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Journal of Renewable Materials 2020年第6期8卷 675-686页

作者： Dragomir Vassilev Nadezhda Petkova yulian tumbarski Milena Koleva Panteley Denev Department of Physics Chemistry and EcologyTechnical University of GabrovoGabrovo5300Bulgaria Department of Inorganic and Organic Chemistry University of Food TechnologiesPlovdiv4002Bulgaria Department of Microbiology University of Food TechnologiesPlovdiv4002Bulgaria

Undenicylic acid(10:1)is known as an antifungal agent and an active ingredient of many topical medicines[1–6].The present research investigates the preparation of aliphatic esters of 10-undecylic acid with butanol and i-amyl alcohol by the conventional and ultrasound-assisted syntheses as well as the structural elucidation of the resulting compounds,by FTIR and NMR *** antimicrobial properties of the obtained 10-undecylenic esters were tested against Gram-positive bacteria(Staphylococcus aureus;Enterococcus faecalis;Listeria monocytogenes),Gram-negative bacteria(Escherichia coli;Salmonella sp.)and filamentous fungi(Penicillium sp.;Aspergillus niger;Fusarium moniliforme)using the conventional agar-well diffusion *** results demonstrated that all esters had insignificant antibacterial activity.i-Amyl-10-undecylenate and t-butyl-10-undecylenate showed activity against both Gram-positive and Gram-negative bacteria,while i-butyl-10-undecylenate and n-butyl-10-undecylenate were effective only against Gram-positive bacteria *** contrast,all 10-undecylenic esters demonstrated high antifungal activity,which was most pronounced in ***,the obtained products can be successfully used as promising antifungal agents for various pharmaceutical formulations as well as biocontrol means against plant pathogens.

关键词： 10-undecylenate alkyl esters FTIR and NMR spectroscopy antimicrobial activity

Physicochemical Characterization and Antimicrobial Properties of Inulin Acetate Obtained by Microwave-Assisted Synthesis

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Journal of Renewable Materials 2020年第4期8卷 365-381页

作者： Nadezhda Petkova Radka Arabadzhieva Dragomir Vassilev Gergana Gencheva yulian tumbarski Tsveteslava Ignatova-Ivanova Sevginar Ibryamova Mina Todorova Milena Koleva Panteley Denev Department of Organic Chemistry and Inorganic Chemistry University of Food TechnologiesPlovdiv4002Bulgaria Department of Physics Chemistry and EcologyTechnical University of GabrovoGabrovo5300Bulgaria Department of Microbiology University of Food TechnologiesPlovdiv4002Bulgaria Department of Biology Konstantin Preslavsky University of ShumenShumenBulgaria

Microwave-assisted irradiation was performed for esterification of chicory inulin with high degree of polymerization with acetic anhydride without a solvent only with a *** resulting esters were characterized by melting point,hydrophilic-lipophilic balance,thin-layer chromatography,ultraviolet spectroscopy,Fourier transform infrared spectroscopy(FTIR)and nuclear magnetic resonance(NMR)*** acetate demonstrated a high degree of acetylation(2.5-3.0)and presented a white,water-insoluble substance with bitter *** FTIR and NMR spectra confirmed esterification and demonstrated the incorporation of hydrophobic residue to the water soluble inulin *** capacity,water holding,oil-holding capacities,the foamability,foam stability and emulsifying properties were also *** acetate showed promising foam stability 52%for 60 min and formed stable emulsions at concentration 0.2 g/L with 50 and 80%oil *** water holding capacity was lower than the oil holding *** addition to this,for the first time,the antimicrobial potential of inulin acetate was tested against seventeen microorganisms(Gram-positive and Gram-negative bacteria,yeasts and fungi).Inulin acetate(10 mg/ml)inhibited the growth of Bacillus cereus,Escherichia coli ATCC 8739,Salmonella abony,Candida albicans and Penicillium ***,inulin acetate demonstrated antimicrobial activity at concentration 1 mg/ml against Listeria monocytogenes 863,Escherichia coli 3398,Candida albicans 8673,Fusarium oxysporum and Aspergillus *** current study demonstrated the applications of“green”synthesized inulin acetate as a foaming agent,oil-in-water emulsion stabilizer and antimicrobial substance in pharmaceutical,agricultural and cosmetic preparations.

关键词： Inulin acetates microwave irradiation FTIR and NMR spectroscopy foams emulsions antimicrobial activity

RBSDE's with jumps and the related obstacle problems for integral-partial differential equations

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Science China Mathematics 2006年第4期49卷 557-573页

作者： FAN yulian School of Mathematical Sciences Peking University Beijing 100871 China

The author proves, when the noise is driven by a Brownian motion and an independent Poisson random measure, the one-dimensional reflected backward stochastic differential equation with a stopping time terminal has a unique solution. And in a Markovian framework, the solution can provide a probabilistic interpretation for the obstacle problem for the integral-partial differential equation.

关键词： reflected backward stochastic differential equation, obstacle problem for the integral-partial differential equation, viscosity solution.

Liver mitochondrial and whole-animal level metabolic compensation in a catfish during seasonal acclimatization

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Current Zoology 2011年第1期57卷 109-115页

作者： yulian YAN Xiaojun XIE Institute of Hydrobiology and Water Environment School of Life Science Southwest University Chongqing 400715 China

To examine whether metabolic compensation during seasonal acclimatization at the liver mitochondrial level is consistent with that at the whole-animal level, respiration rates of liver mitochondria and resting metabolic rates in winter- and sum- meracclimatized southern catfish （Silurus meridionalis Chen） were measured. At 12.5, 17.5, 22.5, 27.5 and 32.5~C, the mean values of state 3 respiration rates were 12.21, 13.84, 18.96, 24.78 and 32.01 nmol O2min-1 mg-1 mitochondrial protein in the winter group, and 8.56, 9.20, 17.32, 22.74 and 26.32 nmol 02 min-1 mgq in the summer group, respectively. At the five assay temperatures the resting metabolic rates were 24.86, 42.68, 61.59, 84.10 and 125.65 mg 02 h-1 kgI body mass in the winter group, and 22.89, 40.59, 52.94, 75.13 and 109.35 mg Oz h-1 kg-1 in the summer group, respectively. Total mitochondrial respiration rates in the liver organ were estimated based on state 3 respiration rates, mitochondrial protein content and organ mass, and the mean values were 72.96, 71.87, 112.47, 167.35 and 183.27 nmol Ozmin-lin the winter group, and were 47.89, 47.39, 105.67, 138.18 and 132.29 nmol 02 min-1 in the summer group, respectively. Metabolic compensation caused by seasonal acclimatization occurred at the liver mitochondrial level and compensation at the liver organ level was found to be more efficient because of an in- crease in metabolic capacity of mitochondria and a boost in organ mass. Metabolic compensation at the whole-animal level was not detected. During seasonal acclimatization, the effect of metabolic compensation at liver mitochondrial level is inconsistent with that at the whole-animal level in the southern catfish. This may be due to different degrees of regulation of metabolic mechanisms among various tissues and organs in an acclimatized organism

关键词： Metabolic compensation Mitochondrial respiration Seasonal acclimatization Silurus meridionalis

Detecting protein complexes from DPINs by density based clustering with Pigeon-Inspired Optimization Algorithm

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Science China(Information Sciences) 2016年第7期59卷 30-43页

作者： Xiujuan LEI yulian DING Fang-Xiang WU School of Computer Science Shaanxi Normal University School of Mathematical Sciences Nankai University Division of Biomedical Engineering University of Saskatchewan

Detecting protein complexes is crucial to understand principles of cellular organization. Plenty evidences have indicated that sub-graphs with high density in protein-protein interaction(PPI) network, especially dynamic PPI network(DPIN), usually correspond to protein complexes. As a well-known density-based clustering algorithm, Density-Based Spatial Clustering of Applications with Noise(DBSCAN) has been used in many areas due to its simplicity and the ability to detect clusters of different sizes and shapes. However, one of its limitations is that the performance of DBSCAN depends on two specified parameters ε and Min Pts, where εrepresents the maximum radius of a neighborhood from an observing point while Min Pts means the minimum number of data points contained in such a neighborhood. In this article, we develop a new method named as P-DBSCAN to detect protein complexes in DPIN by using Pigeon-Inspired Optimization(PIO) Algorithm to optimize the parameters ε and Min Pts in DBSCAN. The experiments on DIP and MIPS datasets show that P-DBSCAN outperforms the state-of-the-art methods for protein complex detection in terms of several criteria such as precision, recall and f-measure.

关键词： dynamic protein-protein interaction network(DPIN) pigeon-inspired optimization(PIO) protein complex density based clustering gene expression

Tropical cyclones and multiscale climate variability: The active western North Pacific typhoon season of 2018

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Science China Earth Sciences 2020年第1期63卷 1-11页

作者： Liang WU Hongjie ZHANG Tao FENG yulian TANG Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100190China College of Oceanography Hohai UniversityNanjing 210098China

The 2018 typhoon season in the western North Pacific(WNP) was highly active, with 26 named tropical cyclones(TCs) from June to November, which exceeded the climatological mean(22) and was the second busiest season over the past twenty years. More TCs formed in the eastern region of the WNP and the northern region of the South China Sea(SCS). More TCs took the northeast quadrant in the WNP, recurving from northwestward to northward and causing heavy damages in China's Mainland(69.73 billion yuan) in 2018. Multiscale climate variability is conducive to an active season via an enhanced monsoon trough and a weakened subtropical high in the WNP. The large-scale backgrounds in 2018 showed a favorable environment for TCs established by a developing central Pacific(CP) El Ni?o and positive Pacific meridional mode(PMM)episode on interannual timescales. The tropical central Pacific(TCP) SST forcing exhibits primary control on TCs in the WNP and large-scale circulations, which are insensitive to the PMM. During CP El Ni?o years, anomalous convection associated with the TCP warming leads to significantly increased anomalous cyclonic circulation in the WNP because of a Gill-type Rossby wave response. As a result, the weakened subtropical high and enhanced monsoon trough shift eastward and northward, which favor TC genesis and development. Although such increased TC activity in 2018 might be slightly suppressed by interdecadal climate variability, it was mostly attributed to the favorable interannual background. In addition, high-frequency climate signals,such as intraseasonal oscillations(ISOs) and synoptic-scale disturbances(SSDs), interacted with the enhanced monsoon trough and strongly modulated regional TC genesis and development in 2018.

关键词： Tropical cyclone Multiscale climate variability Typhoon season of 2018 Western North Pacific

Synthesis of novel active ester ether resin and its effects on positive thermal CTP plates

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Chinese Science Bulletin 2013年第13期58卷 1536-1542页

作者： SHA XuZheng PANG yulian ZOU YingQuan College of Chemistry Beijing Normal University

A novel active ester ether resin, consisting of p-hydroxyphenylacetic acid and a mixed-phenol novolac resin, was produced by the addition of ethyl vinyl ether to a carbonyl novolac resin. This study investigated the conditions of its synthesis and characterized its structure using infrared and 1 H NMR spectroscopies, and gel-permeation chromatography. Its solubility in alkaline solution differed greatly before and after decomposition. The results of thermal gravimetric analysis confirmed the formation of an active ester ether resin of p-hydroxyphenylacetic acid and novolac resin. The resin had acidolysis activity at room temperature and pyrolysis activity at high temperatures (140-200°C) and could be used in the imaging layer of a positive thermal plate for computer-to-plate processes as an inhibitor/accelerator to improve its alcohol resistance, alkali resistance, sensitivity, lattice point reducibility, and developing tolerance.

关键词：酸解活性热敏CTP 树脂酯醚合成热板对羟基苯乙酸计算机直接制版

Revealing the anti-sintering phenomenon on silica-supported nickel catalysts during CO_(2)hydrogenation

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Journal of Environmental Sciences 2024年第6期140卷 270-278页

作者： Liuqingqing Yang Tiancheng Pu Feixiang Tian yulian He Minghui Zhu State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China University of Michigan-Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong UniversityShanghai 200240China School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

The CO_(2)catalytic hydrogenation represents a promising approach for gas-phase CO_(2)utilization in a direct *** to its excellent hydrogenation ability,nickel has been widely studied and has shown good activities in CO_(2)hydrogenation reactions,in addition to its high availability and low ***,Ni-based catalysts are prone to sintering under elevated temperatures,leading to unstable catalytic *** the present study,various characterization techniques were employed to study the structural evolution of Ni/SiO_(2)during CO_(2)*** anti-sintering phenomenon is observed for both 9%Ni/SiO_(2)and 1%Ni/SiO_(2)during CO_(2)hydrogenation at 400℃.Results revealed that Ni species were re-dispersed into smaller-sized nanoparticles and formed Ni^(0)active *** interestingly,this anti-sintering phenomenon leads to distinct outcomes for two catalysts,with a gradual increase in both reactivity and CH_(4)selectivity for 9%Ni/SiO_(2)presumably due to the formation of abundant surface Ni°from redispersion,while an apparent decreasing trend of CH_(4)selectivity for 1%Ni/SiO_(2)sample,presumably due to the formation of ultra-small nanoparticles that diffuse and partially filled the mesoporous pores of the silica support over ***,the redispersion phenomenon was found relevant to the H_(2)gas in the reaction environment and enhanced as the H_(2)concentration *** finding is believed to provide in-depth insights into the structural evolution of Ni-based catalysts and product selectivity control in CO_(2)hydrogenation reactions.

关键词： Carbon dioxide utilization CO_(2)hydrogenation Nickel-based catalysts Anti-sintering Structural evolution

Relaxed Stability Criteria for Time-Delay Systems:A Novel Quadratic Function Convex Approximation Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 996-1006页

作者： Shenquan Wang Wenchengyu Ji yulian Jiang Yanzheng Zhu Jian Sun College of Electrical and Electronic Engineering Changchun University of TechnologyChangchun 130012China the College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China Key Laboratory of Complex Systems Intelligent Control and Decision Beijing Institute of TechnologyBeijing 100081China

This paper develops a quadratic function convex approximation approach to deal with the negative definite problem of the quadratic function induced by stability analysis of linear systems with time-varying *** introducing two adjustable parameters and two free variables,a novel convex function greater than or equal to the quadratic function is constructed,regardless of the sign of the coefficient in the quadratic *** developed lemma can also be degenerated into the existing quadratic function negative-determination(QFND)lemma and relaxed QFND lemma respectively,by setting two adjustable parameters and two free variables as some particular ***,for a linear system with time-varying delays,a relaxed stability criterion is established via our developed lemma,together with the quivalent reciprocal combination technique and the Bessel-Legendre *** a result,the conservatism can be reduced via the proposed approach in the context of constructing Lyapunov-Krasovskii functionals for the stability analysis of linear time-varying delay ***,the superiority of our results is illustrated through three numerical examples.

关键词： Equivalent reciprocal combination technique quadratic function convex approximation approach stability timevarying delay

Monte Carlo simulation of GEM-based for 14 MeV neutron detector

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Science China(Physics,Mechanics & Astronomy) 2013年第9期56卷 1740-1744页

作者： WANG XiaoDong ZHANG yulian ZHANG ChunHui HU BiTao School of Nuclear Science and Technology Lanzhou University

A new concept of neutron detector based on Gas Electron Multiplier(GEM) technology is presented in this paper,in which a novel multi-layer high density polyethylene(HDPE) as neutron-to-proton converter is proposed and studied with Geant4 toolkit for fast 14 MeV *** preliminary results show that the detection efficiency of the detector with 400 converter units is higher than 2.3% and reconstruction accuracy of the incident neutron position is higher than 2.6%.

关键词： gas electron multiplier 14 MeV neutron detection efficiency position reconstruction