Multi-component Dirac equation hierarchy and its multi-component integrable couplings system

A general scheme for generating a multi-component integrable equation hierarchy is proposed. A simple 3M-dimensional loop algebra \tilde{X} is produced. By taking advantage of \tilde{X}, a new isospectral problem is established and then by making use of the Tu scheme the multi-component Dirac equation hierarchy is obtained. Finally, an expanding loop algebra \tilde{F}_M of the loop algebra \tilde{X} is presented. Based on the \tilde{F}_M, the multi-component integrable coupling system of the multi-component Dirac equation hierarchy is investigated. The method in this paper can be applied to other nonlinear evolution equation hierarchies.     

无涂层高速钢刀具钻削压铸铝合金时的磨损机理图

考察与无涂层高速钢刀具在无润滑条件下钻削压铸铝合金（ＡｌＳｉ９Ｃｕ３）时的磨损特性和磨损机理图,并对不同磨损区域进行了划分。发现在不同的进给量及切削速度下,刀具的磨损量变化呈明显的规律性,按磨损机理可分为粘着磨损区、粘着磨损和磨粒磨损区、磨粒磨损区、严重塑性变形磨损区和热磨损区等５个区域。刀具在粘着磨损区的磨损较小,帮就刀具的耐磨寿命而言,粘着磨损区可视为最佳切削区域。     

面向任务保障的多组件系统效益优化策略

为了保障系统在执行任务期间高可靠、高效益的运行,从系统效益的角度出发,构建了系统可靠性模型,采用边际效应思想构建了效益重要度,提出了一种面向任务保障的多组件系统效益优化策略。当系统可靠度下降到设定阈值时,计算系统各组件的效益重要度,选择效益重要度最大的组件进行备件分配,如此进行迭代,直到完成任务保障,形成最优的备件分配序列。通过该策略实现了以运行效益最优为目标,以系统可靠度和任务保障时长为约束的备件分配序列。最后,通过数值仿真验证了该策略的可行性。     

数值模拟在陶瓷粉末压制成型中的应用

本文介绍了陶瓷粉末成型过程有限元数值模拟所需用的Drucker-Prager-Cap模型以及材料屈服准则,分别概述了数值模拟方法在陶瓷粉末干压法成型、冷等静压法成型中的应用进展及存在的问题,并介绍了有限元分析在成型件开裂方面的研究进展。     

A Switchable Catalyst Duo for Acyl Transfer Proximity Catalysis and Regulation of Substrate Selectivity

Enzymes are encoded with a gamut of information to catalyze a highly selective transformation by selecting the proper reactants from an intricate mixture of constituents. Mimicking biological machinery, two switchable catalysts with differently sized cavities and allosteric control are conceived that allow complementary size-selective acyl transfer in an on/off manner by modulating the effective local concentration of the substrates. Selective activation of one of two catalysts in a mixture of reactants of similar reactivity enabled upregulation of the desired product.     

2-取代-4(3H)-喹唑啉酮在Br(o)nsted酸性功能化离子液体中的微波合成

以N-甲基咪唑、吡啶为起始原料,合成了二种新型Br(o)nsted酸性功能化离子液体:1-(4-磺酸基)苄基-3-甲基咪唑硫酸氢根盐(3a),N-(4-磺酸基)苄基吡啶硫酸氢根盐(3b),以其作为反应介质与催化剂,研究了2-取代-4(3H)-喹唑啉酮的三组分、一锅法微波合成.结果表明,当n(2-氨基苯甲酸):n(酰氯):n(乙酸铵):n(3a或3b)=1:1.2:1.5:0.1时,反应6 min即可完成,产率81%～95%.离子液体经减压蒸馏、真空干燥可重复使用3次,催化活性基本保持不变.     

2-取代-4(3H)-喹唑啉酮在BrФnsted酸性功能化离子液体中的微波合成

以N-甲基咪唑、吡啶为起始原料,合成了二种新型BrФnsted酸性功能化离子液体:1-(4-磺酸基)苄基-3-甲基咪唑硫酸氢根盐(3a),N-(4-磺酸基)苄基吡啶硫酸氢根盐(3b),以其作为反应介质与催化剂,研究了2-取代-4(3H)-喹唑啉酮的三组分、一锅法微波合成.结果表明,当n(2-氨基苯甲酸):n(酰氯):n(乙酸铵):n(3a或3b)=1:1.2:1.5:0.1时,反应6min即可完成,产率81%～95%.离子液体经减压蒸馏、真空干燥可重复使用3次,催化活性基本保持不变.     

HPVC皮带轮的注塑模设计与应用

针对HPVC皮带轮制件的结构与材料特点,给出了皮带轮合理的成型工艺及注射成型参数;对注塑模具的结构与工作过程、分型面选择、排气机构、模具成型件、浇注系统、脱模机构等作了详细的设计阐述,提出了该类模具设计的注意要点.     

Heteropoly acid supported on activated natural clay-catalyzed synthesis of 3,4-dihydropyrimidinones/thiones through Biginelli reaction under solvent-free conditions

Dihydropyrimidinones/thiones (DHPM’s) have been prepared by one-pot condensation of methyl acetoacetate, aldehydes, urea/thiourea in the presence of heteropoly-11-tungsto-1-vanadophosphoric acid, H₄[PVW₁₁O₄₀]?·?32H₂O, (HPV) supported on activated natural clay (HPVAC) under solvent-free reaction condition have been proposed. The DHPM derivatives were identified through elemental analysis and melting point measurements and characterized by FT-IR, ¹H-NMR, ¹³C-NMR spectroscopic methods.