[en] The 'Cone algorithm' for the identification of jets is studied in some detail. Two methods are given to identify jets using the momenta of final state particles. Making use of the data sample produced by the LUND-PYTHIA Monte Carlo generator hadron-hadron collision events, the two methods are tested and compared with each other. An effective and practical method to identify jets is obtained

No abstract available

[en] In the present investigation, Al-12Si, Al-20Si and Al-25Si (wt%) alloys were synthesized by spray atomization and deposition technique. The wear resistance of the alloys was studied using a pin-on-disc machine under four loads, namely 8.9, 17.8, 26.7 and 35.6 N. The microstructures, worn surfaces and the debris were analyzed in a scanning electron microscope. It has been found that the effect of Si content on dry sliding wear of spray-deposited Al-Si alloy was associated with applied loads. At lower load (8.9 N), with increasing Si content, the wear rate of the alloy was decreased. At higher load (35.6 N), spray-deposited Al-20Si alloy exhibited superior wear resistance to the Al-12Si and Al-25Si alloys

[en] The ANISN code, the DOT 3.5 code and the Combinatorial Geometry Full Energy Range Monte Carlo code are used to calculate the core neutron spectra of HFETR. HFETR core is simplified as composed of fuels, beryllium reflector, surrounded by aluminium and water. Irradiation channels and capsules are put into the central position of the core (K11). By analysing the calculation results of different core arrangements, some valuable conclusions are derived for the optimal radius of a cylinder flux trap, the analytical expression of epithermal neutron spectra and other calculated results are compared with experimental results of spectra and spectrum parameters

[en] Although switching systems have been investigated intensively, there are few results about limit cycles bifurcated from switching systems with degenerate singular point. In this paper, a method to compute focal values for degenerate critical point of switching systems was proposed. Furthermore, we studied a quartic system in order to illustrate the efficiency of our method.

[en] Highlights: • The model of energy storage of subcritical CFB boilers is established. • The capacity and increment rate of heat storage are quantified. • A novel load control strategy is proposed to improve the quick load change ability. • An application on the 300 MW CFB unit proves the load change rate to 5–8 MW/min. - Abstract: The energy storage of circulating fluidized bed (CFB) boilers on fuel side cannot be ignored due to the special combustion type different from pulverized coal boilers. The sizable energy storage makes it possible for CFB units to enhance the quick load change ability and to increase the scale of new energy power connected into grid. Through mechanism analysis, the model of energy storage of subcritical CFB boilers has been established for the first time. Then by the project practice, the quantitative analysis is demonstrated for the capacity and control characteristics of energy storage on fuel side and steam water side. Based on the control characteristics and the transformation of the energy storage, a coordinated control system (CCS) control strategy named advanced energy balance (AEB) is designed to shorten the response time through the use of energy storage and to accelerate the load change speed of subcritical CFB units. Finally, a case study on a 300 MW CFB unit proves the feasibility of the proposed control strategy.

No abstract available

[en] Yttrium oxide (Y₂O₃) films have successfully been applied as anti-reflection (AR) and anti-oxidation films for diamond. For significant adhesion improvement between Y₂O₃ coating and diamond, aluminum nitride (AlN) as an interlayer is introduced. Y₂O₃ and AlN films were prepared by RF magnetron sputtering of Y₂O₃ ceramic target in Ar atmosphere and pure Al metal target in Ar + N₂ atmosphere, respectively. The Y₂O₃ and AlN films were studied by X-ray diffraction, X-ray photoelectron spectroscopy, Atomic force microscopy and Spectroscopic ellipsometry. Adherent Y₂O₃/AlN films on high optical quality chemical vapor deposition diamond with optimum thicknesses for infrared transmission enhancement in 8–10 μm were obtained by a Fourier transform infrared spectrometer. More than 28% increase in maximum transmission was observed for Y₂O₃/AlN//Diamond//AlN/Y₂O₃. Comparing between the designed and experimental AR effects for Y₂O₃/AlN film in 8–10 μm wavebands, experimental average AR effects are smaller for the absorption and scattering loss. AR effects for the Y₂O₃/AlN films on CVD diamond are proved to be excellent.

[en] A low energy ion implanter for the energy range 100 eV-60 keV has been designed, manufactured and tested in the ion beam laboratory of the Institute of Physics. The system consists of a 30 kV extraction system, an analyzing magnet, a deceleration or acceleration system of changeable voltage from 0 up to 30 kV, electrostatic scanning system and a UHV target chamber. Three different ion sources can be used at the ion implanter: A Penning ion source, a hollow cathode ion source and a negative sputtering ion source. The system has been designed for ion beam materials modification, surface analysis and atomic-molecular physics research. (orig.)

[en] A stainless-steel target chamber for ion implantation and ion beam analysis in-situ, like RBS, channelling and charged particle reactions, is described. A 3-axis precise goniometer with 2-dimension parallel movements and two Au-Si surface barrier detectors with different solid angles have been istalled in the chamber. The target chamber has a good base pressure, no evidence of oil contamination, quick sample replacement and high efficiency for various ion beam analysis. Those have been demonstrated by the experiences of four years utilization