134 research outputs found
Soil, wheat, cabbage and drinking water iodine in relation to human iodine status and iodine deficiency disorders in Xinjiang Province, China
Iodine is an essential trace element for humans and animals. A lack in the diet can
lead to iodine deficiency disorders (IDD) the most common manifestation being
goitre, an enlargement of the thyroid gland in the neck. Infants born to severely Ideficient
mothers may suffer cretinism and I-deficiency is the world's most common
cause of preventable mental retardation. In many countries this problem has been
tackled successfully using medical interventions such as the iodination of table salt.
Xinjiang Province in northwest China is a remote desert region where goitre and
cretinism have been reported for many years. People in this region do not like the
taste of iodised salt and prefer to use local rock-salt with very low concentrations of
iodine. As an alternative treatment, previous investigators added potassium-iodate to
irrigation waters in an attempt to increase the I-concentrations of crops and animals in
the food supply and the I-status of the population. Initial successes were reported but
the long-term effectiveness of the method had not been tested. The present study aims
to assess environmental controls on iodine uptake into the food chain and in Xinjiang
had the opportunity to study three contrasting area
Finite Word Length FIR Filter Design Using Integer Programming Over a Discrete Coefficient Space
The article of record as published may be found at http://dx.doi.org/10.1109/TASSP.1982.1163925Published in: IEEE Transactions on Acoustics, Speech, and Signal Processing (Volume: 30 , Issue: 4 , Aug 1982)It is demonstrated that the improvement achieved by using integer programming over simple coefficient rounding in the design of finite impulse response (FIR) filters with discrete coefficients is most significant when the discrete coefficient space is the powers-of-two space or when a specification is to be met with a given coefficient word length by increasing the filter length. Both minimax and least square error criteria are considered
Experimental preparation of Werner state via spontaneous parametric down-conversion
We present an experiment of preparing Werner state via spontaneous parametric
down-conversion and controlled decoherence of photons in this paper. In this
experiment two independent BBO (beta-barium borate) crystals are used to
produce down-conversion light beams, which are mixed to prepare Werner state.Comment: 6 pages, 4 figures and 2 table
Optical realization of universal quantum cloning
Beyond the no-cloning theorem, the universal symmetric quantum cloning
machine was first addressed by Buzek and Hillery. Here, we realized the
one-to-two qubits Buzek-Hillery cloning machine with linear optical devices.
This method relies on the representation of several qubits by a single photon.
We showed that, the fidelities between the two output qubits and the original
qubit are both 5/6 (which proved to be the optimal fidelity of one-to-two
qubits universal cloner) for arbitrary input pure states.Comment: 5 Pages, 2 Figure
Perturbative QCD analysis of decays
We study the first observed charmless modes, the
decays, in perturbative QCD formalism. The obtained branching ratios
are larger than
from QCD factorization. The comparison of the predicted magnitudes and phases
of the different helicity amplitudes, and branching ratios with experimental
data can test the power counting rules, the evaluation of annihilation
contributions, and the mechanism of dynamical penguin enhancement in
perturbative QCD, respectively.Comment: 14 pages, 2 tables, brief disscussion on hard sacle added, version to
appear in PR
Reducing the communication complexity with quantum entanglement
We propose a probabilistic two-party communication complexity scenario with a
prior nonmaximally entangled state, which results in less communication than
that is required with only classical random correlations. A simple all-optical
implementation of this protocol is presented and demonstrates our conclusion.Comment: 4 Pages, 2 Figure
Tip-functionalized carbon nanotubes under electric fields
We investigated the electronic structures of chemically modified carbon nanotube tips under electric fields using density functional calculations. Hydrogen, oxygen, and hydroxyl group-terminated nanotubes have been considered as field emitters or probe tips. In the case of the open-ended tubes, the field emission originates primarily from the dangling-bond states localized at the edge, whereas the pentagonal defects are the main source of the field emission in the capped tubes. The open-ended nanotube with a zigzag edge is an efficient field emitter because of the localized electronic states around the Fermi level and the atomic alignment of carbon-carbon bonds along with external electric fields. Tip functionalization alters the local density of states as well as the chemical selectivity of nanotubes in various ways. The correlations between atomic geometries of chemically functionalized tips and their electronic structures are further discussed. We propose that a hydrogen-terminated tube would be a promising probe tip for selective chemical imaging.open252
Light cone QCD sum rules study of the semileptonic heavy and transitions to and baryons
The semileptonic decays of heavy spin--1/2, and
baryons to the light spin-- 1/2, and baryons are investigated
in the framework of the light cone QCD sum rules. In particular, using the most
general form of the interpolating currents for the heavy baryons as well as the
distribution amplitudes of the and baryons, we calculate all
form factors entering the matrix elements of the corresponding effective
Hamiltonians in full QCD. Having calculated the responsible form factors, we
evaluate the decay rates and branching fractions of the related transitions.Comment: 30 Pages, 5 Figures and 18 Table
Representational predicaments for employees: Their impact on perceptions of supervisors\u27 individualized consideration and on employee job satisfaction
A representational predicament for a subordinate vis-Ć -vis his or her immediate superior involves perceptual incongruence with the superior about the subordinate\u27s work or work context, with unfavourable implications for the employee. An instrument to measure the incidence of two types of representational predicament, being neglected and negative slanting, was developed and then validated through an initial survey of 327 employees. A subsequent substantive survey with a fresh sample of 330 employees largely supported a conceptual model linking being neglected and negative slanting to perceptions of low individualized consideration by superiors and to low overall job satisfaction. The respondents in both surveys were all Hong Kong Chinese. Two case examples drawn from qualitative interviews illustrate and support the conceptual model. Based on the research findings, we recommend some practical exercises to use in training interventions with leaders and subordinates. Ā© 2013 Copyright Taylor and Francis Group, LLC
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