In order to examine how a propagator behaves in non-perturbative theories and how its behavior is influenced by the choice of a covariant gauge a truncated Dyson-Schwinger equation is used to numerically investigate t...In order to examine how a propagator behaves in non-perturbative theories and how its behavior is influenced by the choice of a covariant gauge a truncated Dyson-Schwinger equation is used to numerically investigate the properties of fermions and bosons in 3D quantum electrodynamics QED and a series of self-consistent solutions for the fermion propagator in the Nambu and Wigner phases are obtained. These numerical solutions show that the propagator behaves very differently in the Landau gauge domain and in the infrared energy region outside it.By using the propagators in the Nambu and Wigner phases under various gauges it is further investigated how the fermion equivalent pressure difference and fermion condensation change with the gauge parameters.These results indicate that the phase transition described by the CJT equivalent potential and the chiral phase transition described by the chiral condensation are not completely identical.展开更多
Due to the negligible non-perturbation effect in the low-energy region, quantum chromodynamics （QCD） is limited to be applied to hadron problems in particle physics. However, QED has mature non-perturbation models w...Due to the negligible non-perturbation effect in the low-energy region, quantum chromodynamics （QCD） is limited to be applied to hadron problems in particle physics. However, QED has mature non-perturbation models which can be applied to Fermi acting-energy between quark and gluon. This paper applies quantum electrodynamics in 2 ＋ 1 dimensions （QED3） to the Fermi condensation problems. First, the Dyson-Schwinger equation which the fermions satisfy is constructed, and then the Fermi energy gap is solved. Theoretical calculations show that within the chirality limit, there exist three solutions for the energy gap; beyond the chirality limit, there are two solutions; all these solutions correspond to different fermion condensates. It can be concluded that the fermion condensates within the chirality limit can be used to analyze the existence of antiferromagnetic, pseudogap, and superconducting phases, and two fermion condensates are discovered beyond the chirality limit.展开更多
Based on three-dimensional quantum electrodynamics theory,a set of truncated Dyson-Schwinger（D-S） equations are solved to study photon and fermion propagators with the effect of vacuum polarization.Numerical studies...Based on three-dimensional quantum electrodynamics theory,a set of truncated Dyson-Schwinger（D-S） equations are solved to study photon and fermion propagators with the effect of vacuum polarization.Numerical studies show that condensation and the value of fermion mass depends heavily on how the D-S equations are truncated.By solving a set of coupled D-S equations,it is also found that the fermion propagator shows a clear dependence on the order parameter.The truncated D-S equations under unquenched approximation are used to study the mass-function and chiral condensation of the fermions.The results under the unquenched approximation are clearly different from the ones under quenched approximation.With the increase in the order parameter,the fermion condensation in the unquenched approximation decreases when 0≤ξ5,while it increases when ξ5.However,nothing like this is observed in the quenched approximation,which indicates that there may be flaws in the quenched approximations.展开更多
Rapid industrialization in Vietnam has resulted in the difficult task of finding means to properly manage the generation of industrial waste. In an attempt to deal with this problem, the Vietnamese government revised ...Rapid industrialization in Vietnam has resulted in the difficult task of finding means to properly manage the generation of industrial waste. In an attempt to deal with this problem, the Vietnamese government revised the Law on Environmental Protection of 2005, with which it imposed strict regulations on industrial waste generators and the waste they discharge. However, questions remain about the current industrial solid waste management system because of the discrepancy between the ideals embodied in the Law and the actual practices occurring in industry. We report here on the effectiveness of governmental policies, focusing on environmental performance in industrial zones in Ho Chi Minh City （HCMC）, Vietnam. We examined government records, and reports from waste generators, as well as waste treatment methods at sites. In addition, on-site surveys were carried out at 44 companies in HCMC in 2009 and 2010 to obtain a better understanding of the companies＇ handling of and attitude toward the industrial waste they produced. Our results show that the incoherence of the revised Law and regulations in industrial waste management has caused a serious pressure on domestic landfills. We conclude that there is a strong need for change in the current regulatory and management system in order to increase the effectiveness of environmental management for future sustainable development.展开更多
Negative skin friction (NSF) is one of the important problems when designing a pile foundation. However, the influence of loading sequence on the dragload and downdrag for pile foundation is seldom studied. In this pa...Negative skin friction (NSF) is one of the important problems when designing a pile foundation. However, the influence of loading sequence on the dragload and downdrag for pile foundation is seldom studied. In this paper, a three-dimensional numerical model was established using FLAC3D. Compared with the results of model test, the established model could be used to study the NSF of pile foundation. The influencing factors were discussed including the length-diameter ratio of pile and the loading sequence of pile head load and surcharge. A case history was analyzed using FLAC3D. The calculated results are in good agreement with the measured results. It is concluded that the dragload and downdrag are remarkably influenced by the loading sequence of pile head load and surcharge. The dragload and downdrag reach the maximum values under the condition of surcharge after pile head load.展开更多
This study examines the nature of the social discourse of advertising used as a brand positioning discourse. The focus is on consumer advertising, which is directed toward the promotion of some product or service to t...This study examines the nature of the social discourse of advertising used as a brand positioning discourse. The focus is on consumer advertising, which is directed toward the promotion of some product or service to the general public. This paper aimed at analyzing some different commercial advertisements [product/non-product ads] to investigate the intentions and techniques of consumer product companies to reach more consumers and sell more products. Norman Fairclough＇s 3-D model and Kress and Van Leeuwen＇s grammar of visual design were used to analyze the data for professionals, but we are pointed on using stereotypes. When we consider gender stereotypes, we look at notions about the supposedly traditional behaviors of men and women and the characteristics and standards of these behaviors, as grounded in our culture and society. In addition, this study provides analyses of some ads, using different ways of interpretations. All materials are taken from Latvian media.展开更多
A short presentation of chemical engineering evolution,as guided by its paradigms,is exposed.The first paradigm–unit operations–has emerged as a necessity of systematization due to the explosion of chemical industri...A short presentation of chemical engineering evolution,as guided by its paradigms,is exposed.The first paradigm–unit operations–has emerged as a necessity of systematization due to the explosion of chemical industrial applications at the end of 19th century.The birth in the late 1950s of the second paradigm–transport phenomena–was the consequence of the need for a deep,scienti fic knowledge of the phenomena that explain what happens inside of unit operations.In the second part of 20th century,the importance of chemical product properties and qualities has become essentially in the market fights.Accordingly,it was required with additional and even new fundamental approaches,and product engineering was recognized as the third paradigm.Nowadays chemical industry,as a huge materials and energy consumer,and with a strong ecological impact,couldn't remain outside of sustainability requirements.The basics of the fourth paradigm–sustainable chemical engineering–are now formulated.展开更多
The formation of brominated trihalomethanes (THMs-Br) which is proved more carcinogenic than their chlorinated analogues reported was very different at various water qualities.This study was performed to assess the ef...The formation of brominated trihalomethanes (THMs-Br) which is proved more carcinogenic than their chlorinated analogues reported was very different at various water qualities.This study was performed to assess the effects of water quality parameters (bromide concentration,pH value and ammonia concentration),chlorination conditions (chlorine dose,reaction time) and ratios of Br-/DOC and Br-/Cl2 consumption on the formation and distribution of THMs-Br in chlorination.The results showed good correlation between the bromine incorporation factor (BIF) n(Br) and Br-/Cl2 consumption ratio.The formation of total THM (TTHM) was found to decrease with increasing ammonia concentration but to increase with bromide concentration and pH value.The n(Br) trends were significantly affected by the presence of bromide concentration.The effects on the molar yields of THMs were more strongly influenced by bromide concentration and dissolved organic carbon (DOC) concentration than pH value and natural organic matter (NOM) source.High Br-/DOC and Br-/Cl2 favor the formation of THMs-Br over chlorinated THMs (THMs-Cl).The experimental data including the main parameters such as bromide,DOC,ammonia,pH and reaction time were used for developing the predictive model for THMs-Br.展开更多
We study the molecular state in three-component Fermi gases with a single impurity of ~6Li immersing in a no-interacting Fermi sea of ^(40)K in the presence of an equal weight combination of Rashba-type and Dresselhau...We study the molecular state in three-component Fermi gases with a single impurity of ~6Li immersing in a no-interacting Fermi sea of ^(40)K in the presence of an equal weight combination of Rashba-type and Dresselhaustype spin-orbit coupling. In the region where the Fermi sea has two disjointed Fermi surfaces, we find that there are two Fulde–Ferrell-like molecular states with dominating contributions from the lower helicity branch. Decreasing the scattering length or the spin-orbit coupled Fermi energy, we find the Fulde–Ferrell-like molecular state with small center-of-mass momentum is always energy favored and the other one will suddenly disappear.展开更多
基金The National Natural Science Foundation of China(No.10947127)the Science Foundation of Southeast University(No.11047005)
文摘In order to examine how a propagator behaves in non-perturbative theories and how its behavior is influenced by the choice of a covariant gauge a truncated Dyson-Schwinger equation is used to numerically investigate the properties of fermions and bosons in 3D quantum electrodynamics QED and a series of self-consistent solutions for the fermion propagator in the Nambu and Wigner phases are obtained. These numerical solutions show that the propagator behaves very differently in the Landau gauge domain and in the infrared energy region outside it.By using the propagators in the Nambu and Wigner phases under various gauges it is further investigated how the fermion equivalent pressure difference and fermion condensation change with the gauge parameters.These results indicate that the phase transition described by the CJT equivalent potential and the chiral phase transition described by the chiral condensation are not completely identical.
基金The National Natural Science Foundation of China(No.11047005)the Science Foundation of Southeast University
文摘Due to the negligible non-perturbation effect in the low-energy region, quantum chromodynamics （QCD） is limited to be applied to hadron problems in particle physics. However, QED has mature non-perturbation models which can be applied to Fermi acting-energy between quark and gluon. This paper applies quantum electrodynamics in 2 ＋ 1 dimensions （QED3） to the Fermi condensation problems. First, the Dyson-Schwinger equation which the fermions satisfy is constructed, and then the Fermi energy gap is solved. Theoretical calculations show that within the chirality limit, there exist three solutions for the energy gap; beyond the chirality limit, there are two solutions; all these solutions correspond to different fermion condensates. It can be concluded that the fermion condensates within the chirality limit can be used to analyze the existence of antiferromagnetic, pseudogap, and superconducting phases, and two fermion condensates are discovered beyond the chirality limit.
基金The Science Foundation of Southeast University,the National Natural Science Foundation of China (No. 11047005)
文摘Based on three-dimensional quantum electrodynamics theory,a set of truncated Dyson-Schwinger（D-S） equations are solved to study photon and fermion propagators with the effect of vacuum polarization.Numerical studies show that condensation and the value of fermion mass depends heavily on how the D-S equations are truncated.By solving a set of coupled D-S equations,it is also found that the fermion propagator shows a clear dependence on the order parameter.The truncated D-S equations under unquenched approximation are used to study the mass-function and chiral condensation of the fermions.The results under the unquenched approximation are clearly different from the ones under quenched approximation.With the increase in the order parameter,the fermion condensation in the unquenched approximation decreases when 0≤ξ5,while it increases when ξ5.However,nothing like this is observed in the quenched approximation,which indicates that there may be flaws in the quenched approximations.
文摘Rapid industrialization in Vietnam has resulted in the difficult task of finding means to properly manage the generation of industrial waste. In an attempt to deal with this problem, the Vietnamese government revised the Law on Environmental Protection of 2005, with which it imposed strict regulations on industrial waste generators and the waste they discharge. However, questions remain about the current industrial solid waste management system because of the discrepancy between the ideals embodied in the Law and the actual practices occurring in industry. We report here on the effectiveness of governmental policies, focusing on environmental performance in industrial zones in Ho Chi Minh City （HCMC）, Vietnam. We examined government records, and reports from waste generators, as well as waste treatment methods at sites. In addition, on-site surveys were carried out at 44 companies in HCMC in 2009 and 2010 to obtain a better understanding of the companies＇ handling of and attitude toward the industrial waste they produced. Our results show that the incoherence of the revised Law and regulations in industrial waste management has caused a serious pressure on domestic landfills. We conclude that there is a strong need for change in the current regulatory and management system in order to increase the effectiveness of environmental management for future sustainable development.
基金Supported by National Natural Science Foundation of China (No.50679015)China Postdoctoral Science Foundation (No.20090461062)
文摘Negative skin friction (NSF) is one of the important problems when designing a pile foundation. However, the influence of loading sequence on the dragload and downdrag for pile foundation is seldom studied. In this paper, a three-dimensional numerical model was established using FLAC3D. Compared with the results of model test, the established model could be used to study the NSF of pile foundation. The influencing factors were discussed including the length-diameter ratio of pile and the loading sequence of pile head load and surcharge. A case history was analyzed using FLAC3D. The calculated results are in good agreement with the measured results. It is concluded that the dragload and downdrag are remarkably influenced by the loading sequence of pile head load and surcharge. The dragload and downdrag reach the maximum values under the condition of surcharge after pile head load.
文摘This study examines the nature of the social discourse of advertising used as a brand positioning discourse. The focus is on consumer advertising, which is directed toward the promotion of some product or service to the general public. This paper aimed at analyzing some different commercial advertisements [product/non-product ads] to investigate the intentions and techniques of consumer product companies to reach more consumers and sell more products. Norman Fairclough＇s 3-D model and Kress and Van Leeuwen＇s grammar of visual design were used to analyze the data for professionals, but we are pointed on using stereotypes. When we consider gender stereotypes, we look at notions about the supposedly traditional behaviors of men and women and the characteristics and standards of these behaviors, as grounded in our culture and society. In addition, this study provides analyses of some ads, using different ways of interpretations. All materials are taken from Latvian media.
文摘A short presentation of chemical engineering evolution,as guided by its paradigms,is exposed.The first paradigm–unit operations–has emerged as a necessity of systematization due to the explosion of chemical industrial applications at the end of 19th century.The birth in the late 1950s of the second paradigm–transport phenomena–was the consequence of the need for a deep,scienti fic knowledge of the phenomena that explain what happens inside of unit operations.In the second part of 20th century,the importance of chemical product properties and qualities has become essentially in the market fights.Accordingly,it was required with additional and even new fundamental approaches,and product engineering was recognized as the third paradigm.Nowadays chemical industry,as a huge materials and energy consumer,and with a strong ecological impact,couldn't remain outside of sustainability requirements.The basics of the fourth paradigm–sustainable chemical engineering–are now formulated.
基金Project supported by the National Hi-Tech Research and Development Program (863) of China (No.2006AA06Z311)the National Natural Science Foundation of China (No.50808052)
文摘The formation of brominated trihalomethanes (THMs-Br) which is proved more carcinogenic than their chlorinated analogues reported was very different at various water qualities.This study was performed to assess the effects of water quality parameters (bromide concentration,pH value and ammonia concentration),chlorination conditions (chlorine dose,reaction time) and ratios of Br-/DOC and Br-/Cl2 consumption on the formation and distribution of THMs-Br in chlorination.The results showed good correlation between the bromine incorporation factor (BIF) n(Br) and Br-/Cl2 consumption ratio.The formation of total THM (TTHM) was found to decrease with increasing ammonia concentration but to increase with bromide concentration and pH value.The n(Br) trends were significantly affected by the presence of bromide concentration.The effects on the molar yields of THMs were more strongly influenced by bromide concentration and dissolved organic carbon (DOC) concentration than pH value and natural organic matter (NOM) source.High Br-/DOC and Br-/Cl2 favor the formation of THMs-Br over chlorinated THMs (THMs-Cl).The experimental data including the main parameters such as bromide,DOC,ammonia,pH and reaction time were used for developing the predictive model for THMs-Br.
基金Supported by the National Basic Research Program of China(973 Program)under Grant Nos.2013CBA01502,2013CB834100the National Natural Science Foundation of China under Grant Nos.11374040,11475027,11575027,11274051,and 11075020
文摘We study the molecular state in three-component Fermi gases with a single impurity of ~6Li immersing in a no-interacting Fermi sea of ^(40)K in the presence of an equal weight combination of Rashba-type and Dresselhaustype spin-orbit coupling. In the region where the Fermi sea has two disjointed Fermi surfaces, we find that there are two Fulde–Ferrell-like molecular states with dominating contributions from the lower helicity branch. Decreasing the scattering length or the spin-orbit coupled Fermi energy, we find the Fulde–Ferrell-like molecular state with small center-of-mass momentum is always energy favored and the other one will suddenly disappear.
