Research on residual stress in SiCf reinforced titanium matrix composites

Haitao Qu,Hongliang Hou,Bing Zhao,Song Lin 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.17 No.2

This study aimed to theoretical calculate the thermal residual stress in continuous SiC fiber reinforced titanium matrix composites. The analytical solution of residual stress field distribution was obtained by using coaxial cylinder model, and the numerical solution was obtained by using finite element model (FEM). Both of the above models were compared and the thermal residual stress was analyzed in the axial, hoop, radial direction. The results indicated that both the two models were feasible to theoretical calculate the thermal residual stress in continuous SiC fiber reinforced titanium matrix composites, because the deviations between the theoretical calculation results and the test results were less than 8%. In the titanium matrix composites, along with the increment of the SiC fiber volume fraction, the longitudinal property was improved, while the equivalent residual stress was not significantly changed, keeping the intensity around 600 MPa. There was a pronounced reduction of the radial residual stress in the titanium matrix composites when there was carbon coating on the surface of the SiC fiber, because carbon coating could effectively reduce the coefficient of thermal expansion mismatch between the fiber and the titanium matrix, meanwhile, the consumption of carbon coating could protect SiC fibers effectively, so as to ensure the high-performance of the composites. The support of design and optimization of composites was provided though theoretical calculation and analysis of residual stress.

Construction of Cognitive Radio Based Emergency Communication System and Application Scenario Analysis

Haitao Wang,Hui Chen,Shicai Zhu,Lihua Song 보안공학연구지원센터 2013 International Journal of Smart Home Vol.7 No.3

Development of a Virtual Teaching Platform for Remotely Operated Vehicles

Yingfei Zan,Haitao Zhu,Lei Song,Lihao Yuan 국제이네비해양경제학회 2018 International Journal of e-Navigation and Maritime Vol.10 No.1

Courses on the motion and operation of remotely operated vehicles (ROV) tend to feature abstract theoretical concepts, numerous formulas, combinations of mathematical and physical concepts and teaching that is disconnected from practice. As with the development of computer technology, the dynamic connection between the combination of the highly-realistic visual effects of simulation and theoretical classroom teaching has the aesthetic characteristics of a physical science. In this study, a virtual teaching platform for ROVs was developed on the basis of current virtual simulation technologies, as well as the needs of courses focused on ROV motion and operation. Based on detailed analyses of the functional and performance requirements of a virtual teaching platform for ROVs, the system was subdivided into six subsystems: remote-control simulation, dynamic and kinematic mathematical modeling, underwater operation tools simulation, visual scene display, teacher control and network administration, using an object-oriented design method featuring modularization and standardization. The subsystems facilitate modular development, integration and function extension, and support the openness, inheritance and reusability of the system. The platform is used to intuitively acquaint students with ROVs’ kinetic characteristics and operating methods by means of intuitive 3D models, precise motion calculation, and real operating scenes. Based on teaching practice in colleges and universities, a typical work-task-oriented practical teaching system was developed, along with the application of course design and scenario design for the ROV virtual teaching platform. Through interactive operation, students can dynamically and intuitively observe the motion of ROVs during navigation, helping them to learn about hydrodynamic performance. With simulated ROV operation, students learn about the principles of dynamic mechanical tools as well as the relationships between the interaction forces of ROVs. This contributes to disciplinary progress in naval architecture and ocean engineering, as well as the development of students’ practical engineering competence.

Molecular Orbital Gating Surface-Enhanced Raman Scattering

Guo, Chenyang,Chen, Xing,Ding, Song-Yuan,Mayer, Dirk,Wang, Qingling,Zhao, Zhikai,Ni, Lifa,Liu, Haitao,Lee, Takhee,Xu, Bingqian,Xiang, Dong American Chemical Society 2018 ACS NANO Vol.12 No.11

<P>One of the promising approaches to meet the urgent demand for further device miniaturization is to create functional devices using single molecules. Although various single-molecule electronic devices have been demonstrated recently, single-molecule optical devices which use external stimulations to control the optical response of a single molecule have rarely been reported. Here, we propose and demonstrate a field-effect Raman scattering (FERS) device with a single molecule, an optical counterpart to field-effect transistors (a key component of modern electronics). With our devices, the gap size between electrodes can be precisely adjusted at subangstrom accuracy to form single molecular junctions as well as to reach the maximum performance of Raman scattering via plasmonic enhancement. Based on this maximum performance, we demonstrated that the intensity of Raman scattering can be further enhanced by an additional ∼40% if the orbitals of the molecules bridged two electrodes were shifted by a gating voltage. This finding not only provides a method to increase the sensitivity of Raman scattering beyond the limit of plasmonic enhancement, but also makes it feasible to realize addressable functional FERS devices with a gate electrode array.</P> [FIG OMISSION]</BR>

Dynamic Island Partition for Distribution System with Renewable Energy to Decrease Customer Interruption Cost

Junpeng Zhu,Wei Gu,Ping Jiang,Shan Song,Haitao Liu,Huishi Liang,Ming Wu 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.6

When a failure occurs in active distribution system, it will be isolated through the action of circuit breakers and sectionalizing switches. As a result, the network might be divided into several connected components, in which distributed generations could supply power for customers. Aimed at decreasing customer interruption cost, this paper proposes a theoretically optimal island partition model for such connected components, and a simplified but more practical model is also derived. The model aims to calculate a dynamic island partition schedule during the failure recovery time period, instead of a static islanding status. Fluctuation and stochastic characteristics of the renewable distributed generations and loads are considered, and the interruption cost functions of the loads are fitted. To solve the optimization model, a heuristic search algorithm based on the hill climbing method is proposed. The effectiveness of the proposed model and algorithm is evaluated by comparing with an existing static island partitioning model and intelligent algorithms, respectively.

Dynamic Island Partition for Distribution System with Renewable Energy to Decrease Customer Interruption Cost

Zhu, Junpeng,Gu, Wei,Jiang, Ping,Song, Shan,Liu, Haitao,Liang, Huishi,Wu, Ming The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.6

When a failure occurs in active distribution system, it will be isolated through the action of circuit breakers and sectionalizing switches. As a result, the network might be divided into several connected components, in which distributed generations could supply power for customers. Aimed at decreasing customer interruption cost, this paper proposes a theoretically optimal island partition model for such connected components, and a simplified but more practical model is also derived. The model aims to calculate a dynamic island partition schedule during the failure recovery time period, instead of a static islanding status. Fluctuation and stochastic characteristics of the renewable distributed generations and loads are considered, and the interruption cost functions of the loads are fitted. To solve the optimization model, a heuristic search algorithm based on the hill climbing method is proposed. The effectiveness of the proposed model and algorithm is evaluated by comparing with an existing static island partitioning model and intelligent algorithms, respectively.

Licochalcone A, a Natural Inhibitor of c-Jun <i>N</i>-Terminal Kinase 1

Yao, Ke,Chen, Hanyong,Lee, Mee-Hyun,Li, Haitao,Ma, Weiya,Peng, Cong,Song, Nu Ry,Lee, Ki Won,Bode, Ann M.,Dong, Ziming,Dong, Zigang American Association for Cancer Research 2014 Cancer Prevention Research Vol.7 No.1

<P>The c-<I>Jun N</I>-terminal kinases (JNK) play an important role in many physiologic processes induced by numerous stress signals. Each JNK protein appears to have a distinct function in cancer, diabetes, or Parkinson's disease. Herein, we found that licochalcone A, a major phenolic constituent isolated from licorice root, suppressed JNK1 activity but had little effect on JNK2 <I>in vitro</I> activity. Although licochalcone A binds with JIP1 competitively with either JNK1 or JNK2, a computer simulation model showed that after licochalcone A binding, the ATP-binding cleft of JNK1 was distorted more substantially than that of JNK2. This could reduce the affinity of JNK1 more than JNK2 for ATP binding. Furthermore, licochalcone A inhibited JNK1-mediated, but not JNK2-mediated, c-Jun phosphorylation in both <I>ex vivo</I> and <I>in vitro</I> systems. We also observed that in colon and pancreatic cancer cell lines, JNK1 is highly expressed compared with normal cell lines. In cancer cell lines, treatment with licochalcone A or knocking down JNK1 expression suppressed colon and pancreatic cancer cell proliferation and colony formation. The inhibition resulted in G<SUB>1</SUB> phase arrest and apoptosis. Moreover, an <I>in vivo</I> xenograft mouse study showed that licochalcone A treatment effectively suppressed the growth of HCT116 xenografts, without affecting the body weight of mice. These results show that licochalcone A is a selective JNK1 inhibitor. Therefore, we suggest that because of the critical role of JNK1 in colon cancer and pancreatic carcinogenesis, licochalcone A might have preventive or therapeutic potential against these devastating diseases. <I>Cancer Prev Res; 7(1); 139–49. ©2013 AACR</I>.</P>

Tailoring ZSM-5 zeolite through metal incorporation: Toward enhanced light olefins production via catalytic cracking: A minireview

Yuchen Sha,Lei Han,Ruoyu Wang,Peng Wang,Haitao Song 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.126 No.-

The steam cracking of hydrocarbons has been the major process for light olefins production in recent decades. Recent studies have shown that a considerable amount of propylene and ethylene can be producedby hydrocarbon cracking on modified ZSM-5 zeolite. Various modified elements and post-treatmentmethods have been employed to fulfil the improvement of the catalytic performance over ZSM-5 zeolite. This article focuses on the research progress about the catalytic cracking of hydrocarbons over metalincorporatedZSM-5 zeolite. The mechanism of propylene and ethylene production via catalytic crackingof various hydrocarbons over ZSM-5 zeolite is summarized and the influences of different metal species,such as alkaline earth and alkali metal elements, rare earth metal elements, transition metals, etc. on bothactivity and stability are also discussed. Moreover, the synergistic influence of bimetallic components ismentioned as well. In particular, the effects of different synthetic methods and structures of metal speciesare discussed. We hope that this review will kindle the future rational design of metal-incorporated zeolitecatalysts to realize efficient catalytic cracking of hydrocarbons for light olefins production.