定向井双油管及潜油电泵完井技术

通过对涠１０─３油田７口井次的施工实践，介绍有关双油管完井的一般井下管柱结构、完井工具及其作用、现场施工的工艺等。另外，还向读者简单介绍涠１０─３油田大斜度井电泵的完井方法和管柱结构。     

树根桩在基础加固工程中的应用

树根桩对于已建建筑物的地基加固纠偏具有独到之处，效果显著。通过工程实例分析，对树根桩的设计原理、施工方法和其承载力作了阐述。     

索车的研制及在轨道顺槽的应用

索车适用于10°以下的坡度,运输距离1000m以内,适用于综掘工作面顺槽的材料、设备运输,且能够适应于起伏坡度不大的巷道,是实现长距离连续运输的一种经济实用新型辅助运输设备。     

风积粉细砂隧道施工中的注浆加固技术

神朔铁路杏树峁隧道采用低压渗入性注浆方法，在风积粉细砂地层中压注改性水玻璃浆液，解决了隧道施工中的超前支护、注浆矽化加固的可注性，浆液选材配比及注浆工艺待技术问题，有效地控制了漏砂、坍塌和结构过量沉降等问题的发生。本文根据现场实践，应用注浆固结理论，对风积粉细砂注浆加固后的强度和稳定性进行了分析。     

关于大角度范围内四元数与欧拉角转换的思考

在存在大角度姿态机动的场景中,航天飞行器通常采用基于姿态四元数的姿态运动模型,同时又多以欧拉角形式给定其期望姿态,因此研究四元数到欧拉角的转换关系十分必要.但是,姿态四元数与欧拉角之间并不存在一一对应的关系.以飞行器姿态为纽带,依据姿态四元数和欧拉角与飞行器姿态之间的内在关系,对各种可能出现的情形进行分析,在控制所对应的期望姿态的牵引下,确定出符合姿态控制利益的姿态四元数到欧拉角的转换关系.鉴于姿态四元数到欧拉角转换关系的复杂性,在飞行器进行大角度姿态机动控制时,建议采用基于四元数的姿态运动模型.     

Enhanced sound absorption properties of porous ceramics modified by graphene oxide films

Under the condition of constant thickness, improving the low-frequency sound absorption performance of conventional sound-absorbing materials is a challenging research topic. To address this issue, a new reduced graphene oxide/polyvinyl alcohol (RGO/PVA) porous composite ceramic was fabricated using freeze-drying and optimized by redesigning the internal connecting pores of porous ceramic matrixes with a reticular microstructure using RGO and PVA. The as-prepared porous structure showed significant enhancement in the low-frequency sound absorption band compared with pristine porous ceramics. In addition, the hybrid porous ceramics exhibited low thermal conductivity. These favorable properties indicate that the hybrid sound-absorbing ceramics have potential application prospects for noise reduction in the fields of construction and electrical and mechanical devices.     

Multiscale SiCnw and carbon fiber reinforced SiOC ceramic with enhanced mechanical and microwave absorption properties

The hierarchical SiOC/SiCnws/CF composites (A/B/C structure) were designed via precursor infiltration and pyrolysis process. The SiOC ceramics served as the wave-transparent characteristic materials to adjust the impedance matching. Herein, the in situ growth of SiCnws not only was used for the absorber but served as the reinforcement of SiOC matrix composites. In detail, the SiOC/SiCnws/CF-1200°C-2 exhibits excellent electromagnetic absorption performance with minimum reflection loss of −46 dB at 14.4 GHz with the thickness of 1.6 mm, and its effective absorption band reaches 4.3 GHz. Its compressive strength reaches 8.69 and 16.41 MPa in z and x/y directions, separately. This contribution has a guidance for the application of carbon fiber/ceramics matrix composites in harsh environment.     

管材专用PPR的等温结晶动力学

研究了管材专用无规共聚聚丙烯(PPR)的结晶温度和等温结晶行为,利用Avrami方程对等温结晶过程和动力学进行了分析。结果表明:北欧化工公司的PPR1具有更高的结晶温度、结晶度以及更快的结晶速率。同一结晶温度条件下,国产PPR3的结晶度达到一半的时间略高于其他PPR。利用Hoffman-Lauritzen结晶动力学理论计算得到了PPR的成核常数和结晶生长时大分子在垂直于分子链方向的折叠表面自由能(σ_e),与其他试样相比,PPR1的σ_e最低,PPR3的σ_e最高,结晶速率最慢。通过偏光显微镜照片可以发现,PPR1的球晶尺寸最小,PPR3和PPR4的球晶较大,球晶尺寸比较接近。     

Component analysis and risk assessment of biogas slurry from biogas plants

Massive amounts of biogas slurry are produced due to the development of biogas plants. The pollution features and the risk of biogas slurry were fully evaluated in this work. Thirty-one biogas slurry samples were collected from sixteen different cities and five different raw materials biogas plants (e.g. cattle manure, swine manure, straw-manure mixture, kitchen waste and chicken manure). The chemical oxygen demand (COD), ammonia nitrogen (NH₄⁺ - N), anions (e.g. Cl^-,SO₄^2-, NO₃^- and PO₄^-3), antibiotics (e.g. sulphonamides, quinolones, β₂-receptor agonists, macrolides, tetracyclines and crystal violet) and heavy metals (e.g. Cu, Cd, As, Cr, Hg, Zn and Pb) contents from these biogas slurry samples were systematically investigated. On this basis, risk assessment of biogas slurry was also performed. The concentrations of COD, NH₄⁺ and PO₄^-3 in biogas slurry samples with chicken manure as raw material were significantly higher than those of other raw materials. Therefore, the biogas slurry from chicken manure raw material demonstrated the most serious eutrophication threat. The antibiotic contents in biogas slurry samples from swine manure were the highest among five raw materials, mostly sulphonamides, quinolones and tetracyclines. Biogas slurry revealed particularly serious arsenic contamination and moderate potential ecological risk. The quadratic polynomial stepwise regression model can quantitatively describe the correlation among NH₄⁺ - N, PO₄^-3 and heavy metals concentration of biogas slurry. This work demonstrated a universal potential threat from biogas slurry that can provide supporting data and theoretical basis for harmless treatment and reuse of biogas slurry.     

汽车B柱内饰板热流道大型精密注塑模设计

汽车B柱内饰板产品分为左右各一件,大小和形状不完全相同,其体积大、结构复杂,内部有斜螺丝柱和较多的斜异形内孔,侧面卡扣位多,其外形为3D弧形曲面、表面质量要求高,注塑时容易出现填充困难及缩痕、翘曲变形等缺陷。针对以上特点,设计了一套一模两腔、热流道成型、多种复杂抽芯机构联合脱模的精密注塑模具。为保证两件产品同时填充且具有相同的成型质量,采用三板模结构以及两个顺序阀热喷嘴进胶转冷流道在产品侧面进胶的方式。详述了整体式模芯结构、热流道浇注系统、冷却系统、排气系统、导向定位系统及弹镶针机构、T槽直接和间接抽斜滑块机构、斜抽芯机构和斜顶机构等多种联合脱模机构的设计要点,解决了B柱左右内饰板注塑过程中的脱模困难及熔体填充和生产周期长等问题,通过优化组合设计,从整体上简化和优化了模具结构,降低了模具制造成本。