Thermodynamic database of the phase diagrams in the Mg-Al-Zn-Y-Ce system

The Mg-Al-Zn-Y-Ce system is one of the key systems for designing high-strength Mg alloys. The purpose of the present article is to develop a thermodynamic database for the Mg-Al-Zn-Y-Ce multicomponent system to design Mg alloys using the calculation of phase diagrams （CALPHAD） method, where the Gibbs energies of solution phases such as liquid, fcc, bcc, and hcp phases were described by the subregular solution model, whereas those of all the compounds were described by the sublattice model. The thermodynamic parameters describing Gibbs energies of the different phases in this database were evaluated by fitting the experimental data for phase equilibria and thermodynamic properties. On the basis of this database, a lot of information concerning stable and metastable phase equilibria of isothermal and vertical sections, molar fractions of constituent phases, the liquidus projection, etc., can be predicted. This database is expected to play an important role in the design of Mg alloys.     

Layered Mg-Al spinel supported Ce-Fe-Zr-O oxygen carriers for chemical looping reforming

A series of layered Mg-Al spinel supported Ce-Fe-Zr-O oxygen carriers were prepared for co-production of syngas and pure hydrogen via chemical looping steam reforming (CLSR). The presence of magnesium-aluminum layered double oxides (MgAl-LDO) significantly increases the specific surface area of the mixed oxides, reduces the particle size of CeO₂-based solid solution and promotes the dispersion of free Fe₂O₃. When reacting with methane, MgAl-LDO supported oxygen carrier shows much lower temperature for methane oxidation than the pure CeFe-Zr-O sample, indicating enhanced low-temperature reactivity. Among different Ce-Fe-Zr-O(x)/MgAl-LDO samples, the Ce-Fe-Zr-O(40 wt%)/MgAl-LDO sample shows the best performance for the selective oxidation of methane to syngas and the H₂ production by water splitting. After a long period of high temperature redox experiment, the Ce-Fe-Zr-O(40 wt%)/MgAl-LDO oxygen carrier still shows high activity for syngas generation. The comparison on the morphology of the fresh and cycled oxygen carriers indicates that the Mg-Al spinel support still forms a stable skeleton structure with high dispersion of active components on the surface after the long-term cycling, which contributes to excellent redox stability of the Ce-Fe-Zr-O(40 wt%)/MgAl-LDO oxygen carrier.     

延长窑用耐火材料使用周期的措施

Φ5.8 m×97 m回转窑用耐火材料的使用周期太短,吨熟料碱性砖砖耗曾达3.0kg以上。从配置、施工、 使用维护和质量管理等方面采取措施后,2003年吨熟料碱性砖砖耗降到0.6kg左右。     

变电站设备状态智能识别系统技术研究

针对目前变电站采用人工巡检判断设备状态的方式存在作业效率低、工作质量不高、巡检人员的安全难以保障的问题,集成应用开关状态综合判断技术、刀闸状态综合判断技术、智能巡检技术和视频联动技术等关键技术,研制了变电站设备状态智能识别系统,通过与数据采集与监视控制(SCADA)系统的信息交互,实现了变电站开关、刀闸设备状态的远程智能识别.该系统可在变电设备倒闸操作、定期巡检、专项巡检以及日常设备状态监视中代替人工巡检开关、刀闸设备状态,及时发现并预警设备状态隐患,提高了巡检效率和质量,降低了运行人员的劳动强度,保障了人身及设备安全.通过在500 kV文山变电站的应用实例表明,应用该系统在单台主变停电倒闸操作中可节省5.63工时,验证了系统的实用性和有效性.     

物联网智能终端适配中间件开发模式

针对目前大多数的智能终端应用开与服务开发,需针对终端不同种类、不同的操作系统等进行定制,存在开发周期长,成本高,增加了重复性劳动和资源浪费的问题,阐述并提出研发一款适合各类智能终端的物联网应用适配中间件,以匹配不同数据源和不同终端.研究了中间件的系统架构和技术架构,采用面向对象的思想,融合MVC(Model View Control),Adapter,Singleton等多种设计模式.智能终端中间件能够提高物联网领域行业应用能力,扩大物联网领域的接入渠道.     

Long-term ultra-precision phase synchronization technique for locking the repetition rate of OFCs based on FLOM-PD

Long-term ultra-precision synchronization between optical frequency combs (OFCs) and microwave oscillators is important for various fields, including scientific observation, smart grid, positioning and navigation, etc. Here, a phase-locked loop system based on fiber loop optical-microwave phase detector (FLOM-PD) is proposed to realize the synchronization of the repetition rate of OFCs and rubidium atomic clocks. Firstly, the scheme and locking process of the system are elaborated, then the mathematical model of the system is established, and the feasibility of the scheme is proved by theoretical analysis and experimental verification. After synchronization, the instability of the system reaches 8.69×10-12 at 1 s and 2.94×10-13 at 1 000 s, indicating that the phase synchronization system can achieve ultra-precision and stability of OFCs repetition rate.     

Biochemical responses of the copepod Centropages tenuiremis to CO(2)-driven acidified seawater

An ecophysiological experiment was conducted to examine the biochemical effects of acidified seawater containing elevated concentration of CO(2) (C(CO2) 0.08, 0.20, 0.50 and 1.00%) on the copepod Centropages tenuiremis. AchE, ATPase, SOD, GPx, GST, GSH level and GSH/GSSG ratio of the copepod were analyzed. The results showed that elevated C(CO2) and the duration of culture time significantly influenced several biochemical indices in C. tenuiremis (ATPase, GPx, GST, GSH and SOD). Furthermore, the principal component analysis results indicated that 72.32% of the overall variance was explained by the first three principal components (GPx, SOD and GSH). Changes in GPx and GSH levels may play a significant role in the antioxidant defense of copepods against seawater acidification. The long-term response of copepods to seawater acidification and the synergistic effects of acidification with other environmental factors, such as temperature, salinity and trace metal need further investigation.     

Effects of Heat Treatment on Dimension Stability of Larch Pallet Decks

The useful life of wooden pallets is lower because of the defects in lumbers. The quality of lumber can be significantly enhanced by heat treatment. In this paper, the larch pallet decks samples were heat-treated under the conditions of different time and temperatures. The quantity of water uptake has reduced 16.8％ under the condition of 250 ℃ for 150 min. The resistance of water absorption efficiency increases 165.34％ under the condition of 175 ℃ for 90 min. The anti-shrink efficiency increases 72.08％ under the condition of 250 ℃ for 90min. The results showed that the dimension stability of larch panels can be improved by heat treatment. The condition of 250 ℃ for 180 min is the best heat treating condition to improve the dimension stability.