Conditions for Nondistortion Interrogation of Quantum System

Under some physical considerations, we present a universal formulation to study the possibility of localizing a quantum object in a given region without disturbing its unknown internal state. When the interaction between the object and probe wave function takes place only once, we prove the necessary and sufficient condition that the object's presence can be detected in an initial state preserving way. Meanwhile, a conditioned optimal interrogation probability is obtained.Comment: 5 pages, Revtex, 1 figures, Presentation improved, corollary 1 added. To appear in Europhysics Letter

Effect and Compensation of Timing Jitter in Through-Wall Human Indication via Impulse Through-Wall Radar

Impulse through-wall radar (TWR) is considered as one of preferred choices for through-wall human indication due to its good penetration and high range resolution. Large bandwidth available for impulse TWR results in high range resolution, but also brings an atypical adversity issue not substantial in narrowband radars — high timing jitter effect, caused by the non-ideal sampling clock at the receiver. The fact that impulse TWR employs very narrow pulses makes little jitter inaccuracy large enough to destroy the signal correlation property and then degrade clutter suppression performance. In this paper, we focus on the timing jitter impact on clutter suppression in through-wall human indication via impulse TWR. We setup a simple timing jitter model and propose a criterion namely average range profile (ARP) contrast is to evaluate the jitter level. To combat timing jitter, we also develop an effective compensation method based on local ARP contrast maximization. The proposed method can be implemented pulse by pulse followed by exponential average background subtraction algorithm to mitigate clutters. Through-wall experiments demonstrate that the proposed method can dramatically improve through-wall human indication performance

On the nature of the lightest scalar resonances

We briefly review the recent progresses in the new unitarization approach being developed by us. Especially we discuss the large $N_c$ $\pi\pi$ scatterings by making use of the partial wave $S$ matrix parametrization form. We find that the $\sigma$ pole may move to the negative real axis on the second sheet of the complex $s$ plane, therefore it raises the interesting question that this `$\sigma$' pole may be related to the $\sigma$ in the linear $\sigma$ model.Comment: Talk presented by Zheng at ``Quark Confinement and Hadron Spectroscopy VI'', 21--25 Sept. 2004, Cagliari, Italy. 3 pages with 2 figure

Search for a circum-planetary material and orbital period variations of short-period Kepler exoplanet candidates

A unique short-period Mercury-size Kepler exoplanet candidate KIC012557548b has been discovered recently by Rappaport et al. (2012). This object is a transiting disintegrating exoplanet with a circum-planetary material - comet-like tail. Close-in exoplanets, like KIC012557548b, are subjected to the greatest planet-star interactions. This interaction may have various forms. In certain cases it may cause formation of the comet-like tail. Strong interaction with the host star, and/or presence of an additional planet may lead to variations in the orbital period of the planet. Our main aim is to search for comet-like tails similar to KIC012557548b and for long-term orbital period variations. We are curious about frequency of comet-like tail formation among short-period Kepler exoplanet candidates. We concentrate on a sample of 20 close-in candidates with a period similar to KIC012557548b from the Kepler mission.Comment: 19 pages, 75 figures, AN accepte

An effective ant-colony based routing algorithm for mobile ad-hoc network

An effective Ant-Colony based routing algorithm for mobile ad-hoc network is proposed in this paper. In this routing scheme, each path is marked by path grade, which is calculated from the combination of multiple constrained QoS parameters such as the time delay, packet loss rate and bandwidth, etc. packet routing is decided by the path grade and the queue buffer length of the node. The advantage of this scheme is that it can effectively improve the packet delivery ratio and reduce the end-to-end delay. The simulation results show that our proposed algorithm can improve the packet delivery ratio by 9%-22% and the end-to-end delay can be reduced by 14%-16% as compared with the conventional QAODV and ARA routing schemes

Efecto del estrés producido por la mezcla de sales en la concentración de aldehído malónico, proteínas y enzimas antioxidantes de Leymus chinensis de tres colores foliares diferentes

The mixed salt stress is common in nature. Salt stressalways affects plant growth. Different plant species have different adaptive capacity to salty soil. Leymus chinensis is an herbaceous plant with different leaf colors. However, little research was conducted to explore the different tolerance mechanisms to salt stress among the three different leaf colour genotypes of Leymus chinensis (grey green, transitional color, yellow green). Pot experiments for Leymus chinensis in three leaf colors were conducted under mixed salt treatments in 2010. Malondialdehyde (MDA) and protein concentrations, and the activity of various antioxidant enzymes [i.e., superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDHAR)] were determined and compared among the three leaf color genotypes of Leymus chinensis. The concentrations of MDA and protein, and the activity of antioxidant enzymes showed an increasing trend with increasing pHs in almost all three leaf colors, and all of them became highest when salt stress and pH values were also highest. Moreover, antioxidant enzymes were the highest in the grey-green leaf color, and the lowest in the yellow green leaf color after exposure to the same pH treatment. The results suggested that all three leaf colors of Leymus chinensis were tolerant to salt stress, and the salt-tolerance declined according to the order of grey green > transitional color > yellow green of Leymus chinensis. This study can give us a better understanding of the intra-species adaptation to mixed salt soils.El estrés causado por mezcla de sales en el suelo es común en la naturaleza. El estrés salino siempre afecta el crecimiento de las plantas. Plantas de especies diferentes difieren en su capacidad de adaptación al estrés por sales en el suelo. Leymus chinensis es una planta herbácea con diferentes colores foliares. Sin embargo, se han conducido pocos estudios tendientes a determinar los diferentes mecanismos de tolerancia al estrés salino entre los tres genotipos de color foliar diferente de L. chinensis (grisáceo verdoso, color intermedio, amarillo verdoso). En 2010, se condujeron experimentos en macetas usando genotipos de L. chinensis de tres colores diferentes de hoja expuestos o no a tratamientos conteniendo una mezcla de sales. Las concentraciones de aldehído malónico (MDA) y proteínas, y la actividad de varias enzimas antioxidantes [es decir, la superóxido dismutasa (SOD), catalasa (CAT), ascórbico peroxidasa (APX), glutatión reductasa (GR), dehidroascórbico reductasa (DHAR) y monodehidroascórbico reductasa (MDHAR)] se determinaron y compararon entre los tres genotipos de color foliar diferente de L. chinensis. Las concentraciones de MDA y proteínas, y la actividad de enzimas antioxidantes mostraron una tendencia a incrementarse a mayores pHs en casi todos los colores foliares, y las tendencias en los tres colores foliares alcanzaron su punto máximo cuando el estrés salino y los valores de pH fueron máximos. Más aún, las concentraciones de las enzimas antioxidantes fueron las más altas en el color grisáceo verdoso, intermedias en el color intermedio, y las más bajas en el color amarillo verdoso después de la exposición al mismo tratamiento de pH. Los resultados sugirieron que los genotipos de los tres colores foliares de L. chinensis fueros tolerantes al estrés salino, y la tolerancia a la sal declinó de acuerdo al orden grisáceo verdoso > color intermedio > amarillo verdoso de L. chinensis. Este estudio puede proveer un mejor entendimiento de la adaptación intraespecífica de L. chinensis a suelos salinos.Fil: Zhou, C.. Chinese Academy of Science; China. Liaoning University; ChinaFil: Busso, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Yang, Y. G.. Liaoning University; ChinaFil: Zhang, Z.. Shenyang University; ChinaFil: Wang, Z. W.. Chinese Academy of Science; ChinaFil: Yang, Y. F.. Northeast Normal University; ChinaFil: Han, X. G.. Chinese Academy of Science; Chin

Analyticity and the NcN_c counting rule of SS matrix poles

By studying $\pi\pi$ scattering amplitudes in the large $N_c$ limit, we clarify the $N_c$ dependence of the $S$ matrix pole position. It is demonstrated that analyticity and the $N_c$ counting rule exclude the existence of $S$ matrix poles with ${\cal M}, \Gamma\sim O(1)$. Especially the properties of $\sigma$ and $f_0(980)$ with respect to the $1/N_c$ expansion are discussed. We point out that in general tetra-quark resonances do not exist.Comment: This paper replaces hep-ph/0412175. The latter is withdraw