Investigations on Gilbert damping, Curie temperatures and thermoelectric properties in CoFeCrZ quaternary Heusler alloys

Xiao-Ping Wei,Peifeng Gao,Ya-Ling Zhang 한국물리학회 2020 Current Applied Physics Vol.20 No.4

Exchange interactions and Curie temperatures of CoFeCrZ (Z=P, As, Sb, Ge) quaternary Heusler alloys are studied by using the spin-polarized relativistic Korringa-Kohn-Rostoker method. Electronic calculations show that the CoFeCrZ alloys apart from CoFeCrP are ferromagnetic half-metals, and their integer magnetic moments obey the Slater-Pauling rule. It is confirmed that the calculated Curie temperatures are evidently higher than room temperature. Further, we discuss the dependency of magnetic moments and Curie temperatures with respect to lattice constants. A smaller Gilbert damping parameters imply that these alloys have lower energy loss in spintronics applications. In addition, the thermoelectric properties of CoFeCrZ in both spin channels are calculated based on the BoltzTrap code. Results indicate that the Seebeck coefficients of CoFeCrZ (Z=As, Sb, Ge) are remarkably higher than 1000 μV/K. Overall, we think that the CoFeCrAs, CoFeCrSb and CoFeCrGe alloys are promising candidates in future spintronic and thermoelectric applications.

Distributed Dual-rate Consensus Predictive Control of Looper Tension System in Hot Rolling Mills

Xiao-Dong Zhang,Shao-Shu Gao,Xin-Ping Liu,Ting-Pei Huang 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.2

This paper considers a dual-rate distributed predictive control strategy for the looper tension system in hot rolling mills, which is a typical multi-agent system with directed communication topology. First, we establish an interconnected model for looper tension control system and the disturbances from the neighbors are considered effectively. Second, the consensus control protocol is developed based on the proposed control strategy to improve the robustness and stability of the multi-agent, and the sufficient conditions for consensus are developed. We update and implement all the agent controllers sequentially in one output sampling period and begin a new cycle at the next sampling instant, which leads the multi-agent control system is of fast control updating rate and slow output sampling rate. The control inputs of neighbors can be obtained to compensate the coupling effects, and the cooperation of controllers are improved. Finally, simulation results verify the proposed control strategy and corresponding results.

Detection of Powdery Mildew of Bitter Gourd Based on NIR/Fluorescence Spectra

Gao Jia Yu,Wei Dong Zheng,Wang Xiang,Tang Jin Cheng,Xu Ji Tong,Zhao Ping,Ning Xiao Feng 한국농업기계학회 2023 바이오시스템공학 Vol.48 No.3

Purpose Powdery mildew as one of the common vegetable diseases has very rapid infection. Its outbreak will bring about disastrous consequences to vegetable output; thus, it is of key importance to do rapid identifi cation and prevention of powdery mildew. Methods In this test, 100 bitter gourd leaves were collected as research samples, and the data of near-infrared spectra, fl uorescence spectra, and chromatic values L*a*b* , and the classic K-S algorithm was adopted to divide the sample sets; then, the quantitative forecasting and qualitative discrimination models were established. First, Pearson’s correlation analysis was carried out to fi nd the feasibility of taking a * as the modeling parameter, through cross-validation; the quantitative forecasting model was optimized by the PLSR (partial least squares regression) method. The model is also optimized by extracting the spectral feature bands using the continuous projection SPA method. Results The optimization results showed that the MSC + SPA + PLSR quantitative forecasting model of near-infrared spectra could eff ectively improve model precision, which was signifi cantly higher than that of fl uorescence spectra. Classifi cation Leaner was used to establish the quantitative forecasting model. Compared with the model of near-infrared spectra, the SPA + SVM qualitative discrimination model of fl uorescence spectra could improve the identifi cation precision of powdery mildew of bitter gourd as high as 98% through training. Conclusion This study proposed diff erent combination methods based on quantitative forecasting and qualitative discrimination and could provide a method and reference to the identifi cation of powdery mildew of bitter gourd.

First-Principles Study of the Elastic, Hardness and Electronic Properties of MoAlB under High Pressure

Xiao Ling Zhu,Wei Yang,Shan Shan Gao,Jin Ping Zhang 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.74 No.5

The structure, elastic and electronic properties of MoAlB have been studied under high pressure by using first principles. The optimized lattice parameters, elastic constants, bulk moduli, and shear moduli agree well with experimental and other theoretical values. The relationships of the lattice constants with pressure indicated an anisotropic behavior. The calculated elastic constants satisfy the mechanical stability conditions. Our calculated Vickers hardness of MoAlB is 11.56~GPa, which agrees with the experimental data and confirms its having a relatively softer nature than the other borides. The Cauchy pressure, the Poisson's ratio and the $G/B$ value suggest that MoAlB is a brittle solid under ambient conditions, but the brittleness decreases with increasing pressure. The band structure and the density of states reveal the metallic feature of MoAlB, and the energy levels shift toward both sides of the Fermi level with increasing pressure. The Mulliken population and density of states suggest a mixture bonding nature of covalence and metallicity in MoAlB.

Optimal Monochromatic Imaging of Spectral Computed Tomography Potentially Improves the Quality of Hepatic Vascular Imaging

Xiao-Ping Yin,Bu-Lang Gao,Cai-Ying Li,Huan Zhou,Liang Zhao,Ya-Ting Zheng,Yong-Xia Zhao 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.4

Objective: To investigate the efficiency of spectral computed tomography (CT) optimal monochromatic images in improving imaging quality of liver vessels. Materials and Methods: The imaging data of 35 patients with abdominal CT angiography were retrospectively analyzed. Hepatic arteries, portal veins, and hepatic veins were reconstructed with mixed energy (quality check, QC), 70 keV and optimal monochromatic mode. Comparative parameters were analyzed including CT value, image noise (IN), contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and subjective qualitative analysis. Results: The optimal monochromatic value for assessment of the common hepatic artery, portal vein, and hepatic vein ranged between 49 keV and 53 keV, with a mean of 51 keV. There were statistically significant differences (p < 0.001) among the optimal monochromatic, 70 keV and QC images with regards to the hepatic vascular CT value, IN, CNR, SNR, and subjective qualitative score. CNR of the common hepatic artery in the optimal monochromatic, 70 keV and QC groups was 24.6 ± 10.9, 18.1 ± 8.3, and 11.6 ± 4.6, respectively (p < 0.001) with subjective scores of 4.7 ± 0.2, 4.0 ± 0.3, and 3.6 ± 0.4, respectively (p < 0.001). CNR of the hepatic portal vein was 6.9 ± 2.7, 4.3 ± 1.9, and 3.0 ± 2.1, respectively (p < 0.001) with subjective scores of 4.5 ± 0.3, 3.9 ± 0.4, and 3.3 ± 0.3, respectively (p < 0.001). CNR of the hepatic vein was 5.7 ± 2.3, 4.2 ± 1.9, and 2.7 ± 1.4, respectively with subjective scores of 4.3 ± 0.3, 3.8 ± 0.4, and 3.2 ± 0.3, respectively (p < 0.001). Conclusion: Optimal monochromatic images can lead to improvement in the imaging parameters and optimization of the image quality of the common hepatic artery, hepatic portal vein and hepatic vein compared with conventional mixed kV and with 70 keV datasets.

R ese a rch on State Trend Prediction of Hydr a ulic Turbine Units Based on Mult dimensional and Multi condition Data

Xiao ping Jiang,Xiang Gao,Chao Shi 한국유체기계학회 2022 International journal of fluid machinery and syste Vol.15 No.2

Aiming at the problem that it is difficult to accurately predict the flexible operation conditions and state trend of hydraul ic turbine, in this paper a cascade model of BP LSTM classification prediction is proposed, which can identify the working conditions of existing fusion data, and then predict the measuring points of different working conditions. Based on the pressure parameters of hydraulic turbine units, t he improved BP neural network is used to determine the operation conditions of hydraulic turbine units, and the classified data is redivided to establish the multivariate LSTM prediction model. By optimizing the parameters of the multivariate LSTM predict i on model, such as the structure, the number of network layers and the number of hidden layer neurons, finally established the cascade model of BP LSTM classification prediction of time series of hydraulic turbine units. Through experimental verification a n d analysis, BP LSTM classification prediction model can predict the operation trend of measuring points under different working conditions after classification. Compared with other models, BP LSTM model has higher prediction accuracy and better effect. Th e cascade model of BP LSTM classification prediction of time series provides a model basis for the research of predictive control of hydraulic turbine units.

Research on magnetorheological damper suspension with permanent magnet and magnetic valve based on developed FOA-optimal control algorithm

Ping Xiao,Hong Gao,Limin Niu 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.7

Due to the fail safe problem, it was difficult for the existing Magnetorheological damper (MD) to be widely applied in automotive suspensions. Therefore, permanent magnets and magnetic valves were introduced to existing MDs so that fail safe problem could be solved by the magnets and damping force could be adjusted easily by the magnetic valve. Thus, a new Magnetorheological damper with permanent magnet and magnetic valve (MDPMMV) was developed and MDPMMV suspension was studied. First of all, mechanical structure of existing magnetorheological damper applied in automobile suspensions was redesigned, comprising a permanent magnet and a magnetic valve. In addition, prediction model of damping force was built based on electromagnetics theory and Bingham model. Experimental research was conducted on the newly designed damper and goodness of fit between experiment results and simulated ones by models was high. On this basis, a quarter suspension model was built. Then, fruit Fly optimization algorithm (FOA)-optimal control algorithm suitable for automobile suspension was designed based on developing normal FOA. Finally, simulation experiments and bench tests with input surface of pulse road and B road were carried out and the results indicated that working performance of MDPMMV suspension based on FOA-optimal control algorithm was good.

CCDC26 Gene Polymorphism and Glioblastoma Risk in the Han Chinese Population

Wei, Xiao-Bing,Jin, Tian-Bo,Li, Gang,Geng, Ting-Ting,Zhang, Jia-Yi,Chen, Cui-Ping,Gao, Guo-Dong,Chen, Chao,Gong, Yong-Kuan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.8

Background: Glioblastoma (GBM) is an immunosuppressive tumor whose median survival time is only 12-15 months, and patients with GBM have a uniformly poor prognosis. It is known that heredity contributes to formation of glioma, but there are few genetic studies concerning GBM. Materials and Methods: We genotyped six tagging SNPs (tSNP) in Han Chinese GBM and control patients. We used Microsoft Excel and SPSS 16.0 statistical package for statistical analysis and SNP Stats to test for associations between certain tSNPs and risk of GBM in five different models. ORs and 95%CIs were calculated for unconditional logistic-regression analysis with adjustment for age and gender. The SHEsis software platform was applied for analysis of linkage disequilibrium, haplotype construction, and genetic associations at polymorphism loci. Results: We found rs891835 in CCDC26 to be associated with GBM susceptibility at a level of p=0.009. The following genotypes of rs891835 were found to be associated with GBM risk in four different models of gene action: i) genotype GT (OR=2.26; 95%CI, 1.29-3.97; p=0.019) or GG (OR=1.33; 95%CI, 0.23-7.81; p=0.019) in the codominant model; ii) genotypes GT and GG (OR=2.18; 95%CI, 1.26-3.78; p=0.0061) in the dominant model; iii) GT (OR=2.24; 95%CI, 1.28-3.92; p=0.0053) in the overdominant model; iv) the allele G of rs891835 (OR=1.85; 95%CI, 1.14-3.00; p=0.015) in the additive model. In addition, "CG" and "CGGAG" were found by haplotype analysis to be associated with increased GBM risk. In contrast, genotype GG of CCDC26 rs6470745 was associated with decreased GBM risk (OR=0.34; 95%CI, 0.12-1.01; p=0.029) in the recessive model. Conclusions: Our results, combined with those from previous studies, suggest a potential genetic contribution of CCDC26 to GBM progression among Han Chinese.

Magnetic Properties in Iron Film System Deposited on Liquid Surfaces

Jian-Ping Xie,Quan-Lin Ye,Xiao-Jun Xu,Gao-Xiang Ye 한국자기학회 2008 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Prevalence and Age, Gender and Geographical Area Distribution of Esophageal Squamous Cell Carcinomas in North China from 1985 to 2006

Feng, Xiao-Shan,Yang, Yan-Tong,Gao, She-Gan,Ru, Yi,Wang, Gong-Ping,Zhou, Bo,Wang, Yu-Feng,Zhang, Peng-Fei,Li, Pu-Yu,Liu, Yong-Xuan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.5

Objective: To establish the prevalence and distribution profile of esophageal squamous cell carcinomas (ESCCs) over a 22-yr period in North China. Methods: Using endoscopy for primary diagnosis and histological analysis for the further confirmation, a total of 74,854 ESCC patients aged 20-89 between January 1985 and December 2006 were investigated to analyze the epidemiological profile including prevalence rates, distribution of age-of-onset, gender and geographical area of ESCC in Luoyang, the highest incidence area of North China. Results: A total of 4092 cases of ESCC were finally diagnosed among 74,854 patients who had their first endoscopies. The prevalence among males was higher than that among females (p<0.01), resulting in an overall male:female OR of 1.2 (95%CI, 1.2-1.3). The prevalence in rural areas was higher than in urban areas (p<0.01), resulting in an overall rural:urban OR of 2.6 (95%CI, 2.4-2.9). The rural:urban ORs and the 95% CI increased continuously from 2.6, 2.3-3.0 to 2.7, 2.2-3.3, respectively, for 4 consecutive periods during the 22-yr study period. Moreover, the median age of onset among females was higher than that among males (p<0.01). For both sexes and in both areas, the prevalence rates declined and the median age of onset rose for 4 consecutive periods in the 22-yrs time frame (p<0.01). Conculsions: These data reveal the epidemiological profile of ESCC in the area of North China, and suggest that urban areas and rural people account for a growing proportion of the ESCC patients although the prevalence of ESCC significantly declined and the median age-of-onset postponed over the 22-yrs period. Moreover, the prevalence status of ESCC in rural areas also underlines the need for public health initiatives aimed at reducing risk factors of this fatal disease.