807 research outputs found
Interwar Innovation in Three Navies: U.S. Navy, Royal Navy, Imperial Japanese Navy
In 1919, three major naval powers—Great Britain, Japan, and the United States—faced two major challenges: integrating new technology into their doctrines and organizations, and coping with reduced naval expenditures and arms treaties that came as a postwar reaction to armaments spending
Innovation in Carrier Aviation
This study is about innovations in carrier aviation and the spread of those innovations from one navy to the navy of a close ally. The innovations are the angled flight deck; the steam catapult; and the mirror and lighted landing aid that enabled pilots to land jet aircraft on a carrier’s short and narrow flight deck.https://digital-commons.usnwc.edu/usnwc-newport-papers/1036/thumbnail.jp
The Development of the Angled-Deck Aircraft Carrier—Innovation and Adaptation
In the years immediately after World War II, three British innovations—the angled flight deck, steam catapult, and optical landing aid—enabled the modern aircraft carrier. How did the U.S. Navy take such quick advantage of them, and why were they not American innovations in the first place
A lattice model of hydrophobic interactions
Hydrogen bonding is modeled in terms of virtual exchange of protons between
water molecules. A simple lattice model is analyzed, using ideas and techniques
from the theory of correlated electrons in metals. Reasonable parameters
reproduce observed magnitudes and temperature dependence of the hydrophobic
interaction between substitutional impurities and water within this lattice.Comment: 7 pages, 3 figures. To appear in Europhysics Letter
Two-component generalizations of the Camassa-Holm equation
A classification of integrable two-component systems of non-evolutionary partial differential equations that are analogous to the Camassa-Holm equation is carried out via the perturbative symmetry approach. Independently, a classification of compatible pairs of Hamiltonian operators is carried out, which leads to bi-Hamiltonian structures for the same systems of equations. Some exact solutions and Lax pairs are also constructed for the systems considered
Formation energy and interaction of point defects in two-dimensional colloidal crystals
The manipulation of individual colloidal particles using optical tweezers has
allowed vacancies to be created in two-dimensional (2d) colloidal crystals,
with unprecedented possibility of real-time monitoring the dynamics of such
defects (Nature {\bf 413}, 147 (2001)). In this Letter, we employ molecular
dynamics (MD) simulations to calculate the formation energy of single defects
and the binding energy between pairs of defects in a 2d colloidal crystal. In
the light of our results, experimental observations of vacancies could be
explained and then compared to simulation results for the interstitial defects.
We see a remarkable similarity between our results for a 2d colloidal crystal
and the 2d Wigner crystal (Phys. Rev. Lett. {\bf 86}, 492 (2001)). The results
show that the formation energy to create a single interstitial is
lower than that of the vacancy. Because the pair binding energies of the
defects are strongly attractive for short distances, the ground state should
correspond to bound pairs with the interstitial bound pairs being the most
probable.Comment: 5 pages, 2 figure
A new dromaeosaurid (Dinosauria: Theropoda) from the Upper Cretaceous Wulansuhai Formation of Inner Mongolia, China
We describe a new dromaeosaurid theropod from the Upper Cretaceous Wulansuhai Formation of Bayan Mandahu, Inner
Mongolia. The new taxon, Linheraptor exquisitus gen. et sp. nov., is based on an exceptionally well-preserved, nearly
complete skeleton. This specimen represents the fifth dromaeosaurid taxon recovered from the Upper Cretaceous
Djadokhta Formation and its laterally equivalent strata, which include the Wulansuhai Formation, and adds to the known
diversity of Late Cretaceous dromaeosaurids. Linheraptor exquisitus closely resembles the recently reported Tsaagan
mangas. Uniquely among dromaeosaurids, the two taxa share a large, anteriorly located maxillary fenestra and a contact
between the jugal and the squamosal that excludes the postorbital from the infratemporal fenestra. These features suggest
a sister-taxon relationship between L. exquisitus and T. mangas, which indicates the presence of a unique dromaeosaurid
lineage in the Late Cretaceous of Asia. A number of cranial and dental features seen in L. exquisitus and T. mangas, and
particularly some postcranial features of L. exquisitus, suggest that these two taxa are probably intermediate in
systematic position between known basal and derived dromaeosaurids. The discovery of Linheraptor exquisitus is thus
important for understanding the evolution of some salient features seen in the derived dromaeosaurids
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