In coal-fired power generation industry, parameters such as particle size affect combustion efficiency. Especially in the application of two-phase flow clean energy, the parameters such as particle velocity, particle ...In coal-fired power generation industry, parameters such as particle size affect combustion efficiency. Especially in the application of two-phase flow clean energy, the parameters such as particle velocity, particle size distribution and concentration are very important, because the coal particle velocity, concentration or size range have an impact on the whole combustion process. This paper introduces an optical measurement setup based on the transmission fluctuation correlation spectrum measurement technique, which realizes the simultaneous measurement of particle velocity, particle size distribution and concentration. Compared with image method, ultrasonic spectrum method and other methods, the experimental device is simple and low-cost.展开更多
The Three Gorges Reservoir is a good site for the further researches on reservoir induced seismicity due to decades＇ seismic monitoring. After the first water impounding in 2003, seismic activity becomes more frequen...The Three Gorges Reservoir is a good site for the further researches on reservoir induced seismicity due to decades＇ seismic monitoring. After the first water impounding in 2003, seismic activity becomes more frequent than that before water impoundment. In order to quantitatively study, the relationship between the water level fluctuation and earthquakes in TGR, we introduced statistical methods to attain the goal. First of all, we relocated the earthquakes in TGR region with double difference method and divided the earthquakes into 5 clusters with clustering analysis method. Secondly, to examine the impacts of water level fluctuation in different water filling stages on the seismic activity in the 5 clusters, a series of statistical analyses are applied. Pearson correlation results show that only the 175 m water level fluc- tuation has significantly positive impacts on the seismic activity in clusters I, II, III and V with correlation coefficients of 0.44, 0.38, 0.66 and 0.63. Cross-correlation analysis demonstrates that 0, ], 0 and 0 month time delay separately for the clusters I, II, III and V exists. It illustrated the influences of the water loading and pore pressure diffusion on induced earthquakes. Cointegration tests and impulse response analysis denoted that the 175 m water level only had long term and significant effects just on the seismic events in the intersection region of the Fairy Mount Fault and Nine-brook Fault. One standard deviation shock to 175 m water level increased the seismic activity in cluster V for the first 3 months, and then the negative influence was shown. After 7 months, the negative impulse response becomes stable. The long-term effect of the 175 m water impoundment also proved the important role of pore pressure diffusion in RIS with time.展开更多
A viable strategy for enhancing photovoltaic performance is to comprehend the underlying quantum physical regime of charge transfer in a double quantum dots(DQD) photocell. This work explored the photovoltaic performa...A viable strategy for enhancing photovoltaic performance is to comprehend the underlying quantum physical regime of charge transfer in a double quantum dots(DQD) photocell. This work explored the photovoltaic performance dependent spatially correlated fluctuation in a DQD photocell. The effects of spatially correlated fluctuation on charge transfer and output photovoltaic efficiency were explored in a proposed DQD photocell model. The results revealed that the charge transport process and the time to peak photovoltaic efficiency were both significantly delayed by the spatially correlated fluctuation, while the anti-spatially correlated fluctuation reduced the output peak photovoltaic efficiency. Further results revealed that the delayed response could be suppressed by gap difference and tunneling coefficient within two dots. Subsequent investigation demonstrated that the delayed response was caused by the spatial correlation fluctuation slowing the generative process of noise-induced coherence, which had previously been proven to improve the quantum photovoltaic performance in quantum photocells. And the reduced photovoltaic properties were verified by the damaged noise-induced coherence owing to the anti-spatial correlation fluctuation and a hotter thermal ambient environment. The discovery of delayed response generated by the spatially correlated fluctuations will deepen the understanding of quantum features of electron transfer, as well as promises to take our understanding even further concerning quantum techniques for high efficiency DQD solar cells.展开更多
We study the multiplicity fluctuation and correlation of identified mesons and baryons formed at hadronization by the quark combination mechanism in the context of ultra-relativistic heavy-ion collisions. Based on the...We study the multiplicity fluctuation and correlation of identified mesons and baryons formed at hadronization by the quark combination mechanism in the context of ultra-relativistic heavy-ion collisions. Based on the statistical method of free quark combination, we derive the two-hadron multiplicity correlations, including meson-meson and meson-baryon correlations, and take the effects of quark number fluctuation at hadronization into account by a Taylor expansion method. After including the decay contributions, we calculate the dynamical fluctuation observable ν_（dyn） for Kπ, pπ and Kp pairs and discuss what underlying physics can be obtained by comparing with data from Pb-Pb collisions at sNN^（1/2）=2.76 Te V and simulations from the HIJING and AMPT event generators.展开更多
The statistical performance of AR high resolution array processor in presence of correlated sensor signal fluctuation is studied. Mean square inverse beam pattern and pointing error are examined. Special attention is ...The statistical performance of AR high resolution array processor in presence of correlated sensor signal fluctuation is studied. Mean square inverse beam pattern and pointing error are examined. Special attention is paid to the effects of reference sensor and correlation between sensors. It is shown that fluctuation causes broadening or even distortion of the mean square inverse beam pattern. Phase fluctuation causes pointing error. Its standard variance is proportional to that of fluctuation and is related to the number of sensors of the array. Correlation between sensors has important effects on pointing error.展开更多
The moments and moment products of conserved charges are believed to be sensitive to critical fluctuations,which have been adopted in determining the QCD critical point.Using a dynamical multiphase transport model,we ...The moments and moment products of conserved charges are believed to be sensitive to critical fluctuations,which have been adopted in determining the QCD critical point.Using a dynamical multiphase transport model,we reproduce the centrality and energy dependences of moments and moment products of net-charge multiplicity distributions in Au+Au collisions,measured by the Beam Energy Scan program at the RHIC.No non-monotonic energy dependence is observed.We infer that the moment products develop during the dynamical evolution of heavy-ion collisions.The observed difference based on the expectation of the Poisson baseline indicates a positive two-particle correlation between positively and negatively charged particles,which can arise from different dynamical processes at different stages.Therefore,to adopt moments and moment products of net-charge multiplicity distributions in determining the QCD critical point of relativistic heavy-ion collisions,it is essential to consider the dynamical evolution.展开更多
Mix-cumulants of conserved charge distributions are sensitive observables for probing properties of the QCD medium and phase transition in heavy-ion collisions.To perform precise measurements,efficiency correction is ...Mix-cumulants of conserved charge distributions are sensitive observables for probing properties of the QCD medium and phase transition in heavy-ion collisions.To perform precise measurements,efficiency correction is one of the most important step.In this study,using the binomial efficiency model,we derive efficiency correction formulas for mutually exclusive and inclusive variables.The UrQMD model is applied to verify the validity of these formulas for different types of correlations.Furthermore,we investigate the effect of the multiplicity loss and contamination emerging from the particle identifications.This study provides important steps toward future measurements of mixed-cumulants in relativistic heavy-ion collisions.展开更多
文摘In coal-fired power generation industry, parameters such as particle size affect combustion efficiency. Especially in the application of two-phase flow clean energy, the parameters such as particle velocity, particle size distribution and concentration are very important, because the coal particle velocity, concentration or size range have an impact on the whole combustion process. This paper introduces an optical measurement setup based on the transmission fluctuation correlation spectrum measurement technique, which realizes the simultaneous measurement of particle velocity, particle size distribution and concentration. Compared with image method, ultrasonic spectrum method and other methods, the experimental device is simple and low-cost.
基金financially supported by the fund of the institute of seismology,China Earthquake Administration(IS201616254)National Natural Science Foundation of China(41572354,41304046)
文摘The Three Gorges Reservoir is a good site for the further researches on reservoir induced seismicity due to decades＇ seismic monitoring. After the first water impounding in 2003, seismic activity becomes more frequent than that before water impoundment. In order to quantitatively study, the relationship between the water level fluctuation and earthquakes in TGR, we introduced statistical methods to attain the goal. First of all, we relocated the earthquakes in TGR region with double difference method and divided the earthquakes into 5 clusters with clustering analysis method. Secondly, to examine the impacts of water level fluctuation in different water filling stages on the seismic activity in the 5 clusters, a series of statistical analyses are applied. Pearson correlation results show that only the 175 m water level fluc- tuation has significantly positive impacts on the seismic activity in clusters I, II, III and V with correlation coefficients of 0.44, 0.38, 0.66 and 0.63. Cross-correlation analysis demonstrates that 0, ], 0 and 0 month time delay separately for the clusters I, II, III and V exists. It illustrated the influences of the water loading and pore pressure diffusion on induced earthquakes. Cointegration tests and impulse response analysis denoted that the 175 m water level only had long term and significant effects just on the seismic events in the intersection region of the Fairy Mount Fault and Nine-brook Fault. One standard deviation shock to 175 m water level increased the seismic activity in cluster V for the first 3 months, and then the negative influence was shown. After 7 months, the negative impulse response becomes stable. The long-term effect of the 175 m water impoundment also proved the important role of pore pressure diffusion in RIS with time.
基金the National Natural Science Foundation of China (Grant Nos. 62065009 and 61565008)Yunnan Fundamental Research Projects, China (Grant No. 2016FB009)。
文摘A viable strategy for enhancing photovoltaic performance is to comprehend the underlying quantum physical regime of charge transfer in a double quantum dots(DQD) photocell. This work explored the photovoltaic performance dependent spatially correlated fluctuation in a DQD photocell. The effects of spatially correlated fluctuation on charge transfer and output photovoltaic efficiency were explored in a proposed DQD photocell model. The results revealed that the charge transport process and the time to peak photovoltaic efficiency were both significantly delayed by the spatially correlated fluctuation, while the anti-spatially correlated fluctuation reduced the output peak photovoltaic efficiency. Further results revealed that the delayed response could be suppressed by gap difference and tunneling coefficient within two dots. Subsequent investigation demonstrated that the delayed response was caused by the spatial correlation fluctuation slowing the generative process of noise-induced coherence, which had previously been proven to improve the quantum photovoltaic performance in quantum photocells. And the reduced photovoltaic properties were verified by the damaged noise-induced coherence owing to the anti-spatial correlation fluctuation and a hotter thermal ambient environment. The discovery of delayed response generated by the spatially correlated fluctuations will deepen the understanding of quantum features of electron transfer, as well as promises to take our understanding even further concerning quantum techniques for high efficiency DQD solar cells.
基金Supported by National Natural Science Foundation of China(11575100)
文摘We study the multiplicity fluctuation and correlation of identified mesons and baryons formed at hadronization by the quark combination mechanism in the context of ultra-relativistic heavy-ion collisions. Based on the statistical method of free quark combination, we derive the two-hadron multiplicity correlations, including meson-meson and meson-baryon correlations, and take the effects of quark number fluctuation at hadronization into account by a Taylor expansion method. After including the decay contributions, we calculate the dynamical fluctuation observable ν_（dyn） for Kπ, pπ and Kp pairs and discuss what underlying physics can be obtained by comparing with data from Pb-Pb collisions at sNN^（1/2）=2.76 Te V and simulations from the HIJING and AMPT event generators.
文摘The statistical performance of AR high resolution array processor in presence of correlated sensor signal fluctuation is studied. Mean square inverse beam pattern and pointing error are examined. Special attention is paid to the effects of reference sensor and correlation between sensors. It is shown that fluctuation causes broadening or even distortion of the mean square inverse beam pattern. Phase fluctuation causes pointing error. Its standard variance is proportional to that of fluctuation and is related to the number of sensors of the array. Correlation between sensors has important effects on pointing error.
基金Supported in part by the Strategic Priority Research Program of Chinese Academy of Sciences(XDB34030000)the National Natural Science Foundation of China(11890710,11890714,11835002,11961131011)the Guangdong Major Project of Basic and Applied Basic Research(2020B0301030008)。
文摘The moments and moment products of conserved charges are believed to be sensitive to critical fluctuations,which have been adopted in determining the QCD critical point.Using a dynamical multiphase transport model,we reproduce the centrality and energy dependences of moments and moment products of net-charge multiplicity distributions in Au+Au collisions,measured by the Beam Energy Scan program at the RHIC.No non-monotonic energy dependence is observed.We infer that the moment products develop during the dynamical evolution of heavy-ion collisions.The observed difference based on the expectation of the Poisson baseline indicates a positive two-particle correlation between positively and negatively charged particles,which can arise from different dynamical processes at different stages.Therefore,to adopt moments and moment products of net-charge multiplicity distributions in determining the QCD critical point of relativistic heavy-ion collisions,it is essential to consider the dynamical evolution.
基金Supported by the National Key Research and Development Program of China(2020YFE0202002,2018YFE0205201)the National Natural Science Foundation of China(12122505,11890711,11861131009)Ito Science Foundation and JSPS KAKENHI(25105504,19H05598)。
文摘Mix-cumulants of conserved charge distributions are sensitive observables for probing properties of the QCD medium and phase transition in heavy-ion collisions.To perform precise measurements,efficiency correction is one of the most important step.In this study,using the binomial efficiency model,we derive efficiency correction formulas for mutually exclusive and inclusive variables.The UrQMD model is applied to verify the validity of these formulas for different types of correlations.Furthermore,we investigate the effect of the multiplicity loss and contamination emerging from the particle identifications.This study provides important steps toward future measurements of mixed-cumulants in relativistic heavy-ion collisions.
