TA18钛合金管材织构对环向拉伸性能的影响

利用织构增强原理,开发出了TA18(Ti-3Al-2.5V)钛合金860 MPa级高强度管材,保证了管材的工艺性能,同时又具有优异的力学服役性能。标准规定反映径向织构的管材收缩应变比(CSR)大于1.3,但对上限值未作规定。本研究设计出小管径的环向拉伸夹具,测试了不同CSR管材的环向拉伸力学性能,分析织构对环向抗拉强度的影响,发现存在一个最有利的CSR值为1.75,大于或小于该CSR值时都会导致管材环向屈服强度下降。进一步测定了对应管材的极图和ODF图,从微观结构上可以解释这一规律和本质。环向抗拉强度下降会引起液压系统工作时疲劳强度降低,CSR值的上限在工艺设计时应当加以控制。本研究对发展安全可靠的航空液压系统具有十分重要的理论意义和工程应用价值。     

Highly efficient[C8mim][Cl] ionic liquid accompanied with magnetite nanoparticles and different salts for interfacial tension reduction

The 1-octyl-3-methylimidazolium chloride, [C_8 mim][Cl] ionic liquid(IL) was used as a novel surfactant in n-heptane/water system. The interfacial tensions(IFT) were measured and corresponding variations were investigated. An IFT reduction of 80.8% was appropriate under the IL CMC of about 0.1 mol·L~(-1) and stronger effects were achieved when magnetite nanoparticles and salts were present profoundly under alkaline p Hs.The equilibrium IFT data were accurately simulated with the Frumkin adsorption model. Hereafter, the saturated surface concentration, equilibrium constant and interaction parameter were obtained and their variations were demonstrated. Further, emulsion stability and contact angle of oil/water interface over quartz surface were studied. The oil/water emulsion stability was hardly changed with nanoparticles; however, the stability of oil/water + IL emulsions was significantly improved. It was also revealed that the presence of sodium and calcium chloride electrolytes fortifies the IL impact, whereas sodium sulfate weakens. From dynamic IFT data and fitting with kinetic models, it was found that the IL migration toward interface follows the mixed diffusion–kinetic control model. Consequently, the IL diffusion coefficient and the appropriate activation energy were determined.     

立式退火炉张力设定模型及应用

带钢在立式退火炉内发生瓢曲、跑偏的临界张力与炉辊凸度、带钢规格都存在一定关系，但缺乏合理的定量分析方法，难以科学制定不同规格、不同钢种带钢的炉内单位张力。通过引入瓢曲风险因子BRI，可以定量地分析炉内板带瓢曲风险，从而确定冷硬板带炉内张力设定上限，即板带发生热瓢曲的临界张力σC，为连退炉加热段和冷却段的张力控制提供依据。采用该方法对连退炉加热、冷却区的张力进行了优化，应用结果表明，优化后的张力值与实测值更加吻合。     

Study on the Adaptability of Alkanolamide (LDEA) Lowering Oil/Water Interfacial Tension to Different Crude Oils

In order to investigate the high interfacial activity and fair oil phase adaptability of alkanolamide, “1:1” type lauric acid diethanolamide impurities (LDEA) were synthesized and purified by the column chromatography method to obtain dodecanoic acid diethanolamide (C₁₂DEA), ester mixture, etc. The exact structures of these compounds were further confirmed by IR, gas chromatogrph with mass spectroscopy (GC–MS), and NMR. The influence of each component on the interfacial tension of oil/water (IFT) was studied by systematic quantitative analysis. The results showed that (i) the strength of each system to reduce oil/water IFT is C₁₂DEA /DEA ≈ LDEA > C₁₂DEA/DEA/ESTER > C₁₂DEA/NaOH > C₁₂DEA > C₁₂DEA/ESTER > DEA. This indicates that LDEA contributes to the reduction of the oil/water IFT and the enhanced adaptability of crude oil in this order: DEA > > ESTER; (ii) when the IFT of the LDEA/DEA system reached an ultralow value, the minimum content of DEA in the system was 1%, and the maximum ester content was less than 5% when the LDEA/DEA/ESTER system reached the ultralow IFT; (iii) the possible mechanism of effect of LDEA components on the IFT and oil phase adaptability was proposed as the synergistic process among the hydrogen bonding, alkali effect, and interface self-assembly of molecules in the interfacial layer. The contribution of these three factors were hydrogen bonding > alkali effect > interface self-assembly.     

Interface control for resolved CFD-DEM with capillary interactions

In this work, a resolved CFD–DEM coupling model for the simulation of gas-liquid-solid flows is developed: the interface capturing method based on the colour function is employed for fluids (i.e. a gas and liquid) whilst Discrete Element Method (DEM) is used for particles. The Volume Penalisation (VP) method is adopted to consider the hydrodynamic interactions between fluids and particles along with the Immersed Free Surface (IFS) method, which artificially extends the gas-liquid interface into the interior of the particle to account for the wettability. The unique point of the proposed model is that the thickness of the gas-liquid interface can be controlled by using both interface compression and diffuse interface techniques simultaneously. From the simulation results, it is presented that the accurate evaluation of the surface tension force as well as the capillary force can be achieved by appropriately controlling the interface thickness. Moreover, the major two methods in the literature to calculate the capillary force are compared in this work. The validity of the proposed model is presented for both static and dynamic cases. The behaviour of two colliding particles with a dynamic liquid bridge is then simulated to demonstrate the applicability of the proposed model to a complex three-phase system.     

刚性索动力学系统的约化与索力测量

为解决索力动测中弯曲刚度的耦合影响问题，研究刚性索动力学系统的约化及相应的索力算法。对系统时间和空间进行坐标缩放，建立新时空坐标体系，使原方程约化为最简形式——所有系数均为1或-1，得到频率比互等关系；求解新坐标下的动力学方程，导出固支条件下的频率方程，分析其频率-梁长和频率比-梁长函数特性，提出基于频率比互等关系的双频式索力算法。给出两组10个算例均与现有文献吻合良好。研究表明：系统频率在新坐标下仅由单一参数决定；双频式算法可将索力测量的双参数反问题转化为单参数反问题，实现对索力和弯曲刚度的解耦；与其他方法相比，该方法有两个特点：①两个无量纲参数均具有明确的意义，便于工程人员掌握；②参数区间不受限，不需要对参数区间进行预判或近似处理。     

基于PLC的钢丝绳罐道液压自动张紧系统设计研究

设计了一种基于PLC的钢丝绳罐道液压自动张紧系统。该系统能够根据检测到的罐道钢丝绳张力的大小,自动实现补油、报警及各钢丝绳张力平衡等功能。与传统的张紧装置相比,该液压张紧系统安装方便,可靠性高,人机交互界面良好。从而为矿井的安全运行提供了有力保障。     

泡沫除尘机理与泡沫药剂配方的要求

本文分析了泡沫的产生、泡沫除尘机理和表面活性的结构和性质，认为泡沫药剂配方中一般有起泡剂、湿润剂、稳定剂、增溶剂等助剂（表面活性剂），才能有效地降低粉尘，并通过实验确定了泡沫高度、表面张力和表面活性剂溶液浓度之间的变化关系，为研制泡沫药剂配方提供一定的理论和实验依据。