改性含钛高炉渣中钙钛矿浮选分离工艺研究

为了实现攀钢含钛高炉渣中钛组分的有效回收,对其进行了化学组分的调整和高温选择性析出处理,在此基础上,进行了改性渣中主要矿物的浮选、人工混合矿浮选、改性渣浮选等研究。结果表明,辛基异羟肟酸(OHA)对三种矿物表现出一定的捕收能力和选择性;捕收剂与抑制剂用量对浮选效果未有明显效果,且耗酸量较大;通过SEM和EDX分析表明,各矿物表面被针状硫酸钙覆盖导致捕收剂与抑制剂对矿物的作用效果减弱,因此需要寻求较为有效的表面处理剂对改性渣处理后再进行浮选分离。     

我国煤矿巷道围岩控制技术发展70年及展望

为解决掘进工作面顶板稳定性影响因素多、空顶距取值不合理导致掘进速度慢的难题,基于响应面法通过数值模拟手段,研究煤巷掘进工作面顶板三向应力及变形规律,分析影响掘进工作面顶板变形的关键因素及其交互作用关系。研究结果表明：在掘进工作面前方约1倍洞径处应力调整及变形开始显现,至掘进工作面后方1倍洞径时应力调整基本稳定,在掘进工作面后方约2倍洞径时顶板变形基本稳定;顶板变形与顶板泥岩黏聚力和支护强度呈负相关关系,与顶板泥岩厚度及空顶距呈正相关关系,通过响应面法进行多因素交互分析是确定特定条件下掘进工作面合理空顶距的有效手段。根据赵庄煤矿33082巷地质条件,设置合理空顶距为2 m,支护强度提高至0.25 MPa,应用结果表明巷道稳定性得到保证,且巷道掘进速度也由原先的180 m/月提高至350 m/月,掘进速度显著提高。

     

基于SIMOTION D425运动控制系统的CAM曲线

介绍了CAM曲线在西门子SIMOTION D425自动化系统中的应用。为达到伺服电机能运行任意给定曲线的目的,采用CAM曲线方法,即运用Scout软件仿真从轴跟随主轴的响应运动并得到相应仿真曲线,从而可以直观地看出配置曲线和仿真曲线之间的关系。实践证明,CAM曲线功能不但可以实现这一目的,而且使得主轴与从轴的关系更加灵...     

1.8V音频∑△调制器的设计

介绍了一种适用于语音信号处理的16位24 kHz ∑△调制器.该电路采用单环三阶单比特量化形式,利用Matlab优化调制器系数.电路采用SIMC 0.18μm CMOS工艺实现,通过Cadence/Spectre仿真器进行仿真.仿真结果显示,调制器在128倍过采样率时,带内信噪比达到107 dB,满足设计要求.     

发动机连杆与曲轴的有限元分析

为了保证扩缸后的发动机能正常工作,采用有限元法对连杆和曲轴强度进行计算分析.首先采用ANSYS软件,导入CAD图并进行网格划分和边界力的施加,建立连杆和曲轴的三维计算模型.通过计算,得到了在最大爆发压力下的连杆和曲轴的应力和应变分布;应用计算得出的应力代入疲劳安全系数公式得出连杆和曲轴的疲劳安全系数,得出该发动机扩缸后曲轴和连杆是安全的.     

内燃机CAD数据库管理系统的研究与实现

本文尝试根据内燃机计算机辅助设计（CAD）过程数据的复杂性，基于商用数据库Microsoft公司的FoxPro软件开发出一套内燃机CAD数据库管理系统，以交互方式完成了内燃机现代设计的全程管理，并提供了保证系统安全性措施，同时，利用OLE技术成功地实现了应用软件和数据库之间的数据传递。整个系统在实际使用中取得了令人满意的效果。     

还原气氛对高铬砖性能的影响

为了有效提高高铬砖的常温物理性能和抗侵蚀性能,延长其在水煤浆加压气化炉中的使用寿命,在埋炭条件下,分别于1350、1450和1550℃烧成高铬砖,并与1700℃空气中烧成试样对比,研究了烧成气氛(埋炭和空气气氛)对高铬砖体积密度、显气孔率、常温耐压强度和抗熔渣渗透性能的影响。结果表明:随着温度升高,高铬砖的显气孔率下降、体积密度增加,而1450℃埋炭烧成高铬砖的常温耐压强度最高,达到214MPa;埋炭能显著降低高铬砖的烧成温度和改善其显微结构;1450℃埋炭烧成高铬砖的抗熔渣渗透能力优于1700℃空气中烧成试样的。     

纳米SiO2对超硫酸盐水泥性能影响研究

为了克服超硫酸盐水泥(SSC)早期强度低的难题,探究了纳米SiO₂(NS)对SSC水化硬化性能的调控效果与机理。研究了NS对SSC力学性能、产物组成、微观结构和形貌,以及孔隙结构的影响规律。结果表明:掺入NS可显著提升SCC力学性能,其中3 d抗压强度提升了32%,3 d抗折强度提升了28%,90 d抗压强度提升了近一倍;同时,NS能够显著密实SSC孔隙结构,使其临界孔径从72.8 nm降低至6.5 nm。NS的增强机理主要为促进矿粉水化,增加产物中C-(A)-S-H凝胶的生成量和聚合度。本文证明了NS提升SSC水化硬化性能的可行性,为低碳SSC的性能提升提供了新思路。     

Enhancement of Photocatalytic Activity of Bi2O3–BiOI Composite Nanosheets through Vacancy Engineering

Vacancy engineering is an effective strategy to enhance solar‐driven photocatalytic performance of semiconductors. It is highly desirable to improve the photocatalytic performance of composite nanomaterials by the introduction of vacancies, but the role of vacancies and the heterostructure in the photocatalytic process is elusive to the composite nanomaterials. Herein, the introduction of I vacancies can significantly enhance the photocatalytic activity of Bi₂O₃–BiOI composite nanosheets in a synergistic manner. The excellent photocatalytic performance of the Bi₂O₃–BiOI composites is attributed to the combination of Bi₂O₃ and BiOI and the existence of I vacancies in Bi₂O₃–BiOI composites. Specifically, density functional theory calculation shows that the existence of I vacancies would create a new electric states vacancy band below the conduction band of BiOI and thus can reduce the bandgap of BiOI nanosheets. This greatly facilitates the scavenging of the photogenerated electron on the surface of BiOI by Bi₂O₃, therefore, enhancing the overall photocatalytic activity of the composites. The enhanced photocatalytic efficiency is demonstrated by the degradation of tetracycline (TC), which reaches 96% after 180 min and by the high total organic carbon (TOC) removal (89% after 10 h visible light irradiation). This study provides a novel approach for the design of high‐performance composite catalysts.     

Modular Graphene‐Based 3D Covalent Networks: Functional Architectures for Energy Applications

The development of ordered graphene‐based materials combining high stability, large surface areas, ability to act as absorbent of relevant chemical species, and solution processability is of significance for energy applications. A poorly explored approach relies on the controlled nanostructuration of graphene into robust and highly ordered 3D networks as a route to further leverage the exceptional properties of this unique material. Here, a simple yet effective and scalable one‐step method is reported to prepare graphene‐based 3D covalent networks (G3DCNs) with tunable interlayer distance via controlled polymerization of benzidines with graphene oxide at different reaction temperatures under catalyst‐ and template‐free conditions. The reduced form of G3DCNs is used as electrodes in supercapacitors; it reveals a high specific capacitance of 156 F g^?1 at a current density of 1 A g^?1 in a two‐electrode configuration and 460 F g^?1 at a current density of 0.5 A g^?1 in a three‐electrode configuration, combined with an excellent cycling stability over 5000 cycles. The present study will promote the quantitative understanding of structure–property relationship, for the controlled fabrication of 3D graphene‐based multifunctional materials.