在RGB显示器中生成一致的LED亮度

发光二极管（LED）在各种终端设备中已经被广泛使用，从汽车前照灯、交通信号灯、文字显示器、广告牌及大屏幕视频显示器，到普通及建筑照明和LCD背光等最新应用，LED的迅速采用使得最普通的设备也需要重新设计。随着LED效率与亮度的增加以及成本的减少，LED有可能会取代消费类应用中的传统照明技术。本文通过比较采用基于LED的LCD背光的大屏幕显示器中所使用的一些技术，阐述如何解决在使用LED时所面对的一些设计挑战。     

Effect of rapid solidification and small additions of Zn and Bi on the structure and properties of Sn-Cu eutectic alloy

The Sn-Cu eutectic alloy has been produced by rapid solidification using the melt-spinning technique, and both Zn and Bi have been added individually to it, in the ratio 0.5 wt.%. X-ray diffraction (XRD) analysis and differential thermal analysis (DTA) have been carried out. Resistivity, Vickers microhardness (HV), and yield stress (σ_y) have been measured. Also a new method for measuring creep has been described using a HV tester. The creep measured by this method is termed “microcreep.” It is a quick, nondestructive method and requires a small sample, about 1 cm², with thickness 1 mm or less. The results show that formation of Cu₃₉Sn₁₁ occurs due to the addition of both Zn and Bi. The addition of Zn increases HV and σ_y, but slightly lowers the creep resistance; however, the addition of Bi deteriorates the creep resistance. Also, it is found that the creep rate of as-quenched melt-spun alloys is high.     

Kinetic resolution of alpha-acetoxy N-acyl oxazolidinethiones by a chiral O-nucleophilic acyl transfer catalyst

The kinetic resolution of alpha-acetoxy N-acyl oxazolidinethiones using the chiral, nonracemic O-nucleophilic acyl transfer catalyst 8 is described. The reaction proceeds on a variety of substrates in excellent yields, with s-factors ranging from 17 to 31.     

Poly(vinyl alcohol)-Graft-Poly(ethylene glycol)-Supported Hydroxyproline Catalysis of Stereoselective Aldol Reactions

Summary: The good swelling and high loading of poly(vinyl alcohol)-graft-poly(ethylene glycol) (PVA-g-PEG) resins proved to be effective for performing supported proline-catalyzed aldol reactions stereoselectively in a wide range of polar non-protic, protic and non-polar solvents as well as in neat substrate. The catalysts could be recovered by filtration and recycled, without significant loss of activity. The use of poly(vinyl alcohol)-graft-poly(ethylene glycol) matrix improved the solubility of the proline-derived catalysts and expanded the scope of permissible solvents for performing selective aldol chemistry.     

Existence of nonnegative solutions for parabolic problem on Dirichlet forms

In this work, we investigate perturbed parabolic problem on measure spaces. For strongly local Dirichlet form, we obtain some results on existence and uniqueness of nonnegative solution. We also presented some examples as an applications.     

Synthesis of Some New Thiazolo[3,2‐a]pyrimidine Derivatives and Their Applications as Disperse Dyes

A series of novel thiazolo[3,2‐a]pyrimidine derivatives were synthesized by using β‐ketoanilides 1a–c as starting materials and as key intermediates for preparation of new pyrimidinecompounds 3a–e and fused heterocyclic pyrimidine derivatives 5a–c . The new compounds were transformed to disperse dyes 6a,b and 7 . The chemical structures were elucidated by spectroscopic and elemental analyses and found to be in good agreement with the proposed structures. The versatility of compounds 6a,b and 7 for textile dyeing as disperse dyes was reported. The synthesized dyes were applied to polyester fabrics by using high temperature dyeing method at 120°C. The dye uptake expressed as color strength (k/s) of the dyed samples has been measured. Moreover, the color strength was examined in detail. In addition, the position of color in CIELAB coordinates (L*, a*, b*, h, and C*) was assessed. The color fastness of the dyed samples gave excellent results for washing and rubbing; however, the light fastness was moderate. Raman spectra of dyed samples unequivocally excluded ring dyeing and found to match with the proposed structures.     

Software‐defined networking approach for enhanced evolved packet core network

The evolved packet core (EPC) network is the mobile network standardized by the 3rd Generation Partnership Project and represents the recent evolution of mobile networks providing high‐speed data rates and on‐demand connectivity services. Software‐defined networking (SDN) is recently gaining momentum in network research as a new generation networking technique. An SDN‐based EPC is expected to introduce gains to the EPC control plane architecture in terms of simplified, and perhaps even software‐based, vendor independent infrastructure nodes. In this paper, we propose a novel SDN‐based EPC architecture along with the protocol‐level detailed implementation and provide a mechanism for identifying information fields exchanged between SDN‐EPC entities that maintains correct functionality with minimal impact on the conventional design. Furthermore, we present the first comprehensive network performance evaluation for the SDN‐based EPC versus the conventional EPC and provide a comparative analysis of 2 networks performances identifying potential bottlenecks and performance issues. The evaluation focuses on 2 network control operations, namely, the S1‐handover and registration operations, taking into account several factors, and assessing performance metrics such as end‐to‐end delay (E2ED) for completion of the respective control operation, and EPC nodes utilization figures.     

Synthesis of nano-sized zeolite-Y functionalized with 5-amino-3-thiomethyl 1H-pyrazole-4-carbonitrile for effective Fe(III)-chelating strategy

Zeolite crystals having faujasite-type (FAU) topology in the nanometer range were first synthesized from amorphous rice husk ash at a low temperature of 363 K under autogenous pressure. Following this, surface functionalization of the produced zeolite with 5-amino-3-thiomethyl 1H-pyrazole-4-carbonitrile (pyrazole; Py) was carried out by two different methods, namely liquefied-period adsorption of Py (Py/Y_im) and a flexible ligand method (Py/Y_ss). The latter provides a larger amount of Py formed into as-made zeolite-Y. The sorption of Fe(III) onto Py/NaY afforded large meso–macroporosity introduced by the aggregation–assembly between Fe(III)Py complexes and NaY zeolite, which was typically evidenced for Fe(III)Py/Y_ss. The materials were characterized by XRD, FT-IR spectroscopy, thermal analysis (TGA) and porous structure by N₂ adsorption–desorption at 77 K. The XRD evaluation showed that the zeolite structure was managed right after adding Fe(III) to Py/Y, although a change in intensity of the zeolite reflections on complex formation was noticed. The FT-IR spectrum of Fe(III)Py/Y_ss exhibited two bands at 3594 and 3542 cm^?1 assigned to bridging hydroxyl groups associated with a Brönsted site, which did not exist in the spectra of Fe(III)Py/Y_im and Fe(III)-exchanged as-made NaY zeolite. This effect was ascribed to the induced greater electronegativity of the ligand towards Fe(III) species in dissociation of water molecules, producing acidic protons that are potential Brönsted acid sites. It was also evident that the Fe(III) adsorption capacity on Py/Y_ss is greater than on as-made NaY zeolite and Py/Y_im, owing most likely to the increasing concentration of the incorporating Py ligand which leads to an increase in the number of binding sites. The Fe(III) adsorption onto Py/Y_ss was well described by the pseudo-second-order kinetic model. Density functional theory (B3LYP/6-311G*) was performed to understanding the interaction mode of the ligand and complex with zeolite. The QSPR was calculated depending on the optimization geometries, frontier molecular orbitals, thermodynamic parameters, and global chemical reactivates, which were discussed for the studied compounds. The HOMOs, LUMOs and molecular electrostatic potentials were plotted to elucidate the interaction manner of the tested compounds with the zeolite. The nonlinear optical properties were elucidated via 1st and 2nd hyper-polarizabilities. The auto-degradation behavior was predicted for the complex, based on the ionization optional and bond dissociation enthalpy. The interactions between P_y and Fe(III)P_y with the zeolite surface have been described with molecular dynamics using a Monte Carlo simulation.