Magnetic skyrmions are localized and topologically protected spin configurations, which are of both fundamental and applied interests for future electronics. In this work, we propose a voltage-gated ...skyrmion transistor within the well-established framework of micromagnetics. Its operating conditions and processes have been theoretically investigated and demonstrated, in which the gate voltage can be used to switch on/off a circuit. Our results provide the first time guidelines for practical realization of hybrid skyrmionic-electronic devices.
The anomalous rod shape in carbon isotopes has been investigated in the framework of the cranking covariant density functional theory, and two mechanisms to stabilize such a novel shape with respect ...to the bending motion, extreme spin, and isospin are simultaneously discussed for the first time in a self-consistent and microscopic way. By adding valence neutrons and rotating the system, we have found the mechanism stabilizing the rod shape; i.e., the σ orbitals (parallel to the symmetry axis) of the valence neutrons, important for the rod shape, are lowered by the rotation due to the Coriolis term. The spin and isospin effects enhance the stability of the rod-shaped configuration. This provides a strong hint that a rod shape could be realized in nuclei towards extreme spin and isospin.
In order to study the temporal and spatial variations of PM2.5 and its chemical compositions in the region of Beijing, Tianjin, and Hebei (BTH), PM2.5 samples were collected at four urban sites in ...Beijing (BJ), Tianjin (TJ), Shijiazhuang (SJZ), and Chengde (CD), and also one site at Shangdianzi (SDZ) regional background station over four seasons from 2009 to 2010. The samples were weighted for mass concentrations and analyzed in the laboratory for chemical profiles of 19 elements (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, Sr, Ti, V, and Zn), eight water-soluble inorganic ions (Na+ , NH4+ , K+ , Mg2+ , Ca2+ , Cl- , NO3- , and SO42- , and carbon fractions (OC and EC). The concentrations of PM2.5 and its major chemical species were season dependent and showed spatially similar characteristics in the plain area of BTH. The average annual concentrations of PM2.5 were 71.8-191.2 μg m-3 at the five sites, with more than 90% of sampling days exceeding 50 μg m-3 at BJ, TJ, and SJZ. PM2.5 pollution was most serious at SJZ, and the annual concentrations of PM2.5 , secondary inorganic ions, OC, EC, and most crustal elements were all highest. Due to stronger photochemical oxidation, the sum of concentrations of secondary inorganic ions (NH4+ , NO3- , and SO42- was highest in the summer at SDZ, BJ, TJ, and CD. Analysis of electric charges of water-soluble inorganic ions indicated the existence of nitric acid or hydrochloric acid in PM2.5 . For all five sites, the concentrations of OC, EC and also secondary organic carbon (SOC) in the spring and summer were lower than those in the autumn and winter. SOC had more percentages of increase than primary organic carbon (POC) during the winter. The sums of crustal elements (Al, Ca, Fe, Mg, Ti, Ba, and Sr) were higher in the spring and autumn owing to more days with blowing or floating dust. The concentrations of heavy metals were at higher levels in the BTH area by comparison with other studies. In Shijiazhuang and Chengde, the PM2.5 pollution was dominated by coal combustion. Motor vehicle exhausts and coal combustion emissions both played important roles in Tianjin PM2.5 pollution. However, motor vehicle exhausts had played a more important role in Beijing owing to the reduction of coal consumption and sharp increase of cars in recent years. At SDZ, regional transportation of air pollutants from southern urban areas was significant.
Membrane biofilm reactors (MBfRs) deliver gaseous substrates to biofilms that develop on the outside of gas-transfer membranes. When an MBfR delivers electron donors hydrogen (H
2
) or methane (CH
4
...), a wide range of oxidized contaminants can be reduced as electron acceptors, e.g., nitrate, perchlorate, selenate, and trichloroethene. When O
2
is delivered as an electron acceptor, reduced contaminants can be oxidized, e.g., benzene, toluene, and surfactants. The MBfR’s biofilm often harbors a complex microbial community; failure to control the growth of undesirable microorganisms can result in poor performance. Fortunately, the community’s structure and function can be managed using a set of design and operation features as follows: gas pressure, membrane type, and surface loadings. Proper selection of these features ensures that the best microbial community is selected and sustained. Successful design and operation of an MBfR depends on a holistic understanding of the microbial community’s structure and function. This involves integrating performance data with omics results, such as with stoichiometric and kinetic modeling.
This experiment was conducted to evaluate the effect of diets with different energy and emulsifier (Lipidol, active ingredient: lysophospholipids; LPL) levels on growth performance, nutrient ...digestibility, body composition, and serum profile in broilers. A total of 864 one-day-old male Ross 308 broilers (45.3 ± 0.6 g) was used in a 28-day experiment. Broilers were allotted to a 2 × 3 factorial arrangement design with 2 levels of energy (starter: ME = 2,950 kcal/kg for energy reduced diet and 3,050 kcal/kg for basal diet; finisher: ME = 3,100 kcal/kg for energy reduced diet and 3,200 kcal/kg for basal diet) and 3 levels of emulsifier supplementation (zero, 0.05, and 0.10%) according to their initial BW. There were 8 replicate cages per treatment with 18 broilers per cage. Broilers fed basal diets had higher (P < 0.05) body weight gain (BWG, d zero to 14) and lower (P < 0.05) feed conversion ratio (FCR, d zero to 14 and d zero to 28) than those fed reduced energy diets. Broilers fed LPL supplementation diets also had higher (P < 0.05) BWG (d zero to 14) and lower (P < 0.05) FCR (d zero to 14, d 15 to 28, and d zero to 28) than those fed without LPL supplementation diets. On d 14, the apparent total tract digestibility (ATTD) of DM, nitrogen (N), and gross energy (GE) was increased (P < 0.05) by LPL supplementation. The low density lipoprotein cholesterol, total cholesterol, and triglycerides concentrations also were decreased (P < 0.05) by LPL supplementation on d 14. The relative weight of abdominal fat was higher (P < 0.05) in basal diet treatments, but lower (P < 0.05) in LPL supplementation treatments. In conclusion, LPL supplementation can increase growth performance and nutrient digestibility, decrease cholesterol and triglycerides concentration in the starter period, and decrease the abdominal fat percentage in broilers.
Silver nanorod arrays with different lengths fabricated by oblique angle deposition at various vapor deposition angles have been studied systematically on their morphologies, optical reflections, and ...surface-enhanced Raman scattering (SERS) responses. The tilting angle β of Ag nanorods increases with the increase of the deposition angle θ, while the diameter D and density n of Ag nanorods grow as power laws of the length L, D ∼ L p and n ∼ L −γ, where the exponents are p ∼ 0.30−0.34 and γ ∼ 0.23−0.40 for different deposition angles, respectively. The optical reflectance from these substrates depends not only on the length of the Ag nanorods but also on the deposition angle. It is found that the SERS enhancement factor decreases nearly monotonically with the increase of the reflectance at SERS excitation wavelength, and the highest SERS enhancement factor can reach close to 109. We have developed a phenomenological model based on the assumption that the absorbance (reflection) of the nanorod array is directly linked to the local electric field, and it predicts a similar trend to that of the experimental observation. The empirical results can help us to design better Ag nanorod array SERS substrates, and can also be used as a quality control measurement method for SERS substrate production.
Multicomponent rotational nanomotors consisting of Pt‐coated TiO2 nanoarms grown upon ≈2.01‐µm‐diameter silica microbeads designed by dynamic shadowing growth are presented. When exposed to H2O2, the ...structures rotate about an axis through the center of the microbead and perpendicular to the TiO2 nanoarm at a rate of 0.15 Hz per % H2O2 concentration. The rotational frequency increases parabolically when the surface tension of the solution is altered by the addition of sodium dodecyl sulphate; both relationships are explainable by a nanobubble‐ejection model.
The analysis of rotational multicomponent catalytic nanomotors consisting of 2.01‐µm‐diameter silica microbeads with Pt‐coated TiO2 arms fabricated by dynamic shadowing growth is presented. The nanomotors rotate about the center of the microbead at a constant rate in hydrogen peroxide, explainable by the balance of the drive and drag force as shown in the figure.
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