FORMATION OF PRECIPITATED AUSTENITE IN 9%Ni STEEL AND ITS PERFORMANCE AT CRYOGENIC TEMPERATURE

The formation of precipitated austenite in 9% Ni steel exposed at the temperature of α+γ re-gion and its influence on impact tonghness at cryogenic temperature have been studied.Austenite-rich and ferrite-rich bands are formed during soaking because of the re-distribu-tion of elements of C,N and Ni.The former phase is enriched of Ni,Mn,C and N,while thelatter one is relatively pure.Part of the austenite formed at intermediate temperatures trans-forms into martensite when the steel is cooled down to room temperature.The complex struc-ture which consists of fine martensite and austenite exhibits a moderate strength and highenough cryogenic toughness.The austenite enriched of C,N and Ni is still stable at thecryogenic temperature.The tearing ridges on the impact fracture surface is densely occupiedby the precipitated austenite,elongated along the tearing direction.One of the importantcause of the excellent eryogenic properties is that the precipitated austenite absorbs theimpurities and thus purifies the matrix of the steel.     

EFFECT OF δ-Fe CONTENTS ON HYDROGEN EMBRITTLEMET SUSCEPTIBILITY FOR AUSTENITIC Fe-Cr-Ni-Mn-N STEELS

采用高压气相充氢后进行缺口试样拉伸试验的方法,证实了δ铁素体含量的增加显著提高Fe-Cr-Ni-Mn-N系奥氏体不锈钢的氢脆敏感性.     

配电网柔性开关设备关键技术及其发展趋势

柔性开关设备(soft open point,SOP)是一种可在配电网若干关键节点上替代传统联络开关的新型柔性一次设备。随着柔性开关设备的引入,有助于提高配电网运行的安全性、灵活性与可靠性,推动未来配电网形态的改变。文中简要阐述了柔性开关设备的基本原理,对柔性开关设备与传统配电灵活交流输电(distribution flexible AC transmission system,DFACTS)设备进行比较分析。结合柔性开关设备的结构、原理与功能,重点围绕背靠背柔性开关设备梳理了拓扑结构、运行优化、控制保护以及系统接入方面的关键技术。结合现有的工程实践与示范应用,对柔性开关设备装置研发、调控技术、接入模式方面的发展趋势进行了展望。     

世界大变局中的城市定位与产业转型

与发达国家相比,我国城市发展受长期行政分割和管理体制束缚的影响,城市间的不协调发展现象大量存在,主要表现在区域内大量基础设施重复建设、产业结构趋同性高、整体国际竞争力缺乏培育这三方面。城市产业转型是一个长期复杂的过程,面对全球经济的复杂形势和资源环境约束日渐趋紧的严峻局面,更需要政府、城市、企业等主体的大力支持和协调配合,因此再造城市产业竞争优势、创新区域间竞争合作机制、建立培育中小企业孵化器、完善城市治理结构和制度这四条途径是我国转型期的积极应对路径。     

FeS@onion-like carbon nanocapsules embedded in amorphous carbon for the lithium ion batteries with excellent cycling stability

The development of lithium ion battery with long-term cycle stability is considered to be a prerequisite for commercialization. Onion-like carbon coated FeS nanocapsules embedded in amorphous carbon (FeS@OLC/a-C) is designed and one-step developed via discharging the Fe-C composite ingot under the atmosphere of Ar and H₂S. In FeS@OLC/a-C nanocomposites, ~ 8.9?nm FeS@OLC nanocapsules with an average onion-like shell of 2?nm are covered by the amorphous carbon. The formation mechanism has been proposed for FeS@OLC/a-C nanocomposites. As the lithium ion battery anode candidate, FeS@OLC/a-C nanocomposite electrode have the advantages of good cycling stability (719.2 mAh g^?1 after being cycled at 0.1?A?g^?1 for 200 times) and excellent high-rate performances (569.3 mAh g^?1 for 2?A?g^?1, 540.9 mAh g^?1 for 4?A?g^?1, 466.6 mAh g^?1 for 8?A?g^?1 and 340.0 mAh g^?1 for 16?A?g^?1), which originates from the combined effect of small FeS nanoparticles, the onion-like carbon layers and amorphous carbon. The design idea in this paper provides a new approach for improving the cycling stability and rate capability of lithium ion battery.     

Thermal shrinkage of fabrics used for out layer of firefighter protective clothing under flash fire

The thermal shrinkage of the firefighter protective clothing can greatly affect its thermal protective performance. In this study, a novel and systematic approach to measure the thermal shrinkage of fabrics used for the firefighter protective clothing is presented. The study was limited to fabrics that are used for the outer layer of fire fighter clothing. A total of six different fabrics were tested. They were exposed to a short duration simulation of a structural fire using a Thermal Protection Performance tester. The exposed fabrics were then scanned with a hand‐held laser scanner for their 3D surface appearance. Software named Geomagic Studio was used to deal with the point clouds of the fabric images. Another software package named ArcGis, which was normally used in geological studies, was then used to analyze the heights and slope angles of the tags and crests of the burned fabrics. The results showed that for the fabrics tested the thicker and heavier the fabric, the smaller was the thermal shrinkage. Copyright © 2014 John Wiley & Sons, Ltd.     

碳纤维布加固混凝土结构在改造工程中的应用

介绍了碳纤维布在实际结构改造加固中的应用,对其加固原理、计算方法和施工要点进行了论述。     

Development of a humanoid robot for underwater use

In this research, we have developed a swimming robot with a fluttering kick with two legs, which can swim freely both on the surface of water and under water. We have established a control method for all the different types of motion of this robot, e.g., swimming in a straight line, turning, diving, or rising up in the water. Furthermore, by optimizing the three-dimensional action of this underwater robot, we can expect an improvement in its performance for complex work.     

“Nummite”的宝石学特征研究

"Nuummite"以宝石的身份出现在临近中国的泰国珠宝市场上,但是作为国内空白的研究项目,国内在暂时没有任何关于"Nuummite"的可靠实验数据和资料。所以笔者通过对外国针对此类宝石或此类宝石产地的研究性论文进行分析研究,并红外光谱和常规检测手段对宝石进行有损和无损的测试,对宝石的宝石学特征和矿物学特征进行分析研究,以得出"Nuummite"的基本性质、结构和构造的详细结果。为国内的宝石学类书籍,如系统宝石学等科研型书记提供可信,可靠的数据资料和研讨方向。"Nuummite"有较为明显的特征红外光谱谱图,在(400~1200cm)-1的范围内,主要有两个主要的双峰吸收峰,三个较低的吸收峰,两个阶梯状吸收峰,还有一个平缓的宽吸收带。可以作为以后研究"Nuummite"的红外光谱特征谱图的重要资料。     

氯化镁溶液氨气鼓泡反应制备纳米氢氧化镁

引言 氢氧化镁(magnesium hydroxide,MH)具有分解温度较高、热稳定性好、无毒、无烟及抑烟等特点,适合作为无机添加型阻燃剂,国外已有六十余年的研究与生产历史[1].MH也是制备高纯MgO的主要原料[2-5],同时作为酸性废水的中和剂、重金属废水的吸附剂及烟气脱硫剂,在绿色环保领域应用广泛.