Combined effects of obstacles and fine water mist on a methane-air explosion of a semi-closed pipe were investigated experimentally.In this study,the diameter of the water mist,the location,and the number of obstacles...Combined effects of obstacles and fine water mist on a methane-air explosion of a semi-closed pipe were investigated experimentally.In this study,the diameter of the water mist,the location,and the number of obstacles was considered.The results demonstrated that 5 μm water mist present a significant suppression affected while 45 μm shows a slight promotion effected on a gas explosion of the condition without obstacles.In the presence of an obstacle,however,the inhibitory effect of 5 μm water veils of mist dropped significantly during flame propagation,and the effect of 45 μm water veils of mist changed from the enhancement of inhibition,and its inhibitory effect was significant.The inhibitory effect of 45 μm water veils of mist on gas explosion weakened firstly and then enhanced with the increasing distance between obstacle location from the ignition location as well as in several obstacles.展开更多
Gd_(2) O_(3) nanoparticles modified g-C_(3) N_(4) photocatalytic composites were synthesized by a simple one-step hydrothermal method.The structure,morphology,optical properties of the prepared photocatalyst were char...Gd_(2) O_(3) nanoparticles modified g-C_(3) N_(4) photocatalytic composites were synthesized by a simple one-step hydrothermal method.The structure,morphology,optical properties of the prepared photocatalyst were characterized by X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM),field emission transmission electron microscopy(FETEM) and X-ray photoelectron spectroscopy(XPS).The result demonstrates that gadolinium is mainly dispersed on the surface of g-C_(3) N_(4) in the form of Gd_(2) O_(3),and does not destroy the lattice structure of g-C_(3) N_(4).Besides,the gadolinium can cause the red shift of the absorption edge of light,narrow the band gap,and increase the separation efficiency of the photogenerated electron and hole of g-C_(3) N_(4).Especially,the specific surface area of g-C_(3) N_(4) can be significantly increased.Furthermore,g-C_(3) N_(4)/Gd-0.05 displays the highest photodegradation performance when it is used for degradation of methyl orange(MO),methylene blue(MB) and Rhodamine B(RhB).The photodegradation rate of g-C_(3) N_(4)/Gd-0.05 composites is 72.4% for MO,95.5% for RhB,100% for MB after120 min under visible light(λ> 420 nm) irradiation.Narrow band gap promotes the separation of photogenerated electron and hole,which enhances the photocatalytic activity of g-C_(3) N_(4).It is noted that g-C_(3) N_(4)/Gd-0.05 exhibits excellent photocatalytic stability by the photocurrent and the cyclic photodegradation of MO.展开更多
基金financial supports of the National Key Research and Development Program of China(2018YFC0808103)the National Natural Science Foundation of China (51774115, 51604095)。
文摘Combined effects of obstacles and fine water mist on a methane-air explosion of a semi-closed pipe were investigated experimentally.In this study,the diameter of the water mist,the location,and the number of obstacles was considered.The results demonstrated that 5 μm water mist present a significant suppression affected while 45 μm shows a slight promotion effected on a gas explosion of the condition without obstacles.In the presence of an obstacle,however,the inhibitory effect of 5 μm water veils of mist dropped significantly during flame propagation,and the effect of 45 μm water veils of mist changed from the enhancement of inhibition,and its inhibitory effect was significant.The inhibitory effect of 45 μm water veils of mist on gas explosion weakened firstly and then enhanced with the increasing distance between obstacle location from the ignition location as well as in several obstacles.
基金Project supported by the National Natural Science Foundation of China (51664047,21667019,22066017)the First Training-class High-end Talents Projects of Science and Technology Innovation in Jiangxi Province (CK202002473)+4 种基金the Key of Natural Science Foundation of Jiangxi Province (20171ACB20016)the Jiangxi Province Major Academic and Technical Leaders Cultivating Object Program (20172BCB22014)the Science and Technology Department of Jiangxi Province(20181BCB18003,20181ACG70025)the Key of Science and Technology Research of the Jiangxi Provincial Department of Education (GJJ191044,GJJ191058)Fujian Key Laboratory of Measurement and Control System for Of-Shore Environment (S1-KF1703)。
文摘Gd_(2) O_(3) nanoparticles modified g-C_(3) N_(4) photocatalytic composites were synthesized by a simple one-step hydrothermal method.The structure,morphology,optical properties of the prepared photocatalyst were characterized by X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM),field emission transmission electron microscopy(FETEM) and X-ray photoelectron spectroscopy(XPS).The result demonstrates that gadolinium is mainly dispersed on the surface of g-C_(3) N_(4) in the form of Gd_(2) O_(3),and does not destroy the lattice structure of g-C_(3) N_(4).Besides,the gadolinium can cause the red shift of the absorption edge of light,narrow the band gap,and increase the separation efficiency of the photogenerated electron and hole of g-C_(3) N_(4).Especially,the specific surface area of g-C_(3) N_(4) can be significantly increased.Furthermore,g-C_(3) N_(4)/Gd-0.05 displays the highest photodegradation performance when it is used for degradation of methyl orange(MO),methylene blue(MB) and Rhodamine B(RhB).The photodegradation rate of g-C_(3) N_(4)/Gd-0.05 composites is 72.4% for MO,95.5% for RhB,100% for MB after120 min under visible light(λ> 420 nm) irradiation.Narrow band gap promotes the separation of photogenerated electron and hole,which enhances the photocatalytic activity of g-C_(3) N_(4).It is noted that g-C_(3) N_(4)/Gd-0.05 exhibits excellent photocatalytic stability by the photocurrent and the cyclic photodegradation of MO.