DP800高强钢板的点焊工艺性能研究

对800MPa级国产双相钢板（DP800）进行了电阻点焊工艺研究,并对点焊部位进行金相分析、显微硬度分析、剪切试验及扫描断口分析。双相钢板点焊接头的断裂方式以韧性断裂为主;最佳工艺参数为焊接电流11000A、焊接时间30周波、焊接压力0．25MPa。     

基于模糊层次分析方法大型桥梁工程项目风险评估

大型桥梁工程规划、施工、运营期间面临众多不确定性因素影响,初步对工程项目进行风险识别,构建大型桥梁工程项目的风险评价指标体系,在传统层次分析法中引入模糊数学理论,建立了桥梁工程项目风险模糊层次分析模型,并将此模型在一座特大桥项目中运用,验证了这种风险评估方法的有效性和实用性。     

A new approach of intelligent design and optimization for shell nosing

Preform design for shell nosing product without machining the inner surface after forming is an experience-extensive work. Generally, the initial design needs to be modified and simulated consequently to get proper preform and nosing die, and the iterative process is time consuming. This paper puts forward a new approach, in which the suitable initial design can be obtained by knowledge-based intelligent technology and the optimal design can be acquired by finite element method (FEM) based geometrical modification. With the CAX object model as the bridge of CAD and CAE, the CAD model with simulation knowledge can be transferred into CAE automatically, and the CAE result can be automatically utilized as well. Based on the comparison between the simulated shape and the desired shape, the dissatisfactory area will be modified. A new simulation and modification process will be carried out based on the modified design. The process is repeated iteratively to get the optimal design. This approach utilizes the commercial CAD and CAE software, without the need of complex back-forward FEM procedures. Based on the new approach, an in-home intelligent shell nosing design and optimization system is developed, and a case study proves that this system can reach a reasonable design efficiently.     

Evolving mechanism of eutectic carbide in as-cast AISI M2 high-speed steel at elevated temperature

AbstractThe evolution in type,size and shape of carbides in as-cast American Iron and Steel Institute(AISI) M2 high-speed steel before and after annealing were investigated.The micromechanism which was responsible for those changes was also analyzed and discussed.At the initial stage of reheating,metastable M2C-type carbide decomposed continuously.M6C-type carbide nucleated at the interface of M2C/γfirstly and grow from surface to center.Then MC-type carbide nucleated at both surface of M6C/M6C and inner of M6C.With the increasing decomposition of the metastable M2C-type carbide,the rod-shaped construction of eutectic carbide began necking,fracturing and spheroidizing gradually.Held enough time or reheated at higher temperature,particle-shaped product aggregated and grew up apparently,while secondary carbide precipitated in cell and grew up less sig- nificantly than the former.Based on the above microstructural observation,the thermodynamic mechanism for decomposition of M2C carbide,for spheroidization of products,and for the growth of particles were analyzed.The rate equations of carbides evolution were derived,too.It shows that the evolving rate is controlled by diffusion coefficients of alloy atoms,morphology of eutectic carbides and heating temperature.     

Cooperative threat assessment of multi-aircrafts based on synthetic fuzzy cognitive map

Threat assessment is one of the most important parts of the tactical decisions, and it has a very important influence on task allocation. An application of fuzzy cognitive map (FCM) for target threat assessment in the air combat is introduced. Considering the fact that the aircrafts participated in the cooperation may not have the same threat assessment mechanism, two different FCM models are established. Using the method of combination, the model of cooperative threat assessment in air combat of multi-aircrafts is established. Simulation results show preliminarily that the method is reasonable and effective. Using FCM for threat assessment is feasible.     

一种船用LNG发动机动态负载响应特性的优化方法

为了优化LNG发动机动态响应性能，本文提出了一种并联调峰方案，利用并联调峰装置来进行负载响应特性的优化。并联调峰装置由电池功率变换器和锂电池组等组成，能实现能量的双向流动，可以根据负载的变化，很好的对电网进行补偿，平衡外部负载变化引起的系统能量波动。     

公路水运工程试验检测大数据平台设计与应用

通过分析公路水运工程试验检测业务管理现状，设计并研发“公路水运试验检测大数据平台”,解决了数据汇集、存储和接入问题，完成了基于数据标准和业务标准的试验检测大数据仓库建设，实现了检测流程和检测值结果静态数据的常规一阶矩和二阶矩分布统计，初步解决了行业多级权限管理、报告质量监管、多维数据统计和跨域数据分析的问题，为报告质量监督、原材厂家优选、工程质量把控提供有力的数据支撑。     

绿色低碳理念下城市次支路网建设规划思考

西安市道路网规模从“增量时代”进入了“增量”与“存量”并重的时代，交通拥堵和环境污染问题日益突出，需要遵循绿色低碳理念进行城市路网建设规划，以降低交通拥堵和环境污染带来的影响。通过对现状城市路网进行调查，分析总结了路网存在的主要问题，提出了路网建设规划的目标、策略以及要求，以提升路网运行效率，降低碳排放，增强城市交通可持续发展，建设更有韧性的宜居城市。