Natures and anthropogenic particulates can travel long distances on wind flows, but negative electrical charge due to friction can increase dispersion. Models for calculations of distance travelling of biological part...Natures and anthropogenic particulates can travel long distances on wind flows, but negative electrical charge due to friction can increase dispersion. Models for calculations of distance travelling of biological particulate matter with and without charge are never been calculated in a theoretical approach. Nor do we realize the fact that we can calculate actual distances if we take the charge on particles in account. Particles that travel through the air encounter friction. Friction can be described in two ways;either in a smooth constant way through the air with its viscous forces, or in a turbulent chaotic eddies and vortices and other flow instabilities. In case of only viscous forces are to be concerned, it can be described as a lower Reynolds number than one, while in all other setting it always must be described by Reynolds numbers larger than or equal to one. This article describes the calculated effects on particles, either in a low Reynolds number and thus as a Navier-Stokes equation or Stokes’ Law or, in case of non-laminar and complex forces in an equal or higher Reynolds number according to the third Law of Newton. In addition some striking examples of particle travelling are given with evidence of natural particulate matter long distance dispersion.展开更多
Sorption is an important process that controls the fate and transport of herbicides in the soil and aquifer environment.However,sorption of these pollutants on natural microporous mineral materials has received little...Sorption is an important process that controls the fate and transport of herbicides in the soil and aquifer environment.However,sorption of these pollutants on natural microporous mineral materials has received little attention.This study investigated the sorption of four model s-triazine herbicides,namely,atrazine,metribuzin,ametryn,and prometryn,on two common natural zeolites(i.e.,clinoptilite and Fe-mordenite)and two common clays(i.e.,kaolin and attapulgite)with microporosity in batch experiments.The results showed that the sorption of s-triazines on the natural zeolites increased in the order of metribuzin<atrazine<ametryn<prometryn,which corresponded approximately to the order of increasing sorbate hydrophobicity and indicated the significant contribution of the hydrophobic effect.In contrast,the sorption of s-triazines on the natural clays increased in the order of metribuzin<atrazine<prometryn<ametryn,which corresponded to the order of increasing sorbate basicity and indicated the significant contribution of cation exchange and electrostatic interactions.The sorption of these s-triazines on the mineral materials was strongly pH-dependent,resulting from the pH dependence of the mineral surface charge and protonation/deprotonation of the s-triazines.Common alkali and alkaline earth cations at low concentrations had no significant impact on the sorption of s-triazines on the natural microporous mineral materials.Meanwhile,the presence of Fe^(3+)(at 0.05 mmol/L)significantly enhanced the sorption of atrazine,ametryn,and prometryn by increasing the protonation of s-triazine molecules in the interfacial region between the mineral surface and bulk solution(due to hydrolysis of Fe^(3+)).Co-sorption of s-triazines on the natural microporous mineral materials exhibited significant competitive effects when these herbicides are sorbed through similar mechanisms.The findings of this study provide insights on the interactions of s-triazine herbicides with natural microporous mineral materials,which help better understan展开更多
Dual-fuel premixed charge compression ignition (DF-PCCI) combustion has been proven to be a viable alternative to conventional diesel combustion in heavy-duty compression ignition engines due to its low nitrogen oxide...Dual-fuel premixed charge compression ignition (DF-PCCI) combustion has been proven to be a viable alternative to conventional diesel combustion in heavy-duty compression ignition engines due to its low nitrogen oxides (NOx) and particulate matter (PM) emissions. When natural gas (NG) is applied to a DF-PCCI engine, its low reactivity reduces the maximum pressure rise rate under high loads. However, the NG–diesel DF-PCCI engine suffers from low combustion efficiency under low loads. In this study, an injection strategy of fuel supply (NG and diesel) in a DF-PCCI engine was investigated in order to reduce both the fuel consumption and hydrocarbon (HC) and carbon monoxide (CO) emissions under low load conditions. A variation in the NG substitution and diesel start of energizing (SOE) was found to effectively control the formation of the fuel–air mixture. A double injection strategy of diesel was implemented to adjust the local reactivity of the mixture. Retardation of the diesel pilot SOE and a low fraction of the diesel pilot injection quantity were favorable for reducing the combustion loss. The introduction of exhaust gas recirculation (EGR) improved the fuel economy and reduced the NOx and PM emissions below Euro VI regulations by retarding the combustion phasing. The combination of an NG substitution of 40%, the double injection strategy of diesel, and a moderate EGR rate effectively improved the combustion efficiency and indicated efficiency, and reduced the HC and CO emissions under low load conditions.展开更多
文摘Natures and anthropogenic particulates can travel long distances on wind flows, but negative electrical charge due to friction can increase dispersion. Models for calculations of distance travelling of biological particulate matter with and without charge are never been calculated in a theoretical approach. Nor do we realize the fact that we can calculate actual distances if we take the charge on particles in account. Particles that travel through the air encounter friction. Friction can be described in two ways;either in a smooth constant way through the air with its viscous forces, or in a turbulent chaotic eddies and vortices and other flow instabilities. In case of only viscous forces are to be concerned, it can be described as a lower Reynolds number than one, while in all other setting it always must be described by Reynolds numbers larger than or equal to one. This article describes the calculated effects on particles, either in a low Reynolds number and thus as a Navier-Stokes equation or Stokes’ Law or, in case of non-laminar and complex forces in an equal or higher Reynolds number according to the third Law of Newton. In addition some striking examples of particle travelling are given with evidence of natural particulate matter long distance dispersion.
基金This work was supported in parts by the National Natural Science Foundation of China(Grant Nos.41725015,U2006212,and 41472324).
文摘Sorption is an important process that controls the fate and transport of herbicides in the soil and aquifer environment.However,sorption of these pollutants on natural microporous mineral materials has received little attention.This study investigated the sorption of four model s-triazine herbicides,namely,atrazine,metribuzin,ametryn,and prometryn,on two common natural zeolites(i.e.,clinoptilite and Fe-mordenite)and two common clays(i.e.,kaolin and attapulgite)with microporosity in batch experiments.The results showed that the sorption of s-triazines on the natural zeolites increased in the order of metribuzin<atrazine<ametryn<prometryn,which corresponded approximately to the order of increasing sorbate hydrophobicity and indicated the significant contribution of the hydrophobic effect.In contrast,the sorption of s-triazines on the natural clays increased in the order of metribuzin<atrazine<prometryn<ametryn,which corresponded to the order of increasing sorbate basicity and indicated the significant contribution of cation exchange and electrostatic interactions.The sorption of these s-triazines on the mineral materials was strongly pH-dependent,resulting from the pH dependence of the mineral surface charge and protonation/deprotonation of the s-triazines.Common alkali and alkaline earth cations at low concentrations had no significant impact on the sorption of s-triazines on the natural microporous mineral materials.Meanwhile,the presence of Fe^(3+)(at 0.05 mmol/L)significantly enhanced the sorption of atrazine,ametryn,and prometryn by increasing the protonation of s-triazine molecules in the interfacial region between the mineral surface and bulk solution(due to hydrolysis of Fe^(3+)).Co-sorption of s-triazines on the natural microporous mineral materials exhibited significant competitive effects when these herbicides are sorbed through similar mechanisms.The findings of this study provide insights on the interactions of s-triazine herbicides with natural microporous mineral materials,which help better understan
基金supported by the National Natural Science Foundation of China(10804027,11011140321)Natural Science Foundation of Education Department of Henan Province,China(2011A140003)~~
基金the Global-Top Project,Development of Advanced Combustion Technology for Global Top Low Emission Vehicle(2016002070001)the Ministry of Environment(MOE)of Korea for financial support by the Center for Environmentally Friendly Vehicle(CEFV)
文摘Dual-fuel premixed charge compression ignition (DF-PCCI) combustion has been proven to be a viable alternative to conventional diesel combustion in heavy-duty compression ignition engines due to its low nitrogen oxides (NOx) and particulate matter (PM) emissions. When natural gas (NG) is applied to a DF-PCCI engine, its low reactivity reduces the maximum pressure rise rate under high loads. However, the NG–diesel DF-PCCI engine suffers from low combustion efficiency under low loads. In this study, an injection strategy of fuel supply (NG and diesel) in a DF-PCCI engine was investigated in order to reduce both the fuel consumption and hydrocarbon (HC) and carbon monoxide (CO) emissions under low load conditions. A variation in the NG substitution and diesel start of energizing (SOE) was found to effectively control the formation of the fuel–air mixture. A double injection strategy of diesel was implemented to adjust the local reactivity of the mixture. Retardation of the diesel pilot SOE and a low fraction of the diesel pilot injection quantity were favorable for reducing the combustion loss. The introduction of exhaust gas recirculation (EGR) improved the fuel economy and reduced the NOx and PM emissions below Euro VI regulations by retarding the combustion phasing. The combination of an NG substitution of 40%, the double injection strategy of diesel, and a moderate EGR rate effectively improved the combustion efficiency and indicated efficiency, and reduced the HC and CO emissions under low load conditions.
