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Mechanisms of sodium and potassium ions transfer facilitated by dibenzo-15-crown-5 across the water/1,2-dichloro-ethane interface using micropipettes

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Chinese Science Bulletin 2002年第16期47卷 1325-1329页

作者： Su, B Shao, YH Chinese Acad Sci Changchun Inst Appl Chem State Key Lab Electroanalyt Chem Changchun 130022 Peoples R China

The transfer of sodium and potassium ions facilitated by dibenzo-15-crown-5 (DB15C5) has been studied at the micro-water/l,2-dichloroethane (water/DCE) interface supported at the tip of a micropipette. Cyclic volt-ammetric measurements were performed in two limiting conditions: the bulk concentration of Na+ or K+ in the aqueous phase is much higher than that of DB15C5 in the organic phase (DB15C5 diffusion controlled process) and the reverse condition (metal ion diffusion controlled process). The mechanisms of the facilitated Na+ transfer by DB15C5 are both transfer by interfacial complexation (TIC) with 1:1 stoichiometry under these two conditions, and the corresponding association constants were determined at log β1 = 8.97±0.05 or log β1 = 8.63±0.03. However, the transfers of K+ facilitated by DB15C5 show different behavior. In the former case it is a TIC process and its stoichiometry is 1:2, whereas in the latter case two peaks during the forward scan were observed, the first of which was

关键词： water/DCE interface micropipettes facilitated ion trans-fer DB15C5.

Dynamic response of a Q&P steel to high-strain-rate tension

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Acta Mechanica Solida Sinica 2017年第5期30卷 484-492页

作者： Huanran Wang Wenchao Zhang Dongfang Ma Bohan Ma Danian Chen Xin Yang Chunlei Fan Mechanics and Materials Science Research Center Ningbo UniversityNingboZhejiang 315211China China Science lab Research&Development CenterGeneral Motors CompanyShanghai 202106China

The experimental study on the volume fraction of retained austenite for QP980CR steel under high-strain-rate tension is briefly described. An interrupted tensile split Hopkinson bar （TSHB） is developed to control the elongation of specimens. The QP980CR steel sam- ples recovered from the interrupted TSt-IB tests are investigated using synchrotron X-ray diffraction （XRD） to analyze the effects of strain and strain rate on the martensitic trans- formation of retained austenite. A constitutive model of QP980CR steel coupling with the transformation-induced plasticity （TRIP） effect is presented based on Delannay＇s mean-field modeling. The stress-strain curves of quasi-static and dynamic tensile tests for QP980CR steel are compared with the results predicted by the presented constitutive model. The dif- fuse necking of QP980CR steel sheet specimens in TSHB tests is analyzed using Batra and Vv＇ei＇s instability criterion and the presented constitutive model. The effects of strain rate and temperature on the dynamic tensile fracture strain of QP980CR steel are also given.

关键词： Interrupted Hopkinson testPhase transformationMultiphase constitutive modelDynamic fractureQP980CR steel

Bioinspired polyimide film with fire retardant and gas barrier properties by gravity-induced deposition of montmorillonite

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Aggregate 2023年第6期4卷 200-208页

作者： Qiao-Xi Yu Run-Xin Bei Jia-Hui Liu Yan-Wei He Si-Wei Liu Zhen-Guo Chi Jia-Rui Xu Yi Zhang PCFM lab GD HPPC LabGuangdong Engineering Technology Research Centre for High-performance Organic and Polymer Photoelectric Functional FilmsState Key Laboratory of Optoelectronic Materials and TechnologiesSchool of ChemistrySun Yat-sen UniversityGuangzhouChina

Flame retardants play a crucial role in improving theﬂame retardant properties of polymer *** recent years,environmental problems caused byﬂame retar-dants have attracted widespread *** is urgent to use green and effective methods to prepareﬂame retardant *** nanocomposites with lay-ered structures seem to provide effective ideas,but in general,their hydrophilic raw materials limit their applications in certainﬁ***,we prepared biomimetic composites with a layered“brick-and-mortar”structure by gravity-induced depo-sition using polyimide as the polymer matrix and montmorillonite(MMT)as theﬁ*** well-arranged structures of the composite material could isolate oxygen and prevent combustible gases from *** gas barrier performance has been greatly improved,in which the water vapor transmission rate and the oxygen trans-mission rate decreased by 99.18%and three orders of magnitude,***ﬂame retardant performance has also been improved,and its limiting oxygen index can reach 67.9%.The polyimide matrix can be converted to water-insoluble by ther-mal imidization of water-soluble poly(amic acid)salt precursors,which endows the composites with low *** coating containing MMT can protect against polyurethane(PU)foam fromﬁ*** the conical calorimetric test,the coated sample self-extinguished,and the peak heat release rate,total heat release,and total smoke production are signiﬁcantly decreased by 53.39%,40.69%,and 53.03%,*** advantage of these properties,this work utilizes a facile method to prepare biomimetic composites with low moisture absorption,excellent gas barrier properties,andﬂame retardancy,which have great application potential.

关键词： bioinspired composite ﬁre retardant gas barrier gravity-induced deposition polyimide

Analysis and performance exploration of high performance(HfO_2) SOI FinFETs over the conventional(Si_3N_4) SOI FinFET towards analog/RF design

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Journal of Semiconductors 2018年第12期39卷 68-74页

作者： Neeraj Jain Balwinder Raj VLSI Design lab Department of Electronics and Communication Engineering Dr.B.R.Ambedkar National Institute of Technology (NIT)

Nowadays FinFET devices have replaced the MOS devices almost in all complex integrated circuits of electronic gadgets like computer peripherals, tablets, and smartphones in portable electronics. The scaling of FinFET is ongoing and the analog/RF performance is most affected by increased SCEs(short channel effects) in sub22 nm technology nodes. This paper explores the analog/RF performance study and analysis of high performance device-D2(conventional Hf02 spacer SOI FinFET) and device-D3(source/drain extended Hf02 spacer SOI FinFET) over the device-D1(conventional Si3 N4 spacer SOI FinFET) at 20 nm technology node through the 3-D(dimensional) simulation process. The major performance parameters like I(ON current), I(OFF current), gm(transconductance), gd(output conductance), A(intrinsic gain), SS(sub-threshold slope), TGF = g/I(trans-conductance generation factor), VEA(early voltage), GTFP(gain trans-conductance frequency product), TFP(tansconductance frequency product), GFP(gain frequency product), and f(cut-off frequency) are studied for evaluating the analog/RF performance of different flavored SOI FinFET structures. For analog performance evaluation,device-D3 and D2 give better results in terms of gm, ID(drain current) and SS parameters, and for RF performance evaluation device-D1 is better in terms of f, GTFP, TFP, and GFP parameters both at low and high values of V=0.05 V and V=0.7 V respectively.

关键词： SOI FinFET SCEs intrinsic gain trans-conductance cut-off frequency

Genome-Wide Analysis of DNA Methylation in Soybean

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Molecular Plant 2013年第6期6卷 1961-1974页

作者： Qing-Xin Song Xiang Lu Qing-Tian Li Hui Chen Xing-Yu Hu Biao Ma Wan-Ke Zhang Shou-Yi Chen Jin-Song Zhang State Key lab of Plant Genomics Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China

Cytosine methylation is an important mechanism for dynamical regulation of gene expression and trans- posable element （TE） mobility during plant developmental processes. Here, we identified the transcription start sites of genes using high-throughput sequencing and then analyzed the DNA methylation status in soybean roots, stems, leaves, and cotyledons of developing seeds at single-base resolution. Profiling of DNA methylation in different organs revealed 2162 differentially methylated regions among organs, and a portion of hypomethylated regions were correlated with high expression of neighboring genes. Because of the different distribution of class I TEs （retrotransposons） and class II TEs （DNA transposons）, the promoters of the lowest-expressed genes showed higher levels of CG and CHG methyla- tion but a lower level of CHH methylation. We further found that the CHH methylation level of class II TEs was higher than class I TEs, possibly due to the presence of more smRNAs in class II TEs. In cotyledons of developing seeds, smRNA abundance was roughly positively correlated with hypermethylated regions but negatively related to hypomethylated regions. These studies provide significant insights into the complicated interplays among DNA methylation, smRNA abundance, TE distribution, and gene expression in soybean.

关键词： soybean DNA methylation, differentially methylated regions, organs.

Role of cytomegalovirus on the maturation and function of monocyte derived dendritic cells of liver transplant patients

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World Journal of transplantation 2016年第2期6卷 336-346页

作者： Mohammad Hossein Karimi Afsoon Shariat Ramin Yaghobi Talat Mokhtariazad Seyed Mohammad Moazzeni Shiraz trans-plant Research Center Shiraz University of Medical Sciences Department of Microbiology Faculty of Basic SciencesKazerun BranchIslamic Azad University College of Basic Sciences Tehran Science and Research BranchIslamic Azad University Department of Virology School of Public HealthTehran University of Medical Sciences Department of Immunology Faculty of Medical SciencesTarbiat Modarres University

AIM: To study the impact of association between cytomegalovirus(CMV) pathogenesis with dendritic cell(DC) maturation and function was evaluated in CMV reactivated liver transplanted patients in comparing with non-reactivated ones, and healthy controls. METHODS: Monocyte derived dendritic cells(Mo DCs) was generated from collected ethylenediaminetetraacetic acid-treated blood samples from patient groups and controls. In these groups, expression rates and mean fluorescent intensity of DC markers were evaluated using flowcytometry technique. Secretion of cytokines including: interleukin(IL)-6, IL-12 and IL-23 were determined using enzyme-linked immunosorbent assay methods. The gene expression of toll-like receptor 2(TLR2), TLR4 and IL-23 were analyzed using in-house real-time polymerase chain reaction ***: Results have been shown significant decreases in: Expression rates of Mo DC markers including CD83, CD1 a and human leukocyte antigen DR(HLA-DR), the mean fluorescence intensitys for CD1 a and HLA-DR, and secretion of IL-12 in CMV reactivated comparedwith non-reactivated liver transplanted patients. On the other hand, significant increases have been shown in the secretions of IL-6 and IL-23 and gene expression levels of TLR2, TLR4 and IL-23 from Mo DCs in CMV reactivated compared with non-reactivated liver transplanted recipients. CONCLUSION: DC functional defects in CMV reactivated recipients, such as decrease in expression of DC maturation markers, increase in secretion of proinflammatory cytokines, and TLRs can emphasize on the importance of CMV infectivity in development of liver rejection in transplanted patients.

关键词： Cytomegalovirus Dendritic cells Liver transplantation

Controllable synthesis of polyoxovanadate-based coordination polymer nanosheets with extended exposure of catalytic sites

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Nano Research 2016年第12期9卷 3858-3867页

作者： Aruuhan Bayaguud Kun Chen Yongge Wei Key lab of Organic Optoelectronics & Molecular Engineering of Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 China State Key laboratory of Natural and Biomimetic Drugs Peking University Beijing 100191 China

Two-dimensional nanomaterials have become a hot research topic, and progress in research on them in the past decade has been substantial. Here we demonstrate a molecule-based bottom-up method to synthesize freestanding polyoxometalate- based nanosheets in two different ways. The trans substitution of ligands with carboxylate functionality promoted the coordination of organically derivatized hexavanadate with zinc ions with preferential directionality, which led to the formation of coordination polymer nanosheets. Characterization with transmission electron microscopy, powder X-ray diffraction, and infrared spectroscopy confirmed the morphology, structural composition, and preferential direction of the nanosheets. The microwave-assisted heating method and solvent addition method were proved to be effective for the preparation of POM-based nanosheet structures. The nanosheets were found to catalyze the aerobic oxidation of propanethiol （n-PrSH） to its corresponding disulfide （PrSSPr） under mild conditions.

关键词： polyoxometalate nanosheet bottom-up catalysis

transmission Index Research of Parallel Manipulators Based on Matrix Orthogonal Degree

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Chinese Journal of Mechanical Engineering 2017年第6期30卷 1396-1405页

作者： Zhu-Feng Shao Jiao Mo Xiao-Qiang Tang Li-Ping Wang State Key laboratory of Tribology and Institute of Manufacturing Engineering Tsinghua UniversityBeijing 100084 China Beijing Key lab of Precision/Ultra-precision Manufacturing Equipments and Control Tsinghua UniversityBeijing 100084 China

Performance index mance evaluation, and is the is the standard of perfor- foundation of both perfor- mance analysis and optimal design for the parallel manipulator. Seeking the suitable kinematic indices is always an important and challenging issue for the parallel manipulator. So far, there are extensive studies in this field, but few existing indices can meet all the requirements, such as simple, intuitive, and universal. To solve this problem, the matrix orthogonal degree is adopted, and generalized transmission indices that can evaluate motion/force trans- missibility of fully parallel manipulators are proposed. transmission performance analysis of typical branches, end effectors, and parallel manipulators is given to illus- trate proposed indices and analysis methodology. Simula- tion and analysis results reveal that proposed transmission indices possess significant advantages, such as normalized finite （ranging from 0 to l）, dimensionally homogeneous, frame-free, intuitive and easy to calculate. Besides, pro- posed indices well indicate the good transmission region and relativity to the singularity with better resolution than the traditional local conditioning index, and provide a novel tool for kinematic analysis and optimal design of fully parallel manipulators.

关键词： transmission index Parallel mechanism Kinematic performance Matrix orthogonal degree

FOUR NEW GLYCOSIDES, LIGUROBUSTOSIDES A, B, C AND D FROM LIGUSTRUM ROBUSTUM

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Chinese Chemical Letters 1996年第4期7卷 341-344页

作者： Tian, J Zhang, HJ Sun, HD Pan, LT Yao, P Chen, DY ACAD SINICA KUNMING INST BOTLAB PHYTOCHEMKUNMING 650204PEOPLES R CHINA GUIZHOU INST TRADIT CHINESE MED GUIYANG 550002PEOPLES R CHINA

Four new glycosides named ligurobustosides A, B, C and D have been isolated from Ligustrum robustum and their structures identified as geraniol 3-O-alpha-L-rhamnopyranosyl-beta-D-glucopyranoside (1), geraniol-O-alpha-L-rhamnopyranosyl-4-cafferoyl-beta-D- glucopyranoside (2), geraniol 3-O-alpha-L-rhamnopyranosyl-4-trans-P-coumaroyl -beta-D-glucopyranoside (3) and geraniol 3-O-alpha-L-rhamnopyranosyl-4-cis P-coumaroyl-beta-D-glucopyranoside (4), respectively.

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