New Strategy for Optimizing the Properties of Copper Halide Organic-Inorganic Hybrid Lighting-emitting Materials

Copper(I) halide organic-inorganic hybrid luminescent materials have many advantages, such as diverse structure, facile synthesis, high luminescent efficiency, tunable optical performance, etc., and show a broad application prospect in energy-saving lighting, display and other fields. However, compared with commercial rare-earth-metal-based phosphors, the reported hybrids generally suffer from poor stability and low luminescent efficiency, which are the bottleneck problem of their practical application. With the aim of developing high-performance organic-inorganic hybrid luminescent materials, a new synthesis strategy has been reported. This strategy can systematically design and synthesis copper(I) halide ionic hybrid structures by combining the covalent bonding and ionic bonding between inorganic and organic components into one structure, and use their synergistic effect to optimizing their properties. This design method is expected to develop high-performance organic-inorganic hybrid luminescent materials, promote the in-depth understanding of this field, and provide new ideas for the optimization of other types of hybrid materials.     

Model-free adaptive nonlinear control of the absorption refrigeration system

Nonlinear Dynamics - Based on the model-free adaptive control (MFAC) theory, the temperature tracking control problem of single-effect LiBr/H2O absorption chiller is explored. Due to the complex...     

Experimental study of impact of lubricant-derived ash on oxidation reactivity of soot generated in diesel engines

The objective of the present study was to understand how the lubricant-derived ash-loaded diesel particulate filter (DPF) impacted the soot oxidation reactivity during the regeneration process. Four major commercial lubricant additives (i.e. Ca, Zn-P, Ca-Zn-P, and Mo-P) were heated up in a muffle furnace to generate ash particles, which were mixed with diesel soot in a loose-contact pattern for further analysis. Thermogravimetric analysis (TGA) was employed for both non-isothermal and isothermal conditions to examine the oxidation reaction parameters, including ignition temperature, peak temperature and burnout temperature. In the meantime, the sizes and nanostructures of the primary soot particles during the oxidation process were characterized by high-resolution transmission electron microscopy (HRTEM). Results showed that lubricant-derived ashes accelerated the oxidation of soot particles as indicated by the reduced oxidation characteristic temperatures and increased oxidation rate. Based on the analysis of HRTEM images, both surface and internal burning phenomena existed in the oxidation processes of pure soot conditions and soot-ash mixtures conditions. The structures of shell-core, onion- and capsule-like, hollow and carbonization fragments appeared sequentially through the entire oxidation processes. Comparing to the pure soot conditions, the tendency of surface burning of the soot particles was notably increased by the lubricant-derived ashes. It was thus concluded that, the lubricant-derived ash components played the role as catalyst to promote soot oxidation and favor the whole regeneration process, even though the ashes may deteriorate performance of DPF by increased backpressures.     

面向宽带接入与泛在感知应用的基于双波长的线性化光载无线链路

Radio-over-Fiber ( RoF ) technologies have been considered to be a promising solution to broadband access and ubiquitous sensing. We present a novel approach using dual-wavelength lights to suppress the nonlinear intermodulation distortion in intensity-modulated RoF link both theoretically and experimentally. The system we proposed mainly consists of two Laser Diodes (LDs ) at different wavelengths, a commercial available Mach-Zehnder Modulator (MZM) and a Photo Detector (PD). More than 25 dB suppression of the Third-order Intermodulation Distortion (IMD3) is achieved by adjusting the wavelength and optical power of the laser. Besides , the output of the MZM is then sent to the photodetector via a single fiber, which simplifies the system complexity for distribution of RF signals over long distances .     

Ratiometric DNA Walking Machine for Accurate and Amplified Bioassay

DNA walking machines opened new avenues for the biosensing and demonstrated great success in the past few years. Since DNA machines are mainly nonequilibrium systems driven by dynamic interactions, the matrix effects on DNA machines is a bottleneck and more intricate than common DNA-mediated assays, especially for complicated physiological samples. Herein, to realize an accurate and reliable quantitative machine, a ratiometric DNA walking machine was developed in human serums and cell lysates based on the elemental isotope ratio measurement. The target DNA-triggered walking machine converted and amplified biological signals into mass spectrometric signal ratios (¹⁹⁷Au/¹¹⁵In) via a burnt-bridge mechanism. Under the optimized conditions, the limit of detection (LOD, 3σ) was 8 fM for target DNA, with a dynamic linear range of 0.05–0.7 pM. The ratiometric DNA walking machine was directly applied in human serum samples with satisfactory recoveries of 94 to 105 %, demonstrating an excellent stability and a high accuracy. Combining the aptamer-based specific recognition, the proposed DNA machine is expected to be a versatile platform for other targets, such as small biomolecules and proteins.     

Facile synthesis of Fe3O4/reduced graphene oxide/polyvinyl pyrrolidone ternary composites and their enhanced microwave absorbing properties

In this paper, ternary nanocomposites of Fe₃O₄/reduced graphene oxide/polyvinyl pyrrolidone (Fe₃O₄/rGO/PVP) as a novel type of electromagnetic microwave absorbing materials were synthesized by a three-step chemical approach. First, Fe₃O₄ nanospheres were made by solvent thermal method. Successively, the Fe₃O₄ particles were assembled with rGO after having activated by para-aminobenzoic acid. PVP grafting and reduction of GO happened simultaneously in the third step. It is found that the electromagnetic absorption (EA) performance of synthesized ternary composites with suitable PVP amount had been significantly enhanced comparing to Fe₃O₄ and Fe₃O₄/rGO. Merely 15?wt% low loading in paraffin and thin as 2.8?mm can reach effective EA bandwidth (below ?10 Db) of 11.2?GHz, and the highest reflection loss reached ?67?dB at 10.7?GHz. It was demonstrated that these composites show an effective route to novel microwave absorbing material design.