ALBERT

Description: The regenerated cellulose (RCE) hydrogels were successfully prepared via an easy and green environmental method in N-methylmorpholine-N-oxide (NMMO) aqueous solution. The effect of cellulose content on the thermostability properties, swelling behavior and retention rate of hydrogels was investigated. The thermostability of RCE hydrogels was slightly enhanced with the addition of 8 wt% cellulose, the highest decomposition temperature rose from 335 °C to 352 °C, and the least heat loss is about 75.60%. The equilibrium swelling ratio increases from 394.12% for 3% cellulose hydrogels to 619.46% for 8% cellulose hydrogels. The retention ratio increases from 1.13% to 28.46%.

Description: DNA Topoisomerases are essential to resolve topological problems during DNA metabolism in all species. However, the prevalence and function of RNA topoisomerases remain uncertain. Here, we show that RNA topoisomerase activity is prevalent in Type IA topoisomerases from bacteria, archaea, and eukarya. Moreover, this activity always requires the conserved Type IA core domains and the same catalytic residue used in DNA topoisomerase reaction; however, it does not absolutely require the non-conserved carboxyl-terminal domain (CTD), which is necessary for relaxation reactions of supercoiled DNA. The RNA topoisomerase activity of human Top3β differs from that of Escherichia coli topoisomerase I in that the former but not the latter requires the CTD, indicating that topoisomerases have developed distinct mechanisms during evolution to catalyze RNA topoisomerase reactions. Notably, Top3β proteins from several animals associate with polyribosomes, which are units of mRNA translation, whereas the Top3 homologs from E. coli and yeast lack the association. The Top3β-polyribosome association requires TDRD3, which directly interacts with Top3β and is present in animals but not bacteria or yeast. We propose that RNA topoisomerases arose in the early RNA world, and that they are retained through all domains of DNA-based life, where they mediate mRNA translation as part of polyribosomes in animals.

Description: CaFeAs 2 is a parent compound of recently discovered 112-type iron-based superconductors. It is predicted to be a staggered intercalation compound that naturally integrates both quantum spin Hall insulating and superconducting layers and an ideal system for the realization of Majorana modes. We performed a systematical angle-resolved photoemission spectroscopy and first-principles calculation study of the slightly electron-doped CaFeAs 2 . We found that the zigzag As chain of 112-type iron-based superconductors play a considerable role in the low-energy electronic structure, resulting in the characteristic Dirac-cone like band dispersion as the prediction. Our experimental results further confirm that these Dirac cones only exist around the X but not Y points in the Brillouin zone, breaking the S 4 symmetry at iron sites. Our findings present the compelling support to the theoretical prediction that the 112-type iron-based superconductors might host the topological nontrivial edge states. The slightly electron doped CaFeAs 2 would provide us a unique opportunity to realize and explore Majorana fermion physics.

Description: An ultrasonic enhanced salt-containing hydrodistillation (UESHD) method for separating essential oil from lavender ( Lavandula angustifolia ) flowers was investigated using response surface methodology (RSM). The experimental data obtained from a 27-run experiment were fitted to a second-order polynomial equation. The optimal conditions were determined by the 3D response surface and the contour plots derived from the models. The efficiency of UESHD and conventional hydrodistillation (HD) was compared. The extraction yield of UESHD was two-fold higher than that of HD. In addition, GC-MS results indicated some differences in composition and content between the two essential oils from UESHD and HD. An ultrasonic enhanced salt-containing hydro-distillation (UESHD) method was developed to separate lavender essential oil. The extraction yield of the oil was optimized by statistical software, the separation conditions by the Box-Behnken design. UESHD enabled a more than two-fold yield of essential oil than conventional hydrodistillation.

Description: Author(s): S. P. Hu, G. L. Zhang, J. C. Yang, H. Q. Zhang, P. R. S. Gomes, J. Lubian, X. G. Wu, J. Zhong, C. Y. He, Y. Zheng, C. B. Li, G. S. Li, W. W. Qu, F. Wang, L. Zheng, L. Yu, Q. M. Chen, P. W. Luo, H. W. Li, Y. H. Wu, W. K. Zhou, B. J. Zhu, and H. B. Sun The measurements of complete fusion cross sections for Li 6 + Zr 96 have been performed at energies around the Coulomb barrier by the online γ -ray method. The complete fusion cross sections at above-barrier energies were found to be suppressed by ∼ 25 % . A comparison of the systematics of complete fusion ... [Phys. Rev. C 91, 044619] Published Thu Apr 30, 2015

Description: In order to reduce the effect of laser imprint in direct-drive ignition scheme a low-density foam buffered target has been proposed. This target is driven by a laser pulse with a low-intensity foot at the early stage of implosion, which heats the foam and elongates the thermal conduction zone between the laser absorption region and ablation front, increasing the thermal smoothing effect. In this paper, a relatively strong foot pulse is adopted to irradiate the critical-density foam buffered target. The stronger foot, near 1 × 10 14  W/cm 2 , is able to drive a radiative shock in the low-density foam, which helps smooth the shock and further reduce the effect of laser imprint. The radiative shock also forms a double ablation front structure between the two ablation fronts to further stabilize the hydrodynamics, achieving the similar results to a target with a high-Z dopant in the ablator. 2D analysis shows that for the critical-density foam buffered target irradiated by the strong foot pulse, the laser imprint can be reduced due to the radiative shock in the foam and an increased thermal smoothing effect. It seems viable for the critical-density foam buffered target to be driven by a relatively strong foot pulse with the goal of reducing the laser imprint and achieving better implosion symmetry in the direct-drive laser fusion.

Description: Author(s): C. L. Guo, G. L. Zhang, S. P. Hu, J. C. Yang, H. Q. Zhang, P. R. S. Gomes, J. Lubian, X. G. Wu, J. Zhong, C. Y. He, Y. Zheng, C. B. Li, G. S. Li, W. W. Qu, F. Wang, L. Zheng, L. Yu, Q. M. Chen, P. W. Luo, H. W. Li, Y. H. Wu, W. K. Zhou, B. J. Zhu, and H. B. Sun Measurements of complete and incomplete fusion cross sections for Li 6 + Sm 154 have been performed at energies above the Coulomb barrier by the online γ -ray method, to investigate the effect of breakup and inelastic couplings on the complete fusion (CF) of this weakly bound system. We show that inelast… [Phys. Rev. C 92, 014615] Published Tue Jul 14, 2015

Description: SUMMARY The propagation delay when radar signals travel from the troposphere has been one of the major limitations for the applications of high precision repeat-pass Interferometric Synthetic Aperture Radar (InSAR). In this paper, we first present an elevation-dependent atmospheric correction model for Advanced Synthetic Aperture Radar (ASAR—the instrument aboard the ENVISAT satellite) interferograms with Medium Resolution Imaging Spectrometer (MERIS) integrated water vapour (IWV) data. Then, using four ASAR interferometric pairs over Southern California as examples, we conduct the atmospheric correction experiments with cloud-free MERIS IWV data. The results show that after the correction the rms differences between InSAR and GPS have reduced by 69.6 per cent, 29 per cent, 31.8 per cent and 23.3 per cent, respectively for the four selected interferograms, with an average improvement of 38.4 per cent. Most importantly, after the correction, six distinct deformation areas have been identified, that is, Long Beach–Santa Ana Basin, Pomona–Ontario, San Bernardino and Elsinore basin, with the deformation velocities along the radar line-of-sight (LOS) direction ranging from −20 mm yr −1 to −30 mm yr −1 and on average around −25 mm yr −1 , and Santa Fe Springs and Wilmington, with a slightly low deformation rate of about −10 mm yr −1 along LOS. Finally, through the method of stacking, we generate a mean deformation velocity map of Los Angeles over a period of 5 yr. The deformation is quite consistent with the historical deformation of the area. Thus, using the cloud-free MERIS IWV data correcting synchronized ASAR interferograms can significantly reduce the atmospheric effects in the interferograms and further better capture the ground deformation and other geophysical signals.

Description: A series of short and steep unidirectionally migrating deep-water channels, which are typically without levees and migrate progressively northeastward, are identified in the Baiyun depression, Pearl River Mouth Basin. Using three-dimensional seismic and well data, the current study documents their morphology, internal architecture, and depositional history, and discusses the distribution and depositional controls on the bottom current–reworked sands within these channels. Unidirectionally migrating deep-water channels consist of different channel-complex sets (CCSs) that are, overall, short and steep, and their northeastern walls are, overall, steeper than their southwestern counterparts. Within each CCS, bottom current–reworked sands in the lower part grade upward into muddy slumps and debris-flow deposits and, finally, into shale drapes. Three stages of CCSs development are recognized: (1) the early lowstand incision stage, during which intense gravity and/or turbidity flows versus relatively weak along-slope bottom currents of the North Pacific intermediate water (NPIW-BCs) resulted in basal erosional bounding surfaces and limited bottom current–reworked sands; (2) the late lowstand lateral-migration and active-fill stage, with gradual CCS widening and progressively northeastward migration, characterized by reworking of gravity- and/or turbidity-flow deposits by vigorous NPIW-BCs and the CCSs being mainly filled by bottom current–reworked sands and limited slumps and debris-flow deposits; and (3) the transgression abandonment stage, characterized by the termination of the gravity and/or turbidity flows and the CCSs being widely draped by marine shales. These three stages repeated through time, leading to the generation of unidirectionally migrating deep-water channels. The distribution of the bottom current–reworked sands varies both spatially and temporally. Spatially, these sands mainly accumulate along the axis of the unidirectionally migrating deep-water channels and are preferentially deposited to the side toward which the channels migrated. Temporally, these sands mainly accumulated during the late lowstand lateral-migration and active-fill stage. The bottom current–reworked sands developed under the combined action of gravity and/or turbidity flows and along-slope bottom currents of NPIW-BCs. Other factors, including relative sea level fluctuations, sediment supply, and slope configurations, also affected the formation and distribution of these sands. The proposed distribution pattern of the bottom current–reworked sands has practical implications for predicting reservoir occurrence and distribution in bottom current–related channels.

Description: Author(s): S. P. Hu, G. L. Zhang, J. C. Yang, H. Q. Zhang, P. R. S. Gomes, J. Lubian, J. L. Ferreira, X. G. Wu, J. Zhong, C. Y. He, Y. Zheng, C. B. Li, G. S. Li, W. W. Qu, F. Wang, L. Zheng, L. Yu, Q. M. Chen, P. W. Luo, H. W. Li, Y. H. Wu, W. K. Zhou, B. J. Zhu, and H. B. Sun We report the measurement of one-neutron stripping to excited-state cross sections from the weakly bound projectile Li 6 to the Zr 96 target at near-barrier energies by the online γ -ray spectroscopy method. Transitions of the Zr 97 nucleus were clearly identified by γ − γ coincidences. This cross section… [Phys. Rev. C 93, 014621] Published Fri Jan 29, 2016