Fungal Cell Wall-Graphene Oxide Microcomposite Membrane for Organic Solvent Nanofiltration

High permeability and selectivity have long been pursued in membrane separation technology. However, this purpose remains a paramount challenge for molecular separations mainly limited by the trade-off between permeance and -selectivity. Here, a bio-utilization strategy based on deep understanding of bio-features to fabricate a cell wall-graphene oxide microcomposite membrane for organic solvent nanofiltration is rationally designed. The membrane displays a unique configuration with alternating stacking of cell wall layers and ultrathin graphene oxide layers. Moreover, the interactions between the cell wall and graphene oxide as well as between the membrane and solvent are mainly revealed by all atom molecular dynamics to uncover the possible working principle of the membrane. Specifically, the strong graphene oxide-cell wall interaction and anti-swelling behavior of the cell wall together restrict the expansion of the graphene oxide layer to promise high selectivity. Meanwhile, the well-developed porosity of the cell wall allows a high throughput of various solvents through the membrane, showing excellent rejection for small molecules and solvent permeance as high as 56 L m² h¹ bar⁻¹. The proposed cell wall microcomposite 2D structure could encourage the practical applications of GO-based membranes.     

Laser-Induced Graphene Assisting Self-Conversion Reaction for Sulfur-Free Aqueous Cu-S Battery

In aqueous/nonaqueous metal-sulfur batteries, sulfur-based redox couple exhibits significant challenges mainly due to its low electrochemical kinetics, potential shuttle effect, and large volume change. Although massive researches have been conducted to optimize or replace metal anode and cathode composite, major challenges caused by the dependency on sulfur-based redox couple still remain. In this study, a novel redox couple of CuS/Cu₂S, which provides the same theoretical capacity (based on conventional S/S²⁻ redox couple) by changing the valence of ion charge carrier, is proposed. For achieving high reversibility, commercially viable laser-induced graphene (LIG) is fabricated and used for the first time in aqueous metal-sulfur batteries. By virtue of the synergism between novel redox couple and LIG, aqueous CuS/Cu₂S battery delivers a highly reversible capacity of 1654.9 mAh g⁻¹ in the initial cycle and retains 91.2% with 1509.5 mAh g⁻¹ after 328 cycles. When being cycled at 2.8 A g⁻¹, its reversible capacity still retains 92.1% after 410 cycles. This study provides a new choice by using a sulfur-free redox couple from screening thermodynamic parameters and analyzes the functional mechanism of LIG by density functional theory, aiming to innovate the energy storage mechanism of aqueous metal-sulfur batteries.     

电子束引发苯乙烯在PVA无纺布上的接枝共聚反应

研究了用电子束预辐照的PVA无纺布引发苯乙烯溶液接枝共聚时有机溶剂、单体浓度、反应温度、时间、莫尔盐用量等各种因素对接枝率和接枝效率的影响。     

杜比全景声电影混录棚系统案例探究(下)——以和声创影杜比全景声混录棚为例

作为杜比公司新一代的音频技术,杜比全景声的出现,既使观众的观影感受有了质的飞跃,又为声音创作者提供了更具表现力的创作平台.为顺应市场需求,越来越多的电影创作人,选择杜比全景声格式的声音.同时,对支持杜比格式的混录棚的技术指标也备受业内人士关注.以北京和声创影基于杜比全景声格式搭建的混录棚为重点,从系统搭建、声学环境、实际操作、应用情况等方面进一步了解了杜比全景声技术,也通过对该棚的分析和介绍为今后的混录棚制作提供一定的参考意见.     

Simultaneous screening for lipophilic and hydrophilic toxins in marine harmful algae using a serially coupled reversed-phase and hydrophilic interaction liquid chromatography separation system with high-resolution mass spectrometry

The presence of toxins in harmful algal blooms (HABs) poses considerable concerns because of their potential adverse effects on ecological environments and human health. When marine HABs occur, efficient screening and identification of toxins in different kinds of HAB algae remains a challenge. In this study, the applicability of serial coupling of reversed-phase liquid chromatography (RPLC) and hydrophilic interaction chromatography (HILIC) combined with high resolution mass spectrometry (HR-MS) for the simultaneous screening and identification of various kinds of known lipophilic and hydrophilic toxins in HAB algae was investigated for the first time. Ultrasound-assisted extraction (UAE) was explored to extract both lipophilic and hydrophilic toxins in algae simultaneously. As in most cases, toxin standards were not available; therefore, an identification procedure based on accurate mass data and chromatographic behavior was proposed. According to this procedure, eight known lipophilic toxins and 11 hydrophilic toxins were successfully detected in a single injection, and the proposed method was validated. Satisfactory sensitivity, repeatability (RSD <14.87%) and recovery (89.4–105.8%) of the method were achieved. A major advantage of the proposed method is that it can almost detect members of all eight groups of marine algal toxins in a single run. Using this method, several known toxins in different marine toxigenic algae including Alexandrium tamarense, Alexandrium minutum and Prorocentrum lima were successfully observed and identified. This work demonstrates that RPLC/HILIC-HR-MS combined with an accurate mass list of known marine algal toxins may be used as a powerful tool for screening of different classes of known toxins in marine harmful algae.     

Synthesis and photovoltaic properties of amorphous polymers based on dithienylbenzothiadiazole‐triphenylamine with hexyl side chains on different positions of thienyl groups

We synthesized and characterized three new amorphous dithienylbenzothiadiazole (TBT)‐triphenylamine (TPA) polymers for application in bulk‐heterojunction (BHJ) organic photovoltaic (OPV) cells. Poly(3HTBT‐TPA) has hexyl side chains on the thienyl groups (pointing toward the benzothiadiazole (BTD) unit), and poly(4HTBT‐TPA) has hexyl side chains on the thienyl groups (pointing outward from the BTD unit). The incident photon to current conversion efficiencies (IPCEs) in the region from 550 to 650 nm for the OPV cells prepared using poly(4HTBT‐TPA) were higher than those for the OPV cells prepared using poly(3HTBT‐TPA) because the absorption spectrum for the poly(4HTBT‐TPA) has a slightly red‐shifted absorption edge. We also demonstrated that the poly(4HTBT‐TPA)‐based OPV performance is independent of the fabrication process, so using an amorphous film to fabricate BHJ OPV cells offers great advantages over using a polycrystalline film in terms of the high reproducibility of the OPV performance. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2536–2544     

When Missionary Astronomy Encountered Chinese Astrology: Johann Adam Schall von Bell and Chinese Calendar Reform in the Seventeenth Century

Physics in Perspective - Western missionaries played an important role as go-betweens, promoting communication and interaction between Europe and China in science, culture, and religion. In 1644,...     

高温铜氧化物超导体的某些新进展评论

文中对近年来有关高温铜氧化物超导体(HTS)的某些重要实验的进展情况作了评述。强调目前处于HTS实验研究应起主导作用的阶段,特别是对HTS电子液体中反常电荷分布的观察,察微观瞬的技术改进实验结果,有助于解决对HTS超导机制的争论。对HTS的应用基础技术提出了建议方向。