强碱三元复合驱色谱分离及其影响因素——以大庆油区喇嘛甸油田为例

三元复合驱油体系中驱油剂的协同效应,会使油水间的界面张力大幅度下降,原油采收率大幅度提高;但三元复合驱油体系的色谱分离现象也会破坏其协同效应和完整性,揭示色谱分离现象及其影响因素对于改善三元复合驱油效果具有十分重要意义。以油藏工程和分析化学理论为指导,以化学分析和物理模拟为技术途径,并以大庆喇嘛甸油田典型区块地质特征和流体性质为研究对象,开展强碱三元复合驱色谱分离现象及其影响因素研究。结果表明,采用前置高浓度聚合物段塞后,可以有效扩大波及体积,但表面活性剂与碱和聚合物之间无因次等浓距增加,色谱分离现象加剧。大庆油区喇嘛甸油田不同区块油水性质差异对色谱分离现象存在影响,原因在于部分重烷基苯石油磺酸进入油相,影响水相中浓度检测值。强碱三元复合驱油体系中表面活性剂与碱和聚合物之间色谱分离程度比较严重,碱与聚合物之间较弱。     

Enhance cycling performance of LiMn2O4 cathode by Sr2+ and Cr3+ doping

Spinel LiSr_0·1Cr_0·1Mn_1·8O₄ was synthesised by high temperature solid state method in order to enhance the electrochemical performance. The LiSr_0·1Cr_0·1Mn_1·8O₄ (LSCMO) materials were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical tests. The XRD and SEM studies confirm that LSCMO had spinel crystal structure with a space group of Fd3m, and the particle of LSCMO shows irregular shape. The cyclic voltammetry data illustrated that the heavy current charge–discharge performance of LMO was improved by Sr²⁺ and Cr³⁺ doping. The galvanostatic charge–discharge of LSCMO cathode materials was measured at 1, 5, 10 and 20 C. The results indicated that LSCMO improved the capacity retention.     

层叠顺序对UHMWPE-铝合金板抗冲击性能影响

为探究层叠顺序对双硬度UHMWPE-铝合金板抗冲击性能影响,以高分子聚乙烯(UHMWPE)板、7075高强铝合金板为对象,利用一级轻气炮开展一系列平头和卵形弹打靶试验,对靶板弹道极限速度、能量吸收率、破坏模式等进行分析.揭示板材层叠顺序对接触式高分子聚乙烯-铝合金靶板防护性能的影响规律.结果表明:平头弹撞击下,UHMWPE板在前铝合金板在后的叠放顺序("软+硬")防护性能更高;卵形弹撞击下,两种叠放顺序靶板防护性能相近;两种叠放顺序靶板在平头弹撞击下均发生"冲塞破坏",在卵形弹冲击下均发生"延性扩孔"破坏.     

无失效数据机载多余度EWIS可靠性研究

针对高可靠度机载多余度EWIS各组成部分寿命服从指数分布但参数未知的情况，提出采用无失效数据可靠度分析方法评估EWIS的可靠度水平。通过Monte-Carlo仿真方法对连接形式为“先并联、后串联”EWIS各组成部分寿命进行抽样，利用“最小最大值”方法获得系统寿命的抽样值，用概率纸检验法初步判断EWIS寿命是否服从威布尔分布，再用Pearson拟合优度检验法判断EWIS寿命是否服从威布尔分布。结合无故障飞行时间的样本值与EWIS寿命服从威布尔分布的假设，采用无失效数据分析方法评估EWIS的可靠度水平。研究方法对机载多余度EWIS无失效数据可靠度分析有一定的贡献。     

Ultrafast Electron–Phonon Coupling at Metal-Dielectric Interface

Energy transfer from photo-excited electrons in a metal thin film to the dielectric substrate is important for understanding the ultrafast heat transfer process across the two materials. Substantial research has been conducted to investigate heat transfer in a metal-dielectric structure. In this work, a two-temperature model in metal was used to analyze the interface electron and dielectric substrate coupling. An improved temperature and wavelength-dependent Drude–Lorentz model was implemented to interpret the signals obtained in optical measurements. Ultrafast pump-and-probe measurements on Au-Si samples were carried out, where the probe photon energy was chosen to be close to the interband transition threshold of gold to minimize the influence of non-equilibrium electrons on the optical response and maximize the thermal modulation to the optical reflectance. Electron-substrate interface thermal conductance at different pump laser fluences was obtained, and was found to increase with the interface temperature.     

井工转露天采区顶板厚度不足诱发滑坡问题研究

井工转露天开采是安全生产遇到的新问题。以紫金山金铜矿为背景，利用数值模拟法系 统研究了井 工转露天开采工况下顶板厚度从 68 m 逐渐减小至 44 m 时顶板的安全性，界定出顶板最小安 全厚度为 45 m。同时 系统研究了顶板厚度变化对上部边坡应力场的影响特点，得出随着顶板变薄坡脚处塑性破坏区 增大，导致边坡稳 定性变小的规律，并通过边坡稳定性分析计算验证其正确性。因此在井工转露天开采过程中， 为了确保安全生产 需要确保顶板有足够的厚度，避免作业设备和工作人员坠入老井采区及滑坡灾害发生。     

Flame characteristics of premixed H2-air mixtures explosion venting in a spherical container through a duct

The explosion venting duct can effectively reduce the hazard degree of a gas explosion and conduct the venting energy to the safe area. To investigate the flame quantitative propagation law of explosion venting with a duct, the effects of hydrogen fraction and explosion venting duct length on jet flame propagation characteristics of premixed H₂-air mixtures were analyzed through experiment and simulation. The experiment results under initial conditions of room temperature and 1 atm show that when hydrogen fraction was high enough, part of the unburned hydrogen was mixed with air again to reach an ignitable concentration, resulting in the secondary combustion was easier produced and the duration of the secondary flame increased. With the increase of venting duct length, the flame front distance and propagation velocity increased. Meanwhile, the spatial distribution of pressure field and temperature field, and the propagation process and mechanism of the flame venting with a duct were analyzed using FLUENT software. The variation of the pressure wave and the pressure reflection oscillation law in the explosion venting duct was captured. Therefore, in the industrial explosion venting design with a duct, the hazard caused by the coupling of venting pressure and venting flame under different fractions should be considered comprehensively.     

弱相互作用调控表面活性剂自组装(Ⅱ)——表面活性剂的结构与设计

介绍了表面活性剂的结构、性质以及分类,综述了阴离子表面活性剂、阳离子表面活性剂、两性离子表面活性剂、非离子表面活性剂的分子间弱相互作用。另外,简述了低聚型表面活性剂和其他新型表面活性剂的结构及应用。