Synergistic effect of bulk phase doping and layered-spinel structure formation on improving electrochemical performance of Li-Rich cathode material

In this study, La was doped into the lithium layer of Li-rich cathode material and formed a layered-spinel hetero-structure. The morphology, crystal structure, element valence and kinetics of lithium ion migration were studied by field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). The La doped lithium-rich cathode material exhibited similar initial discharge capacity of 262.8 mAh g^?1 at 0.1 C compared with the undoped material, but the discharge capacity retention rate can be obviously improved to 90% after 50 cycles at 1.0 C. Besides that, much better rate capability and Li⁺ diffusion coefficient were observed. The results revealed that La doping not only stabilized the material structure and reduced the Li/Ni mixing degree, but also induced the generation of spinel phase to provide three-dimensional diffusion channels for lithium ion migration. Moreover, the porous structure of the doped samples also contributed to the remarkable excellent electrochemical performance. All of these factors combined to significantly improve the electrochemical performance of the material.     

Study on wax precipitation characteristics of wax deposit in pipes

Wax deposit properties are a significant concern in pipeline pigging during waxy crude oil transportation. In the present work, the impacts of flow conditions and oil properties on the wax precipitation characteristics of wax deposits are investigated. A flow loop apparatus was developed to conduct wax deposition experiments using four crude oils collected from different field pipes. The differential scanning calorimetry (DSC) technique was employed to observe the wax precipitation characteristics of crude oil and wax deposit. The results show that the wax content and the wax appearance temperature (WAT) of the deposits increase with shear stress and radial temperature gradient, and decrease with radial wax molecule concentration gradient near the pipe wall. The DSC tests on the wax deposits revealed that the deposit wax content is strongly correlated to the oil wax content. Furthermore, an empirical correlation was developed to predict the wax content and the WAT of the wax deposit. Verification of the empirical correlation using the different oils indicated that the average relative error of the wax content prediction and average absolute error of WAT prediction were 13.2% and 3.6°C, respectively.     

空心轴液压联轴器内套设计参数的计算分析

研究了空心轴液压联轴器内套内侧压力沿轴向的变化规律以及压力与对应径向变形位移的比值沿轴向的变化规律，为设计空心轴液压联轴器内套壁厚提供了理论依据。     

准噶尔盆地加快天然气勘探有利条件及预探领域分析

准噶尔盆地天然气资源十分丰富,勘探潜力巨大。该盆地具备形成大气区的地质背景,发育石炭系、二叠系、侏罗系三套气源岩,演化程度高,气源条件充足;发育多类型、多套储集体和四套区域盖层,形成了有利的储盖组合及成藏配置。通过对五彩湾、滴西、莫索湾、莫北地区典型气藏的分析研究,该盆地发育多种气藏类型,包括构造型、古潜山型、火山岩内幕型及地层(不整合遮挡)型。通过研究指出,天然气勘探的现实领域有陆东—五彩湾地区、陆西—莫北—莫索湾地区;待突破的领域有腹部下组合大型古隆起及岩性气藏、南缘冲断带;正在准备的勘探领域主要为煤层气。     

基于CFD分析技术的水力优化设计方法在云南绿水河二级电站机组改造项目中的应用

云南绿水河二级电站高水头混流式水轮发电机组,由于受到当时的技术水平限制,自1969年设备投运后问题较多,电站进行了多次技术改造,但机组仍然存在机组效率低下、汽蚀和泥沙磨损问题,同时由于转轮的过流能力有限,远没有充分利用现有水力资源,本次电站改造的目标是提效增容,充分利用水力资源,改善汽蚀性能和解决泥沙磨损问题,保证机长期安全稳定运行,改造范围是对2号、3号和4号机组进行全面改造.电站改造采用基于CFD技术的水力优化设计方法的核心技术对电站存在的问题进行了针对性设计,给出了行之有效的全面解决方案,成功地完成了电站改造目标.     

Granular multiple kernel learning for identifying RNA-binding protein residues via integrating sequence and structure information

Neural Computing and Applications - RNA-binding proteins play an important role in the biological process. However, the traditional experiment technology to predict RNA-binding residues is...     

基于实验方法的硅胶圆管柔性关节静力学研究

采用两种不同材料的硅胶管和弹性骨架制作了柔性关节,对其进行静力学实验,得出了在相同气压下的弯曲角度和夹持力,并建立了柔性关节形变模型,获得了其气压下的形变特性。研究结果表明: 硅胶胶管邵氏硬度越小,其剪切弹性模量和弹性模量越小,其硅胶管制的柔性关节柔性和力学特性越好。该研究为弹性硅胶管在气动人工驱动器的应用进一步研究奠定了基础。     

Revit二次开发在水泥厂三维设计中的应用

随着科学技术的迅猛发展,建筑设计也在由二维向三维发展。近年来,在BIM（Building Information Modeling）建筑信息模型技术被写入建筑业发展“十二五”规划,并且列入住建部、科技部“十三五”等规划之后,BIM的概念逐渐深入人心,相关技术也随之迅速发展。 Autodesk Revit作为一款应用广泛的建筑信息模型三维设计软件,能够从初步设计、参数化、可视化、数据分析等方面提高设计效率和准确性,使用Revit进行水泥厂设计,不仅能使业主和施工人员更加直观的了解生产线布置,还能更好地统计工程量,对于一些复杂的管路布置,可以通过Revit设置条件生成相应的管路、部件明细表便于订货及工程量统计。在现在建筑的不断复杂化,设计要求也不断提高的大环境下,Revit软件自身所带的功能已不能满足现在建筑设计要求,对其二次开发已迫在眉睫[1]。Revit提供了丰富的应用程序编程接口供使用者进行二次开发,通过编程接口,用户可以结合.Net Framework生成动态链接库文件,在Revit用户界面中添加自定义组件,通过程序集成多项操作,自动完成复杂的建模工作,进一步深化三维设计的自动化和智能化,提高设计效率和质量。     

数控系统加减速控制与程序段终点速度规划

加减速控制是CNC系统的关键技术之一。以前的加减速控制技术通常或单独采用前加减速控制，或单独采用后加减速控制。本文提出一种采用前加减速控制，同时结合运用后加减速控制算法原理的策略并且在加工前选择速度曲线模型，以提高数控系统的加工精度、实时性和通用性。同时本文进一步分析了在数控系统加工过程中，在程序段终点处存在速度无规则突跳的现象，讨论了该现象所带来的问题并提出了解决这些问题的办法。     

原位TiB2颗粒增强铝基复合材料及其力学性能

对原位反应合成TiB2／A356铝基复合材料微观组织和力学拉伸性能进行了研究。结果表明，原位反应生成的颗粒增强相在复合材料基体中分布均匀，基体与颗粒间的界面洁净。复合材料强度随着颗粒含量的增加显著提高，与基体合金相比，TiB2质量分数为8％的TiB2／A356复合材料强度和弹性模量的提高幅度约为28％，TiB2质量分数为16％的TiB2／A356复合材料强度和弹性模量的提高幅度约为35％。复合材料的断裂主要是由于基体与颗粒界面脱粘，在拉伸应力作用下由此萌生微裂纹并扩展，导致界面处的基体撕裂，从而降低复合材料塑性。