Precision nanoscale domain engineering of lithium niobate via UV laser induced inhibition of poling

Continuous wave ultraviolet (UV) laser irradiation at lambda=244 nm on the +z face of undoped and MgO doped congruent lithium niobate single crystals has been observed to inhibit ferroelectric domain inversion. The inhibition occurs directly beneath the illuminated regions, in a depth greater than 100 nm during subsequent electric field poling of the crystal. Domain inhibition was confirmed by both differential domain etching and piezoresponse force microscopy. This effect allows the formation of arbitrarily shaped domains in lithium niobate and forms the basis of a high spatial resolution micro-structuring approach when followed by chemical etching

Heat transport of electron-doped Cobaltates

Within the t-J model, the heat transport of electron-doped cobaltates is studied based on the fermion-spin theory. It is shown that the temperature dependent thermal conductivity is characterized by the low temperature peak located at a finite temperature. The thermal conductivity increases monotonously with increasing temperature at low temperatures T $<$ 0.1$J$, and then decreases with increasing temperature for higher temperatures T $>$ 0.1$J$, in qualitative agreement with experimental result observed from Na$_{x}$CoO$_{2}$ .Comment: 4 pages, 1 fig, corrected typos, accepted for publication in Commun. Theor. Phy

An Evaluation Of Provision In A School Designated As Catering For Pupils Categorised As Having 'Emotional And Behavioural Difficulties' In The Light Of The Perspectives And Expectations Of Its Various Stakeholders

Line End is an 11-16 day school for pupils categorised as having emotional and behavioural difficulties (EBD). It is maintained by Farside Local Education Authority, and provides secondary education for pupils who are statemented as having emotional and behavioural difficulties. Some have additional learning difficulties, this assessment being based on reading ages that are considerably lower than their chronological ages, and scores in KS2 SATs that are below National averages. All referrals come through the local authority’s special educational needs department; invariably, the pupils who are placed at Line End either transfer from the EBD primary unit, or are those who have been excluded from mainstream secondary schools within the borough. The aim of the study is to establish the extent to which Line End is felt to be effective by its various stakeholders; and in establishing this position, it is first important to elicit the criteria by which the various stakeholders judge the school to be effective. The first phase of the study, therefore, is aimed at eliciting these stakeholder criteria, whilst the second phase focuses on the extent to which the school is perceived to be effective in its various areas of provision, based on these very criteria. A subsequent analysis of findings seeks to examine stakeholder perspectives, and the extent to which there is congruence and/or divergence of perspective amongst and between stakeholders might create conflict or tensions between and amongst stakeholders. Findings from the first phase of the study suggest that there is broad agreement amongst stakeholders about what should constitute effective provision for Line End pupils: addressing both academic and emotional/behavioural needs effectively, providing a safe and positive environment in which to make such provision, and providing opportunities for the reintegration of pupils to mainstream where appropriate and practicable. These three areas reflect the three major aims of the school as outlined in the staff handbook, and alongside these as key indicators of quality, stakeholders included relationships between home and school, and the management/organisation of the school -the extent to which it was strategically or ‘crisis’ managed. Findings from the second phase of the research suggested that the school was perceived to be effective by virtually all of its stakeholders - in some areas for some of the time. There were differences of perspective within stakeholder groups, and sometimes differences of emphasis between stakeholder groups. These differences did not necessarily lead to tension, as it was possible for differing perspectives to co-exist; the tensions became evident when perspectives conflicted rather than co-existed, as the group or individual who held the greatest power would invariably have its way in translating its perspective into policy and practic

Ultrastrong conductive in situ composite composed of nanodiamond incoherently embedded in disordered multilayer graphene

Traditional ceramics or metals cannot simultaneously achieve ultrahigh strength and high electrical conductivity. The elemental carbon can form a variety of allotropes with entirely different physical properties, providing versatility for tuning mechanical and electrical properties in a wide range. Here, by precisely controlling the extent of transformation of amorphous carbon into diamond within a narrow temperature–pressure range, we synthesize an in situ composite consisting of ultrafine nanodiamond homogeneously dispersed in disordered multilayer graphene with incoherent interfaces, which demonstrates a Knoop hardness of up to ~53 GPa, a compressive strength of up to ~54 GPa and an electrical conductivity of 670–1,240 S m(–1) at room temperature. With atomically resolving interface structures and molecular dynamics simulations, we reveal that amorphous carbon transforms into diamond through a nucleation process via a local rearrangement of carbon atoms and diffusion-driven growth, different from the transformation of graphite into diamond. The complex bonding between the diamond-like and graphite-like components greatly improves the mechanical properties of the composite. This superhard, ultrastrong, conductive elemental carbon composite has comprehensive properties that are superior to those of the known conductive ceramics and C/C composites. The intermediate hybridization state at the interfaces also provides insights into the amorphous-to-crystalline phase transition of carbon

Shipping to heterogeneous customers with competing carriers

__Problem definition:__ We consider a shipper transporting and selling a short-life-cycle product to a destination market. Customers in the destination market obtain higher utility if they receive the product earlier but their time preferences are heterogeneous. Two transportation service providers (i.e., carriers) offer distinct speeds and competing freight rates. This study analyzes the shipper’s optimal shipping strategy under carrier competition. __Academic/Practical relevance:__ Perishable products are commonly shipped via multiple means of transport. The faster the mode of transport is, the more expensive it is, but speed enables the product to reach the market with higher quality. In addition to the trade-off between speed and cost, the competition between carriers can also influence the shipper’s transportation procurement strategies. Our model highlights the implications of carrier competition in a dual sourcing problem. __Methodology:__ We study a two-stage game-theoretical framework: Carriers first compete on freight rates, and then the shipper determines the shipping schedule. __Results:__ The shipper may benefit from product differentiation via dual-mode shipping, in which the shipment that arrives earlier is sold at a premium price. In equilibrium, the shipper’s profit can be U-shaped in the speed difference between carriers. Dual sourcing may be inferior to simply restricting a single shipping service in a winner-take-all fashion. __Managerial implications:__ This study reveals an underlying trade-off between the operational advantage from product differentiation and the cost advantage from carrier competition. To benefit from either of these advantages, a shipper should use two carriers with either very distinct or very similar speeds. Single sourcing may bring an additional cost advantage that outweighs the value of production differentiation through dual sourcing

Kinetic energy driven superconductivity in the electron doped cobaltate Nax_{x}CoO2⋅y_{2}\cdot yH2_{2}O

Within the charge-spin separation fermion-spin theory, we have shown that the mechanism of superconductivity in the electron doped cobaltate Na$_{x}$CoO$_{2}\cdot y$H$_{2}$O is ascribed to its kinetic energy. The dressed fermions interact occurring directly through the kinetic energy by exchanging magnetic excitations. This interaction leads to a net attractive force between dressed fermions, then the electron Cooper pairs originating from the dressed fermion pairing state are due to the charge-spin recombination, and their condensation reveals the superconducting ground state. The superconducting transition temperature is identical to the dressed fermion pair transition temperature, and is suppressed to a lower temperature due to the strong magnetic frustration. The optimal superconducting transition temperature occurs in the electron doping concentration $\delta\approx 0.29$, and then decreases for both underdoped and overdoped regimes, in qualitative agreement with the experimental results.Comment: 6 pages, 2 figs, corrected typos, accepted for publication in Commun. Theor. Phy

A Ordem de Cristo no contexto de uma economia de mercês. Critérios de provimento de cargos e ofícios nos séculos XVII e XVIII: o caso da capitania do Espírito Santo

Neste trabalho, partimos do conceito original de ordem religioso-militar e dissertamos sobre a história da Ordem de Cristo, a qual identificamos e descrevemos as origens medievais como ordem religioso-militar e a sua criação ou fundação por necessidade estratégica da monarquia portuguesa para proteger e manter o patrimônio templário no território português. Seguimos para a descrição de um panorama do Brasil colonial inserido no Império ultramarino português, as suas estruturas e práticas político-administrativas com ênfase no sistema de capitanias hereditárias e do governo-geral criados pela monarquia portuguesa. Apresentamos a discussão da dualidade MetrópoleColônia e a busca do controle político e administrativo periférico pelo centro do poder português. Em continuação, abordamos a consolidação de uma economia de mercês, que atuava na seleção de servidores para a burocracia no reino e nas conquistas ultramarinas portuguesas. Assim, na época moderna desenha-se um novo modelo de cavaleiro das ordens militares que se definia como servidor destacado do rei, limpo de sangue e com cabedal que lhe permitisse não sujar as mãos com trabalho e então o interesse nas ordens militares, em particular pelo hábito da Ordem de Cristo, generaliza-se por toda a sociedade portuguesa. Concluindo o trabalho, caracterizamos a formação da capitania do Espírito Santo e a partir de fontes manuscritas e impressas que abarcam os séculos XVII e XVIII dissertamos sobre as inflexões de uma economia de mercês que se consolidava e sobre a presença da Ordem de Cristo em um contexto regional de provimento de cargos e ofícios na capitania do Espírito Santo

Measurements of the Mass and Full-Width of the ηc\eta_c Meson

In a sample of 58 million $J/\psi$ events collected with the BES II detector, the process J/$\psi\to\gamma\eta_c$ is observed in five different decay channels: $\gamma K^+K^-\pi^+\pi^-$, $\gamma\pi^+\pi^-\pi^+\pi^-$, $\gamma K^\pm K^0_S \pi^\mp$ (with $K^0_S\to\pi^+\pi^-$), $\gamma \phi\phi$ (with $\phi\to K^+K^-$) and $\gamma p\bar{p}$. From a combined fit of all five channels, we determine the mass and full-width of $\eta_c$ to be $m_{\eta_c}=2977.5\pm1.0 ({stat.})\pm1.2 ({syst.})$ MeV/$c^2$ and $\Gamma_{\eta_c} = 17.0\pm3.7 ({stat.})\pm7.4 ({syst.})$ MeV/$c^2$.Comment: 9 pages, 2 figures and 4 table. Submitted to Phys. Lett.

Prunella vulgaris: A comprehensive review of chemical constituents, pharmacological effects and clinical applications.

Prunella vulgaris (PV) is a perennial herb belonging to the Labiate family and is widely distributed in northeastern Asian countries such as Korea, Japan, and China. It is reported to display diverse biological activities including anti-microbial, anti-cancer, and anti-inflammation as determined by in vitro or in vivo studies. So far, about 200 compounds have been isolated from PV plant and majority of these have been characterized mainly as triterpenoids, sterols and flavonoids, followed by coumarins, phenylpropanoids, polysaccharides and volatile oils. This review summarizes and analyzes the current knowledge on the chemical constituents, pharmacological activities, mechanisms of action and clinical applications of the PV plant including its potential as a future medicinal plant. Although some of the chemical constituents of the PV plant and their mechanism of action have been investigated the biological activities of many of these remain unknown and further clinical trials are required to further enhance its reputation as a medicinal plant