Pulsed laser ablation in liquid for micro-/nanostructure generation

Pulsed laser ablation in liquid is an approach for micro-/nanostructure generation directly from bulk materials. It has grown rapidly as a research field of photochemistry and physical chemistry in the last decade, and represents a combinatorial library of constituents and interactions, but the understanding of this library is still insufficient. This review attempts to build up a comprehensive mechanistic scenario of pulsed laser ablation in liquid and illustrate the underlying principles to micro-/nanostructure generation. Various structures produced by this method have been summarized that provide prototypes for potential applications in sensing, optoelectronics, and biomedicine, etc.     

Facile synthesis and characterization of high-performance NiMoO<Subscript>4</Subscript> · <Emphasis Type="Italic">x</Emphasis>H<Subscript>2</Subscript>O nanorods electrode material for supercapacitors

One-dimensional NiMoO₄ · xH₂O nanorods were synthesized by a facile template-free hydrothermal method as a potential electrode material for supercapacitors. The influences of reaction temperature, reaction time, and nickel source on the properties of resultant samples were investigated. Electrochemical data reveal that the as-synthesized one-dimensional NiMoO₄ · xH₂O nanorod superstructures can deliver a remarkable specific capacitance (SC) of 1131 F g^?1 at a current density of 1 A g^?1 and remain as high as 914 F g^?1 at 10 A g^?1 in a 6 M KOH aqueous solution. Moreover, there is only 6.2 % loss of the maximum SC after 1000 continuous charge–discharge cycles at the high current density of 10 A g^?1. Such outstanding electrochemical performance may be owing to the unique one-dimensional hierarchical structures, which can facilitate the electrolyte ions and electrons to easily contact the NiMoO₄ nanorod building blocks and then allow for sufficient faradaic reactions to take place, even at high current densities.     

Hexa-peri-benzocoronene with two extra K-regions in an ortho-configuration

There are three possible isomers for hexa-peri-hexabenzocoronene (HBC) with two extra K-regions, but only two of them have been reported, namely with the meta- and para-configurations. Herein, we describe the synthesis of HBC 4 with two extra K-regions in the ortho-configuration, forming a longer zigzag edge compared with the other two isomers. The structure of 4 was validated by laser desorption/ionization time-of-flight mass analysis and nuclear magnetic resonance spectra, as well as Raman and infrared spectroscopies supported by density functional theory calculations. The optical properties of 4 were investigated by UV/vis absorption and ultrafast transient absorption spectroscopy. Together with the analysis of aromaticity, the influence of the zigzag edge on the π-conjugation pathway and HOMO–LUMO gaps of the three isomers were investigated.

We reported the synthesis of hexa-peri-benzocoronene (HBC) with two extra K-regions adopting an ortho-configuration. The systematical study provides deep insights about the effect of zigzag edge on the π-conjugated pathway and molecular design.     

Multi-mode Gaussian Modulated Continuous-Variable Measurement-Device-Independent Quantum Key Distribution

We propose a novel multi-mode Gaussian modulated continuous variable measurement-device-independent quantum key distribution (MDI-CVQKD) protocol where Alice and Bob prepare independent and identically distributed Gaussian modulated coherent states in multiple independent modes respectively along with Charlie using a traditional noise homodyne detector to measure. Since it is completely handed over to an untrusted third party (Charlie) to measure, this protocol can effectively eliminate the defects of the actual detector. As well as, we also proved that the multi-mode MDI-CVQKD protocol can reduce electronic noise. The simulation results show that the multi-mode Gaussian modulated MDI-CVQKD protocol can indeed significantly improve the key rate of the original Gaussian modulated MDI-CVQKD protocol, and extend the maximum secure transmission distance of the secret key.

     

多孔材料填充薄壁结构吸能的相互作用效应

研究多孔材料填充薄壁结构的相互作用效应产生的机理,并建立了表征模型. 以泡沫 铝填充帽形结构为例,发现压溃的填充物分为致密区、过致密区和未变形区3个区域. 基于 理想可压缩假设建立了填充多孔材料分析模型,获得各区域体积变化和等效应变等关系;结 合薄壁结构超叠缩单元模型,对填充结构各组分的能量吸收进行了拆分. 研究表明,薄壁结 构的吸能略有增加,多孔材料的吸能增加40{\%}左右. 过致密区的形成是相互作用效应的 主要原因.     

9-亚胺二苯并型环状碘鎓盐的合成

二苯并型环状碘鎓盐(结构通式如1)是一类人工合成的化合物,近30年的研究表明,某些二苯并型环状碘鎓盐具有抑菌、降血压,抗辐射及抗心律失常^[1-4]等生理活性.     

Antibacterial and surface-enhanced Raman scattering (SERS) activities of AgCl cubes synthesized by pulsed laser ablation in liquid

We used pulsed laser ablation in liquid to fabricate silver chloride (AgCl) nanocubes directly from a bulk Ag target in sodium chloride (NaCl) solution. We optimized particle size and investigated the surface properties of the cubes for their Surface Enhanced Raman Scattering (SERS) behavior relative to Rhodamine 6G (R6G). The SERS behavior was related to the surface properties, clearness, and morphology, i.e., varied atomic arrangements and surface energies of different facets of the cubes. In addition, we have demonstrated that our easily synthesized AgCl cubes were antibacterial with a high efficiency to decontaminate Escherichia coli upon contact. Our results can be extended to generate particle-based coatings with antibacterial properties.     

Interaction between (1,1'-Binaphthalene)-2,2'-diol and Lecithin Liposome

The interaction between (1,1′‐binaphthalene)‐2,2′‐diol (BINOL) and lecithin liposome was studied by UV‐Vis, fluorescence and ¹H NMR spectroscopies. BINOL can obviously associate with lecithin liposome and the preferential binding site of BINOL with lecithin liposome is located in the headgroup region. The hydrogen bond and electrostatic interaction should exist in BINOL/liposome system, which restricts intra‐annular rotation of naphthol moieties. Therefore, the fluorescence intensity of BINOL increases when a small quantity of liposome is added into the system. The partition coefficient K_D between the lecithin liposome and the aqueous phase is 310.9. With the increase of BINOL concentration, the micropolarity (I₁/I₃) and membrane fluidity of liposome decreased, while the viscosity of membrane increased.     

热处理对氢气放电实验用靶的影响

对本底靶进行热处理后用TiT源重新开展打靶实验,未知谱线消失,证明未知谱线不是由靶中杂质造成的。将同种材料制成的两块本底靶分别进行热处理和不做任何处理,置于氢气放电源中进行照射生成源照靶,用TiT源打这两块源照靶发现照射前经热处理的靶产生的4条未知谱线较强,证明热处理能够增强靶吸附未知粒子的能力。     

Visualization of Ferroelectric Domains in Thin Films of Molecular Materials Using Confocal Micro-Raman Spectroscopy

Ferroelectrics are an important class of functional materials. Among all their unique properties, the study of their ferroelectric domains and domain walls is of great interest due to their importance in ferroelectric applications. There are many methods to characterize ferroelectric domains, namely, scanning probe microscopy, optical microscopy, electron microscopy, etc. Currently, newly emerged molecular ferroelectrics are attracting much attention from chemists, physicists and researchers in material sciences due to their structural flexibility, light mass, simple fabrication, etc. However, for the characterization of molecular ferroelectric domains, most conventional methods require either a complicated preparation process or direct contact between physical probes and material surfaces, limiting the development of molecular ferroelectric materials. In this report, we have demonstrated that confocal micro-Raman spectroscopy, as a nondestructive and noncontact in-situ method, is very suitable for studying the ferroelectric polarization and structures of domains in molecular ferroelectrics. Taking recently reported molecular ferroelectric trimethylchloromethyl ammonium trichlorocadmium(II) (TMCM-CdCl₃) as an example, the non-180° domains have been characterized and visualized at different temperatures. Such a simple and extendable method requires minimum sample preparation, which would further benefit the research of molecular ferroelectric domain engineering and promote the miniaturization and integration of molecular ferroelectric films.