Local dimming algorithm and color gamut calibration for RGB LED backlight LCD display

A 32 in RGB LED backlight unit is developed. A local dimming algorithm is designed for the backlight, and grid-noise artifacts in the LC driving signal are successfully removed with consideration of the backlight distribution to provide identical intensity from each LED block. The 32 in RGB LED backlight LCD display has achieved a static display contrast of over 20000:1 and an average power reduction of 30%. We have also obtained the color gamut transformation matrix for transferring a cold cathode fluorescent lamp BLU LCD display gamut system to our RGB LED BLU LCD display gamut system, and extended the color saturation by suppositional color expansion method. As a result, the color has been accurately reproduced in RGB LED BLU LCD display with more richness and more saturation.     

Exact three-body local correlations for excited states of the 1D Bose gas

We derive an exact analytic expression for the three-body local correlations in the Lieb-Liniger model of 1D Bose gas with contact repulsion. The local three-body correlations control the thermalization and particle loss rates in the presence of terms which break integrability, as is realized in the case of 1D ultracold bosons. Our result is valid not only at finite temperature but also for a large class of nonthermal excited states in the thermodynamic limit. We present finite temperature calculations in the presence of external harmonic confinement within local density approximation, and for a highly excited state that resembles an experimentally realized configuration.     

Hydrogenation mechanism in lanthanum-activated magnesium films

With density-functional theory, the dissociative chemisorptions and diffusion processes of hydrogen on both pure and La-doped Mg(0001) surfaces are studied. Calculation results show that the energy barrier obtained for hydrogen dissociation on the La-doped Mg(0001) surface is smaller due to back-donated bonding between molecular H₂ and doped La atom. The obtained diffusion barriers (0.8–0.22 eV) imply a fast motion of atomic H on La-doped Mg(0001) surface.     

A practical expected-value-approach model to assess the relevant procurement costs

As an improvement to a series of expected value approach models, this study presents a supplier portfolio decision model, rather than a number of suppliers decision model. The model assesses risks as costs, considers types of heterogeneity in a procurement process and links the assessed terms in the programming model with accounting concepts. The model is then confirmed by using a procurement decision case with real data. The analysis has several implications for modelling, application and practice. In the light of the counterexamples shown, some thoughts pertaining to procurement decisions in supply management are reconsidered.     

Effects of Preparation Method on the Performance of Ni/Al2O3 Catalysts for Hydrogen Production by Bio-Oil Steam Reforming

Steam reforming of bio-oil derived from the fast pyrolysis of biomass is an economic and renewable process for hydrogen production. The main objective of the present work has been to investigate the effects of the preparation method of Ni/Al₂O₃ catalysts on their performance in hydrogen production by bio-oil steam reforming. The Ni/Al₂O₃ catalysts were prepared by impregnation, co-precipitation, and sol?Cgel methods. XRD, XPS, H₂-TPR, SEM, TEM, TG, and N₂ physisorption measurements were performed to characterize the texture and structure of the catalysts obtained after calcination and after their subsequent use. Ethanol and bio-oil model compound were selected for steam reforming to evaluate the catalyst performance. The catalyst prepared by the co-precipitation method was found to display better performance than the other two. Under the optimized reaction conditions, an ethanol conversion of 99% and a H₂ yield of 88% were obtained.     

扩展的Boussinesq系统Lax对的Bcklund变换和递推求解公式的导出

本文研究2+1维的扩展经典Boussinesq系统。首先,研究了系统的Lax对,找出了一个形式十分新颖的带有一个任意函数的Bcklund变换。然后,又导出了Lax对的特征函数的生成公式。最后,利用Bcklund变换和Lax对特征函数生成公式相结合得出了Lax对的递推求解公式。利用此递推公式,求出了一些Lax对的解。     

Group-theoretical investigation of the tunneling splitting patterns of enolic acetylacetone

Extensive experimental and theoretical studies for enolic acetylacetone have been presented in the literature, but studies of the tunneling splitting patterns are still lacking. In this work we adopt the C_s symmetry equilibrium structure and apply a group-theoretical formalism to study the tunneling splitting pattern of the ground vibrational level of enolic acetylacetone. Enolic acetylacetone has three large-amplitude motions, one intramolecular hydrogen transfer and two methyl torsions. Therefore, the C_s structure of enolic acetylacetone has 18 (3 × 3 × 2) equivalent equilibrium molecular frameworks, nine (3 × 3) of them are from the two methyl torsions, and two are from the intramolecular hydrogen transfer. Tunneling motions among the 18 equivalent molecular frameworks split the ground vibrational level into eight sublevels: A₁, A₄, E₁, E₂, E₃, E₄, G(1) and G(2). In enolic acetylacetone the intramolecular hydrogen transfer induces a rearrangement of the CC, CO single and double bonds, and then triggers two additional 60° internal rotations, one in each of the two methyl groups attached to the hydrogen-bonded malonaldehyde ring. This interaction further complicates the tunneling splitting patterns and increases the difficulty of spectral analysis. In this work the influence of the intramolecular hydrogen transfer on the energy order of the eight sublevels is determined by a group-theoretical formalism.     

Synthesis and characterization of luminescent osmium(II) carbonyl complexes based on chelating dibenzoylmethanate and halide ligands

Octahedral Os(II) complexes 1-5 with formula [Os(CO)3X(dbm)] are prepared through utilization of both solid-state pyrolysis and ligand exchange reactions. These complexes exhibit prominent 3pi-pi* phosphorescence with unusually long lifetimes (29-64 micros) and high quantum yields (0.08-0.13).     

光子晶体及其应用

光子晶体是８０年代末提出的新概念和新材料,文章简单回顾了光子晶体的历史,重点阐述了其主要特征以及可能的应用,同时论述了研究光子晶体的几种理论方法。     

罗布泊遥感影像"耳纹"特征分析及其环境意义

研究典型干旱区的罗布泊,对揭示区域环境演变特征和全球变化具有重要意义.从遥感影像上的"耳纹"特征入手,通过光谱、土壤和地表参数等分析,认为:地表全盐含量和结构差异是形成罗布泊遥感影像"耳纹"特征的直接原因;光谱、全盐含量和土壤粒径的分析结果具有很好的一致性."耳纹"记录下了罗布泊地区的环境演变特征,这些特征表明:受全球环境影响,湖水在气候不断干旱的过程中逐渐干涸,干涸过程的气候调整,使罗布泊地区经历了两次相对湿润的气候环境,前一次较长,后一次很短.