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Stress corrosion behavior of 2195-T8 Al-Li alloy with an artificial pit exposed to a 30vol%HNO3 solution

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Chinese Journal of Aeronautics 2023年第2期36卷 304-315页

作者： Dejun LIU Gan TIAN Zhengwei YANG guofeng JIN wei ZHANG Yin WANG Huali wei School of Missile Engineering Rocket Force University of EngineeringXi'an 710038China Xi'an Institute of Aerospace Composites Xi'an 710025China

This paper experimentally studied the stress corrosion behavior of 2195-T8 Al-Li alloys with prefabricated pits in 30vol%HNO3.The microstructure was observed and determined by the scanning electron microscopy and the transmission electron microscopy.The typical corrosion features,i.e.,regular or irregular corrosion pits and sub/intergranular corrosion,were investigated,and the role of stress were analyzed.The statistical results of the number and area of corrosion pits in various sizes were studied using an improved image processing method.Experimental results demonstrate that stress affects the intergranular corrosion or sub-intergranular corrosion of the alloy most,and promotes them to evolve into cracks under stress corrosion.Stress also plays a role in accelerating corrosion severity of certain corrosion feature.The number of corrosion pits with an area of 0–50μm~2 can be seen as an index to reflect the degree of corrosion.Besides,a corrosion phenomenon,i.e.,the pit bottom in the site with the maximum stress locally suffering from no severe corrosion,was observed and discussed.

关键词： Al-Li alloy Artificial pit Corrosion features Image processing Stress corrosion

Sequential One-Pot Three-Enzyme Synthesis of the Tetrasaccharide Repeating Unit of Group B Streptococcus Serotype Ⅷ Capsular Polysaccharide

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Chinese Journal of Chemistry 2022年第9期40卷 1039-1044页

作者： Min Liang wei Gong Chongzhen Sun Jielin Zhao Hong Wang Zonggang Chen Min Xiao guofeng Gu National Glycoengineering Research Center Shandong Provincial Key Laboratory of Carbohydrate Chemistry and GlycobiologyShandong University72 Binhai RoadQingdaoShandong 266237China School of Pharmaceutical Science Shandong University44 West Wenhua RoadJinanShandong 250012China NMPA Key Laboratory for Quality Research and Evaluation of Carbohydrate-based Medicine Shandong UniversityQingdaoShandong 266237china

The biochemical property and functional identification of three recombinant glycosyltransferases,includingβ-1,4-rhamnosyltransferase(Cps8R),β-1,4-galactosyltransferase(Cps8) and α-2,3-sialyltransferase(Cps8K)involved in the biosynthesis of the tetrasaccharide repeating unit of serotypeⅧcapsular polysaccharide(CPS)of Group B Streptococci(GBS),were systematically investigated.Subsequently,these recombinant enzymes were employed for one-pot three-enzyme efficient synthesis of the tetrasaccharide repeating unit of GBS serotypeⅧCPS using the chemically synthesized Glca-PP-(CH2)ir-OPh as the starting substrate in a satisfying yieldof 87%.

关键词： Streptococcus agalactiae Capsular polysaccharide Oligosaccharides Enzyme catalysis Biosynthesis

Risk factors in blood for attacks of angina in patients with coronavirus disease 2019 and stable angina

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Chinese Medical Journal 2023年第11期136卷 1373-1375页

作者： Song Geng Donghui Zhou Qi Wang guofeng Wang wei wei Tao Yu Zhiying Duan Jing Liu Fei Yu Yuanzhe Jin Department of Cardiology The Fourth Affiliated Hospital of China Medical UniversityShenyangLiaoning 110032China Department of Cardiology Shenyang Fourth People’s HospitalShenyangLiaoning 110031China Translational Medicine Center The Fourth Affiliated Hospital of China Medical UniversityShenyangLiaoning 110032China

To the Editor:Patients with coronary heart disease(CHD)complicated by coronavirus disease 2019(COVID-19)are at an increased risk of coronary events.Many studies have reported an association between cardiovascular disease and COVID-19.It is also known that patients with COVID-19 have worse outcomes and an increased mortality risk if they have cardiovascular disease.[1]According to a report by the World Health Organization,the estimated COVID-19 mortality rate is about 3.4%overall;however,in patients with cardiovascular disease,this figure increases to 10.5%,which is higher than the death rate in those with underlying diabetes(7.3%)or chronic respiratory diseases(6.3%).

关键词： angina mortality patients

MgTiO3/MgTi2O5/TiO2 heterogeneous belt-junctions with high photocatalytic hydrogen production activity

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Nano Research 2017年第1期10卷 295-304页

作者： Ling Meng Zhiyu Ren wei Zhou Yang Qu guofeng Wang Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education School of Chemistry and Materials ScienceHeilongjiang University Harbin 150080 China

An effective photocatalytic hydrogen production catalyst comprising MgTiO3/ MgTi2O5/TiO2 heterogeneous belt-junctions was prepared using magnesium ions by a thermally driven doping method. The tri-phase heterogeneous junction was confirmed by X-ray powder diffraction （XRD）, transmission electron microscopy （TEM）, and high-resolution TEM （HRTEM）. The as-prepared MgTiOg/MgTi2OJ TiO2 heterojunctions exhibited a very high photocatalytic hydrogen production activity （356.1 mol·g0.1mgcat·h^-1） and an apparent quantum efficiency （50.69% at 365 nm） that is about twice of that of bare TiO2 nanobelts （189.4mol·g0.1mgcat·h^-1）. Linear sweep voltage and transient photocurrent characterization as well as analysis of the electrochemical impedance spectra and Mott-Schottky plots revealed that the high photocatalytic performance is caused by the one-dimensional structure, which imparts excellent charge transportation characteristic, and the MgTiO3/MgTi2O5/TiO2 tri-phase heterojunction, which effectively drives the charge separation through the inherent electric field. This titanate-based tri-phase heterogeneous junction photocatalyst further enriches the catalyst system for photocatalytic hydrogen production.

关键词： MgTiO3/MgTi2O5/TiO2,heterogeneousbelt-junctions,photocatalytic hydrogenproduction

Lithium-ion modified cellulose as a water-soluble binder for Li-O2 battery

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Frontiers in Energy 2022年第3期16卷 502-508页

作者： Chenyi Hu Aiming Wu Fengjuan Zhu Liuxuan Luo Fan Yang guofeng Xia Guanghua wei Shuiyun Shen Junliang Zhang Institute of Fuel Cells School of Mechanical EngineeringMOE Key Laboratory of Power and Machinery EngineeringShanghai Jiao Tong UniversityShanghai200240China SJTU-Paris Tech Elite Institute of Technology Shanghai Jiao Tong UniversityShanghai200240China

An environment-friendly,water-soluble,and cellulose based binder(lithium carboxymethyl cellulose,CMC-Li)was successfully synthesized by using Li+to replace Na+in the commercial sodium carboxymethyl cellulose(CMC-Na).Li-O2 batteries based on the CMC-Li binder present enhanced discharge specific capacities(11151 mAh/g at 100 mA/g)and a superior cycling stability(100 cycles at 200 mA/g)compared with those based on the CMC-Na binder.The enhanced performance may originate from the electrochemical stability of the CMC-Li binder and the ion-conductive nature of CMC-Li,which promotes the diffusion of Li+in the cathode and consequently retards the increase of charge transfer resistance of the cathode during cycling.The results show that the water-soluble CMC-Li binder can be a green substitute for poly(vinylidene fluoride)(PVDF)binder based on organic solvent in the lithium oxygen batteries(LOBs).

关键词： cellulose binder specific capacity cyclability lithium-oxygen batteries

Preparation of nanostructured mesoporous Ni Co_2O_4 and its electrocatalytic activities for water oxidation

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Journal of Energy Chemistry 2015年第3期24卷 271-277页

作者： Genyan Hao wei Wang guofeng Gao Qiang Zhao Jinping Li Research Institute of Special Chemicals Taiyuan University of Technology

Nanostructured mesoporous Ni Co2O4,Co3O4 and Ni O spinel oxides were prepared through the hydroxide coprecipitation method using EG（ethylene glycol） as solvent without any template.The Ni Co2O4 powders were analyzed by TGA,XRD,N2adsorption-desorption,SEM and EDS.And the electrocatalytic properties of Ni Co2O4/Ti,Co3O4/Ti and Ni O/Ti electrodes for oxygen evolution in 0.1 mol/L KOH（p H = 13）were tested by cyclic voltammetry,Tafel curves and electrolysis.The result shows that Ni Co2O4/Ti electrode has higher electrocatalytic activity in oxygen evolution reaction than Co3O4/Ti and NiO/Ti electrodes.Ni Co2O4/Ti electrode prepared at 350°C has the highest apparent current density and the highest true current density.The Tafel slope of Ni Co2O4/Ti electrode prepared at 350°C is 68.49 m V/dec.

关键词： water splitting nanostructure Ni Co2O4 electrocatalytic properties

CD64指数PCT和CD4^(+)T淋巴细胞亚群联合预测模型对高甘油三酯血症性急性胰腺炎早期感染的预测价值

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中国急救医学 2023年第12期43卷 976-981页

作者：魏国峰张泓安徽医科大学第一附属医院急诊医学科安徽合肥230022 合肥市第二人民医院(安徽医科大学附属合肥医院)急诊医学科安徽合肥230011

目的探讨多指标联合预测模型对高甘油三酯血症性急性胰腺炎(HTG-AP)患者早期继发感染的临床应用价值。方法收集2021年1月至2023年5月在安徽医科大学第一附属医院、合肥市第二人民医院就诊的248例HTG-AP患者的临床资料,并根据早期是否... 详细信息

目的探讨多指标联合预测模型对高甘油三酯血症性急性胰腺炎(HTG-AP)患者早期继发感染的临床应用价值。方法收集2021年1月至2023年5月在安徽医科大学第一附属医院、合肥市第二人民医院就诊的248例HTG-AP患者的临床资料,并根据早期是否继发感染分为感染组和非感染组。分析并比较两组的一般资料、感染指标等。应用单因素分析及二分类Logistic回归分析筛选HTG-AP患者早期继发感染的独立影响因素,建立多指标联合预测模型。通过受试者工作特征(ROC)曲线、Hosmer-Lemeshow拟合优度和决策曲线分析(DCA)评估模型的区分度、准确性和临床实用性。结果 248例HTG-AP患者分为感染组70例,非感染组178例。两组患者空腹血糖、感染相关指标包括中性粒细胞百分比、CRP、CD4^(+)T淋巴细胞亚群、PCT、CD64指数比较差异有统计学意义(P<0.05);CD64指数、PCT、CD4^(+)T淋巴细胞亚群为HTG-AP早期继发感染的独立预测因子。三者联合预测模型(AUC为0.865)对HTG-AP早期继发感染的诊断价值优于单个指标,敏感度(78.5%)和特异度(87.7%)均较高,阳性预测值71.83%,阴性预测值91.08%。校准后联合预测模型的预测结果与临床实际观察结果一致性较高;通过Bootstrap内部验证,联合预测模型校准后的AUC值为0.865,其预测效能曲线与临床实际发生的曲线具有良好的一致性;DCA分析显示阈概率为12%~88%时,可预测HTG-AP早期继发感染。结论基于CD64指数、PCT、CD4^(+)T淋巴细胞亚群建立的多指标联合预测模型可早期诊断HTG-AP继发感染。

关键词：高甘油三酯血症性急性胰腺炎(HTG-AP) 感染诊断预测模型 CD64指数 CD4^(+)T淋巴细胞亚群

One step method of structure engineering porous graphitic carbon nitride for efficient visible-light photocatalytic reduction of Cr(Ⅵ)

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Journal of Materials Science & Technology 2021年第12期71卷 211-220页

作者： Xueru Chen Yin Zhang Dashui Yuan Wu Huang Jing Ding Hui Wan wei-Lin Dai guofeng Guan State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringJiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing Tech UniversityNanjing 210009China Department of Chemistry&Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan UniversityShanghai 200433China

Porous g-C_(3)N_(4)nanosheets(PCN)were prepared by the nickel-assisted one-step thermal polymerization method.Hydrogen(H2)which was produced by the reaction between nickel(Ni)foam and ammonia(NH3)defined the structure and properties of PCN.During the formation of PCN,the participation of H2 not only enhanced the spacing between layers but also boosted the specific surface area that more active sites were exposed.Additionally,H2 promoted pores formation in the nanosheets,which was beneficial to the transfer of photons through lamellar structure and improved the absorption efficiency of visible light.Remarkably,the obtained PCN possessed better Cr(Ⅵ)photocatalytic reduction efficiency than pure g-C_(3)N_(4).The reaction rate constant(k)of PCN(0.013 min-1)was approximately twice that of bare g-C_(3)N_(4)(0.007 min-1).Furthermore,the effects of original pH and concentration of Cr(Ⅵ)-containing solution on re moval efficiency of Cr(Ⅵ)were explored.A possible photocatalytic mecha nism was proposed based on the experiments of radical scavengers and photoelectrochemical characterizations.

关键词： Porous carbon nitride Nickel foam Hydrogen Cr(VI) Photocatalysis

One-step fabrication of nitrogen-deficient carbon nitride through pyrolysis of melamine and 1,2,4-triazole for its enhanced photocatalytic degradation

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Green Chemical Engineering 2021年第3期2卷 317-326页

作者： Jing Ding Zongyuan Li Xueru Chen Yiwei Jiao Dashui Yuan wei Du Hui Wan guofeng Guan State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringJiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing Tech UniversityNanjing210009China Department of Chemistry&Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan UniversityShanghai200433China

The construction of defects in semiconductor photocatalysts,as a kind of modification methods,plays an indispensable role in the enhancement of the photocatalytic performance.Herein,nitrogen defects were successfully introduced into the framework of graphite carbon nitride(CN-T_(x))through thermal polymerization with melamine and 1,2,4-triazole as precursors.The existence of nitrogen defects in CN-T_(x) were confirmed to be located at the two-coordinated(N_(2c))C■N-C lattice sites,which resulted in the destruction of its planar structure and the initiation of n-π^(*)electron transition that greatly expanded the response range to visible light and improved the separation efficiency of photogenerated charge carrier.More significantly,CN-T_(x) could enhance photocatalytic water purification activity towards different kinds of pollutants.The photocatalytic rates of CN-T_(3) were estimated to be 2.54(tetracycline)and 2.31(2-hydroxynaphthalene)times higher than those of pristine g-C3N4.Furthermore,the possible photocatalytic degradation mechanism over CN-T_(x) photocatalyst was proposed by free radical trapping experiments combined with ERS characterization.This work provides an in-depth understanding of the important role of nitrogen defects in the electronic structure and chemical properties of g-C3N4 and its photocatalytic water purification performance.

关键词： Nitrogen defect Carbon nitride 1,2,4-Triazole Photocatalysis Water purification