云锡1360基础平台岩巷掘进掏槽爆破参数优化

针对云锡1360基础平台岩巷掘进循环进尺小、炮孔利用率低的问题,在优化掘进爆破参数的基础上,通过现场试验对比三级楔形与中心桶形混合掏槽、二级九孔与中心桶形混合掏槽、三级双空孔菱形掏槽、二级六棱柱与中心三角柱形混合掏槽的爆破效果,以掘进进尺、掏槽孔利用率,掏槽孔残孔深度、平巷轮廓成型等指标作为评价爆破参数优劣的标准。试验结果表明,在致密的大理岩和破碎且带有泥质夹层的岩石中,分别采用三级楔形与中心桶形混合掏槽(孔深3.4m)和三级双空孔菱形掏槽(孔深2.7m)能够取得良好的爆破效果。     

Statistical Analysis with Dingo Optimizer Enabled Routing for Wireless Sensor Networks

Security is a vital parameter to conserve energy in wireless sensor networks (WSN). Trust management in the WSN is a crucial process as trust is utilized when collaboration is important for accomplishing trustworthy data transmission. But the available routing techniques do not involve security in the design of routing techniques. This study develops a novel statistical analysis with dingo optimizer enabled reliable routing scheme (SADO-RRS) for WSN. The proposed SADO-RRS technique aims to detect the existence of attacks and optimal routes in WSN. In addition, the presented SADO-RRS technique derives a new statistics based linear discriminant analysis (LDA) for attack detection, Moreover, a trust based dingo optimizer (TBDO) algorithm is applied for optimal route selection in the WSN and accomplishes secure data transmission in WSN. Besides, the TBDO algorithm involves the derivation of the fitness function involving different input variables of WSN. For demonstrating the enhanced outcomes of the SADO-RRS technique, a wide range of simulations was carried out and the outcomes demonstrated the enhanced outcomes of the SADO-RRS technique.     

低浓度全尾砂充填材料泌水及其调控机理

针对低浓度全尾砂充填过程中的泌水造成输送堵管充填体强度不均匀和体积沉缩等问题,进行尾砂级配、胶凝材料用量、料浆浓度、固水材料掺量的正交实验,分析了各种因素对泌水率的影响,根据电阻率(ER)测试、SEM-EDS和XRD探讨了固水材料的作用机理。结果表明,充填料浆的泌水率随着尾砂细颗粒、胶砂比、浓度和固水材料掺量的增加而降低,料浆的浓度和固水材料掺量对泌水率的影响最显著。添加5%的固水材料可使充填材料泌水率降低10%,初始粘度降低30%,2 h粘度降低53%,28 d抗压强度提高20%。固水材料可改善充填材料的孔隙率,提高充填材料水化体系的SO₄^2-浓度和pH值,生成钙矾石、斜方钙沸石以及C-S-H凝胶和硅铝酸盐凝胶的混合物,消耗大量自由水,高分子聚合物通过分子缠绕提高了体系的稳定性,改善了充填材料的泌水现象。     

Design of heterogeneous mechanical tests: Numerical methodology and experimental validation

Standard material parameters identification strategies for constitutive equations generally use an extensive number of classical tests for collecting the required experimental data. Recently, new specimen geometries for heterogeneous tests were designed to enhance the richness of the strain field and capture supplementary strain states using full‐field measurement techniques. The butterfly specimen is an example of such a geometry, designed through a numerical optimization procedure where an indicator capable of evaluating the heterogeneity and the richness of strain information is used. The aim of this work is to experimentally validate the heterogeneous butterfly mechanical test in the parameter identification framework. Blanks of mild steel DC04 are cut with the butterfly geometry, and specific grips are designed. Tests are performed with Digital Image Correlation technique, and a Finite Element Model Update inverse strategy is used for the parameter identification, as well as the calculation of the indicator. The identification strategy is accomplished with the data obtained from the experimental tests, and the results are compared with quasi‐homogeneous tests.     

等应变速率固结试验的研究

等应变速率固结试验是连续加荷固结试验的一种方法。连续加荷固结试验是一种比较合理的,有一定理论依据的快速固经试验方法。试验结果优于常规固结试验。通过对比试验资料分析研究,证实连续加行固结试验,可以大大缩短试验时间,改善试样受力条件,得到更可靠的试验结果。     

止水帷幕缝隙渗漏变化过程试验研究

由于施工工艺的原因,止水帷幕一般存在缝隙。在长期渗流的作用下,带缝隙的止水帷幕渗漏量如何发展需要进一步研究。因此,作者自行设计并制作了砂槽模型模拟带裂缝的止水帷幕,并开展了一系列的渗流试验。试验考虑了水力条件、砂样级配和缝隙尺度因素的影响。结果表明,在水头不变的情况下,各试验中均出现了渗漏量下降的现象,但水头升高则会破坏这一现象。缝隙渗漏量下降的实质是砂颗粒移动和聚集导致淤堵的产生,淤堵位置可能在上下游缝口、缝隙进出口或缝隙内。当砂样粒径较细时,缝隙渗漏量下降效果最为显著;当下游回填级配不稳定的砂样时,缝隙渗漏量下降效果不佳。     

机组告警信息地面实时监控系统设计

机组告警信息对于保障民机飞行安全有着至关重要的作用,为了保障民机试飞地面安全实时监控任务,需要开发一套系统能够在试飞过程中精确地给出机组告警信息.机组告警信息内容来源于机上多个子系统,重点研究了如何从遥测接收的PCM流中精确解析出告警信息以及地面实时系统各个模块间的通信及功能设计.采用了典型的C/S (Client/Server)结构来搭建系统,通过对告警信息进行分类判决和设计虚警抑制机制实现了机组告警信息的正确解析.经多个飞行起落验证,该系统运行稳健,告警信息与机上显示内容相符,可满足地面指挥和试飞工程师的监控需求.该系统为民机试飞任务的顺利进行提供了保障,值得后续民机型号借鉴.     

基于孔穴扩张理论的黏性土不排水剪强度计算

确定黏性土不排水抗剪强度(c_u)的常规测试方法存在着取样扰动或测试深度不足等缺陷,提出了基于孔穴扩张理论的黏性土不排水抗剪强度的测试方法,并应用于花岗岩残积黏性土、辉绿岩残积黏性土和花岗岩残积砂质黏性土的旁压试验和静力触探试验成果解释中,将两种试验得到的c_u值进行对比。结果表明:旁压理论的假设条件导致旁压试验得到的c_u值较静力触探试验得到的c_u值大,其中等容剪切法计算过程对初始扰动和应变数据的选择非常敏感,导致计算结果差异较大;直接传统法能够克服初始扰动,c_u值受临塑压力的影响较小,计算结果与土体性质以及试验点深度较吻合,其c_u值约为静力触探试验的1.2倍,是一种简单、有效的确定黏性土不排水抗剪强度的方法。     

Surface properties of polymers prepared from trimethylsilyldimethylamine and hexamethyldisilazane by glow discharge polymerization

Polymers prepared from the monomers trimethylsilyldimethylamine and hexamethyldisilazane by glow discharge polymerization were analysed by elemental analysis and infrared spectroscopy, and some surface properties were investigated. Although the polymers formed from both monomers have similar chemical structures involving CH₂, CH, Si---CH₃, Si---CH₂---CH---₂---Si, Si---O---Si, and Si---O---C groups, there is a significant difference in nitrogen residues. The nitrogen residues in polymers formed from trimethylsilyldimethylamine exist mainly as amide groups, and the residues in the polymers from hexamethyldisilazane exist as disilazanyl groups. This difference is evident in the surface energy, especially in the polar contribution. The relative ratio of polar and to dispersive contributions to the surface energy is higher for the polymers from hexamethyldisilazane (0.6) than for those from trimethylsilyldimethylamine (0.3). Adhesion between these plasma films and polymer substrates subjected to modification was also examined.