定向凝固NiAl多相合金的高温超塑性研究

本文研究了Ni-30Al-5Mo-0.5Hf金属间化合物的显微组织及其超塑性变形行为.该合金是由NiAl/Ni3Al/Mo三相组成,在NiAl中分散着大量的条状Ni3Al.在1050-1100℃,应变速率为5.2X10-4-6.24X10-3s-1拉伸变形时,合金呈现超塑性行为;1050℃,5.2X10-4s-1时的最大延伸率达160％,此时对应的应变速率敏感指数为0.46.超塑性变形的机理主要是由于变形过程中的动态回复和再结晶,同时合金中的NiAl和Ni3Al两相在高温下可以协调变形.     

OXIDATION BEHAVIOUR OF HIGH Cr CAST IRON

The oxidation behaviour of high Cr Cast iron was investigated at 950 and 800℃ in termsof Cr content in matrix and the amount of carbide.The morphology and types of oxidefilms and the microstructure of subsurface were also examined.The main conclusionsare:1)The original chromium content in the matrix determines the type of oxide filmand it is an important factor for the oxidation resistance of high chromium cast iron;2)The oxidation resistance improves with increasing carbide content at 950℃ because ofthe decomposition of the carbide,while the decompsition of the carbide do not take placeat 800℃ so the oxidation resisteance do not improve with increasing carbide volume.     

黄铜表面多层化学转化膜特性研究

黄铜经苯并三氮唑(BTA)和络合钝化剂PVA溶液钝化处理后,表面耐蚀性明显提高,椭圆偏振法和X射线光电子能谱法(XPS)研究表明,PVA能在Cu(I)BAT薄膜上继续外延生长成膜,BTA—PVA混合液钝化处理效果与先用BTA、后用PVA溶液钝化处理效果基本相同、钝化处理后的化学转化膜大体上为三层结构,即Cu_2O/Cu(I)BTA/PVA膜     

中国钢铁业发展与评估

分析了世界钢铁业的发展态势，归纳了20世纪90年代中国钢铁工业取得的重大成就，讨论了中国钢铁工业的定位与钢铁产品的需求量及钢铁材料的价格走势。回顾归纳了钢铁生产工艺流程的发展进程，分析和展望了钢铁企业的模式，规模与企业集团化的方向，提出要积极定位钢铁企业的社会／经济角色，并对未来5－10年内中国钢铁业的发展战略重点提出如下建议：技术路线方面：全面推进节能－清洁生产技术，确立完善的清洁生产工艺流程，从源头上协调解决成本、质量、劳动生产率、 环境等问题。－调整产品结构方面：重点投资增加扁平材的产能以及对几个特殊钢厂进行生产流程集成化改造，以解决高质量合金钢品种问题；－改革方面：积极、分步地形成集团化企业，确立区域市场优势，在集团化体制下进一步优化企业结构、提高市场竞争力。     

含Mn的TiAl基合金的组织和性能SCIEI

Ti-33wt-％Al-(1.6—4.5)wt-％Mn合金是一种γ+α_2两相合金,但α_2相的分数很少。由于Mn原子比Ti和Al原子半径都小,加入Mn使γ相晶格的α和c轴都减小,并使c/α更接近于1。Mn促进了γ相中孪晶的形成,并提高了TiAl基合金室温塑性变形的能力。     

Effect of the Presence of Ceria in the NSR Catalyst on the Hydrothermal Resistance and Global DeNOx Performance of Coupled LNT–SCR Systems

The global performance of coupled LNT–SCR systems, addressed to high NOx-to-N₂ conversion, minimal ammonia slip and null N₂O production, as well as the hydrothermal resistance of single NSR and SCR monolith catalysts and their coupling is discussed. Pt–Ba/Al₂O₃ and Pt–Ce–Ba/Al₂O₃ were washcoated on cordierite monoliths as NSR catalysts, and Cu/CHA was washcoated on similar monoliths as SCR catalysts. Both monoliths were coupled in two subsequent reactors to conform the LNT–SCR system. Previously to washcoating, the fresh powder catalysts and after severe hydrothermal aging were fully characterized by N₂ adsorption–desorption isotherms at 77 K, X-ray diffraction, NH₃ temperature-programmed desorption, and H₂ chemisorption to relate textural and chemical characteristics with the DeNO_x performance. The Cu/CHA catalyst shows an excellent hydrothermal resistance for the NH₃–SCR reaction. Incorporation of ceria to the model Pt–BaO/Al₂O₃is beneficial for the NO-to-NOx oxidation and NO₂ storage, improving NO conversion at low temperature and reducing the NH₃ slip. However, addition of ceria is detrimental for the hydrothermal resistance of the NSR catalyst. However, this detrimental effect is minimized when the NSR catalyst is coupled with the Cu/CHA monolith downstream of the NSR catalyst, achieving the coupled LNT–SCR device high NO conversion and minimal NH₃ slip with superior N₂ selectivity for an extended temperature windows, including as low as 220 °C, and maintaining performance even after severe hydrothermal aging.     

Determination of isoflavones in commercial soy products by HPLC and coulometric electrode array detection

The concentrations of the isoflavones daidzein, genistein and glycitein were determined in a large number of commercially-available soy products by high-performance liquid chromatography with coulometric electrode array detection using estriol as internal standard.During extraction, the naturally occurring glycosides were converted into their respective aglycones by acid hydrolysis. The analytes were separated on a C-18 reversed phase column, eluted with methanol/acetonitrile/50 mM sodium acetate pH 4.8 (40/5/55, v/v/v), and detected by a coulometric electrode array detector using twelve electrodes set to potentials between +250 and +800 mV (in increments of 50 mV) against palladium reference electrodes.The isoflavones could be determined over a wide concentration range (0.8–1135.0 mg/kg for daidzein, 1.9–1442.5 mg/kg for genistein and 0.5–154.6 mg/kg for glycitein). The recovery of the isoflavones in the different matrices was determined by the standard addition method and varied between 40.9–94.4%. The detection limits (S/N=3) depend on the matrix of the soy product and were found for daidzein between 0.3–1.6 mg/kg, for genistein between 0.3–1.7 mg/kg and for glycitein between 0.5–2.3 mg/kg.     

Galton 2011 revisited: a bibliometric journey in the footprints of a universal genius

Commemorating the 100th death anniversary of Francis Galton, this paper is a bibliometric impact analysis of the works of this outstanding scientist and predecessor of scientometrics. Citation analysis was done in Web of Science, Scopus and Google Scholar (Publish or Perish) in order to retrieve the most cited books and journal articles. Additionally references were identified where Galton was rather mentioned than cited in order to analyze the phenomenon of obliteration by incorporation. Finally occurrence counts of Galton’s works in obituaries, Festschrift, the website Galton.org, major encyclopaedias and biographical indexes were compared to citation counts. As an outcome Galton’s works are increasingly cited or mentioned. Obliteration (use of eponyms) applies to one-third of Galton’s works and seems to be typical for fields like mathematics or statistics, whereas citations are more common in psychology. The most cited books and journal articles are also the most mentioned with remarkable correlation. Overall citation analysis and occurrence counting are complementary useful methods for the impact analysis of the works of “giants”.