Application of the induction plasma to the synthesis of two dimensional steam methane reforming Ni/Al2O3 catalyst

The purpose of the study is to develop a new protocol for preparing supported two dimensional catalysts with high external and low internal surface by combining thermal plasma spraying and thermal plasma chemical vapour deposition (TPCVD) processes. The method was tested for the production of an Al₂O₃ supported Ni catalysts used for methane steam reforming. The deposition of catalytic materials is made in 2 successive steps. The first step deals with alumina powder sprayed by induction plasma spraying (IPS) on a molybdenum substrate. The experimental conditions have been turned towards γ-Al₂O_3. The second stage deals with the deposition of nickel at the nanometric scale on the alumina layer using the thermal plasma chemical vapour deposition method. This last step was focused on the study of the influence of the nozzle type employed for the nickel solution spraying, the reactor internal pressure, the concentration and the flow rate of nickel salts solution, Ni(NO₃)₂·6H₂O, on the catalyst response. The formulations were tested as methane steam reforming catalysts.The results demonstrate that the catalyst morphology depends on plasma projection conditions and show the effectiveness of combining IPS and TPCVD processes for producing catalysts in methane steam reforming.     

Spectroscopic characterisation of a cross-flow plasma jet

The aim of this work is to study the thermal characteristics and electron density based on atomic and molecular emission of a new plasma jet at atmospheric pressure. The novelty of our jet is its generation with a single electrode, the plasma gas flowing perpendicularly to the RF powered electrode (13.56 MHz, 10³ V). Optical emission of the plasma was collected in two ways: the normal viewing mode and the axial viewing mode. The plasma characteristic parameters as function of helium flow-rate, plasma power and position of the investigated zone were studied. The excitation, vibrational and rotational temperatures are in the range of 1500-2350 K, 3500-4400 K and 450-1100 K, respectively. The electron number densities are in the range of 10¹³-10¹⁴ cm⁻³. For qualitative observations regarding the atomic and molecular processes in the plasma we used the relative intensities of the most representative lines of He, N₂, O, H and .     

覆盆子发酵酒发酵工艺响应面优化研究

以覆盆子干果为原料,通过响应面设计对覆盆子发酵酒的发酵工艺条件（温度、酵母菌接种量、蔗糖添加量）进行优化。研究结果表明,优化后的覆盆子发酵酒工艺条件为：覆盆子干果经粉碎至60目,料水比（1∶40）,发酵温度为25.3℃,接种量0.72%,蔗糖添加量20.53%,此条件下,乙醇浓度为13.19%vol,总黄酮含量2.58 mg/mL。得到的覆盆子发酵酒澄清透明,色泽金黄,爽口协调,口味纯正,理化卫生指标均符合果酒要求。     

Melt processed blends of poly(styrene-co-acrylonitrile) and poly(phenylene ether) compatibilized with polystyrene-b-polybutadiene-b-poly(methyl methacrylate) triblock terpolymers

Polystyrene-b-polybutadiene-b-poly(methyl methacrylate) triblock terpolymers (SBM) with equal (symmetric) and different (asymmetric) block lengths were used to compatibilize polymer blends based on poly(2,6-dimethyl-1,4-phenylene ether) (PPE) and poly(styrene-co-acrylonitrile) (SAN). First, the rheological behavior of the individual components and their binary mixtures was investigated. Based on the results, samples of PPE, SAN and SBM in weight ratios of 32/48/20 were melt blended and the morphology development during melt processing was investigated. It was found that a raspberry morphology, i.e. dispersion of PPE in SAN with rubbery PB domains at the PPE/SAN interface, could be achieved with a symmetric SBM with under sufficiently high shear rate, while a symmetric SBM with did not yield the desired morphology. Asymmetric SBMs with long PS blocks dissolved in the PPE phase did not display the expected compatibilization effect. In order to obtain a raspberry morphology with asymmetric copolymers it is suggested to pre-blend the SBM with SAN before adding the PPE. Finally it is shown that a commercial PPE containing High Impact Polystyrene (HIPS) as a toughness modifier can be compatibilized with SAN by melt processing using a symmetric SBM triblock terpolymer with      

Atmospheric pressure plasma jet operated at narrow gap spacings

The atmospheric pressure plasma jet (APPJ) makes use of a dielectric-barrier-free radio-frequency (RF) glow discharge for the production of a non-equilibrium plasma. Usually the APPJ is operated in the alpha mode at gap spacings in the mm range, where the alpha sheath thickness is in the order of 200-300 μm. Narrow gap spacings are experimentally not yet investigated, but it is expected that the bulk region of the alpha discharge should disappear and the discharge should exhibit a sheath-only structure.In order to provide experimental evidence for such situations, APPJs with gap spacings down to 0.1 mm are investigated. The electric properties of the APPJ are studied by measuring the current and voltage characteristics. Time-averaged images of the front view of the discharge are taken with a digital camera. By using an image-intensified gateable video camera the time development of the discharge is studied with nanosecond resolution.It was possible to sustain alpha discharges at gap spacings down to 100 μm, whereby the voltage needed decreases down to an rms voltage of 70 V. A weak indication for a laterally oscillating sheath in the 100 μm gap was found.     

Formal verification technique for grid service chain model and its application

Ensuring the correctness and reliability of large-scale resource sharing and complex job processing is an important task for grid applications. From a formal method perspective, a grid service chain model based on state Pi calculus is pro- posed in this work as the theoretical foundation for the service composition and collaboration in grid. Following the idea of the Web Service Resource Framework (WSRF), state Pi calculus enables the life-cycle management of system states by associating the actions in the original Pi calculus with system states. Moreover, model checking technique is exploited for the design-time and run-time logical verification of grid service chain models. A grid application scenario of the dynamic analysis of material deformation structure is also provided to show the effective- ness of the proposed work.     

Enhancement of electron heating in an ECR trap having a mixed multipole field - A Monte Carlo study

In electron cyclotron resonance (ECR) ion sources, confinement of ions and electrons is achieved with the help of an axial field in combination with a multipolar field. Generally sextupoles are used for this purpose. In a few sources, quadrupoles and octupoles also have been used. But sextupoles have been found to be most useful. We have investigated whether a combination of different multipoles can improve the performance of an ECR trap. A mixture of a sextupolar field and a dipole field has been found to enhance the electron heating to a large extent.     

“On-line” cleaning of optical components in a multi-TW-Ti:Sa laser system

Terawatt laser systems are affected by the problem that optical components, typically installed in vacuum, get contaminated with carbon. In this paper, we describe an “on-line” cleaning system, based on a radiofrequency discharge, to avoid carbon production or to clean optical components if carbon is already deposited. The advantage of such a cleaning system is the direct installation along the beam line which not only allows a fast and reproducible cleaning of the components without removing them from the beam line, but also allows a preventive treatment of the most sensitive optics from further contamination.     

基于树莓派的物联网ZigBee网关的设计与实现

利用树莓派这种体积小、成本低、便于携带的微型主机实现了一个电能监测ZigBee网络的多网融合网关,并基于非阻塞异步I/O,实现了PC端和手机端的并发访问.各部分功能均通过实验进行了验证.     

基于改进YOLOv5的树莓派火焰识别系统

火灾会对人员与财产安全造成巨大危害,如何迅速、准确地检测火焰出现具有重要意义。为实现高大空间条件下火焰的准确识别,设计了一种具有二自由度、可全方位检测环境情况的红外摄像头,并结合深度学习对目标检测算法YOLOv5进行改进;利用K-Means聚类算法匹配出9个聚类中心宽高维度替换原网络anchor参数;考虑了目标框相对比例,对损失函数进行优化,并用于树莓派上实现火焰识别。测试结果表明：改进的YOLOv5算法在树莓派上单张检测耗时2.9 s,较无改进YOLOv5算法减少78%;系统查准率为100%,识别目标框置信度均在0.9以上,能够快速准确识别出火焰。