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Tensile properties and microstructure of rheo-diecast 7075 alloy prepared by serpentine channel process

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China Foundry 2019年第3期16卷 161-167页

作者： Wei-min Mao Wen-zhi Zhu School of Materials Science and Engineering University of Science & Technology Beijing Beijing 100083 China State Key Laboratory of Materials Processing and Die & Mould Technology Huazhong University of Science & Technology Wuhan 430074 China

A semisolid slurry of 7075 aluminum alloy was prepared by means of a serpentine channel process(SCP) and rheo-diecasting. The influences of pouring temperature during slurry preparation,the injection pressure and die preheat temperature on the mechanical properties and microstructure of a rheo-diecast 7075 aluminum alloy were investigated. The results show that the as-cast strength and elongation of the tensile samples were 210-260 MPa and 0.2%-1.7%,respectively,with an injection pressure of 130 MPa,a pouring temperature of 700-720 oC,a preheat temperature of 280-350 oC,and a plunger speed of 0.5 m·s-1. The results also show that the aged strength and elongation of the tensile samples were 420-453 MPa and 1.0%-1.4%,respectively,when the alloy solution was treated at 470 oC for 12 h and aged at 120 oC for 24 h. The substantial shrinkage porosity in the 7075 aluminum alloy tensile samples was the main cause of low elongation.

关键词： serpentine channel rheo-die casting 7075 aluminum alloy microstructure tensile properties

Spontaneous Hydrogen Production Coupled with Glucose Valorization through Modulating Au-Pt Coordination on Ultrathin Au3Pt Twin Nanowires

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Angewandte Chemie 2025年

作者： Hao Shi Prof. Tanyuan Wang Zijie Lin Shuxia Liu Xuan Liu Ruixin Zhou Prof. Zhao Cai Prof. Yunhui Huang Prof. Qing Li State Key Laboratory of Material Processing and Die & Mould Technology School of Materials Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China Faculty of Materials Science and Chemistry China University of Geosciences (Wuhan) Wuhan Hubei 430074 China

Organics electrooxidation coupled hydrogen production has attracted increasing attention due to the low operation voltage. Nevertheless, the spontaneous production of hydrogen coupled with organics valorization remains challenging. Herein, we develop ultrathin Au / Pt twin nanowire (NW) catalysts for both electrochemical glucose oxidation and hydrogen evolution reaction towards a spontaneous hydrogen production system. The more Pt−Au coordination and the localized tensile strain generated on twin boundaries of Au 3 Pt NWs facilitate the selective glucose electro-oxidation to gluconic acid (GNA) compared to Pt NWs (a low onset potential of 0.07 V RHE and selectivity >90 %). In situ spectroscopy and theoretical calculations reveal that Au 3 Pt NWs could reduce the energy barriers for GNA generation and alleviate the poisoning of Pt sites via a ′Pt-to-Au site transfer′ mechanism, which facilitates the desorption of strongly absorbed gluconolactone. Therefore, the asymmetric cell equipped with Au 3 Pt NWs catalysts realizes the spontaneous hydrogen production and glucose valorization with a peak power of 50 mW, which outputs the voltage of 0.24 V at 50 mA cm −2 , outperforming the state-of-the-art electrolyzers for hydrogen production. The production of 1 kg H 2 of the device is accompanied with $64.2 valorization of the anode product ($1200 ton −1 for GNA), and 5.36 kW h of generated electricity.

关键词： spontaneous hydrogen production glucose oxidation twin nanowires AuPt alloys tandem catalysis

The Important Role of Diatomite on Multifunctional Modified Separator of Li-S Battery

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SSRN 2024年

作者： Yan, Chenyu Jiang, Zhiyi Yang, Caihong Dong, Xiongbo Zhang, Shilin Tu, Feiyue Li, Tianbao Li, Mitch Guijun Tang, Aidong Yang, Huaming Engineering Research Center of Nano-Geomaterials of Ministry of Education Laboratory of Advanced Mineral Materials Key Laboratory of Functional Geomaterials in China Nonmetallic Minerals Industry Faculty of Materials Science and Chemistry China University of Geosciences Wuhan430074 China College of Chemistry and Chemical Engineering Central South University Changsha410083 China Changsha Research Institute of Mining and Metallurgy Co. LTD Changsha410012 China Division of Integrative Systems and Design Department of Electronic and Computer Engineering The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong School of Minerals Processing and Bioengineering Central South University Changsha410083 China

The commercial applications of Li-S batteries are limited by decreased cycling performance caused by the shuttle effect of polysulfides, slower kinetic reaction rates, and lithium anode dendrites. This study demonstrates the important role of diatomite (DT) in regulating cycle performance of modified separator for Li-S batteries. A multifunctional separator (Co/NC/DT) with DT as a carrier assembled high loading Co nanocluster (size 2-4 nm) is prepared. The N-doped carbon is immobilized via Si-N bond between DT and N-doped carbon. The depth profiles of XPS indicates that the ratio of pyrrolic N to pyridinic N of Co/NC/DT reaches 5.31 at the etching of 100 nm vs 0.83 for Co/NC at surface, which suggesting that mainly N species is pyrrolic N after the addition of DT. Theoretical calculations confirm that cobalt nanoclusters grown on pyrrolic N-doped carbon have a lower adsorption energy for a series of polysulfides species compared to that on pyridinic N-doped carbon and can reduce the energy barrier, especially only 0.09 eV for reduction from Li2S6 to Li2S4. In-situ X-ray diffraction analysis confirms Co/NC/DT can effectively promote formation of Li2S. Lithium anode in-situ optical microscopy observation shows the modified separator could reduce lithium dendrites effectively. Li-S battery assembled with the modified separator can reach an initial capacity of 1331.3 mAh g-1 at 0.2 C and cycle 1500 cycles at 1.0 C with a decay of only 0.039% per cycle. Through regulation of DT, Co/NC/DT accelerates the conversion from long-chain sulfur to short-chain sulfur and Li+ transfer rate, resulting in improving cycling performance. © 2024, The Authors. All rights reserved.

关键词： Separators

Efficient Selective Adsorption of Cytokine IL-6 and Other Middle-Macromolecular Toxins in the Serum of Uremia Patients with Specially Designed Porous Hollow Carbon Spheres

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SSRN 2022年

作者： Zhao, Xiaohuan Wang, Chong Xu, Boyang Liang, Jie Guo, Yiqing Gong, Ming Zhao, Yun Huang, Yilun Li, Yuehong Zhao, Ming Zhuang, Daming Gong, Qianming School of Materials Science and Engineering Tsinghua University Beijing100084 China School of Chemistry and Chemical Engineering Beijing Institute of Technology Beijing100081 China Beijing Tsinghua Changgung Hospital School of Clinical Medicine Tsinghua University Beijing102218 China Key Laboratory for Advanced Materials Processing Technology Ministry of Education Beijing100084 China SINOPEC Beijing Research Institute of Chemical Industry Beijing100013 China

Abnormally elevated middle-macromolecular toxins such as interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF- α) in human blood are fatal precipitating factors for patients suffered from immune-related diseases, especially for uremia and COVID-19 critical patients, while the effective clearance of them has always been problematic in clinic. In this work, porous hollow carbon spheres (HCSs) with different size and pore structure has been successfully prepared. The removal efficiency for IL-6 in PBS solution is about 99.8%, even in the serum of uremic patients, HCSs could remove 94.75% and 98.33% of parathyroid hormone (PTH) and β 2 -microglobulin (β 2 -MG) efficiently within 5-10 min, and particularly, the adsorption of IL-6 and TNF- α is 17.6 and 11.4 times higher over that of the existing commercial hemoperfusion adsorbents. The adsorption balance can be achieved in 60min, which would greatly shorten the current clinical treatment duration. Moreover, HCSs with different pore structure exhibit distinct adsorption selectivity for IL-6 and TNF- α, which is of special significance for modifying the middle-macromolecular cytokine level in the complicated human blood environment. © 2022, The Authors. All rights reserved.

关键词： Adsorption

Core-satellite metal-organic framework@upconversion nanoparticle superstructures via electrostatic self-assembly for efficient photodynamic theranostics

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Nano Research 2020年第12期13卷 3377-3386页

作者： Zhike Li Xi Qiao Guihua He Xin Sun Danhua Feng Liefeng Hu Hua Xu Hai-Bing Xu Shengqian Ma Jian Tian Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Hubei Province Engineering and Technology Research Center for Fluorinated PharmaceuticalsSchool of Pharmaceutical SciencesWuhan UniversityWuhan430071China State Key Laboratory of Bioelectronics School of Biological Science and Medical EngineeringSoutheast UniversityNanjing210096China Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules Hubei Collaborative Innovation Center for Advanced Organic Chemical MaterialsCollege of Chemistry and Chemical EngineeringHubei UniversityWuhan430062China Department of Chemistry University of North TexasDentonTX76201USA

The nanoplatforms based on upconversion nanoparticles(UCNPs)have shown great promise in amplified photodynamic therapy(PDT)triggered by near-infrared(NIR)***,their practical in vivo applications are hindered by the overheating effect of 980 nm excitation and low utilization of upconversion luminescence(UCL)by *** solve these defects,core-satellite metal-organic framework@UCNP superstructures,composed of a single metal-organic framework(MOF)NP as the core and Nd3+-sensitized UCNPs as the satellites,are designed and synthesized via a facile electrostatic self-assembly *** superstructures realize a high co-loading capacity of chlorin e6(Ce6)and rose bengal(RB)benefitted from the highly porous nature of MOF NPs,showing a strong spectral overlap between maximum absorption of photosensitizers and emission of *** in vitro and in vivo experiments demonstrate that the dual-photosensitizer superstructures have trimodal(magnetic resonance(MR)/UCL/fluorescence(FL))imaging functions and excellent antitumor effectiveness of PDT at 808 nm NIR light excitation,avoiding the laser irradiation-induced overheating *** study provides new insights for the development of highly efficient PDT nanodrugs toward precision theranostics.

关键词： core-satellite structures upconversion nanoparticles(UCNPs) nanoscale metal-organic frameworks photodynamic therapy theranostics

Polyethylene Terephthalate Ammonia Hydrolysate Greatly Increased Bacterial Cellulose Production

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SSRN 2022年

作者： Sun, Su Ullah, Mati Wang, Quan Zhang, Yanbo Chen, Li Ullah, Muhammad Wajid Zhou, Jiangang State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile University Wuhan430200 China College of Life Science and Technology Huazhong University of Science and Techn ology Wuhan430074 China Central China Normal University Library Wuhan430079 China Biofuels Institute School of the Environment and Safety Engineering Jiangsu University Zhenjiang212013 China

A major challenge to large-scale production and utilization of bacterial cellulose (BC) for various applications is its low yield and productivity by bacterial cells and the high cost of feedstock. A supplementation of the classical expensive Hestrin and Schramm (HS) medium with 1% polyethylene terephthalate ammonia hydrolysate (PETAH) resulted in as high as 215% yield. Although the physicochemical properties of BC were not significantly influenced, the BC produced in PETAH-supplemented HS medium showed a lower degree of crystallinity, and higher surface area, which showed 1.66 times higher adsorption capacity for tetracycline than BC produced in HS medium. The PETAH-supplemented HS medium respectively enhanced the activity of α-UDP-glucose pyrophosphorylase and α-phosphoglucomutase by 30.63% and 135.24% and decreased the activity of pyruvate kinase and phosphofructokinase by 40.34% and 52.63%. The results of this study provide insights into the activation mechanism of Taonella mepensis by PETAH supplementation for high productivity of BC. © 2022, The Authors. All rights reserved.

关键词： Productivity

synthesis and Application of Copper-Based Nanostructured Catalysts in Carbon Dioxide Reduction

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cMat 2025年第1期2卷

作者： Ying-Shan Xue Miao He Ping Wang Cheng Yang Jia-Sai Yao Tian-Bao Zhang Muhammad Usman Aslam Xiao-Hua Sun Zhen-Xing Li State Key Laboratory of Heavy Oil Processing College of New Energy and Materials China University of Petroleum (Beijing) Beijing China Muhammad Nawaz Sharif University of Engineering and Technology Muktan Multan Pakistan

The continuous increase in the concentration of carbon dioxide (CO 2 ) in the atmosphere is a wake-up call for global environmental problems. In recent years, more and more electrochemical, photochemical, thermochemical, and other means have been applied to the use of converting CO 2 into value-added chemicals or fuels, leveraging the characteristics of material nanostructures to catalyze the reduction of CO 2 , reduce the concentration of CO 2 in the atmosphere, facilitate a balanced carbon-neutral energy cycle, and generate renewable energy for human use. Among the options available, copper-based materials have been established as the sole category capable of converting CO 2 into a variety of reduction products, including 16 hydrocarbons, such as carbon monoxide (CO) and hydrocarbons, as well as widely used alcohols. This paper outlines various synthesis approaches for copper-based nanostructured catalysts and explores their applications in the electrocatalytic, photocatalytic, and thermocatalytic reduction of CO 2 . Finally, it discusses the current challenges and summarizes potential solutions and strategies for the future advancement of CO 2 conversion technology.

关键词： carbon dioxide electrocatalytic reduction carbon dioxide photocatalytic reduction carbon dioxide thermal catalytic reduction copper-based catalysts nanostructured materials synthesis technology

Experimental Isothermal Section of the System Cr-Nb-Ru at 1100℃

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SSRN 2022年

作者： Du, Yong Long, Qian-Xin Zhou, Jingjing Yan, Jialin Deng, Jianqiu Yao, Qingrong Zhou, Huaiying Shang, Shun-Li Liu, Zi-Kui Engineering Research Center of Electronic Information Materials and Devices Ministry of Education Guilin University of Electronic Technology Guilin541004 China School of Materials Science and Engineering Lanzhou Jiaotong University Gansu Lanzhou730050 China Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials Guangxi Nanning530004 China State Key Laboratory of Powder Metallurgy Central South University Changsha410083 China Department of Materials Science and Engineering The Pennsylvania State University University ParkPA16802 United States

In the present work, the phase equilibria of the Cr-Nb-Ru system at 1100℃ were investigated via a combination of diffusion triple and equilibrated alloys. The samples were examined by means of X-ray diffraction and electron probe microanalysis. The isothermal section of the Cr-Nb-Ru ternary system at 1100℃ was constructed, which consists of 11 single-phase regions, 19 two-phase regions, and 9 three-phase regions. One new ternary compounds τ was discovered, which has a cubic Ag5Zn8-type structure and space group I-43m (No.217) with a = 0.93407(3) nm. The homogeneity ranges for the phases in this system are established. Three miscibility gaps were observed, corresponding to Cr solid dissolved in HCP(Ru), Nb solid dissolved in HCP(Ru) and Ru solid dissolved in BCC(Cr)，respectively. The miscibility gap of Nb and Cr solid dissolved in HCP(Ru) go through each other. © 2022, The Authors. All rights reserved.

关键词： Ternary systems

Molecularly Tunable Heterostructured Co-Polymers Containing Electron-Deficient and -Rich Moieties for Visible-Light and Sacrificial-Agent-Free H2O2Photosynthesis

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Angewandte Chemie 2024年第29期136卷

作者： Jingzhao Cheng Wang Wang Jianjun Zhang Sijie Wan Prof. Bei Cheng Prof. Jiaguo Yu Prof. Shaowen Cao State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology 122 Luoshi Road Wuhan 430070 P. R. China Hubei Technology Innovation Center for Advanced Composites Wuhan University of Technology 122 Luoshi Road Wuhan 430070 P. R. China Laboratory of Solar Fuel Faculty of Materials Science and Chemistry China University of Geosciences 68 Jincheng Street Wuhan 430078 P. R. China

As an alternative to hydrogen peroxide (H 2 O 2 ) production by complex anthraquinone oxidation process, photosynthesis of H 2 O 2 from water and oxygen without sacrificial agents is highly demanded. Herein, a covalently connected molecular heterostructure is synthesized via sequential C−H arylation and Knoevenagel polymerization reactions for visible-light and sacrificial-agent-free H 2 O 2 synthesis. The subsequent copolymerization of the electron-deficient benzodithiophene-4,8-dione (BTD) and the electron-rich biphenyl (B) and p -phenylenediacetonitrile (CN) not only expands the π-conjugated domain but also increases the molecular dipole moment, which largely promotes the separation and transfer of the photoinduced charge carriers. The optimal heterostructured BTDB-CN 0.2 manifested an impressive photocatalytic H 2 O 2 production rate of 1920 μmol g −1 h −1 , which is 2.2 and 11.6 times that of BTDB and BTDCN. As revealed by the femtosecond transient absorption (fs-TA) and theoretical calculations, the linkage serves as a channel for the rapid transfer of photogenerated charge carriers, enhancing the photocatalytic efficiency. Further, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) uncovers that the oxygen reduction reaction occurs through the step one-electron pathway and the mutual conversion between C=O and C−OH with the anchoring of H + during the catalysis favored the formation of H 2 O 2 . This work provides a novel perspective for the design of efficient organic photocatalysts.

关键词： molecular heterostructure H2O2 dipole moment channel reaction path