Matter Dynamics Research Articles

INFLUENCE OF INTRINSIC PINNING ON THE RESISTIVE PROPERTIES OF YBa2Cu3O7-δ SINGLE CRYSTALS

The dynamics of vortex matter in YBa 2 Cu 3 O 7-δ single crystal with unidirectional twin boundaries is studied experimentally in a wide range of velocities of the magnetic flux in a tilted magnetic field. It is determined that with the orientation of the magnetic field vector in the locality of the ab-plane, the dynamics of the magnetic flux near the melting temperature of the vortex lattice can be described by the Kim–Anderson model and as the temperature is lowered, by the theory of collective pinning on small-scale defects or by the vortex glass model. The intrinsic pinning caused by the layered crystal structure of the material has an impact on the dynamics of magnetic flux and this effect increases with the decreasing of the temperature.

Ultrafast Dynamics of Magnetic Domain Structures Probed by Coherent Free-Electron Laser Light

The free-electron laser (FEL) sources FLASH in Hamburg, LCLS at Stanford, and FERMI in Trieste provide XUV to soft X-ray radiation (FLASH and FERMI) or soft to hard X-ray radiation (LCLS) with unprecedented parameters in terms of ultrashort pulse length, high photon flux, and coherence. These properties make FELs ideal tools for studying ultrafast dynamics in matter on a previously unaccessible level. This paper first reviews results obtained at FEL sources during the last few years in the field of magnetism research. We start with pioneering experiments at FLASH demonstrating the feasibility of magnetic scattering at FELs [1, 2], then present pump–probe scattering experiments [3, 4] as well as the first FEL magnetic imaging experiments [5], and finally discuss a limitation of the scattering methods due to a quenching of the magnetic scattering signal by high-fluence FEL pulses [6]. All of the presented experiments exploit the X-ray magnetic circular dichroism effect [7, 8] to obtain element-specific magnetic scattering contrast, as known from synchrotron experiments [9–12].

Seasonal dynamics of suspended matter in waters of Lake Khanka

Outline maps of the distribution of suspended mineral matter in the waters of Lake Khanka are constructed from the summer, spring, autumn, and winter observation results. The analysis allows distinguishing seasonal variations in the distribution of suspended mineral matter over the lake water area and shows that the lake ecosystem functions under conditions of an uninterrupted annual cycle of suspended matter concentration.

Role of local curvature in grain boundary sliding in a deformed polycrystal

The paper considers experimental and theoretical principles of accounting for curvature in multiscale computer simulation of the behavior of interfaces as independent planar subsystems in a loaded polycrystal. Dynamics of matter and energy flows along grain boundaries is studied using a hybrid discrete-continuous method of excitable cellular automata, which combines synergetic principles of discrete switching and laws of continuum mechanics. It is shown that these flows have a rotational-wave nature and depend on the loading conditions of a grain boundary.

Implementation of a simplified approach to radiative transfer in general relativity

We describe in detail the implementation of a simplified approach to radiative transfer in general relativity by means of the well-known neutrino leakage scheme (NLS). In particular, we carry out an extensive investigation of the properties and limitations of the NLS for isolated relativistic stars to a level of detail that has not been discussed before in a general-relativistic context. Although the numerous tests considered here are rather idealized, they provide a well-controlled environment in which to understand the relationship between the matter dynamics and the neutrino emission, which is important in order to model the neutrino signals from more complicated scenarios, such as binary neutron-star mergers. When considering nonrotating hot neutron stars we confirm earlier results of one-dimensional simulations, but also present novel results about the equilibrium properties and on how the cooling affects the stability of these configurations. In our idealized but controlled setup, we can then show that deviations from the thermal and weak-interaction equilibrium affect the stability of these models to radial perturbations, leading models that are stable in the absence of radiative losses, to a gravitational collapse to a black hole when neutrinos are instead radiated.

Generation and Measurement of Isolated 160-Attosecond XUV Laser Pulses at 82 eV

Isolated attosecond extreme-ultraviolate (XUV) pulses are generated based on high-harmonic-generation from a neon gas cell driven by carrier-envelope phase stabilized sub-5-fs Ti:sapphire laser pulses at repetition rate of 1 kHz. Temporal characterization of isolated attosecond XUV pulses is demonstrated to be 160-attosecond by attosecond streaking spectroscopy. The development of attosecond source and streaking spectroscopy will allow scientists to explore the electron dynamics in matter.

Soil organic matter dynamics after C3–C4 vegetation change of red soil in Southern, China: Evidence from natural 13C abundance

Soil samples from natural forests and adjacent farmland were analyzed to investigate the dynamics of soil organic matter of red soil in Southern, China. Based on the δ13C values and the content of soil organic matter, the data indicated that the turnover of soil organic matter under the virgin forest was slower than that under cultivation. Soil organic matter is fresh in coarse sand and oldest in fine silt and clay. Also, the soil light fraction contained the younger organic matter than soil heavy fraction and bulk soil. Deforestation has accelerated the decomposition rate of soil organic matter and reduced the proportion of active components in SOM and thus soil fertility.

Effect of total particular matter on growth and survival of tilapia in shrimp-tilapia cage poly-culture ponds

JI Tilapia is a new hybrid and salt tolerant species developed for culture and published in the 1 339th announcement of Agriculture Ministry of China in February 2010.We investigated the dynamics of total particular matter(TPM) and particular organic matter(POM) in 3 shrimp-tilapia poly-culture ponds(406,407,and 408) in Dianbai,Maoming City,Guangdong province between August and October,2010.In addition,we evaluated the effects of POM on the growth and survival of tilapia.The concentration of TPM ranged between 35.0 and 153.8 mg/L,(83.1±34.1) mg/L.The concentration of particular inorganic matter(PIM) ranged between 19.0 and 54.0 mg/L,(34.3±11.8) mg/L,and constituted 41.28% of TPM.The dry weight of plankton(PZ) ranged between 2.43 and 22.48 mg/L,(9.63±5.91) mg/L,and constituted 11.59% of TPM.The dry weight of phytoplankton(DWP) ranged from 2.298 to 22.105 mg/L,(8.99±5.98) mg/L,and constituted 10.81% of TPM.The dry weight of zoo-plankton(DWZ) ranged from 0.018 to 2.724 mg/L,(0.65±0.61) mg/L,and constituted 0.78% of TPM.Particular debris and bacteria ranged from 14.339 to 97.958 mg/L,(38.97±25.53) mg/L,and accounted for 81.77% of POM.The average rates of weight gain and specific growth were significantly higher in tilapia cultivated in the cages within Pond 407 than in the other two ponds.However,there were no significant differences in tilapia survival among the three ponds.

ASTROPHYSICAL EVIDENCE FOR AN EXTRA DIMENSION: PHENOMENOLOGY OF A KALUZA–KLEIN THEORY

In this brief review, we discuss the viability of a multi-dimensional geometrical theory with one compactified dimension. We discuss the case of a Kaluza–Klein (KK) fifth-dimensional theory, addressing the problem by an overview of the astrophysical phenomenology associated with this five-dimensional (5D) theory. By comparing the predictions of our model with the features of the ordinary (four-dimensional (4D)) Relativistic Astrophysics, we highlight some small but finite discrepancies, expectably detectible from the observations. We consider a class of static, vacuum solutions of free electromagnetic KK equations with three-dimensional (3D) spherical symmetry. We explore the stability of the particle dynamics in these spacetimes, the construction of self-gravitating stellar models and the emission spectrum generated by a charged particle falling on this stellar object. The matter dynamics in these geometries has been treated by a multipole approach adapted to the geometric theory with a compactified dimension.

Seasonal dynamics of soil light fraction organic matter in purple paddy soils

Seasonal dynamics of soil light fraction organic matter in purple paddy soils

Field Level Assessment of Soil Organic Matter and Nutritional Dynamics under Vegetated and Non Vegetated Ecosystems in Hotan River Basin, Xinjiang, China

Carbon dioxide is major cause of the greenhouse effect which is believed to be warming the Earth’s climate, the balance between accumulation of soil organic matter (SOM) and its loss through microbial respiration has global implications. In our study we have investigated dynamics of SOM during 2003-2011. Field investigations were conducted at two fields: fallow land and land cultivated by Tamarix. The following soil chemical properties also were evaluated: pH, electrical conductivity (EC), total and available NPK. The results revealed that amount of nutrients in soils are varied within two fields.

广州大夫山雨季林内外空气TSP和PM2.5浓度及水溶性离子特征

There is national research interest in the dynamics of airborne particulate matter(PM) due to its detrimental effects on air quality and human health. Both regional surveys and locally intensive monitoring of PM,particularly particles less than 2.5 micrometers in diameter(PM2.5),are now being conducted throughout China. The main research emphases include the spatial distribution,chemical characteristics,and main sources of airborne PM2.5in many urban areas,as well as industrial sites.The Pearl River Delta(PRD) is one of the highly urbanized and industrialized regions in China. Unfortunately, accompanying the rapid eco-social developments,the PRD has also deteriorated in terms of air,soil and water quality during the last few decades. Air pollution has been a serious environmental problem for many years now and frequent haze episodes in this region were often attributed to high concentrations of airborne PM 2.5. Forests play an important role in reducing airborne particulate matter and in maintaining air quality. In order to improve the urban environment and to serve the public health,many urban forests have been constructed to scavenge the huge amounts of dust through the forest canopy. However,the influence of the forest canopy on particulate matter water-soluble ions has seldom been studied to date. In the present study,we regularly monitored concentrations of the total suspended particulates(TSP),PM 2.5 and their water-soluble ions(Na+,NH+ 4,Ca2+,K+,Mg2+,SO2-4,NO-3,NO-2,Cl-and F-) from both inside and outside a suburban forest in Guangzhou,during the rainy season of 2012. The objective of this study was to reveal the importance of tree canopies in scavenging airborne particles and their water-soluble ions. The results showed that the forest canopy significantly reduced the concentrations of PM 2.5 and TSP(P 0.05). The concentrations of diurnal PM 2.5 and TSP inside the forest were(40.2±10.5) g / cm3and(101.3±33.2) g / cm3respectively, increasing to(55.8± 13.0) g / cm3and(116.6 ± 35.4) g / cm3outside the forest,respectively. SO2-4,Na+,NH+ 4 and NO-3 were the most abundant ions in both TSP and PM 2.5,accounting for more than 80% of total ions. The concentrations of SO2-4,Na+and NO-3 outside the forest were significantly higher than those inside,with the exception of NH+ 4. Correlation analysis on the ions revealed that during the study period,the principal water-soluble ions existed in the form of NaCl, Na 2 SO 4,NH 4 HSO 4 and NH 4 NO 3. Na+and Cl-in the water-soluble fraction of PM 2.5 and TSP were mainly sourced from sea salt,while the presence of other ions was predominantly influenced by anthropogenic sources. The ratios of c(NO-3) / c(SO2-4) in TSP and PM 2.5,both inside and outside the forest were less than 0.30,indicating that the stationary sources,e. g. coal burning,power plants and other industrial emissions,might be the main contributors to aerosols at the study site. The ratios of c(NO-3) /c(SO2-4) in TSP were higher than those in PM 2.5,implying that the mobile sources contributed more to TSP than to PM 2.5. Our results demonstrated that tree canopies could filter PM 2.5 and reduce concentrations of all watersoluble ion species,with the exception of NH+ 4,suggesting that urban forests can improve air quality.

Matter dynamics with respect to influences of C3and C4plants in four subtropical grasslands of Nilgiri Biosphere Reserve, the Western Ghats, India

Biomass changes, net primary production and transfer dynamics of dry matter in four subtropical humid montane grasslands at Ebbenadu, Korakundah, Thiashola and Wenlockdown in Nilgiri Biosphere Reserve (NBR), the Western Ghats, India, were investigated. Despite the early report of a higher density and dominance of <TEX>$C_4$</TEX> species over <TEX>$C_3$</TEX> species in these grasslands, no functional study of matter production had previously been carried out. Therefore, in order to determine the roles played by these two groups of species, the present study was attempted. The study revealed that the dry matter and net primary production contributed by <TEX>$C_4$</TEX> species were much greater than those of its <TEX>$C_3$</TEX> counterpart in all the grasslands. The turnover rate of aboveground dry matter for both <TEX>$C_3$</TEX> and <TEX>$C_4$</TEX> species was generally rapid, whereas it was slow for belowground parts, and litter components of <TEX>$C_3$</TEX> and <TEX>$C_4$</TEX> species together. In all grasslands, generally about 60% and 10% of the input were channeled to aboveground and belowground parts, respectively, by the <TEX>$C_4$</TEX> species, whereas the <TEX>$C_3$</TEX> species transferred only about 22% and 8% of dry matter to aboveground and belowground parts, respectively. The total disappearance of dry matter was 2.73, 2.10, 3.19, and <TEX>$1.96\;g\;m^{-2}\;day^{-1}$</TEX> in Ebbenadu, Korakundah, Thiashola and Wenlockdown grasslands, which was 48.83%, 44.30%, 54.81%, and 41.09% of the total input, respectively, in these grasslands. This resulted in a considerable surplus dry matter production in all the grasslands studied. This balance sheet of dry matter in community function indicates that all the four studied grasslands were supporting the existing wild animals adequately in terms of pasture supply. The study further revealed that the stronger establishment of <TEX>$C_4$</TEX> species rather than their <TEX>$C_3$</TEX> counterparts, in terms of higher density and dominance, has driven them to play major roles in matter dynamics and system transfer functions in all the four grasslands studied. This fact evidenced that pasture from <TEX>$C_4$</TEX> species for wild animals was determined to be higher in comparison to that of <TEX>$C_3$</TEX> species.

X-ray imaging detectors

Advances in detector technology, in concert with new synchrotron sources, x-ray optics, and computational methods, are opening new ways to probe the structure and dynamics of matter.

Potential of on-farm produced compost and organic amendments in soil fertility management for organic maize production in southwestern Nigeria

Soil fertility is central to organic crop production in the low activity soils of southwestern Nigeria. Studies on the use of organic amendments in the management of soil fertility and productivity have indicated the potential of organic practices in this region. In an experiment to study the effects of 5, 10 and 15 t ha−1 of composted pig manure on soil organic matter (SOM) and nutrient dynamics, compost was applied in 2005 and 2006 while land was left fallow in 2007. Parameters observed include aggregate stability, SOM fractions and N mineralization (laboratory and field incubation). Macroaggregate stability indices increased with compost rates. Distribution of SOM fractions, which accounted more for aggregate stability than total organic carbon with time, was better in compost-treated cultivated land compared to adjacent grassland. Nitrogen mineralization was highest with 10 t ha−1 of compost in both years. Soil chemical properties and nutrient uptake of maize after fallowing also showed that 10 t ha−1 of compost was most effective. Observations from another study involving green manure, compost, organo-mineral and mineral fertilizers have also demonstrated significant effects of organic amendments on soil fauna and other properties compared to mineral fertilizer even in the short run without yield compromise.

Die Phyllosphäre — ein mikrobielles Domizil

The phyllosphere is the surface and interior of aerial parts of vascular plants. It is colonized by bacteria, fungi, archaea, and protists which are adapted to nutrient and water resource limitations, UV exposure and high temperature shifts. Our investigations address the plant’s fitness, the mutualistic interaction, microbial safety of plant products as well as the effect of phyllosphere communities on matter dynamics in ecosystems.

Eccentric black hole-neutron star mergers: Effects of black hole spin and equation of state

There is a high level of interest in black hole-neutron star binaries, not only because their mergers may be detected by gravitational wave observatories in the coming years, but also because of the possibility that they could explain a class of short duration gamma-ray bursts. We study black hole-neutron star mergers that occur with high eccentricity as may arise from dynamical capture in dense stellar regions such as nuclear or globular clusters. We perform general relativistic simulations of binaries with a range of impact parameters, three different initial black hole spins (zero, aligned and antialigned with the orbital angular momentum), and neutron stars with three different equations of state. We find a rich diversity across these parameters in the resulting gravitational wave signals and matter dynamics, which should also be reflected in the consequent electromagnetic emission. Before tidal disruption, the gravitational wave emission is significantly larger than perturbative predictions suggest for periapsis distances close to effective innermost stable separations, exhibiting features reflecting the zoom-whirl dynamics of the orbit there. Guided by the simulations, we develop a simple model for the change in orbital parameters of the binary during close-encounters. Depending upon the initial parameters of the system, we find that mass transfer during nonmerging close-encounters can range from essentially zero to a sizable fraction of the initial neutron star mass. The same holds for the amount of material outside the black hole post-merger, and in some cases roughly half of this material is estimated to be unbound. We also see that nonmerging close-encounters generically excite large oscillations in the neutron star that are qualitatively consistent with $f$-modes.

Dynamics of hot and dense nuclear and partonic matter

The dynamics of hot and dense nuclear matter is discussed from the microscopic transport point of view. The basic concepts of the Hadron-String-Dynamical transport model (HSD)—derived from Kadanoff-Baym equations in phase phase—are presented as well as “highlights” of HSD results for different observables in heavy-ion collisions from 100 A MeV (SIS) to 21 A TeV(RHIC) energies. Furthermore, a novel extension of the HSD model for the description of the partonic phase—the Parton—Hadron-String-Dynamics (PHSD) approach—is introduced. PHSD includes a nontrivial partonic equation of state—in line with lattice QCD—as well as covariant transition rates from partonic to hadronic degrees of freedom. The sensitivity of hadronic observables to the partonic phase is demonstrated for relativistic heavy-ion collisions from the FAIR/NICA up to the RHIC energy regime.

Quality and dynamics of soil organic matter in a typical Chernozem of Ukraine under different long-term tillage systems

Kravchenko, Y., Rogovska, N., Petrenko, L., Zhang, X., Song, C. and Chen, Y. 2012. Quality and dynamics of soil organic matter in a typical Chernozem of Ukraine under different long-term tillage systems. Can. J. Soil Sci. 92: 429-438. Tillage has been reported to induce changes in soil organic matter (SOM) concentrations and quality. Conversion of plow-tillage to minimum till and no-till (NT) farming enhances the SOM pool. Enrichment of the SOM pool is essential for maintaining fertility of Chernozems, advancing food security, and improving the environment. The main objective of this study was to examine the effect of different tillage systems on the SOM concentration, its quality and dynamics including CO2 assimilation by heterotrophic bacteria and humus characteristics - the carbon (C) concentration in humic substances and the labile soil organic C fraction (SOCL) extracted with 0.1 N NaOH - as well as the molecular masses, spectroscopic parameters and physiological effects of humic acids on germinating...

Long-term fertilization effects on carbon and nitrogen in particle-size fractions of a Chinese Mollisol

Yan, Y., He, H., Zhang, X., Chen, Y., Xie, H., Bai, Z., Zhu, P., Ren, J. and Wang, L. 2012. Long-term fertilization effects on carbon and nitrogen in particle-size fractions of a Chinese Mollisol. Can. J. Soil Sci. 92: 509� 519. The response of soil organic matter (SOM) dynamics to long-term fertilization may be deduced from changes in the accumulation and distribution of different soil organic carbon (SOC) and nitrogen (N) pools. The SOC and N in particle-size fractions were therefore measured to assess the influences of pig manure and synthetic fertilizer application on the characteristics of these pools. A long-term fertilization experiment, established in 1979 in the Mollisol area (Gongzhuling, China) was used for this study. Composite soil samples (0� 20 cm) were collected in 2005 from 12 treatment plots that had received annual applications of pig manure, synthetic fertilizers or combinations of both. Soils were fractionated into fine clay (B0.2 mm), coarse clay (0.2� 2 mm), silt (2� 50 mm), fine sand (50� 250 mm) and coarse sand (250� 2000 mm) and then SOC and N contents in each particle-size fraction were measured. Although most of the SOC and N were associated with clay and silt fractions, the large proportion of silt in the soil mass played a key role in the retention of SOC and N. The application of pig manure alone increased accumulation of SOC and N in each particle-size fraction, but preferential enrichment was found in the coarse sand fraction. This indicates that pig manure is efficient in restoring SOM in the temperate Chinese Mollisol under a tilled maize (Zea mays L.) monocropping system and having a long frozen period in winter. The application of synthetic fertilizers had no clear effect on SOC and N accumulation or their distribution in particle-size fractions. However, the combined application of pig manure and synthetic fertilizers enhanced the accumulation of SOC and N in all particle-size fractions, and led to a shift of SOC and N from fine to coarse particles. We extended the hierarchy model for SOC protection to consider a shift in SOC accumulation from fine to coarse particles, depending on the initial SOC content of the specific soil. The findings reveal a clear positive interaction between pig manure and synthetic fertilizers that may improve the quantity of SOM in the temperate Chinese Mollisol.