bluuebunny/crossref_metadata_2025_split huggingface dataset:
Confinement levels in SiGe quantum wells studied by charge spectroscopy
Authors: KaganFF Miron , Antonova Irina , Neustroev Efim , Smagulova Svetlana , Alekseev Pavel , Ray Samit , Sustersic Nathan , Kolodzey James 
Published: October 2009

AbstractQuantum confinement levels in SiGe quantum wells (QW) with different Ge contents were observed by means of charge deep‐level transient spectroscopy (Q‐DLTS) and transport measurements in the temperature range from 80 to 300 K. This turns out to be possible due to a passivation of structure surface with an organic monolayer. The confined levels became apparent through DLTS measurements as various activation energies in temperature dependence of the rate of carrier emission from the QW. It was found that the recharging of SiGe QWs and carrier emission accomplish due to thermo‐stimulated tunneling. The steps in the current‐voltage characteristics originated from direct tunneling via the confined states were found to determine the current flow at high fields. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of Ga(NAsP) lattice matched to Si
Authors: Karcher C. , Grüning H. , Güngerich M. , Klar P. J. , Kunert B. , Volz K. , Stolz W. , Heimbrodt W. 
Published: October 2009

AbstractIII/V semiconductors containing dilute amounts of N exhibit remarkable features such as a strong increase of the effective mass of the electrons, a huge red‐shift of the band gap compared to the host material and a weak pressure dependence of the PL band position. We examined these features by studying the affect of N incorporation onto the band formation of the alloys Ga(NAs) and Ga(NP). The dispersion‐free N‐related impurity band interacts in a repulsive way with the conduction band of the host material. The novel As‐rich Ga(NAsP) alloy exhibits both the electronic as well as the mechanical properties to serve as an active laser material for III/V integration onto Si substrates. We studied the optical properties by means of photoluminescence, excitation and modulation spectroscopy as well as pressure dependence. Energies of the interband transitions within the MQW have been successfully simulated by a type I QW calculation, yielding a CB to VB offset ration of about 1:2. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Surface morphology of indium phosphide grown on silicon by nano‐epitaxial lateral overgrowth
Authors: Junesand Carl , Olsson Fredrik , Xiang Yu , Gau Ming‐Horng , Lourdudoss Sebastian 
Published: October 2009

AbstractInP is grown on Si by nano‐epitaxial lateral overgrowth (NELOG or nano‐ELOG) on patterns consisting of net‐type openings under different growth conditions. Surface morphology is characterized with AFM and profilometer and optical quality assessed by Micro Photoluminescence measurements (μ‐PL). Results show that growth conditions affect both morphology and optical quality, with thicker layers generally corresponding to better surface morphology. Lower growth temperature seems to improve surface morphology irrespective of thickness, and ELOG layers exhibit significantly better morphology than the planar layer. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystal growth and p‐type conductivity control of AlGaN for high‐efficiency nitride‐based UV emitters
Authors: Mori T. , Nagamatsu K. , Nonaka K. , Takeda K. , Iwaya M. , Kamiyama S. , Amano H. , Akasaki I. 
Published: October 2009

AbstractMicrostructural analysis was carried out to clarify the compositional dependence of the generation of dislocations in AlxGa1‐xN on an underlying AlN layer grown by metalorganic vapor phase epitaxy. When the film thickness is less than 1.5 μm, the threading dislocation density (TDD) increases with decreasing AlN molar fraction. However, when the film thickness exceeds 1.5 μm, TDD becomes maximum at x around 0.5. The growth of AlGaN on a grooved AlN template is effective in reducing TDD for all AlN molar fractions. TDD in AlGaN, which is close to binaries such as GaN and AlN, is a few 107 cm–2, while for the intermediate composition with x around 0.5, TDD is still at mid 108 cm–2. The activation energy of Mg in AlGaN is found to show a strong Mg concentration dependence with a negative one‐third power law in Al0.25Ga0.75N and Al0.5Ga0.5N as well as in GaN. Overdoping of Mg causes an increase in the activation energy for every composition; from this, the optimum Mg concentration for realizing the highest hole concentration can be deduced. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical absorption of rutile SnO2 and TiO2
Authors: Thomazi Fabiano , Roman Lucimara Stolz , Silva Antonio Ferreira da , Persson Clas 
Published: October 2009

AbstractThe electronic band‐edge structure and optical response of rutile SnO2 and TiO2 are studied, employing a fully relativistic projected augmented wave method within the local density approximation (LDA). A quasi‐particle model corrects the LDA band‐gap energies, which is used to fit the on‐site self‐interaction correction (SIC) potential LDA+USIC. We show that inclusion of this k‐dependent SIC‐like potential correction, as well as inclusion of polaronic screening are of outermost importance for accurately determining the electronic structure and optical properties. For both SnO2 and TiO2, the calculated absorption coefficient α (ω) reveals a very small optical band‐edge absorption in the photon energy region Eg ≤ ħω ≤ ∼Eg +Δ (Δ = 0.8 eV and 0.5 eV for SnO2 and TiO2, respectively). The main difference between SnO2 and TiO2 is the presence of the unoccupied low‐energy 3d conduction‐band states in TiO2 which yield flat conduction bands and a very strong optical absorption for ħω > Eg +Δ. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical transport in carbon nanotube coatings of silica fibers
Authors: Ksenevich Vitaly , Dauzhenka Taras , Seliuta Dalius , Kasalynas Irmantas , Kivaras Tomas , Valusis Gintaras , Galibert Jean , Helburn Robin , Lu Qi , Samuilov Vladimir 
Published: October 2009

AbstractElectrical properties and magnetoresistance (MR) of single‐wall carbon nanotubes coatings of silica fibers were investigated in temperature range 1.8‐300 K and magnetic fields up to 8 T. The dependence of resistance vs temperature, R (T), and MR within the range of 2∼8 K can be explained by a 3D variable range hopping transport. In the temperature range of 8‐300 K, R (T) dependencies can be interpreted by fluctuation‐induced tunnelling model. The determined carrier transport features were supported by additional measurements of change in conductivity in strong 10 GHz microwave fields and measurements of THz radiation induced photocurrent at various lattice temperatures. The features of carrier transport in SWCNTs‐SiO2 coatings are compared with those in free‐standing single walled carbon nanotube fibers. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Equivalent potential of water for electronic structure of asparagine
Authors: Gao Yang , Shen Xiaohong , Zheng Haoping 
Published: October 2009

AbstractThe equivalent potential of water for the electronic structure of asparagine(Asn) is constructed by using the first‐principles, all‐electron, ab initio calculation. The process is composed of three steps. The first step is to determine the geometric structure of Asn+nH2O system with a minimum energy. The second step is to calculate the electronic structure of Asn with the potential of water molecules by using the self‐consistent cluster‐embedding (SCCE) method, based on the result obtained in the first step. The last step is to calculate the electronic structure of Asn with the potential of dipole after replacing water molecules with dipoles. The results show that the major effect of water molecules on Asn' electronic structure be raising the occupied electronic states by 0.034 Ry on average and narrowing energy gap by 0.91%. The effect of water on the electronic structure of Asn can be well simulated by using dipole potential. The obtained equivalent potential can be applied directly to the electronic structure calculation of protein in solution by using the SCCE method. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Positron emission tomography kinetic modeling algorithms for small animal dopaminergic system imaging
Authors: Topping Geoffrey J. , Dinelle Katie , Kornelsen Rick , McCormick Siobhan , Holden James E. , Sossi Vesna 
Published: October 2009

AbstractSmall animal positron emission tomography (PET) imaging allows in vivo quantification of lesion‐ or treatment‐induced neurochemical changes in animal models of disease. Important for quantification are the kinetic modeling methods used to determine biologically‐relevant parameters of tracer‐tissue interaction. In this work, we evaluate modeling algorithms for the dopaminergic tracers 11C‐dihydrotetrabenazine (DTBZ), 11C‐methylphenidate (MP), and 11C‐raclopride (RAC), used to image the dopaminergic system in the unilateral 6‐hydroxydopamine lesioned rat model of Parkinson's disease. For the presynaptic tracers, PET measures are compared with autoradiographic binding measurements using DTBZ and [3H]WIN 35,428 (WIN). We independently developed a new variant of the tissue‐input Logan graphical modeling method, and compared its performance with the simplified Logan graphical method and the simplified reference tissue with basis functions method (SRTM), for region of interest (ROI) averaged time activity curves (TACs) and parametric imaging. The modified graphical method was found to be effectively unbiased by target tissue noise and has advantages for parametric imaging, while all tested methods were equivalent for ROI‐averaged data. Synapse 64:200–208, 2010. © 2009 Wiley‐Liss, Inc.
International Whaling Commission/International Decade of Cetacean Research (IWC/IDCR) Southern Minke Whale assessment cruise, 1978–79
Authors: Best Peter B. , Ohsumi Seiji 
Published: October 2009

The Minke Whale (Balaenoptera acutorostrata) represents the last major baleen whale resource of the Southern Ocean. Concerted exploitation for Minke Whales began in the 1971–72 season, so that it is especially important now that management of this species be placed on an adequate scientific basis.Despite the accumulation of a considerable amount of basic information on the biological and population parameters of the species remarkably early in its history of exploitation (Ohsumi and others, 1970; Ohsumi and Masaki, 1975; Masaki, 1979), reliable estimates of stock size have proved extremely elusive. Initially, population estimates had to be based entirely on sightings (Ohsumi and Masaki, 1971) as trends in catch per unit of effort were not discernible. These estimates were variable, and sensitive to the extrapolation procedures used to cover areas or seasons for which no data were available. Eventually a decline in catch per unit effort was detected in one Southern Hemisphere Area, Area IV (70°E to 130°E), although this was not statistically significant (IWC, 1977). Most of the recent population estimates have been calculated (directly or indirectly) from an analysis of the decline in Area IV, with the results extrapolated to other Southern Hemisphere areas, based on relative densities from sightings information. Despite a rigorous analysis of catch per unit effort data at the Seattle meeting of the Scientific Committee of the International Whaling Commission (IWC) in May 1978, there was much variability in the Minke Whale population estimates—as much as 3.5 times, depending on the assumptions made (IWC, 1979)—causing the adequacy of assessments based solely on data from catch per unit effort to be questioned. The variability arose with the adoption of a deliberately conservative regime of exploitation (which should produce only a small change in relative abundance), and the reduced amount (and localized nature) of the effort used. Moreover, the only independent data available was based on sightings, and was too variable to place any confidence in detecting significant changes in abundance.
The use and abuse of polar environmental resources
Authors: Holdgate Martin W. 
Published: October 2009

AbstractLiving resources of polar zones (areas limited by the 10°C isotherm for the warmest month) have in the past been developed exploitively: examples range from 17th century Arctic whales to musk oxen, caribou, and most recently fin fish stocks from Antarctic waters. Mineral resources as yet remain under-developed, particularly in the Antarctic. This is due to a combination of technological problems imposed by the harsh environment, and marketing problems accentuated by remoteness. Recent scientific and technological advances make further mineral exploitation feasible, though markets do not as yet justify the high costs of development in the Antarctic, where there remain unsolved technical and transportation problems. Future exploitation of living resources is likely to be more conservative than hitherto, especially in the Antarctic where the Treaty System provides potential safeguards. Management plans based on rational decision-making, and incorporating environmental safety measures, are needed to ensure that all further development of renewable natural resources, at either end of the earth, is conducted on a sustainable basis, and that all development proceeds with minimal environmental disturbance.
Drilling in eastern Taylor Valley, Antarctica, 1982–83: some preliminary results
Authors: Robinson P.H. , Elston D. P. , Rieck H. J. 
Published: October 2009

ABSTRACTInitial results from a programme of drilling in eastern Taylor Valley, Ross Dependency, Antarctica, in 1982–83 show lithological correlations with earlier drilling work in the same area. A preliminary interpretation suggests that drift deposits represent at least two glacial episodes, probably Ross I and pre-Ross I, separated by periods of proglacial sandur development and lake sedimentation. Further drilling is planned for 1983–84.
Beauchêne Island: a historical account
Authors: Smith R. I. Lewis 
Published: October 2009

AbstractSouthernmost of the Falkland Islands, Beauchêne Island (52° 54' S, 59° 09' W, area 3 km2) is a wildlife reserve with large colonies of Black-browed albatrosses and Rockhopper penguins. Discovered and named in 1701 by the French explorer Jacques Gouin de Beauchesne, it was noted by many early navigators and visited frequently by fur sealers in the 19th century. This article draws attention to early reports and outlines what is known of its history.
The fate of Rusanov's Gerkules expedition in the Kara Sea, 1913; Some Further details and recent developments
Authors: Barr William 
Published: October 2009

AbstractThe Russian explorer V. A. Rusanov's geological expeditions to Novaya Zemlya (1908–11) gained him the experience that, in 1912, secured his appointment as leader of a government expedition to Svalbard. In the sealing ship Gerkules Rusanov and 14 others left Aleksandrovsk on 26 June, spending most of July and August staking claims, collecting specimens and inspecting coalmining operation around the islands. In late August Gerkules headed east for Novaya Zemlya and an attempt at the Northeast Passage. Neither ship nor crew were seen again, but relics of the expedition have since been found on islands in the Kara Sea; in 1978 a plaque commemorating the expedition was erected on Mys Primetnyy, where a campsite and many relics were identified.
The Scottish National Antarctic Expedition 1902–04
Authors: Bernstein Ralph E. 
Published: October 2009

On 21 July 1904, just over 80 years ago, the barque-rigged, Norwegian-built auxiliary steamshipScotiasailed home up the Clyde with members of the Scottish National Antarctic Expedition (SNAE), concluding one of the most successful expeditions of the heroic period of Antarctic exploration. Contemporaneous with the more spectacular British Antarctic Expedition (1901–03) commanded by Robert Falcon Scott, theScotiaparty under William Spiers Bruce had overwintered on Laurie Island (60° 44ʹ S, 44° 50ʹ W) in the South Orkney Islands, explored for the first time the oceanography of the Weddell Sea, assembled an important collection of scientific material, and discovered Coats Land, an icebound stretch of the East Antarctica coast.While Scott'sDiscoveryexpedition had emphasized geographical exploration inland from the Ross Sea sector of Antarctica, Bruce in theScotiahad concentrated more on scientific discovery in the Weddell Sea sector. On 12 November 1904 in Edinburgh, members of theScotiaandDiscoveryexpeditions were guests at the 20th anniversary dinner of the Royal Scottish Geographical Society, Bruce and Scott together responding to a presidential toast that honoured the success of both.
Prospects for the northern Canadian native economy
Authors: Cox Bruce A. 
Published: October 2009

AbstractMuch ink has been spilled over the future prospects of a Northern native economy based on a mix of hunting, trapping and wage work. Information on the mixed economy appeared during debates over Northern pipeline development which raged during the 1970s; though the native lifestyle came under close scrutiny during that period, sceptics remain unconvinced of the very existence, let alone the viability, of a native mixed economy. In their view a way of life based on harvesting ‘country foods’ is moribund and should give place as soon as possible to a full-fledged wage economy; those who think otherwise, including the authors of pipeline inquiries, are misguided romantics. This paper re-examines the debates over the prospects for a native hunting economy, and comes down on the side of its proponents. The author concludes that, given proper institutional support, a mixed economy should persist into the next century, and shows that the critics of the bush economy have underestimated its contribution to the welfare of Northern natives.
North Atlantic sea-creatures in the King's Mirror (Konungs Skuggsjá)
Authors: Whitaker Ian 
Published: October 2009

ABSTRACTThe 12th century Norwegian text Konungs Skuggsjá (King's Mirror), a didactic work prepared by one or several authors, probably for the education of a king's sons, provides some of the earliest known descriptions of sea-creatures (legendary and real) inhabiting northern Atlantic waters. Most of the descriptions give sufficient detail to allow identification with species common in the area today. This article (the second of two articles on Konungs Skuggsjá; see Polar Record, (1985), 23(141): 615–27), presents translated sections of the original text, and possible identifications of 26 species with discussion, notes and comments.
The Dutch in the Arctic in the late 19th century
Authors: Bruyns Willem F. J. Mörzer 
Published: October 2009

ABSTRACTFollowing the founding of the Aardrijkskundig Genootschap [Dutch Geographical Society] in 1873 there was a brief revival of Dutch interest and participation in the Arctic. The schooner Willem Barents, specially built for the purpose, made annual voyages into the European Arctic from 1878 to 1884, placing memorial stones at sites where the Dutch had operated in earlier centuries and collecting scientific data. During the International Polar Year, 1882–83 the Dutch expedition was caught in pack ice and its ship Varna was lost. Thereafter Dutch interest in the Arctic waned, and Willem Barents was sold in 1886.
The meaning of political development in the north
Authors: Morehouse Thomas A. 
Published: October 2009

ABSTRACTPolitical development in the north (and elsewhere) often occurs in a context of confrontation and conflict between values of community and stability on one hand and economic growth and change on the other. Indigenous peoples of the north may not be able to resist strong tides of social and economic change—‘development’ toward forms of the dominant social, economic and political institutions—but they can substantially affect the terms of their integration into dominant societies. Alaska Natives seek both autonomy through tribal governments and access to the benefits of dominant institutions. Their ability to achieve and reconcile these purposes is a basic measure of their political development.
John Ross and Bellot Strait: personality versus discovery
Authors: Savelle James M. , Holland Clive 
Published: October 2009

ABSTRACTDuring his voyage to the North American Arctic in 1829–933 John Ross was twice on the verge of discovering Bellot Strait, once in August 1829 and again in June 1832. The discovery would have done much to redeem his reputation, shattered in his earlier Arctic voyage of 1818, and might have helped him to delineate, or even sail through, a northwest passage. Using previously unpublished material, this article examines the circumstances in which Ross failed to recognize the strait, and suggests that, for reasons of personal rather than physical constraint, he did not take advantage of the two opportunities presented
Charles Bénard's first expedition to Novaya Zemlya, 1908
Authors: Barr William 
Published: October 2009

ABSTRACTIn the summer of 1908 the Mission Océanographique Arctique Française sailed from Dunkirk aboard the ketchJacques Cartier. Sponsored by the Société d'Océanographie du Golfe de Gascogne and led by Charles Bénard, its major aims were to study the fisheries potential of the Barents Sea, to explore Gusinaya Zemlya on the south island of Novaya Zemlya, to chart and sound the bays and straits of that area, to carry out geological investigations, and to make a traverse of Matochkin Shar, which bisects Novaya Zemlya. The expedition established itself at Belush'ya Guba, from where Bénard and his companions explored much of Gusinaya Zemlya and surveyed, sounded and charted the adjacent waters. An attempt at crossing the south island, made by the medical officer Candiotti, was unsuccessful. Later, accompanied by the Russian geologist Vladimir Aleksandrovich Rusanov, Candiotti sailed through Matochkin Shar and made the first crossing of the north island, from Neznayemyy Zaliv to Krestovaya Guba. The expedition ended on rather a sour note: Bénard abandoned his ship and crew at Arkhangel'sk, leaving the organizing committee with the problems of unravelling the mess and repatriating the crew.
The growth, structure and disintegration of Arctic ice shelves
Authors: Jeffries Martin O. 
Published: October 2009

AbstractThe north coast of Ellesmere Island is the location of the only known ice shelves in the northern hemisphere. Present Arctic ice shelves are as much as 40–50 m thick and occupy sheltered fiords and embayments. These thick floating ice masses are remnants of the once-extensive Ellesmere Ice Shelf that has disintegrated since 1876–1906, when Aldrich and Peary respectively travelled along the coast. Reasons for the disintegration are not clear, but it has created many ice islands that have been known to circulate in the Arctic Ocean for 35 years or more. Both ice islands and ice shelves are readily distinguished from their surroundings by an undulating surface topography of parallel ridges and troughs up to 300 m apart. The undulations probably owe their origin to the effects of wind and meltwater. Since 1952 these large ice masses have been the subject of considerable research. Ice shelf growth began about 4000 BP, when glaciers flowed off the land and remained afloat in fiords and inlets, and sea ice grew thick and remained fast to the coast. The glacier and sea ice acted as platforms for further thickening both by surface accumulation of snow and ice and by undersurface accretion of fresh, brackish and saline ice. Although much has been learned about the growth, structure and behaviour of arctic ice shelves, questions still remain concerning ice island calving mechanisms, bottom freezing, thick sea ice growth and origins of the ridges and troughs.