In this work, we fabricate an efficient and stable photocatalyst system which has superior recyclability even under concentrated acidic conditions. The photocatalyst is prepared by assembling magnetic graphitic nanoca...In this work, we fabricate an efficient and stable photocatalyst system which has superior recyclability even under concentrated acidic conditions. The photocatalyst is prepared by assembling magnetic graphitic nanocapsules, titania(Ti O2) and graphene oxide(GO) into a complex system through π-π stacking and electrostatic interactions. Such catalytic complex demonstrates very high stability. Even after dispersal into a concentrated acidic solution for one month, this photocatalyst could still be recycled and maintain its catalytic activity. With methyl orange as the model molecule, the photocatalyst is demonstrated to rapidly decompose the molecules with very high photocatalytic activity under both concentrated acidic and neutral condition. Moreover, this photocatalyst retains approximately 100 wt% of its original photocatalytic activity even after multiple experimental runs, of magnetic recycling. Finally, using different samples from natural water sources and different dyes, this GO/ magnetic graphitic nanocapsule/Ti O2 system also demonstrates its high efficiency and recyclability for practical application.展开更多
A model of the irreversible regenerative Brayton refrigeration cycle working with paramagnetic materials is established,in which the regeneration problem in two constant-magnetic field processes and the irreversibilit...A model of the irreversible regenerative Brayton refrigeration cycle working with paramagnetic materials is established,in which the regeneration problem in two constant-magnetic field processes and the irreversibility in two adiabatic processes are considered synthetically.Expressions for the COP,cooling rate,power input,theminimum ratio of the two magnetic fields,etc.,are derived.It is found that the influence of the irreversibility and the regeneration on the main performance parameters of the magnetic Brayton refrigerator is remarkable.It is important that we have obtained several optimal criteria,which may provide some theoretical basis for the optimal design and operation of the Brayton refrigerator.The results obtained in the paper can provide some new theoretical information for the optimal design and performance improvement of real Brayton refrigerators.展开更多
基金supported by the National Basic Research Program of China(2013CB932702)the Research Fund for the Program on National Key Scientific Instruments and Equipment Development(2011YQ0301241402)+1 种基金the National Natural Science Foundation of China(21105025)the Hunan Innovation and Entrepreneurship Program
文摘In this work, we fabricate an efficient and stable photocatalyst system which has superior recyclability even under concentrated acidic conditions. The photocatalyst is prepared by assembling magnetic graphitic nanocapsules, titania(Ti O2) and graphene oxide(GO) into a complex system through π-π stacking and electrostatic interactions. Such catalytic complex demonstrates very high stability. Even after dispersal into a concentrated acidic solution for one month, this photocatalyst could still be recycled and maintain its catalytic activity. With methyl orange as the model molecule, the photocatalyst is demonstrated to rapidly decompose the molecules with very high photocatalytic activity under both concentrated acidic and neutral condition. Moreover, this photocatalyst retains approximately 100 wt% of its original photocatalytic activity even after multiple experimental runs, of magnetic recycling. Finally, using different samples from natural water sources and different dyes, this GO/ magnetic graphitic nanocapsule/Ti O2 system also demonstrates its high efficiency and recyclability for practical application.
基金supported by the Program for Excellent Young Teachers of Shanghai,China (Grant No.thc-20100036)
文摘A model of the irreversible regenerative Brayton refrigeration cycle working with paramagnetic materials is established,in which the regeneration problem in two constant-magnetic field processes and the irreversibility in two adiabatic processes are considered synthetically.Expressions for the COP,cooling rate,power input,theminimum ratio of the two magnetic fields,etc.,are derived.It is found that the influence of the irreversibility and the regeneration on the main performance parameters of the magnetic Brayton refrigerator is remarkable.It is important that we have obtained several optimal criteria,which may provide some theoretical basis for the optimal design and operation of the Brayton refrigerator.The results obtained in the paper can provide some new theoretical information for the optimal design and performance improvement of real Brayton refrigerators.
