Although metal oxide-zeolite hybrid materials have long been known to achieve enhanced catalytic activity and selectivity in NO_(x)removal reactions through the inter-particle diffusion of intermediate species,their s...Although metal oxide-zeolite hybrid materials have long been known to achieve enhanced catalytic activity and selectivity in NO_(x)removal reactions through the inter-particle diffusion of intermediate species,their subsequent reaction mechanism on acid sites is still unclear and requires investigation.In this study,the distribution of Brønsted/Lewis acid sites in the hybrid materials was precisely adjusted by introducing potassium ions,which not only selectively bind to Brønsted acid sites but also potentially affect the formation and diffusion of activated NO species.Systematic in situ diffuse reflectance infrared Fourier transform spectroscopy analyses coupled with selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR)reaction demonstrate that the Lewis acid sites over MnO_(x)are more active for NO reduction but have lower selectivity to N_(2)than Brønsted acids sites.Brønsted acid sites primarily produce N_(2),whereas Lewis acid sites primarily produce N_(2)O,contributing to unfavorable N_(2)selectivity.The Brønsted acid sites present in Y zeolite,which are stronger than those on MnO_(x),accelerate the NH_(3)-SCR reaction in which the nitrite/nitrate species diffused from the MnO_(x)particles rapidly convert into the N_(2).Therefore,it is important to design the catalyst so that the activated NO species formed in MnO_(x)diffuse to and are selectively decomposed on the Brønsted acid sites of H-Y zeolite rather than that of MnO_(x)particle.For the physically mixed H-MnO_(x)+H-Y sample,the abundant Brønsted/Lewis acid sites in H-MnO_(x)give rise to significant consumption of activated NO species before their inter-particle diffusion,thereby hindering the enhancement of the synergistic effects.Furthermore,we found that the intercalated K+in K-MnO_(x)has an unexpected favorable role in the NO reduction rate,probably owing to faster diffusion of the activated NO species on K-MnO_(x)than H-MnO_(x).This study will help to design promising metal oxide-zeolite hybrid catalysts by identifying the role of the acid sites in two different constituents.展开更多
The role of university English instructors has evolved significantly over the years,encompassing various aspects.This paper explores the evolution of the role of university English instructors and examines the current...The role of university English instructors has evolved significantly over the years,encompassing various aspects.This paper explores the evolution of the role of university English instructors and examines the current challenges and opportunities they face in today’s educational landscape.It delves into the multifaceted nature of their responsibilities and discusses the importance of continuous professional development to meet the evolving needs of students and the demands of the profession.展开更多
This article delves into the intricate landscape of gender roles within China,employing a historical lens to dissect the evolution of these roles throughout key periods of Chinese societal transformation.The study cen...This article delves into the intricate landscape of gender roles within China,employing a historical lens to dissect the evolution of these roles throughout key periods of Chinese societal transformation.The study centres on three pivotal epochs in contemporary China:the pre-liberation era(prior to 1949),the era of socialist construction(1949-1978),and the phase of economic reform(post-1978).Despite the undeniably persistent underpinning of traditional gender roles throughout history,this analysis offers insight into the essence of feminist movements-an ongoing struggle against the subjugation of women.While notable strides have been made in enhancing the status and rights of women in recent decades,it becomes evident that achieving genuine gender equality necessitates a more nuanced approach beyond the mere expansion of educational and occupational opportunities for women.True transformation mandates heightened awareness of gender inequality across all societal domains,catalysing collective participation in social initiatives by both genders.This article underscores the imperative of multifaceted engagement to drive meaningful and lasting shifts in gender dynamics.展开更多
专门用途英语(English for Specific Purpose,简称ESP)是大学英语教学改革的主要发展方向。ESP教学,师资是关键,大学英语教师的专业素质和专业发展已成为决定ESP教学成败的重要因素。文章以ESP教学理念为依托,探讨大学英语教师向ESP教...专门用途英语(English for Specific Purpose,简称ESP)是大学英语教学改革的主要发展方向。ESP教学,师资是关键,大学英语教师的专业素质和专业发展已成为决定ESP教学成败的重要因素。文章以ESP教学理念为依托,探讨大学英语教师向ESP教师转型过程中的角色定位。在ESP教学理念指导下,大学英语教师在教学中扮演着教学的动态需求分析者、具备英语知识和跨专业知识的教学者、以学生为中心的课程设计者和精通ESP教学评估的研究者等多元化角色。以角色转换为基础,文章还提出通过自我发展途径、合作发展途径和校本培训途径来调整和优化大学英语教师发展路径,以完善大学英语教师知识结构,为实现其职业的专业化发展指明方向。展开更多
文摘Although metal oxide-zeolite hybrid materials have long been known to achieve enhanced catalytic activity and selectivity in NO_(x)removal reactions through the inter-particle diffusion of intermediate species,their subsequent reaction mechanism on acid sites is still unclear and requires investigation.In this study,the distribution of Brønsted/Lewis acid sites in the hybrid materials was precisely adjusted by introducing potassium ions,which not only selectively bind to Brønsted acid sites but also potentially affect the formation and diffusion of activated NO species.Systematic in situ diffuse reflectance infrared Fourier transform spectroscopy analyses coupled with selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR)reaction demonstrate that the Lewis acid sites over MnO_(x)are more active for NO reduction but have lower selectivity to N_(2)than Brønsted acids sites.Brønsted acid sites primarily produce N_(2),whereas Lewis acid sites primarily produce N_(2)O,contributing to unfavorable N_(2)selectivity.The Brønsted acid sites present in Y zeolite,which are stronger than those on MnO_(x),accelerate the NH_(3)-SCR reaction in which the nitrite/nitrate species diffused from the MnO_(x)particles rapidly convert into the N_(2).Therefore,it is important to design the catalyst so that the activated NO species formed in MnO_(x)diffuse to and are selectively decomposed on the Brønsted acid sites of H-Y zeolite rather than that of MnO_(x)particle.For the physically mixed H-MnO_(x)+H-Y sample,the abundant Brønsted/Lewis acid sites in H-MnO_(x)give rise to significant consumption of activated NO species before their inter-particle diffusion,thereby hindering the enhancement of the synergistic effects.Furthermore,we found that the intercalated K+in K-MnO_(x)has an unexpected favorable role in the NO reduction rate,probably owing to faster diffusion of the activated NO species on K-MnO_(x)than H-MnO_(x).This study will help to design promising metal oxide-zeolite hybrid catalysts by identifying the role of the acid sites in two different constituents.
文摘The role of university English instructors has evolved significantly over the years,encompassing various aspects.This paper explores the evolution of the role of university English instructors and examines the current challenges and opportunities they face in today’s educational landscape.It delves into the multifaceted nature of their responsibilities and discusses the importance of continuous professional development to meet the evolving needs of students and the demands of the profession.
文摘This article delves into the intricate landscape of gender roles within China,employing a historical lens to dissect the evolution of these roles throughout key periods of Chinese societal transformation.The study centres on three pivotal epochs in contemporary China:the pre-liberation era(prior to 1949),the era of socialist construction(1949-1978),and the phase of economic reform(post-1978).Despite the undeniably persistent underpinning of traditional gender roles throughout history,this analysis offers insight into the essence of feminist movements-an ongoing struggle against the subjugation of women.While notable strides have been made in enhancing the status and rights of women in recent decades,it becomes evident that achieving genuine gender equality necessitates a more nuanced approach beyond the mere expansion of educational and occupational opportunities for women.True transformation mandates heightened awareness of gender inequality across all societal domains,catalysing collective participation in social initiatives by both genders.This article underscores the imperative of multifaceted engagement to drive meaningful and lasting shifts in gender dynamics.
文摘专门用途英语(English for Specific Purpose,简称ESP)是大学英语教学改革的主要发展方向。ESP教学,师资是关键,大学英语教师的专业素质和专业发展已成为决定ESP教学成败的重要因素。文章以ESP教学理念为依托,探讨大学英语教师向ESP教师转型过程中的角色定位。在ESP教学理念指导下,大学英语教师在教学中扮演着教学的动态需求分析者、具备英语知识和跨专业知识的教学者、以学生为中心的课程设计者和精通ESP教学评估的研究者等多元化角色。以角色转换为基础,文章还提出通过自我发展途径、合作发展途径和校本培训途径来调整和优化大学英语教师发展路径,以完善大学英语教师知识结构,为实现其职业的专业化发展指明方向。
