检索结果-南通市图书馆

Unimolecular Reactions of E-Glycolaldehyde Oxide and Its Reactions with One and Two Water Molecules

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research 2024年第1期6卷 809-824页

作者： Yan Sun Bo Long Donald G.Truhlar Department of Physics Guizhou UniversityGuiyang 550025China College of Materials Science and engineering Guizhou Minzu UniversityGuiyang 550025China Department of Chemistry Chemical Theory Centerand Supercomputing InstituteUniversity of MinnesotaMinneapolisMN 55455-0431USA

The kinetics of Criegee intermediates are important for atmospheric modeling.However,the quantitative kinetics of Criegee intermediates are still very limited,especially for those with hydroxy groups.Here,we calculate rate constants for the unimolecular reaction of E-glycolaldehyde oxide[E-hydroxyethanal oxide,E-(CH_(2)OH)CHOO],for its reactions with H_(2)O and(H_(2)O)_(2),and for the reaction of the E-(CH_(2)OH)CHOO…H_(2)O complex with H_(2)O.For the highest level of electronic structure,we use W3X-L//CCSD(T)-F12a/cc-pVDZ-F12 for the unimolecular reaction and the reaction with water and W3X-L//DF-CCSD(T)-F12b/jun-cc-pVDZ for the reaction with 2 water molecules.For the dynamics,we use a dual-level strategy that combines conventional transition state theory with the highest level of electronic structure and multistructural canonical variational transition state theory with small-curvature tunneling with a validated density functional for the electronic structure.

关键词： structure kinetics molecular

Ultrafine ordered L1_(2)-Pt-Co-Mn ternary intermetallic nanoparticles as high-performance oxygen-reduction electrocatalysts for practical fuel cells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第6期93卷 157-165,I0005页

作者： Enping Wang Liuxuan Luo Yong Feng Aiming Wu Huiyuan Li Xiashuang Luo Yangge Guo Zehao Tan Fengjuan Zhu Xiaohui Yan Qi Kang Zechao Zhuang Daihui Yang Shuiyun Shen Junliang Zhang China-UK Low Carbon College Shanghai Jiao Tong UniversityShanghai 201306China institute of Fuel Cells Key Laboratory for Power Machinery and Engineering of MOESchool of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Tangfeng Energy Technology Co.Ltd. Shanghai 201306China State Key Laboratory of Advanced chemical Power Sources Guizhou Meiling Power Sources Co.Ltd.Zunyi 563003GuizhouChina School of Chemistry and chemical engineering Chongqing UniversityChongqing 400044China institute of New Energy for Vehicles School of Materials Science and EngineeringTongji UniversityShanghai 201804China Department of chemical engineering Columbia UniversityNY 10027USA

The long-range periodically ordered atomic structures in intermetallic nanoparticles(INPs)can significantly enhance both the electrocatalytic activity and electrochemical stability toward the oxygen reduction reaction(ORR)compared to the disordered atomic structures in ordinary solid-solution alloy NPs.Accordingly,through a facile and scalable synthetic method,a series of carbon-supported ultrafine Pt_3Co_(x)Mn_(1-x)ternary INPs are prepared in this work,which possess the"skin-like"ultrathin Pt shells,the ordered L1_(2) atomic structure,and the high-even dispersion on supports(L1_(2)-Pt_3Co_(x)Mn_(1-x)/~SPt INPs/C).Electrochemical results present that the composition-optimized L1_(2)-Pt_3Co_(0.7)Mn_(0.3)/~SPt INPs/C exhibits the highest electrocata lytic activity among the series,which are also much better than those of the pristine ultrafine Pt/C.Besides,it also has a greatly enhanced electrochemical stability.In addition,the effects of annealing temperature and time are further investigated.More importantly,such superior ORR electrocatalytic performance of L1_(2)-Pt_3Co_(0.7)Mn_(0.3)/~SPt INPs/C are also well demonstrated in practical fuel cells.Physicochemical characterization analyses further reveal the major origins of the greatly enhanced ORR electrocata lytic performance:the Pt-Co-Mn alloy-induced geometric and ligand effects as well as the extremely high L1_(2) atomic-ordering degree.This work not only successfully develops a highly active and stable ordered ternary intermetallic ORR electrocatalyst,but also elucidates the corresponding"structure-function"relationship,which can be further applied in designing other intermetallic(electro)catalysts.

关键词： Platinum Cobalt Manganese Oxygen reduction reaction Ordered intermetallic L1_(2)atomic structure Proton-exchange membrane fuel cell

Two-dimensional silica enhanced solid polymer electrolyte for lithium metal batteries

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第2期85卷 146-154页

作者： Zhihong Luo Weiyong Li Chong Guo Ya Song Mingxia Zhou Yan Shi Jing Xu Long Li Bin Shi Quansheng Ouyang Jiao-jing Shao Guangmin Zhou School of Materials and Metallurgy Guizhou UniversityGuiyang550025China State Key Laboratory of Advanced chemical Power Sources Zunyi563003China Graphene Materials engineering Research Center of guizhou Colleges and Universities Guiyang550025China Tsinghua-Berkeley Shenzhen institute&Tsinghua Shenzhen International Graduate Schoo Tsinghua UniversityShenzhen518055China

Solid polymer electrolytes(SPEs)are promising substitutes for current flammable liquid electrolytes to achieve high-safety and high-energy-density lithium metal batteries.Polyethylene oxide(PEO)based solid polymer electrolytes have attracted increasing attention because of their excellent flexibility,manufacturability,light weight,and low-cost processing,while they often suffer from low ionic con-ductivity at room temperature,low lithium transference number and unsatisfactory interfacial resis-tance,which largely restrain their practical application.Herein,two-dimensional holey silica nanosheets(2D-HSN)as the fillers,together with LiNO_(3) as the electrolyte additive,are introduced in a PEO/poly(-vinylidene fiuoride-co-hexafluoropropylene)(PVDF-HFP)blended polymer matrix to obtain a SPE.The incorporation of HSN filler creates supplementary channels for lithium ion migration and lowers the crystallinity of the polymer,thereby facilitating the movement of lithium ions.The HSN-based SPE demonstrates higher ionic conductivity up to 3.7 x 10-4 S cm-1 at 30℃,larger Li+transference number close to 0.34,and more stable lithium plating/stripping than that without the fillers,and HSN can promote the formation of more stable solid electrolyte interphase(SEI)layer.The as-assembled LiFePO4||Li batteries deliver a high specific capacity of 159 mA h g-1 with the capacity retention of 95.5%after 200 cycles at 30℃,as well as superior rate performance and cycling stability compared to that using the blank SPE.

关键词： Vermiculite nanosheets Two-dimensional silica Solid polymer electrolytes FillersLithium metal batteries

Molecularly engineered lignin to polyphenol via organocatalysis as an active sunscreen ingredient

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Bioresources and Bioproducts 2024年第2期9卷 197-210页

作者： Yuanlong Guo Pengcheng Liu Lei Deng Changwei Lui Michael North Gang Hu Qitian Huang Zongbao Kent Zhao Haibo Xie Department of Polymeric Materials&engineering Guizhou UniversityGuiyang 550025China KZJ New Materials Group guizhou Co.Ltd. Guizhou 551200China Green Chemistry Centre of Excellence Department of ChemistryUniversity of YorkYork YO105DDUK Dalian institute of chemical Physics Chinese Academy of SciencesDalian 116023China

Phenolation is one of the effective strategies to synthesize lignin-based polyphenols,improve lignin’s properties,and extend its value-added applications in biological,medicinal and cosmetic fields.Herein,by taking the structural feature advantage of lignin,an effective and green strategy was developed to molecularly engineer lignin into a robust lignin-3-(2-hydroxyphenyl)propionate ester(LPPE)derivative via a transesterification reaction between 3,4-dihydrocoumarin(DHC)and the aliphatic hydroxyls in lignin under organocatalysis.The strategy is optimized and the novel derivative was systematically characterized by ^(1)H,^(13)C and ^(31)P nuclear magnetic resonance(NMR)and Fourier transform infrared(FT-IR)spectroscopy.The findings indicated that the successful introduction of 3-(2-hydroxyphenyl)propionate groups using a OH groups/DHC/organic base mo-lar ratio of 1꞉1꞉0.3 at 120℃ for 6 h increased the content of phenolic hydroxyl groups from 1.7931 to 3.0179 mmol/g,and the LPPE exhibited excellent ultraviolet-absorbing and antioxidant per-formance with up to 90%free radical scavenging activity within 20 min using 5 mg/mL of LPPE.In addition,good biocompatibility and a high Sun protection factor(SPF)value of 40.9 were achieved at 5%(w)dosage of LPPE in the cream,indicating its significant application potential in sunscreen.

关键词： Phenolation of lignin Organocatalysis 3,4-dihydrocoumarin Antioxidant Sunscreen cream

Storage, form, and influencing factors of karst inorganic carbon in a carbonate area in China

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 Earth Sciences 2024年第3期67卷 725-739页

作者： Chaochao DU Xiaoyong BAI Yangbing LI Qiu TAN Cuiwei ZHAO Guangjie LUO Luhua WU Fei CHEN Chaojun LI Chen RAN Sirui ZHANG Lian XIONG Fengjiao SONG Biqin XIAO Zilin LI Yingying XUE Mingkang LONG Qing LUO Xiaoyun ZHANG Minghui LI Xiaoqian SHEN Shu YANG State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China School of Geography and Environmental Sciences Guizhou Normal UniversityGuiyang 550001China CAS Center for Excellence in Quaternary Science and Global Change Xi'an 710061China guizhou Provincial Key Laboratory of Geographic State Monitoring of Watershed Guizhou Normal CollegeGuiyang 550018China College of Resources and Environmental engineering Guizhou UniversityGuiyang 550025China

Carbonate rock chemical weathering carbon sinks reduce the rate of increase of the atmospheric CO_(2) concentration and global warming. However, uncertainty still exists in the estimation results of carbonate rock chemical weathering carbon sink fluxes(CCSF), and the contributions of climate change and ecological restoration to the CCSF are not clear. To this end, we compiled published site data on ion concentrations in different watersheds in China and used a classical thermodynamic dissolution model to reassess the potential and spatial and temporal patterns of the CCSF in China from 1991 to 2020. We quantified the contributions of temperature(MAT), precipitation(MAP), evapotranspiration(ET), soil water(SM), and the normalized difference vegetation index(NDVI) to the CCSF. The results revealed that(1) China's CCSF was 22.76 t CO_(2)km^(-2)yr^(-1), which was higher than the global average(15.77 t CO_(2)km^(-2)yr^(-1)). The total carbonate rock chemical weathering carbon sink(CCS) was 4772.67×10^(4)t CO_(2), contributing 14.91% of the global CCS through a carbonate rock area of 252.98×10^(4)km^(-2).(2) China's CCSF decreased gradually from southeast to northwest, with values of 33.14, 12.93, and7.27 t CO_(2)km^(-2)yr^(-1)in the southern karst, Qinghai-Tibetan karst, and northern karst regions, respectively.(3) The overall CCSF in China exhibited an increasing trend from 1991 to 2020, with a rate of increase of 0.16 t CO_(2)km^(-2)yr^(-1).(4) The contributions of the MAP, MAT, ET, SM, and NDVI to the CCSF were 63.3%, 3.02%, 27.5%, 3.1%, and 3.05%, respectively. Among them, the increase in precipitation was the main contributor to the increase in the CCSF in China over the last 30 years, while the enhancement of ET offset part of the positive contribution of the increase in precipitation to the CCSF. In conclusion, the results of this study provide a systematic quantification of the magnitude, the patterns, and the influencing factors of CCS over a long time series in China. The results are of great significance an

关键词： Carbonate rocks Carbon sinks Patterns Influencing factors Thermodynamic dissolution modeling

metallurgical performance evaluation of space-weathered Chang’e-5 lunar soil

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1241-1248页

作者： Chen Li Wenhui Ma Yang Li Kuixian Wei Center for Lunar and Planetary Sciences Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Faculty of metallurgical and Energy engineering Kunming University of Science and TechnologyKunming 650093China

Space metallurgy is an interdisciplinary field that combines planetary space science and metallurgical engineering.It involves systematic and theoretical engineering technology for utilizing planetary resources in situ.However,space metallurgy on the Moon is challenging because the lunar surface has experienced space weathering due to the lack of atmosphere and magnetic field,making the mi-crostructure of lunar soil differ from that of minerals on the Earth.In this study,scanning electron microscopy and transmission electron microscopy analyses were performed on Chang’e-5 powder lunar soil samples.The microstructural characteristics of the lunar soil may drastically change its metallurgical performance.The main special structure of lunar soil minerals include the nanophase iron formed by the impact of micrometeorites,the amorphous layer caused by solar wind injection,and radiation tracks modified by high-energy particle rays inside mineral crystals.The nanophase iron presents a wide distribution,which may have a great impact on the electromagnetic prop-erties of lunar soil.Hydrogen ions injected by solar wind may promote the hydrogen reduction process.The widely distributed amorph-ous layer and impact glass can promote the melting and diffusion process of lunar soil.Therefore,although high-energy events on the lun-ar surface transform the lunar soil,they also increase the chemical activity of the lunar soil.This is a property that earth samples and tradi-tional simulated lunar soil lack.The application of space metallurgy requires comprehensive consideration of the unique physical and chemical properties of lunar soil.

关键词： space metallurgy Chang’e-5 lunar soil space weathering metallurgical performance

Ligand modulation of active center to promote lead-free Cs2AgInCl6 photocatalytic CO2 reduction

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第8期95卷 660-669页

作者： Baofei Sun Wei Chen Yanyi Huang Daofu Wu Heng Luo Faguang Kuang Hongmei Ran Yichen Liu Liqin Gao Jinchen Zhou Bo Gao Qiang Huang Xiaosheng Tang Key Laboratory of Human Brain Bank for Functions and Diseases of Department of Education of guizhou Province College of Basic Medical Guizhou Medical University College of Optoelectronic engineering Chongqing University of Posts and Telecommunications School of Electromechanical and Automotive engineering Yantai University State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences Key Laboratory of Optoelectronic Technology & SystemsMinistry of Education College of Optoelectronic Engineering Chongqing University Key Laboratory of Optoelectronic Technology & Systems(Ministry of Education) College of Optoelectronic Engineering Chongqing University School of Materials Science and engineering Zhengzhou University

Metal halide perovskites（MHP） are potential candidates for the photocatalytic reduction of CO2due to their long photogenerated carrier lifetime and charge diffusion length.However,the conventional long-chain ligand impedes the adsorption and activation of CO2molecules in practical applications.Here,a ligand modulation technology is employed to enhance the photocatalytic CO2reduction activity of lead-free Cs2AgInCl6microcrystals（MCs）.The Cs2AgInCl6MCs passivated by Oleic acid（OLA） and Octanoic acid（OCA） are used for photocatalytic CO2reduction.The results show that the surface defects and electronic properties of Cs2AgInCl6MCs can be adjusted through ligand modulation.Compared with the OLA-Cs2AgInCl6,the OCA-Cs2AgInCl6catalyst demonstrated a significant improvement in the catalytic yield of CO and CH4.The CO and CH4catalytic yields of OCA-Cs2AgInCl6reached 171.88 and34.15 μmol g-1h-1which were 2.03 and 12.98 times higher than those of OLA-Cs2AgInCl6,and the total electron consumption rate of OCA-Cs2AgInCl6was 615.2 μmol g-1h-1which was 3.25 times higher than that of OLA-Cs2AgInCl6.Furthermore,in situ diffuse reflectance infrared Fourier transform spectra revealed the enhancement of photocatalytic activity in Cs2AgInCl6MCs induced by ligand modulation.This study illustrates the potential of lead-free Cs2AgInCl6MCs for efficient photocatalytic CO2reduction and provides a ligand modulation strategy for the active promotion of MHP photocatalysts.

关键词： Lead-free perovskite Photocatalysis CO2 reduction Reactive mechanism Surface ligand

A review of solid-state lithium metal batteries through in-situ solidification

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第1期67卷 67-86页

作者： Pan Xu Zong-Yao Shuang Chen-Zi Zhao Xue Li Li-Zhen Fan Aibing Chen Haoting Chen Elena Kuzmina Elena Karaseva Vladimir Kolosnitsyn Xiaoyuan Zeng Peng Dong Yingjie Zhang Mingpei Wang Qiang Zhang Beijing Key Laboratory of Green chemical Reaction engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China National and Local Joint engineering Laboratory for Lithium-ion Batteries and Materials Preparation Technology Key Laboratory of Advanced Battery Materials of Yunnan ProvinceFaculty of Metallurgical and Energy EngineeringKunming University of Science and TechnologyKunming 650093China institute of Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China College of chemical and Pharmaceutical engineering Hebei University of Science and TechnologyShijiazhuang 050018China Ordos Carbon Neutral Research and Application Co. Ltd.Ordos City 017010China Ufa institute of Chemistry UFRC RAS Ufa 450054Russia institute for Carbon Neutrality Tsinghua UniversityBeijing 100084China Shanxi Research institute for Clean Energy Tsinghua UniversityTaiyuan 030032China

High-energy-density lithium metal batteries are the next-generation battery systems of choice,and replacing the flammable liquid electrolyte with a polymer solid-state electrolyte is a prominent conduct towards realizing the goal of high-safety and high-specific-energy devices.Unfortunately,the inherent intractable problems of poor solid-solid contacts between the electrode/electrolyte and the growth of Li dendrites hinder their practical applications.The in-situ solidification has demonstrated a variety of advantages in the application of polymer electrolytes and artificial interphase,including the design of integrated polymer electrolytes and asymmetric polymer electrolytes to enhance the compatibility of solid–solid contact and compatibility between various electrolytes,and the construction of artificial interphase between the Li anode and cathode to suppress the formation of Li dendrites and to enhance the high-voltage stability of polymer electrolytes.This review firstly elaborates the history of in-situ solidification for solid-state batteries,and then focuses on the synthetic methods of solidified electrolytes.Furthermore,the recent progress of in-situ solidification technology from both the design of polymer electrolytes and the construction of artificial interphase is summarized,and the importance of in-situ solidification technology in enhancing safety is emphasized.Finally,prospects,emerging challenges,and practical applications of in-situ solidification are envisioned.

关键词： in-situ solidification polymer electrolyte artificial solid electrolyte interphase rechargeable lithium metal batteries dendrite-free lithium metal anode

Simultaneous acceleration of sulfur reduction and oxidation on bifunctional electrocatalytic electrodes for quasi-solid-state Zn–S batteries

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第5期67卷 1531-1538页

作者： Mingli Wang Hong Zhang Tianhang Ding Fangjun Wu Lin Fu Bin Song Pengfei Cao Ke Lu institutes of Physical Science and Information Technology School of Materials Science and EngineeringKey Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationAnhui UniversityHefei 230601China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China School of Chemistry and chemical engineering Harbin Institute of TechnologyHarbin 150001China School of Chemistry and chemical engineering Guizhou UniversityGuiyang 550025China institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123China State Key Lab of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China

The incomplete sulfur reduction and high ZnS re-oxidation energy barrier along with severe side reactions during the battery cycling compromise the practical application of Zn–S electrochemistry. Herein, a bifunctional electrocatalytic sulfur matrix that simultaneously accelerates the sulfur reduction and ZnS oxidation is proposed to realize a highly-efficient Zn–S cell. It is revealed that the N-heteroatom hotspots are more favorable for facilitating the conversion of S to ZnS while the CoO nanocrystal substantially lowers the ZnS activation energy barrier thereby suppressing the formation of disproportionation species(e.g.,SO_(4)^(2-)) and accumulation of inactive ZnS. Accordingly, the Co O anchored on the N-doped carbon-supported sulfur cathode delivers a high Zn^(2+)storage capacity of 1,172 m Ahg^(-1)and outstanding cycling stability with a capacity retention of 71.6% after500 cycles with a high average Coulombic efficiency of 97.8%. Simultaneously, the stable cycling of solid-state Zn–S pouch cells with an energy density of 585 Whkg^(-1)sulfuris also demonstrated. Moreover, the postmortem analysis reveals that the degradation of Zn–S cells is mainly attributed to the limited reversibility of Zn anodes rather than the ZnS decomposition and/or accumulation. The approach to the bidirectional catalysis manipulated the sulfur redox provides a new perspective to realize the theoretical potentials of Zn–S cells.

关键词： Zn–S battery bifunctional catalysts solid-state battery sulfur redox degradation mechanism