Currently, synthesis of nanoparticles from several noble metals like palladium, tin, copper, silver and gold etc. has received more attention because of their unique properties as well as their application in different fields. Furthermore, silver nanoparticles play an important role in pharmaceutical industries because they function like antibacterial agents which carry less toxic effects. In case of industrial applications, silver particles (inkjet inks) having regular dispersions are helpful in making different electronic circuits. Over the period, various synthetic methods for the synthesis of silver nanoparticles were reported i.e. physical, chemical, and photochemical. However, most of the available techniques are expensive and not eco-friendly i.e. environmentally harmful. There are various factors such as the methods of synthesis, temperature, dispersing agent, surfactant etc. which greatly influence the quality and quantity of the synthesized nanoparticles and ultimately affect their properties. It is also pertinent to mention here that the main target for these silver nanoparticles was not only to synthesize in nano range, but also require easy, eco-friendly and economical synthesis of the nanoparticles. Therefore, this review mainly goes through the several methods of synthesis of nanoparticles which should be based on the green approach, and easy to be synthesized at low cost. In addition, we also discussed some approaches to fabricate silver-based nanoparticles, their enhanced properties and their different type of applications such as electrical conductivity, antibacterial, optical, photocatalytic properties.

Silver nanoparticles: various methods of synthesis, size affecting factors and their potential applications–a review

We propose and demonstrate an ultra-broadband mode converter based on a cascade chirped long-period fiber grating (CLPFG) written in a two-mode fiber. The mode converter can convert fundamental mode ( ${\rm{HE}}_{11}^{even}$ and ${\rm{HE}}_{11}^{odd}$ modes) into the first order cylindrical vector (CV) modes (TE01, TM01, ${\rm{HE}}_{21}^{even}$ and ${\rm{HE}}_{21}^{{odd}}$ modes). We design and analyze the mode conversion characteristics of this kind of grating in theory. The simulation results show a 10 dB bandwidth of 170 nm and 20 dB bandwidth of 145 nm can be achieved by optimizing the parameters of the CLPFG. In the terms of experiment, we achieve the broadband mode converter with 10 dB bandwidth of 170 nm from 1472 nm to 1642 nm.

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Ultra-Broadband Mode Converter Using Cascading Chirped Long-Period Fiber Grating

Visible light positioning (VLP) is widely believed to be a cost-effective answer to the growing demand for service-based indoor positioning. Meanwhile, high accuracy localization is very important for mobile robots in various scenes including industrial, domestic and public transportation workspace. In this paper, an indoor robot VLP localization system based on Robot Operating System (ROS) is presented for the first time, aiming at promoting the application of VLP in mature robotic system. On the basis of our previous researches, we innovatively designed a VLP localization package which contains the basic operation control of the robots, the features extraction and recognition of the LED-ID, cm-level positioning, and robust dynamic tracking algorithms. This package exploited the proposed lightweight algorithm, distributed framework design, the loose coupling characteristics of the ROS, and the message communication methods among different nodes. What's more, an efficient LED-ID detection scheme is proposed to ensure the lightweight and accuracy of the positioning. A prototype system has been implemented on a Turtlebot3 Robot 1 1 Experiment Demonstration is available at: https://kwanwaipang.github.io/Image/ROS.mp4 . . Experimental results show that the proposed system can provide robot indoor positioning accuracy within 1 cm and an average computational time of only 0.08 s.

/pdf/high-accuracy-robot-indoor-localization-scheme-based-on-34hshmvmfx.pdf

High-Accuracy Robot Indoor Localization Scheme Based on Robot Operating System Using Visible Light Positioning

L-phenylalanine-imprinted polydopamine-coated CdS/CdSe n-n type II heterojunction as an ultrasensitive photoelectrochemical biosensor for the PKU monitoring.

Thiabendazole is likely to cause thyroid hormone imbalances and liver damage at high doses. Conventional detection methods are time-consuming with cumbersome pretreatment or insufficient sensitivity. Herein, Metal-organic framework (MOF, Mil-101(Fe))modified with inositol hexaphosphate (IP6)is fabricated by a solvothermal method and thenAg-Au-IP6-Mil-101(Fe) is obtained by in original position of MOF surface with the aid of IP6. The as-prepared Ag-Au-IP6-Mil-101(Fe) substrate exhibits high stability. Certain target molecules containing atoms of N or S could access the proximity to the surface of Au-IP6-Mil-101(Fe) substrate by the strong interaction with Fe3+ in the MOF, leading to improvement of SERS detection sensitivity. As a real application, Ag-Au-IP6-Mil-101 based Raman strategy is developed to achieve rapid detection of thiabendazole in juice and has good linearity in the range of 1.5 ppm˜75 ppm with correlation coefficient (R2) of 0.986. The detection limit for TBZ reached 50 ppb in juice sample, which meets the requirement of the national standard. In addition, the Ag-Au-IP6-Mil-101(Fe)substrate possessing peroxidase-like activity could degrade organic dyes within a short time.

Kaikai Xu

Papers

Silicon MOS Optoelectronic Micro-Nano Structure Based on Reverse-Biased PN Junction