High Transverse Momentum Results from the STAR Collaboration

The STAR collaboration presents new measurements of high p_T hadron production in Au+Au and p+p collisions at RHIC. We extend the previously reported suppression of inclusive hadron and large azimuthal anisotropies to much higher transverse momentum, decisively establishing the existence of strong medium effects on hadron production well into the perturbative regime. Near-angle two-particle correlations show directly that hadrons at pT > 4 GeV/c result from the fragmentation of jets. Additional evidence for the onset of perturbative QCD in this region comes from the flavor dependence of the inclusive yields and elliptic flow. Finally, comparison of back-to-back hadron pairs at high pT in p+p and in Au+Au collisions at various centralities reveals a striking suppression of high pT back-to-back pairs in the most central Au+Au collisions. All of these phenomena suggest a picture in which partons or their hadronic fragments are strongly absorbed in the bulk matter, with the observed hadrons resulting from jets produced on the periphery of the collision zone and directed outwards.Comment: Plenary talk at QM2002 in Nantes/France, to be published in the conference proceedings (Nuc.Phys.), 10 page

Magnetic anisotropy terms in [110] MBE grown REFe2 films involving the strain term ???

The magnetic anisotropy parameters in [110] MBE grown films of REFe2 compounds are not the same as those in the bulk. This is due to the presence of a shear strain εxy, frozen in during crystal growth. In this paper, calculated magnetic anisotropy parameters for [110] MBE grown REFe2 films, that directly involve the shear strain εxy, are presented and discussed. In addition to the usual first order Callen and Callen term K˜'2, there are nine second order terms six of which involve cross terms between εxy and the cubic crystal field terms B4 and B6. Two of the second order cross terms are identified as being important: K˜"242(T) and K˜"262(T). Of these, the rank-two term K˜"242(T) dominates over a large temperature range. It has the same angular dependence as the first order term K˜'2, but with a more rapid temperature dependence. The correction at T = 0K for TbFe2, DyFe2, HoFe2, ErFe2, and TmFe2, amounts to ~+9.2%, -13.9%, -11.6%, +22.7%, and 27.1%, respectively. Similar comments are made concerning the rank-four K˜"264(T) term

Metastable behavior of vortex matter in the electronic transport processes of homogenous superconductors

We study numerically the effect of vortex pinning on the hysteresis voltage-temperature (V-T) loop of vortex matter. It is found that different types of the V-T loops result from different densities of vortex pinning center. An anticlockwise V-T loop is observed for the vortex system with dense pinning centers, whereas a clockwise V-T loop is brought about for vortices with dilute pinning centers. It is shown that the size of the V-T loop becomes smaller for lower experimental speed, higher magnetic field, or weak pinning strength. Our numerical observation is in good agreement with experiments

Accounting for variability in the detection and use of markers for simple and complex traits

There are many sources of variability in gene–phenotype associations. During the measurement of genotype and phenotype and during selection, researchers must deal with experimental error in trials; gene-gene interaction (epistasis) for sub-traits and observed traits; trait-trait interaction (pleiotropy) and gene- or genotype-by-environment interaction. These effects can be structured in a framework that allows simulation of the entire gene-environment ‘landscape’. Studies of these landscapes have been published by others. Here we aim to explain with simple examples some of the types of insights that can be made. A current challenge for breeders working with simple marker–phenotype associations is to design selection strategies that can rapidly create new combinations of multiple marker-based traits. For a real-world example in wheat, we have used simulation to show how gene enrichment during early generations (selection of homozygotes and heterozygotes with desirable alleles) can greatly reduce resource requirements when combining 9 genes into one genotype through marker-assisted selection. Another wheat example compares phenotypic and QTL-based selection for coleoptile length where the QTL also had a pleiotropic association with plant height. These simulations show the relative negative effects of either low heritability, or less than complete detection of QTL associated with traits. Finally, we revisit a marker-assisted selection (MAS) example whereby a QTL study is undertaken on a population for a complex trait, and then those QTL are used in selection. This process is subject to all sources of error described above. If the trait is complex, then interactions among sub-traits; between sub-traits and the environment; or between the chromosomal locations of controlling genes, create an extremely ‘rugged’ selection landscape that slows breeding progress. In this situation, a detailed understanding of some of these interactions is required if MAS is to be able to exceed the progress of conventional breedin

Occurrence and risk assessment of polycyclic aromatic hydrocarbons in soil from the Tiefa coal mine district, Liaoning, China.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;In order to evaluate soil-associated polycyclic aromatic hydrocarbons (PAHs) pollution from coal mine activities in Tiefa coal mine, Northeast China, 16 PAHs identified as priority pollutants by US Environmental Pollution Agency were determined in mining zone soil (MZS), agricultural soil (AS), local lake bank soil (LBS), a vertical soil profile and three coal gangue samples. The total concentration of 16 PAHs (defined as &Sigma;(16)PAH, dry weight) in surface soil ranged from 5.1 to 5642.3 ng g(-1), with an arithmetic mean of 1118.3 ng g(-1). &Sigma;(16)PAH values at the sites from MZS are significantly higher than those found in AS and LBS. The vertical distribution of PAHs indicated that these compounds can penetrate the deeper layers of the soil, especially the low-rings compounds. A complex of petrogenic origin and pyrolytic sources was found within the study area, as suggested by the isomeric ratios of PAHs. According to principal component analysis (PCA), four factors were identified in the source contribution, including coal combustion, unburned coal particulates, coal gangue and vehicular emissions. The degree of contamination and the PAH toxicity assessment suggested that the soils of the study area have been seriously polluted and pose a high potential health risk.</span

Two-band second moment model and an interatomic potential for caesium

A semi-empirical formalism is presented for deriving interatomic potentials for materials such as caesium or cerium which exhibit volume collapse phase transitions. It is based on the Finnis-Sinclair second moment tight binding approach, but incorporates two independent bands on each atom. The potential is cast in a form suitable for large-scale molecular dynamics, the computational cost being the evaluation of short ranged pair potentials. Parameters for a model potential for caesium are derived and tested

Another tetraquark structure in the π+χc1\pi^+ \chi_{c1} invariant mass distribution

In this article, we assume that there exists a scalar hidden charm tetraquark state in the $\pi^+ \chi_{c1}$ invariant mass distribution, and study its mass using the QCD sum rules. The numerical result $M_{Z}=(4.36\pm0.18) \rm{GeV}$ is consistent with the mass of the Z(4250). The Z(4250) may be a tetraquark state, other possibilities, such as a hadro-charmonium resonance and a $D_1^+\bar{D}^0+ D^+\bar{D}_1^0$ molecular state are not excluded.Comment: 14 pages, 14 figure, correct some type error

Disordered materials for high-performance lithium-ion batteries: A review

Disordered materials (DMs) have become promising materials in the advancement of lithium-ion batteries (LIBs). Their disordered, open structure is conductive to facilitate efficiency lithium-ion storage. DMs with tunable compositions also possess abundant defects that can interact with Li+, further enhancing their electrochemical performances in LIBs. Yet, revealing the structural origin of the superior electrochemical properties of DM-based LIBs remains a challenge. In this article, we review recent advances in the development of DM-based components for LIBs, such as anodes, cathodes, coating layers, and solid-state electrolytes. We give an overview on the primary methods utilized in preparing and characterizing DMs, while also describing the mechanisms involved in DM synthesis. This review article also addresses the correlation between the structural properties of DMs and their electrochemical performances. Moreover, we elucidate the challenges and future perspectives in the advancement of DM-based LIBs. We outline the key advantages of DMs in enhancing LIB performance over their crystalline counterparts, providing insights for developing superior LIBs through tailored DM development.</p

The gravity load simulator – Re-visited

A review of loading arrangements for lateral buckling tests on pultruded glass fibre reinforced polymer (GFRP) beams is presented. It is suggested that the Gravity Load Simulator (GLS), used for similar tests on steel beams could also be used for lateral buckling tests on GFRP beams and, moreover, it could be analysed and designed using exact calculations rather than the iterative method used more than 50 years ago. This conclusion is demonstrated by re-analysing the old iteratively designed GLS. The exact analysis is then used to analyse and design a new GLS for lateral buckling tests on pultruded GFRP beams. The new GLS was fabricated from aluminium bar and plate and details of its overall dimensions and layout and the types of bearings used in its pin joints are described. Thereafter, the test arrangement and instrumentation used to demonstrate the GLS's accuracy, i.e. maintaining the horizontal translation of the jack's base as the GLS sways in the lateral buckling plane, is presented. It is shown that the GLS performs extremely well and its use in laboratory testing is illustrated

Complex scale-free networks with tunable power-law exponent and clustering

This article is made available through the Brunel Open Access Publishing Fund. It is distributed under a Creative Commons License (http://creativecommons.org/licenses/by/3.0/). Copyright @ 2013 Elsevier B.V.We introduce a network evolution process motivated by the network of citations in the scientific literature. In each iteration of the process a node is born and directed links are created from the new node to a set of target nodes already in the network. This set includes mm “ambassador” nodes and ll of each ambassador’s descendants where mm and ll are random variables selected from any choice of distributions plpl and qmqm. The process mimics the tendency of authors to cite varying numbers of papers included in the bibliographies of the other papers they cite. We show that the degree distributions of the networks generated after a large number of iterations are scale-free and derive an expression for the power-law exponent. In a particular case of the model where the number of ambassadors is always the constant mm and the number of selected descendants from each ambassador is the constant ll, the power-law exponent is (2l+1)/l(2l+1)/l. For this example we derive expressions for the degree distribution and clustering coefficient in terms of ll and mm. We conclude that the proposed model can be tuned to have the same power law exponent and clustering coefficient of a broad range of the scale-free distributions that have been studied empirically.EPSR