Fabrication and Interface Structural Behavior of Mg/Al Thickness-Oriented Bonding Sheet via Direct Extrusion

Lei Gao,Feng Li,Ye Wang,Xing Mao Xiao,Peng Da Huo 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

Solid-state bonding of heterogeneous materials is one of the effective ways to achieve light weight. An extrusion formingprocess for Mg/Al thickness-oriented bonding sheet was carried out. Due to triaxial compressive stress in the extrusion container,the AZ31 and AA6061 billets were deformed and the bonding and forming of Mg/Al thickness-oriented sheet can berealized by this method. The observation results of the bonding position by using XRD, SEM and EDS showed that: at theforming temperature with 360–420 °C, it had a good bonding interface, and the width of the transition layer increased withthe increase of the forming temperature. The presence of brittle intermetallic compounds in the transition layer indicated thatmetallurgical bonding had occurred at the interface. Considering all factors comprehensively, when the forming temperaturewas 390 °C, the bonding quality was appropriate. Its tensile-shear strength was 42 MPa, the width of the interface transitionlayer was about 10 μm, and the microhardness was about 164.3 HV. This method provided scientific guidance and technicalreserves for green forming of Mg/Al sheets.

Fine-tuning the Electronic Structure of Organic Dyes for Dye-Sensitized Solar Cells

Gao, Peng,Tsao, Hoi Nok,Grä,tzel, Michael,Nazeeruddin, Mohammad K. American Chemical Society 2012 Organic letters Vol.14 No.17

<P>A series of metal-free organic dyes exploiting different combinations of (hetero)cyclic linkers (benzene, thiophene, and thiazole) and bridges (4<I>H</I>-cyclopenta[2,1-<I>b</I>:3,4-<I>b′</I>]dithiophene (CPDT) and benzodithiophene (BDT)) as the central π-spacers were synthesized and characterized. Among them, the sensitizer containing the thiophene and CPDT showed the most broad incident photon-to-current conversion efficiency spectra, resulting in a solar energy conversion efficiency (η) of 6.6%.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/orlef7/2012/orlef7.2012.14.issue-17/ol301730c/production/images/medium/ol-2012-01730c_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ol301730c'>ACS Electronic Supporting Info</A></P>

URBAN LAKE FUNCTIONS IN ECOSYSTEM AND LANDSCAPE BUILDING IN BEIJING CITY

GAO PENG-JIE,WANG LIANXING 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

De novo malignancy after liver transplantation

Peng Ji Gao,Jie Gao,Zhao Li,Zhi Ping Hu,Ji Ye Zhu 대한외과학회 2015 Annals of Surgical Treatment and Research(ASRT) Vol.88 No.4

Purpose: The aim of this study is to evaluate the incidence of de novo malignancy after liver transplantation (LT) and compare with those among the general Chinese population. Methods: A total of 466 patients who had a minimum follow-up time of 6 months were enrolled in the study. All data of medical records and follow up were retrospectively reviewed. Results: The incidence rate of de novo malignancy was 3.0% (14 in 466 patients). The median elapsed time from transplant to the diagnosis of de novo malignancy was 42 months (range, 6 to 106 months). The cumulative risk for development of de novo malignancy was 1.6%, 2.7%, and 8.2% at 3, 5 and 10 years after LT, respectively. The patients were all male. The types of de novo tumors included digestive system tumor (8 in 14), lung cancer (2 in 14), urologic neoplasm (2 in 14), and hematologic malignant tumor (2 in 14). Over a mean follow-up of 24 months after diagnosis of de novo malignancy, 7 patients (50.0%) died; the overall 5-year patient survival rate was 54.5%. The relative risk of malignancy following LT was 9.5 folds higher than the general Chinese population. Conclusion: The relative risk of malignancy following LT was much higher than the general Chinese population. Digestive system tumor is the most common type of de novo malignancy after LT in China.

Complex Background Palm Segmentation using SVM

Gao Peng,Li Liang 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.5

An efficient method is proposed to enhance complex background segmentation for pre-processing in palmprint recognition. In this paper, we integrate texture and haze features by applying Laws masks to the image represented in YCbCr color space, and use these features of a patch with its neighborhood information to determine hand and non-hand regions by support vector machine (SVM). Compared with other methods, our algorithm demonstrated robustness to changing illumination and a complex environment and we obtain a relatively clear hand shape with an average accuracy of 94.96%. The images in our experiments are taken with popular mobile phones in our laboratory.

Dynamic Beehive Detection and Tracking System Based on YOLO V5 and Unmanned Aerial Vehicle

Gao Peng,이강빈,쿠스위디얀토 루카스 위쿠,유승화,Hu Kai,Liang Gaotian,Chen Yufeng,Wang Weixing,Liao Fei,정유석,전문석,최인찬,한웅철 한국농업기계학회 2022 바이오시스템공학 Vol.47 No.4

Purpose With urban development and improvements in human living conditions, wild beehives in densely populated areas present a threat to human safety. The traditional manual method of clear beehives may result in secondary injury to humans. Methods This paper proposes a beehive detection model based on YOLO V5 by introducing the Shufe Block V2 and depthwise separable convolution (DSC) modules to decrease the original model parameters. The model can be deployed on edge computation devices such as Raspberry 4B with good detection accuracy. The PID algorithm and dual servo motors were combined with the object detection model to track the beehive automatically. The results of experiments showed that the inference speed of the improved beehive detection model was 92.5% faster than the original YOLO V5s model, although the detection accuracy and other indicators were not signifcantly diferent. Results The accuracy of the system in this study was as high as 96% in real-time detection, and the maximum recognition distance was 2.5 m. The performance test results of the system deployed on an unmanned aerial vehicle (UAV) showed that 90% of the beehive tracking process could be completed within 2 s, positioning the object in the center of the images collected by the camera. At the same time, when the UAV was moving at random, the detection and tracking system could still follow the beehive quickly and automatically. Conclusion The detection model and tracking system established in this paper provide important support to reduce the secondary damage to the rescue workers that may occur in beehive governance.

Direct conversion of CO₂ into liquid fuels with high selectivity over a bifunctional catalyst

( Peng Gao ) 한국화학공학회 2017 NICE Vol.35 No.5

Optimized Kalman Filter with Multi-sensor Fusion and Auto-Encoder Neural Network for Navigation Systems of Agricultural Autonomous Mobile Robots

( Peng Gao ),( Lee Hyeonseung ),( Chan-woo Jeon ),( Changho Yun ),( Hak-jin Kim ),( Xiongzhe Han ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.2

In unmanned navigation of agricultural machinery, it’s crucial to make accurate positioning. Although Real-time Kinematic Global Positioning System (RTK-GPS) and other accurate positioning technologies had made significant progress, when the unmanned vehicles were in the region with poor satellite signal, such as near buildings, woods, etc., its positioning became poor. To solve this problem, this study proposed an advanced Kalman Filter algorithm based on RTK-GPS, Inertial measurement unit (IMU), and encoder for multi-sensor fusion which achieved position prediction under the condition of poor satellite signals. An unsupervised Auto-Encoder model based on convolutional neural networks was proposed in this study. Auto-Eecoder and Auto-Dncoder had asymmetrical structures with three-layer convolution to generate the denoised data to optimize state equation and measurement equation noise covariance Q and R of Kalman Filter. Using the optimized Q and R matrices, the state equation and measurement equation were constructed. The Nvidia Jetson Nano development board was used as the experimental platform to test in open-air and shade-covered environments. The results showed that the proposed algorithm had better positioning accuracy than RTK-GPS in the two environments and could still accurately predict the vehicle position in real-time with poor signals.

A Compact UWB and Bluetooth Slot Antenna for MIMO/Diversity Applications

Peng Gao,Shuang He 한국전자통신연구원 2014 ETRI Journal Vol.36 No.2

A novel compact pattern diversity slot antenna for ultrawideband(UWB) and Bluetooth applications is presented. Thisantenna consists of two modified coplanar waveguides thatfeed staircase-shaped radiating elements, wherein two differentfork-like stubs are placed at the 45º axis. The measured resultsshow that this proposed antenna operates from 2.3 GHz to12.5 GHz, covering Bluetooth, WLAN, WiMAX, and UWB. Theperformance of radiation patterns and the correspondingenvelope correlation coefficient prove this antenna is suitablefor MIMO/diversity systems. Also, the antenna’s compact sizemakes it a good candidate for portable devices.

Bearing Capacity Test and Calculation Theory on CHS X-Joints Stiffened with Joint-Plates

Chenzhong Gao,Dachang Zhang,Mingcheng Cui,Peng Peng 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.2

In this study, three circular hollow sections (CHS) tubular X-joints strengthened with different external stiffeners or not were investigated by experimental and nonlinear finite element anlaysis (FEA) to study the bearing capacities, failure modes, and the strengthening effect of joint-plates. The test results showed that the bearing capacity of the X-joints could be improved by using the stiffened joint-plate, and the joint failure process was delayed, and the cambered surface of chord was straightened by tensile braces. Compared with the tested results, the nonlinear FEA could simulate the failure modes and its bearing capacity behavior of steel tubular X-joints well. To estimate the contribution of joint-plates on bearing capacity, four kinds of parameters were selected, and the corresponding FEA of stiffened X-joint were performed. Then, the influencing law on bearing capacity of different parameters was investigated. According to the superposition method of bearing capacities, the annular calculation model and the multi-parameter calculation theory of stiffened circular steel tubular X-joints were proposed, in which the coefficients were determined through regression analysis. Lastly, the comparisons on tested, simulated, and theoretical bearing capacities of stiffened X-joints were carried out, and there had good agreement between them.