期刊文献+
共找到127,717篇文章
< 1 2 250 >
每页显示 20 50 100
Formylation of N-arylpyrazole containing active amino group using Vilsmeier-Haack reaction
1
作者 Yi Luo Ping Zhong Xiao Hong Zhang Qiu Lian Lin Ye Na Chen 《Chinese Chemical Letters》 SCIE CAS CSCD 2008年第4期383-386,共4页
关键词 vilsmeier-haack reaction N-arylpyrazole FORMYLATION AMINO SYNTHESIS
下载PDF
Reaction视频中用户弹幕信息交互行为的情感反应生成机理研究
2
作者 叶许婕 赵宇翔 +2 位作者 张妍 李金昊 Preben Hansen 《信息资源管理学报》 2024年第2期104-120,共17页
深入挖掘Reaction视频中弹幕信息交互行为的情感反应机理有助于理解用户弹幕创作背后的情感生成原因及情感变化过程。本文基于情感反应模型,利用定向内容分析法对哔哩哔哩网站中11个热门视频的弹幕信息资源、视频内容以及reactor反应情... 深入挖掘Reaction视频中弹幕信息交互行为的情感反应机理有助于理解用户弹幕创作背后的情感生成原因及情感变化过程。本文基于情感反应模型,利用定向内容分析法对哔哩哔哩网站中11个热门视频的弹幕信息资源、视频内容以及reactor反应情况展开编码研究,构建了Reaction视频中用户弹幕信息交互行为的情感反应生成机理模型。研究发现,Reaction视频弹幕信息交互行为中的情感反应生成机理总体上遵循“信息刺激-情感反应”的路径,信息刺激有时会独立唤醒情绪或特定情感态度,有时也会通过唤醒特定情感态度进而影响情绪或内化情感态度的生成。该模型有助于提升情感反应理论在计算机协助交流中的情境化探索,也将为社交媒体中用户与信息交互提供优化建议。 展开更多
关键词 reaction视频 弹幕 用户信息交互 情感反应模型 定向内容分析
下载PDF
Tuning electronic structure of RuO_(2)by single atom Zn and oxygen vacancies to boost oxygen evolution reaction in acidic medium 被引量:1
3
作者 Qing Qin Tiantian Wang +7 位作者 Zijian Li Guolin Zhang Haeseong Jang Liqiang Hou Yu Wang Min Gyu Kim Shangguo Liu Xien Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期94-102,I0003,共10页
The poor stability of RuO_(2)electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers.To dramatically enhance the durability of RuO_(2)to construct ... The poor stability of RuO_(2)electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers.To dramatically enhance the durability of RuO_(2)to construct activity-stability trade-off model is full of significance but challenging.Herein,a single atom Zn stabilized RuO_(2)with enriched oxygen vacancies(SA Zn-RuO_(2))is developed as a promising alternative to iridium oxide for acidic oxygen evolution reaction(OER).Compared with commercial RuO_(2),the enhanced Ru–O bond strength of SA Zn-RuO_(2)by forming Zn-O-Ru local structure motif is favorable to stabilize surface Ru,while the electrons transferred from Zn single atoms to adjacent Ru atoms protects the Ru active sites from overoxidation.Simultaneously,the optimized surrounding electronic structure of Ru sites in SA ZnRuO_(2)decreases the adsorption energies of OER intermediates to reduce the reaction barrier.As a result,the representative SA Zn-RuO_(2)exhibits a low overpotential of 210 mV to achieve 10 mA cm^(-2)and a greatly enhanced durability than commercial RuO_(2).This work provides a promising dual-engineering strategy by coupling single atom doping and vacancy for the tradeoff of high activity and catalytic stability toward acidic OER. 展开更多
关键词 ELECTROCATALYST Acidic oxygen evolution reaction Electronic structure engineering DURABILITY reaction barrier
下载PDF
The reaction mechanism and interfacial crystallization of Al nanoparticle-embedded Ni under shock loading
4
作者 Yifan Xie Jian-Li Shao +1 位作者 Rui Liu Pengwan Chen 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期114-124,共11页
The shock-induced reaction mechanism and characteristics of Ni/Al system,considering an Al nanoparticle-embedded Ni single crystal,are investigated through molecular dynamics simulation.For the shock melting of Al nan... The shock-induced reaction mechanism and characteristics of Ni/Al system,considering an Al nanoparticle-embedded Ni single crystal,are investigated through molecular dynamics simulation.For the shock melting of Al nanoparticle,interfacial crystallization and dissolution are the main characteristics.The reaction degree of Al particle first increases linearly and then logarithmically with time driven by rapid mechanical mixing and following dissolution.The reaction rate increases with the decrease of particle diameter,however,the reaction is seriously hindered by interfacial crystallization when the diameter is lower than 9 nm in our simulations.Meanwhile,we found a negative exponential growth in the fraction of crystallized Al atoms,and the crystallinity of B2-NiAl(up to 20%)is positively correlated with the specific surface area of Al particle.This can be attributed to the formation mechanism of B2-NiAl by structural evolution of finite mixing layer near the collapsed interface.For shock melting of both Al particle and Ni matrix,the liquid-liquid phase inter-diffusion is the main reaction mechanism that can be enhanced by the formation of internal jet.In addition,the enhanced diffusion is manifested in the logarithmic growth law of mean square displacement,which results in an almost constant reaction rate similar to the mechanical mixing process. 展开更多
关键词 Shock-induced reaction Molecular dynamics simulations Interfacial crystallization reaction mechanism
下载PDF
Exciting lattice oxygen of nickel–iron bi-metal alkoxide for efficient electrochemical oxygen evolution reaction
5
作者 Saihang Zhang Senchuan Huang +8 位作者 Fengzhan Sun Yinghui Li Li Ren Hao Xu Zhao Li Yifei Liu Wei Li Lina Chong Jianxin Zou 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期194-201,I0005,共9页
High efficiency,cost-effective and durable electrocatalysts are of pivotal importance in energy conversion and storage systems.The electro-oxidation of water to oxygen plays a crucial role in such energy conversion te... High efficiency,cost-effective and durable electrocatalysts are of pivotal importance in energy conversion and storage systems.The electro-oxidation of water to oxygen plays a crucial role in such energy conversion technologies.Herein,we report a robust method for the synthesis of a bimetallic alkoxide for efficient oxygen evolution reaction(OER)for alkaline electrolysis,which yields current density of 10 mA cm^(-2)at an overpotential of 215 mV in 0.1 M KOH electrolyte.The catalyst demonstrates an excellent durability for more than 540 h operation with negligible degradation in activity.Raman spectra revealed that the catalyst underwent structure reconstruction during OER,evolving into oxyhydroxide,which was the active site proceeding OER in alkaline electrolyte.In-situ synchrotron X-ray absorption experiment combined with density functional theory calculation suggests a lattice oxygen involved electrocatalytic reaction mechanism for the in-situ generated nickel–iron bimetal-oxyhydroxide catalyst.This mechanism together with the synergy between nickel and iron are responsible for the enhanced catalytic activity and durability.These findings provide promising strategies for the rational design of nonnoble metal OER catalysts. 展开更多
关键词 Oxygen evolution reaction Nickel-iron bi-metal alkoxide Lattice oxygen-mediated reaction mechanism Alkaline electrolysis ELECTROCATALYSTS
下载PDF
In situ infrared, Raman and X-ray spectroscopy for the mechanistic understanding of hydrogen evolution reaction
6
作者 Andi Haryanto Kyounghoon Jung +1 位作者 Chan Woo Lee Dong-Wan Kim 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期632-651,I0014,共21页
Hydrogen production by water reduction reactions has received considerable attention because hydrogen is considered a clean-energy carrier,key for a sustainable energy future.Computational methods have been widely use... Hydrogen production by water reduction reactions has received considerable attention because hydrogen is considered a clean-energy carrier,key for a sustainable energy future.Computational methods have been widely used to study the reaction mechanism of the hydrogen evolution reaction(HER),but the calculation results need to be supported by experimental results and direct evidence to confirm the mechanistic insights.In this review,we discuss the fundamental principles of the in situ spectroscopic strategy and a theoretical model for a mechanistic understanding of the HER.In addition,we investigate recent studies by in situ Fourier transform infrared(FTIR),Raman spectroscopy,and X-ray absorption spectroscopy(XAS) and cover new findings that occur at the catalyst-electrolyte interface during HER.These spectroscopic strategies provide practical ways to elucidate catalyst phase,reaction intermediate,catalyst-electrolyte interface,intermediate binding energy,metal valency state,and coordination environment during HER. 展开更多
关键词 Hydrogen evolution reaction Infrared spectroscopy Raman spectroscopy X-ray absorption spectroscopy reaction mechanism
下载PDF
Solvent effects on Diels-Alder reaction in ionic liquids:A reaction density functional study
7
作者 Zijiang Dou Weiqiang Tang +1 位作者 Peng Xie Shuangliang Zhao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期180-188,共9页
Extensive experimental studies have been performed on the Diels-Alder(DA)reactions in ionic liquids(ILs),which demonstrate that the IL environment can significantly influence the reaction rates and selectivity.However... Extensive experimental studies have been performed on the Diels-Alder(DA)reactions in ionic liquids(ILs),which demonstrate that the IL environment can significantly influence the reaction rates and selectivity.However,the underlying microscopic mechanism remains ambiguous.In this work,the multiscale reaction density functional theory is applied to explore the effect of 1-butyl-3-methylimidazolium hexafluorophosphate([BMIM][PF_(6)])solvent on the reaction of cyclopentadiene(CP)with acrolein,methyl acrylate,or acrylonitrile.By analyzing the free energy landscape during the reaction,it is found that the polarization effect has a relatively small influence,while the solvation effect makes both the activation free energy and reaction free energy decrease.In addition,the rearrangement of local solvent structure shows that the cation spatial distribution responds more evidently to the reaction than the anion,and this indicates that the cation plays a dominant role in the solvation effect and so as to affect the reaction rates and selectivity of the DA reactions. 展开更多
关键词 Solvent effect Ionic liquids Diels-Alder reaction reaction density functional theory
下载PDF
Sulfur doped iron-nitrogen-hard carbon nanosheets as efficient and robust noble metal-free catalysts for oxygen reduction reaction in PEMFC
8
作者 Bin Liu Jiawang Li +6 位作者 Bowen Yan Qi Wei Xingyu Wen Huarui Xie Huan He Pei Kang Shen Zhi Qun Tian 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期422-433,I0010,共13页
Transition metal-nitrogen-carbon(M-N-C)as a promising substitute for the conventional noble metalbased catalyst still suffers from low activity and durability for oxygen reduction reaction(ORR)in proton exchange membr... Transition metal-nitrogen-carbon(M-N-C)as a promising substitute for the conventional noble metalbased catalyst still suffers from low activity and durability for oxygen reduction reaction(ORR)in proton exchange membrane fuel cells(PEMFCs).To tackle the issue,herein,a new type of sulfur-doped ironnitrogen-hard carbon(S-Fe-N-HC)nanosheets with high activity and durability in acid media were developed by using a newly synthesized precursor of amide-based polymer with Fe ions based on copolymerizing two monomers of 2,5-thiophene dicarboxylic acid(TDA)as S source and 1,8-diaminonaphthalene(DAN)as N source via an amination reaction.The as-synthesized S-Fe-N-HC features highly dispersed atomic Fe Nxmoieties embedded into rich thiophene-S doped hard carbon nanosheets filled with highly twisted graphite-like microcrystals,which is distinguished from the majority of M-N-C with soft or graphitic carbon structures.These unique characteristics endow S-Fe-N-HC with high ORR activity and outstanding durability in 0.5 M H_(2)SO_(4).Its initial half-wave potential is 0.80 V and the corresponding loss is only 21 m V after 30,000 cycles.Meanwhile,its practical PEMFC performance is a maximum power output of 628.0 mW cm^(-2)and a slight power density loss is 83.0 m W cm^(-2)after 200-cycle practical operation.Additionally,theoretical calculation shows that the activity of Fe Nxmoieties on ORR can be further enhanced by sulfur doping at meta-site near FeN_(4)C.These results evidently demonstrate that the dual effect of hard carbon substrate and S doping derived from the precursor platform of amid-polymers can effectively enhance the activity and durability of Fe-N-C catalysts,providing a new guidance for developing advanced M-N-C catalysts for ORR. 展开更多
关键词 Transition metal-nitrogen-carbon Oxygen reduction reaction Hard carbon Amide based polymer reaction Proton exchange membrane cells
下载PDF
Petrology of Spinel-Lherzolite Xenoliths from Mazéléand Others Northen Xenoliths Localities of Cameroon Volcanic Line: Exchange Reactions and Equilibrium State
9
作者 Nguihdama Dagwai Kamgang Pierre +2 位作者 Mbowou Gbambié Isaac Bertrand Chazot Gilles Ngounouno Ismaïla 《Open Journal of Geology》 CAS 2024年第5期629-653,共25页
The alkaline volcanism of the Cameroon Volcanic Line in its northern domain has raised many fresh enclaves of peridotites. The samples selected come from five (05) different localities (Liri, in the plateau of Kapsiki... The alkaline volcanism of the Cameroon Volcanic Line in its northern domain has raised many fresh enclaves of peridotites. The samples selected come from five (05) different localities (Liri, in the plateau of Kapsiki, Mazélé in the NE of Ngaoundéré, Tello and Ganguiré in the SE of Ngaoundéré and Likok, locality located in the west of Ngaoundé). The peridotite enclaves of the above localities show restricted mineralogical variation. Most are four-phase spinel-lherzolites, indicating that this is the main lithology that forms the lithospheric mantle below the shallow zone. No traces of garnet or primary plagioclase were detected, which strongly limits the depth range from which the rock fragments were sampled. The textures and the wide equilibrium temperatures (884˚C - 1115˚C) indicate also entrainment of lherzolite xenoliths from shallow depths within the lithosphere and the presence of mantle diapirism. The exchange reactions and equilibrium state established in this work make it possible to characterize the chemical composition of the upper mantle of each region and test the equilibrium state of the phases between them. Variations of major oxides and incompatible elemental concentrations in clinopyroxene indicate a primary control by partial melting. The absence of typical “metasomatic” minerals, low equilibration temperatures and enriched LREE patterns indicate that the upper mantle below septentrional crust of Cameroun underwent an event of cryptic metasomatic enrichment prior to partial melting. The distinctive chemical features, LREE enrichment, strong U, Ce and Pr, depletion relative to Ba, Nb, La, Pb, and T, fractionation of Zr and Hf and therefore ligh high Zr/Hf ratio, low La/Yb, Nb/La and Ti/Eu are all results of interaction of refractory peridotite residues with carbonatite melts. 展开更多
关键词 XENOLITHS Upper Mantle Northern Region Adamawa Cameroon Volcanic Line Exchange reaction
下载PDF
Precisely Control Relationship between Sulfur Vacancy and H Absorption for Boosting Hydrogen Evolution Reaction
10
作者 Jing Jin Xinyao Wang +4 位作者 Yang Hu Zhuang Zhang Hongbo Liu Jie Yin Pinxian Xi 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第4期14-24,共11页
Ef fective and robust catalyst is the core of water splitting to produce hydrogen.Here, we report an anionic etching method to tailor the sulfur vacancy(VS) of NiS_(2) to further enhance the electrocatalytic performan... Ef fective and robust catalyst is the core of water splitting to produce hydrogen.Here, we report an anionic etching method to tailor the sulfur vacancy(VS) of NiS_(2) to further enhance the electrocatalytic performance for hydrogen evolution reaction(HER). With the VS concentration change from 2.4% to 8.5%, the H* adsorption strength on S sites changed and NiS_(2)-VS 5.9% shows the most optimized H* adsorption for HER with an ultralow onset potential(68 m V) and has long-term stability for 100 h in 1 M KOH media. In situ attenuated-total-reflection Fourier transform infrared spectroscopy(ATR-FTIRS) measurements are usually used to monitor the adsorption of intermediates. The S-H* peak of the Ni S_(2)-VS 5.9% appears at a very low voltage, which is favorable for the HER in alkaline media. Density functional theory calculations also demonstrate the Ni S_(2)-VS 5.9% has the optimal |ΔG^(H*)| of 0.17 e V. This work offers a simple and promising pathway to enhance catalytic activity via precise vacancies strategy. 展开更多
关键词 Hydrogen evolution reaction S vacancies NANOSHEET H Adsorption
下载PDF
Mapping out the reaction network of humin formation at the initial stage of fructose dehydration in water
11
作者 Xing Fu Yexin Hu +4 位作者 Ping Hu Hui Li Shuguang Xu Liangfang Zhu Changwei Hu 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第6期1016-1026,共11页
The formation of humins hampers the large-scale production of 5-hydroxymethylfurfural(HMF)in biorefinery.Here,a detailed reaction network of humin formation at the initial stage of fructose-to-HMF dehydration in water... The formation of humins hampers the large-scale production of 5-hydroxymethylfurfural(HMF)in biorefinery.Here,a detailed reaction network of humin formation at the initial stage of fructose-to-HMF dehydration in water is delineated by combined experimental,spectroscopic,and theoretical studies.Three bimolecular reaction pathways to build up soluble humins are demonstrated.That is,the intermolecular etherification of β-furanose at room temperature initiates the C12 path,whereas the C-C cleavage of a-furanose at 130-150℃ leads to C11 path,and that of open-chain fructose at 180℃ to C11' path.The successive intramolecular dehydrations and condensations of the as-formed bimolecular intermediates lead to three types of soluble humins.We show that the C12 path could be restrained by using HCl or AlCl_(3) catalyst,and both the C12 and C110 paths could be effectively inhibited by adding THF as a co-solvent or accelerating heating rate via microwave heating. 展开更多
关键词 Carbohydrates 5-HYDROXYMETHYLFURFURAL reaction network Soluble humins TAUTOMER
下载PDF
Study on synergistic leaching of potassium and phosphorus from potassium feldspar and solid waste phosphogypsum via coupling reactions
12
作者 Chao Li Shizhao Wang +3 位作者 Yunshan Wang Xuebin An Gang Yang Yong Sun 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第1期117-129,共13页
To achieve the resource utilization of solid waste phosphogypsum(PG)and tackle the problem of utilizing potassium feldspar(PF),a coupled synergistic process between PG and PF is proposed in this paper.The study invest... To achieve the resource utilization of solid waste phosphogypsum(PG)and tackle the problem of utilizing potassium feldspar(PF),a coupled synergistic process between PG and PF is proposed in this paper.The study investigates the features of P and F in PG,and explores the decomposition of PF using hydrofluoric acid(HF)in the sulfuric acid system for K leaching and leaching of P and F in PG.The impact factors such as sulfuric acid concentration,reaction temperature,reaction time,material ratio(PG/PF),liquid–solid ratio,PF particle size,and PF calcination temperature on the leaching of P and K is systematically investigated in this paper.The results show that under optimal conditions,the leaching rate of K and P reach more than 93%and 96%,respectively.Kinetics study using shrinking core model(SCM)indicates two significant stages with internal diffusion predominantly controlling the leaching of K.The apparent activation energies of these two stages are 11.92 kJ·mol^(-1)and 11.55 kJ·mol^(-1),respectively. 展开更多
关键词 PHOSPHOGYPSUM Potassium feldspar Coupling reaction LEACHING Waste treatment Kinetics
下载PDF
Why Don’t We Adequately Identify and Manage Adverse Drug Reactions despite Having the Needed Information?
13
作者 Mark J. Kupersmith Karl Kieburtz 《Health》 2024年第2期148-159,共12页
Importance/Objective: Adverse Drug Reactions (ADRs) are unavoidable, but recognizing and addressing ADRs early can improve wellness and prevent permanent injury. We suggest that available medical information and digit... Importance/Objective: Adverse Drug Reactions (ADRs) are unavoidable, but recognizing and addressing ADRs early can improve wellness and prevent permanent injury. We suggest that available medical information and digital/electronic methods could be used to manage this major healthcare problem for individual patients in real time. Methods: We searched the available digital applications and three literature databases using the medical subject heading terms, adverse drug reaction reporting systems or management, filtered by clinical trial or systemic reviews, to detect publications with data about ADR identification and management approaches. We reviewed the reports that had abstract or summary data or proposed or implemented methods or systems with potential to identify or manage ADRs in clinical settings. Results: The vast majority of the 481 reports used retrospectively collected data for groups of patients or were limited to surveying one population group or class of medication. The reports showed potential and definite associations of ADRs for specific drugs and problems, mostly, but not exclusively, for patients in hospitals and nursing homes. No reports described complete methods to collect comprehensive data on ADRs for individual patients in a healthcare system. The digital applications have ADR information, but all are too cumbersome or incomplete for use in active clinical settings. Several studies suggested that providing information about potential ADRs to clinicians can reduce these problems. Conclusion and Relevance: Although investigators and government agencies agree with the need, there is no comprehensive ADR management program in current use. Informing the patient’s healthcare practitioners of potential ADRs at the point of service has the potential for reduction of these complications, which should improve healthcare and reduce unneeded costs. 展开更多
关键词 Adverse Drug reaction Medication Side Effect Identification Medication Complication Medication Safety
下载PDF
Selective photosynthesis of Z-olefins through crystalline metal-organic cage-initiated expeditious cascade reactions
14
作者 Jia-Ni Lu Yunze Huang +6 位作者 Yuan-Sheng Xia Long-Zhang Dong Lei Zhang Jing-Jing Liu Lan-Gui Xie Jiang Liu Ya-Qian Lan 《Carbon Energy》 SCIE EI CAS CSCD 2024年第3期118-131,共14页
The semi-hydrogenation of alkyne to form Z-olefins with high conversion and high selectivity is still a huge challenge in the chemical industry.Moreover,flammable and explosive hydrogen as the common hydrogen source o... The semi-hydrogenation of alkyne to form Z-olefins with high conversion and high selectivity is still a huge challenge in the chemical industry.Moreover,flammable and explosive hydrogen as the common hydrogen source of this reaction increases the cost and danger of industrial production.Herein,we connect the photocatalytic hydrogen evolution reaction and the semihydrogenation reaction of alkynes in series and successfully realize the high selective production of Z-alkenes using low-cost,safe,and green water as the proton source.Before the cascade reaction,a series of isomorphic metal–organic cage catalysts(Co_(x)Zn_(8−x)L_(6),x=0,3,4,5,and 8)are designed and synthesized to improve the yield of the photocatalytic hydrogen production.Among them,Co_(5)Zn_(3)L_(6) shows the highest photocatalytic activity,with a H_(2) generation rate of 8.81 mmol g^(−1) h^(−1).Then,Co_(5)Zn_(3)L_(6) is further applied in the above tandem reaction to efficiently reduce alkynes to Z-alkenes under ambient conditions,which can reach high conversion of>98%and high selectivity of>99%,and maintain original catalytic activity after multiple cycles.This“one-pot”tandem reaction can achieve a highly selective and safe stepwise conversion from water into hydrogen into Z-olefins under mild reaction conditions. 展开更多
关键词 alkyne semi-hydrogenation hydrogen evolution reaction metal-organic cages photocatalysis Z-olefins
下载PDF
Diffusion and reaction mechanism of limestone and quartz in fluxed iron ore pellet roasting process
15
作者 Yufeng Guo Jinlai Zhang +5 位作者 Shuai Wang Jianjun Fan Haokun Li Feng Chen Kuo Liu Lingzhi Yang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第3期485-497,共13页
The increase to the proportion of fluxed pellets in the blast furnace burden is a useful way to reduce the carbon emissions in the ironmaking process.In this study,the interaction between calcium carbonate and iron or... The increase to the proportion of fluxed pellets in the blast furnace burden is a useful way to reduce the carbon emissions in the ironmaking process.In this study,the interaction between calcium carbonate and iron ore powder and the mineralization mechanism of fluxed iron ore pellet in the roasting process were investigated through diffusion couple experiments.Scanning electron microscopy with energy dispersive spectroscopy was used to study the elements’diffusion and phase transformation during the roasting process.The results indicated that limestone decomposed into calcium oxide,and magnetite was oxidized to hematite at the early stage of preheating.With the increase in roasting temperature,the diffusion rate of Fe and Ca was obviously accelerated,while the diffusion rate of Si was relatively slow.The order of magnitude of interdiffusion coefficient of Fe_(2)O_(3)-CaO diffusion couple was 10^(−10) m^(2)·s^(−1) at a roasting temperature of 1200℃for 9 h.Ca_(2)Fe_(2)O_(5) was the initial product in the Fe_(2)O_(3)-CaO-SiO_(2) diffusion interface,and then Ca_(2)Fe_(2)O_(5) continued to react with Fe_(2)O_(3) to form CaFe_(2)O_(4).With the expansion of the diffusion region,the sillico-ferrite of calcium liquid phase was produced due to the melting of SiO_(2) into CaFe_(2)O_(4),which can strengthen the consolidation of fluxed pellets.Furthermore,andradite would be formed around a small part of quartz particles,which is also conducive to the consolidation of fluxed pellets.In addition,the principle diagram of limestone and quartz diffusion reaction in the process of fluxed pellet roasting was discussed. 展开更多
关键词 fluxed iron ore pellet LIMESTONE HEMATITE QUARTZ diffusion reaction
下载PDF
Theoretical analysis of the double-differential cross-sections of neutron,proton,deuteron,^(3)He,andαfor the p+^(6) Li reaction
16
作者 Fang-Lei Zou Xiao-Jun Sun +10 位作者 Jing-Shang Zhang Hai-Rui Guo Yin-Lu Han Rui-Rui Xu Xi Tao Ji-Min Wang Xiao-Dong Sun Yuan Tian Tao Ye Yong-Li Xu Chun-Tian Liang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第3期181-197,共17页
Based on the unified Hauser–Feshbach and exciton model,which can describe the particle emission processes between discrete energy levels with energy,angular momentum,and parity conservations,a statistical theory of l... Based on the unified Hauser–Feshbach and exciton model,which can describe the particle emission processes between discrete energy levels with energy,angular momentum,and parity conservations,a statistical theory of light nucleus reaction(STLN)is developed to calculate the double-differential cross-sections of the outgoing neutron and light charged particles for the proton-induced^(6) Li reaction.A significant difference is observed between the p+^(6) Li and p+^(7) Li reactions owing to the discrepancies in the energy-level structures of the targets.The reaction channels,including sequential and simultaneous emission processes,are analyzed in detail.Taking the double-differential cross-sections of the outgoing proton as an example,the influence of contaminations(such as^(1) H,^(7)Li,^(12)C,and^(16)O)on the target is identified in terms of the kinetic energy of the first emitted particles.The optical potential parameters of the proton are obtained by fitting the elastic scattering differential cross-sections.The calculated total double-differential cross-sections of the outgoing proton and deuteron at E_(p)=14 MeV agree well with the experimental data for different outgoing angles.Simultaneously,the mixed double differential cross-sections of^(3) He andαare in good agreement with the measurements.The agreement between the measured data and calculated results indicates that the two-body and three-body breakup reactions need to be considered,and the pre-equilibrium reaction mechanism dominates the reaction processes.Based on the STLN model,a PLUNF code for the p+^(6) Li reaction is developed to obtain an ENDF-6-formatted file of the double-differential cross-sections of the nucleon and light composite charged particles. 展开更多
关键词 Statistical theory of light nucleus reaction p+^(6)Li reaction Light composite charged particle Double-differential cross-sections Two-body breakup Three-body breakup
下载PDF
Particle agglomeration and inhibition method in the fluidized pyrolysis reaction of waste resin
17
作者 Congjing Ren Peng Zhang +3 位作者 Qi Song Zhengliang Huang Yao Yang Yongrong Yang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第3期135-147,共13页
This work investigated the pyrolysis reaction of waste resin in a fluidized bed reactor.It was found that the pyrolysis-generated ash would adhere to the surface of ceramic particles,causing particle agglomeration and... This work investigated the pyrolysis reaction of waste resin in a fluidized bed reactor.It was found that the pyrolysis-generated ash would adhere to the surface of ceramic particles,causing particle agglomeration and defluidization.Adding kaolin could effectively inhibit the particle agglomeration during the fluidized pyrolysis reaction through physical isolation and chemical reaction.On the one hand,kaolin could form a coating layer on the surface of ceramic particles to prevent the adhesion of organic ash generated by the pyrolysis of resin.On the other hand,when a sufficient amount of kaolin(-0.2%(mass))was added,the activated kaolin could fully contact with the Na+ ions generated by the pyrolysis of resin and react to form a high-melting aluminosilicate mineral(nepheline),which could reduce the formation of low-melting-point sodium sulfate and thereby avoid the agglomeration of ceramic particles. 展开更多
关键词 Pyrolysis reaction of waste resin FLUIDIZATION Particle agglomeration KAOLIN
下载PDF
Boosted Electrocatalytic Glucose Oxidation Reaction on Noble-Metal-Free MoO_(3)-Decorated Carbon Nanotubes
18
作者 Yu-Long Men Ning Dou +3 位作者 Yiyi Zhao Yan Huang Lei Zhang Peng Liu 《Transactions of Tianjin University》 EI CAS 2024年第1期63-73,共11页
Electrocatalytic glucose oxidation reaction(GOR)has attracted much attention owing to its crucial role in biofuel cell fabrication.Herein,we load MoO_(3)nanoparticles on carbon nanotubes(CNTs)and use a discharge proce... Electrocatalytic glucose oxidation reaction(GOR)has attracted much attention owing to its crucial role in biofuel cell fabrication.Herein,we load MoO_(3)nanoparticles on carbon nanotubes(CNTs)and use a discharge process to prepare a noblemetal-free MC-60 catalyst containing MoO_(3),Mo_(2)C,and a Mo_(2)C–MoO_(3)interface.In the GOR,MC-60 shows activity as high as 745μA/(mmol/L cm^(2)),considerably higher than those of the Pt/CNT(270μA/(mmol/L cm^(2)))and Au/CNT catalysts(110μA/(mmol/L cm^(2))).In the GOR,the response minimum on MC-60 is as low as 8μmol/L,with a steady-state response time of only 3 s.Moreover,MC-60 has superior stability and anti-interference ability to impurities in the GOR.The better performance of MC-60 in the GOR is attributed to the abundant Mo sites bonding to C and O atoms at the MoO_(3)–Mo_(2)C interface.These Mo sites create active sites for promoting glucose adsorption and oxidation,enhancing MC-60 performance in the GOR.Thus,these results help to fabricate more effi cient noble-metal-free catalysts for the fabrication of glucose-based biofuel cells. 展开更多
关键词 Interface eff ect ELECTROCATALYSIS Molybdenum oxide GLUCOSE Oxidation reaction
下载PDF
Optimizing 3d spin polarization of CoOOH by in situ Mo doping for efficient oxygen evolution reaction
19
作者 Zhichao Jia Yang Yuan +6 位作者 Yanxing Zhang Xiang Lyu Chenhong Liu Xiaoli Yang Zhengyu Bai Haijiang Wang Lin Yang 《Carbon Energy》 SCIE EI CAS CSCD 2024年第1期236-244,共9页
Transition-metal oxyhydroxides are attractive catalysts for oxygen evolution reactions(OERs).Further studies for developing transition-metal oxyhydroxide catalysts and understanding their catalytic mechanisms will ben... Transition-metal oxyhydroxides are attractive catalysts for oxygen evolution reactions(OERs).Further studies for developing transition-metal oxyhydroxide catalysts and understanding their catalytic mechanisms will benefit their quick transition to the next catalysts.Herein,Mo-doped CoOOH was designed as a high-performance model electrocatalyst with durability for 20 h at 10 mAcm−2.Additionally,it had an overpotential of 260 mV(glassy carbon)or 215 mV(nickel foam),which was 78 mV lower than that of IrO_(2)(338 mV).In situ,Raman spectroscopy revealed the transformation process of CoOOH.Calculations using the density functional theory showed that during OER,doped Mo increased the spin-up density of states and shrank the spin-down bandgap of the 3d orbits in the reconstructed CoOOH under the electrochemical activation process,which simultaneously optimized the adsorption and electron conduction of oxygen-related intermediates on Co sites and lowered the OER overpotentials.Our research provides new insights into the methodical planning of the creation of transition-metal oxyhydroxide OER catalysts. 展开更多
关键词 ELECTROCATALYST in situ Raman Mo-doped CoOOH oxygen evolution reaction
下载PDF
Steering surface reconstruction of hybrid metal oxides for efficient oxygen evolution reaction in water splitting and zinc-air batteries
20
作者 Jie Zhu Junxue Chen +7 位作者 Xida Li Kun Luo Zewei Xiong Zhiyu Zhou Wenyun Zhu Zhihong Luo Jingbin Huang Yibing Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期383-393,共11页
Surface reconstruction yields real active species in electrochemical oxygen evolution reaction(OER)conditions;however,rationally regulating reconstruction in a targeted manner for constructing highly active OER electr... Surface reconstruction yields real active species in electrochemical oxygen evolution reaction(OER)conditions;however,rationally regulating reconstruction in a targeted manner for constructing highly active OER electrocatalysts remains a formidable challenge.Here,an electrochemical activation strategy with selective etching was utilized to guide the reconstruction process of a hybrid cobalt-molybdenum oxide(CoMoO_(4)/Co_(3)O_(4)@CC)in a favorable direction to improve the OER performance.Both in-situ Raman and multiple ex-situ characterization tools demonstrate that controlled surface reconstruction can be easily achieved through Mo etching,with the formation of a dynamically stable amorphous-crystalline heterostructure.Theoretical calculations together with experimental results reveal that the synergistic effects between amorphous CoOOH and crystalline Co_(3)O_(4) are crucial in enhancing the catalytic performance.Consequently,the reconstructed CoMoO_(4)/Co_(3)O_(4)@CC exhibits a low overpotential of 250 mV to achieve a current density of 10 mA cm^(-2) in 1 M KOH,and more importantly it can be practiced in electrolytic water splitting and rechargeable zinc-air batteries devices,achieving ultra-long stability for over 500 and 1200 h,respectively.This work provides a promising route for the construction of high-performance electrocatalysts. 展开更多
关键词 ELECTROCATALYST Oxygen evolution reaction Surface reconstruction Selective etching Amorphous-crystalline heterostructures
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部