Vibration behavior of trapezoidal sandwich plate with functionally graded-porous core and graphene platelet-reinforced layers

Di Liang,Qiong Wu,Xuemei Lu,Vahid Tahouneh 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.36 No.1

In this study, free vibration behavior of trapezoidal sandwich plates with porous core and two graphene platelets (GPLs) reinforced nanocomposite outer layers are presented. The distribution of pores and GPLs are supposed to be functionally graded (FG) along the thickness of core and nanocomposite layers, respectively. The effective Young’s modulus of the GPL-reinforced (GPLR) nanocomposite layers is determined using the modified Halpin-Tsai micromechanics model, while the Poisson’s ratio and density are computed by the rule of mixtures. The FSDT plate theory is utilized to establish governing partial differential equations and boundary conditions (B.C.s) for trapezoidal plate. The governing equations together with related B.C.s are discretized using a mapping- generalized differential quadrature (GDQ) method in the spatial domain. Then natural frequencies of the trapezoidal sandwich plates are obtained by GDQ method. Validity of current study is evaluated by comparing its numerical results with those available in the literature. A special attention is drawn to the role of GPLs weight fraction, GPLs patterns of two faces through the thickness, porosity coefficient and distribution of porosity on natural frequencies characteristics. New results show the importance of this permeates on vibrational characteristics of porous/GPLR nanocomposite plates. Finally, the influences of B.C.s and dimension as well as the plate geometry such as face to core thickness ratio on the vibration behaviors of the trapezoidal plates are discussed.

Fused Polypeptide with DEF Induces Apoptosis of Lung Adenocarcinoma Cells

Liang, Ai-Ling,Zhang, Ting-Ting,Zhou, Ning,Huang, Di-Nan,Liu, Xin-Guang,Liu, Yong-Jun,Tu, Zhi-Guang Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

To analyze the effects of a new unknown peptide DEF on the growth of tumor cells, a fused polypeptide TAT-DV1-DEF was designed and synthesized. The lung adenocarcinoma cell line GLC-82 treated with TAT-DV1-DEF was analyzed with a cell counting kit 8, and the location of polypeptides in cells was observed under laser confocal microscopy. The efficiency of polypeptide transfection and changes in nuclear morphology were analyzed by flow cytometry and fluorescence microscopy, respectively. Finally, the mechanism of tumor cell growth inhibition was evaluated by Western blotting. We found that TAT-DV1-DEF could significantly inhibit the growth of the lung adenocarcinoma cell line GLC-82, but not the normal human embryonic kidney cell line HEK-293. Polypeptides were found to be mostly localized in the cytoplasm and some mitochondria. The efficiency of polypeptide transfection in the two cell types was approximately 99%. Apoptotic nuclei were observed under fluorescence microscopy upon treatment with polypeptides and DAPI staining. Western blot analyses indicated that the polypeptide inhibition of tumor cell growth was apoptosis dependent. In the present study, we demonstrated that fused polypeptides could induce apoptosis of the lung adenocarcinoma cell line GLC-82, indicating that the new unknown peptide DEF has antitumor effects.

An Optimized Control Method Based on Dual Three-Level Inverters for Open-end Winding Induction Motor Drives

Di Wu,Liang-Cheng Su,Xiao-Jie Wu,Guo-Dong Zhao 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.2

An optimized space vector pulse width modulation (SVPWM) method with common mode voltage elimination and neutral point potential balancing is proposed for an open-end winding induction motor. The motor is fed from both of the ends with two neutral point clamped (NPC) three-level inverters. In order to eliminate the common mode voltage of the motor ends and balance the neutral point potential of the DC link, only zero common mode voltage vectors are used and a balancing control factor is gained from calculation in the strategy. In order to improve the harmonic characteristics of the output voltages and currents, the balancing control factor is regulated properly and the theoretical analysis is provided. Simulation and experimental results show that by adopting the proposed method, the common mode voltage can be completely eliminated, the neutral point potential can be accurately balanced and the harmonic performance for the output voltages and currents can be effectively improved.

Control Over the Branched Structures of Platinum Nanocrystals for Electrocatalytic Applications

Ma, Liang,Wang, Chengming,Gong, Ming,Liao, Lingwen,Long, Ran,Wang, Jinguo,Wu, Di,Zhong, Wei,Kim, Moon J.,Chen, Yanxia,Xie, Yi,Xiong, Yujie American Chemical Society 2012 ACS NANO Vol.6 No.11

<P>Structural control of branched nanocrystals allows tuning two parameters that are critical to their catalytic activitythe surface-to-volume ratio, and the number of atomic steps, ledges, and kinks on surface. In this work, we have developed a simple synthetic system that allows tailoring the numbers of branches in Pt nanocrystals by tuning the concentration of additional HCl. In the synthesis, HCl plays triple functions in tuning branched structures <I>via</I> oxidative etching: (i) the crystallinity of seeds and nanocrystals; (ii) the number of {111} or {100} faces provided for growth sites; (iii) the supply kinetics of freshly formed Pt atoms in solution. As a result, tunable Pt branched structurestripods, tetrapods, hexapods, and octopods with identical chemical environmentcan be rationally synthesized in a single system by simply altering the etching strength. The controllability in branched structures enables to reveal that their electrocatalytic performance can be optimized by constructing complex structures. Among various branched structures, Pt octopods exhibit particularly high activity in formic acid oxidation as compared with their counterparts and commercial Pt/C catalysts. It is anticipated that this work will open a door to design more complex nanostructures and to achieve specific functions for various applications.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2012/ancac3.2012.6.issue-11/nn304237u/production/images/medium/nn-2012-04237u_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn304237u'>ACS Electronic Supporting Info</A></P>

Cloning and differential expression of three heat shock protein genes associated with thermal stress from the wolf spider Pardosa pseudoannulata (Araneae: Lycosidae)

Sun Liang-Yu,Liu Jing,Li Qin,Fu Di,Zhu Jia-Yun,Guo Jian-Jun,Xiao Rong,Jin Dao-Chao 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.1

Pardosa pseudoannulata is the main predatory natural enemy of crop pests in a paddy ecosystem. When P. pseudoannulata is exposed to unfavorable temperature conditions, the response of heat shock proteins could resist the damage, and is therefore, conducive to the organism’s rapid adaptation to the surrounding stress environ ment. In this study, we explored the roles of hsp70 and hsp90 genes in response to heat stress, using the rapid amplification of cDNA ends technique and cloned full-length cDNAs of Pphsp70, Pphsp83, and Pphsp90. The mRNA expression levels of the three genes under different temperature stresses (25, 28, 31, 34, 37, 40, and 43 ◦ C) and with different duration stresses (4, 8, 12, 16, and 20 h) were analyzed by quantitative real-time polymerase chain reaction. The full-length cDNA of Pphsp70, Pphsp83, and Pphsp90 was 2331 base pair (bp), 2466 bp, and 2663 bp, respectively. Phylogenetic analysis of amino acid sequences of Pphsp70, Pphsp83, and Pphsp90 showed that the sequences had high homology with that of other spiders. The mRNA expression of all three genes was extremely significantly up-regulated at 43 ◦ C. Moreover at 43 ◦ C, the expression of all three genes in both female and male spiders at the duration of 4 h was the highest compared to that of other stress duration groups. Therefore, it can be inferred that the three genes of P. pseudoannulata play a crucial protective role in resistance in a high-temperature environment.

Triterpenoid saponins from Clinopodium chinense (Benth.) O. Kuntze and their biological activity

Yin-Di Zhu,Jing-Yi Hong,Feng-Da Bao,Na Xing,Ling-Tian Wang,Zhong-Hao Sun,Yun Luo,Hai Jiang,Xudong Xu,Nai-Liang Zhu,Hai-Feng Wu,Gui-Bo Sun,Jun-Shan Yang 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.12

Four new ursane-type triterpenoid saponins, clinopoursaponins A–D (1–4), six new oleanane-type triterpenoid saponins, clinopodiside VII–XII (5–10), as well as eight known triterpene analogues (11–18), were isolated from the aerial parts of Clinopodium chinense (Benth.) O. Kuntze. The structures of the new compounds were determined based on extensive spectral analyses, including 1D (1H and 13C) and 2D NMR experiments (COSY, NOESY, HSQC, 2D TOCSY, HSQC-TOCSY and HMBC), HR-ESI-MS and chemical methods. Compounds 1–18 were evaluated for their protective effects against anoxia/reoxygenation-induced apoptosis in H9c2 cells and cytotoxicities against murine mammary carcinoma cell line 4T1. Compounds 8, 9 and 18 exhibited significant protective effects, while compound 1 exhibited cytotoxic activity with IC50 value of 7.4 μm compared to 7.6 μm for the positive control 10-hydroxycamptothecin.

A survey of Trust Management in WSNs, Internet of Things and Future Internet

( Kai-di Chang ),( Jiann-liang Chen ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.1

Nowadays, most researchers and manufacturers always pay attention on wireless sensor networks (WSNs) due to its potential applications in many regions such as military, industrial and civilian areas. WSNs are the basic components of Internet of Things (IoT) and the key to machine-to-machine communications and the future Internet. Also, the security is an essential element for deploying WSNs. Recently the concept of trust-based mechanism was proposed in WSNs such as traditional cryptographic and authentication mechanisms. However, there is lack a survey on trust management for WSNs, IoT even future Internet. In this paper, we discuss the concept and potential application areas of trust management for WSNs and IoT worlds. Furthermore, we survey different trust management issues (i.e., cluster, aggregation, reputation). Finally, future research directions with respect to trust management in WSNs and future IoT world are provided. We give not only simple WSNs for IoT environments but also a simulated bootstrap platform to provide the discussion of open challenges and solutions for deploying IoT in Future Internet.

Advanced Path-Migration Mechanism for Enhancing Signaling Efficiency in IP Multimedia Subsystem

( Kai-di Chang ),( Chi-yuan Chen ),( Shih-wen Hsu ),( Han-chieh Chao ),( Jiann-liang Chen ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.1

Since Internet Protocol (IP) is the most important protocol in Next Generation Networks (NGNs), 3rd Generation Partnership Project (3GPP) utilizes Session Initial Protocol (SIP) based on IP as the base protocol for negotiating sessions in IP Multimedia Subsystem (IMS). Different from traditional circuit-switched network, in IMS, the media traffic and signaling are delivered through IP transport. The media traffic may affect the signaling efficiency in core network, due to traffic collisions and best effort packets delivery. This paper proposes a novel path-migration mechanism for enhancing the traffic efficiency in integrated NGN-IMS. The simulation results show that the interference and traffic collision can be reduce by applying proposed path-migration mechanism and the signaling efficiency in core network can be improved with higher system capability and voice quality.

Challenges to Next Generation Services in IP Multimedia Subsystem

( Kai Di Chang ),( Chi Yuan Chen ),( Jiann Liang Chen ),( Han Chieh Chao ) 한국정보처리학회 2010 Journal of information processing systems Vol.6 No.2

An Optimized Control Method Based on Dual Three-Level Inverters for Open-end Winding Induction Motor Drives

Wu, Di,Su, Liang-Cheng,Wu, Xiao-Jie,Zhao, Guo-Dong The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.2

An optimized space vector pulse width modulation (SVPWM) method with common mode voltage elimination and neutral point potential balancing is proposed for an open-end winding induction motor. The motor is fed from both of the ends with two neutral point clamped (NPC) three-level inverters. In order to eliminate the common mode voltage of the motor ends and balance the neutral point potential of the DC link, only zero common mode voltage vectors are used and a balancing control factor is gained from calculation in the strategy. In order to improve the harmonic characteristics of the output voltages and currents, the balancing control factor is regulated properly and the theoretical analysis is provided. Simulation and experimental results show that by adopting the proposed method, the common mode voltage can be completely eliminated, the neutral point potential can be accurately balanced and the harmonic performance for the output voltages and currents can be effectively improved.