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Investigation of the unloading yield effect in 7075 Al alloys based on microstructural and digital image correlation analysis

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Materials Characterization 2021年 173卷

作者： Choi, Howook Kim, Hwangsun Jeong, Hye-Jin Shin, Eunjoo Woo, Wanchuck Hong, Sung-Tae Lee, Myoung-Gyu Han, Heung Nam Department of Materials Science and Engineering & Research Institute of Advanced Materials Seoul National University 1 Gwanak-ro Gwanak-gu Seoul08826 Korea Republic of Memory Process Development Team Semiconductor R&D Center Samsung Electronics 1 Samsungjeonja-ro Hwaseong-si Gyeonggi-do18448 Korea Republic of Neutron Science Centre Korea Atomic Energy Research Institute PO Box 105 Yuseong-gu Daejeon305-600 Korea Republic of Departments of Mechanical engineering University of Ulsan 93 Daehak-ro Nam-gu Ulsan Korea Republic of

The unloading yield effect (UYE), which indicates that the reloading flow stress overshoots the monotonically loaded flow stress during uniaxial tensile test, was investigated by evaluating three aluminum alloy 7075 sheets with different precipitate states: solution heat-treated (SHT), aged for 20 min (A20, underaged), aged for 80 min (A80, peak aged) and aged for 240 min (A240, overaged). The precipitate states of A20 and A240 specimens were characterized by transmission electron microscope (TEM) and small-angle neutron scattering (SANS) analyses. The UYE was exhibited only in artificially aged specimens, but not in the SHT specimen. It was confirmed that the root cause of UYE is the interaction between the precipitate and dislocation during unloading. In addition, it was observed that strain instability is inevitably generated during stress overshoot owing to temporal geometric softening. The temporal strain instability diffused to the neighboring region in the case of A20 specimen, but that of A240 specimen directly influenced the premature localized necking or failure, resulting in a significant reduction in elongation. © 2021 Elsevier Inc.

关键词： Image correlation

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Electron trap-induced charge accumulation and surface reaction kinetics synergistically enhance overall nitrogen photofixation

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Chinese Chemical Letters 2025年第8期36卷

作者： Li, Longjian Zhang, Ping Yu, Yongchong Tuerhong, Reyila Su, Xiaoping Han, Lijuan Liu, Enzhou Jiang, Jizhou Key Laboratory of Environment-Friendly Composite Materials of the State Ethnic Affairs Commission Gansu Province Engineering Research Center for Biomass Functional Composite Materials Key Laboratory for the Utilization of Environment Friendly Composite Materials and Biomass in Universities of Gansu Province Gansu Province Research Center for Basic Sciences of Surface and Interface Chemistry College of Chemical Engineering Northwest Minzu University Lanzhou 730030 China Gansu Natural Energy Research Institute Gansu Academy of Science Lanzhou 730046 China School of Chemical Engineering Xi'an Key Laboratory of Special Energy Materials Northwest University Xi'an 710069 China School of Materials Science and Engineering Key Laboratory of Green Chemical Engineering Process of Ministry of Education Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education Wuhan Institute of Technology Wuhan 430205 China

Available online Further oxidation of NH3 produced via photocatalytic N2 fixation represents a promising strategy to enhance the economic value of N2 fixation. This work employs first-principles density functional theory (DFT) calculations to demonstrate that incorporating Co into NiO improves both N2 adsorption and activation as well as M-N electron exchange intensity. Guided by these predictions, a novel Co single-atom photocatalyst supported by nanoconfined NiO@C nanosheets was synthesized using a direct metal atomization method, achieving high HNO3 production (60.54 %). NH4⁺ and NO3⁻ production rates during N2 photofixation reached 67.97 µmol gcat⁻¹ h⁻¹ and 104.28 µmol gcat⁻¹ h⁻¹, respectively. The overall N2 → NH3 → HNO3 photofixation pathway was validated through in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and ¹⁵N isotopic labeling. Mechanistic studies reveal that Co single-atom introduction serves as an electron trap, enhancing photogenerated electron accumulation with a five-fold increase in carrier density compared to NiO@C, as observed via in-situ X-ray photoelectron spectroscopy (XPS). This synergistic effect between electron traps and N2 adsorption/activation sites at Co single-atom centers supports rapid N2 reduction kinetics. Additionally, nanoconfined ink-bottle pores in the carbon layer impede NH3 desorption, further boosting NO3⁻ production. This work offers a comprehensive approach to optimizing N2 photofixation through electron regulation and surface reaction kinetics.

关键词： Co single-atom Electron trap N2 photofixation Nanoconfined NiO@C NO3− production

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Effect of glass fiber hybridization and radiation treatment to improve the performance of sustainable natural fiber-based hybrid (jute/glass) composites

Next Sustainability

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Next Sustainability 2025年 6卷

作者： S.H. Mahmud S.C. Das A. Saha T. Islam D. Paul M.W. Akram M.S. Jahan M.Z.I. Molla M.A. Gafur R.A. Khan Department of Textile Engineering National Institute of Textile Engineering and Research University of Dhaka Dhaka 1000 Bangladesh Department of Textile Engineering Mawlana Bhashani Science and Technology University Tangail 1902 Bangladesh Institute of Radiation and Polymer Technology Atomic Energy Research Establishment Bangladesh Atomic Energy Commission Savar Dhaka 1349 Bangladesh Department of Manufacturing and Civil Engineering Norwegian University of Science and Technology Gjøvik 2815 Norway Pabna Textile Engineering College Pabna Bangladesh Department of Textile Engineering Jashore University of Science and Technology Jessore 7408 Bangladesh Department of Textiles Merchandising and Interiors University of Georgia Athens GA 30602 USA Department of Textile and Fibre Engineering Indian Institute of Technology Delhi New Delhi India Department of Fashion Design and Apparel Engineering National Institute of Textile Engineering and Research University of Dhaka Dhaka 1000 Bangladesh Department of Material and Metallurgical Engineering Bangladesh University of Engineering and Technology Dhaka Bangladesh Pilot Plant and Process Development Centre (PP & PDC) Bangladesh Council of Scientific and Industrial Research Dhaka 1205 Bangladesh

The current work aims to utilize sustainable natural fibers such as jute fiber in composite materials and a sustainable technology such as gamma (γ) irradiation to further treat the composites for their performance enrichment. First, synthetic glass fibers were hybridized to improve the performance of natural fiber composites (NFCs) with different stacking sequences. Jute fabrics were used as a natural fiber reinforcement and unsaturated polyester resin was employed as a thermoset polymer matrix. Composite laminates were manufactured by compression molding using a heat press machine. After hybridization, the mechanical properties and water resistance were improved compared to the neat NFCs (i.e., jute fiber composites, J0). The tensile strength, bending strength, tensile modulus, bending modulus, and impact strength were improved to 7–56, 5–53, 21–54, 27–69, and 199–387 %, respectively, than the J0. Further, gamma (γ) irradiation (5.0 kGy) was employed as a sustainable and chemical-free technology to treat the hybrid composite materials and improve the performance, and the optimum improvement was revealed for H3 (G 2 J 4 G 2 ) hybrid composites. For H3, the enhancement of tensile, bending and impact strength was revealed at approximately 28, 65 and 27 %, respectively, while the tensile and bending modulus were exhibited at approximately 27 and 71 %, respectively, compared to their non-irradiated composite ones. Further characterization of the composites was studied by FTIR (Fourier Transform Infrared) spectroscopy and SEM (Scanning Electron Microscopy) experimentation.

关键词： Natural fiber composites (NFCs) Hybrid composites Sustainable composites Stacking sequence Thermoset polymer matrix Gamma (γ) irradiation

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Correction: Surface Polarity Dependent Photo-response of GaN MSM Ultraviolet (UV) Sensors

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Transactions on Electrical and Electronic Materials 2024年第6期25卷 860-860页

作者： Shin, Seung Heon Kim, Dong-Seok Woo, Jong-Chang Lee, Heon Bok Hahm, Sung-Ho Kim, Do-Kywn Department of Semiconductor Process Equipment Korea Polytechnics Anseong-si Republic of Korea Korea Multi-Purpose Accelerator Complex Korea Atomic Energy Research Institute Gyeongju-si Republic of Korea Process Development Samsung Electronics co. Semiconductor R&D Center Suwon Republic of Korea School of Electronic Engineering and Computer Science Kyungpook National University Daegu Republic of Korea Department of Semiconductor Materials and Applications Seongnam-si Republic of Korea

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Plant-mediated green synthesis and characterization of silver nanoparticles using Phyllanthus emblica fruit extract

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Materials Today: Proceedings 2021年 42卷 1867-1871页

作者： Sajib Aninda Dhar Rashedul Alam Chowdhury Shaon Das Md. Khalid Nahian Dipa Islam Md. Abdul Gafur Pilot Plant and Process Development Centre (PP & PDC) Bangladesh Council of Scientific and Industrial Research Dr. Qudrat I Khuda Road Dhaka 1205 Bangladesh Department of Materials and Metallurgical Engineering Bangladesh University of Engineering and Technology Zahir Raihan Road Dhaka 1000 Bangladesh Nuclear Safety and Security Division Bangladesh Atomic Energy Regulatory Authority (BAERA) E-12/A Shahid Shahabuddin Shorok Dhaka 1207 Bangladesh Biomedical and Toxicological Research Institute (BTRI) Bangladesh Council of Scientific and Industrial Research Dr. Qudrat I Khuda Road Dhaka 1205 Bangladesh

A cost-effective and non-hazardous approach was carried out for the plant-mediated green synthesis of metallic nanomaterials utilizing the fruit extract of Indian gooseberry (Amla) or Phyllanthus emblica . In this study, silver nanoparticles were effectively synthesized from silver nitrate precursors through a facile and eco-friendly method using the fruit extract of Phyllanthus emblica as a reducing and stabilizing agent. The ultraviolet–visible (UV–Vis) spectroscopy, x-ray diffraction analysis, field emission scanning electron microscopy (FESEM), and energy dispersive x-ray analysis (EDX) were employed to characterize the synthesized nanoparticles. A face-centered cubic crystalline structure and elemental silver phase were identified by x-ray diffraction analysis. The Rietveld refinement determined the average crystallite size (Lvol-IB) of the silver nanoparticles’ as 16.29 nm. The microstructural analysis revealed the spherical shape of the as-synthesized silver nanoparticles and the average grain size ranged between 60 and 80 nm. The development of elemental silver was affirmed by the EDX spectrum. The bio-reduction of silver ions and the formation of silver nanoparticles were ascertained by the UV–Vis spectral analysis. A surface plasmon resonance peak was found at 453 nm. The well-balanced size and shape of the synthesized elemental silver nanoparticles suggested the Phyllanthus emblica fruit extract as an effective reducing agent.

关键词： Green synthesis Silver nanoparticle Phyllanthus emblica Fruit extract

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Sensitivity Analysis of Building Energy Performance Assessment Based on Machine-Learning Models 11th

Sensitivity Analysis of Building Energy Performance Assessme...

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11th International Symposium on Heating, Ventilation and Air Conditioning, ISHVAC 2019

作者： Tian, Wei Shi, Jiaxin de Wilde, Pieter Sun, Yu Zhu, Chuanqi Yin, Baoquan College of Mechanical Engineering Tianjin University of Science and Technology Tianjin300222 China Tianjin International Joint Research and Development Center of Low-Carbon Green Process Equipment Tianjin300222 China Chair of Building Performance Analysis Environmental Building Group University of Plymouth PlymouthDevonPL4 8AA United Kingdom School of Architecture Harbin Institute of Technology Harbin150000 China Tianjin Architecture Design Institute Tianjin300074 China

ISBN: (纸本)9789811395277

Variance-based sensitivity analysis in combination with machine-learning techniques has been increasingly applied in energy analysis of buildings in order to reduce computational cost of running a large number of energy models with sufficient accuracy. This paper compares the performance of two sensitivity analysis methods based on machine-learning models for building energy assessment: multivariate adaptive regression splines (MARS) and Cubist (CB). An office building located in Tianjin, China, is used as a case study with the EnergyPlus simulation program, to study the characteristics of these two sensitivity analysis methods. The results indicate that sufficient sample number is required to obtain reliable sensitivity analysis results in building energy assessment and subsequent HVAC system design and sizing. It is recommended to use at least two machine-learning models for variance-based sensitivity methods to allow the comparison of ranking results. The consistency of results from these learning methods should be thoroughly checked since the parameters in tuning these machine-learning models have significant influences on ranking results. © 2020, Springer Nature Singapore Pte Ltd.

关键词： Sensitivity analysis

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Approximate Bayesian Computation in Parameter Estimation of Building Energy Models 11th

Approximate Bayesian Computation in Parameter Estimation of ...

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11th International Symposium on Heating, Ventilation and Air Conditioning, ISHVAC 2019

作者： Zhu, ChuanQi Tian, Wei de Wilde, Pieter Yin, Baoquan College of Mechanical Engineering Tianjin University of Science and Technology Tianjin300222 China Tianjin International Joint Research and Development Center of Low-Carbon Green Process Equipment Tianjin300222 China Chair of Building Performance Analysis Environmental Building Group University of Plymouth PlymouthDevonPL4 8AA United Kingdom Tianjin Architecture Design Institute Tianjin300074 China

ISBN: (纸本)9789811395277

Model calibration is a necessary step to create reliable energy models in building retrofit. Bayesian computation in model calibration has attracted more attention because it can make full use of prior knowledge on building parameters. However, the likelihood function is hard to be computed in Bayesian computation due to the complexity of building energy simulation models. Approximate Bayesian computation (ABC) is a likelihood-free method to infer unknown parameters in complicated computational models by approximating the likelihood function with simulation. The ABC method is inherently computationally intensive since a large number of simulation runs are required to find reliable inferred values. This paper proposes a method for combining the ABC technique and the machine-learning method to compute unknown parameters in parameter estimation of building energy models. The results show that this method can provide reliable estimations of unknown parameters when calibrating building energy models. © 2020, Springer Nature Singapore Pte Ltd.

关键词： Parameter estimation

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Discovery of STAT3 and Histone Deacetylase (HDAC) Dual-Pathway Inhibitors for the Treatment of Solid Cancer

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Journal of medicinal chemistry 2021年第11期64卷 7468-7482页

作者： Yuhao Ren Shanshan Li Ren Zhu Chengying Wan Dongmei Song Jiawen Zhu Guiping Cai Sihui Long Lingyi Kong Wenying Yu Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines China Pharmaceutical University 24 Tong Jia Xiang Nanjing 210009 People's Republic of China. Key Laboratory for Green Chemical Process of Ministry of Education Hubei Key Laboratory of Novel Reactor and Green Chemical Technology Hubei Engineering Research Center for Advanced Fine Chemicals School of Chemical Engineering and Pharmacy Wuhan Institute of Technology 206 1st Rd Optics Valley East Lake New Technology Development District Wuhan Hubei 430205 China.

Nowadays, simultaneous inhibition of multiple targets through drug combination is an important anticancer strategy owing to the complex mechanism behind tumorigenesis. Recent studies have demonstrated that the inhibition of histone deacetylases (HDACs) will lead to compensated activation of a notorious cancer-related drug target, signal transducer and activator of transcription 3 (STAT3), in breast cancer through a cascade, which probably limits the anti-proliferation effect of HDAC inhibitors in solid tumors. By incorporating the pharmacophore of the HDAC inhibitor SAHA (vorinostat) into the STAT3 inhibitor pterostilbene, a series of potent pterostilbene hydroxamic acid derivatives with dual-target inhibition activity were synthesized. An excellent hydroxamate derivate, compound , inhibited STAT3 ( = 33 nM) and HDAC (IC = 23.15 nM) with robust potency . Compound also showed potent anti-proliferation ability and . Our study provides the first STAT3 and HDAC dual-target inhibitor for further exploration.

关键词： Cells Inhibitors Inhibition Cancer Peptides and proteins

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Evaluating the Effects of Dams on Riparian Vegetation Dynamics in the Tibetan Plateau

SSRN

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SSRN 2021年

作者： Liu, Yunlong Lu, Hongwei Tian, Peipei Qiu, Lihua State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin University Tianjin300072 China Key Laboratory of Water Cycle and Related Land Surface Process Institute of Geographic Science and Natural Resources Research Chinese Academy of Science Beijing100101 China Institute of Blue and Green Development Shandong University Weihai264209 China School of new energy North China Electric Power University Beijing100101 China

As the third pole of the world, the Qinghai-Tibet Plateau (QTP) has a very special climate and geographical environment. In the past 20 years, with the increasing demand for clean energy, more than ten hydropower stations have been built. The impacts of these hydropower stations on riparian vegetation (RV) have only been described qualitatively in previous studies, but the mechanism of the impacts has not been explained. This study selected eight representative large-scale hydropower stations in the QTP, calculated and analyzed the dynamics of the standardized difference vegetation index (NDVI) of the RV pre-and post the dams construction, combined with the measured temperature and precipitation data to explore the driving factors of RV changes. The results show that the dams promoted the growth of RV and they were the main contributor (>50%) while precipitation and temperature had relatively small impacts. The effect of dams varies for different regions, compared with the sub-cold regions, it was more significant in humid and semi-humid regions of temperate zone. In addition, these dams mainly affected RV in an indirect way through regulating the regional climate, promoting precipitation and lowing temperature and these effects may come from the increase of the upstream water surface area. This study reveals the mechanism and contribution of the dam to riparian vegetation, and provides a reference for vegetation protection in the process of hydropower development in ecologically fragile areas. © 2021, The Authors. All rights reserved.

关键词： Regression analysis

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The short-term effects of COVID-19 outbreak on dietary diversity and food security status of Iranian households (A case study in Tehran province)

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Journal of Cleaner Production 2021年 281卷 124537页

作者： Pakravan-Charvadeh, Mohammad Reza Mohammadi-Nasrabadi, Fatemeh Gholamrezai, Saeed Vatanparast, Hassan Flora, Cornelia Nabavi-Pelesaraei, Ashkan Department of Agricultural Economics and Rural Development Faculty of Agriculture Lorestan University Khorramabad Iran Research Department of Food and Nutrition Policy and Planning National Nutrition and Food Technology Research Institute Faculty of Nutrition Sciences and Food Technology Shahid Beheshti University of Medical Sciences Tehran Iran College of Pharmacy and Nutrition University of Saskatchewan SaskatoonSK Canada Distinguished Professor Department of Sociology Iowa State University United States Department of Agricultural Machinery Engineering Faculty of Agricultural Engineering and Technology University of Tehran Karaj Iran Head of Process Engineering & Systems Improvement Management of Fruit and Vegetables Organizations Tehran Municipality Tehran Iran

Currently, the COVID-19 outbreak is spreading fast in 185 countries and has engaged most people around the world. COVID-19 imposes severe and tragic consequences on people's health due to the high rate of spread and potentially fatal impacts. In this study, the association of socio-economic factors with food security and dietary diversity is assessed before and during the COVID-19 pandemic. Data from 299 respondents were collected by an online standard questionnaire. Household Dietary Diversity Score (HDDS) and Household Food Insecurity Access Scale (HFIAS) were calculated. A multinomial regression model was applied to determine factors associated with HDDS and HFIAS before and during COVID-19 outbreak. Food security of Iranian households improved during the initial COVID-19 pandemic period (P © 2020 Elsevier Ltd

关键词： COVID-19

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