非晶Mg65-xNi21Pr14Agx合金电极的制备及其放电性能

用铜模喷铸法制备了非晶Mg65-x Ni21-Pr14Ag x合金,采用球磨方法细化了合金颗粒。系统研究了不同Ag含量对非晶合金电极充放电行为、放电容量、循环稳定性、高倍率放电等性能的影响规律。结果表明,Ag元素的添加改善了合金电极充/放电性能,随着Ag含量的增加,非晶合金电极的最大放电容量和循环稳定性均呈现先增大后减小的规律,其高倍率放电性能也有所提高,适量Ag的添加可明显改善非晶MgNi-Pr系合金的放电性能。     

微油点火技术在火电厂的应用研究

对火电厂微油点火系统的工作原理、系统组成、点火流程进行了分析,阐述了微油点火系统应包括燃油系统、小油量气化油枪、压缩空气系统、高压风系统、电点火装置以及PLC控制系统等主要子系统的作用.为了确保锅炉点火安全,系统的火焰检测采用紫外光加红外光(UV/IR)双路检测,分三个阶段来实现.     

Influence of the build orientation on the fatigue strength of EOS maraging steel produced by additive metal machine

This paper presents a research dealing with the dependence of the fatigue strength of maraging steel parts, manufactured by direct selective laser sintering, on the production build orientation. Three sets of specimens have been manufactured according to the ISO 1143 Standard (2010) by EOSINT M280 additive manufacturing machine, with the following heat and mechanical treatments, in agreement with the recommendations by the material manufacturer and current literature. The expected outcomes are the Fatigue Limit values of the material and the maximum number of cycles observed at different stress levels for three different build orientations (three different angles, 0°, 45° and 90°, between the build direction and the longitudinal axis of the samples). The results have been processed and compared by statistical methods in order to determine the fatigue curves in the finite life domain and the fatigue limits, along with their confidence bands and intervals, and to investigate the significance of the build orientation factor.     

An approach to conceptual and embodiment design within a new product development lifecycle framework

The design of new innovative products is the result of an accurate and precise management of knowledge sources all over its life cycle, such as technology, market, competitors and suppliers. The work contributes with a framework that shows how the knowledge sources influence in the state-of-the-art and market needs so that they become opportunities for innovating products addressing the whole product life cycle. It provides a systematic path from the early generation of ideas to the production of a new product proposal. Through a deep analysis of previous research works of new product innovation life cycle development frameworks and linking it with knowledge management, strategic planning and scorecards, we came out with a structured contribution. The result considers the concurrent activities and its relationships all the way through the product life cycle that can help in creativity and innovation, combined with a process management proposal. Managing the sources of knowledge in highly dynamic markets and technologies is one of the major difficulties involved in innovative products design and development. The emerging knowledge from external sources is confronted with organisation internal knowledge and experience in order to achieve the first product correct.     

正交法探讨均相碱催化制备生物柴油的优化条件

以菜籽油为原料,甲醇钠为催化剂,二异丙醚为共溶剂,通过酯交换法制取生物柴油,并考察了醇油摩尔比、催化剂用量、共溶剂用量、反应时间和温度对生物柴油产率的影响.通过正交试验得出菜籽油与甲醇酯交换反应的最优条件为:醇油比为6:1,甲醇钠催化剂用量为油重的1.2%,共溶剂与油的摩尔比为1.2 :1,反应温度60℃,反应时间80min,低速120r/min搅拌强度下,转化率达到96.45%.制得的生物柴油各理化指标均符合美国和德国生物柴油测试标准.     

两种复合软管生产过程的环境影响评价

目的分别研究用于牙膏包装铝塑复合软管和全塑复合软管的4个生产单元对环境的影响,为此类型包装材料对环境影响的评估以及工艺改进提供参考。方法采用生命周期评价方法定性定量地分析其对能耗和环境的影响,通过eFootprint软件,在线完成全生命周期评价,包括建模、计算分析和数据质量评估。结果2种产品对初级能源消耗、气候变化和生态毒性的影响较大,其主要影响均来自复合空白带的生产,以及盖子、管肩和内衬的注塑成型。每个铝塑复合软管和全塑复合软管分别消耗2.53,2.18 MJ的初级能源,排放123,70.5 g影响气候变化的气体,释放0.012,0.005生态毒性物质。结论在所研究的系统边界内,铝塑复合软管对能源的消耗和对环境的影响均比全塑复合软管高。     

盐冻循环条件下SBS改性沥青砂浆的力学性能分析?

在寒冷地区,冬季路面极易出现积雪结冰现象,常使用融雪盐对路面进行融雪除冰,融雪盐的使用会对沥青混合料产生侵蚀。沥青砂浆作为沥青混凝土材料的重要组成部分,在力学性能方面发挥了极其重要的作用。对 SBS 改性沥青盐冻循环前后的三大指标(针入度、软化点和延度)进行了测试,对经历不同盐冻循环的沥青砂浆试件进行单轴压缩蠕变实验,并通过扫描电镜(SEM)研究其微观结构的变化。结果表明,冻融循环和荷载应力会造成沥青砂浆力学性能的下降,因此在昼夜温差较大的北方寒冷地区的冬季应尽量限制重载车辆的通行量以及融雪盐的用量,以减少对路面结构的损坏。     

Introduction of mechanistic-empirical pavement design into pavement carbon footprint analysis

Transportation authorities and industrial organisations are currently faced with the need to incorporate greenhouse gas (GHG) impacts into pavement designs. GHG emissions have been evaluated for individual projects with unique external environments. These estimates cannot be applied to future projects with different external environments. This paper presents a GHG estimation method to assist in low-carbon design for future pavement construction. The method uses mechanistic-empirical pavement design guide to create comparable structures with different pavement techniques, traffic volumes, climate conditions, etc. The method is illustrated using the Maryland Intercounty Connector (ICC) project, which was paved with hot mix asphalt. The results show that if the ICC’s asphalt base layer was paved with foam stabilised base, GHG emissions would be reduced by up to 18.8 thousand metric tons, an equivalent to 56.5% of the total pavement construction emissions. The GHG savings would generate $111,200 of carbon offsets, which compensate approximately 5.7% of the pavement costs.     

自振空化射流研究与应用进展

介绍一种新型射流——自振空化射流的设计原理、冲击压力特性、冲蚀破岩特性和现场应用情况。研究表明，以风琴管结构为基础设计的喷嘴可以产生强烈的自振空化射流，与锥角为 120°的普通锥形喷嘴相比，冲击压力脉动幅度和峰值分别提高24 ％和37 ％，冲蚀岩石效果提高1～2倍。自振空化射流已成功应用到石油工程中，研制出自振空化射流钻头、高压旋转自振空化射流处理近地层技术和自激波动注水技术，取得明显的经济效益。     

Experimental and numerical characterization of low cycle fatigue and creep fatigue behaviour of P92 steel welded joint

Low cycle fatigue (LCF) and creep fatigue interaction (CFI) behaviour of P92 steel welded joint were investigated experimentally and numerically. Strain‐controlled LCF tests at different strain amplitudes and CFI tests at different peak strain holding time were conducted. Evolutions of cyclic stress response, mean stress, and creep strain during cycling were described, in which the influence of strain amplitude and holding time were investigated. A specific heat treatment process was proposed to get the homogenous simulated material of fine grain region and coarse grain region in the heat affected zone. Material parameters of parent material, fine grain heat affected zone, coarse grain heat affected zone, and weld metal in the unified viscoplasticity model were then determined and validated. To predict the LCF and CFI behaviour of welded joint, 3‐dimensional unified viscoplasticity model with a modified isotropic variable was compiled into ABAQUS UMAT. The comparison between the predicted and experimental result under LCF and CFI loadings showed that the simulation results were reasonable and agreed with the experimental data well.