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Confinement of ionomer for electrocatalytic CO2 reduction reaction via efficient mass transfer pathways

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National Science Review 2024年第2期11卷 168-176页

作者： Xiaowei Du Peng zhang Gong zhang Hui Gao Lili zhang Mengmeng zhang Tuo Wang Jinlong Gong School of Chemical Engineering and Technology Key Laboratory for Green Chemical Technology of the Ministry of Education Tianjin University Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) National Industry-Education Platform of Energy Storage Tianjin University Joint School of the National University of Singapore and Tianjin University International Campus of Tianjin University Haihe Laboratory of Sustainable Chemical Transformations

Gas diffusion electrodes（GDEs） mediate the transport of reactants, products and electrons for the electrocatalytic CO2reduction reaction（CO2RR） in membrane electrode assemblies. The random distribution of ionomer, added by the traditional physical mixing method, in the catalyst layer of GDEs affects the transport of ions and CO2. Such a phenomenon results in elevated cell voltage and decaying selectivity at high current densities. This paper describes a pre-confinement method to construct GDEs with homogeneously distributed ionomer, which enhances mass transfer locally at the active centers. The optimized GDE exhibited comparatively low cell voltages and high CO Faradaic efficiencies（FE > 90%） at a wide range of current densities. It can also operate stably for over 220 h with the cell voltage staying almost unchanged. This good performance can be preserved even with diluted CO2feeds, which is essential for pursuing a high single-pass conversion rate. This study provides a new approach to building efficient mass transfer pathways for ions and reactants in GDEs to promote the electrocatalytic CO2RR for practical applications.

关键词： CO2 electroreduction gas diffusion electrode mass transfer ionomer Ag catalyst

Possibilities for the synthesis of superheavy element Z=121 in fusion reactions

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Nuclear Science and Techniques 2024年第6期35卷 90-100页

作者： Ming-Hao zhang Yu-Hai zhang Ying Zou Xiu-Xiu Yang Gen zhang Feng-Shou zhang The Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China School of Physical Science and Technology Guangxi UniversityNanning 530004China National Laboratory of Heavy Ion Accelerator of Lanzhou Center of Theoretical Nuclear PhysicsLanzhou 730000China

Based on the dinuclear system model,the calculated evaporation residue cross sections matched well with the current experimental *** synthesis of superheavy elements Z=121 was systematically studied through combinations of stable projectiles with Z=21-30 and targets with half-lives exceeding 50 *** influence of mass asymmetry and isotopic dependence on the projectile and target nuclei was investigated in *** reactions^(254)Es(^(46)Ti,3n)^(297)121 and^(252)Es(^(46)Ti,3n)^(295)121 were found to be experimentally feasible for synthesizing superheavy element Z=121,with maximal evaporation residue cross sections of 6.619 and 4.123 fb at 219.9 and 223.9 MeV,respectively.

关键词： Superheavy nuclei Dinuclear system model Fusion reaction Evaporation residue cross section

基于准维多区模型的DME发动机燃烧数值模拟

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华中科技大学学报（自然科学版） 2006年第12期34卷 101-104页

作者：张鹏张煜盛莫春兰华中科技大学能源与动力工程学院湖北武汉430074

提出了一种基于准维多区模型的直喷式二甲醚发动机燃烧过程的数值模拟方法,其中喷雾模拟考虑了燃油分布、液滴蒸发和空气卷吸对喷雾混合的影响,自燃着火过程的模拟以二甲醚着火反应机理为基础,建立了计及温度、压力和燃空当量比因素的... 详细信息

提出了一种基于准维多区模型的直喷式二甲醚发动机燃烧过程的数值模拟方法,其中喷雾模拟考虑了燃油分布、液滴蒸发和空气卷吸对喷雾混合的影响,自燃着火过程的模拟以二甲醚着火反应机理为基础,建立了计及温度、压力和燃空当量比因素的着火滞燃期数据库,通过将该数据库与准维多区喷雾混合模型相耦合,对二甲醚发动机的性能和一氧化氮排放进行了预测分析.实验结果表明,模拟计算结果与实测数据符合较好.

关键词：内燃机二甲醚燃烧模型滞燃期数据库

Degradable magnesium alloy suture promotes fibrocartilaginous interface regeneration in a rat rotator cuff transosseous repair model

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Journal of Magnesium and Alloys 2024年第1期12卷 384-393页

作者： Baoxiang zhang Wen zhang Fei zhang Chao Ning Mingyang An Ke Yang Lili Tan Qiang zhang Department of Sports Medicine Chinese PLA General HospitalBeijing 100853China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Medical School of PLA Beijing 100853China Institute of Orthopedics Chinese PLA General HospitalBeijing Key Lab of Regenerative Medicine in OrthopedicsKey Lab of Musculoskeletal Trauma&War Injuries of Chinese PLABeijing 100853China

Despite transosseous rotator cuff tear repair using sutures is widely accepted for tendon-bone fixation,the fibrocartilaginous enthesis regeneration is still hardly achieved with the traditional *** the present work,degradable magnesium(Mg)alloy wire was applied to suture supraspinatus tendon in a rat acute rotator cuff tear model with Vicryl Plus 4±0 absorbable suture as *** shoulder joint humerus-supraspinatus tendon complex specimens were retrieved at 4,8,and 12 weeks after *** Mg alloy suture groups showed better biomechanical properties in terms of ultimate load to *** observation showed that hyperplastic response of the scar tissue at the tendon-bone interface is progressively alleviated over time in the both Mg alloy suture and Vicryl suture *** the histological analysis,for Mg alloy suture groups,chondrocytes appear to proliferate at 4 weeks postoperatively,and the tendon-bone interface showed an orderly structural transition zone at 8 weeks *** collagenous fiber tended to be aligned and the tendon-bone interlocking structures apparently formed,where transitional structure from unmineralized fibrocartilage to mineralized fibrocartilage was closer to the native fibrocartilaginous *** vivo degradation of the magnesium alloy wire was completed within 12 *** results indicated that Mg alloy wire was promising as degradable suture with the potential to promotes fibrocartilaginous interface regeneration in rotator cuff repair.

关键词： Rotator cuff repair Mg alloy wire Tendon-bone healing Fibrocartilaginous interface

Diatomic Pd catalyst with conjugated backbone for synergistic electrochemical CO_(2)reduction

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Nano Research 2024年第6期17卷 4850-4855页

作者： Wenxuan zhang Mengran zhang Hongjuan Wang Wen zhang Min zhang MOE International Joint Laboratory of Materials Microstructure Institute for New Energy Materials and Low Carbon TechnologiesSchool of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion School of Chemistry and Chemical EngineeringTianjin University of TechnologyTianjin 300384China

Double-site catalysts have attracted widespread attention in the field of electrocatalysis due to their high metal loading,adjustable active centres,and electronic valence ***,the development of bimetallic sites catalysts that coordinate with definite atoms is still in the exploratory ***,we designed and synthesized a bimetallic palladium complex(BPB-Pd_(2))with conjugated *** supported BPB-Pd_(2)was applied to electrochemical CO_(2)reduction reaction(CO_(2)RR)for the first *** as-obtained BPB-Pd_(2)gives an exceptional Faradaic efficiency of CO(FECO)of 94.4%at−0.80 V *** hydrogen electrode(RHE),which is significantly superior to monoatomic palladium catalyst(BPB-Pd1).The density functional theory(DFT)calculations revealed that the essential reason for the outstanding activity of BPB-Pd_(2)toward CO_(2)RR was that the electronic effect between diatomic palladium reduces the free energy change for CO_(2)RR ***,BPB-Pd_(2)exhibits moderate free energy change to form COOH*intermediate,which was beneficial for the generation of CO in CO_(2)RR.

关键词： synthesis electrocatalysis CO_(2)reduction bimetallic palladium complex synergistic catalysis

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实时棒材图像识别与跟踪方法研究

北京航空航天大学学报 2006年第5期32卷 575-579页

作者：张育胜付永领北京航空航天大学自动化科学与电气工程学院北京100083

多目标识别跟踪的关键问题是特征提取和目标匹配.为了提取生产线上堆积棒材的特征,提出粘连目标分割和多目标识别的方法.采用中值滤波和形态学滤波去除噪声,自适应阈值化和分水岭变换分割粘连目标;然后采用区域统计、参数识别、噪声区... 详细信息

多目标识别跟踪的关键问题是特征提取和目标匹配.为了提取生产线上堆积棒材的特征,提出粘连目标分割和多目标识别的方法.采用中值滤波和形态学滤波去除噪声,自适应阈值化和分水岭变换分割粘连目标;然后采用区域统计、参数识别、噪声区域去除以及聚类分析等手段进行目标特征识别,提取出棒材的质心点坐标作为特征;对棒材图像序列提出采用模板匹配、相近位移匹配和Kalman滤波的方法建立跟踪链,通过插入、删除、更新链节点进行目标跟踪;对于图像处理中可能出现的漏检目标和虚增目标,进行了计数结果校正.在现场采集了100帧连续图像后,采用此方法跟踪计数的精度为96.2%.

关键词：多目标识别跟踪模板匹配特征点对应 Kalman滤波

Road map for, and technical challenges of, carbon-nanotube integrated circuit technology

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National Science Review 2024年第3期11卷 14-16页

作者： Jia Si Panpan zhang Zhiyong zhang Key Laboratory for the Physics and Chemistry of Nanodevices and Center for Carbon-based Electronics School of Electronics Peking University State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

The past decade has witnessed an explosion of research on carbon-nanotube(CNT) electronics due to their outstanding properties, including an ultrathin body, a high carrier mobility and a high saturation velocity.

关键词： TRANSISTORS

Solid Bronsted acidity boosts adsorption reactivity of nano-adsorbent for water decontamination

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Frontiers of Environmental Science & Engineering 2024年第7期18卷 23-34页

作者： Sikai Cheng Zhixian Li Kaisheng zhang Qingrui zhang Xiaolin zhang Bingcai Pan State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China Environmental Materials and Pollution Control Laboratory Institute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China Hebei Key Laboratory of Heavy Metal Deep-remediation in Water and Resource Reused Qinhuangdao 066004China Research Center for Environmental Nanotechnology(ReCENT) Nanjing UniversityNanjing 210023China

Despite the development of various Lewis acidic nano-adsorbents for fluoride removal through innersphere coordination,strong competition for hydroxyl ions still hinders efficient water *** addition,the critical issue of polysilicate scaling that results from the ubiquitous silicates must be *** tackle these issues,an alternative approach to enhancing adsorption reactivity by modifying nano-adsorbents with dual Lewis and Bronsted acidity is *** feasibility of this approach is demonstrated by growing zirconium phosphate(ZrP)inside a gel-type anion exchanger,N201,to produce nanocomposite ZrP@N201,in which the confined ZrP contained an otherwise metastable amorphous phase with Lewis acidic Zr^(4+) sites and Bronsted acidic monohydrogen phosphate groups(-O_(3)POH).Compared with the Lewis acidic nano-zirconium oxide analog(HZ0@N201),ZrP@N201 exhibited a greatly improved adsorption capacity(117.9 vs.52.3 mg/g-Zr)and mass transfer rate(3.56×10^(-6) vs.4.55×10^(-7) cm/s),while bulk ZrP produced a thermodynamically stableα-phase with Bronsted acidity that exhibited negligible adsorption capability toward *** enhanced defluoridation activity of ZrP@N201 is attributed to Bronsted acidity and the increased outer electron density of ZA+sites,as corroborated using XPS and solid-state NMR ***,Bronsted acidity strengthens the resistance of ZrP@N201 to silicate,allowing its full regeneration during cyclic *** tests demonstrated 3-10 times the amount of clean water from(waste)for ZrP@N201 as compared to both HZO@N201 and the widely used activated aluminum *** study highlights the potential of developing nano-adsorbents with dual acidities for various environmental remediation applications.

关键词： Nanocomposite Selective adsorption Fluoride removal Dual Lewis and Bronsted acidity Regeneration

Flexible regulation engineering of titanium nitride nanofibrous membranes for efficient electromagnetic microwave absorption in wide temperature spectrum

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Nano Research 2024年第3期17卷 1666-1675页

作者： Cuiping Li Lu zhang Shuai zhang Qiqi Yu Dan Li Lei zhang Chunhong Gong Jingwei zhang Institute of Functional Polymer Composites College of Chemistry and Molecular SciencesHenan UniversityKaifeng 475004China National&Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials Henan UniversityKaifeng 475004China

Simultaneous development of well impedance matching and strong loss capability has become a mainstream method for achieving outstanding electromagnetic microwave absorption(EMWA)performances over wide temperature ***,it is difficult to pursue both due to the mutual restraint of relationship between impedance matching and loss capability about ***,we propose a flexible regulation engineering of titanium nitride(TiN)nanofibrous membranes(NMs,TNMs),which could be distributed uniformly in the polydimethylsiloxane(PDMS)matrix and contributed to the formation of abundant local conductive networks,generating the local conductive loss and enhancing the loss ability of ***,when the TNMs are used as functional units and dispersed in the matrix,the corresponding composites exhibit an outstanding anti-reflection effect on *** hoped,under the precondition of good impedance matching,local conductive loss and polarization loss together improve the loss capacity at room temperature,and polarization loss can compensate the local conductive loss to acquire effective dielectric response at elevated *** from the reasonably synergistic loss ability caused by flexible regulation engineering,the corresponding composites exhibit the perfect EMWA performances in a wide temperature range from 298 to 573 *** work not only elaborates the ponderable insights of independent membrane in the composition-structure-function connection,but also provides a feasible tactic for resolving coexistence of well impedance matching and strong loss capability issues in wide temperature spectrum.

关键词： flexible titanium nitride nanofibrous membranes local conductive loss dielectric loss electromagnetic microwave absorption wide temperature spectrum