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The liquefaction of biomass is an important technology to converse the biomass into valuable biofuel. The common technologies for liquefaction of biomass are indirect liquefaction and direct liquefaction. The indirect liquefaction refers to the Fischer–Tropsch (F–T) process using the syngas of biomass as the raw material to produce the liquid fuel, including methyl alcohol, ethyl alcohol, and dimethyl ether. The direct liquefaction of biomass refers to the conversion biomass into bio-oil, and the main technologies are hydrolysis fermentation and thermodynamic liquefaction. For thermodynamic liquefaction, it could be divided into fast pyrolysis and hydrothermal liquefaction. In addition, this review provides an overview of the physicochemical properties and common upgrading methods of bio-oil.

To explore the structure-activity relationship of membrane-targeting cationic ligands on a silver nanoparticle surface in an antibiotic-resistant antibacterial and antibiofilm activity assay, a series of functionalized silver nanocomposites were synthesized. Tuning the structural configuration, molecular weight, and side-chain length of the cationic ligands on the nanoparticle surface provided silver nanocomposites with effective antibacterial activity against both antibiotic-resistant Gram-negative and Gram-positive bacteria, including bacterial biofilms. These silver nanocomposites did not trigger hemolytic activity. Significantly, the bacteria did not develop resistance to the obtained nanocomposites even after 30 generations. A study of the antibacterial mechanism confirmed that these nanocomposites could irreversibly disrupt the membrane structure of bacteria and effectively inhibit intracellular enzyme activity, ultimately leading to bacterial death. The silver nanocomposites (64 μg/mL) could eradicate 80% of an established antibiotic-resistant bacterial biofilm. The strong structure-activity relationship toward antibacterial and antibiofilm activity suggests that variations in the conformational property of the functional ligand could be valuable in the discovery of new nano-antibacterial agents for treating pathogenic bacterial infections.

Abstract:The government green purchase is widely considered to be an effective means of promoting sustainable consumption. However, how to identify the greener product is the biggest obstacle of government green purchase and it has not been well solved. A quantitative evaluation method is provided to measure the green degree of different products of the same use function with an indicator system established, which includes fundamental indicators, general indicators, and leading indicators. It can clearly show the products' green extent by rating the scores of different products, which provides the government a tool to compare the green degree of different products and select greener ones. A comprehensive evaluation case of a project purchasing 1635 desk computers in Tianjin government procurement center is conducted using the green degree evaluation system. The environmental performance of the products were assessed quantitatively, and the evaluation price, which was the bid price minus the discount (the discount rate was according to the total scores attained by their environmental performance), and the final evaluation price ranking from low to high in turn is supplier C, D, E, A, and B. The winner, supplier C, was not the lowest bid price or the best environmental performance, but it performed well at both bid price and environmental performance so it deserved the project. It shows that the green extent evaluation system can help classify the different products by evaluating their environment performance including structure and connection technology, selection of materials and marks, prolonged use, hazardous substances, energy consumption, recyclability rate, etc. and price, so that it could help to choose the greener products.