Heat Transfer Characteristics in Horizontal Rectangular Channel of Multi-Channel Cylinder Dryer

Lijie Qiao,Jixian Dong,Zhuozhi Yang,Sha Wang,Huan Liu,Bo Wang,Lingbo Kong 한국펄프·종이공학회 2020 펄프.종이기술 Vol.52 No.3

Characterization of the Pressure Drop during Condensation in Channels of Multi-Channel Cylinder Dryer Using Homogeneous and Separated Flow Models

Lijie Qiao,Jixian Dong,Huan Liu,Bo Wang,Sha Wang,Yan Dong,Haozeng Guo 한국펄프·종이공학회 2021 펄프.종이기술 Vol.53 No.4

Synthesis and Characterization of a Fluid-Like Novel Aniline Pentamer

Mengkui Wang,Jing Huang,Quanling Yang,Zhikang Liu,Lijie Dong,Shan Wang,Chuanxi Xiong 한국고분자학회 2018 Macromolecular Research Vol.26 No.3

A fluid-like novel aniline pentamer was synthesized by oxidative coupling and chemically doped with nonylphenol polyoxyethylene ether sulfate (NPES). The chemical structure, morphology, rheological behavior and conductivity of the assynthesized aniline pentamer were investigated. Unlike conventional aniline oligomers, this aniline pentamer exhibited a fluid-like behavior in the absence of any solvent at room temperature. Moreover, the aniline pentamer fluid showed liquid crystal characteristics. Combination of the fluid-like behavior, liquid crystal characteristics and good conductivity makes the aniline pentamer a promising environmentally friendly fluid for various applications such as field-effect transistors, liquid crystal devices, electrorheological materials, corrosion protection and other devices requiring electroactivity. This work provides a facile way to synthesizing flowable aniline oligomers with liquid crystal characteristics.

Sensitive Electrochemical Determination of Hyperin Based on Electrochemically Activated ZrO2 Nanoparticles-Modified Carbon Paste Electrode

Na Wang,Jianyao Kou,Lijie Wang,Fei Wang,Kui Lu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.5

A novel electrochemically activated ZrO2 nanoparticles modified carbon paste electrode (CPE) (ZrO2-CPE(ox)) was prepared and applied for selective and sensitive determination of hyperin. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectra and electrochemical experiment were used to characterize the ZrO2 nanoparticles and investigate the electrochemical performance of the ZrO2-CPE(ox). Compared with bare CPE and electrochemically activated CPE (CPE(ox)), the ZrO2-CPE(ox) got more reactive sites by electrochemical treatment and exhibited larger effective surface area and more excellent electrochemical catalytic activity toward the redox of hyperin. Under the optimum conditions, the oxidation peak currents showed a linear relationship with the concentrations of hyperin in the range of 5.0 x 10 -9 – 2.0 x 10 -6 mol L -1 and 2.0 x 10 -6 – 1.2 x 10 -5 mol L -1, and a low detection limit of 1.0 x 10 -9 mol L -1 was achieved for hyperin. Moreover, the proposed method exhibited an excellent selectivity, stability, reproducibility and repeatability, which make it very suitable for a potential choice for determining the concentrations of hyperin in drug matrices.

Design a Laboratory Rotating Test Bench for the Multi-Channel Dryer Experiment

Sha Wang,Jixian Dong,Changke Tan,Bo Wang,Lijie Qiao,Huan Liu 한국펄프·종이공학회 2019 펄프.종이기술 Vol.51 No.5

The dryer of paper machine has problem in discharging condensate water. When the dryer rotates at a high speed, the condensate water that is not discharged in time will form a water ring, resulting in low drying efficiency and high energy consumption. Thus, based on the multi-channel dryer proposed by others, a series of experiments was carried out on multi-channel dryer under static condition. However, due to the fact that the research condition of condensation and heat transfer of multi-channel dryer is not exactly the same as the actual working condition, the multi-channel dryer has not been introduced to the market. To address the above problems, this paper presented a rotating test bench which can better simulate the actual working condition of dryer and expounded the working principle of the test bench, as well as the design and calculation of rotary device of the test bench. Finite element analysis software was used to analyze the stress on the dryer channel. In order to avoid resonance problems, modal numerical analysis was conducted on the test bench, which provided experimental conditions for the further study of multi-channel dryer.

SIMULATION STUDY ON VEHICLE RIDE COMFORT BASED ON FINITE ELEMENT MODEL AND PSEUDO-EXCITATION METHOD

Wang Wenzhu,Lijie Dong,Liu Gang,Wei Jun,Zhang Zhenwei 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.4

This research aims to develop a new vehicle ride comfort simulation technology. The basic principle of pseudo-excitation method (PEM) is summarized, and the specific method of PEM is proposed to solve the finite element model (FEM) of vehicle. Taking a simple 7-degree-of-freedom (DOF) car spatial model as an example, the traditional and new methods are compared. Simulation results show that they are completely consistent, thereby verifying the effectiveness of the new method. At the same time, through the simulation process, the new method is simpler and more efficient without deducing complex mathematical formulas and software programming. Finally, the ride comfort simulation of a car’s complex FEM is performed. FEM can consider the parts of the vehicle as elastic bodies and closer to the real vehicle. The PEM transforms random vibration analysis into simple harmonic vibration analysis, which improves the efficiency of the solution greatly. Therefore, the combination of the FEM and the PEM cannot only solve the problem of model accuracy but also the problem of solving efficiency, which has strong practical engineering application value.

Influence of Porosity on Mechanical Behavior of Porous Cu Fabricated via De‑Alloying of Cu–Fe Alloy

Lijie Zou,Fei Chen,Hao Wang,Qiang Shen,Enrique J. Lavernia,Lianmeng Zhang 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.1

We report on a study of the mechanical behavior of porous Cu containing micron-sized pores and fabricated by de-alloyingof a Cu–Fe precursor alloy. Our results show that the minimum volume fraction of pores that can be obtained by using anapproach that involves de-alloying of a Cu–Fe precursor alloy is approximately 40 vol%. Moreover, the average pore sizeformed by de-alloying Cu–Fe of varying compositions is in the range of 1.5–4.0 μm. Our mechanical behavior results revealthat the yield stress increases from 3.9 to 58.6 MPa as the volume fraction of porosity decreases from 78.9% to 39.3%. Moreover, our data shows that the influence of porosity on the relative yield stress and relative Young’s modulus conformsto the scaling equations of Gibson and Ashby as formulated for open-cell porous metals. The pore cell characteristics anddeformation modes of porous Cu produced by de-alloying Cu–Fe alloys were discussed in the context of the observed fluctuationsin the value of the constants C and n in the Gibson-Ashby scaling equation. The evolution of microstructure duringcompressive deformation of porous Cu was studied and the results reveal an increase in the fraction of low-angle grainboundaries, an increase in the number of twins and a decrease in the average grain size with increasing strain from 0% to 70%.

AP2α negatively regulates PDHA1 in cervical cancer cells to promote aggressive features and aerobic glycolysis in vitro and in vivo

Lijie Zhao,Rong Geng,Yi Huang,Jiping Zhang,Haiying Cheng,Cankun Zhou,Yifeng Wang 대한부인종양학회 2023 Journal of Gynecologic Oncology Vol.34 No.5

Objective: As a gate-keeper enzyme link, pyruvate dehydrogenase E1 subunit alpha (PDHA1) functions as a key regulator during glycolysis and the mitochondrial citric acid cycle, which has been reported in several tumors. Nevertheless, the effects of PDHA1 on biological behaviors and metabolism remain unclear in cervical cancer (CC) cells. The study aims to explore the PDHA1 effects on glucose metabolism in CC cells and its possible mechanism. Methods: We first determined the expression levels of PDHA1 and activating protein 2 alpha (AP2α) as a PDHA1 potential transcription factor. The effects of PDHA1 in vivo were evaluated through a subcutaneous xenograft mouse model. Cell Counting Kit-8 assay, 5-ethynyl-2′-deoxyuridine (EdU) labeling assay, Transwell invasion assay, wound healing assay, Terminal deoxynucleotidyl transferase dUTP nick end labeling assay and flow cytometry were performed in CC cells. Oxygen consumption rate (OCR) levels were determined to reflect aerobic glycolysis level in gastric cancer cells. Reactive oxygen species (ROS) level was measured with 2′, 7′-dichlorofluorescein diacetate kit. The relationship between PDHA1 and AP2α was examined by conducting chromatin immunoprecipitation assay and electrophoretic mobility shift assay. Results: In CC tissues and cell lines, PDHA1 was downregulated, while AP2α was upregulated. Overexpression of PDHA1 remarkedly inhibited the proliferation, invasion and migration of CC cells, and tumor growth in vivo, as well as promoted OCR, apoptosis and ROS production. Moreover, AP2α directly bound to PDHA1 within suppressor of cytokine signaling 3 promoter region to negatively regulate PDHA1 expression level. What is more, PDHA1 knockdown could effectively reversed the AP2α silencing-mediated suppressive effects on cell proliferation, invasion, migration, and the promotive effects of AP2α knockdown on OCR, apoptosis and ROS production. Conclusions: Our findings demonstrate that AP2α negatively regulated PDHA1 via binding to PDHA1 gene promoter to promote malignant CC cell behaviors, which may provide a potential approach for CC therapeutics.

Mechanical Properties and Microstructure of Lime-Treated Red Clay

Lijie Chen,Xuejun Chen,He Wang,Xiang Huang,Yu Song 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.1

This research conducted a triaxial test on lime-treated clay with different contents to analyze the effect of mechanical properties. Scanning electron microscope (SEM) and low-field nuclear magnetic resonance (NMR) analysis were used to analyze the effect. X-ray diffraction (XRD) was used to analyze the chemical changes of calcium oxide on red clay. The results show that with the increase of calcium oxide content, the strength increases, and it can be increased by 282% at 200 kPa confining pressure. The calcium oxide in the red clay reactedwith the water in the soil to form calcium hydroxide. The alkaline environment will erode the edge of the soil particles and cause pores to become larger. SEM observed that the addition of calcium oxide caused the agglomeration of soil particles and changed the pore structure of red clay. Low-field NMR showed that calcium oxide had a significant effect on the pore structure of red clay. Calcium oxide increased the total pore volume of the soil sample. Calcium oxide had a substantial influence on the three pore distribution ranges, I (1.1 − 11 μm), II (15 − 137 μm), and III (137 − 512 μm). The porosity fitted with shear strength, it negatively correlated with I and III, and positively correlated with II.

A self-healing hydrogel derived flexible all-solid-state supercapacitors based on dynamic borate bonds

Lijie Tang,Yan Ma,Caixia Yang,Enxiang Liang,Hong Yin,Qiong Wan,Jiance Zhang,Wei Wang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.118 No.-

Flexible energy storage devices are susceptible to damage, which might result in safety issues. In thispaper, a self-healing flexible P(AAPBA-co-P4-AC) gel electrolyte based on dynamic borate bond crosslinkingstrategy is reported. On the one hand, it is simple to process into complicated shapes or patterns,and on the other hand, it could rapidly return to its original state after stress damage. Even after ten timesself-healing, the gel has the same mechanical properties as the non-damaged gel. Furthermore, this gelcan also be applied in all-solid-state supercapacitors without the need of extra electrolytes. Becausethe gel has a large number of hydroxyl groups, it has a high affinity for the activated carbon electrode,and the supercapacitors can maintain 100% initial performance under various angles or strains. Afterten thousand times cycles charge–discharge, the supercapacitors using the gel after twenty times selfhealingprocess can retain 90% of its initial capacity, which is only 4% lower than the non-damagingsupercapacitors, demonstrating high self-healing ability.