Universality of Finite-Size Corrections to Geometrical Entanglement in One-Dimensional Quantum Critical Systems

Xi-Jing Liu,Bing-Quan Hu,Sam Young Cho,Huan-Qiang Zhou,Qian-Qian Shi 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.7

Recently, the finite-size corrections to the geometrical entanglement per lattice site in the spin- 1/2 chain have been numerically shown to scale inversely with system size, and its prefactor b has been suggested to be possibly universal [Q-Q. Shi et al., New J. Phys. 12, 025008 (2010)]. As possible evidence of its universality, the numerical values of the prefactors have been confirmed analytically by using the Affleck-Ludwig boundary entropy with a Neumann boundary condition for a free compactified field [J-M. Stephan et al., Phys. Rev. B 82, 180406(R) (2010)]. However, the Affleck-Ludwig boundary entropy is not unique and does depend on conformally invariant boundary conditions. Here, we show that a unique Affleck-Ludwig boundary entropy corresponding to a finitesize correction to the geometrical entanglement per lattice site exists and show that the ratio of the prefactor b to the corresponding minimum groundstate degeneracy gmin for the Affleck- Ludwig boundary entropy is a constant for any critical region of the spin-1 XXZ system with the single-ion anisotropy, i.e., b/(2 log2 gmin) = −1. Previously studied spin-1/2 systems, including the quantum three-state Potts model, have verified the universal ratio. Hence, the inverse finite-size correction to the geometrical entanglement per lattice site and its prefactor b are universal for one-dimensional critical systems.

Prevalence and Risk Factors of Postdialysis Fatigue in Patients Under Maintenance Hemodialysis: A Systematic Review and Meta-Analysis

You Qian,Bai Ding-xi,Wu Chen-xi,Chen Huan,Hou Chao-ming,Gao Jing 한국간호과학회 2022 Asian Nursing Research Vol.16 No.5

Purpose: Despite the high prevalence of postdialysis fatigue (PDF) in maintenance hemodialysis patients, no meta-analysis on the prevalence and risk factors of PDF has yet been published. This study aimed to identify the prevalence of PDF and explore its related factors. Methods: PubMed, Embase, CENTRAL, Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and the four Chinese databases (National Knowledge Infrastructure [CNKI], Chinese Biomedical Literature database [SinoMed], Wanfang Digital Periodicals [WANFANG], and Chinese Science and Technology Periodicals [VIP] database) were searched from inception up to July 2022. This study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The articles were independently searched by two reviewers, and the relevant data were extracted. The Agency for Healthcare Research and Quality was used to assess the quality of the included studies. Results: Thirteen articles with 2,118 participants were included. The pooled prevalence was 60.0%. The meta-analysis results revealed that the ultrafiltration volume, mean arterial pressure after dialysis, and good sleep quality were potentially associated with PDF, whereas only good sleep quality (odds ratio 0.24, 95% confidence interval 0.19e0.30) was significantly associated with PDF. Conclusion: PDF is common in maintenance hemodialysis patients, which is related to the ultrafiltration volume, sleep quality, and mean arterial pressure after dialysis. However, the mechanism underlying the risk factors and PDF remains unknown. Further research is warranted to investigate the risk factors, intervention, treatment, and mechanism in maintenance hemodialysis patients.

Recent Developments in the Effects of Different Dopants on the Structure and Property of Lithium Titanate Material

Xi-Yang Li,Qian-Lin Chen,Min Yang,Ya-Nan Li,Jing-Bo Ma 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.3

The lithium titanium spinel Li4Ti5O12 has attracted more and more attention as anode materials applied in lithium ion batteries. Li4Ti5O12 material has been found to be able to intercalate lithium ions without deformation of the lattice. However, compared with graphite and other anode materials, the low conductivity of Li4Ti5O12 restricts its charging and discharging rate. Doping is deemed to be a businesslike method to enhance ionic and electronic conductivity of Li4Ti5O12. This paper reviews the effects of Li4Ti5O12 with different doping ions on different crystal lattice states. And it has been found by a summary that the doping objective of doping ions at Li4Ti5O12 is also different. Moreover, the applications of ion doping in different fields of Li4Ti5O12 are prospected.

New ZVZCT Bidirectional DC-DC Converter Using Coupled Inductors

Qian, Wei,Zhang, Xi,Li, Zhe,Jin, Wenqiang,Wiedemann, Jochen The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

In this study, a novel zero voltage zero current transition (ZVZCT) bidirectional DC-DC converter is proposed by employing coupled inductors. This converter can turn the main switch on at ZVZCT and it can turn it off with zero voltage switching (ZVS) for both the boost and buck modes. These characteristics are obtained by using a simple auxiliary sub-circuit regardless of the power flow direction. In the boost mode, the auxiliary switch achieves zero current switching (ZCS) turn-on and ZVS turn off. Due to the coupling inductors, this converter can make further efficiency improvements because the resonant energy in the capacitor or inductor can be transferred to the load. The main diode operates with ZVT turn-on and ZCS turn-off in the boost mode. For the buck mode, there is a releasing circuit to conduct the currents generated by the magnetic flux leakage to the output. The auxiliary switch turns on with ZCS and it turns off with ZVT. The main diode also turns on with ZVT and turns off with ZCS. The design method and operation principles of the converter are discussed. A 500 W experimental prototype has been built and verified by experimental results.

A New Approach to Solve the TSP using an Improved Genetic Algorithm

Qian Gao,Young Im Cho,Su mei Xi 한국지능시스템학회 2011 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.11 No.4

Genetic algorithms are one of the most important methods used to solve the Traveling Salesman Problem. Therefore, many researchers have tried to improve the Genetic Algorithm by using different methods and operations in order to find the optimal solution within reasonable time. This paper intends to find a new approach that adopts an improved genetic algorithm to solve the Traveling Salesman Problem, and compare with the well known heuristic method, namely, Kohonen Self-Organizing Map by using different data sets of symmetric TSP from TSPLIB. In order to improve the search process for the optimal solution, the proposed approach consists of three strategies: two separate tour segments sets, the improved crossover operator, and the improved mutation operator. The two separate tour segments sets are construction heuristic which produces tour of the first generation with low cost. The improved crossover operator finds the candidate fine tour segments in parents and preserves them for descendants. The mutation operator is an operator which can optimize a chromosome with mutation successfully by altering the mutation probability dynamically. The two improved operators can be used to avoid the premature convergence. Simulation experiments are executed to investigate the quality of the solution and convergence speed by using a representative set of test problems taken from TSPLIB. The results of a comparison between the new approach using the improved genetic algorithm and the Kohonen Self-Organizing Map show that the new approach yields better results for problems up to 200 cities.

Theoretical study on photoelectric properties of lead-free mixed inorganic perovskite RbGe1-xSnxI3

Xi-Zi Deng,Qian-Qi Zhao,Yu-Qing Zhao,Meng-Qiu Cai 한국물리학회 2019 Current Applied Physics Vol.19 No.3

The recent discoveries of lead-free halide perovskites have come into notice as promising photovoltaic materials due to their high solar-to-electrical efficiency conversion. However, these perovskites suffer from large effective masses, wide band gap and affected photovoltaic performance. It is well known that it is an effective means to overcome the above shortcomings by changing the metallic ion concentration and position for the inorganic perovskite. Herein, we study the geometrical, electronic, and optical properties of RbGe1-xSnxI3 with various compositions of metal atoms by performing the Density Functional Theory (DFT). Besides, we systematically investigate how the doping positions of stannum (Sn) atoms affect the electronic structure by taking mixed metal RbGe0.50Sn0.50I3 compound as an example. The results show that RbGe1-xSnxI3 exhibits the semiconducting property with the tunable direct band gaps by changing its proportions. Compared to other two doping positions in the perovskite RbGe0.50Sn0.50I3, the configuration with Sn atom at equator plane has better mobility of electron and optical absorption properties. Our works demonstrate that the modification of metal concentration and position will modulate the optoelectronic performance and photovoltaic properties of mixed metal perovskites.

The role of WRKY47 gene in regulating selenium tolerance in Arabidopsis thaliana

Xi Wu,Manzhi Tao,Yun Meng,Xiangyu Zhu,Liangwen Qian,Alia Shah,Wei Wang,Shuqing Cao 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.1

Selenium stress has a serious impact on the growth of plants. However, the available understanding on the mechanism of Se stress response is still insufficient. In this study, we found that the WRKY47 gene plays an important role in maintaining Se homeostasis and tolerance in Arabidopsis thaliana. Expression of WRKY47 is induced by Se stress. The wrky47 mutants are sensitive to Se stress, and this sensitivity is associated with a decrease in the transcription levels of Se-detoxify genes HMT1 and HMT3. Surprisingly, the WRKY47-overexpression lines also showed increased sensitivity to Se stress and had increased Se content; this correlates to an increase in the transcription level of Se-uptake gene PHT1;4 but not Se-detoxify genes HMT1 and HMT3. Our results suggest that gain- and loss-of-function mutations in WRKY47 enhance the sensitivity of A. thaliana plants to Se stress through different mechanisms.

An Ontology-Based Information Retrieval Model for Similarity Matching

Qian Gao,Young Im Cho,Sumei Xi 한국지능시스템학회 2012 한국지능시스템학회 학술발표 논문집 Vol.22 No.1

Comparison of the activities of photosystem II of four table grapevine cultivars during high-temperature stress

Qian Zha,Xiaojun Xi,Aili Jiang,Yihua Tian 한국원예학회 2018 Horticulture, Environment, and Biotechnology Vol.59 No.3

High-temperature stress influences the growth and development of grapevines, and plant responses to this stress vary between laboratory and natural conditions. In the present study, the responses to high-temperature stress in four grapevine cultivars (‘Summer Black’, ‘Zuijinxiang’, ‘Hupei1#’, and ‘Shenfeng’) were studied by comparing chlorophyll a fluorescence and the levels of heat-shock protein 21 (HSP21) after exposure to control (35 °C in controlled laboratory conditions or at 37 °C in a greenhouse with naturally fluctuating temperatures) and high-temperature stress treatments (45 °C in laboratory conditions or 42 °C in the field conditions). Leaf water loss in ‘Summer Black’ was less than that in the three other cultivars after treatment at 45 °C. Some parameters (ΨEo, Wk, RCQA, and Mo) of photosystem II (PSII) activity were altered in ‘Shenfeng’, ‘Zuijinxiang’, and ‘Hupei1#’, but were unaltered in ‘Summer Black’ after treatment at 45 °C. Other parameters (maximum photochemical efficiency (Fv/Fm), performance index on absorption basis (PIABS), ΦPo, ΦEo, and HSP21 levels) were altered in ‘Summer Black’, but to a lesser extent than in the three other cultivars under high-temperature stress. Unlike ‘Summer Black’, extreme injury owing to leaf water loss to ‘Shenfeng’, ‘Zuijinxiang’, and ‘Hupei1#’ could be explained by disruption of PSII activity. Furthermore, there were the observed differences in PSII activity between in laboratory and field conditions, which could be considered as the mechanisms for high-temperature acclimation and other environment factors.

A New Approach of Domain Dictionary Generation

Xi, Su Mei,Cho, Young-Im,Gao, Qian Korean Institute of Intelligent Systems 2012 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.12 No.1

A Domain Dictionary generation algorithm based on pseudo feedback model is presented in this paper. This algorithm can increase the precision of domain dictionary generation algorithm. The generation of Domain Dictionary is regarded as a domain term retrieval process: Assume that top N strings in the original retrieval result set are relevant to C, append these strings into the dictionary, retrieval again. Iterate the process until a predefined number of domain terms have been generated. Experiments upon corpus show that the precision of pseudo feedback model based algorithm is much higher than existing algorithms.