Grain refinement in low SFE and particle-containing nickel aluminium bronze during severe plastic deformation at elevated temperatures

The influence of particle size and morphology on grain refinement in low stacking fault energy(SFE)alloys was studied by comparing the grain structures in single-and multi-phase Al-bronze(AB)alloys following equal channel angular pressing(ECAP)between 350 and 500℃.In particular,nickel aluminium bronze(NAB)was chosen as it contained both coarse and fine rounded particles,as well as a lamellar phase which evolved during ECAP.Grain refinement in the single-phase alloy was achieved through dynamic recrystallisation initiated at deformed twin boundaries.By contrast,different mechanisms were observed in the particle-containing NAB.Recrystallisation around the coarse κⅡ particles(～5 μm)was promoted through particle stimulated nucleation(PSN),whereas recrystallisation in the region of the fine κⅣ(～0.4μm)was delayed due to the activation of secondary slip.Grain refinement in areas of the lamellar κⅢ showed significant variation,depending on the lamellar orientation relative to the shear plane of ECAP.As the lamellae deformed,numerous high angle grain boundaries were generated between fragments and served as nucleation sites for recrystallisation,while PSN occurred around spheroidised lamellae.The spreading of the κⅢ particles by ECAP then enhanced the total area of recrystallised grains.     

Thermo-economic analysis of a direct supercritical CO2 electric power generation system using geothermal heat

A comprehensive thermo-economic model combining a geothermal heat mining system and a direct supercritical CO₂ turbine expansion electric power generation system was proposed in this paper. Assisted by this integrated model, thermo-economic and optimization analyses for the key design parameters of the whole system including the geothermal well pattern and operational conditions were performed to obtain a minimal levelized cost of electricity (LCOE). Specifically, in geothermal heat extraction simulation, an integrated wellbore-reservoir system model (T2Well/ECO2N) was used to generate a database for creating a fast, predictive, and compatible geothermal heat mining model by employing a response surface methodology. A parametric study was conducted to demonstrate the impact of turbine discharge pressure, injection and production well distance, CO₂ injection flowrate, CO₂ injection temperature, and monitored production well bottom pressure on LCOE, system thermal efficiency, and capital cost. It was found that for a 100 MW_e power plant, a minimal LCOE of $0.177/kWh was achieved for a 20-year steady operation without considering CO₂ sequestration credit. In addition, when CO₂ sequestration credit is $1.00/t, an LCOE breakeven point compared to a conventional geothermal power plant is achieved and a breakpoint for generating electric power generation at no cost was achieved for a sequestration credit of $2.05/t.     

Synthesis of CeO2 nanoparticles using flame-assisted spray pyrolysis and solid state diffusion routes

The stable and crystalline phase of pure nanostructured CeO2 was directly synthesized by flame-assisted spray pyrolysis and solid state diffusion route. Different characterization techniques, including X-ray diffraction(XRD), scanning electron microscopy(SEM), Fourier transform infrared spectroscopy(FTIR), ultraviolet–visible(UVVis), and thermo gravimetric analysis(TGA) were employed to examine the structural, morphological, optical, and thermal properties of the final product. Similarly, the comparative carbon dioxide(CO2)-sensing response of as-synthesized Ce O2 nanoparticles by both routes was also reported. The CeO2 nanoparticles synthesized by solid state diffusion method exhibit good sensitivity(3.38 %) at room temperature,low operating temperature(398 K), fast response time(32 s),and recovery time(36 s) along with good stability.     

Rare earth metals sorption recovery from uranium in situ leaching process solutions

Sorption characteristics of ion exchange resins 001×7,005×8,D72 regarding rare earth metals(REM) during extraction from barren solution of uranium sorption in dynamic conditions were investigated. It was identified that D72 resin capacity on analyzed REM was 2.46 mg cm-3 after passing 220 BV(bed volume) of initial solution with 95% recovery of element of REM with the lowest affinity. Researches on REM desorption in dynamic conditions from investigated ion exchange resins by solution of 1.7 mol·L-1HNO3 and 8.0 mol·L-1NH4NO3 with 0.2 mol·L-1 HNO3 passing were carried out. It was identified that using desorption solution based on ammonium nitrate allows to achieve acceptable recovery degree of REM from the resin. The possibility of organization of a circulating desorption solution system increases the perspectives of nitrate ammonium solution usage.     

形简意深 广州先歌兄弟总经理潘永久爱驾奔驰AMG赏析

外表朴素,内藏玄机从整车改装效果而言,在AEA芸芸众车中,潘总的奔驰AMG并不属于让人眼前一亮的类型。全车改装风格主要以配合回原车内饰为大前提,也是潘永久或者说先歌兄弟一贯的改装思路。虽无花俏的装饰工艺,但这台改装后的AMG却胜在耐看。在大多数情况下,高音喇叭都是经过重新倒模安装在A柱或车门上,这两种安装方式不论是对于高音指向,还是说后续系统调试都能为技师减少一定工作量。但不可避免的是,上述两种安装方式都会破坏AMG原有美感。有见及此,先歌技     

十分方便——Mocis魔骑士Mstart测试报告评测

如今汽车电子类产品要想快速发展,除了传统渠道、4S店、电商一个都不能少之外,还得挖空心思去做更多体验式的功能招揽消费者。将产品借由手机APP做增值服务是目前行业类使用率比较高模式,至于这招管不管用还真的是各花入各眼了。     

满足消费者诉求——善领领航星EX700导航电子狗一体机评测

自古以来,伟大产品的诞生无不因为满足了人们的核心诉求,电灯的伟大在于满足了人们的照明需求,汽车的伟大在于满足了人们的交通需求,导航仪、电子狗则是因为解决了人们的驾车导航和安全问题。人类的需求是产品诞生的土壤。商品经济发展到今天,企业不再一味不顾需求而野蛮生产商品了,它开始注重人们对产品的诉求,人们对产品的要求也不再停止在简单的能够解决某些问题上面。在同类商品满目琳琅的情况下,人们对产品细节的关注提升到了一个新的高度,例如产品外观、材质、体验、交互等,而这些因素往往成为今天大部分产品能否脱颖而出的制胜关键。     

基于中心距离特征的联机手写维吾尔文全形态字母识别研究

为了提高联机手写维吾尔文字母的正确识别率,根据维吾尔文字母的手写特点,提出了中心距离特征CDF(Center Distance Feature)、并基于CDF进行了一系列识别实验。在实验中,该文采集了400个人的手写字母样本,利用CDF的三种不同的实施方案(CDF-2,CDF-4,CDF-8)分别对维吾尔文字的32个母独立形态和128个所有形态进行了识别实验,并对实验结果进行了分析。实验结果表明,CDF是一种非常适合于维吾尔文字母识别的特征,有待于进一步改进和优化。     

基于云计算的维吾尔文输入法的研究与实现

云计算技术在应用开发界引发了巨大的变化。从目前最领先的云计算技术入手,以云输入为例,研究输入法的联想实现,首次实现基于云计算的维吾尔文云输入法,弥补了该领域的空缺。在输入法的设计和实现过程中引入Ajax技术,JavaScript技术和XML数据库技术来解决相关数据的访问、存储和处理问题。     

变速变桨距风力发电机组的智能控制

针对传统PI控制技术难以兼顾风力发电机组转速与输出功率之间的平衡,提出变速变桨运行控制方法。将风力发电机组的功率误差和功率误差变化率作为判断依据和控制策略,再结合模糊控制器,弥补了传统PI控制器的不足。通过Matlab仿真,结果表明:风速持续变化和瞬变时,模糊控制器都能够稳定风力发电机组的输出功率,降低电机的运行速度,同时缩短调节时间和加快变桨距执行机构的运行速度。