检索结果-内蒙古大学图书馆

SSRN 2023年

作者： Baraldi, Rafael Bispo da Silva, Douglas de Gouveia, Guilherme Lisboa Garcia, Amauri Spinelli, José Eduardo Department of Materials Engineering Federal University of São Carlos UFSCar SP São Carlos13565-905 Brazil Federal University of São Carlos Graduate Program in Materials Science and Engineering SP São Carlos13565-905 Brazil Department of Manufacturing and Materials Engineering University of Campinas SP Campinas13083-860 Brazil

Microstructures are the strategic link between cast alloys processing and their properties. The investigation of α-Al morphologies is regarded as critical for broadening the potential applications of cast Al-Ce alloys. These alloys are anticipated to offer high-temperature strength. Moreover, Ce is the most abundant rare-earth element in the Earth’s crust. A central task is changing the Ce content (4.0, 6.0 and 10.1 wt.% Ce) and observing the morphologies, particularly when extremely high cooling rates - 102 to 103 K/s - are attained during cast-centrifugal Cu-mold operations. In the present contribution, rapid solidification of the Al-4wt.% Ce alloy led to generation of high cooling rate cells. A eutectic mixture of Al11Ce3 fibers and lamellae filled the intercellular spacings. Using the Hunt-Lu model, an experimental cell spacing of roughly 6.3 μm was obtained with a suitable equivalence to the modeling outcomes, corresponding to a solidification velocity of 3.1 mm/s and a cooling rate of approximately 155 K/s. © 2023, The Authors. All rights reserved.

关键词： Cells

来源：评论

学校读者我要写书评

暂无评论

Flexible, charged biopolymers in monovalent and mixed-valence salt: Regimes of anomalous electrostatic stiffening and of salt insensitivity

引用

Physical Review E 2021年第1期104卷 014504-014504页

作者： Sarah N. Innes-Gold David R. Jacobson Philip A. Pincus Mark J. Stevens Omar A. Saleh Materials Department and Biomolecular Science and Engineering Program University of California Santa Barbara California 93106 USA

The conformations of biological polyelectrolytes (PEs), such as polysaccharides, proteins, and nucleic acids, affect how they behave and interact with other biomolecules. Relative to neutral polymers, PEs in solution are more locally rigid due to intrachain electrostatic repulsion, the magnitude of which depends on the concentration of added salt. This is typically quantified using the Odijk-Skolnick-Fixman (OSF) electrostatic-stiffening model, in which salt-dependent Debye-Hückel (DH) screening modulates intrachain repulsion. However, the applicability of this approach to flexible PEs has long been questioned. To investigate this, we use high-precision single-molecule elasticity measurements to infer the scaling with salt of the local stiffness of three flexible biopolymers (hyaluronic acid, single-stranded RNA, and single-stranded DNA) in both monovalent and mixed-valence salt solutions. In monovalent salt, we collapse the data across all three polymers by accounting for charge spacing, and find a common power-law scaling of the electrostatic persistence length with ionic strength with an exponent of 0.66±0.02. This result rules out simple OSF pictures of electrostatic stiffening. It is roughly compatible with a modified OSF picture developed by Netz and Orland; alternatively, we posit the exponent can be explained if the relevant electrostatic screening length is the interion spacing rather than the DH length. In mixed salt solutions, we find a regime where adding monovalent salt, in the presence of multivalent salt, does not affect PE stiffness. Using coarse-grained simulations, and a three-state model of condensed, chain-proximate, and bulk ions, we attribute this regime to a “jacket” of ions surrounding the PE that regulates the chain's effective charge density as ionic strength varies. The size of this jacket in simulations is again consistent with a screening length controlled by interion spacing rather than the DH length. Taken together, our results describ

关键词： Biomolecules Polyelectrolytes Single polymer chains

来源：评论

学校读者我要写书评

暂无评论

Strain-tuning of domain walls in multilayer graphene probed in the quantum Hall regime

引用

Physical Review B 2022年第8期105卷 L081408-L081408页

作者： Paul Anderson Yifan Huang Yuanjun Fan Sara Qubbaj Sinisa Coh Qin Zhou Claudia Ojeda-Aristizabal Department of Physics and Astronomy California State University Long Beach Long Beach California 90840 USA Department of Mechanical and Materials Engineering University of Nebraska Lincoln Nebraska 68588-0526 USA Department of Mechanical Engineering and Materials Science and Engineering Program University of California Riverside Riverside California 92521 USA

Domain walls, topological defects that define the frontier between regions of different stacking order in multilayer graphene, have proved to host exciting physics. The ability to tune these topological defects in situ in an electronic transport experiment brings a wealth of possibilities in terms of fundamental understanding of domain walls as well as for electronic applications. Here, we demonstrate, through a MEMS (microelectromechanical system) actuator and magnetoresistance measurements, the effect of domain walls in multilayer graphene quantum Hall effect. Reversible and controlled uniaxial strain triggers the topological defects, manifested as addtional quantum Hall effect plateaus as well as a discrete and reversible modulation of the current across the device. Our findings are supported by theoretical calculations and constitute indication of the in situ tuning of topological defects in multilayer graphene probed through electronic transport, opening the way for the use of reversible topological defects in electronic applications.

关键词： Domain walls Transport phenomena Graphene Resistivity measurements Tight-binding model

来源：评论

学校读者我要写书评

暂无评论

Novel spent bleaching earth industrial waste as low-cost ceramic membranes material: elaboration and characterization

引用

materials Today: Proceedings 2023年 87卷 136-140页

作者： Rahma A. Elma M. Roil Bilad M. Isnasyauqiah Rahman Wahid A. Sirajul Huda M. Resa Lamandau D. Doctoral Program of Environemntal Science Postgraduate Program Lambung Mangkurat University Jl Brigjen H. Hasan Basri Kayutangi South Kalimantan Banjarmasin 70123 Indonesia Materials and Membranes Research Group (M2ReG) Lambung Mangkurat University Jl A. Yani Km 36 South Kalimantan Banajrbaru 70714 Indonesia Chemical Engineering Department Engineering Faculty Lambung Mangkurat University Jl A. Yani Km 36 South Kalimantan Banajrbaru 70714 Indonesia Faculty of Integrated Technologies Universiti Brunei Darussalam Gedung BE1410 Brunei Darussalam

Ceramic membrane support derived from spent bleaching earth (SBE) become a novel study due to their low-cost, sustainable features, abundance material, and there is not yet applicated as membrane. In this study, flat disk ceramic membrane configuration was fabricated and characterized from solid waste of crude palm oil bleaching process by pressing method in different SBE loading mass (38–42 %wt.). The SBE as raw material was deoiled using n-hexane and acetone solvent, followed by fabricated it become flat disk SBE membranes. Afterward, the SBE flat disk membranes was characterized through fourier-transform infrared spectroscopy (FTIR) and X-ray fluorescence (XRF) analyzer. The result exhibits the flat disk SBE ceramic membrane has dimension of 41 and 6 mm for diameter and thickness, respectively. SBE membranes indicating have montmorillonite structure due to presence of silica as main component materials of SBE. Besides that, the existence of siloxane vibration band in SBE membranes for the sample after regeneration with n-hexane and acetone were dominated over using raw SBE. It concludes the oil residue was removed and produced SBE membrane properties become robust with less organic contaminant. © 2023

关键词： Ceramic membrane CPO Pressing method SBE Support

来源：评论

学校读者我要写书评

暂无评论

Unveiling Activated Carbon Degradation in Supercapacitor Using Liquid Cell Transmission Electron Microscopy

SSRN

引用

SSRN 2024年

作者： Tan, Daniel Q. Chen, Junyan Rao, Xinqiang Zhang, Fuming Ein-Eli, Yair Department of Materials Science and Engineering Guangdong Technion-Israel Institute of Technology 241 Daxue Road Shantou515063 China Department of Materials Science and Engineering Technion-Israel Institute of Technology Haifa3200003 Israel The Nancy and Stephen Grand Technion Energy Program Technion-Israel Institute of Technology Haifa3200003 Israel Guangdong Provincial Key Laboratory of Materials and Technology for Energy Conversion Guangdong Technion-Israel Institute of Technology 241 Daxue Road Shantou515063 China

Electrode stability critically impacts energy storage device performance, and despite theoretical recognition, directly observing the evolving electrode-electrolyte interface during the charge-discharge cycle of a supercapacitor remains challenging. This work directly addresses the technical gap by employing a liquid cell-assisted in-situ transmission electron microscopy. This innovative approach realizes real-time observation of the dynamic response of the activated carbon electrode during an electrical cycling of the supercapacitor cells. Driving the cell potential above a certain threshold potential during cycling leads to gas evolution that initiates cascade of events, causing the active carbon to disintegrate. This is being manifested in electrode’s mass loss and a rapid capacity decline upon further cycling. Nano-layer oxide coating of the activated carbon electrode using an atomic layer deposition effectively suppresses electrode-electrolyte reactions, stabilizing the electrode and improving the electrochemical properties. The first in-situ transmission electron microscope liquid cell design using an activated carbon substrate represents a breakthrough in understanding supercapacitors degradation, offering a working strategy for electrode dynamics investigation of various energy storage devices. © 2024, The Authors. All rights reserved.

关键词： Atomic layer deposition

来源：评论

学校读者我要写书评

暂无评论

Utilization of Pineapple Crown Fiber and Recycled Polypropylene for Production of Sustainable Composites

引用

Journal of Renewable materials 2020年第10期8卷 1327-1341页

作者： Alexandra Augusta Reichert Mariana Ribas de Sá Gabriela Escobar Hochmuller da Silva Cesar Augusto Gonçalves Beatrice AndréRicardo Fajardo Amanda Dantas de Oliveira Postgraduate Program in Materials Science and Engineering(PPGCEM) Federal University of Pelotas(UFPel)Pelotas96075-630Brazil Technology Development Center(CDTec) Materials EngineeringFederal University of Pelotas(UFPel)Pelotas96075-630Brazil Postgraduate Program in Materials Science and Engineering(PPGCEM) Federal University of São Carlos(UFSCar)São Carlos13565-905Brazil Laboratory of Technology and Development of Composites and Polymeric Materials Federal University of Pelotas(UFPel)Pelotas96010-900Brazil

Nowadays,the production of consumer goods is based on the use of non-renewable raw materials,which in recent years has been performing as a problem for the *** the large number of available biofibers in nature,their use in the development of polymeric composites has inevitably emerged,it is also necessary to take into account the countless discarded plastics that still have the potential to be *** this work,fibers were extracted from pineapple crown residues and utilized to compose sustainable composites using recycled polypropylene from cups discarded in the trash as a ***,it is known that for good performance,it is necessary to achieve a good chemical interaction between the fiber and the *** order to improve this interaction,alkaline mercerization treatment was carried out on the surface of the fibers removing some components incompatible with the *** this work,the effect of the mercerization treatment on the properties of the fibers was studied,as well as their interaction with the *** effect of fiber concentration on the mechanical and thermal properties of composites was also *** of 5 and 7 wt%were used for both natural and mercerized fibers.A decrease in the number of degradation stages was observed through thermogravimetry analyses(from four in natural fiber to two in mercerized fibers),showing that the mercerization performed on the fibers was *** increase in the degree of crystallinity of mercerized fibers was also observed through the results of X-ray *** techniques indicate that amorphous compounds,such as hemicellulose and lignin,were partially *** the tensile test,it could be noted that all composites presented higher values of de elastic modulus than recycled polypropylene without added load;however,there were no differences in the elastic modulus between the different types of fibers and load ***,it is interesting to use fibers as r

关键词： Recycling composites polypropylene biofibers pineapple crown

来源：评论

学校读者我要写书评

暂无评论

Methods of Printing Copper for PCB Repair

Methods of Printing Copper for PCB Repair

引用

Electronic Components and Technology Conference (ECTC)

作者： Dylan J. Richmond Emuobosan Enakerakpo Mohammed Alhendi Peter McClure Mark D. Poliks Materials Science &#x0026 Engineering Program Binghamton University Binghamton NY Department of Systems Science Industrial Engineering Binghamton University Binghamton NY Universal Instruments Corporation Conklin NY

Damage and defects that occur in printed circuit board assembly (PCBA) often lead to the disposal of expensive components. In cases where laminate and circuitry have been removed, traditional repairs in the manufacturing process have not been able to return devices into service. This study examines the use of aerosol jet printing (AJP) and traditional engineering fluid dispensing (EFD) as methods to service repairs of damaged *** mount component failures on PCBAs may occur as a result of a bad solder joint or problems with the component. In order to salvage such a PCBA, the component must be physically removed from the board and a new be attached. During the removal of PCBA components, pad cratering may occur, where the pad and laminate are damaged/removed along with the component. This leaves behind a crater in place of the pad, rendering the board unrepairable and thus, unusable. Trace damage is another common failure in PCBs. A repair to either sort of damage often requires reconnections of intricate circuitry to be made. Trace repair has traditionally been serviced by soldering a wire between the undamaged regions, rerouting the connection. In the case of fine conductive traces, as seen in devices which are becoming smaller as heterogeneous packaging innovations continue to progress, traditional methods will not be able to service this sort of *** jet printing, a direct-write additive manufacturing process commonly used in flexible hybrid electronics, could save expensive PCBs by repairing cratered pads and damaged traces. The use of AJP has been successful in repairing damaged modules, however the process has not been optimized for general repairs on FR4. The use of AJP and EFD to repair damaged circuitry on FR4 laminate and to fill pad craters with copper nanoparticle ink is demonstrated. Copper ink structures are uniformly sintered to achieve a solderable surface and good adhesion to the exposed laminate and remaining copper on the PCB. P

关键词：

来源：评论

学校读者我要写书评

暂无评论

Optimization of Printing Parameters for Printing of Ordinary Portland Cement using a Custom-made 3D Printer 21

Optimization of Printing Parameters for Printing of Ordinary...

引用

21st International Union of materials Research Societies International Conference in Asia, IUMRS-ICA 2021

作者： Chaiyotha, D. Pinitsoontorn, S. Chindaprasirt, P. Payakaniti, P. Materials Science and Nanotechnology Program Department of Physics Faculty of Science Khon Kaen University Khon Kaen40002 Thailand NANOTEC -KKU RNN on Nanomaterials Research and Innovation for Energy Khon Kaen University Khon Kaen40002 Thailand Sustainable Infrastructure Research and Development Center Department of Civil Engineering Faculty of Engineering Khon Kaen University Khon Kaen40002 Thailand

3D printing techniques have recently received a lot of attention as a new technique for forming construction materials, due to benefits over the traditional cast. In this research, ordinary Portland cement (OPC) paste was formed using a 3D extruder. Optimized mixture and printing parameters were determined. Compressive strengths of the printed and the traditionally casted OPC paste were measured after the specimens were cured in saturated limewater for 7, 14 and 28 days, respectively. The result led to the conclusion that the most suitable mixture for printing was achieved at the water to cement ratio of 0.35 with water reducing and retarding admixture added. The optimum printing parameters were the printing speed of 60 mm/min and the feed rate of 120 ml/s. Compressive strength of the 5 x 5 x 5 cm3 hollowed and filled cubic printed specimens, were compared with casted cement paste. The strengths of both the printed and the casted specimens were higher with longer curing durations. The highest levels of strength were achieved at 12.36 MPa on the printed specimens and 80.88 MPa when testing the casted samples. © Published under licence by IOP Publishing Ltd.

关键词： 3D printers

来源：评论

学校读者我要写书评

暂无评论

A robust bendable IrO_x thin film via mild alkaline solution process for neuron stimulating electrodes

引用

Surfaces and Interfaces 2024年 44卷

作者： Tso, Kuang-Chih Chan, Tzu-Ying Yu, Tsung-Chun Tao, Yu-Jen Chu, Chao-Yi Chen, San-Yuan Lee, Jyh-Fu Ohta, Jun Chen, Po-Chun Wu, Pu-Wei Graduate Program of Accelerator Light Source National Yang Ming Chiao Tung University Hsinchu 300 Taiwan Division of Materials Science Graduate School of Science and Technology Nara Institute of Science Technology Nara Ikoma Takayama 8916-5 Japan Department of Materials Science and Engineering National Yang Ming Chiao Tung University Hsinchu 300 Taiwan Institute of Materials Science and Engineering National Taipei University of Technology Taipei 106 Taiwan National Synchrotron Radiation Research Center Hsinchu 300 Taiwan

We demonstrate a unique chemical formula to deposit hydrous iridium oxide thin film on a platinum-coated polyimide substrate. In a mild alkaline solution, the iridium (III) precursor undergoes the ligand exchange and hydrolysis reaction to become the iridium (III) dimers that are physically adsorbed on the substrate for subsequent heterogeneous condensation and growth of amorphous hydrous iridium oxide thin film. Both UV–Vis and X-ray absorption spectroscopy (XAS) are employed to determine the reaction steps involved. The chemical nature and crystallinity of the hydrous iridium oxide thin film are investigated by XAS, X-ray photon spectroscopy, and X-ray diffraction. The hydrous iridium oxide thin film reveals an impressive normalized charge storage capacity (CSC) of 0.3 mC/cm²-nm and a low impedance (80.5 Ω) at 1k Hz. In addition, in bending test of 3,000 cycles, the hydrous iridium oxide thin film retains 91.2 % of its initial normalized CSC without any physical crack and delamination. The cell viability test suggests negligible bio-toxicity. Our results provide a solid evidence of fabricating a robust flexible electrode for neural interfaces for potential use in implantable electronic devices. © 2023 Elsevier B.V.

关键词： Bio-electrode Flexible substrate Implantable electronic devices Iridium dimers Iridium oxide Polyimide

来源：评论

学校读者我要写书评

暂无评论

Efficient copper plating on glass substrates through amine-functionalized nanocomposite-immobilized silver nanoparticles

引用

Colloids and Surfaces A: Physicochemical and engineering Aspects 2024年 688卷

作者： Chiang, Tang-Lun Cheng, An-Yu You, Jhu-Lin Chang, Chang-Pin Ger, Ming-Der School of Defense Science Chung Cheng Institute of Technology National Defense University Taoyuan335 Taiwan Department of Chemical & Materials Engineering Chung Cheng Institute of Technology National Defense University Taoyuan335 Taiwan System Engineering and Technology Program National Chiao Tung University Hsinchu300 Taiwan

Amine-functionalized silver nanocatalyst was synthesized using polyethyleneimine (PEI) and glutaraldehyde (GA) and applied to electroless copper on the glass substrate. The formation mechanism of the polyethyleneimine-glutaraldehyde (PEI-GA) was firstly analyzed, then the polyethyleneimine-glutaraldehyde-silver (PEI-GA-Ag) was measured, which showed that the silver nanoparticles (AgNPs) were spherical with an average size of about 5 nm and a narrow particle distribution, and PEI-GA-Ag was analyzed by UV-Vis to demonstrate the synthesized AgNPs were uniformly dispersed and stable without agglomeration for a period of 10 months. The application of PEI-GA-Ag nanocomposite in the glass metallization process resulted in the formation of a complete, uniform copper layer on grit-blasted glass, which passed adhesion tests successfully without flaking. After 10 mins of electroless copper plating, the thickness of the copper layer is approximately 1 µm, displaying a sheet resistance of 0.018 Ω/square, and the resistivity is 1.8×10−6 Ωcm, which is close to that of a bulk copper. This proposes that PEI-GA-Ag has excellent stability and catalytic efficiency and can be effectively used in electroless plating processes to replace conventional expensive palladium colloid catalysts. © 2024 Elsevier B.V.

关键词： Silver nanoparticles

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：