Frequency study of porous FGPM beam on two-parameter elastic foundations via Timoshenko theory

Wenhua Huang,Vahid Tahouneh 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.40 No.1

The goal of this study is to fill this apparent gap in the area about investigating free vibration of Functionally Graded Piezoelectric Materials (FGPMs) nanobeams with porosity resting on two-parameter elastic foundations, under voltage load considering Timoshenko beam model and nonlocal theory. The elastic foundation is considered as a Pasternak model with adding a shear layer to the Winkler model. The electromechanical and mechanical properties of the nanobeam (such as elastic, piezoelectric, dielectric coefficients and mass density) are FG in the thickness direction of the beam. Based on Hamilton principle, governing equations of the problem are derived. The Differential Quadrature Method (DQM) for solution of these equations are employed to determine the natural frequencies of the FGPM nanobeams at different Boundary Conditions (B.C.s). The influences of supporting conditions, the porosity coefficient and patterns including even and uneven, nonlocal parameter, Winkler foundation modulus, shear elastic foundation modulus, external voltage and power-law index on the electromechanical vibration characteristics of the FGPM nanobeams are discussed in details. It is found that the FG index and nonlocal parameter will reduce the natural frequencies of the FG nanobeam, while the Winkler and Pasternak moduli of the foundation show an opposite tendency.

Induction of Apoptosis by Icariside II through Extrinsic and Intrinsic Signaling Pathways in Human Breast Cancer MCF7 Cells

HUANG, Chaoqing,CHEN, Xiaoguang,GUO, Baolin,HUANG, Wenhua,SHEN, Ting,SUN, Xinguang,XIAO, Peigen,ZHOU, Qing Japan Society for Bioscience, Biotechnology and Ag 2012 Bioscience, biotechnology, and biochemistry Vol.76 No.7

CNN-based Skip-Gram Method for Improving Classification Accuracy of Chinese Text

( Wenhua Xu ),( Hao Huang ),( Jie Zhang ),( Hao Gu ),( Jie Yang ),( Guan Gui ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.12

Text classification is one of the fundamental techniques in natural language processing. Numerous studies are based on text classification, such as news subject classification, question answering system classification, and movie review classification. Traditional text classification methods are used to extract features and then classify them. However, traditional methods are too complex to operate, and their accuracy is not sufficiently high. Recently, convolutional neural network (CNN) based one-hot method has been proposed in text classification to solve this problem. In this paper, we propose an improved method using CNN based skip-gram method for Chinese text classification and it conducts in Sogou news corpus. Experimental results indicate that CNN with the skip-gram model performs more efficiently than CNN-based one-hot method.

Influence of Initial Damage Degree on the Degradation of Concrete Under Sulfate Attack and Wetting–Drying Cycles

Yujing Lv,Wenhua Zhang,Fan Wu,Huang Li,Yunsheng Zhang,Guodong Xu 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.5

The previous researches on the degradation process of concrete under sulfate attack mainly focus on non-damaged concrete. It may lead to an excessive evaluation of the durability of the structure, which is detrimental to the safety of the structure. In this paper, three different damage degrees of concrete specimens with non-damaged (D0) and initial damage of 10% (D₁) and 20% (D₂) were prefabricated and subjected to sulfate attack and wetting–drying cycles. With the increase of sulfate attack cycles (0, 30, 60, 90, 120, 150 cycles), the changes in mass loss, relative dynamic modulus of elasticity, and the stress–strain curve were studied. The results show that the mass of the D0 specimen had been increasing continuously before 150 sulfate attack cycles. The mass of D₁ and D₂ had been increasing before 60 cycles, and decreasing after 60 cycles. At 150 cycles, the mass loss of D0, D₁, D₂ were − 1.054%, 0.29% and 3.20%, respectively. The relative dynamic modulus of elasticity (RDME) of D0 specimen increases continuously before 90 sulfate attack cycles. After 90 cycles, the RDME gradually decreases. However, for D₁ and D₂ specimens, the RDME began to decrease after 30 cycles. The damage degree has an obvious influence on the compressive strength and elastic modulus. For the D0 specimen, the compressive strength and elastic modulus increased continuously before 90 cycles and decreased after 90 cycles. The compressive strength and elastic modulus of D₁ and D₂ specimens began to decrease after 30 cycles. The stress–strain curves of concrete with different initial damage degrees were established, and the fitting results were good. Finally, based on the analysis of experimental data, the degradation mechanism of concrete with initial damage under the sulfate wetting–drying cycle was discussed.

Highly frequency-, temperature-, and bias-stable dielectric properties of 500 °C processed Bi2SiO5 thin films with low dielectric loss

Yifu Ke,Wenhua Huang,Santhosh Kumar Thatikonda,Ruqi Chen,Chuangye Yao,Ni Qin,Dinghua Bao 한국물리학회 2020 Current Applied Physics Vol.20 No.6

Excellent dielectric frequency, bias, and temperature stability of bismuth silicate (Bi2SiO5, BSO) thin films with a low dielectric loss has been obtained in this study. The thin films were prepared on Pt/Ti/SiO2/Si substrates by a chemical solution deposition method at a relatively low annealing temperature of 500 °C. The BSO films have a preferred growth along (200) orientation with dense fine-grained surface morphology. The dielectric constant and dielectric loss of the thin film annealed at 500 °C are 57 and 0.01, respectively, at 100 kHz, with little change between 1 kHz and 100 kHz and in the bias electric field range between−250 kV/cm and 250 kV/cm, indicating that the thin film exhibits a low dielectric loss as well as excellent frequency and bias field stability. The dielectric- temperature measurements confirmed that the BSO thin film annealed at 500 °C also has good temperature stability between 150 K and 450 K. Our results suggest that the BSO thin films have potential applications in the next-generation integrated capacitors.

Ti-doping induced antiferroelectric to ferroelectric phase transition and electrical properties in Sm-PbZrO3 thin films

Thatikonda Santhosh Kumar,Huang Wenhua,Du Xingru,Yao Chuangye,Ke Yifu,Wu Jiang,Qin Ni,Bao Dinghua 한국물리학회 2021 Current Applied Physics Vol.24 No.-

The antiferroelectric (Pb0.985Sm0.01) (Zr1-xTix)O3 (Ti-PSZO) thin films were synthesized on Pt(111)/Ti/SiO2/Si substrates using a chemical solution deposition method. The films were crystallized in the perovskite phase with a preferential orientation along (111) direction. With Ti doping in PSZO, a gradual transformation from antiferroelectric to ferroelectric phase transition was noticed at room temperature owing to the Ti doping induced lattice distortion. The phase transition has been confirmed through the P - E hysteresis loops, X-ray diffraction (peak shifting), capacitance-voltage measurements, and Raman scattering analysis. The thin film with Ti = 0.15 doping displayed a ferroelectric behavior with high dielectric constant and large dielectric tunability of about 62%. Also, Ti doping altered the Curie temperature (Tc) and enhanced the order of dielectric diffuseness. It is believed that Ti-doping in PSZO is an effective way to induce an antiferroelectric - ferroelectric phase transition and to tailor the electrical characteristics of PSZO thin films.

Dibenzoheptazethrene Isomers with Different Biradical Characters: An Exercise of Clar’s Aromatic Sextet Rule in Singlet Biradicaloids

Sun, Zhe,Lee, Sangsu,Park, Kyu Hyung,Zhu, Xiaojian,Zhang, Wenhua,Zheng, Bin,Hu, Pan,Zeng, Zebing,Das, Soumyajit,Li, Yuan,Chi, Chunyan,Li, Run-Wei,Huang, Kuo-Wei,Ding, Jun,Kim, Dongho,Wu, Jishan American Chemical Society 2013 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.135 No.48

<P><I>Clar’s aromatic sextet rule</I> has been widely used for the prediction of the reactivity and stability of polycyclic aromatic hydrocarbons with a <I>closed-shell</I> electronic configuration. Recent advances in <I>open-shell</I> biradicaloids have shown that the number of aromatic sextet rings plays an important role in determination of their ground states. In order to test the validity of this rule in singlet biradicaloids, the two soluble and stable dibenzoheptazethrene isomers <B>DBHZ1</B> and <B>DBHZ2</B> were prepared by different synthetic approaches and isolated in crystalline form. These two molecules have different numbers of aromatic sextet rings in their respective biradical resonance forms and thus are expected to exhibit varied singlet biradical character. This assumption was verified by different experimental methods, including nuclear magnetic resonance (NMR), electron spin resonance (ESR), superconducting quantum interference device (SQUID), steady-state and transient absorption spectroscopy (TA), and X-ray crystallographic analysis, assisted by unrestricted symmetry-broken density functional theory (DFT) calculations. <B>DBHZ2</B>, with more aromatic sextet rings in the biradical form, was demonstrated to possess greater biradical character than <B>DBHZ1</B>; as a result, <B>DBHZ2</B> exhibited an intense one-photon absorption (OPA) in the near-infrared region (λ<SUB>abs</SUB><SUP>max</SUP> <I>=</I> 804 nm) and a large two-photon absorption (TPA) cross-section (σ<SUP>(2)</SUP><SUB>max</SUB> = 2800 GM at 1600 nm). This investigation together with previous studies indicates that Clar’s aromatic sextet rule can be further extended to the singlet biradicaloids to predict their ground states and singlet biradical characters.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2013/jacsat.2013.135.issue-48/ja410279j/production/images/medium/ja-2013-10279j_0012.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja410279j'>ACS Electronic Supporting Info</A></P>

Coexistence of resistive switching and magnetism modulation in sol-gel derived nanocrystalline spinel Co3O4 thin films

Chuangye Yao,Wei Hu,Muhammad Ismail,Santhosh Kumar Thatikonda,Aize Hao,Shuai He,Ni Qin,Wenhua Huang,Dinghua Bao 한국물리학회 2019 Current Applied Physics Vol.19 No.11

We report the coexistence of resistive switching and magnetism modulation in the Pt/Co3O4/Pt devices, where the effects of thermal annealing and film thickness on the resistive and magnetization switching were investigated. The sol-gel derived nanocrystalline Co3O4 thin films obtained crack-free surface and crystallized cubic spinel structure. The 110 nm Co3O4 film based device annealed at 600 °C exhibited optimum resistive switching parameters. From I–V curves fitting and temperature dependent resistance, the conduction mechanism in the high-voltage region of high resistance state was dominated by Schottky emission. Magnetization-magnetic field loops demonstrated the ferromagnetic behaviors of the Co3O4 thin films. Multilevel saturation magnetization of the Co3O4 thin films can be easily realized by tuning the resistance states. Physical resistive switching mechanism can be attributed to the rejuvenation and annihilation of conductive filament consisting of oxygen vacancies. Results suggest that Pt/Co3O4/Pt device shows promising applications in the multifunctional electromagnetic integrated devices.