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The ability to tune the size, shape, composition and surface properties impart nanoparticles with the desired functions for bio-application. This article highlights some of the recent examples in the exploration of metal (e.g., gold and silver) nanoparticles, especially those with magnetic properties and bio-conjugated structures, as theranostic nanoprobes. Such nanoprobes exhibit tunable optical, spectroscopic, magnetic, and electrical properties for signal amplifications. Examples discussed in this article will focus on the nanoproble-enhanced colorimetric detection and surface enhanced Raman scattering (SERS) detection of biomarkers or biomolecules such as proteins and DNAs. The understanding of factors controlling the biomolecular interactions is essential for the design of SERS nanoprobes with theranostic functions.

Reducing the dissolution of Mn from LiMn2O4 (LMO) and enhancing the stability of film electrodes are critical and challenging for Li+ ions selective extraction via electrochemically switched ion exchange technology. In this work, we prepared a nitrogen-doped carbon cladding LMO (C-N@LMO) by polymerization of polypyrrole and high-temperature annealing in the N2 gas to achieve the above purpose. The modified C-N@LMO film electrode exhibited lower Mn dissolution and better cyclic stability than the LMO film electrode. The dissolution ratio of Mn from the C-N@LMO film electrode decreased by 42% compared to the LMO film electrode after 10 cycles. The cladding layer not only acted as a protective layer but also functioned as a conductive shell, accelerating the migration rate of Li+ ions. The intercalation equilibrium time of the C-N@LMO film electrode reached within an hour during the extraction of Li+ ions, which was 33% less compared to the pure LMO film electrode. Meanwhile, the C-N@LMO film electrode retained evident selectivity toward Li+ ions, and the separation factor was 118.38 for Li+ toward Mg2+ in simulated brine. Therefore, the C-N@LMO film electrode would be a promising candidate for the recovery of Li+ ions from salt lakes.

In the present work, a new preconcentration method of trace elements by adsorption onto a niobium wire has been developed for electrothermal atomization atomic absorption spectrometry (ETAAS) with a tungsten tube atomizer. Detection limits (pg·mL−1) by this method combined with ETAAS were 45 for bismuth, 7.0 for cadmium, 20 for copper, 1.3 for gold, 36 for lead, 65 for manganese, 9.5 for rhodium and 19 for silver.

A response surface method was used to optimize the purification and concentration of gluconic acid from fermentation broth using an integrated membrane system. Gluconobacter oxydans was used for the bioconversion of the glucose in sugarcane juice to gluconic acid (concentration 45 g∙L–1) with a yield of 0.9 g∙g–1. The optimum operating conditions, such as trans-membrane pressure (TMP), pH, cross-flow rate (CFR) and initial gluconic acid concentration, were determined using response surface methodology. Five different types of polyamide nanofiltration membranes were screened and the best performing one was then used for downstream purification of gluconic acid in a flat sheet cross-flow membrane module. Under the optimum conditions (TMP = 12 bar and CFR = 400 L∙h–1), this membrane retained more than 85% of the unconverted glucose from the fermentation broth and had a gluconic acid permeation rate of 88% with a flux of 161 L∙m–2∙h–1. Using response surface methods to optimize this green nanofiltration process is an effective way of controlling the production of gluconic acid so that an efficient separation with high flux is obtained.

The bind-free carbon cloth-supported electrodes hold the promises for high-performance electrochemical capacitors with high specific capacitance and good cyclic stability. Considering the close connection between their performance and the amount of carbon material loaded on the electrodes, in this work, NiCo2O4 nanowires were firstly grown on the substrate of active carbon cloth to provide the necessary surface area in the longitudinal direction. Then, the quinone-rich nitrogen-doped carbon shell structure was formed around NiCo2O4 nanowires, and the obtained composite was used as electrode for electric double layer capacitor. The results showed that the composite electrode displayed an area-specific capacitance of 1794 mF·cm−2 at the current density of 1 mA·cm−2. The assembled symmetric electric double layer capacitor achieved a high energy density of 6.55 mW·h·cm−3 at a power density of 180 mW·cm−3. The assembled symmetric capacitor exhibited a capacitance retention of 88.96% after 10000 charge/discharge cycles at the current density of 20 mA·cm−2. These results indicated the potentials in the preparation of the carbon electrode materials with high energy density and good cycling stability.

A gliding arc discharge (GRD) reactor was used to decompose ethanol into primarily H2 and CO with small amounts of CH4, C2H2, C2H4, and C2H6. The ethanol concentration, electrode gap, input voltage and Ar flow rate all affected the conversion of ethanol with results ranging from 40.7% to 58.0%. Interestingly, for all experimental conditions the SH2/SCO selectivity ratio was quite stable at around 1.03. The mechanism for the decomposition of ethanol is also described.

The design of two-stage pusher centrifuges have developed rapidly, but a good understanding of the theory behind their practice is a long-standing problem. To better understand centrifugal filter processes, the computational fluid dynamics (CFD) software program FLUENT has been used to model the three-dimensional geometry and to simulate multiphase flows based on Euler-Euler, moving mesh, dynamic mesh and porous media models. The simulation tangential velocities were a little smaller than those for rigid-body motion. In the stable flow region, the radial velocities were in good agreement with the theoretical data. Additionally, solid concentration distribution were obtained and also showed good agreement with the experimental data. These results show that this simulation method could be an effective tool to optimize the design of the two-stage pusher centrifuge.

The electrochemical conversion of CO2-H2O into CO-H2 using renewable energy is a promising technique for clean syngas production. Low-cost electrocatalysts to produce tunable syngas with a potential-independent CO/H2 ratio are highly desired. Herein, a series of N-doped carbon nanotubes encapsulating binary alloy nanoparticles (MxNi-NCNT, M= Fe, Co) were successfully fabricated through the co-pyrolysis of mela-mine and metal precursors. The MxNi-NCNT samples exhibited bamboo-like nanotubular structures with a large specific surface area and high degree of graphitization. Their electrocatalytic performance for syngas production can be tuned by changing the alloy compositions and modifying the electronic structure of the carbon nanotube through the encapsulated metal nanoparticles. Consequently, syngas with a wide range of CO/H2 ratios, from 0.5:1 to 3.4:1, can be produced on MxNi-NCNT. More importantly, stable CO/H2 ratios of 2:1 and 1.5:1, corresponding to the ratio to produce biofuels by syngas fermentation, could be realized on Co1Ni-NCNT and Co2Ni-NCNT, respectively, over a potential window of −0.8 to −1.2 V versus the reversible hydrogen electrode. Our work provides an approach to develop low-cost and potential-independent electrocatalysts to effectively produce syngas with an adjustable CO/H2 ratio from electrochemical CO2 reduction.

Na+, Cl− and K+ are the most abundant electrolytes present in biological fluids that are essential to the regulation of pH homeostasis, membrane potential and cell volume in living organisms. Herein, we report synthetic crown ether-thiourea conjugates as a cation/anion symporter, which can transport both Na+ and Cl− across lipid bilayers with relatively high transport activity. Surprisingly, the ion transport activities were diminished when high concentrations of K+ ions were present outside the vesicles. This unusual behavior resulted from the strong affinity of the transporters for K+ ions, which led to predominant partitioning of the transporters as the K+ complexes in the aqueous phase preventing the transporter incorporation into the membrane. Synthetic membrane transporters with Na+, Cl− and K+ transport capabilities may have potential biological and medicinal applications.