3,917 research outputs found
Quantum-state filtering applied to the discrimination of Boolean functions
Quantum state filtering is a variant of the unambiguous state discrimination
problem: the states are grouped in sets and we want to determine to which
particular set a given input state belongs.The simplest case, when the N given
states are divided into two subsets and the first set consists of one state
only while the second consists of all of the remaining states, is termed
quantum state filtering. We derived previously the optimal strategy for the
case of N non-orthogonal states, {|\psi_{1} >, ..., |\psi_{N} >}, for
distinguishing |\psi_1 > from the set {|\psi_2 >, ..., |\psi_N >} and the
corresponding optimal success and failure probabilities. In a previous paper
[PRL 90, 257901 (2003)], we sketched an appplication of the results to
probabilistic quantum algorithms. Here we fill in the gaps and give the
complete derivation of the probabilstic quantum algorithm that can optimally
distinguish between two classes of Boolean functions, that of the balanced
functions and that of the biased functions. The algorithm is probabilistic, it
fails sometimes but when it does it lets us know that it did. Our approach can
be considered as a generalization of the Deutsch-Jozsa algorithm that was
developed for the discrimination of balanced and constant Boolean functions.Comment: 8 page
Thermodynamics of Extended Bodies in Special Relativity
Relativistic thermodynamics is generalized to accommodate four dimensional
rotation in a flat spacetime. An extended body can be in equilibrium when its
each element moves along a Killing flow. There are three types of basic Killing
flows in a flat spacetime, each of which corresponds to translational motion,
spatial rotation, and constant linear acceleration; spatial rotation and
constant linear acceleration are regarded as four dimensional rotation.
Translational motion has been mainly investigated in the past literature of
relativistic thermodynamics. Thermodynamics of the other two is derived in the
present paper.Comment: 8 pages, no figur
The African Lungfish (\u3cem\u3eProtopterus dolloi\u3c/em\u3e): Ionoregulation and Osmoregulation in a Fish out of Water
Although urea production and metabolism in lungish have been thoroughly studied, we have little knowledge of how internal osmotic and electrolyte balance are controlled during estivation or in water. We tested the hypothesis that, compared with the body surface of teleosts, the slender African lungfish (Protopterus dolloi) body surface was relatively impermeable to water, Na+ and Cl- due to its greatly reduced gills. Accordingly, we measured the tritiated water (3H-H2O) flux in P. dolloi in water and during air exposure. In water, 3H-H2O efflux was comparable with the lowest measurements reported in freshwater teleosts, with a rate constant (K) of 17.6% body water h-1. Unidirectional ion fluxes, measured using 22Na+ and 36Cl-, indicated that Na+ and Cl- influx was more than 90% lower than values reported in most freshwater teleosts. During air exposure, a cocoon formed within 1 wk that completely covered the dorsolateral body surface. However, there were no disturbances to blood osmotic or ion (Na+, Cl-) balance, despite seven- to eightfold increases in plasma urea after 20 wk. Up to 13-fold increases in muscle urea (on a dry-weight basis) were the likely explanation for the 56% increase in muscle water content observed after 20 wk of air exposure. The possibility that muscle acted as a âwater reservoirâ during air exposure was supported by the 20% decline in body mass observed during subsequent reimmersion in water. This decline in body mass was equivalent to 28 mL water in a 100-g animal and was very close to the calculated net water gain (approximately 32 mL) observed during the 20-wk period of air exposure. Tritiated water and unidirectional ion fluxes on air-exposed lungfish revealed that the majority of water and ion exchange was via the ventral body surface at rates that were initially similar to aquatic rates. The 3H-H2O flux declined over time but increased upon reimmersion. We conclude that the slender lungfish body surface, including the gills, has relatively low permeability to water and ions but that the ventral surface is an important site of osmoregulation and ionoregulation. We further propose that an amphibian-like combination of ventral skin water and ion permeability, plus internal urea accumulation during air exposure, allows P. dolloi to extract water from its surroundings and to store water in the muscle when the water supply becomes limited
Structural behaviour of post-installed reinforcement bars in moment connections of wall-slabs
Post-installed reinforcement (PIR) bars helps to facilitate retrofitting works, mitigate misplaced reinforcement problems, as well as support newly casted additions. However, the use of PIR has not been addressed in the major reinforced concrete (RC) design codes worldwide. Recently, the European standards have introduced a beneficial coefficient of moments in EN 1992-4 2018 for concrete fastenings which allows compliant PIR systems to be designed by using the bonded anchor (BA) design method. However, when applying this method to wall-slab connection design, the moment resisting capacity is often limited by the lack of bar spacing and small concrete covers. This means that the method neglects long embedment depths and the connections designed based on this method are prone to brittle failure. In this paper, the strut and tie model (STM), which can better describe PIR with long embedment depths, together with the fundamental reinforced concrete (RC) theory is used to improve the ductility of moment connections with PIR bars. An experimental study is conducted to explore the structural behaviour of applying PIR bars that connect the wall and slab. Validations on the proposed STM and supplement to the BA design methods are made. From the experimental findings, measures are then proposed to enhance the ductility of the moment connections
Fermented pumpkin-based beverage inhibits key enzymes of carbohydrate digesting and extenuates postprandial hyperglycemia in type-2 diabetic rats
A novel functional pumpkin-based beverage fermented by Lactobacillus mali K8 (FPJ) was produced. FPJ possessed higher ferric reducing antioxidant power (FRAP, 270.76 ÎŒM TE/100 ml) and radical scavenging activity (RSAâIC50, 7.56 mg mlâ1) compared with non-inoculated control (PJ) (102.99 ÎŒM TE/100 ml and IC50 52.78 mg mlâ1). Up to an IC50 of 23.71 and 5.27 mg mlâ1 of α-amylase and α-glucosidase inhibitions were demonstrated by FPJ, close to that of acarbose (IC50 4.86 and 0.048 mg mlâ1, respectively). Oral administration of FPJ significantly lowered post-meal blood glucose levels in low-dose streptozotocin (STZ) and high-fat diet-treated rat â a reduction of incremental areas under the curve 2334 versus 2689 mmol min lâ1. Thus, it may open new dietary measure in managing postprandial hyperglycaemia
Pulsed squeezed light: simultaneous squeezing of multiple modes
We analyze the spectral properties of squeezed light produced by means of
pulsed, single-pass degenerate parametric down-conversion. The multimode output
of this process can be decomposed into characteristic modes undergoing
independent squeezing evolution akin to the Schmidt decomposition of the
biphoton spectrum. The main features of this decomposition can be understood
using a simple analytical model developed in the perturbative regime. In the
strong pumping regime, for which the perturbative approach is not valid, we
present a numerical analysis, specializing to the case of one-dimensional
propagation in a beta-barium borate waveguide. Characterization of the
squeezing modes provides us with an insight necessary for optimizing homodyne
detection of squeezing. For a weak parametric process, efficient squeezing is
found in a broad range of local oscillator modes, whereas the intense
generation regime places much more stringent conditions on the local
oscillator. We point out that without meeting these conditions, the detected
squeezing can actually diminish with the increasing pumping strength, and we
expose physical reasons behind this inefficiency
Unified Treatment of Heterodyne Detection: the Shapiro-Wagner and Caves Frameworks
A comparative study is performed on two heterodyne systems of photon
detectors expressed in terms of a signal annihilation operator and an image
band creation operator called Shapiro-Wagner and Caves' frame, respectively.
This approach is based on the introduction of a convenient operator
which allows a unified formulation of both cases. For the Shapiro-Wagner
scheme, where , quantum phase and amplitude
are exactly defined in the context of relative number state (RNS)
representation, while a procedure is devised to handle suitably and in a
consistent way Caves' framework, characterized by , within the approximate simultaneous measurements of
noncommuting variables. In such a case RNS phase and amplitude make sense only
approximately.Comment: 25 pages. Just very minor editorial cosmetic change
Effects of geometric anisotropy on local field distribution: Ewald-Kornfeld formulation
We have applied the Ewald-Kornfeld formulation to a tetragonal lattice of
point dipoles, in an attempt to examine the effects of geometric anisotropy on
the local field distribution. The various problems encountered in the
computation of the conditionally convergent summation of the near field are
addressed and the methods of overcoming them are discussed. The results show
that the geometric anisotropy has a significant impact on the local field
distribution. The change in the local field can lead to a generalized
Clausius-Mossotti equation for the anisotropic case.Comment: Accepted for publications, Journal of Physics: Condensed Matte
Nonlinear ac response of anisotropic composites
When a suspension consisting of dielectric particles having nonlinear
characteristics is subjected to a sinusoidal (ac) field, the electrical
response will in general consist of ac fields at frequencies of the
higher-order harmonics. These ac responses will also be anisotropic. In this
work, a self-consistent formalism has been employed to compute the induced
dipole moment for suspensions in which the suspended particles have nonlinear
characteristics, in an attempt to investigate the anisotropy in the ac
response. The results showed that the harmonics of the induced dipole moment
and the local electric field are both increased as the anisotropy increases for
the longitudinal field case, while the harmonics are decreased as the
anisotropy increases for the transverse field case. These results are
qualitatively understood with the spectral representation. Thus, by measuring
the ac responses both parallel and perpendicular to the uniaxial anisotropic
axis of the field-induced structures, it is possible to perform a real-time
monitoring of the field-induced aggregation process.Comment: 14 pages and 4 eps figure
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