检索结果-南通市图书馆

Deciphering the linear relationship in the activity of the oxygen reduction reaction on Pt electrodes:A decisive role of adsorbates

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第7期94卷 70-77页

作者： Haowen Cui yan-xia chen Hefei National Research Center for Physical Sciences at Microscale and Department of Chemical Physics University of Science and Technology of ChinaHefei 230026AnhuiChina

Despite substantial efforts in developing high-performance catalysts for the oxygen reduction reaction(ORR),the persistent challenge lies in the high onset overpotential of the ORR,and the effect of the elec-trolyte solution cannot be ***,we have systematically investigated the impact of adsorbate species and concentration,as well as solution pH,on the ORR activity on Pt(111)and Pt(poly)*** results all tend to establish a linear quantitative relationship between the onset potential for ORR and the adsorption equilibrium potential of the *** finding indicates the decisive role of adsorbates in the onset potential for ORR,suggesting that the adsorption potential of adsorbates can serve as an intuitive criterion for ORR *** support for this conclusion is derived from experimental results obtained from the oxygen evolution reaction on Pt(poly)with different adsorbate species and from the hydrogen evolution reaction on Pt(111)with iodine *** further propose both an empirical equation for the onset potential for ORR and the concept of a potential-regulated adsor-bate shielding effect to elucidate the influence of adsorbates on ORR *** study provides new insights into the high onset overpotential of the ORR and offers potential strategies for predicting and enhancingORRactivity inthefuture.

关键词： Oxygen reduction reaction Activity Adsorbate Equilibrium potential Pt(111)

Long noncoding RNA protein-disulfide isomerase-associated 3 regulated high glucose-induced podocyte apoptosis in diabetic nephropathy through targeting miR-139-3p

在线全文

学校读者我要写书评

暂无评论

World Journal of Diabetes 2024年第2期15卷 260-274页

作者： Yin-Xi He Ting Wang Wen-xian Li yan-xia chen Department of Orthopaedic Trauma The Third Hospital of ShijiazhuangShijiazhuang 050000Hebei ProvinceChina Department of Endocrinology The Second Hospital of Hebei Medical UniversityShijiazhuang 050000Hebei ProvinceChina Department of Endocrinology The First Hospital of ZhangjiakouZhangjiakou 075000Hebei ProvinceChina

BACKGROUND Podocyte apoptosis plays a vital role in proteinuria pathogenesis in diabetic nephropathy(DN).The regulatory relationship between long noncoding RNAs(lncRNAs)and podocyte apoptosis has recently become another research hot spot in the DN *** To investigate whether lncRNA protein-disulfide isomerase-associated 3(Pdia3)could regulate podocyte apoptosis through miR-139-3p and revealed the underlying *** Using normal glucose or high glucose(HG)-cultured podocytes,the cellular functions and exact mechanisms underlying the regulatory effects of lncRNA Pdia3 on podocyte apoptosis and endoplasmic reticulum stress(ERS)were *** Pdia3 and miR-139-3p expression were measured through quantitative real-time polymerase chain *** cell viability was detected through the cell counting kit-8 colorimetric *** podocyte apoptosis rate in each group was measured through flow *** interaction between lncRNA Pdia3 and miR-139-3p was examined through the dual luciferase reporter ***,western blotting was performed to detect the effect of lncRNA Pdia3 on podocyte apoptosis and ERS via *** The expression of lncRNA Pdia3 was significantly downregulated in HG-cultured ***,lncRNA Pdia3 was involved in HG-induced podocyte ***,the dual luciferase reporter assay confirmed the direct interaction between lncRNA Pdia3 and *** Pdia3 overexpression attenuated podocyte apoptosis and ERS through miR-139-3p in HG-cultured *** Taken together,this study demonstrated that lncRNA Pdia3 overexpression could attenuate HG-induced podocyte apoptosis and ERS by acting as a competing endogenous RNA of miR-139-3p,which might provide a potential therapeutic target for DN.

关键词： Long noncoding RNAs Diabetic nephropathy Podocyte apoptosis Endoplasmic reticulum stress Competing endogenous RNA

A case of herpesviral corneal endotheliitis presenting with corneal endothelial defect

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2024年第7期17卷 1375-1378页

作者： yan-xia chen Han Deng xiao-Yun Ke Min Fu Department of Ophthalmology Women and Children’s HospitalSchool of MedicineXiamen UniversityXiamen 361003Fujian ProvinceChina Department of Ophthamology Zhujiang HosptialSouthern Medical UniversityGuangzhou 510280Guangdong ProvinceChina

Dear Editor,Corneal endotheliitis,first reported in 1982 as an autoimmune disorder by Khodadoust and Attarzadeh[1],is now recognized to be frequently induced by viral infections,including varicella zoster virus(VZV),cytomegalovirus(CMV)and herpes simplex virus(HSV),that can cause inflammatory and immune-related injuries or direct damages to corneal endothelial cells[2-3].In cases with this type of endotheliitis of viral origin,manifestations may include conjunctival ciliary congestion or mixed congestion,corneal subepithelial bulla,localized corneal edema,keratic precipitates(KP)characteristic to the edema area,puckered posterior elastic lamina,mild anterior chamber reaction,intraocular pressure(IOP)elevation in presence of inflammation in trabecular meshwork,and endothelial decompensation[3-4].Accurate diagnosis of viral corneal endotheliitis is challenging due to its complex presentation,leading to a high misdiagnosis *** the best of our knowledge,there was no previous report of viral corneal endotheliitis presenting with corneal endothelial defects in the English literature.

关键词： corneal injuries herpes

Selective catalytic oxidation of NO over iron and manganese oxides supported on mesoporous silica

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Natural Gas Chemistry 2008年第3期17卷 273-277页

作者： Junfeng Zhang yan Huang xia chen Department of Environmental Science and Engineering Xiangtan University Xiangtan 411105 Hunan China

The selective catalytic oxidation （SCO） of NO was studied on a catalyst consisting of iron-manganese oxide supported on mesoporous silica （MPS） with different Mn/Fe ratios. Effects of the amount of manganese and iron, oxygen, and calcination temperature on NO conversion were also investigated. It was found that the Mn-Fe/MPS catalyst with a Mn/Fe molar ratio of 1 showed the highest activity at the calcination temperature of 400 °C. The results showed that over this catalyst, NO conversion reached 70% under the condition of 280 °C and a space velocity of 5000 h-1. SO2 and H2O had no adverse impact on the reaction activity when the SCO reaction temperature was above 240 °C. In addition, the SCO activity was suppressed gradually in the presence of SO2 and H2O below 240 °C, and such an effect was reversible after heating treatment.

关键词： selective catalytic oxidation of NO nitrogen monoxide mesoporous silica iron manganese

Restructuring of 4H Phase Au Nanowires and its Catalytic Behavior toward CO Electro-oxidation

在线全文

学校读者我要写书评

暂无评论

化学物理学报(英文) 2023年第5期36卷 533-544,I0001页

作者： Xuxu Ye Bingyu Liu Da Zhou yan xia chen Department of Chemical Physics and Hefei National Research Center for Physical Science at the Microscale University of Science and Technology of ChinaHefei 230026China

Au nanowires in 4H crystalline phase(4H Au NWs)are synthesized by colloid solution *** crys-talline phase and surface structure as well as its performance toward electrochemical oxidation of CO be-fore and after removing adsorbed oleylamine molecules(OAs)intro-duced from its synthesis are evaluat-ed by high-resolution transmission electron microscopy(HR-TEM),X-ray diffraction(XRD),underpoten-tial deposition of Pb(Pb-upd)and cyclic *** methods,*** acid cleaning,electrochemical oxidation cleaning,and diethylamine replacement,have been tried to remove the adsorbed *** all methods,upon the removal of the adsorbed OAs,the morphology of 4H gold nanoparticles is found to gradually change from nanowires to large dumbbell-shaped nanoparticles,accompanying with a transition from the 4H phase to the face-centered cubic *** the other hand,the Pb-upd results show that the sample sur-faces have almost the same facet composition before and after removal of the adsorbed *** electrochemical cleaning with continuous potential scans up to 1.3 V,CO electro-oxida-tion activity of the 4H Au sample is significantly *** CO electro-oxidation activi-ty is compared with results on the three basel Au single crystalline surfaces reported in the lit-erature,possible origins for its enhancement are discussed.

关键词： Phase engineering Crystalline phase transition 4H phase Au nanowires Pb un-der potential deposition CO electro-oxidation

Electrochemical Study on Hydrogen Evolution and CO2 Reduction on Pt Electrode in Acid Solutions with Different pH

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2018年第5期31卷 626-634,735页

作者： Jing yang Jie Wei Wei chen yan-xia chen Hefei National Laboratory for Physical Science at the Microscale and Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China

Hydrogen evolution reaction(HER)is the major cathodic reaction which competes CO2 reduction reaction(CO2 RR)on Pt *** level understanding on how these two reactions interact with each other and what the key factors are of CO2 RR kinetics and selectivity will be of great help in optimizing electrolysers for CO2 *** this work,we report our results of hydrogen evolution and CO2 reduction on Pt(111)and Pt film electrodes in CO2 saturated acid solution by cyclic voltammetry and infrared *** solution with pH>2,the major process is HER and the interfacial pH increases abruptly during HER;COad is the only adsorbed intermediate detected in CO2 reduction by infrared spectroscopy;the rate for COad formation increases with the coverage of UPD-H and reaches maximum at the onset potential for HER;the decrease of COad formation under HER is attributed to the available limited sites and the limited residence time for the reduction intermediate(Had),which is necessary for CO2 adsorption and reduction.

关键词： Hydrogen evolution reaction CO2 Reduction Pt(111) Acidic solution pH effect Infrared spectroscopy

The determination of thermal junction potential difference

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2018年第8期61卷 1020-1024页

作者： Nestor Uwitonze Wei chen Da Zhou Zhengda He yan-xia chen Hefei National Laboratory for Physical Sciences at Microscale Department of Chemical Physics University of Science and Technology of China

A novel method has been designed and exploited to determine the thermal junction potential difference(TJPD) between two acids or alkalies of the same composition but with different temperature. The absolute value of measured TJPD between two strong acids(or alkalies) maintained at different temperatures increases with increasing of the temperature difference between the two electrolytes over the range from 0 to 40 °C. In strong acids, the hot end always has the lower potential while in strong alkalies, the cold end has the lower potential. This is because the ions of fast diffusion rate contribute most to the TJPD. Our results demonstrate the importance of the correction for TJPD in deriving the kinetic parameters when studying the temperature effect on reaction kinetics.

关键词： thermal junction potential difference temperature effect electrocatalysis electrode kinetics activation energy

Effect of mass transfer and solution composition on the quantification of reaction kinetics by differential electrochemical mass spectrometry

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2021年第5期30卷 412-419页

作者： Wei chen Nestor Uwitonze Fan He Matthew MSartin Jun Cai yan-xia chen Hefei National Laboratory for Physical Sciences at Microscale Department of Chemical PhysicsUniversity of Science and Technology of ChinaHefei 230026AnhuiChina

Differential electrochemical mass spectrometry(DEMS)is one of the most powerful techniques for both the mechanistic and kinetic study of complicated electrocatalytic *** can provide information on the nature and yields of the products generated,their production rate,and the structure-activity relationship between the electrocatalysts and the target *** precise calibration of the mass signal is a prerequisite for the accurate evaluation of reaction *** this work,we use the oxidation reactions of CO and HCOOH to demonstrate how certain conditions,such as the flow rate and solution composition,affect the collection efficiency and ionization probability of the species to be *** parameters can affect the determination of the mass calibration constant and the accuracy of the subsequent quantitative DEMS *** show the relationship between the mass calibration constant and the flow rate,and provide strategies for eliminating this and the related problems.

关键词： Differential electrochemical mass spectrometry Quantitative analysis Calibration Flow rate Background correction

Preparation of Surfactant-Free Pt and PtRu Nanoparticles with High Activity for Methanol Oxidation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2014年第3期27卷 332-336页

作者： Yao Yao Jun Cai Yong-li Zheng yan-xia chen Hefei National Laboratory for Physical Sciences at the Microscale Department of Chemical PhysicsUniversity of Science and Technology of China Hefei 230025 China

A simple and green approach to synthesize highly active electro-catalysts for methanol oxi- dation reaction （MOR） without using any organic agents is described. Pt nanoparticles are directly deposited on the pre-cleaned and pre-oxidized multiwall carbon nanotubes （MWC- NTs） from Pt salt by using CO as the reductant. MOR activity has been characterized by both cyclic voltammetry and chronoamperometry, the current density and mass specific current at the peak potential （ca. 0.9 V vs. RHE） reaches 11.6 mA/cm^2 and 860 mA/mgpt, respectively. After electro-deposition of Ru onto the Pt/MWCNTs surface, the catalysts show steady state mass specific current of 20 and 80 mA/mgpt at 0.5 and 0.6 V, respectively.

关键词： Pt nano-electrocatalyst PtRu nano-electrocatalyst Green synthesis Methanol oxidation reaction Carbon monoxide