Improving the precision of multiparameter estimation in the teleportation of qutrit under amplitude damping noise

Since the initial discovery of quantum teleportation, it is devoted to transferring unknown quantum states from one party to another distant partner. However, in the scenarios of remote sensing, what people truly care about is the information carried by certain parameters. The problem of multiparameter estimation in the framework of qutrit teleportation under amplitude damping (AD) noise is studied. Particularly, two schemes are proposed to battle against AD noise and enhance the precision of multiparameter estimation by utilizing weak measurement (WM) and environment-assisted measurement (EAM). For two-phase parameters encoded in a qutrit state, the analytical formulas of the quantum Fisher information matrix (QFIM) can be obtained. The results prove that the scheme of EAM outperforms the WM one in the improvements of both independent and simultaneous estimation precision. Remarkably, the EAM scheme can completely ensure the estimation precision against the contamination by AD noise. The reason should be attributed to the fact that EAM is carried out after the AD noise. Thus, it extracts information from both the system and the environment. The findings show that the techniques of WM and EAM are helpful for remote quantum sensing and can be generalized to other qutrit-based quantum information tasks under AD decoherence.Comment: 9 pages, 5 figures, accepted by Annalen der Physi

Dissecting the γ\gamma-ray emissions of the nearby galaxies NGC 1068 and NGC 253

Intrigued by recent high-energy study results for nearby galaxies with gamma-ray emission and in particular NGC~1068 that has been detected as a neutrino-emitting source by the IceCube Neutrino Observatory, we conduct detailed analysis of the $\gamma$-ray data for the galaxies NGC~1068 and NGC~253, obtained with the Large Area Telescope onboard {\it the Fermi Gamma-ray Space Telescope}. By checking for their possible spectral features and then constructing light curves in corresponding energy ranges, we identify flare-like activity from NGC ~1068 in $\geq$2\,GeV energy range and significant long-term variations of NGC~253 in $\geq$5\,GeV energy range. In the former, the emission appears harder in the two half-year flare-like events than that in the otherwise `quiescent' state. In the latter, there is a 2-times decrease in the flux before and after MJD~57023, which is clearly revealed by the test-statistic maps we obtain. Considering studies carried out and models proposed for the $\gamma$-ray emissions of the two sources, we discuss the implications of our findings. The jet in NGC~1068 may contribute to the \gr\ emission. The nature of the long-term variations in NGC~253 is not clear, but the variation part of the emission may be connected to the very-high-energy (VHE) emission of the galaxy and could be verified by VHE observations.Comment: 9 pages, 6 figures, 2 tables, submitted to Ap

TLS-bridged co-prediction of tree-level multifarious stem structure variables from worldview-2 panchromatic imagery: a case study of the boreal forest

In forest ecosystem studies, tree stem structure variables (SSVs) proved to be an essential kind of parameters, and now simultaneously deriving SSVs of as many kinds as possible at large scales is preferred for enhancing the frontier studies on marcoecosystem ecology and global carbon cycle. For this newly emerging task, satellite imagery such as WorldView-2 panchromatic images (WPIs) is used as a potential solution for co-prediction of tree-level multifarious SSVs, with static terrestrial laser scanning (TLS) assumed as a ‘bridge’. The specific operation is to pursue the allometric relationships between TLS-derived SSVs and WPI-derived feature parameters, and regression analyses with one or multiple explanatory variables are applied to deduce the prediction models (termed as Model1s and Model2s). In the case of Picea abies, Pinus sylvestris, Populus tremul and Quercus robur in a boreal forest, tests showed that Model1s and Model2s for different tree species can be derived (e.g. the maximum R2 = 0.574 for Q. robur). Overall, this study basically validated the algorithm proposed for co-prediction of multifarious SSVs, and the contribution is equivalent to developing a viable solution for SSV-estimation upscaling, which is useful for large-scale investigations of forest understory, macroecosystem ecology, global vegetation dynamics and global carbon cycle.This work was financially supported in part by the National Natural Science Foundation of China [grant numbers 41471281 and 31670718] and in part by the SRF for ROCS, SEM, China. (41471281 - National Natural Science Foundation of China; 31670718 - National Natural Science Foundation of China; SRF for ROCS, SEM, China)http://www-tandfonline-com.ezproxy.bu.edu/doi/abs/10.1080/17538947.2016.1247473?journalCode=tjde20Published versio

HAZ Phase Transformation and Thermal Damage for Laser Remanufacturing a High-Strength Stainless Steel

It briefly introduced laser remanufacturing, which was an advanced repairing method to refabricate damaged components based on laser forming technologies. The possible factors in determining the performance of the laser remanufacturing FV520B were studied by numerical simulation and experimental methods. First, the results of free dilatometry test showed that the volume effect of phase transformations were corresponding to the transformation temperatures and heating rate of the laser process had remarkable effects on the kinetics of phase transformation. In addition, the evolution of temperature fields of the single-pass and multi-layer laser cladding processes were analyzed by numerical simulation method based on deactivate and reactivate element theory. A combined method of dilatometry and metallography was conducted to reveal the effect of cooling condition and phase transformation on the microstructure of HAZ. The maximum temperature of thermal cycle had a dominating effect on the microstructure, microhardness and phase transformation temperature rather than cooling rate. Thermal cycles had a significant effect on the metallographic transformation and consequently decided the mechanical performance. Microhardness and tensile tests were conducted and the results showed that strength and ductility of laser remanufacturing FV520B were equivalent to that of forgings

A modified ant colony optimization algorithm for network coding resource minimization

The paper presents a modified ant colony optimization approach for the network coding resource minimization problem. It is featured with several attractive mechanisms specially devised for solving the network coding resource minimization problem: 1) a multi-dimensional pheromone maintenance mechanism is put forward to address the issue of pheromone overlapping; 2) problem-specific heuristic information is employed to enhance the heuristic search (neighboring area search) capability; 3) a tabu-table based path construction method is devised to facilitate the construction of feasible (link-disjoint) paths from the source to each receiver; 4) a local pheromone updating rule is developed to guide ants to construct appropriate promising paths; 5) a solution reconstruction method is presented, with the aim of avoiding prematurity and improving the global search efficiency of proposed algorithm. Due to the way it works, the ant colony optimization can well exploit the global and local information of routing related problems during the solution construction phase. The simulation results on benchmark instances demonstrate that with the five extended mechanisms integrated, our algorithm outperforms a number of existing algorithms with respect to the best solutions obtained and the computational time

Tetra-μ-benzoato-κ8 O:O′-bis­[(benzoic acid-κO)nickel(II)]

The title compound, [Ni2(C7H5O2)4(C7H6O2)2], is composed of two NiII ions, four bridging benzoate anions and two η1-benzoic acid mol­ecules. The [Ni2(PhCOO)4] unit adopts a typical paddle-wheel conformation. The center between the two NiII atoms represents a crystallographic center of inversion. In addition, each NiII ion also coordinates to one O atom from a benzoic acid mol­ecule. The crystal packing is realised by inter­molecular hydrogen-bonding inter­actions and π–π stacking inter­actions, with a centroid–centroid distance of 3.921 (1) Å

Rare manifestation of familial vitreous amyloidosis caused by Gly103Arg transthyretin

AIM: To identify and analyze the genotype of the patients with special ocular manifestations of familial vitreous amyloidosis (FVA) in a Chinese Han family. METHODS: Pars plana vitrectomy (PPV) surgery was performed on a 52-year-old Chinese woman presented with vitreous amyloidosis and progressive visual impairment, without evidence of cardiac, renal, gastrointestinal, central nervous system or peripheral nervous system dysfunction. During the surgery, the patient presented with a gray-white dense and thick cotton wool-like change in the vitreous body, accompanied by complete retinal detachment. Additionally, hard, free and movable yellow-white deposits were observed in the posterior pole and surrounding retina, the vitreous and subretinal deposits were examined by Congo red staining and immunohistochemical pathological examination, and whole exome sequencing was performed on blood samples from the patient and her cousin. RESULTS: During the operation, it was discovered that there was a complete detachment of the retina and a significant amount of hard, free-floating yellow-white deposits were observed beneath the posterior pole and surrounding retina. This is an exceedingly rare ocular manifestation. Pathological examination of the vitreous and subretinal deposit specimens revealed positive Congo red staining, as well as elevated vascular endothelial growth factor (VEGF) expression in vascular endothelial cells within the sediment specimens upon immunohistochemical examination. The patient and her cousin both exhibited a heterozygous mutation in Glyl03Arg within the transthyretin (TTR) gene, resulting in a substitution of glycine (Gly) at position 103 with arginine (Arg). CONCLUSION: FVA may present with various ocular manifestations, but panretinal detachment is a rare occurrence. In cases where retinal detachment persists for an extended period of time, amyloid deposits may form under the retina through retinal tears, leading to subretinal deposits that can impede retinal reattachment and negatively impact visual prognosis. Elevated levels of VEGF in the eyes of FVA patients may indicate an overexpression state, necessitating careful postoperative follow-up. The heterozygous mutation Gly103Arg may represent a unique pathogenic site in Chinese individuals

Poly[(μ2-quinoline-3-carboxyl­ato-κ2 N:O)(μ2-quinoline-3-carboxyl­ato-κ3 N:O,O′)cadmium]

In the title compound, [Cd(C10H6NO2)2]n, the CdII atom is coordinated by three O atoms and two N atoms from four quinoline-3-carboxyl­ate (L −) ligands, leading to a distorted trigonal–bipyramidal geometry. The L − ligands link the CdII atoms into a plane parallel to (100), with one ligand being tridentate, coordinating via the N atom and chelating a second Cd atom, and the other being bidentate, bridging two Cd atoms via the N and one O atom.. This two-dimensional network extends into a double-layer network by π–π inter­actions, with centroid–centroid distances of 3.680 (2) and 3.752 (2) Å. Another type of π–π inter­action between pyridine rings [centroid–centroid distance = 3.527 (2) Å] leads to a three-dimensional supra­molecular architecture