Synthesis and characterization of diphenylaminodiphenyl stryl based alternating copolymers

Zhao, Qinghua,Kim, Yun-Hi,Dang, Thi Tuyet Mai,Shin, Dong-Cheol,You, Hong,Kwon, Soon-Ki Wiley Subscription Services, Inc., A Wiley Company 2007 Journal of polymer science Part A, Polymer chemist Vol.45 No.3

<P>Diphenylaminobiphenylated stryl based alternating copolymers with phenyl or fluorene, which were expected to have a terphenylene vinylene backbone containing an (N,N-diphenylamino)biphenyl pendant and a phenyl/fluorene/phenylene vinylene backbone containing an (N,N-diphenylamino)biphenyl pendant, were synthesized by a Suzuki coupling reaction. The obtained copolymers were confirmed with various types of spectroscopy. The alternating copolymers showed good hole-injection properties because of their low oxidation potential and good solubility and high thermal stability with a high glass-transition temperature. The alternating copolymers showed blue emissions because of the adjusted conjugation lengths; the maximum wavelength was 460 nm for poly{4,4′-biphenylene-α-[4″-(N,N′-diphenylamino)diphenyl]vinylene-alt-5-(2′-ethylhexyloxy)-2-methoxybenzene} and 487 nm for poly{4,4′-biphenylene-α-[4″-(N,N′-diphenylamino)diphenyl] vinylene-alt-9,9-dihexylfluorene}. The maximum brightness of indium tin oxide/poly(3,4-ethylene dioxythiophene)/polymer/LiF/Al devices with poly{4,4′-biphenylene-α-[4″-(N,N′-diphenylamino)diphenyl]vinylene-alt-5-(2′-ethylhexyloxy)-2-methoxybenzene} or poly{4,4′-biphenylene-α-[4″-(N,N′-diphenylamino)diphenyl]vinylene-alt-9,9-dihexylfluorene} as the emitting layer was 250 or 1000 cd/m<SUP>2</SUP>, respectively. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 341–347, 2007</P> <B>Graphic Abstract</B> <P>Poly{4,4′-biphenylene-α-[4″-(N,N′-diphenylamino)diphenyl]vinylene-alt-5-(2′-ethylhexyloxy)-2-methoxybenzene} and poly {4,4′-biphenylene-α-[4″-(N,N′-diphenylamino)diphenyl]vinylene-alt-9, 9-dihexylfluorene} had a regular structure of alternation between diphenylaminobiphenylated stryl and dihexylfluorene moieties or between diphenylaminobiphenylated stryl and 5-(2′-ethylhexyloxy)-2-methoxybenzene moieties. The indium tin oxide/poly(3,4-ethylene dioxythiophene)/polymer/LiF/Al devices with poly{4,4′-biphenylene-α-[4″-(N,N′-diphenylamino)diphenyl]vinylene-alt-5-(2′-ethylhexyloxy)-2-methoxybenzene} or poly{4,4′-biphenylene-α-[4″-(N,N′-diphenylamino) diphenyl]vinylene-alt-9,9-dihexylfluorene} as the emitting layer showed blue emissions (maximum wavelength = 460 or 487 nm) with maximum brightness of 250 or 1000 cd/m<SUP>2</SUP>, respectively. <img src='wiley_img/0887624X-2007-45-3-POLA21740-gra001.gif' alt='wiley_img/0887624X-2007-45-3-POLA21740-gra001'> </P>

『초등학생을 위한 표준 한국어 학습 도구』 교재 내용 분석 - ‘한국어 교육과정(2017)’과 ‘국어과 교육과정’을 기준으로 -

zhao qinghua 서울대학교 국어교육연구소 2020 국어교육연구 Vol.45 No.-

본 연구에서는 2017년에 개정·고시된 '한국어 교육과정'에 기반하여 2019년에 출간된 『초등학생을 위한 표준 한국어 학습 도구』교재의 내용과 교육과정의 연계성을 분석하였다. 본 연구에서는 먼저 『초등학생을 위한 표준 한국어학습 도구』교재와 '한국어 교육과정(2017)'의 학습 재료와의 연계성을 분석하였다. 그 결과 의사소통 기능, 텍스트 유형, 학습 도구 한국어 어휘 부분에서 전반적으로 교육과정의 내용을 잘 반영하고 있지만 일부 학습 한국어에서 중요하게 다루어야 하는 의사소통 기능과 텍스트 유형이 누락되어 있는 것을 확인하였다. 다음으로 본 연구에서는 『초등학생을 위한 표준 한국어 학습 도구』교재의 읽기와 쓰기 영역과 '국어과 교육과정(2015)'의 읽기와 쓰기 학습 요소의 연계성을 비교 분석하였다. 그 결과 『초등학생을 위한 표준 한국어 학습 도구 1~2 학년』교재에서는 국어과 교육과정의 읽기와 쓰기 학습 요소가 잘 반영되어 있었으나 『초등학생을 위한 표준 한국어 학습 도구 3~4학년』교재에서는 쓰기학습 요소가, 『초등학생을 위한 표준 한국어 학습 도구 5~6학년』교재에서는읽기 요소가 상당 부분 반영되지 않은 것을 확인하였다.

Synchronization of two non-identical coupled exciters in a non-resonant vibrating system of plane motion

Chunyu Zhao,Qinghua Zhao,Yimin Zhang,Bangchun Wen 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.1

In the average method of modified small parameters, the synchronization of two coupled exciters is converted to a problem on the existence and stability of zero solutions for the average differential equations of small parameters over the average period of two exciters. To implement frequency capture, the torque of frequency capture should be greater than or equal to the absolute value of the difference between the residual electromagnetic torques of the two motors. Because each exciter is involved in the motion of the vibrating system it has excited, its relative moment of inertia is reduced. The reduction is proportional to half its coefficient of cosine effect of phase angles (CCEPA). Because one of the exciters is involved in the motion excited by the other, a coupled moment of inertia exists for the two exciters. The stability of the synchronization of the two exciters is affected by the reduction of their relative moments of inertia and their moment of coupling inertia. For the synchronization to be stable, two conditions must be satisfied: (1) the non-dimensional relative moments of inertia of the two exciters are all greater than zero, and (2) four times the product of their non-dimensional relative moments is greater than the square of the coefficient of coupled cosine effect (CCCPA). The stability of synchronization depends solely on the ratios of the masses of the two exciters to the mass of the vibrating system and the ratio of the distance between one exciter and the centroid of the rigid frame to the equivalent rotating radius of the vibrating system about its centroid of the rigid frame, and is independent of the parameters of the two induction motors.

중국 중도입국 청소년의 한국어 쓰기 통사적 복잡성 발달 양상 연구

조청화 ( Zhao Qinghua ) 이중언어학회 2020 이중언어학 Vol.80 No.-

This research examines the Korean synthetic complexity of the fast growing number of immigrant youths entering Korea through collecting two composition materials which are writing after watching a short clip and diary writing during three month period. While both quantitative and qualitative analyzes are used, for quantitative method, words per writing, words per sentence and embedded clauses per writing were analyzed and for qualitative method, usage patterns and errors of coordinate and embedded clauses were analyzed. As a result, two out of three learners showed a steady increase in producing complex sentences and the other learner who had a relatively rapid syntactic development showed a U-shaped curve. Furthermore, there was a difference in using complex sentences and frequency within the learners in both dairy and short video clip writing. In detail, all three learners used time adverb clauses, and reason or cause adverb clauses the most and noun, adnominal and quotation clauses were only used in certain forms. Lastly, time adverb clause ‘-go’ and ‘-(ah)seo/(uh)seo’ were the mostly used adverb clauses but also at the same time the error of overgeneralization was detected. (Seoul National University)

중국 이주배경 청소년의 한국어 구어 사용에 나타난 복잡성과 정확성 연구

조청화 ( Zhao Qinghua ) 이중언어학회 2022 이중언어학 Vol.86 No.-

The purpose of this study is to analyze the complexity and accuracy developments of Korean in three Chinese immigrant youths based on the Dynamic System Theory. The analysis of three participants showed different developmental trends and nonlinearities of development and regression in syntactic complexity, lexical complexity, and accuracy. Furthermore, the educational characteristics of each student were discussed along with the changes in complexity and accuracy. The immigrant youths who have been involved in the Korean language classes utilized various and stable Korean phrases and sentences, while their lexical varieties were somewhat limited. On the other hand, the youths who have only attended basic classes tended to have limited complexity in their Korean phrases and sentences. Moreover, extracurricular activities and Korean friends were shown to be important factors affecting their Korean abilities. According to the study, youths who have participated more in extracurricular activities or kept interactions with Korean friends demonstrated better diversities in vocabulary. This result implies that it is necessary to continue Korean education through extracurricular programs, like Korean preparatory classes, for immigrant youths. The Results of this study shed light on Korean language education for immigrant youths, on which there has been little study, by examining the influential factors and the aspects of Korean language education in immigrant youths using qualitative methods. (Seoul National University)

IP-10 Expression in Patients with Chronic HBV Infection and Its Ability to Predict the Decrease in HBsAg Levels after Treatment with Entecavir

Zhao, Kai,Yang, Tao,Sun, Mimi,Zhang, Wei,An, Yong,Chen, Gang,Jin, Lei,Shang, Qinghua,Song, Wengang Korean Society for Molecular and Cellular Biology 2017 Molecules and cells Vol.40 No.6

Interferon-${\gamma}$-inducible protein 10 (IP-10), also known as chemokine C-X-C motif ligand (CXCL) 10, is closely associated with antiviral immunity and the progression of chronic hepatitis B (CHB). However, the value of baseline serological and histological IP-10 expression levels in predicting the efficacy of the antiviral response to nucleoside/nucleotide analogues (NAs) is still unknown. In our research, intrahepatic and peripheral IP-10 expression levels were systemically examined before and after treatment with entecavir (ETV). Baseline serological and histological IP-10 expression levels were significantly increased in patients with CHB, particularly in patients with higher degrees of liver inflammation and liver fibrosis. Moreover, higher baseline intrahepatic IP-10 levels indicated better prognoses in patients with CHB after entecavir therapy. The baseline IP-10 level was also positively associated with several clinical parameters, including baseline levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatitis B virus (HBV) DNA, and hepatitis B surface antigen (HBsAg), and with the decrease in HBsAg levels after treatment. In addition, monocyte-derived IP-10 was expressed at higher levels in patients with CHB than in patients with liver cirrhosis (LC) and healthy controls (HC). According to the results of our in vitro experiments, IP-10 directly promoted hepatocyte apoptosis. Based on these findings, baseline serological and histological IP-10 levels might predict CHB severity and the decrease in HBsAg levels after entecavir therapy.

TGF-β promotes pericyte-myofibroblast transition in subretinal fibrosis through the Smad2/3 and Akt/mTOR pathways

Zhao Zhenzhen,Zhang Yumeng,Zhang Chaoyang,Zhang Jingting,Luo Xueting,Qiu Qinghua,Luo Dawei,Zhang Jingfa 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Subretinal fibrosis remains a major obstacle to the management of neovascular age-related macular degeneration. Choroidal pericytes were found to be a significant source of subretinal fibrosis, but the underlying mechanisms of pericyte-myofibroblast transition (PMT) remain largely unknown. The goal of this study was to explore the role and potential mechanisms by which PMT contributes to subretinal fibrosis. Choroidal neovascularization (CNV) was induced by laser photocoagulation in transgenic mice with the collagen1α1-green fluorescent protein (Col1α1-GFP) reporter, and recombinant adeno-associated virus 2 (rAAV2)-mediated TGF-β2 (rAAV2-TGF-β2) was administered intravitreally to further induce PMT. Primary mouse choroidal GFP-positive pericytes were treated with TGF-β2 in combination with siRNAs targeting Smad2/3, the Akt inhibitor MK2206 or the mTOR inhibitor rapamycin to examine cell proliferation, migration, and differentiation into myofibroblasts. The involvement of the Akt/mTOR pathway in PMT in subretinal fibrosis was further investigated in vivo. Intraocular TGF-β2 overexpression induced GFP-positive pericyte infiltration and PMT in subretinal fibrosis, which was mimicked in vitro. Knockdown of Smad2/3 or inhibition of Akt/mTOR decreased cell proliferation, PMT and migration in primary mouse pericytes. Combined inhibition of Smad2/3 and mTOR showed synergistic effects on attenuating α-smooth muscle actin (α-SMA) expression and cell proliferation. In mice with laser-induced CNV, the administration of the Akt/mTOR inhibitors suppressed pericyte proliferation and alleviated the severity of subretinal fibrosis. Our results showed that PMT plays a pivotal role in subretinal fibrosis, which was induced by TGF-β2 through the Smad2/3 and Akt/mTOR pathways. Thus, inhibiting PMT may be a novel strategy for the treatment of subretinal fibrosis.

IP-10 Expression in Patients with Chronic HBV Infection and Its Ability to Predict the Decrease in HBsAg Levels after Treatment with Entecavir

Kai Zhao,Tao Yang,Mimi Sun,Wei Zhang,Yong An,Gang Chen,Lei Jin,Qinghua Shang,Wengang Song 한국분자세포생물학회 2017 Molecules and cells Vol.40 No.6

Interferon-γ-inducible protein 10 (IP-10), also known as chemokine C-X-C motif ligand (CXCL) 10, is closely associ-ated with antiviral immunity and the progression of chronic hepatitis B (CHB). However, the value of baseline serological and histological IP-10 expression levels in predicting the efficacy of the antiviral response to nucleoside/nucleotide analogues (NAs) is still unknown. In our research, intrahepatic and peripheral IP-10 expression levels were systemically examined before and after treatment with entecavir (ETV). Baseline serological and histological IP-10 expression levels were significantly increased in patients with CHB, particularly in patients with higher degrees of liver inflammation and liver fibrosis. Moreover, higher baseline intrahepatic IP-10 levels indicated better prognoses in patients with CHB after entecavir therapy. The baseline IP-10 level was also positively associated with several clinical parameters, including baseline levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatitis B virus (HBV) DNA, and hepatitis B surface antigen (HBsAg), and with the decrease in HBsAg levels after treatment. In addition, monocyte-derived IP-10 was expressed at higher levels in patients with CHB than in patients with liver cirrhosis (LC) and healthy controls (HC). According to the results of our in vitro experiments, IP-10 directly promoted hepatocyte apoptosis. Based on these findings, baseline serological and histological IP-10 levels might predict CHB severity and the decrease in HBsAg levels after entecavir therapy.

Design of Android-Based Remote Terminal System for RGV

Shang Qinghua,Zhao Xinyue,Zhang Helong,Wang Su 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.7

This paper proposes a new method that utilized Android mobile phone to control the RGV (Rail Guided Vehicle)running through WIFI network to overcome the disadvantages of the traditional remote control can only control one-way communication for RGV in the Logistics and warehousing and realize two-way communication between the RGV and remote controller . The system is based on Android platform, and established a remote terminal system by all Android support resources. In this paper, it described the structure, function, software flow of the RGV remote terminal system and communication protocol between Android client and the RGV. The design is based on the Modbus TCP / IP protocol, to achieve a two-way communication between Android phone and the RGV.

Structural Behaviour of an Assembled Steel Joint Composed of CHS KK-Joint and Doubler Plate for Connection with Steel Tensile Rods

Bo Zhao,Han Zhu,Yue Yin,Zhuo Liu,Qinghua Han 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.2

Structural behavior of an assembled steel joint composed of CHS KK-joint and a doubler plate for connection with steel tensile rods was studied. A full-scale test was conducted for the assembled joint on a special made self-balanced reaction frame with three high strength steel strands to apply tensile loads on two ear plates and compressive load on the chord member of the joint. Ultimate load carrying capacity, failure mode and stress distribution of the joint under monotonic loads were obtained experimentally. The static behavior of the joint was also determined by nonlinear fi nite element analysis. The results of numerical analysis agreed very well with those of the test, which verifi ed the rationality of the fi nite element model. The hysteretic behavior of the joint was then studied by fi nite element analysis. Hysteretic curve was obtained, based on which ductile ratio and energy dissipation factor were calculated. Outcomes from both the test and the fi nite element analysis proved that the assembled joint has satisfactory load carrying capacity and acceptable seismic performance.