A new roll shifting strategy with varying stroke and varying step was investigated,Two characteristic parameters including cat ear height and gap contour smoothness were introduced to assess the effect of shifting str...A new roll shifting strategy with varying stroke and varying step was investigated,Two characteristic parameters including cat ear height and gap contour smoothness were introduced to assess the effect of shifting strategy on roll wear,and the relation between characteristic parameters and shifting strategy was established.Both varying stroke and varying step can reduce cat ear height and gap contour smoothness,so the shifting strategy with varying stroke and varying step is better than the one with either varying stroke or varying step,Based on the effect of shifting control parameters on characteristic parameters of roll wear,the selection principle of these shifting control parameters was gained.A case study was conducted to validate the proposed roll shifting strategy,reducing uncontrollable quartic loading gap contour,improving strip profile and extending rolling length of a rolling campaign.展开更多
In order to promote the development of foreign trade, prevent unqualified commodities from flowing out of China and poor quality commodities from import, China’s departments of commodity inspection have strengthened ...In order to promote the development of foreign trade, prevent unqualified commodities from flowing out of China and poor quality commodities from import, China’s departments of commodity inspection have strengthened their inspection, checking supervision and management of the quality of import and export commodities. According to statistics from the State展开更多
Electrochemical reduction reaction of nitrogen(NRR)offers a promising pathway to produce ammonia(NH_(3))from renewable energy.However,the development of such process has been hindered by the chemical inertness of N_(2...Electrochemical reduction reaction of nitrogen(NRR)offers a promising pathway to produce ammonia(NH_(3))from renewable energy.However,the development of such process has been hindered by the chemical inertness of N_(2).It is recently proposed that hydrogen species formed on the surface of electrocatalysts can greatly enhance NRR.However,there is still a lack of atomiclevel connection between the hydrogenation behavior of electrocatalysts and their NRR performance.Here,we report an atomistic understanding of the hydrogenation behavior of a highly twinned ZnSe(T-ZnSe)nanorod with a large density of surface atomic steps and the activation of N_(2)molecules adsorbed on its surface.Our theoretical calculations and in situ infrared spectroscopic characterizations suggest that the atomic steps are essential for the hydrogenation of T-ZnSe,which greatly reduces its work function and efficiently activates adsorbed N_(2)molecules.Moreover,the liquid-like and free water over T-ZnSe promotes its hydrogenation.As a result,T-ZnSe nanorods exhibit significantly enhanced Faradaic efficiency and NH3 production rate compared with the pristine ZnSe nanorod.This work paves a promising way for engineering electrocatalysts for green and sustainable NH3 production.展开更多
基金Project(50974039) supported by the National Natural Science Foundation of China
文摘A new roll shifting strategy with varying stroke and varying step was investigated,Two characteristic parameters including cat ear height and gap contour smoothness were introduced to assess the effect of shifting strategy on roll wear,and the relation between characteristic parameters and shifting strategy was established.Both varying stroke and varying step can reduce cat ear height and gap contour smoothness,so the shifting strategy with varying stroke and varying step is better than the one with either varying stroke or varying step,Based on the effect of shifting control parameters on characteristic parameters of roll wear,the selection principle of these shifting control parameters was gained.A case study was conducted to validate the proposed roll shifting strategy,reducing uncontrollable quartic loading gap contour,improving strip profile and extending rolling length of a rolling campaign.
文摘In order to promote the development of foreign trade, prevent unqualified commodities from flowing out of China and poor quality commodities from import, China’s departments of commodity inspection have strengthened their inspection, checking supervision and management of the quality of import and export commodities. According to statistics from the State
基金the National Natural Science Foundation of China(Nos.52071231 and 51722103)the Natural Science Foundation of Tianjin city(No.19JCJQJC61900).
文摘Electrochemical reduction reaction of nitrogen(NRR)offers a promising pathway to produce ammonia(NH_(3))from renewable energy.However,the development of such process has been hindered by the chemical inertness of N_(2).It is recently proposed that hydrogen species formed on the surface of electrocatalysts can greatly enhance NRR.However,there is still a lack of atomiclevel connection between the hydrogenation behavior of electrocatalysts and their NRR performance.Here,we report an atomistic understanding of the hydrogenation behavior of a highly twinned ZnSe(T-ZnSe)nanorod with a large density of surface atomic steps and the activation of N_(2)molecules adsorbed on its surface.Our theoretical calculations and in situ infrared spectroscopic characterizations suggest that the atomic steps are essential for the hydrogenation of T-ZnSe,which greatly reduces its work function and efficiently activates adsorbed N_(2)molecules.Moreover,the liquid-like and free water over T-ZnSe promotes its hydrogenation.As a result,T-ZnSe nanorods exhibit significantly enhanced Faradaic efficiency and NH3 production rate compared with the pristine ZnSe nanorod.This work paves a promising way for engineering electrocatalysts for green and sustainable NH3 production.
