The competitive behavior for O2 and CO2 reaction during char oxy-fuel combustion: effects of temperature and inherent minerals

Journal of Thermal Analysis and Calorimetry - Coal O2/CO2 combustion is a promising carbon capture and storage technology for coal-fired power plant. Char consumption rate prediction is essential...     

线性分布荷载作用下梯度功能压电悬臂梁的解

采用逆解法求解了上表面受线性分布荷载作用的压电悬臂梁执行器，其中体积力$F_z$ 呈非线性分布. 首先确定了应力函数和电位移函数的多项式表达式，进而研究了该问题的 通解，以及体积力的不同分布对解答的影响. 常体积力和无体力情况下的解可以由上述 解直接得到. 本文为研究其它类型的压电梯度微观结构提供了一种可行的方法.     

Rhombicuboctahedral Ag100: Four-Layered Octahedral Silver Nanocluster Adopting the Russian Nesting Doll Model

Precise atomic structure of metal nanoclusters (NCs) is fundamental for elucidating the structure–property relationships and the inherent size-evolution principles. Reported here is the largest known FCC-based (FCC=face centered cubic) silver nanocluster, [Ag₁₀₀(SC₆H₃^3,4F₂)₄₈(PPh₃)₈]⁻: the first all-octahedral symmetric nesting Ag nanocluster with a four-layered Ag₆@Ag₃₈@Ag₄₈S₂₄@Ag₈S₂₄P₈ structure, consistent symmetry elements, and a unique rhombicuboctahedral morphology distinct from theoretical predictions and previously reported FCC-based Ag clusters. DFT studies revealed extensive interlayer interactions and degenerate frontier orbitals. The FCC-based Russian nesting doll model constitutes a new platform for the study of the size-evolution principles of Ag NCs.     

铜催化芳硼酸与亚磷酸酯在空气下的有氧碳-磷氧化偶联反应

在Cu(OAc)2/TMEDA体系催化下,芳硼酸与亚磷酸二乙酯可在室温下以空气为直接氧化剂通过氧化偶联反应生成芳基膦酸酯化合物.该反应使用较为廉价低毒的铜盐为催化剂,不怕水、不怕氧,底物适用范围较广,目标产物选择性高、收率良好.因此,与已知金属催化卤代芳烃的碳-磷偶联反应相比是一种相对温和高效的合成芳基膦酸酯的方法.     

Hierarchical diversity entropy for the early fault diagnosis of rolling bearing

Nonlinear Dynamics - Intelligent fault diagnosis provides great convenience for the prognostic and health management of the rotating machinery. Recently, the multiscale diversity entropy has been...     

磨西河流域泥石流流域形态的非线性特征

泥石流是磨西河流域地质环境演化的一个重要地表过程,研究该流域内泥石流的地貌发育及演化特征可为磨西河流域第四纪以来地质环境的演变提供重要信息。通过对流域51条泥石流沟地貌形态的统计分析发现,磨西河流域内泥石流的分布在空间上表现出明显的不均性,流域内泥石流沟的数量与对应的主沟长度、主沟纵比降及流域面积之间存在着明显的分形现象,具有较高的自相似性。结果表明,泥石流沟谷形态的非线性演化特征及现象是对磨西河流域冰川环境和地质构造环境响应的直接结果,主要体现在现代冰川对流域的强烈侵蚀和贡嘎山隆升而导致流域的强烈下切。研究结果可为流域内泥石流灾害的形成机理、防灾减灾及流域环境演化提供理论依据。     

Rhombicuboctahedral Ag100: Four‐Layered Octahedral Silver Nanocluster Adopting the Russian Nesting Doll Model

Precise atomic structure of metal nanoclusters (NCs) is fundamental for elucidating the structure–property relationships and the inherent size‐evolution principles. Reported here is the largest known FCC‐based (FCC=face centered cubic) silver nanocluster, [Ag₁₀₀(SC₆H₃^3,4F₂)₄₈(PPh₃)₈]^?: the first all‐octahedral symmetric nesting Ag nanocluster with a four‐layered Ag₆@Ag₃₈@Ag₄₈S₂₄@Ag₈S₂₄P₈ structure, consistent symmetry elements, and a unique rhombicuboctahedral morphology distinct from theoretical predictions and previously reported FCC‐based Ag clusters. DFT studies revealed extensive interlayer interactions and degenerate frontier orbitals. The FCC‐based Russian nesting doll model constitutes a new platform for the study of the size‐evolution principles of Ag NCs.     

The quantitative monitoring of mechanochemical reaction between solid l-tartaric acid and sodium carbonate monohydrate by terahertz spectroscopy

The solid-state reaction of chiral tartaric acid and alkali carbonate was studied by terahertz time-domain spectroscopy (THz-TDS). The sodium tartrate dihydrate was synthesized with high efficiency by mechanical grinding in the solid-state without waste that is particularly sustainable and environmentally benign. Distinct THz absorptions were observed for reactants and products. It indicates that THz spectroscopy is sensitive to different materials and crystal structures. The characteristic THz absorption peak at 1.09 THz of l (+)-Tartaric acid was selected for quantitative analysis. The reaction kinetics could be expressed by the Second-order equation and the Jander equation, which is consistent with a three-dimensional diffusion mechanism. The combination of multi-techniques including synchrotron radiation X-ray powder diffraction (SRXRPD), Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM) was used to investigate the grinding process and presented supporting evidences. The results demonstrate that THz spectroscopy technique has great potential applications in process monitoring and analysis in pharmaceutical and chemical synthesis industry.     

A pair of unprecedented cyclohexylethanoid enantiomers containing unusual trioxabicyclo[4.2.1]nonane ring from Clerodendrum bungei

A pair of unprecedented enantiomers (1a/1b) of cyclohexylethanoid bearing an unusual trioxabicyclo[4.2.1]nonane ring, along with two known structurally related cyclohexylethanoids, (+)-rengyolone (2) and cleroindicin E (3), were isolated from the aerial parts of Clerodendrum bungei. The structures and absolute configurations of the enantiomers were determined by comprehensive spectroscopic analysis, single-crystal X-ray diffraction, and quantum mechanical calculation of the electronic circular dichroic (ECD) spectra. The postulated biogenetic pathway of 1a/1b was also discussed.