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Recent Advances in Mechanistic Understanding of Metal-Free Carbon Thermocatalysis and Electrocatalysis with Model Molecules

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Nano-Micro Letters 2024年第7期16卷 74-97页

作者： Wei Guo linhui Yu ling Tang Yan Wan yangming lin CAS Key Laboratory of Design and Assembly of Functional Nanostructures Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002People’s Republic of China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen 361021People’s Republic of China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002People’s Republic of China Institute of Urban Environment Chinese Academy of SciencesXiamen 361021People’s Republic of China

Metal-free carbon,as the most representative heterogeneous metal-free catalysts,have received considerable interests in electro-and thermo-catalytic reac-tions due to their impressive performance and *** the past decade,well-designed carbon catalysts with tunable structures and heteroatom groups coupled with various characterization techniques have proposed numerous reaction ***,active sites,key intermediate species,precise structure-activity relationships and dynamic evolution processes of carbon catalysts are still rife with controversies due to the monotony and limitation of used experimental *** this Review,we sum-marize the extensive efforts on model catalysts since the 2000s,particularly in the past decade,to overcome the influences of material and structure limitations in metal-free carbon *** both nanomolecule model and bulk model,the real contribution of each alien species,defect and edge configuration to a series of fundamentally important reactions,such as thermocatalytic reactions,electrocatalytic reactions,were systematically *** with in situ techniques,isotope labeling and size control,the detailed reaction mechanisms,the precise 2D structure-activity relationships and the rate-determining steps were revealed at a molecular ***,the outlook of model carbon catalysis has also been proposed in this work.

关键词： Metal-free carbon catalysts Model catalyst Electrocatalysis Active site Reaction mechanisms

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Fe-N-C core-shell catalysts with single low-spin Fe(Ⅱ)-N_(4)species for oxygen reduction reaction and high-performance proton exchange membrane fuel cells

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Journal of Energy Chemistry 2024年第6期93卷 538-546,I0013页

作者： Yan Wan linhui Yu Bingxin Yang Caihong Li Chen Fang Wei Guo Fang-Xing Xiao yangming lin Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen 361021FujianChina CAS Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021FujianChina Fujian Institute of Research on the Structure of Matter Chinese Academy of SciencesFuzhou 350002FujianChina College of Materials Science and Engineering Fuzhou UniversityNew CampusMinhou 350108FujianChina College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350117FujianChina

Fe-N-doped carbon materials(Fe-N-C)are promising candidates for oxygen reduction reaction(ORR)relative to Pt-based catalysts in proton exchange membrane fuel cells(PEMFCs).However,the intrinsic contributions of Fe-N_(4)moiety with different chemical/spin states(e.g.D1,D2,D3)to ORR are unclear since various states coexist *** the present work,Fe-N-C core-shell nanocatalyst with single lowspin Fe(Ⅱ)-N_(4)species(D1)is synthesized and identified with ex-situ ultralow temperature Mossbauer spectroscopy(T=1.6 K)that could essentially differentiate various Fe-N_(4)states and invisible Fe-O *** quantifying with CO-pulse chemisorption,site density and turnover frequency of Fe-N-C catalysts reach 2.4×10^(-9)site g^(-1)and 23 e site~(-1)s^(-1)during the ORR,***-wave potential(0.915V_(RHE))of the Fe-N-C catalyst is more positive(approximately 54 mV)than that of Pt/***,we observe that the performance of PEMFCs on Fe-N-C almost achieves the 2025 target of the US Department of Energy by demonstrating a current density of 1.037 A cm^(-2)combined with the peak power density of 0,685 W cm^(-2),suggesting the critical role of Fe(Ⅱ)-N_(4)site(D1).After 500 h of running,PEMFCs still deliver a power density of 1.26 W cm^(-2)at 1.0 bar H_(2)-O_(2),An unexpected rate-determining step is figured out by isotopic labelling experiment and theoretical *** work not only offers valuable insights regarding the intrinsic contribution of Fe-N_(4)with a single spin state to alkaline/acidic ORR,but also provides great opportunities for developing high-performance stable PEMFCs.

关键词： Fuel cells Oxygen reduction reaction Non-platinum group metals(PGMs) Isotopic labelling Active site TOF

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Recent progress of carbon-based metal-free materials in thermal-driven catalysis

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Journal of Energy Chemistry 2021年第7期30卷 318-335页

作者： Shuchang Wu linhui Yu Guodong Wen Zailai Xie yangming lin School of Pharmaceutical and Materials Engineering Taizhou UniversityTaizhou 318000ZhejiangChina Max Planck Institute for Chemical Energy Conversion Stiftstrasse 34-36Mülheim an der Ruhr 45470Germany Institute of Metal Research Chinese Academy of SciencesShenyang 110016LiaoningChina Fujian Provincial Key Laboratory of Electrochemical Energy Storage Materials Fuzhou UniversityFuzhou 350016FujianChina

The carbon-based metal-free materials as catalysts(named as carbocatalysts) have been attracting tremendous attentions in electric-,solar-and thermal-driven reactions *** to electrocatalysis and photocatalysis,the thermal-driven catalysis(thermocatalysis) including liquid phase and gas phase reactions involves wider scope and is relatively easy to realize practical large-scale *** the past several years,some striking achievements on the design of new carbon-based metal-free materials with well-defined structures and heteroatom groups as well as the revelation of new reaction mechanisms and active sites in thermocatalysis have been ***,comparative discussions regarding these recent achievements have been rarely *** this review,we systematically summarize and discuss six kinds of carbocatalysts and their applications in *** materials include typical oxygen-attached carbon,surface modified carbon(graft with certain organic compounds),mono-doped carbon,co-doped carbon,carbon nitride and materials with carbon as *** new reaction processes as well as the related reaction mechanisms,active sites and intermediates are reviewed ***,an outlook on the in-depth investigation of the metalfree carbocatalysis in the future is provided.

关键词： Carbocatalysis Metal-free Thermal-driven catalysis Active sites

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Probing the intrinsic catalytic activity of carbon nanotubes for the metal-free oxidation of aromatic thiophene compounds in ionic liquids

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Journal of Energy Chemistry 2019年第5期28卷 131-137页

作者： Qingqing Gu Yuxiao Ding Zigeng Liu yangming lin Robert Schlogl Saskia Heumann Dangsheng Su Shenyang National Laboratory for Material Science Institute of Metal ResearchChinese Academy of SciencesWenhua Road 72Shenyang 110016LiaoningChina University of Chinese Academy of Sciences Beijing 100049China Max Planck Institute for Chemical Energy Conversion Stiftstrasse 34-3645470 Millheim a.d.RuhrGermany Fritz Haber Institute of the Max Planck Society Faradayweg 4-614195 BerlinGermany

A metal-free catalytic system combining oxidized carbon nanotubes (oCNTs) and ionic liquids (ILs) is presented for the oxidation of aromatic thiophene compounds with H2O2 as an oxidant. The oCNTs exhibit impressively high activity and stability in the system, which show an even better performance than those of some reported metal catalysts. The ILs are proved to have indispensable influence on the enhanced catalytic performance of the oCNTs. Detailed characterization by TG-MS and XPS demonstrates that the carbonyl groups are the active sites for the oxidation process, which is further supported by the deactivation and the model catalysts experiments. The quantitative analysis of different oxygen groups in oCNTs could be achieved by an isothermal temperature programmed TG-MS method. The concentration of carbonyl groups is 1.46 mmol per 1 g oCNTs and the tuiriover frequency of oCNTs could also be obtained (10.7 h^-1 in the presence of OmimPF6). H2O2 decomposition experiments combined with the EPR results reveal that the presence of OmimPF6 can avoid the intermediate HO· to form O2 and then improve the catalytic performance of oCNTs for the oxidation of dibenzothiophene.

关键词： Carbon nanotubes Metal-free catalysis Oxidative desulfurization Ionic liquids

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To inhibit coffee ring effect in inkjet printing of light-emitting polymer films by decreasing capillary force

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Chinese Chemical Letters 2019年第1期30卷 135-138页

作者： Xinhong Yu Rubo Xing Zhongxiang Peng yangming lin Zhonghui Du Junqiao Ding Lixiang Wang Yanchun Han State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences

Polymer thin film with uniform thickness and flat surface profile is the key point for polymer light emitting diodes(PLEDs) by inkjet printing. However, the coffee ring effect is usually observed due to the mismatch between the evaporation of the solvent and the decrease of solution volume, which promotes the formation of radial flow from the interior of the drop to the edge. In this paper, coffee ring effects of inkjet printed poly(spirobifluorene) films were proposed to be restrained by decreasing capillary force by adding co-solvent with high boiling point and high viscosity to the main solvent. The low evaporation rate of the co-solvent can reduce the driving force of the radial flow; meanwhile the high viscosity of the co-solvent can increase the resistance of the radial flow. Thus, polymer films with improve uniformity can be obtained due to the suppression of the radial flow. The device performance was greatly improved under the condition of proper film thickness and film uniformity and the maximum luminous efficiency of devices with inkjet printed poly(spirobifluorene) can reach 80% of the spin-coated devices.

关键词： Inkjet printing Coffee ring effect Polymer film Uniformity Organic light emitting diodes

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Reevaluation by the CRISPR/Cas9 knockout approach revealed that multiple pluripotency-associated lncRNAs are dispensable for pluripotency maintenance while Snora73a/b is essential for pluripotency exit

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Science China Life Sciences 2024年第10期67卷 2198-2212页

作者： Zhen Li Xuefei Li Jingxia lin yangming Wang Huiqing Cao Jiajian Zhou Institute of Molecular Medicine College of Future TechnologyPeking University Dermatology Hospital Southern Medical University Beijing Advanced Center of RNA Biology (BEACON) Peking University

Many long noncoding RNAs(lncRNAs) have been identified through siRNA-based screening as essential regulators of embryonic stem cell(ESC) pluripotency. However, the biological and molecular functions of most lncRNAs remain unclear. Here, we employed CRISPR/Cas9-mediated knockout technology to explore the functions of 8 lncRNAs previously reported to promote pluripotency in mouse ESCs. Unexpectedly, all of these lncRNAs were dispensable for pluripotency maintenance and proliferation in mouse ESCs when disrupted individually or in combination. Single-cell transcriptomic analysis also showed that the knockout of these lncRNAs has a minimal impact on pluripotency gene expression and cell identity. We further showed that several small hairpin RNAs(shRNAs) previously used to knock down lncRNAs caused the downregulation of pluripotency genes in the corresponding lncRNA-knockout ESCs, indicating that off-target effects likely responsible for the pluripotency defects caused by these shRNAs. Interestingly, linc1343-knockout and linc1343-knockdown ESCs failed to form cystic structures and exhibited high expression of pluripotency genes during embryoid body(EB) differentiation. By reintroducing RNA products generated from the linc1343 locus, we found that two snoRNAs, Snora73a and Snora73b, but not lncRNAs, could rescue pluripotency silencing defects during EB differentiation of linc1343 knockout ESCs. Our results suggest that the 8 previously annotated pluripotency-regulating lncRNAs have no overt functions in conventional ESC culture; however, we identified snoRNA products derived from an annotated lncRNA locus as essential regulators for silencing pluripotency genes.

关键词： long noncoding RNAs embryonic stem cells CRISPR/Cas9 snoRNAs stem cell differentiation

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Genetic source,migration and accumulation of helium under deep thermal fluid activities:A case study of Ledong diapir area in Yinggehai Basin,South China Sea

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Petroleum Exploration and Development 2024年第3期51卷 753-766页

作者： FENG Ziqi HAO Fang HU lin HU Gaowei ZHANG Yazhen LI yangming WANG Wei LI Hao XIAO Junjie TIAN Jinqiang State Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao 266580China School of Geosciences China University of Petroleum(East China)Qingdao 266580China Laboratory for Marine Mineral Resources Qingdao Marine Science and Technology CenterQingdao 266237China Hainan Branch of CNOOC(China)Co. Ltd.Haikou 570312China

Based on the geochemical parameters and analytical data,the heat conservation equation,mass balance law,Rayleigh fractionation model and other methods were used to quantify the in-situ yield and external flux of crust-derived helium,and the initial He concentration and thermal driving mechanism of mantle-derived helium,in the Ledong Diapir area,the Yinggehai Basin,in order to understand the genetic source,migration and accumulation mechanisms of helium under deep thermal fluid *** average content of mantle-derived He is only 0.0014%,the ^(3)He/^(4)He value is(0.002–2.190)×10^(−6),and the R/Ra value ranges from 0.01 to 1.52,indicating the contribution of mantle-derived He is 0.09%–19.84%,while the proportion of crust-derived helium can reach over 80%.Quantitative analysis indicates that the crust-derived helium is dominated by external input,followed by in-situ production,in the Ledong diapir *** crust-derived helium exhibits an in-situ 4 He yield rate of(7.66–7.95)×10^(−13)cm^(3)/(a·g),an in-situ 4 He yield of(4.10–4.25)×10^(−4)cm^(3)/g,and an external 4 He influx of(5.84–9.06)×10^(−2)cm^(3)/*** results may be related to atmospheric recharge into formation fluid and deep rock-water *** ratio of initial mole volume of 3 He to enthalpy(W)is(0.004–0.018)×10^(−11) cm^(3)/J,and the heat contribution from the deep mantle(X_(M))accounts for 7.63%–36.18%,indicating that deep hot fluid activities drive the migration of mantle-derived 3 *** primary helium migration depends on advection,while the secondary migration is controlled by hydrothermal degassing and gas-liquid *** deep to shallow layers,the CO_(2/3) He value rises from 1.34×10^(9)to 486×10^(9),indicating large amount of CO_(2)has *** the influence of deep thermal fluid,helium migration and accumulation mechanisms include:deep heat driven diffusion,advection release,vertical hydrothermal degassing,shallow lateral migration,accumulation in traps far from faults,

关键词： deep thermal fluid helium genetic source migration and accumulation mechanism Yinggehai Basin

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内氧化法制备Al_2O_3/Cu复合材料的再结晶行为

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稀有金属材料与工程 2005年第7期34卷 1039-1042页

作者：李红霞田保红林阳明李士凯刘平河南科技大学河南洛阳471039

以Cu2O为氧化剂,采用Cu-Al合金粉末内氧化及后续的粉末冶金法制备了Al2O3/Cu复合材料。并将不同Al2O3含量的试样进行不同变形量的冷拔处理,在氮气保护下进行高温退火处理(700℃～1050℃,1h)。研究了硬度随退火温度的变化规律,观察了显... 详细信息

以Cu2O为氧化剂,采用Cu-Al合金粉末内氧化及后续的粉末冶金法制备了Al2O3/Cu复合材料。并将不同Al2O3含量的试样进行不同变形量的冷拔处理,在氮气保护下进行高温退火处理(700℃～1050℃,1h)。研究了硬度随退火温度的变化规律,观察了显微组织。结果表明:在铜基体中弥散分布着纳米级的Al2O3颗粒;经900℃,1h退火后Al2O3/Cu复合材料的硬度可保持室温的87%以上;其再结晶温度高达1000℃;变形量和Al2O3含量增加均使硬度提高,但对软化和再结晶温度影响不大。

关键词： Al2O3/Cu复合材料再结晶内氧化硬度

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基于氧在固态铜中进行非稳态扩散的动力学研究

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金属热处理 2005年第C期30卷 223-227页

作者：李红霞田保红林阳明康布熙刘平河南科技大学材料科学与工程学院河南洛阳471003

在内氧化动力学实验的基础上，研究了铝质量分数为0．19％、0．42％、0．72％和0．94％的铜铝合金平板形试样在1023K、1123K、1223K和1273K温度下的内氧化动力学，并采用定量金相技术测量了内氧化层的深度，推导了平板形状铜铝合金试样... 详细信息

在内氧化动力学实验的基础上，研究了铝质量分数为0．19％、0．42％、0．72％和0．94％的铜铝合金平板形试样在1023K、1123K、1223K和1273K温度下的内氧化动力学，并采用定量金相技术测量了内氧化层的深度，推导了平板形状铜铝合金试样的内氧化动力学方程。经内氧化实验检验证明，该方程可以较精确的描述平板形状铜铝合金的内氧化动力学。基于该方程和内氧化深度测试，计算出了氧在铜中的渗透率。

关键词：非稳态扩散 Cu-Al合金内氧化动力学

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喷墨打印聚合物薄膜均匀性调控研究进展

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应用化学 2018年第2期35卷 129-136页

作者：林杨鸣曲轶于新红韩艳春长春理工大学高功率半导体激光国家重点实验室长春130022 中国科学院长春应用化学研究所高分子物理与化学国家重点实验室长春130022

聚合物发光显示材料具有发光颜色在全可见光区可调、可溶液简单加工及适用于柔性大面积基底的特点,成为目前研究的热点。在聚合物发光薄膜图案化技术中,喷墨打印因为具有加工过程简单高效、适用于溶液方式加工、柔性的加工过程等特点而... 详细信息

聚合物发光显示材料具有发光颜色在全可见光区可调、可溶液简单加工及适用于柔性大面积基底的特点,成为目前研究的热点。在聚合物发光薄膜图案化技术中,喷墨打印因为具有加工过程简单高效、适用于溶液方式加工、柔性的加工过程等特点而被认为是最具有应用潜力的技术。高质量聚合物薄膜的制备是高精度发光显示器件制作的关键,但喷墨打印液滴在干燥过程中通常伴随着"咖啡环"现象,造成薄膜不均匀沉积。因此,消除"咖啡环"现象,实现聚合物薄膜的均匀沉积,是喷墨打印高性能器件的重要研究方向。本文主要论述了"咖啡环"效应的产生机理,如何抑制喷墨打印聚合物薄膜加工过程中的"咖啡环"效应,最终实现聚合物薄膜均匀性调控。

关键词：喷墨打印聚合物薄膜咖啡环效应

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