Effect of Ion Source Current on the Microstructure and Properties of Cr-DLC Coatings Prepared by Ion Beam-Assisted Arc Ion Plating

Yao Cai,Huidong Liu,Ye Ma,Qiang Wan,Hao Cheng,Yan Liu,Yanming Chen,Qingsong Mei,Bing Yang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.5

Cr-containing diamond-like carbon (Cr-DLC) nanocomposite coatings were synthesized by ion beam-assisted arc ion plating with varying hollow cathode ion source (HCIS) currents. The morphologies, compositions and microstructures were characterized by scanning electronic microscopy (SEM), atomic force microscopy (AFM), X-Ray photoelectron spectrometer (XPS), Raman spectroscopy, grazing incidence X-ray diffraction (GIXRD) and high-resolution transmission electron microscopy (HRTEM). Hardness and friction coefficient were investigated by using nanoindentation and ball-on-disc tribometer, respectively. With no HCIS current, the coating exhibits the maximal growth rate and a rough surface, as well as lower hardness and elastic modulus. With the increasing HCIS current from 40 A to 80 A, the growth rate and the content of chromium carbide decrease obviously, the sp3/sp2 ratio increases initially to the maximum at the HCIS current of 60 A, the highest hardness and elastic modulus are obtained at the HCIS current of 50 A. It is also revealed that moderate HCIS current can reduce surface roughness obviously and promote tribological properties. The correlation of the HCIS current with the microstructure and performance of Cr-DLC coating has been established.

Numerical Investigation on the Design and Optimization of Stacking Pattern for High Flexural Performance Carbon Fiber Reinforced Resin Matrix Composites

Yao Cai,Xizhong An,Qingchuan Zou,Dengzhi Yao,Haitao Fu,Hao Zhang,Xiaohong Yang 한국섬유공학회 2022 Fibers and polymers Vol.23 No.9

The stacking sequences of fiber-reinforced composites for optimization of turbine blades with the bestperformance have become a focus of attention. However, the optimization and design principles of its flexural performanceare not yet mature. Referring to the problems in previous work, a 3D finite element flexural model of carbon fiber reinforcedcomposites was established based on the Abaqus/Explicit VUMAT subroutine through the Tsai-Wu failure criterion. Theinfluencing laws and optimization mechanisms of different stacking patterns (e.g., different orientations, number oforientation plies, combination of multiple orientation plies, and symmetry/asymmetry structures) on the flexural properties ofthe composites were systematically investigated, and corresponding design references for the optimization of stackingpatterns were given. The results show that the smaller the value of |θ-45 °| (θ represents the angle of the orientation ply), themore obvious the stress reduction of the orientation ply, and the orientation ply located in the outer layer is more conducive tothe improvement of flexural performance. As the number of orientation plies increases, the flexural strength anddisplacement increase, but the stability decreases, in which the laminate with 50 % 0 ° orientation plies has the best overallperformance. In addition, the stability ranking of the laminate stacking sequences for the same 0 ° orientation ply proportionis: multi-orientation asymmetric > multi-orientation symmetric > single-orientation symmetric. In particular, the [75/02/60/30/02/15] laminate has the best overall performance with the flexural strength of 974 MPa and the Y-axis offset of 0.057 mm,and its stability is 66 % higher than that of the [15/02/75]S laminate. Under the same tensile/compressive stresses, the actualstress of the warp/weft in the orientation ply is less than the maximum ideal stress and the stress of Y-axis direction SY ≠ 0,which delays the fracture of the orientation ply and causes displacement offset, and the increase of the number of orientationplies will aggravate this effect. The obtained highlighted results can provide valuable references for the design andoptimization of stacking patterns of plain fabric-reinforced laminates with high flexural properties.

Effects of graded levels of cupric citrate on growth performance, antioxidant status, serum lipid metabolites and immunity, and tissue residues of trace elements in weaned pigs

Chu Cai Peng,Jia You Yan,Bin Dong,Lin Zhu,Yao Yao Tian,Li Min Gong 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.4

Objective: The goal of this study was to investigate the effects of cupric citrate (CuCit) on growth performance, antioxidant indices, serum lipid metabolites, serum immune indices, and tissue residues of copper (Cu), zinc, and iron in weaned pigs. Methods: A total of 180 weaned pigs (Duroc×Landrace×Large White) with an average body weight of 8.98±1.21 kg were randomly assigned to a corn-soybean meal control ration, or 4 similar rations with 30, 60, 120, or 240 mg/kg Cu as CuCit. All diets contained 10 mg/kg Cu as cupric sulfate from the vitamin-mineral premix. The experiment was divided into two phases: 0 to 14 d (phase 1) and 15 to 28 d (phase 2). Results: Average daily gain (ADG; linearly, p<0.01) and average daily feed intake (ADFI; linearly and quadratically, p<0.05) were affected by an increase in CuCit during phase 2. Overall period, ADG (p<0.05) and ADFI (p<0.01) were linearly increased with increasing dietary levels of CuCit. Serum malondialdehyde concentrations (p<0.05) and glutathione peroxidase activity (p<0.01) linearly decreased and increased respectively with an increase in CuCit. Serum levels of Cu-Zn superoxide dismutase were linearly affected with an increase in CuCit (p<0.01). Hepatic malondialdehyde levels decreased with an increase in CuCit (linearly and quadratically, p<0.01). Serum total cholesterol concentrations were quadratically affected (p<0.05) and decreased in pigs fed Cu as CuCit at 60 and 120 mg/kg and increased in pigs fed 240 mg/kg Cu as CuCit. Serum high-density lipoprotein concentrations were linearly affected with an increase in CuCit (p<0.01). Serum IL-1β levels were quadratically affected (p<0.05) by dietary treatment. Compared with other treatments, 240 mg/kg Cu from CuCit quadratically increased hepatic (p<0.01) and renal (p<0.05) Cu concentrations, and quadratically decreased hepatic and renal iron concentrations (p<0.05). Conclusion: Cu administered in the form of CuCit at a dosage range of 30 to 60 mg/kg, effectively enhanced the growth performance and antioxidant status of weaned pigs.

Effects of Castration on Androgen Receptor, IGF-I Ea, MGF and Myostatin Gene Expression in Skeletal Muscles of Male Pigs

Yao, Yuchang,Cai, Zhaowei,Zhang, Lifan,Zhao, Chunjiang,Wu, Keliang,Xu, Ningying,Liu, Gang,Wu, Changxin Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.8

Castration of male pig produces significant negative effects on skeletal muscle development. The androgen receptor (AR), two splice variants of insulin-like growth factor-I (IGF-I Ea and MGF) and the myostatin gene may play important roles in this process. In the present study, the expression of AR, IGF-I Ea, MGF and myostatin genes in three skeletal muscles, the brachialis, longissimus and semitendinosus, were studied using real-time quantitative RT-PCR. Our experimental design used 14 pairs of male Landrace sire${\times}$Yorkshire dam piglets. The two piglets in each pair were full sibs, one of which was castrated at 21 d of age; the other remained intact. The study group was divided into subgroups of equal size. Animals in the first subgroup were slaughtered at 147 d and those of the second at 210 d of age. Carcass weight and lean meat yield were similar between boars and barrows at 147 d of age (p>0.05), whereas barrows had lower carcass weight and less lean meat yield at 210 d of age (p<0.05). Castration caused down-regulation of AR gene expression at both 147 and 210 d of age (p<0.05). The two splice variants of the IGF-I gene from porcine skeletal muscle were cloned using RT-PCR, and it was found that MGF differs from IGF-I Ea in having a 52-base insert in the last coding exon of the mRNA. Both splice variants were down-regulated by castration only at 210 d of age (p<0.05). No differences in expression of the myostatin gene were observed between boars and barrows at either 147 or 210 d of age (p>0.05). These results suggest that the downregulation of AR, IGF-I Ea and MGF gene expression following castration helps to explain the negative effect of castration on skeletal muscle development.

Image Denoising Algorithm Based on Non Related Dictionary Learning

Yao Nan,Wang KaiSheng,Cai Yue 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.3

In allusion to the partial texture information loss during image deniosing process, an image denoising algorithm based on non related dictionary learning is proposed in this article. In this algorithm, the noise image is firstly divided into mutually overlapped image blocks, and a certain quantity of these image blocks are randomly selected for subsequent dictionary learning; then, non related dictionary learning technology is adopted to obtain the redundant dictionary with relatively strong irrelevance; finally, the sparse encoding algorithm is adopted to obtain the sparse representation coefficient of each image block in the redundant dictionary, and such sparse representation coefficients are used to recover the original image. The experiment result shows: since the redundant dictionary obtained through non related dictionary learning technology can strongly represent the image texture information, PSNR (Peak Signal to Noise Ratio) of the algorithm proposed in this article is superior to that of the existing advanced algorithm, and the algorithm can well keep the image detail and texture information, thus to improve visual effect.

Full-Scale Experiment and Ultimate Bearing Capacity Assessment of Reinforced Concrete Drainage Culverts with Defects

Yao Tang,Yongchang Cai,Dongyang Feng 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.11

In this paper, three full-scale box culvert specimens with different defect cases were designed and carried out based on the field investigation results of typical cross-sections in Shanghai Drainage Line. According to the test data, the cracking development, load-deformation curve, failure modes, and the ultimate bearing capacity of the specimens were analyzed and studied. In addition, a finite element model (FEM) based on a plastic damage model of concrete was established, and its parameters were determined by the experimental results and sensitivity analysis. The FEM simulation results agreed well with the experiment. On the basis of the characteristic curve of "load-deflection" and the failure modes obtained from the test and numerical simulation, an ultimate bearing capacity evaluation model and practical method were established and put forward, which can provide references for the safety evaluation, prevention as well as reinforcement of large diameter rectangular drainage box culverts with defects.

Application of Intelligent Video Monitoring System in Electric Power Construction

Yao Nan,Wang KaiSheng,Cai Yue 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.4

Since the image based intelligent video monitoring system has limited viewing angle, the blind monitoring zone will easily appear when the target is not in the field range of the camera. In order to solve the above problem, an intelligent video monitoring system with auditory function is proposed in this article on the basis of the advantages of sound localization. Firstly, the linear microphone array is acquired and the time delay estimation technology is adopted for sound localization; secondly, the camera is driven to turn to the sound source position to acquire video information; finally, the image detection program is adopted to locate and track the target in a real-time manner, and meanwhile the system feasibility is verified through the simulation experiment. The result shows that the system has good localization and tracking accuracy.

Anti-Distortion Image Contrast Enhancement Algorithm Based on Fuzzy Statistical Analysis of the Histogram Equalization

Yao Nan,Wang KaiSheng,Cai Yue 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.4

In order to solve such problems as excessive enhancement and chessboard effect, difficult image brightness keeping and distortion in the image enhancement algorithm based on histogram equalization, an anti-distortion image contrast enhancement algorithm based on fuzzy statistics and sub-histogram equalization is proposed in this article. Specifically, the fuzzy set theory is introduced therein to convert the image into fuzzy matrix; then, by virtue of the membership function and the probability of the image gradation, the weighting function is embedded to construct the weighted fuzzy histogram calculation model; then, the mid-value of the initial image is adopted to divide the fuzzy histogram into two sub-histograms, and the corresponding cumulative density functions are defined, and the transformation models thereof are also constructed; then, the inverse transformation function is established to realize defuzzification and output the enhanced image. The experimental data show: compared with the present image enhancement algorithm based on histogram equalization, this algorithm can significantly eliminate excessive enhancement and noise amplification, thus to not only have better visual enhancement quality and anti-distortion performance, but also have maximum AIC (Average Information Contents) value and minimum NIQE (Natural Image Quality Evaluator) value.

Synthesis, Characterization and Antioxidant Activity of a Novel Organogermanium Sesquioxide with Resveratrol

Yao, Shuguang,Jiang, Jinhuan,Yang, Peihui,Cai, Ji-Ye Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.4

Feasibility analysis of using a two-stage nutation drive as joint reducer for industrial robots

Yongwu Cai,Ligang Yao,Jun Zhang,Zhiyu Xie,Jinlong Hong 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.4

Nutation drive claims the advantages of high load capacity, large transmission ratio, desirable stability, low noise, and compact volume, which makes it an excellent alternative to typical joint reducers used in industrial robots. This paper proposes a novel two-stage nutation drive as a joint reducer for the industrial robot. The working principle of the nutation movement is first introduced followed by an analysis of transmission characteristics. The transmission ratio, the transmission efficiency as well as the structural schematic of the proposed nutation drive are presented. Finite element analysis of the main components, including nutation sleeve and bevel gears, was performed. Finally, a prototype was designed, manufactured and tested to verify the feasibility of applying the nutation drive as a joint reducer for industrial robots.