Inhibition of stress corrosion cracking in 304 stainless steel through titanium ion implantation

The effects of titanium ion implantation on the stress corrosion cracking (SCC) behaviour of 304 austenitic stainless steel were studied. Slow strain rate tests (SSRTs) were conducted on 304 steel in air and in 5?wt-% NaCl solution. The microscopic effects of ion implantation were evaluated by Stopping and Range of Ions in Matter Procedures (SRIM). Fracture morphologies and microstructures were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The fracture surfaces illustrate that ion implantation significantly inhibits the corrosion pits that initiate SCC. A dense passive film, which inhibits SCC, was formed during the ion implantation process. SCC initiation was restrained due to the dense dislocation nets that were generated by titanium ion implantation.

Highlights

• Ion implantation inhibits SCC susceptibility.

• The lack of Cr at the grain boundary leads to the expansion of SCC along the grain boundary.

• Implantation-induced damage leads to high-density dislocations.

• The surface was amorphised due to high-density dislocations.

     

N~＋注入诱变选育纤维素酶高产菌株及发酵产酶营养因子优化研究

应用低能氮离子（N＋）注入技术对纤维素酶产生菌里氏木霉（Trichoderma reesei）进行诱变选育,在能量为10 keV,注量为150×10^14和200×10^14N＋/cm^2的条件下分别筛选得到3株纤维素酶高产菌株,连续5代遗传稳定性实验结果表明,所得到的高产菌株遗传稳定性较好,羧甲基纤维素酶活力均提高到3.300 IU/mL以上,较出发菌株（2.698 IU/mL）提高了20.0%以上。采用Plackett-Burman实验设计法和旋转中心组合设计法系统地研究高产菌株150-1-1发酵营养因子组成,得到了纤维素酶产量随葡萄糖、麸皮和微晶纤维素等营养因子的变化规律及相应的响应面分析图。实验结果表明,葡萄糖、麸皮和微晶纤维素浓度与纤维素酶活存在显著的相关性,当葡萄糖浓度为4.9 g/L,麸皮浓度为23.0 g/L,微晶纤维素浓度为7.7 g/L时,150-1-1纤维素酶滤纸酶活力达到2.439 IU/mL,较优化前（2.000 IU/mL）提高了22.0%。     

Nitrogen removal from eutrophic water by floating-bed-grown water spinach (Ipomoea aquatica Forsk.) with ion implantation

The aim of this study was to investigate the use of water spinach (Ipomoea aquatica Forsk.) with N(+) ion-beam implantation for removal of nutrient species from eutrophic water. The mutated water spinach was grown on floating beds, and growth chambers were used to examine the growth of three cultivars of water spinach with ion implantation for 14 days in simulated eutrophic water at both high and low nitrogen levels. The specific weight growth rates of three cultivars of water spinach with ion implantation were significantly higher than the control, and their NO(3)-N and NH(4)-N removal efficiencies were also greater than those of the control. Furthermore, compared with the control, the nitrogen contents in the plant biomass with ion implantation were higher as well.     

“八合一”理念下城市滨水空间营造的 六个维度

上海自2002年启动黄浦江两岸综合开发后,于2014年底提出《黄浦江两岸地区公共空间建设三年行动计划》,作为其中杨浦滨江南段公共空间的总设计师团队,深度介入了上海城市滨水空间的复兴。依托实践提出“八合一”理念,即城市设计、建筑设计、景观设计、市政设计、水工设计、生态修复、智能设计和艺术设计协同合作;并在突破学科壁垒的基础之上,构建包含系统化空间营造、历史文脉延续、基础设施复合、场景节点构筑、生态环境修复和公共艺术植入的六维城市滨水空间再生体系。     

Wearing and Corrosion Resistance of TAMZ Alloy Implanted by Carbon Ion in Hank’s Body Fluid

人体模拟体液Hank’s溶液中对碳离子注入TAMZ合金的耐蚀耐磨行为进行研究。结果表明,碳离子注入TAMZ合金表面形成含碳量1.07%的均匀改性层,碳离子注入层厚度达9 μm。碳离子注入后,TAMZ表面形成无序层膜,经XRD分析主要由TiC和Ti组成。Hank’s溶液中电化学测试结果表明,注入碳离子的TAMZ合金腐蚀电位升高、电荷转移电阻增大,阳极极化电流密度降低,改善了电化学性能。其原因归结于碳离子注入后碳化物的无序层膜的形成阻滞了合金元素的溶解,提高了膜层的耐蚀性能。Hank’s溶液中注入碳离子的TAMZ合金的摩擦系数和比磨损率均明显小于基体TAMZ合金,硬度提高;而且经摩擦的碳离子注入TAMZ合金比基体TAMZ合金的阳极极化电流密度小、电荷转移电阻大,表明碳离子注入改性层在人体模拟液环境中具有优良的耐磨、耐蚀性能     

探析日本现代建筑对传统文化的吸纳和表达

日本现代建筑设计尊重文化,在此基础上又具备创新精神。文化在变迁发展中与设计息息相关,日本现代建筑的转译和隐喻恰能将其体现。文章通过对日本文化的介绍,并在对日本现代建筑特征进行概括的基础上,总结日本现代建筑对传统文化的吸纳和表达。     

The enhanced anticoagulation for graphene induced by COOH+ ion implantation

Graphene may have attractive properties for some biomedical applications, but its potential adverse biological effects, in particular, possible modulation when it comes in contact with blood, require further investigation. Little is known about the influence of exposure to COOH⁺-implanted graphene (COOH⁺/graphene) interacting with red blood cells and platelets. In this paper, COOH⁺/graphene was prepared by modified Hummers'' method and implanted by COOH⁺ ions. The structure and surface chemical and physical properties of COOH⁺/graphene were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and contact angle measurement. Systematic evaluation of anticoagulation, including in vitro platelet adhesion assays and hemolytic assays, proved that COOH⁺/graphene has significant anticoagulation. In addition, at the dose of 5 × 10¹⁷ ions/cm², COOH⁺/graphene responded best on platelet adhesion, aggregation, and platelet activation.     

Advances in ion beam modification of semiconductors

This review provides an overview of the current status of ion-implantation research in silicon, germanium and the compound semiconductors SiC, GaN and ZnO. The discussion of silicon includes recent developments in metrology and device simulation, as well as a brief discussion of emerging applications in photovoltaics and quantum electronics. That of Ge includes a more detailed overview of doping, radiation damage and annealing processes due to the renewed research interest in this material. Finally, the discussion of compound semiconductors focuses on the newer wide bandgap materials where there are remaining implantation issues to be solved and potentially new implantation applications emerging.     

Progress and applications of cluster ion beam technology

Cluster ion beam processing has been extensively developed during the 25 years since the concept originated. Low energy surface interaction effects, lateral sputtering phenomena and high-rate chemical reaction effects have been explored experimentally and have been explained by means of molecular dynamics (MD) modeling. Practical production equipment for a wide range of applications has also been successfully developed. The technology is now advancing rapidly in the fields of sub-nanoscale processing of metals, semiconductors and insulating materials. This paper reviews important events which have taken place during the development with emphasis placed on emerging new advances which have occurred during several recent years.