In the framework of MSSM the probability of Z0-boson decay to chaxginos in a strong electromagnetic field, Z X＋X-, is analyzed. The method of calculations employs exact solutions of relativistic wave equations for ch...In the framework of MSSM the probability of Z0-boson decay to chaxginos in a strong electromagnetic field, Z X＋X-, is analyzed. The method of calculations employs exact solutions of relativistic wave equations for charginos in a crossed electromagnetic field. Analytic expression for the decay width is obtained at an arbitrary value of the parameter which characterizes the external-field strength Fμv and Z%boson momentum qv. The process Z0→ X＋X- is forbidden in a vacuum for the case of relatively heavy charginos： Mx±mz/2. However, in an intense electromagnetic background this reaction could take place in the region of superstrong fields （x〉1）.展开更多
Petroleum based oils,the so-called mineral oils,are used for impregnating solid insulations or filling products of very large number of electric materials:transformers,reactors,cables,bushings,circuit breakers,tap cha...Petroleum based oils,the so-called mineral oils,are used for impregnating solid insulations or filling products of very large number of electric materials:transformers,reactors,cables,bushings,circuit breakers,tap changers, etc.In these equipments,oil is exposed to electrical stress and may experience electrical discharges under certain circumstances.Since the electrical stress is unavoidable in power equipments,the ability of oil to resist decomposition under electrical stress is of great importance for the safety of these devices.Electrical stress together with heat and moisture,in the presence of oxygen,oxidises the oil producing free radicals,acids and sludge that are deleterious to the transformer.In this paper,the effect of electrical discharges on oil properties is reported.The results indicate that quality of oil is considerably affected with increasing voltage stress.Comparing oil properties before and after voltage application allows assessing the outcome of random secondary chemical reactions between large oil born free radicals.展开更多
Objective:To explore the reduction effect for the indoor ^(222)Rn(Rn)by Fresh Air Ventilation(FAV)system,a novel commercial ventilation device in China.Methods:The indoor concentrations of Rn and its decay products(Rn...Objective:To explore the reduction effect for the indoor ^(222)Rn(Rn)by Fresh Air Ventilation(FAV)system,a novel commercial ventilation device in China.Methods:The indoor concentrations of Rn and its decay products(RnD)in three residential rooms,two in Beijing and one in Hefei city,Anhui province,before and after FAVS functioned were measured using an active continuous method.The air exchange rate was monitored by measuring CO_(2) concentration using the tracer gas method.Results:In the three rooms,the FAVS reduced the Rn concentrations from(162±80)Bq/m^(3) to(63±22)Bq/m^(3) and decreased the RnD concentrations from(64±35)Bq/m^(3) to(13±6)Bq/m^(3) on average,a decrease of(59±25)% in the Rn concentrations and a drop of(77±18)%in the RnD concentrations.Considering dose conversion factors of Rn and RnD,FAVS decreased the exposure dose by(76±20)%.Besides,FAVS increased the air exchange rates from 0.17 h^(-1) to 0.56 h^(-1) on average.Conclusions:FAVS can effectively reduce indoor Rn and RnD concentrations by improving the air exchange,serving as a valuable supplement to existing radon mitigation methods,especially in extreme climates.展开更多
文摘In the framework of MSSM the probability of Z0-boson decay to chaxginos in a strong electromagnetic field, Z X＋X-, is analyzed. The method of calculations employs exact solutions of relativistic wave equations for charginos in a crossed electromagnetic field. Analytic expression for the decay width is obtained at an arbitrary value of the parameter which characterizes the external-field strength Fμv and Z%boson momentum qv. The process Z0→ X＋X- is forbidden in a vacuum for the case of relatively heavy charginos： Mx±mz/2. However, in an intense electromagnetic background this reaction could take place in the region of superstrong fields （x〉1）.
文摘Petroleum based oils,the so-called mineral oils,are used for impregnating solid insulations or filling products of very large number of electric materials:transformers,reactors,cables,bushings,circuit breakers,tap changers, etc.In these equipments,oil is exposed to electrical stress and may experience electrical discharges under certain circumstances.Since the electrical stress is unavoidable in power equipments,the ability of oil to resist decomposition under electrical stress is of great importance for the safety of these devices.Electrical stress together with heat and moisture,in the presence of oxygen,oxidises the oil producing free radicals,acids and sludge that are deleterious to the transformer.In this paper,the effect of electrical discharges on oil properties is reported.The results indicate that quality of oil is considerably affected with increasing voltage stress.Comparing oil properties before and after voltage application allows assessing the outcome of random secondary chemical reactions between large oil born free radicals.
文摘Objective:To explore the reduction effect for the indoor ^(222)Rn(Rn)by Fresh Air Ventilation(FAV)system,a novel commercial ventilation device in China.Methods:The indoor concentrations of Rn and its decay products(RnD)in three residential rooms,two in Beijing and one in Hefei city,Anhui province,before and after FAVS functioned were measured using an active continuous method.The air exchange rate was monitored by measuring CO_(2) concentration using the tracer gas method.Results:In the three rooms,the FAVS reduced the Rn concentrations from(162±80)Bq/m^(3) to(63±22)Bq/m^(3) and decreased the RnD concentrations from(64±35)Bq/m^(3) to(13±6)Bq/m^(3) on average,a decrease of(59±25)% in the Rn concentrations and a drop of(77±18)%in the RnD concentrations.Considering dose conversion factors of Rn and RnD,FAVS decreased the exposure dose by(76±20)%.Besides,FAVS increased the air exchange rates from 0.17 h^(-1) to 0.56 h^(-1) on average.Conclusions:FAVS can effectively reduce indoor Rn and RnD concentrations by improving the air exchange,serving as a valuable supplement to existing radon mitigation methods,especially in extreme climates.
