检索结果-南通市图书馆

Phosphine/Benzocyclone-based Neutral Nickel Catalysts for Ethylene Polymerization and Copolymerization with Polar Monomers

引用

chinese Journal of Polymer Science 2024年第2期42卷 202-212,I0007页

作者： Fei wang Li Pan Vladislav A.Tuskaev Svetlana ch.Gagieva Yue-Sheng Li Tianjin Key Lab of Composite&Functional Materials School of Material Science and EngineeringTianjin UniversityTianjin300072China Department of chemistry Lomonosov Moscow State UniversityRussian Federation InstitutionLeninskie Gory 1Moscow119991Russian Federation A N Nesmeyanov Institute of Organoelement Compounds Russian Academy of SciencesVavilova st.28Moscow119991Russian Federation

The efficient copolymerization of olefin with polar monomers using nickel-based catalysts presents a longstanding challenge. In this contribution, three phosphine-benzocyclone ligands and corresponding neutral nickel catalysts(Ni1: Ar = Ph;Ni2: Ar = 2-(C_(6)H_(5))C_(6)H_(4);Ni3: Ar = 2-[2',6'-(Me O)_(2)-C_(6)H3]C_(6)H_(4)) were prepared and applied for the ethylene polymerization and copolymerization with polar monomers without any cocatalyst. The bulky substituent groups in complexes Ni2 and Ni3 contributed to high catalytic activities(up to 7.24×10^(6) and 9.04×10^(6)g·mol Ni^(-1)·h^(-1), respectively), and produced high-molecular-weight polyethylene(Mw up to 545.7 k Da). Complex Ni3 exhibited high activities for ethylene polymerization at the level of 10^(6) g·mol Ni^(-1)·h^(-1) across a wide range from 30 ℃ to 120 ℃, exhibiting excellent high temperature tolerance. These nickel complexes were also effectively employed in the copolymerization of ethylene with methyl acrylate, ethyl acrylate, butyl acrylate and lauryl acrylate, producing copolymers with high molecular weights(Mw up to 80.5 k Da) and high polar monomer incorporation(up to 8.2 mol%). Microstructure analyses revealed that the introduction of large sterically hindered substituents facilitated the incorporation of polar functional units into the polymer backbone. This study demonstrates the potential of these nickel-based catalysts for efficient copolymerization of olefin with polar monomers.

关键词： Neutral nickel catalyst Ethylene polymerization Copolymerization Polar acrylate monomers

来源：

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

The origins of catalytic selectivity for the electrochemical conversion of carbon dioxide to methanol

引用

Nano Research 2024年第1期17卷 5-17页

作者： Tian wang Yating wang Yuhang Li chunzhong Li Key Laboratory for Ultrafine Materials of Ministry of Education Shanghai Engineering Research Center of Hierarchical NanomaterialsFrontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Materials Science and EngineeringEast China University of Science&TechnologyShanghai 200237China School of chemical Engineering East China University of Science&TechnologyShanghai 200237China

The electrocatalytic conversion of carbon dioxide(CO_(2))into useful fuels and chemical feedstocks is an emerging route to alleviate global warming and reduce reliance on fossil ***(ch_(3)OH),as one of the most significant and widely used liquid fuels that can be generated by CO_(2)reduction,is essential in the chemical *** this minireview,we unravel the origins of the selective formation of ch_(3)OH via CO_(2)reduction,including catalyst composition designs,local structure modulations,and electrolyte/catalyst interface ***,the remaining challenges and perspectives for the CO_(2)-to-ch_(3)OH reduction are proposed.

关键词： methanol carbon dioxide(CO_(2))reduction reaction electrochemistry electrocatalyst catalyst-electrolyte interface

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asymmetric copolyimide membranes fabricated by nonsolvent-induced phase separation for He/ch_(4) and He/N_(2) separation

引用

Frontiers of chemical Science and Engineering 2024年第4期18卷 97-106页

作者： Ying Li Lu wang Junyan Xie Yong Dai Xuehong Gu Xuerui wang State Key Laboratory of Materials-Oriented chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 211816China Quzhou Membrane Material Innovation Institute Quzhou 324000China

Membrane gas separation is considered an energy-saving technique to extract He from natural gas due to no phase change and room temperature ***,the membrane performance was strongly limited by the trade-off between permeance and ***,novel 4,4′-(hexafluoroisopropylidene)diphthalic anhydride(6FDA)-2,2′-bis(3-amino-4-hydroxyphenyl)hexafluoropropane(APAF)-5-amino-2-(4-aminobenzene)benzimidazole(BIA)asymmetric membranes with a thickness of 300 nm were successfully prepared by the non-solvent induced phase separation *** membrane performance was modulated by regulating dope solution compositions(e.g.,tetrahydrofuran and polymer concentration).The ideal He/ch_(4) selectivity was 124 and the optimized He permeance reached 87 GPU,beyond the current upper ***/ch_(4) selectivity was 75 and He permeance was 73 GPU for the binary mixture feed containing 0.2 mol%*** membrane showed good resistance to CO_(2) and C_(2)H_(6),which are the typical impurities in natural *** 6FDA-APAF-BIA membranes have good stability(>160 h),which can provide great potential in He extraction from natural gas.

关键词： He separation membrane natural gas copolyimide

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Expression Recognition Method Based on Convolutional Neural Network and Capsule Neural Network

引用

Computers, Materials & Continua 2024年第4期79卷 1659-1677页

作者： Zhanfeng wang Lisha Yao School of Computer Science and Artificial Intelligence Chaohu UniversityHefei238000China School of Big Data and Artificial Intelligence Anhui Xinhua UniversityHefei230088China

Convolutional neural networks struggle to accurately handle changes in angles and twists in the direction of images,which affects their ability to recognize patterns based on internal feature levels. In contrast, CapsNet overcomesthese limitations by vectorizing information through increased directionality and magnitude, ensuring that spatialinformation is not overlooked. Therefore, this study proposes a novel expression recognition technique calledCAPSULE-VGG, which combines the strengths of CapsNet and convolutional neural networks. By refining andintegrating features extracted by a convolutional neural network before introducing theminto CapsNet, ourmodelenhances facial recognition capabilities. Compared to traditional neural network models, our approach offersfaster training pace, improved convergence speed, and higher accuracy rates approaching stability. Experimentalresults demonstrate that our method achieves recognition rates of 74.14% for the FER2013 expression dataset and99.85% for the CK+ expression dataset. By contrasting these findings with those obtained using conventionalexpression recognition techniques and incorporating CapsNet’s advantages, we effectively address issues associatedwith convolutional neural networks while increasing expression identification accuracy.

关键词： Expression recognition capsule neural network convolutional neural network

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Highly selective photocatalytic reduction of CO_(2) to ch_(4) on electron-rich Fe species cocatalyst under visible light irradiation

引用

Carbon Energy 2024年第1期6卷 255-266页

作者： Qianying Lin Jiwu Zhao Pu Zhang Shuo wang Ying wang Zizhong Zhang Na Wen Zhengxin Ding Rusheng Yuan Xuxu wang Jinlin Long State Key Laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou UniversityFuzhouChina

Efficient photocatalytic reduction of CO_(2) to high-calorific-value ch4,an ideal target product,is a blueprint for C_(1)industry relevance and carbon neutrality,but it also faces great ***,we demonstrate unprecedented hybrid SiC photocatalysts modified by Fe-based cocatalyst,which are prepared via a facile impregnation-reduction method,featuring an optimized local electronic *** exhibits a superior photocatalytic carbon-based products yield of 30.0μmol g^(−1) h^(−1) and achieves a record ch_(4) selectivity of up to 94.3%,which highlights the effectiveness of electron-rich Fe cocatalyst for boosting photocatalytic performance and ***,the synergistic effects of directional migration of photogenerated electrons and strongπ-back bonding on low-valence Fe effectively strengthen the adsorption and activation of reactants and intermediates in the CO_(2)→ch_(4) *** study inspires an effective strategy for enhancing the multielectron reduction capacity of semiconductor photocatalysts with low-cost Fe instead of noble metals as cocatalysts.

关键词： artificial synthesis of ch_(4) electronic structure optimization Fe species cocatalyst photocatalytic CO_(2) reduction SiC

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ni-Cu bimetallic alloy anchored on nitrogen-doped carbon nanotubes for CO_(2)-to-ch_(4)electrochemical conversion

引用

Nano Research 2024年第8期17卷 6922-6930页

作者： Jing Li chuanyong Jing Jin wang School of Environment Beijing Key Laboratory of Aqueous Typical Pollutants Control and Water Quality SafeguardBeijing Jiaotong UniversityBeijing 100044China State Key Laboratory of Environmental chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Tangshan Research Institute Beijing Jiaotong UniversityTangshan 063000China

Electrocatalytic CO_(2)reduction to ch_(4)remains challenging due to multi-electron transfer and intermediates ***,we synthesized electrocatalysts by growing Ni-Cu alloy structure on nitrogen-doped carbon nanotubes(NixCuy-NCNT)for electrocatalytic CO_(2)reduction reaction(CO_(2)RR)via hydrothermal method followed by *** optimized Ni_(1)Cu_(1)-NCNT demonstrated a superior CO_(2)RR performance,achieving 99.7%FEch_(4)(FE=Faradaic efficiency)and 11.54 mA·cm^(−2)current density at−1.2 V *** hydrogen electrode(RHE),which outperformed single metal *** outstanding performance was due to the electrons transferred from Cu to Ni and Ni-Cu alloy shifted the d-band center toward the Fermi level,which was more conducive to the intermediate *** situ electrochemical attenuated total reflection(EC-ATR)and density functional theory(DFT)calculations revealed the appearance of*chO intermediate and the pathway during the CO_(2)RR *** design of the bimetallic electrocatalyst in this study provides a new perspective for the highly selective reduction of CO_(2).

关键词： electrocatalytic CO_(2)reduction Ni-Cu alloy nitrogen-doped carbon nanotube(NCNT) electrochemical attenuated total reflection(EC-ATR) density functional theory(DFT)calculations

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Sustainable all-weather CO2 utilization by mimicking natural photosynthesis in a single material

引用

National Science Review 2024年第2期11卷 177-187页

作者： Xianjin Shi Yu Huang Ran Long Zhenyu wang Liqin wang Junji Cao Gangqiang Zhu Yujie Xiong State Key Laboratory of Loess and Quaternary Geology(SKLLQG) Key Laboratory of Aerosol Chemistry and Physics Institute of Earth EnvironmentChinese Academy of Sciences Center of Excellence in Quaternary Science and Global change Chinese Academy of Sciences University of chinese Academy of Sciences Hefei National Research Center for Physical Sciences at the Microscale School of Chemistry and Materials Science and National Synchrotron Radiation Laboratory University of Science and Technology of China Institute of Atmospheric Physics Chinese Academy of Sciences School of Physics and Information Technology Shaanxi Normal University

Solar-driven CO2conversion into hydrocarbon fuels is a sustainable approach to synchronously alleviating the energy crisis and achieving net ***,the dependence of the conversion process on solar illumination hinders its practical application due to the intermittent availability of sunlight at night and on cloudy or rainy ***,we report a model material of Pt-loaded hexagonal tungsten trioxide（Pt/h-WO3） for decoupling light and dark reaction processes,demonstrating the sustainable CO2conversion under dark conditions for the first *** such a material system,hydrogen atoms can be produced by photocatalytic water splitting under solar illumination,stored together with electrons in the h-WO3through the transition of W6+to W5+and spontaneously released to trigger catalytic CO2reduction under dark ***,we demonstrate using natural light that ch4production can persist at night and on rainy days,proving the accomplishment of all-weather CO2conversion via a sustainable way.

关键词： sustainable CO2 utilization artificial photosynthesis all-weather application charge storage

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Enhanced gas production and CO_(2) storage in hydrate-bearing sediments via pre-depressurization and rapid CO_(2) injection

引用

chinese Journal of chemical Engineering 2024年第3期67卷 126-134页

作者： Hongnan chen Yifei Sun Bojian Cao Minglong wang Ming wang Jinrong Zhong changyu Sun Guangjin chen State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China School of chemistry and chemical Engineering Changsha University of Science&TechnologyChangsha 410114China

Carbon emission reduction and clean energy development are urgent demands for mankind in the coming *** an efficient CO_(2) storage method can significantly reduce CO_(2) emissions in the short *** this study,we attempted to construct sediment samples with different residual ch_(4) hydrate amounts and reservoir conditions,and then investigate the potentials of both CO_(2) storage and enhanced ch_(4) recovery in depleted gas hydrate deposits in the permafrost and ocean zones,*** results demonstrate that CO_(2) hydrate formation rate can be significantly improved due to the presence of residual hydrate seeds;However,excessive residual hydrates in turn lead to the decrease in CO_(2) storage *** by the T-P conditions of the reservoir,the storage amount of liquid CO_(2) can reach 8 times that of gaseous CO_(2),and CO_(2) stored in hydrate form reaches 2-4 ***,we noticed two other advantages of this *** is that CO_(2) injection can enhance ch_(4) recovery rate and increases ch_(4) recovery by 10%-20%.The second is that hydrate saturation in the reservoir can be restored to 20%-40%,which means that the solid volume of the reservoir avoids serious ***,this is crucial for protecting the goaf *** summary,this approach is greatly promising for high-efficient CO_(2) storage and safe exploitation of gas hydrate.

关键词： Hydrate Depressurization CO_(2) storage ch_(4) production Reservoir remediation

来源：

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

characteristics Variation of Atmospheric CO_(2)and ch_(4)in Yongxing Island,South china Sea

引用

Journal of Ocean University of china 2024年第2期23卷 438-446页

作者： LV Honggang JIANG Yifei wang Haiyan Key Laboratory of Marine Hazards Forecasting National Marine Environmental Forecasting CenterMinistry of Natural Resources(MNR)Beijing 100081China National Marine Environmental Forecasting Center Beijing 100081China

Using the observation data in Yongxing Island,South china Sea(SCS)from December 2013 to November 2018,the multiple time scales variation of atmospheric CO_(2)and ch_(4)were analyzed to understand their temporal variation characteristics and controlling *** regional-averaged background mole fractions of CO_(2)and ch_(4)both show a single-period sinusoidal variation with a lower value at noon and a higher value in the wee *** the seasonal scale,they exhibited a significant seasonal difference with higher values in winter and lower values in *** the annual scale,CO_(2)and ch_(4)both show an increasing trend,with an annual growth rate of approximately 3.2 ppm and 12 ppb,*** annual growth rate at this site was higher than the global *** change in atmospheric CO_(2)and ch_(4)in Yongxing Island was probably caused by the higher emission of the surrounding areas and the airflows driven by ***,the long-term and high-resolution greenhouse gases(GHGs)dataset will aid relevent researchers and decision-makers in performing more in-depth studies for GHG sources in order to derive effective strategies.

关键词： carbon dioxide methane observation backward trajectory atmospheric transport

来源：

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

Enriched electrophilic oxygen species facilitate acidic oxygen evolution on Ru-Mo binary oxide catalysts

引用

Nano Research 2024年第3期17卷 1165-1172页

作者： Yaya wang Yunzhou Wen Yumeng cheng Xinhong chen Mengjiao Zhuansun Tongbao wang Jun Li Debora Meira Huarui Sun Jun Wei Jia Zhou Yuhang wang Sisi He Shenzhen Key Laboratory of Flexible Printed Electronics Technology Harbin Institute of Technology(Shenzhen)University TownShenzhen 518055China School of Science Harbin Institute of Technology(Shenzhen)University TownShenzhen 518055China Institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory of Advanced Negative Carbon TechnologiesSoochow UniversitySuzhou 215123China Frontiers Science Center for Transformative Molecules Shanghai Jiao Tong UniversityShanghai 200240China Science Division Canadian Light SourceSaskatoonSKS7N 2V3Canada Photon Science Division Argonne National LaboratoryLemontIL60439USA School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)University TownShenzhen 518055China

The polymer electrolyte membrane(PEM)electrolyzers are burdened with costly iridium(Ir)-based catalysts and high operation overpotentials for the oxygen evolution reaction(OER).The development of earth-abundant,highly active,and durable electrocatalysts to replace Ir is a critical step in reducing the cost of green hydrogen *** we develop a Ru5Mo4Ox binary oxide catalyst that exhibits high activity and stability in acidic *** electron-withdrawing property of Mo enriches the electrophilic surface oxygen species,which promotes acidic OER to proceed via the adsorbate evolution *** a result,we achieve a 189 mV overpotential at 10 mA·cm^(-2) and a Tafel slope of 48.8 mV·dec^(-1).Our catalyst demonstrates a substantial 18-fold increase in intrinsic activity,as evaluated by turnover frequency,compared to commercially available RuO_(2) and IrO_(2) ***,we report a stable OER operation at 10 mA·cm^(-2) for 100 h with a low degradation rate of 2.05 mV·h^(-1).

关键词： electrocatalysis oxygen evolution reaction(OER) ruthenium(Ru)-based oxide molybdenum electrophilic oxygen

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：