The key factors in fabrication of high-quality ordered macroporous copper film

The template-directed fabrication of highly-ordered porous film is of significant importance in implementation of the photonic band gap structure. The paper reports a simple and effective method to improve the electrodeposition of metal porous film by utilizing highly-ordered polystyrene spheres (PSs) template. By surface-modification method, the hydrophobic property of the PSs template surfaces was changed into hydrophilic one. It was demonstrated that the surface modification process enhanced the permeability of the electrolyte solution in the nanometer-sized voids of the colloidal template. The homogeneously deposited copper film with the highly-ordered voids in size of less than 500 nm was successfully obtained. In addition, it was found that large defects, such as microcracks in the template, strongly influenced the macroporous films quality. An obvious preferential growth in the cracked area was observed.     

Study of the effect of ligands on the fluorescence properties of terbium ternary complexes

Four ternary complexes of Tb(III) were synthesized by introducing the first ligand (L₁) (N-phenylanthranilic acid (N-HPA), α-furoic acid (FURA)) and the second ligand (L₂) (1,10-phenanthroline (Phen), 2,2′-dipyridyl (Bipy)), respectively. These complexes were characterized by elemental analysis, infrared spectra, XRD, UV spectra and fluorescence spectra. The effect of L₁ and L₂ on the fluorescence properties of terbium complexes was discussed. It showed that all the complexes exhibited ligand-sensitized green emission. The fluorescent intensity increased in the sequence of Tb(FURA)₃Bipy < Tb(N-PA)₃Phen < Tb(FURA)₃Phen < Tb(N-PA)₃Bipy. It indicated that L₁ affected fluorescence properties of the complexes differently when the corresponding L₂ altered. Meanwhile, the influence of L₂ on the luminescence properties of the complexes also depends on L₁. The results showed that L₁ and L₂ affected each other and worked together as a whole. The matching of L₁, L₂ and Tb³⁺ ion is very important to the luminescence properties of Tb(III) ternary complexes.     

Soluble porphyrin-bisindolylmaleimides dyad and pentamer as saturated red luminescent materials

Novel soluble porphyrin-bisindolylmaleimides dyad and pentamer have been prepared conveniently by coupling of amino-porphyrins and bisindolylmaleic anhydride. The bisindolylmaleimide groups function as the antenna to efficiently enhance the intramolecular energy transfer to the porphyrin core. These compounds may serve as good candidates of red-light emitting materials for organic light-emitting diodes.     

Polarization-independent silicon photonic grating coupler for large spatial light spots

We design and demonstrate a one-dimensional grating coupler with a low polarization-dependent loss(PDL)for large spatial light spots.Based on current fabrication conditions,we first utilize genetic algorithms to find the optimal grating structure including the distributions of duty and periods,making the effective refractive index of transverse electric mode the same as that of transverse magnetic mode.The designed grating coupler is fabricated on the common silicon-on-insulator platform and the PDL is measured to be within 0.41 d B covering the C-band.     

Some remarks on X(6900)

The analysis of the LHCb data on \begin{document}$X(6900)$\end{document} found in the di-\begin{document}$J/\psi$\end{document} system was performed using a momentum-dependent Flatté-like parameterization. The use of the pole counting rule and spectral density function sum rule provides consistent evidence that both confining and molecular states are possible. Alternatively, the nature of \begin{document}$X(6900)$\end{document} cannot be distinguished if only the di-\begin{document}$J/\psi$\end{document} experimental data with current statistics are available. Nevertheless, we found that the lowest state in the di-\begin{document}$J/\psi$\end{document} system likely has the same quantum numbers as \begin{document}$X(6900)$\end{document}, and \begin{document}$X(6900)$\end{document} is probably not interpreted as a \begin{document}$J/\psi-\psi(2S)$\end{document} molecular state.     

Isomer-specific influences on ignition and intermediates of two C5 ketones in an RCM

Ketones have been considered as potential biofuels and main components of blend stock for internal engines. To better understand the chemical kinetics of ketones, ignition delay times of 2-pentanone (propyl methyl ketone, PMK) and 3-pentanone (diethyl ketone, DEK) were measured at temperatures of 895–1128 K under 10 and 20 bar, at equivalence ratios (?) of 0.5 and 1.0 in a rapid compression machine (RCM). To explore the impact of carbonyl functionality and resonance stabilized structures of fuel radicals on their combustion kinetics, high-temperature pyrolysis at 1130 K and relatively low-temperature oxidation at 950 K studies were performed in an RCM, and the time-resolved species concentration profiles under these two conditions were quantified using a fast sampling system and gas chromatography (GC). A new kinetic model containing low-temperature reactions was built aiming at predicting the pyrolysis and oxidation behaviors of both ketones. The consumption pathways of the resonance stabilization fuel radicals through oxygen addition and following reactions are promoted since the decomposition rates of these radicals are about 4 orders magnitudes lower than regular fuel radicals. The occurrences of the so-called “addition-dissociation reactions”, i.e., ketones reacting with a hydrogen yielding aldehyde or reacting with a methyl radical yielding shorter-chain-length ketones, are verified in pyrolysis experiments. Based on experiments and model analysis, the carbonyl functionality in both ketones is preserved during the process of β-scissions of fuel radicals and α-scissions of fuel-related acyl radicals, resulting in the direct formation of CO and ketene. However, the position of carbonyl functionality has a significant impact on the species pools.     

Mineral-derived Li4SiO4-based adsorbent for post-combustion CO2 capture: An experimental and kinetic investigation

Li₄SiO₄-based adsorbent is considered as a promising choice for the CO₂ removal from power plants’ flue gases. However, the relatively high raw materials cost still limits its industrial applications. In this work, aiming to reduce the cost of Si-source, three novel natural occurring minerals including the pumicestone, the montmorillonite and the attapulgite were employed as Si-sources for the production of Li₄SiO₄-based adsorbents. The phase composition, surface morphology as well as the cyclic CO₂ ad-desorption performance of obtained adsorbents were experimentally and kinetically investigated. It is found that the Si content of minerals directly determines the adsorption capacity of adsorbents, resulting in a relatively high and stable capacity of nearly 0.1 g/g within 22 cycles for the pumicestone derived adsorbent compared with other adsorbents obtained from minerals. Moreover, the excess Ca inside the minerals is found forming CaO, which is harmful to the desorption performance of adsorbent owing to the occurrence of Li–Ca–CO₂ interactions. As a consequence, Si-source with high Ca content was proven inadaptable for the synthesis of Li₄SiO₄-based adsorbent, which provides guidance for the future selection of mineral Si-sources in this field.     

基于最新势能面的C(1D)+H2反应的环聚合分子动力学研究

本文利用环聚合分子动力学方法对C(¹D)+H₂反应开展了详细的理论研究. 计算中使用了最近构建的Zhang-Ma-Bian(ZMB)从头算势能面,该势能面对锥形交叉附近区域以及范德华区域均有精确的描述. 环聚合分子动力学计算得到的热反应速率常数与最新实验值吻合很好. 与前人计算结果比较,发现在?¹A′电子基态的ZMB-a势能面上获得的反应速率常数远大于前人构建的RKHS势能面上的结果,这是由于ZMB势能面上的范德华鞍具有与之前势能面上的范德华阱完全不同的动态学作用,表明环聚合分子动力学方法能够处理范德华作用引起的势能面拓扑结构所导致的动态学效应. 本文还揭示了b¹A′′电子激发态ZMB-b势能面以及量子效应对反应的重要性.     

Pure single line oscillation of HF lasers in fine atmospheric window

Applied Physics B - A correction to this paper has been published: https://doi.org/10.1007/s00340-021-07611-y     

Joule–Thomson expansion of RN-AdS black hole immersed in perfect fluid dark matter

In this paper, we study the Joule–Thomson expansion for RN-Ad S black holes immersed in perfect fluid dark matter. As perfect fluid dark matter is one of the dark matter candidates, we are interested in how it influences the thermodynamic properties of black holes. Firstly, the negative cosmological constant could be interpreted as thermodynamic pressure and its conjugate quantity as the thermodynamic volume, which give us more physical insights into the black hole. Moreover, we derive the thermodynamic definitions and study the critical behaviour of the black hole. Secondly,the explicit expression of Joule–Thomson coefficient is obtained from the basic formulas of the pressure, the volume, the entropy and the temperature. Then, we obtain the inversion curves in terms of charge Q and parameter λ. Furthermore, we analyse the isenthalpic curve in T–P graph with the cooling–heating region determined by the inversion curve. At last, we derive the ratio of minimum inversion temperature to critical temperature and compare the result with that in the RN-Ad S case.