Study of temperature-induced structural evolution in (Na0.5Bi0.5)TiO3- (K0.5Bi0.5)TiO3-(K0.5Na0.5)NbO3 lead-free ceramics

Xing Liu,Jiwei Zhai,Bo Shen,Feng Li,Yang Zhang,Peng Li,Baihui Liu 한국물리학회 2017 Current Applied Physics Vol.17 No.5

In this work, the temperature-induced structural evolution in 0.79(Na0.5Bi0.5)TiO3-0.2(K0.5Bi0.5)TiO3- 0.01(K0.5Na0.5)NbO3 (NKBNT) lead-free ceramics was investigated by Raman microscopic spectroscopy combined with electrical macroscopic measurements. The NKBNT ceramics possess the local structure with the coexisted rhombohedral R3c and tetragonal P4bm polar-nano-regions (PNRs). The R3c and P4bm PNRs coexist in a wide temperature range, then the local structure transforms to the P4bm PNRs around the temperature of dielectric maximum (Tm) evidenced by the doublet splitting of Ti-O modes (peak B) and oxygen octahedral vibrational modes (peak C). The discontinuous changes of wavenumber and linewidth of peak B2 and peak C3 as well as the dielectric local maxima around the rhombohedral-tetragonal phase transition temperature (TRT) are considered to result from the thermal evolution of R3c and P4bm PNRs. The macroscopic changes of non-polar phase with electric field and temperature were investigated by the temperature-dependent polarization-electric field (P-E) loops, current-electric field (I-E) loops and bipolar strain (S-E) curves. The electric-field level necessary to form the long-range ferroelectric order from non-polar phase associated with the stability of the induced ferroelectric phase depends strongly on the temperature.

Construction of optimal designs for quantile regression model via particle swarm optimization

Zhai Yi,Xing Chen,Fang Zhide 한국통계학회 2023 Journal of the Korean Statistical Society Vol.52 No.4

As an extension of mean regression and being robust against outliers, quantile regression has been used in many fields such as biomedicine, ecology, economics. However, it is theoretically and computationally challenging to find the optimal experimental design for quantile regression due to the complexity of the optimiza- tion problem. The purpose of this paper is to provide theoretical necessary conditions for A- and c-optimality of a design separately, and a numerical algorithm to find optimal designs for quantile regression models. The algorithm is constructed through particle swarm optimization so as to solve the problem of non-convexity of optimality criteria. In this paper, the algorithm is applied to obtain locally as well as Bayesian optimal designs for Michaelis–Menten, Emax and Exponential quantile regression models. We demonstrate that this technique can be applied to a variety of optimality criteria and scale functions without making any further assumption.

Who achieves superior rates of upward social mobility and better labor market outcomes in China: international student returnees or postgraduates who study domestically?

Keyu Zhai,Xing Gao 서울대학교 교육연구소 2021 Asia Pacific Education Review Vol.22 No.2

Given the growth in student mobility and transnational higher education, there is an abundance of research on international students’ studying and living experiences in a new environment. However, their poststudy transitions and social mobility have rarely been touched. This study addresses how student returnees perform in China’s labor market and social mobility, following their accomplishment of their master degree in the UK and return to China. In theoretical considerations of the graduates’ social mobility, Bourdieu’s capital theory helps identify the capital accumulation and conversion in the social mobility process. Based on a survey to collect data, 756 questionnaires are collected, including 347 questionnaires for returnees and 409 questionnaires for home graduates. Multi-regression model and visualization are employed to analyze the collected data. This study reports that home graduates have better performance in social mobility than their peers. Additionally, employment preference and spatial mobility between international and home graduates represent large diversity.

Synthesis of mesoporous PrxZr1-xO2-δ solid solution with high thermal stability for catalytic soot oxidation

Hongcheng Li,Kongzhai Li,Xing Zhu,Yunpeng Du,Yonggang Wei,Kang Zhai,Hua Wang 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.54 No.-

The fabrication of mesoporous PrxZr1xO2d solid solutions with different Pr/Zr molar ratios is reported in the present work. Based on a systematic investigation, the anion of Zr precursor and template species are found to play the most important roles for the formation of mesoporous structure. The triblock copolymer Pluronic F127 template helps to generate porosity in the matrix by self-assembly into micelle, while the additional Cl1 from Zr precursor can lead to the enhancement of the interaction between non-ionic micelles. The physicochemical properties of the obtained samples were studied by means of N2 sorption analysis, TEM, XRD, H2-TPR, O2-TPD and XPS technique. It is found that, compared with the nonmesoporous counterparts, the mesoporous PrxZr1xO2d solid solutions possess much higher specific surface area (139 m2 g1) and enhanced redox ability. Also, the ability to release oxygen is improved after aging at high temperature. For the catalytic soot oxidation, the fresh mesoporous Pr0.1Zr0.9O2d catalyst (calcinated at 500 C) shows high activity in a loose contact condition (T50 = 399 C). It should be highlighted that the T50 values over the three mesoporous PrxZr1xO2d samples decrease by 8–24 C after aging at 800 C for 3 h. This suggests that the mesoporous PrxZr1xO2d solid solution is an ideal candidate for catalytic application at high temperatures.

Halomonas tibetensis sp. nov., isolated from saline lakes on Tibetan Plateau

Hui-bin Lu,Peng Xing,Lei Zhai,Dorji Phurbu,Qian Tang,Qing-long Wu 한국미생물학회 2018 The journal of microbiology Vol.56 No.7

Strains pyc13T and ZGT13 were isolated from Lake Pengyan and Lake Zigetang on Tibetan Plateau, respectively. Both strains were Gram-negative, catalase- and oxidase-positive, aerobic, rod-shaped, nonmotile, and nonflagellated bacteria. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains pyc13T and ZGT13 belong to the genus Halomonas, with Halomonas alkalicola 56-L4-10aEnT as their closest neighbor, showing 97.4% 16S rRNA gene sequence similarity. The predominant respiratory quinone of both strains was Q-9, with Q-8 as a minor component. The major fatty acids of both strains were C18:1 ω6c/C18:1 ω7c, C16:1 ω6c/C16:1 ω7c, C16:0, and C12:0 3OH. The polar lipids of both strains consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, glycolipid, phospholipids of unknown structure containing glucosamine, and unidentified phospholipids. The DNA G + C content of pyc13T and ZGT13 were 62.6 and 63.4 mol%, respectively. The DNA-DNA hybridization values of strain pyc13T were 34, 41, 61, 35, and 35% with the reference strains H. alkalicola 56-L4-10aEnT, H. sediminicola CPS11T, H. mongoliensis Z-7009T, H. ventosae Al12T, and H. fontilapidosi 5CRT, respectively. Phenotypic, biochemical, genotypic, and DNA-DNA hybridization data showed that strains pyc13T and ZGT13 represent a new species within the genus Halomonas, for which the name H. tibetensis sp. nov. is proposed. The type strain is pyc13T (= CGMCC 1.15949T = KCTC 52660T).

Research on Smart Campus Based on the Internet of Things and Virtual Reality

Youliang Huang,Sajid Ali,Xiaoming Bi,Xing Zhai,Renquan Liu,Fengying Guo,Peng Yu 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.12

Smart campus is an inevitable trend in the development of digital campus construction. With the development of the Internet of Things (IoT) and Virtual Reality (VR) technology, these technologies become the key to the construction of smart campus. The major objective of this study put forward a smart campus system prototype based on Internet technology. This paper firstly introduces the definition and characteristics of the IoT and VR technology. Secondly, presents the architecture and implementation methodology of the system prototype, and analyzes the core idea of smart campus. Finally, discuss the problems should be noticed in the smart campus construction.

Prevalence of Spina Bifida Occulta and Its Relationship With Overactive Bladder in Middle-Aged and Elderly Chinese People

Jun Wei Wu,Yu Rong Xing,Yi Bo Wen,Tian Fang Li,Quan De Feng,Xiao Ping Shang,Yun Long Li,Jin Jin Feng,Xin Xin Wang,Rong Qun Zhai,Xiang Fei He,Tao Chen,Xin Jian Liu,Jian Guo Wen 대한배뇨장애요실금학회 2016 International Neurourology Journal Vol.20 No.2

Purpose: To investigate the prevalence of spina bifida occulta (SBO) and its relationship with the presence of overactive bladder (OAB) in middle-aged and elderly people in China. Methods: A cross-sectional community-based survey was carried out at 7 communities in Zhengzhou City, China from December 15, 2013 to June 10, 2014, where residents aged over 40 years were randomly selected to participate. All of the participants underwent lumbosacral radiographic analysis and relevant laboratory tests. A questionnaire including basic information, past medical history and present illness, and the OAB symptom score was filled out by all participants. Chi-square tests and logistic regression were used for data analysis with a P-value of <0.05 denoting statistical significance. Results: A total of 1,061 subjects were qualified for the final statistical analysis (58.8±11.7 years; male, 471 [44.4%]; female, 590 [55.6%]). The overall prevalence of SBO was 15.1% (160 of 1,061): 18.3% (86 of 471) in men and 12.5% (74 of 590) in women. Among these subjects, 13.7% (145 of 1,061) had OAB: 13.2% (62 of 471) in men and 14.1% (83 of 590) in women. The results of logistic regression showed that age, SBO, history of cerebral infarction (HCI), and constipation were risk factors for OAB (P<0.05), while sex, history of childhood enuresis (HCE), body mass index (BMI), and diabetes mellitus (DM) were not (P>0.05). In men, age, SBO, and constipation were risk factors for OAB (P<0.05), while HCE, BMI, DM, HCI, and benign prostate hyperplasia were not (P>0.05). In women, age, SBO, and HCI were risk factors for OAB (P<0.05), while HCE, BMI, DM, vaginal delivery, and constipation were not (P>0.05). Conclusions: The prevalence of SBO is high and it is related to OAB in middle-aged and elderly people in China.

PLCE1 Gene in Esophageal Cancer and Interaction with Environmental Factors

Guo, Li-Yan,Zhang, Shen,Suo, Zhen,Yang, Chang-Shuang,Zhao, Xia,Zhang, Guo-An,Hu, Die,Ji, Xing-Zhao,Zhai, Min Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.7

Objective: To study the PLCE1 gene rs2274223 polymorphism with regard to esophageal cancer and its interaction with diet, lifestyle, psychological and environmental factors in Southwest Shandong province. Materials and Methods: A case series study (case-case) was conducted. Questionnaire data were collected and 3 ml-5ml venous blood was drawn for DNA extraction among the qualified research subjects. PLCE1 gene polymorphism was detected after PCR amplification of DNA. SPSS 13.0 software was used for statistical analysis of the data. Results: The three genotypes A/A, A/G and G/G PLCE1 gene rs2274223 was 31, 16 and 4 cases, accounting for 60.8%, 31.4%, 0.08% respectively. The difference of three genotypes (AA/GA/GG) proportion between negative and positive family history of patients was statistically significant, ${\chi}^2=6.213$, p=0.045. There was no statistically significant relationship between PLCE1 gene rs2274223 polymorphism and smoking, drinking, ${\chi}^2=0.119$, p=0.998, and ${\chi}^2=1.727$, p=0.786. There was no linkage of the three rs2274223 PLCE1 gene genotypes (AA/GA/GG) proportion with eating fried, pickled, hot, mildew, overnight, smoked, excitant food, eat speed, salt taste or not (p>0.05). or with living environment pollution and nine risk factors of occupational exposure (p>0.05). There was no statistically significant difference in TS scores between different genotype of rs2274223 PLCE1 gene. Conclusions: The PLCE1 rs2274223 polymorphism has a relationship with family history of esophageal cancer, but does not have any significant association with age, gender, smoking, alcohol drinking, food hygiene, eating habits, living around the environment and occupation in cases.