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Synergistic construction of nano nickel and lanthanum tungstate matrix for CO_(2) -tolerant PCEC:Achieving stable CO_(2) methanation
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作者 Chenhao Wang Xiaoyun Miao +3 位作者 Ting Luo Xingzhi Zhu Xiaofeng Ye Zhaoyin Wen 《Journal of Energy Chemistry》 2026年第3期146-155,共10页
CO_(2) hydrogenation using protonic ceramic electrolysis cells(PCECs)to produce fuel gases such as CH_(4)and CO has been considered as a promising technology for effective CO_(2) utilization.However,the long-term stab... CO_(2) hydrogenation using protonic ceramic electrolysis cells(PCECs)to produce fuel gases such as CH_(4)and CO has been considered as a promising technology for effective CO_(2) utilization.However,the long-term stability of conventional PCECs based on Y and Yb doped BaZrO_(3)-BaCeO_(3)(BCZYYb)proton conductors is severely limited by their susceptibility to carbonate formation under high concentration CO_(2) .In this work,a new type PCEC based on CO_(2) -tolerant La_(5.6)WO_(11.4-δ)(LWO)material is firstly constructed.A three-layer porous-dense-porous LWO ceramic scaffold is fabricated via a pressing,dip-coating and cosintering process,followed by Ni and La_(0.6)Sr_(0.4)CoO_(3-δ)(LSC)catalyst impregnation to ensure the chemical compatibility among materials and form an efficient PCEC-based CO_(2) hydrogenation reactor.Benefits from the synergistic catalysis of nano nickel and LWO,the reactor gets a CH_(4)selectivity of over 50%at 600℃under 20%CO_(2) concentration,and it operates stably for over 320 h at 600–650℃under high CO_(2) concentrations of 50–80%,showing no degradation in CO_(2) conversion rate or CH_(4)selectivity.Postmortem analysis demonstrates that the CO_(2) absorption characteristics of LWO and the morphological uniformity of nano nickel lead to stable CO_(2) methanation.This study provides a viable strategy for designing highly stable PCEC-based CO_(2) hydrogenation reactors. 展开更多
关键词 CO_(2)hydrogenation Protonic ceramic electrolysis cell lanthanum tungstate METHANATION Stability
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Influence of pH on impurities in preparation of lanthanum cerium carbonate by magnesium bicarbonate precipitation
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作者 Chunguang Song Meng Wang +5 位作者 Haiqing Hao Yongke Hou Zongyu Feng Yanyan Zhao Zhihe Dou Xiaowei Huang 《Journal of Rare Earths》 2025年第5期1067-1073,共7页
To solve the problem of ammonia wastewater pollution generated from preparing rare earth carbonate using the ammonium bicarbonate precipitation method,an eco-friendly precipitant,magnesium bicarbonate,was used to prep... To solve the problem of ammonia wastewater pollution generated from preparing rare earth carbonate using the ammonium bicarbonate precipitation method,an eco-friendly precipitant,magnesium bicarbonate,was used to prepare lanthanum cerium carbonate.The lanthanum cerium sulfate solution obtained from the smelting and separation of Baotou mixed rare earth ore was used as the raw material.The influence of pH on the content of impurities,including SO^(2-)_(4)and magnesium,and the existing states of SO^(2-)_(4)n lanthanum cerium carbonate products,as well as the thermal decomposition behavior of the products,were deeply explored.SO^(2-)_(4)mainly exists in the form of rare earth sulfate complex salts in lanthanum cerium carbonate products.The fo rmation of the salts can be effectively avoided by adjusting the pH of the precipitation process.Then the content of SO^(2-)_(4)in the product is controlled.When the pH ranges from 6.00 to 7.12,the content of SO^(2-)_(4)in the product ranges from 0.42 wt%to 0.99 wt%.The content of MgO is lower than 0.04 wt%.Both contents meet the requirements of the national standard GB/T 16479-2020.In this study,lanthanum cerium carbonate products with low-content SO^(2-)_(4)were prepared.In addition,the existing states of SO^(2-)_(4)in the products are revealed.The research provides a new method for controlling the impurity content in preparing lanthanum cerium carbonate. 展开更多
关键词 lanthanum cerium sulfate lanthanum cerium carbonate Magnesium bicarbonate PRECIPITATION Sulfate ions Rare earths
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High-Pressure Phase Transitions and Mechanisms in Lanthanum Mononitride
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作者 Hao Chen Dan Zhou +1 位作者 Ying Xu Quan Li 《Chinese Physics Letters》 2025年第6期163-169,共7页
A longstanding discrepancy between theoretical predictions and experimental observations on the highpressurestructural transformations of lanthanum mononitride(LaN)has posed challenges for understandingthe behavior of... A longstanding discrepancy between theoretical predictions and experimental observations on the highpressurestructural transformations of lanthanum mononitride(LaN)has posed challenges for understandingthe behavior of heavy transition metal mononitrides.Here,we systematically investigate the structural evolutionof LaN under high pressure using first-principles calculations combined with angle-dispersive synchrotron X-raydiffraction,identifying the phase transition sequence and corresponding phase boundaries.Analyses of energetics,kinetic barriers,and lattice dynamics reveal distinct mechanisms driving these transitions.These results clarifythe structural stability of LaN and offer guidance for studying other heavy transition metal mononitrides withcomplex electronic behavior under extreme conditions. 展开更多
关键词 phase transition sequence understandingthe behavior heavy transition metal mononitridesherewe high pressure phase transitions lanthanum mononitride theoretical predictions lattice dynamics structural stability lanthanum mononitride lan
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Regulation mechanism of active magnesium oxide on precipitation of lanthanum hydroxide 被引量:2
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作者 Jianwei Zhao Haiqing Hao +4 位作者 Yanyan Zhao Meng Wang Xu Sun Zongyu Feng Xiaowei Huang 《Journal of Rare Earths》 2025年第6期1264-1271,I0007,共9页
Precipitation is often used for the preparation of La(OH)_(3)with precipitants of liquid alkali and ammonia.To solve the problems of high cost and wastewater pollution caused by common precipitants,the active MgO synt... Precipitation is often used for the preparation of La(OH)_(3)with precipitants of liquid alkali and ammonia.To solve the problems of high cost and wastewater pollution caused by common precipitants,the active MgO synthesized by pyrolysis was used as the precipitant to prepare La(OH)_(3).The species distribution of LaCl_(3)and LaCl_(3)-MgCl_(2)mixed system solution was calculated,and the kinetic analysis of the precipi-tation process was carried out to confirm the key factors influencing the precipitation of La(OH)_(3).The results show that La(OH)_(3)with D_(50)of 5.57μm,a specific surface area of 25.70 m^(2)/g,a rod-like shape,and MgO content of 0.044 wt%,was successfully prepared by adding active MgO.The precipitation ratio of La reaches 99.92%.The La(OH)_(3)precipitation is controlled by the diffusion process.The activity of MgO has a significant influence on MgO content in the precipitate.The preparation of La(OH)_(3)by active MgO provides a potential way for an eco-friendly preparation method of rare earth. 展开更多
关键词 Active magnesium oxide PRECIPITATION lanthanum hydroxide REGULATION Rare earths
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A novel lanthanum-modified polytitanium chloride coagulant:Efficient algae removal and enhanced photocatalytic ability of recycled algal sludge 被引量:1
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作者 Tingyu Yang Jinling Zhang +2 位作者 Jinglei Qin Xianyao Wu Hongshang Peng 《Journal of Rare Earths》 2025年第11期2405-2413,I0004,共10页
The removal of harmful cyanobacterial blooms(HCBs)and reuse of the resulting algal sludge are pressing issues in current environmental governance and ecological conservation.Aiming at tackling the abovementioned chall... The removal of harmful cyanobacterial blooms(HCBs)and reuse of the resulting algal sludge are pressing issues in current environmental governance and ecological conservation.Aiming at tackling the abovementioned challenges,titanium(Ti)-based coagulants are promising candidates.However,most of them suffer from poor stability and weak actual algal removal ability,and recycling of the algal sludge usually produces titanium dioxide(TiO_(2))with low photocatalytic ability.In this work,a lanthanum(La)-modified polytitanium chloride(La-PTC)coagulant is reported.La in the La-PTC coagulant serves a"kill two birds with one stone"strategy in algae removal and algae sludge reuse.Owing to the introduction of La ions,the La-PTC coagulant exhibits ultra-high stability and excellent algae removal capability with an efficiency of 98.71%,which is 7.25%higher than that of PTC coagulant.Moreover,recycling algae sludge can prepare high catalytic(2.45 times the commercial P25 TiO_(2))La/C-TiO_(2),where the presence of La enhances its visible light response range and inhibits electron hole recombination.The strategy of this La modified coagulant can not only achieve efficient re moval of HCBs,but also transfo rm the recovered algal sludge into photocatalysts with higher catalytic capacity. 展开更多
关键词 Algae removal PTC coagulant lanthanum ion Algae sludge recovery TiO_(2)photocatalyst Rare earths
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Syntheses,proton conduction,and transport mechanism of two three‑dimensional lanthanum phosphite‑oxalates
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作者 LU Yang HUANG Liangliang +2 位作者 ZHAO Wei WANG Xin BI Yanfeng 《无机化学学报》 北大核心 2025年第10期2127-2137,共11页
To develop proton-conducting materials with high hydrothermal and acid-base stability and to elucidate the proton-transport mechanism through visualized structural analysis,two new lanthanum phosphite-oxalates with 3D... To develop proton-conducting materials with high hydrothermal and acid-base stability and to elucidate the proton-transport mechanism through visualized structural analysis,two new lanthanum phosphite-oxalates with 3D frameworks,designated as[La(HPO_(3))(C_(2)O_(4))0.5(H_(2)O)_(2)](La‑1)and(C_(6)H_(16)N_(2))(H_(3)O)[La_(2)(H_(2)PO_(3))_(3)(C_(2)O_(4))_(3)(H_(2)O)](La‑2)(C_(6)H_(14)N_(2)=cis-2,6-dimethylpiperazine),were prepared by hydrothermal and solvothermal conduction,respectively.La‑1 was constructed with lanthanum phosphite 2D layers and C_(2)O_(4)^(2-)groups,whereas La‑2 was constructed with lanthanum oxalate 2D layers and H_(2)PO^(3-)groups.Alternating current(AC)impedance spectra indicate that the pro-ton conductivities of both compounds could reach 10^(-4)S·cm^(-1)and remain highly durable at 75℃and 98%of rela-tive humidity(RH).Due to the abundance of H-bonds in La‑2,theσof La‑2 was higher than that of La‑1.La‑1 exhibited excellent water and pH stability.CCDC:2439965,La‑1;443776,La‑2. 展开更多
关键词 OPEN-FRAMEWORK lanthanum phosphite-oxalate proton conductivity stability
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Effect of lanthanum on microstructure of a nickel-based single crystal superalloy
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作者 Hong Gao Kai Guan +3 位作者 Ren-jie Cui Jian-chao Qin Zi-han Zhao Zhao-hui Huang 《China Foundry》 2025年第1期55-64,共10页
To enhance the high-temperature oxidation resistance and mechanical properties of a secondgeneration nickel-based superalloy,various concentrations of lanthanum(La)ranging from 5.0×10^(-5)wt.%to 3.4×10^(-4)w... To enhance the high-temperature oxidation resistance and mechanical properties of a secondgeneration nickel-based superalloy,various concentrations of lanthanum(La)ranging from 5.0×10^(-5)wt.%to 3.4×10^(-4)wt.%are added to the alloy.The microstructure of the nickel-based single crystal superalloy with trace of La was examined by means of SEM,EDS and TEM.Results show the addition of La decreases the segregation of elements and increases the amount ofγ/γ′eutectics of the as-cast alloy,and in the interdendritic region,the growth of eutectics is accompanied by the growth of strip clusters composed of Ni_(5)La and Ni_(3)Ta.As the La content in the alloy increases,the proportion of Ni_(5)La in the cluster increases.After heat treatment,incipient melting occurs in the cluster regions,leading to an increase in microporosity compared to the original as-cast samples.Furthermore,the heat treatment alters the shape of the clusters from a strip morphology to an elliptical one,and it changes their composition from Ni_(5)La and Ni_(3)Ta to a combination of Ni_(5)La,Ni_(3)Ta,and MC carbides. 展开更多
关键词 single crystal superalloy lanthanum MICROSTRUCTURE heat-treatment precipitate phase
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Lanthanum-based nanomaterials for oxygen evolution reaction
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作者 Miao He Ping Wang +3 位作者 Jiasai Yao Yifei Li Senyao Meng Zhenxing Li 《Journal of Rare Earths》 2025年第6期1091-1099,I0001,共10页
Rare earth has a unique electronic structure and brings highly anticipated properties in light,electricity,heat and magnetism.Lanthanum is widely distributed among the rare earth elements and has a great potential for... Rare earth has a unique electronic structure and brings highly anticipated properties in light,electricity,heat and magnetism.Lanthanum is widely distributed among the rare earth elements and has a great potential for the electrocatalytic application.This paper reviews the common types and synthesis methods of lanthanum-based catalysts used in the electrocatalytic oxygen evolution reaction,and highlights the optimization of lanthanum-based catalysts.The electronic structure and active sites of the catalysts can be adjusted through atomic doping,interfacial modulation,and structural defects to enhance the OER.Further,the development of lanthanum-based catalyst is envisioned. 展开更多
关键词 Rare earths lanthanum Oxygen evolution reaction Synthesis method ELECTROCATALYSIS
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Lanthanum-doped NiCoFe_(2)O_(4)ferrite nanocomposites:Synthesis,characterization,and electrochemical investigation for hybrid supercapacitors
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作者 Muhammad Hamza Waris Muhammad Azhar Mumtaz +6 位作者 Amir Muhammad Afzal Muhammad Waqas Iqbal Muhammad Imran Sohail Mumtaz Rizwan Khan Ghulam Dastgeer Aboud Ahmed Awadh Bahajjaj 《Journal of Rare Earths》 2025年第8期1685-1692,I0004,共9页
Rare earth elements have gained considerable popularity in electronic devices as vital elements in electrical and dielectric materials.In this manuscript,NiCoFe_(2)O_(4)nanocomposite was synthesized using the sol-gel ... Rare earth elements have gained considerable popularity in electronic devices as vital elements in electrical and dielectric materials.In this manuscript,NiCoFe_(2)O_(4)nanocomposite was synthesized using the sol-gel method and doped with the rare earth element lanthanum(La)to improve the structural,morphological and electrochemical properties.First,the structural and morphological characteristics of NiCoFe_(2)O_(4)and La@NiCoFe_(2)O_(4)nanocomposite were measured.Three-and two-electrode setups were used to assess the electrochemical properties of La@NiCoFe_(2)O_(4).At 1.5 A/g,the La@NiCoFe_(2)O_(4)shows a very high specific capacity value of 1622.5 C/g.Next,a two-electrode configuration with a La@NiCoFe_(2)O_(4)and an activated carbon(AC)was designed.With an impressive power density(PD)of 2207 W/kg,a remarkable energy density(ED)of 42.2 Wh/kg,and a specific capacity of 268.0 C/g,the resulting supercapattery device displays exceptional characteristics.Supercapacitor devices,in particular,demonstrate exceptional cycle stability,while the device as a whole has a high capacitive retention(CR)value of 89.0%after 5000 cycles.These results indicate that La@NiCoFe_(2)O_(4)is a possible material for the design of future energy storage system electrodes due to its numerous desirable characteristics. 展开更多
关键词 lanthanum Rare earths Two-electrode assembly Energy density Power density Hybrid supercapacitor
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A review of doping strategy for rapid Li^(+) migration in the stable lithium lanthanum zirconate solid electrolytes
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作者 Shu-Xiao Yan Zi-Jian Zhao +2 位作者 Yong Zheng Bilal Khalid Gui-Ying Tian 《Rare Metals》 2025年第7期4446-4478,共33页
Given the safety concerns and low energy density induced by liquid electrolytes,the interest in solidstate lithium metal batteries is rapidly growing.Among various solid electrolytes,garnet-type lithium lanthanum zirc... Given the safety concerns and low energy density induced by liquid electrolytes,the interest in solidstate lithium metal batteries is rapidly growing.Among various solid electrolytes,garnet-type lithium lanthanum zirconate (LLZO) has attracted extensive attention due to its numerous advantages.This review systematically summarizes the intrinsic issues faced by unstable bare LLZO and the resolution strategy of metallic doping in the electrochemical application.It comprehensively discusses the doping arrangements for high ionic conductivity based on element types and gap filling using second phases/sintering aids for LLZO grains/pellets.Emphasizing diverse doping strategies for bulk LLZO,it relates to simulation and characterization findings along with novel synthesis approaches.By identifying the inherent scientific questionsof LLZO,this review bridges the long-existing gaps between the doping strategy guidelines for suitable crystalline phase and the surge of high Li^(+)conductivity for practical solid-state lithium batteries. 展开更多
关键词 Lithium lanthanum zirconate Solid-state battery Metallic doping Cubic phase
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Lanthanum chloride or citrate is absorbed mainly via M cells in gastrointestinal tracts with lanthanum phosphates as the transformed species 被引量:1
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作者 Huixia Huang Huixue Liu +2 位作者 Xiaojie Ma Hui Guan Xiaogai Yang 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2018年第8期553-564,共12页
In the present study, we investigated the transformed species and the absorptive mechanism of rare earth elements(REEs) in gastrointestinal(GI) tract, using La Cl3 and La Cit as representative compounds. Artificia... In the present study, we investigated the transformed species and the absorptive mechanism of rare earth elements(REEs) in gastrointestinal(GI) tract, using La Cl3 and La Cit as representative compounds. Artificial gastric and intestinal fluids were used to simulate the environment of the digestive tract in vivo. The inductively coupled plasma mass spectrometry(ICP-MS) result showed that more than 99.9% of La Cl3 and La Cit formed precipitation in artificial intestinal fluid, with the average size distribution of 200 nm(2-h incubation) increasing to 600 nm(24-h incubation) determined by dynamic light scattering(DLS), indicating the aggregation of the particles. The Fourier transform infrared spectroscopy(FTIR) analysis demonstrated that the constituents of these particles were mainly in the form of lanthanum phosphates. To explore the transport mechanism of REEs in GI tract, the mice Peyer's patches(PPs) and intestinal epithelium were separated to evaluate the content of lanthanum by ICP-MS following oral administration with 2 or 100 mg/kg/day of La Cit for 7 d. The results showed that the amount of lanthanum phosphate particles absorbed by PPs was significantly greater than that of intestinal epithelium, indicating that lanthanum particles might be phagocytosed mainly by M cells located in the follicle-associated epithelium(FAE) overlying PPs. Furthermore, Caco-2 cell monoculture and Caco-2/Raji B cell coculture models were established to simulate intestinal epithelial cells and FAE, respectively. The result showed that the transport of lanthanum in Caco-2/Raji B coculture model was significantly higher than that in Caco-2 monoculture model(about 60 times higher), and the level of lanthanum in the basal compartment of Caco-2 monoculture model was very low, supporting that M cells were the main route for lanthanum phosphate particles to be transported and absorbed. Taken together, these data suggested that La Cl3 and La Cit in GI tract were absorbed mainly via M cells with lanthanum phosphates as transformed species. The obtained results would provide the theoretical basis for the rational application of REEs in agriculture and medicine. 展开更多
关键词 lanthanum chloride (LaCl3) lanthanum citrate (LaCit) lanthanum phosphates Artificial intestinal fluid Peyer's patches M cells Caco-2 cell monoculture model Caco-2/Raji B cells coculture model Transport and absorption
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Kinetics of thermal decomposition of lanthanum oxalate hydrate 被引量:13
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作者 詹光 余军霞 +2 位作者 徐志高 周芳 池汝安 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第4期925-934,共10页
Lanthanum oxalate hydrate La2(C2O4)3·10H2O,the precursor of La2O3 ultrafine powders,was prepared by impinging stream reactor method with PEG 20000 as surfactant.Thermal decomposition of La2(C2O4)3·10H2O ... Lanthanum oxalate hydrate La2(C2O4)3·10H2O,the precursor of La2O3 ultrafine powders,was prepared by impinging stream reactor method with PEG 20000 as surfactant.Thermal decomposition of La2(C2O4)3·10H2O from room temperature to 900 °C was investigated and intermediates and final solid products were characterized by FTIR and DSC-TG.Results show that the thermal decomposition process consists of five consecutive stage reactions.Flynn-Wall-Ozawa(FWO) and Kissinger-Akahira-Sunose(KAS) methods were implemented for the calculation of energy of activation(E),and the results show that E depends on α,demonstrating that the decomposition reaction process of the lanthanum oxalate is of a complex kinetic mechanism.The most probable mechanistic function,G(α)=[1-(1+α)1/3]2,and the kinetic parameters were obtained by multivariate non-linear regression analysis method.The average E-value that is compatible with the kinetic model is close to value which was obtained by FWO and KAS methods.The fitting curve matches the original TG curve very well. 展开更多
关键词 lanthanum oxalate decahydrate TG-DSC thermal decomposition multivariate non-linear regression analysis
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Preparation, friction and wear properties of hydrophobic lanthanum borate nanorods in rapeseed oil 被引量:2
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作者 谷科城 陈波水 +4 位作者 王雪梅 王九 方建华 吴江 黄立川 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第11期3578-3584,共7页
Oleic acid (denoted as OA) surface-caped lanthanum borate nanorods, abbreviated as OA/LaBO3·H2O, were prepared via hydrothermal method. The microstructures of the as-prepared OA/LaBO3·H2O nanorods were chara... Oleic acid (denoted as OA) surface-caped lanthanum borate nanorods, abbreviated as OA/LaBO3·H2O, were prepared via hydrothermal method. The microstructures of the as-prepared OA/LaBO3·H2O nanorods were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The friction and wear properties of OA/LaBO3·H2O nanorods in rapeseed oil were evaluated with a four-ball tribo-tester. The results show that the as-prepared OA/LaBO3·H2O nanorods are hydrophobic and display nanorods morphology with uniform diameter of about 50 nm and length of up to 500 nm. In the meantime, OA/LaBO3·H2O nanorods can obviously improve the anti-wear and friction-reducing capacities of rapeseed oil, and the optimal anti-wear and friction-reducing properties of rapeseed oil were obtained at an OA/LaBO3·H2O content of 1% (mass fraction). 展开更多
关键词 lanthanum borate nanorod HYDROPHOBICITY PREPARATION friction wear rapeseed oil
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LaO_(x)(OH)_(y) supported platinum catalysts for CO oxidation:Deactivation by formation of lanthanum carbonate 被引量:3
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作者 Luozhen Jiang Junxiang Chen Rui Si 《Journal of Rare Earths》 SCIE EI CAS CSCD 2021年第3期297-304,I0003,共9页
Platinum catalyst for CO oxidation has been studied for decades,due to its high activity and good stability.In this work,we prepared three different lantha num oxide or hydroxide supports(LaO_(x)(OH)_(y)),and deposite... Platinum catalyst for CO oxidation has been studied for decades,due to its high activity and good stability.In this work,we prepared three different lantha num oxide or hydroxide supports(LaO_(x)(OH)_(y)),and deposited platinum(Pt) with 0.5 at% via an impregnation approach to synthesize Pt/LaO_(x)(OH)_(y) catalysts.However,we find that these catalysts perform a poor stability for the CO oxidation reaction.The fresh and used samples were comprehensively characterized by multiple techniques including power X-ray diffraction(XRD),X-ray absorption fine structure(XAFS),transmission electron microscopy(TEM),temperature-programmed reduction by carbon monoxide(CO-TPR) and thermogravimetric analysis(TGA),to demonstrate that the oxidized platinum atoms or clusters,without any component of Pt-Pt metallic bond,are highly dispersed on the surface of LaO_(x)(OH)_(y).Furthermore,the as-formed lanthanum carbonate(La_(2)O_(2)CO_(3)) during the exposure to ambient circumstances or in the reaction atmosphere of CO+O_(2),severely impair the reactivity of Pt/LaO_(x)(OH)_(y).On the basis of the obtained experimental results,we have drawn a conclusion that the oxidized P_(t)O_(x) atoms or PtxOy clusters are the active species for CO oxidation,while the formation of lanthanum carbonate is the origin of deactivation on reactivity. 展开更多
关键词 Platinum catalyst lanthanum oxide lanthanum hydroxide CO oxidation Structure-activity relationship Rare earths
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Gas solid techniques for preparation of pure lanthanum hexaboride 被引量:2
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作者 Mukherjee A. Gulnar A.K. +1 位作者 Sahoo D.K. Krishnamurthy N. 《Rare Metals》 SCIE EI CAS CSCD 2012年第3期285-289,共5页
The processes reported for the preparation of lanthanum hexaboride (LaB6) from lanthanum oxide involve the use of carbon either elemental or in the form of boron carbide or elemental boron itself as reducing agents, f... The processes reported for the preparation of lanthanum hexaboride (LaB6) from lanthanum oxide involve the use of carbon either elemental or in the form of boron carbide or elemental boron itself as reducing agents, fused salts at high temperatures or reactions which require the product boride to be leached out. Each of these techniques either increases the process costs and/or increases chances of contamination in fi-nal product. Pure LaB6 can best be prepared by a reaction which produces a gaseous byproduct. In the present study, such a reaction was successfully used to yield pure lanthanum hexaboride. The process involved mixing of anhydrous lanthanum chloride with aluminium and boron and heating the charges under dynamic argon flow. Lanthanum chloride is known to be highly hygroscopic; hence the process using improperly dehydrated LaCl3 led to the formation of lanthanum oxychloride which does not convert to LaB6 under conditions wherein LaCl3 converts. Not only the formation of AlCl3 but also its continuous removal from the reaction zone is necessary for the success of the process. 展开更多
关键词 lanthanum oxychloride lanthanum hexaboride aluminium GAS-SOLID
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Effect of Lanthanum on Growth and Extracellular Enzyme Acitivty of Erwinia Chrysanthemi in vitro 被引量:1
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作者 Liu Qingdu (School of Life Science, University of Science and Technology of China, Hefei 230026, China) Zhang Jian , Cheng Heyuan (Department of Plant Protection, Anhui Agricultural University, Hefei 230036, China) 《Journal of Rare Earths》 SCIE EI CAS CSCD 1999年第2期64-67,共4页
The effect of lanthanum on the growth and extracellular enzyme activity of Erwinia chrysanthemi(Ech) was studied. Lanthanum inhibited the growth of Ech in solid culture at the concentration of 50, 100, 150, 200, 250, ... The effect of lanthanum on the growth and extracellular enzyme activity of Erwinia chrysanthemi(Ech) was studied. Lanthanum inhibited the growth of Ech in solid culture at the concentration of 50, 100, 150, 200, 250, 300 and 350 mgL-1, and the inhibition increased with the increase of the RE concentration. The formation of colony delayed and the diameter of colony decreased. Lanthanum stimulated the growth of Ech within 24h when the lanthanum concentration was less than 200 mgL-1 in liquid medium, but significantly inhibited the growth of Ech with the increase of lanthanum concentration and culture time. When the concentration was higher than 350 mgL-1, the growth of Ech was inhibited completely both in solid and liquid culture. The extracellular enzyme acitivity of Ech was affected by lanthanum at 200 mgL-1. The activity of cellulose was promoted more than that of protease but the activity of pectinase was decreased. The maceration to potato tuber tissue decreased when the cell free filtrate was tr 展开更多
关键词 Rare earths lanthanum Erwinia chrysanthemi Extracellular enzyme Maceration eated with lanthanum.
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Dinitrogen fixation mediated by lanthanum hydride
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作者 Hanxue Yan Wenbo Gao +9 位作者 Jirong Cui Weijin Zhang Qijun Pei Qianru Wang Yeqin Guan Sheng Feng Han Wu Hujun Cao Jianping Guo Ping Chen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第9期1-7,I0001,共8页
Dinitrogen fixation is one of the key reactions in chemistry, which is closely associated with food, environment, and energy. It has been recently recognized that the hydride materials containing negatively charged hy... Dinitrogen fixation is one of the key reactions in chemistry, which is closely associated with food, environment, and energy. It has been recently recognized that the hydride materials containing negatively charged hydrogen(H~-) show promises for Nfixation and hydrogenation to ammonia. Herein, we report that rare earth metal hydrides such as lanthanum hydride can also fix Neither by heating to 200 °C or ball milling under ambient Npressure and temperature. The Nfixation by lanthanum hydride may proceed via an intermediate lanthanum hydride-nitride(La-H-N) structure to form the final lanthanum nitride product. The hydride ion functions as an electron donor, which provides electrons for Nactivation possibly mediated by the lanthanum atoms. It is observed that N–H bond is not formed during the Nfixation process, which is distinctly different from the alkali or alkaline earth metal hydrides. The hydrolysis of La-H-N to ammonia is feasible using water as the hydrogen source. These results provide new insights into the nitrogen fixation by hydride materials and more efforts are needed for the development of rare earth metal-based catalysts and/or nitrogen carriers for ammonia synthesis processes. 展开更多
关键词 HYDRIDE lanthanum hydride Nitrogen fixation lanthanum hydride-nitride Rare earth metal hydride
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Comparison of toxicity between lanthanum oxide nanoparticles and lanthanum chloride
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作者 Kun Huang Songchang Lai +5 位作者 Miao Guo Xingwu Zhu Jiashuangwei Yuan Zhehao Liu Gonghua Hu Yanfang Gao 《Journal of Rare Earths》 SCIE EI CAS CSCD 2024年第2期424-430,I0007,共8页
Due to the wide application of rare earth elements,lanthanum(La) is gradually accumulated in our living environment.Lanthanum can enter the body through a variety of routes,which has a series of effects on various sys... Due to the wide application of rare earth elements,lanthanum(La) is gradually accumulated in our living environment.Lanthanum can enter the body through a variety of routes,which has a series of effects on various systems.As a consequence,the safety of lanthanum deserves our attention.This study aims to compare the toxicity of lanthanum oxide nanoparticles(La_(2)O_(3) NPs) and lanthanum chloride(LaCl_(3)) and enrich the toxicity evaluation of lanthanum.Therefore,a 30 d intragastal experiment was conducted.C57BL/6j mice were given by La_(2)O_(3) NPs solution and LaCl_(3) solution respectively at doses of 0,30,60 and120 mg/kg BW(lanthanum content).The results show that,compared with the control group,both La_(2)O_(3)NPs and LaCl_(3) can reduce the body weight of female mice in the high-dose group,but for male mice,the high-dose La_(2)O_(3) NPs solution can increase the body weight,while LaCl_(3) has the opposite effect.The coefficients of liver,kidney,heart,lung,uterine and ovaries increase first and then decrease with the exposure dose,but testes and epididymides coefficient keep increasing with the exposure of LaCl_(3) and La_(2)O_(3) NPs.La_(2)O_(3) NPs and LaCl_(3) can reduce the concentration of triglycerides(TG) and increase the level of low density lipoprotein(LDL),but the effect of La_(2)O_(3) NPs is more obvious.La_(2)O_(3) NPs and LaCl_(3) can reduce the concentration of malondialdehyde(MDA),increase the total antioxidant capacity(T-AOC)and enhance the activity of catalase(CAT),but LaCl_(3) has more obvious protective effects on oxidative stress.La_(2)O_(3) NPs and LaCl_(3) have potential risks to liver,and the toxicity of La_(2)O_(3) NPs might be higher than that of LaCl_(3). 展开更多
关键词 Rare earth elements lanthanum oxide nanoparticles lanthanum chloride Lipid metabolism Oxidative stress
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Effect of lanthanum content on microstructure and magnetic properties of non-oriented electrical steels 被引量:27
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作者 万勇 陈伟庆 吴绍杰 《Journal of Rare Earths》 SCIE EI CAS CSCD 2013年第7期727-733,共7页
The effect of lanthanum content in the range of 04).01 1 wt.%, on the inclusion size distribution, microstructure, texture and magnetic properties of three non-oriented electrical steels was studied. After final anne... The effect of lanthanum content in the range of 04).01 1 wt.%, on the inclusion size distribution, microstructure, texture and magnetic properties of three non-oriented electrical steels was studied. After final annealing, lanthanum effectively inhibited the precipitation of MnS precipitates in steel, the formations of La2O2S and LaS inclusions not only acted as nuclei of AlN precipitates, but also combined with A1203 and formed composite inclusions with larger size. Grain size firstly increased and then decreased with lanthanum content increasing. Steel containing 0.0066 wt.% lanthanum obtained the largest grain size, the strongest { 110} 〈 110〉 texture and the weakest { 112}〈110〉 texture among all the tested steels. Magnetic flux density firstly increased and then decreased, core loss firstly dramatically decreased and then slightly decreased with lanthanum content increasing. Among the three tested steels, steel with 0.0066 wt.% lanthanum demonstrated the best comprehensive magnetic properties mainly through the development of favorable texture and appropriate final grain size. 展开更多
关键词 lanthanum non-oriented electrical steel grain size TEXTURE magnetic property rare earths
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Effects of lanthanum addition on corrosion resistance of hot-dipped galvalume coating 被引量:23
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作者 杨栋 陈建设 +1 位作者 韩庆 刘奎仁 《Journal of Rare Earths》 SCIE EI CAS CSCD 2009年第1期114-118,共5页
Effects of La addition on corrosion resistance of hot-dipped galvalume coating steel wire were investigated.The corrosion resistance of Zn-Al-Si-La alloy coatings containing 0, 0.02wt.%, 0.05wt.%, 0.1wt.% and 0.2wt.% ... Effects of La addition on corrosion resistance of hot-dipped galvalume coating steel wire were investigated.The corrosion resistance of Zn-Al-Si-La alloy coatings containing 0, 0.02wt.%, 0.05wt.%, 0.1wt.% and 0.2wt.% La were evaluated by various tests such as copper-accelerated acetic acid salt spray testing(CASS), immersion test in 3.5% NaCl solution, electrochemical tests including weak polarization curves and electrochemical impedance spectroscopy(EIS) tests, scanning electron microscope(SEM) test and X-ray diffraction(XRD) test.It was found that the corrosion resistance of galvalume coating could be improved by adding proper amounts of La.Meanwhile, the mechanism of the improvement of corrosion resistance by La addition was discussed. 展开更多
关键词 lanthanum galvalume coating weight loss weak polarization curves electrochemical impedance spectroscopy rare earths
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