Quantum direct secret sharing with efficient eavesdropping-check and authentication based on distributed fountain codes

We propose to use a simple and effective way to achieve secure quantum direct secret sharing. The proposed scheme uses the properties of fountain codes to allow a realization of the physical conditions necessary for the implementation of no-cloning principle for eavesdropping-check and authentication. In our scheme, to achieve a variety of security purposes, nonorthogonal state particles are inserted in the transmitted sequence carrying the secret shares to disorder it. However, the positions of the inserted nonorthogonal state particles are not announced directly, but are obtained by sending degrees and positions of a sequence that are pre-shared between Alice and each Bob. Moreover, they can confirm that whether there exists an eavesdropper without exchanging classical messages. Most importantly, without knowing the positions of the inserted nonorthogonal state particles and the sequence constituted by the first particles from every EPR pair, the proposed scheme is shown to be secure.

Fountain; Lucerne Cities, Towns, and Villages

Handwritten information on back of photo(s).

Atomic fountain of laser-cooled Yb atoms for precision measurements

We demonstrate launching of laser-cooled Yb atoms in a cold atomic fountain. Atoms in a collimated thermal beam are first cooled and captured in a magneto-optical trap (MOT) operating on the strongly allowed S-1(0) -> P-1(1) transition at 399 nm (blue line). They are then transferred to a MOT on the weakly allowed S-1(0) -> P-3(1) transition at 556 nm (green line). Cold atoms from the green MOT are launched against gravity at a velocity of around 2.5 m/s using a pair of green beams. We trap more than 107 atoms in the blue MOT and transfer up to 70% into the green MOT. The temperature for the odd isotope Yb-171 is similar to 1 mK in the blue MOT, and reduces by a factor of 40 in the green MOT.

Studies on helium flow in experimental loops with different impedances operated with fountain effect pumps

An experimental flow loop with He II flow driven by fountain effect pumps (FEPs) is studied with respect to operation at different flow impedances and with thermal loads applied at different positions. The measured values of temperature, flow rate and pressure drop are compared with calculations resulting from a simplified model which assumes ideal performance of the porous plug and of the heat exchangers and which does not take into account Gorter-Mellink (GM) conduction. The main features of the loop are shown to be well described by this model. Refined calculations with a more complex model, including GM conduction of the He II, are only required for predicting the temperature distribution in some discrete regions of the loop.

Phase variations and phase shift in a TE011 mode microwave cavity used for in a miniature Rb fountain frequency standard

It is the first time in China that the phase variations and phase shift of microwave cavity in a miniature Rb fountain frequency standard are studied, considering the effect of imperfect metallic walls. Wall losses in the microwave cavity lead to small traveling wave components that deliver power from the cavity feed to the walls of cavity. The small traveling wave components produce a microradian distribution of phase throughout the cavity ity, and therefore distributed cavity phase shifts need to be considered. The microwave cavity is a TE011 circular cylinder copper cavity, with round cut-hole of end plates (14mm in diameter) for access for the atomic flux and two small apertures in the center of the side wall for coupling in microwave power. After attenuation alpha is calculated, field variations in cavity are solved. The field variations of the cavity are given. At the same time, the influences of loaded quality factor QL and diameter/height (2a/d) of the microwave cavity on the phase variations and phase shift are considered. According to the phase variation and phase shift of microwave cavity we select the parameters of cavity, diameter 2a = 69.2mm, height d = 34.6mm, QL = 5000, which will result in an uncertainty delta(Delta f / f0 ) < 4.7 x 10(-17) and meets the requirement for the miniature Rb fountain frequency standard with accuracy 10(-15).

Geochemical characterization of the fire-fountain fed deposits of Las Herrerias volcano (Campo de Calatrava Volcanic Field, Ciudad Real)

The Las Herrerias volcano (Bolanos de Calatrava, Campo de Calatrava Volcanic Field) is characterized by the great amount and variety of fire-fountain fed deposits. All these deposits are compositionally similar, being constituted by magnesium-rich (MgO = 11.58-4.19%), aluminium-poor (Al2O3 = 9.64-10.99%) highly sodic (Na2O = 2.24-3.81%) melanephelinites, with high contents in rare earth-elements (10x-200x chondrite), particularly in light-rare earth elements with respect to the heavy ones [(La/Lu)(N) = 32-35]. Contrary to the equivalent melanephelinites of this volcanic field, the relatively low contents in Ni (233-286 ppm), Cr (393-520 ppm) and magnesium number (Mg* = 45-54) indicate that these rocks do not correspond with primary melts. On the other hand, the variable distribution of clinopyroxene in the magma during eruption would be responsible for the slight compositional differences observed in the studied samples. Finally, we argue that these fire fountains were developed in a continental intraplate setting.

Wilkinson Hall and Gentle Soring Fountain, Chapman College, Orange, California

Wilkinson Hall and "Gentle Spring" fountain, Chapman College, Orange, California. J.E. Wilkinson was a former trustee, chairman of the board, and acting president. This building was the first on the campus of Orange Union High Schooi, designed by local architect, C.B. Bradshaw and constructed in 1905 by R. J. Noble. In 1921 it was moved 250 feet and turned 90 degrees to its current location. Acquired in 1954 by Chapman College. it houses the Provost’s office, Academic Affairs, English & Comparative Literature, Graduate Studies, and the departments of Religion and Philosophy. It is listed in the National Registry for Historical Buildings.

Wilkinson Hall and Gentle Spring Fountain, Chapman College, Orange, California

Wilkinson Hall and "Gentle Spring" fountain, Chapman College, Orange, California. J.E. Wilkinson was a former trustee, chairman of the board, and acting president. This building was the first on the campus of Orange Union High Schooi, designed by local architect, C.B. Bradshaw and constructed in 1905 by R. J. Noble. In 1921 it was moved 250 feet and turned 90 degrees to its current location. Acquired in 1954 by Chapman College. it houses the Provost’s office, Academic Affairs, English & Comparative Literature, Graduate Studies, and the departments of Religion and Philosophy. It is listed in the National Registry for Historical Buildings.

The magic fountain by H.R.H. princess Gloriana.

Un cuento de hadas moderno es la base de una reveladora crítica a la publicación de famosos. La princesa Gloriana decide ser escritora, aunque ni la gramática, ni la ortografía, ni la puntuación sean sus puntos fuertes y escribe una obra de 34 palabras titulada la fuente mágica. No es una buena historia, en realidad es horrible, p ero no importa:Cuando eres de la casa real, escribir no es un problema. Cada uno de sus cortesanos hacen comentarios sobre lo maravilloso que es la historia y la princesa cree que es tan buena que debería ser publicada. El público en general se enfrenta con la elección de A: la compra de un ejemplar de la obra, o B: ir a la cárcel por un período de seis meses. De pronto, obviamente,la obra se convierte en un éxito. La Princesa se encuentra muy solicitada en los programas de artes y espectáculos de televisión, de chats e incluso en la portada de una revista. La llegada del Príncipe Waldo le proporciona una nueva historia con final feliz.

The cleft ion fountain: a two-dimensional kinetic model

The transport of ionospheric ions from a source in the polar cleft ionosphere through the polar magnetosphere is investigated using a two-dimensional, kinetic, trajectory-based code. The transport model includes the effects of gravitation, longitudinal magnetic gradient force, convection electric fields, and parallel electric fields. Individual ion trajectories as well as distribution functions and resulting bulk parameters of density, parallel average energy, and parallel flux for a presumed cleft ionosphere source distribution are presented for various conditions to illustrate parametrically the dependences on source energies, convection electric field strengths, ion masses, and parallel electric field strengths. The essential features of the model are consistent with the concept of a cleft-based ion fountain supplying ionospheric ions to the polar magnetosphere, and the resulting plasma distributions and parameters are in general agreement with recent low-energy ion measurements from the DE 1 satellite.