Effect of Cr2O3 on the viscosity and structure of slag (or glass) of CaO-MgO-Al2O3-SiO2 system

Wang Yifan,Wang Yici,Zhang Yunhao,Chai Yifan,Zhao Fengguang,Luo Guoping 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.7

The glass-ceramics of CaO-MgO-Al2O3-SiO2-Cr2O3 system was prepared by melting method using blast furnace slag, low-carbon ferrochrome alloy slag and quartz sand as raw materials, and the effect of Cr2O3 on the viscosity and structure of slag (or glass) of CaO-MgO-Al2O3-SiO2 (CMAS) system at high temperature was studied. The Urbain viscosity prediction model was established and optimized, and the effect of Cr2O3 on the structure of slag (or glass) was studied by Raman spectroscopy. The results show that when the mass fraction of Cr2O3 is in the range of 0.85–2.05%, the viscosity of slag (or glass) of CMAS system decreases with the increase of Cr2O3 content. The average relative errors between the experimented viscosity value and the calculated viscosity value obtained by using the optimized Urbain model are less than 20%, which is effective and universal for the viscosity prediction of slag (or glass) of CaO-MgO-Al2O3-SiO2-Cr2O3 system. With the increase of Cr2O3 content, the complex silicon oxygen tetrahedrons (Q3) disintegrate into a larger number of simple silicon oxygen tetrahedrons (Q0, Q1, Q2), resulting in the sparse structure of the melt network and a decrease in macroscopic viscosity.

Anti-Inflammatory Activity of Phenylethanoids from Acanthus ilicifolius var. xiamenensis

Yifan Zhang,Jinhuang Shen,Xinhua Ma,Yubin He,Yonghong Zhang,Dairong Cao 한국식품영양과학회 2023 Journal of medicinal food Vol.26 No.2

Acanthus ilicifolius var. xiamenensis is a traditional herbal medicine in China. In this study, the anti-inflammatory activities of active ingredients of A. ilicifolius var. xiamenensis were investigated in RAW 264.7 cells and Freund's complete adjuvant-induced arthritic rats. Results showed that n-butanol extract exerted antiarthritic potential by reducing paw edema, arthritis score, and altered hematological and biochemical parameters in experimental rats. Phytochemical studies on n-butanol extract resulted in the isolation of five alkaloids (1–5) and five phenylethanoids (6–10). The anti-inflammatory assay of compounds 1–10 on lipopolysaccharide (LPS)-treated RAW 264.7 cells indicated that phenylethanoids 9 and 10 exhibited notable inhibitory activities. The result indicated that compounds 9 and 10 attenuated inflammation by decreasing the production of nuclear factor kappa-B (NF-κB) p65, inhibitory subunit of NF kappa B alpha, Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), and inducible nitric oxide synthase in LPS-mediated RAW 264.7 macrophages. Phenylethanoids 9 and 10 increased the expression of interleukin-10 and endothelial nitric oxide synthase. Therefore, compounds 9 and 10 showed anti-inflammatory activity by regulation of NF-κB and JAK/STAT signaling pathways.

Novel Schemes to Optimize Sampling Rate for Compressed Sensing

YiFan Zhang,Xuan Fu,Qixun Zhang,Zhiyong Feng,Xiaomin Liu 한국통신학회 2015 Journal of communications and networks Vol.17 No.5

The fast and accurate spectrum sensing over an ultra- wide bandwidth is a big challenge for the radio environment cogni- tion. Considering sparse signal feature, two novel compressed sens- ing schemes are proposed, which can reduce compressed sampling rate in contrast to the traditional scheme. One algorithm is dynam- ically adjusting compression ratio based on modulation recogni- tion and identification of symbol rate, which can reduce compres- sion ratio. Furthermore, without priori information of the modu- lation and symbol rate, another improved algorithm is proposed with the application potential in practice, which does not need to reconstruct the signals. The improved algorithm is divided into two stages, which are the approaching stage and the monitoring stage. The overall sampling rate can be dramatically reduced with- out the performance deterioration of the spectrum detection com- pared to the conventional static compressed sampling rate algo- rithm. Numerous results show that the proposed compressed sens- ing technique can reduce sampling rate by 35%, with an acceptable detection probability over 0.9.

A Novel Control Scheme Based on the Synchronous Frame for APF

Yifan Wang,Hong Zheng,Ruoyin Wang,Wen Zhu 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.6

For the purpose of enhancing the performance of the shunt active power filter (APF), this paper presents a novel Fast Weighted Compound Control (FWCC) strategy based on the synchronous frame. In this control strategy, the proposed new repetitive controller can work faster and more stably by reducing the internal model cycle and introducing a damping coefficient. In addition, the harmonic detector can be removed to simplify the structure of the APF owing to the improvements. Furthermore, a proportional-integral (PI) controller is added to work in parallel with the repetitive controller by using a weighted ratio. Then, a convergence speed analysis and design algorithm are given in detail. Simulation and experimental results show that the harmonic distortion is reduced from 2.91% to 1.89%. In addition, the content for each of the characteristic harmonic orders has decreased by more than three times.

The Response of Plant Photosynthesis and Stomatal Conductance to Fine Particulate Matter (PM2.5) based on Leaf Factors Analyzing

Yifan Li,Yujie Wang,Bin Wang,Yunqi Wang,Weiqing Yu 한국식물학회 2019 Journal of Plant Biology Vol.62 No.2

The effects of particles on the photosynthesis ofvegetation, which is a sink for fine particulate matter (PM2.5)deposition, are still not well understood. Here, we carried outindoor measurements to evaluate the variation dynamics ofnet photosynthetic rate and stomatal conductance of fourplant species with different leaf characteristics under differentPM2.5 levels. Then tree leaves were sampled and the grooveproportion, leaf trichome density, stomatal density and stomatalsize were quantitatively studied by scanning electron microscopy(SEM). The stomatal conductance of the 4 species had aclose positive correlation with photosynthetic rate. Netphotosynthetic rate and stomatal conductance declined overtime at elevated PM2.5, and the rate of the decline becamemore rapid with higher concentration of PM2.5. The inhibitingeffect might be caused by the closure of the stomata and thedecrease of stomatal conductance, which was proved by thereduction of the stomatal size of under the condition of PM2.5pollution. Leaf trichome and groove seemed to show aprotective role for plants from PM2.5 exposure and be responsiblefor the difference of photosynthetic rate and stomatal conductanceunder the condition of PM2.5 pollution. The higher grooveproportion and the presence of trichomes on the leaf surfacein Neolitsea aurata and Lindera kwangtungensis absorbedsome particulate matters and buffered the effect of PM2.5pollution on stomata.

Effects of carboxylesterase gene silence on wheat aphid Sitobion avenae (Fabricius)

Yifan Zhang,Fei Deng,Yongliang Fan,Zhangwu Zhao 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.2

Multifunctional carboxylesterase (CarE) has been found in all animals, plants and microbes, and belongs to a superfamily enzyme of serine hydrolase involved in detoxification, allelochemical tolerance and some specific hormone or pheromone metabolism. Insects usually utilize carboxylesterases to detoxify xenobiotics, and positively correlated with insect resistance to some insecticides. Despite the importance of CarEs in insects, carboxylesterases and their functions in wheat aphid Sitobion avenae (Fabricius) have not been clear. In this study, a sequence that encodes a carboxylesterase protein from S. avenae (SaCarE) was sequenced and cloned. After aligning the encoded amino acid sequence of the SaCarE gene with other known CarEs of insects, we found that the CarE gene was highly conserved in insects. The SaCarE mRNA levels at different developmental stages of S. avenae were gradually increased from the first instar of nymphs to adult stage. RNAi was employed to further explore its functions, in which oral ingestion of SaCarE double-stranded RNA from the third instar nymph significantly knocked down SaCarE expression, and significantly decreased ecdysis index in S. avenae. These results indicate that SaCarE is functional in S. avenae and could serve one of the potential target genes for management of S. avenae.

Estimating Escalator vs Stairs Choice Behavior in the Presence of Entry Railing: A Field Study

Yifan Zhuang,Andreas Schadschneider,Han Cheng,Lizhong Yang 대한토목학회 2018 KSCE Journal of Civil Engineering Vol.22 No.12

Entry railings at escalator/stairs system are intervention measures for passenger flow and play a crucial role in local infrastructure optimization in mass transit stations. This paper presents an analysis of the choice between escalators and stairs with mixed logit models, by considering for the first time the length of the entry railing as one of the crucial parameters. Based on a pilot questionnaire survey, a large-scale field study was conducted in Changsha, China and a sample of 11010 passengers was drawn. The datasets of the whole sample and the grouped samples were applied for model calibrations, respectively. The results indicate that the sensitivity to the railing length show significant heterogeneity in preferences, as well as middle age, luggage carrying and density in front of the escalator (ESDEN). All models are validated to have good prediction accuracy. The mixed model outperforms the binary model in predicting the stairs usage, but slightly overestimates the escalator usage. The analysis reinforces earlier findings showing that lengthening the railing (2.5 ~ 3.9 m) reduces the sensitivity of individual diversity to dynamic ESDEN, thus further enhancing the predictive ability by 4.35%. Our results provide unique insights for planners and policymakers on designing and managing transportation systems.

Intestinal Anti-Inflammatory Effects of Selenized Ulva pertusa Polysaccharides in a Dextran Sulfate Sodium-Induced Inflammatory Bowel Disease Model

Yifan Wang,Han Ye,Leke Qiao,Chunying Du,Zhengpeng Wei,Ting Wang,Jingfeng Wang,Ruizhi Liu,Peng Wang 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.3

The purpose of this study was to examine the alleviative effects of selenized polysaccharides from Ulva pertusa (ulvan-Se) on inflammatory bowel disease (IBD) in mice. The dextran sulfate sodium (DSS)-induced IBD mouse model was used to explore the protective effects of ulvan-Se on the intestinal mechanical and immune barrier. At doses less than 1208 mg/kg·bw ulvan-Se showed no significant damage to Institute of Cancer Research (ICR) mice in an acute toxicity test. The results showed that DSS destroyed the mechanical barrier, which includes epithelial cells, while ulvan-Se promoted mRNA expression of tight junction proteins (zonula occludens protein 1, occludin, and claudin-1) and inhibited the infiltration of white blood cells into the intestines. At 100 mg/kg·bw, ulvan-Se enhanced the antioxidant capacity of mice more effectively than the 50 mg/kg·bw ulvan-Se. Furthermore, ulvan-Se improved the intestinal immune barrier by increasing immunoglobulin A and immunoglobulin M, while regulating the levels of interleukin (IL)-1β, interferon-γ, and IL-4. Oral administration of ulvan-Se also suppressed tumor necrosis factor-α, IL-1β, IL-6, and cyclooxygenase-2 mRNA expression mediated by the nuclear factor kappa B pathway. Taken together, our findings reveal that ulvan-Se could be used as a potential alternative supplement for reducing intestinal inflammation in IBD.

Fluorescent and Colorimetric Chemosensors for Anions, Metal Ions, Reactive Oxygen Species, Biothiols, and Gases

Yifan Liu,Ying Hu,이송이,이다영,윤주영 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.10

Colorimetric and fluorescent chemosensors have been actively studied in recent years, and this article covers our contributions to colorimetric and fluorescent chemosensors in detecting anions, metal ions, reactive oxygen species (ROS), reactive nitrogen species (RNS), biothiols, and gases. The chemosensors discussed in this article are categorized according to their corresponding analytes, and the final part is devoted to polydiacetylene-based chemosensors. We hope that this article will be beneficial in the design of chemosensors for various important analytes.

Behaviour and design of stainless steel shear connectors in composite beams

Yifan Zhou,Brian Uy,Jia Wang,Dongxu Li,Xinpei Liu 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.46 No.2

Stainless steel-concrete composite beam has become an attractive structural form for offshore bridges and iconic high-rise buildings, owing to the superior corrosion resistance and excellent ductility of stainless steel material. In a composite beam, stainless steel shear connectors play an important role by establishing the interconnection between stainless steel beam and concrete slab. To enable the best use of high strength stainless steel shear connectors in composite beams, high strength concrete is recommended. To date, the application of stainless steel shear connectors in composite beams is still very limited due to the lack of research and proper design recommendations. In this paper, a total of seven pushout specimens were tested to investigate the load-slip behaviour of stainless steel shear connectors. A thorough discussion has been made on the differences between stainless steel bolted connectors and welded studs, in terms of the failure modes, load-slip behaviour and ultimate shear resistance. In parallel with the experimental programme, a finite element model was developed in ABAQUS to simulate the behaviour of stainless steel shear connectors, with which the effects of shear connector strength, concrete strength and embedded connector height to diameter ratio (h/d) were evaluated. The obtained experimental and numerical results were analysed and compared with existing codes of practice, including AS/NZS 2327, EN 1994-1-1 and ANSI/AISC 360-16. The comparison results indicated that the current codes need to be improved for the design of high strength stainless steel shear connectors. On this basis, modified design approaches were proposed to predict the shear capacity of stainless steel bolted connectors and welded studs in the composite beams.