热轧带钢蛇行过程的动态模拟仿真

带钢在轧制过程中，由于一些因素影响会使带钢轧机左右受力不对称，从而产生蛇行现象。文中对影响蛇行的因素进行了分析，并应用Matlab软件对热轧带钢的蛇行过程进行模拟仿真，其结果与生产实际情况相符合。     

Preparation of Li[Ni1/3Co1/3Mn1/3]O2 powders for cathode material in secondary battery by solid-state method

Employing Li2CO3, NiO, Co3O4, and MnCO3 powders as starting materials, Li[Ni1/3Co1/3Mn1/3]O2 was synthesized by solid-state reaction method.Various grinding aids were applied during milling in order to optimize the synthesis process.After successive heat treatments at 650 and 950 ℃, the prepared powders were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy, and transmission electron microscopy.The powders prepared by adding salt (NaCl) as grinding aid exhibit a clear R3m layer structure.The powders by other grinding aids like heptane show some impurity peaks in the XRD pattern.The former powders show a uniform particle size distribution of less than 1 μm average size while the latter shows a wide distribution ranging from 1 to 10 μm.Energy dispersive X-ray (EDX) analysiss show that the ratio of Ni, Co, and Mn content in the powder is approximately 1/3, 1/3, and 1/3, respecively.The EDX data indicate no incorporation of sodium or chlorine into the powders.Charge-discharge tests gave an initial discharge capacity of 160 mAh·g-1 for the powders with NaCl addition while 70 mAh·g-1 for the powders with heptane.     

A Sieve Bootstrap For The Test Of A Unit Root

Abstract. In this paper, we consider a sieve bootstrap for the test of a unit root in models driven by general linear processes. The given model is first approximated by a finite autoregressive integrated process of order increasing with the sample size, and then the method of bootstrap is applied for the approximated autoregression to obtain the critical values for the usual unit root tests. The resulting tests, which may simply be viewed as the bootstrapped versions of Augmented Dickey–Fuller (ADF) unit root tests by Said and Dickey (1984 ), are shown to be consistent under very general conditions. The asymptotic validity of the bootstrap ADF unit root tests is thus established. Our conditions are significantly weaker than those used by Said and Dickey. Simulations show that bootstrap provides substantial improvements on finite sample sizes of the tests.     

Maximum entropy reconstruction of compositional depth profiles from electron probe microanalysis data

Electron probe microanalysis (EPMA) is a powerful method for the quantitative determination of the elemental composition of micro-regions of a sample surface. Here, we report on the development of a method of reconstructing compositional depth profiles in thin films from EPMA data measured over a range of electron beam energies, using maximum entropy data processing. The method gives quantitative information on film compositions up to approximately 1 μm in depth, with a lateral spatial resolution of approximately 1 μm. The method is tested using both simulated data and measured experimental data from well-characterized model sample structures.     

DIFFUSIONAL MODEL WITH AND WITHOUT SHRINKAGE DURING SALTED FISH MUSCLE DRYING

Abstract

The drying process of salted pieces of shark muscle (Carckarhinus limbatus) was accomplished using three air conditions (20 ^°C -40 %RH; 30 ^°C - 30 %RH; 40 ^°C - 45 %RH) and two air velocities (0.5 m/s; 3.0 m/s). Shrinkage of material during drying was correlated as a linear function between linear dimension and moisture content. The experimental drying data were obtained using both the diffusional model with moisture content parameter (considering no shrinkage) and the diffusional model with moisture concentration parameter (considering shrinkage). The values of effective diffusivity varied between 1.50×l0^?10m²/s and 2 85×l0^?10m²/s for drying process considering no shrinkage and between 0.87×l0^?10m²/s and 1.61×l0^?10m²/s for process considering shrinkage. The activation energy was calculated assuming an Arrhenius' type equation. The values were 17.94 KJ/mol with the air velocity of 0.5 m/s and 21.94 kJ/mol with the air velocity of 3,0 m/s for effective diffusivity without shrinkage. The values were 2.04 kJ/mol with the air velocity of 0.5 m/s and 16.12 kJ/mol with the air velocity of 3.0 m/s for effective diffusivity with shrinkage. These low activation energy values, calculated considering the shrinking effect, show that the side effects during drying reduces the effective diffusivity dependence on temperature     

IRON CONTENT, SENSORY EVALUATION, AND CONSUMER ACCEPTANCE OF FOOD COOKED IN IRON UTENSILS

The purpose of this study was to determine the effect of cooking food in iron utensils on the iron content, sensory quality, and consumer acceptance/ preference of the food. Hamburger patties and applesauce were cooked in iron and in glass utensils and were analyzed for iron content by atomic absorption spectrophotometry and evaluated by a trained sensory panel, by consumers, and for chroma, pH, and refractometer changes. Cooking hamburger patties and applesauce in iron utensils increased iron in the food, did not affect sensory quality or consumer acceptance/preference of hamburger patties, but affected the color and flavor and decreased consumer acceptance/preference for applesauce.     

Enhanced wear and fatigue properties of Ti-6AI-4V alloy modified by plasma carburizing/CrN coating

Ti6Al4Valloyhasbeenusedextensively inaerospace,automotiveandbiomedicalindus triesduetoitsexcellentmechanicalreliability,corrosionresistance,biocompatibilityandhigh specificstrength[1].Oneofthemostimportant featuresofthematerialwhichshouldbeim provedforawiderapplicationofTi6Al4Vis wearbehavior.Degradationofsurfaceduetothe wearcoulddeterioratethemechanicalreliability andfatiguelife.Mechanicalandwearproperties ofTibasealloysareknowntobelargelyaffected bythemorphology,size,distributionandvol ume…