浮式生产储油装置(FPSO)技术经济评价指标分析及论证

文章简述了一种特殊船型--浮式生产储油装置的特点、功能及其技术经济指标的选取.针对这种特殊船型的实际工况,给出相应的技术经济评价指标,并对传统国标(GB11697-89)提出了修正意见.实践表明,修正后的技术经济指标评价体系应用于FPSO的评价是适用的和可靠的.     

甘肃省职业教育市场化发展战略研究

职业教育迎来了空前好的发展机遇,甘肃职业教育也随之取得了长足的进步,但同时也存在不少问题.本文在对此分析的基础上,从市场化的角度提出了甘肃职业教育的发展思路.     

大连湾特大桥桩基溶洞处理

对大连湾特大桥桩基溶洞的技术处理进行了探讨。     

应用结构可靠性原理研究船舶纵弯曲强度

本文第一部分综述了结构可靠性原理,以及用以进行结构安全检验的全概率法、第二水平法和第一水平法。为便于实际应用和利用尽可能多的概率信息,较详细地讨论了第二水平法。第二部分对于船舶纵弯曲的屈服失效模式,简要地阐述了如何建立船体梁的载荷效应和抗弯能力的概率模型,以及如何应用这三种方法的基本途径。最后强调指出了应用可靠性原理制订船舶结构安全检验新规则的重要性和进一步应做的工作。     

聚氨酯前驱体基化学改性沥青及其改性机理

环保耐久材料的研究与应用对实现道路工程可持续发展具有重大的意义,采用以异氰酸酯为活性官能团的聚氨酯前驱体基反应型改性剂（PRM）制备改性沥青在环境保护和性能提升方面展现出了显著价值。采用"微观-介观-宏观"的跨尺度表征方法,对PRM改性机制进行了详细分析。通过与SBS改性沥青进行对照,评价了PRM改性沥青的流变学性能和抗热氧老化性能,明确了PRM改性沥青混合料的路用性能。研究结果表明：PRM改性过程存在明显化学变化,依托于改性过程中生成的氨基甲酸酯和脲等官能团,能够在沥青内部建立基于沥青质组分的共价交联网络结构。这一过程不仅促使沥青组分发生选择性聚集和沥青质重新构型,同时增大了沥青的表面自由能,从而获得更加稳定的内部结构。PRM改性沥青较基质沥青温度敏感性有所降低,展现出了良好的抵抗高温永久变形、抵抗疲劳破坏、抵抗低温开裂和抵抗热氧老化的能力。与SBS改性沥青相比,PRM在提升沥青高温性能、抗疲劳性能和抗热氧老化性能方面具有明显优势,并有望将改性沥青生产温度降低至140℃~150℃。结合沥青混合料路用性能测试结果,2.5%改性剂掺量PRM改性沥青混合料展现了与4%改性剂掺量SBS改性沥青混合料相当的低温性能、更好的高温性能和水稳定性能,PRM在提升沥青混合料路用性能方面具有显著优势。     

Shape optimization of a torsion beam axle for improving vehicle handling performance

In this study, shape optimization was conducted for a vehicle’s rear suspension torsion beam to improve its dynamic handling performance. To determine the design variables affecting the vehicle roll characteristics, a sensitivity analysis was conducted using the result of a Taguchi experiment with 6 factors in 8 runs. The upper and lower-flange lengths and web thickness of the torsion beam section, as well as the vertical height difference between the inner and outer of torsion beams, were determined as design variables through sensitivity analysis of the opposite wheel travel test for optimization of the torsion beam axle. The Box–Behnken experimental design with 4 factors and 27 runs was performed using the selected design variables and by performing opposite wheel travel analysis according to the experimental design, and the response surface functions of the roll stiffness, roll steer coefficient, roll center height, and mass of the torsion beam were generated. Using these response functions, shape optimization was conducted for the torsion beam of the rear suspension system. Dynamic performance analysis was performed by applying the optimized H-shaped torsion beam to the rear suspension of the vehicle dynamics model, and it was validated that the dynamic response performance of the optimized vehicle was improved.     

Investigation of turbulent flows in a waterjet intake duct using stereoscopic PIV measurements

Stereoscopic particle image velocimetry measurements were made in a wind tunnel using a prototype waterjet model. The main wind tunnel provided the vehicle velocity and a secondary wind tunnel was set up as the waterjet propulsion model. Pressure distributions along the ramp and lip sides inside the duct were measured for three jet velocity to vehicle velocity ratios. Three-dimensional velocity fields were obtained at the intake entrance and the nozzle exit of the waterjet system. The flow into the duct was faster in the lip region than on the ramp side. Because of the variation in intake geometry from a rectangular to a circular section and because of the sudden curvature change on the lip side, a pair of counter-rotating vortices was observed in the mean velocity field at the nozzle exit. In addition, the turbulent kinetic energy correlated with the vortex pair was stronger on the lip side than in other areas. Dominant large-scale structures were extracted by using a snapshot proper orthogonal decomposition analysis. It was found that most of the turbulent kinetic energy was attributed to at least three vortices near the nozzle exit. This detailed three-dimensional velocity field will be useful for the verification of CFD simulations applied to the waterjet system.     

多用途拖船尾滚筒结构强度计算及研究

该文采用有限元方法对某型多用途拖船尾滚筒的结构强度及稳定性进行了分析及计算,尝试利用了积分加载的方式施加结构的外载荷,分两种不同的工况对结构的主要参数进行了具体分析和比较,计算结果及经验分析验证了该外载荷施加方式的正确性,为尾滚筒的结构强度设计及稳定性分析工作提供了一定的参考。     

基于CPS的超大城市地铁机电设备智能运维体系设计

以北京、上海、广州为代表的超大城市地铁网络呈现出"规模体量大、线路分布广、枢纽数量多、运营负荷强度大"的特点,这对地铁机电设备运维管理提出了更高要求。传统运维主要以"人工经验型"维修为主,辅助一定的自动化检测装置,存在检测手段不足、数据传输实时性差等问题,难以实现对全网机电设备运行状况的实时跟踪和分析。针对上述问题,文章通过建立具有 CPS 技术特征的超大城市地铁机电设备智能运维体系,实现设备的运行状态在线检测、故障诊断、库存物料动态调整等功能,助力超大城市地铁安全、可靠地运营。     

摩托车发动机气门阀座的加工与刀具介绍

单刃可调硬质合金铰刀类刀具,结构比普通铰刀刀具复杂,由于有导向条的导向、支撑等作用,加工精度比普通铰刀类刀具要高,但这种刀具使用不当很容易折断;普通铰刀类刀具, 结构相对简单,调刀、换刀容易,调刀简单,完全能满足加工精度要求。