检索结果-内蒙古大学图书馆

arXiv 2025年

作者： da Gomes, Djardiel S. Felix, Isaac M. Radel, Willian F. Dias, Alexandre C. Ribeiro Junior, Luiz A. Pereira Junior, Marcelo L. State University of Campinas Gleb Wataghin Institute of Physics Department of Applied Physics Campinas São Paulo13083-859 Brazil University of Brasília Faculty UnB Planaltina Materials Science Postgraduate Program Federal District Brasília Brazil Center for Agri-food Science and Technology Federal University of Campina Grande Paraíba Pombal58840-000 Brazil University of Brasília Institute of Physics Physics Postgraduate Program Federal District Brasília70910900 Brazil Institute of Physics International Center of Physics University of Brasília Federal District Brasília70910-900 Brazil Institute of Physics University of Brasília Federal District Brasília70910-900 Brazil Computational Materials Laboratory University of Brasília Federal District Brasília70910900 Brazil University of Brasília College of Technology Department of Electrical Engineering Federal District Brasília70910-900 Brazil

Recently synthesized Porous 12-Atom-Wide Armchair Graphene Nanoribbons (12-AGNRs) [Nano Lett. 2024, 24, 10718-10723]exhibit tunable properties through periodic porosity, enabling precise control over their electronic, optical, thermal, and mechanical behavior. This work presents a comprehensive theoretical characterization of pristine and porous 12-AGNRs based on density functional theory (DFT) and molecular dynamics (MD) simulations. DFT calculations reveal substantial electronic modifications, including band gap widening and the emergence of localized states. Analyzed within the Bethe–Salpeter equation (BSE) framework, optical properties highlight strong excitonic effects and significant absorption shifts. Thermal transport simulations indicate a pronounced reduction in conductivity due to enhanced phonon scattering at nanopores. At the same time, MD-based mechanical analysis shows decreased stiffness and strength while maintaining structural integrity. Despite these modifications, porous 12-AGNRs remain mechanically and thermally stable. These findings establish porosity engineering as a powerful strategy for tailoring graphene nanoribbons’ functional properties, reinforcing their potential for nanoelectronic, optoelectronic, and thermal management *** Codes 00-xx © 2025, CC BY.

关键词： Nanoribbons

来源：评论

学校读者我要写书评

暂无评论

Comparison of Cu−Al−Ni−Mn−Zr shape memory alloy prepared by selective laser melting and conventional powder metallurgy

引用

Transactions of Nonferrous Metals Society of China 2020年第12期30卷 3322-3332页

作者： Dennis GERA Jonadabe SANTOS Cláudio SKIMINAMI Piter GARGARELLA Postgraduate Program in Materials Science and Engineering Federal University of São CarlosSão CarlosBrazil Materials Engineering Department Federal University of São CarlosR.Washington Luískm 235-SP 310São CarlosBrazil

This work aimed to investigate and critically analyze the differences in microstructural features and thermal stability of Cu−11.3Al−3.2Ni−3.0Mn−0.5Zr shape memory alloy processed by selective laser melting(SLM)and conventional powder *** specimens were produced by sintering 106−180μm pre-alloyed powders under an argon atmosphere at 1060°C without secondary *** specimens were consolidated through melting 32−106μm pre-alloyed powders on a Cu−10Sn *** properties were measured through Vickers hardness *** scanning calorimetry was conducted to assess the martensitic transformation temperatures.X-ray diffraction patterns were collected to identify the metallurgical *** and scanning electron microscopy was used to analyze the microstructural features.b′1 martensite was found,irrespective of the processing route,although coarser martensitic variants were present in *** conventional powder metallurgy samples,intergranular eutectoid constituents and stabilized austenite also formed at room ***-specimens showed similar average hardness values to the SLM-specimens,albeit with high standard deviation linked to the *** specimens processed by SLM showed reversible martensitic transformation(T0=171°C).PM-processed specimens did not show shape memory effects.

关键词： shape memory alloys powder metallurgy additive manufacturing selective laser melting Cu-based alloys

来源：评论

学校读者我要写书评

暂无评论

Boosting the Photocatalytic Activity of G-C3n4/Zno Heterojunctions Through Optimal Control of Mass Ratio

SSRN

引用

SSRN 2022年

作者： da Silva, Fausthon Fred da Silva, Rodolfo Bezerra Silva, Thayse R. de Macedo, Daniel Araujo Su, Bo Biomaterials Engineering Bristol Dental School University of Bristol Lower Maudlin Street BristolBS1 2LY United Kingdom PB João Pessoa58051-900 Brazil RN Mossoró59610-090 Brazil Materials Science and Engineering Postgraduate Program UFPB João Pessoa58051-900 Brazil

Carbon nitride (CN, g-C3N4) has emerged as a promising high-activity photocatalyst, despite some disadvantages like fast electron-hole recombination. The formation of CN-based heterojunctions is a viable strategy to overcome unwanted recombination processes. However, the precise control of the experimental parameters during the heterojunction formation is still needed to boost the photocatalytic efficiency. Herein, the influence of the mass ratio on the photocatalytic performance of CN/ZnO heterojunctions was investigated. The samples were obtained at room temperature via impregnation method and ultrasonic treatment. Heterojunctions were characterised by XRD and FT-IR, and interactions between the components were evidenced by the shifts in the diffraction patterns and vibrational spectra. The morphologies were investigated via SEM/TEM, confirming the formation of heterojunction interfaces. A strong influence of the CN/ZnO ratio was found on bandgaps, crystallite sizes. Photocatalytic activity was evaluated using rhodamine B dye in aqueous solution. High photocatalytic performances were obtained for CN/ZnO ≥ 1, and the best ratio was 2. The control of mass ratio changed the formation mechanism from type II heterojunction (CN/ZnO © 2022, The Authors. All rights reserved.

关键词： Carbon nitride

来源：评论

学校读者我要写书评

暂无评论

A Review of Carbon dots (CDs) Application in Sensing and Removing Medical Waste 5

A Review of Carbon dots (CDs) Application in Sensing and Rem...

引用

5th International Conference on Energy, Environmental and Information System, ICENIS 2020

作者： Alkian, Ilham Sutanto, Heri Aprimanti Utami, Bella Rafika Duri, Inten A'Yuni, Dewi Qurrota Hadiyanto, H Master Program of Environmental Science School of Postgraduate Studies Diponegoro University Semarang Indonesia Department of Physics Faculty of Science and Mathematics Diponegoro University Semarang Indonesia Department of Chemical Engineering Faculty of Engineering Diponegoro University Semarang Indonesia Smart Materials Research Center Diponegoro University Semarang Indonesia

Carbon dots materials (CDs) have the capability in the management of medical waste problem because of its advantage in the detection and degradation of pollutants. The synthesized CDs through various processes and raw materials have been applied to medical wastes, especially antibiotics such as tetracycline (TC), amoxicillin (AMX), para-Nitrophenol (p-NP), doxycycline (DC), ciprofloxacin (CIP), and oxytetracycline (OTC). These antibiotics are detected by utilizing changes in the luminescence property of CDs from the turn-off and turn-on mechanisms. Afterward, the degradation process is conducted using CDs as support materials agent semiconductors in the photosynthesis scheme. In general, CDs can be referred to as multifunction smart materials with the ability to detecting the presence of the antibiotics in simple, sensitive, and selective ways, and potency of medical pollutant removal clearly and effectively. © The Authors, published by EDP sciences, 2020.

关键词： Antibiotics

来源：评论

学校读者我要写书评

暂无评论

Chemical and Structural Analysis of Graphene Oxide Reduced with Naringenin: A Natural Product-Based Alternative

引用

Journal of materials Research and Technology 2025年

作者： Antonio Augusto Martins Pereira Junior Filipe Kayodè Felisberto dos Santos Filipe de Almeida Araújo Odilon Souza Leite-Barbosa Leandra Altoé Valdir Florêncio da Veiga Junior Higher School of Engineering Technology and Innovation University of the Federal District Professor Maia Nunes Brasília 70.635-815 Brazil Chemical Engineering Section Military Institute of Engineering Rio de Janeiro 22.290-270 Brazil Postgraduate Program in Materials Science and Engineering Federal University of São Carlos São Carlos 13.565-905 Brazil Postgraduate Program in Materials Science and Engineering Military Institute of Engineering Rio de Janeiro 22.290-270 Brazil Department of Engineering and Technology Federal University of Espírito Santo São Mateus 29932-540 Brazil

Regarding the reduction of graphene oxide (GO), which is usually carried out by conventional methods, which brings with it technical problems and socio-environmental concerns related to the use of hazardous chemical compounds, such as hydrazine and sodium borohydride, to avoid these risks, in this work, a new and safer approach is reported for the preparation of RGO based on naringenin, a natural flavonoid found in citrus residues, being used as a green reducing agent. Morphological analysis via SEM revealed a veil-like structure with fewer wrinkles and agglomerates in RGO/naringenin samples. XRD analysis showed the disappearance of the GO peak at 10° and the emergence of a broad shoulder around 26°, indicating partial restoration of graphitic domains. FTIR spectra indicated a significant decrease in O–H and C=O bands, consistent with removal of oxygen-containing groups. Raman analysis demonstrated a reduction in structural defects, with the ID/IG ratio decreasing from 1.03 (GO) to 0.93 (RGO/naringenin). TGA results showed improved thermal stability, with an increase in residual mass from 26.6% (pure RGO) to 34.1% (RGO/naringenin). DSC analysis corroborated these findings by displaying milder exothermic events. These results confirm the efficacy of naringenin as a sustainable and efficient reducing agent for RGO production.

关键词： Graphene Naringenin Green Chemistry Reduced Graphene Oxide Sustainability

来源：评论

学校读者我要写书评

暂无评论

Investigation of a novel biocide material for biocorrosion in simulated seawater: A case study on Tinospora cordifolia extract

引用

Case Studies in Chemical and Environmental engineering 2024年 10卷

作者： Royani, Ahmad Hanafi, Muhammad Aigbodion, Victor Sunday Prastya, Muhammad Eka Verma, Chandrabhan Mubarak, Nabisab Mujawar Alfantazi, Akram Manaf, Azwar Research Center for Metallurgy National Research and Innovation Agency – BRIN Kawasan Puspiptek Banten Tangerang Selatan 15314 Indonesia Postgraduate Program of Materials Science Study Department of Physics Faculty of Mathematics and Natural Sciences Universitas Indonesia Depok 16424 Indonesia Research Center for Pharmaceutical Ingredients and Traditional Medicine National Research and Innovation Agency – BRIN Kawasan Puspiptek Banten Tangerang Selatan 15314 Indonesia Department of Metallurgical and Materials Engineering University of Nigeria Nsukka 410001 Nigeria Department of Chemical and Petroleum Engineering Khalifa University of Science and Technology P.O. Box 127788 Abu Dhabi United Arab Emirates Petroleum and Chemical Engineering Faculty of Engineering Universiti Teknologi Brunei Bandar Seri Begawan BE1410 Brunei Darussalam Department of Biosciences Saveetha School of Engineering Saveetha Institute of Medical and Technical Sciences Chennai India

This case report investigates the preventive effect of Tinospora cordifolia extract on biocorrosion induced by Pseudomonas aeruginosa on mild steel API 5L in the simulated seawater medium. Electrochemical techniques, spectroscopic techniques, and surface analysis were employed to investigate biocide performance and corrosion behavior. P. aeruginosa has been shown to enhance iron dissolution in seawater medium. These findings point to the role of P. aeruginosa bacteria in forming differential oxygen, which causes corrosion. Morphology results from atomic Fourier microscopy (AFM) highlight the presence of P. aeruginosa in biotic environments, where the surface is rougher than in abiotic conditions. On the other hand, adding T. cordifolia to the biotic medium resulted in a smoother and more homogeneous surface without any significant deterioration. Electrochemical findings reveal that adding 300 mg L⁻¹ of T. cordifolia extract prevents the microbiologically influenced corrosion (MIC) of steel API 5L, with an optimum effectiveness value of 74.50 % after 21 days of incubation. This protective effect is caused by forming a more compact iron oxide surface layer and the adsorption of phenolic active compounds such as Moupinamide and others on the surface of mild steel API 5L, as detected by liquid chromatography-mass/spectrometry-mass spectrometry (LCMS-MS), Fourier-transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FE-SEM) techniques. © 2024 The Authors

关键词： Bio-corrosion Biofilm Green biocide Plant extract Pseudomonas aeruginosa Tinospora cordifolia

来源：评论

学校读者我要写书评

暂无评论

X-Ray Induced Degradation During Xps Analysis of Dicarboxylic Acid Powders

SSRN

引用

SSRN 2023年

作者： Ferreira, José Mario Trindade, Gustavo F. Simonelli, George de Moraes Pires, Carlos Augusto Da Silva, Ana Cristina Morais Rossi, Jesualdo Luiz dos Santos, Luiz Carlos Lobato Johnson, Patrick Alfred Department of Materials Science and Engineering Iowa State University AmesIA50011 United States Faculty of Engineering and Physical Sciences University of Surrey SurreyGU2 7XH United Kingdom National Physical Laboratory Middlesex TeddingtonTW11 0LW United Kingdom Chemical Engineering Postgraduate Program Federal University of Bahia 40210-630 Brazil Nuclear and Energy Research Institute - IPEN São Paulo05508-000 Brazil University of Wyoming United States

It is widely recognized that exposure to X-rays during XPS analysis can decompose different materials, resulting in mass loss and changes in chemical composition. These effects are evident in the near-edge X-ray absorption structure spectra of dicarboxylic acid powders, posing a fundamental limit to sensitivity for surface chemical analysis. Understanding the chemistry and kinetics of radiation decomposition is necessary for the accuracy and validation of XPS analysis on dicarboxylic acids. Here we evaluate the impact of X-ray exposure on characterizing chemical changes in three different dicarboxylic acids with varying aliphatic carbon chain lengths. From this investigation we propose straightforward correlations relating the tendency for radiation-induced decomposition based on the chemical structure of the acids. We employed two types of spectra, those acquired with minimal interaction (snapshot) and high-resolution spectra obtained over an extended period, to show that normal analysis conditions are likely to degrade these type of materials. © 2023, The Authors. All rights reserved.

关键词： X ray photoelectron spectroscopy

来源：评论

学校读者我要写书评

暂无评论

Colorimetric changes in two radial positions caused by wood-decaying fungi in wood of seven eucalypt species

引用

Southern Hemisphere Forestry Journal 2025年第1-2期87卷

作者： Pedro Nicó de Medeiros Neto Juarez Benigno Paes João Gabriel Missia da Silva Fabricio Gomes Gonçalves Daniela Minini Libânia da Silva Ribeiro Fernanda Dalfiôr Maffioletti 1 Academic Unit of Forestry Engineering Federal University of Campina Grande Patos Paraíba Brazil 2 Department of Forest and Wood Science Federal University of Espírito Santo Jerônimo Monteiro Espírito Santo Brazil 3 Postgraduate Program in Forest Sciences Federal University of Espírito Santo Jerônimo Monteiro Espírito Santo Brazil 4 Postgraduate Program in Forestry Engineering Federal University of Paraná Curitiba Paraná Brazil 5 Postgraduate Program in Materials Science and Engineering Federal University of Campina Grande Campina Grande Paraíba Brazil

This research aimed to determine the colorimetric alterations of the wood of seven eucalypt species caused by fungal decay in two positions in the pith–bark direction (median heartwood and transition region, containing the heartwood and sapwood), during wood exposure to agents that cause deterioration. Two 12-year-old trees were randomly sampled for each species, from which a 2.20 m log was removed from the first basal section of each tree for biological assays with brown and white rot fungi and measurements of colorimetric variables. As a sampling strategy for the assays, two positions were evaluated in the pith–bark direction (1 = median heartwood and 2 = heartwood and sapwood transition region). The data analysis used theFtest from analysis of variance (ANOVA) and the Scott–Knott test to compare means (p< 0.05). Regarding eucalypt species, the greatest mass loss caused by the fungusRhodonia placentawas in the wood ofEucalyptus grandis(38.13%) in the median heartwood position, which also occurred with the fungusGloeophyllum trabeum, with mass loss of 24.76%. The wood fromE. pellitawas less susceptible to colorimetric alteration of the wood in the median heartwood (6.29), followed by wood fromE. saligna(8.51) andE. robusta(7.42). The correlations related to the colorimetric variation resulting from the fungal attack showed that only the attack caused byGloeophyllum trabeumdid not show a relationship between the change in wood colour and the mass loss values.

关键词： biological assays colour variation mass loss

来源：评论

学校读者我要写书评

暂无评论

Effect of dual modification on structural, functional and dielectric properties of cassava starch

Food Physics

引用

Food Physics 2025年 2卷

作者： Cremasco, Paula Figueiredo M. Siqueira, Karine Mayuri Pistoni Sobral, Paulo José do Amaral Velloso, Walter Ferreira de Lima, César Gonçalves Gut, Jorge Andrey Wilhelms Moraes, Izabel Cristina Freitas Postgraduate Program in Materials Science and Engineering Faculty of Animal Science and Food Engineering University of São Paulo Avenue Duque de Caxias Norte São Paulo Pirassununga 13635900 Brazil Department of Biossistems Engineering Faculty of Animal Science and Food Engineering University of São Paulo Avenue Duque de Caxias Norte São Paulo Pirassununga 13635900 Brazil Department of Food Engineering Faculty of Animal Science and Food Engineering University of São Paulo Avenue Duque de Caxias Norte São Paulo Pirassununga 13635900 Brazil Food Research Center (FoRC) University of São Paulo Lake Street São Paulo São Paulo 05508-080 Brazil Departament of Basic Sciences Faculty of Animal Science and Food Engineering University of São Paulo Avenue Duque de Caxias Norte São Paulo Pirassununga 13635900 Brazil Department of Chemical Engineering Polytechnic School University of São Paulo Lake Street São Paulo São Paulo 05508-080 Brazil

The combined effect of hydrocolloid addition and microwave heating on the structural, physical and functional properties of cassava starch remains underexplored, despite individual studies on these modification methods. The dielectric properties, important for the microwave treatment of starch, have received little attention in recent studies. Cassava starch with and without addition of hydrocolloids (guar and xanthan gums) was modified by microwave heating for two different exposure times, and its structural, functional, and dielectric properties were studied. The dual modification enhanced the swelling power and oil holding capacity of the starch, reduced its gelatinization temperature, and did not alter its crystallinity. Notably, xanthan-modified starch microwaved for 6 min exhibited higher color variation (ΔE*) and increased granules agglomeration, while the microwave treatment alone roughened the surface of the starch granules. The mean diameters D[4,3] of starch increased with xanthan gum addition, microwave treatment (6 min), and their combination. The relative permittivity (ε’), loss factor (ε”) and penetration depth (D_p) were lower for samples modified by the combined method. Considering the type of hydrocolloid and the microwave exposure time, the combined modification significantly influenced the properties of starch, offering a promising approach to producing starch with enhanced functional properties. © 2024 KeAi Communications Co., Ltd

关键词： Biopolymers Cassava starch Guar Microwave Xanthan

来源：评论

学校读者我要写书评

暂无评论

Insights about defects in rare earth-doped Sr 4 Al 14 O 25 via a classical computational modelling approach

引用

Physica B: Condensed Matter 2025年 714卷

作者： Giordano Frederico da Cunha Bispo Adriano Borges Andrade Eduily Benvindo Vaz Freire Anderson Lira de Sales Santos Zélia Soares Macedo Marcos Vinicius dos Santos Rezende Mário Ernesto Giroldo Valerio Postgraduate Program in Materials Science and Engineering (P2CEM) Federal University of Sergipe 49107-230 São Cristovão SE Brazil Physics Department Federal University of Sergipe 49107-230 São Cristovão SE Brazil Postgraduate Program in Physics Campus Ministro Petrônio Portella Federal University of Piauí Teresina PI Brazil

Strontium aluminates doped and co-doped with rare earth ions (RE 3+ and RE 2+ ) have been extensively explored for their long-lasting afterglow properties. This study investigates the potential defects created by these dopants via classical computational modelling. In the first part, isovalent and aliovalent substitutions of RE 3+ were analysed, along with the resulting lattice strain caused by doping. The results showed that interstitial oxygen is the most energetically favourable charge compensation mechanism, except for Lu 3+ , Yb 3+ , Tm 3+ , and Er 3+ , which prefer isovalent substitution at the Al 3+ sites. The second part of the study examined possible mechanisms for RE 3+ → RE 2+ reduction, a key aspect that governs the long-lasting afterglow processes. Divalent ions exhibited a high possibility of reduction in the presence of CO which is consistent with experimental data on luminescent properties. Finally, the study focused on codoping systems with Eu 2+ and Dy 3+ , testing various reduction atmospheres and charge compensation mechanisms.

关键词：

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：