2,570 research outputs found

    Study on the extraction method of transverse open crack’s information

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    For the fault rotor – bearing system caused by transverse open crack. The dynamic model of crack rotor system is established by the crack compliance coefficient matrix which is derived from the stress intensity factor and strain energy density function. The stiffness matrix of rotor system which contains transverse crack faults is different from the health rotor. So the surplus dynamics equation of cracked rotor system can be deduced by comparing the dynamics equations of the crack fault and health rotor system, which is on the basis of getting the compliance coefficient matrix. Furthermore, the information of open crack’s location and crack’s depth can be extracted from the vibration signal by analyzing force condition on both ends of the shaft segment where crack exist and combining with the residual dynamic equation. The extraction method for crack information only needs to collect the vibration signals of the three different node positions under two different speeds. Finally, the feasibility of the method can be verified with simulation and experiment

    The Study of Dust Formation of Six Tidal Disruption Events

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    This paper investigates eleven (UV-)optical-infrared (IR) spectral energy distributions (SEDs) of six tidal disruption events (TDEs), which are ASASSN-14li, ASASSN-15lh, ASASSN-18ul, ASASSN-18zj, PS18kh, and ZTF18acaqdaa. We find that all the SEDs show evident IR excesses. We invoke the blackbody plus dust emission model to fit the SEDs, and find that the model can account for the SEDs. The derived masses of the dust surrounding ASASSN-14li, ASASSN-15lh, ASASSN-18ul, ASASSN-18zj, PS18kh, and ZTF18acaqdaa are respectively 0.71.0(1.52.2)×104M\sim0.7-1.0\,(1.5-2.2)\times10^{-4}\,M_\odot, 0.63.1(1.46.3)×102M\sim0.6-3.1\,(1.4-6.3)\times10^{-2}\,M_\odot, 1.0(2.8)×104M\sim1.0\,(2.8)\times10^{-4}\,M_\odot, 0.11.6(0.33.3)×103M\sim0.1-1.6\,(0.3-3.3)\times10^{-3}\,M_\odot, 1.0(2.0)×103M\sim1.0\,(2.0)\times10^{-3}\,M_\odot, and 1.1(2.9)×103M\sim 1.1\,(2.9)\times10^{-3}\,M_\odot, if the dust is graphite (silicate). The temperature of the graphite (silicate) dust of the six TDEs are respectively 11401430(12101520)\sim1140-1430\,(1210-1520)\,K, 10301380(11001460)\sim1030-1380\,(1100-1460)\,K, 1530(1540)\sim1530\,(1540)\,K, 9601380(10201420)\sim960-1380\,(1020-1420)\,K, 900(950)\sim900\,(950)\,K, and 1600(1610)\sim1600\,(1610)\,K. By comparing the derived temperatures to the vaporization temperature of graphite (1900\sim 1900\,K) and silicate (11001500\sim 1100-1500\,K), we suggest that the IR excesses of PS18kh can be explained by both the graphite and silicate dust, the rest five TDEs favor the graphite dust while the silicate dust model cannot be excluded. Moreover, we demonstrate the lower limits of the radii of the dust shells surrounding the six TDEs are significantly larger than those of the radii of the photospheres at the first epochs of SEDs, indicating that the dust might exist before the the TDEs occurred.Comment: 13 pages, 4 figures, 4 tables, submitted to Ap

    Threshold quantum cryptograph based on Grover's algorithm

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    Grover's operator in the two-qubit case can transform a basis into its conjugated basis. A permutation operator can transform a state in the two conjugated bases into its orthogonal state. These properties are included in a threshold quantum protocol. The proposed threshold quantum protocol is secure based the proof that the legitimate participators can only eavesdrop 2 bits of 3 bits operation information on one two-qubit with error probability 3/8. We propose a scheme to detect the Trojan horse attack without destroying the legal qubit.Comment: 7 pages, 1 figure

    Penta­aqua­(1H-benzimidazole-5,6-di­carboxyl­ato-κN 3)cobalt(II) penta­hydrate

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    In the title mononuclear complex, [Co(C9H4N2O4)(H2O)5]·5H2O, the CoII atom exhibits a distorted octa­hedral geometry involving an N atom of a 1H-benzimidazole-5,6-dicarboxyl­ate ligand and five water O atoms. A supra­molecular network is generated through inter­molecular O—H⋯O hydrogen-bonding inter­actions involving the coordinated and uncoordinated water mol­ecules and the carboxyl O atoms of the organic ligand. An inter­molecular N—H⋯O hydrogen bond is also observed

    FOXE1 polyalanine tract length screening by MLPA in idiopathic premature ovarian failure

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    <p>Abstract</p> <p>Background</p> <p>FOXE1 is one of the candidate genes for genetic predisposition to premature ovarian failure (POF) and it contains an alanine tract. Our purpose is to assess the influence of length of the alanine tract of FOXE1 on genetic susceptibility to POF.</p> <p>Methods</p> <p>The group studied consisted of 110 Chinese patients with idiopathic POF and 110 women from normal controls. The polyalanine tract and flanking sequence of FOXE1 was screened using the Multiple Ligation-dependent Probe Amplification (MLPA) technique and directly sequenced.</p> <p>Results</p> <p>Three variants of FOXE1-polyalanine length, containing 12, 14, or 16 alanine residues, and 5 different genotypes were identified. There were significantly lower frequencies of the 14/14 genotypes in cases with POF (X2 = 119.73, P = 0.001), as compared with the controls. The incidence of 16/16 genotypes of FOXE1-polyalanine was significantly higher in patients with POF (X2 = 3.403, P = 0.001) in comparison to the controls. The FOXE1 14 alanine allele was significantly less common in the POF patient group (186/220) than the controls (216/220) (X2 = 25.923, P = 0.0001). The FOXE1 16 alanine allele was significantly more common in the POF patient group (28/220) than the controls (4/220) (X2 = 19.412, P = 0.0001).</p> <p>Conclusion</p> <p>This finding provides evidence that polyalanine repeat expansions in FOXE1 may be responsible for the genetic aetiology of POF in Chinese women.</p

    catena-Poly[[diaqua­(1,10-phenanthroline-κ2 N,N′)nickel(II)]-μ-1H-benzimidazole-5,6-dicarboxyl­ato-κ2 N 3:O 6]

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    In the title complex, [Ni(C9H4N2O4)(C12H8N2)(H2O)2]n, the NiII atom is hexa­coordinated by one N and one O atom from two different 1H-benzimidazole-5,6-dicarboxyl­ate ligands, two N atoms from one 1,10-phenanthroline ligand and two water mol­ecules. The flexible 1H-benzimidazole-5,6-dicarboxyl­ate ligands link the NiII centres, forming an infinite zigzag chain parallel to [001]. The crystal packing is governed by inter­molecular hydrogen-bonding inter­actions of the O—H⋯O, N—H⋯O and C—H⋯O types

    Study on the extraction method of transverse open crack’s information

    Get PDF
    For the fault rotor – bearing system caused by transverse open crack. The dynamic model of crack rotor system is established by the crack compliance coefficient matrix which is derived from the stress intensity factor and strain energy density function. The stiffness matrix of rotor system which contains transverse crack faults is different from the health rotor. So the surplus dynamics equation of cracked rotor system can be deduced by comparing the dynamics equations of the crack fault and health rotor system, which is on the basis of getting the compliance coefficient matrix. Furthermore, the information of open crack’s location and crack’s depth can be extracted from the vibration signal by analyzing force condition on both ends of the shaft segment where crack exist and combining with the residual dynamic equation. The extraction method for crack information only needs to collect the vibration signals of the three different node positions under two different speeds. Finally, the feasibility of the method can be verified with simulation and experiment

    Study on the extraction method of transverse open crack’s information

    Get PDF
    For the fault rotor – bearing system caused by transverse open crack. The dynamic model of crack rotor system is established by the crack compliance coefficient matrix which is derived from the stress intensity factor and strain energy density function. The stiffness matrix of rotor system which contains transverse crack faults is different from the health rotor. So the surplus dynamics equation of cracked rotor system can be deduced by comparing the dynamics equations of the crack fault and health rotor system, which is on the basis of getting the compliance coefficient matrix. Furthermore, the information of open crack’s location and crack’s depth can be extracted from the vibration signal by analyzing force condition on both ends of the shaft segment where crack exist and combining with the residual dynamic equation. The extraction method for crack information only needs to collect the vibration signals of the three different node positions under two different speeds. Finally, the feasibility of the method can be verified with simulation and experiment

    Spike in transient photocurrent of organic solar cell: Exciton dissociation at interface

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    The effect of exciton interfacial dissociation on transient photocurrent (TPC) in a single-layer organic solar cell is investigated within a time-dependent device model. The spike observed in TPC experiments is attributed to exciton dissociation at the electrode/organic interface. In comparison with the observed negative signal of transient photovoltage (TPV), the spike more directly reflects the charge processes at the interface. Moreover, numerical results show that the spike of TPC is sensitive to the voltage applied on the device and the hole mobility of the organic semiconductor. Further investigation on the spike by the favorable TPC technique is suggested to provide details about the exciton and carrier processes at the interface
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