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991.
Amphiphilic block copolymers are synthesized by sulfonation of poly(styrene-b-methyl methacrylate) (PS-b-PMMA) using acetyl sulfate, and are blended with poly(vinylidene fluoride) (PVDF) to prepare a new proton exchange membrane, in which PMMA is miscible with PVDF. The morphology and the transport properties of the membranes are investigated as functions of the degree of sulfonation as well as the blend ratio. Notable transition of phase-separated morphology is observed as the PVDF content of the blend is increased. Both the proton conductivity and the ion-exchange capacity (IEC) of the membrane increase with increasing the degree of sulfonation of PS-b-PMMA, and they are also enhanced as the phase-separated domains of blend membrane are well-ordered. Unlike the Nafion membrane, the proton conductivity of the blend membrane increases up to 90 °C, indicating the blend membrane shows better thermal stability than the Nafion membrane. 相似文献
992.
Alterations in the gastrointestinal neuromuscular function related to age have been demonstrated in human and animal models. This study analyzes the effects of the aging process on the area of the neuronal cell bodies of the myenteric plexus in the antimesenteric and intermediate regions of the ileal circumference of Wistar, 12 month-old in comparison 3 month-old animals. The ileum was removed and whole-mount preparations immunostained by the antibody anti-myosin-V were processed. The morphometric analyses were performed using a computerized image analysis system, with a subsequent distribution of neurons by size in intervals of 100 micro2. The cellular body morphometry revealed a significant increase in the size of the myosin-V- immunoreactive myenteric neurons from 12 month-old animals when compared with 3 month-old animals. However, significant differences between the regions were not observed; these observations were not age-dependent. The implications of these results in relation to the increase of the body weight, size of the small intestine, general organization of the myenteric plexus, staining method of neurons and the possible factors involved in the regulation and/or control of the volume of neronal cells due to aging, are discussed. 相似文献
993.
de Oliveira João Paulo Lima Santana Alexandre J. Stelmastchuk Simão N. 《Journal of Dynamical and Control Systems》2022,28(2):423-437
The purpose of this paper is to present explicitly the solution curve for commutative affine control systems on Lie groups under the assumption that the automorphisms associated with the linear vector fields commutes. If we assume that the derivations associated with the linear vector fields of the system are inner, we obtain a simpler solution and we show some results of controllability. To finish, we work with conjugation by homomorphism of Lie groups between affine systems.
相似文献994.
Jo Min Cheol Kim Selim Park Hyung Keun Hong Sung Suk Kim Hong Kyu Kim Hyoung Seop Lee Sunghak 《Metallurgical and Materials Transactions A》2020,51(7):3384-3391
Metallurgical and Materials Transactions A - Formation possibilities of adiabatic shear bands (ASBs) or cracks in two commercial ultra-high-strength armor steels composed of martensite were... 相似文献
995.
Intelligent Service Robotics - Advances in reinforcement learning algorithms allow robots to learn complex tasks such as object manipulation. However, most of these tasks have been implemented only... 相似文献
996.
997.
Victor Hugo De Oliveira João Mário Santos de França Francisco Mário Viana Martins 《Papers in Regional Science》2020,99(4):1019-1043
Using data from the Damage Assessment Reports from the Civil Defence, the current study investigates the relationship between the damage caused by natural disasters and local development at the municipality level in Ceará state, Brazil. The results show that a better urban and water supply infrastructure, a lower population density, and a higher proportion of own revenues relative to total revenues are associated with smaller disaster damage. However, economic development in terms of GDP per capita exhibits a convex relationship with the impact of natural disasters across municipalities, reflecting the potential decreasing returns of preventive investments due to the highly hazardous environment that involves municipalities. 相似文献
998.
Flavien Contarato Murielle Bach Joël Krier Anne Gobled Pierre Mille 《International Journal of Applied Ceramic Technology》2020,17(3):990-997
In the context of the assembly of a cutting tool for wood machining, this article proposes to evaluate the residual stress in a ceramic plate (Al2O3-ZrO2) induced by a brazing step with a cemented tungsten carbide (WC-Co) through a brazing filler (Ag-Cu-Ti). The residual stresses were evaluated using neutron and X-ray diffraction method. Moreover, a mathematical model was used in the case of a three layer assembly, which is based on mechanical properties such as: the thermal coefficient, the Young's modulus, the Poisson's ratio and the thickness of each layer. The observation of the chemical mapping of the brazing filler before and after the assembly, using energy dispersive X-ray spectroscopy (EDX), showed the chemical migration of the titanium to the ceramic oxide and the tungsten carbide. It was estimated that the brazed assembly is under a flexural stress, with a maximum in a compressive stress area near the brazing joint which reaches 85.6 MPa. This stress value reaches 12% of the bending strength allowed by the ceramic (716 MPa). The discussion proposes to highlight the limits of each method. The mathematical model has however shown good accuracy to give a first estimated residual stress in the ceramic plate. 相似文献
999.
Silva João Sousa e Gonçalves Ramiro Branco Frederico Pereira António Au-Yong-Oliveira Manuel Martins José 《Universal Access in the Information Society》2019,18(3):703-716
Universal Access in the Information Society - Equal access to all software and digital content should be a reality in the Digital Era. This argument is something defended both by existing... 相似文献
1000.
de Freitas Veneroso João Mateus Dias Marlon Ueda Alberto Ribas Sabir Ribeiro-Neto Berthier Ziviani Nivio de Souza e Silva Edmundo 《Scientometrics》2019,121(3):1269-1291
Scientometrics - The notions of reputation and popularity in academia are critical for taking decisions on research grants, faculty position tenure, and research excellence awards. These notions... 相似文献