Understanding the roles of Brønsted/Lewis acid sites on manganese oxide-zeolite hybrid catalysts for low-temperature NH_(3)-SCR

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.

Exploration of the Evolution of Teacher Roles and Professional Development Needs Among University English Instructors

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.

Women’s Social Roles and Peace Building in Al-Abassiya Locality:2012-2024

This research focused on the social roles of women in Al-Abassiya locality,South Kordofan State,examining the obstacles they face and the impact on their participation in peace building.Using qualitative methods,data were collected through various means,revealing that conflicts have significantly affected women’s lives,particularly in rural areas.Women play key roles in family,education,health services,and humanitarian aid,but their involvement in conflict resolution and peace building activities is limited.Obstacles include cognitive,economic,social,and institutional barriers.Recommendations include providing education and training programs,strengthening economic status,ensuring women’s representation in decision-making bodies,advocating for legal reforms promoting gender equality,improving access to information technologies,educating communities on women’s involvement in peace building,and providing support services for women affected by conflicts.

On the representation of roles

The related work to reveal the primary characteristics of roles underlying the existing approaches is analyzed. Then, it is demonstrated that the representation of roles is rather complex and error-prone in these approaches. Especially, the constraints among roles in the same context cannot be expressed by the current web ontology language （OWL）. To solve these problems, a novel model of role is presented and a corresponding ontology language is provided for representing this model. The key idea underlying the solution is that a role should be regarded as an element of a certain context and a context as a structured thing which is comprised of some internal elements. The structure of context possesses inherent modularity and local semantics, whereby the representation of roles and context is significantly simplified.

A Survey into Teachers＇ Roles in Web-based College English Autonomous Learning

The paper, with the backdrop of web-based autonomous learning put forward by the recent college English teaching reform, aims to explore teachers＇ roles in this learning process in students＇ perception through the means of questionnaires and interviews. It further analyzes the possible reasons why students perceive their teachers＇ roles in such a way, in the hope of providing some implications for web-based college English autonomous learning.

Change of Teachers' Roles in the Intensive Reading Class

This paper gives an account of characteristics of the intensive reading in English teaching, and change of teachers’ roles in the learner-centered teaching approach. Suggestions are put forward as to how to be a qualified teacher in the intensive reading class accordingly.

To be or not to be——College English teacher′s possible roles

Traditionally, in a teacher-centered class, students are deprived of right, for teachers take up the platform and play a “leading” role. What are the college English teacher′s possible roles? The paper tends to shed light on it by kicking the teacher′s traditional roles.

The Exploration of the Helpful Roles Teacher Can Play to Help non-English Major Students Improve Their English Writing

It is commonly known that writing is an advanced skill which is essential in language learning but at the same time the most difficult task for learners. This paper is with the aim to explore helpful roles that teacher can play to help non-English major students improve their English writing, so as to help improve their writing ability in the author's context.

鱼类褪黑素合成酶系编码基因的系统进化与生理功能

褪黑素是一种小分子神经递质,主要在脊椎动物的松果腺中合成与分泌,到达机体各部位来参与调控生物节律、生殖、生长与发育等生理过程。在鱼类中,松果腺是一个复合体,主要由类光感细胞构成,具有感光与内分泌双重功能。褪黑素的生物合成从色氨酸开始,涉及色氨酸羟化酶(TPH)、芳香族L-氨基酸脱羧酶(AAAD)、芳香烷胺-N-乙酰转移酶(AANAT)和乙酰色胺甲基转移酶(ASMT)。前期,我们通过对众多脊椎动物开展比较基因组学研究,发现这4个褪黑素合成酶系编码基因的系统进化与脊椎动物的物种进化基本一致,表明这些基因(同褪黑素一样)都很保守。有意思的是,在鱼类中各催化酶基因拷贝数出现显著增加,但四倍体与二倍体鱼中的拷贝数并不一定是2∶1,这是因为鱼类基因组复制后存在部分基因丢失的现象。此外,在大多数鱼类基因组中还鉴定到一些新基因,譬如aaad-like和asmt-like,可能拥有新的功能;有的催化酶基因缺失、出现移码突变或假基因化,可提升物种对特殊生境(诸如洞穴或深海)的生存适应性。本综述主要以我们团队近十年来的相关工作为主线,综合简介鱼类褪黑素合成酶系编码基因的系统进化与生理功能,以期深入理解褪黑素对鱼类生殖内分泌活动的影响,为进一步促进鱼类性腺发育、人工繁殖和分子育种等提供指导和支撑。

College English Teachers' Roles in CAI

With continuing advances in technology, computer-assisted instruction provides opportunities for individualized, interactive instruction. The philosophy of constructivism has encouraged instructional designers to create less behavioral, more democratic programs that promote learner control. In the area of ESL (English as a second language), computers are seen to be a highly motivating, instructional tool.

Endoscopic ultrasound: Current roles and future directions

Endoscopic ultrasound(EUS), developed in the 1980 s, was initially predominantly used for guidance of fine needle aspiration; the last 25 years, however, have witnessed a major expansion of EUS to various applications, both diagnostic and therapeutic. EUS has become much more than a tool to differentiate different tissue densities;tissue can now be characterized in great detail using modalities such as elastography; the extent of tissue vascularity can now be learned with increasing precision. Using these various techniques, targets for biopsy can be precisely pinpointed. Upon reaching the target, tissue can then be examined microscopically in real-time, ensuring optimal targeting and diagnosis. This article provides a comprehensive review of the various current roles of EUS, including drainage of lesions, visualization and characterization of lesions, injection, surgery, and vascular intervention. With EUS technology continuing to develop exponentially, the article emphasizes the future directions of each modality.

Multifarious roles of carbon quantum dots in heterogeneous photocatalysis

As a new member of carbon material family, carbon quantum dots (CQDs) have attracted tremendous attentions for their potentials in the heterogeneous photocatalysis applications. Due to the unique microstructure and optical properties, the roles of CQDs played in the CQDs-based photocatalytic systems have been found to be diverse with the continuous researches in this regard. Herein, we provide a concise minireview to elaborate the multifarious roles of CQDs in photocatalysis, including photoelectron mediator and acceptor, photosensitizer, photocatalyst, reducing agent for metal salt, enhancing adsorption capacity and spectral converter. In addition, the perspectives on future research trends and challenges are proposed, which are anticipated to stimulate further research into this promising field on designing a variety of efficient CQDs-based photocatalysts for solar energy conversion. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B. V. and Science Press. All rights reserved.

The Roles of Teachers in English Teaching

The issue of improving the efficiency of college English teaching and learning has long puzzled our educators and English teachers.There are many ways to help the solving of the problem,but in China,where English is mainly taught in classroom,the teacher is a very important factor to influence the result of English teaching.In order to solve the problem,the teacher must know exactly what roles he should play in the process of teaching and make some changes in his old teaching methods.

The Roles of Countrywomen in Controlling Non-point Source Pollution

The main causes of non-point source pollution in Taihu Lake are the improper ways of crop production, animal husbandry, and daily runoff. The paper discusses the relationship between countrywomen and non-point source pollution control by 731 questionnaires in Weidu village and 466 questionnaires in Dapu Town. The roles of countrywomen have changed in families and they have close relationship with non-point source pollution. Furthermore, we discuss the possibility and methods of organizing countrywomen in non-point source pollution control.

Study on the Roles of a Teacher in College English Teaching Mode Based on the Internet

With the rapid development of modern technology and all-round reform in national college English teaching,Internet-Based teaching mode has become a new trend of college English teaching.Therefore,in the new teaching mode,the teacher should turn an inculcator into an instructor,facilitator and participant in teaching;a passive user of textbook into a dominant and modeler of courses;a planner of teaching specific tasks into an organizer of teaching process,a helper and shepherd of learning knowledge.

Group Multi-Role Assignment With Conflicting Roles and Agents

Group role assignment(GRA)is originally a complex problem in role-based collaboration(RBC).The solution to GRA provides modelling techniques for more complex problems.GRA with constraints(GRA+)is categorized as a class of complex assignment problems.At present,there are few generally efficient solutions to this category of problems.Each special problem case requires a specific solution.Group multi-role assignment(GMRA)and GRA with conflicting agents on roles(GRACAR)are two problem cases in GRA+.The contributions of this paper include:1)The formalization of a new problem of GRA+,called group multi-role assignment with conflicting roles and agents(GMAC),which is an extension to the combination of GMRA and GRACAR;2)A practical solution based on an optimization platform;3)A sufficient condition,used in planning,for solving GMAC problems;and 4)A clear presentation of the benefits in avoiding conflicts when dealing with GMAC.The proposed methods are verified by experiments,simulations,proofs and analysis.

Roles and Functions of Tourism Destinations in Tourism Region of South Anhui:A Tourist Flow Network Perspective

Theoretic and practical significance has been highlighted in the research of the roles and functions of destinations,as destinations are restricted by the spatial structure based on tourist flow network from the perspective of relationship.This article conducted an empirical analysis for Tourism Region of South Anhui(TRSA) and revealed the necessity and feasibility of studying the roles and functions of destinations from tourist flow network's perspective.The automorphic equivalence analysis and centrality analysis were used to classify 16 destinations in TRSA into six role types:tourist flow distribution center,hub of tourist flows,passageway destination,common touring destination,attached touring destination,and nearly isolated destination.Some suggestions were given on suitable infrastructure construction and destinations service designs according to their functions in network.This destination role positioning was based on tourist flow network structure in integral and macroscopic way.It provided an important reference for the balanced and harmonious development of all the destinations of TRSA.In addition,this article verified the applicability of social network analysis on tourist flow research in local scale,and expanded this method to destination role and function positioning.

Modeling the Roles of Precipitation Increasing in Glacier Systems Responding to Climate Warming—Taking Xinjiang Glaciated Region as Example

The studies on prediction of climate in Xinjiang almost show that the precipitation would increase in the coming 50 years, although there were surely some uncertainties in precipitation predictions. On the basis of the structure of glacier system and nature of equilibrium line altitude at steady state （ELAo）, a functional model of the glacier system responding to climate changes was established, and it simultaneously involved the rising of summer mean temperature and increasing of mean precipitation. The results from the functional model under the climatic scenarios with temperature increasing rates of 0.01, 0.03 and 0.05 K/year indicated that the precipitation increasing would play an evident role in glacier system responding to climate change： if temperature become 1 ℃ higher, the precipitation would be increased by 10%, which can slow down the glaciers retreating rate in the area by 4 %, accelerate runoff increasing rate by 8 % and depress the ELAo rising gradient by 24 m in northern Xinjiang glacier system where semi-continental glaciers dominate, while it has corresponding values of only 1%, 5 % and 18m respectively in southern Xinjiang glacier system, where extremely continental glaciers dominate.

Roles of State Strategy of Adaptation to Climate Change in China

For the adverse impacts of climate change, China gov- ernment should place the problem of adaptation to climate change on the agenda. It is time to institute and implement a state adap- tive strategy to reduce the adverse impacts on economy, commu- nity and people's health and life by international cooperation and our own endeavor. A state strategy of adaptation to climate change should be closely linked with other current interrelated national strategies, and they should be supplemented and improved by each other. This paper discusses the roles of the state strategy of adaptation to climate change in the state climate change integra- tive strategy, the environmental protection strategy, and the sus- tainable development strategy in China. Furthermore, it proposes the main aims of the state adaptive strategy of China.

Exosomes-mediated tumor treatment: One body plays multiple roles

Exosomes are vesicles secreted by a variety of living cells,containing proteins,RNA and other components,which are nanoscale capsules commonly existed in the body.Exosomes play important roles in a variety of physiological and pathological processes by participating in material and information exchange between cells,which can playmultiple roles in tumor treatment.On the one hand,exosomes can be used as carriers and biomarkers,participate in the apoptosis signaling pathway and improve chemotherapy resistance,thus playing beneficial roles in tumor treatment.On the other hand,exosomes play unfavorable roles in tumor treatment.Tumor cell exosomes contain PD-L1,which is a nuclear weapon for tumor growth,metastasis,and immunosuppression.In addition,exosomes can not only promote the epithelial-mesenchymal transition process,tumor angiogenesis and chemoresistance,but also participate in the autocrine pathway.In this review,the multiple roles of exosomes and their prospects in the treatment of tumor were reviewed in detail.