Structure and Properties of Nonstoichiometric Y1-xNbxO1.5+x for Thermal Barrier Coatings

Understanding the effect of nonstoichiometry on material properties is of critical importance for the Thermal Barrier Coatings (TBCs) application. In this work, the effect of nonstoichiometry was systematically investigated in Y₃NbO₇, a recently identified promising TBCs material for next-generation gas turbine engines. The results show that the nonstoichiometry effect mediates the microstructure, mechanical properties, thermophysical properties, oxygen ionic conductivity and optical transmittance. The results suggest that the oxygen ionic conductivity is correlated to the mass diffusion in the oxygen-deficient fluorite oxides Y_1-xNb_xO_1.5+x. The stoichiometric composition Y₃NbO₇, with the lowest thermal conductivity and slowest mass diffusion in Y_1-xNb_xO_1.5+x series, is optimal for the TBCs application, which can be of relevance for TBCs material design and coating fabrication.     

Ligand free copper-catalyzed heterogeneous O-arylation reaction under green condition

A highly porous Zn-based iso-reticular metal–organic framework (IRMOF-3) has been selected for covalent modification. Pyridine-2-aldehyde has been used to decorate the free amine group of IRMOF-3 in the porous matrix. Schiff base moiety thus generated has been availed to anchor copper(II) ions to prepare the desired catalyst that catalyzes O-arylation reactions heterogeneously under mild reaction conditions. Porous catalyst demonstrates size selectivity in products when various substrates undergo O-arylation with α and β-naphthol.     

First-Principles Prediction of Superconductivity in Hole Doping of MgCN2

Journal of Superconductivity and Novel Magnetism - Hydrogen-based, boron-based, and carbon-based compounds have been the focus of previous investigations in the process of searching for...     

计及补偿效果的需求侧资源调频辅助服务市场机制研究

随着智能电网的发展,需求侧资源参与调频已成为可能,如何量化传统自动发电控制（automatic generation control,AGC）机组与需求侧资源对系统调频的贡献,鼓励需求侧资源参与调频市场是当下亟待解决的问题。在考虑了传统AGC机组和需求侧资源不同的调频性能以及需求侧资源对传统AGC机组替代效果的基础上,建立了电能-调频联合市场出清与补偿模型。基于IEEE 14节点系统数据进行实证分析,仿真结果表明该模型可以大幅度提升需求侧资源在市场中的中标概率与收益,减少系统对调频备用容量的需求和购买费用。     

应急情况下最少转发节点的传感器网络组播路由树算法

在抢险救灾等应急情况下,传感器网络的节点能量更为有限。为减少无用转发的能量消耗,利用无线信道的广播特性,根据广播子树删除思想,提出一种基于最短路由树、具有最少转发节点的组播路由树生成算法。对该算法进了证明和详细分析,并针对实际需要,给出使用范围更广泛的分布式实现方法。仿真分析说明,算法的分布式实现方法可减少ODMRP的转发节点数,大大降低数据发送次数,接收成员节点较多时尤为明显。最少转发节点的组播路由树的网络总开销最小,是延长网络生存时间的有效方法。     

基桩多信号完整性检测的研究

低应变反射波法目前在基桩完整性检测中应用广泛，但应用该方法检测尚存在测试信息量不足、缺陷特征反映不全面等问题。针对这些问题，提出了一种多信号基桩完整性检测系统，即多点激励、多点拾振，应用以多次覆盖原理为中心的数据处理方法。实践表明，多信号检测能够有效地抑制干扰，提高信噪比和测试精度，从向增加了判断桩身质量的准确性和可靠度，显示出良好的应用前景。并且该系统可以推广应用到结构的完整性检测中去，效果会更好。     

Generation of simultaneous H+ and He+ band EMIC waves in the nightside radiation belt

Science China Technological Sciences - Previous studies have shown that EMIC waves occur preferentially in the afternoon sector of the magnetosphere. Here we report obliquely propagating H+ and He+...     

南京南站主体钢结构混层法吊装施工

针对第三代大型铁路客运站房设计特点及施工难点,以南京南站屋面以下主体钢结构吊装为实例,经过吊装方案比选,提出了混层吊装法,用以解决施工现场复杂、场地狭小、构件规格大且数量多、工程量大且工期紧、专业交叉施工搭接繁多等技术难点。实践表明,混层吊装法不但切实可行,而且可以有效缩短施工工期,提高安装效率,满足大型客运站房复杂的施工要求,并形成了大型铁路客运站房主体钢结构混层法吊装施工技术。     

3种颜色空间的亮度分量在伪装效果评价中的应用

结合伪装效果评价的要求,以中国颜色体系为基础,建立了CIE1976L*a*b*、LMS、ιαβ这3种颜色空间的64级亮度分量数据库,利用灰度直方图相似度算法,分析了以上3种亮度分量在伪装效果评价中的应用问题.实验结果表明,L*分量具有均匀性较好,Lm分量和ι分量分别在灰度较低和灰度较高时,其伪装效果的评价结果与人眼判读...     

量化颜色直方图的改进与应用

对图像进行灰度量化时,容易把颜色不同而灰度相同的像素归为一类,造成量化误差而影响评价结果。基于HSV颜色空间,通过统计样本数据,结合人眼观察彩色的视觉特性,确定了颜色量化范围,建立了适合伪装特点的颜色直方图,利用距离函数进行了目标颜色特征的伪装效果评价。实验结果表明,利用改进的量化颜色直方图评价目标伪装效果,能够客观地...