Some features associated with Eastern China Precipitation (ECP), in terms of mean climatology, sea-sonal cycle, interannual variability are studied based on monthly rainfall data. The rainfall behavior over Eastern Ch...Some features associated with Eastern China Precipitation (ECP), in terms of mean climatology, sea-sonal cycle, interannual variability are studied based on monthly rainfall data. The rainfall behavior over Eastern China has fine spatial structure in the seasonal variation and interannual variability. The revealed characteristics of ECP motivate us dividing Eastern China into four sub—regions to quantify significant lag—correlations of the rainfalls with global sea surface temperatures (SSTs) and to study the ocean’s pre-dominant role in forcing the eastern China summer monsoon rainfalls. Lagged correlations between the mid—eastern China summer monsoon rainfalls (MECSMRs) and the global SSTs, with SST leading to rain-fall, are investigated. The most important key SST regions and leading times, in which SSTs are highly corre-lated with the MECSMRs, are selected. Part of the results confirms previous studies that show links between the MECSMRs and SSTs in the eastern equatorial Pacific associated with the El Nino — Southern Oscillation (ENSO) phenomenon. Other findings include the high lag correlations between the MECSMRs and the SSTs in the high and middle latitude Pacific Ocean and the Indian Ocean, even the SSTs over the Atlantic Ocean, with SST leading—time up to 4 years. Based on the selected SST regions, regression equa-tions are developed by using the SSTs in these regions in respective leading time. The correlation coefficient between the observed rainfalls and regressed rainfalls is over 0.85. The root mean square error (RMSE) for regressed rainfall is around 65% of the standard deviation and about 15% of the mean rainfall. The regression equation has also been evaluated in a forecasting mode by using independent data. Discussion on the consistence of the SST—rainfall correlation with circulation field is also presented. Key words Summer monsoon - Rainfall - SST - Regression This work was jointed supported by Chinese Academy of Sciences under Grant “Hundred Talents” for “Validation of Coupled Climate models” and by U.S. Department of Energy under Grant DEFG0285ER 60314 to SUNY at Stony Brook. The authors are grateful to Professor R. D. Cess at SUNY, Stony Brook for his supports.展开更多
Some countries have announced national benchmark rates,while others have been working on the recent trend in which the London Interbank Offered Rate will be retired at the end of 2021.Considering that Turkey announced...Some countries have announced national benchmark rates,while others have been working on the recent trend in which the London Interbank Offered Rate will be retired at the end of 2021.Considering that Turkey announced the Turkish Lira Overnight Reference Interest Rate(TLREF),this study examines the determinants of TLREF.In this context,three global determinants,five country-level macroeconomic determinants,and the COVID-19 pandemic are considered by using daily data between December 28,2018,and December 31,2020,by performing machine learning algorithms and Ordinary Least Square.The empirical results show that(1)the most significant determinant is the amount of securities bought by Central Banks;(2)country-level macroeconomic factors have a higher impact whereas global factors are less important,and the pandemic does not have a significant effect;(3)Random Forest is the most accurate prediction model.Taking action by considering the study’s findings can help support economic growth by achieving low-level benchmark rates.展开更多
Monte Carlo simulations are performed to study the phase diagram of liquid crystals formed by bent-core molecules with a strong transverse dipole moment deviating from their angular bisector.The results show that the ...Monte Carlo simulations are performed to study the phase diagram of liquid crystals formed by bent-core molecules with a strong transverse dipole moment deviating from their angular bisector.The results show that the strong dipolar interaction,after suppressing uniaxial phases,encourages biaxiality,which leads to a Landau point or even to a Landau line in the phase diagram,inducing a more stable biaxial nematic phase.It is also found that a deviation of dipole moment from the angular bisector also suppresses uniaxiality in the small bend-angle regime.展开更多
Taking into account the surface-coupling strength effect,we discuss the phase transitions of a finite thickness cell bounded by surfactant-laden interfaces in a magnetic field perpendicular to the substrate and it is ...Taking into account the surface-coupling strength effect,we discuss the phase transitions of a finite thickness cell bounded by surfactant-laden interfaces in a magnetic field perpendicular to the substrate and it is compared with that of a semi-infinite system.It is found that the larger the thickness,the closer the three-dimensional phase transition surface of the finite system to that of the semi-infinite one.The simulation also shows that when a magnetic field is applied to a nematic semi-infinite sample,an orientational phase transition first takes place close to the interface and then extends to the inner space as the temperature increases.展开更多
Stretched polymers will lose their possible configurations if they are mixed with nanoparticles or touch a hard wall, which leads to a strong depletion attraction responsible for the enrichment of nanoparticles near s...Stretched polymers will lose their possible configurations if they are mixed with nanoparticles or touch a hard wall, which leads to a strong depletion attraction responsible for the enrichment of nanoparticles near substrates. Moreover, it is found that there exists a sacrifice mechanism in confined pure polymer samples or polymer-nanoparticle mixtures, that part of the polymers, in order to reach a minimum free energy for the total system, are adsorbed on hard walls even though they lose their conformation. The current study provides a simple yet effective approach for the design of thin polymer composites.展开更多
Based on the fact that rubbed groove patterns also affect the anchoring of liquid crystals at substrates,a quartic coupling is included in constructing the surface energy for a liquid crystal cell.The phase diagram an...Based on the fact that rubbed groove patterns also affect the anchoring of liquid crystals at substrates,a quartic coupling is included in constructing the surface energy for a liquid crystal cell.The phase diagram and the wetting behaviors of the liquid crystal cell,bounded by surfactant-laden interfaces in a magnetic field perpendicular to the substrate are discussed by taking the quartic coupling into account.The nematic order increases at the surface while it decreases in the bulk as a result of the introduction of quartic substrate-liquid crystal coupling,indicating that the groove anchoring makes the liquid crystal molecules align more orderly near the substrate than away from it.This causes a different wetting behavior：complete wetting.展开更多
We present the results of molecular dynamics simulations of net positively charged fullerene nanoparticles in salt- free and salt-added solution. The aggregation of fullerene （C60）-like nanoparticle and counterion a...We present the results of molecular dynamics simulations of net positively charged fullerene nanoparticles in salt- free and salt-added solution. The aggregation of fullerene （C60）-like nanoparticle and counterion are studied in detail as a function of temperatures and a finite salt concentration. Our simulations show that the strong conformation changes as temperature changes. The net positively-charged nanoparticles do not repel each other but are condensed under proper temperatures. If salts are added, the aggregated nanoparticles will be disaggregated due to the Debye screening effect.展开更多
The static and dynamic properties of a system of end-grafted flexible ring polymer chains grafted to a flat substrate and exposed to a good solvent are studied by using a molecular dynamics method. The monomers are de...The static and dynamic properties of a system of end-grafted flexible ring polymer chains grafted to a flat substrate and exposed to a good solvent are studied by using a molecular dynamics method. The monomers are described by a coarse-grained bead-spring model. Varying the grafting density p and the degree of polymerization or chain length N, we obtain the density profiles of monomers, study the structural properties of the chain （radius of gyration, bond orientational parameters, etc.）, and also present the dynamic characteristics such as chain energy and bond force. Compared with a linear polymer brush, the ring polymer brush exhibits different static and dynamic properties for moderate or short chain length, while it behaves like linear polymer brush in the regime of long chain length.展开更多
文摘Some features associated with Eastern China Precipitation (ECP), in terms of mean climatology, sea-sonal cycle, interannual variability are studied based on monthly rainfall data. The rainfall behavior over Eastern China has fine spatial structure in the seasonal variation and interannual variability. The revealed characteristics of ECP motivate us dividing Eastern China into four sub—regions to quantify significant lag—correlations of the rainfalls with global sea surface temperatures (SSTs) and to study the ocean’s pre-dominant role in forcing the eastern China summer monsoon rainfalls. Lagged correlations between the mid—eastern China summer monsoon rainfalls (MECSMRs) and the global SSTs, with SST leading to rain-fall, are investigated. The most important key SST regions and leading times, in which SSTs are highly corre-lated with the MECSMRs, are selected. Part of the results confirms previous studies that show links between the MECSMRs and SSTs in the eastern equatorial Pacific associated with the El Nino — Southern Oscillation (ENSO) phenomenon. Other findings include the high lag correlations between the MECSMRs and the SSTs in the high and middle latitude Pacific Ocean and the Indian Ocean, even the SSTs over the Atlantic Ocean, with SST leading—time up to 4 years. Based on the selected SST regions, regression equa-tions are developed by using the SSTs in these regions in respective leading time. The correlation coefficient between the observed rainfalls and regressed rainfalls is over 0.85. The root mean square error (RMSE) for regressed rainfall is around 65% of the standard deviation and about 15% of the mean rainfall. The regression equation has also been evaluated in a forecasting mode by using independent data. Discussion on the consistence of the SST—rainfall correlation with circulation field is also presented. Key words Summer monsoon - Rainfall - SST - Regression This work was jointed supported by Chinese Academy of Sciences under Grant “Hundred Talents” for “Validation of Coupled Climate models” and by U.S. Department of Energy under Grant DEFG0285ER 60314 to SUNY at Stony Brook. The authors are grateful to Professor R. D. Cess at SUNY, Stony Brook for his supports.
文摘Some countries have announced national benchmark rates,while others have been working on the recent trend in which the London Interbank Offered Rate will be retired at the end of 2021.Considering that Turkey announced the Turkish Lira Overnight Reference Interest Rate(TLREF),this study examines the determinants of TLREF.In this context,three global determinants,five country-level macroeconomic determinants,and the COVID-19 pandemic are considered by using daily data between December 28,2018,and December 31,2020,by performing machine learning algorithms and Ordinary Least Square.The empirical results show that(1)the most significant determinant is the amount of securities bought by Central Banks;(2)country-level macroeconomic factors have a higher impact whereas global factors are less important,and the pandemic does not have a significant effect;(3)Random Forest is the most accurate prediction model.Taking action by considering the study’s findings can help support economic growth by achieving low-level benchmark rates.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10974162 and 11074208.
文摘Monte Carlo simulations are performed to study the phase diagram of liquid crystals formed by bent-core molecules with a strong transverse dipole moment deviating from their angular bisector.The results show that the strong dipolar interaction,after suppressing uniaxial phases,encourages biaxiality,which leads to a Landau point or even to a Landau line in the phase diagram,inducing a more stable biaxial nematic phase.It is also found that a deviation of dipole moment from the angular bisector also suppresses uniaxiality in the small bend-angle regime.
基金by the National Science Foundation of China under Grant Nos 50873083 and 10974162.
文摘Taking into account the surface-coupling strength effect,we discuss the phase transitions of a finite thickness cell bounded by surfactant-laden interfaces in a magnetic field perpendicular to the substrate and it is compared with that of a semi-infinite system.It is found that the larger the thickness,the closer the three-dimensional phase transition surface of the finite system to that of the semi-infinite one.The simulation also shows that when a magnetic field is applied to a nematic semi-infinite sample,an orientational phase transition first takes place close to the interface and then extends to the inner space as the temperature increases.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10974162 and 11074208)
文摘Stretched polymers will lose their possible configurations if they are mixed with nanoparticles or touch a hard wall, which leads to a strong depletion attraction responsible for the enrichment of nanoparticles near substrates. Moreover, it is found that there exists a sacrifice mechanism in confined pure polymer samples or polymer-nanoparticle mixtures, that part of the polymers, in order to reach a minimum free energy for the total system, are adsorbed on hard walls even though they lose their conformation. The current study provides a simple yet effective approach for the design of thin polymer composites.
基金supported by the National Natural Science Foundation of China(Grant No.11374243)
文摘Based on the fact that rubbed groove patterns also affect the anchoring of liquid crystals at substrates,a quartic coupling is included in constructing the surface energy for a liquid crystal cell.The phase diagram and the wetting behaviors of the liquid crystal cell,bounded by surfactant-laden interfaces in a magnetic field perpendicular to the substrate are discussed by taking the quartic coupling into account.The nematic order increases at the surface while it decreases in the bulk as a result of the introduction of quartic substrate-liquid crystal coupling,indicating that the groove anchoring makes the liquid crystal molecules align more orderly near the substrate than away from it.This causes a different wetting behavior：complete wetting.
基金Project supported by the Natural Science Foundation of Fujian Province of China(Grant No.2012J05008)
文摘We present the results of molecular dynamics simulations of net positively charged fullerene nanoparticles in salt- free and salt-added solution. The aggregation of fullerene （C60）-like nanoparticle and counterion are studied in detail as a function of temperatures and a finite salt concentration. Our simulations show that the strong conformation changes as temperature changes. The net positively-charged nanoparticles do not repel each other but are condensed under proper temperatures. If salts are added, the aggregated nanoparticles will be disaggregated due to the Debye screening effect.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 50873083 and 10974162)
文摘The static and dynamic properties of a system of end-grafted flexible ring polymer chains grafted to a flat substrate and exposed to a good solvent are studied by using a molecular dynamics method. The monomers are described by a coarse-grained bead-spring model. Varying the grafting density p and the degree of polymerization or chain length N, we obtain the density profiles of monomers, study the structural properties of the chain （radius of gyration, bond orientational parameters, etc.）, and also present the dynamic characteristics such as chain energy and bond force. Compared with a linear polymer brush, the ring polymer brush exhibits different static and dynamic properties for moderate or short chain length, while it behaves like linear polymer brush in the regime of long chain length.
