Cu-SiC磨具制备及其性能表征

笔者描述了铜-碳化硅磨具的制备过程,采用热压成形法制备了Cu-SiC磨具。该磨具主要由铜粉、酚醛环氧树脂和碳化硅磨料组成。研究了树脂、碳化硅与辅助磨料的种类、组成对磨具性能的影响。结果表明:当加入适量铜粉,复合材料磨损率会下降、耐磨性能会提高,被磨削表面不易出现凹痕、孔洞;但是铜粉添加过量时,磨具磨损率会增加。较佳配方组成为:35wt%树脂、45wt%碳化硅、15.56wt%铜粉、4.44wt%白刚玉。     

Mild oxidative degradation of spent auricularia auricular substrate and molecular composition of carboxylic acids in the resulting soluble portion

Spent auricularia auricular substrate(SAAS) was oxidatively degraded with aqueous hydrogen peroxide(AHPO)/acetic anhydride(AAH) to produce carboxylic acids(CAs) under mild conditions. The results show that up to 53.6% of the organic matter in SAAS was converted to the soluble species(SSs). In total 122 CAs were detected in the SSs by the analysis with a gas chromatograph/mass spectrometer, which can be classified into 29 group components, mainly being aliphatic acids and along with small amount of aromatic acids. Among the aliphatic acids, normal alkanedioic acids are the most abundant. The detected aromatic acids include benzoic acids,phthalic acids, trimellitic acids, pyromellitic acids, and their derivatives. The synergistic oxidation and the released ·OH, CH_3COO·, and HOO· induced by AHPO/AAH play crucial roles in oxidatively degrading SAAS.     

Prediction of curved oil–water interface in horizontal pipes using modified model with dynamic contact angle

In this study, interface shapes of horizontal oil–water two-phase flow are predicted by using Young-Laplace equation model and minimum energy model. Meanwhile, the interface shapes of horizontal oil–water twophase flow in a 20 mm inner diameter pipe are measured by a novel conductance parallel-wire array probe(CPAP). It is found that, for flow conditions with low water holdup, there is a large deviation between the model-predicted interface shape and the experimentally measured one. Since the variation of pipe wetting characteristics in the process of fluid flow can lead to the changes of the contact angle between the fluid and the pipe wall, the models mentioned above are modified by considering dynamic contact angle. The results indicate that the interface shapes predicted by the modified models present a good consistence with the ones measured by CPAP.     

Egg shell waste as an activation agent for the manufacture of porous carbon

Egg shell waste was used as an activation agent directly for the manufacture of a biomass-derived porous carbon,which possessed a surface area of 626 m~2·g~(-1) and was rich in nitrogen, sulfur and oxygen functionalities. The activation mechanism was proposed, and the carbon showed its potential to act as an adsorbent for the adsorptive removal of various contaminants from both aqueous and non-aqueous solutions, possessing maximum adsorption capacities of 195.9, 185.1, 125.5 and 44.6 mg·g~(-1) for sulfamethoxazole, methyl orange, diclofenac sodium and dibenzothiophene, respectively. Through the utilization of egg shell waste as a sustainable activation agent, this work may help to make the widely applied biomass-derived porous carbons more economical and ecological.