Evaluation of contrast metrics for liquid‐crystal displays under different viewing conditions

Abstract— A psychophysical experiment was carried out to assess the perceptual contrast on a large‐sized liquid‐crystal display (LCD) under nine phases of viewing conditions. Based on the results, six contrast models employing different color attributes or the index of just‐noticeable difference (JND) were developed. Their performances were also tested by the visual data of the nine phases, which indicated that the model C_Q employing CIECAM02 brightness gives the best performance in predicting visual data under different viewing conditions among those models. A preprocessing step was also proposed to utilize the contrast model C_Q conveniently in the practical contrast evaluation of LCDs.     

Aluminum. II. Derivation of C v0from C p and comparison to C v0 calculated from anharmonic models

The specific heat at constant pressure, C _p, of aluminum measured by Ditmars, Plint, and Shukla has been reduced to the volume V ₀ appropriate for 0 K employing the Murnaghan equation. The C _v0 thus obtained is compared with the theoretical C _v0 calculated in the harmonic and the lowest-order anharmonic approximation from three different pseudopotentials (Harrison, Ashcroft, and Dagens-Rasolt-Taylor) as well as a phenomenological Morse potential. The higher-order ( ⁴) anharmonic contributions are calculated from the same nearest-neighbor Morse potential as in the lowest-order anharmonic theory. The role of the vacancy and the higher-order anharmonic contributions to C _v0 has been examined and we conclude that the ⁴ contributions to C _v0 are much smaller than the vacancy contribution. After removal of the vacancy contribution, the reduced C _v0 is found to be in excellent agreement with the Ashcroft and Harrison pseudopotentials as well as the Morse potential including the ² and ⁴ contributions to C _v0.     

低碳钢显微结构的EBSD表征

近年来,新开发的电子背散射衍射技术将多晶材料的显微组织、微区成分与结晶学数据分析联系起来,能对晶界类型、取向、位向差和结构及其分布进行观察、统计测定和定量分析,从而建立了晶界结构、取向和织构等与多晶材料性能的定量和半定量关系,成为现代材料研究的重要实验技术。笔者结合低碳钢生产中的一些实际问题,扼要介绍了电子背散射衍射技术中的晶体取向图在多晶材料显微结构表征中的应用。     

Simulation of polycrystalline aluminum tensile test with crystal plasticity finite element method

The crystal plasticity was implemented in the finite element method（FEM） software ABAQUS through the user subroutine UMAT. By means of discretizing the space at the grain level with the Voronoi diagram method, a polycrystal model was built and used in the FEM analysis. The initial orientation of each grain was generated based on the orientation distribution function（ODF）. The developed model was successfully applied in simulation of polycrystalline aluminium samples deformed by the tensile tests. The theoretical strain--stress relation was in good agreement with the experimental result. The simulation results show that the grain size has significant effect on the deformation behavior. The initial plastic deformation usually occurs at grain boundaries, and multiple slip often results in an enhanced local hardening at grain boundaries.     

Fabrication of High Performance PET/TLCP Fibers through the Synergistic Interfacial Enhancement and Compatibilization of Functional 1D and 2D Carbon Nanomaterials

The maleic anhydride functionalized graphene oxide (GO-MA) is fabricated by an efficient and solvent-free Diels–Alder reaction. Polyethylene terephthalate (PET)/thermotropic liquid crystal polyester (TLCP), PET/TLCP/GO-MA, PET/TLCP/aminated multi-walled carbon nanotubes (MWCNTs-NH₂), and PET/TLCP/GO-MA/MWCNTs-NH₂ composite fibers are systematically melt-spun. The structure and compatibilizing effects of GO-MA and MWCNTs-NH₂ on the mechanical, thermal, and crystallization properties of the composite fibers are indicated. The non-isothermal crystallization kinetics and X-ray diffraction (XRD) data show that TLCP and nanofillers can change the crystalline morphology of PET. The mechanical properties of the fibers rise with increasing TLCP content. The tensile strength 929 MPa and modulus 17.5 GPa of the fibers with 7 wt% TLCP and 0.25 wt% nanofillers (0.1 wt% GO-MA and 0.15 wt% MWCNTs-NH₂) are significantly higher than those with 7 wt% TLCP (tensile strength 622 MPa and modulus 16.1 GPa) and even higher than those with 15% TLCP (tensile strength 836 MPa, and modulus 18.0 GPa). When the GO-MA and MWCNTs-NH₂ co-exist, the anti-dripping phenomenon is improved. Therefore, the TLCP, GO, and MWCNTs synergistically strengthens the mechanical properties. This is promising for the industrial fabrication of high-strength fibers.     

Structural Basis for The Recognition of Deaminated Nucleobases by An Archaeal DNA Polymerase

With increasing temperature, nucleobases in DNA become increasingly damaged by hydrolysis of exocyclic amines. The most prominent damage includes the conversion of cytosine to uracil and adenine to hypoxanthine. These damages are mutagenic and put the integrity of the genome at risk if not repaired appropriately. Several archaea live at elevated temperatures and thus, are exposed to a higher risk of deamination. Earlier studies have shown that DNA polymerases of archaea have the property of sensing deaminated nucleobases in the DNA template and thereby stalling the DNA synthesis during DNA replication providing another layer of DNA damage recognition and repair. However, the structural basis of uracil and hypoxanthine sensing by archaeal B-family DNA polymerases is sparse. Here we report on three new crystal structures of the archaeal B-family DNA polymerase from Thermococcus kodakarensis (KOD) DNA polymerase in complex with primer and template strands that have extended single stranded DNA template 5’-overhangs. These overhangs contain either the canonical nucleobases as well as uracil or hypoxanthine, respectively, and provide unprecedented structural insights into their recognition by archaeal B-family DNA polymerases.     

Controllable synthesis of pure monodispersed zirconia nanopowders with tetragonal phase

Nanopowders of pure zirconia have been synthesized using citric acid (CA)-assisted lamellar liquid crystal template method. The microstructure of the zirconia powder prepared at the different mole ratios of CA to zirconium oxynitrate (ZN) was characterized by FT-IR, X-ray diffraction (XRD), laser particle size analyzer, Raman spectroscopy, and scanning electron microscope (SEM) methods. The phase structure of the sodium dodecyl sulfate (SDS)/C₁₀H₂₁OH/H₂O system before and after adding mixing solution CA and ZN was determined by POM (Polarizing Optical Microscope). The results show that lamellar structure of the SDS/C₁₀H₂₁OH/H₂O system after adding mixing solution CA and ZN is stable. The presence of CA inhibits agglomeration and growth of zirconia particle. The crystallite size of zirconia powders decreases and agglomerates lowly with addition of CA. Fourier transform infrared spectrometry (FI-IR) analyses reveal that the structure of chelating organic complex is maintained in zirconia structure at high-temperature calcination to cause oxygen vacancies which stabilizes the tetragonal phase of zirconia. The zirconia powders remained the single metastable tetragonal phase at the molar ratios of CA to ZN ranging from 1:3 to 5:1. The crystallite size of zirconia with spherical morphology varied from 32.2 to 20.1 nm with the increase of the molar ratio of CA to ZN in the range of 1:3 to 5:1.     

单晶高温合金定向凝固过程中初生碳化物的上浮现象SCIEI

本文在一种抗热腐蚀单晶镍基高温合金平面及胞状液-固界面定向凝固条件下,发现了初生碳化物(TiC)的上浮现象并分析了其形成原因。     

Passivation of Fe-Cr alloys studied with ICP-AES and EQCM

The response of sputter deposited Fe-15Cr and Fe-25Cr alloys to a rapid potential increase in the passive region was studied using two in situ methods: electrochemical quartz crystal microbalance and inductive coupled plasma-atomic emission spectroscopy (ICP-AES). Both methods indicated an increase in the dissolution rate of iron following the potential change; the total amount of material dissolved being higher for the Fe-15Cr alloy. For both alloys, about 10% of the total dissolved material was Cr. This result compared well with experiments on a 430 stainless steel. ICP-AES is shown to be useful for the in situ determination of partial currents of metal dissolution using solution analysis in a flow cell.     

水量对锐钛矿溶胶制备、结构及光催化性能的影响

选择“钛酸丁酯-水-乙醇-盐酸”的溶胶．凝胶反应体系，考察反应物水的用量变化对反应过程、溶胶结构和光催化性能的影响，并获得了含有锐钛矿晶体、具有光催化性能的氧化钛溶胶。钛酸丁酯与水的摩尔比为1：2、1：4、1：8时，会逐渐形成凝胶，溶胶常温干燥后的粉体呈无定型结构，透射电镜中只能观察到细小的成膜粒子，溶胶不能使罗丹明B溶液分解褪色。钛酸丁酯与水的摩尔比为1：40、1：100、1：200时，钛酸丁酯发生充分水解，有可能形成稳定的溶胶；溶胶常温干燥后的粉体呈锐钛矿晶型，且结晶强度随水的用量的增加而增强；透射电镜中可观察到松散的团聚体、初显正方形较为紧密的结晶体和致密规则的正方形锐钛矿晶体；各溶胶均可催化降解罗丹明B使其褪色。