宣钢1260 m3高炉扩容大修改造设计

宣钢l260m^3高炉大修改造时将炉容扩大到l350m^3，对高炉本体系统设备及冷却系统、自动控制及检测系统进行了全面的改造更新，在炉腹、炉腰及炉身下部高热负荷区域采用铜冷却壁，取消炉身中上部铸铁冷却壁凸台，并采用薄内衬等先进、适用、可靠、成熟的技术。     

Mechanical properties of iron processed by severe plastic deformation

In the present study, the mechanical properties of Fe processed via severe plastic deformation (equal-channel angular pressing (ECAP)) at room temperature were investigated for the first time. The grain size of annealed Fe, with an initial grain size of about 200 μm, was reduced drastically during ECAP. After eight passes, the grain size reaches 200 to 400 nm, as documented by means of transmission electron microscopy (TEM). The value of microhardness during pressing increases 3 times over that of the starting material after the first pass and increases slightly during subsequent pressing for higher-purity Fe. Examination of the value of microhardness after eight passes as a function of post-ECAP annealing temperature shows a transition from recovery to recrystallization, an observation that resembles the behavior reported for heavily deformed metals and alloys. The tensile and compression behaviors were examined. In tension, a drop in the engineering stress-engineering strain curve beyond maximum load was observed both in the annealed Fe and the ECAP Fe. This drop is related to the neck deformation. The fracture surface, examined by scanning electron microscopy (SEM), shows vein patterns, which is different from the dimples found on the fracture surface of annealed Fe. In compression, an initial strain-hardening region followed by a no-strain-hardening region was observed in the ECAP Fe. The yield strength in tension of the ECAP Fe was observed to be higher than that in compression. The strengthening mechanisms and softening behavior are discussed.     

Interpretation of scatterometer ocean surface wind vector EOFs over the Northwestern Pacific

Satellite scatterometer winds over the northwestern Pacific were analyzed with the vector empirical orthogonal function (VEOF) method. The Hilbert-Huang transform (HHT), a newly developed non-linear and non-stationary time series data processing method, was also employed in the analysis. A combination of European Remote Sensing Satellite (ERS) −1/2 scatterometer, NASA Scatterometer (NSCAT) and NASA's Quick Scatterometer (QuikSCAT) winds covering the period from January 1992 to April 2000 and the area of 0-50°N, 100-148°E constitutes the baseline for this study. The results indicate that annual cycles dominate the two leading VEOF modes. The first VEOF shows the East Asian monsoon features and the second represents a spring-autumn oscillation. We removed the annual signal from the data set and calculated the interannual VEOFs. The first interannual VEOF represents the interannual variability existing in the spring-autumn oscillation. The temporal mode is correlated with the Southern Oscillation Index (SOI), but has a half-year lag with respect to the SOI. The spatial mode of the first interannual VEOF reflects the response of the tropical and extratropical winds to ENSO events. The second interannual VEOF is another ENSO related mode, and the temporal VEOF mode is correlated with the SOI with a correlation coefficient of 0.78, revealing the wind variability over mid-latitudes, which is associated with ENSO events. Further analysis indicated that the wind variability over the coast of East Asia represents anomalies of a Hadley cell. The quasi-biennial oscillation (QBO) was found in the temporal mode, indicating and verifying that the QBO in the wind fields is related to ENSO events. The third VEOF shows the interannaul variability in the winter-summer mode and displays the interannual variability of the East Asian monsoon. The three leading interannual VEOFs are statistically meaningful as confirmed by a significance test.     

Formation and retention of local melted films in AZ91 friction stir spot welds

The formation of local melted films during friction stir spot welding of as-cast AZ91D and thixomolded AZ91 material is investigated. The average temperatures close to the tip of the rotating pin vary from 438 to 454 °C during the dwell period in friction stir spot welding. These measured temperature values are higher than the melting temperature of α-Mg + Mg₁₇Al₁₂ eutectic (437 °C). It is suggested that the temperature in the stir zone during the dwell period is determined by the relative proportions of α-Mg and (α-Mg + Mg₁₇Al₁₂) eutectic material, which are incorporated during friction stir spot welding. Based on the stir zone temperature measurements and a detailed examination of material located at the root of the pin thread it is suggested that material is moved downwards via the pin thread and into the stir zone during the dwell period in friction stir spot welding. Evidence of local melted film formation is observed in the stir zone of AZ91 spot welds. It is suggested that melted films are retained since their dissolution rate is much slower in the high temperature stir zone than it is when melted films is formed in the stir zone during Al 7075-T6 friction stir spot welding. The spontaneous melting temperature, solute diffusion rate and the thermodynamic driving force for droplet dissolution are much higher during Al 7075-T6 friction stir spot welding.     

Determining stress intensity factors of composites using crack opening displacement

The main purpose of this paper is to find the mixed-mode stress intensity factors of composite materials using the crack opening displacement (COD). First, a series solution of the composite material with a crack was used to evaluate COD values. Then, the least-squares method was used to calculate mixed-mode stress intensity factors. This algorithm can be applied to any method that generates or measures COD values. The major advantage of this method is that COD values very near the crack tip are not necessary. Both finite element simulations and laboratory experiments were applied to validate this least-squares method with acceptable accuracy if the even terms of the series solution are removed.     

以不同PAN系炭纤维布制备燃料电池气体扩散层之研究

采用石墨化PAN系炭纤维布制备了高分子电解质燃料电池气体扩散层。通过电学实验、X-ray绕射与元素分析考察了所制气体扩散层的性能。结果表明：随热处理温度的升高，气体扩散层的电阻率降低，L2增加，d（x）2减小。高温处理后的炭纤维布作为高分子电解质燃料电池气体扩散层显示了较高的电池效能。     

Failure Analysis of Fuel System Assemblies

Fuel system assemblies used on recreational watercraft failed after a short time in service in a seawater environment. Examination of the assemblies revealed significant degradation of the polyacetal connectors of the wire subassemblies. Optical and microscopic evaluations indicated the complete loss of connector material implying decomposition of the resin, along with mud-cracking and a rough surface morphology signifying chemical attack. An elemental analysis performed on both an intact connector and degraded connector suggested a potential chemical agent in the form of zinc chloride. At elevated temperatures, concentrated zinc chloride solutions are known to decompose polyacetal resins. The source of the zinc chloride was established as corrosion products that resulted during the dezincification of the internal brass connector through exposure to saltwater in the application.     

蒸发油气污染的生物控制技术探讨

生物降解气态有机污染物的研究是近年来发展起来的大气污染控制新领域。通过介绍生物降解气态有机污染物的基本原理，探讨石油储运过程中的蒸发油气污染运用生物控制技术的可行性，提出需要解决的问题和研究的重点。     

1D selection of 2D objects in head-worn displays

In current desktop user interfaces, selection is usually accomplished easily with a mouse or a similar two-dimensional locator. In wearable computing, however, controlling two dimensions simultaneously gets significantly harder: a change in one dimension results easily in an undesired change in the other dimension as well when the user is occupied with a parallel task – such as walking. We present a way to overcome this problem by applying one-dimensional selection for graphical user interfaces in head-worn displays. Our new interaction technique allows a wearable computer user to perform object selection tasks easily and accurately. The technique is based on a visible circle on the screen. The user controls the circle, altering its radius with a one-dimensional valuator. The midpoint of the circle is in the middle of the screen. The object currently on the perimeter of the circle is highlighted and can be selected. Our preliminary usability evaluation, applying our custom evaluation method designed especially for walking users, indicates that the proposed technique is usable also when walking.