Mechanisms of dopants influence on hydrogen uptake in COF-108: A first principles study

Mechanisms of dopants (Li, Na, Mg, and Al) influence on hydrogen uptake in COF-108 were investigated by means of first principles. The binding energy of dopants in COF-108 was estimated from the first principles total energy calculations. All doped systems are shown positive binding energies with the metallic state of the dopant as the reference. The lowest binding energy of 0.518 eV appeared in the Na-doped system while a large amount of energy (2.692 eV) is required for Al to dope into COF-108. Electronic structure analysis shows that dopants Li and Na move the conduction band crossing the Fermi energy level and introduce weakly bonded electrons near the Fermi energy, which may polarize the hydrogen molecules. It is expectable that interaction between hydrogen molecule and the host COF-108 could be enhanced by the polarization of hydrogen molecule. Therefore the hydrogen uptake will be improved in the doped systems. Dopant Mg slightly reduces the band gap between the valence and conduction bands, but is hard to build chemical bonds with the host atoms owing to the less overlaps between the bond peaks of Mg and the COF-108. It hardly affects the electron distributions of the COF-108 and therefore weakly changes the chemical interactions between atoms in COF-108.     

The effects of cooking oil fume condensates (COFCs) on the vegetative growth of Salvinia natans (L.) All.

Cooking oil fumes (COF) and their condensates (COFCs), which are suspected of causing human lung cancers, are hazardous materials to environments. The effects of COFCs on the vegetative growth of Salvinia natans (L.) All., a free-floating aquatic fern, are discussed in this paper. The results showed that there were no differences of the number of floating leaves and the mean numbers of new leaves of S. natans in all groups, but these indices in experimental groups were influenced obviously at the late stage. COFCs also influenced stem length and number of buds of S. natans. COFCs could cause the floating leaves to turn yellow and individuals to die quickly. All these effects were correlated with the concentration of COFCs and the time. When the concentration of COFCs was ≥0.18 g/l, above 80% individuals would die in a short time. COFCs had significant impacts on the decrease in photosynthetic areas of S. natans by making the floating leaves turn yellow faster and accelerating the decomposition. There were some components in minute amount benefiting to the growth of S. natans. S. natans was sensitive to COFCs and could be a potential indicator for monitoring COFCs pollution in aquatic environments.     

Biobased Poly-phosphonate Additives from Methyl Linoleates‡

Poly-dialkyl phosphonates were synthesized by reacting methyl linoleate with dimethyl, diethyl, and di-n-butyl phosphites in the presence of free radical initiator and positively identified and characterized using gas chromatography–mass spectrometry (GC-MS), nuclear magnetic resonance (NMR; ¹H, ¹³C, ³¹P), and Fourier transform infrared (FTIR). Neat poly-dialkyl phosphonates and their blends in high-oleic sunflower oil (HOSuO) and polyalphaolefin (PAO-6) base oils were investigated for their physical, chemical, and tribological properties. At room temperature, the poly-dialkyl phosphonates displayed much better solubility in HOSuO than in PAO-6. Solubility in the base oils increased in the order dimethyl?<?diethyl?<?di-n-butyl. Relative to methyl linoleate, the neat poly-dialkyl phosphonates displayed higher density, higher kinematic viscosity, higher oxidation stability, and better cold flow (lower pour point and cloud point) properties. As an additive (0–10% w/w) in HOSuO, increasing concentration of poly-di-n-butyl phosphonate resulted in increasing onset and peak oxidation temperatures and decreasing cloud point. Poly-di-n-butyl phosphonate blends in HOSuO also showed lower four-ball antiwear (AW) coefficient of friction (COF) and wear scar diameter (WSD) than corresponding blends with zinc dialkyl dithiophosphate (ZDDP). As an additive (0–10% w/w) in PAO-6 base oil, poly-di-n-butyl phosphonate displayed lower four-ball antiwear COF and comparable WSD relative to similar blends of ZDDP in PAO-6. The results indicate that poly-dialkyl phosphonates are promising biobased AW additives with comparable or better performance than current petroleum-based commercial AW additives such as ZDDP.     

Prediction of slip resistance in climbing systems

The objective of this study was to develop a predictive model describing the slip resistance of various climbing surfaces. In a four-factor experiment, seven commonly used metal grating step surfaces were evaluated, along with four types of shoe soles (crepe, leather, ribbed-rubber, and oil-resistant-rubber); three contaminant conditions (dry, wet-water, and diesel fuel); and direction of force application. The results showed that the available slip resistance coefficients (ASRC) varied primarily as a function of sole material and contaminants. This result and the significant interactions between sole and step surfaces suggest that the appropriate selection of shoe soles and control of contaminants may be the most effective way of attaining adequate ASRC values. A predictive equation was developed using multiple regression which described the evaluated conditions with binary indicator variables. To increase the equation's applicability, the step surfaces were described in terms of generic features such as: painted vs. bare metal surface; ring vs. point protrusions; edge orientation; contact area, and protrusion height gradient. The equation explained 89% of the variance in the original data. In a validation study, the equation explained 80% of the variance in slip resistance for a new step surface under the original set of sole, contaminant, and directionality conditions.     

激光热喷涂Co30Cr8W1.6C3Ni1.4Si涂层在PAO+2.5%MoDTC油中摩擦学特性

为了提高TC4合金的耐磨性能,采用激光热喷涂技术在其表面制备了Co₃₀Cr₈W_1.6C₃Ni_1.4Si涂层。通过扫描电子显微镜（SEM）和X射线衍射（XRD）分析了涂层的形貌和物相,并通过摩擦磨损实验研究了涂层在PAO+2.5% MoDTC（质量分数）油中的磨损行为。结果表明,激光热喷涂的Co₃₀Cr₈W_1.6C₃Ni_1.4Si涂层主要由Ti、WC_1-x、CoO、Co₂Ti₄O和CoAl相组成,在涂层界面形成冶金结合。在激光功率为1000、1200和1400 W时所制备的涂层平均摩擦因数分别为0.151、0.120和0.171,其对应的磨损率分别为1.17×10^-6、1.33×10^-6和2.80×10^-6 mm³?N^-1?m^-1,磨损机理为磨粒磨损,其枝晶尺寸对降磨起主要作用。     

Effects of Loadings on Friction and Wear Behaviors of Cathodic Arc Ion Plating AlTiN Coating at High Temperature

A layer of AlTiN coating was deposited on YT14 cutting tool by cathodic arc ion plating (CAIP) and the coefficients of friction (COFs) of the AlTiN coating under different loads at a temperature of 800°C were investigated with a high-temperature wear tester. The wear morphologies, chemical elements, and phases of the coating after wear were analyzed with scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and X-ray diffraction (XRD), respectively, and the contours of wear tracks were investigated with a comprehensive measurement tester for material surface performance. The effects of loads on COFs and wear resistance of the AlTiN coating were analyzed, and the wear mechanism of the AlTiN coating at high temperature is discussed. The results show that the mixed oxides of Al₂O₃ and TiO₂ are produced under high temperature to improve the lubrication performance and wear resistance of the AlTiN coating. The average COFs of the coating under loads of 5, 7, and 9 N are 0.6495, 0.5897, and 0.3898, respectively. The COFs of the coating decrease with increasing load; as a result, the AlTiN coating is suitable for heavy loads at high temperature. The friction and wear mechanisms of the AlTiN coating are primarily composed of oxidation wear and abrasive wear, accompanied by fatigue wear and adhesive wear.     

挠性覆铜板用电解铜箔

概述了电解铜箔"U-WZ箔"和"DFF箔"的开发和特性,它们适用于COF用途等挠性覆铜板的铜箔。     

Effect of abrasive particle concentration on preliminary chemical mechanical polishing of glass substrate

Effect of abrasive particle concentration on material removal rate (MRR), MRR per particle and the surface quality in the preliminary chemical mechanical polishing (CMP) of rough glass substrate was investigated. Experimental results showed that the MRR increases linearly with the increase of abrasive concentration and reaches to the maximum when the abrasive concentration is 20 wt.%, and then tends to be stable. When the abrasive concentration increases from 2 to 5 wt.%, the MRR per particle increases greatly and reaches a peak. Then the MRR per particle decreases almost linearly with the increase of the abrasive concentration. The root mean squares (RMS) roughness almost decreases with increasing particle concentration. In addition, in situ coefficient of friction (COF) was also conducted during the polishing process and the zeta potentials of abrasive particles in slurry with different solid concentration were also characterized. Results show that COF value is not related to zeta potential but be sensitive to glass surface conditions in terms of rough peaks in preliminary polishing of glass substrate.     

液晶显示器模块IC构装技术

文章综述了目前LCM的几种构装技术,并以列表的形式对其各项指标进行了比较,最后得出结论：Fine Pitch导通技术是未来研究的重点。