Shear-strain induced structural relaxation of Cu Σ3 [110](112) symmetric tilt grain boundary: The role of foreign atoms and temperature

Li Yang,Xue Hongtao,Zhou Xin,Tang Fuling,Li Xiuyan,Ren Junqiang,Lu Xuefeng 한국물리학회 2021 Current Applied Physics Vol.28 No.-

Grain boundaries (GBs) relaxation is a promising and effective strategy to improving GB stability or stabilizing nanocrystalline metals. However, previous studies mainly focused on nanocrystalline pure metals and GB behaviors therein, without considering the role of foreign atoms such as impurity or alloying atoms in GB relaxation. In this work, the shear-strain induced structural relaxation of pure Cu Σ3 [110](112) symmetric tilt GBs (STGBs), and the effects of foreign elements (Fe and Ni) and temperature on the GB relaxation were investigated in detail by molecular dynamics method. The results show that shear strain can trigger the structural relaxation of pure, Fe- and Ni-containing Cu GBs by the emission of Shockley partial dislocations from Cu GBs. Both Fe and Ni have impediment effects on the shear-strain induced GB relaxation, though the content of Fe or Ni atom (0.00165 at.%) is quite low in the GB model. The temperature cannot trigger GB relaxation independently within the considered temperature range, but play a positive role in the shear-strain induced structural relaxations of pure, Fe- and Ni-containing Cu Σ3 [110](112) STGBs. Our work might gain new insights into the mechanically induced GB relaxation in nanocrystalline copper and could be beneficial for improving the stability of Cu GBs.

APPROXIMATE SOLUTIONS TO ONE-DIMENSIONAL BACKWARD HEAT CONDUCTION PROBLEM USING LEAST SQUARES SUPPORT VECTOR MACHINES

Wu, Ziku,Li, Fule,Kwak, Do Young Chungcheong Mathematical Society 2016 충청수학회지 Vol.29 No.4

This article deals with one-dimension backward heat conduction problem (BHCP). A new approach based on least squares support vector machines (LS-SVM) is proposed for obtaining their approximate solutions. The approximate solution is presented in closed form by means of LS-SVM, whose parameters are adjusted to minimize an appropriate error function. The approximate solution consists of two parts. The first part is a known function that satisfies initial and boundary conditions. The other is a product of two terms. One term is known function which has zero boundary and initial conditions, another term is unknown which is related to kernel functions. This method has been successfully tested on practical examples and has yielded higher accuracy and stable solutions.

Approximate solutions to one-dimensional backward heat conduction problem using least squares support vector machines

곽도영,Ziku Wu,Fule Li 충청수학회 2016 충청수학회지 Vol.29 No.4

This article deals with one-dimension backward heat conduction problem (BHCP). A new approach based on least squares support vector machines (LS-SVM) is proposed for obtaining their approximate solutions. The approximate solution is presented in closed form by means of LS-SVM, whose parameters are adjusted to minimize an appropriate error function. The approximate solution consists of two parts. The first part is a known function that satisfies initial and boundary conditions. The other is a product of two terms. One term is known function which has zero boundary and initial conditions, another term is unknown which is related to kernel functions. This method has been successfully tested on practical examples and has yielded higher accuracy and stable solutions.

Optimization the extraction of anthocyanins from blueberry residue by dual-aqueous phase method and cell damage protection study

Yuan Gao,Yubin Ji,Fuling Wang,Wenlan Li,Xiaomeng Zhang,Zhihui Niu,Zhuo Wang 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.13

Blueberry residue is usually discarded as waste,but has a high anthocyanins content. The extraction methodof anthocyanins from blueberry residue with ultrasonicassisted dual-aqueous phase system was optimized. Interms of the principle of central group and design (CCD)experimental design, three-factor and five-level responsesurface analysis was adopted to optimize the extractionconditions with the extraction rate of anthocyanins. Theoptimum extraction rate of anthocyanin was12.372 ± 0.078 mg/g. Anthocyanin extract could protectthe pBR322 DNA oxidative damage induced by Fentonreagent, increase the superoxide dismutase(SOD) and glutathioneperoxidase (GSH-Px) enzyme activities, anddecrease the H2O2-induced cell apoptosis of human normalliver cell (LO2 cell). The study indicates that the extractionrate of anthocyanin was increased by optimized ultrasonicassisted dual-aqueous phase system. The anthocyaninextract could protect DNA and LO2 cell from oxidativedamage.

Endophytic Fungi from Dalbergia odorifera T. Chen Producing Naringenin Inhibit the Growth of Staphylococcus aureus by Interfering with Cell Membrane, DNA, and Protein

Yuan Gao,Yubin Ji,Wenlan Li,Fuling Wang,Fuling Wang,Xiaomeng Zhang,Zhihui Niu,Lulu Zhou,Lijun Yan 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.2

This study focused on the antibacterial effects of the endophytic fungi producing naringenin from Dalbergia odorifera T. Chen against Staphylococcus aureus. The antibacterial activity was measured by the inhibition diameters, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). The time-killing curve was also used to evaluate its antibacterial efficacy. The results of antibacterial activity determinations showed that endophytic fungi secondary metabolites can inhibit the growth of five pathogenic bacteria (S. aureus, Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa, and Bacillus subtilis) and the most sensitive strain was S. aureus that had the MIC and MBC values of 0.13 and 0.50 mg/mL, respectively. The membrane permeability study was measured by a DNA leakage assay and electrical conductivity assay. Furthermore, the whole-cell protein lysates and DNA fragmentation assay was evaluated. The morphology of S. aureus treated with the endophytic fungi products was observed by scanning electron microscopy (SEM). The probable antibacterial mechanism of endophytic fungi secondary metabolites was the increased membrane permeability that leads to leaks of nucleic acids and proteins. SEM results further confirmed that the extracts can interfere with the integrity of S. aureus cell membrane and further inhibit the growth of bacteria, resulting in the death of bacteria. This study provides a new perspective for the antibacterial functions of endophytic fungi secondary metabolites for biomedical applications.

EFFECT OF THIOPHENE IN BITHIAZOLE-BRIDGED SENSITIZERS ON THE PERFORMANCE OF DYE-SENSITIZED SOLAR CELLS

XIAOYU ZHANG,JIANLI HUA,JINXIANG HE,WENJUN WU,HANS AGREN,XIN LI,FULING GUO 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.5

In this paper, we have designed and synthesized four bithiazole-bridged sensitizers (BT-T2,TBT-T2, BT-T3 and TBT-T3) with triphenylamine and indoline as the donor segment andapplied them to dye-sensitized solar cells (DSSCs). For triphenylamine-based sensitizers as BT-T2 and TBT-T2, adding one thiophene unit between triphenylamine donor and bithiazolemoiety not only led to bathochromic shift of the maximum absorption and increase of molarextinction coe±cient, but also enhanced the photovoltaic conversion e±ciency from 7.12% ofBT-T2 to 7.51% of TBT-T2. But for indoline-based sensitizers as BT-T3 and TBT-T3,adding one thiophene unit between indoline donor and bithiazole moiety resulted in hypochro-matic shift instead of bathochromic shift. We employed the density functional theory (DFT)calculations to further investigate the in°uence of the thiophene unit on their optical and elec-tronic properties and photovoltaic performance of corresponding DSSC devices. Given theresults, a reasonable explanation is the introduction of thiophene unit suppressed the intramo-lecular charge transfer and charge separation in the conjugation system of indoline-based sen-sitizer, which led to the hypochromatic shift of the maximum absorption wavelength and ¯nallythe low Jsc . Since the Jsc dropped sharply from 15.26 mAcm? 2 to 4.52 mAcm? 2 , the photovoltaicconversion e±ciency decreased dramatically from 7.86% to 1.93%.

A Fully Integrated SoC for Smart Capsule Providing In-Body Continuous pH and Temperature Monitoring

Heng Liu,Hanjun Jiang,Jingpei Xia,Zhexiang Chi,Fule Li,Zhihua Wang 대한전자공학회 2016 Journal of semiconductor technology and science Vol.16 No.5

This paper presents a SoC (System-on-a-Chip) dedicated for a single-chip smart capsule which can be used to continuously monitor human alimentary canal pH and temperature values. The SoC is composed of the pH and temperature sensor interface circuit, a wireless transceiver, the power management circuit and the flow control logic. Fabricated in 0.18 μm standard CMOS technology, the SoC occupies a die area of ~9 mm². The SoC consumes 6.15 mW from a 3 V power supply, guaranteeing the smart capsule battery life is no less than 24 hours when using 50 mAh coin batteries. The experimental results show that measurement accuracy of the smart capsule is ±0.1 pH and ±0.2°C for pH and temperature sensing, respectively, which meets the requirement of in-body pH and temperature monitoring in clinical practice.

A Fully Integrated SoC for Smart Capsule Providing In-Body Continuous pH and Temperature Monitoring

Liu, Heng,Jiang, Hanjun,Xia, Jingpei,Chi, Zhexiang,Li, Fule,Wang, Zhihua The Institute of Electronics and Information Engin 2016 Journal of semiconductor technology and science Vol.16 No.5

This paper presents a SoC (System-on-a-Chip) dedicated for a single-chip smart capsule which can be used to continuously monitor human alimentary canal pH and temperature values. The SoC is composed of the pH and temperature sensor interface circuit, a wireless transceiver, the power management circuit and the flow control logic. Fabricated in $0.18{\mu}m$ standard CMOS technology, the SoC occupies a die area of ${\sim}9 mm^2$. The SoC consumes 6.15 mW from a 3 V power supply, guaranteeing the smart capsule battery life is no less than 24 hours when using 50 mAh coin batteries. The experimental results show that measurement accuracy of the smart capsule is ${\pm}0.1$ pH and ${\pm}0.2^{\circ}C$ for pH and temperature sensing, respectively, which meets the requirement of in-body pH and temperature monitoring in clinical practice.

Preparation and characterization of boron films used for boron-lined gaseous neutron detectors

Deng Chao,Wang Qibiao,Wu Yadong,Peng Shuming,Liu Fule,Li Huailiang,Cheng Jianfeng,Tuo Xianguo 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.79 No.7

Boron-lined gaseous neutron detectors are being widely used in neutron detection to replace 3He proportional counters, and the boron film’s parameters comprise the key factors influencing the performance of such detectors. However, the method of characterizing boron film is relatively simple at present. In this study, boron films stuck to ultrathin glass substrate with different mass proportions of epoxy to natural boron (MPENBs) were prepared. A variety of characterization methods, including scanning electron microscopy, energy-dispersive X-ray spectroscopy, white-light interferometry, and multiple tape tests, were used to test the boron films simultaneously, and the test results are discussed herein. Moreover, neutron imaging was conducted to analyze the uniformity of boron-10 atoms. These characterization results demonstrate that the optimized MPENB formulation is 0.16 with the boron atomic ratio of chemical elements (ARCE) at approximately 68.8% and surface roughness Sa = 1.457 μm and that the structure of boron film is uniform and fluffy, contributing to improving the boron-lined method.