A fully robotic method for the determination of acid values in olive oil without titration

A method for the determination of acid values (AV) in olive oil without titration is proposed, based on pH measurements on an oil sample emulsion in a suitable reagent and fully automated using a robotic station. The robot performs the weighing of the sample, adds the reagent, emulsifies both, and measures the pH of the emulsion. The data are acquired and treated by the computer. After optimization, two versions of the measurement step (interpolation within a calibration curve and addition of standard) are developed and applied to 51 oil samples with AV values that also have been determined by the standard method based on potentiometric titration. Both versions are statistically compared with the standard method, and no significant differences are found. Excellent correlation (R>0.99) between all three methods demonstrates the usefulness of the fully automated approach that works at a sample rate of 15 sample h⁻¹ with relative standard deviations lower than 2.5%.     

A facile method for fabricating nano/microfibrous three-dimensional scaffold with hierarchically porous to enhance cell infiltration

The integration of electrospinning and traditional needle punching technologies were demonstrated for fabricating a new three-dimensional (3D) scaffold to enhance the cellular infiltration. This 3D scaffold combined the advantages of electrospun polycaprolactone (PCL) nanofibrous mats and carded chitosan microfibrous webs to construct hierarchically porous, which have three regions: the large pores (about 500 μm) on the nanofibrous mats generated by needle punching, could induce the massive cells infiltration into the inner scaffold; the small pores (30–200 μm) of the microfibrous webs allowed space for continuous cellular infiltration; and the inherent smaller pores of the nanofibrous mats (1–17 μm) which play a key role in providing a platforms for cell adhesion and proliferation. In addition, the 3D scaffold exhibited appropriate mechanical properties and significantly high initial cell attachment, proliferation, and infiltration, suggesting that its great potential in tissue engineering. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47046     

基于核极限学习机的快速主动学习方法及其软测量应用

为提高主动学习方法的运行效率和降低人工标记成本,提出一种基于核极限学习机的快速主动学习方法,并将其应用于软测量建模中。首先,采用核极限学习机对无标记样本进行信息评估,将无标记样本的置信度作为样本选择评价准则,选择对改善模型性能最有价值的无标记样本进行标记;其次,充分考虑每次迭代过程的运算信息,引入矩阵反演公式优化样本选择策略,提升迭代过程样本评估的运行效率;最后,应用矩阵相似度理论对迭代过程的已标记样本数据进行信息度量,并将其作为迭代终止依据,以最小的标记代价提升模型性能。将所提方法应用于硫回收过程H₂S和SO₂浓度软测量研究中,仿真结果表明:所提方法不仅标记代价小,而且提高了迭代的快速性,比较全面地提升了主动学习算法的性能。通过开展本研究工作,为少标记样本情况下的软测量技术应用提供了一种新方法。     

A facile and efficient method for preparation of chiral supported poly(styrene–divinylbenzene) copolymers

A new and efficient method for preparation of optically active poly(styrene–divinylbenzene) copolymers (PS-DVB) is presented here. This is carried out by Friedel–Crafts acylation reaction of chiral N-phthaloyl -leucine acid chloride with PS-DVB beads in the presence of aluminum chloride as Lewis acid catalyst and 1,2-dichloroethane as the solvent at ambient temperature. Reagents’ amounts and reaction conditions are mentioned and four samples with different amounts of functionality have been prepared. Final products were characterized by FT-IR and elemental analysis. The results obtained confirm that the above modification in preparation of chiral supported PS-DVB has been achieved well and in moderate yield.