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Dynamic nanoscale imaging of enriched CO adlayer on Pt(111)confined under h-BN monolayer in ambient pressure atmospheres

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Nano Research 2019年第1期12卷 85-90页

作者： Hao Wu pengju ren Peng Zhao Zhongmiao Gong Xiaodong Wen Yi Cui Qiang Fu Xinhe Bao Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China State Key Lab of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China National Energy Center for Coal to Clean Fuels Synfuels China Co.LtdBeijing 101400China State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China Vacuum Interconnected Nanotech Workstation Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123China

Fun dame ntal un derstandi ng of chemistry confined to nano space remains a challe nge since molecules en capsulated in confined microe nviron merits are difficult to be ***,we show that CO adsorptio n on Pt(111)8nfined un der mono layer hexago nal boron nitride(h-BN)can be dynamically imaged using near ambient pressure seanning tunneling microscope(NAP-STM)and thanks to tunneling transparency of the top h-BN *** observed CO superstructures on Pt(111)in different CO atmospheres allow to derive surface coverages of CO adlayers,which are higher in the 8nfined nano space between h-BN and Pt(111)than those on the ope n Pt surface un der the same *** NAP-STM imaging data together with theoretical calculations confirm confinement-induced molecule enrichment effect within the 2D nano space,which reveals new chemistry aroused by the confined nano reactor.

关键词： two-dimensional materials confinement effect near ambient pressure scanning tunneling microscope(NAP-STM) molecule enrichment

Unveiling chain–chain interactions in CO2-based crystalline stereocomplexed polycarbonates by solid-state NMR spectroscopy and DFT calculations

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Journal of Energy Chemistry 2018年第2期27卷 361-366页

作者： Zhenchao Zhao pengju ren Ye Liu Kangbo Zhao Xiao-Bing Lu Weiping Zhang State Key Laboratory of Fine Chemicals School of Chemical Engineering Dalian University of Technology Dalian 116024 Liaoning China Srate Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences Taiyuan 030001 Shanxi China national Energy Center for Coal to Clean Fuels Synfuels China Co. Ltd Huairou District Beijing 101400 China

CO2-based stereocomplexed polycarbonates derived from the intermolecularly interlocked interaction between the enantiopure polymers with the opposite configuration exhibit high crystallinity, excellent thermal and mechanical stabilities. Deep insights into the mechanism of stereocomplexation are of particular importance to the design and manufacture of new promising and sustainable polycarbonates with enhanced physicochemical properties. Our solid-state NMR experiments linking with DFT computations clearly reveal the specific chain-chain interactions in a typical stereocomplexed poly（4,4-dimethyl-3,5,8-trioxabicyclo[5.1.0] octane carbonate）（PCXC）.13C CP/MAS NMR,1H DUMBO MAS NMR and 13C/1H relaxation-time measurements indicate that the formation of stereocomplex reduces the local mobilities of carbonyl, methine and methylene groups in each chain of PCXC significantly. Through a combination of two-dimensional 1H-13C HETCOR NMR and DFT calculation analysis, the cis-/trans-conformations and packing models of PCXC chains in the amorphous, enantionpure isotactic and stereocomplexed polycarbonates are identified. The splitting of 13C and 1H NMR chemical shifts of methine groups in the backbone carbon region demonstrates the ordered interlock interactions between the R-and S-chain in the stereocomplexed PCXC.

关键词： Stereocomplexed polycarbonates Crystalline carbonate polymers Stacking interaction Solid-state NMR DFT

Fe5C2 nanoparticles as low-cost HER electrocatalyst:the importance of Co substitution

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Science Bulletin 2018年第20期63卷 1358-1363页

作者： Siwei Li pengju ren Ce Yang Xi Liu Zhen Yin Weizhen Li Hanjun Yang Jian Li Xiaoping Wang Yi Wang Ruochen Cao Lili Lin Siyu Yao Xiaodong Wen Ding Ma College of Chemistry and Molecular Engineering Peking University Beijing 100871China State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China Syncat@Beijing Synfuels China Technology Co. LtdBeijing 101407China State Key Laboratory of Separation Membranes and Membrane Processes Department of Chemical Engineering Tianjin Polytechnic UniversityTianjin 300387China

Constructing and understanding the doping effect of secondary metal in transition metal carbide(TMC)catalysts is pivotal for the design of low-cost hydrogen evolution reaction(HER) electrocatalysts. In this work, we developed a wet-chemistry strategy for synthesizing Co-modified Fe_5C_2 nanoparticles((Fe_(1-x)Cox)_5C_2 NPs) as highly active HER electrocatalysts in basic solution. The structure of(Fe_(1-x)Cox)_5C_2 NPs was characterized by X-ray diffraction(XRD), extended X-ray absorption fine structure spectra(EXAFS) and scanning/transmission electron microscopy(S/TEM), indicating that the isomorphous substitution of cobalt in the lattice of Fe_5C_2.(Fe_(0.75) Co_(0.25))_5C_2 exhibited the best HER activity(174 mV for j = -10 mA/cm^2). Computational calculation results indicate that Co provides the most active site for HER. X-ray adsorption spectra(XAS) studies further suggested that the electron transfer in Fe–C bonds are enhanced by the substitution of Co, which modulates the hydrogen adsorption on the adjacent electronic-enriched carbon, and therefore promotes HER activity. Our results affirm the design of lowcost bimetallic TMCs based HER catalysts.

关键词： Wet-chemistry synthesis Bimetallic transition metal carbide Iron Cobalt Hydrogenation evolution reaction

Tunable redox reactions and catalytic activities by using carbon nanotube confined spaces

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Tunable redox reactions and catalytic activities by using ca...

Synthesis and characterization of an unusual snowflake-shaped ZSM-5 zeolite with high catalytic performance in the methanol to olefin reaction

中国化学会第十二届全国量子化学会议

作者： Jianping Xiao Shujing Guo pengju ren Xiulian Pan Xinhe Bao State Key Laboratory of Catalysis (SKLC) Dalian Institute of Chemical Physics (DICP)Chinese Academy of Science (CAS)

We performed calculations based on density functional theory and experimental studies to investigate the confinement effects in carbon *** found in the confined interior cavities of carbon nanotubes,the dissociative binding energies of CO,N2,and O2 are always weaker with respect to those on the same catalysts(Fe,Fe Co,Rh Mn,and Ru)supported on the *** weakened binding energies can be used to successfully interpret the pervious experimental observations in redox reactions,as well as being capable of predicting the activities of these catalysts in conjunction with theoretical microkinetic *** experimental results have also validated these predictions in two probe reactions,namely,the Fischer-Tropsch and ammonia *** present work demonstrates that a confined environment can result in significant strains on encapsulated catalysts and change their electronic ***,confinement effects exhibit the capability of tuning the intrinsic activity of catalysts.

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Chinese Journal of Catalysis 2016年第2期37卷 308-315页

作者：李静刘粟侥张怀科吕恩静任鹏举任杰中国科学院山西煤炭化学研究所煤间接液化国家工程实验室山西太原030001 中国科学院大学北京100049 中科合成油技术有限公司北京101407

The ZSM-5 zeolite with an unusual snowflake-shaped morphology was hydrothermally synthesized for the first time,and compared with common ellipsoidal and boat-like shaped *** samples were characterized by N2 adsorption-desorption,X-ray fluorescence spectroscopy,scanning electron microscopy,X-ray diffraction,magic angle spinning nuclear magnetic resonance,temperature-programmed desorption of ammonia,and infrared spectroscopy of pyridine *** results suggest that the BET surface area and SiO2/Al2O3 ratio of these samples are similar,while the snowflake-shaped ZSM-5 zeolite possesses more of the（101） face,and distortion,dislocation,and asymmetry in the framework,resulting in a larger number of acid sites than the conventional *** for the methanol to olefin（MTO） reaction were prepared by loading Ca on the *** snowflake-shaped Ca/ZSM-5 zeolite exhibited excellent selectivity for total light olefin（72%） and propene（39%） in *** catalytic performance influenced by the morphology can be mainly attributed to the snowflake-shaped ZSM-5 zeolite possessing distortion,dislocation,and asymmetry in the framework,and lower diffusion limitation than the conventional samples.

关键词： ZSM-5 zeolite Modification Methanol to olefins

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平板电视数字视频后处理芯片的设计与实现

西安交通大学学报 2008年第10期42卷 1285-1289页

作者：葛晨阳郑南宁任鹏举冯耀西安交通大学人工智能与机器人研究所西安710049

针对我国平板显示器件数字视频处理技术及芯片开发的需求,提出一种新结构的数字视频后处理芯片DTV100的设计方案及其关键技术指标.采用高效的SDRAM控制器实时地完成三维视频降噪、去隔行、帧频提升和运动补偿消锯齿、电影模式处理.提出... 详细信息

针对我国平板显示器件数字视频处理技术及芯片开发的需求,提出一种新结构的数字视频后处理芯片DTV100的设计方案及其关键技术指标.采用高效的SDRAM控制器实时地完成三维视频降噪、去隔行、帧频提升和运动补偿消锯齿、电影模式处理.提出了一种基于运动边缘检测的三维自适应降噪算法和基于双线性插值的视频缩放算法的硬件实现方法,该方法具有结构简单、硬件资源开支少、性能稳定的特点.依照规范的芯片设计流程,采用0.25μm CMOS工艺实现数字视频处理专用集成电路.与同类芯片的比较实验表明,该芯片性价比高.不同降噪因子的三维降噪功能测试表明,该芯片功能正常,达到了预期的技术指标.

关键词：数字视频自适应降噪视频缩放

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一种基于FPGA的卷积神经网络模型设计

航空兵器 2019年第2期26卷 15-20页

作者：丁晓彤徐佩任鹏举中国空空导弹研究院河南洛阳471009 航空制导武器航空科技重点实验室河南洛阳471009 西安交通大学西安710000

武器装备的智能化已经成为一种发展趋势,卷积神经网络(CNN)在图像识别、目标检测和跟踪任务中展现出优异的性能,因此,将卷积神经网络算法应用于相关武器有助于提升其在复杂战场环境下的精确目标识别和抗干扰能力。本文提出了一种基于FPG... 详细信息

武器装备的智能化已经成为一种发展趋势,卷积神经网络(CNN)在图像识别、目标检测和跟踪任务中展现出优异的性能,因此,将卷积神经网络算法应用于相关武器有助于提升其在复杂战场环境下的精确目标识别和抗干扰能力。本文提出了一种基于FPGA的卷积神经网络模型设计方法,并且在Xilinx Virtex-7系列FPGA验证了其功能的正确性。该模型具有可配置、可重构的高灵活性,移植能力强,适用范围广。

关键词：智能化目标识别卷积神经网络 FPGA 武器装备

基于高预测性的稀疏矩阵向量乘法并行计算优化

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计算机研究与发展 2023年第9期60卷 1973-1987页

作者：夏天付格林曲劭儒罗中沛任鹏举人机混合增强智能全国重点实验室(西安交通大学) 西安710049 视觉信息与应用国家工程研究中心(西安交通大学) 西安710049 西安交通大学人工智能与机器人研究所西安710049

稀疏矩阵向量乘法(sparse matrix-vector multiplication,SpMV)是广泛应用于科学计算、工业仿真和智能计算等领域的重要算法,是核心的计算行为之一.在一些应用场景中,需要进行多次的SpMV迭代,以完成精确的数值模拟、线性代数求解和图分... 详细信息

稀疏矩阵向量乘法(sparse matrix-vector multiplication,SpMV)是广泛应用于科学计算、工业仿真和智能计算等领域的重要算法,是核心的计算行为之一.在一些应用场景中,需要进行多次的SpMV迭代,以完成精确的数值模拟、线性代数求解和图分析收敛等计算要求.受限于SpMV本身的高度随机性和稀疏性所导致的数据局部性极差、缓存效率极低、计算模式非常不规则等问题,导致其计算负载成为当前高性能处理器的优化难点和研究热点.基于现代高性能超标量乱序处理器的架构特征,深入研究SpMV的各类性能瓶颈,并且提出从提升可预测性和降低程序复杂度的角度进行全面的性能优化.其核心思想是:通过构建串行访问的数据结构,提升数据访问的规律性和局部性,大幅度优化数据预取效率和缓存利用效率;通过构建规则的分支跳转条件,提升程序的分支预测准确率,有效提升程序执行效率;通过灵活运用SIMD指令集,有效提升计算资源利用率.通过对以上特性的优化,该方法可以显著缓解性能瓶颈,大幅度提升处理器资源、缓存资源和访存带宽的利用率,并且获得与主流商用计算库MKL相比平均2.6倍的加速比,相比于现有最先进算法获得平均1.3倍的加速比.

关键词：矩阵向量乘法稀疏矩阵计算矩阵格式分支预测数据预取

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现代医院医务人员素质谈

现代医院 2002年第2期2卷 36-39页

作者：任鹏举解放军第181医院 541002

素质是指人的先天的解剖生理特点,主要是感觉器官和神经系统方面的特点,特别是大脑的本质特征。在先天的基础上,受后天的教育训练、生产实践、社会实践、科学文化实践、环境影响,并通过自身努力而逐步形成的活动能力、基本品质和素养。... 详细信息

素质是指人的先天的解剖生理特点,主要是感觉器官和神经系统方面的特点,特别是大脑的本质特征。在先天的基础上,受后天的教育训练、生产实践、社会实践、科学文化实践、环境影响,并通过自身努力而逐步形成的活动能力、基本品质和素养。现代通常讲的素质,是指人们所从事的某个行业某项工作应具备的基本条件和内在特征。现代医院医务人员应具备的素质,主要有政治素质、管理素质、专业技术素质、思想道德素质、科学文化素质、健康与体能素质等。

关键词：医务人员素质