Laser Heated Emissive Probes Design and Development under National Fusion Program and Potential Measurement

Emissive probes are the tools for the direct deter- mination of the plasma potential ~PL and they deliver a more reliable measure of φPL compared to the indi- rect measurements with cold Langmuir probes. The emissive probe works on the principle of compensating the well-known asymmetry of the I-V characteristic of a single cold Langmuir probe by an electron emission current from the probe into the plasma. In an ideal case, the saturated value of floating potential V（А,em） of a highly emissive probe should equal the plasma potential. A conventional emissive probe usu- ally consists of a loop of tungsten wire heated by an electric current passing through it. These conven- tional emissive probes containing an electric current- heated metal wire loop suffer a huge drawback when it comes to their lifetime. The metal wire used in these probes evaporates and subsequently breaks when heated with high current, leading to frequent replacements of these wires. When used in ultra high vacuum （UHV） plasma systems, frequent replacement of these wires requires frequent vacuum breaks in the plasma systems. In many plasma systems espe- cially in magnetized toroidal hot plasmas like toka- maks, where determination of the electric fields leads to a great deal of useful information, frequent breaking of the vacuum is impossible for changing the filament of the emissive probes. Hence, along with the other drawbacks of the conventional emissive probes such as limited emission current, bending in a magnetic field makes their use impractical in these plasma systems. The most suitable alternative is the emissive probes heated by a focused infra-red laser. Due to them having several advantages over the conventional emis- sive probes, laser heated emissive probes （LHEPs） are found to have more and more uses in plasma systems. The advantages of the LHEP are： longer lifetime （no filament breaking issues）, attainment of higher tem- perature without melting or evaporation and thus higher emissivity, no deformation of the pr     

Modelling avalanche flows

We present a lattice model that illustrates avalanche flow ina driven, disordered system. Structural disorder is associatedwith rectangular grains that have orientational degrees of freedom.Grain orientation transitions couple the evolving disorder withsurface instabilities. The simulated event size distributionhas features in common with observed surface granular flow and,in contrast to previous sandpile models, does not have a simplescaling behaviour. We have identified properties of the sandpilesurface that correlate with the internal structural disorder.The simulation results support a model of granular dynamicsin which surface flow and granular relaxation processes arestrongly coupled.     

Influence of near-edge processes in the elemental analysis using X-ray emission-based techniques

The near-edge processes, such as X-ray absorption fine structure (XAFS) and resonant Raman scattering (RRS), are not incorporated in the available theoretical attenuation coefficients, which are known to be reliable at energies away from the shell/subshell ionization thresholds of the attenuator element. Theoretical coefficients are generally used to estimate matrix corrections in routine quantitative elemental analysis based on various X-ray emission techniques. A tabulation of characteristic X-ray energies across the periodic table is provided where those X-rays are expected to alter the attenuation coefficients due to XAFS from a particular shell/subshell of the attenuator element. The influence of XAFS to the attenuation coefficient depends upon the atomic environment and the photoelectron wave vector, i.e., difference in energies of incident X-ray and the shell/subshell ionization threshold of the attenuator element. Further, the XAFS at a shell/subshell will significantly alter the total attenuation coefficient if the jump ratio at that shell/subshell is large, e.g., the K shell, L₃ subshell and M₅ subshell. The tabulations can be considered as guidelines so as to know what can be expected due to XAFS in typical photon-induced X-ray emission spectrometry.     

Harder–Narasimhan Filtrations which are not split by the Frobenius maps

We will produce a smooth projective scheme X over ?, a rank 2 vector bundle V on X with a line subbundle L having the following property. For a prime p, let F _p be the absolute Fobenius of X _p , and let L _p ???V _p be the restriction of L???V. Then for almost all primes p, and for all t?≥?0, $(F_p^*)^t L_P \subset (F_p^*)^t V_p$ is a non-split Harder-Narasimhan filtration. In particular, $(F_p^*)^t V_p$ is not a direct sum of strongly semistable bundles for any t. This construction works for any full flag veriety G/B, with semisimple rank of G?≥?2. For the construction, we will use Borel–Weil–Bott theorem in characteristic 0, and Frobenius splitting in characteristic p.     

Non-properness of the functor of <Emphasis Type="Italic">F</Emphasis>-trivial bundles

We study the properness of the functor of F-trivial bundles by relating it to the base change question for the fundamental group scheme of Nori.     

可见光下具有高光子效应和光催化活性的CuS-石墨烯氧化物/TiO2复合材料的制备（英文）

CuS-graphene oxide/TiO2 composites were prepared using a sol-gel method to improve the photocatalytic performance of the photocatalyst. The composites were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray analysis, and transmission electron microscopy. The photocatalytic activities were examined by the degradation of methylene blue (MB) under visible-light irradiation. The photodegradation of MB under visible-light irradiation reached 90.1% after 120 min. The kinetics of MB degradation was plotted alongside the values calculated from the Langmuir-Hinshelwood equation. The CuS-graphene oxide/TiO2 sample prepared using 0.2 mol of TiO2 showed the best photocatalytic activity. This was attributed to a cooperative reaction as a result of increased photoabsorption by graphene oxide and an increased photocatalytic effect by CuS.