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Dynamic cooperations between lattice oxygen and oxygen vacancies for photocatalytic ethane dehydrogenation by a self-restoring LaVO_(4)catalyst

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Chinese Chemical Letters 2024年第3期35卷 171-176页

作者： Fen Wei Weichao xue Zhiyang Yu xue feng lu Sibo Wang Wei Lin Xinchen Wang State Key Laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou UniversityFuzhou 350108China

Thermocatalytic nonoxidative ethane dehydrogenation(EDH)is a promising strategy for ethene production but suffers from intense energy consumption and poor catalyst durability;exploring technology that permits efficient EDH by solar energy remains a giant challenge.Herein,we present that an oxygen vacancy(O_v)-rich LaVO_(4)(LaVO_(4)-O_v)catalyst is highly active and stable for photocatalytic EDH,through a dynamic lattice oxygen(O_(latt.))and O_(v)co-mediated mechanism.Irradiated by simulated sunlight at mild conditions,LaVO_(4)-O_(v)effectively dehydrogenates undiluted ethane to produce C_(2)H_(4)and CO with a conversion of 2.3%.By loading a small amount of Pt cocatalyst,the evolution and selectivity of C_(2)H_(4)are enhanced to 275μmol h^(-1)g^(-1)and 96.8%.Of note,LaVO_(4)-O_(v)appears nearly no carbon deposition after the reaction.The isotope tracked reactions reveal that the consumed O_(latt.)recuperates by exposing the used catalyst with O_(2),thus establishing a dynamic cycle of O_(latt.)and achieving a facile catalyst regeneration to preserve its intrinsic activity.The refreshed LaVO_(4)-O_(v)exhibits superior reusability and delivers a turnover number of about 305.The O_(v)promotes photo absorption,boosts ethane adsorption/activation,and accelerates charge separation/transfer,thus improving the photocatalytic efficiency.The possible photocatalytic EDH mechanism is proposed,considering the key intermediates predicted by density functional theory(DFT)and monitored by in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS).

关键词： Photocatalysis Ethane dehydrogenation Ethene LaVO_(4) Oxygen vacancy

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Temporal and Spectral Characteristics of Persistent Emission and Special Bursts of Magnetar SGR J1935+2154 Based on Insight-HXMT

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Research in Astronomy and Astrophysics 2024年第6期24卷 227-235页

作者： xue-feng lu Li-Ming Song Ming-Yu Ge Shuang-Nan Zhang Jin-lu Qu Ce Cai Cong-Zhan Liu Cheng-Kui Li Yu-Cong Fu Ying-Chen Xu Key Laboratory of Particle Astrophysics Institute of High Energy Physics University of Chinese Academy of Sciences Chinese Academy of Sciences College of Physics and Hebei Key Laboratory of Photophysics Research and Application Hebei Normal University Department of Astronomy Beijing Normal University

In October 2022, the magnetar SGR J1935+2154 entered the active outburst state. During the episode, the InsightHXMT satellite carried out a long observation that lasted for 20 days. More than 300 bursts were detected, and a certain amount of persistent radiation signals were also accumulated. This paper mainly introduces the results of persistent radiation profile folding and period search based on Insight-HXMT data. At the same time, the burst phase distribution characteristics, spectral lag results of burst, the spectral characteristics of zero-lag bursts and the time-resolved spectral evolution characteristics of high-flux bursts are reported. We found that there is no significant delay feature during different energy bands for the bursts of SGR J1935+2154. The observed zero-lag burst does not have a unique spectrum. The time-resolved spectrum of the individual burst has consistent spectral types and spectral parameters at different time periods of the burst. We also find that the burst number phase distribution and the burst photon phase distribution have the same tendency to concentrate in specific regions of the persistent emission profile.

关键词： dense matter magnetic fields radiation mechanisms: general

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Structural and functional design of geopolymer adsorbents:a review

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Tungsten 2024年第1期6卷 48-76页

作者： Hai-Ze Jin Chen-Xi Qiu Yan-Song Li Bao Liu Jun-Yi Liu Qiao Chen xue-feng lu Cui-Xia Li Qi-Kun Wang School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050China State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals Lanzhou 730050China Shenyang Nonferrous Metals Research Institute Co. LTDShenyang 110000China Automotive Engineering Research Institute Jiangsu UniversityZhenjiang 212013China School of Materials Science and Engineering Jingdezhen Ceramic UniversityJingdezhen 333403China

The water pollution derived from the discharge of heavy metals,antibiotics,dyes and surfactants wastewater,etc.has seriously affected human survival and ecological security.As an efficient and low-cost physical wastewater treatment process,the adsorption is a continuous hot spot in related scientific research and applications.Geopolymers are non-crystal or semi-crystalline materials with high-efficiency adsorption performance due to the alkali metal ions that balance the electronegative aluminosilicate skeleton can be efficiently replaced by other cations in the aqueous environment.The related studies of different application conditions,service objects and morphological differences of geopolymer adsorbents based on structure-function design have been in-depth exploration and investigation.This review aims to summarize the research progres s of the structure-function design based on the geopolymerization mechanism and kinetics and service requirements.An overview of service characteristics and progress of geopolymers in the wastewater treatment field(e.g.,dyes,heavy metals,radionuclides,surfactants,antibiotics,ammonium,phosphorus,nitrogen and CO_(2),etc.)are systematically discussed.And the evolution and development of morphological differences and the relationship of structure-function design of geopolymer adsorbents were compared and reviewed.Finally,the challenge worth overcoming,the trends worth considering and perspectives worth developing are highlighted.

关键词： Geopolymer Wastewater Adsorption Structure-function design Application

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Structure stability, electronic property and voltage profile of LiFe_(1-n)NnP_(1-m)M_(m)O_(4) olivine cathode material

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Rare Metals 2021年第12期40卷 3512-3519页

作者： Zhi-Hong Cui xue-feng lu Jian-Hua luo Xin Guo Hong-Tao xue Fu-Ling Tang State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metal Department of Materials Science and EngineeringLanzhou University of TechnologyLanzhou 730050China

First-principles computational studies under density functional theory(DFT) framework were used to investigate the structural stability, conductivity and voltage profile of LiFe_(1-n)NnP_(1-m)M_(m)O_(4)(N, M = Si or S) electrode materials. It is found that the Li FeP_(7/8)Si_(1/8)O_(4) system has the most stable structure. After doping, the band gap values of the systems decrease gradually, and LiFe_(7/8)S_(1/8)PO_(4) system has a minimum band gap of 1.553 e V, attributed to the hybridization of the Fe-d and S-p orbital electrons. The Li Fe P7/8 S1/8 O4 system demonstrates the characteristic of n-type semiconductor, and other doping systems have the feature of p-type semiconductor. Charge density difference maps show that the covalent property of Si-O bond is enhanced in the Li FeP_(7/8)Si_(1/8)O_(4) system. The average distance of Li and O atoms in the S doping systems increases from 0.21026 to 0.21486 and 0.21129 nm, respectively,indicating that doping broadens significantly the channel of Li ion de-intercalation in LiFe_(7/8)S_(1/8)PO_(4) and LiFeP_(7/8)S_(1/8)O_(4). Additionally, the results of lithium intercalation potential imply that the voltages of the doping systems fallinto the range of 2.23-2.86 V.

关键词： Energy storage materials First principles Battery cathode LiFePO_(4) Doping Electronic properties

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Microstructure evolution and mechanical properties of 316L austenitic stainless steel with aluminum addition by warm rolling

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Journal of Iron and Steel Research(International) 2018年第10期25卷 1068-1077页

作者： Xin GUO Pei-qing La Heng Li Yu-peng Wei xue-feng lu State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metal Lanzhou University of Technology Lanzhou 730050 Gansu China Key Laboratory of Nonferrous Metal Alloys and Processing Ministry of Education Lanzhou University of Technology Lanzhou 730050 Gansu China

Microstructure evolution and mechanical properties of 316L austenitic stainless steel with aluminum addition by warm rolling at 550 ℃ were investigated. It is found that sample is composed of an ashen austenite matrix, a gray black ferrite phase and a small number of NiCx. The average grain sizes are 21.62, 19.66 and 19.49 μm for samples with the rolling deformation of 30%, 50% and 70%, respectively. The yield strength and tensile strength of samples with solid solution time of 30 min and deformation of 70% are higher. The fracture modes are similar and belong to toughness fracture. The fracture surfaces of the samples are composed of relatively large equal-axis ductile dimples （5-15 μm） and fine scattered ones around the dimples （〈 5 μm）. As the rolling deformation increases, the quantity of subgrain boundary increases and the 〈 101 〉 orientation is more prominent. {001 } 〈 110 〉 rotation-cube textures are present in ferrite phase of samples and weak Goss texture is formed in austenite pole images.

关键词： AISI 316L austenitic stainless steel Warm rolling Tensile property Fracture mechanism Deformationtexture

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In-orbit performance of HE onboard Insight-HXMT in the first 5 years

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Radiation Detection Technology and Methods 2023年第1期7卷 3-14页

作者： Xu-Fang Li Cong-Zhan Liu Yi-Fei Zhang Xiao-Bo Li Zheng-Wei Li xue-feng lu Zhi Chang Ming-Yu Ge Juan Zhang Yu-Peng Xu Fang-Jun lu Li-Ming Song Shuang-Nan Zhang Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of Science19B Yuquan RoadShijingshan DistrictBeijing 100049China

Purpose The high-energy X-ray telescope(HE),one of the three main payloads of the Insight-HXMT mission,is composed of eighteen NaI(Tl)/CsI(Na)phoswich detectors,where NaI(Tl)serves as the primary detector covering 20–250 keV,and CsI(Na)is used as an active shield detector to suppress the background of NaI(Tl)and also serves as an all-sky gammaray burst monitor covering 0.2–3MeV.In this paper,we review the in-orbit performance of HE in the first 5 years since Insight-HXMT was launched on June 15,2017.Methods The major performances we concern include the gain and energy resolution of NaI(Tl)and CsI(Na)detectors,the performance of pulse shape discriminator(PSD)and system dead time.In this work,we investigate these performances mainly using the data of blank-sky observations and the data when the telescope is in earth occultation.Results The overall performance of HE/NaI(Tl)is very stable in the first 5 years,whereas the gain of HE/CsI(Na)shows a continuously increasing trend and should be calibrated regularly.Conclusion In general,HE is still in good health and well-calibrated status after five-year’s operation.The in-orbit performance of HE has no significant deviation from expectation.HE is expected to be in operation healthily for another several years of extended mission life.

关键词： Insight-HXMT Hard X-ray telescope Scintillation detector In-orbit

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Position-selected cocatalyst modification on a Z-scheme Cd_(0.5)Zn_(0.5)S/NiTiO_(3) photocatalyst for boosted H_(2) evolution

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Materials Reports(Energy) 2023年第4期3卷 52-59页

作者： Bifang Li Wenyu Guo xue feng lu Yidong Hou Zhengxin Ding Sibo Wang State Key Laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou UniversityFuzhouFujian350116PR China

Photocatalytic water splitting by semiconductors is a promising technology to produce clean H_(2) fuel,but the efficiency is restrained seriously by the high overpotential of the H_(2)-evolution reaction together with the high recombination rate of photoinduced charges.To enhance H_(2) production,it is highly desirable yet challenging to explore an efficient reductive cocatalyst and place it precisely on the right sites of the photocatalyst surface to work the proton reduction reaction exclusively.Herein,the metalloid NixP cocatalyst is exactly positioned on the Z-scheme Cd_(0.5)Zn_(0.5)S/NiTiO_(3)(CZS/NTO)heterostructure through a facile photodeposition strategy,which renders the cocatalyst form solely at the electron-collecting locations.It is revealed that the directional transfer of photoexcited electrons from Cd_(0.5)Zn_(0.5)S to Ni_(x)P suppresses the quenching of charge carriers.Under visible light,the CZS/NTO hybrid loaded with the Ni_(x)P cocatalyst exhibits an optimal H_(2) yield rate of 1103μmol h^(-1)(i.e.,27.57 mmol h^(-1)g^(-1)),which is about twofold of pristine CZS/NTO and comparable to the counterpart deposited with the Pt cocatalyst.Besides,the high apparent quantum yield(AQY)of 56%is reached at 400 nm.Further,the mechanisms of the cocatalyst formation and the H2 generation reaction are discussed in detail.

关键词： Photocatalysis Ni_(x)P Cocatalysts Z-scheme H_(2)evolution

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Authentication and distinction of Shenmai injection with HPLC fingerprint analysis assisted by pattern recognition techniques

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Journal of Pharmaceutical Analysis 2012年第5期2卷 327-333页

作者： xue-feng lu Kai-Shun Bi Xu Zhao Xiao-Hui Chen School of Pharmacy Shenyang Pharmaceutical UniversityWenhua Road 103Shenhe DistrictShenyang 110016China

In this paper, the feasibility and advantages of employing high performance liquid chromatographic （HPLC） fingerprints combined with pattern recognition techniques for quality control of Shenmai injection were investigated and demonstrated. The Similarity Evaluation System was employed to evaluate the similarities of samples of Shenmai injection, and the HPLC generated chromatographic data were analyzed using hierarchical clustering analysis （HCA） and soft independent modeling of class analogy （SIMCA）. Consistent results were obtained to show that the authentic samples and the blended samples were successfully classified by SIMCA, which could be applied to accurate discrimination and quality control of Shenmai injection. Furthermore, samples could also be grouped in accordance with manufacturers. Our results revealed that the developed method has potential perspective for the original discrimination and quality control of Shenmai injection.

关键词： Shenmai injection High performance liquidchromatography Fingerprint Pattern recognition

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Five-year in-orbit background of Insight-HXMT

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Radiation Detection Technology and Methods 2023年第1期7卷 34-47页

作者： Jin-Yuan Liao Shu Zhang Juan Zhang Gang Li Zhi Chang Yu-Peng Chen Ming-Yu Ge Jing Jin xue-feng lu Yuan You xue-Lei Cao Yong Chen Yue Huang Wei-Chun Jiang Xiao-Bo Li Xu-Fang Li Zheng-Wei Li Cong-Zhan Liu Ying Tan Yan-Ji Yang Yi-Fei Zhang Hai-Sheng Zhao Fang-Jun lu Yu-Peng Xu Jin-lu Qu Li-Ming Song Shuang-Nan Zhang Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of Sciences19B Yuquan RoadShijingshan DistrictBeijing 100049China Key Laboratory of Stellar and Interstellar Physics and School of Physics and Optoelectronics Xiangtan UniversityYuhu DistrictXiangtan 411105China University of Chinese Academy of Sciences 19A Yuquan RoadShijingshan DistrictBeijing 100049China Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of Sciences20A Datun RoadChaoyang DistrictBeijing 100012China

Purpose We present the five-year in-orbit background evolution of Insight-HXMT since the launch,as well as the effects of the background model in data analysis.Methods The backgrounds of the three main payloads,i.e.,low-energy telescope,medium-energy telescope,and high-energy telescope,are described.The evolution of the background over time is obtained by simply comparing the background in every year during the in-orbit operation of Insight-HXMT.Results The major observational characteristics of the Insight-HXMT in-orbit background are presented,including the light curve,spectrum,geographical distribution,and long-term evolution.The systematic error in background estimation is investigated for every year.Conclusion The observational characteristics of the five-year in-orbit background are consistent with our knowledge of the satellite design and the space environment,and the background model is still valid for the latest observations of Insight-HXMT.

关键词： Instrumentation:detectors Space vehicles:instruments Methods:data analysis X-rays:general

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Hydrocracking diversity in n-dodecane isomerization on Pt/ZSM-22 and Pt/ZSM-23 catalysts and their catalytic performance for hydrodewaxing of lube base oil

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Petroleum Science 2020年第6期17卷 1752-1763页

作者： Shan-Bin Gao Zhen Zhao xue-feng lu Ke-Bin Chi Ai-Jun Duan Yan-feng Liu Xiang-Bin Meng Ming-Wei Tan Hong-Yue Yu Yu-Ge Shen Meng-Chen Li State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China Petrochemical Research Institute PetroChina Company LimitedBeijing 100195China

Nobel metallic Pt/ZSM-22 and Pt/ZSM-23 catalysts were prepared for hydroisomerization of normal dodecane and hydrodewaxing of heavy waxy lube base oil.The hydroisomerization performance of n-dodecane indicated that the Pt/ZSM-23 catalyst preferred to crack the C-C bond near the middle of n-dodecane chain,while the Pt/ZSM-22 catalyst was favorable for breaking the carbon chain near the end of n-dodecane.As a result,more than 2%of light products(gas plus naphtha)and3%more of heavy lube base oil with low-pour point and high viscosity index were produced on Pt/ZSM-22 than those on Pt/ZSM-23 while using the heavy waxy vacuum distillate oil as feedstock.

关键词： Isomerization Hydrocracking Catalysts Pt/ZSM-22 Pt/ZSM-23 Dodecane lube base oil

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