13 years’ operational experience of SPring-8 vacuum system

The first electron beam was stored in SPring-8 storage ring in March 1997. An overview of the 13 years’ operational experience concerning the vacuum system of the SPring-8 storage ring is presented. The evolution of the vacuum system and their performance are summarized. Moreover, the main vacuum failures and their impact on accelerator operation are described in detail. We analyze the relationship between the difference types of vacuum failure and downtime of user experiment.     

微波场中加热高钛高炉渣的数值模拟

利用微波加热技术在高钛高炉渣内引发裂纹的实验过程中发现炉渣局部区域发生热失控现象.为探寻高钛高炉渣在微波场中产生热失控的原因,使用 FEMAP 和 wave-jω 软件计算了在多模式微波炉中高钛高炉渣及其周围空间内微波场和热三维分布情况,并对比研究了钙钛矿相和普通高炉渣吸收微波的能力.通过计算结果可知几乎所有的微波能都集中在被加热的高钛高炉渣试样中,即微波具有加热高钛渣自身而非周围环境的特点.另外,高钛高炉渣试样中微波场分布不均匀,且分散在炉渣中的钙钛矿相比其他矿物相更易被微波加热.以上 2 因素作用下微波加热高钛高炉渣时局部区域发生热失控现象.     

Real-time controllable fire using textured forces

Fluid dynamics can produce realistic looking fire effects, which are heavily used in animation and films. However, the parameters of the various underlying physical equations are not intuitive enough to be controlled easily. As a result, animators face problems when editing the fine details of the fire, especially the turbulence and growth at the fire surface. In this paper, we propose a new approach to enable animators to interactively edit such fine details using textured forces. These techniques involve mapping a texture onto the simulation that controls the creation of new forces, growing the fire into specific shape and adding the natural turbulence of fuel ignition. These textures can be edited using an intuitive user interface that allows forces to be painted directly onto the fire. Our system can be integrated into existing GPU fluid solvers to run in real-time. As a result, it is applicable for interactive applications such as 3D computer games.     

Effects of phosphorus content on generation and growth of cracks in nickel–phosphorus platings owing to thermal cycling

We observed crack generation and structural changes in electroless nickel–phosphorus (Ni–P) plating layers formed on copper-metalized silicon nitride substrates both during thermal cycling from ? 40 to 250 °C and during storage (not cycling) at 250 °C in order to investigate the effect of the phosphorus contents on crack generation and growth in the Ni–P platings. The used platings contained phosphorus at three different contents: 2.1 wt% [Ni–P(low)], 6.5 wt% [Ni–P(med)], and 10.9 wt% [Ni–P(high)]. The generation time and the amount of cracks were strongly dependent on their phosphorus contents. More cracks appeared after thermal cycling than after storage at 250 °C. In Ni–P(low), cracks were generated after 200 thermal cycles, whereas no cracks were observed even after 250 h of storage at 250 °C. In Ni–P(med) and Ni–P(high), both during thermal cycling and storage at 250 °C, cracks formed during or after crystallization of the amorphous layers. These results suggest that the primary factors affecting the generation of cracks in electroless Ni–P platings are crystallization of the Ni–P platings and repeated changes in thermal stress.     

How to identify water from thickener aqueous solutions by touch

Water detection is one of the most crucial psychological processes for many animals. However, nobody knows the perception mechanism of water through our tactile sense. In the present study, we found that a characteristic frictional stimulus with large acceleration is one of the cues to differentiate water from water contaminated with thickener. When subjects applied small amounts of water to a glass plate, strong stick-slip phenomena with a friction force of 0.46 ± 0.30 N and a vertical force of 0.57 ± 0.36 N were observed at the skin surface, as shown in previous studies. Surprisingly, periodic shears with acceleration seven times greater than gravitational acceleration occurred during the application process. Finite-element analyses predicted that these strong stimuli could activate tactile receptors: Meissner''s corpuscle and Pacinians. When such stimuli were applied to the fingertips by an ultrasonic vibrator, a water-like tactile texture was perceived by some subjects, even though no liquid was present between the fingertip and the vibrator surface. These findings could potentially be applied in the following areas: materials science, information technology, medical treatment and entertainment.