Parametric study on nonlinear dynamic characteristics of functionally graded graphene nanoplatelets reinforced composite plates

Wen-xing Lu,Jianen Chen,Wei Zhang,Jun Liu 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.12

The nonlinear dynamics of functionally graded graphene nanoplatelets (GPLs) reinforced composite plates are studied based on the first-order shear deformation theory (FSDT). The ordinary differential equation of the plate is derived by Hamilton principle and Galerkin method. The multi-scale method is used to analyze the jump forces. The effects of GPL distribution pattern, weight fraction, total number of layers and plate size on the resonance peak under sweep excitations, the maximal amplitude and attenuation time under impact loads, the jump force under harmonic excitations are quantitatively studied. The highest nonlinearity is found for the plate with uniform GPL distribution. The change of the number of layers has no effect on the nonlinearity but affects the natural frequency. The size of the plate and weight fraction of GPL both influence the natural frequency and nonlinearity, thereby influencing the dynamic characteristics.

Introducing Network Situation Awareness into Software Defined Wireless Networks

( Xing Zhao ),( Tao Lei ),( Zhaoming Lu ),( Xiangming Wen ),( Shan Jiang ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.3

The concept of SDN (Software Defined Networking) endows the network with programmability and significantly improves the flexibility and extensibility of networks. Currently a plenty of research works on introducing SDN into wireless networks. Most of them focus on the innovation of the SDN based architectures but few consider how to realize the global perception of the network through the controller. In order to address this problem, a software defined carrier grade Wi-Fi framework called SWAN, is proposed firstly. Then based on the proposed SWAN architecture, a blueprint of introducing the traditional NSA (Network Situation Awareness) into SWAN is proposed and described in detail. Through perceiving various network data by a decentralized architecture and making comprehension and prediction on the perceived data, the proposed blueprint endows the controllers with the capability to aware of the current network situation and predict the near future situation. Meanwhile, the extensibility of the proposed blueprint makes it a universal solution for software defined wireless networks SDWNs rather than just for one case. Then we further research one typical use case of proposed NSA blueprint: network performance awareness (NPA). The subsequent comparison with other methods and result analysis not only well prove the effectiveness of proposed NPA but further provide a strong proof of the feasibility of proposed NSA blueprint.

Rapid assessment of suspension bridge deformation under concentrated live load considering main beam stiffness: An analytical method

Wen-ming Zhang,Jia-qi Chang,Xing-hang Shen,Xiao-fan Lu,Tian-cheng Liu 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.88 No.1

With the gradual implementation of long-span suspension bridges into high-speed railway operations, the main beam’s bending stiffness contribution to the live load response permanently grows. Since another critical control parameter of railway suspension bridges is the beam-end rotation angle, it should not be ignored by treating the main beam deflection as the only deformation response. To this end, the current study refines the existing method of the main cable shape and simply supported beam bending moment analogy. The bending stiffness of the main beam is considered, and the main beam’s analytical expressions of deflection and rotation angle in the whole span are obtained using the cable-beam deformation coordination relationship. Taking a railway suspension bridge as an example, the effectiveness and accuracy of the proposed analytical method are verified by the finite element method (FEM). Comparison of the results by FEM and the analytical method ignoring the main beam stiffness revealed that the bending stiffness of the main beam strongly contributed to the live load response. Under the same live load, as the main beam stiffness increases, the overall deformation of the structure decreases, and the reduction is particularly noticeable at locations with original larger deformations. When the main beam stiffness is increased to a certain extent, the stiffening effect is no longer pronounced.

Expression and Significance of Microsomal Prostaglandin Synthase-1 (mPGES-1) and Beclin-1 in the Development of Prostate Cancer

Xu, Lu-Wei,Qian, Ming,Jia, Rui-Peng,Xu, Zheng,Wu, Jian-Ping,Li, Wen-Cheng,Huang, Wen-Bin,Chen, Xing-Guo Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

The aim of this study was to investigate the expression and significance of microsomal prostaglandin synthase-1 (mPGES-1) and Beclin-1 in the development of prostate cancer (PCa). Immunohistochemistry was performed on paraffin-embedded sections with rabbit polyclonal against mPGES-1 and Beclin-1 in 40 PCa, 40 benign prostatic hyperplasia (BPH) and 10 normal prostate specimens for this purpose. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied for mRNA expression of mPGES-1 and Beclin-1, while MTT assays were used to ascertain the best working concentration of the mPGES-1 inhibitor (CAY10526). The effect of CAY10526 treatment on expression of Beclin-1 in DU-145 cells was studied using Western blot analysis. Localization of Beclin-1 and mPGES-1 was in endochylema. Significant differences in expression was noted among PCa, BPH and normal issues (P<0.05). Beclin-1 expression inversely correlated with mPGES-1 expression in PCa tissue (P<0.05). CAY10526 could significantly block mPGES-1 expression and the proliferation of DU-145 cells (P<0.05), while increasing Beclin-1 levels (P<0.05). Overexpression of mPGES-1 could decrease the autophagic PCa cell death. Inhibiting the expression of mPGES-1 may lead to DU-145 cell death and up-regulation of Beclin-1. The results suggest that inhibition of mPGES-1 may have therapeutic potential for PCa in the future.

Effect of HPFRCC on Seismic Performance of Beam-Column-Slab Subassembly

Ting-Ting Lu,Xing-Wen Liang 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.12

High performance fiber reinforced cementitious composites (HPFRCC) material exhibits strain-hardening and multiple cracking behaviors. Using HPFRCC in the reinforced concrete (RC) frame is considered to improve the seismic performance and damage mechanism of structure. Three beam-column-slab subassemblies were tested under cyclic loading, and eight frame models were simulation by ABAQUS. In this paper, the effect of substitution of concretewith HPFRCC on the seismic performance and damage mechanism of subassemblies was investigated. According to the test results, the lateral bearing capacity and deformability of beam-column-slab subassemblies increased by above 10% through using the HPFRCC material in the expected damage positions. The shear resistance of the joint zone with HPFRCC material increased by 1.6%, the shear deformation of the joint zone decreased by 7.9%. And the contribution of slab bars to the beam flexural bearing strength also decreased for that the yielding range and the strain amplitude of slab bars are limited through using HPFRCC material. Consequently, the subassemblies were prone to the “strong column - weak beam” damage mechanism to using HPFRCC material in the expected damage positions.

The Entrainment Effect of a Debris Avalanche on the Erodible Substrate in the Presence of Water Flow

Peng-yuan Lu,Xing-guo Yang,Jia-wen Zhou 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.1

Debris avalanches generally entrain the erodible deposits on their runout path, which can greatly influence their movement process, particularly in the presence of water flow. To study the entrainment effect of debris avalanches, physical modeling experiments were conducted that considered the impact of hopper elevation, the grain size of substrate materials and water flow. The experiment results indicate that the materials entrained by a debris avalanche increase with an increase in elevation of the hopper and particle size of the substrate materials in the rear region of the substrate. The presence of water flow can magnify the entrainment effect and enhance the mobility of the debris avalanche. However, the effect of water flow on the entrainment effect is significantly related to the grain size of the deposits. With a decrease in grain size, a water stream is easier to generate, which can cause intense scouring of the substrate materials and enhance the mobility of the mixed flow of debris and entrained deposits, ultimately leading to a greater affected area.

Dynamic and static properties of sandwich-like graphene-reinforced composite plate

Min Sun,Wen-xing Lu,Minghui Yao,Jianen Chen 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.6

A graphene-reinforced composite plate (GRCP) with a sandwich-like structure is proposed. The nonlinear mechanical characteristics of the sandwich-like GRCP are investigated and compared to those of functionally graded and uniform GRCPs. The modified HalpinTsai model is employed to estimate the material parameters, and the Hamilton principle is used to derive the governing equation for the composite plates. The effects of the graphene nanoplatelet (GPL) distribution patterns, weight fraction, and the number of layers on the static and dynamic nonlinear responses of the plates are investigated. The results show that the various GPL distribution patterns have different enhancement effects on plates. Compared with the graded and uniform distribution patterns, the sandwich-like distribution pattern has significant advantages in terms of anti-vibration and anti-bending properties. Furthermore, it is found that the stresses of the sandwich-like GRCPs are discontinuous, there exist stress mutation phenomena between the surface layers and the pure matrix layer.

Sublethal effects of beta-cypermethrin on the bird cherry-oat aphid Rhopalosiphum padi (Hemiptera: Aphididae)

Qing-Qing Zhang,Wen-Qiang Li,Zeng-Bin Lu,Li-Li Li,Yi Yu,Chao Li,Xing-Yuan Men 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.3

Rhopalosiphum padi is a sap-sucking aphid and an important pest of wheat that causes considerable yield loss. Beta-cypermethrin, a synthetic pyrethroid pesticide, has a broad insecticide spectrum and is considered effective for aphid control, while its residual concentrations may have sublethal effects on R. padi. Here, the sublethal effects of beta-cypermethrin on R. padi were conducted under laboratory conditions. The acute toxicity test showed that LC 10 , LC 20 , and LC 25 of beta-cypermethrin to R. padi adults were 0.003, 0.031 and 0.079 mg L −1 , respectively. The pre-adult survival rate was significantly reduced by all three concentrations. LC 20 significantly extended the development duration of 1st instar nymphs, pre-oviposition period, and oviposition period of R. padi. The adult longevity was also reduced by LC 25 . However, the fecundity did not differ between the betacypermethrin treatment and control. For life table parameters, both the finite rate (λ) and intrinsic rate of increase (r) decreased at LC 10 and LC 20 , as well as the net reproductive rate (R 0 ) reduced at LC 10 and LC 25 , while mean generation time (T) increased at LC 20 . Thus, at the concentrations of beta-cypermethrin tested here, there were negative impacts on R. padi fitness by decreased pre-adult survival rate, λ, r, and R 0 , and delayed the development of some stages and increased T.

Anomalous magnetization jumps in granular Pb superconducting films

Zhang An-Lei,Jiang Wan-Yan,Chen Xing-Hong,Zhang Xiao-Ke,Lu Wen-Lai,Chen Fei,Feng Zhen-Jie,Cao Shi-Xun,Zhang Jin-Cang,Ge Jun-Yi 한국물리학회 2022 Current Applied Physics Vol.35 No.-

In granular superconductors, the grain boundaries are closely related to the vortex dynamics and the macroscopic superconducting properties. In our research, Pb films with different grain sizes were prepared by tuning the substrate temperature. With the grain size decreasing, Pb films are prone to feature the anomalous magnetization jumps in the M − T curves, while in the M − H curves flux avalanche happens. Both phenomena appear in the same region of the H − T phase diagram and thus are considered to have the same origin. The further theoretical analysis shows that with grain size decreasing the pinning mechanism evolves from a mixed δTc and δl pinning to the δl pinning mechanism. The results shed light on the study of pinning mechanism for granular superconductors and is beneficial to the potential application of manipulating vortex pinning by regulation of intrinsic defects.

Identification of novel rheumatoid arthritis-associated MiRNA-204-5p from plasma exosomes

Wu Long-Fei,Zhang Qin,Mo Xing-Bo,Lin Jun,Wu Yang-Lin,Lu Xin,He Pei,Wu Jian,Guo Yu-Fan,Wang Ming-Jun,Ren Wen-Yan,Deng Hong-Wen,Lei Shu-Feng,Deng Fei-Yan 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Rheumatoid arthritis (RA) is an autoimmune disease characterized by infiltration of immune cells in the synovium. However, the crosstalk of immune cells and synovial fibroblasts is still largely unknown. Here, global miRNA screening in plasma exosomes was carried out with a custom microarray (RA patients vs. healthy controls = 9:9). A total of 14 exosomal miRNAs were abnormally expressed in the RA patients. Then, downregulated expression of exosomal miR-204-5p was confirmed in both the replication (RA patients vs. healthy controls = 30:30) and validation groups (RA patients vs. healthy controls = 56:60). Similar to the findings obtained in humans, a decreased abundance of exosomal miR-204-5p was observed in mice with collagen-induced arthritis (CIA). Furthermore, Spearman correlation analysis indicated that plasma exosomal miR-204-5p expression was inversely correlated with disease parameters of RA patients, such as rheumatoid factor, erythrocyte sedimentation rate, and C-reactive protein. In vitro, our data showed that human T lymphocytes released exosomes containing large amounts of miR-204-5p, which can be transferred into synovial fibroblasts, inhibiting cell proliferation. Overexpression of miR-204-5p in synovial fibroblasts suppressed synovial fibroblast activation by targeting genes related to cell proliferation and invasion. In vivo assays found that administration of lentiviruses expressing miR-204-5p markedly alleviated the disease progression of the mice with CIA. Collectively, this study identified a novel RA-associated plasma exosomal miRNA-204-5p that mediates the communication between immune cells and synovial fibroblasts and can be used as a potential biomarker for RA diagnosis and treatment.