现浇钢筋混凝土结构中施工缝的处治

整浇混凝土中存在施工缝的问题，这是由于施工过程中某种因素的影响所致。施工缝处理不当，将会严重影响工程质量，甚至造成质量事故。对这种不容忽视的施工缝的存在，国家现行施工规范对施工缝的留置有其详细的规定。在实施中掌握不严会出现随意性。施工技术人员应认真了解施工缝的留置位置及处理措施，设计人员对施工缝的处理要严肃妥当，不要回避施工中多种不利因素的存在。     

现浇框架柱电动滑模施工

现浇框架柱滑模施工中，对工程设计的要求必须建筑平面应尽可能一致，工程施工的要求应尽可能一次滑动施工完成，这样才能实现施工机械化，减轻劳动强度。简化施工程序，加快施工进度，改善施工条件，提高工程质量，降低工程成本。     

责任会计在施工企业中的应用

对于施工企业来说，它的的基本经济活动是施工活动。施工活具有流动性大、施工生产分散、地点不固定等特点，所以，施工企业需要采用分级核算、分级管理的办法。在成本核算方面施工企业要按照每项工程分别进行成本核算，即要求采用“定单成本计算法”，同时，施工企业的施工周期比较长，要按照“已完工程”分期计算预算成本和实际成本，并与建设单位进行工程价款的结算。     

大保公路K435+690大桥柔性高墩施工技术

利用山区有利的V型地形条件，立足现有设备，通过采用天桥施工方案，使最高墩76．7m的高墩施工变为两部分，下部施工最大高度45m，上部施工高度30余m，极大简化了施工工艺，降低了施工难度，节约了施工设备和工程成本，提供了一种在山区施工高墩的新方法，也为类似工程施工提供了一种可供借鉴的方法。     

三层曲中墙连拱隧道施工技术

结合云南思小高速公路麻地河四号三层曲中墙连拱隧道，首先根据现场监控量测实际情况。重新制定了麻地河四号隧道的施工技术方案，取消两侧壁导坑，采甩中导洞单洞掘进方式；其次，分析讨论麻地河四号隧道的整个施工过程。重点讨论了三层曲中墙连拱隧道中隔墙施工技术，总结三层曲中墙连拱隧道施工技巧和施工经验，提出一些有益的施工成果。最后，分析讨论施工过程中的监控量测数据，总结监测反馈信息，真正做到现场监控量测与信息反馈施工技术，保证了隧道的科学、安全施工。     

广州新白云机场旅客航站楼预应力施工

本文主要介绍广州新白云国际机场旅客航站楼的预应力施工，施工时同时存在有粘结和无粘结预应力两种施工形式，预应力筋用量大，施工时采用应力和应变双向控制，施工效果良好，各项指标均满足国家规范要求。     

试论寒冷地区钻孔灌注桩的施工

冬季是个不易施工的季节，而钻孔灌注桩则是冬季基础施工的一种好方法。实践证明：在低温下桩在土中由地温作用自身保温养生条件优越。而桩的施工方法简单，施工面积小，减少了大量的土方运输，施工工期快，承载力高，桩身强度计算一般不难满足要求，是一种质量好，效益高，进度快的施工方案。     

浅谈施工组织设计的改进

施工组织设计是施工技术和施工管理的有机结合体，是指导施工的重要技术经济文件，其本身的质量对工程建设的成败和经济效益具有决定性的影响。因此，提高施工组织设计编制工作的质量具有重大意义。现对施工阶段施工组织设计编制工作的改进提出一些粗浅的见解。     

高速公路土质路基施工

以高速公路土质路基施工为主，阐明路基施工的基本过程，如施工准备及施工组织管理等。     

浅谈施工项目管理

为使施工项目有一个好的工程质量，履行合约，产生效益，项目经理就必然要对施工项目进行全权负责，也就应该围绕着施工项目进行管理，本文就施工项目管理谈点体会。     

Hierarchical estimation of vehicle state and tire forces for distributed in-wheel motor drive electric vehicle without previously established tire model

In this paper, a hierarchical estimator combined with the nonlinear observer and particle filter (PF) is proposed to accurately estimate the vehicle state and tire forces of distributed in-wheel motor drive electric vehicles (DIMDEVs) when the traditional tire models are not available. The proposed estimator consists of lower and upper layers. The lower layer, i.e. longitudinal tire force nonlinear observer (LTFNO) aims at estimating the longitudinal force based on the available drive/brake torques and rotational speed of wheels. The convergence of LTFNO is proved by the invariant set principle. The upper layer receives these estimated longitudinal tire forces from LTFNO and estimates the vehicle state including lateral tire forces based on an expert model (EM). The designed EM utilizes basic knowledge and rules about tire characteristics to approximate the unknown lateral tire force. The upper estimator combines with EM (EEM) to further improve the accuracy. The EEM takes the modeling errors and disturbances into account and avoids the usage of complex established tire models. Then PF is applied in the upper layer to complete the estimation, which only needs measurable longitudinal/lateral accelerations and yaw rate signals. Finally, the effectiveness of the designed hierarchical estimator is verified by Carsim and Simulink co-simulations. The results show the proposed strategy can accurately estimate the vehicle state and tire forces in real-time.     

浅谈汽车轮胎保养与使用

汽车轮胎对行驶安全性起着十分重要的作用,轮胎的状况对汽车的动力性、制动性、平顺性、行驶稳定性和燃料的经济性有着直接的影响,所以对轮胎的保养很重要,必须保证汽车轮胎的技术状况在要求的范围内。文中主要介绍了汽车轮胎的重要性,论述了汽车轮胎检查保养的手段、汽车轮胎的正确使用方法及维护维修技巧。     

轮胎制造业技术性贸易措施研究

技术性贸易壁垒给我国轮胎制品的出口贸易带来了巨大的障碍。本文分析了主要发达国家对轮胎产业设置的技术性贸易措施及我国技术法规的现状,提出了我国轮胎出口应对国外技术贸易壁垒的政策措施。     

Integrated tire slip energy dissipation and lateral stability control of distributed drive electric vehicle with mechanical elastic wheel

Stability and energy consumption have always been important issues in electric vehicle research. Excessive slip energy not only aggravates tire wear, but also consumes energy of electric vehicle. In order to ensure the lateral stability and to reduce the slip energy dissipation of the distributed drive electric vehicle (DDEV) equipped with Mechanical Elastic Wheel (MEW), an integrated framework considering both tire slip energy dissipation and lateral stability control is proposed. The SESC (Slip Energy and Stability Control) is a hierarchical control framework for DDEV with MEW. A PID speed tracking controller and an (Integral Terminal Slide Mode) ITSM controller are designed at the upper-level controller. The ITSM controller can improve the lateral stability of the vehicle by obtaining the desired yaw moment. Speed tracking controller can stabilize the speed of the vehicle and obtain the desired longitudinal force. At the lower-level controller, the brush model of the MEW is proposed to express tire slip energy. In order to reduce the error of the vehicle dynamics and the slip energy dissipation, a mixed objective function including a holistic corner controller (HCC) and a minimum tire slip energy characterization is proposed. The proposed control framework is verified by Carsim and Matlab/Simulink under emergency simulation conditions. The simulation results show that the SESC based method can improve the lateral stability of DDEV with MEW effectively, and has better performance compared with fuzzyPID+AD based method. Meanwhile, the SESC achieves less slip energy than conventional torque distribution method.     

Path tracking control strategy for the intelligent vehicle considering tire nonlinear cornering characteristics in the PWA form

To improve the path tracking control performance of the intelligent vehicle under critical maneuvers, a novel control strategy is introduced in this work. Considering that the tire cornering characteristics show high nonlinearities and uncertainties under those special driving conditions, a three-dimensional piecewise affine (PWA) identification method is proposed to realize the nonlinear modeling of the tire cornering characteristics for the first time. On this basis, the PWA model of the vehicle lateral dynamics is established. To obtain the vehicle target yaw rate for path tracking, a driver direction control model with adaptive preview time is put forward. Then, the linear quadratic optimal control method is further adopted to design multiple path tracking controllers for different working areas of the affine subsystems, thus the optimal steering angles of the front wheels can be generated to guarantee the path tracking performance for the intelligent vehicle under a wide range of driving conditions. Finally, to evaluate the performance of the proposed path tracking control strategy which considers the tire nonlinear cornering characteristics in the PWA form, the CarSim-Simulink co-simulation work is conducted. The co-simulation results show that the proposed control strategy presents significant performance advantages over the other two methodologies and demonstrates satisfactory path tracking control performance.     

浅析科技馆的运营管理

科技馆是弘扬科学精神,传播科学思想和科学方法,普及科学知识,提高公民科学素质的重要场所.随着科教兴国战略与《公民科学素质行动计划纲要》的颁布实施,目前全国科技馆建设事业蓬勃发展,科技馆的数量与规模不断壮大,科普展教活动不断创新,为推动社会科技进步与建设创新型国家做出了巨大贡献.本文以科技馆运营管理工作为切入点,通过对科技馆运营现状、运营管理目标与特点,以及科技馆运营管理措施建议等方面进行简要分析,以期能更好地充分发挥科技馆功能作用,推进科技馆的可持续发展.     

Nonlinear control of an antilock braking system in the presence of tire–road friction uncertainties

An Antilock Braking System (ABS) is characterized by nonlinear dynamics, which render more difficult the design of a controller for high performance. The problem is even harder due to the uncertainties on the parameters appearing in its dynamics. In this paper, an ABS laboratory setup is considered, which mimics a quarter car model. A super–twisting controller is proposed to overcome the problem due to parameter uncertainties. This controller is designed in order to impose a reference value of the tire slip. Two cases are considered: in the first, nominal ABS parameters are used in the controller, whereas in the second the controller embeds an estimator of the tire–road friction coefficient, which is one of most critical parameters. The friction coefficient is estimated in finite–time by means of a high–order sliding mode differentiator. The original contributions of the paper are the real–time implementation of the super–twisting controller for the laboratory setup under study, and the use of a super–twisting estimator to provide a finite–time estimation of the friction coefficient between the tire and the road, along with a comparison with classical PI–like and super–twisting controllers, available in the literature. The ABS laboratory setup allows checking experimentally the performance of the proposed nonlinear dynamic controller, showing a considerable increase of the efficiency of the control system.     

飞机起落架动力学仿真技术研究

在对某型飞机摇臂式起落架进行合理简化后,应用有限元软件Abaqus对其进行了有限元模型建模和动力学仿真分析,得到了轮胎与地面间的相互作用力。仿真分析结果与试验结果吻合得很好,表明研究方法正确,计算模型合理。     

Robust H∞ dynamic output-feedback control for four-wheel independently actuated electric ground vehicles through integrated AFS/DYC

This paper simultaneously addresses the parameter/state uncertainties, external disturbances, input saturations, and actuator faults in the handling and stability control for four-wheel independently actuated (FWIA) electric ground vehicles (EGVs). Considering the high cost of the available sensors for vehicle lateral velocity measurement, a robust H_∞ dynamic output-feedback controller is designed to control the vehicle motion without using the lateral velocity information. The investigated parameter/state uncertainties include the tire cornering stiffness, vehicle mass, and vehicle longitudinal velocity. The unmodeled terms in the vehicle lateral dynamics model are dealt as the external disturbances. Faults of the active steering system and in-wheel motors can cause dangerous consequences for driving, and are considered in the control design. Input saturation issues for the tire forces can deteriorate the control effects, and are handled by the proposed strategy. Integrated control with active front steering (AFS) and direct yaw moment (DYC) is adopted to control the vehicle yaw rate and sideslip angle simultaneously. Simulation results based on a high-fidelity and full-car model via CarSim-Simulink show the effectiveness of the proposed control approach.     

压裂泵阀箱失效研究

压裂泵是油气田上产增存的主要设备,但其液力端阀箱却经常早期失效。通过对现场使用的各型压裂泵阀箱的综合对比分析,对阀箱基体常见失效准则进行了归纳,开展了阀箱失效模式的研究。综合现场失效数据分析,认为疲劳开裂是阀箱最主要和最危险的失效模式。