Kinetic and Mechanistic Studies on Reactions of Pyrrolidone Derivatives with Ozone

Reactions of various pyrrolidone derivatives (NRPs = 2-pyrrolidone (2P), N-methyl-2-pyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), N-n-propyl-2-pyrrolidone (NProP), N-n-butyl-2-pyrrolidone (NBP), N-iso-butyl-2-pyrrolidone (NiBP), N-n-pentyl-2-pyrrolidone (NPP), N-neopentyl-2-pyrrolidone (NNPP), N-dimethylpropyl-2-pyrrolidone (NDPP), N-cyclohexyl-2-pyrrolidone (NCP)) with O₃ have been studied under pseudo–first-order conditions with excess O₃ in aqueous solution of pH 2.0 at various temperatures (278–298 K). It was found that the reaction rates is expressed as –d[NRPs]/dt = k[NRP][O₃], that the second-order rate constants (k) slightly increase with increasing the effective charges in order of NMP, NEP, NProP, NBP and NPP, and that the k values of NBP and NPP are larger than those of more bulky NiBP and more bulky NNPP and NDPP, respectively. In these reactions, the ΔH^? values are consistent with each other, while the ΔS^? values decrease with decreasing length of alkyl groups. Furthermore, it was found that reactions of NRPs (NMP, NEP, NProP, NBP, and NPP) with O₃ show the linear relationship between the obtained ΔS^? values and the softness of NRPs. From these results, it was proposed that the reactions of NRPs with O₃ proceed through the interaction between O₃ and N atom of NRPs. The analyses of products in the reactions of NRPs with O₃ were also carried out by ¹³C-NMR and GC/MS measurements, and indicated that N-alkylsuccinimide and N-acyl-2-pyrrolidone are produced through intramolecular side-chain oxidations of α-carbon of NRPs. From these results, it is proposed that the reactions of NRPs with O₃ proceed through the mechanism with the selective attacks of O₃ to N atom of NRPs.     

Terahertz absorption spectra of Fatty acids and their analogues

Absorption spectra in the terahertz (THz) region between 10 and 400 cm(-1) were measured for fatty acids and their analogues at room temperature. Saturated fatty acids such as palmitic and stearic acids had some sharp peaks, while unsaturated fatty acids such as oleic, linoleic and linolenic acids had two distinct peaks at 247 and 328 cm(-1). These peaks apparently derived from the carboxylic group because oleyl alcohol had no distinct peak. The THz absorption spectra of fatty acids may be affected by the crystalline as well as the chemical structure. The THz absorption spectra of oleic acid esters depended on ester types, although all oleic acid esters had some peaks due to the ester group. THz absorbance of fatty acids positively correlated with concentration. Based on these results, THz spectrometry may be a good analytical method for the non-destructive qualitative and quantitative evaluation of fatty acids and their analogues.     

带式输送机用双功率高效节能型隔爆电动机及控制装置的研制

针对煤矿井下的带式输送机要求高起动转矩和时变负载运行的特点,运用复合连接新技术,"去匝"新技术和双向切换控制技术,设计研发了一种双功率隔爆三相异步电动机及控制装置。它可根据输送机负载的变化自动调节电动机功率,达到节能运行,以提高功率因数和运行效率。该电动机及控制装置经煤矿井下工业性试验运行,取得了较好的效果。     

铁法矿区高瓦斯低透气性煤层群卸压煤层气抽采钻孔布置

基于铁法矿区高瓦斯低透气性煤层群地质及开采技术条件,采用物理模拟方法系统分析了煤层群不同开采顺序时采动裂隙演化特征,运用CFD（Computational Fluid Dynamics）Fluent分析了U型负压通风条件下采空区瓦斯流动规律,总结了铁法矿区卸压煤层气抽采钻孔布置原则。研究结果表明：回采巷道内侧约在工作面倾斜长度的1/3处为采动裂隙发育区、距回风巷30~80 m范围为高浓度瓦斯富集区。铁法矿区煤层气抽采钻孔布置的原则为：垂直方向上钻孔终孔位置布置在断裂带下1/3处、地面钻井的合理间距不小于100~150 m、沿工作面倾斜方向靠回风巷（1/3~1/2）工作面斜长范围为最佳的钻孔位置。     

Thickness‐Dependent Structure–Property Relationships in Strained (110) SrRuO3 Thin Films

Thickness‐dependent structure–property relationships in strained SrRuO₃ thin films on GdScO₃ (GSO) substrates are reported. The film is found to have epitaxially stabilized crystal structures that vary with the film thickness. Below 16 nm, the √2a_pc × √2a_pc × 2a_pc monoclinic structure is stabilized while above 16 nm the film has the a_pc × 2a_pc × a_pc tetragonal structure. The thickness‐dependent structural changes are ascribed to the substrate‐induced modification in the RuO₆ octahedral rotation pattern, which highlights the significance of the octahedral rotations for the epitaxial strain accommodation in the coherently‐grown films. Close relationships between the structural and physical properties of the films are also found. The monoclinic film has the uniaxial magnetic easy axis 45° away from the [110]_GSO direction while the tetragonal film has the one that lies along the in‐plane [1–10]_GSO direction. The results demonstrate that the octahedral rotations in the strained perovskite oxide thin films are a key factor for determining their structure phases and physical properties.     

Cellular and Exosomal Regulations of Sepsis-Induced Metabolic Alterations

Sepsis is a sustained systemic inflammatory condition involving multiple organ failures caused by dysregulated immune response to infections. Sepsis induces substantial changes in energy demands at the cellular level leading to metabolic reprogramming in immune cells and stromal cells. Although sepsis-associated organ dysfunction and mortality have been partly attributed to the initial acute hyperinflammation and immunosuppression precipitated by a dysfunction in innate and adaptive immune responses, the late mortality due to metabolic dysfunction and immune paralysis currently represent the major problem in clinics. It is becoming increasingly recognized that intertissue and/or intercellular metabolic crosstalk via endocrine factors modulates maintenance of homeostasis, and pathological events in sepsis and other inflammatory diseases. Exosomes have emerged as a novel means of intercellular communication in the regulation of cellular metabolism, owing to their capacity to transfer bioactive payloads such as proteins, lipids, and nucleic acids to their target cells. Recent evidence demonstrates transfer of intact metabolic intermediates from cancer-associated fibroblasts via exosomes to modify metabolic signaling in recipient cells and promote cancer progression. Here, we review the metabolic regulation of endothelial cells and immune cells in sepsis and highlight the role of exosomes as mediators of cellular metabolic signaling in sepsis.     

Local atomic structure of a near-sigma 5 tilt grain boundary in MgO

Clear understanding of the structure–property relation in polycrystalline materials requires atomic-resolution imaging of grain boundary (GB) structures especially for the GBs with misalignments. In this study, we apply a bicrystal technique to fabricate the Σ5 and near-Σ5 GBs of MgO with tunable bonding angle and demonstrate that the misalignments in GBs could be compensated by a periodic displacement shift complete dislocation array. The atomic-resolution images reveal that the near-Σ5 GB is composed of an array of normal Σ5 GB structural units intercalated by deformed Σ17 GB units. The atomic-scale characterization presented is applicable to other GB species in a range of polycrystalline materials.     

Aerothermodynamic shape optimization of hypersonic blunt bodies

The aim of this study is to develop a reliable and efficient design tool that can be used in hypersonic flows. The flow analysis is based on the axisymmetric Euler/Navier–Stokes and finite-rate chemical reaction equations. The equations are coupled simultaneously and solved implicitly using Newton's method. The Jacobian matrix is evaluated analytically. A gradient-based numerical optimization is used. The adjoint method is utilized for sensitivity calculations. The objective of the design is to generate a hypersonic blunt geometry that produces the minimum drag with low aerodynamic heating. Bezier curves are used for geometry parameterization. The performances of the design optimization method are demonstrated for different hypersonic flow conditions.