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To ensure the safety of power cables, temperature monitoring of power cables is critical. In view of the shortcomings of some optical fibre measurement products, a long-distance distributed optical fibre sensor is proposed, which has the advantages of high measurement sensitivity, fast response speed, low false alarm rate, large measurement length, and stable operation. The distributed optical fibre vibration sensing measurement equipment is used to monitor the vibration signals along the cable in real time, and the signal changes before and after the breakdown fault are visually displayed by the patio-temporal spectrum diagram, and the vibration signal of the breakdown point is analysed in time and frequency. The performance of the system was tested, and the experiment verified that the temperature measurement accuracy error range of the temperature measurement system is about ± 5 °C, and it has good stability. At the same time, the positioning accuracy is very high, and the fault point can be accurately located. This can avoid the occurrence of cable accidents.

In many astrophysical black hole systems, episodic jets of plasma blobs have been observed, which are much faster and more powerful than continuous jets. A magnetohydrodynamical model was proposed by Yuan et al. to study the formation of episodic jets in Sgr A*. By taking Sgr A* and a stellar mass black hole as examples, we modify the model of Yuan et al. by including the effects of relativity, and further study the relativistic motion and expansion of episodic jets of plasma blobs. Then we study the collision between two consecutive ejections in the modified model, and calculate the magnetic energy released in the collision. Our results show two consecutive blobs can collide with each other, and the released magnetic energy is more than 10(50) erg, which supports the idea that a gamma-ray burst is powered by the collision of episodic jets, as suggested by Yuan & Zhang.

We obtain preliminary limits on a logarithmic correction to the Newtonian gravitational potential by using five binary pulsars: PSR J0737-3039, PSR B1534+12, PSR J1756-2251, PSR B1913+16 and PSR B2127+11C. This kind of correction may originate from fundamental frameworks, like string theories, effective models of grav- ity due to quantum effects and the non-local gravity scheme. We estimate the upper limit of the Tohline-Kuhn-Kruglyak parameter ‚ and the lower limit of the Fabris- Campos parameter fi, which parameterize the correction and are connected to each other by fi‚ = i1. By analyzing the advances of periastron of these binary pulsars, we find that the preliminary upper limit of fi is 0:19 § 0:14 kpc i1 and the prelimi- nary lower limit of ‚ is i5:2 § 3:8 kpc. They are compatible with the bounds based on dynamics of spiral galaxies but quite different from those given by solar system dynamics. These results indicate that this logarithmic correction might be more ob- servable in current timings of binary pulsars than in motions of the solar system.

Synchronization of Kuramoto phase oscillators arranged in real complex neural networks is investigated. It is shown that the synchronization greatly depends on the sets of natural frequencies of the involved oscillators. The influence of network connectivity heterogeneity on synchronization depends particularly on the correlation between natural frequencies and node degrees. This finding implies a potential application that inhibiting the effects caused by the changes of network structure can be balanced out nicely by choosing the correlation parameter appropriately.

New physics beyond the standard model of particles might cause deviation from the inverse-square law of gravity. In many theoretical models of modified gravity, it is parameterized by the Yukawa correction to the Newtonian gravitational force in terms of two parameters fi and ‚. Here fi is a dimensionless strength parameter and ‚ is a length scale. Using the supplementary advances in perihelia provided by INPOP10a and EPM2011 ephemerides, we obtain new upper limits on the deviation from the inverse-square law when the uncertainty of the Sun's quadrupole moment is taken into account. We find that INPOP10a yields the upper limits as fi = 3:1£10 i11 and ‚ = 0:15 au, and EPM2011 gives fi = 5:2 £ 10 i11 and ‚ = 0:21 au. In both of them, fi is at least 10 times less than the previous results.

We give the bilinear form and n-soliton solutions of a (2+1)-dimensional [(2+1)-D] extended shallow water wave (eSWW) equation associated with two functions v and r by using Hirota bilinear method. We provide solitons, breathers, and hybrid solutions of them. Four cases of a crucial ϕ ( y ) , which is an arbitrary real continuous function appeared in f of bilinear form, are selected by using Jacobi elliptic functions, which yield a periodic solution and three kinds of doubly localized dormion-type solution. The first order Jacobi-type solution travels parallelly along the x axis with the velocity ( 3 k 1 2 + α , 0 ) on (x, y)-plane. If ϕ ( y ) = sn ( y , 3 / 10 ) , it is a periodic solution. If ϕ ( y ) = cn ( y , 1 ) , it is a dormion-type-I solutions which has a maximum ( 3 / 4 ) k 1 p 1 and a minimum − ( 3 / 4 ) k 1 p 1 . The width of the contour line is ln [ ( 2 + 6 + 2 + 3 ) / ( 2 + 6 − 2 − 3 ) ] . If ϕ ( y ) = sn ( y , 1 ) , we get a dormion-type-II solution (26) which has only one extreme value − ( 3 / 2 ) k 1 p 1 . The width of the contour line is ln [ ( 2 + 1 ) / ( 2 − 1 ) ] . If ϕ ( y ) = sn ( y , 1 / 2 ) / ( 1 + y 2 ) , we get a dormion-type-III solution (21) which shows very strong doubly localized feature on (x,y) plane. Moreover, several interesting patterns of the mixture of periodic and localized solutions are also given in graphic way.

On-line monitoring of dissolved gas in transformer oil can effectively judge the early fault of transformer. The existing monitoring devices are generally based on gas chromatography, which need to be replaced carrier gas and calibrated periodically, therefore, the maintenance work is heavy. In recent years, photoacoustic spectrum technology with the advantages of high accuracy and no carrier gas required is gradually stressed, but its measurement accuracy is susceptible to mechanical vibration and noise, and its main components such as modulation disk is prone to failure. For this reason, this paper proposes an on-line monitoring device for dissolved gas in transformer oil based on spectrum technology, which doesn't need carrier gas and maintenance during operation. The device is simpler and lighter in structure and better in performance. The device can on-line monitor 7 kinds of dissolved gas in transformer oil, and has functions such as transformer fault diagnosis, remote alarm, local man-machine interaction, local storage, and supports multiple communication modes such as IEC61850 protocol. The field application shows that the device can provide the basis for transformer fault diagnosis.

The two dimensions hole-doped t—t'—J—U model was studied based on the Gutzwiller approach and the renormalized mean-field theory. The phase diagrams of gossamer superconductors and the effects of the next-nearest-neighbor hopping (t') on superconductivity and antiferromagnetism based on the t—t'—J—U model were investigated. The results show that the qualitative feature of the phase diagrams in the t—t'—J—U model is the same as in the case of the t—J—U model. The antiferromagnetic order coexists with the d-wave superconductivity (dSC) in the underdoped region below the doping δ ≈ 0.1 and is enhanced by the t'. The dSC order is slightly suppressed by t' in the underdoped region and greatly enhanced in the overdoped region. The dSC order is pushed to a larger doping region and the coexistence region of the AF and dSC extends to higher doping.

We report combined magnetic susceptibility, dielectric constant, nuclear quadruple resonance (NQR) and zero-field nuclear magnetic resonance (NMR) measurements on single crystals of multiferroics CuBr$_2$. High quality of the sample is demonstrated by the sharp magnetic and magnetic-driven ferroelectric transition at $T_N=T_C\approx$ 74~K. The zero-field $^{79}$Br and $^{81}$Br NMR are resolved below $T_N$. The spin-lattice relaxation rates reveal charge fluctuations when cooled below 60~K. Evidences of an increase of NMR linewidth, a reduction of dielectric constant, and an increase of magnetic susceptibility are also seen at low temperatures. These data suggest an emergent instability which competes with the spiral magnetic ordering and the ferroelectricity. Candidate mechanisms are discussed based on the quasi-one-dimensional (1D) nature of the magnetic system.

We study the formation mechanism and microstructure of nickel (Ni) atomic aggregates on the silicone oil surfaces by atomic force microscopy (AFM). Initially, the deposited atoms nucleate and form the compact clusters on the liquid surfaces. Then they perform Brownian motion and adhere upon impact. Finally the branched aggregates are formed. The Ni aggregates exhibit granular structure. The mean size of the granularities in the aggregates is of the order of 10 nm and it decreases with the nominal film thickness. The experiment shows that the Ni aggregates perform a directional diffusion towards the sample edge. The interpretation for this phenomenon is presented.

A technique and system of measuring screw thread parameter based on the theory of laser measurement is presented in this paper, which can be carried out the automated measurement of screw thread parameter. An inspection instrument was designed and produced, which included exterior imaging system of optical path, transverse displacement measurement system, axial displacement measurement system, and a module to deal with, control and assess the data in the upper system. The inspection and estimate of the screw thread contour curve were completed by using position sensitive device (PSD) as photoelectric detector to measure the coordinate data of the screw thread contour curve in the transverse section, and using precise raster to measure the axial displacement of the precision worktable under the screw thread test criterion., computer can gives a measured result according to coordinate data of the screw thread obtained by PSD. The relation between measured spot and image is established, and optimum design of the system organization are introduced, including the image length of receiving lens focal length optical system and the choice of PSD , and some main factor affected measuring precision are analyzed. The experimental results show that the measurement uncertainty of screw thread minor diameter can reach 0. 5μm, which can meet most requests for the measurement of screw thread parameter.

When laser-beam passes through non-isothermal and non-isoconcentration gas, measurement result is influenced by different refractive index in gas flow layer. This paper analyses the regularities of index of refraction distribution in gas flow field, presents the factors that effect on the measurement errors, estimates the position errors of the indicating light-spot and modifies the measurement result in laser-beam measure.

A new fabrication technique based on etching is employed to convert a copper foil into a porous structure with an array of micron size pores. The motivation stems from the need to develop a more efficient and controllable gas diffusion medium for fuel cell applications. The influence of mask shape, mask width and etching time was investigated experimentally. A correlation to predict trench width with etching time was derived; normalizing by mask width allows one to collapse the data. The etching rates to obtain micro-scale features, which are of the order of 1–2 µ mm in –1 , are mainly dominated by the mask width due to mass-transport resistance. It is possible to control the pore dimensions, porosity and pore size distributions with this technique. (Some figures in this article are in colour only in the electronic version)

The thermodynamic properties of proton transport along hydrogen-bonded systems at finite temperatures have been studied by our model. We first derive the dynamic equations of the proton transport and find the solutions and the free energy of the systems. Finally, we obtain the specific heats of the hydrogen bonded systems, resulting from the motion of the soliton, by using transfer integral way. The theoretical value is basically consistent with the experimental data.

The generic behavior of both flow-induced phase separations and rheological responses of complex fluids has been studied. We solve a two-fluid model numerically in a strong-flow regime without using the diffusive equation linearization and adiabatic approximation. Our results show that the formation of the mechanical shear bands and the fluid composition bands can be closely interrelated. We have identified correlations between the microstructure evolution and rheology, and also different mechanisms to reach the steady state. The rheological signature of demixing fluids under shear is that the dependence of the steady-state shear stress on shear rate changes from non-linear to linear. The model selects a steady-state stress in a natural physical way for non-monotonic constitutive equations under strong flow.

An algorithm for the biochemical imaging of heterogeneity in the bio-tissue with finite parallel-plane geometry simultaneously using the data of reflectance and transmittance of diffuse-photon density waves is presented. In this algorithm, the priori knowledge of heterogeneity is not needed. This algorithm is suitable for the imaging of heterogeneity in the large volume tissue and in small organs. To reduce the errors produced by the algorithm, it is suggested that the experiment should be performed in two steps, at first step the light source should be placed at one boundary to measure the data of reflectance and transmittance, and these data are used to construct the heterogeneous function in the half space close to the light source; at the second step the light source should be placed at another boundary to measure the data of reflectance and transmittance, these data are used to construct the heterogeneous function in another half space closed to the light source; after taking above two steps the heterogeneous function in the whole space is constructed.

Diode-laser absorption computerized tomography is applied to the diagnosis of the plume generated by an arcjet thruster. A protection stack is designed to carry a laser beam into the arcjet flow field at any location in the vacuum chamber. The experimental system is developed to reconstruct the maps of the temperature and the atomic number density by utilizing a small number of line-of-sight measurements. It has been demonstrated to be a convenient and useful method for the measurement of plume parameters and for monitoring the performance of the arcjet.

We give a study on the general Moller transformation and emphatically introduce its differential form. In this paper, a definition of acceleration is given in spacetime language and the inertial reference frame is also settled. With a discussion of the geodesic equations of motion, the differential form of the general Moller transformation at arbitrary direction is presented.

Using the transport theory to describe the near infrared light propagating in tissue with finite parallel-plane geometry, and taking the zero-boundary condition, we obtain the analytical expression of average photon density and Green's function incorporating the boundary effects in the homogeneous tissure. Making use of perturbation theory we also obtain the analytical expression of scattered wave induced by the heterogeneity, and present the 2-dimensional spatial transform of scattered wave with respect to transverse coordinate. If the information of heterogeneity on depth and thickness is available, diffraction tomography formula is presented to save the time of image reconstruction; if the information is unknown, we suggest to obtain the inhomogeneous function from the one-dimensional integral equation of 2-dimensional spatial transform of scattered wave applying the direct matrix method or iterative method for image reconstruction. This approach avoids directly solving three-dimensional integral equation of scattered wave. In our proposed approach the strong points of the direct matrix method, iterative method, and diffraction tomography are fully combined.

Shear banding of wormlike micelle solution has been studied in the context of constitutive instability of the Johnson-Segalman (JS) model plus Newtonian stress. We have incorporated a higher-order gradient term of the deformation-rate tensor into the JS model for investigating the dynamics of a mechanical interface in shear-banded flow. Two-dimensional modelling of the new model has been carried out by a general Lagrangian-Eulerian scheme. Within the unstable region, our results show that the new term plays an important role in selecting steady-state shear stress and the selected stress is independent of the nominal shear rate. The transit period of reaching the steady state can be much longer than the intrinsic relaxation time of the JS fluid. We have verified the experimental evidence on the existence of mechanical metastable regime, over which hysteresis in flow curve might occur. The model captures many features of experimental results on shear banded flow.

Presented here is a study of the large pT J/ production in double pomeron exchange processes via gluon fragmentation at hadron colliders. We use three sets of parametrization (hard gluon, hard quark, and soft gluon) for the parton distribution in the pomeron to estimate the production cross section. We find that the J/ production rate is sensitive to the gluon component of the pomeron. Especially, at the LHC the soft gluon parametrization gives the J/ production rate two order of magnitude larger than that hard gluon parametrization gives.

An abrasive single-sided lapping approach is applied to the thinning of assembled cells of liquid crystal displays (LCDs). The approach reduces the thickness and weight of the panels, thereby enhancing the aesthetics and ease of use of portable display devices. In this study, a new mathematical model has been developed to describe the mechanism applied to this advanced technology and verified by experiments. The model can help find the optimum parameters for the thinning process and the suitable dimensions of a single-sided lapping machine for the LCD cell thinning process.

We investigate the standard model Higgs decays into heavy quarkonia and in both colour-singlet and colour-octet mechanisms. It is found that in production the contribution through colour-octet processes overwhelm that in colour-singlet processes in the intermediate region and the fraction ratio is comparatively large, but in production the contribution through the colour-octet mechanism is negligible.

We present an analysis of the production from double-parton (DP) scattering and single-parton (SP) scattering in the large region via colour-octet gluon fragmentation. We find that at the Tevatron the DP production is at the edge of the detectability at present, and at the LHC, the DP cross section will dominate over the SP cross section in the lower region (i.e. ). We also conclude that the colour-octet mechanism is of crucial importance to the double production at high-energy hadron colliders.

In this paper, the antifriction behaviours of (3:1) molecules and their crystal powder were evaluated by different methods. It was found that the crystal powder possessed hexagonal close packed (hcp) crystal structure with a = 10.1 A and c = 16.55 A, and a transformation of crystal structure from hcp to face centred cubic (fcc) occurred easily during friction (burnishing). It was confirmed that two kinds of process, breakage of powder coagulated by nanoscale single crystals and rearrangement of the molecules along the friction direction, had occurred under the friction force. The extreme pressure (EP) performance of as an additive in paraffin liquid was investigated on an SRV oscillating wear machine. It was found that the extreme pressure load (EP value) of paraffin liquid was increased by dispersion of powder, accompanied by a slight improvement in the antifriction behaviour. it was confirmed that the improvement in EP value and antifriction behaviour of oil was dependent on the crystal structure of powder, but independent of the spherical molecular structure of or . The burnishing experimental results also proved that the antifriction behaviour was determined by the crystal structure and had no relation to the molecular structure. It was also found that fullerenes possessed some physical properties similar to those of graphite. Since the formation of compact fullerenes with high shear strength during friction can be effectively prevented by some other lubricants, it is suggested that fullerenes should be mixed with other lubricants for tribological application.

Superconducting cables offer the advantages of lower loss, lighter weight and smaller dimensions, as compared to conventional cables. A 4 m, 2 kA, AC, HTS cable system was developed for the purpose of study. The cable conductor was made of Bi-2223 tapes. A space maintained as a vacuum between two corrugated stainless steel tubes functions as a cryostat surrounding the superconductor. A closed cycle liquid nitrogen cooling system was exploited. The cable was matched with two terminations, which connect the cable conductor at cryogenic temperature to an outside common electric conductor at room temperature and offer a path for liquid nitrogen. A series of tests were carried out to verify the functions of the system. Important data were obtained which can be used for making longer HTS cable systems.

We discuss the final state interaction effects at high energies via a multi-channel N/D method. We find that the 2 by 2 charge--exchange final state interactions typically contribute an enhancement factor of a few times $10^{-2}$ in the $B$ meson decay amplitudes, both for the real and the imaginary part. We also make some discussions on the elastic rescattering effects., Comment: 10 pages, revtex

Relative absorption intensities of the Fermi resonance polyads of isolated C-H chromophore for the CHCl3 molecule are calculated by one-dimensional dipole moment surface which had been obtained by the ab initio density functional method B3PW91 with 6-311++G(3df, 2pd) basis set, and agree very well with the experimental results. It is shown that the nonlinearity of the dipole moment surface in the vicinity of the equilibrium configuration is responsible for the intensities anomaly, i.e. the unusual strong intensities of the second Fermi resonance polyad.

The global transonic solutions describing advection dominated accretion flows around black holes are obtained by directly integrating the set of differential equations from the sonic point inward to the horizon and outward. The results show that the sonic points can locate themselves at almost any radius, regardless of the viscous parameter α and polytropic index γ. This result is greatly different with previous ones. Example solutions with very different values of Rs from 4.3 to 300Rg and with γ = 1.5, 5/3 are given explicitly. The consistency between this result and that in inviscid flows is emphasized.

It is well known that fluorescence x-ray absorption spectroscopy suffers from the self-absorption effects for thick and concentrated samples. In this study, a simple correction method is provided for correcting the self-absorption effects of fluorescence x-ray absorption near edge structure (XANES) spectrum for multilayer samples. This method is validated by application on fluorescence XANES spectra for a Cr/C multilayer measured at different incidence angles. The errors produced by the self-absorption effects for the measured fluorescence x-ray absorption spectra without corrections are also estimated and discussed.