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Preparation and performance analysis of Ti-25Nb-3Zr-2Sn-3Mo microarc oxidized macro-micro-nano tertiary structure film layers

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JOURNAL OF VACUUM SCIENCE & technology A 2024年第1期42卷 013101-013101页

作者： Yan, Xing Wang, Jingyi Wang, Cenyi Xu, Jia Yu, Sen Li, Yang Zhang, Yuan Xie, Guobin Yang, Mei Southwest Petr Univ Sch New Energy & Mat Chengdu 610500 Peoples R China Northwest Inst Nonferrous Met Res Shaanxi Key Lab Biomed Met Mat Xian 710016 Peoples R China Sichuan Petr Construction Co Ltd Chengdu 610000 Peoples R China Baoji Petr Steel Pipe Co Ltd Ziyang Branch Ziyang 641300 Peoples R China

After undergoing microarc oxidation, titanium alloys exhibit significantly enhanced biocompatibility, making them a subject of extensive research in the field of biomedical applications. In this study, a two-step microarc oxidation method was used to prepare a film layer with both macro-micro-nano tertiary structures on beta-type titanium alloy Ti-3Zr-2Sn-3Mo-25Nb (TLM), using a phosphate-nitrate mixed electrolyte for the first step of microarc oxidation and a borate body electrolyte for the second step of microarc oxidation. The effects of NaOH concentration, microarc oxidation voltage, and time on the size and distribution of macropores prepared by microarc oxidation in the first step were investigated by SEM, energy dispersive spectroscopy, XRD, and metallurgical microscopy. The wettability of the prepared three-level structured film and its ability to induce hydroxyapatite deposition were evaluated through contact angle testing and simulated body fluid immersion experiments. The overall research findings indicate that the two-step microarc oxidation process yielded macropores with diameters ranging from 200 to 400 mu m, along with micro-nanostructures measuring 2-15 mu m and 10-100 nm. The increase in the NaOH concentration in the electrolyte decreased the size of the macropores. The increase in the microarc oxidation time increased the size of macropores;the voltage affected the distribution and number of macropores. The prepared macro-micro-nano tertiary structured membrane layers have excellent wettability and the ability to induce hydroxyapatite precipitation, indicating that they possess good biocompatibility. This study provides a reference for the medical development of alloys.

关键词： Niobium alloys

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Effect of temperature and loading mode on flexural properties and failure mechanisms of fine weave punctured C/C composites over 2000 ° C

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COMPOSITES COMMUNICATIONS 2024年 51卷

作者： Yao, Tianlei Li, Diansen Zuo, Hongmei Jia, Xiaolong Jiang, Lei Beihang Univ Sch Chem Key Lab Bioinspired Smart Interfacial Sci & Techno Minist Educ Beijing 100191 Peoples R China Anhui Polytech Univ Adv Fiber Mat Engn Res Ctr Anhui Prov Sch Text & Garment Wuhu 241000 Peoples R China Beijing Univ Chem Technol State Key Lab Organ Inorgan Composites Beijing 100029 Peoples R China

Fine weave punctured C/C composites are extensively utilized in aerospace applications owing to their superior mechanical properties. The effects of temperature over 2000 degrees C and loading mode on the flexural properties and failure mechanism were reported. It was found that the load-displacement curves of Y-direction flexure showed linear characteristics, but those of Z-direction flexure showed nonlinear characteristics because of interlayer failure. The flexural performances in the Z-direction were significantly higher than in the Y-direction. Both Yand Z-directions flexural strengths increased dramatically, but flexural moduli initially climbed and subsequently declined with increasing temperature. In contrast with room temperature, the Yand Z-direction flexural strengths increased by 55.6 % and 188.5 % at 2000 degrees C, while their corresponding flexural moduli increased by 14.3 % and 40.4 % at 1200 degrees C. Flexural failure in the Y direction was primarily distributed along the rows of Zyarns. Due to narrower slits and tighter composite connections, failure gradually spreads over the Z-yarns at higher temperatures. While, the failure cracks of Z-direction flexural specimens were mainly distributed in the interlayer. As the temperature rose, the carbon fiber monofilaments of the pulled Z-direction yarns became harder linked, with neater breaks.

关键词： C/C composite Ultra-high temperatures Flexural properties Failure mechanisms

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Preparation of a Janus copper mesh via nanoparticle interface self-assembly for unidirectional water transportation

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CHEMICAL COMMUNICATIONS 2023年第90期59卷 13506-13509页

作者： Chen, Chaolang Zhu, Linfeng Jiang, Ruisong Li, Xuan Sichuan Univ Sch Mech Engn Chengdu 610065 Peoples R China Tsinghua Univ Dept Mech Engn Beijing 100084 Peoples R China

A simple colloidal particle interface assembly method is presented to fabricate Janus meshes. The transport mechanism of water on the Janus mesh was fully revealed by experimental observation and numerical simulation. Furthermore, a liquid-assisted ultrafast transport of water droplets on the Janus mesh was presented (transport speed was increased by more than 20 times).

关键词： Self assembly

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Influences of Sc(NO3)3 on characteristics of micro-arc oxidation coatings

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SURFACE engineering 2023年第3期39卷 307-314页

作者： Yang, Shaolan Wang, Ping Liu, Jiwei Southwest Petr Univ Sch New Energy & Mat Chengdu Peoples R China Southwest Petr Univ Sch New Energy & Mat Chengdu 610500 Peoples R China

Micro-arc oxidation (MAO) coatings were fabricated on 2195 aluminium-lithium alloy substrate, using a silicate and phosphate electrolyte with variable scandium nitrate (Sc(NO3)(3)) concentrations. The properties of the coatings were analysed by scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical workstation. The comprehensive analysis demonstrates that adding proper amount of Sc(NO3)(3) increased the oxidation voltage, which transformed the worm shape discharge micropores into round-hole shape, and the MAO coatings presented a double-layer structure. The primary phase composition of the coatings was gamma-Al2O3, alpha-Al2O3, Sc2O3 and Al3Sc. The optimum concentration of Sc(NO3)(3) was 0.6 g L-1. The hardness reached a maximum value of (1284 +/- 43.5) HV, which was about 2.5 times higher than that without adding. The self-corrosion current density reduced from 138.00 x 10(-)(7) A cm(-2) (substrate) to 3.65 x 10(-)(7) A cm(-2), which was approximately two orders of magnitude lower, indicating that the corrosion resistance was improved.

关键词： MAO aluminium-lithium alloy Sc(NO3)(3) coating characteristics phase microstructure corrosion resistance

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Analysis of Flow Pattern and Bubble Behavior in Slab Continuous Casting with Mold electromagnetic Stirring

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STEEL RESEARCH INTERNATIONAL 2025年第3期96卷

作者： Lu, Haibiao Cheng, Qiao Zhong, Yunbo Cheng, Changgui Ren, Weili Ren, Zhongming Lei, Zuosheng Shanghai Univ State Key Lab Adv Special Steel Shanghai 200444 Peoples R China Shanghai Univ Shanghai Key Lab Adv Ferrometallurgy Shanghai 200444 Peoples R China Wuhan Univ Sci & Technol State Key Lab Refractories & Met Wuhan 430081 Hubei Peoples R China Wuhan Univ Sci & Technol Hubei Prov Key Lab New Proc Ironmaking & Steelmaki Wuhan 430081 Hubei Peoples R China

The electromagnetic stirring (EMS) and argon blowing are the widely recognized and extensively employed technologies to control the flow pattern in slab continuous casting, and their interaction is directly linked to the final product. To investigate the flow pattern, bubble characteristics under mold EMS and argon blowing, a mathematical model coupling the electromagnetic field, two-phase flow is constructed. The population balance model (PBM) under the Eulerian frame is applied to describe the bubbles breakage and coalescence. The results show that the flow regime under the interaction of argon blowing and EMS transfers from bubble ascending flow to intermediate flow to horizontal recirculation flow as EMS current increases, and the large argon flow rate could suppress the formation of horizontal recirculation flow. Meanwhile, EMS can promote the coalescence of bubbles, with the increasing EMS current, the bubble numbers decrease first and then increase, and the bubble mean diameter increases first and then decreases. For obtaining the horizontal recirculation flow, the suitable argon flow rate and EMS current should be matched suitably. The flow pattern and bubble characteristics in a slab mold under argon blowing and electromagnetic stirring (EMS) are investigated using mathematical model. The flow regime within the mold shifts from bubble ascent flow to intermediate flow to horizonal recirculation flow as EMS current increases. For obtaining rational horizonal recirculation flow, it should balance the argon flow rate and EMS *** (c) 2024 WILEY-VCH GmbH

关键词： argon injection bubble characteristics electromagnetic stirring flow pattern slab continuous casting

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Privacy-Preserving Boolean Range Query With Temporal Access Control in Mobile Computing

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IEEE TRANSACTIONS ON KNOWLEDGE AND DATA engineering 2023年第5期35卷 5159-5172页

作者： Tong, Qiuyun Li, Xinghua Miao, Yinbin Liu, Ximeng Weng, Jian Deng, Robert H. H. State Key Lab Integrated Serv Networks Xian 710071 Shaanxi Peoples R China Xidian Univ Sch Cyber Engn Xian 710071 Shaanxi Peoples R China Xidian Univ Sch Cyber Engn State Key Lab Integrated Serv Networks Xian 710071 Shaanxi Peoples R China Minist Educ Engn Res Ctr Big data Secur Xian 710071 Shaanxi Peoples R China Key Lab Blockchain & Cyberspace Governance Zhejian Hangzhou 310058 Zhejiang Peoples R China Fuzhou Univ Sch Math & Comp Sci Key Lab Informat Secur Network Syst Fuzhou 350108 Fujian Peoples R China Jinan Univ Coll Cyber Secur Guangzhou 510632 Guangdong Peoples R China Guangdong Key Lab Data Secur & Privacy Preserving Guangzhou 510632 Guangdong Peoples R China Singapore Management Univ Sch Informat Syst Singapore 178902 Singapore

With increasingly popular GPS-equipped mobile devices (e.g., smartphones, tablets, laptops), massive spatio-textual data has been outsourced to cloud servers for storage and analysis such as spatial keyword search. However, existing privacy-preserving spatial keyword query schemes only support coarse-grained non-temporal access control in single user sharing scenario, which does not scale well in time-related scenes such as message valid period. To solve the above issues, we propose Privacy-preserving Boolean Range Query with Temporal access control in mobile computing (PBRQ-T). Specifically, we first achieve PBRQ with linear search complexity using the adapted Gray code, Bloom filter, and Katz-Sahai-Waters encryption. Then, we provide fine-grained and temporal access control in PBRQ based on the forward/backward derivation function and attribute-based encryption, where PBRQ is executed only when the spatio-textual data is accessible. Finally, an enhanced PBRQ-T (i.e., PBRQ-T+) with faster-than-linear search complexity is proposed by constructing a Quadtree index structure. Our formal security analysis shows that data privacy and index privacy can be guaranteed during the query process. Our extensive experiments using a real-world dataset demonstrate the efficiency and feasibility of our schemes.

关键词： Encryption Access control Cryptography Indexes Reflective binary codes keyword search Mobile computing Boolean range query mobile computing privacy-preserving temporal access control

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Zn, Fe Dual-Atom Sites Catalyst Constructed by Metal Vacancy Strategy for Oxygen Reduction Reaction and Zn-Air Battery

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ACS APPLIED ENERGY MATERIALS 2024年第8期7卷 3061-3070页

作者： Ye, Mingfu Wang, Jieyue Zhan, Linxiao Wang, Mingyue Yan, Weijie Wang, Yawu Yang, Kang Liu, Huifang Tan, Yiwei Wang, Wenhai Chen, Chang Wu, Konglin Anhui Univ Technol Key Lab Green Fabricat & Surface Technol Adv Met M Minist Educ Maanshan 243002 Peoples R China Anhui Univ Technol Inst Clean Energy & Adv Nanocatalysis iClean Sch Chem & Chem Engn Maanshan 243002 Peoples R China Anhui Univ Technol Sch Mat Sci & Engn Maanshan 243002 Peoples R China Tsinghua Univ Engn Res Ctr Adv Rare Earth Mat Dept Chem Beijing 100084 Peoples R China Nanjing Univ Technol State Key Lab Mat Oriented Chem Engn Nanjing 211816 Peoples R China

Developing highly efficient electrocatalysts toward oxygen reduction reaction is significant for Zn-air battery (ZAB), which is still arduous. In this work, based on a metal vacancy strategy, we synthesized an atomically dispersed Zn, Fe dual-atom catalyst on N-doped carbon (Zn, Fe/NC) by pyrolyzing the ZIF-8, postadsorbing Fe3+, and second pyrolysis steps. Due to the introduction of Fe atoms, the obtained Zn, Fe/NC-800 catalyst displays outstanding performance in an alkaline electrolyte (half-wave potential: 0.881 V), which approaches closely that of commercial Pt/C (0.903 V). Theoretical calculations indicate that the excellent activity of Zn and Fe/NC-800 can be attributed to the integration of Fe atoms that effectively optimizes the rate-limiting step. Zn, Fe/NC-800 also presents robust durability and strong methanol tolerance. Moreover, the ZAB assembled with Zn, Fe/NC-800 delivers charge-discharge cycling life (550 h) at 10 mA cm(-2) without noticeable decay. Furthermore, Zn, Fe/NC-800 even show a glorious flexible adaptability when employed as the cathode in a flexible ZAB.

关键词： Zn, Fe dual-atom sites metal vacancy strategy oxygen reduction reaction Zn-air battery

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Supramolecular ionogels enable highly efficient electrochromism

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MATERIALS HORIZONS 2025年第6期12卷 1992-2001页

作者： Zhou, Kaijian Tang, Liang Kuang, Guoqiang Zhang, Jun Li, Zhiyong Xing, Guoqiang Jiang, Xueao Chen, Zhanying Tao, Yijie Zhang, Yan Zhang, Shiguo Hunan Univ Coll Mat Sci & Engn State Key Lab Adv Design & Mfg Technol Vehicle Changsha 410082 Hunan Peoples R China Henan Normal Univ Sch Chem & Chem Engn Xinxiang 453007 Henan Peoples R China

Ionogels are a promising solution to improve the functionality of electrochromic devices (ECDs) by solving issues related to traditional liquid electrolytes, such as volatility, toxicity, and leakage. However, manufacturing ionogels is complicated as it often involves cross-linking polymerization or chemical sol-gel processes, requiring large amounts of inorganic or polymeric gelators. This results in low ionic conductivity and poor ECD performance. This study demonstrates the fabrication of highly conductive supramolecular ionogels by directly solidifying an ionic liquid (IL) using a low-molecular-weight gelator with a very low content (5 wt%). The resulting ionogel, DBS-G, exhibited self-healing properties, high optical transmittance (>86%), and high ionic conductivity (3.12 mS cm(-1)) comparable to the pure IL. When combined with a conjugated thiophene-based electrochromic polymer or by incorporating electrochromic viologen derivatives and ferrocene into the ionogel, the constructed five-or three-layer ECDs demonstrate electrochromic performance comparable to IL electrolyte and surpassing polymer gelator-based ionogels. They exhibit high optical contrast, rapid response, high coloring efficiency, good cycle stability, and can operate effectively in a broad temperature range from -25 degrees C to 80 degrees C. Furthermore, the adhesive properties of DBS-G facilitate the fabrication of flexible ECDs, which exhibit commendable electrochromic performance and cycle stability under bending conditions.

关键词： Sol-gel process

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Laser-guided thin-film self-rolling for asymmetric small-scale swimmers

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RARE METALS 2025年 1-14页

作者： Chen, Yi Lu, Xu-Peng Kim, Minseong Yang, Rong-Liang Tan, Min Yuan, Qiao-Ya-Xiao Poon, Wing Yan Chan, Yee Him Timothy Lee, Connie Kong Wai Xu, Yang Liu, Yang Li, Mitch Gui-Jun Hong Kong Univ Sci & Technol Div Integrat Syst & Design Kowloon Clear Water Bay Hong Kong 999077 Peoples R China Hong Kong Univ Sci & Technol State Key Lab Adv Displays & Optoelect Technol Kowloon Clear Water Bay Hong Kong 999077 Peoples R China Hong Kong Polytech Univ Dept Appl Phys Kowloon Hong Kong 999077 Peoples R China

Small-scale robots are promising miniaturized devices in biomedicine. Thin-film self-assembly is a commonly used strategy to fabricate tubular small-scale robots. However, the existing methods have limitations like complex manufacturing processes and limited control of self-assembly behavior. Herein, we present a recently developed laser-guided self-assembly strategy that transforms platinum/gold bilayer thin films into three-dimensional tubular structures. These structures function as chemically actuated, asymmetrically designed small-scale swimmers. Micro-roll structures with customizable geometrical asymmetry are prepared through a precise laser-guided rolling process, in which the laser settings can digitally control the rolling behavior because of the point-to-point laser-material interaction. Furthermore, the as-fabricated micro-rolls could be directly peeled off the substrate and transferred to the target container by laser irradiation. The specially designed cone-like asymmetric platinum/gold micro-roll can swim forward in the hydrogen peroxide solution by ejecting bubbles from the large open end. The movement of small-scale swimmers in open water can be precisely controlled by adjusting their asymmetry, which is achieved through carefully designed laser scanning paths. The interactions of the asymmetric small-scale swimmers with various boundaries (both fixed and untethered) are systematically investigated and summarized. Micro-roll encapsulation with empty capsules can be integrated into the laser transfer process. The dissolution of capsules and release of small-scale swimmers in aqueous solutions are demonstrated. This research indicates the potential of the one-step laser-guided self-assembly and forward transfer method in manufacturing and encapsulating miniaturized devices. (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic

关键词： Platinum Micro-swimmers Laser fabrication

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Multifunctional laser-induced graphene circuits and laser-printed nanomaterials toward non-invasive human kidney function monitoring

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BIOSENSORS & BIOELECTRONICS 2024年 259卷 116386页

作者： Huang, Yangyi Zhong, Haosong Yang, Rongliang Pan, Yexin Lin, Jing Lee, Connie Kong Wai Chen, Siyu Tan, Min Lu, Xupeng Poon, Wing Yan Yuan, Qiaoyaxiao Li, Mitch Guijun Hong Kong Univ Sci & Technol Ctr Smart Mfg Div Integrat Syst & Design Kowloon Clear Water Bay Hong Kong 999077 Peoples R China Chinese Natl Engn Res Ctr Tissue Restorat & Recons Hong Kong Branch Kowloon Clear Water Bay Hong Kong 999077 Peoples R China

Faced with the increasing prevalence of chronic kidney disease (CKD), portable monitoring of CKD-related biomarkers such as potassium ion (K+), creatinine (Cre), and lactic acid (Lac) levels in sweat has shown tremendous potential for early diagnosis. However, a rapidly manufacturable portable device integrating multiple CKD-related biomarker sensors for ease of sweat testing use has yet to be reported. Here, a portable electrochemical sensor integrated with multifunctional laser-induced graphene (LIG) circuits and laser-printed nanomaterials based working electrodes fabricated by fully automatic laser manufacturing is proposed for noninvasive human kidney function monitoring. The sensor comprises a two-electrode LIG circuit for K+ sensing, a three-electrode LIG circuit with a Kelvin compensating connection for Cre and Lac sensing, and a printed circuit board based portable electrochemical workstation. The working electrodes containing Cu and Cu2O nanoparticles fabricated by two-step laser printing show good sensitivity and selectivity toward Cre and Lac sensing. The sensor circuits are fabricated by generating a hydrophilic-hydrophobic interface on a patterned LIG through laser. This sensor recruited rapid laser manufacturing and integrated with multifunctional LIG circuits and laserprinted nanomaterials based working electrodes, which is a potential kidney function monitoring solution for healthy people and kidney disease patients.

关键词： Kidney function monitoring Portable sensors Laser manufacturing Laser-induced graphene circuit Laser-printed nanomaterials

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