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Chromium (Cr(VI)) pollution poses a serious threat to the ecological environment and biological health; therefore, there is an urgent need to develop advanced technologies for Cr(VI) detection and removal. Here, a novel fluorescent wood sponge (citric acid modified wood sponge decorated with carbon dots, CA/WS-CDs) was constructed combining hierarchical porous wood sponge (WS) and carbon dots (CDs) via chemical bonding, which could simultaneously detect and remove hexavalent Cr(VI) in an aqueous medium. The chemical and physical structure of the fluorescent wood sponge was characterized, and its detection and adsorption performances for Cr(VI) were studied. The results demonstrated that the CA/WS-CDs showed excellent performance for Cr(VI) detection and removal. After being immersed in a Cr(VI) solution (50 mL, 50 mg L−1) at 25 °C for 24 h, the strong blue fluorescence of CA/WS-CDs-3 under 365 nm light weakened and fluorescence quenching started to occur, which makes the fluorescent wood sponge a detector of Cr(VI). Moreover, this novel fluorescent wood sponge had a higher adsorption ability for Cr(VI) (maximum adsorption capacity, 450.5 mg g−1), and its sorption performance met Langmuir and pseudo-second-order models. Furthermore, FTIR and XPS analysis confirmed that the hierarchical structure of the fluorescent wood sponge provided many effective sorption sites and ion transport channels, thereby guaranteeing the selective detection and efficient adsorption properties for Cr(VI). Such intriguing Cr(VI) warning and sorption performance make the proposed CA/WS-CDs hold huge prospects for practical environmental remediation.

Feedstock recovery plays a crucial role in the further application of polylactic acid (PLA), yet it still lacks efficient ways, resulting from an unclear understanding of PLA pyrolysis. Hence, the co-pyrolysis of PLA and the major components of biomass additives cellulose, hemicellulose and lignin was carried out to enhance the feedstock lactide yield and explore the pyrolysis mechanism. Compared to cellulose/PLA and hemicellulose/PLA, the co-pyrolysis of lignin/PLA had the strongest synergistic effects. Based on in situ FTIR and Py-GC/MS, the promoting mechanism was as follows: 4-ethyl-2-methoxy-phenol produced by the pyrolysis of lignin provided additional free radicals for the free radical reaction of PLA so that the production of lactide increased by 162.8%. The activation energy of co-pyrolysis was 30.6% and 13.8% lower than those of lignin and PLA, respectively, which was also due to the fact that lignin promoted the free radical reaction of PLA. It was indicated that co-pyrolysis required less energy than that of single pyrolysis. In addition, the generated lactide was not well-compatible with other bio-oils and solidified at room temperature, so it could be recycled by simple physical separation. This work provided a new method for the reuse of large amounts of waste PLA and lignin waste such as papermaking black liquor.

Frequent oil-spill accidents have posed serious threats to ecosystem balance and the efficiency of resources use. Hydrophobic adsorbents that can adsorb and recover oil without causing secondary pollution are ideal candidates for the remediation of oil contamination in water. However, these composites are inefficient for crude oil-spills cleanup because crude oil has low liquidity of at room temperature. Increasing the temperature can effectively enhance the flowability of crude oil. To achieve efficient crude-oil heating and removal in situ, wood aerogels were immersed in Ti

In this study, poplar chemi-mechanical pulp was used as a raw material to investigate the effect of enzymatic hydrolysis lignin (EHL) content on the tensile strength and hydrophobicity of molded fiber materials (MFMs). The tensile strength and hydrophobic properties of the fabricated MFMs with different EHL contents were evaluated, and changes in their microstructure, chemical structure, and thermal stability were characterized via scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric (TG) analysis, respectively. Results show that under the experimental conditions used herein, the addition of EHL could increase the tensile strength and surface water contact angle of MFMs up to 20.3 MPa and 95.0°, respectively. The SEM observations indicate that the addition of EHL expanded the contact area between the EHL and fibers, thereby reducing the holes between fibers. The FTIR and TG analyses indicated that hot-pressing degraded EHL to form small molecular substances and improved the reaction with aldehydes produced via carbohydrate degradation, improving both the inter-fiber bonding strength and hydrophobicity of the MFM surface.

Cellulose nanocrystals (CNCs) were fabricated using rubber wood (RW) as the raw material via acid hydrolysis followed by ultrasonication. The CNCs samples were then grafted with succinic anhydride to obtain modified CNCs, hereafter called CS. The CS samples were subsequently coated with a cationic surfactant, cetyltrimethyl ammonium bromide, and the obtained samples were named as CC. The morphology, chemical structure, and thermal stability of the RW, CNCs, CS, and CC samples were characterized using transmission electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis, respectively. Finally, the drug release performance was investigated using CC as the drug carrier and hesperidin, a hydrophobic drug, as the model drug. The drug release mechanism was also considered. The results of this study identified a new route for the high-value utilization of RW and also demonstrated that RW could be used as a novel substrate for the construction of cellulose-based hydrophobic drug delivery systems.

Nanocellulose crystals (NCCs) were successfully prepared via acid hydrolysis from an abundant agricultural waste (tea stalk) in China. The effective factors for NCC yield were modeled by the response surface methodology (RSM). The RSM determined the reaction conditions (H2SO4 concentration, hydrolysis temperature, and reaction time) that optimized the yield of tea stalk NCCs (TNCCs). Under the optimized operating conditions, the fundamental properties of TNCCs were characterized via transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), laser diffraction particle-size analyzer, and scanning probe microscopy (SPM). Wood NCCs (WNCCs) and microcrystalline NCCs (MNCCs) were simultaneously prepared from common wood and microcrystalline cellulose under the same conditions. The results show that TNCCs not only shows similar physical and chemical properties with WNCCs and MNCCs, but also has better stability. Therefore, this study offers novel routes for high-valued utilization of tea stalk and provides some theoretical guidance for utilizing cellulose obtained from tea stalk.

Person search aims to search for a target person among multiple images recorded by multiple surveillance cameras, which faces various challenges from both pedestrian detection and person re-identification. Besides the large intra-class variations owing to various illumination conditions, occlusions and varying poses, background clutters in the detected pedestrian bounding boxes further deteriorate the extracted features for each person, making them less discriminative. To tackle these problems, we develop a novel approach which guides the network with segmentation masks so that discriminative features can be learned invariant to the background clutters. We demonstrate that joint optimization of pedestrian detection, person re-identification and pedestrian segmentation enables to produce more discriminative features for pedestrian, and consequently leads to better person search performance. Extensive experiments on two widely used benchmark datasets prove the superiority of our approach. In particular, our proposed model achieves the state-of-the-art performance (86.3% mAP and 86.5% top-1 accuracy) on CUHK-SYSU dataset.

In this study, halloysite (Hal)/cellulose nanofiber (CNF) composite films were prepared using vacuum-filtering assembly method. Microstructures, chemical composition, crystal structures, thermal performances, mechanical properties, and light transmission properties of the composite films were characterized. The results showed that Hal was well uniformly dispersed in the composite films. The interactions between Hal and CNF endowed the formation of a robust network structure, and the surfaces of the composite films were rough by the addition of Hal. X-ray diffraction result showed the crystallinity of CNF declined by Hal, while the thermal stability of the composite films increased remarkably. The tensile strength of the composite films increased compared with pure CNF film, for example, the tensile strength and the elongation at break of the composite film with 3 Hal was 41.9 MPa and 11.7%, respectively. As the content of Hal in the composite film increased, the light transmittance of the composite film decreased, since the addition of Hal led to a growth in the haze of the composite films. The prepared high-performance Hal/CNF composite films show promising application in degradable food package.

Visual target tracking is the key problem in intelligent video processing. Particle Filter is classic and effective in visual target tracking algorithms, but it needs to analyze a large amount of probability statistic, leading to high algorithm complexity and low calculation efficiency. FPGA provides a competitive alternative for hardware acceleration to these applications. In this paper, we modify Particle Filter algorithm and propose a FPGA- based hardware accelerating architecture. Experiments show the embedded architecture is robust and shows a great real-time performance.