Hasil untuk "Materials Science"

A. Bochevarov, Edward D Harder, Thomas F Hughes et al.

Jaguar is an ab initio quantum chemical program that specializes in fast electronic structure predictions for molecular systems of medium and large size. Jaguar focuses on computational methods with reasonable computational scaling with the size of the system, such as density functional theory (DFT) and local second-order Moller–Plesset perturbation theory. The favorable scaling of the methods and the high efficiency of the program make it possible to conduct routine computations involving several thousand molecular orbitals. This performance is achieved through a utilization of the pseudospectral approximation and several levels of parallelization. The speed advantages are beneficial for applying Jaguar in biomolecular computational modeling. Additionally, owing to its superior wave function guess for transition-metal-containing systems, Jaguar finds applications in inorganic and bioinorganic chemistry. The emphasis on larger systems and transition metal elements paves the way toward developing Jaguar for its use in materials science modeling. The article describes the historical and new features of Jaguar, such as improved parallelization of many modules, innovations in ab initio pKa prediction, and new semiempirical corrections for nondynamic correlation errors in DFT. Jaguar applications in drug discovery, materials science, force field parameterization, and other areas of computational research are reviewed. Timing benchmarks and other results obtained from the most recent Jaguar code are provided. The article concludes with a discussion of challenges and directions for future development of the program. © 2013 Wiley Periodicals, Inc.

A. Mahadevi, G. N. Sastry

N. Denzin, Y. Lincoln

A. Luque, S. Hegedus

T. Kimoto

S. Eliseeva, J. Bünzli

T. Ebbesen

Ton de Jong, M. Linn, Z. Zacharia

W. Callister

M. Trudeau

A. Pickering

R. Graham, D. Knuth, Or Patashnik

Marc A. Meyers, K. Chawla

Fully revised and updated, the new edition of this classic textbook places a stronger emphasis on real-world test data and trains students in practical materials applications; introduces new testing techniques such as micropillar compression and electron back scatted diffraction; and presents new coverage of biomaterials, electronic materials, and cellular materials alongside established coverage of metals, polymers, ceramics and composites. Retaining its distinctive emphasis on a balanced mechanics-materials approach, it presents fundamental mechanisms operating at micro- and nanometer scales across a wide range of materials, in a way that is mathematically simple and requires no extensive knowledge of materials, and demonstrates how these microstructures determine the mechanical properties of materials. Accompanied by online resources for instructors, and including over 40 new figures, over 100 worked examples, and over 740 exercises, including over 280 new exercises, this remains the ideal introduction for senior undergraduate and graduate students in materials science and engineering.

M. Madou

D. Miracle

A. Barabási, Maximino Aldana-Gonzales

D. Brunette, P. Tengvall, M. Textor et al.

H. Damme

X. Hou, Y. S. Zhang, G. Trujillo‐de Santiago et al.

Feifan Liu, Lun He, Lvlv Ji et al.

ABSTRACT Due to a positive standard reaction Gibbs free energy (ΔrGmθ) of 237.1 kJ mol−1, electric energy input is indispensable for hydrogen production by conventional electrochemical water splitting. This energy requirement can be reduced by replacing the anodic oxygen evolution reaction to thermodynamic favorable small‐molecules oxidation reactions. In this work, anodic formaldehyde oxidation reaction (FOR) in alkaline media was paired with cathodic hydrogen evolution reaction (HER) in acidic media to establish a thermodynamically downhill system. The utilization of electrochemical neutralization energy in a hybrid alkaline‐acidic electrolyte configuration enables a further decrease in ΔrGmθ. Therefore, the resulting hybrid alkaline‐acidic formaldehyde‐proton fuel cell (FPFC) exhibits a significantly reduced ΔrGmθ of −101.5 kJ mol−1. A bifunctional Ru‐doped Cu catalyst (Ru─Cu NTs@CM) was designed and synthesized to simultaneously promote the kinetics of acidic HER and alkaline FOR, demonstrating superior catalytic activity and durability to pristine Cu and Ru catalysts. This catalyst enabled concurrent bipolar H2 production and electricity generation from the assembled FPFC, reaching a peak power density of 18.3 mW cm−2 at 53.4 mA cm−2. A combination of (quasi) in situ characterizations and theoretical calculations unveiled the important mechanistic role of Ru‐doping in enhancing the Cu catalyst's activity and stability.