Numerical analysis and case study on the mitigation of mining damage to the floor of no. 5 coal seam of Taiyuan Group by grouting

Based on the geological condition of panel 22507 of the no. 5 coal seam at Dongjiahe coal mine, numerical analysis of the stability and water permeability of the floor aquiclude before and after grouting was conducted using Rock Failure Process Analysis (F-RFPA2D). The dynamic development, extension, and distribution of the cracks in the aquiclude are discussed. It is shown that grouting can increase the effective thickness of the aquiclude, reduce the floor damage depth, and control the floor water inrush path, thus effectively improving the overall strength and water blocking capability of the aquiclude. These numerical study results were applied to facilitate relevant engineering work at Dongjiahe coal mine. The mitigation measures involved grouting the floor of the no. 5 coal seam, allowing panel 22507 to be mined safely above confined water. This exercise provided invaluable experience in preventing water inrush hazards

Dinitrogen Activation in the Gas Phase: Spectroscopic Characterization of C–N Coupling in the V₃C⁺ + N₂ Reaction

We report on cluster-mediated C–N bond formation in the gas phase using N2 as a nitrogen source. The V3C+ + N2 reaction is studied by a combination of ion-trap mass spectrometry with infrared photodissociation (IRPD) spectroscopy and complemented by electronic structure calculations. The proposed reaction mechanism is spectroscopically validated by identifying the structures of the reactant and product ions. V3C+ exhibits a pyramidal structure of C1 symmetry. N2 activation is initiated by adsorption in an end-on fashion at a vanadium site, followed by spontaneous cleavage of the N≡N triple bond and subsequent C−N coupling. The IRPD spectrum of the metal nitride product [NV3(C=N)]+ exhibits characteristic C=N double bond (1530 cm-1) and V-N single bond (770, 541 and 522 cm-1) stretching bands

Enhanced Production of Palmarumycins C12 and C13 in Mycelial Liquid Culture of the Endophytic Fungus Berkleasmium

Purpose: To evaluate in situ macroporous resin adsorption for enhancement of palmarumycins C12 and C13 production in mycelial liquid culture of the endophytic fungus Berkleasmium sp. Dzf12.Methods: Ten macroporous adsorption resins (D-101, D1300, HPD-100, X-5, AB-8, DM130, ADS-17, DA-201, NKA-9 and S-8) were tested for absorption of palmarumycins C12 and C13 in mycelial liquid culture of the endophytic fungus Berkleasmium sp. Dzf12.Results: Among the resins, DA-201 showed the most significant enhancing effect on accumulation of palmarumycins C12 and C13 in mycelial liquid culture of endophytic fungus Berkleasmium sp. Dzf12. When resin DA-201 was applied to the medium at a concentration of 4.17 % on day 11 and then harvested on day 15, the maximal yield of palmarumycins C12 and C13 was 149.86 and 55.78 mg/L, which correspond to 70.69- and 1.82-fold higher than for control (2.12 and 30.70 mg/L, respectively). Approximately 95.81 % of palmarumycin C12 and 87.20 % of palmarumycin C13 were distributed in resin DA-201.Conclusion: The results indicate that in situ resin adsorption is an effective strategy for enhancing the production of palmarumycins C12 and C13, and also for facilitating their recovery from the mycelial liquid culture of Berkleasmium sp. Dzf12.Keywords: Endophytic fungus, Berkleasmium sp. Dzf12, Spirobisnaphthalene, Palmarumycin, Macroporous adsorption resins, Mycelial liquid cultur

Multitemporal Very High Resolution from Space: Outcome of the 2016 IEEE GRSS Data Fusion Contest

In this paper, the scientific outcomes of the 2016 Data Fusion Contest organized by the Image Analysis and Data Fusion Technical Committee of the IEEE Geoscience and Remote Sensing Society are discussed. The 2016 Contest was an open topic competition based on a multitemporal and multimodal dataset, which included a temporal pair of very high resolution panchromatic and multispectral Deimos-2 images and a video captured by the Iris camera on-board the International Space Station. The problems addressed and the techniques proposed by the participants to the Contest spanned across a rather broad range of topics, and mixed ideas and methodologies from the remote sensing, video processing, and computer vision. In particular, the winning team developed a deep learning method to jointly address spatial scene labeling and temporal activity modeling using the available image and video data. The second place team proposed a random field model to simultaneously perform coregistration of multitemporal data, semantic segmentation, and change detection. The methodological key ideas of both these approaches and the main results of the corresponding experimental validation are discussed in this paper

Majorana Neutrinos and Gravitational Oscillation

We analyze the possibility of encountering resonant transitions of high energy Majorana neutrinos produced in Active Galactic Nuclei (AGN). We consider gravitational, electromagnetic and matter effects and show that the latter are ignorable. Resonant oscillations due to the gravitational interactions are shown to occur at energies in the PeV range for magnetic moments in the $10^{-17} \mu_B$ range. Coherent precession will dominate for larger magnetic moments. The alllowed regions for gravitational resonant transitions are obtained.Comment: 11 pages, 8 figures, Latex; requires revtex and epsf.tex submitted to Physical Review

Combination therapy of orally administered glycyrrhizin and UVB improved active-stage generalized vitiligo

Abstract Glycyrrhizin has been used clinically for several years due to its beneficial effect on immunoglobulin E (IgE)-induced allergic diseases, alopecia areata and psoriasis. In this study, glycyrrhizin, ultraviolet B light (UVB) or a combination of both were used to treat active-stage generalized vitiligo. One hundred and forty-four patients between the ages of 3 and 48 years were divided into three groups: group A received oral compound glycyrrhizin (OCG); group B received UVB applications twice weekly, and group C received OCG+UVB. Follow-ups were performed at 2, 4, and 6 months after the treatment was initiated. The Vitiligo Area Scoring Index (VASI) and the Vitiligo Disease Activity (VIDA) instrument were used to assess the affected body surface, at each follow-up. Results showed that 77.1, 75.0 and 87.5% in groups A, B and C, respectively, presented repigmentation of lesions. Responsiveness to therapy seemed to be associated with lesion location and patient compliance. Adverse events were limited and transient. This study showed that, although the three treatment protocols had positive results, OCG and UVB combination therapy was the most effective and led to improvement in disease stage from active to stable

Hydrodynamics and Nonlocal Conductivities in Vortex States of Type II Superconductors

A hydrodynamical description for vortex states in type II superconductors is presented based on the time-dependent Ginzburg-Landau equation (TDGL). In contrast to the familiar extension of a single vortex dynamics based on the force balance, our description is consistent with the known hydrodynamics of a rotating neutral superfluid and correctly includes informations on the Goldstone mode. Further it enables one to examine nonlocal conductivities perpendicular to the magnetic field in terms of Kubo formula. The nonlocal conductivities deviate from the usual vortex flow expressions typically when the nonlocality parallel to the field becomes weaker than the perpendicular one measuring a degree of positional correlations, and, for instance, the superconducting contribution of dc Hall conductivity nonlocal only in directions perpendicular to the field becomes vanishingly small in the situations with large shear viscosity, leading to an experimentally measurable relation $\rho_{xy} \sim {\rho_{xx}^2}$ among the total resistivity components. Other situations are also discussed on the basis of the resulting expressions.Comment: 12 pages, no figures, to appear in J. Phys. Soc. Jpn. in October, 199

Turbulence and Multiscaling in the Randomly Forced Navier Stokes Equation

We present an extensive pseudospectral study of the randomly forced Navier-Stokes equation (RFNSE) stirred by a stochastic force with zero mean and a variance $\sim k^{4-d-y}$, where $k$ is the wavevector and the dimension $d = 3$. We present the first evidence for multiscaling of velocity structure functions in this model for $y \geq 4$. We extract the multiscaling exponent ratios $\zeta_p/\zeta_2$ by using extended self similarity (ESS), examine their dependence on $y$, and show that, if $y = 4$, they are in agreement with those obtained for the deterministically forced Navier-Stokes equation ($3d$NSE). We also show that well-defined vortex filaments, which appear clearly in studies of the $3d$NSE, are absent in the RFNSE.Comment: 4 pages (revtex), 6 figures (postscript

Graphene-based modulation-doped superlattice structures

The electronic transport properties of graphene-based superlattice structures are investigated. A graphene-based modulation-doped superlattice structure geometry is proposed and consist of periodically arranged alternate layers: InAs/graphene/GaAs/graphene/GaSb. Undoped graphene/GaAs/graphene structure displays relatively high conductance and enhanced mobilities at elevated temperatures unlike modulation-doped superlattice structure more steady and less sensitive to temperature and robust electrical tunable control on the screening length scale. Thermionic current density exhibits enhanced behaviour due to presence of metallic (graphene) mono-layers in superlattice structure. The proposed superlattice structure might become of great use for new types of wide-band energy gap quantum devices.Comment: 5 figure

Electronic Origin of High Temperature Superconductivity in Single-Layer FeSe Superconductor

The latest discovery of high temperature superconductivity signature in single-layer FeSe is significant because it is possible to break the superconducting critical temperature ceiling (maximum Tc~55 K) that has been stagnant since the discovery of Fe-based superconductivity in 2008. It also blows the superconductivity community by surprise because such a high Tc is unexpected in FeSe system with the bulk FeSe exhibiting a Tc at only 8 K at ambient pressure which can be enhanced to 38 K under high pressure. The Tc is still unusually high even considering the newly-discovered intercalated FeSe system A_xFe_{2-y}Se_2 (A=K, Cs, Rb and Tl) with a Tc at 32 K at ambient pressure and possible Tc near 48 K under high pressure. Particularly interesting is that such a high temperature superconductivity occurs in a single-layer FeSe system that is considered as a key building block of the Fe-based superconductors. Understanding the origin of high temperature superconductivity in such a strictly two-dimensional FeSe system is crucial to understanding the superconductivity mechanism in Fe-based superconductors in particular, and providing key insights on how to achieve high temperature superconductivity in general. Here we report distinct electronic structure associated with the single-layer FeSe superconductor. Its Fermi surface topology is different from other Fe-based superconductors; it consists only of electron pockets near the zone corner without indication of any Fermi surface around the zone center. Our observation of large and nearly isotropic superconducting gap in this strictly two-dimensional system rules out existence of node in the superconducting gap. These results have provided an unambiguous case that such a unique electronic structure is favorable for realizing high temperature superconductivity