The efficiency of activating fluxes in manual argon‐arc welding

The results of development of a Mo–Ni layered composition, based on OT4 titanium alloys, using the ecologically efficient magnetron methods, are presented. The mechanism of formation of the joint in the OT4–Mo contact pair in the coating deposition stage are described. It is shown that in the thermal conditions of brazing the layer composition (850°C) mutual diffusion penetration of the material takes place ensuring the high quality of bonding in the OT4–Mo and Mo–Ni contact pairs.     

A workload balancing genetic algorithm for the quay crane scheduling problem

This paper proposes a novel genetic algorithm to deal with the quay crane scheduling problem (QCSP), which is known to be one of the most critical tasks in terminal operations because its efficiency and the quality of the schedule directly influence the productivity of the terminal. QCSP has been studied intensively in recent years. Algorithms in this field are concerned in the solution quality obtained and the required computational time. As QCSP is known to be NP-hard, heuristic approaches are widely adopted. The genetic algorithm proposed is constructed with a novel workload balancing heuristics, which is capable of considering the loading conditions of different quay cranes (QCs) during the reassignment of task-to-QC. The idea is modelled as a fuzzy logic controller to guide the mutation rate and mutation mechanism of the genetic algorithm. As a result, the proposed algorithm does not require any predefined mutation rate. Meanwhile, the genetic algorithm can more adequately reassign tasks to QCs according to the QCs’ loading condition throughout the evolution. The proposed algorithm has been tested with the well-known benchmark problem sets in this field and produces some new best solutions in a much shorter computational time.     

Yard planning for vessel services with a cyclical calling pattern

In a land-scarce container terminal, congestions in the terminal yard due to highly concentrated workload often lead to unsatisfactory terminal productivity. Currently, yard planners use their experience to design a yard template for determining the storage locations of export containers to be loaded onto vessels deployed to services with a cyclical calling pattern. This article studies the problem of designing a yard template that balances the workload in an export yard. The template design problem is formulated as an integer program. It is found that the computational time required to optimally solve realistic sizes of the template design problem is unacceptably long. This article proposes a simpler integer program as an approximate model. On the basis of the analysis on the approximate model, a heuristic is developed to solve the template design problem. Results of computational experiments show that the heuristic can find effective solutions for the template design problem.     

Scheduling operations of a rail crane and container deliveries between rail and port terminals

This article addresses the problem of scheduling container transfer operations in rail terminals. The overall problem can be divided into three smaller problems: constructing a dual-cycle delivery task by matching inbound and outbound containers; determining parking positions for trucks; and sequencing the delivery tasks for transfer by the rail crane. This article provides a mathematical model to obtain the optimal solutions to these problems, and suggests genetic and heuristic algorithms to reduce computational time when solving larger problems. Numerical experiments are conducted to validate the performance of the suggested heuristic algorithms.     

Processing of N-terminal unnatural amino acids in recombinant human interferon-beta in Escherichia coli

Incorporation of unnatural amino acids into recombinant proteins represents a powerful tool for protein engineering and protein therapeutic development. While the processing of the N-terminal methionine (Met) residues in proteins is well studied, the processing of unnatural amino acids used for replacing the N-terminal Met remains largely unknown. Here we report the effects of the penultimate residue (the residue after the initiator Met) on the processing of two unnatural amino acids, L-azidohomoalanine (AHA) and L-homopropargylglycine (HPG), at the N terminus of recombinant human interferon-beta in E. coli. We have identified specific amino acids at the penultimate position that can be used to efficiently retain or remove N-terminal AHA or HPG. Retention of N-terminal AHA or HPG can be achieved by choosing amino acids with large side chains (such as Gln, Glu, and His) at the penultimate position, while Ala can be selected for the removal of N-terminal AHA or HPG. Incomplete processing of N-terminal AHA and HPG (in terms of both deformylation and cleavage) was observed with Gly or Ser at the penultimate position.     

基于嵌入式以太网的变电站基层网络构建

本文介绍了一种利用变电站的智能终端集成嵌入式以太网.各智能终端再通过集线器与上层网络通讯的局域网组网方法。以此完成了间隔层和站控层之间的实时通信任务.从而实现了整个变电站工业控制网络与因特网之间的信息无缝连接。     

绿色机场航站楼节能设计

结合机场能耗分析,以电能节约为重点目标,以被动式节能设计方法,在整体上规划机场场地,使机场通过适应场地自然环境达到节能,在建筑单体上突出对航站楼进行节能设计;用主动式节能方法重点探讨了机场空调和照明的节能,并且介绍了智能控制的应用和太阳能在机场运用的现状和前景.     

基于无线传感器网络的RFID系统

采用无线传感网络ZigBee的树型组网方式代替传统的RFID网络系统,不仅能降低RFID系统的成本,而且能使RIFD组网更加灵活,省去了传统RFID系统繁琐的布线,提高了系统实用性和可靠性。系统由管理服务器、网关节点、路由节点、RFID终端节点组成。采用低成本通信芯片CC2430和FM1702SL组成RFID终端节点,具有体积小、低成本、低功耗等特点,适合使用在识别距离比较短,数据传输比较远,网络比较繁杂应用场合,系统具有较强的实用性和灵活性。     

运用模态综合法的车桥自激激励耦合振动分析

针对车桥耦合振动影响自动化码头集装箱小车-低架桥结构安全和使用效率的问题,基于双协调自由界面模态综合法求解了车桥系统在轨道不平顺和轮对蛇形运动自激激励下的耦合振动时域响应,轨道不平顺时程通过Shinozuka一元多维平稳随机过程模拟法从轨道谱生成。用量纲分析法推导了结构动力模型相似条件,设计了试验模型,结合模型试验分析了铅芯橡胶支座、小车速度对车桥耦合振动响应的影响。模型试验与原型仿真结果相互验证表明:模态综合求解车桥耦合振动响应的仿真方法合理;使用铅芯橡胶支座可有效减小车桥加速度响应和支柱反力;车桥加速度响应随着小车速度的增大而增大,系统横向共振临界车速低于竖向车速,临界车速可由简支梁在移动集中力作用下车桥共振条件来估算。     

太原机场新技术应用示范工程的组织与实施

简要介绍了太原武宿国际机场航站楼工程概况及施工内容,着重阐述了该项目新技术应用示范工程的组织与实施情况,包括组织管理体系建设、新技术推广应用等内容及其相应措施,对今后同类项目施工管理具有指导意义。