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The second generation of high temperature superconducting (HTS) strip has the outstanding characteristics of high critical temperature, high load current density and high critical magnetic field, so the HTS coils wound by the strip have broad application prospects in the field of electric power, such as magnetic energy storage system, high speed maglev train and wind power generation system. In order to promote the further development of HTS magnetic energy storage system (SMES), this paper conducts the modelling and simulation research on the ac losses of a 100- MJ toroid-type HTS SMES. Firstly, the geometric structure of the system are introduced. Then, the ac loss models of HTS coils and the non-superconducting components in the energy storage system are established by H-formulation and A-formulation, respectively. Based on both the models, we calculate the ac losses of HTS coils and related components during the process of energy storage and release. Finally, the model coils are winded and impregnated to show the structure.

The second generation of high temperature superconducting (HTS) strip has the outstanding characteristics of high critical temperature, large current-carrying density and high critical magnetic field, and the HTS magnets made by the strip have broad application prospects in the field of electric power, such as magnetic energy storage system, high-speed maglev train and wind power generation system. In order to promote the further development of a superconducting magnetic energy storage (SMES) system, this paper conducts modelling and simulation research on the AC losses of single solenoid type magnet for 10 kJ SMES system. Firstly, this paper optimizes the geometric parameters of the HTS magnet in the SMES system, in which the inner diameter, turns and pancake number of the superconducting magnet are the optimization variables, energy storage is the constraint condition, and the total consumption of the HTS strip is the optimization objective. Secondly, based on the T-A method, this paper established the AC loss model of single solenoid HTS magnets and calculated the AC losses of HTS magnets and thermal-conducting copper plates during the energy storage and energy release of the energy storage system.

Ozone is a kind of secondary pollutant with high oxidability and strong biohazard.Long-term monitoring shows that the ozone concentration in Beijing exurban region is obviously higher than that of the urban and the suburb regions.The value of AOT40,from May to September reached 98.9mg/m3,which might already have negative influence on the growth of the wild plants.Via investigation near the long-term monitoring spot sited in Mangshan Forest Park,and referring to the assessment standard of visible symptoms of ozone injury which comes from investigation and imitation experiment of other countries,we found that 15 ozone-sensitive species with obvious ozone foliar injury symptoms among 26 woody plants,including arbor and shrubs,These 15 plants species include Grewia biloba var.parviflora,Lespedeza floribunda,Lespedeza tomentosa,Cotinus coggygria var.pubescens,Rhus typhina,Caragana frutex,Vitex negundo var.heterophylla,Prunus davidiana,Prunus sibirica,Ampelopsis humulifolia,Prunus triloba,Juglans mandshurica,Quercus wutaishanica,Rubus crataegifolius,Spiraea trilobata.The typical symptoms of the ozone foliar injury are dark stipple,mottling and tip burn.The colors of the injury symptoms changed from light to deep,including white,gray,yellow,brown and tan,the latter three were more usual.It showed that the woody plants in Beijing exurban region,including arbor and shrubs,had already suffered the hazard of ambient ozone.Besides,the other 11 woody plant species,including Pinus bungeana,Platycladus orientalis,Koelreuteria paniculata,Morus alba,Broussonetia papyrifera,Ziziphus jujuba var.spinosa,Pinus pumila,Pinus tabulaeformis,Ulmus pumila,Corylus mandshurica,Populus davidiana,showed similar symptoms of the previous plants.But further research is still necessary to investigate the factors lead to the injury symptoms.