China-Africa corporate advertising is emerging as an example of the corporate advertising genre in response to the specific rhetorical context of China-Africa win-win cooperation.Drawing on Bhatia’s Critical Genre An...China-Africa corporate advertising is emerging as an example of the corporate advertising genre in response to the specific rhetorical context of China-Africa win-win cooperation.Drawing on Bhatia’s Critical Genre Analysis(2017),this study explores the text-internal and text-external generic features of China-Africa corporate advertising by analyzing 50 collected samples.The analysis of text-internal prominence shows that China-Africa corporate advertising is unique in its frequent use of win-win-oriented and sector-dependent technical lexicons to indicate the promotional intent.It is also found that move structures vary across different sub-types of ChinaAfrica corporate advertising.Text-externally,the findings reveal a mixture of different discourses within the discursive space of China-Africa corporate advertising.In addition,the results suggest that Chinese companies invest more rhetorical efforts in enhancing the China-Africa community than African counterparts who tend to perceive China-Africa cooperation as the main avenue to attract worldwide partnerships.The findings have some practical implications for discourse construction in the Belt and Road Initiative context and shed light on the evolving nature of advertising discourse,particularly in the China-Africa win-win business context.展开更多
BACKGROUND： To evaluate and summarize the effects of cerebral perfusion and vascular reserve on the treatment of SICAS. Recently, research on β-amyloid protein has focused on the regulatory effects of estrogen or ph...BACKGROUND： To evaluate and summarize the effects of cerebral perfusion and vascular reserve on the treatment of SICAS. Recently, research on β-amyloid protein has focused on the regulatory effects of estrogen or phytoestrogen on its deposition. However, there have been only a few reports on dynamic changes of β -amyloid protein deposition in hippocampus of ovariectomized rats. OBJECTIVE： To measure β -amyloid protein deposition in the hippocampal formation of ovariectomized rats by using immunohistochemistry; to observe time-dependent dynamic changes. DESIGN： Randomized controlled animal study. SETTING： Third Xiangya Hospital of Central South University. MATERIALS： The experiment was carried out in the Central Laboratory of the Third Xiangya Hospital of Central South University from November 2005 to December 2006. Fifty healthy female Sprague Dawley （SD） rats, weighing （293 ± 10） g, were provided by the Animal Laboratory of Xiangya Medical College, Central South University. All rats had neither a childbearing history nor hepatic or renal disease, or skeletal deformity. β-amyloid protein immunohistochemical kit was provided by Wuhan Boster Company. The experiment was in accordance with animal ethics standards. METHODS： All rats were randomly divided into five groups, including normal control group （n = 10）, sham operation group （n = 10）, and ovariectomized group （n = 30）. After anesthesia in the ovariectomized group, the bilateral ovaries were separated and resected. The same volume of fat was resected in the sham operation group. Rats from the normal control group, however, did not receive any surgical treatments. Rats in the normal control group and sham operation group were sacrificed by anesthesia 7 weeks after surgery. Every ten rats from the ovariectomized group was respectively sacrificed at 7, 15, and 30 weeks after surgery. lmmunohistochemistry was used to detect β-amyloid protein deposition in hippocampal sections. Cell counting and gray value measurements served to record the dynamic changes in β-amyloid protein deposition. MAIN OUTCOME MEASURES： （1） Morphological changes. （2） Positive cell counts from β -amyloid protein stainings and gray value measurements. RESULTS： All 50 rats were involved in the final analysis. （1） Morphological changes. β -amyloid-positive cells were detected in the hippocampus of all rats. Biebrich scarlet stained neurites with a swollen cytoplasm. A few β -amyloid-positive cells were observed in all groups 7 weeks after surgery, and plasma and neurites were slightly stained. By 15 weeks after surgery, a number of β -amyloid-positive cells were observed in the ovariectomized group, and plasma and neurites were also slightly stained. By 30 weeks after surgery, however, many β-amyloid-positive cells were observed in the ovariectomized group. These cells were partially aggregated and darkly stained. （2） Positive cell counts and gray value of β-amyloid protein in hippocampus. At 7 weeks after surgery, cell counts and gray value measurements were not significantly different in the ovariectomized group compared to the sham operation group and normal control group （P 〉 0.05）. Cell counts and gray value measurements were higher in the ovariectomized group by 15 weeks compared to those by 7 weeks in the normal control group, sham operation group and ovariectomized group （P 〈 0.05）. At 30 weeks after surgery, cell counts and gray value measurements were higher in the ovariectomized group compared to the normal control group. In addition, there were significant differences between sham operation group and ovariectomized group, at 7 and 15 weeks after operation （P 〈 0.05-0.01 ）. Cell counts and gray value measurements increased in all groups over time. CONCLUSION： Extended estrogen deficiency in rats can increase β-amyloid protein deposition in the hippocampus and the deposition increases over time.展开更多
A 22-year-old man with a 2-year history of heroin vapor inhalation developed spongiform leukoencephalopathy and underwent clinical and home-based rehabilitative treatments. Activities of daily living were measured usi...A 22-year-old man with a 2-year history of heroin vapor inhalation developed spongiform leukoencephalopathy and underwent clinical and home-based rehabilitative treatments. Activities of daily living were measured using the Functional Independence Measure at discharge and at 6, 12, and 24 months after discharge. His neurological symptoms gradually disappeared with rehabilitative treatment, and the functional scale scores increased from 55 on admission to 105 at 24 months after discharge. These results suggest that home-based rehabilitation was effective in ameliorating the pathology and improving activities of daily living in this patient with heroin-induced spongiform leukoencephalopathy.展开更多
The capacity to generate high-precision droplets within Lab-on-a-Chip(LOC)devices is essential for numerous biochemical applications,such as DNA sequencing and drug delivery.In this study,we introduce an optoelectrowe...The capacity to generate high-precision droplets within Lab-on-a-Chip(LOC)devices is essential for numerous biochemical applications,such as DNA sequencing and drug delivery.In this study,we introduce an optoelectrowetting(OEW)-based droplet manipulation system that utilizes a novel droplet dispensing strategy,enabling precise nanoliter droplet dispensing with tunable droplet volume.The system comprises an OEW microchip,a liquid crystal display(LCD)projector connected to a laptop for generating customized light patterns,and a microscope equipped with a charge-coupled device(CCD)camera mounted above the OEW microchip for real-time observation.Simulations and experiments were conducted to investigate the optimal conditions for high-precision droplet dispensing.The system demonstrated exceptional stability in generating uniform droplets,with a minimum relative error(RE)of 0.45%and coefficient of variation(CV)of 2.49%for dispensing droplets of a volume of 36.52 nL.An experiment was conducted to dispense droplets of varying sizes,demonstrating the system’s exceptional capability to generate droplets across a broad size range.The system was further validated through its application in polymerase chain reaction(PCR)amplification,confirming its performance in small-scale biochemical reactions.The results indicate that the proposed OEW droplet dispensing system is highly proficient in generating high-precision small-scale droplets with tunable volume.It also demonstrates its capability for biochemical processing and superior performance in sub-200 nL droplet dispensing compared to conventional pipetting techniques.This advancement holds significant potential for enhancing the performance and efficiency of LOC devices in biochemical research and clinical applications.展开更多
Developing efficient and durable hydrogen evolution reaction(HER)electrocatalysts is critical for industrial and sustainable hydrogen production.Herein,a simple co-precipitation strategy is proposed to success-fully c...Developing efficient and durable hydrogen evolution reaction(HER)electrocatalysts is critical for industrial and sustainable hydrogen production.Herein,a simple co-precipitation strategy is proposed to success-fully construct catalysts with a Mott-Schottky heterojunction by coupling a transition-metal phosphate to the surface of stripped MXene thin-layer nanosheets(M_(3)(PO_(4))_(2)@MXene,M=Co,Ni,and Fe).The Co_(3)(PO_(4))_(2)@MXene with a unique tightly connected 2D/2D heterostructure and built-in electric field induces directional electron transfer at the interface,regulates the polarized structure of the active sites,and accelerates both mass and electron transport.Consequently,the optimized Co_(3)(PO_(4))_(2)@MXene demonstrates outstanding HER performance,achieving low overpotentials of 46 and 58.6 mV at 10 mA cm^(−2)in alkaline freshwater and seawater electrolytes,respectively.Moreover,the Co_(3)(PO_(4))_(2)@MXene het-erojunction catalyst maintains stable operation at a high current density of 500 mA cm^(−2)for over 100 h in alkaline seawater electrolytes.More importantly,Co3(PO_(4))_(2)@MXene can offer a low potential of 1.71 V at 500 mA cm^(−2)with stable operation for 50 h in a flow-type alkaline seawater electrolyser.This study pro-vides a unique heterostructure in an electrocatalyst for an efficient HER and presents its potential appli-cation in seawater electrolysis.展开更多
Exploring highly efficient,economical and environment friendly electrocatalysts for the hydrogen and oxygen evolution reactions(HER and OER)is necessary but challenging for economical water splitting.Herein,FeS_(2) na...Exploring highly efficient,economical and environment friendly electrocatalysts for the hydrogen and oxygen evolution reactions(HER and OER)is necessary but challenging for economical water splitting.Herein,FeS_(2) nanoparticles were anchored on the surface of MXene through a simple adsorption-growth route(FeS_(2)@MXene).By virtue of the large active surface area of FeS_(2) and its robust interfacial interaction with conductive and hydrophilic MXene nanosheets,the obtained FeS_(2)@MXene composite can accelerate the transfer of mass/charge and facilitate contact between water molecules and reactive sites of FeS_(2).Specifically,MXene as a support material can not only alter the electrophilicity of the active centers of FeS_(2) through modulating the electron density but also prevent the aggregation of FeS_(2),thereby promoting activity and stability.The optimized FeS_(2)@MXene delivers a 10 mA cm-2 current density at overpotentials of 87 and 240 mV in alkaline solution for the HER and OER,respectively,which is comparable with reported transition metal sulfide(TMS)based catalysts.More importantly,in situ Raman spectroscopy reveals that the FeOOH generated during the OER process as a actual active species enhances the intrinsic activity of the catalyst.This work paves a new way for the interface engineering of TMS-based electrocatalysts towards water splitting.展开更多
Developing hierarchical heterostructures as bifunctional electrocatalysts which promote renewable hydrogen production is a desirable but challenging technology in electrochemical water splitting.Herein,the interface e...Developing hierarchical heterostructures as bifunctional electrocatalysts which promote renewable hydrogen production is a desirable but challenging technology in electrochemical water splitting.Herein,the interface engineering of the FeNi_(2)Se_(4)-FeNi LDH composite is achieved by the in situ growth of FeNi LDH nanosheets and the subsequent partial selenization treatment.Enhanced mass transfer and accelerated gas release are achieved in such a unique self-supported hierarchical heterostructure during overall water splitting.Moreover,the strong electronic interaction between FeNi_(2)Se_(4) and FeNi LDH optimizes the electron redistribution of Fe and Ni sites,which significantly improves the interfacial reactivity of reactants and/or intermediates with the hybrid catalyst.Benefiting from increased active sites and enhanced intrinsic activity,the hybrid electrocatalyst requires only a potential of 205 mV for the oxygen evolution reaction(OER)and a potential of 106 mV for the hydrogen evolution reaction(HER)to realize 10 mA cm^(−2).Specifically,the optimized FeNi_(2)Se_(4)-FeNi LDH as a bifunctional electrode in overall water splitting delivers 10 mA cm^(−2) at a low cell voltage of 1.56 V driven by a solar cell.This strategy by rational design of heterostructures thus paves an efficient pathway to fabricate active and non-precious bifunctional electrocatalysts for overall water splitting.展开更多
Developing stable and efficient single-atom electrocatalysts for the acidic oxygen evolution reaction(OER)is crucial for advancing proton exchange membrane water electrolysis(PEMWE).However,the lack of precisely tailo...Developing stable and efficient single-atom electrocatalysts for the acidic oxygen evolution reaction(OER)is crucial for advancing proton exchange membrane water electrolysis(PEMWE).However,the lack of precisely tailored coordination environments capable of preventing Ir single-atom dissolution remains a critical barrier.Herein,we construct Ir single-atom catalysts supported on Co_(3)O_(4)(IrSA-Co_(3)O_(4))via the synchronized formation of Co defects and the immobilization of Ir single atoms during precursor pyrolysis.Atomically dispersed Ir atoms are anchored at octahedral Co defect sites,forming a configuration of single atoms confined within the spinel lattice.Benefiting from the oxygen-bridged electronic coupling within the Ir–O–Co configuration,the electronic structure of Ir sites is optimized to enable moderate intermediate adsorption while mitigating dissolution.As a result,IrSA-Co_(3)O_(4)achieves a low overpotential of 199 mV at 10 mA cm^(−2)in 0.5 M H_(2)SO_(4)and operates stably for 150 h at 200 mA cm^(−2)during PEMWE.This work provides new insights into the rational design of stable single-atom catalysts for acidic OER by effectively suppressing active-site dissolution.展开更多
For years, personal and social voices have been the issue of discussion on voice construction in written discourse(e.g., Elbow, 1999;Flowerdew, 2011;Hyland, 2002, 2010 a, 2012 b;Mauranen, 2013;Ramanathan & Atkinso...For years, personal and social voices have been the issue of discussion on voice construction in written discourse(e.g., Elbow, 1999;Flowerdew, 2011;Hyland, 2002, 2010 a, 2012 b;Mauranen, 2013;Ramanathan & Atkinson, 1999;Tardy, 2005). However, there is a lack of an integrated examination of the dimensions which determine voice construction in writing from personal and social perspectives. This article re-examines the issue of voice construction through a critical review of previous literature on identity in written discourse. It is argued that there are five major dimensions for the construction of voice in written discourse. How writers appropriate their voice according to such five dimensions as genre, transition, culture, discipline and audience will be discussed. This paper lends further support to the view that voice in written discourse is both personal and social. As it is known, good writing expresses both personal and social voices. However, based on the dominant dimension(s), voice construction should be adjusted. Sometimes personal voice is boldly expressed;sometimes social voice is;and some other times the boundary between the two is unnoticeable. The study provides an integrated framework as well as pedagogical implications for the teaching of academic writing within L1 and L2 contexts.展开更多
设计基于界面工程的氧/氢析出反应(OER/HER)双功能电催化剂对在高电流密度下同时实现低过电位和稳定的水分解操作至关重要.本文中,我们报告了一种硼化策略以巧妙地定制固定在泡沫铁(IF)上的金属有机框架(MOF).硼原子诱导了Fe-MOF纳米片...设计基于界面工程的氧/氢析出反应(OER/HER)双功能电催化剂对在高电流密度下同时实现低过电位和稳定的水分解操作至关重要.本文中,我们报告了一种硼化策略以巧妙地定制固定在泡沫铁(IF)上的金属有机框架(MOF).硼原子诱导了Fe-MOF纳米片的结构重构,包括粗糙表面、氧空位以及结晶Fe-MOF和非晶Fe–B之间的面内异质结.面内异质结调节铁位点的d带中心以降低OER/HER能垒.优化的Fe–B/FeMOF/IF在10 m A cm^(-2)下驱动OER和全解水,分别仅需1.44和1.53 V.水分解系统在500 m A cm^(-2)下工作100小时以后的结构变化和性能衰减可忽略不计.该工作为异质结构界面的工程提供了启示,并促进了先进电催化剂的合理设计.展开更多
Recent research on academic discourse has revealed the intersection of writing and writer identity construction. However, some terms that are being used in writer identity study are sometimes not only interchangeably ...Recent research on academic discourse has revealed the intersection of writing and writer identity construction. However, some terms that are being used in writer identity study are sometimes not only interchangeably used without making an explicit connection between them but also used in a way that may cause misunderstanding. The paper is intended to tease out four key terms, namely, stance, voice, self, and identity so that the respective role that each plays in academic written discourse can be differentiated on the one hand, and their interrelationship can be clarified on the other. It is hoped that such a panoramic picture can offer some pedagogical implications for academic writing teaching and research and provide some insights into the research on writer identity construction in academic written discourse as well.展开更多
Based on Bhatia＇s multi-dimensional analytical framework for discourse analysis, we explore key issues involved in genres construction such as private intention, manipulation of generic value and interdiscursive stra...Based on Bhatia＇s multi-dimensional analytical framework for discourse analysis, we explore key issues involved in genres construction such as private intention, manipulation of generic value and interdiscursive strategies. Two prefaces and two book reviews by expert linguists were collected and analyzed at great length from both text-internal and text-external perspectives. Meanwhile, four professionals from relevant disciplines were interviewed for their insights into the issues investigated. Through examining textual features, covert interdiscursivity and narrative accounts of the professional writers, the following findings are generated. 1） Generic variation occurs within and between the two genres due to expert writers＇ intentional manipulation of generic value. 2） Interdiscursive strategies like ＂genre embedding＂, ＂genre bending＂ and ＂genre mixing＂ are exploited by expert writers to achieve their particular private intention. Specifically, preface genre can be presented, to some extent, as a research article mixed with some promotional flavor, and features of research article genre, promotional genre and introductory genre are found mixed in the review genre. 3） Representations of the preface and book review genres such as linguistic feature, move structure and interdiscursivity are ultimately affected by generic value, authors＇ private intention, professional practice and disciplinary culture. The findings have important implications for ESP/EAP writing practitioners and learners.展开更多
Based on Burgess and Ivani?’s(2010) framework of the discoursal construction of writer identity, this paper explores the interaction between citation practices and identity construction in Chinese EFL learners’ MA t...Based on Burgess and Ivani?’s(2010) framework of the discoursal construction of writer identity, this paper explores the interaction between citation practices and identity construction in Chinese EFL learners’ MA thesis writing. A mixed approach of textual analysis and interviews was adopted to examine the citation features of MA theses and the identities Chinese EFL learners constructed through citation selection. It was found that students’ selection of citations reflects their linguistic identity, academic and disciplinary identity, as well as novice identity. Their citation practices project different discursive selves to readers. By adjusting the number and relevance of references, they intend to construct a knowledgeable and credible self. The use of ineffective citations and references not only projects an unfavorable impression on readers but reflects a lack of authorial identity. This study has significant implications for the teaching of academic English and the supervision of thesis writing.展开更多
基金the research output of the National Social Sciences research project entitled“A Genre-based Study of the Dynamic Intertextual and Interdiscursive System in Chinese and Foreign Professional Discourse”(NO.17BYY033)。
文摘China-Africa corporate advertising is emerging as an example of the corporate advertising genre in response to the specific rhetorical context of China-Africa win-win cooperation.Drawing on Bhatia’s Critical Genre Analysis(2017),this study explores the text-internal and text-external generic features of China-Africa corporate advertising by analyzing 50 collected samples.The analysis of text-internal prominence shows that China-Africa corporate advertising is unique in its frequent use of win-win-oriented and sector-dependent technical lexicons to indicate the promotional intent.It is also found that move structures vary across different sub-types of ChinaAfrica corporate advertising.Text-externally,the findings reveal a mixture of different discourses within the discursive space of China-Africa corporate advertising.In addition,the results suggest that Chinese companies invest more rhetorical efforts in enhancing the China-Africa community than African counterparts who tend to perceive China-Africa cooperation as the main avenue to attract worldwide partnerships.The findings have some practical implications for discourse construction in the Belt and Road Initiative context and shed light on the evolving nature of advertising discourse,particularly in the China-Africa win-win business context.
文摘BACKGROUND： To evaluate and summarize the effects of cerebral perfusion and vascular reserve on the treatment of SICAS. Recently, research on β-amyloid protein has focused on the regulatory effects of estrogen or phytoestrogen on its deposition. However, there have been only a few reports on dynamic changes of β -amyloid protein deposition in hippocampus of ovariectomized rats. OBJECTIVE： To measure β -amyloid protein deposition in the hippocampal formation of ovariectomized rats by using immunohistochemistry; to observe time-dependent dynamic changes. DESIGN： Randomized controlled animal study. SETTING： Third Xiangya Hospital of Central South University. MATERIALS： The experiment was carried out in the Central Laboratory of the Third Xiangya Hospital of Central South University from November 2005 to December 2006. Fifty healthy female Sprague Dawley （SD） rats, weighing （293 ± 10） g, were provided by the Animal Laboratory of Xiangya Medical College, Central South University. All rats had neither a childbearing history nor hepatic or renal disease, or skeletal deformity. β-amyloid protein immunohistochemical kit was provided by Wuhan Boster Company. The experiment was in accordance with animal ethics standards. METHODS： All rats were randomly divided into five groups, including normal control group （n = 10）, sham operation group （n = 10）, and ovariectomized group （n = 30）. After anesthesia in the ovariectomized group, the bilateral ovaries were separated and resected. The same volume of fat was resected in the sham operation group. Rats from the normal control group, however, did not receive any surgical treatments. Rats in the normal control group and sham operation group were sacrificed by anesthesia 7 weeks after surgery. Every ten rats from the ovariectomized group was respectively sacrificed at 7, 15, and 30 weeks after surgery. lmmunohistochemistry was used to detect β-amyloid protein deposition in hippocampal sections. Cell counting and gray value measurements served to record the dynamic changes in β-amyloid protein deposition. MAIN OUTCOME MEASURES： （1） Morphological changes. （2） Positive cell counts from β -amyloid protein stainings and gray value measurements. RESULTS： All 50 rats were involved in the final analysis. （1） Morphological changes. β -amyloid-positive cells were detected in the hippocampus of all rats. Biebrich scarlet stained neurites with a swollen cytoplasm. A few β -amyloid-positive cells were observed in all groups 7 weeks after surgery, and plasma and neurites were slightly stained. By 15 weeks after surgery, a number of β -amyloid-positive cells were observed in the ovariectomized group, and plasma and neurites were also slightly stained. By 30 weeks after surgery, however, many β-amyloid-positive cells were observed in the ovariectomized group. These cells were partially aggregated and darkly stained. （2） Positive cell counts and gray value of β-amyloid protein in hippocampus. At 7 weeks after surgery, cell counts and gray value measurements were not significantly different in the ovariectomized group compared to the sham operation group and normal control group （P 〉 0.05）. Cell counts and gray value measurements were higher in the ovariectomized group by 15 weeks compared to those by 7 weeks in the normal control group, sham operation group and ovariectomized group （P 〈 0.05）. At 30 weeks after surgery, cell counts and gray value measurements were higher in the ovariectomized group compared to the normal control group. In addition, there were significant differences between sham operation group and ovariectomized group, at 7 and 15 weeks after operation （P 〈 0.05-0.01 ）. Cell counts and gray value measurements increased in all groups over time. CONCLUSION： Extended estrogen deficiency in rats can increase β-amyloid protein deposition in the hippocampus and the deposition increases over time.
基金supported by Project of Science and Technology Department of Hunan Province, No. 2009SK3171
文摘A 22-year-old man with a 2-year history of heroin vapor inhalation developed spongiform leukoencephalopathy and underwent clinical and home-based rehabilitative treatments. Activities of daily living were measured using the Functional Independence Measure at discharge and at 6, 12, and 24 months after discharge. His neurological symptoms gradually disappeared with rehabilitative treatment, and the functional scale scores increased from 55 on admission to 105 at 24 months after discharge. These results suggest that home-based rehabilitation was effective in ameliorating the pathology and improving activities of daily living in this patient with heroin-induced spongiform leukoencephalopathy.
基金supported in part by Guangdong-Hong Kong-Macao Joint Laboratory on Micro-Nano Manufacturing Technology(Grant No.2021LSYS004)National Natural Science Foundation of China(Grant No.62403231)+1 种基金National Natural Science Foundation of China(Grant No.31927802)Shenzhen Science and Technology Innovation Commission(Grant No.RCJC20200714114436046).
文摘The capacity to generate high-precision droplets within Lab-on-a-Chip(LOC)devices is essential for numerous biochemical applications,such as DNA sequencing and drug delivery.In this study,we introduce an optoelectrowetting(OEW)-based droplet manipulation system that utilizes a novel droplet dispensing strategy,enabling precise nanoliter droplet dispensing with tunable droplet volume.The system comprises an OEW microchip,a liquid crystal display(LCD)projector connected to a laptop for generating customized light patterns,and a microscope equipped with a charge-coupled device(CCD)camera mounted above the OEW microchip for real-time observation.Simulations and experiments were conducted to investigate the optimal conditions for high-precision droplet dispensing.The system demonstrated exceptional stability in generating uniform droplets,with a minimum relative error(RE)of 0.45%and coefficient of variation(CV)of 2.49%for dispensing droplets of a volume of 36.52 nL.An experiment was conducted to dispense droplets of varying sizes,demonstrating the system’s exceptional capability to generate droplets across a broad size range.The system was further validated through its application in polymerase chain reaction(PCR)amplification,confirming its performance in small-scale biochemical reactions.The results indicate that the proposed OEW droplet dispensing system is highly proficient in generating high-precision small-scale droplets with tunable volume.It also demonstrates its capability for biochemical processing and superior performance in sub-200 nL droplet dispensing compared to conventional pipetting techniques.This advancement holds significant potential for enhancing the performance and efficiency of LOC devices in biochemical research and clinical applications.
基金supported by the National Natural Science Foundation of China(22075141 and 52371226)the Scientific and Technological Innovation Special Fund for Carbon Peak and Carbon Neutrality of Jiangsu Province(BK20220039)+6 种基金the Opening Project of the State Key Laboratory of High Performance Ceramics and Superfine Microstructure(SKL202208SIC)the Natural Science Foundation of Jiangsu Province(BK20210311 and BK20221482)the Fundamental Research Funds for the Central Universities(NS2023032)State Key Laboratory for Modification of Chemical Fibers and Polymer Materials(KF2312)the Postgraduate Research&Practice Innovation Program of NUAA(xcxjh20230603)the Key Research and Development Program(Industrial)of Yancheng City(BE2023001)the Open Foundation of Shanghai Jiao Tong University Shaoxing Research Institute of Renewable Energy and Molecular Engineering(Grant No.JDSX2023019).
文摘Developing efficient and durable hydrogen evolution reaction(HER)electrocatalysts is critical for industrial and sustainable hydrogen production.Herein,a simple co-precipitation strategy is proposed to success-fully construct catalysts with a Mott-Schottky heterojunction by coupling a transition-metal phosphate to the surface of stripped MXene thin-layer nanosheets(M_(3)(PO_(4))_(2)@MXene,M=Co,Ni,and Fe).The Co_(3)(PO_(4))_(2)@MXene with a unique tightly connected 2D/2D heterostructure and built-in electric field induces directional electron transfer at the interface,regulates the polarized structure of the active sites,and accelerates both mass and electron transport.Consequently,the optimized Co_(3)(PO_(4))_(2)@MXene demonstrates outstanding HER performance,achieving low overpotentials of 46 and 58.6 mV at 10 mA cm^(−2)in alkaline freshwater and seawater electrolytes,respectively.Moreover,the Co_(3)(PO_(4))_(2)@MXene het-erojunction catalyst maintains stable operation at a high current density of 500 mA cm^(−2)for over 100 h in alkaline seawater electrolytes.More importantly,Co3(PO_(4))_(2)@MXene can offer a low potential of 1.71 V at 500 mA cm^(−2)with stable operation for 50 h in a flow-type alkaline seawater electrolyser.This study pro-vides a unique heterostructure in an electrocatalyst for an efficient HER and presents its potential appli-cation in seawater electrolysis.
基金supported by the National Natural Science Foundation of China[51871119,51901100 and 22075141]the High-Level Entrepreneurial and Innovative Talents Program of Jiangsu Province,the Six Talent Peak Project of Jiangsu Province[2018-XCL-033]+1 种基金the China Postdoctoral Science Foundation[2018M640481 and 2019T120426]the Jiangsu Postdoctoral Research Fund[2019K003].
文摘Exploring highly efficient,economical and environment friendly electrocatalysts for the hydrogen and oxygen evolution reactions(HER and OER)is necessary but challenging for economical water splitting.Herein,FeS_(2) nanoparticles were anchored on the surface of MXene through a simple adsorption-growth route(FeS_(2)@MXene).By virtue of the large active surface area of FeS_(2) and its robust interfacial interaction with conductive and hydrophilic MXene nanosheets,the obtained FeS_(2)@MXene composite can accelerate the transfer of mass/charge and facilitate contact between water molecules and reactive sites of FeS_(2).Specifically,MXene as a support material can not only alter the electrophilicity of the active centers of FeS_(2) through modulating the electron density but also prevent the aggregation of FeS_(2),thereby promoting activity and stability.The optimized FeS_(2)@MXene delivers a 10 mA cm-2 current density at overpotentials of 87 and 240 mV in alkaline solution for the HER and OER,respectively,which is comparable with reported transition metal sulfide(TMS)based catalysts.More importantly,in situ Raman spectroscopy reveals that the FeOOH generated during the OER process as a actual active species enhances the intrinsic activity of the catalyst.This work paves a new way for the interface engineering of TMS-based electrocatalysts towards water splitting.
基金supported by the National Natural Science Foundation of China(51871119 and 22075141)High-Level Entrepreneurial and Innovative Talents Program on Jiangsu Province,Jiangsu Provincial Founds for Natural Science Foundation(BK20180015)+1 种基金China Postdoctoral Science Foundation(2018M640481 and 2019T120426)Jiangsu Postdoctoral Research Fund(2019K003).
文摘Developing hierarchical heterostructures as bifunctional electrocatalysts which promote renewable hydrogen production is a desirable but challenging technology in electrochemical water splitting.Herein,the interface engineering of the FeNi_(2)Se_(4)-FeNi LDH composite is achieved by the in situ growth of FeNi LDH nanosheets and the subsequent partial selenization treatment.Enhanced mass transfer and accelerated gas release are achieved in such a unique self-supported hierarchical heterostructure during overall water splitting.Moreover,the strong electronic interaction between FeNi_(2)Se_(4) and FeNi LDH optimizes the electron redistribution of Fe and Ni sites,which significantly improves the interfacial reactivity of reactants and/or intermediates with the hybrid catalyst.Benefiting from increased active sites and enhanced intrinsic activity,the hybrid electrocatalyst requires only a potential of 205 mV for the oxygen evolution reaction(OER)and a potential of 106 mV for the hydrogen evolution reaction(HER)to realize 10 mA cm^(−2).Specifically,the optimized FeNi_(2)Se_(4)-FeNi LDH as a bifunctional electrode in overall water splitting delivers 10 mA cm^(−2) at a low cell voltage of 1.56 V driven by a solar cell.This strategy by rational design of heterostructures thus paves an efficient pathway to fabricate active and non-precious bifunctional electrocatalysts for overall water splitting.
基金supported by the National Natural Science Foundation of China(92472117,22402081,22509085,and 52371226)the Natural Science Foundation of Jiangsu Province(BK20210311,BK20221482,and BK20251369)+2 种基金the China National Postdoctoral Program for Innovative Talents(BX20250441)the China Postdoctoral Science Foundation(2025M774272)the Jiangsu Funding Program for Excellent Postdoctoral Talent.
文摘Developing stable and efficient single-atom electrocatalysts for the acidic oxygen evolution reaction(OER)is crucial for advancing proton exchange membrane water electrolysis(PEMWE).However,the lack of precisely tailored coordination environments capable of preventing Ir single-atom dissolution remains a critical barrier.Herein,we construct Ir single-atom catalysts supported on Co_(3)O_(4)(IrSA-Co_(3)O_(4))via the synchronized formation of Co defects and the immobilization of Ir single atoms during precursor pyrolysis.Atomically dispersed Ir atoms are anchored at octahedral Co defect sites,forming a configuration of single atoms confined within the spinel lattice.Benefiting from the oxygen-bridged electronic coupling within the Ir–O–Co configuration,the electronic structure of Ir sites is optimized to enable moderate intermediate adsorption while mitigating dissolution.As a result,IrSA-Co_(3)O_(4)achieves a low overpotential of 199 mV at 10 mA cm^(−2)in 0.5 M H_(2)SO_(4)and operates stably for 150 h at 200 mA cm^(−2)during PEMWE.This work provides new insights into the rational design of stable single-atom catalysts for acidic OER by effectively suppressing active-site dissolution.
基金supported by the National Social Science Fund of China entitled “A Genre-Based Study of the Dynamic Interdiscursive System in Chinese and English Professional Discourse”(17BYY033)
文摘For years, personal and social voices have been the issue of discussion on voice construction in written discourse(e.g., Elbow, 1999;Flowerdew, 2011;Hyland, 2002, 2010 a, 2012 b;Mauranen, 2013;Ramanathan & Atkinson, 1999;Tardy, 2005). However, there is a lack of an integrated examination of the dimensions which determine voice construction in writing from personal and social perspectives. This article re-examines the issue of voice construction through a critical review of previous literature on identity in written discourse. It is argued that there are five major dimensions for the construction of voice in written discourse. How writers appropriate their voice according to such five dimensions as genre, transition, culture, discipline and audience will be discussed. This paper lends further support to the view that voice in written discourse is both personal and social. As it is known, good writing expresses both personal and social voices. However, based on the dominant dimension(s), voice construction should be adjusted. Sometimes personal voice is boldly expressed;sometimes social voice is;and some other times the boundary between the two is unnoticeable. The study provides an integrated framework as well as pedagogical implications for the teaching of academic writing within L1 and L2 contexts.
基金supported by the National Natural Science Foundation of China(51871119,22075141,and 22101132)the Scientific and Technological Innovation Special Fund for Carbon Peak and Carbon Neutrality of Jiangsu Province(BK20220039)+1 种基金Jiangsu Provincial Founds for Natural Science Foundation(BK20210311)Jiangsu Postdoctoral Research Fund(2021K547C)。
文摘设计基于界面工程的氧/氢析出反应(OER/HER)双功能电催化剂对在高电流密度下同时实现低过电位和稳定的水分解操作至关重要.本文中,我们报告了一种硼化策略以巧妙地定制固定在泡沫铁(IF)上的金属有机框架(MOF).硼原子诱导了Fe-MOF纳米片的结构重构,包括粗糙表面、氧空位以及结晶Fe-MOF和非晶Fe–B之间的面内异质结.面内异质结调节铁位点的d带中心以降低OER/HER能垒.优化的Fe–B/FeMOF/IF在10 m A cm^(-2)下驱动OER和全解水,分别仅需1.44和1.53 V.水分解系统在500 m A cm^(-2)下工作100小时以后的结构变化和性能衰减可忽略不计.该工作为异质结构界面的工程提供了启示,并促进了先进电催化剂的合理设计.
基金supported by China National Social Sciences Grant entitled “A Genre-based Study of the Dynamic Interdiscursive System in Chinese and English Professional Discourse”(NO.17BYY033)
文摘Recent research on academic discourse has revealed the intersection of writing and writer identity construction. However, some terms that are being used in writer identity study are sometimes not only interchangeably used without making an explicit connection between them but also used in a way that may cause misunderstanding. The paper is intended to tease out four key terms, namely, stance, voice, self, and identity so that the respective role that each plays in academic written discourse can be differentiated on the one hand, and their interrelationship can be clarified on the other. It is hoped that such a panoramic picture can offer some pedagogical implications for academic writing teaching and research and provide some insights into the research on writer identity construction in academic written discourse as well.
基金supported by China National Social Sciences Grant entitled A Genre-based Study of the Dynamic Interdiscursive System in Chinese and English Professional Discourse(NO.17BYY033)
文摘Based on Bhatia＇s multi-dimensional analytical framework for discourse analysis, we explore key issues involved in genres construction such as private intention, manipulation of generic value and interdiscursive strategies. Two prefaces and two book reviews by expert linguists were collected and analyzed at great length from both text-internal and text-external perspectives. Meanwhile, four professionals from relevant disciplines were interviewed for their insights into the issues investigated. Through examining textual features, covert interdiscursivity and narrative accounts of the professional writers, the following findings are generated. 1） Generic variation occurs within and between the two genres due to expert writers＇ intentional manipulation of generic value. 2） Interdiscursive strategies like ＂genre embedding＂, ＂genre bending＂ and ＂genre mixing＂ are exploited by expert writers to achieve their particular private intention. Specifically, preface genre can be presented, to some extent, as a research article mixed with some promotional flavor, and features of research article genre, promotional genre and introductory genre are found mixed in the review genre. 3） Representations of the preface and book review genres such as linguistic feature, move structure and interdiscursivity are ultimately affected by generic value, authors＇ private intention, professional practice and disciplinary culture. The findings have important implications for ESP/EAP writing practitioners and learners.
基金supported by China National Social Sciences Grant entitled “A Genre-based Study of the Dynamic Interdiscursive System in Chinese and English Professional Discourse”(NO.17BYY033)
文摘Based on Burgess and Ivani?’s(2010) framework of the discoursal construction of writer identity, this paper explores the interaction between citation practices and identity construction in Chinese EFL learners’ MA thesis writing. A mixed approach of textual analysis and interviews was adopted to examine the citation features of MA theses and the identities Chinese EFL learners constructed through citation selection. It was found that students’ selection of citations reflects their linguistic identity, academic and disciplinary identity, as well as novice identity. Their citation practices project different discursive selves to readers. By adjusting the number and relevance of references, they intend to construct a knowledgeable and credible self. The use of ineffective citations and references not only projects an unfavorable impression on readers but reflects a lack of authorial identity. This study has significant implications for the teaching of academic English and the supervision of thesis writing.
