Enantioselective aerobic oxidative cross-dehydrogenative coupling …
Introduction The oxidative cross-dehydrogenative coupling (CDC) reaction has emerged rapidly as one of the most straightforward and atom-economical strategies for forming C–C bonds through the direct coupling of two C(sp3)–H bonds, as it does not require additional prefunctionalization of substrates, and thus largely reduces the number …
Thermal stability of ultrafine-grained aluminum in the …
For annealing temperatures up to 423 K, the microstructures of all four materials remained essentially unchanged by comparison with the as-pressed material shown in Fig. 1.However, annealing at 473 K gave a duplex microstructure of large and small grains in pure Al and the two Al–Mg alloys whereas in the Al–0.2%Zr alloy no large …
Pore Chemistry of Metal–Organic Frameworks
The pores in metal–organic frameworks (MOFs) can be functionalized by placing chemical entities along the backbone and within the backbone. This chemistry is enabled by the architectural, thermal, and chemical robustness of the frameworks and the ability to characterize them by many diffraction and spectroscopic techniques.
Chiral covalent organic frameworks for asymmetric catalysis …
Covalent organic frameworks (COFs), covalently assembled from the condensation reactions of organic building blocks, are a fascinating class of functional porous materials with two- or three-dimensional crystalline organic structures. Generally, it is preferable to use symmetric and rigid building blocks to construct highly crystalline COFs ...
Strength, grain refinement and solute nanostructures …
Two tensile test specimens with dimensions specified in Fig. 1 were machined from each disk using the electric discharge machining method. Tensile tests …
Microstructural characteristics of an ultrafine grain …
ELSEVIER Microstructural Characteristics of an Ultrafine Grain Metal Processed with Equal-Channel Angular Pressing Minoru ,* Zenji Horita/ …
Developing Ultrafine Grain Sizes Using Severe Plastic …
Z. Horita. Department of Materials Science and Engineering, Faculty of Engineering, Kyushu University, Fukuoka 812-8581 (Japan) ... [email protected]; Search for more papers by this author. M. , M. . Department of Technology, Fukuoka University of Education, Munakata, Fukuoka 811-4192 (Japan) Search for more …
Equal-channel angular pressing: A novel tool for …
3 Altmetric. Metrics. Abstract. The principles of equal-channel angular (ECA) pressing are reviewed. It is demonstrated that this processing procedure is capable of introducing an …
Metal-Organic Framework-Based Nanomaterials for Electrocatalysis
Metal-organic frameworks (MOFs) with high surface area and tunable chemical structures have attracted tremendous attention. Recently, there has been increasing interest in deriving advanced materials from MOFs for electrochemical energy storage and conversion.
Transparent films of metal-organic frameworks for
Transparent films of metal-organic frameworks for optical applications. Ultrasonication during layer-by-layer MOF film synthesis improves film quality. These MOF films are transparent and more homogenous with reduced surface roughness. These MOF films are suited for optical applications, e.g. as coatings and sensors.
Factors influencing microstructural development in …
Processing through the imposition of severe plastic deformation (SPD) provides an opportunity for achieving very significant grain refinement in bulk materials. Although …
Fabrication of bulk ultrafine-grained materials through
Ultrafine grain sizes were introduced into samples of an Al-3 pct Mg solid solution alloy and a cast Al-Mg-Li-Zr alloy using the process of equal-channel angular (ECA) pressing. The Al-3 pct Mg alloy exhibited a grain size of ∼0.23 µm after pressing at room temperature to a strain of ∼4, but there was significant grain growth when the pressed material was …
Structural evolution and the Hall-Petch relationship …
Acta mater. Vol. 45, No. 11, pp. 4751-S7, 1997 Acta Metallurgica Inc. Published by Elsevier Science Ltd Printed in Great Britain 1359-6454/97 $17.00 + 0.00 …
Achievement of Low Temperature Superplasticity in a Commercial
p.489 Home Materials Science Forum Materials Science Forum Vols. 447-448 Achievement of Low Temperature Superplasticity in... Achievement of Low Temperature Superplasticity in a Commercial Aluminium Alloy Processed by Equal-Channel Angular Extrusion
Robust bonding and one-step facile synthesis of tough …
The strength of the united bonding strongly depends on the preparation conditions. Fig. 2 shows the effect of the cross-linker density in the second polymerization on the peeling energy which is defined as the energy to create a unit fractured surface between the two bonded gel sheets. When no or little amount (0.001 mol%) of the cross-linker was used, …
Emerging Multifunctional Metal–Organic Framework Materials
Volume 28, Issue 40 p. 8819-8860. Review. Emerging Multifunctional Metal–Organic Framework Materials. Bin Li, Bin Li. Department of Chemistry, University of Texas at San Antonio, San Antonio, Texas, 78249 United States. Search for more papers by this author. Hui-Min Wen, Hui-Min Wen.
Comparative efficacy and acceptability of 21 antidepressant
Andrea Cipriani 1, Toshi A 2, Georgia Salanti 3, Anna Chaimani 4, Lauren Z Atkinson 5, Yusuke Ogawa 2, Stefan Leucht 6, Henricus G Ruhe 7, Erick H Turner 8, Julian P T Higgins 9, Matthias Egger 3, Nozomi Takeshima 2, Yu Hayasaka 2, Hissei Imai 2, Kiyomi Shinohara 2, Aran Tajika 2, John P A Ioannidis 10, John R …
Covalent Organic Frameworks: Structures, Synthesis, …
Covalent organic frameworks (COFs) are crystalline porous polymers formed by a bottom-up approach from molecular building units having a predesigned geometry …
Optimizing the rotation conditions for grain …
Authors and Affiliations. the Department of Materials Science and Engineering, Kyushu University, 812-8581, Fukuoka, Japan. Keiichiro Oh-Ishi (Research Associate), Zenji …
Equal-channel angular pressing of commercial aluminum …
Using equal-channel angular (ECA) pressing at room temperature, the grain sizes of six different commercial aluminum-based alloys (1100, 2024, 3004, 5083, 6061, and 7075) were reduced to within the submicrometer range. These grains were reasonably stable up to annealing temperatures of ∼200 °C and the submicrometer grains were retained in the …
Ambient aqueous-phase synthesis of covalent organic frameworks …
The development of a mild, low cost and green synthetic route for covalent organic frameworks (COFs) is highly desirable in order to open the door for practical uses of this new family of crystalline porous solids. Herein, we report a general and facile strategy to prepare a series of microporous or mesoporo Most popular 2019-2020 materials and …
Covalent Organic Frameworks: Structures, Synthesis, and …
Covalent organic frameworks (COFs) are crystalline porous polymers formed by a bottom-up approach from molecular building units having a predesigned geometry that are connected through covalent bonds.
Factors influencing microstructural development in equal …
Processing through the imposition of severe plastic deformation (SPD) provides an opportunity for achieving very significant grain refinement in bulk materials. Although different SPD procedures are available, the process of equal-channel angular pressing (ECAP) is especially attractive because it can be scaled easily to produce relatively large …
Grain Refinement of Aluminum using Equal-Channel Angular Pressing
M. , Z. Horita, M. Nemoto and T. G. Langdon in Proceedings of the International Symposium on Light Metals, edited by M Bouchard and A. Faucher (The Canadian Institute of Mining, Metallurgy and Petroleum, Montreal, Quebec, Canada, 1999), p. 583. Google Scholar
Review: Processing of metals by equal-channel …
Abstract. Equal-channel angular pressing (ECAP) is a processing method in which a metal is subjected to an intense plastic straining through simple shear without any corresponding …
The high-temperature creep properties of materials …
Processing through the application of severe plastic deformation (SPD) is now an accepted procedure for introducing very significant grain refinement into bulk solids. Typically, experiments show that the materials processed in this way have grain sizes in the submicrometer or even the nanometer range. This exceptional grain refinement provides …
Synthesis, Structure, and Metalation of Two New Highly …
The structure of MOF-525 was obtained by analysis of powder X-ray diffraction data. The structures of MOF-535 and -545 were resolved from synchrotron single-crystal data. MOF-525, -535, and -545 have Brunauer–Emmett–Teller surface areas of 2620, 1120, and 2260 m 2 /g, respectively. In addition to their large surface areas, both porphyrin ...
Unprecedented capacitive deionization performance of interconnected
The exploration of new carbon materials to overcome the rapid performance decay of common carbon materials in oxygenated saline water (i.e., natural saline water) is the biggest challenge for the industrial application of the capacitive deionization (CDI) technology.In this work, we first report the layer-by-layer motif synthesis of 3D …
Enhanced grain growth in an Al-Mg alloy with ultrafine grain …
ELSEVIER Materials Science and EnNneering A216 (1996) 41-46 MATERIALS SCIENCE & ENGINEERING A Enhanced grain growth in an AI-Mg alloy with ultrafine grain size Jingtao Wangla, Minoru 2'a, Zenji Horitaa, Minoru Nemotoa, Ruslan Z. Valievb, Terence G. Langdonc ~Departme~t of Materials Science and …
Principles of superplasticity in ultrafine-grained materials
where the diffusion coefficient, D, is equal to D gb for grain boundary diffusion, G is the shear modulus, b is the Burgers vector, k is Boltzmann's constant, the exponent of the inverse grain size, p, is ∼2, the stress exponent, n (=1/m), is ∼2 and A is a dimensionless constant having a value of ∼10 []. An important characteristic of the …