检索结果-南通市图书馆

Highly active sites of low spin Fe^(Ⅱ)N_(4)species:The identification and the ORR performance

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nano Research 2021年第1期14卷 122-130页

作者： Huizhu Cai Bingbing Chen xiao Zhang Yuchen Deng dequan xiao Ding Ma Chuan Shi State Key Laboratory of Fine Chemicals College of Chemical EngineeringDalian University of TechnologyDalian 116024China College of Chemistry and Molecular Engineering and College of Engineering Peking UniversityBeijing 100871China Center for Integrative Materials Discovery Department of Chemistry and Chemical EngineeringUniversity of New HavenCT 06516USA

Over recent years,catalytic materials of Fe-N-C species have been recognized being active for oxygen reduction reaction(ORR).However,the identification of active site remains challenging as it generally involves a pyrolysis process and mixed components being *** Fe_(3)C/C and Fe_(2)N/C samples were synthesized by temperature programmed reduction of Fe precursors in 15%CH_(4)/H_(2)and pure NH_(3),*** acid leaching of Fe_(2)N/C sample,only single sites of FeN_(4)species were presented,providing an ideal model for identification of catalytic functions of the single sites of FeN_(4)in ORR.A correlation was conducted between the concentration of Fe^(Ⅱ)N_(4)in low spin state by Mossbauer spectra and the kinetic current density at 0.8 V in alkaline media,and such a structure-performance correlation assures the catalytic roles of low spin Fe^(Ⅱ)N_(4) species as highly active sites for the ORR.

关键词： single sites of FeN_(4) oxygen reduction reaction structure-performance correlation electrocatalysis

Single-atom zinc catalyst for co-production of hydrogen and fine chemicals in soluble biomass solution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advanced Powder Materials

Advanced Powder Materials 2022年第4期1卷 99-107页

作者： Jiliang Ma Xinze Li Yancong Li Gaojie Jiao Hang Su dequan xiao Shangru Zhai Runcang Sun Liaoning Key Lab of Lignocellulose Chemistry and BioMaterials Liaoning Collaborative Innovation Center for Lignocellulosic BiorefineryCollege of Light Industry and Chemical EngineeringDalian Polytechnic UniversityDalian116034China Center for Integrative Materials Discovery Department of Chemistry and Chemical EngineeringUniversity of New Haven300 Boston Post RdWest HavenCT06516United States

Single-atom photocatalysts(SAPCs)have attracted great interests due to their remarkable atom utilization efficiency,excellent activity,and selectivity,yet no application in synchronous biorefinery and water ***,efficient SAPCs based on atomically dispersed Zn atoms on carbon nitride(named Zn-mCN)were *** verified that Zn-mCN has widened adsorption range of visible-light and lowered ability of electron-hole recombination,leading to excellent photocatalytic redox activity for synchronous biorefinery and water splitting to co-produce lactic acid(selectivity up to 91.0%)and hydrogen(-15898.8μmolg^(-1)h^(-1)).This system has excellent universality for small-molecule monosaccharides and macromolecular *** experiments showed that h^(+),1O2,·O_(2)-and·OH can promote the simultaneous production of lactic acid and *** work realized full utilization of whole redox reaction and provided a novel strategy for efficient and concomitant production of hydrogen and value-added chemicals from biomass-derived feedstocks aqueous solutions.

关键词： Biorefinery Single-atom photocatalyst Photocatalysis Hydrogen Co-production

Highly efficient K-Fe/C catalysts derived from metal-organic frameworks towards ammonia synthesis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2019年第9期12卷 2341-2347页

作者： Pengqi Yan Wenhan Guo Zibin Liang Wei Meng Zhen Yin Siwei Li Mengzhu Li Mengtao Zhang Jie Yan dequan xiao Ruqiang Zou Ding Ma Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular Engine ering and College of Engineeringand BIC-ESATPeking UniversityBeijing 100871China Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials Department of Materials Science and EngineeringCollege of EngineeringPeking UniversityBeijing 10087China State Key Laboratory of Separation Membranes and Membrane Processes School of Chemistry and Chemical EngineeringTianjin Polytechnic UniversityTianjin 300387China Department of Chemistry and Chemical Engineering University of New HavenWest HavenCT 06516USA

Fe-based catalysts have been discovered as the best elementary metal-based heterogeneous catalysts for the ammonia synthesis in industrial application during the last ***,a novel and scalable strategy is developed to prepare the K-promoted Fe/C catalyst with extremely high Fe loading (> 50 wt.%) through pyrolysis of the Fe-based metal-organic framework (MOF) *** obtained K-Fe/C catalysts exhibited superior activity and stability towards ammonia *** weight-specific reaction rate of Fe/C with K2O as promoter can achieve 12.4 mmol·g-1·h-1 at 350 ℃ and 30.4 mmol·g-1·h-1 at 400 ℃,approximately four and two times higher than that of the commercial fused-iron catalyst (3.4 mmol·g-1·h-1 at 350 ℃ and 16.7 mmol·g-1·h-1 at 400 ℃) under the same condition,*** excellent performance of K-Fe/C can be ascribed to the inherited structure derived from the metal-organic frame precursors and the promotion of potassium,which can modify the binding energy of reactant molecules on the Fe surface,transfer electrons to iron for effective activation of nitrogen,prevent agglomeration of Fe nanoparticle (NPs) and restrain side reaction of carbon matrix to methane.

关键词： metal-orga nic frameworks pyrolysis ammonia syn thesis ir on nano particles K promotion

Crystal-phase engineering of PdCu nanoalloys facilitates selective hydrodeoxygenation at room temperature

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Innovation 2022年第1期3卷 31-37页

作者： Shaopeng Li Minghua Dong Mi Peng Qingqing Mei Yanyan Wang Junjuan Yang Youdi Yang Bingfeng Chen Shulin Liu dequan xiao Huizhen Liu Ding Ma Buxing Han Beijing National Laboratory for Molecular Sciences Key Laboratory of Colloid and Interface and ThermodynamicsCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China School of Chemical Science University of Chinese Academy of SciencesBeijing 100049China Beijing National Laboratory for Molecular Engineering College of Chemistry and Molecular Engineering and College of EngineeringBIC-ESATPeking UniversityBeijing 100871China Center for Integrative Materials Discovery Department of Chemistry and Chemical EngineeringUniversity of New HavenWest HavenCT 06516USA

Selective hydrodeoxygenation of biomass-derived aromatic alcohols to value-added chemical or fuel is of great importance for sustainable biomass upgrading,and hydrodeoxygenation of 5-hydroxymethylfurfural(HMF)to 2,5-dimethylfuran(DMF)is one of the most attractive *** the conversion of HMF to DMF using H_(2)at ambient temperature is *** this work,we used PdCu nanoalloys to catalyze the selective hydrodeoxygenation reaction of HMF to DMF using H_(2)as the reducing *** reaction path and the product selectivity are governed by the crystallographic phase of the PdCu *** was discovered that body-centered cubic(BCC)PdCu nanoalloys supported on activated carbon(AC)exhibited outstanding performance with 93.6%yield of DMF at room temperature(PdCu/AC-BCC).A combination of experimental and density functional theory(DFT)studies showed that the tilted adsorption modes of furanic intermediates on PdCu-BCC nanoalloy surfaces accounted for the high selectivity of DMF;however,furan ring was activated on PdCu face-centered cubic(FCC)nanoalloy ***,PdCu/AC-BCC could also catalyze the hydrodeoxygenation of other aromatic alcohols at room temperature while maintaining the aromatic *** work opens the way for selective hydrodeoxygenation of the aromatic alcohols at room temperature with the aromatic ring intact.

关键词： alcohols aromatic selectivity

Vacuum System for HL-2A Tokamak

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Southwestern Institute of Physics Annual Report

Southwestern Institute of Physics Annual Report 2004年第1期 51-54页

作者： CAO Zeng CUI Chenghe FU Weidong LIU dequan CAI xiao GAO xiaoyan

The vacuum system of today＇s tokamak devices is designed to meet the operational requirements of the experiments. The operation can be divided into five modes, （1） pumping down and leak detecting of the vacuum vessel, （2） baking, （3） plasma-facing component （PFC） conditioning, （4）evacuating and controlling of the particles at plasma edge, （5） plasma discharge experiments.

关键词： Pumping system Pumping divertor GDC system

Electron Heat Transport during Center Fuelling by Pellet Injection on HL-2A Tokamak

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Southwestern Institute of Physics Annual Report

Southwestern Institute of Physics Annual Report 2005年第1期 1-3页

作者： DING Xuantong YANG Qingwei YAN Longwen LIU dequan xiao Zhenggui ZHU Genliang LIU Yi ZHOU Yan PAN Yudong CUI Zhengying LIU Zetian SHI Zhongbing JI xiaoquan xiao Weiwen LIU Yong

The improved energy confinement has been observed in many tokamaks with center pellet injection since 1980＇s. The pellet enhanced performance （ PEP ） was achieved with high power additional heating in JET and other large tokamaks. The mechanism of the PEP mode has been analyzed theoretically . The analysis shows that a few mechanisms are involved in the reduction of anomalous transport and the relative weight of these mechanisms depends on the experimental conditions. In this paper we report the pellet injection experiment results without auxiliary heating on HL-2A tokamak. Our works focus on the investigation of the electron heat transport in ohmic discharges with center pellet fuelling.

关键词： Electron heat transport Confinement Pellet injecting

Tumor inflammation-specific self-amplifying fluorescent molecular probes induce an anti-tumor immune response

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 2025年第1期68卷 273-287页

作者： Shuguang Yang Lijun Hu Hong xiao Zecong xiao Xintao Shuai PCFM Lab of Ministry of Education School of Materials Science and EngineeringSun Yat-sen UniversityGuangzhou 510275China Nanomedicine Research Center The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhou 510630China Department of Medical Ultrasound The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhou 510630China Department of Ultrasound The Fifth Affiliated HospitalSun Yat-sen UniversityZhuhai 519000China

Enhancing the concentration of exogenous molecular drugs within the tumor microenvironment through enzyme-catalyzed polymerization presents a novel strategy for cancer ***,the optimization of the catalytic efficiency is often impeded by the inefficient expression of ***,we reported a self-amplifying fluorescent molecular probe,Bis-HTPICG,for photodynamic therapy(PDT)and subsequent PDT-induced *** Bis-HTP-ICG probe possesses a noticeable enzyme-catalyzed polymerization facilitated by myeloperoxidase(MPO),a crucial enzyme secreted by neutrophils at inflammation *** exposure to laser irradiation,Bis-HTP-ICG showed a high PDT efficacy,inducing an acute inflammatory response that stimulates further recruitment of neutrophils and then elevated MPO *** heightened level of MPO enhances the accumulation of the Bis-HTP-ICG via self-polymerization or binding with intratumoral proteins following MPO enzyme catalysis,instigating a self-amplifying chain reaction cycle involving Bis-HTP-ICG,neutrophils and ***,PDT efficiently incites immunogenic cell death(ICD)in tumor cells,initiating an anti-tumor immune response including dendritic cells(DCs)maturation,T cell proliferation and reprogramming of tumor-associated neutrophils(TANs).This work portrays a promising strategy for self-amplification of fluorescent molecular probes through adjustable enzyme levels,potentially offering a unique avenue to enhance the tumor accumulation of molecular drugs for improved tumor therapy.

关键词： fluorescent molecular probes self-amplifying myeloperoxidase photodynamic therapy

离子自组装合成侧链型偶氮复合物及其聚集形态研究

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

化学学报 2010年第20期68卷 2111-2118页

作者：沙静林坤华赵永超刘明江波肖德泉殷勤俭四川大学化学学院成都610064 四川大学分析测试中心成都610064 耶鲁大学化学系康奈迪克州纽黑文市06522

用溶液聚合法制备了4-乙烯基吡啶与丙烯腈的无规共聚物(P4VP-r-AN),采用1HNMR,13CNMR,DSC和FTIR等手段确定了其结构和组成.粘度法测得其粘均分子量为1.06×104g/mol,由其1HNMR谱峰面积估算得到4-乙烯基吡啶链段的质量百分含量约为87.1%... 详细信息

用溶液聚合法制备了4-乙烯基吡啶与丙烯腈的无规共聚物(P4VP-r-AN),采用1HNMR,13CNMR,DSC和FTIR等手段确定了其结构和组成.粘度法测得其粘均分子量为1.06×104g/mol,由其1HNMR谱峰面积估算得到4-乙烯基吡啶链段的质量百分含量约为87.1%.以质子化的4-乙烯基吡啶-丙烯腈无规共聚物(P4VP+-r-AN)为模板,与酸性间胺黄(MY)在水溶液中通过离子自组装,制备了一种侧链型偶氮复合物(P4VP-r-AN/MY).用1HNMR,FT-IR,DSC,UV-Vis,SEM,TEM和HRTEM&EDS(高分辨率透射电镜与X射线能谱联用)等手段研究了该复合物的聚集形态及自组装过程.研究发现MY通过静电相互作用复合到P4VP+-r-AN链上并发生聚集,使复合物分子链聚集形成尺寸为10～200nm的球形聚集体.P4VP-r-AN/MY中,MY与P4VP-r-AN的物质的量之比为***&EDS测试结果显示P4VP-AN/MY球形聚集体中硫元素的分布接近球形,与聚集体的形状几乎一致,表明MY分子在该组装物中主要以球形纳米聚集体的形式存在.

关键词：离子自组装聚电解质酸性间胺黄偶氮复合物球形聚集体

Target Search and Navigation in Heterogeneous Robot Systems with Deep Reinforcement Learning

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Machine Intelligence Research 2025年第1期22卷 79-90页

作者： Yun Chen Jiaping xiao Department of Mechanical Engineering University of AlabamaTuscaloosa35487USA School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore639798Singapore

Collaborative heterogeneous robot systems can greatly enhance the efficiency of target search and navigation *** this paper,we design a heterogeneous robot system consisting of an unmanned aerial vehicle(UAV)and an unmanned ground vehicle(UGV)for search and rescue missions in unknown *** system is able to search for targets and navigate to them in a maze-like mine environment with the policies learned through deep reinforcement learning *** the training process,if two robots are trained simultaneously,the rewards related to their collaboration may not be properly ***,we introduce a multi-stage reinforcement learning framework and a curiosity module to encourage agents to explore unvisited *** in simulation environments show that our framework can train the heterogeneous robot system to achieve the search and navigation with unknown target locations while existing baselines may *** UGV achieves a success rate of 89.1%in the mission within the original environment,and maintains a 67.6%success rate in untrained complex environments.

关键词： Heterogeneous intelligent systems deep reinforcement learning multiagent systems robot learning target search