Tighter constraints of multiqubit entanglement in terms of R\'{e}nyi-α\alpha entropy

Quantum entanglement plays essential roles in quantum information processing. The monogamy and polygamy relations characterize the entanglement distributions in the multipartite systems. We present a class of monogamy inequalities related to the $\mu$th power of the entanglement measure based on R\'{e}nyi-$\alpha$ entropy, as well as polygamy relations in terms of the $\mu$th powered of R\'{e}nyi-$\alpha$ entanglement of assistance. These monogamy and polygamy relations are shown to be tighter than the existing ones.Comment: 10 pages, 2 figure

Tetrahedron genuine entanglement measure of four-qubit systems

Quantifying genuine entanglement is a key task in quantum information theory. We study the quantification of genuine multipartite entanglement for four-qubit systems. Based on the concurrence of nine different classes of four-qubit states, with each class being closed under stochastic local operation and classical communication, we construct a concurrence tetrahedron. Proper genuine four-qubit entanglement measure is presented by using the volume of the concurrence tetrahedron. For non genuine entangled pure states, the four-qubit entanglement measure classifies the bi-separable entanglement. We show that the concurrence tetrahedron based measure of genuine four-qubit entanglement is not equivalent to the genuine four-partite entanglement concurrence. We illustrate the advantages of the concurrence tetrahedron by detailed examples.Comment: 23 pages, 4 figure

Adiabatic Fidelity for Atom-Molecule Conversion in a Nonlinear Three-Level \Lambda-system

We investigate the dynamics of the population transfer for atom-molecule three-level $\Lambda$-system on stimulated Raman adiabatic passage(STIRAP). We find that the adiabatic fidelity for the coherent population trapping(CPT) state or dark state, as the function of the adiabatic parameter, approaches to unit in a power law. The power exponent however is much less than the prediction of linear adiabatic theorem. We further discuss how to achieve higher adiabatic fidelity for the dark state through optimizing the external parameters of STIRAP. Our discussions are helpful to gain higher atom-molecule conversion yield in practical experiments.Comment: 4 pages, 5 figure

(5-Bromo-2-hy­droxy­phen­yl)(4-propyl­cyclo­hex­yl)methanone

In the title compound, C16H21BrO2, the cyclo­hexane ring adopts a chair conformation. The hy­droxy and carbonyl groups are involved in an intra­molecular O—H⋯O hydrogen bond. In the crystal, weak C—H⋯O inter­actions link the mol­ecules into zigzag chains along [010]

A Multi-camera Network System for Markerless 3D Human Body Voxel Reconstruction

This paper presents a fully automated system for real-time 3D human visual hull reconstruction and skeleton vox-els extraction. The main contributions include: (1) A novel network based system is presented, which uses AXIS net-work cameras as video capture device, and performs a parallel processing among data capture, 3D voxel recon-struction and display. (2) A new human visual hull re-construction algorithm is given. This approach firstly seg-ments the foreground accurately by an efficient Gaussian Mixture Model (GMM) and a shadow model in HSV color space, then extends the standard Shape-From-Silhouette (SFS) algorithm with online Region-of-Interest (ROI) esti-mation and binary searching, and finally construct skele-ton probability visual hull with distance transform. Exper-iments with real video sequences show that the system can process eleven 640x480 video sequences at a frame rate of 15fps, and construct human body voxels reliably in complex scenarios with cast shadows, various body configurations and multiple persons. 1

Study on erosion and stability of the ecological slope

Rainfall is the main influencing factor causing slope erosion, landslide, and instability in loess; thus, it is vital to comprehend the process of rainfall erosion on various slope surfaces and water penetration inside the slope. In this paper, the loess sample is from Heifangtai in Gansu Province, and triaxial shear tests were conducted on loess with roots under varying water contents to evaluate the slope-reinforcing impact of roots. The slope surface erosion process was analyzed using a soil moisture sensor and matric suction meter to monitor the variation of matric suction in the middle slope and slope foot in response to varying precipitation levels. The numerical simulation approach is utilized to analyze the fluctuation of slope stability under the effect of varying rainfall intensities and humid heat, and the analytical solution of the safety factor is compared to the model solution. The results indicate that the shortest generation time for bare slope runoff is 6 min, whereas the greatest generation time for the Bermuda grass slope is 12 min; the shorter the period, the less water penetration and the simpler it is to reach the slope erosion stage. The slope’s rise increases runoff velocity, strengthening water resistance on the slope surface. When the test slope is 30°, the maximum mass of scouring sediment on the bare slope is 15.2 g from 24 to 36 min, compared to 14.7 g from 24 to 36 min when the test slope is 60°. The amount of scouring reduces as the slope increases. The slope safety factor declined from 3.51 to 2.84 after 24 h of heavy rain, and the loss rate accelerated as the rainfall intensity increased