Effects of rare earth on inclusions and corrosion resistance of 10PCuRE weathering steel

The types,morphologies and distributions of nonmetallic inclusions in Cu-P weathering steels with and without rare earth were analyzed through a quantitative image analyzer,scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS)attached to SEM.Solid-soluble content of rare earth in the steels was analyzed by non-aqua electroanalysis and ICP.The results showed that rare earth modified the types and the morphologies of inclusions in the weathering steels.The small spherical rare earth oxysulfides and rare earth sulphides replaced the elongated MnS inclusions in the RE weathering steels.The rare earth inclusions dispersedly distributed and most inclusions were smaller than 2 μm in size.The optimum content of RE was 0.0065%-0.016% for 10PCuRE weathering steels containing about0.002% oxygen and 0.004% sulfur.Solid-soluble content of rare earth in steels was(14-20)x 10-6,which can act as a micro-alloying element.The corrosion resistance of 10PCuRE weathering steels and Q235 were studied by dry-wet cyclic immersion test.Their corrosion rates were obtained respectively.The polarization curves and pitting corrosion behaviors of weathering steels with and without rare earth were measured by electrochemical methods.The corrosion resistance of Cu-P weathering steels was improved by adding an appropriate amount of rare earth.Less and fewer rare earth inclusions largely decreased pitting susceptibility and rate of pit propagation.The pitting potential and the resistance against pitting corrosion of the RE weathering steel were significantly improved due to the modification of rare earth to inclusions.     

Lanthanide NIR luminescence for telecommunications, bioanalyses and solar energy conversion

Present-day advanced technologies heavily rely on the exciting magnetic and spectroscopic properties of lanthanide ions. In particular, their ability to generate well-characterized and intense near-infrared (NIR) luminescence is exploited in any modern fiber-optic telecommunication network. In this feature article, we first summarize the whereabouts underlying the design of highly luminescent NIR molecular edifices and materials. We then focus on describing the main trends in three applications related to this spectral range: telecommunications, biosciences, and solar energy conversion. In telecommunications, efforts concentrate presently on getting easily processable polymer-based waveguide amplifiers. Upconversion nanophosphors emitting in the visible after NIR excitation are now ubiquitous in many bioanalyses while their application to bio-imaging is still in its early stages; however, highly sensitive NIR-NIR systems start to be at hand for both in vitro and in vivo imaging, as well as dual probes combining magnetic resonance and optical imaging. Finally, both silicon-based and dye-sensitized solar cells benefit from the downconversion and upconversion capabilities of lanthanide ions to harvest UV and NIR solar light and to boost the overall quantum efficiency of these next-generation devices.     

Evaluation of D113 cation exchange resin for the removal of Eu(Ⅲ) from aqueous solution

Batch adsorption experiments were conducted for the adsorption of Eu(Ⅲ) ions from aqueous solution by D113 resin. The results indicated that D113 resin could adsorb Eu(Ⅲ) ion effectively from aqueous solution. The adsorption was strongly dependent on pH of the medium with enhanced adsorption as the pH turned from 3.50 to 7.00 and the optimal adsorption condition was in HAc-NaAc medium with pH value of 6.50. The maximum uptake capacity of Eu(Ⅲ) ions was 290.9 mg/g D113 at 298 K, at an initial pH value of 6.50. The overall adsorption process was best described by Lagergren-first-order kinetics. When Freundlich and Langmuir isotherms were tested, the latter had a better fit with the experimental data. The thermodynamic parameters such as free energy (G) which were all negative, indicated that the adsorption of Eu(Ⅲ) ions onto D113 resin was spontaneous and the positive value of enthalpy (H) showed that the adsorption was endothermic in nature. Thomas model was applied to experimental column data to determine the characteristic parameters of column useful for process design. Furthermore, Eu(Ⅲ) could be eluted by using 3.0 mol/L HCl solution and the D113 resin could be regenerated and reused.     

Phase structure and temperature dependent luminescence properties of Sr2LiSiO4F: Eu2+ and Sr2MgSi2O7: Eu2+ phosphors

Green-emitting Sr2LiSiO4F:Eu2+ and blue-emitting Sr2MgSi2O7:Eu2+ phosphors were synthesized by the conventional high temperature solid-state route,respectively.Their structures and photoluminescenee properties were comparatively investigated.It was found that the mixture phases of Sr2MgSi2O7 and SrF2 were obtained when a part of Sr2+ in Sr2LiSiO4F was replaced by some amount of Mg2+ in order to design the possible SrMgLiSiO4F:Eu2+ phosphor.Based on the photoluminescence analysis,Sr2LiSiO4F:Eu2+ phosphor exhibited a green broad emission band of main peak at 513 nm under the excitation of 365 nm,while the Sr2MgSi2O7:Eu2+ and SrMgLiSiO4F:Eu2+ phosphor showed blue emission centered at 467 nm.The temperature dependent photoluminescence properties and room temperature decay time for the three kinds of phosphors were also discussed in this paper.     

Er3+-substituted W-type barium ferrite: preparation and electromagnetic properties

Er3+-substituted W-type barium ferrites Ba1-xErx(Zn0.3Co0.7)2Fe16O27(x=0.00,0.05,0.10,0.15,0.20)were synthesized by polymer adsorbent combustion method.Samples were characterized by X-ray diffraction analysis(XRD),X-ray fluorescence(XRF),scanning electron microscopy(SEM)and network analyzer to investigate the relationships among Er3+concentration,crystal structure,surface mcrphology and electromagnetic properties.All the XRD patterns showed pure phase of W-type barium ferrite when x≤0.15,while the impurity phase of ErFeO3 appeared when x=0.20.The pure W-type barium ferrite showed a hexagonal flake shape.In addition,the microwave electromagnetic properties of samples were analyzed in the frequency range of 2-18 GHz.It was indicated that the electromagnetic properties were significantly improved when Er3+doping content was 0.10.The reasons were also discussed using electromagnetic theory.The optimized ferrite exhibited excellent microwave absoption performance.The maximum of reflection loss(RL)reached about-27.4 dB and RL was below-10dB at the frequency range from 8.4 GHz to 18 GHz,when the thickness was 2.6 mm.     

EXAFS investigation and luminescent properties of nanosized Tb: Lu2O3 phosphors

Nanosized terbium doped Lu2O3 phosphors were synthesized via a modified co-precipitation processing.The as-prepared Tb:Lu2O3 phosphors was consisted of well crystallized nanosized sphere particles with a diameter of about 30 nnx Local structure of Tb ions in Lu2O3 lattice was investigated by an analytical approach based on Fourier transformation of the extended X-ray absorption fine structure(EXAFS) data.X-ray near edge structure (XANES) spectra suggested that all Tb ions doped were tervalonce.EXAFS results indicated that Tb ions have entered the Lu2O3 cubic lattice by means of solid solution.The coordination number and first shell Tb-O distance dropped with the increasing of Tb concentration.Emission spectra of the phosphors was shown to be typical for Tb3+ with main components at 542,550 and 490 nm,derived from irradiative relaxation of 5D4 level.The emission intensity decreased severely with the increasing of Tb concentration from 1 mol.% to 15 tool.%,suggesting a significant concentration quenching above 1 mol.% Tb.The reduction of emission intensity was interpreted by higher distortion derived relaxation among the surface state resident Tb3+ ions.     

Multi-Pass Simulation of Heavy Plate Rolling Including Intermediate Forced Cooling

Thermomechanical Controlled Processing (TMCP) including accelerated cooling after the final hot rolling pass is a well-established technology,widely applied in HSLA steel plate production.However,there are still certain limitations,especially for thicker plate.The rolling schedule includes a long holding period (HP) after the roughing stage to allow the temperature to fall sufficiently for optimised TMCP during finishing.Intermediate Forced Cooling (IFC) applied during the HP can increase productivity by decreasing the required hold time,can restrict austenite grain growth,and can also improve the subsequent strain penetration in thick plate with further metallurgical benefits.Multi-pass plane strain compression (PSC) tests have been performed on the thermomechanical compression (TMC) machine at Sheffield University including different severities of IFC.Clearly it is impossible to simulate all aspects of the temperature and strain gradients present in thick plates in laboratory specimens,and most of the tests were conducted at temperatures and strains calculated by Finite Element modelling as relevant to specific positions through the plate thickness.However,some aspects of the gradients were addressed with tests using cold platens.The results have indeed shown that IFC can shorten the HP and reduce austenite grain growth and its variation across thick plate.     

Overview of Particles and Bubbles in Continuously Cast Steel

This paper gives an overview of phenomena associated with particles and bubbles in continuously cast steel. During steel processing from deoxidation to solidification the inclusion population undergoes changes with opportunities of removal. Flotation is an important separation mechanism. Inclusion particles may accumulate in the solidifying strand, thus forming enriched bands, which depend on the type of casting machine. Bubbles are created during inert gas injection. They also change in size, can float out, but also form accumulation bands. The interaction of bubbles and particles is discussed. Internal structure that recently has been observed on the inner surface of bubbles will be reviewed.     

烦恼 快乐 艺术——池莉“人生三部曲”解读

池莉的"人生三部曲"--<烦恼人生>、<不谈爱情>、<太阳出世>诉尽了普普通通的市民烦恼,小说中主人公被柴米油盐、吃喝拉撒、老婆孩子等琐事所烦着,从而构成他们的"烦恼人生".然而池莉通过自己的艺术创作,以积极的人生态度,又让读者体会到生活本身的快乐,"烦恼人生"中包含着"快乐人生".     

属性块在工程图形中的研究与应用

介绍了在工程图形中用属性块标注表面粗糙度的方法.采用属性块不仅能避免大量重复性的工作,还能节省大量的存储空间,具有提高绘图速度、质量,便于修改,资源共享等应用价值.     

热轧带钢传热模拟及变形区换热系数的确定

采用数值模拟方法研究了带钢热轧区轧件传热和温度场分布规律.结合现场生产中测温数据,建立了轧制变形区内轧件与轧辊接触传热界面换热系数(HTC)统计模型.分析了辊缝变形区中轧件断面上温度演变和分布特点.研究结果表明,热轧带钢热轧区传热数值模拟计算结果与实际吻合良好;变形区内轧件与轧辊接触传热界面换热系数不仅与平均单位压力相关,而且与轧制速度相关;轧件在轧制变形区存在很大的温度梯度.     

铝带箔轧机中对流换热特性影响因素的数值模拟

在对分段冷却控制研究的基础上 ,应用 ANSYS有限元软件首次系统地模拟分析了铝带轧机轧制时 ,影响工作辊与冷却液之间换热特性的因素。结果表明 ,冷却液喷射速度和温度以及冷却液的粘度变化对对流换热特性有着明显的影响 ;对流换热特性对喷嘴与工作辊之间距离的变化不敏感 ,冷却液喷射角度的变化对对流换热特性有一定的影响。     

Synthesis and photoluminescence of a dendritic europium complex with carbazole moieties

A novel dendritic europium complex containing grafted carbazole units as functional peripheries was synthesized and characterized. The Foerster energy transfer from the peripheries of carbazole units to β-diketonate as well as from the hgands to the central Eu（Ⅲ） ions in the complex was demonstrated. Under the excitation of carbazole units and β-diketonate, characteristic red emission peaks at 612 nm with four shoulders due to the Eu（Ⅲ） ion transition of 5^D0→7^FJ （J=0-4） were observed for the complex.     

Integrated and independent learning of hand-related constituent sequences.

In almost all daily activities fingers of both hands are used in coordinated succession. The present experiments explored whether learning in such tasks pertains not only to the overall sequence spanning both hands but also to the constituent sequences of each hand. In a serial reaction time task, 2 repeating hand-related sequences were intertwined, so that actions of one hand alternated with actions of the other hand. Integrated learning of the overall sequence was weak when the constituent sequences were uncorrelated (Experiment 1) and massive when they were correlated (Experiment 2). Both experiments yielded evidence suggesting partly independent learning of the hand-related sequences. There were no reliable indications of intermanual transfer of this hand-related sequence knowledge. The findings suggest that after sufficient training of coordinated action sequences involving several limbs, a part of the acquired sequence knowledge begins to be represented in an effector-specific manner. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

1420冷轧CAPL机组一次冷却炉带钢温度控制模型的改进

宝钢１４２０ｍｍ冷轧工程ＣＡＰＬ机组是镀锡原板退火专用生产线，采用计算机控制各炉室的带钢温度。对一次冷却炉（１ＣＦ）在调度中出现的带钢温度控制不稳定的状况，从冷却风机转速和挡板使用量对带钢温度控制的影响入手，分析了原模型控制存在的问题。为达到稳定控制的目的，增加了调节参数，修正控制模型，并取得了良好成效。     

Transfer designs and formulas.

This paper includes a comprehensive analysis of the several experimental designs available for the study of transfer of training. The discussion is restricted to the experimental designs and formulae that are appropriate in 2 types of transfer studies—verbal transfer, and predifferentiation, not including motor transfer. The uses and misuses of the various designs and transfer formulae are presented. 78 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Doped Organic Electroluminescence from a Novel Rare Earth Complex Tb （3-metho） 3 phen

A novel rare earth complex Tb (3-metho)3phen was synthesized and characterized. The complex was doped into PVK to improve the conductivity and film-forming property of Tb(3-metho) 3phen. A device with a structure of ITO/PVK: Tb(3-metho)3phen/Al was fabricated to study the eleetrolumineseent properties of Tb(3-metho) 3 phen. And the optoluminescent and AFM properties of this device were also studied, which proved the existence of energy transfer from PVK to Tb(3-metho)3phen. As a result, a pure green emission with sharp spectral band at 547.5 nm was observed.     

摩擦片打滑过程中的热传导模型

摩擦片打滑时，摩擦偶的实际接触是在摩擦表面的微凸体之间进行的，摩擦热的产生具有微区瞬间的特点，从而引起摩擦面局部温度过高，根据摩擦片打滑的特点和导热理论，建立了接触点处的热传导模型，依该模型分析了接触区域温度分布的特点，得知温度沿材料厚度方向呈线性分布，接触点瞬时温度与单位面积摩滑功率和打滑时间成正比，通过验证，用该模型计算所得的结果与文献所得结论相符，并且该模型更能反映摩擦表面温度的实际情况。     

红外辐射涂料的传热强化及其工业性试验研究

定性地分析了红外辐射涂料在工业炉上应用的节能机制。根据自行研制红外辐射涂料的性能与特点，提出了简便的涂料施工新工艺，制定了系统的试验研究方案，同时，对其强化辐射传热与实际应用节能效果进行了讨论与分析。