Tailor-made porous nanotube arrays are of great technological interest for the development of high-performance optical and electrochemical energy storage devices. Herein, we report facile successive ...electro-deposition (ED) methods to fabricate three-dimensional (3D) hierarchical porous NiO nanotube arrays on nickel foam with the help of ZnO nanorod template. The obtained hierarchical porous NiO nanotubes have a diameter of ∼170 nm and consist of interconnected branch nanoflakes of ∼10 nm. The resulting NiO nanotube arrays are well characterized as positive electrode materials for supercapacitor application by cyclic voltammetry (CV) and galvanostatic charge/discharge measurements. Due to the unique architecture, the NiO nanotube arrays exhibit a high capacitance of 675 F g−1 at the 2 A g−1 and 569 F g−1 at 40 A g−1, respectively, as well as good cycling stability. The proposed synthesis method is expected for fabrication of other nanotube arrays for applications in solar cells, gas sensors and Li ion batteries.
Hierarchical porous NiO nanotube arrays are prepared via facile successive electro-deposition methods and show superior supercapacitor performance with high capacitance. Display omitted
•Construct a hierarchical porous NiO nanotube array.•Porous nanotube array shows high pseudo-capacitive properties.•Porous nanotube array structure is favorable for fast ion and electron transfer.
A fundamental requirement for the development of advanced electronic device architectures based on graphene nanoribbon (GNR) technology is the ability to modulate the band structure and charge ...carrier concentration by substituting specific carbon atoms in the hexagonal graphene lattice with p- or n-type dopant heteroatoms. Here we report the atomically precise introduction of group III dopant atoms into bottom-up fabricated semiconducting armchair GNRs (AGNRs). Trigonal-planar B atoms along the backbone of the GNR share an empty p-orbital with the extended π-band for dopant functionality. Scanning tunneling microscopy (STM) topography reveals a characteristic modulation of the local density of states along the backbone of the GNR that is superimposable with the expected position and concentration of dopant B atoms. First-principles calculations support the experimental findings and provide additional insight into the band structure of B-doped 7-AGNRs.
Compact neutron star binary systems are produced from binary massive stars through stellar evolution involving up to two supernova explosions. The final stages in the formation of these systems have ...not been directly observed. We report the discovery of iPTF 14gqr (SN 2014ft), a type Ic supernova with a fast-evolving light curve indicating an extremely low ejecta mass (≈0.2 solar masses) and low kinetic energy (≈2 × 10
ergs). Early photometry and spectroscopy reveal evidence of shock cooling of an extended helium-rich envelope, likely ejected in an intense pre-explosion mass-loss episode of the progenitor. Taken together, we interpret iPTF 14gqr as evidence for ultra-stripped supernovae that form neutron stars in compact binary systems.
Aspergillus niger-fermented Ginkgo biloba leaves (FR) and its comparative effect with vitamin E (VE) and nonfermented (NF) Ginkgo leaves on growth, lipid metabolism, antioxidant capacity, and meat ...quality of broiler chicks were investigated. In total, 360 one-day-old broiler chicks were randomly allocated into 6 dietary treatments, which were then denoted as control group (basal diet), VE group (containing respectively 15 and 30 IU/kg of all-rac-α-tocopherol acetate in the starter and grower phase), NF group (containing respectively 0.35% and 0.7% NF in the starter and grower phase), and FR1, FR2, and FR3 groups containing respectively 0.2, 0.35, and 0.5% FR in the starter and 0.4, 0.7, and 1.0% FR in the grower phase. The results on performance showed that a significant (P < 0.05) reduction of feed:gain ratio of birds in the FR2 group (22–42 d and 1–42 d) was observed when compared with that of the control and NF groups. With dietary FR increasing, the serum α-tocopherol concentration increased linearly (P = 0.001). Compared with the control, broilers had higher (P < 0.05) serum high-density lipoprotein concentration, total superoxide dismutase activities, and total antioxidant capacity when they were provided with the FR2 and FR3 diet. Whereas the low-density lipoprotein and triglyceride concentrations were lower (P < 0.05 or P < 0.01) in broilers from FR2 or FR3 groups. As the dietary FR increased, abdominal fat (P = 0.002) and muscle malondialdehyde (P = 0.001) concentrations decreased. Furthermore, 24-h pH, 24-h drip loss, and cooking loss were greatly improved (P < 0.05) as the levels of FR increased. Birds fed with FR had a lower (P < 0.05) C16:0 and C18:0 concentrations but a greater (P = 0.001) concentration of C18:2, C18:3, and C20:4 than that of the control. In conclusion, FR can improve the growth performance and lipid metabolism of broilers with decreased abdominal fat deposition. Also, the antioxidant capacity and meat quality improving effects observed in broilers fed FR products might result from the increased retention of α-tocopherol and reduction in lipid peroxidation, as evidenced by the decrease in malondialdehyde and the increase in total superoxide dismutase activities.
Daya Bay presents the first measurement of cosmogenic $^8$He isotope
production in liquid scintillator, using an innovative method for identifying
cascade decays of $^8$He and its child isotope, ...$^8$Li. We also measure the
production yield of $^9$Li isotopes using well-established methodology. The
results, in units of 10$^{-8}\mu^{-1}$g$^{-1}$cm$^{2}$, are 0.307$\pm$0.042,
0.341$\pm$0.040, and 0.546$\pm$0.076 for $^8$He, and 6.73$\pm$0.73,
6.75$\pm$0.70, and 13.74$\pm$0.82 for $^9$Li at average muon energies of
63.9~GeV, 64.7~GeV, and 143.0~GeV, respectively. The measured production rate
of $^8$He isotopes is more than an order of magnitude lower than any other
measurement of cosmogenic isotope production. It replaces the results of
previous attempts to determine the ratio of $^8$He to $^9$Li production that
yielded a wide range of limits from 0 to 30\%. The results provide future
liquid-scintillator-based experiments with improved ability to predict
cosmogenic backgrounds.
The subfamily of the Lemnoideae belongs to a different order than other monocotyledonous species that have been sequenced and comprises aquatic plants that grow rapidly on the water surface. Here we ...select Spirodela polyrhiza for whole-genome sequencing. We show that Spirodela has a genome with no signs of recent retrotranspositions but signatures of two ancient whole-genome duplications, possibly 95 million years ago (mya), older than those in Arabidopsis and rice. Its genome has only 19,623 predicted protein-coding genes, which is 28% less than the dicotyledonous Arabidopsis thaliana and 50% less than monocotyledonous rice. We propose that at least in part, the neotenous reduction of these aquatic plants is based on readjusted copy numbers of promoters and repressors of the juvenile-to-adult transition. The Spirodela genome, along with its unique biology and physiology, will stimulate new insights into environmental adaptation, ecology, evolution and plant development, and will be instrumental for future bioenergy applications.
We present the first measurements of the electric and magnetic form factors of the neutron in the time-like (positive \(q^2\)) region as function of four-momentum transfer. We explored the ...differential cross sections of the reaction \(e^+e^- \rightarrow \bar{n}n\) with data collected with the BESIII detector at the BEPCII accelerator, corresponding to an integrated luminosity of 354.6 pb\(^{-1}\) in total at twelve center-of-mass energies between \(\sqrt{s} = 2.0 - 2.95\) GeV. A relative uncertainty of 18% and 12% for the electric and magnetic form factors, respectively, is achieved at \(\sqrt{s} = 2.3935\) GeV. Our results are comparable in accuracy to those from electron scattering in the comparable space-like (negative \(q^2\)) region of four-momentum transfer. The electromagnetic form factor ratio \(R_{\rm em}\equiv |G_E|/|G_M|\) is within the uncertainties close to unity. We compare our result on \(|G_E|\) and \(|G_M|\) to recent model predictions, and the measurements in the space-like region to test the analyticity of electromagnetic form factors.
Same Day Delivery (SDD) online shopping may generate different influences on physical store shopping from conventional online shopping, but few studies have explored this new and burgeoning channel ...and its impacts. Using retrospective survey data in Nanjing, this study investigates the impacts of SDD online shopping on local store shopping. Quasi-longitudinal analyses of the retrospective data show that SDD online shopping substitutes for local store shopping, and that changes in local shopping are associated with SDD online shopping frequency. These results suggest that SDD online shopping may change local shopping travel and alter the distribution of commercial land uses over time. Moreover, a comparison between quasi-longitudinal and cross-sectional analyses suggests that cross-sectional results are not reliable. Future studies should move beyond cross-sectional design.
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