Thread Rolling: An Efficient Mechanical Pretreatment for Corn Stover Saccharification

Sugar cane bagasse and corn stalks are rich in lignocellulose, which can be degraded into monosaccharides through enzymatic hydrolysis. Appropriate pretreatment methods can effectively improve the efficiency of lignocellulose enzymatic hydrolysis. To enhance the efficiency of enzymatic hydrolysis, thread rolling pretreatment as a physical pretreatment was applied in this study. The influence of raw material meshes size after pretreatment was also taken as the research target. Specific surface area analysis, Scanning electron microscope (SEM), X-rays diffraction (XRD), and Fourier transform infrared (FT-IR) were used for characterizations. The results showed that, the total monosaccharide recovery rates of the raw materials, 20–40 mesh, 40–60 mesh, and 60–80 mesh enzymolysis substrates were 17.6%, 34.58%, 37.94%, and 50.69%, respectively. The sample after pretreatment showed a better recovery of monosaccharide than that of the raw material. Moreover, the enzymolysis substrates with a larger mesh exhibited a higher recovery of monosaccharide than that of the enzymolysis substrates with smaller meshes. This indicated that thread rolling pretreatment can effectively improve the efficiency of enzymatic hydrolysis

A Multiple-Input Multiple-Output Inverse Synthetic Aperture Radar Imaging Method Based on Multidimensional Alternating Direction Method of Multipliers

The disadvantages of the traditional Inverse Synthetic Aperture Radar (ISAR) imaging method based on Fourier transform include large data storage and long collection time. The Compressive Sensing (CS) theory can use limited data to restore an image with the sparsity of the image, reducing the cost of data collection. However for multidimensional data, the traditional compressive sensing methods need to convert three-dimensional data into a one-dimensional vector, causing the storage and calculation burden. Therefore, this study proposes a fast MultiDimensional Alternating Direction Method of Multipliers ((MD-ADMM)) sparse reconstruction method for Multiple-Input Multiple-Output ISAR (MIMO-ISAR) imaging. The CS model based on the tensor signal was established, and the model with the ADMM algorithm was optimized. The measured matrix is decomposed into a tensor modal product, and matrix inversion is replaced by tensor element division, significantly reducing memory consumption and computational burden. Fast ISAR imaging can be achieved by a small amount of data sampling by the proposed method. Compared with other tensor compressed sensing methods, this method has the advantages of stronger robustness, higher image quality, and computational efficiency. The effectiveness of the proposed method can be invalidated by simulated and measured data

Intermetallic Palladium–Zinc Nanoparticles for the Ultraselective Hydrogenative Rearrangement of Furan Compounds

The tandem hydrogenative rearrangement of furan aldehydes/ketones into cyclopentanones is crucial for synthesizing biobased fine chemicals but remains challenging because of the complexity of the tandem reaction network. Herein, intermetallic PdZn nanoparticle-supported catalysts were prepared, which showed a high catalytic efficiency for synthesizing 3-methyl cyclopentanone with a 96.3% yield from 5-methyl furfural at the hitherto lowest temperature of 120 °C. Furthermore, they exhibited catalytic generality for the synthesis of cyclopentanones with yields above 90% from other furan aldehydes (i.e., furfural, 5-hydroxymethyl furfural, and 5-ethyl furfural) and furan ketones (i.e., 2-furan methyl ketone and 2-furan ethyl ketone). Investigations into the catalytic mechanism showed that H2 was heterolytically activated on the Pd–Zn pair to form H––Pd–Zn–H3O+ via an ionic water-mediated pathway, which not only functioned as unconventional active sites for the carbonyl group hydrogenation step but also provided Brønsted acid sites for ring opening and intramolecular aldol condensation steps. This study presents an exciting strategy for the bifunctional catalysis of challenging substrates by generating transient H+–H– pairs using advanced intermetallic alloy catalysts