A New BODIPY Derivative Bearing Piperazine Group

Qi, Xin,Kim, Sook-Kyung,Jun, Eun-Jin,Xu, Li,Kim, Sung-Jin,Yoon, Ju-Young Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.12

A new BODIPY derivative bearing piperazine group was synthesized and its fluorescent changes towards metal ions as well as pH are studied. The title compound displayed a moderate selectivity for Hg2+ among the metal ions examined.

A Comparison between Traditional and Modern Ethics from the Perspective of Social Philosophy

( Xin Qi Jia ) , ( Wan Fu Xi ) 한국윤리학회 2014 倫理硏究 Vol.95 No.1

Social philosophy is the study of people`s conception of basic social objectives. It can be divided into two categories based on two different basic objectives: harmony and strength. Harmony-oriented social philosophy and strength-oriented social philosophy are dominant in traditional society and modern society respectively. From the perspective of social philosophy, we can understand better the differences between traditional ethics and modern ethics.

Investigating Research Trend of Rock Climbing in China Using Semantic Network Analysis

( Xin Qi ),( Shanying Huang ) 아시아스포츠융합과학회 2022 Asia Pacific Journal of Applied Sport Sciences Vol.3 No.1

PURPOSE The objectives of this study were as follows: (1) studying the core authors and institutions of rock climbing to understand the connections between them, (2) investigate the keyword changes, research hotspots, and development trends of rock climbing in different periods, and (3) discovering the subgroup areas of rock climbing and study their knowledge structure. METHOD The bibliometrics visualization software CiteSpace was used in this study. Semantic network analysis was performed on 376 valid papers published in CNKI during 1996-2021. The word frequency, mediating centrality, co-occurrence map, and clustering for the keywords were separately investigated. RESULT In terms of author collaboration, there are mainly four academic cooperation circles between Ma Chuhong, Guo Wei, Zhang Bo, and Li Yuanyuan. In terms of institutional cooperation networks, little cooperation occurs between rock climbing research institutions in China. Since 2009, rock climbing sport, rock climbing, current situation, feasibility, university, extreme sports, enthusiasts, artificial rock climbing, and other keywords have the highest frequency. Into rock climbing sport, rock climbing, and colleges and universities, keywords such as outdoor sports, college students, training, development, and sports tourism have become the focus of research since 2010. The rock-climbing knowledge structure consists of six sub-areas, which are G1 rock climbing, G2 college, G3 strategy, G4 climbing, G5 sports tourism, and G6 school training. CONCLUSION First, the field of rock-climbing keyword research has changed dramatically over the past 20 years. College student training and sports tourism in rock climbing are the current and future research hotspots and trends. Second, a few keywords have made significant contributions to rock climbing. Keyword semantic network analysis provides a new idea and research method for exploring the development of rock climbing.

Utilization of electron beam to modulate electron injection over Schottky barrier

Qi Zhang,Junjie Qi,Yunhua Huang,Huifeng Li,Xin Li,Ruoshui Wang,Yue Zhang 한국물리학회 2011 Current Applied Physics Vol.11 No.3

Modulation of electron injection over Schottky barrier was realized by employing electron beam irradiation on the metal/ZnO-nanowire contact. The structure revealed a good response to the illumination at a scanning frequency of 0.1 Hz, which can be enhanced by increasing bias and decreased with the increase of electron beam energy. These phenomena can be attributed to the Schottky barrier formed at the metal/ZnO-nanowire interface which limits the electron transport across the contact. The electron beam irradiation gives rise to high efficiency of electron injection over the barrier, while the interplay between charge discreteness, coherent scattering, and Coulomb interaction may reduce the conductivity.

PACS Based on DICOM Standards for the Scalability of Research and Implementation

Xin Qi 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.11

With the increasing popularity of DICOM devices, traditional medical equipment is still in a large number of applications. This paper is aimed at the shortcomings of the terminal design and expansion of the existing medical imaging system and analyze them. Complete medical imaging system based on DICOM, it also has the ability to support traditional equipment and third party software at the same time, a complete design scheme is given in this paper. We adopt a loosely coupled design between system components, data transmission uses a common XML data format and Web Service technology to achieve data transmission of distributed component. The proposed scheme has proven case to support, the system has good expansibility, it can be upgraded with the enterprise's equipment, it is compatible with old and new equipment and it greatly improve the practical and cost-effective system.

Sitagliptin attenuates endothelial dysfunction independent of its blood glucose controlling effect

Xin-Miao Chang,Fei Xiao,Qi Pan,Xiao-Xia Wang,Li-Xin Guo 대한생리학회-대한약리학회 2021 The Korean Journal of Physiology & Pharmacology Vol.25 No.5

Although the contributions of sitagliptin to endothelial dysfunction in diabetes mellitus were previously reported, the mechanisms still undefined. Autophagy plays an important role in the development of diabetes mellitus, but its role in diabetic macrovascular complications is unclear. This study aims to observe the effect of sitagliptin on macrovascular endothelium in diabetes and explore the role of autophagy in this process. Diabetic rats were induced through administration of high-fat diet and intraperitoneal injection of streptozotocin. Then diabetic rats were treated with or without sitagliptin for 12 weeks. Endothelial damage and autophagy were measured. Human umbilical vein endothelial cells were cultured either in normal glucose or in high glucose medium and intervened with different concentrations of sitagliptin. Rapamycin was used to induce autophagy. Cell viability, apoptosis and autophagy were detected. The expressions of proteins in c-Jun N-terminal kinase (JNK)-Bcl-2-Beclin-1 pathway were measured. Sitagliptin attenuated injuries of endothelium in vivo and in vitro. The expression of microtubuleassociated protein 1 light chain 3 II (LC3II) and beclin-1 were increased in aortas of diabetic rats and cells cultured with high-glucose, while sitagliptin inhibited the over-expression of LC3II and beclin-1. In vitro pre-treatment with sitagliptin decreased rapamycin-induced autophagy. However, after pretreatment with rapamycin, the protective effect of sitagliptin on endothelial cells was abolished. Further studies revealed sitagliptin increased the expression of Bcl-2, while inhibited the expression of JNK in vivo. Sitagliptin attenuates injuries of vascular endothelial cells caused by high glucose through inhibiting over-activated autophagy. JNK-Bcl-2-Beclin-1 pathway may be involved in this process.

Bond-Orientational Order in Melting of Colloidal Crystals

Xin Qi,Yong Chen,Yan Jin,Yao-Hui Yang 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.4

Using Brownian dynamics simulation, we study the orientational order in the melting transition of a colloidal system with a `soft' Yukawa potential. The bond-orientational order parameter ⓒ6 and the bond-orientational order function gB(r) are calculated in two-dimensional systems. We found that a two-stage transition and a hexatic phase indeed exist in two-dimensional melting, which is consistent with the prediction of the Kosterlitz-Thouless-Halperin-Nelson-Young theory. For comparing with the melting process in three-dimensional systems, we introduce the probability distribution of the single-particle local-order parameter. Based on extensive simulations, the break- down of local order is qualitatively suggested only to occur on the fractional part of the colloidal system for the two-dimensional melting, but in three-dimensional melting, that breakdown takes place on the whole system at the same time.F

Synthesis, second-harmonic generation (SHG), and photoluminescence (PL) properties of noncentrosymmetric bismuth selenite solid solutions, Bi_2-<i>x</i>Ln_<i>x</i>SeO₅ (Ln = La and Eu; <i>x</i> = 0–0.3)

Qi, Hai-Xin,Jo, Hongil,Oh, Seung-Jin,Ok, Kang Min Elsevier 2018 SOLID STATE SCIENCES Vol.76 No.-

<P><B>Abstract</B></P> <P>A series of La<SUP>3+</SUP> or Eu<SUP>3+</SUP>-doped noncentrosymmetric (NCS) bismuth selenite solid solutions, Bi<SUB>2-<I>x</I> </SUB>Ln<SUB> <I>x</I> </SUB>SeO<SUB>5</SUB> (<I>x</I> = 0.1, 0.2, and 0.3), have been successfully synthesized via standard solid-state reactions under vacuum with Bi<SUB>2</SUB>O<SUB>3</SUB>, La<SUB>2</SUB>O<SUB>3</SUB> (or Eu<SUB>2</SUB>O<SUB>3</SUB>), and SeO<SUB>2</SUB> as starting materials. Crystal structures and phase purities of the resultant materials were thoroughly characterized by powder X-ray diffraction using the Rietveld method. The results clearly show that the reported materials crystallize in the orthorhombic space group, <I>Abm</I>2 (No. 39), and exhibit pseudo-three-dimensional frameworks consisting of BiO<SUB>3</SUB>, BiO<SUB>5</SUB>, and SeO<SUB>3</SUB> polyhedra that share edges and corners. Detailed diffraction studies indicate that the cell volume of Bi<SUB>2-<I>x</I> </SUB>Ln<SUB> <I>x</I> </SUB>SeO<SUB>5</SUB> decreases with an increasing amount of Ln<SUP>3+</SUP> on the Bi<SUP>3+</SUP> sites. However, no ordering between Ln<SUP>3+</SUP> and Bi<SUP>3+</SUP> was observed in the Bi<SUB>2-<I>x</I> </SUB>Ln<SUB> <I>x</I> </SUB>SeO<SUB>5</SUB> solid solutions. Powder second-harmonic generation (SHG) measurements, using 1064 nm radiation, reveal that SHG efficiencies of Bi<SUB>2-<I>x</I> </SUB>Ln<SUB> <I>x</I> </SUB>SeO<SUB>5</SUB> solid solutions continuously decrease as more Ln<SUP>3+</SUP> cations are added to the sites of polarizable Bi<SUP>3+</SUP> cations. Photoluminescence (PL) measurements on Bi<SUB>2-<I>x</I> </SUB>Eu<SUB> <I>x</I> </SUB>SeO<SUB>5</SUB> exhibit three specific emission peaks at 592, 613, and 702 nm (<SUP>5</SUP>D<SUB>0</SUB> → <SUP>7</SUP>F<SUB>1, 2, 4</SUB>) owing to the 4f-4f intrashell transitions of Eu<SUP>3+</SUP> ions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> New selenite solid solutions, Bi<SUB>2-<I>x</I> </SUB>Ln<SUB> <I>x</I> </SUB>SeO<SUB>5</SUB> (Ln = La and Eu; <I>x</I> = 0–0.3) were synthesized. </LI> <LI> The structures were determined by X-ray diffraction. </LI> <LI> The alignment of polarizable Bi<SUP>3+</SUP> cations is critical to second-harmonic generation. </LI> <LI> Photoluminescence measurements exhibit specific emission peaks due to the 4f-4f intrashell transitions of Eu<SUP>3+</SUP> ions. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Second-harmonic generation (SHG) and photoluminescence (PL) properties of NCS bismuth selenite solid solutions, Bi<SUB>2-<I>x</I> </SUB>Ln<SUB> <I>x</I> </SUB>SeO<SUB>5</SUB> (Ln = La and Eu; <I>x</I> = 0–0.3) are presented.</P> <P>[DISPLAY OMISSION]</P>

Current boundary‑based predictive current control of induction machines with lower switching frequencies

Xin Qi,Chenyu Wang,Boxuan Tian,Mario Pacas,Xiangyang Shi,Aibin Jia 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.2

An excessively high switching frequency causes significant losses in inverters, especially in high-power applications, which should be avoided. Predictive control, based on a circular boundary restriction strategy presented in this paper, can effectively suppress current distortion while reducing the switching frequency. Until now, this method has been implemented with the same boundaries for both the torque component and flux component of the stator current vector. Due to the physical behavior of an induction motor, a higher current distortion tolerance of the flux component of the stator current vector can be accepted without affecting the torque. Therefore, in this work, the circular boundary restriction strategy is modified to configure larger boundaries for the flux component than for the torque component. This is done to achieve an even lower switching frequency. Furthermore, an additional improvement can be expected if only the boundaries of the torque component are strictly maintained, while the magnetizing current can exceed its boundary to some extent. The predictive control method based on this new strategy is experimentally tested to determine its feasibility. A method based on the circular boundary strategy is also implemented under the same testing conditions, and the performances of both strategies are compared.

Research on the construction and practice of blended teaching model based on flipped classroom

Xin QI,Shi-mei JIN ASCONS 2022 IJASC Vol.4 No.2

Background/Objectives: In the background of the information age, the blended teaching mode is more suitable for students at this stage, but for college students, the simple blended teaching can not guarantee the students' learning enthusiasm, and there are still cases of mixed credits and improper learning attitude. Methods/Statistical analysis: This study introduces the concept of flipped classroom, combines it with blended teaching, and builds a blended teaching mode based on flipped classroom, and takes the elective course of "Modern Education Technology" as an example to practice teaching. Findings: The teaching mode can improve the teaching effect and The teaching mode can improve teaching effectiveness and enhance students' interest in learning. Improvements/Applications: In implementing the flipped classroom-based blended teaching model, universities should pay attention to the combination of students' main role and teachers' guidance, ensure the communication channels between teachers and students, and pay attention to the diversity of evaluation methods.