蒙脱土负载［C14mim］+有机阳离子催化合成柠檬酸三丁酯

通过咪唑基离子液体和蒙脱土在甲苯溶液中的离子交换反应，将热稳定性高的咪唑基有机阳离子［C₁₄mim］⁺交换吸附进入蒙脱土片层间，制备了蒙脱土负载的有机阳离子固体催化剂［C₁₄mim］⁺/MMT。利用XRD和TGA对催化剂的结构与性能进行了表征和测定，研究了蒙脱土负载有机阳离子固体催化剂的催化性能，初步考察了其稳定性及再次使用效率。研究结果表明，［C₁₄mim］⁺/MMT在合成无毒增塑剂柠檬酸三丁酯的酯化反应中表现出较高的催化活性，可循环使用。与未负载的C₁₄mimBF₄相比，［C₁₄mim］⁺/MMT具有催化活性高、稳定性好和易分离的特点。     

关于基体曲率的热障涂层残余应力分析

采用空心和实心四相同心圆模型,导出了轴对称温度应力状态下的位移公式,分析了基体曲率对热障涂层残余应力的影响。结果表明:热障涂层结构中各层内既有环向应力,又有径向应力,应力大小与温降成线性关系;当陶瓷层在外层时,在氧化层/陶瓷层和粘结层/氧化层界面上产生垂直界面的拉应力,且实心模型的拉应力远大于空心模型的拉应力;当陶瓷层在里层时,空心模型中相应界面上的应力为压应力。     

Technical note: Plasma-sprayed ceramic thermal barrier coatings for smooth intermetallic alloys

A durable ceramic thermal barrier coating is applied directly to a smooth, highly oxidation resistant intermetallic alloy in two layers. The first layer of ceramic is applied by low pressure plasma spraying and the second layer is applied by conventional atmospheric pressure plasma spraying. This approach would allow the use of plasma sprayed ceramic coatings in applications where a metallic bond coat is not desirable.     

河北南部电网TBC方式下AGC控制策略的研究

在华北、东北联网以后,河北南部电网的自动发电控制(AGC)采用TBC方式运行,AGC控制目标以及考核标准均发生变化,需要对AGC控制策略进行必要的调整,以保证系统的稳定、经济运行.文章分析了AGC在FTC和TBC方式下的功率调整情况以及在TBC方式下可能采取的控制策略,通过试验提出了河北南部电网AGC在TBC方式下的控制策略,即A1、A2组合调整策略,实际运行经验表明该控制策略满足TBC方式的控制要求.     

双链式区块链交易监管研究

最近,作为去中心化的分布式帐本,区块链使人们能够在不可信赖的环境中进行安全可靠的交易,慢慢地被应用于各个领域。但是,逐渐出现了一些问题,用户隐私信息泄露,存在非法的交易且缺乏有效的监管,智能合约市场存在漏洞等。针对区块链非法交易,提出了监管链的概念,并建立了可以有效监管区块链交易的交易区块链（TBC）和监管区块链（RBC）双链结构。为了提高智能合约的安全性,进一步在监管链中建立智能合约市场,并设计了用于智能合约功能校验的零知识证明算法。理论和数据分析表明,双链结构具有高效率和可扩展性强。实验结果表明机器学习算法对于区块链交易数据的分类准确性达到95.0%,并证明了零知识证明校验智能合约功能的可行性。     

Study of the coating stability of a TBC system

Abstract

The degradation of thermal barrier coatings is closely linked to their spalling resistance which depends on the stability of the protective oxide scale produced by oxidation of the bond-coat. This study deals with a characterisation of the oxide layer, its interfaces with the bond-coat and the ceramic and their evolution during isothermal oxidation at 1,100°C. The microstructural evolution of the bond-coat, the outer part of the superalloy and the ceramic layer was also studied.     

Enhanced calcium–magnesium–aluminosilicate (CMAS) resistance of GdAlO3 (GAP) for composite thermal barrier coatings

The impact of calcium–magnesium–alumino-silicate (CMAS) degradation is a critical factor for development of new thermal and environmental barrier coatings. Several methods of preventing damage have been explored in the literature, with formation of an infiltration inhibiting reaction layer generally given the most attention. Gd₂Zr₂O₇ (GZO) exemplifies this reaction with the rapid precipitation of apatite when in contact with CMAS. The present study compares the CMAS behavior of GZO to an alternative thermal barrier coating (TBC) material, GdAlO₃ (GAP), which possesses high temperature phase stability through its melting point as well as a significantly higher toughness compared with GZO. The UCSB laboratory CMAS (35CaO–10MgO–7Al₂O₃–48SiO₂) was utilized to explore equilibrium behavior with 50:50 mol% TBC:CMAS ratios at 1200, 1300, and 1400°C for various times. In addition, 8 and 35 mg/cm² CMAS surface exposures were performed at 1425°C on dense pellets of each material to evaluate the infiltration and reaction in a more dynamic test. In the equilibrium tests, it was found that GAP appears to dissolve slower than GZO while producing an equivalent or higher amount of pore blocking apatite. In addition, GAP induces the intrinsic crystallization of the CMAS into a gehlenite phase, due in part to the participation of the Al₂O₃ from GAP. In surface exposures, GAP experienced a substantially thinner reaction zone compared with GZO after 10 h (87 ± 10 vs. 138 ± 4 μm) and a lack of strong sensitivity to CMAS loading when tested at 35 mg/cm² after 10 h (85 ± 13 versus 246 ± 10 μm). The smaller reaction zone, loading agnostic behavior, and intrinsic crystallization of the glass suggest this material warrants further evaluation as a potential CMAS barrier and inclusion into composite TBCs.     

Thermal radiative properties of zirconium oxide films in the near-infrared wavelengths

Thermal barrier coatings (TBCs) using yttria-stabilized zirconium dioxide (YSZ) are widely used in gas turbines to protect metal components against the high combustion product temperature. Increasing combustion temperature and pressure, radiative heat transfer becomes an essential portion of the overall heat transfer in TBCs. This necessitates a greater understanding of the thermal radiative properties of YSZ films, especially in the near-infrared wavelength range. The commonly used Kubelka–Munk (KM) method in the radiative property reduction from the measured transmittance and reflectance spectra of YSZ films can incur inaccurate results when the coating optical thickness is not sufficiently large. The discrete ordinates method with the asymmetric spherical ring angular quadrature can solve the radiative transfer equation with good accuracy in optically thin media. Considering the solution accuracy and computational efficiency, a hybrid approach of combining the KM and discrete ordinate methods is used to invert radiative properties. The absorption and scattering coefficients of air plasma sprayed YSZ films are determined over the wavelength range from 1 to 2.6 μm at room temperature. Over this near-infrared wavelength range, the scattering coefficient decreases with the increasing wavelength, and the absorption coefficient is very small overall.     

电力市场下的互联系统自动发电控制改进模式

自动发电控制（AGC）作为能量管理系统（EMS）中最重要的控制功能之一,能有效地提高电网互联系统频率质量,提高经济效益和管理水平。但随着我国电力系统市场化体制改革的不断深入和完善,互联系统原先以联络线和频率偏差控制（TBC）模式为主的频率控制方式就成了电力市场环境下互联系统区域间交易的壁垒。为了适应现代电力市场环境的要求,提出一种新的以TBC为基础、满足二次辅助服务市场开放要求的区域间AGC改进模式。     

界面粗糙度对氧化层残余应力分布的影响

根据热障涂层中陶瓷层和粘结层界面间的氧化层界面形貌和界面粗糙情况,建立了具有氧化层的热障涂层平面应变模型,模拟计算了氧化层界面残余应力分布,分析了粗糙度对氧化层残余应力分布的影响.计算结果表明,随粗糙度的增加,氧化层中的X和Y方向应力值均不断增加,沿着波形下降的趋势应力逐渐增大,波谷处应力最大,且X方向的应力值远大于y的方向应力值.