Trace surface fluorination and tungsten-intercalation cooperated dual modification induced photo-activity enhancement of titanium dioxide

Yifan Xu,Zhongyuan Liu,Kunlun Wang,Chunyao Niu,Pengfei Yuan,Jin You Zheng,Young Soo Kang,Xiao Li Zhang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.108 No.-

General modification that utilizes insoluble tungstic acid or highly toxic hydrofluoric acid to improvecharge separation and transfer in TiO2 results in considerable issues such as uneven doping, significantimpacts on particle size and morphology, as well as environmental hazards. In the present work, an environmentalbenign one-pot dual-modification approach was demonstrated that uses soluble sodium tungstateand only trace-level sodium fluoride as replacements. The photoactivity efficiency for decolorationof methylene blue (MB) solution was improved by 33.6% and 119.5% under ultraviolet and visible light,respectively. Meanwhile, the photocurrent density reached an enhancement by 181.2% by this dualmodification. The dual-modification had negligible influence on the crystal structure and the surface areaof the TiO2 nanoparticles. Density functional calculation suggested the remarkable improvements of thephotocatalysis of TiO2 can be ascribed to the rapid charge separation and transfer owing to the downshiftof conduction band from the tungsten doping and localized spatial charge separation from the surfacefluorination enabled by the dual-modification approach.

Preparation and performance of non-sintered lightweight aggregates derived from textile sludge and coal fly ash

Yueqing Xu,Xinyu Wu,Houhu Zhang,Qingya Zhang,Yifan Xu 대한환경공학회 2023 Environmental Engineering Research Vol.29 No.3

The feasibility of preparing non-sintered lightweight aggregate using textile sludge and coal fly ash as the main raw materials was investigated. Extensive experiments were conducted to analyze the effects of different coal fly ash/sludge ratio, sodium silicate addition and curing time on the performance of non-sintered lightweight aggregates (NSLWAs). The optimal preparation parameters were determined as follows: coal fly ash/cement ratio of 2.2, textile sludge addition of 20%, sodium silicate addition of 10%, and curing time of 28 days. Under these optimal preparation conditions, the cylindrical compressive strength of NSLWAs was relatively high. The test results of Zn leaching toxicity test and S content all met the relevant standards and environmental safety requirements. NSLWA has a dense internal structure with uniformly distributed grains. By analyzing the hydration reaction mechanism during the NSLWAs preparation, it can be obtained that part of Zn<SUP>2+</SUP> was stabilized by conversion into insoluble Ca(Zn(OH)₃)₂・2H₂O, while the remaining part was solidified and stabilized through encapsulation and adsorption of hydration products. Furthermore, it was discovered that pozzolanic admixtures played a crucial role in the hydration and hardening process of NSLWAs, and the presence of C-S-H gel and Mullite contributed to the increase in cylinder compressive strength of NSLWAs.

Changpingibacter yushuensis gen. nov., sp. nov., isolated from fluvial sediment in Qinghai Tibet Plateau of China

Jiao Yifan,Zhang Sihui,Yang Jing,Lai Xin-He,Dong Kui,Cheng Yanpeng,Xu Mingchao,Zhu Wentao,Lu Shan,Jin Dong,Pu Ji,Huang Ying,Liu Liyun,Wang Suping,Xu Jianguo 한국미생물학회 2022 The journal of microbiology Vol.60 No.2

Two facultatively anaerobic, short rod-shaped, non-motile, Gram-stain-positive, unknown bacterial strains (JY-X040T and JY-X174) were isolated from fluvial sediments of Tongtian River in Yushu Tibetan Autonomous Prefecture, Qinghai province, China. Cells formed translucent, gray, round and convex colonies, with a diameter of less than 0.5 mm after 5 days of incubation at 30°C on brain heart infusion-5% sheep blood agar. The 16S rRNA gene sequence similarity between strain JY-X040T and Fudania jinshanensis 313T is 93.87%. In the four phylogenetic trees constructed based on the 16S rRNA gene and 423 core genes, the two isolates form an independent branch, phylogenetically closest to F. jinshanensis 313T, but could not be classified as a member of the genus Fudania or any other genus of the family Arcanobacteriaceae. The DNA G + C content of strain JY-X040T was 57.8%. Calculation results of average nucleotide identity, digital DNADNA hybridization value and amino acid identity between strain JY-X040T and F. jinshanensis 313T are 69.9%, 22.9%, and 64.1%. The major cellular fatty acids were C16:0 (23%) and C18:1ω9c (22%). The cell-wall peptidoglycan type was A5α (L-Lys-L-Ala-L-Lys-D-Glu). The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and four unidentified components. The whole-cell sugars contained rhamnose and ribose. MK-10(H4) was the sole respiratory quinone. The minimum inhibitory concentration of streptomycin was 32 μg/ml. All physiological, biochemical, chemotaxonomic and genomic characteristics support that strains JY-X040T and JY-X174 represent members of a novel species in a new genus, Changpingibacter yushuensis gen. nov., sp. nov. The type strain is JY-X040T (GDMCC 1.1996T = KCTC 49514T).

Three-dimensional Printed Mg-Doped β-TCP Bone Tissue Engineering Scaffolds: Effects of Magnesium Ion Concentration on Osteogenesis and Angiogenesis In Vitro

Yifan Gu,Jing Zhang,Xinzhi Zhang,Guiping Liang,Tao Xu,Wei Niu 한국조직공학과 재생의학회 2019 조직공학과 재생의학 Vol.16 No.4

BACKGROUND: Three-dimensional (3D) printed bone tissue engineering scaffolds have been widely used in research and clinical applications. b-TCP is a biomaterial commonly used in bone tissue engineering to treat bone defects, and its multifunctionality can be achieved by co-doping different metal ions. Magnesium doping in biomaterials has been shown to alter physicochemical properties of cells and enhance osteogenesis. METHODS: A series of Mg-doped TCP scaffolds were manufactured by using cryogenic 3D printing technology and sintering. The characteristics of the porous scaffolds, such as microstructure, chemical composition, mechanical properties, apparent porosity, etc., were examined. To further study the role of magnesium ions in simultaneously inducing osteogenesis and angiogenesis, human bone marrow mesenchymal stem cells (hBMSCs) and human umblical vein endothelial cells (HUVECs) were cultured in scaffold extracts to investigate cell proliferation, viability, and expression of osteogenic and angiogenic genes. RESULTS: The results showed that Mg-doped TCP scaffolds have the advantages of precise design, interconnected porous structure, and similar compressive strength to natural cancellous bone. hBMSCs and HUVECs exhibit high proliferation rate, cell morphology and viability in a certain amount of Mg2?. In addition, this concentration of magnesium can also increase the expression levels of osteogenic and angiogenic biomarkers. CONCLUSION: A certain concentration of magnesium ions plays an important role in new bone regeneration and reconstruction. It can be used as a simple and effective method to enhance the osteogenesis and angiogenesis of bioceramic scaffolds, and support the development of biomaterials and bone tissue engineering scaffolds.

Sensing formic acid with a water-based chitosan lanthanide luminescence film

Xu Zheng,Xi Chen,Xudong Yu,Yifan Yang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.125 No.-

A sensitive and selective formic acid sensor could be useful in detecting this corrosive acid in industrial,medical, and environmental settings. Herein, we present a film for detection of formic acid. We introducedchitosan as a film-forming factor to creatively overcome the problem that chitosan dissolves inacids. A carboxylic acid-carbon dot solution was used to replace the strong acid solution and prepare aluminescent film in which the color changed from green to blue when it was exposed to formic acid. Integrated data analysis of the film was used to distinguish vapor from formic acid/water solutions at differentconcentrations and with a detection limit of 0.01% v/v. The selectivity of the sensor was also investigated. After fumigation with ethanol and other common solvents, there was no response similar to thatfor formic acid. It is believed that films based on lanthanide complexes and chitosan could prevent corrosionand injury from formic acid.

Iterative self-transfer learning: A general methodology for response time-history prediction based on small dataset

Xu Yongjia,Lu Xinzheng,Fei Yifan,Huang Yuli 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.5

There are numerous advantages of deep neural network surrogate modeling for response time-history prediction. However, due to the high cost of refined numerical simulations and actual experiments, the lack of data has become an unavoidable bottleneck in practical applications. An iterative self-transfer learning method for training neural networks based on small datasets is proposed in this study. A new mapping-based transfer learning network, named as deep adaptation network with three branches for regression (DAN-TR), is proposed. A general iterative network training strategy is developed by coupling DAN-TR and the pseudo-label strategy, and the establishment of corresponding datasets is also discussed. Finally, a complex component is selected as a case study. The results show that the proposed method can improve the model performance by near an order of magnitude on small datasets without the need of external labeled samples, well behaved pre-trained models, additional artificial labeling, and complex physical/mathematical analysis.

Effects of fireworks on air quality in the main urban area of Nanchong City during the spring festival of 2014-2019

Yifan Qian,Xu Yuan,Wen Dou,Jian Hu,Jie Xia,Danyu Li,Qing Zheng,Ping Zhang,Qiumei Quan,Yunxiang Li 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.2

The sources and variation trend of ambient air pollutants, the duration of pollution process and the conditions for decontamination were analyzed in this essay based on the ambient air pollutants data, PM<SUB>2.5</SUB> source analysis data and meteorological factors in Nanchong City during 2014 to 2019. The results indicated that the concentrated discharge of fireworks on New Year’s Eve was the main reason for the sharp deterioration of the ambient air quality. PM<SUB>2.5</SUB> and PM<SUB>10</SUB> concentrations increased significantly after fireworks were set off, and the peak value appeared at about 02:00 on the Lunar New Year’s Day, but the value of PM<SUB>2.5</SUB>/PM<SUB>10</SUB> did not change significantly. The concentration of SO₂ in gaseous pollutants was slightly affected by fireworks, while NO₂, CO and O₃ were not affected basically. Having been affected by fireworks, the concentrations and percentages of K⁺, Cl⁻ and Mg<SUP>2+</SUP> of the water-solubility ions in PM<SUB>2.5</SUB> significantly increased at the 0.01 level. Meanwhile, the concentrations and percentages of the metal elements, including Cu, Pb, Mg, Al, K and Ba, significantly increased at the 0.05 level. Restricted to the topography and meteorological factors, the duration of the pollution was prolonged.

A gearbox fault feature extraction method based on wingsuit flying search algorithm-optimized orthogonal matching pursuit with a compound time-frequency atom dictionary

Yifan Mao,Feiyun Xu,Xun Zhao,Xiaoan Yan 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.11

Gearbox vibration signals are usually disturbed under strong noise. Therefore, the fault feature frequency cannot be extracted accurately and effectively. In order to extract the fault feature of the gearbox, a method based on compound time-frequency atomic dictionary and orthogonal matching pursuit (OMP) optimized by wingsuit flying search algorithm (WFSA) is proposed. Firstly, according to the feature of the gearbox fault vibration signal, a compound time-frequency atomic dictionary composed of steady state modulation dictionary and impact modulation dictionary is designed. In addition, in order to improve the accuracy and efficiency of signal sparse decomposition. In this paper, WFSA is used to optimize the dictionary atomic parameters in OMP, so that the dictionary atom approximated the original signal better. Through simulation analysis and experimental verification and compared with the commonly used gearbox fault feature extraction methods, the superiority and effectiveness of the method are verified.

Reliability analysis of nuclear safety-class DCS based on T-S fuzzy fault tree and Bayesian network

Zhang Xu,Deng Zhiguang,Jian Yifan,Huang Qichang,Peng Hao,Ma Quan 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.5

The safety-class (1E) digital control system (DCS) of nuclear power plant characterized structural multiple redundancies, therefore, it is important to quantitatively evaluate the reliability of DCS in different degree of backup loss. In this paper, a reliability evaluation model based on T-S fuzzy fault tree (FT) is proposed for 1E DCS of nuclear power plant, in which the connection relationship between components is described by T-S fuzzy gates. Specifically, an output rejection control system is chosen as an example, based on the T-S fuzzy FT model, the key indicators such as probabilistic importance are calculated, and for a further discussion, the T-S fuzzy FT model is transformed into Bayesian Network(BN) equivalently, and the fault diagnosis based on probabilistic analysis is accomplished. Combined with the analysis of actual objects, the effectiveness of proposed method is proved

In-Plane Dynamics Characteristics and Multi-Objective Optimization of Negative Poisson’s Ratio Honeycomb Structure with Power Function Curve

Zhu Yifan,Xu Feng Xiang,Guan Yijie,Zou Zhen,Duan Libin,Du Zhanpeng,Ma Hongfeng 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.5

As an alternative to the conventional concave hexagonal honeycomb structure (CHHS), a negative Poisson’s ratio honeycomb structure with power function curve (NHPC) was devised. The relationship between the power function exponent (PFE) and normalized power function coefficient (NPFC) of honeycomb structure and its equivalent Poisson’s ratio (EPR) was explored to identify the range of variables required for the negative Poisson’s ratio effect. To investigate the in-plane mechanical properties and energy absorption characteristics of NHPC, the deformation mode, dynamic response, and energy absorption characteristics under various impact velocities were studied by constructing an in-plane impact simulation model. The results showed that NHPC obviously exhibited a negative Poisson’s ratio effect on medium and low impact velocities, and the deformation was primarily uniform. As the NPFC increased, the honeycomb structure was less prone to stress concentration, while the peak crushing force (PCF) and the specific energy absorption (SEA) declined and the plateau stress increased. A multi-objective optimization experiment was operated with low PCF and high SEA as the targets within the range of design variables in order to generate the optimal NHPC. According to the experimental findings, the improved NHPC showed a 25.48 % reduction in PCF and a 19.29 % increase in SEA. This paper provides theoretical recommendations for improving the energy absorption and structural optimization of the honeycomb structure.