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Exploring impedance spectrum for lithium-ion batteries diagnosis and prognosis:A comprehensive review 被引量:1
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作者 Xinghao Du Jinhao Meng +2 位作者 Yassine Amirat Fei Gao Mohamed Benbouzid 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期464-483,I0010,共21页
Lithium-ion batteries have extensive usage in various energy storage needs,owing to their notable benefits of high energy density and long lifespan.The monitoring of battery states and failure identification are indis... Lithium-ion batteries have extensive usage in various energy storage needs,owing to their notable benefits of high energy density and long lifespan.The monitoring of battery states and failure identification are indispensable for guaranteeing the secure and optimal functionality of the batteries.The impedance spectrum has garnered growing interest due to its ability to provide a valuable understanding of material characteristics and electrochemical processes.To inspire further progress in the investigation and application of the battery impedance spectrum,this paper provides a comprehensive review of the determination and utilization of the impedance spectrum.The sources of impedance inaccuracies are systematically analyzed in terms of frequency response characteristics.The applicability of utilizing diverse impedance features for the diagnosis and prognosis of batteries is further elaborated.Finally,challenges and prospects for future research are discussed. 展开更多
关键词 Lithium-ion battery Impedance spectrum Temperature monitoring Failure diagnosis Health prognosis
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High Order ADER-IPDG Methods for the Unsteady Advection-Diffusion Equation
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作者 Michel Bergmann Afaf Bouharguane +1 位作者 Angelo Iollo Alexis Tardieu 《Communications on Applied Mathematics and Computation》 EI 2024年第3期1954-1977,共24页
We present a high-order Galerkin method in both space and time for the 1D unsteady linear advection-diffusion equation. Three Interior Penalty Discontinuous Galerkin (IPDG) schemes are detailed for the space discretiz... We present a high-order Galerkin method in both space and time for the 1D unsteady linear advection-diffusion equation. Three Interior Penalty Discontinuous Galerkin (IPDG) schemes are detailed for the space discretization, while the time integration is performed at the same order of accuracy thanks to an Arbitrary high order DERivatives (ADER) method. The orders of convergence of the three ADER-IPDG methods are carefully examined through numerical illustrations, showing that the approach is consistent, accurate, and efficient. The numerical results indicate that the symmetric version of IPDG is typically more accurate and more efficient compared to the other approaches. 展开更多
关键词 ADVECTION-DIFFUSION GALERKIN Arbitrary high order DERivatives(ADER)approach Interior Penalty Discontinuous Galerkin(IPDG) High-order schemes Empirical convergence rates
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Integrating theory with the nanoreactor concept to synthesize hollow carbon sphere-encapsulated PtNi alloys for enhanced H_(2) generation
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作者 Yufeng Wu Minwei Song +3 位作者 Ziyi Zhao Guang-Hui Wang Changlong Wang Didier Astruc 《Carbon Energy》 SCIE EI CAS CSCD 2024年第7期150-162,共13页
The rational design of efficient bimetallic nanoparticle(NP)catalysts is challenging due to the lack of theoretical understanding of active components and insights into the mechanisms of a specific reaction.Here,we re... The rational design of efficient bimetallic nanoparticle(NP)catalysts is challenging due to the lack of theoretical understanding of active components and insights into the mechanisms of a specific reaction.Here,we report the rational design of nanoreactors comprising hollow carbon sphere-confined PtNi bimetallic NPs(PtNi@HCS)as highly efficient catalysts for hydrogen generation via ammonia borane hydrolysis in water.Using both density functional theory calculations and molecular dynamics simulations,the effects of an active PtNi combination and the critical synergistic role of a hollow carbon shell on the molecule diffusion adsorption behaviors are explored.Kinetic isotope effects and theoretical calculations allow the clarification of the mechanism,with oxidative addition of an O-H bond of water to the catalyst surface being the rate-determining step.The remarkable catalytic activity of the PtNi@HCS nanoreactor was also utilized for successful tandem catalytic hydrogenation reactions,using in situ-generated H_(2) from ammonia borane with high efficiency.The concerted design,theoretical calculations,and experimental work presented here shed light on the rational elaboration of efficient nanocatalysts and contribute to the establishment of a circular carbon economy using green hydrogen. 展开更多
关键词 ammonia borane hydrogen NANOALLOY NANOREACTOR solid catalyst
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What If the Protection against Oxidation of Chromia-Forming Alloys Was Not Always Due to the Chromia Layer?
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作者 Boris Contri Stéphane Valette +1 位作者 Marina Soustre Pierre Lefort 《American Journal of Analytical Chemistry》 CAS 2024年第9期286-302,共17页
Chromia-forming alloys have good resistance to oxidizing agents such as O2, CO2, … It is accepted that the protection of these alloys is always due to the chromia layer formed at the surface of the alloys, which acts... Chromia-forming alloys have good resistance to oxidizing agents such as O2, CO2, … It is accepted that the protection of these alloys is always due to the chromia layer formed at the surface of the alloys, which acts as a barrier between the oxidizing gases and the alloy substrates, forming a diffusion zone that limits the overall reaction rate and leads to parabolic kinetics. But this was not verified in the study devoted to Inconel®625 the oxidation in CO2 that was followed by TGA, with characterizations by XRD, EDS and FIB microscopy. Contrary to what was expected and accepted in similar studies on other chromia-forming alloys, it was shown that the diffusion step that governs the overall reaction rate is not located inside the chromia layer but inside the alloy, precisely inside a zone just beneath the interface alloy/chromia, this zone being depleted in chromium. The chromia layer, therefore, plays no kinetic role and does not directly protect the underlying alloy. This result was demonstrated using a simple test that consisted in removing the chromia layer from the surface of samples partially oxidized and then to continue the thermal treatment: insofar as the kinetics continued without any change in rate, this proved that this surface layer of oxide did not protect the substrate. Based on previous work on many chromia-forming alloys, the possibility of a similar reaction mechanism is discussed. If the chromia layer is not the source of protection for a number of chromia-forming alloys, as is suspected, this might have major consequences in terms of industrial applications. 展开更多
关键词 Chromia-Forming Alloys Chromia Layer Oxidation Protection Inconel®625 Kinetics
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Diatom and Diatomite: Different Focus on Natural Media to Material Science Path
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作者 Secou Sall Vasiliki Papaefthimiou +7 位作者 Thierry Dintzer Fabrice Vigneron Eric Brendlé Pierre Petit Tom Ferte Saliha Haddoum Sana Labidi Corinne Petit 《American Journal of Analytical Chemistry》 CAS 2024年第1期1-29,共29页
Bio-silica issued from diatom, a microalgae, is attracted increasing attention in material science thanks to its peculiar nanoarchitecture and related properties with versatile applications. The present work is a deep... Bio-silica issued from diatom, a microalgae, is attracted increasing attention in material science thanks to its peculiar nanoarchitecture and related properties with versatile applications. The present work is a deep analysis on morphological and chemical properties of bio-silica issued from fossil origin (diatomaceous earth) and living one (algal paste). An optimization in purification protocol was performed to obtain multiparous bio-silica from its raw media with keeping its original shape entirely. Multiple characterization methods as scanning electronic microscopy (SEM), infrared spectroscopy, x-ray diffraction (DRX), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), nitrogen adsorption and inverse gas chromatography (IGC), were used to check the purification protocol efficiency as well as to gather accurate information on morphology and chemical composition of diatom material obtained in large amount. 展开更多
关键词 DIATOM DIATOMITE Bio-Silica PURIFICATION Frustule
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Locally Enhanced Flow and Electric Fields Through a Tip Effect for Efficient Flow‑Electrode Capacitive Deionization
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作者 Ziquan Wang Xiangfeng Chen +5 位作者 Yuan Zhang Jie Ma Zhiqun Lin Amor Abdelkader Maria‑Magdalena Titirici Libo Deng 《Nano-Micro Letters》 SCIE EI CAS 2025年第2期1-17,共17页
Low-electrode capacitive deionization(FCDI)is an emerging desalination technology with great potential for removal and/or recycling ions from a range of waters.However,it still suffers from inefficient charge transfer... Low-electrode capacitive deionization(FCDI)is an emerging desalination technology with great potential for removal and/or recycling ions from a range of waters.However,it still suffers from inefficient charge transfer and ion transport kinetics due to weak turbulence and low electric intensity in flow electrodes,both restricted by the current collectors.Herein,a new tip-array current collector(designated as T-CC)was developed to replace the conventional planar current collectors,which intensifies both the charge transfer and ion transport significantly.The effects of tip arrays on flow and electric fields were studied by both computational simulations and electrochemical impedance spectroscopy,which revealed the reduction of ion transport barrier,charge transport barrier and internal resistance.With the voltage increased from 1.0 to 1.5 and 2.0 V,the T-CC-based FCDI system(T-FCDI)exhibited average salt removal rates(ASRR)of 0.18,0.50,and 0.89μmol cm^(-2) min^(-1),respectively,which are 1.82,2.65,and 2.48 folds higher than that of the conventional serpentine current collectors,and 1.48,1.67,and 1.49 folds higher than that of the planar current collectors.Meanwhile,with the solid content in flow electrodes increased from 1 to 5 wt%,the ASRR for T-FCDI increased from 0.29 to 0.50μmol cm^(-2) min^(-1),which are 1.70 and 1.67 folds higher than that of the planar current collectors.Additionally,a salt removal efficiency of 99.89%was achieved with T-FCDI and the charge efficiency remained above 95%after 24 h of operation,thus showing its superior long-term stability. 展开更多
关键词 Flow-electrode Capacitive deionization Current collector Tip effect DESALINATION
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Study of Cassava Contraction during Its Convective Drying
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作者 Kondia Honoré Ouoba Abdou-Salam Ganamé +5 位作者 Aboubakar Compaoré Abdoul Salam Ibrango Désiré Bama Salifou Ouedraogo Francois Zougmoré Hélène Desmorieux 《Journal of Biophysical Chemistry》 2024年第3期35-45,共11页
During this study, a focus is placed on the physical transformations that cassava undergoes during convective drying. The product continually changes its size, shape, and even its texture and consistency. The more moi... During this study, a focus is placed on the physical transformations that cassava undergoes during convective drying. The product continually changes its size, shape, and even its texture and consistency. The more moisture a product loses, the smaller its size. Firstly, the results show that water parameters such as mass or moisture content are reduced according to the drying principle. The dimensions length L, width l and thickness e decrease following a linear trend. The mathematical equations describing them were determined using the Excel office tool. This trend impacts surface and volume parameters, which in turn decrease almost linearly with the water content of the product. Note that the R2 coefficient is not always acceptable, confirming the complexity of the behavior of organic products. 展开更多
关键词 Dimensions Reduction SHRINKAGE Index I
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Advancements in the application of natural extracts for atopic dermatitis treatment
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作者 Yi Peng Miaohong Yang +6 位作者 Ju Wen Huixiong Chen Weihua Shen Ling Jiang Yi Li Li Lin Zhiyun Du 《Journal of Dermatologic Science and Cosmetic Technology》 2024年第2期45-52,共8页
Atopic dermatitis,a common chronic inflammatory skin disease,has an unclear etiology and may involve multiple factors such as genetic predisposition,immune abnormalities,and impaired skin barrier function.Currently,th... Atopic dermatitis,a common chronic inflammatory skin disease,has an unclear etiology and may involve multiple factors such as genetic predisposition,immune abnormalities,and impaired skin barrier function.Currently,there is no specific medication available for the complete cure of atopic dermatitis.The current treatment approaches mainly focus on symptom relief and control rather than curative treatment.Some commonly used medications for atopic dermatitis,such as topical corticosteroids and immunosuppressants,may have certain adverse reactions and side effects.This review summarizes the research progress on natural extracts in the treatment of atopic dermatitis,aiming to provide a foundation for the development of safe and side-effectfree medications. 展开更多
关键词 Atopic dermatitis Natural extracts TREATMENT
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The mechanisms of melanogenesis inhibition by glabridin:molecular docking,PKA/MITF and MAPK/MITF pathways 被引量:7
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作者 Chunxing Pan Xiaoying Liu +9 位作者 Yating Zheng Zejun Zhang Yongliang Li Biao Che Guangrong Liu Lanyue Zhang Changzhi Dong Haji Akber Aisa Zhiyun Du Zhengqiang Yuan 《Food Science and Human Wellness》 SCIE CSCD 2023年第1期212-222,共11页
Glabridin is the main ingredient of hydrophobic fraction in licorice extract and has been shown to have anti-melanogenesis activity in skins.However,the underlying mechanism(s)remain not completely understood.The aim ... Glabridin is the main ingredient of hydrophobic fraction in licorice extract and has been shown to have anti-melanogenesis activity in skins.However,the underlying mechanism(s)remain not completely understood.The aim of this study is thus to elucidate the possible mechanisms related to the melanogenesis suppression by glabridin in cultured B16 murine melanoma cells and in UVA radiation induced hyperpigmentation model of BALB/c mice as well.Molecular docking simulations revealed that between catalytic core residues and the compound.The treatment by glabridin significantly downregulated both transcriptional and/or protein expression of melanogenesis-related factors including melanocyte stimulating hormone receptor(MC1R),microphthalmia-associated transcription factor(MITF),tyrosinase(TYR),TYR-related protein-1(TRP-1)and TRP-2 in B16 cells.Both PKA/MITF and MAPK/MITF signaling pathways were found to be involved in the suppression of melanogenesis by glabridin in B16 cells.Also in vivo glabridin therapy significantly reduced hyperpigmentation,epidermal thickening,roughness and inflammation induced by frequent UVA exposure in mice skins,thus beneficial for skin healthcare.These data further look insights into the molecular mechanisms of melanogenesis suppression by glabridin,rationalizing the application of the natural compound for skin healthcare. 展开更多
关键词 GLABRIDIN MELANOGENESIS Molecular docking PKA/MITF pathway MAPK/MITF pathway
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“On-off”switch for H_(2)and O_(2)generation from HCOOH resp.H_(2)O_(2) 被引量:1
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作者 Wenkai Huang Fuhua Xu +2 位作者 Dong‐Sheng Li Didier Astruc Xiang Liu 《Carbon Energy》 SCIE CSCD 2023年第3期75-86,共12页
In spite of the numerous advances in the development of H_(2)and O_(2)evolutions upon water splitting,the separation of H_(2)from O_(2)still remains a severe challenge.Herein,the novel dual-functional nanocatalysts Pd... In spite of the numerous advances in the development of H_(2)and O_(2)evolutions upon water splitting,the separation of H_(2)from O_(2)still remains a severe challenge.Herein,the novel dual-functional nanocatalysts Pd/carbon nanosphere(CNS),obtained via immobilization of ultrafine Pd nanoparticles onto CNS,are developed and employed for both selective H_(2)generation from HCOOH dehydrogenation and O_(2)evolution from H_(2)O_(2)decomposition.In these reactions,the highest activities for Pd/CNS-800(i.e.,calcinated at 800℃)are 2478 h−1 and 993 min^(−1)for H_(2)and O_(2)evolution,respectively.The highly efficient and selective“on-off”switch for selective H_(2)generation from HCOOH is successfully realized by pH adjustment.This novel and highly efficient nanocatalyst Pd/CNS-800 not only provides new approaches for the promising application of HCOOH and H_(2)O_(2)as economic and safe H_(2)and O_(2)carriers,respectively,for fuel cells,but also promotes the development of“on-off”switch for on-demand H_(2)evolution. 展开更多
关键词 carbon nanospheres H_(2)generation O_(2)evolution “on-off”switch Pd nanoparticles
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Moisture-Induced Non-Equilibrium Phase Segregation in Triple Cation Mixed Halide Perovskite Monitored by In Situ Characterization Techniques and Solid-State NMR 被引量:1
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作者 Mohammad Ali Akhavan Kazemi Nicolas Folastre +9 位作者 Parth Raval Michel Sliwa Jean Marie Vianney Nsanzimana Sema Golonu Arnaud Demortiere Jean Rousset Olivier Lafon Laurent Delevoye G.N.Manjunatha Reddy Frédéric Sauvage 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第2期185-194,共10页
Environmental stability is a major bottleneck of perovskite solar cells.Only a handful of studies are investigating the effect of moisture on the structural degradation of the absorber.They mostly rely on ex situ expe... Environmental stability is a major bottleneck of perovskite solar cells.Only a handful of studies are investigating the effect of moisture on the structural degradation of the absorber.They mostly rely on ex situ experiments and on completely degraded samples,which restrict the assessment on initial and final stage.By combining in situ X-ray diffraction under controlled 85%relative humidity,and live observations of the water-induced degradation using liquid-cell transmission electron microscopy,we reveal two competitive degradation paths leading on one hand to the decomposition of state-of-theart mixed cation/anion(Cs_(0.05)(MA_(0.17)FA_(0.83))_(0.95)Pb(Br_(0.17)I_(0.83))_(3)(CsMAFA)into PbI_(2) through a dissolution/recrystallization mechanism and,on the other hand,to a non-equilibrium phase segregation leading to CsPb_(2)Br_(5) and a Cesium-poor/iodide-rich Cs_(0.05)-x(MA_(0.17)FA_(0.83))_(0.95)Pb(Br_(0.17-2y)I_(0.83)+2y)_(3) perovskite.This degradation mechanism is corroborated at atomic-scale resolution through solid-state ^(1)H and ^(133)Cs NMR analysis.Exposure to moisture leads to a film containing important heterogeneities in terms of morphology,photoluminescence intensities,and lifetimes.Our results provide new insights and consensus that complex perovskite compositions,though very performant as champion devices,are comparatively metastable,a trait that limits the chances to achieve long-term stability. 展开更多
关键词 liquid-cell transmission electron microscopy moisture degradation perovskite stability phase segregation solid-state NMR
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Machine Learning With Data Assimilation and Uncertainty Quantification for Dynamical Systems:A Review 被引量:2
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作者 Sibo Cheng César Quilodrán-Casas +14 位作者 Said Ouala Alban Farchi Che Liu Pierre Tandeo Ronan Fablet Didier Lucor Bertrand Iooss Julien Brajard Dunhui Xiao Tijana Janjic Weiping Ding Yike Guo Alberto Carrassi Marc Bocquet Rossella Arcucci 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第6期1361-1387,共27页
Data assimilation(DA)and uncertainty quantification(UQ)are extensively used in analysing and reducing error propagation in high-dimensional spatial-temporal dynamics.Typical applications span from computational fluid ... Data assimilation(DA)and uncertainty quantification(UQ)are extensively used in analysing and reducing error propagation in high-dimensional spatial-temporal dynamics.Typical applications span from computational fluid dynamics(CFD)to geoscience and climate systems.Recently,much effort has been given in combining DA,UQ and machine learning(ML)techniques.These research efforts seek to address some critical challenges in high-dimensional dynamical systems,including but not limited to dynamical system identification,reduced order surrogate modelling,error covariance specification and model error correction.A large number of developed techniques and methodologies exhibit a broad applicability across numerous domains,resulting in the necessity for a comprehensive guide.This paper provides the first overview of state-of-the-art researches in this interdisciplinary field,covering a wide range of applications.This review is aimed at ML scientists who attempt to apply DA and UQ techniques to improve the accuracy and the interpretability of their models,but also at DA and UQ experts who intend to integrate cutting-edge ML approaches to their systems.Therefore,this article has a special focus on how ML methods can overcome the existing limits of DA and UQ,and vice versa.Some exciting perspectives of this rapidly developing research field are also discussed.Index Terms-Data assimilation(DA),deep learning,machine learning(ML),reduced-order-modelling,uncertainty quantification(UQ). 展开更多
关键词 ASSIMILATION OVERCOME apply
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Petrology of lherzolite xenoliths of HosséréSédévolcano(Adamawa plateau,Ngaoundéréarea,Cameroon)
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作者 O.F.Nkouandou J.M.Bardintzeff +3 位作者 Fagny Mefire Njankouo Ndassa A.A.Sahabo H.Adama 《Acta Geochimica》 EI CAS CSCD 2023年第5期817-831,共15页
Numerous mantle xenoliths 6–12 cm in size and sub-angular to rounded in shape occur within Mio-Pliocene basanite lavas of the monogenic volcano of HosséréSédé in the Adamawa plateau.Xenoliths of s... Numerous mantle xenoliths 6–12 cm in size and sub-angular to rounded in shape occur within Mio-Pliocene basanite lavas of the monogenic volcano of HosséréSédé in the Adamawa plateau.Xenoliths of spinel lherzolite exhibit protogranular,equigranular or porphyroclastic texture.Microprobe chemical analyses show that olivine is highly magnesian(Fo_(88-90)),clinopyroxene crystals are diopside and augite(Wo_(41.6–49.6)En_(45.3–53.7)Fs_(4.2–6.2)),orthopyroxene crystals are enstatite(Wo 1.4–1.5 En_(88.6–89.0)Fs_(9.6–9.9))and spinel crystals are mainly Al-spinel associ-ated to minor Cr-spinel.Estimated temperatures and pressures through empirical formulas show that HosséréSédé noliths have equilibrated between 1085 and 1204℃and 1.08 to 1.57 GPa,corresponding to sampling depths of 36 and 52 km.Detailed petrographical and mineral chemistry of HosséréSédénoliths evidences the com-plex nature and composition of the subcontinental lithosphere under the Adamawa plateau.This may involve a probable uplift of the whole area after a limited exten-sional event,possible metasomatism through melt infiltration during shearing of the lithospheric mantle along the Pan African strike-slip fault system. 展开更多
关键词 Cameroon Adamawa HosséréSédé Subcontinental lithosphere XENOLITH PERIDOTITE LHERZOLITE
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Modeling of Fixed Bed Adsorption Column Parameters of Iron(II) Removal Using Ferrihydrite Coated Brick
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作者 Oscar Allahdin Eric Foto +3 位作者 Nicole Poumayé Olga Biteman Joseph Mabingui Michel Wartel 《American Journal of Analytical Chemistry》 CAS 2023年第4期184-201,共18页
Fixed-bed operating experimental column conditions were studied to evaluate the performance of brick from Bangui Region (in Central African Republic), coated with iron oxyhydroxide (ferrihydrite) for the removal of ir... Fixed-bed operating experimental column conditions were studied to evaluate the performance of brick from Bangui Region (in Central African Republic), coated with iron oxyhydroxide (ferrihydrite) for the removal of iron(II) from aqueous solution. The prediction of theoretical breakthrough profiles using Bohart and Adams sorption model was employed to achieve characteristic parameters such as depth of exchange zone, time required for exchange zone to move vertically, moving rate for the exchange zone and adsorption capacity useful for fixed-bed column reactor was investigated under varying operating conditions. The effects of bed depth and flow rate on iron(II) adsorption were studied. Our finding revealed that the Brick from Bangui Region (in Central African Republic), coated with ferrihydrite was a very efficient media for the removal of Fe(II) ions from water. The experimental data showed that the depth and the moving rate (10.3 ± 0.6 cm) and (0.208 ± 0.006 cm/min) respectively of the exchange zone (adsorption zone) were independent of variability of the height of the adsorbent bed column, however the variations of the flow rate affect the moving rate of the exchange zone. The bed depth service time (BDST) model was used and permitted us to predict the service times of columns operated at various flow rates and bed depths and these predicted values were compared with the experimental values. 展开更多
关键词 Iron Oxyhydroxide-Coated Brick Iron(II)-Adsorption Column Study Break-through Curve BDST
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Promotion effects of alkali metals on iron molybdate catalysts for CO_(2)catalytic hydrogenation
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作者 Yong Zhou Aliou Sadia Traore +9 位作者 Deizi V.Peron Alan J.Barrios Sergei A.Chernyak Massimo Corda Olga V.Safonova Achim Iulian Dugulan Ovidiu Ersen Mirella Virginie Vitaly V.Ordomsky Andrei Y.Khodakov 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第10期291-300,I0009,共11页
CO_(2)hydrogenation is an attractive way to store and utilize carbon dioxide generated by industrial processes,as well as to produce valuable chemicals from renewable and abundant resources.Iron catalysts are commonly... CO_(2)hydrogenation is an attractive way to store and utilize carbon dioxide generated by industrial processes,as well as to produce valuable chemicals from renewable and abundant resources.Iron catalysts are commonly used for the hydrogenation of carbon oxides to hydrocarbons.Iron-molybdenum catalysts have found numerous applications in catalysis,but have been never evaluated in the CO_(2)hydrogenation.In this work,the structural properties of iron-molybdenum catalysts without and with a promoting alkali metal(Li,Na,K,Rb,or Cs)were characterized using X-ray diffraction,hydrogen temperatureprogrammed reduction,CO_(2)temperature-programmed desorption,in-situ^(57)Fe Mossbauer spectroscopy and operando X-ray adsorption spectroscopy.Their catalytic performance was evaluated in the CO_(2)hydrogenation.During the reaction conditions,the catalysts undergo the formation of an iron(Ⅱ)molybdate structure,accompanied by a partial reduction of molybdenum and carbidization of iron.The rate of CO_(2)conversion and product selectivity strongly depend on the promoting alkali metals,and electronegativity was identified as an important factor affecting the catalytic performance.Higher CO_(2)conversion rates were observed with the promoters having higher electronegativity,while low electronegativity of alkali metals favors higher light olefin selectivity. 展开更多
关键词 CO_(2)utilization Iron molybdate catalysts PROMOTION Alkali metals Light olefins In-situ characterization
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Study of the Temperature-Programmed Desorption of Carbon Dioxide (CO2) on Zeolites X Modified with Bivalent Cations
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作者 Charly Mve Mfoumou Francis Ngoye +4 位作者 Pradel Tonda-Mikiela Ferdinand Evoung Evoung Landry Biyoghe Bi-Ndong Thomas Belin Samuel Mignard 《Journal of Environmental Protection》 CAS 2023年第1期66-82,共17页
Study of physisorbed and chemisorbed carbon dioxide (CO<sub>2</sub>) species was carried out on the NaX zeolite modified by cationic exchanges with bivalent cations (Ca<sup>2+</sup> and Ba<s... Study of physisorbed and chemisorbed carbon dioxide (CO<sub>2</sub>) species was carried out on the NaX zeolite modified by cationic exchanges with bivalent cations (Ca<sup>2+</sup> and Ba<sup>2+</sup>) by temperature-programmed desorption of CO<sub>2</sub> (CO<sub>2</sub>-TPD). Others results were obtained by infrared to complete the study. The results of this research showed, in the physisorption region (213 - 473 K), that the cationic exchanges on NaX zeolite with bivalent cations increase slightly the interactions of CO<sub>2</sub> molecule with adsorbents and/or cationic site. Indeed, the desorption energies of physisorbed CO<sub>2</sub> obtained on the reference zeolite NaX (13.5 kJ·mol<sup>-1</sup>) are lower than that of exchanged zeolites E-CaX and E-BaX (15.77 and 15.17 kJ·mol<sup>-1</sup> respectively). In the chemisorbed CO<sub>2</sub> region (573 - 873 K), the desorption energies related to desorbed species (bidentate carbonates: CO<sub>3</sub>2-</sup>) on the exchanged zeolites E-CaX and E-BaX are about 81 kJ·mol<sup>-1</sup>, higher than the desorbed species (bicarbonates: HCO<sub>3</sub>2-</sup>) on the reference R-NaX (62 kJ·mol<sup>-1</sup>). In addition, the exchanged E-BaX zeolite develops the secondary adsorption sites corresponding to bicarbonates species with desorption energies of 35 kJ·mol<sup>-1</sup> lower to desorption energies of bicarbonates noted on the reference zeolite NaX. 展开更多
关键词 Adsorption Faujasite X Chemisorbed and Physisorbed CO2 Exchanged Zeolites Bivalent Cations Temperature-Programmed Desorption (TPD) Infrared
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大气压直流氩等离子体光谱诊断研究 被引量:35
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作者 屠昕 陆胜勇 +4 位作者 严建华 马增益 潘新潮 岑可法 CHERON Bruno 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2006年第10期1785-1789,共5页
通过光谱诊断系统测量了大气压直流氩等离子体射流在弧室内和弧室出口的发射光谱,利用波尔兹曼曲线斜率法计算了射流的电子温度,根据ArⅠ谱线的斯塔克展宽得到射流的电子密度,并对氩等离子体射流满足局域热力学平衡(LTE)状态的判定标准... 通过光谱诊断系统测量了大气压直流氩等离子体射流在弧室内和弧室出口的发射光谱,利用波尔兹曼曲线斜率法计算了射流的电子温度,根据ArⅠ谱线的斯塔克展宽得到射流的电子密度,并对氩等离子体射流满足局域热力学平衡(LTE)状态的判定标准进行了分析,结果表明在文章的实验条件下大气压直流氩等离子体射流达到局域热力学平衡。 展开更多
关键词 等离子体 光谱诊断 电子温度 电子密度 斯塔克展宽 局域热力学平衡
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酵母细胞影响红曲霉次生代谢产物的研究 被引量:8
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作者 朱振元 满金浩 +2 位作者 刘安军 尚校兰 张勇民 《现代食品科技》 EI CAS 2009年第2期136-140,共5页
通过红曲液体培养,研究酵母细胞对红曲霉次生代谢产物的影响。结果表明在红曲霉液体发酵中添加酿酒酵母细胞破壁液,亲水性色素提高了37.53%,疏水性色素提高了24.58%,Monacolin K增加了57.27%。
关键词 红曲霉 酿酒酵母 色素 Monacolin K
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古尼虫草抗肿瘤活性成分的提取分离及活性测定 被引量:8
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作者 朱振元 陈熙 +3 位作者 周家萍 刘安军 张雅洁 张勇民 《食品科学》 EI CAS CSCD 北大核心 2009年第9期200-203,共4页
虫草是一类珍贵的生物资源,本实验对古尼虫草菌丝体甲醇提取物的抗肿瘤活性成分进行了研究。通过甲醇浸提、正己烷、乙酸乙酯萃取得到古尼虫草甲醇粗提物0.6194g,其得率为2.06%。将得到的甲醇粗提物用乙醚:正己烷:甲醇=5:5:1的溶液为洗... 虫草是一类珍贵的生物资源,本实验对古尼虫草菌丝体甲醇提取物的抗肿瘤活性成分进行了研究。通过甲醇浸提、正己烷、乙酸乙酯萃取得到古尼虫草甲醇粗提物0.6194g,其得率为2.06%。将得到的甲醇粗提物用乙醚:正己烷:甲醇=5:5:1的溶液为洗脱剂进行硅胶柱层析分离纯化,获得3个组分(FB1、FB2、FB3)。通过红外光谱和核磁共振H谱对分离组分FB3进行了初步检测,结果显示为甾体类化合物。采用MTT比色法检测分离组分FB3的抗肿瘤活性,发现其对MCF-7和HL-7702细胞株有抑制作用,最强抑制率达84.54%。 展开更多
关键词 古尼虫草 提取 分离 抗肿瘤
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大气压直流双阳极等离子弧脉动特性研究 被引量:6
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作者 屠昕 严建华 +3 位作者 马增益 潘新潮 岑可法 CHERON Bruno 《中国电机工程学报》 EI CSCD 北大核心 2006年第20期113-117,共5页
等离子弧的脉动特性是表征等离子体物理状态和过程的重要参数之一,等离子体射流的非稳定性和阳极斑点在电极上的运动是引起等离子弧脉动的主要原因,是等离子体技术的实际应用和进一步发展的关键。该文介绍了一种大气压直流双阳极等离子... 等离子弧的脉动特性是表征等离子体物理状态和过程的重要参数之一,等离子体射流的非稳定性和阳极斑点在电极上的运动是引起等离子弧脉动的主要原因,是等离子体技术的实际应用和进一步发展的关键。该文介绍了一种大气压直流双阳极等离子发生器,通过对等离子弧电信号进行时域和频域分析,研究了载气成分、载气流量和弧电流等参数的变化对等离子弧脉动特性的影响,结果表明在文中的实验条件下等离子弧的伏安特性呈上升趋势,纯氩气作为载气时等离子弧的脉动特性主要和电源的交流分量有关,氩氮混合气体作为载气时等离子弧的脉动特性除了和电源的交流分量有关,还和弧室内存在的赫姆霍茨共振有关,其共振频率独立于气体流量和弧电流的变化。 展开更多
关键词 等离子炬 双阳极 脉动 伏安特性 赫姆霍茨共振
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