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Interface sites on vanadia-based catalysts are highly active for NO_(x) removal under realistic conditions

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Journal of Environmental Sciences 2024年第2期136卷 523-536页

作者： Zhihui Lv Guangzhi He Wenshuo Zhang Jingjing Liu Zhihua Lian Yang Yang Zidi Yan guangyan xu Wenpo Shan Yunbo Yu Hong He State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341000China Ningbo Research Center for Urban Environment Chinese Academy of SciencesNingbo 315800China

TiO_(2)-supported V_(2)O_(5)catalysts are commonly used in NO_(x)reduction with ammonia due to their robust catalytic performance.Over these catalysts,it is generally considered that the active species are mainly derived from the vanadia species rather than the intrinsic structure of V-O-Ti entities,namely the interface sites.To reveal the role of V-O-Ti entities in NH_(3)-SCR,herein,we prepared TiO_(2)/V_(2)O_(5)catalysts and demonstrated that V-O-Ti entities were more active for NO_(x)reduction under wet conditions than the V sites(V=O)working alone.On the V-O-Ti entities,kinetic measurements and first principles calculations revealed that NH_(3)activation exhibited a much lower energy barrier than that on V=O sites.Under wet conditions,the V-O-Ti interface significantly inhibited the transformation of V=O to V-OH sites thus benefiting NH_(3)activation.Under wet conditions,meanwhile,the migration of NH_(4)^(+)from Ti site neighboring the V-O-Ti interface to Ti site of the V-O-Ti interface was exothermic;thus,V-O-Ti entities together with neighboring Ti sites could serve as channels linking NH_(3)pool and active centers for activation of NH_(4)^(+).This finding reveals that the V-O-Ti interface sites on V-based catalysts play a crucial role in NO_(x)removal under realistic conditions,providing a new perspective on NH_(3)-SCR mechanism.

关键词： NO_(x)removal Vanadia-based catalysts V-O-Ti entities Interface sites Reaction mechanism

Nano-sized alumina supported palladium catalysts for methane combustion with excellent thermal stability

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Journal of Environmental Sciences 2023年第4期126卷 333-347页

作者： Wei Shi guangyan xu xuewang Han Yingjie Wang Zhi Liu Sen xue Nannan Sun Xiaoyan Shi Yunbo Yu Hong He State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Weichai Power Co. Ltd.Weifang 261061China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China

Pd/Al_(2)O_(3)catalysts supported on Al_(2)O_(3)of different particle sizes were synthesized and applied in methane combustion.These catalysts were systematically characterized by Brunauer-Emmett-Teller (BET),X-ray diffraction (XRD),high resolution-transmission electron microscopy (HR-TEM),high-angle annular dark?eld-scanning transmission electron microscopy (HAADF-STEM),H_(2)-temperature-programmed reduction (H_(2)-TPR),O_(2)-temperature-programmed oxidation (O_(2)-TPO),X-ray photoelectron spectroscopy (XPS),and X-ray absorption?ne structure (XAFS).The characterization results indicated that nanosized Al_(2)O_(3)enabled the uniform dispersion of palladium nanoparticles,thus contributing to the excellent catalytic performance of these nano-sized Pd/Al_(2)O_(3)catalysts.Among them,Pd/Al_(2)O_(3)-nano-10 (Pd/Al_(2)O_(3)supported by alumina with an average particle size of 10 nm)showed superior catalytic activity and stability for methane oxidation under harsh practical conditions.It maintained excellent catalytic performance for methane oxidation for50 hr and remained stable even after harsh hydrothermal aging in 10 vol.%steam at 800℃ for 16 hr.Characterization results revealed that the strong metal-support interactions and physical barriers provided by Al_(2)O_(3)-nano-10 suppressed the coalescence ripening of palladium species,and thus contributed to the superior sintering resistance of the Pd/Al_(2)O_(3)-nano-10 catalyst.

关键词： Methane combustion Pd/Al_(2)O_(3) Hydrothermal stability Metal-support interaction Physical barriers

Advances in emission control of diesel vehicles in China

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Journal of Environmental Sciences 2023年第1期123卷 15-29页

作者： guangyan xu Wenpo Shan Yunbo Yu Yulong Shan Xiaodong Wu Ye Wu Shaojun Zhang Liqiang He Shijin Shuai Hailong Pang xuefeng Jiang Heng Zhang Lei Guo Shufen Wang Feng-Shou Xiao Xiangju Meng Feng Wu Dongwei Yao Yan Ding Hang Yin Hong He Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China Institute of Urban Environment Chinese Academy of SciencesXiamen 361021China Tsinghua University Beijing 100084China Army Military Transportation University Tianjin 300161China Dongfeng Motor Corporation Wuhan 430101China China National Heavy Duty Truck Group Company Limited Jinan 250000China Zhejiang University Hangzhou 310027China Chinese Research Academy of Environmental Sciences Beijing 100012China

Diesel vehicles have caused serious environmental problems in China.Hence,the Chinese government has launched serious actions against air pollution and imposed more stringent regulations on diesel vehicle emissions in the latest China VI standard.To fulfill this stringent legislation,two major technical routes,including the exhaust gas recirculation(EGR)and high-efficiency selective catalytic reduction(SCR)routes,have been developed for diesel engines.Moreover,complicated aftertreatment technologies have also been developed,including use of a diesel oxidation catalyst(DOC)for controlling carbon monoxide(CO)and hydrocarbon(HC)emissions,diesel particulate filter(DPF)for particle mass(PM)emission control,SCR for the control of NOx emission,and an ammonia slip catalyst(ASC)for the control of unreacted NH3.Due to the stringent requirements of the China VI standard,the aftertreatment system needs to be more deeply integrated with the engine system.In the future,aftertreatment technologies will need further upgrades to fulfill the requirements of the near-zero emission target for diesel vehicles.

关键词： Diesel vehicles Legislation Emission control Aftertreatment system Nitrogen oxides Particulate matter

基于改进Faster R-CNN的隧道衬砌中离散实体目标自动检测研究

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铁道学报 2024年第2期46卷 171-180页

作者：崔广炎王艳辉徐杰丁冠军秦湘怡任秋阳北京交通大学先进轨道交通自主运行全国重点实验室北京100044 北京交通大学交通运输学院北京100044 北京交通大学北京市城市交通信息智能感知与服务工程技术研究中心北京100044 北京交通大学城市轨道交通运营安全管理技术及装备交通运输行业研发中心北京100044

隧道衬砌中离散实体目标的检测精度和时效性直接关乎隧道的运营安全,采用图像视觉技术进行图像自动解译可极大提升检测效率和结果的准确性,因此基于离散实体目标的雷达图像数据构建自定义雷达数据集合,并提出一套改进的Faster R-CNN算... 详细信息

隧道衬砌中离散实体目标的检测精度和时效性直接关乎隧道的运营安全,采用图像视觉技术进行图像自动解译可极大提升检测效率和结果的准确性,因此基于离散实体目标的雷达图像数据构建自定义雷达数据集合,并提出一套改进的Faster R-CNN算法对隧道衬砌中的离散实体目标进行自动检测。该算法首先对现有Faster R-CNN网络的特征提取模块进行改进,提出一套全新的轻量化特征提取网络ResNet_FMBConv对雷达图像特征进行深度挖掘;基于ResNet_FMBConv网络改进现有特征金字塔(FPN)结构,实现对多尺寸下目标的精准辨识。其次,基于实测和仿真的雷达图像数据构建离散实体目标的自定义雷达数据集合,通过几何变换方法对雷达图像进行数据增强后用于算法验证。结果表明,改进算法在IOU=0.50∶0.95情况下的检测精确率、召回率、F 1分数和FPS分别为45.1%、54.0%、49.1%和21.65 fps。在保证召回率基本持平的情况下,同比YOLOv3_spp、SSD、Retinanet和Faster R-CNN等目标检测算法的精确率和F 1分数分别提升2%~9%和1%~6%。同时,试验结果表明改进后的特征提取网络ResNet_FMBConv也优于现有Resnet-50、VGG16、Efficientnet_b0和Mobilenetv3等目标分类网络。

关键词：离散实体目标检测 Faster R-CNN ResNet_FMBConv模块 GPR 特征金字塔

Super solutions of the model RB

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Frontiers of Computer Science 2022年第6期16卷 191-193页

作者： guangyan ZHOU Wei xu Department of Mathematics Beijing Technology and Business UniversityBeijing 100048China School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China

1 Introduction Constraint satisfaction problems(CSPs)have come to play a prominent role in the area of computer science,statistical physics and information theory.A CSP instance involves a set of variables and a set of constraints,and the task is to find a solution(an assignment of variables that satisfies all the constraints)or to prove the unsolvability.Model RB[1]is a CSP model proposed to overcome the trivial unsatisfiability of standard Model B[2].

关键词： theory. constraints trivial

肾脏不同区域体素内不相干运动扩散加权成像定量参数诊断IgA肾病的价值

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中华放射学杂志 2024年第6期58卷 640-646页

作者：翟雪陈仆周少鹏白旭赵建王涌张利蔡广研王松王海屹解放军总医院第一医学中心放射诊断科北京100853 解放军总医院第一医学中心肾内科北京100853

目的探讨肾脏不同区域体素内不相干运动扩散加权成像(IVIM-DWI)参数在区别IgA肾病患者与健康志愿者中的价值。方法本研究为横断面研究,前瞻性收集2022年2月至2023年9月在解放军总医院第一医学中心接受肾脏穿刺活检术(左肾下极)并经病理... 详细信息

目的探讨肾脏不同区域体素内不相干运动扩散加权成像(IVIM-DWI)参数在区别IgA肾病患者与健康志愿者中的价值。方法本研究为横断面研究,前瞻性收集2022年2月至2023年9月在解放军总医院第一医学中心接受肾脏穿刺活检术(左肾下极)并经病理证实的84例IgA肾病患者(IgA肾病组)及34例健康志愿者(对照组)的肾脏IVIM-DWI图像资料,分别在右肾皮质、髓质和实质勾画感兴趣区,测量相应区域的表观扩散系数(ADC)、真扩散系数(D)、假性扩散系数(D^(*))和灌注分数(f)。采用独立样本t检验或Mann-Whitney U检验比较IgA肾病组与对照组间各区域IVIM-DWI参数的差异,对差异有统计学意义的参数进行受试者操作特征曲线分析,计算曲线下面积(AUC)。结果IgA肾病组与对照组间肾皮质ADC、肾实质ADC、肾皮质D、肾实质D和肾髓质f差异有统计学意义(Z=-3.03、-2.21、-2.62、-2.03、-2.03,P=0.002、0.027、0.009、0.043、0.042),其诊断IgA肾病的AUC(95%CI)分别为0.679(0.586~0.762)、0.630(0.537~0.717)、0.654(0.535~0.774)、0.619(0.497~0.742)和0.620(0.495~0.745)。2组间肾髓质ADC、D,肾皮质、髓质和实质D*,肾皮质和肾实质f差异无统计学意义(P>0.05)。结论肾脏IVIM-DWI定量参数受不同测量区域影响,其中肾皮质和肾实质ADC、D和肾髓质f可用于初步诊断IgA肾病。

关键词：肾小球肾炎,IgA 磁共振成像体素内不相干运动扩散加权成像

MRI预测乳腺非特殊型浸润性导管癌Luminal分型的临床价值

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黑龙江医学 2024年第8期48卷 945-948,952页

作者：许东陈代辉斯光晏刘勇王欧成郭锐西南医科大学附属中医医院放射科四川泸州646000 泸县第二人民医院四川泸州646100

目的:探讨乳腺非特殊型浸润性导管癌Luminal分型的MRI表现,为乳腺非特殊型浸润性导管癌的诊疗提供更优的选择。方法:回顾性分析2018年10月8日—2021年12月1日经样本医院手术病理证实为乳腺非特殊型浸润性导管癌的119例女性患者的临床及... 详细信息

目的:探讨乳腺非特殊型浸润性导管癌Luminal分型的MRI表现,为乳腺非特殊型浸润性导管癌的诊疗提供更优的选择。方法:回顾性分析2018年10月8日—2021年12月1日经样本医院手术病理证实为乳腺非特殊型浸润性导管癌的119例女性患者的临床及影像学资料。比较Luminal型和非Luminal型的临床特征及MRI影像特征。绘制ROC曲线,计算ROC曲线下的面积及截断点。结果:119例乳腺非特殊型浸润性导管癌中,Luminal型72例,非Luminal型47例。患者有无淋巴结转移、肿瘤的最大径、肿瘤形态、TIC曲线、最小表观扩散系数(apparent diffusion coefficient,ADC)值和平均ADC值比较,差异统计学意义(P<0.05)。当最小ADC值和平均ADC值分别为0.851×10^(-3)mm^(2)/s、0.849×10^(-3)mm^(2)/s时,其特异度和敏感度分别为0.553、0.806和0.681、0.750,ROC曲线下面积分别为0.745、0.761。结论:MRI可以提高乳腺非特殊型浸润性导管癌的诊断效能,其ADC值可作为其临床及预后的重要指标,更有利于临床进行更精准的治疗。

关键词：乳腺非特殊型浸润性导管癌 Luminal分型临床价值

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基于区块链的医药数据追溯探索研究

中国数字医学 2024年第1期19卷 24-28页

作者：王存库陈光焰傅丽雅许德俊海南省卫生健康委员会统计信息中心海口570100 上海信医科技有限公司

目的:探讨基于区块链的医药数据追溯与监测技术的可行性和有效性。方法:提出了一种基于区块链的医药数据追溯与监测系统架构,并通过与药品监管码的结合,设计了相应的数据流程和加密安全机制,利用分布式账本技术,实现医药数据的可信追溯... 详细信息

目的:探讨基于区块链的医药数据追溯与监测技术的可行性和有效性。方法:提出了一种基于区块链的医药数据追溯与监测系统架构,并通过与药品监管码的结合,设计了相应的数据流程和加密安全机制,利用分布式账本技术,实现医药数据的可信追溯和实时监测。结果:基于区块链的医药数据追溯与监测系统能够实现医药数据的可信追溯和实时监测。相比传统方法,该系统具有更高的数据可信度和安全性,在医药监管、药品追溯和健康管理等方面具有广泛的应用场景。结论:基于区块链的医药数据追溯与监测技术,提高了药品的可塑性和安全性,具备良好的可行性。

关键词：区块链医药数据:追溯:监测

Telomere-to-telomere pear (Pyrus pyrifolia) reference genome reveals segmental and whole genome duplication driving genome evolution

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Horticulture Research 2023年第11期10卷 106-119页

作者： Manyi Sun Chenjie Yao Qun Shu Yingyun He Guosong Chen guangyan Yang Shaozhuo xu Yueyuan Liu Zhaolong xue Jun Wu College of Horticulture State Key Laboratory of Crop Genetics&Germplasm Enhancement and UtilizationNanjing Agricultural UniversityNanjingJiangsu 210095China Zhongshan Biological Breeding Laboratory No.50 Zhongling StreetNanjingJiangsu 210014China Institute of Horticulture Yunnan Academy of Agricultural SciencesKunming 650205China

Previously released pear genomes contain a plethora of gaps and unanchored genetic regions.Here,we report a telomere-to-telomere(T2T)gap-free genome for the red-skinned pear,‘Yunhong No.1’(YH1;Pyrus pyrifolia),which is mainly cultivated in Yunnan Province(southwest China),the pear’s primary region of origin.The YH1 genome is 501.20 Mb long with a contig N50 length of 29.26 Mb.All 17 chromosomes were assembled to the T2T level with 34 characterized telomeres.The 17 centromeres were predicted and mainly consist of centromeric-specific monomers(CEN198)and long terminal repeat(LTR)Gypsy elements(≥74.73%).By filling all unclosed gaps,the integrity of YH1 is markedly improved over previous P.pyrifolia genomes(‘Cuiguan’and‘Nijisseiki’).A total of 1531 segmental duplication(SD)driven duplicated genes were identified and enriched in stress response pathways.Intrachromosomal SDs drove the expansion of disease resistance genes,suggesting the potential of SDs in adaptive pear evolution.A large proportion of duplicated gene pairs exhibit dosage effects or sub-/neo-functionalization,whichmay affect agronomic traits like stone cell content,sugar content,and fruit skin russet.Furthermore,as core regulators of anthocyanin biosynthesis,we found that MYB10 and MYB114 underwent various gene duplication events.Multiple copies of MYB10 and MYB114 displayed obvious dosage effects,indicating role differentiation in the formation of red-skinned pear fruit.In summary,the T2T gap-free pear genome provides invaluable resources for genome evolution and functional genomics.

关键词： dosage evolution driving