASLD,improved diagnostic accuracy has been demonstrated by combining LS measurements with other blood test-based scores and simple clinical parameters(agile scores based on age,sex,platelet count,aminotransferases,and diabetes).This study reviews the limitations of TE-based diagnostics and discusses the combined scoring algorithm.In conclusion,the sequence of LS measurements along assessment of other important clinical markers is an effective,low-cost,reliable tool to identify and monitor fibrosis progression in MASLD.
基金supported by the National Natural Science Foundation of China(Nos.U1301234,21277003)the Ministry of Science and Technology of China(No.2014BAC21B03)the Science and Technology Plan of Shenzhen Municipality
文摘Water-soluble organic matter（WSOM） represents a critical fraction of fine particles（PM2.5）in the air, but its changing behaviors and formation mechanisms are not well understood yet, partly due to the lack of fast techniques for the ambient measurements. In this study,a novel system for the on-line measurement of water-soluble components in PM2.5, the particle-into-liquid sampler（PILS）–Nebulizer–aerosol chemical speciation monitor（ACSM）, was developed by combining a PILS, a nebulizer, and an ACSM. High time resolution concentrations of WSOM, sulfate, nitrate, ammonium, and chloride, as well as mass spectra, can be obtained with satisfied quality control results. The system was firstly applied in China for field measurement of WSOM. The mass spectrum of WSOM was found to resemble that of oxygenated organic aerosol, and WSOM agreed well with secondary inorganic ions. All evidence collected in the field campaign demonstrated that WSOM could be a good surrogate of secondary organic aerosol（SOA）. The PILS–Nebulizer–ACSM system can thus be a useful tool for intensive study of WSOM and SOA in PM2.5.
基金supported by the National Natural Science Foundation of China (No.41875155)Natural Key Research and Development Program of China (No.2019YFA0607004)+1 种基金Environment and Conservation Fund/Woo Wheelock Green Fund (No.ECWW09EG04)Strategic Priority Research Program (B)of the Chinese Academy of Sciences (No.XDB05040502)。
文摘Fireworks(FW)could significantly worsen air quality in short term during celebrations.Due to similar tracers with biomass burning(BB),the fast and precise qualification of FW and BB is still challenging.In this study,online bulk and single-particle measurements were combined to investigate the contributions of FW and BB to the overall mass concentrations of PM_(2.5)and specific chemical species by positive matrix factorization(PMF)during the Chinese New Year in Hong Kong in February 2013.With combined information,fresh/aged FW(abundant ^(140)K_(2)NO_(3)^(+)and ^(213)K_(3)SO_(4)^(+)formed from ^(113)K_(2)Cl^(+)discharged by fresh FW)can be extracted from the fresh/aged BB sources,in addition to the Second Aerosol,Vehicles+Road Dust,and Sea Salt factors.The contributions of FW and BB were investigated during three high particle matter episodes influenced by the pollution transported from the Pearl River Delta region.The fresh BB/FW contributed 39.2%and 19.6%to PM_(2.5)during the Lunar Chinese New Year case.However,the contributions of aged FW/BB enhanced in the last two episodes due to the aging process,evidenced by high contributions from secondary aerosols.Generally,the fresh BB/FW showed more significant contributions to nitrate(35.1%and15.0%,respectively)compared with sulfate(25.1%and 5.9%,respectively)and OC(14.8%and11.1%,respectively)on average.In comparison,the aged FW contributed more to sulfate(13.4%).Overall,combining online bulk and single-particle measurement data can combine both instruments’advantages and provide a new perspective for applying source apportionment of aerosols using PMF.
基金supported by the National Science Fund for Distinguished Young Scholars(No.61925102)the National Natural Science Foundation of China(No.62201086,92167202,62201087,62101069)BUPT-CMCC Joint Innovation Center,and State Key Laboratory of IPOC(BUPT)(No.IPOC2023ZT02),China。
文摘Visible light communication(VLC)has attracted much attention in the research of sixthgeneration(6G)systems.Furthermore,channel modeling is the foundation for designing efficient and robust VLC systems.In this paper,we present extensive VLC channel measurement campaigns in indoor environments,i.e.,an office and a corridor.Based on the measured data,the large-scale fading characteristics and multipath-related characteristics,including omnidirectional optical path loss(OPL),K-factor,power angular spectrum(PAS),angle spread(AS),and clustering characteristics,are analyzed and modeled through a statistical method.Based on the extracted statistics of the above-mentioned channel characteristics,we propose a statistical spatial channel model(SSCM)capable of modeling multipath in the spatial domain.Furthermore,the simulated statistics of the proposed model are compared with the measured statistics.For instance,in the office,the simulated path loss exponent(PLE)and the measured PLE are 1.96and 1.97,respectively.And,the simulated medians of AS and measured medians of AS are 25.94°and 24.84°,respectively.Generally,the fact that the simulated results fit well with measured results has demonstrated the accuracy of our SSCM.
文摘In this paper,to study the mechanical responses of a solid propellant subjected to ultrahigh acceleration overload during the gun-launch process,specifically designed projectile flight tests with an onboard measurement system were performed.Two projectiles containing dummy HTPB propellant grains were successfully recovered after the flight tests with an ultrahigh acceleration overload value of 8100 g.The onboard-measured time-resolved axial displacement,contact stress and overload values were successfully obtained and analysed.Uniaxial compression tests of the dummy HTPB propellant used in the gunlaunched tests were carried out at low and intermediate strain rates to characterize the propellant's dynamic properties.A linear viscoelastic constitutive model was employed and applied in finite-element simulations of the projectile-launching process.During the launch process,the dummy propellant grain exhibited large deformation due to the high acceleration overload,possibly leading to friction between the motor case and propellant grain.The calculated contact stress showed good agreement with the experimental results,though discrepancies in the overall displacement of the dummy propellant grain were observed.The dynamic mechanical response process of the dummy propellant grain was analysed in detail.The results can be used to estimate the structural integrity of the analysed dummy propellant grain during the gun-launch process.
文摘Based on the theory of multi-body system (MBS), bine’s and huston’s methods are applied to an on-line measuring system of machining center in this paper. Through the study on modeling technique, the comprehensive model for errors calculation in an on-line measuring System of machining center have been built for the first time. Using this model, the errors can be compensated by soft.ware and the measuring accuracy can be enhanced without any more inveSt. This model can be used in all kinds of machining center.
文摘Although near infrared (NIR) spectroscopy has been evaluated for numerous applications, the number of actual on-line or even on-site industrial applications seems to be very limited. In the present paper, the attempts to produce online predictions of the chemical oxygen demand (COD) in wastewater from a pulp and paper mill using NIR spectroscopy are described. The task was perceived as very challenging, but with a root mean square error of prediction of 149 mg/l, roughly corresponding to 1/10 of the studied concentration interval, this attempt was deemed as successful. This result was obtained by using partial least squares model regression, interpolated reference values for calibration purposes, and by evenly distributing the calibration data in the concentration space. This work may also represent the first industrial application of online COD measurements in wastewater using NIR spectroscopy.
基金This work was supported by the National Natural Science Foundation of China under Grant No. 40525016.
文摘Combining the system of rapid collection of ambient particles and ion chromatography, the system of rapid collection of fine particles and ion chromatography （RCFP-IC） was established to automatically analyze on-line the concentrations of water-soluble ions in ambient particles. Here, the general scheme of RCFP-IC is described and its basic performance is tested. The detection limit of RCFP-IC for SO4^2-, NO3^-, NO2^-, Cl^- and F- is below 0.3μg m^-3. The collection efficiency of RCFP-IC increases rapidly with increasing sized particles. For particles larger than 300 nm, the collection efficiency approaches 100%. The precision of RCFP-IC is more than 90% over 28 repetitions. The response of RCFP-IC is very sensitive and no obvious cross-pollution is found during measurement. A comparison of RCFP-IC with an integrated filter measurement indicates that the measurement of RCFP-IC is comparable in both laboratory experiments and field observations. The results of the field experiment prove that RCFP-IC is an effective on-line monitoring system and is helpful in source apportionment and pollution episode monitoring.
文摘This paper studies a strongly convergent inertial forward-backward-forward algorithm for the variational inequality problem in Hilbert spaces.In our convergence analysis,we do not assume the on-line rule of the inertial parameters and the iterates,which have been assumed by several authors whenever a strongly convergent algorithm with an inertial extrapolation step is proposed for a variational inequality problem.Consequently,our proof arguments are different from what is obtainable in the relevant literature.Finally,we give numerical tests to confirm the theoretical analysis and show that our proposed algorithm is superior to related ones in the literature.
文摘In our study of super quantum discord between two excitonic qubits inside a coupled semiconductor quantum dots system,our primary focus is to uncover the impact of weak measurement on its quantum characteristics.To achieve this,we analyze how varying the measurement strength x,affects this super quantum correlation in the presence of thermal effects.Additionally,we assess the effect of this variation on the system's evolution against its associated quantum parameters;external electric fields,exciton-exciton dipole interaction energy and F?rster interaction.Our findings indicate that adjusting x to smaller values effectively enhances the super quantum correlation,making weak measurements act as a catalyst.This adjustment ensures its robustness against thermal effects while preserving the non-classical attributes of the system.Furthermore,our study unveils that the effect of weak measurements on this latter surpasses the quantum effects associated with the system.Indeed,manipulating the parameter x allows the weak measurement to function as a versatile tool for modulating quantum characteristics and controlling exciton-exciton interactions within the coupled semiconductor quantum dots system.
