The roles of deformation and orientation in heavy-ion collisions induced by light deformed nuclei at intermediate energy

The reaction dynamics of axisymmetric deformed $^{24}$Mg + $^{24}$Mg collisions have been investigated systematically by an isospin-dependent quantum molecular dynamics (IDQMD) model. It is found that different deformations and orientations result in apparently different properties of reaction dynamics. We revealed that some observables such as nuclear stopping power ($R$), multiplicity of fragments, and elliptic flow are very sensitive to the initial deformations and orientations. There exists an eccentricity scaling of elliptic flow in central body-body collisions with different deformations. In addition, the tip-tip and body-body configurations turn out to be two extreme cases in central reaction dynamical process.Comment: 5 pages, 7 figures, to appear in Physical Review C (Rapid Communication

On a sharp volume estimate for gradient Ricci solitons with scalar curvature bounded below

In this note, we obtain a sharp volume estimate for complete gradient Ricci solitons with scalar curvature bounded below by a positive constant. Using Chen-Yokota's argument we obtain a local lower bound estimate of the scalar curvature for the Ricci flow on complete manifolds. Consequently, one has a sharp estimate of the scalar curvature for expanding Ricci solitons; we also provide a direct (elliptic) proof of this sharp estimate. Moreover, if the scalar curvature attains its minimum value at some point, then the manifold is Einstein.Comment: 15 pages. Added some references and an appendix to give a more simple computation of the volume estimat

Molecular Cloning and Identification of Novel ω-gliadin Genes from Species

Gliadin is a main component of gluten proteins that affect functional properties of bread making and contributes to the viscous nature of doughs. In this study, thirteen novel ω-gliadin genes were identified in several Triticum species, which encode the ARH-, ATDand ATN-type proteins. Two novel types of ω-gliadins: ATD- and ATN- have not yet been reported. The lengths of 13 sequences were ranged from 927 to 1269 bp and the deduced mature proteins were varied from 309 to 414 residues. All 13 genes were pseudogenes because of the presence of internal stop codons. The primary structure of these ω-gliadin genes included a signal peptide, a conserved N-terminal domain, a repetitive domain and a conserved C-terminus. In this paper, we first characterize ω-gliadin genes from T. timopheevi ssp. timopheevi and T. timopheevi ssp. araraticum. The ω-gliadin gene variation and the evolutionary relationship of ω-gliadin family genes were also discussed

Optoelectronic oscillator for 5G wireless networks and beyond

With the development of 5G wireless network and beyond, the wireless carrier frequency will definitely reach millimeter-wave (mm-wave) and even terahertz (THz). As one of the key elements in wireless networks, the local oscillator (LO) needs to operate at mm-wave and THz band with lower phase noise, which becomes a major challenge for commercial LOs. In this article, we investigate the recent developments of the electronic integrated circuit (EIC) oscillator and the optoelectronic oscillator (OEO), and especially investigate the prospect of OEO serving as a qualified LO in the 5G wireless network and beyond. Both the EIC oscillators and OEOs are investigated, including their basic theories of operation, representative techniques and some milestones in applications. Then, we compare the performances between the EIC oscillators and the OEOs in terms of frequency accuracy, phase noise, power consumption and cost. After describing the specific requirements of LO based on the standard of 5G and 6G wireless communication systems, we introduce an injection-locked OEO architecture which can be implemented to distribute and synchronize LOs. The OEO has better phase noise performance at high frequency, which is greatly desired for LO in 5G wireless network and beyond. Besides, the OEO provides an easy and low-loss method to distribute and synchronize mm-wave and THz LOs. Thanks to photonic integrated circuit development, the power consumption and cost of OEO reduce gradually. It is foreseeable that the integrated OEO with lower cost may have a promising prospect in the 5G wireless network and beyond

Structural and superconducting properties in LaFeAs1-xSbxO1-yFy

We report the antimony (Sb) doping effect in a prototype system of iron-based supercon-ductors LaFeAsO1-yFy (y=0, 0.1, 0.15). X-ray powder diffraction indicates that the lattice pa-rameters increase with Sb content within the doping limit. Rietveld structural refinements show that, with the partial substitution of Sb for As, while the thickness of the Fe2As2 layers increases significantly, that of the La2O2 layers shrinks simultaneously. So a negative chemical pressure is indeed "applied" to the superconducting-active Fe2As2 layers, in con-trast to the effect of positive chemical pressure by the phosphorus doping. Electrical resis-tance and magnetic susceptibility measurements indicate that, while the Sb doping hardly influences the SDW anomaly in LaFeAsO, it recovers SDW order for the optimally-doped sample of y=0.1. In the meantime, the superconducting transition temperature can be raised up to 30 K in LaFeAs1-xSbxO1-yFy with x=0.1 and y=0.15. The Sb doping effects are discussed in term of both J1-J2 model and Fermi Surface (FS) nesting scenario.Comment: 7 pages, 4 figures, 1 table. to be published in Science in China Series

Expression of tung tree diacylglycerol acyltransferase 1 in E. coli

<p>Abstract</p> <p>Background</p> <p>Diacylglycerol acyltransferases (DGATs) catalyze the final and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. Database search has identified at least 59 DGAT1 sequences from 48 organisms, but the expression of any DGAT1 as a full-length protein in <it>E. coli </it>had not been reported because DGAT1s are integral membrane proteins and difficult to express and purify. The objective of this study was to establish a procedure for expressing full-length DGAT1 in <it>E. coli</it>.</p> <p>Results</p> <p>An expression plasmid containing the open reading frame for tung tree (<it>Vernicia fordii</it>) DGAT1 fused to maltose binding protein and poly-histidine affinity tags was constructed and expressed in <it>E. coli </it>BL21(DE3). Immunoblotting showed that the recombinant DGAT1 (rDGAT1) was expressed, but mostly targeted to the membranes and insoluble fractions. Extensive degradation also occurred. Nonetheless, the fusion protein was partially purified from the soluble fraction by Ni-NTA and amylose resin affinity chromatography. Multiple proteins co-purified with DGAT1 fusion protein. These fractions appeared yellow in color and contained fatty acids. The rDGAT1 was solubilized from the insoluble fraction by seven detergents and urea, with SDS and Triton X-100 being the most effective detergents. The solubilized rDGAT1 was partially purified by Ni-NTA affinity chromatography. PreScission protease digestion confirmed the identity of rDGAT1 and showed extensive precipitation following Ni-NTA affinity purification.</p> <p>Conclusions</p> <p>This study reports the first procedure for expressing full-length DGAT1 from any species using a bacterial expression system. The results suggest that recombinant DGAT1 is degraded extensively from the carboxyl terminus and associated with other proteins, lipids, and membranes.</p

Effects of charge doping and constrained magnetization on the electronic structure of an FeSe monolayer

The electronic structural properties in the presence of constrained magnetization and a charged background are studied for a monolayer of FeSe in non-magnetic, checkerboard-, and striped-antiferromagnetic (AFM) spin configurations. First principles techniques based on the pseudopotential density functional approach and the local spin density approximation are utilized. Our findings show that the experimentally observed shape of the Fermi surface is best described by the checkerboard AFM spin pattern. To explore the underlying pairing mechanism, we study the evolution of the non-magnetic to the AFM-ordered structures under constrained magnetization. We estimate the strength of electronic coupling to magnetic excitations involving an increase in local moment and, separately, a partial moment transfer from one Fe atom to another. We also show that the charge doping in the FeSe can lead to an increase in the density of states at the Fermi level and possibly produce higher superconducting transition temperatures

Measurement of electron antineutrino oscillation based on 1230 days of operation of the Daya Bay experiment

A measurement of electron antineutrino oscillation by the Daya Bay Reactor Neutrino Experiment is described in detail. Six 2.9-GWth nuclear power reactors of the Daya Bay and Ling Ao nuclear power facilities served as intense sources of nu((e) over bar)\u27s. Comparison of the (v) over bare rate and energy spectrum measured by antineutrino detectors far from the nuclear reactors (similar to 1500-1950 m) relative to detectors near the reactors (similar to 350-600 m) allowed a precise measurement of (v) over bar (e) disappearance. More than 2.5 million (v) over bar (e) inverse beta-decay interactions were observed, based on the combination of 217 days of operation of six antineutrino detectors (December, 2011-July, 2012) with a subsequent 1013 days using the complete configuration of eight detectors (October, 2012-July, 2015). The (v) over bar (e) rate observed at the far detectors relative to the near detectors showed a significant deficit, R = 0.949 +/- 0.002(stat) +/- 0.002(syst). The energy dependence of (v) over bar (e) disappearance showed the distinct variation predicted by neutrino oscillation. Analysis using an approximation for the three-flavor oscillation probability yielded the flavor-mixing angle sin(2)2 theta(13) = 0.0841 +/- 0.0027(stat) +/- 0.0019(syst) and the effective neutrino mass-squared difference of broken vertical bar Delta m(ee)(2)vertical bar = (2.50 +/- 0.06(stat) +/- 0.06(syst)) x 10(-3) eV(2). Analysis using the exact three-flavor probability found Delta m(32)(2) = (2.45 +/- 0.06(stat) +/- 0.06d(syst)) x 10(-3) eV(2) assuming the normal neutrino mass hierarchy and Delta m(32)(2) = (-2.56 +/- 0.06(stat) +/- 0.06(syst)) x 10(-3) eV(2) for the inverted hierarchy