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The Mn-Zn ferrite nanoparticles with a spinel structure were successfully prepared by using chemical co-precipitation method. The formed magnetic ferrite particles were coated on the surface of Fe-6.5 wt%Si alloy particles with the epoxy resin to prepare the powder core. The influence of magnetic ferrite insulation on the magnetic properties of the powder core was studied. Insulating with a moderate quantity of ferrite was found to improve the effective permeability and the loss of the powder core, while the inadequate insulation and the excessive insulation with ferrite led to the rapid growth of the eddy-current loss at high frequency and the remarkable decrease of the effective permeability, respectively. The effective demagnetizing field determined by the core’s density and the magnetic nature of the ferrite were proposed to be the main causes of the variation of the core’s magnetic performance. Loss separation fitting revealed that the hysteresis loss is much higher than the eddy-current loss for the core measured at the frequency lower than 120 kHz. This suggested that improving the effective permeability and the loss of the powder core in low-frequency range should focus on the means of reducing the effective demagnetizing field.

Four new deep ultraviolet (DUV) borates Li7Na2KRb2B12O24, Li7.35Na2.36K1.50Cs0.78B12O24, Li6.97Na2.63K1.24Cs1.15B12O24, and Li7.27Na2.67Rb2.06B12O24 have been produced by high temperature solution method in open air. The structural analysis suggests that they all crystallize in the same trigonal space group R 3 ¯ (No. 148), and possess the identical isolated B12O24 groups. Structural comparison among alkali-metal borates with BnO2n in their chemical formulas have been discussed. In addition, infrared spectra were used to verify their structural validity. Furthermore, the UV–Vis–NIR diffuse reflectance spectra reveal that they exhibit short cutoff edges below 180 nm (6.88 eV). The first-principles theoretical studies carried out to increase the understanding of electronic structure and linear optical property.

The thermodynamic behavior of near ground-state isomers of Au 55 clusters are investigated through molecular-dynamic simulations using an n -body effective potential. During relaxation at certain energies, non-reversible structural transitions (from cuboctahedron to icosahedron, and then to disordered configuration) occur well below the melting temperature. We show in this Letter on a picosecond scale the motion of the individual atoms in a cluster during these transformations, demonstrating that the processes involved are either collective distortions of the entire cluster or migration of individual or small groups of atoms. In both cases the cohesive energies of the system go smoothly without any significant barrier during transitions.

Based on the Hadj-Romdhane–Danner model of the chromatographic process, the infinite dilution diffusion coefficients of n -hexane, n -heptane, n -octane and toluene in polyisobutylene (PIB) have been measured at temperatures in the range of 323.2–373.2 K by inverse gas chromatography (IGC). The measured infinite dilution diffusion coefficients for the toluene/PIB system were compared with the diffusivity data at finite concentration determined previously from NMR experimental method by using the Vrentas–Duda free volume theory. The good agreements indicate the IGC method studied in this work is reliable. Moreover, the correlations of the experimental data with the free volume equation were preformed. The correlated results show that the free volume theory is a quite good description of the relationship between the observed solvent diffusion coefficient and temperature.

The Ulleung Basin in the East Sea (Sea of Japan) is a semi-enclosed basin surrounded by shallow sills and straits. Detailed observation of X-radiographs and thin sections of core sediments from the Ulleung Interplain Gap reveals five mud facies: laminated mud, crudely laminated mud, homogeneous mud, bioturbated mud and laminated Mn-carbonate mud. The laminated and homogenous muds were most likely deposited from turbidity currents, whereas the bioturbated and crudely laminated muds were formed by pelagic/hemipelagic sedimentation under oxic and anoxic bottom-water conditions, respectively. The laminated Mn-carbonate mud occurs at the lithologic boundary between the turbidite and hemipelagic laminated mud (last glacial) and the pelagic bioturbated mud (Lateglacial to Holocene). Mn-carbonates were formed at the sediment–water interface, probably reflecting an abrupt change in bottom-water oxygenation caused by sea-level rise during the last deglaciation. Profiles of redox-sensitive elements also support an anoxic to oxic change of bottom-water conditions during this period.

A gas-liquid-solid inverse fluidization airlift bioreactor was proposed by combining advantages of external-loop airlift reactors and inverse fluidized beds. This airlift bioreactor comprises a gas-liquid riser, a gas separator, a liquid-solid inverse fiuidized downcomer and a bottom connector. The effects of the gas velocity and the particle loading on the gas holdup in the riser and the liquid circulation velocity in the loop were investigated. Liquid-solid inverse fluidization in the downcomer was also studied. The gas holdup in the riser was experimentally found to increase with the increase in the particle loading and in the gas velocity. The liquid circulation velocity decreased with the increase in the particle loading whereas it increased with the gas velocity. It was found that the Richardson and Zaki model fitted experimental data of bed expansion of liquid-solid inverse fluidization in the downcomer well. Based on an energy balance, two hydrodynamic models were proposed to predict the liquid circulation velocity in the present bioreactor. It was shown that the present models gave a good fit to experimental data in this bioreactor.

N2O emissions from agricultural, forest and grassland ecosystems in China were in situ measured by closed chamber method, and estimation of total annual N2O emissions from these ecosystems and a technique mitigating N2O emission from agricultural soil were reported. The results showed: (1) the annual emissions of N2O from rice, maize, soybean and wheat field, temperate forest and temperate grassland in China were 1.08–2.99, 0.47–4.51, 1.98, 1.02–2.93, 0.28–1.28 and 0.27–0.61 kg N 2 O – N ha −1 , respectively. The total annual N2O emissions from agricultural, forest and temperate grassland ecosystems in China were estimated as 152.49, 94.10 and 112.13 Gg N, respectively. Industrially co-crystallized ammonium bicarbonate (AB) with dicyandiamide, substituting for ammonium bicarbonate in China, decreased N2O emission significantly from a meadow brown soil in laboratory (80.2% at soil moisture 12% and 40.0% at soil moisture 22%, respectively) and upland field condition (74.0%).

A detailed facies analysis of long piston-core sediments from the Ulleung Basin reveals four mud facies: laminated mud, crudely laminated mud, bioturbated mud, and homogenous mud. The laminated and homogeneous muds were most likely deposited from turbidity currents, whereas the bioturbated and crudely laminated muds were formed by hemipelagic/pelagic sedimentation under well-oxygenated and poorly oxygenated bottom-water conditions, respectively. A detailed analysis of vertical distribution of the mud facies together with a chronostratigraphic framework derived from correlative tephra layers with known eruption ages reveals paleoenvironmental changes during the late Quaternary. During the period between 49 and 23 ka, eustatic lowering of sea level facilitated frequent slope failure, resulting in repeated deposition of fine-grained turbidites on the basin floor. Normal hemipelagic sediments were intensively bioturbated under well-oxygenated bottom-water conditions. During the period between 23 and ∼13 to 11 ka, deposition from turbidity currents continued, but hemipelagic sediments were non-bioturbated under poorly oxygenated bottom water conditions. The bottom-water deoxygenation is attributed to further lowering of sea level during the last glacial period and consequent intensified stratification in the water column by freshwater supply to the nearly isolated sea. Primary laminae preserved in the crudely laminated mud generally exhibit low compositional bimodality in backscattered electron images, which suggests low surface primary productivity and presence of superficial micro-bioturbation. After rapid rise of sea level at ∼13 to 11 ka, the slopes were stabilized and pelagic sedimentation has prevailed under well-oxygenated bottom-water conditions.

The literature data of dilute solution viscosity for binary blend indicate that the intrinsic viscosity of binary polyblend can be obtained from the values of corresponding constituent polymers by using the weighted additive law. This law was also testified by measurement of CS/PEG polyblend in this work. On the basis of it, the α criterion of polymer–polymer miscibility determined by viscosity, proposed by Sun et al., is simplified. Since the revised criterion is a function of three variables: (1) the intrinsic viscosity for polymeric components (2) the weight fraction of polymeric components (3) the difference of the cross Huggins coefficient for polyblend and geometric average of Huggins coefficient for the constituent polymers, it is of more definite physical significance. Furthermore, it was proved that the revised criterion has the same judgment ability as that of the α criterion by using six binary blend systems, i.e. PVC/PMMA, PB(OH)/PBA, PB(OH)/PBMA, PVC/PiBMA, PMMA/PiBMA, PMMA/PiBMA, and three new binary blend systems measured in this work, i.e. PEG-6K/CS, PEG-10K/CS, PEG-20K/CS.

High-resolution (3.5 kHz) seismic profiles from the slope of the Korea Plateau, East Sea (Sea of Japan) show an extensive area of slide deposits with prominent slump scars. The sediment displaced from the steep slope (5–7°) is less expansive than massive failure deposits on gradual slopes (1–2°). Seaward of a large trough, thick wavy stratified sediments cover the gentle slope. Cyclic loading by earthquakes is the most probable triggering mechanism for the slope instability in this area. The topmost (2–3 m) sediment is chiefly composed of hemipelagic mud with interbeds of turbidites and volcanogenic material. These sediments are highly plastic and shear resistant (over 4 kPa at the surface) in both stable and failed areas. Grain size decreases seaward, from sandy mud on the shelf to silty clay on the lower slope. Total organic matter and water contents are closely associated with sediment texture, both increasing with clay amounts from 5–10% and from 50 up to 200%, respectively.

Sedimentary characteristics and geotechnical properties of the fine-grained sediments in the South Sea were analysed on 45 sediment cores collected in part of the sea. A map of surface sediment distribution in the sea is newly presented, based on the compilation of previous localized data. Grain size of the sediment (7–9ϕ) decreases slightly but systematically with water depth, although some variations in size occur locally along the coastal area. Shear strength is substantial near the sea floor (3–5 kPa) and gradually increases downcore, indicative of slow sedimentation. Water content is largely over 100% and uniform vertically. Organic matter and CaCO 3 increase Atterberg limits of the sediment, which is highlighted in the sediment off Ulsan under the influence of coastal upwelling.

Heavy mineral assemblages of the sand deposit in the southeastern Yellow Sea were examined in order to reveal shelf sedimentation in the absence of significant river discharge. Hornblende dominates the mineral assemblages in most of the area, and originates from the adjacent landmass of igneous and metamorphic rocks. Sand fractions near the mud-dominant area off the southwestern coast of Korea contain the highest heavy mineral concentrations represented by stable minerals such as garnet, epidote, zircon and opaques, and are most probably derived from nearby Cretaceous sedimentary rocks. This mineral distribution, together with other known sedimentological phenomena, can be adequately explained by the shoreface retreat processes. The sand deposit thus appears to be a basal transgressive sand sheet resulting from coastal erosion during Holocene transgression.

The description and prediction of the vapor-liquid equilibrium of molecular fluid mixtures by equation of state is reviewed. Seven equations of state are compared with experimental data. Results of the comparison are reported for mixtures of non-polar and slightly polar substances over a wide image of pressure, temperature, and molecular variety. The experimental data base of the comparison includes 20 symmetric mixtures, 20 methane-containing mixtures, 17 hydrogen mixtures, 18 carbon dioxide mixtures, and 12 nitrogen mixtures. Interaction constants are determined and reported for all the mixtures studied.

The mixing angle of ηη′ is calculated based on the symmetry breaking model. We find the mixing angle θ = 10.4 with m κ = 1200 MeV, while quadratic SU(3) mass formula gives θ = 10.3.