基于DSP的双余度ARINC429总线通信系统的设计与实现

针对某型飞机电气系统数据总线的要求,设计了一种基于DSP技术的双余度ARINC429总线通信系统;该系统用ARINC429专用芯片H18582构成数据收发单元,通过CPLD编程实现系统的逻辑电路设计,双余度技术的应用极大地提高了系统的可靠性;通过该系统,既可实现总线上相关航空电子设备问的通信,也可实现对设备进行检测.具有很强的通用性;该系统在实际应用中取得了良好的效果,达到了预期的设计目的,文章详细介绍了该通信系统的组成、工作原理以及软、硬件设计.     

液体电谐振和血凝抑制试验检测禽流感的2种方法的对比

对禽流感(AI)病毒的快速检测方法进行研究。利用抗体和抗原特异性结合原理,将液体电谐振仪应用于禽流感的检测,与传统的血凝抑制试验方法进行比较。试验结果表明:运用液体电谐振传感仪可对禽流感进行快速检测,与血凝抑制试验相比较,具有灵敏度高、操作简单、检测速度快等优点。     

Comparative Studies on the Extraction of Protactinium Using Different Kinds of Organic Extractants

Abstract

The extraction behavior of Pa(V) from various aqueous solutions was studied using different extractants, namely Amberlite-LA-2 (Amb-LA2), diethylhexyl phosphoric acid (HDEHP), tributylphosphate (TBP) and Tricaprylylmethyl ammonium chloride (TCMA) in toluene. The extraction was carried out from slightly acidic as well as strong acidic solutions of HCl, HBr, and HI, at various temperatures. The extracted species in every case were postulated. Extraction chromatography behavior of Pa(V), its homologue Nb(V), and the chemically similar elements Zr(IV) and Hf(IV) were also studied in the case of TCMA. Radioactive isotopes were used for tracing the corresponding elements. Some separation alternatives were achieved.     

HIx concentration by electro-electrodialysis using stacked cells for thermochemical water-splitting IS process

In the thermochemical water-splitting iodine–sulfur process for hydrogen production, efficient concentration/separation of HI from HIx solution, a mixture of HI–H₂O–I₂, is very important. In this paper, an experimental study on concentrating HI in HIx using stacked electro-electrodialysis (EED) cells was carried out under the conditions of 1atm, 80 °C and the current density of 0.10 A/cm². The performance of EED stacks including 1, 2 and 4 EED units was evaluated. The results showed that multi-unit EED cells could concentrate HI in catholyte much faster than single-unit cells. The apparent transport number (t₊) of all the experiments were very close to 1, while the ratio of permeated quantities of water to H⁺ (β) changed in a relatively larger range of 1.98–2.89. Although the current efficiency will degrade faster when using a multi-unit stack than a single-unit cell at the late stage of EED process, at high iodine content multi-unit stack could maintain quite high current efficiency.     

Synthesis,characterisation and in vitro digestibility of carboxymethyl potato starch rapidly prepared with microwave-assistance

Carboxymethyl potato starch was synthesised with the aid of microwave. Optimal degree of substitution (DS) of 0.32 was obtained at 45 °C in 25 min using aqueous ethanol media with water/solvent of 0.15 at 200 W. The molar ratio of sodium hydroxide and monochloroacetic acid to anhydroglucose unit for optimal DS were 2.5 and 1.0, respectively. FT-IR spectrometry revealed the carboxymethyl starch to show new bands at ν = 1614 cm⁻¹ and ν = 1429 cm⁻¹. Wide angle X-ray diffractometry and DSC revealed a remarkable reduction in starch crystallinity after carboxymethylation, which was consistent with destroyed surface observed in SEM. The digestibility of carboxymethyl starch (CMS) was lower than that of native starch. With similar DS, there was no difference in digestibility of carboxymethyl starch prepared with and without microwave. As DS increased from 0.05 to 0.32, the amount of resistant starch in microwave-assisted carboxymethyl starch was elevated from 14.6% to 20.0%, which was much higher than that of native starch (10.8%).     

Development of Pt-Carbon catalysts using MCM-41 template for HI decomposition reaction in S–I thermochemical cycle

Different Pt-Carbon catalysts have been synthesized by hard templating route and have been employed for production of hydrogen from liquid phase HI decomposition at 160 °C temperature. The physical properties and catalytic activities of these catalysts are compared with that of the platinum on activated carbon catalysts. These catalysts have been characterised by X-Ray diffraction, Raman, SEM and BET surface area. Eluant analysis has been carried out using ICP-OES for evaluation of the extent of noble metal leaching under the catalytic activity test conditions. From the present study we have concluded that MCM-41 based Pt/carbon has higher catalytic activity and stability than other Pt/carbon catalysts.     

REVIEW OF SIMULATION METHODS OF THE DISTILLATION COLUMN AND THERMODYNAMIC MODELS IN THE HI DECOMPOSITION SECTION OF THE IODINE-SULFUR PROCESS

The iodine-sulfur thermochemical water-splitting process (I-S process) is one of the most promising and efficient mass hydrogen production methods without greenhouse gas emissions. To a large extent, distillation in the HI decomposition section of the I-S process affects the efficiency of the entire process. This article summarizes the simulation methods for HI distillation in the iodine-sulfur process, including thermodynamic models, design schemes, and parameter analyses. The performance of the thermodynamic models and heat duties of different flow sheets were compared, and the preferable model and flow sheet are recommended. This study can provide a reference for the selection of thermodynamic models and it is also meaningful for the design and simulation of the HI distillation column.     

Continuous purification of H2SO4 and HI phases by packed column in IS process

Iodine–sulfur (IS) thermo-chemical water-splitting process is a promising technology to produce hydrogen using solar or nuclear energy. To avoid the undesirable side reactions between HI and H₂SO₄ phases formed in Bunsen reaction of IS cycle, it is necessary to purify the two phases. The purification process could be achieved by reverse reaction of Bunsen reaction. In this paper, the purification process in continuous mode by reacting sulfuric acid and HI in a packed column was experimentally studied; the influences of operational parameters, including the reaction temperature, the flow rate of nitrogen gas, and the flow rate of the raw material solutions, on the purification efficiency, were investigated in detail. Based on the results, the suitable conditions for continuous purification process of two phases were proposed.     

Optimization of liquid–liquid phase separation characteristics in the Bunsen section of the sulfur–iodine hydrogen production process

In order to optimize the sulfur–iodine thermochemical cycle, a series of experiments were conducted to investigate the separation characteristics of the liquid–liquid phase in the H₂SO₄/HI/I₂/H₂O quaternary solution produced by Bunsen reaction. The effects of the solution composition in the feed and the operating temperature on the separation characteristics were analyzed to determine the preferable operating conditions in the Bunsen section. The increases in both the iodine content and the operating temperature improved the separation characteristics of the liquid–liquid phase when the occurrence of secondary reactions was neglected. The amount of impurities in both phases obviously decreased as the iodine content increased. The effect of the iodine content was more significant relative to that of the operating temperature. The optimal operating conditions were proposed to achieve the concentrations of HI in the HIx phase in excess of the azeotropic composition.     

基于关系网络的轴承剩余使用寿命预测方法

针对轴承全寿命周期数据获取困难、训练样本少的问题, 提出一种基于关系网络的轴承剩余使用寿命(Remaining useful life, RUL)预测方法. 关系网络是一种基于度量的元学习方法, 在少量训练样本下, 具有快速学习新任务的优点. 设计了一种基于关系网络的轴承健康评估模型, 利用关系网络的嵌入模块提取轴承状态特征, 利用关系模块度量轴承状态特征之间的相似性, 基于相似性构建轴承健康指标(Health indicator, HI); 对健康指标进行Savitzky-Golay滤波平滑处理, 降低振荡对预测结果的影响; 最后利用线性函数对健康指标进行拟合, 得到轴承RUL预测值. 为验证所提方法的有效性, 在PHM2012轴承实测数据集上进行实验. 结果表明, 所得健康指标能够反映轴承的退化趋势, 所得RUL预测结果与空间卷积长短期记忆神经网络 (Convolutional long short-term memory neural network, ConvLSTM)、Transformer、循环神经网络(Recurrent neural network, RNN)、卷积神经网络(Convolutional neural network, CNN) + 长短期记忆网络 (long short-term memory network, LSTM )、编码器−解码器(Encoder-decoder) + 注意力机制 (Attention mechanism)方法相比, 误差百分比分别减少了1.67%, 3.40%, 9.02%, 13.71%, 30.48%. 该方法在少量训练样本的基础上可以取得较好的预测结果, 具有一定的应用价值.