两毫米工程与亚毫米冲压

两毫实工程和亚毫米冲压技术是以提高汽车车身质量为目的而提出来的。介绍了它们的含义、提出背景、研究的内容及成果。通过这一项目的研究，使人们对焊接技术、材料成形加工技术、金融变形机理、冲压设计方法和理论等有了深刻的认识。     

汽车离合器可靠性统计模型

本文通过大量的统计数据分析，获得了汽车离合器摩擦片寿命的统计模型和离合器的１００ｋｍ接合次数统计模型，并应用该统计模型，证实了离合器摩擦片寿命预估理论和实际使用寿命的一致性。     

变速比齿轮齿条式转向器齿条齿面数学模型

本文根据齿轮啮合原理,在转向器某些参数给定的条件下,利用齿轮法线法,由齿轮齿面数学方程导出了满足给定变速比特性与普通螺旋圆柱齿轮相关轭的齿条齿面数学模型。此模型不仅是齿条齿面几何参数,而且还是变速比齿轮齿条传动副的齿面压力角、重合度、齿面滑移率、齿面曲率、齿条螺旋角等重要参数的计算依据。它为该型转向器齿轮齿条传动副的优化设计奠定了理论基础,也为该型转向器的齿条齿面专用加工机床、刀具、模具及检测设备的研制提供了理论依据。此模型曾用于变速比齿轮齿条式转向器齿轮齿条传动副的计算机辅助设计(CAD),其结果,齿条齿面主要几何参数均与变速比齿条样品完全吻合。     

摩托车发动机压缩比计算与校核

压缩比是发动机的基本参数之一,进行准确的计算和校验非常重要,设计和计算过程中需充分考虑公差的存在和影响,以取得更加完善的设计效果.     

Short-term prediction of vehicle waiting queue at ferry terminal based on machine learning method

Ferry service plays an important role in several cities with waterfront areas. Transportation authorities often need to forecast volumes of vehicular traffic in queues waiting to board ships at ferry terminals to ensure sufficient capacity and establish schedules that meet demand. Several previous studies have developed models for long-term vehicle queue length prediction at ferry terminals using terminal operation data. Few studies, however, have been undertaken for short-term vehicular queue length prediction. In this study, machine learning methods including the artificial neural network (ANN) and support vector machine (SVM) are applied to predict vehicle waiting queue lengths at ferry terminals. Through time series analysis, the existence of a periodic queue-length pattern is established. Hence, methodologies used in this study take into account periodic features of vehicle queue data at terminals for prediction. To further consider the cyclical characteristics of vehicle queue data at ferry terminals, a prediction approach is proposed to decompose vehicle waiting queue length into two components: a periodic part and a dynamic part. A trigonometric regression function is introduced to capture the periodic component, and the dynamic part is modeled by SVM and ANN models. Moreover, an assembly technique for combining SVM and ANN models is proposed to aggregate multiple prediction models and in turn achieve better results than could be attained from a lone predictive method. The prediction results suggest that for multi-step ahead vehicle queue length prediction at ferry terminals, the ensemble model outperforms the separate prediction models and the hybrid models, especially as prediction step size increases. This research has important practical significance to both traffic service management interests and the travelers in cities along waterfront areas.     

列车信号机黄闪黄继电器逻辑条件的修改建议

结合新建铁路赣韶线信号施工图设计,针对进站信号机、线路所通过信号机有黄闪黄显示时的电路进行了分析,结合其编码电路中所采用的条件,提出了黄闪黄继电器(USUJ)逻辑条件存在的不足和相应的修改建议。     

Internal Resonances for the Heave Roll and Pitch Modes of a Spar Platform Considering Wave and Vortex Exciting Loads in Heave Main Resonance

The objective of this paper is to study the nonlinear coupling internal resonance of the heave, roll, and pitch response performance of a spar platform when their frequencies are in the ratio of 2:1:1 under wave and vortex exciting loads. The three degree-of-freedom (DOF) nonlinear coupled equations are established by considering a time-varying wet surface with a first-order wave force in heave and pitch and a vortex-induced force in roll. The first-order steady-state response is solved using the multi-scale method in heave main resonance. The multiple solutions of the motion equations are discussed using the analytic method and a numerical simulation. A sensitivity analysis is conducted to test the influence of the damping and internal detuning parameter. The regions of multiple solutions are found, and the jump phenomenon exists with the changes of the wave excitation. The regions of multiple solutions depend on the values of damping and detuning parameter.     

潜堤对平均沿岸流及沿岸流不稳定的影响

潜堤是防止海岸侵蚀的常用护岸建筑物,准确的掌握潜堤前后水动力特性十分必要.本文以斜坡上梯形潜堤为研究对象,基于港池沿岸流实验,通过变换潜堤的位置来分析潜堤对平均沿岸流的影响,通过增加潜堤来观察其对沿岸流不稳定波动频率的影响.结果表明,潜堤离岸越近,垂直岸方向的沿岸流分布有向岸偏移的趋势,同时,会使得沿岸方向上游流速增加越大,使总的沿岸方向的流速分布更均匀;增加潜堤会使沿岸流不稳定某些频率的波动明显加强,同时也会使沿岸流不稳定波动出现新的高频部分.     

锂离子电池电解液研究进展

本文着重介绍了锂离子电池电解液中溶剂、锂盐及添加剂的性能、优缺点及改进方法,并对这些材料的应用作了进一步展望。     

一种基于单片机的雷达发射机功放电源控制系统设计

介绍了一种基于单片机设计的雷达发射机功放电源控制系统。选用ATMEL公司的AT90S8535作为核心器件,由单片机内集成的10 bitA/D进行模数转换,实现实时监测、实时控制、实时显示及报警等功能。给出了该系统的软、硬件主体部分以及电路。实验结果表明,该系统具有精度高、使用简单、成本低和工作稳定可靠等特点,具有一定的应用价值。