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AMPHIPHIliC STAR-BLOCK COPOLYMERS BY IODIDE-MEDIATED RADICAL POLYMERIZATION

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Chinese Journal of Polymer Science 2007年第6期25卷 609-619页

作者： Bing-yi li Yan Shi zhi-feng Fu Wan-tai Yang Shu-ke Jiao State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing 100029 China

Amphiphilic star-block copolymers composed of polystyrene and poly（acrylic acid） were synthesized by iodide- mediated radical polymerization. Firstly, free radical polymerization of styrene was carried out with AIBN as initiator and 1,1,1-trimethyolpropane tri（2-iodoisobutyrate） as chain transfer agent, giving iodine atom ended star-shaped polystyrene with three arm chains, R（polystyrene）3. Secondly, tert-butyl acrylate was polymerization using polystyrene obtained as macro-chain transfer agent, and star-block copolymer, R（polystyrene-b-poly（tert-butyl acrylate））3 with controlled molecular weight was obtained. Finally, amphiphilic star-block copolymer, R（polystyrene-b-poly（acrylic acid））3 was obtained by hydrolysis of R（polystyrene-b-poly（tert-butyl acrylate））3 under acidic condition.

关键词： living radical polymerization Iodide-Mediated radical polymerization Star-block copolymers Amphiphilic copolymers.

Development of a monolithic polymer pipette for solid-phase extraction of liquiritigenin in rat plasma

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Chinese Chemical Letters 2012年第6期23卷 723-726页

作者： Hong Wu Zhang Kang li zhi Xian liang feng YangWang Qi Wen Lu School of Pharmacy Guangdong Pharmaceutical College Guangzhou 510006 China

A monolithic polymer column with mixed-mode interaction was prepared by in situ polymerization in a 1000μL pipette. Two kinds of monomers, butyl methacrylate （BMA） and 2-（dimethylamino）ethyl methacrylate （DMAM） were applied to constructing the mixed-mode interaction of monolithic polymer column. Its solid-phase extraction properties for liquiritigenin （LQG） were evaluated by high performance liquid chromatography （HPLC） with a gradient elution procedure. After the extraction procedure was optimized, the maximum binding capacity and extraction recovery following the optimal extraction procedure were investigated. Calibration curve was expressed as A = 65.9C ＋ 4.53 （r2 = 0.998） with a linear range of 0.151-1.80μg/mL. The experimental results indicate that the monolithic polymer pipette presents good extraction efficiency for LQG. It can be envisaged that the developed monolithic polymer pipette possesses the potential for its application to the enrichment of other flavonoids compounds being similar to the structure of LQG.

关键词： Monolithic polymer pipette Solid phase extraction High performance liquid chromatography liquiritigenin

High-performance ultraviolet-visible photodetector with high sensitivity and fast response speed based on MoS_(2)-on-ZnO photogating heterojunction

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Tungsten 2023年第1期5卷 91-99页

作者： Xing-Lai Zhang Jing li Bing Leng liu Yang Yan-Dong Song Si-Yu feng li-zhi feng Zi-Tong liu Zheng-Wei Fu Xin Jiang Bao-Dan liu Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesNo.72 Wenhua RoadShenyang 110016China School of Material Science and Engineering Northeastern UniversityNo.11 Wenhua RoadShenyang 110819China Foshan Graduate School of Northeastern University No.2 Zhihui RoadFoshan 528300China Department of Plastic Surgery The First Affiliated Hospital of China Medical UniversityNo.155 North Nanjing StreetShenyang 110001China School of Materials Science and Engineering University of Science and Technology of ChinaNo.72 Wenhua RoadShenyang 110016China

Photogating is an effective strategy to modulate the channel conductance of the device with light-induced gate field or voltage,thereby improving the performance of optoelectronic *** this work,to overcome the long response time and low photoresponse of one-dimensional ZnO,a MoS_(2)-on-ZnO photogating vertical heterojunction photodetector is design and ***,the ZnO nanowire with high carrier mobility can response ultraviolet light and supply a highspeed carrier transport channel,while the MoS_(2) flake as a photogating layer can response with visible light and transfer photogenerated electrons into the ZnO nanowire to adjust its ***,the irradiation of visible light is equivalent to applying a photo-induced gate voltage on the ZnO *** addition,the photogenerated electrons will not transmit through the MoS_(2) with low carrier mobility,so that not only the visible light response of the photodetector can be realized,but also its ultraviolet light response is able to be *** ultraviolet light irradiation,the photoresponsivity of the photodetector can be reached to 273 A W-1and the response speed is less than 24 *** important,based on this unique heterojunction structure,MoS_(2)-on-ZnO photodetector also illustrates an excellent visible light response with a high photoresponsivity(74 A W-1) and fast response speed(<24 ms) due to the photogating *** work not only paves the way to design high-performance photodetectors with high photoresponsivity and fast response speed,but also provide a promising approach to improve the performance of optoelectronic devices using photogating effect.

关键词： MoS_(2) ZnO Two-dimension Photogating Photodetectors

Theoretical Insights into the Substituent Effects on the Fluorescence of Boron Complexes of 2-(Benzothiazol-2-yl)phenols: a Quantum Mechanics Study

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Chinese Journal of Structural Chemistry 2020年第2期39卷 243-254,184页

作者： li Hui-Xue WANG Xiao-feng ZHU Yuan-Cheng YUAN Kun LV ling-ling li zhi-feng School of Chemical Engineering and Technology Tianshui Normal UniversityTianshui 741001China

The performance of organic fluorescent materials can be improved by chemical substitutions with auxochrome groups such as amino to increase solubility, alter emitting color, or modify film quality. The complex 6,6-difluoro-6-bora-5-oxa-11-thia-6 a-aza-benzo[a]fluorine(BOBTP) and its derivatives, which possess excellent luminescent property at room temperature, were theoretically simulated by density functional theory. The geometries of the ground state and the first excited state of BOBTPs complexes were investigated and their bond parameters were obtained. Further, these bond parameters are compared with each other, and the computational wavelengths of maximum absorption and emission of studied complexes match up with the experimental values. It was found that amino substituent bonding to appropriate positions of BOBTP can reduce the reorganization energy significantly, which is ascribed to electron-donating effect of the amino group. The reorganization energy also plays an important role in the fluorescence quantum yield of all the BOBTPs. In particular, the radiative decay of complexes 3 and 4 is dominant due to the smaller reorganization energies, so their fluorescence quantum yield is almost 1, on the contrary the non-radiative decay and intersystem crossing rate of both the 1 and 2 can not be ignored for the larger reorganization energies, and the corresponding fluorescence quantum yields were calculated when the radiative decay rate(kr) and nonradiative decay rate(k(nr)) were taken into account.

关键词： theoretical study fluorescence spectrum BOBTPs substituent effects

User-perceived e-mail service QoS parameters and measurement

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The Journal of China Universities of Posts and Telecommunications 2010年第3期17卷 85-90页

作者： li Yong-zhi , liU feng, LEI Zhen-ming, CHEN ling School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China [a] School of Information Communication Engineering Beijing University of Posts Telecommunications Beijing 100876 China

A group of quality of service （QoS） parameters of electronic mail （e-mail） traffic are proposed from users＇ perspective. These parameters cover three fields： delay, throughput and usability. Concept and algorithm of each parameter are presented and its effect on user perceptions is described. In order to evaluate the effectiveness of these parameters, an active measurement system is implemented. Measured results show that the group of QoS parameters we proposed can be used to get a comprehensive view of user-perceived e-mail service QoS.

关键词： user perceptions e-mail service QoS active measurement

Raman Scattering Study of PbSe Grown on(111)BaF_(2) Substrate

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Chinese Physics Letters 2000年第8期17卷 606-608页

作者： YANG Ai-ling WU Hui-Zhen li zhi-feng QIU Dong-Jiang CHANG Yong li Jian-feng P.J.McCann X.M.Fang Department of Information Science and Electronic Engineering Department of Physics Zhejiang UniversityHangzhou 310028 Shanghai Institute of Technical Physics Chinese Academy of SciencesShanghai 200083 The University of Oklahoma NormanOklahoma73019-23USA

PbSe films were grown on(111)-oriented BaF_(2)substrates by using molecular beam *** resolution x-ray diffraction characterization showed good crystalline quality of PbSe *** longitudinal optical phonon at 135cm^(-1)and transverse optical phonon at 47.6cm-1 were observed by Raman scattering *** Raman tensor calculation demonstrates that both transverse-optical and longitudinal-optical(LO)phonons in PbSe crystal are Raman active on(111)-oriented surface,Furthermore,2LO phonon at about 270cm^(-1)and polaron at about 800cm^(-1)in PbSe,were also *** observed Raman frequencies are in good agreement with theoretical calculations using point ion model.

关键词： scattering transverse phonon

Role of long non-coding RNAs in gene regulation and oncogenesis

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Chinese Medical Journal 2011年第15期124卷 2378-2383页

作者： PAN Yan-feng feng Lei ZHANG Xian-qiang SONG li-jie liANG Hong-xia li zhi-qin TAO feng-bao Department of Infectious Disease the First Hospital Affiliated to Zhengzhou University Zhengzhou Henan 450000 China

Objective This article aims to review recent studies on the biological characteristics of long non-coding RNAs （IncRNAs）, transcription regulation by IncRNAs, and the results of recent studies on the mechanism of action of IncRNAs in tumor development. Data sources The data cited in this review were mainly obtained from the articles listed in PubMed and HighWire that were published from January 2002 to June 2010. The search terms were ＂long non-coding RNA＂, ＂gene regulation＂, and ＂tumor＂. Study selection The mechanism of IncRNAs in gene expression regulation, and tumors concerned with IncRNAs and the role of IncRNAs in oncogenesis. Results IncRNAs play an important role in transcription control, and post-transcriptional controlling. IncRNAs are suppressing and promoting factors. regulation by controlling chromatin remodeling, transcriptional involved in many kinds of tumors and play key roles as both Conclusion IncRNAs could perfectly regulate the balance of gene expression system and play important roles in oncogenic cellular transformation.

关键词： long non-coding RNA gene regulation cancer

Expression of dendritic cell-specific intercellular adhesion molecule 3 grabbing nonintegrin on dendritic cells generated from human peripheral blood monocytes

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World Journal of Gastroenterology 2006年第3期12卷 453-456页

作者： Jun li zhi-Hua feng Guang-Yu li Dan-Lei Mou Qing-He Nie The Center of Diagnosis and Treatment for Infectious Dis-eases Tangdu Hospital Fourth Military Medical University Xi'an710038 Shaanxi Province China

AIM： To generate dendritic cells （DCs） from human peripheral blood and to detect the expression of dendritic cell-specific intercellular adhesion molecule 3 grabbing nonintegrin （DC-SIGN; CD209） for the further study of DC-SIGN in hepatitis C virus （HCV） transmission. METHODS： Peripheral blood monocytes were isolated from blood of healthy individuals by Ficoll--Hypaque sedimentation and cultured in complete medium containing rhGM-CSF and rhIL-4. Cells were cultured for seven days, with cytokine addition every two days to obtain immature DCs. Characteristics of the cultured cells were observed under light and scanning microscope, and the expression of DC-SIGN was detected by immunofluorescence staining. RESULTS： After seven-day culture, a large number of cells with typical characteristics of DCs appeared. Their characteristics were observed under light and scanning electron microscope. These cells had a variety of cell shapes such as those of bipolar elongate cells, elaborate stellate cells and DCs. DC-SIGN was detected by immunofluorescence staining and its expression level on cultivated dendritic cells was high. CONCLUSION： DCs with a high expression of DC-SIGN can be generated from human peripheral blood monocytes in complete medium containing rhGM-CSF and rhIL-4.

关键词： Expression of DC-SIGN Dentric cells Peripheral blood monocytes.

气相沉积bcc薄膜时的织构与价电子结构的关系

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材料热处理学报 2008年第1期29卷 171-175页

作者：李志林李志峰黄钦北京化工大学材料科学与工程学院北京100029

应用固体与分子经验电子理论计算了不同bcc金属中团簇的共价电子对总数,结合团簇键能与气相沉积过程中的形核率的关系,认为在非晶或多晶基底上气相沉积bcc金属薄膜时,在较低温度不出现织构;在适当的温度下最可能出现(110)平行基底的织构... 详细信息

应用固体与分子经验电子理论计算了不同bcc金属中团簇的共价电子对总数,结合团簇键能与气相沉积过程中的形核率的关系,认为在非晶或多晶基底上气相沉积bcc金属薄膜时,在较低温度不出现织构;在适当的温度下最可能出现(110)平行基底的织构,(112)、(100)的织构也可能出现,但不会出现(111)织构;温度升高将使不同取向的织构先后消失。推测与现有实验事实符合较好。这一理论和方法还可以继续扩展到hcp金属和化合物等其它薄膜的织构研究。

关键词： bcc金属气相沉积织构电子理论