15,812 research outputs found
Very Singular Similarity Solutions and Hermitian Spectral Theory for Semilinear Odd-Order PDEs
Very singular self-similar solutions of semilinear odd-order PDEs are studied
on the basis of a Hermitian-type spectral theory for linear rescaled odd-order
operators.Comment: 49 pages, 12 Figure
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Retraction Note: An apoptosis-enhancing drug overcomes platinum resistance in a tumour-initiating subpopulation of ovarian cancer.
This Article has been retracted; see accompanying Retraction Note
Basic Education in Cambodia: The Impact of UNESCO onPolicies in the 1990s
Efforts to enhance opportunities for Basic Education have been growing within many developing nations after the1990 World Conference on Education For All (WCEFA) in Jomtien, Thailand. In the face of political turmoil, financial constraint and social insecurity, Cambodia with the encouragement and assistance of the United Nations Educational, Scientific, and Cultural Organization (UNESCO), took measures to increase educational opportunities for all her citizens through Basic Education strategic plans and pledged to eradicate illiteracy by the year 2000. This article examines the joint efforts during the 1990s of this organization as a key assistance and support UN agency for educational policy and strategy formulations, and the Cambodian government as a national agency for educational initiatives and implementation. UNESCO’s inputs for policy implementation are also detailed to evaluate the overall impact of the organization during the last decade. Analyses are based primarily on interviews with some key government policymakers, fieldwork observation and interviews with school-aged children, several speeches of top government officials, and existing related official education statistics and indicators in Cambodia
Hydrostatic pressure induced Dirac semimetal in black phosphorus
Motivated by recent experimental observation of an hydrostatic pressure
induced transition from semiconductor to semimetal in black phosphorus [Chen et
al. in arXiv:1504.00125], we present the first principles calculation on the
pressure effect of the electronic structures of black phosphorus. It is found
that the band crossover and reversal at the Z point occur around the critical
pressure Pc1=1.23 Gpa, and the band inversion evolves into 4 twofold-degenerate
Dirac cones around the Z point, suggesting a 3D Dirac semimetal. With further
increasing pressure the Dirac cones in the Gamma-Z line move toward the Gamma
point and evolve into two hole-type Fermi pockets, and those in the Z-M lines
move toward the M point and evolve into 2 hole-type Fermi pockets up to P=4.0
Gpa. It demonstrates clearly that the Lifshitz transition occurs at
from semiconductor to 3D Dirac semimetal protected by the nonsymmorphic space
symmetry of bulk. This suggests the bright perspective of black phosphorus for
optoelectronic and electronic devices due to its easy modulation by pressure.Comment: 7 pages, 9 figures, and 2 table
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All-Solid-State Batteries Using Rationally Designed Garnet Electrolyte Frameworks
Functioning bulk-type all-solid-state batteries in a practical form factor with composite positive electrodes, using Al-substituted Li7La3Zr2O12 (LLZO) as the solid electrolyte, have been demonstrated for the first time. The devices incorporate bilayers composed of dense LLZO membranes and porous LLZO scaffolds infiltrated with LiNi0.6Mn0.2Co0.2O2 and other components as positive electrodes, combined with lithium anodes. The porous scaffolds are prepared using an easily scaled freeze-tape-casting method. The unidirectional pores of the scaffold facilitate infiltration of cathode components and shorten lithium ion diffusion path lengths, while the addition of a soft ionically conductive solid to the scaffold ensures good contact among the components
Comorbidity and Autism Spectrum Disorder Research Topics: Co-Occurrence of Autism Spectrum Disorder and Achondroplasia
This Research Topic in Frontiers aims to overcome the sparsity of studies regarding comorbidity in ASD. It asks potential participants to explore; question; and when necessary; challenge conventional knowledge regarding ASD. Are standard screening instruments capable of delineating the full range of impairment in ASD in the presence of comorbidities? Given the difficulties in communication for many autistic patients; what red flags point towards the presence of comorbidities and what should constitute appropriate medical screening? How do comorbid conditions relate to maladaptive behaviors? This Research Topic will seek answers to these and other questions while raising awareness of how comorbid conditions increase both mortality and morbidity in ASD. Appropriate contributions will include research articles; case reports as well as population-based studies; information for healthcare providers; assessments for clinical management; and position statements from relevant policy making organizations
Inclusive production of a pair of hadrons separated by a large interval of rapidity in proton collisions
We consider within QCD collinear factorization the inclusive process , where the pair of identified hadrons, , having large
transverse momenta is produced in high-energy proton-proton collisions. In
particular, we concentrate on the kinematics where the two identified hadrons
in the final state are separated by a large interval of rapidity . In
this case the (calculable) hard part of the reaction receives large higher
order corrections . We provide a theoretical input
for the resummation of such contributions with next-to-leading logarithmic
accuracy (NLA) in the BFKL approach. Specifically, we calculate in NLA the
vertex (impact-factor) for the inclusive production of the identified hadron.
This process has much in common with the widely discussed Mueller-Navelet jets
production and can be also used to access the BFKL dynamics at proton
colliders. Another application of the obtained identified-hadron vertex could
be the NLA BFKL description of inclusive forward hadron production in DIS.Comment: 29 pages, 9 figures; corrected few typos and added an acknowledgment;
version to be published on JHEP. arXiv admin note: substantial text overlap
with arXiv:1202.108
Rabbit Production in Selected Urban Areas of Southern Ghana: Status and Implications for Policy and Research
A survey was conducted to elicit information on rabbit keeping in 26 urban areas of southern Ghana. The average age of the rabbit keepers was 44.3 years, and 95.5% of the keepers had formal education. Most of the producers got into rabbit keeping for money to meet urgent family needs, while household consumption was a major factor influencing the decision for rearing rabbits. Personal savings was the main source of income for the establishment of the rabbit enterprises. The major breeds of rabbits kept were the California White, New Zealand White and crossbreds of varied genetic variations. Backyard, small-scale and medium-scale commercial rabbit holdings were held by 18.2, 51.7 and 30.2% of the keepers respectively. The average rabbit population per farm was 77.8, with an average of 8.4 bucks, 21.6 does. Young rabbits formed 70.0% of the rabbit population. Owners of rabbitries usually cared for their animals as hired labour was expensive and often not available. High cost of feed was the most significant constraint to rabbit keeping, and mange was the most common disease affecting the rabbits. Marketing of rabbits was not organized, and this served as a disincentive to expanding the holdings. The rabbits were mostly sold either life or as fresh carcasses at the farm gate. To ensure a rapid growth of the rabbit industry, research should be undertaken to address the identified constraints to production while appropriate policies are put in place to enhance the growth of the industry
Hot electron injection into dense argon, nitrogen, and hydrogen
Hot electrons have been injected into very dense argon, nitrogen, and hydrogen gases and liquids. The current‐voltage characteristics are experimentally determined for densities (N) of argon, nitrogen, and hydrogen ranging from about 10²⁰ to 10²² cm⁻³ and applied fields (E) ranging from about 10 to 10⁴ V cm⁻¹. The argon data show a square root E∕N dependence of the current. The nitrogen and hydrogen data show a complicated dependence of the current on E∕N due to the rapid thermalization in the region of the image potential of the injected electrons through inelastic collision processes not present in argon. A hydrodynamic‐two‐fluid model is developed to analyze the nitrogen and hydrogen data. From the analysis of our data, we obtain the density dependence of the momentum exchange scattering cross section and the energy relaxation time for the injected hot electrons
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