Preparation and electrochemical performance of porous carbon derived from polypyrrole

Wu Lili,Chen Xinguo,Ding Chang,Wang Pitao,Luo Heming 한국탄소학회 2023 Carbon Letters Vol.33 No.2

Supercross-linked polymers are widely used as carbon precursor materials due to their abundant carbon sources and low cost. In this paper, a supercross-linked polymer was prepared by the solvothermal method. The supercross-linked polymer as a precursor and the PPyC-800-A was synthesized by activating this with KOH. The microstructure, structure, and electrochemical performances of porous carbon PPyC-800-A were studied at different of temperature and carbon alkali ratio. According to the results, the porous carbon PPyC-800-1:2 is mainly composed of a stack of spherical particles with a high surface area of 1427.03 m2 g−1, an average pore diameter of 2.32 nm, and a high specific capacitance of 217.7 F g−1 at a current density of 1.0 A g−1 in a 6 M KOH electrolyte. It’s retention rate is 97.58% after 5000 constant current charges and discharges. With a specific capacitance decay rate of 21.91 percent, an energy density of 11.96 Wh kg−1, and a power density of 500.0 W kg−1, the current density rises from 1.0 A g−1 to 10.0 A g−1, exhibiting remarkable electrochemical properties, cycling stability, and energy production performance This study contributes experimental ideas to the field of supercross-linked polymer-derived carbon materials and energy storage.

Study of the preparation and electrochemical performance of porous carbon derived from hypercrosslinked polymers

Wu Lili,Wang Pitao,Chen Xinguo,Zhang Jianqiang,Luo Heming 한국탄소학회 2022 Carbon Letters Vol.32 No.3

Hypercrosslinked polymers HCPs have been widely used as precursors to prepare porous carbon materials because of their highly ordered porous structure and large specific surface area. In this paper, we used a solvothermal method to prepare a hypercrosslinked polymer, and the HCPC-700-A was prepared using an activation method with the hypercrosslinked polymer as the precursor. The effects of different carbon–alkali ratios on the microstructure, composition and electrochemical properties of porous carbon HCP were studied. The results show that the surface of porous carbon HCPC-700-A presents a relatively regular geometric shape, and a large number of pore structures are mainly micro- and mesopores. The specific surface area is 2074.53 m2 g−1, and the average pore size is between 1.29 and 1.93 nm. Porous carbon HCPC-700-1:2 has excellent electrochemical performance in 1 M H2SO4, and the specific capacitance is up to 464.4 F g−1 at a current density of 1 A g−1. The specific capacitance decay rate is 29.72% when the current density is increased from 1 A g−1 to 8 A g−1. After 5000 cycles, the capacitance retention rate is 91.16% at a current density of 2 A g−1, showing excellent electrochemical performance, good cycle stability and perfect energy storage performance. This research provides new experimental ideas for HCPs in the electrochemical energy storage field.

Ultimate strength behavior of steel plate concrete composite slabs:An experimental and theoretical study

Lili Wu,Hui Wang,Zhibin Lin 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.37 No.6

Steel plate-concrete composite slabs provide attractive features, such as more effective loading transfer, and more cost-effective stay-in-place forms, thereby enabling engineers to design more high-performance light structures. Although significant studies in the literatures have been directed toward designing and implementing the steel plate-concrete composite beams, there are limited data available for understanding of the composite slabs. To fill this gap, nine the composite slabs with different variables in this study were tested to unveil the impacts of the critical factors on the ultimate strength behavior. The key information of the findings included sample failure modes, crack pattern, and ultimate strength behavior of the composite slabs under either four-point or three-point loading. Test results showed that the failure modes varied from delamination to shear failures under different design factors. Particularly, the shear stud spacing and thicknesses of the concrete slabs significantly affected their ultimate load-carrying capacities. Moreover, an analytical model of the composite slabs was derived for determining their ultimate load-carrying capacity and was well verified by the experimental data. Further extensive parametric study using the proposed analytical methods was conducted for a more comprehensive investigation of those critical factors in their performance. These findings are expected to help engineers to better understand the structural behavior of the steel plate-concrete composite slabs and to ensure reliability of design and performance throughout their service life.

Development of multigroup cross section library generation system TPAMS

Wen Lili,Wu Haicheng,Chen Ying,Chai Xiaoming,Wu Xiaofei,Tu Xiaolan,Liu Yuan 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.6

Kylin-2 is an advanced neutronics lattice code, developed by Nuclear Power Institute of China. High-precision multigroup cross section library is need for KYLIN-2 to carry out simulation of current pressurized water reactor (PWR) and advanced reactor. In this paper a multigroup cross section library generation system named TPAMS was developed, the methods in TPAMS dealing with resonance data such as subgroup parameters, lambda factor, resonance integral were discussed. Moreover, the depletion chain simplification method was studied. TPAMS can produce multigroup library in binary and ASIIC formats, including detailed data contents for resonance, transport and depletion calculations. A multigroup cross section library has been generated for KYLIN-2 based on TPAMS system. The multigroup cross section library was verified through the analysis of various criticality and burnup benchmarks, the values of multiplication factor and isotope density were compared with the experiment data. Numerical results demonstrate the accuracy of the multigroup cross section library and the reliability of the multigroup cross section library generation system TPAMS.

Study of the Permeability of Tomato Pericarp Etched by Low-energy Ion Beams Based on α-particles Irradiation

Lili Zhang,Lianyun Chen,Xue Xu,Qing Huang,Yuejin Wu 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.3

Low-energy ion beam bio-technology has been applied in the biological field and has gained remarkable success in crop and microbe breeding. However, to understand how low-energy ion beams interact with biological materials remains a challenge for researchers who work for the development of ion-beam bio-technology. In this work,tomato pericarp was used as the target sample to study the effect of ion beams on the permeability of biological objects. A series of experiments were conducted via irradiating tomato pericarp samples with low-energy (10 keV ~ 25 keV)ion beams followed by measuring the pericarp’s permeability using transmissive α particles. The transmissive spectra of α particles and the measurement of the tip number in CR39gave a quantitative evaluation of the sputtering effect caused by low-energy ions. Meanwhile, natural red dye was used to examine the permeability of irradiated tomato pericarp samples. It was found that the sputtering effect is not only proportional to the ion energy and dose, but dependent on the ion type as well. The damage caused by Ar ions due to sputtering was much more severe than that caused by N ions sputtering with the same dose. Therefore,this study not only demonstrates the permeability difference of biological membranes before and after ion irradiation,but also provides the information on how to optimize the experimental conditions for application of the low-energy ion beam in biology.

Study on the internal irreversible losses and process exponent of single screw expanders

Lili Shen,Yuting Wu,Wei Wang,Biao Lei,Wei Duan,Ruiping Zhi 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.3

The irreversible losses including intake pressure, leakage, heat transfer, friction and over-expansion losses have great influence on the expander performance. In this paper, a thermodynamic model is presented to predict the real expansion process exponent and analyze the under-expansion or over-expansion under designed and off-designed operation conditions. The model verified by experimental results has a good agreement. Results showed that the real expansion process exponent of air is higher than the ideal adiabatic index of 1.4 and decreases from 1.716 to 1.644 with the internal volume ratio changing from 1.8 to 6.5. The real expansion process exponent of R123 is close to 1.00 under different internal volume ratio. Compared to the intake pressure, the variation of back pressure has greater influence on the large internal volume ratio than the small one. Thus, to adjust the back pressure is more effective to match the designed condition for the expander with a large internal volume ratio.

Posterior Reversible Encephalopathy Syndrome in a Case of Vancomycin-Induced Acute Kidney Injury

Lily Kim,Leah Kolar,Anju Abu,Laura J Wu 대한신경과학회 2021 Journal of Clinical Neurology Vol.17 No.1

Genome-wide DNA methylation profiling in differentiating Crohn’s disease from intestinal tuberculosis

Wu Hao,Liu Hongchun,Liu Haining,Chen Yanjie,Liu Taotao,Shen Xizhong,Liu Lili 한국유전학회 2022 Genes & Genomics Vol.44 No.5

Background: Differential diagnosis of Crohn's disease (CD) and intestinal tuberculosis (ITB) is still difficult in clinical pratice. DNA methylation has been considered as a favorable area for biomarker exploration and identification. Objective: The purpose of the current study was to evaluate DNA methylation changes between CD and ITB. Methods: We performed a genome-wide association study to identify differentially methylated positions (DMPs), including 8 CD patients (before the initial of biologics or immunomodulators), 6 ITB patients, and 8 healthy controls (HCs), in whole blood DNA using the Infinium HumanMethylation850 BeadChip. Results: Patients in the CD group and ITB group were all observed with hypo-methylated changes compared with HCs. However, the CD group overlaps with the ITB group in DNA methylation, suggesting a stable epigenetic profile between the two diseases. The pathway enrichment analysis showed the alternation in inflammation-related pathway, immune system, and signal transduction. Focused on the DMPs located in the promoter region, further analysis indicated hypermethylation of cg03122532 (5'UTR of KCNJ15) could be a potential CD-specific biomarker. Conclusions: We identified specific differential methylation loci related to CD and ITB in blood DNA. DNA metylation as a important epigenetic modification could contribute to the pathogenesis study and biomarker exploration of the diseases.

Antitumor and Immunomodulating Activity of Polysaccharides from Enteromorpha intestinalis

Lili Jiao,Liping Zhang,Peng Jiang,Mingjiang Wu 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.3

Two polysaccharides (WEA and WEB) were isolated from Enteromorpha intestinalis by hot water extraction, anion-exchange, and gel-permeation chromatography. The average molecular weights (Mw) of the two fractions were 72.03 kDa (WEA) and 60.12 kDa (WEB). WEA was composed of Rha, Xyl, Man, and Glc in a molar ratio of 1.39:1.00:0.13:3.23. WEB consisted of Rha, Xyl,Gal, and GlcA (glucuronic acid) in a molar ratio of 7.32:1.00:0.51:1.28. Both polysaccharides could inhibit tumor growth in S180 tumor-bearing mice, and increased the relative spleen and thymus weight. They also increased the expression of tumor necrosis factor-alpha (TNF-α) in serum. WEA and WEB induced lymphocyte proliferation,increased the production of TNF-α in macrophages, and stimulated macrophages to produce nitric oxide dosedependently through the up-regulation of inducible NO synthase activity. However, no direct cytotoxicity against Sarcoma 180 was investigated in vitro. These results indicate that the antitumor effects of these polysaccharides are associated with immunostimulation.

Isovitexin Protects Mice from Methicillin- Resistant Staphylococcus aureus-Induced Pneumonia by Targeting Sortase A

( Lili Tian ),( Xinliang Wu ),( Hangqian Yu ),( Fengying Yang ),( Jian Sun ),( Tiezhong Zhou ),( Hong Jiang ) 한국미생물생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.10

The rise of methicillin-resistant Staphylococcus aureus (MRSA) has resulted in significant morbidity and mortality, and clinical treatment of MRSA infections has become extremely difficult. Sortase A (SrtA), a virulence determinant that anchors numerous virulence-related proteins to the cell wall, is a prime druggable target against S. aureus infection due to its crucial role in the pathogenicity of S. aureus. Here, we demonstrate that isovitexin, an active ingredient derived from a variety of traditional Chinese medicines, can reversibly inhibit SrtA activity in vitro with a low dose (IC₅₀=24.72 μg/ml). Fluorescence quenching and molecular simulations proved the interaction between isovitexin and SrtA. Subsequent point mutation experiments further confirmed that the critical amino acid positions for SrtA binding to isovitexin were Ala-92, Ile-182, and Trp-197. In addition, isovitexin treatment dramatically reduced S. aureus invasion of A549 cells. This study shows that treatment with isovitexin could alleviate pathological injury and prolong the life span of mice in an S. aureus pneumonia model. According to our research, isovitexin represents a promising lead molecule for the creation of anti-S. aureus medicines or adjuncts.