Nanoparticle-free, Fluorine-free, and Robust Superhydrophobic Cotton Fabric Fabricated Using a Combination of Etching Method and Mist Polymerization Technology

Qingbo Xu,Xinyu Wang,Wei Xu,Yanyan Zhang,Zhenzhen Xu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.6

Immobilizing inorganic or organic particles on cotton fabric to increase the surface roughness, followed by coatingwith low surface reagents to reduce the surface energy, are the dominant strategies to prepare the superhydrophobic cottonsurface. However, the inorganic or organic particles can easily fall off the surface of the fabrics. Thus, the surface roughnessof the fabric could be reduced during the process, resulting in the poor durability of the superhydrophobic fabric. In this work,the surface of the cotton fabric was etched by cellulase. Following this, the treated fabric was grafted using a diblockcopolymer (poly[(methyl methacrylate)-b-(2-(dimethylamino)ethyl)] (PMMA-b-PDMAEMA)), which was synthesizedfollowing the reversible addition-fragmentation chain transfer (RAFT) polymerization process. The mist polymerizationtechnology was used for the process. The coatings successfully endowed the cotton fabric with superhydrophobic properties. The maximum WCA value recorded was 159.9 °. The treated fabric exhibited excellent mechanical and chemical stability. Moreover, the modified cotton sample also exhibited good self-cleaning effects in the presence of solid dust and liquidcontaminants. It also exhibited excellent oil-water separation properties. Therefore, the superhydrophobic fabric preparedusing a combination of the etching method and mist polymerization technology can find its potential application in home andindustrial areas.

A 5.6 kW 11.7 kW per kg Four-Phase Interleaved Buck Converter for the Unmanned Aerial Vehicle

Cheng Xu-Feng,Peng Zhenzhen,Yang Yulong,Liang Zhimin,Wu Chaofeng,Shao Zhiwei,Wang Dianlong 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.2

This paper proposed a 5.6 kW 11.7 kW/kg four-phase interleaved buck converter (FPIBC) for the unmanned aerial vehicle (UAV) low-voltage power system. The UAV mainly concerns the lightweight strategy and the power density of the DC-DC converter. We proposed a comprehensive lightweight strategy with the characteristics of reduced inductor current ripples, small size of fi lter inductors and capacitors, and high output power. The output current ripples are reduced by using interleaved modulation strategy and integrated CLC fi lters cascaded to the input side and output side respectively. In addition, the aluminum based printed circuit board (PCB) is used with SMD power transistors to obtain better heat dissipation capability without fans. With abovementioned methods, the designed DC-DC converter has a power of 5.6 kW @ 0.48 kg, the powerto-weight ratio is improved to be 11.7 kW/kg, and the power density is 3 W/cm 3 . The effi ciency of this DC-DC converter is up to 95.8%.

Tertiary Amination/Hydroxypropylsulfonation of Cornstarch to Improve the Adhesion-to-Fibers and Film Properties for Warp Sizing

Wei Li,Zhenzhen Xu,Zongqian Wang,Changlong Li,Quan Feng,Yanan Zhu 한국섬유공학회 2018 Fibers and polymers Vol.19 No.7

To investigate the effects of tertiary amination/hydroxypropylsulfonation on the adhesion-to-fibers and film properties of corn starch for warp sizing, a series of tertiary aminated and hydroxypropylsulfonated corn starch (TAHPSS) samples were prepared by the tertiary amination and hydroxypropylsulfonation of acid-hydrolyzed corn starch (AHS) with 2- dimethylaminoethyl chloride hydrochloride (DMC-HCl) and 3-chloro-2-hydroxy-1-propanesulfonic acid sodium salt (CHPS-Na) simultaneously. The adhesion was evaluated by measuring the bonding force of starch to the fibers. The film properties were investigated in terms of tensile strength, breaking elongation, degree of crystallinity, and moisture regain. The results showed that tertiary amination/hydroxypropylsulfonation was able to increase bonding forces of starch to cotton and polyester fibers, enhance breaking elongation and moisture regain of the starch film and to decrease the tensile strength and degree of crystallinity of the film, thereby improving the adhesion and reducing film brittleness. Increasing the level of tertiary amination/hydroxypropylsulfonation was favorable for gradually improving the adhesion and decreasing the brittleness. The TAHPSS showed potential for use in cotton warp sizing.

Improvement of the Steroid Dihydroxylation Efficiency from Dehydroepiandrosterone Using a Substrate Pre-induction Biotransformation Process

Hui Li,Zhenzhen Fu,Heng Li,Wenfang Dou,Jinsong Shi,Zhenghong Xu 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.3

This study investigated the effects of hydroxylase cyptochrome P450 inducers on the efficiency of the biotransformation of dehydroepiandrosterone (DHEA) to 3β, 7α, 15α-trihydroxy-5-androsten-17-one (7α,15α-diOHDHEA)by Colletotrichum lini ST-1. Special attention was given to the substrate DHEA being the best inducer and the fact that it could improve the yield of 7α, 15α-diOHDHEA. Based on the effects of the DHEA pre-induction phases and additional concentrations on 7α, 15α-diOHDHEA production, a substrate pre-induction process was established as follows: 2 g/L DHEA was added for the first time after 12 h of inoculation, followed by the second addition of 6 g/L DHEA after 12 h later. The results showed that this substrate pre-induction process improved the content of cytochrome P450 and that the 7α, 15α-diOH-DHEA yield reached 90.1%, which was 26.9%higher than that obtained in the original process.

Effect of inoculants and storage temperature on the microbial, chemical and mycotoxin composition of corn silage

Musen Wang,Shengyang Xu,Tianzheng Wang,Tingting Jia,Zhenzhen Xu,Xue Wang,Zhu Yu 아세아·태평양축산학회 2018 Animal Bioscience Vol.31 No.12

Objective: To evaluate the effect of lactic acid bacteria and storage temperature on the microbial, chemical and mycotoxin composition of corn silage. Methods: Corn was harvested at 32.8% dry matter, and chopped to 1 to 2 cm. The chopped material was subjected to three treatments: i) control (distilled water); ii) 1×106 colony forming units (cfu)/g of Lactobacillus plantarum; iii) 1×106 cfu/g of Pediococcus pentosaceus. Treatments in triplicate were ensiled for 55 d at 20°C, 28°C, and 37°C in 1-L polythene jars following packing to a density of approximately 800 kg/m3 of fresh matter, respectively. At silo opening, microbial populations, fermentation characteristics, nutritive value and mycotoxins of corn silage were determined. Results: L. plantarum significantly increased yeast number, water soluble carbohydrates, nitrate and deoxynivalenol content, and significantly decreased the ammonia N value in corn silage compared with the control (p<0.05). P. pentosaceus significantly increased lactic acid bacteria and yeast number and content of deoxynivalenol, nivalenol, T-2 toxin and zearalenone, while decreasing mold population and content of nitrate and 3-acetyl-deoxynivalneol in corn silage when stored at 20°C compared to the control (p<0.05). Storage temperature had a significant effect on deoxynivalenol, nivalenol, ochratoxin A, and zearalenone level in corn silage (p<0.05). Conclusion: Lactobacillus plantarum and Pediococcus pentosaceus did not decrease the contents of mycotoxins or nitrate in corn silage stored at three temperatures.

A Dual-scale Network with Spatial-temporal Attention for 12-lead ECG Classification

Shuo Xiao,Yiting Xu,Chaogang Tang,Zhenzhen Huang 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.9

The electrocardiogram (ECG) signal is commonly used to screen and diagnose cardiovascular diseases. In recent years, deep neural networks have been regarded as an effective way for automatic ECG disease diagnosis. The convolutional neural network is widely used for ECG signal extraction because it can obtain different levels of information. However, most previous studies adopt single scale convolution filters to extract ECG signal features, ignoring the complementarity between ECG signal features of different scales. In the paper, we propose a dual-scale network with convolution filters of different sizes for 12-lead ECG classification. Our model can extract and fuse ECG signal features of different scales. In addition, different spatial and time periods of the feature map obtained from the 12-lead ECG may have different contributions to ECG classification. Therefore, we add a spatial-temporal attention to each scale sub-network to emphasize the representative local spatial and temporal features. Our approach is evaluated on PTB-XL dataset and achieves 0.9307, 0.8152, and 89.11 on macro-averaged ROC-AUC score, a maximum F1 score, and mean accuracy, respectively. The experiment results have proven that our approach outperforms the baselines.

Aligned nanofibrous collagen membranes from fish swim bladder as a tough and acid-resistant suture for pH-regulated stomach perforation and tendon rupture

Zhaohui Luan,Shuang Liu,Wei Wang,Kaige Xu,Shaosong Ye,Ruijue Dan,Hong Zhang,Zhenzhen Shu,Tongchuan Wang,Chaoqiang Fan,Malcolm Xing,Shiming Yang 한국생체재료학회 2022 생체재료학회지 Vol.26 No.4

Background: Wound closure in the complex body environment places higher requirements on suture’s mechanical and biological performance. In the scenario of frequent mechanical gastric motility and extremely low pH, single functional sutures have limitations in dealing with stomach bleeding trauma where the normal healing will get deteriorated in acid. It necessitates to advance suture, which can regulate wounds, resist acid and intelligently sense stomach pH. Methods: Based on fish swim bladder, a double-stranded drug-loaded suture was fabricated. Its cytotoxicity, histocompatibility, mechanical properties, acid resistance and multiple functions were verified. Also, suture’s performance suturing gastric wounds and Achilles tendon was verified in an in vivo model. Results: By investigating the swim bladder’s multi-scale structure, the aligned tough collagen fibrous membrane can resist high hydrostatic pressure. We report that the multi-functional sutures on the twisted and aligned collagen fibers have acid resistance and low tissue reaction. Working with an implantable “capsule robot”, the smart suture can inhibit gastric acid secretion, curb the prolonged stomach bleeding and monitor real-time pH changes in rabbits and pigs. The suture can promote stomach healing and is strong enough to stitch the fractured Achilles tendon. Conclusions: As a drug-loaded absorbable suture, the suture shows excellent performance and good application prospect in clinical work.

Lotus-Like Nano-Architectures Constructed from Self-Assembled Micelles via Hierarchical Assembly

Rongli Zhang,Xiaoxia Fan,Xiaofang Xu,Jingjing Lv,Zhenzhen Jin,Hui Hao,Cuige Zhang 한국고분자학회 2018 Macromolecular Research Vol.26 No.1

Dopamine modified γ-polyglutamic acid (γ-PGA-DA) copolymer and melamine (Mel) can self-assemble into Mel/γ-PGA-DA micelles via weak intermolecular interactions in aqueous solution containing small amount of methanol. When Mel/γ-PGA-DA micellar solution was cast on the surface of formvar stabilized with carbon support films, the lotus-like nano-architectures were formed on the surface of substrate via hierarchical assembly of micelles. The size of lotus-like nanoarchitectures was approximately 200 nm×500 nm. The possible driving forces for hierarchical assembly of micelles were the solution fluid and interaction between micelles. The hierarchical assembly of micelles was similar to the fractal aggregation of inorganic particles and a possible reason was discussed.

Simultaneous regulation of photoabsorption and ferromagnetism of NaTaO3 by Fe doping

Huan Yang,Liguo Zhang,Lifang Yu,Fang Wang,Zhenzhen Ma,Jie Zhou,Xiaohong Xu 한국물리학회 2018 Current Applied Physics Vol.18 No.11

NaTa1-xFexO3 (0≤x≤0.40) nanocubes were synthesized by a relatively low temperature hydrothermal method, using Ta2O5, FeCl3 and NaOH as the precursors. The UV–vis diffuse reflectance spectra showed that NaTa1-xFexO3 had significant visible-light-absorbing capability, and the absorption edge of NaTaO3 shifted to longer wavelength with the increase of Fe dopants. Moreover, NaTa1-xFexO3 exhibited room-temperature ferromagnetism when Fe3+ occupied Ta5+ sites in NaTaO3 crystal lattice. The ferromagnetism is mainly attributed to the superexchange interactions between doped Fe3+, rather than the contribution of oxygen vacancies caused by Fe doping. Therefore, Fe doping can simultaneously regulate the optical and magnetic properties of NaTaO3 semiconductor, which will enable its potential applications in multifunctional optical-electronics and opticalspintronics devices.

Paste Stability and Desizability of Poly(Sodium Allyl Sulfonate)-g-Starch-g-Poly(Ethyl Acrylate) Used as Warp Sizing Agent

Wei Li,Qian Liu,Guoyu Zhang,Xuedong Cheng,Yingfeng Wang,Zhenzhen Xu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.8

This work aimed to evaluate the paste stability and desizability of new starch grafted copolymer [poly(sodium allylsulfonate)-g-starch-g-poly(ethyl acrylate)] (PSAS-g-starch-g-PEA) for providing an important supporting role in sizingapplication. The PSAS-g-starch-g-PEA samples were prepared by grafting reaction of acid-thinned starch (AHS) with SASand subsequent with EA in water phase. The PSAS-g-starch-g-PEA granules were characterized by Fourier transforminfrared spectroscopy and scanning electron microscopy. Also, paste stability was assessed and desizability was investigatedin terms of desizing efficiency, swelling ability of the film and time interval for the break of starch film in water. Comparedwith control AHS, the PSAS-g-starch-g-PEA had higher paste stability, desizing efficiency and swelling ability, and lowertime interval required, concluding that the PSAS and PEA branches could promote the paste stability and desizability ofstarch. Increasing the number of both branches facilitated the paste stability and desizability. PSAS-g-starch-g-PEA displayedpotential value in textile sizing field.