An hourglass model for the flare of HST-1 in M87

To explain the multi-wavelength light curves (from radio to X-ray) of HST-1 in the M87 jet, we propose an hourglass model that is a modified two-zone system of Tavecchio & Ghisellini (hereafter TG08): a slow hourglass-shaped or Laval nozzle-shaped layer connected by two revolving exponential surfaces surrounding a fast spine, through which plasma blobs flow. Based on the conservation of magnetic flux, the magnetic field changes along the axis of the hourglass. We adopt the result of TG08---the high-energy emission from GeV to TeV can be produced through inverse Compton by the two-zone system, and the photons from radio to X-ray are mainly radiated by the fast inner zone system. Here, we only discuss the light curves of the fast inner blob from radio to X-ray. When a compressible blob travels down the axis of the first bulb in the hourglass, because of magnetic flux conservation, its cross section experiences an adiabatic compression process, which results in particle acceleration and the brightening of HST-1. When the blob moves into the second bulb of the hourglass, because of magnetic flux conservation, the dimming of the knot occurs along with an adiabatic expansion of its cross section. A similar broken exponential function could fit the TeV peaks in M87, which may imply a correlation between the TeV flares of M87 and the light curves from radio to X-ray in HST-1. The Very Large Array (VLA) 22 GHz radio light curve of HST-1 verifies our prediction based on the model fit to the main peak of the VLA 15 GHz radio light curve.Comment: 14 pages, 2 figures, accepted for publication in A

Efficient universal quantum computation with auxiliary Hilbert space

We propose a scheme to construct the efficient universal quantum circuit for qubit systems with the assistance of possibly available auxiliary Hilbert spaces. An elementary two-ququart gate, termed the controlled-double-NOT gate, is proposed first in ququart (four-level) systems, and its physical implementation is illustrated in the four-dimensional Hilbert spaces built by the path and polarization states of photons. Then an efficient universal quantum circuit for ququart systems is constructed using the gate and the quantum Shannon decomposition method. By introducing auxiliary two-dimensional Hilbert spaces, the universal quantum circuit for qubit systems is finally achieved using the result obtained in ququart systems with the lowest complexity

2-(2,4,6-Trichloro­phen­oxy)ethyl bromide

In the title compound, C8H6BrCl3O, there is a weak intra­molecular C—H⋯Cl hydrogen bond involving the O bound methylene group. Intermolecular Cl⋯Cl contacts [3.482 (2) Å] are present in the crystal structure

Algorithms for Complex Systems Reliability Analysis Based on Bayesian Network

With the increase of complex systems functions, the number of its components will rise. This will lead to the amount of state combinations of components increasing exponentially. In order to solve this problem, a new compression algorithm and a new inference algorithm are developed to analyze the reliability of complex systems based on Bayesian Network in this paper. A satellite transmission system reliability is used to validate the proposed algorithms.This work was supported by the National Natural Science Foundation of China (No.51675525 and 11725211)

Hydrogen Generation from Al-NiCl2/NaBH4 Mixture Affected by Lanthanum Metal

The effect of La on Al/NaBH4 hydrolysis was elaborated in the present paper. Hydrogen generation amount increases but hydrogen generation rate decreases with La content increasing. There is an optimized composition that Al-15 wt% La-5 wt% NiCl2/NaBH4 mixture (Al-15 wt% La-5 wt% NiCl2/NaBH4 weight ratio, 1 : 3) has 126 mL g−1 min−1 maximum hydrogen generation rate and 1764 mL g−1 hydrogen generation amount within 60 min. The efficiency is 88%. Combined with NiCl2, La has great effect on NaBH4 hydrolysis but has little effect on Al hydrolysis. Increasing La content is helpful to decrease the particle size of Al-La-NiCl2 in the milling process, which induces that the hydrolysis byproduct Ni2B is highly distributed into Al(OH)3 and the catalytic reactivity of Ni2B/Al(OH)3 is increased therefore. But hydrolysis byproduct La(OH)3 deposits on Al surface and leads to some side effect. The Al-La-NiCl2/NaBH4 mixture has good stability in low temperature and its hydrolytic performance can be improved with increasing global temperature. Therefore, the mixture has good safety and can be applied as on board hydrogen generation material

Common promoter variants of the NDUFV2 gene do not confer susceptibility to schizophrenia in Han Chinese

<p>Abstract</p> <p>Background</p> <p>The NADH-ubiquinone oxidoreductase flavoprotein gene (<it>NDUFV2</it>), which encodes a 24 kD mitochondrial complex I subunit, has been reported to be positively associated with schizophrenia and bipolar disorder in different populations.</p> <p>Methods</p> <p>We genotyped the promoter variants of this gene (rs6506640 and rs1156044) by direct sequencing in 529 unrelated Han Chinese schizophrenia patients and 505 matched controls. Fisher's Exact test was performed to assess whether these two reported single nucleotide polymorphisms (SNPs) confer susceptibility to schizophrenia in Chinese.</p> <p>Results</p> <p>Allele, genotype and haplotype comparison between the case and control groups showed no statistical significance, suggesting no association between the <it>NDUFV2 </it>gene promoter variants and schizophrenia in Han Chinese.</p> <p>Conclusion</p> <p>The role of NDUFV2 played in schizophrenia needs to be further studied. Different racial background and/or population substructure might account for the inconsistent results between studies.</p

Three-dimensional Isotropic Droplets in Rydberg-dressed Bose Gases

We predict a scheme for the creation of isotropic three-dimensional droplets in Rydbeg-dressed Bose gases, which contain both repulsive contact interactions and attractive van der Waals interactions causing the quantum fluctuation effect non-negligible. We present detailed beyond mean-field calculations with Lee-Huang-Yang correction and demonstrate the existence of isotropic droplets under realistic experimental conditions. Stable droplets possess flat-top density distribution, and their chemical potentials decrease with the particle number expansion towarding a critical value. We distinguish droplets from bright solitons through peak density, width of condensate and quantum depletion calculations. We summarize a phase diagram of realizing droplets, and subsequently highlight the stability of droplets by real time evolution as well as collisions. Our work provides a novel platform for investigating excitation spectrum and superfluid nature of droplets

1-(3-Bromopropoxy)-4-chlorobenzene

In the mol­ecule of the title compound, C8H8BrClO, the Cl atom lies slightly out of the aromatic ring plane [displacement = 0.072 (3) Å]. In the crystal structure, a π–π contact between the phenyl rings [centroid–centroid distance = 3.699 (3) Å] may stabilize the structure. There also exists a C—H⋯π contact between the methyl­ene group and the chloro­phenyl ring