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Well-Tailored Dynamic liquid Crystal Networks with Anionically Polymerized Styrene-Butadiene Rubbers toward Modulating Shape Memory and Self-Healing Capacity

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MACROMOLECULES 2021年第6期54卷 2691-2702页

作者： Lei, Lan Han, li Ma, Hongwei Zhang, Ruixue li, xuwen Zhang, Songbo li, Chao Bai, Hongyuan li, Yang Dalian Univ Technol Sch Chem Engn State Key Lab Fine Chem Dept Polymer Sci & EngnLiaoning Key Lab Polymer Dalian 116024 Peoples R China

Well-tailored construction of liquid crystal networks (LCNs) with simultaneous molecular mobility and mechanical enhancement is desirable. Since the properties of polymeric materials are largely a result of the molecular compositions of polymer chains, in the present work, we demonstrate the tuning compositional synthesis of anionically polymerized random styrene-butadiene rubbers (r-SBRs) with well-controlled 75 wt % butadiene (Bd) contents that offer molecular mobility. Microstructural 1,2-olefins of 51.5-64.0 mol % were designed to attach 50 mol % SiH-terminated mesogenic moieties (M) along Bd units using hydrosilylation. As mechanical strength usually conflicts with high molecular mobility, an integrated design derived from the orderly LC stacking and simultaneous crosslinking in various ratios of the dynamic 2(6-isocyanatohexylaminocarbonylamino)-6methyl-4[1H]-pyrimidinone (UPy-NCO) and permanent hexamethylene diisocyanate (HMDI) along 1,4-olefins of Bd units offers necessary mechanical strength and molecular mobility, resulting in a series of dynamic LCNs (r-SBR-g-[***]). LC textures, phase transitions, self-healing/welding, and shape memory capacities were comprehensively studied. All LCNs showed LC textures in POM around T-i (42- 53 degrees C), which definitely contributed to both mechanical performance and molecular mobility due to the 50 mol % orderly LC stacking. Ureidopyrimidinone (UPy) that forms a dynamic H-bond is beneficial for the temporary shape fixity ratio (R-f), recyclability, and self-healing/welding ability while decreasing the shape recovery ratio (R-rec) because UPy can increase breaking elongations but sacrifice the mechanical strength. However, HMDI that forms a covalent crosslink showed the contrary effect, as HMDI can effectively enhance the mechanical strength but reduce the chain mobility. It is evidenced that r-SBR45k-g-[M-0%, 2%] can hardly undergo shape recovery (R-rec = 0) despite R-f = 92.6%, while with regard to r-SBR45k-g

关键词： Deformation Self healing materials Shape memory Differential scanning calorimetry liquid chromatography Chromatography

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The biologically and ecologically important natural products from the Chinese sea hare Bursatella leachii:structures,stereochemistry and beyond

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Chinese Journal of Natural Medicines 2024年第11期22卷 1030-1039页

作者： ZHANG Xinyuan SU Mingzhi ZHU Mingxin CHEN Sha GAO Zhen GUO Yuewei li xuwen School of Chinese Materia Medica Nanjing University of Chinese MedicineNanjing 210023China State Key Laboratory of Chemical Biology Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China Shandong Laboratory of Yantai Drug Discovery Bohai Rim Advanced Research Institute for Drug DiscoveryYantai 264117China

A novel amide alkaloid,bursatamide A(1),featuring an unprecedented propyl-hexahydronaphthalene carbon frame-work,was isolated from the infrequently studied sea hare Bursatella leachi,alongside a new 3-phenoxypropanenitrile alkaloid,bursatellin B(2),and twelve known *** structures of 1 and 2 were elucidated through comprehensive spectroscopic data analyses,while their relative and absolute configurations(ACs)were established through total synthesis and a series of quantum chem-ical calculations,including calculated electronic circular dichroism(ECD)spectra,optical rotatory dispersion(ORD)methods,and DP4^(+) probability *** A(1)demonstrated inhibitory effects against the human pathogenic bacteria listeria monocyt-ogenes and Vibrio ***-bursatellin B(21),a diastereoisomer of 2,exhibited notable antibacterial activity against the fish pathogenic bacterium Streptococcus parauberis FP KSP28,with an MIC90 value of 0.0472 μg·mL^(-1).

关键词： Bursatella leachii Marine natural product Alkaloid Sea hare Antibacterial activity

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Determination of hyperin in seed of Cuscuta chinensis Lam. by enhanced chemiluminescence of CdTe quantum dots on calcein/K₃Fe(CN)₆ system

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FOOD CHEMISTRY 2012年第4期134卷 2383-2388页

作者： Kang, Jing li, xuwen Geng, Jiayang Han, Lu Tang, Jieli Jin, Yongri Zhang, Yihua Jilin Univ Coll Chem Dept Analyt Chem Changchun 130012 Peoples R China

In this paper, 3-mercaptocarboxylic acid (MPA) modified CdTe quantum dots (QDs) were used as sensitizers, to enhance the chemiluminescence (CL) of the calcein/K3Fe(CN)(6) system. A new CL system of CdTe/calcein/K3Fe(CN)(6) was developed. The effects of reactant concentrations and the particle sizes of CdTe QDs on the CL emission were investigated in detail. The possible enhancement mechanism of the CL was also further investigated based on the photoluminescence (PL) and CL spectra. Polyphenols such as chlorogenic acid, quercetin, hyperin, catechin and kaempferol, were observed to inhibit the CL signal of the CdTe/calcein/K3Fe(CN)(6) system and determined by the proposed method. The proposed method was applied to the determination of hyperin in seed of Cuscuta chinensis Lam, and the results obtained were satisfactory. (C) 2012 Elsevier Ltd. All rights reserved.

关键词： Chemiluminescence CdTe quantum dots Polyphenols Seed of Cuscuta chinensis Lam.

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Efficient combination of ionic-liquid-based ultrasound-assisted extraction, complex chromatography, and molecular docking for screening of acetylcholinesterase inhibitors from Ganoderma atrum

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JOURNAL OF FOOD MEASUREMENT AND CHARACTERIZATION 2023年第2期17卷 1228-1240页

作者： Hou, Wanchao liu, Chunming li, Sainan Niu, Huazhou liu, Zhen Zhang, Yuchi Jin, Yongri li, xuwen Jilin Univ Coll Chem Changchun 130021 Jilin Peoples R China Changchun Normal Univ Cent Lab Changchun 130032 Peoples R China

Compounds extracted from Ganoderma atrum (G. atrum) is significantly beneficial to human health, have been incorporated in numerous remedies owing to their brain and kidney health benefits and antiinflammatory and diuretic properties. G. atrum a pilot of homology of medicine and food, has an important development value of functional food and health food. In this study, to develop a new ionic-liquid-based ultrasound-assisted extraction method and bio-affinity ultrafiltration coupled with LC and MS. Moreover, molecular docking was used to evaluate the activity of the AChE inhibitors, which were subsequently isolated and purified using consecutive counter-current chromatography (CCC) and semi-preparative high-performance liquid chromatography (HPLC). Lastly, the active compounds were identified using MS and nuclear magnetic resonance. Four AChE inhibitors, viz. ergosterol, ergosta-7,22-dien-3-one, ergosta-7-en-3 beta-ol, and ergosta-4,6,8(14),22-tetraen-3-one with purities of 92.23%, 90.19%, 90.52% and 96.72%, respectively, were obtained from G. atrum using consecutive CCC (ethyl acetate/methanol/water, 4.0:1.0:7.0, v/v/v) coupled with semi-preparative HPLC (4% A (0-30 min), 4-100% A (30-40 min)). Our results suggested that G. atrum extracts can be used in the potential prevention and treatment of neurodegenerative diseases. It will help to elucidate the mechanisms of action of various medicinal plants at the molecular level and provide more opportunities to discover and develop new potential therapeutic remedies from health care food resources.

关键词： Ganoderma atrum Ionic-liquid Acetylcholinesterase Inhibitor molecular Docking chromatography

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Semisynthesis and bioactive evaluation of oxidized products from 20(S)-ginsenoside Rg₃, Rh₂, protopanaxadiol (PPD) and their 20(R)-epimers as cytotoxic agents

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STEROIDS 2016年 106卷 26-34页

作者： Yang, Jie li, xuwen Sun, Ting Gao, Yan Chen, Yanxin Jin, Yongri li, Yang Jilin Univ Coll Chem Changchun 130021 Peoples R China Jilin Univ Coll Life Sci Changchun 130012 Peoples R China

A series of oxidized products have been systematically semisynthesized from 20(S)-ginsenoside Rg(3), Rh-2, 20(S)-protopanaxadiol (PPD) and their 20(R)-epimers and the majority of these products were evaluated for their cytotoxic activity against HeLa cells and HepG2 cells by MIT assay for the first time. Twenty-two products were obtained and elucidated based on comprehensive H-1 NMR, C-13 NMR, two-dimensional (2D) NMR, and mass spectral data and the results reported in previous literature. All the four ocotillol type saponins (203,24R(delta 86, delta 85);205,24S(delta 87, delta 88);20R,24R(delta 86, delta 86);20R,245(delta 86, delta 87) were obtained. In addition, eight compounds (3, 8, 9, 10, 15, 16, 19 and 22) with the cyclized side chain were firstly identified. Most of the tested compounds possessed cytotoxicity to a certain degree against the two types of cells which implied these oxidized products could play a certain role on anti-cancer functions of the raw materials in vivo. Meanwhile, the results proved that the configurations at C-20 or C-24 and the number of glycosyl at C-3 have important influence on the cytotoxicity. The products 1, 2,11-17, 20 and 22 should possess great activities and deserved further investigation as potential cytotoxic agents. (C) 2015 Elsevier Inc. All rights reserved.

关键词： Semisynthesis Oxidation Ginsenoside Ocotillol Saponin Cytotoxicity

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lignan Extraction from the Roots of Sinopodophyllum emodi Wall by Matrix Solid-Phase Dispersion

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CHROMATOGRAPHIA 2010年第7-8期72卷 713-717页

作者： Shi, Xiaolei li, xuwen liu, Jingbo Zhou, Hongyu Zhang, Hanqi Jin, Yongri Jilin Univ Coll Chem Changchun 130012 Jinlin Province Peoples R China Jilin Univ Coll Quartermaster Technol Changchun 130012 Jinlin Province Peoples R China

A fast and simple procedure based on matrix solid-phase dispersion was carried out for the extraction of three kinds of lignans, including podophyllotoxin, 4'-demethylpodophyllotoxin and podophyllotoxin glucoside, from the dried roots of Sinopodophyllum emodi Wall. After extraction, the lignans were determined by LC. The main experimental parameters, including type of dispersant, type of clean-up absorbent and type and volume of elution solvent, were examined and optimized. Compared with reflux extraction, the proposed method is simpler, faster and more efficient.

关键词： Column liquid chromatography Matrix solid-phase dispersion lignans Scanning electron micrograph

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Design of Signal Source Board Based on PXIe Standard 22

Design of Signal Source Board Based on PXIe Standard

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8th International Conference on Computing and Artificial Intelligence, ICCAI 2022

作者： Tang, Changjiang Wu, Qiang li, xuwen liu, Jie Faculty of Information Technology Beijing University of Technology China

ISBN: (纸本)9781450396110

This paper designs a Signal Source Board based on PXIe standard. The Signal Source Board adopts XCKU060-2FFVA1157I of Xilinx company as the main control chip of the FPGA, AD9144 of ADI company as the DAC, the Host Computer sends the analog signal waveform code table to be generated to the Signal Source Board through the PCIe Bus, and then the FPGA of the Source Board based sends the analog signal waveform code table to two pieces of AD9144 through the JESD204B interface. Finally, the generated analog signal is filtered through the low-pass filter HMC1023, and completes the output of 8-channel analog signal. It achieves the high-quality generation of any modulated signal from baseband to mid-frequency, and meets the synchronous output requirements of 8-channel analog signal. © 2022 ACM.

关键词： Field programmable gate arrays (FPGA)

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Dispersant-assisted dynamic microwave extraction of triazine herbicides from rice

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ANALYTICAL METHODS 2016年第18期8卷 3788-3794页

作者： li, Dan Zhang, Ziwei li, Na Wang, Kun Zang, Shuang Jiang, Jia Yu, Aimin Zhang, Hanqi li, xuwen Jilin Univ Coll Chem Qianjin St 2699 Changchun 130012 Peoples R China Harbin Inst Technol Weihai Sch Marine Sci & Technol Weihai 264209 Peoples R China

A rapid and effective sample pretreatment method, dispersant-assisted dynamic microwave extraction, was first applied to the extraction of six triazine herbicides from rice. The dynamic microwave extraction was coupled with matrix solid-phase dispersion (MSPD). The dispersant in MSPD was used to disperse the sample and adsorb impurities. Microwave irradiation was used to promote the transfer of the analyte and accelerate the extraction. The extraction and clean-up were performed simultaneously. The effects of experimental parameters, including the solvent type, volume of the extraction solvent, microwave power, type of dispersant, mass ratio of dispersant to rice, and flow rate of the extraction solvent, on the recoveries of the analytes were investigated. The limits of detection for the analytes ranged from 0.62 to 1.79 mu g kg(-1). The recoveries of the triazine herbicides in spiked rice samples were in the range of 84.3-101%, and the relative standard deviations were lower than 6.2%.

关键词： Microwave irradiation

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Design and Implementation of Automatic Testing Software Based on Labview and TestStand 22

Design and Implementation of Automatic Testing Software Base...

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8th International Conference on Computing and Artificial Intelligence, ICCAI 2022

作者： Zhang, Youquan li, xuwen Wu, Qiang liu, Jie Beijing University of Technology China

ISBN: (纸本)9781450396110

With the increasing complexity of circuit board function, both the performance index of circuit board and the number of circuit test points are increasing day by day. It is far from satisfying the test demand of large-scale board production manually. In order to realize automatic test of electrical signal on board, automatic configuration of test sequence and automatic generation of test report, this paper designed an automatic test software management platform based on Labview and TestStand, and proposed a solution of automatic generation of test report according to template. And this paper provides a method of parameter configuration and management of instrument and result threshold of automatic test sequence, which further improves the test efficiency of automatic test and realizes unified management of test parameters, compared with gradually configuring instrument parameters in each test step of test sequence. © 2022 ACM.

关键词： Software testing

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DESIGN OF 1553B BUS TESTING and SIMULATING SYSTEM

DESIGN OF 1553B BUS TESTING and SIMULATING SYSTEM

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9th International Conference on Intelligent Information Hiding and Multimedia Signal Processing (IIH-MSP)

作者： Yin, Jie Wu, Qiang Mao, Xuetao Song, Tao li, xuwen Beijing Univ Technol Coll Elect Informat & Control Engn Beijing Peoples R China Beijing Univ Technol Coll Life Sci & Bioengn Beijing Peoples R China

ISBN: (纸本)9780769551203

With the appearance of different manufacturers and types of 1553B bus devices, the problem of the lack of real-time analysis and evaluation of effective tools for bus test method becomes severe. So a set of general configurable and flexible testing and simulating verification system for 1553B bus. In this thesis, a set of real-time hardware and software systems solution is proposed, a novel mechanism of inject fault testing and detect fault is adopted. Besides, the proposed system could receive good performance in practical applications.

关键词： 1553B bus Windows plus RTX Fault injection

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