6,022 research outputs found

    Internal-state thermometry by depletion spectroscopy in a cold guided beam of formaldehyde

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    We present measurements of the internal state distribution of electrostatically guided formaldehyde. Upon excitation with continuous tunable ultraviolet laser light the molecules dissociate, leading to a decrease in the molecular flux. The population of individual guided states is measured by addressing transitions originating from them. The measured populations of selected states show good agreement with theoretical calculations for different temperatures of the molecule source. The purity of the guided beam as deduced from the entropy of the guided sample using a source temperature of 150K corresponds to that of a thermal ensemble with a temperature of about 30 K

    Carrapato, tristeza parasitaria e tripanossomose dos bovinos.

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    Carrapato. O carrapato-do-boi Boophilus microplus: ciclo, biologia e epidemiologia, patogenia e controle. Tristeza parasitaria dos bovinos. Tristeza parasitaria dos bovinos (TPB): conceito, etiologia, transmissao, epidemiologia, diagnostico e controle. Imunidade contra Babesia e Anaplasma. Diagnostico parasitologico da tristeza parasitaria bovina. Diagnostico sorologico da tristeza parasitaria bovina. Diagnostico anatomopatologico da tristeza parasitaria bovina. Trpanossomose Trypanosoma vivax: biologia, diagnostico e controle. Imunidade contra Trypanosoma vivax.bitstream/item/196071/1/Carrapato-tristeza-parasitaria.pd

    Axially linear slopes of composition for “delta” crystals

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    “Delta” crystals are solid solutions of miscible materials with large lattice parameter differences which contain high concentration gradients in one direction (parallel to a lattice plane strongly diffracting X-rays). The system GaSb-InSb has been chosen as suitable for study. By means of a “gradient projection method”, the growth of nearly linear composition profiles with relatively steep slopes of the lattice parameter (up to (Δa/ ) / Δz = 8.3% cm-1), adjustable by the temperature gradient, have been performed. However, the grown ingots were not monocrystalline due to the use of too high a growth rate

    Eg versus x relation from photoluminescence and electron microprobe investigations in p-type Hg1−xCdxTe (0.35 =< x =< 0.7)

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    Combined photoluminescence (at 10 T 300 K) and electron microprobe investigations have been carried out with HgCdTe samples grown from the melt or from solution. By exciting the samples through metallic masks with 200 μm diameter holes fixed with respect to the sample care was taken to pick-up both characteristic X-ray radiation as well as the photoluminescence from the same sample area. The Eg versus x relation determined in this way at T = 30 K has been compared with data from the interband absorption edge by other authors

    Multiresolution kernel matrix algebra

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    We propose a sparse arithmetic for kernel matrices, enabling efficient scattered data analysis. The compression of kernel matrices by means of samplets yields sparse matrices such that assembly, addition, and multiplication of these matrices can be performed with essentially linear cost. Since the inverse of a kernel matrix is compressible, too, we have also fast access to the inverse kernel matrix by employing exact sparse selected inversion techniques. As a consequence, we can rapidly evaluate series expansions and contour integrals to access, numerically and approximately in a data-sparse format, more complicated matrix functions such as AαA^\alpha and exp(A)\exp(A). By exploiting the matrix arithmetic, also efficient Gaussian process learning algorithms for spatial statistics can be realized. Numerical results are presented to quantify and quality our findings

    Electrostatic extraction of cold molecules from a cryogenic reservoir

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    We present a method which delivers a continuous, high-density beam of slow and internally cold polar molecules. In our source, warm molecules are first cooled by collisions with a cryogenic helium buffer gas. Cold molecules are then extracted by means of an electrostatic quadrupole guide. For ND3_3 the source produces fluxes up to (7±47)×1010(7 \pm ^{7}_{4}) \times 10^{10} molecules/s with peak densities up to (1.0±0.61.0)×109(1.0 \pm ^{1.0}_{0.6}) \times 10^9 molecules/cm3^3. For H2_2CO the population of rovibrational states is monitored by depletion spectroscopy, resulting in single-state populations up to (82±10)(82 \pm 10)%.Comment: 4 pages, 4 figures, changes to the text, updated figures and reference

    Geometric Mechanics of Curved Crease Origami

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    Folding a sheet of paper along a curve can lead to structures seen in decorative art and utilitarian packing boxes. Here we present a theory for the simplest such structure: an annular circular strip that is folded along a central circular curve to form a three-dimensional buckled structure driven by geometrical frustration. We quantify this shape in terms of the radius of the circle, the dihedral angle of the fold and the mechanical properties of the sheet of paper and the fold itself. When the sheet is isometrically deformed everywhere except along the fold itself, stiff folds result in creases with constant curvature and oscillatory torsion. However, relatively softer folds inherit the broken symmetry of the buckled shape with oscillatory curvature and torsion. Our asymptotic analysis of the isometrically deformed state is corroborated by numerical simulations which allow us to generalize our analysis to study multiply folded structures

    'Parasitic invasions' or sources of good governance: constraining foreign competition in Hong Kong banking, 1956-81

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    This paper investigates the operation and impact of the moratorium on new banking licences imposed in Hong Kong in 1965 and the claims that foreign banks destabilised the banking system and drained resources from the colony. First it examines foreign banks' attempts to circumvent the moratorium through claims of special circumstances and buying interests in local banks, and secondly it examines the efforts of incumbents to extend barriers to non-bank financial institutions and to branches of foreign banks. The general conclusions are that while the moratorium was aimed at increasing the stability of the banking system, it had the effect of decreasing the regulatory breadth of the government, and reducing incentives for mergers and acquisitions that might have improved governance

    Deoxyephedrine -- mandelic acid diastereomers

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    Resolution of mandelic acid with (-)(R)-deoxyephedrine in 95% ethanol produces essentially nondiscriminating unsolvated binary mandelate salts. (R)deoxyephedrinium (R)-mandelate (I) is orthorhombic, P212121, a = 8.076(2) Å, b = 8.926(3) Å, c = 23.242(15) Å, V = 1675.3(14) Å3 , Z = 4. (R)-deoxyephedrinium (S)-mandelate (II) is monoclinic, P21, a = 16.061(14) Å, b = 8.902(8) Å, c = 19.585(20) Å, β = 111.76(8)°, V = 2600(4) Å3, Z = 6 with three ionpairs comprising the asymmetric unit. The principle interionic interactions are ribbon-like chains of salt-bridge hydrogen bonds which associate protonated secondary ammonium ions with carboxylates in I and II along crystallographic screw axes with a six-atom repeating unit H-N+-H ··· O-C--O [C22(6)]. The (R)-mandelate additionally shows intraion hydrogen bonding and the (S)-mandelate shows interanion hydrogen bonding. Solubilities (in 95% ethanol), fusion points and heats of fusion indicate essentially no diastereometric discrimination. From acetone, the (S)-mandelate salt forms a efflorescent hemiacetone solvated binary phase (III), triclinic, P1, a = 10.869(9) Å, b = 10.838(13) Å, c = 17.138(18) Å, α = 90.32(9)°, β = 91.34(8)°, γ = 108.20(8)°, V = 1917(4) Å3, Z = 4. Ions form hydrogen bonded chains similar to those in II; acetones are unassociated. In I, columns form with the polar hydrogen bonded chains at the core and nonpolar aryl rings radiating and interdigitating adjacent columns. Packing in II and III produces bilayers of alternating polar and nonpolar regions, with acetones of III in the nonpolar regions

    Doing Occidentalism in Contemporary Japan: Nation Anthropomorphism and Sexualized Parody in Axis Power Hetalia,

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    Axis Powers Hetalia (2006–present), a Japanese gag comic and animation series, depicts relations between nations personified as cute boys against a background of World War I and World War II. The stereotypical rendering of national characteristics as well as the reduction of historically charged issues into amusing quarrels between nice-looking but incompetent boys was immensely popular, especially among female audiences in Japan and Asia, and among Euro-American manga, anime, and cosplay fans, but it also met with vehement criticism. Netizens from South Korea, for example, considered the Korean character insulting and in early 2009 mounted a protest campaign that was discussed in the Korean national assembly. Hetalia's controversial success relies to a great extent on the inventive conflation of male-oriented otaku fantasies about nations, weapons, and concepts represented as cute little girls, and of female-oriented yaoi parodies of male-male intimacy between powerful "white" characters and more passive Japanese ones. This investigation of the original Hetalia by male author Hidekaz Himaruya (b. 1985) and its many adaptations in female-oriented dōjinshi (fanzine) texts and conventions (between 2009 and 2011, Hetalia was by far the most adapted work) refers to notions of interrelationality, intersectionality, and positionality in order to address hegemonic representations of "the West," the orientalized "Rest" of the world, and "Japan" in the cross-gendered and sexually parodied mediascape of Japanese transnational subcultures
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