IF 3.9 2区材料科学

Vacuum Pub Date : 2025-08-28 DOI: 10.1016/j.vacuum.2025.114702

Pengfei Liu , Wanfei Hu , Xing Gao , Tiantian Liu , Junying Zhang

{"title":"Controlled C-C coupling of CO on borophene as a non-metallic catalyst: A DFT study on solvent water effects","authors":"Pengfei Liu , Wanfei Hu , Xing Gao , Tiantian Liu , Junying Zhang","doi":"10.1016/j.vacuum.2025.114702","DOIUrl":"10.1016/j.vacuum.2025.114702","url":null,"abstract":"<div><div>C-C controllable coupling is a key factor in the electrocatalytic reduction of CO<sub>2</sub> (CO<sub>2</sub>RR) to C<sub>2</sub> compounds, but the influence of solvent water on C-C coupling in theoretical research lags far behind experiments. Herein, we systematically study the C-C coupling mechanism of CO generated OCCO on borophene surface through DFT, while considering the influence of solvent water. The results indicate that CO can be chemically adsorbed on borophene surface, followed by direct C-C coupling to form chemically adsorbed ∗OCCO. The activation energy barrier for ∗CO to form ∗OCCO on the surface of 2pmmn-borophene is the lowest, at 0.11 eV ∗OCCO can also be directly generated by C-C coupling of CO in both implicit and explicit solvent water models. The trend of energy barrier variation in implicit water models is consistent with that in vacuum environments. In the explicit water model, the activation energy barrier for ∗CO to generate ∗OCCO on the surface of α-borophene is the lowest, with an activation energy of 0.23 eV. The results indicate that the explicit solvent water is crucial in the electrocatalytic reduction of CO<sub>2</sub> in theoretical research. This study provides a new perspective for understanding the efficient C-C coupling of solvent effects in CO<sub>2</sub>RR.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"241 ","pages":"Article 114702"},"PeriodicalIF":3.9,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144920109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of Fe2O3 hybridization in MWCNT and graphene nanoparticles separately on the performance of H-theta Chevron corrugated Plate heat exchanger MWCNT和石墨烯纳米颗粒中Fe2O3杂化对H-theta v形波纹板换热器性能的影响

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-08-28 DOI: 10.1016/j.vacuum.2025.114700

Abdul Razack Mohammad , Dora Nagaraju , Vuppula Santhosh Reddy , T. Raju

{"title":"Influence of Fe2O3 hybridization in MWCNT and graphene nanoparticles separately on the performance of H-theta Chevron corrugated Plate heat exchanger","authors":"Abdul Razack Mohammad , Dora Nagaraju , Vuppula Santhosh Reddy , T. Raju","doi":"10.1016/j.vacuum.2025.114700","DOIUrl":"10.1016/j.vacuum.2025.114700","url":null,"abstract":"<div><div>High-theta chevron corrugated plate heat exchanger is tested with two hybrid nanofluids prepared using Fe<sub>2</sub>O<sub>3</sub>/graphene and Fe<sub>2</sub>O<sub>3</sub>/MWCNT at various concentrations and Reynolds numbers. The hybridization resulted in stable nanofluids with enhanced thermal conductivity due to effective functionalization and synthesis. The results indicated that at an 8 L/min mass flow rate of Fe<sub>2</sub>O<sub>3</sub>/graphene, and Fe<sub>2</sub>O<sub>3</sub>/MWCNT of 0.03 % nanofluid, enhancement by 35 % and 17 % achieved compared to water. It is observed that the F<sub>2</sub>O<sub>3</sub>/graphene hybrid showed improved Nusselt numbers and overall heat transfer coefficient, enhancing PHE efficiency. Higher concentrations of nanoparticles improved heat transfer performance, but increased pressure drops and pumping power. Both FM-0.03 % and FG-0.03 % nanofluids significantly reduced entropy production, with FG-0.03 % being the most effective. However, performance decreased at higher Reynolds numbers due to viscosity and agglomeration issues. The study emphasizes the necessity for thorough testing and long-term stability assessments to optimize nanofluids for practical use, suggesting that combining metal oxides.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"241 ","pages":"Article 114700"},"PeriodicalIF":3.9,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144913975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of high-vacuum arc melting-controlled oxygen content on inclusions and mechanical properties of steels with different refining processes and deoxidizers 高真空电弧熔炼控制氧含量对不同精炼工艺和脱氧剂钢夹杂物和力学性能的影响

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-08-27 DOI: 10.1016/j.vacuum.2025.114697

Wan-Yi Lin , Jyun-Hua Chang , Chun-Hway Hsueh

{"title":"Effects of high-vacuum arc melting-controlled oxygen content on inclusions and mechanical properties of steels with different refining processes and deoxidizers","authors":"Wan-Yi Lin , Jyun-Hua Chang , Chun-Hway Hsueh","doi":"10.1016/j.vacuum.2025.114697","DOIUrl":"10.1016/j.vacuum.2025.114697","url":null,"abstract":"<div><div>In this study, high-vacuum arc melting (VAM) was utilized to remelt and modify the oxygen content in steels with different refining processes and deoxidizers to investigate its effects on inclusions and mechanical properties. Specifically, the oxygen content was controlled at lower (<20 ppm) and higher (>80 ppm) than those in as-received steels (20–40 ppm). The phase and microstructure were examined and Thermo-Calc was used to simulate possible phases. The tensile/fatigue properties and hardness were measured. The results showed that carbides were refined after remelting in VAM and the tensile strength and hardness were enhanced. There was no big difference in tensile strength and hardness of steels with different oxygen contents. However, larger-sized carbides in steels without remelting in VAM resulted in poorer fatigue life. Compared to as-received steels, the non-metallic inclusion density was slightly reduced and acutely raised, respectively, after remelting in VAM with low and high oxygen contents. However, the fatigue properties depended on not only the oxygen content and inclusion densities but also inclusion types resulting from different deoxidizers. As Al<sub>2</sub>O<sub>3</sub> inclusion density increased in Al-deoxidized steels, the fatigue life was reduced. However, the fatigue life was insensitive to SiO<sub>2</sub> inclusion density in Si/Mn-deoxidized steels.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"242 ","pages":"Article 114697"},"PeriodicalIF":3.9,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Local analysis of a DC glow discharge in an inverted coaxial diode 反向同轴二极管直流辉光放电的局部分析

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-08-27 DOI: 10.1016/j.vacuum.2025.114654

L. Córdova-Castillo , I. Camps , A. Figueroa , S. Cuevas

引用次数: 0

Impact of plasma-induced damage on electrical and physical properties of indium tin oxide as interconnecting layers of tandem solar cell applications 等离子体损伤对串联太阳能电池互连层氧化铟锡电学和物理性能的影响

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-08-27 DOI: 10.1016/j.vacuum.2025.114699

Chia-Huai Ho , Chin-Lung Cheng , Yung-Teng Wang

引用次数: 0

3D N-doped graphene emitters on titanium foam: unleashing enhanced electron field emission performance 泡沫钛上的三维n掺杂石墨烯发射器：释放增强的电子场发射性能

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-08-26 DOI: 10.1016/j.vacuum.2025.114698

L.F. Chen , L. Sun , H.Y. Qin

引用次数: 0

Enhanced secondary electron emission characteristics of surface boron-doped diamond films by adjusting the thickness of boron-doping layer 通过调整硼掺杂层的厚度来增强表面掺硼金刚石薄膜的二次电子发射特性

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-08-25 DOI: 10.1016/j.vacuum.2025.114694

Yunrong Wang, Qiang Wei, Zhangcong Xia, Jie Li, Shengli Wu

引用次数: 0

A flexible multimodal piezoresistive sensor for wearable health monitoring and thermal management: integrating high-strain sensing, sound detection, and photothermal conversion 用于可穿戴健康监测和热管理的柔性多模态压阻传感器：集成高应变传感，声音检测和光热转换

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-08-25 DOI: 10.1016/j.vacuum.2025.114695

Gongfei Xue , Bin Wang , Yue Cao , Mouhu Wu , Weijiang Zhao , Hao Dou , Xinfa Qiang

{"title":"A flexible multimodal piezoresistive sensor for wearable health monitoring and thermal management: integrating high-strain sensing, sound detection, and photothermal conversion","authors":"Gongfei Xue , Bin Wang , Yue Cao , Mouhu Wu , Weijiang Zhao , Hao Dou , Xinfa Qiang","doi":"10.1016/j.vacuum.2025.114695","DOIUrl":"10.1016/j.vacuum.2025.114695","url":null,"abstract":"<div><div>The increasing demand for multifunctional wearable devices has sparked concerns in developing multifunctional wearable materials with flexibility, pressure resistance, and effective thermal management to address health monitoring and thermal regulation challenges in demanding environments. In this work, a novel multifunctional piezoresistive sensor, melamine foam/PPy/MXene (KMPM), has been developed, integrating high-strain sensing, health monitoring, sound detection, and photothermal conversion capabilities. It was fabricated via a simple chemical oxidation method and cost-effectively solution-dip-coating technique to deposit polypyrrole (PPy) and MXene onto melamine foam (MF). The KMPM sensor demonstrated a wide detection range (5–21 kPa), high sensitivity (S = 1.81 kPa<sup>−1</sup>), fast response times (165 ms for response, 150 ms for recovery), and exceptional stability (over 3000 cycles). Beyond conventional human motion sensing, it can be used to detect both biological and abiotic sound signals. Notably, KMPM exhibited rapid photothermal responses, reaching temperatures above 340 °C within 15 s when exposed to near-infrared (808 nm) radiation, and maintained a stable surface temperature and heating rate under repeated radiation cycles. It demonstrated the KMPM sensor opened opportunities for applications in thermal management, health monitoring, sound recognition, and wearable devices.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"241 ","pages":"Article 114695"},"PeriodicalIF":3.9,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design and experimental study of a pressure-feedback flow control method for hall-effect electric propulsion systems 霍尔效应电力推进系统压力反馈流量控制方法的设计与实验研究

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-08-25 DOI: 10.1016/j.vacuum.2025.114679

Runzhi Zhu , Luxiang Xu , Shixu Lu , Liexiao Dong , Jian Wang , Ning Guo , Rong Shu

{"title":"Design and experimental study of a pressure-feedback flow control method for hall-effect electric propulsion systems","authors":"Runzhi Zhu , Luxiang Xu , Shixu Lu , Liexiao Dong , Jian Wang , Ning Guo , Rong Shu","doi":"10.1016/j.vacuum.2025.114679","DOIUrl":"10.1016/j.vacuum.2025.114679","url":null,"abstract":"<div><div>To meet the high precision and high stability requirements for propellant flow control in space electric propulsion systems, this study aims to develop a universal flow control module and closed-loop control method based on pressure feedback. Firstly, a mathematical pressure-flow model for straight pipeline sections and throttling devices is established based on principles of fluid mechanics. Then, a dynamic model incorporating time-integration and differentiation correction terms into the traditional model is proposed. Multi-variable linear regression is employed to fit experimental data, enabling precise characterization of mass flow rate responses under low-pressure and low-flow rate conditions. Experimental results show that, under a two-stage pressure reduction structure, there is a strong linear correlation between pressure and mass flow rate (Pearson correlation coefficient <span><math><mo>></mo></math></span> 0.97, <span><math><mrow><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>></mo><mn>0</mn><mo>.</mo><mn>95</mn></mrow></math></span>). Closed-loop control results demonstrate that the dynamic model can significantly shorten system response time, with steady-state error reduced to below 0.5 sccm. These findings indicate that the proposed flow control scheme offers fast response and high precision, effectively addressing both internal and external disturbances, and provides theoretical and experimental support for precise propellant flow control in electric propulsion systems.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"241 ","pages":"Article 114679"},"PeriodicalIF":3.9,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evolution of microscopic contact surface condition in VCB during closing operations after inrush current erosion 冲击流侵蚀后真空断路器闭合过程中微观接触面状态的演变

IF 3.9 2区材料科学

Vacuum Pub Date : 2025-08-23 DOI: 10.1016/j.vacuum.2025.114692

Pu Chen , Yun Geng , Jing Yan , Hannan Shan , Linhuan Wei , Yingsan Geng , Hanyan Xiao , Tianxin Zhuang

引用次数: 0

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