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Archive for April, 2009



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Valuation of Ecosystem Services in Institutional Context

Lowell Pritchard Jr.,
Carl Folke,
and Lance Gunderson
INTRODUCTION
As long as we are forced to make choices, we are
doing valuation. But different approaches to valua-
tion are based on qualitatively different assump-
tions. For example, the economics approach to
valuation is based on the ethical principle of con-
sumer sovereignty, and it privileges the kinds of
decisions individuals make in the marketplace. We
accept the economics approach as a useful partial
approach to decision making in relation to ecosys-
temservices if one is interested in what people think
about and want from services; if one believes that
human preferences are the basis for the value of
services; if one accepts the assumption that adding
individual …

Macroscopic 10-Terabit arrays

Soojin Park,
Dong Hyun Lee,
Ji Xu,
Bokyung Kim,
Sung Woo Hong,
Unyong Jeong,
Ting Xu,
Thomas P. Russell
Generating laterally ordered, ultradense, macroscopic arrays of nanoscopic elements will
revolutionize the microelectronic and storage industries. We used faceted surfaces of commercially
available sapphire wafers to guide the self-assembly of block copolymer microdomains into
oriented arrays with quasi–long-range crystalline order over arbitrarily large wafer surfaces.
Ordered arrays of cylindrical microdomains 3 nanometers in diameter, with areal densities in
excess of 10 terabits per square inch, were produced. The sawtoothed substrate topography
provides directional guidance to the self-assembly of the block copolymer, which is tolerant of
surface defects, such as dislocations. The lateral ordering and lattice orientation …

Effects of Mismatch Strain and Alloy Composition on the Formation of InAs Islands on InAlAs Templates

Y. CORDIER,
1,3 P. MISKA,
1 and D. FERRE2
1.—Institut d’Electronique et de Microélectronique du Nord, U.M.R.-C.N.R.S 8520,
Avenue Poincaré, Université de Lille 1, BP 69, 59652 Villeneuve d’Ascq Cedex, France.
2.—Laboratoire Structure et Propriétés de l’Etat Solide, URA 234, Université de Lille 1,
59650 Villeneuve d’Ascq, France. 3.—e-mail: yvon.cordier@iemn.univ-lille1.fr
InAs islands self-assembled on InAlAs layers lattice mismatched on GaAs
substrates have been grown by molecular beam epitaxy. Both pseudomorphic
and metamorphic InAlAs buffer layers were used as a template to investigate the
effects of strain relaxation on the formation of the islands. The effect of alloy
composition in the metamorphic templates is shown on the density and the shape
of …

Low temperature step-graded InAlAs/GaAs metamorphic buffer layers grown by molecular beam epitaxy

X Z Shang1,3
,SDWu2
, C Liu1
,WXWang2
, LWGuo2
, Q Huang2
and J M Zhou2
1
School of Physics and Technology, Wuhan University, Wuhan 430072, Hubei, People’s
Republic of China
2
State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of
Sciences, Beijing 100080, People’s Republic of China
E-mail: xunzhong@acc-lab.whu.edu.cn
Received 8 December 2005
Published 20 April 2006
Online at stacks.iop.org/JPhysD/39/1800
Abstract
Low-temperature step-graded InAlAs metamorphic buffer layers on GaAs
substrate grown by molecular beam epitaxy were investigated. The strain
relaxation and the composition of the top InAlAs layer were determined by
high-resolution triple-axis x-ray diffraction measurements, which show that
the top InAlAs layer is nearly fully relaxed. Surface morphology was
observed by reflection high-energy electron diffraction pattern and …

Oxide Nanoelectrolics

Cheng Cen,
Stefan Thiel,
Jochen Mannhart,
Jeremy Levy
Electronic confinement at nanoscale dimensions remains a central means of science and
technology. We demonstrate nanoscale lateral confinement of a quasi–two-dimensional electron
gas at a lanthanum aluminate–strontium titanate interface. Control of this confinement using an
atomic force microscope lithography technique enabled us to create tunnel junctions and field-effect
transistors with characteristic dimensions as small as 2 nanometers. These electronic devices can be
modified or erased without the need for complex lithographic procedures. Our on-demand
nanoelectronics fabrication platform has the potential for widespread technological application.

Sedimentation processes and new age constraints on rifting stages in Lake Baikal: results of deep-water drilling

Abstract With this paper we present a first attempt to
combine the direct results on lithology, composition
and age dating in the boreholes BDP-93, BDP-96 and
BDP-97 with geological and seismic data from the areas
where those sections were drilled. The sedimentary
environments represented by the BDP boreholes are
markedly different and possess characteristic litholog-
ical features. The results of the deep drilling provide
the essential means for testing …

Hypothesis for Cretaceous rifting of east Gondwana caused by subducted slab capture

Bruce P. Luyendyk Institute for Crustal Studies and Department of Geological Sciences, University of California,
Santa Barbara, California 93106-1100
ABSTRACT
In the process of subducted slab capture, a spreading ridge approaches subparallel to
a subduction zone following the trailing edge of a downgoing plate. Eventually the down-
going plate is too young and small to subduct, and spreading stops. The spreading ridge
stalls many tens of kilometres outboard of the subduction zone. The subducted plate welds
to the outboard plate across the dormant spreading center and is captured by it. The
captured plate then acquires the motion of the plate it welded to. In the southwest Pacific
the Pacific-Phoenix …

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