Effect of Plastic Deformation and Texture on Corrosion of Cold-Rolled AA6061 in NaCl Neutral Solution

Diaoyu Zhou,Taotao Li,Jing Fan 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6

Effects of plastic deformation on the corrosion behaviors of AA6061 aluminum alloy have been investigated in this work. AA6061 was severely deformed by cold rolling processes and the corrosion behaviors were measured using electrochemicaltests in 3.5 wt% NaCl neutral solution. The microstructures were characterized by SEM combined with EDS. The resultsshowed that plastic deformation induced the decrease of average pitting potential and increase of corrosion rate of AA6061due to the number increase and size decrease of second-phase particles, which formed "small cathode-large anode" microbatterycorrosion mechanism with the aluminum alloy matrix. The influence of crystallographic texture on corrosion propertyis analyzed and a simple relation between average pitting corrosion coefficient and texture coefficient is built and supportedby experiments to elucidate the effects of plastic deformation on corrosion.

The Mediation Effect of Herd Behavior on the Impact of Trust on Purchase Intention: A Focus on Livestream E-commerce in China

Fan Zhou(Fan Zhou),Ki-Hyung Bae(Ki-Hyung Bae),De-Kui Li(De-Kui Li) 한국무역연구원 2023 무역연구 Vol.19 No.2

Thermo-Sensitive Polyurethane Membrane with Controllable Water Vapor Permeation for Food Packaging

Zhou, Hu,Shit, Huanhuan,Fan, Haojun,Zhou, Jian,Yuan, Jixin The Polymer Society of Korea 2009 Macromolecular Research Vol.17 No.7

The size and shape of free volume (FV) holes available in membrane materials control the rate of gas diffusion and its permeability. Based on this principle, a segmented, thermo-sensitive polyurethane (TSPU) membrane with functional gate, i.e., the ability to sense and respond to external thermo-stimuli, was synthesized. This smart membrane exhibited close-open characteristics to the size of the FV hole and water vapor permeation and thus can be used as smart food packaging materials. Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), positron annihilation lifetimes (PAL) and water vapor permeability (WVP) were used to evaluate how the morphological structure of TSPU and the temperature influence the FV holes size. In DSC and DMA studies, TSPU with a crystalline transition reversible phase showed an obvious phase-separated structure and a phase transition temperature at $53^{\circ}C$ (defined as the switch temperature and used as a functional gate). Moreover, the switch temperature ($T_s$) and the thermal-sensitivity of TSPU remained available after two or three thermal cyclic processes. The PAL study indicated that the FV hole size of TSPU is closely related to the $T_s$. When the temperature varied cyclically from $T_s-10{\circ}C$ to $T_s+10^{\circ}C$, the average radius (R) of the FV holes of the TSPU membrane also shifted cyclically from 0.23 to 0.467 nm, exhibiting an "open-close" feature. As a result, the WVP of the TSPU membrane also shifted cyclically from 4.30 to $8.58\;kg/m^2{\cdot}d$, which produced an "increase-decrease" response to the thermo-stimuli. This phase transition accompanying significant changes in the FV hole size and WVP can be used to develop "smart materials" with functional gates and controllable water vapor permeation, which support the possible applications of TSPU for food packaging.

Decentralized Fault Tolerant Control of Modular Manipulators System Based on Adaptive Dynamic Programming

Fan Zhou,Fujie Nie,Tianjiao An,Bing Ma,Yuanchun Li 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.10

This paper presented an original decentralized fault tolerant control approach for modular manipulators which based on adaptive dynamic programming (ADP) algorithm. First, the dynamic model of modular manipulators is established via joint torque feedback technique. Then, the fault tolerant controller is designed which composes of model-based compensation controller, observer-based fault tolerant controller and ADP-based optimal controller. According to ADP algorithm, the Hamiltonian-Jacobi-Bellman (HJB) equation can be tackled by critic neural network (NN). The closed-loop modular manipulators system is guaranteed asymptotic stable based on Lyapunov theory. Experiments are performed to verify the proposed method, and the results have guaranteed its effectiveness.

Torque Sensorless Decentralized Position/Force Control for Constrained Reconfigurable Manipulator via Non-fragile H_∞ Dynamic Output Feedback

Zhou, Fan,Dong, Bo,Li, Yuanchun The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.1

This paper studies the decentralized position/force control problem for constrained reconfigurable manipulator without torque sensing. A novel joint torque estimation scheme that exploits the existing structural elasticity of the manipulator joint with harmonic drive model is applied for each joint module. Based on the estimated joint torque and dynamic output feedback technique, a decentralized position/force control strategy is presented. In order to solve the problem of controller parameter perturbation, the non-fragile robust technique is introduced into the dynamic output feedback controller. Subsequently, the stability of the closed-loop system is proved using the Lyapunov theory and linear matrix inequality (LMI) technique. Finally, two 2-DOF constrained reconfigurable manipulators with different configurations are applied to verify the effectiveness of the proposed control scheme in numerical simulation.

Risk of Serious Neutropenic Events in Cancer Patients Treated with Bevacizumab: A Meta-analysis

Zhou, Fan,Shao, Jiang-Hua,Wu, Lin-Quan,Yin, Xiang-Bao,Yu, Xin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.4

Bevacizumab has been approved for use in combination with chemotherapy to treat many types of cancer but associated neutropenic events, including febrile neutropenia, have been reported. To estimate the incidence and relative risk of neutropenic events in cancer patients treated with bevacizumab combination therapy, we searched PubMed, EMBASE, and Web of Science literature databases, as well as abstracts presented at the American Society of Clinical Oncology conferences, to identify relevant studies published from January 1966 to December 2011. Studies that compared bevacizumab plus chemotherapy or biological therapy with chemotherapy or biological therapy alone, and that had adequate safety data profiles, were selected for analysis. Statistical analyses were conducted to calculate the summary incidence rates, relative risks (RRs), and 95% confidence intervals (CIs) using fixed- or random-effects models. A total of 22 clinical trials involving 15,056 patients were included in the analysis. The summary incidences of high-grade neutropenia (HGN) and high-grade febrile neutropenia (HGFN) in patients receiving bevacizumab was 27.3% (95% CI: 26.4%-28.3%) and 3.91% (95% CI: 3.51%-4.37%), respectively. The risks of HGN (RR=1.10; 95% CI: 1.02-1.19; P=0.02) and HGFN (RR=1.31; 95% CI: 1.08-1.59; P=0.005) were significantly increased in bevacizumab-treated patients, compared to those who did not receive bevacizumab. The RR of bevacizumab-associated HGN, but not HGFN, varied significantly with tumor types (P=0.005). The increased risk of bevacizumab-associated neutropenic events was dose-dependent, as the RR was greater at a dose of 5 mg/kg/week than at 2.5 mg/kg/week. Our findings suggest that bevacizumab addition to cancer therapy significantly increases the risk of serious neutropenic events, and this risk may be dose-dependent.

Torque Sensorless Decentralized Position/Force Control for Constrained Reconfigurable Manipulator via Non-fragile H<SUB>∞</SUB> Dynamic Output Feedback

Fan Zhou,Bo Dong,Yuanchun Li 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.1

This paper studies the decentralized position/force control problem for constrained reconfigurable manipulator without torque sensing. A novel joint torque estimation scheme that exploits the existing structural elasticity of the manipulator joint with harmonic drive model is applied for each joint module. Based on the estimated joint torque and dynamic output feedback technique, a decentralized position/force control strategy is presented. In order to solve the problem of controller parameter perturbation, the non-fragile robust technique is introduced into the dynamic output feedback controller. Subsequently, the stability of the closed-loop system is proved using the Lyapunov theory and linear matrix inequality (LMI) technique. Finally, two 2-DOF constrained reconfigurable manipulators with different configurations are applied to verify the effectiveness of the proposed control scheme in numerical simulation.

Research on the Method for Periodic Estimation of the PN Sequence in the Lower SNR DS/SS Signals

Fan Zhou,Yongxin Feng,Xiaoyu Zhang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.10

The periodic estimation method of the PN sequence in DS Signal is researched. It is hard for traditional methods to estimate PN period of DS/SS accurately in the condition of low Signal-to-noise ratio. On the basis of the traditional spectrum reprocessing and the cepstrum method, a PN period estimation method which has integrated serial average with spectrum reprocessing and the cepstrum are put forward to solve this problem and meet the requirements of lower Signal-to-noise ratio. The simulation results show that, when the period of PN sequence is estimated accurately, the cepstrum method has better estimating performance than the spectrum reprocessing method, and the spectral estimation method has lower Signal-to-noise ratio tolerance after improvements.

The Study of Product Availability in a Dual-channel Distribution Supply Chain with (Q, R) Policy of Retailer

Fan He-hua,Zhou Yong-wei 보안공학연구지원센터 2014 International Journal of Hybrid Information Techno Vol.7 No.6

The paper focus on the supply chain model with a single product in electronic and retail channel, only a supplier and a retailer in system, customers have alternatives to choose the channel that is better suited to their needs, some of them may alternatively switch to the other channel when a stock-out occurs in their preferred channel. Supplier and retailer implement one-for-one and (Q, R) ordering policies respectively to replenish their inventories. We set up the profit model of supply chain by Markov process, and study the product availability of supply chain. The result shows that the stock-out based substitution rate may increase or decrease the efficiency of decentralized supply chain; the centralized supply chain can adjust the based-stock levels timely to different stock-out based substitution rate and benefit from it, the supplier and retailer in a decentralized supply chain are more inattentive to customers’ stock-out based substitution rate, and prone to lose their benefits.

The Influence of Seller Reputation and Trust in Streamers on Live Stream Shopping Purchase Intention: The Moderation Effect of Country Image

Fan Zhou,De-Kui Li,Ki-Hyung Bae The International Academy of Global Business and T 2023 The International Academy of Global Business and T Vol.19 No.5

Purpose - Live streaming e-commerce continues to increase Chinese consumer enthusiasm for purchasing foreign products. The current research focus in the field of live streaming e-commerce is on exploring the impact of various factors on consumer purchase attitudes and intentions. This study aims to investigate the effects of seller reputation in traditional e-commerce and trust in streamers in live streaming e-commerce on consumer purchase intentions. Additionally, it aims to analyze how the country image of Korea moderates the effects of seller reputation and trust in streamers on purchase intentions. Design/Methodology/Approach - This study used the SmartPLS statistical software package to analyze a sample of 341 respondents. Structural Equation Modeling (SEM) was used to conduct path analysis and moderation effect analysis Findings - This study found that in live streaming e-commerce, seller reputation and trust in streamer significantly influence consumer purchase attitudes. Country image plays a moderating role in the relationship between seller reputation and attitude. However, country image does not moderate the relationship between trust in streamer and attitude. These findings contribute to our understanding of the factors that shape consumer attitudes, and illuminate the role of the country image as a moderator in e-commerce. Research Implications - This study has found that product country image plays a moderating role in the relationship between seller reputation and consumer purchase attitudes. It makes a theoretical contribution to existing e-commerce research, and explores the positive impact of product country image in cross-border e-commerce.