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Dual template-induced construction of three-dimensional porous SiO2/NC/Co-CNTs heterostructure with highly dispersed active sites for efficient oxygen evolution reaction

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Tungsten 2024年第3期6卷 585-595页

作者： hai-Qi zhang Xiao-Jun Zeng Qing-Qing zhang Zu-Liang zhang Chu-long Jin Rong-hai Yu School of Materials Science and Engineering Jingdezhen Ceramic University School of Materials Science and Engineering Beihang University

The development and exploration of efficient and economical electrocatalysts for oxygen evolution reaction（OER） represents the main bottleneck to unlocking a sustainable energy scenario based on elec trocataly tic water splitting.Nano scale integration of three-dimensional（3D） porous heterostructure with highly dispersed active sites and good structural stability is challenging.Herein,a dual template route is developed to construct the 3D porous SiO2/nitrogen-doped carbon（NC）/Co-carbon nano tubes（CNTs） hetero structure.Importantly,the hard template（SiO2nano spheres） contributes to 3D porous structure,increases the specific surface area,and promotes the contact area of the electrolyte.At the same time,the soft template（basic zinc carbonate） can control the growth of 1D CNTs and facilitate the exposure of the active sites.Apparently,3D porous SiO2/NC/Co-CNTs hetero structure inherits highly dispersed Co nanoparticles coated by NC.CNTs conductive channels and abundant N hetero atoms doping are reasonably constructed by a dual template strategy.Therefore,SiO2/NC/Co-CNTs catalyst provides an extraordinary activity for the OER in alkaline media,with a low overpotential of 298 mV at a current density of 10 mA·cm-2.Furthermore,SiO2/NC/Co-CNTs hetero structure enables excellent long-term durability with a 10 mV decay in overpotential after 3000 cyclic voltammetry cycles,and 97% remain in current density over 20 h.It is believed that this dual template strategy can provide a new and simple way to construct a highly dispersed active site in electrocatalysts.

关键词： Dual template High dispersion Porous heterostructure Conductive channels Oxygen evolution reaction

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Alloy strategy to synthesize Pt-early transition metal oxide interfacial catalysts

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Nano Research 2024年第4期17卷 3390-3397页

作者： Shi-long Xu Hang Nan Wanqun zhang Yue Lin Sheng-Qi Chu hai-Wei Liang Hefei National Research Center for Physical Sciences at the Microscale Department of ChemistryUniversity of Science and Technology of ChinaHefei 230026China School of Materials and Chemical Engineering Anhui Jianzhu UniversityHefei 230601China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China

Metal oxide supported metal catalysts show promising catalytic performance in many industry-relevant reactions.However,the enhancement of performance is often limited by the insufficient metal/metal oxide interface.In this work,we demonstrate a general synthesis of Pt-early transition metal oxide(Pt-MO_(x),M=Ti,Zr,V,and Y)catalysts with rich interfacial sites,which is based on the air-induced surface segregation and oxidation of M in the supported Pt-M alloy catalysts.Systematic characterizations verify the dynamic structural response of Pt-M alloy catalysts to air and the formation of Pt-MO_(x) catalysts with abundant interfacial sites.The prepared Pt-TiO_(x) interfacial catalysts exhibit improved performance in hydrogenation reactions of benzaldehyde,nitrobenzene,styrene,and furfural,as a result of the heterolytic dissociation of H_(2) at Pt-metal oxide interfacial sites.

关键词： Pt-early transition metal oxide interfacial catalyst alloy oxidation strategy interfacial sites hydrogenation reactions heterolytic dissociation

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The RFI Fast Mitigation Algorithm Based on Block LMS Filter

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Research in Astronomy and Astrophysics 2024年第1期24卷 265-272页

作者： Han Wu hai-long zhang Ya-Zhou zhang Jie Wang Xu Du Ting zhang Xin-Chen Ye Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China National Astronomical Data Center Beijing 100101China

The radio telescope possesses high sensitivity and strong signal collection capabilities.While receiving celestial radiation signals,it also captures Radio Frequency Interferences(RFIs)introduced by human activities.RFI,as signals originating from sources other than the astronomical targets,significantly impacts the quality of astronomical data.This paper presents an RFI fast mitigation algorithm based on block Least Mean Square(LMS)algorithm.It enhances the traditional adaptive LMS filter by grouping L adjacent time-sampled points into one block and applying the same filter coefficients for filtering within each block.This transformation reduces multiplication calculations and enhances algorithm efficiency by leveraging the time-domain convolution theorem.The algorithm is tested using baseband data from the Parkes 64 m radio telescope's pulsar observations and simulated data.The results confirm the algorithm's effectiveness,as the pulsar profile after RFI mitigation closely matches the original pulsar profile.

关键词： methods:data analysis techniques:interferometric (stars:)pulsars:individual(J0437-4715)

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Numerical simulation on sand sedimentation and erosion characteristics around HDPE sheet sand barrier under different wind angles

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Journal of Mountain Science 2024年第2期21卷 538-554页

作者： zhang Kai zhang Peili zhang hailong TIAN Jianjin WANG Zhenghui XIAO Jianhua College of Civil Engineering Lanzhou Jiaotong UniversityLanzhou 730000China Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

For the safety of railroad operations,sand barriers are utilized to mitigate wind-sand disaster effects.These disasters,characterized by multi-directional wind patterns,result in diverse angles among the barriers.In this study,using numerical simulations,we examined the behavior of High Density Polyethylene(HDPE)sheet sand barriers under different wind angles,focusing on flow field distribution,windproof efficiency,and sedimentation erosion dynamics.This study discovered that at a steady wind speed,airflow velocity varies as the angle between the airflow and the HDPE barrier changes.Specifically,a 90°angle results in the widest low-speed airflow area on the barrier’s downwind side.If the airflow is not perpendicular to the barrier,it prompts a lateral airflow movement which decreases as the angle expands.The windproof efficiency correlates directly with this angle but inversely with the wind’s speed.Notably,with a wind angle of 90°,wind speed drops by 81%.The minimum wind speed is found at 5.1H(the sand barrier height)on the barrier’s downwind side.As the angle grows,the barrier’s windproof efficiency improves,extending its protective reach.Sedimentation is most prominent on the barrier’s downwind side,as the wind angle shifts from 30°to 90°,the sand sedimentation area on the barrier’s downwind side enlarges by 14.8H.As the angle grows,sedimentation intensifies,eventually overtakes the forward erosion and enlarges the sedimentation area.

关键词： Multi-wind direction HDPE sheet sand barrier Numerical simulation Windproof efficiency Sedimentation erosion

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Recycling of spent lithium-ion batteries to resynthesize high-performance cathode materials for sodium-ion storage

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Tungsten 2024年第3期6卷 574-584页

作者： hai-Qiang Gong Xing-Yuan Wang long Ye Bao zhang Xing Ou National Engineering Laboratory for High-Efficiency Recovery of Refractory Nonferrous Metals School of Metallurgy and Environment Central South University

The spent lithium-ion batteries recovery has been brought into focus widely for its environmental imperatives and potential profits from the metal components,such as lithium,cobalt,nickel and manganese.However,the weaker pollution and fewer profits of LiMn2O4cathode dispel the enthusiasm and responsibility of industry companies.Thus,a simplified and efncient method to regenerate the sodium-ion cathode materials and separate Li from spent LiMn2O4materials for the profit improvement is proposed.In detail,adjusting the parameters of carbothermal reduction process appropriately,the LiMn2O4spinel structure is destroyed within a short period time and transformed into simple metal oxide.As anticipated,nearly 95 wt.%lithium can be obtained and recovered during the water leaching,while 99 wt.% of manganese can be extracted in acid solution.Noted that the leaching residue can return to the carbothermic reduction,leading to a closed-loop economic recycling process.The regenerated Na0.67Ni0.3Mn0.7O2cathode displays excellent electrochemical performance with superior cycling stability(the initial capacity reaches 95.9 mAh·g-1,and the retention rate reached 98.3% after 100 cycles at 1 C).The delicate strategy of sodium-ion cathode material regenerated from spent LiMn2O4aims to realize lithium separation and material utilization of manganese simultaneously,providing the instructive suggestion to rise up the recycling profits of spent batteries.

关键词： Manganese Spent battery LiMn 2 O 4 cathode Recycling Regenerated Na 0.67 Ni 0.3 Mn 0.7 O 2 Sodium-ion storage

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Flow field, sedimentation, and erosion characteristics around folded linear HDPE sheet sand fence: Numerical simulation study

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Journal of Mountain Science 2024年第1期21卷 113-130页

作者： zhang Kai zhang hailong TIAN Jianjin QU Jianjun zhang Xingxin WANG Zhenghui XIAO jianhua College of Civil Engineering Lanzhou Jiaotong UniversityLanzhou 730000China Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China College of Civil Engineering Chongqing UniversityChongqing 400045China Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

Wind and sand hazards are serious in the Milan Gobi area of the Xinjiang section of the Korla Railway. In order to ensure the safe operation of railroads, there is a need for wind and sand protection in heavily sandy areas. The wind and sand flow in the region is notably bi-directional. To shield railroads from sand, a unique sand fence made of folded linear high-density polyethylene(HDPE) is used, aligning with the principle that the dominant wind direction is perpendicular to the fence. This study employed field observations and numerical simulations to investigate the effectiveness of these HDPE sand fences in altering flow field distribution and offering protection. It also explored how these fences affect the deposition and erosion of sand particles. Findings revealed a significant reduction in wind speed near the fence corner;the minimum horizontal wind speed on the leeward side of the first sand fence(LSF) decreased dramatically from 3 m/s to 0.64 m/s. The vortex area on the LSF markedly impacted horizontal wind speeds. Within the LSF, sand deposition was a primary occurrence. As wind speeds increased, the deposition zone shrank, whereas the positive erosion zone expanded. Close to the folded corners of the HDPE sand fence, there was a notable shift from the positive erosion zone to a deposition zone. Field tests and numerical simulations confirmed the high windproof efficiency(WE) and sand resistance efficiency(SE) in the HDPE sand fence. Folded linear HDPE sheet sand fence can effectively slow down the incoming flow and reduce the sand content, thus achieving good wind and sand protection. This study provides essential theoretical guidance for the design and improvement of wind and sand protection systems in railroad engineering.

关键词： Folded linear HDPE sheet sand fence Numerical simulation Flow field characteristics Protection benefits

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Design Strategies for Aqueous Zinc Metal Batteries with High Zinc Utilization: From Metal Anodes to Anode-Free Structures

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Nano-Micro Letters 2024年第4期16卷 305-349页

作者： Xianfu zhang long zhang Xinyuan Jia Wen Song Yongchang Liu School of Materials Science and Engineering University of Science and Technology Beijing30 College RoadBeijing 100083People’s Republic of China Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyState Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China

Aqueous zinc metal batteries(AZMBs)are promising candidates for next-generation energy storage due to the excellent safety, environmental friendliness, natural abundance, high theoretical specific capacity, and low redox potential of zinc(Zn) metal. However,several issues such as dendrite formation, hydrogen evolution, corrosion, and passivation of Zn metal anodes cause irreversible loss of the active materials. To solve these issues, researchers often use large amounts of excess Zn to ensure a continuous supply of active materials for Zn anodes. This leads to the ultralow utilization of Zn anodes and squanders the high energy density of AZMBs. Herein, the design strategies for AZMBs with high Zn utilization are discussed in depth, from utilizing thinner Zn foils to constructing anode-free structures with theoretical Zn utilization of 100%, which provides comprehensive guidelines for further research. Representative methods for calculating the depth of discharge of Zn anodes with different structures are first summarized. The reasonable modification strategies of Zn foil anodes, current collectors with pre-deposited Zn, and anode-free aqueous Zn metal batteries(AF-AZMBs) to improve Zn utilization are then detailed. In particular, the working mechanism of AF-AZMBs is systematically introduced. Finally, the challenges and perspectives for constructing high-utilization Zn anodes are presented.

关键词： Aqueous zinc metal batteries Zinc anodes High zinc utilization Depth of discharge Anode-free structures

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Chronic infectious unilateral giant thyroid cyst related to diabetes mellitus:A case report

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World Journal of Clinical Cases 2024年第8期12卷 1497-1503页

作者： Jiang-Bo Liu Shi-Lei zhang Wen-long Jiang hai-Kuan Sun Hao-Chen Yang Department of Thyroid and Breast Surgery The First Affiliated HospitalCollege of Clinical MedicineHenan University of Science and TechnologyLuoyang 471000Henan ProvinceChina Clinical Medicine School The First Clinical CollegeChongqing Medical UniversityChongqing 400016China

BACKGROUND Patients rarely develop complicated infections in thyroid cysts.Here,we describe a patient with chronic infected unilateral giant thyroid cyst related to diabetes mellitus(DM).CASE SUMMARY A 66-year-old male was admitted due to an evident neck lump for 5 d after approximately 40 years of gradually progressive neck mass and 7 years of DM.Doppler ultrasound and computed tomography scan showed a giant lump in the left thyroid gland lobe.He was diagnosed with a large thyroid nodule complicated by tracheal dislocation and had surgical indications.Surgical exploration revealed evident inflammatory edema and exudation between the left anterior neck muscles,the nodule and glandular tissue.Fortunately,inflammatory lesions did not affect major neck vessels.Finally,a left partial thyroidectomy was performed.Macroscopic observation showed that the cystic thyroid mass consisted of extensive cystic wall calcification and was rich in massive rough sand-like calculi content and purulent matter.Postoperative pathology confirmed benign thyroid cyst with chronic infection.CONCLUSION The progression of this chronic infectious unilateral giant thyroid cyst may have been related to DM,and identifying blood vessels involvement can prevent serious complications during operation.

关键词： Thyroid nodule Infection Diabetes mellitus Surgery Case report

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Permanent lining castable with low bulk density and thermal conductivity:bauxite castable for tundish obtained by adding pearlescent sand

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Journal of Iron and Steel Research(International) 2024年第3期31卷 634-646页

作者： Yi Wang Jian Yang Bao Wang hai-jun zhang Juan Han Pei-yan Pei Wen-long Lv Jian-an Zhou The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina Wuhan Research Institute of Metallurgical Construction MCCWuhan 430081HubeiChina

The low thermal conductivity and light mass of castables for tundish permanent linings are crucial for minimizing the heat loss of molten steel.In consideration of the low bulk density and thermal conductivity of pearlescent sand,the thermal insulation performance of castables was attempted to be improved by adding pearlescent sand.Pearlescent sand was modified to prevent the strength of its porous structure from deteriorating.The modification mechanism of pearlescent sand and the effect of pearlescent sand on the performance of bauxite castables were studied.The results suggested that the addition of the modified pearlescent sand significantly raised the apparent porosity and decreased the bulk density of bauxite castable.At 1000℃,the bulk density of more than 60%of the modified pearlescent sand-bauxite castable was only 2.03 g/cm^(3).The mechanical properties and thermal shock resistance of the modified pearlescent sand-bauxite castable were inferior to those of conventional bauxite castable but were adequate to meet the use conditions of casta-bles for tundish permanent linings.At high temperatures of 200-800℃,the thermal conductivity of more than 60%of the modified pearlescent sand-bauxite castable was smaller than that of conventional bauxite castable.The addition of the modified pearlescent sand can greatly reduce the thermal conductivity and bulk density of bauxite castable.

关键词： Pearlescent sand-Hydrophobic modification Bauxite castable Thermal insulation performance Mechanical property

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Phase behavior of gas condensate in porous media using real-time computed tomography scanning

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Petroleum Science 2024年第2期21卷 1032-1043页

作者： Wen-long Jing Lei zhang Ai-Fen Li Jun-Jie Zhong hai Sun Yong-Fei Yang Yu-long Cheng Jun Yao Institute of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongChina

The phase behavior of gas condensate in reservoir formations differs from that in pressure-volume-temperature(PVT)cells because it is influenced by porous media in the reservoir formations.Sandstone was used as a sample to investigate the influence of porous media on the phase behavior of the gas condensate.The pore structure was first analyzed using computed tomography(CT)scanning,digital core technology,and a pore network model.The sandstone core sample was then saturated with gas condensate for the pressure depletion experiment.After each pressure-depletion state was stable,realtime CT scanning was performed on the sample.The scanning results of the sample were reconstructed into three-dimensional grayscale images,and the gas condensate and condensate liquid were segmented based on gray value discrepancy to dynamically characterize the phase behavior of the gas condensate in porous media.Pore network models of the condensate liquid ganglia under different pressures were built to calculate the characteristic parameters,including the average radius,coordination number,and tortuosity,and to analyze the changing mechanism caused by the phase behavior change of the gas condensate.Four types of condensate liquid(clustered,branched,membranous,and droplet ganglia)were then classified by shape factor and Euler number to investigate their morphological changes dynamically and elaborately.The results show that the dew point pressure of the gas condensate in porous media is 12.7 MPa,which is 0.7 MPa higher than 12.0 MPa in PVT cells.The average radius,volume,and coordination number of the condensate liquid ganglia increased when the system pressure was between the dew point pressure(12.7 MPa)and the pressure for the maximum liquid dropout,Pmax(10.0 MPa),and decreased when it was below Pmax.The volume proportion of clustered ganglia was the highest,followed by branched,membranous,and droplet ganglia.This study provides crucial experimental evidence for the phase behavior changing process of gas condensate in porous media d

关键词： Gas condensate Pressure depletion Real-time micro-computed tomography scanning Distribution of condensate liquid

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