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Cobalt doping amount determines dominant reactive species in peroxymonosulfate activation via porous carbon catalysts co-doped by cobalt and nitrogen

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Journal of Environmental Sciences 2024年第4期138卷 212-226页

作者： Xiang Li Limeng Wu aiqin zhang Shaohua Wu Yan Lin Chunping Yang Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle Nanchang Hangkong UniversityNanchang 330063China Academy of Environmental and Resource Sciences School of Environmental Science and EngineeringGuangdong University of Petrochemical TechnologyMaoming 525000China College of Environmental Science and Engineering Hunan University and Key Laboratory of Environmental Biology and Pollution Control(Hunan University)Ministry of EducationChangsha 410082China

Switching the reaction routes in peroxymonosulfate(PMS)-based advanced oxidation processes have attracted much attention but remain challenging.Herein,a series of Co-N/C catalysts with different compositions and structures were prepared by using bimetallic zeolitic imidazolate frameworks based on ZIF-8 and ZIF-67(x Zn/Co-ZIFs).Results show that Co doping amount could mediate the transformation of the activation pathway of PMS over CoN/C.When Co doping amount was less than 10%,the constructed x Co-N/C/PMS system(x≤10%)was singlet oxygen-dominated reaction;however further increasing Co doping amount would lead to the generation and coexistence of sulfate radicals and high-valent cobalt,besides singlet oxygen.Furthermore,the nitrogen-coordinated Co(Co-NX)sites could serve as main catalytically active sites to generate singlet oxygen.While excess Co doping amount caused the formation of Co nanoparticles from which leached Co ions were responsible for the generation of sulfate radicals and high-valent cobalt.Compared to undoped N/C,Co doping could significantly enhance the catalytic performance.The 0.5%Co-N/C could achieve the optimum degradation(0.488 min^(-1))and mineralization abilities(78.4%)of sulfamethoxazole among the investigated Co-N/C catalysts,which was superior to most of previously reported catalysts.In addition,the application prospects of the two systems in different environmental scenarios(pH,inorganic anions and natural organic matter)were assessed and showed different degradation behaviors.This study provides a strategy to regulate the reactive species in PMS-based advanced oxidation process.

关键词： Peroxymonosulfate Sulfate radical Singlet oxygen Cobalt Zeolitic imidazolate framework Advanced oxidation process

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Surprised by exceptional stability of confined single-atom cluster catalysts

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Science China Materials 2024年第5期67卷 1676-1677页

作者： aiqin Wang Tao zhang Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian116023China

Single-atom catalysts(SACs)have recently grown as one of the most active frontiers in heterogeneous catalysis[1,2].Intensive research efforts have been invested towards exploring various SACs for thermocatalysis,electrocatalysis as well as photocatalysis,and in most cases,SACs exhibit superior activities and distinctive selectivities compared with the nanoparticle counterparts,thanks to the maximized atom utilization and isolated mononuclear active site structure.In spite of these merits.

关键词： structure catalysis exceptional

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Knockdown of circular RNA (CircRNA)_001896 inhibits cervical cancer proliferation and stemness in vivo and in vitro

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BIOCELL 2024年第4期48卷 571-580页

作者： JIA SHAO CAN zhang YAONAN TANG aiqin HE WEIPEI ZHU Department of Obstetrics and Gynecology The Second Affiliated Hospital of Soochow UniversitySuzhou215004China Department of Gynecology Oncology Affiliated Tumor Hospital of Nantong UniversityNantong226361China

Objective:Previous studies indicated that aberrant circular RNA(circRNA)expression affects gene expression regulatory networks,leading to the aberrant activation of tumor pathways and promoting tumor cell growth.However,the expression,clinical signiﬁcance,and effects on cell propagation,invasion,and dissemination of circRNA_001896 in cervical cancer(CC)tissues remain unclear.Methods:The Gene Expression Omnibus(GEO)datasets(GSE113696 and GSE102686)were used to examine differential circRNA expression in CC and adjacent tissues.The expression of circRNA_001896 was detected in 72 CC patients usingﬂuorescence quantitative PCR.Correlation analysis with clinical pathological features was performed through COX multivariate and univariate analysis.The effect of circRNA_001896 downregulation on CC cell propagation was examined using the cell counting kit-8(CCK-8)test,clonogenic,3D sphere formation,and in vivo tumorigenesis assays.Results:Intersection of the GSE113696 and GSE102686 datasets revealed an increased expression of four circRNAs,including circRNA_001896,in CC tissues.Fluorescence quantitative PCR conﬁrmed circRNA_001896 as a circular RNA.High expression of circRNA_001896 was considerably associated with lymph node metastasis,International Federation of Gynecologists and Obstetricians(FIGO)stage,tumor diameter,and survival period in CC patients.Proportional hazards model(COX)univariate and multivariate analyses revealed that circRNA_001896 expressions are a distinct risk factor affecting CC patients’prognosis.Cellular functional experiments showed that downregulating circRNA_001896 substantially suppressed CC cell growth,colony formation,and 3D sphere-forming ability.In vivo,tumorigenesis analysis in nude mice demonstrated that downregulating circRNA_001896 remarkably reduced the in vivo proliferation capacity of CC cells.Conclusion:CircRNA_001896 is highly expressed in CC tissues and is substantially related to lymph node metastasis,FIGO stage,tumor size,and survival period in patients.Moreover,downregulating cir

关键词： Uterine cervical neoplasms RNA Circular Cell proliferation Cancer stem cells

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Natural attapulgite supported nano-Ni catalysts for the efficient reductive amination of biomass-derived aldehydes and ketones

Green Synthesis and Catalysis

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Green Synthesis and Catalysis 2024年第1期5卷 42-50页

作者： Jia zhang Jian Yang Xuemei Li Bin Mu Hailong Liu Chungu Xia aiqin Wang Zhiwei Huang State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Key Laboratory of Clay Mineral Applied Research of Gansu Province Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

The efficient synthesis of useful primary amines via reductive amination of biomass-based aldehydes and ketones over earth-abundant base metal catalysts is an attractive biomass value-adding technology yet facing lots of challenges.Herein,natural attapulgite(ATP)was applied as support for the fabrication of active Ni catalysts with different Ni loadings(5–30 wt%)by the deposition-precipitation method.The Ni/ATP-550 catalyst with 10–15 wt%Ni loadings was found to present the highest catalytic performance for the synthesis of valuable 5-amino-1-pentanol(5-AP)via reductive amination of biofurfural-derived 2-hydroxytetrahydropyran among a variety of commonly used oxide supports loaded Ni catalysts,as well as ATP supported nickel catalysts with other loadings,achieving 5-AP yield up to 94%.The intrinsic activity of the Ni/ATP catalysts was found to depend strongly on the Ni^(0) crystallite size and Ni^(0) fraction of the catalysts,which generally increased with increasing Ni^(0) crystallite size and fraction,owing probably to the hydrogenation of imine intermediate is a structure-sensitive reaction.The efficient 10Ni/ATP-550 catalyst also exhibited good activity and stability in the reductive amination of several other biomass-derived aldehydes and ketones to their corresponding primary amines with good to excellent yields(81%–99%).This work provided a clean and efficient natural ATP-supported non-noble metal nickel-based catalytic system for the reductive amination of aldehydes and ketones to synthesize high-value-added primary amines,which could be a promising candidate for the industrial production of amines.

关键词： Attapulgite Nano-Ni catalyst Reductive amination 5-Amino-1-pentanol Structure-activity relationship

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Electrical properties and structural optimization of GaN/InGaN/GaN tunnel junctions grown by molecular beam epitaxy

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Journal of Semiconductors 2024年第1期45卷 48-54页

作者： Jun Fang Fan zhang Wenxian Yang aiqin Tian Jianping Liu Shulong Lu Hui Yang School of Nano-Tech and Nano-Bionics University of Science and Technology of ChinaHefei 230026China Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of SciencesSuzhou 215123China

The InGaN films and GaN/InGaN/GaN tunnel junctions(TJs)were grown on GaN templates with plasma-assisted molecular beam epitaxy.As the In content increases,the quality of InGaN films grown on GaN templates decreases and the surface roughness of the samples increases.V-pits and trench defects were not found in the AFM images.p++-GaN/InGaN/n++-GaN TJs were investigated for various In content,InGaN thicknesses and doping concentration in the InGaN insert layer.The InGaN insert layer can promote good interband tunneling in GaN/InGaN/GaN TJ and significantly reduce operating voltage when doping is sufficiently high.The current density increases with increasing In content for the 3 nm InGaN insert layer,which is achieved by reducing the depletion zone width and the height of the potential barrier.At a forward current density of 500 A/cm^(2),the measured voltage was 4.31 V and the differential resistance was measured to be 3.75×10^(−3)Ω·cm^(2)for the device with a 3 nm p++-In_(0.35)Ga_(0.65)N insert layer.When the thickness of the In_(0.35)Ga_(0.65)N layer is closer to the“balanced”thickness,the TJ current density is higher.If the thickness is too high or too low,the width of the depletion zone will increase and the current density will decrease.The undoped InGaN layer has a better performance than n-type doping in the TJ.Polarization-engineered tunnel junctions can enhance the functionality and performance of electronic and optoelectronic devices.

关键词： GaN/InGaN/GaN tunnel junctions polarization-engineering molecular beam epitaxy

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基于4/2-CIR模型的欧式期权定价及实证研究

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运筹与管理 2024年第3期33卷 162-168页

作者：郭精军马爱琴张翠芸兰州财经大学统计与数据科学学院甘肃兰州730020 兰州财经大学甘肃经济发展数量分析研究中心甘肃兰州730020

在假设波动率服从均值回复过程的条件下,探讨了具有随机利率的4/2随机波动率模型下的期权定价问题。首先,基于4/2随机波动率模型提出4/2-CIR随机混合模型,并利用快速傅里叶变换方法推出4/2-CIR随机混合模型下的欧式期权定价公式。其次,... 详细信息

在假设波动率服从均值回复过程的条件下,探讨了具有随机利率的4/2随机波动率模型下的期权定价问题。首先,基于4/2随机波动率模型提出4/2-CIR随机混合模型,并利用快速傅里叶变换方法推出4/2-CIR随机混合模型下的欧式期权定价公式。其次,通过数值分析的方法,对比4/2随机波动率模型与4/2-CIR随机混合模型的定价结果,分析新模型的定价性能,并运用交叉验证法,对模型中参数进行敏感性分析。最后,选取上证50ETF期权数据进行实证分析。研究发现:随机利率对模型定价结果具有显著影响;期权价格对利率的波动率参数不敏感,而对其它参数都较敏感;与经典B-S模型及4/2随机波动率模型相比,4/2-CIR随机混合模型的定价误差更小,定价结果更接近真实值。

关键词： 4/2-CIR随机混合模型期权定价快速傅里叶变换敏感性分析

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Controllable step-flow growth of GaN on patterned freestanding substrate

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Journal of Semiconductors 2024年第2期45卷 46-50页

作者： Peng Wu Jianping Liu Lei Hu Xiaoyu Ren aiqin Tian Wei Zhou Fan zhang Xuan Li Masao Ikeda Hui Yang Key Laboratory of Nanodevices and Applications Suzhou Institute of Nano-tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China University of Chinese Academy of Sciences Beijing 100049China

A new kind of step-flow growth mode is proposed,which adopts sidewall as step source on patterned GaN substrate.The terrace width of steps originated from the sidewall was found to change with the growth temperature and ammonia flux.The growth mechanism is explained and simulated based on step motion model.This work helps better understand the behaviors of step advancement and puts forward a method of precisely modulating atomic steps.

关键词： step-flow growth GaN terrace width step motion

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甘肃省陇中地区小米游离氨基酸组成及综合评价

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食品工业科技 2024年第13期45卷 281-291页

作者：柳利龙张爱琴徐瑞郭斌王青甘肃省农业科学院畜草与绿色农业研究所甘肃兰州730070 甘肃省农业科学院农业质量标准与检测技术研究所甘肃兰州730070

为探究甘肃省陇中地区小米游离氨基酸(free amino acid,FAA)的组成、含量及综合品质差异,以12份小米材料为研究对象,采用液相色谱-串联质谱法测定FAA种类和含量,利用主成分分析(principal component analysis,PCA)和聚类分析(hierarchic... 详细信息

为探究甘肃省陇中地区小米游离氨基酸(free amino acid,FAA)的组成、含量及综合品质差异,以12份小米材料为研究对象,采用液相色谱-串联质谱法测定FAA种类和含量,利用主成分分析(principal component analysis,PCA)和聚类分析(hierarchical cluster analysis,HCA)对小米FAA品质进行综合评价。结果表明:小米中FAA含量丰富,含有19~20种FAA,FAA总量范围在1046.80~1773.85 mg/kg,天冬酰胺(Asn)、天冬氨酸(Asp)、谷氨酸(Glu)和甘氨酸(Gly)是小米中最主要的4种FAA。不同品种小米间FAA种类差异不明显,但FAA含量存在显著差异(P苦味氨基酸>甜味氨基酸>芳香族氨基酸;小米含9种药用氨基酸和3种支链氨基酸,其中药用氨基酸的平均含量为706.34 mg/kg,占FAA总量的比例为53.63%,具有潜在的药用价值;不同品种小米FAA间相关性显著,PCA共提取5个主成分,累计方差贡献率为86.20%,FAA综合评分排名前3的小米依次为陇谷23号、陇谷11号和豫谷18号;HCA将12份小米样品分为4个类群,第Ⅰ类(陇谷23号)和Ⅲ类(陇谷11号和豫谷18号)小米FAA综合品质表现最好,其FAA总量显著高于其他两个类群(P<0.05),而第Ⅱ类(会宁凉谷、陇谷18号、陇谷029号)小米FAA综合品质相对较差,与主成分分析的结果大体一致,可较好地反映不同品种小米间FAA品质的差异性。

关键词：小米游离氨基酸主成分分析聚类分析综合评价

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空间生产视域下赣州古城姚衙前历史文化街区景观更新研究

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城市建筑空间 2024年第1期31卷 66-68页

作者：张爱芹江西理工大学土木与测绘工程学院

历史文化街区景观更新是重要的空间生产过程,不仅能再生产和再分配空间资源,还能重塑街区的建筑形态、空间格局、文化氛围和社会结构,对于保护和传承历史文化遗产具有重要意义。基于空间生产理论,探讨姚衙前历史文化街区的空间演变及面... 详细信息

历史文化街区景观更新是重要的空间生产过程,不仅能再生产和再分配空间资源,还能重塑街区的建筑形态、空间格局、文化氛围和社会结构,对于保护和传承历史文化遗产具有重要意义。基于空间生产理论,探讨姚衙前历史文化街区的空间演变及面临的挑战,从文化空间、生活空间和生产空间3个维度探寻其景观更新的路径方式,以重塑街区活力。

关键词：城市更新空间生产历史文化街区景观空间更新策略

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均值回复跳扩散随机波动率模型下的欧式期权定价研究

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应用数学学报 2024年第2期47卷 333-354页

作者：马爱琴郭精军汪育兵张翠芸兰州财经大学统计与数据科学学院兰州730020 兰州财经大学甘肃经济发展数量分析研究中心兰州730020

考虑到金融市场数据波动的不确定性,本文提出了一个新的对数均值回复跳扩散4/2随机波动率(LMRJ-4/2-SV)模型.首先,构建了LMRJ-4/2-SV模型,并利用FFT等方法获得了基于LMRJ-4/2-SV模型的欧式期权定价公式.其次,对实际市场数据进行描述性... 详细信息

考虑到金融市场数据波动的不确定性,本文提出了一个新的对数均值回复跳扩散4/2随机波动率(LMRJ-4/2-SV)模型.首先,构建了LMRJ-4/2-SV模型,并利用FFT等方法获得了基于LMRJ-4/2-SV模型的欧式期权定价公式.其次,对实际市场数据进行描述性统计分析,探讨标的资产价格变化特征及LMRJ-4/2-SV模型的适用性,并通过粒子群优化算法估计模型参数.最后,基于LMRJ-4/2-SV模型下的期权定价公式及模型参数估计值对欧式期权进行定价,并将其定价结果与4/2、3/2、Heston模型估计值及市场价格进行对比.结果表明:基于LMRJ-4/2-SV模型的欧式期权定价误差最小,定价结果较其它随机波动率模型而言具有明显优势.

关键词：对数均值回复期权定价跳扩散随机波动

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