Barley is cultivated both in highly productive agricultural systems and also in marginal and subsistence environments. Its distribution is worldwide and is of considerable economic importance for animal feed and alcohol production. The overall importance of barley as a human food is minor but there is much potential for new uses exploiting the health benefits of whole grain and beta-glucans. The barley supply chains are complex and show added value at many stages. Germplasm resources for barley are considerable, with much potential for exploitation of its biodiversity available through the use of recently developed genomic and breeding tools. Consequently, substantial gains in crucial sustainability characteristics should be achievable in the future, together with increased understanding of the physiological basis of many agronomic traits, particularly water and nutrient use efficiency. Barley’s ability to adapt to multiple biotic and abiotic stresses will be crucial to its future exploitation and increased emphasis on these traits in elite germplasm is needed to equip the crop for environmental change. Similarly, resource use efficiency should become a higher priority to ensure the crop’s sustainability in the long-term. Clearly barley is a resilient crop with much potential which can be realised in the future. 相似文献
We present an approach for the visualization and interactive analysis of dynamic graphs that contain a large number of time steps. A specific focus is put on the support of analyzing temporal aspects in the data. Central to our approach is a static, volumetric representation of the dynamic graph based on the concept of space-time cubes that we create by stacking the adjacency matrices of all time steps. The use of GPU-accelerated volume rendering techniques allows us to render this representation interactively. We identified four classes of analytics methods as being important for the analysis of large and complex graph data, which we discuss in detail: data views, aggregation and filtering, comparison, and evolution provenance. Implementations of the respective methods are presented in an integrated application, enabling interactive exploration and analysis of large graphs. We demonstrate the applicability, usefulness, and scalability of our approach by presenting two examples for analyzing dynamic graphs. Furthermore, we let visualization experts evaluate our analytics approach.
Magnetic van der Waals (vdW) materials are the centerpiece of atomically thin devices with spintronic and optoelectronic functions. Exploring new chemistry paths to tune their magnetic and optical properties enables significant progress in fabricating heterostructures and ultracompact devices by mechanical exfoliation. The key parameter to sustain ferromagnetism in 2D is magnetic anisotropy—a tendency of spins to align in a certain crystallographic direction known as easy‐axis. In layered materials, two limits of easy‐axis are in‐plane (XY) and out‐of‐plane (Ising). Light polarization and the helicity of topological states can couple to magnetic anisotropy with promising photoluminescence or spin‐orbitronic functions. Here, a unique experiment is designed to control the easy‐axis, the magnetic transition temperature, and the optical gap simultaneously in a series of CrCl3?xBrx crystals between CrCl3 with XY and CrBr3 with Ising anisotropy. The easy‐axis is controlled between the two limits by varying spin–orbit coupling with the Br content in CrCl3?x Brx. The optical gap, magnetic transition temperature, and interlayer spacing are all tuned linearly with x. This is the first report of controlling exchange anisotropy in a layered crystal and the first unveiling of mixed halide chemistry as a powerful technique to produce functional materials for spintronic devices. 相似文献
The selective reduction of nitric oxide by methane or ethane, in the presence and in the absence of a large excess of oxygen, has been investigated on Cu/ZSM-5, Co/ZSM-5, Rh/ZSM-5 and Pt/ZSM-5 catalysts over a wide range of temperatures. It has been found that the maximum nitric oxide conversion is higher with ethane than with methane and the temperature of this maximum is lower with ethane. In the absence of oxygen the order of activity is Rh/ZSM-5>Pt/ZSM-5>Co/ZSM-5> Cu/ZSM-5 with the Cu/ZSM-5 being essentially inactive, while in the presence of oxygen the order is: Rh/ZSM-5>Co/ZSM-5>Cu/ZSM-5> Pt/ZSM-5 when ethane is used as reductant and: Rh/ZSM-5>Co/ZSM-5> Cu/ZSM-5>Pt/ZSM-5 when methane is used. The effect of the oxygen content has been investigated for the Co/ZSM-5 catalyst. It has been found that with a small quantity of oxygen the catalytic activity decreases markedly; with higher oxygen content the activity of the catalyst rises again. It appears that two different reaction schemes may be operative, one in the absence of oxygen the other in the presence of oxygen. It is concluded that neither carbonaceous deposits, nor nitrogen dioxide formation in the gas phase are important in the reaction mechanism on metal-containing zeolites. It is proposed that the reaction is essentially a redox process in which decomposition of nitric oxide occurs on reduced metallic or metal ion sites (the relative activity of each of these depending on the choice of metal), leading to the formation of gaseous nitrogen and adsorbed oxygen, followed by the removal of the adsorbed oxygen by the hydrocarbon, thus recreating the active centres. 相似文献
Competitive electricity markets are undergoing a rapid transformation from systems with large, inflexible baseload resources to ones with smaller, modular, variable resources. Making the grid more flexible is critical to enabling a smooth transition. A significant amount of unused flexibility exists in the system today, but harnessing it requires changes to market rules. 相似文献
Relevant parameters for non-covalent protein functionalization of carbon nanotubes are explored. Multiwalled carbon nanotubes are carboxylated and functionalized with metalloproteins. Using atomic force microscopy (AFM) we quantitatively determine that coverage with nitrogen-doped multiwalled carbon nanotubes is superior compared to coverage with un-doped multiwalled carbon nanotubes, due to enhanced carboxylation. Conformational analysis using a combination of AFM, antibody binding assays, circular dichroism and UV-visible spectroscopy demonstrates that the metalloproteins retain their native structure when adsorbed to nitrogen-doped multiwalled carbon nanotubes irrespective of their size, charge or folding motif. 相似文献
Fully exploiting the properties of graphene will require a method for the mass production of this remarkable material. Two main routes are possible: large-scale growth or large-scale exfoliation. Here, we demonstrate graphene dispersions with concentrations up to approximately 0.01 mg ml(-1), produced by dispersion and exfoliation of graphite in organic solvents such as N-methyl-pyrrolidone. This is possible because the energy required to exfoliate graphene is balanced by the solvent-graphene interaction for solvents whose surface energies match that of graphene. We confirm the presence of individual graphene sheets by Raman spectroscopy, transmission electron microscopy and electron diffraction. Our method results in a monolayer yield of approximately 1 wt%, which could potentially be improved to 7-12 wt% with further processing. The absence of defects or oxides is confirmed by X-ray photoelectron, infrared and Raman spectroscopies. We are able to produce semi-transparent conducting films and conducting composites. Solution processing of graphene opens up a range of potential large-area applications, from device and sensor fabrication to liquid-phase chemistry. 相似文献
We investigated the plume structure of a piezo-electric sprayer system, set up to release ethanol in a wind tunnel, using
a fast response mini-photoionizaton detector. We recorded the plume structure of four different piezo-sprayer configurations:
the sprayer alone; with a 1.6-mm steel mesh shield; with a 3.2-mm steel mesh shield; and with a 5 cm circular upwind baffle.
We measured a 12 × 12-mm core at the center of the plume, and both a horizontal and vertical cross-section of the plume, all
at 100-, 200-, and 400-mm downwind of the odor source. Significant differences in plume structure were found among all configurations
in terms of conditional relative mean concentration, intermittency, ratio of peak concentration to conditional mean concentration,
and cross-sectional area of the plume. We then measured the flight responses of the almond moth, Cadra cautella, to odor plumes generated with the sprayer alone, and with the upwind baffle piezo-sprayer configuration, releasing a 13:1
ratio of (9Z,12E)-tetradecadienyl acetate and (Z)-9-tetradecenyl acetate diluted in ethanol at release rates of 1, 10, 100, and 1,000 pg/min. For each configuration, differences
in pheromone release rate resulted in significant differences in the proportions of moths performing oriented flight and landing
behaviors. Additionally, there were apparent differences in the moths’ behaviors between the two sprayer configurations, although
this requires confirmation with further experiments. This study provides evidence that both pheromone concentration and plume
structure affect moth orientation behavior and demonstrates that care is needed when setting up experiments that use a piezo-electric
release system to ensure the optimal conditions for behavioral observations. 相似文献