Three different potassium phosphates (KH 2 PO 4 , K 2 HPO 4 , and K 3 PO 4 ) were tested as potential homogeneous catalysts for the hydrothermal liquefaction of soybean oil, soy protein, potato starch, microcrystalline cellulose, and their mixture. Na 2 CO 3 and KOH, which have been widely applied in hydrothermal liquefaction (HTL) reactions, were also investigated for comparison to phosphates. The addition of K 2 HPO 4 and K 3 PO 4 , which form basic solutions, led to yields of biocrude from HTL of starch and cellulose that were sometimes 2−5 times higher than those without phosphates. Adding Na 2 CO 3 , which also forms a basic solution, for HTL of polysaccharides also generated higher biocrude yields but not as high as those obtained with added phosphates. The use of KOH (another base) resulted in the highest yield of biocrude from HTL of the mixture. These additives, along with Na 2 CO 3 , also resulted in less solid residue being produced. The additives had almost no positive effect, however, on biocrude production from HTL of soybean oil or soy protein. The biocrudes produced from polysaccharides with added K 2 HPO 4 , K 3 PO 4 , and Na 2 CO 3 have larger heating values and greater energy recoveries. The biocrudes mainly consist of acids/esters, alcohols, phenols, and ketones/aldehydes. The addition of phosphates led to a higher proportion of ketones/aldehydes at the expense of alcohols.

Supercritical fluid extraction (SFE), as a new green extraction technology, has been used in extracting various metal species. The solubilities of chelating agents and corresponding metal chelates are the key factors which influence the efficiency of SFE. Other main properties of them such as stability and selectivity are also reviewed. The extraction mechanisms of mainly used chelating agents are explained by typical examples in this paper. This is the important aspect of SFE of metal ions. Moreover, the extraction efficiencies of metal species also depend on other factors such as temperature, pressure, extraction time and matrix effect. The two main complexation methods namely in-situ and on-line chelating SFE are described in detail. As an efficient chelating agent, tributyl phosphate-nitric acid (TBP-HNO) complex attracts much attention. The SFE of metal ions, lanthanides and actinides as well as organometallic compounds are also summarized. With the proper selection of ligands, high efficient extraction of metal species can be obtained. As an efficient sample analysis method, supercritical fluid chromatography (SFC) is introduced in this paper. Recently, the extraction method combining ionic liquids (ILs) with supercritical fluid has been becoming a novel technology for treating metal ions. The kinetics related to SFE of metal species is discussed with some specific examples.

As an important load-bearing component, steel wire ropes (WRs) are widely used in complex systems such as mine hoists, cranes, ropeways, elevators, oil rigs, and cable-stayed bridges. Non-destructive damage detection for WRs is an important way to assess damage states to guarantee WR’s reliability and safety. With intelligent sensors, signal processing, and pattern recognition technology developing rapidly, this field has made great progress. However, there is a lack of a systematic review on technologies or methods introduced and employed, as well as research summaries and prospects in recent years. In order to bridge this gap, and to promote the development of non-destructive detection technology for WRs, we present an overview of non-destructive damage detection research of WRs and discuss the core issues on this topic in this paper. First, the WRs’ damage type is introduced, and its causes are explained. Then, we summarize several main non-destructive detection methods for WRs, including electromagnetic detection method, optical detection method, ultrasonic guided wave detection method, and acoustic emission detection method. Finally, a prospect is put forward. Based on the review of papers, we provide insight about the future of the non-destructive damage detection methods for steel WRs to a certain extent.

Herein, a selective tandem C–C bond-forming reaction with CO2 was developed to realize the bridging of enaminones and synthesis of 1,4-dihydropyridines, respectively. n-Butylamine significantly promoted this CO2 deoxymethylenation procedure catalyzed by 1,5,7-triazabicyclo[4.4.0]­dec-5-ene (TBD) and ZnCl2. The mechanism involving the formation of bis­(silyl)­acetal, nucleophilic addition, and amine elimination was also interpreted to clarify the bridging of two molecules of enaminones with CO2 and the generation of dihydropyridine derivatives.