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Regulation from gradient to near periodic sequence during anionic copolymerization of styrene and dimethyl-[4-(1-phenyl-vinyl)phenyl]silane (DPE-SiH)

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POLYMER 2022年 244卷 124663-124663页

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

A facile strategy for achieving sequence-controlled polymers with a sufficient molecular diversity is of great importance. The periodic and gradient copolymers of styrene (St) and dimethyl-[4-(1-phenylvinyl)phenyl]silane (DPE-SiH) obtained through the living anionic copolymerization (LACOP) under the variable feed ratios (St:DPE-SiH = 0.5-4) in a nonpolar solvent without additives were well studied in our prior work (Zhang et al., 2019) [34]. Herein, a further study on the critical feed ratio of St (S) and DPE-SiH (D) at 3:1 is performed during the LACOP, where a peculiar interest lies whether a novel sequence will emerge between the periodic and gradient sequence with the additives of t-BuOK and THF. As the whole chain propagation process is monitored using in situ H-1 NMR spectroscopy, the copolymerization kinetics, i.e., the reactivity ratio (r), apparent rate parameters (K-app.), and the copolymer microstructures are investigated. Both t-BuOK and THF favors the incorporation of St into LACOP, as the trends r(St) = 0.1 (gradient sequence without additives) < r(St) = 0.22-0.29 (near periodic sequence for t-BuOK) < r(St) = 0.7-0.76 (near periodic sequence for THF). The near periodic sequences exhibit different periodicities distributed as "DSSDSS " for the t-BuOK and "DSSSDSSS " for the THF in the major. The strategy achieves the sequence regulation from statistically gradient to near periodic copolymers. Furthermore, we observe that the near periodic copolymers exhibit the similar T-g values but over the gradient copolymers.

关键词： living anionic copolymerization Near periodic sequence Additives

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α-Amylase and tyrosinase inhibitory activities, phenolic contents, and antioxidant capacities of wild and cultivated blueberries

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JOURNAL OF FOOD PROCESSING AND PRESERVATION 2021年第1期45卷 e15087-e15087页

作者： Tian, Sizhu li, xuwen Zang, Shuang Jin, Yongri Zhang, Ziwei Yu, Yong Jilin Univ Coll Chem Changchun Peoples R China Jilin Univ Coll Instrumentat & Elect Engn West Minzhu St 938 Changchun 130061 Peoples R China

The phenolic compound contents, antioxidant capacities, and alpha-amylase and tyrosinase inhibitory activities of 10 wild and 19 cultivated blueberries grown in northeast China were evaluated. The results showed that the alpha-amylase inhibitory activities of the blueberries represented, by 1/IC50, correlated with their total phenolic contents (TPCs). Moreover, the tyrosinase inhibitory activities correlated with the total anthocyanin contents (TACs). High-performance liquid chromatography and electrospray mass spectrometry were conducted to determine and identify seven phenolic acids. The average caffeic acid contents of the cultivated and wild blueberries were 277.37 and 17.71 mu g/g, respectively. The total phenolic, anthocyanin, and flavonoid contents were determined. Wild blueberries have higher TPCs, alpha-amylase inhibitory activities, and antioxidant capacities. Cultivated blueberries have higher TACs and exhibit tyrosinase inhibitory activities similar to those of the wild ones. Practical applications This study revealed that wild blueberries have high alpha-amylase inhibitory activities and are effective as natural alpha-amylase inhibitors for the treatment of diabetes. In addition, wild blueberries were found to be rich in phenolics and have high antioxidant capacities. Thus, because of these properties, wild blueberry products with antidiabetic and antioxidant potential can be developed for use in biomedical and pharmaceutical industries.

关键词： Amylases

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Design of 1553B Bus Testing and Simulating System

Design of 1553B Bus Testing and Simulating System

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International Conference on Intelligent Information Hiding and Multimedia Signal Processing (IIHMSP)

作者： Jie Yin Qiang Wu Xuetao Mao Tao Song xuwen li College of Electronic Information and Control Engineering Beijing University of Technology Beijing China

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： Software Monitoring Test equipment Data models Real-time systems Protocols

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Effect of local temperature on the detecting for pulse wave of local blood volume

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International Journal Bioautomation 2013年第2期17卷 91-96页

作者： Yan, Tingting Zhang, Song Yang, lin Yang, Yimin li, xuwen College of Life Science and Bioengineering Beijing University of Technology PingLeYuan 100 Beijing China

[Objective] Temperature of a subject's external body parts is an interference condition in pulse wave of local blood volume measurement. It is necessary to rule it out. By changing the influence factors, an experiment to research the effect of temperature of subjected part in pulse wave of local blood volume measurement was carried out. [Methods] When the 32 experimenters' left middle finger temperature fall below to 20°C, pulse wave of local blood volume would be recorded detected in real-time until the temperature returned to the measured values before the experiment [Results] While the temperature of subjected part ranged from 26°C to 31°C, the parameters of K', K1', K2' and the amplitude of pulse wave remain basically unchanged. [Conclusion] As a result of the research data, it is stipulated that the pulse wave of local blood volume can be measured only if the finger temperature is in the range of 26-31°C.

关键词： Temperature

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Fibrin gel-assisted stone extraction in retrograde intrarenal surgery

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BJU INTERNATIONAL 2022年第2期129卷 170-173页

作者： Yu, Yue Xi, Haibo Chen, Yujun li, xuwen liu, Wei Hu, Jieping Deng, Jun liu, Xiaoqiang lin, Longhui li, Chen Wang, Mengzhen Fu, Bin Wang, Gongxian Kuang, Renrui Zhou, Xiaochen Nanchang Univ Affiliated Hosp 1 Dept Urol Nanchang Jiangxi Peoples R China

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Multi-Target Feeding-Behavior Recognition Method for Cows Based on Improved RefineMask

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SENSORS 2024年第10期24卷 2975页

作者： li, xuwen Gao, Ronghua li, Qifeng Wang, Rong liu, Shanghao Huang, Weiwei Yang, liuyiyi Zhuo, Zhenyuan Tianjin Agr Univ Coll Comp & Informat Engn Tianjin 300384 Peoples R China Beijing Acad Agr & Forestry Sci Res Ctr Informat Technol Beijing 100097 Peoples R China Northwest A&F Univ Coll Informat Engn Xianyang 712100 Peoples R China Beijing Univ Agr Coll Intelligent Sci & Engn Beijing 100096 Peoples R China

Within the current process of large-scale dairy-cattle breeding, to address the problems of low recognition-accuracy and significant recognition-error associated with existing visual methods, we propose a method for recognizing the feeding behavior of dairy cows, one based on an improved RefineMask instance-segmentation model, and using high-quality detection and segmentation results to realize the recognition of the feeding behavior of dairy cows. Firstly, the input features are better extracted by incorporating the convolutional block attention module into the residual module of the feature extraction network. Secondly, an efficient channel attention module is incorporated into the neck design to achieve efficient integration of feature extraction while avoiding the surge of parameter volume computation. Subsequently, the GIoU loss function is used to increase the area of the prediction frame to optimize the convergence speed of the loss function, thus improving the regression accuracy. Finally, the logic of using mask information to recognize foraging behavior was designed, and the accurate recognition of foraging behavior was achieved according to the segmentation results of the model. We constructed, trained, and tested a cow dataset consisting of 1000 images from 50 different individual cows at peak feeding times. The method's effectiveness, robustness, and accuracy were verified by comparing it with example segmentation algorithms such as MSRCNN, Point_Rend, Cascade_Mask, and ConvNet_V2. The experimental results show that the accuracy of the improved RefineMask algorithm in recognizing the bounding box and accurately determining the segmentation mask is 98.3%, which is higher than that of the benchmark model by 0.7 percentage points;for this, the model parameter count size was 49.96 M, which meets the practical needs of local deployment. In addition, the technologies under study performed well in a variety of scenarios and adapted to various light environment

关键词： RefineMask instance segmentation feeding behavior behavioral recognition

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A molecularly imprinted electrochemiluminescence sensor based on ZnO@CdTe for the detection of mevastatin

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MICROCHEMICAL JOURNAL 2024年 203卷

作者： li, Huiling Tian, li Yang, Shuning li, Chao li, Ruidan Song, Yujia Guo, Yanjia li, xuwen Changchun Normal Univ Coll chem Changchun 130032 Peoples R China Jilin Univ Coll Chem Changchun 130012 Peoples R China

In this paper, CdTe quantum dots with near-infrared fluorescence (NIR) and hexagonal prism-shaped ZnO were synthesized, and the composites were characterized for their performance. A sensitive molecularly imprinted electrochemiluminescence (ECL) sensor for the determination of mevastatin was constructed based on ZnO@CdTe and molecularly imprinted polymer (MIP). The highest ECL intensity of the system was obtained by ZnO@CdTe as the main luminophores reacted with the co-reactant K2S2O8. The ECL response generated by the reaction of ZnO@CdTe and K2S2O8 was used as the basic signal detection platform. The MIP was prepared by the electropolymerization process on the above platform, which laid the foundation for forming the mevastatin cavities with specific recognition sites. In addition, the response mechanism was investigated, and the determination conditions were optimized. The ECL intensity change values (Delta I) of the sensor showed a good linear relationship with the logarithm of mevastatin concentration in the range of 2.0 x 10-11 to 2.0 x 10-6 mol L-1, and the limit of detection was 6.7 x 10-12 mol L-1 (S/N = 3). This method obtained satisfactory results in the detection of mevastatin in tablets.

关键词： Molecularly-imprinted ZnO@CdTe Mevastatin Electrochemiluminescence

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Synthesis and characterization of photo-responsive azobenzene side-chain liquid crystalline polystyrenes with a mesogenic phase of wide temperature range

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DYES AND PIGMENTS 2023年 210卷

作者： Zhang, Ruixue Ma, Hongwei li, xuwen Yang, Jiaxin Lai, Meng Zhang, Xueli Wang, Yu li, Yang Han, li Dalian Univ Technol Sch Chem Engn Dept Polymer Sci & Engn State Key Lab Fine ChemLiaoning Key Lab Polymer S Dalian 116024 Peoples R China

Polystyrenes (PSs) that provide photochemical stability are commonly used as the chromophore macromolecular carriers. Herein, PS-based alternating copolymers, i.e., alt-P(D-SiH/Ip), alt-P(D-2SiH/Ip) and alt-P(D-SiH/St), are synthesized through anionically copolymerized Si-H functionalized 1,1-diphenylethylene (DPE-SiH/2SiH) with isoprene (Ip)/styrene (St). Anionically polymerized (4-vinylphenyl)-dimethyl-silane is used as the uniform hydrosilylated PS, i.e., Uni.-P(St-SiH). A series of photo-responsive azobenzene side-chain liquid crystalline PSs combine the above PS-based main chains and the mesogenic moiety composed of azobenzene (Azo) and cholesterol (Chol) groups, i.e., Azo-Chol (M), via the hydrosilylation. The polarized optical microscopic (POM) morphologies and thermal properties of Azo-Chol (M) and Azo-Chol-PSs are studied. As desired, they produce the cholesteric phase of wide temperature range due to the PSs and Chol-groups. Moreover, the photo-responsive behavior irradiated under UV-light of different wavelengths are quantitatively evaluated by time-dependent UV-Vis spectroscopy. Azo-Chol-PSs undergo rapid and reversible trans-cis isomerization under the alternating irradiation of UV and visible light. The trans-to -cis isomerization efficiency under 365 nm UV-light is over that under 290-320 nm UV-light, while over 80% of cis-to-trans efficiency can be realized under 400-500 nm Vis-light irradiation This work would provide guidelines for the effective design of photo-responsive anisotropic materials.

关键词： Polystyrenes living anionic copolymerization Side-chain liquid crystalline polymers Photo-responsive Cholesteric phase

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低共熔溶剂双水相萃取-UPLC法检测吸烟者尿液中杂环胺类化合物

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高等学校化学学报 2024年第3期45卷 47-54页

作者：李敏贺姗姗王宏宇庄家莹金永日李绪文郑州轻工业大学食品与生物工程学院郑州450001 吉林大学化学学院长春130012

为评估香烟烟气中杂环胺的暴露水平,建立了一种基于低共熔溶剂/无机盐双水相萃取-UPLC法测定吸烟者尿液中5种杂环胺(IQ,IQ[4,5-b],Harman,Norharman和Phe-P-1)的方法.制备了7种以氯化胆碱(ChCl)为氢键受体的低共熔溶剂,并对其进行了表征... 详细信息

为评估香烟烟气中杂环胺的暴露水平,建立了一种基于低共熔溶剂/无机盐双水相萃取-UPLC法测定吸烟者尿液中5种杂环胺(IQ,IQ[4,5-b],Harman,Norharman和Phe-P-1)的方法.制备了7种以氯化胆碱(ChCl)为氢键受体的低共熔溶剂,并对其进行了表征;系统考察了影响萃取效率的主要参数,并将该方法与其它方法进行了对比研究.结果表明,在最佳提取条件下,杂环胺(HAAs)的回收率为81.9%~106.2%,日内和日间精密度分别低于2.9%和3.2%,检出限和定量限分别为0.020~0.097 ng/g和0.19~0.39 ng/g.该方法具有操作简单、环境友好及单样品成本低等特点,为尿液中杂环胺的检测提供了一种新方法,在生物样品检测领域具有良好的开发与应用价值.

关键词：杂环胺低共熔溶剂双水相萃取尿液

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Aquaponics model can provide better productivity: Microorganisms affect the growth and health of tilapia

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AQUACULTURE REPORTS 2025年 40卷

作者： Fan, Dingyue Xu, Huimin Meng, Shunlong Fan, limin Song, Chao Qiu, liping li, Dandan Fang, Longxiang liu, Zhuping Bing, xuwen Shanghai Ocean Univ Coll Fisheries & Life Sci Shanghai Peoples R China Chinese Acad Fishery Sci Freshwater Fisheries Res Ctr Sci Observing & Expt Stn Fishery Resources & Envir Wuxi 214081 Peoples R China

Aquaponics is a novel ecological agricultural strategy that combines aquaculture and hydroponic cultivation. The relationships between fish immunological and digestive functions, water quality, and bacterial populations were not well understood. This study aims to investigate the effects of aquaponics on aquaculture water quality, fish growth performance, and fish health, as well as exploring the roles of microbial taxa in these processes. In the present study, three aquaponics systems were established, and three same sized recirculating aquaculture systems (RAS) were constructed to act as controls. To evaluate bacterial community diversity and compositions across different microhabitats in the two systems, we used amplicon-based high-throughput sequencing technique targeting the 16S rRNA gene. In aquaponics, fish had a much greater nitrogen utilization rate, weight gain rate (WGR), feed conversion ratio (FCR), and specific growth rate (SGR) than in controls. The activities of alkaline phosphatase (AKP), acid phosphatase (ACP), lysozyme (LYS), lipase (LPS), and trypsin (TRP) in tissues, all of which are indicators of fish health, were significantly greater in aquaponics than in controls. Aquaponics effectively lowered chlorophyll-a levels while having little effect on other water quality metrics, indicating their potential for better algae control. Water quality measures such as dissolved organic carbon, chlorophyll-a, dissolved oxygen, and ammonia nitrogen had a substantial impact on the fish's immunological and digestive capabilities. In terms of microbial influence, particular gut bacteria-such as the bacterial orders Pseudomonadales, Caulobacterales, Defluviicoccales, Exiguobacterales, and Gemmatales-have been identified as influencing various functions in fish. Among these bacterial orders, we found that Pseudomonadales and Exiguobacterales were more abundant in aquaponics than control systems. This study demonstrated that aquaponics can increase fish health an

关键词： Aquaponics Tilapia growth and health Water quality Microbial community

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