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Chinese Journal of Chemistry 2015年第10期33卷 1178-1188页

作者： lijuan Lu Chaoguo yan College of Chemistry & Chemical Engineering Yangzhou University Yangzhou Jiangsu 225002 China

The base mediated cycloaddition reactions of 4-dimethylamino-l-phenacylpyridinium bromides with two mo- lecular 3-phenaeylideneoxindoles in methylene dichloride afforded functionalized dispirocyclopentyl-3,3＇-bisoxin- doles in good yields and with high diastereoselectivity. The similar cycloaddition reactions of 1-（N,N-dialkylcarba- moylmethyl） and 1-cyanomethyl 4-dimethylamino-pyridinium bromide in refluxing ethanol in the presence of triethylamine a/so resulted in dispirocyclopentyl-3,3＇-bisoxindoles with high diastereoselectivity. The stereochemis- try of dispirocyclopentyl-3,3＇-bisoxindoles was elucidated on the basis of ^1H NMR data and single crystal struc- tures.

关键词： domino reaction cycloaddition reaction pyridinium N-ylide spirooxindole diastereoselectivity

Electronic shell study of prolate Lin(n=15–17)clusters:Magnetic superatomic molecules

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Chinese Physics B 2020年第12期29卷 361-366页

作者： lijuan yan Jianmei Shao Yongqiang Li College of Electronics&Information Engineering Guangdong Ocean UniversityZhanjiang 524088China

The non-spherical lowest-lying Lin(n=15–17)isomers were found with high symmetric compact structures,of which the stability was not rationalized in a previous report(***.1199444(2003)).Based on the newly proposed super-valence bond model,the three prolate lithium clusters can be viewed as magnetic superatomic molecules,which are composed by sharing valence electron pairs and nuclei between two superatom units,namely,Li10 or Li11,and thus their stability can be given a good *** orbital and chemical bonding analysis clearly reveal that the Lin(n=15–17)clusters with prolate shapes are magnetic superatomic *** work may aid in the developments of the cluster-assembled materials or superatom-bonds.

关键词： jellium model geometry and electronic shells magnetic properties stability electron delocalization

弱阳离子交换固相萃取-超高效液相色谱-串联质谱法测定牛奶中13种氨基糖苷类药物残留

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食品科学 2025年第3期46卷 238-245页

作者：何金麟沈鹭英孙婷傅建炜严丽娟徐敦明厦门海关技术中心福建厦门361026 福建省农业科学院福建省农产品质量安全重点实验室福建福州350003

本研究建立弱阳离子交换固相萃取-超高效液相色谱-串联质谱测定牛奶中13种氨基糖苷类药物(安普霉素、阿米卡星、巴龙霉素、潮霉素B、核糖霉素、卡那霉素、链霉素、庆大霉素C1、双氢链霉素、妥布霉素、壮观霉素、新霉素和小诺霉素)的检... 详细信息

本研究建立弱阳离子交换固相萃取-超高效液相色谱-串联质谱测定牛奶中13种氨基糖苷类药物(安普霉素、阿米卡星、巴龙霉素、潮霉素B、核糖霉素、卡那霉素、链霉素、庆大霉素C1、双氢链霉素、妥布霉素、壮观霉素、新霉素和小诺霉素)的检测方法。牛奶样品经乙酸铵缓冲溶液和乙腈提取,弱阳离子交换固相萃取柱净化,SILICA SG80液相色谱柱分离。采用0.1%甲酸溶液和乙腈作为流动相进行梯度洗脱,在电喷雾电离源、正离子模式下进行超高效液相色谱-串联质谱检测,采用基质匹配标准外标法定量。在5.0~500.0 ng/mL范围内,13种氨基糖苷类药物呈现良好的线性关系(R^(2)≥0.998 3)。潮霉素B、核糖霉素、链霉素、妥布霉素和双氢链霉素的检出限均为3μg/kg,定量限均为10μg/kg;安普霉素、阿米卡星、巴龙霉素、卡那霉素、庆大霉素C_(1)、小诺霉素、新霉素和壮观霉素的检出限均为15μg/kg,定量限均为50μg/kg。在1、2倍和5倍的定量限加标水平下,回收率为73.8%~107.4%,相对标准偏差为1.0%~9.8%。该方法灵敏度高、操作简单、稳定性好,可用于检测牛奶中13种氨基糖苷类药物。

关键词：氨基糖苷超高效液相色谱-串联质谱法牛奶弱阳离子交换固相萃取残留

Effects of Plant Community Type on Soil Methane Flux in Semiarid Loess Hilly Region,Central Gansu Province,China

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Advances in Atmospheric Sciences 2022年第8期39卷 1360-1374页

作者： Chuanjie yanG Guang LI lijuan yan Weiwei MA Jiangqi WU yan TAN Shuainan LIU Shikang ZHANG College of Forestry Gansu Agricultural UniversityLanzhou 730070China Gansu Provincial Key Laboratory of Aridland Crop Science Lanzhou 730070China College of Agronomy Gansu Agricultural UniversityLanzhou 730070China

Methane(CH_(4))is an important greenhouse gas second only to CO_(2)in terms of its greenhouse *** plays an important role in controlling soil CH_(4)fluxes,but the spatial variability of soil CH_(4)fluxes during vegetation restoration in Loess Hilly Region(LHR)is not fully *** effects of different plant community types[Medicago sativa grassland(MS);Xanthoceras sorbifolium forestland(XS);Caragana korshinskii bushland(CK);Hippophae rhamnoides shrubland(HR);and Stipa bungeana grassland(SB)]on soil CH_(4)flux in LHR were studied via the static chamber *** results showed that the five plant community types were sinks of soil CH_(4)in LHR,the plant community type significantly affected the soil CH_(4)flux,and the average CH_(4)uptake from high to low was in SB,HR,CK,MS,and *** the whole study period,the soil CH_(4)flux showed similar interannual *** maximum absorption of soil CH_(4)appeared in the growing season,while the minimum appeared in *** CH_(4)uptake was positively correlated with soil temperature and soil *** temperature and moisture are important controlling factors for the temporal variability of soil CH_(4)*** LHR,the Stipa bungeana grassland is the more suitable plant community type for reducing soil CH_(4)*** the process of vegetation restoration in LHR,the soil CH_(4)absorption potential of different plant community types should be considered,ecological benefits should be taken into account,and vegetation more suitable for mitigating the greenhouse effect should be selected.

关键词： plant community type methane temporal variation Loess Hilly Region

Clinical effects of acupuncture therapy for vascular dementia

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Neural Regeneration Research 2011年第3期6卷 193-199页

作者： Zhao, Lei Guo, Yi Xiong, Jun Wang, Wei Du, Yuanhao yan, lijuan Tianjin Univ Tradit Chinese Med Acupuncture & Moxibust Coll Tianjin 300193 Peoples R China Tianjin Univ Tradit Chinese Med Dept Acupuncture & Moxibust Affiliated Hosp 1 Tianjin 300193 Peoples R China

OBJECTIVE： To evaluate clinical acupuncture treatment studies for vascular dementia, as well as to collect high-quality evidence related to clinical acupuncture treatment for clinical diagnosis. DATA SOURCES： PubMed database （1966-2010）, Embase database （1986-2010）, Cochrane Library （Issue 1,2010）, Chinese Biomedical Literature Database （1979-2010）, China HowNet database （1979-2010）, VlP Journals Database （1989-2010）, and Wanfang database （1998-2010） were analyzed by computer.

关键词： acupuncture vascular dementia clinical evidence traditional Chinese medicine

Dynamic Changes of Lakes in Tibet Plateau and the Climate Interaction in the Past Forty Years

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Acta Geologica Sinica(English Edition) 2014年第S1期88卷 34-35页

作者： yan lijuan ZHENG Mianping MLR Key Laboratory of Saline Lake Resources and Environments Institute of Mineral Resources Chinese Academy of Geological Sciences Chinese Academy of Geological Sciences

Lake change,as a mirror of climate change,has obvious indication and warning effect on *** extracting information of all lakes in Tibet Plateau from Landsat of the 1970’s,the 1990’s,around 2000 and 2010 based on RS ... 详细信息

关键词： Tibet Plateau lake dynamic changes remote sensing climate changes

Improved plasmon-assisted photoelectric conversion efficiency across entire ultraviolet-visible region based on antenna-on zinc oxide/silver three-dimensional nanostructured films

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Nano Research 2018年第1期11卷 520-529页

作者： lijuan yan yang Liu yaning yan Lanfang Wang Juan Han yanan Wang Guowei Zhou Mark T. Swihart Xiaohong Xu School of Chemistry and Materials Science of Shanxi Normal University & Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education Linfen 041004 China Department of Chemical and Biological Engineering University at Buffalo (SUNY) Buffalo New York 14260-4200 USA Research Institute of Materials Science of Shanxi Normal University Linfen 041004 China

ZnO has received tremendous attention for applications in photoelectrochemical water splitting, photocatalysis, and photovoltaic devices. However, the photoelectric conversion efficiency of ZnO is limited by the rapid recombination of photoexcited electron-hole pairs and the wide band gap, which allows only a small fraction of the solar spectrum to be absorbed. Recently, substantial research efforts have aimed to increase the photoelectric conversion efficiency across the entire ultraviolet-visible （UV-vis） spectrum by coupling semiconductors such as ZnO with noble metal nanoparticles （NPs）. In this stud~ we compare the performance of a pure ZnO film and ZnO/Ag nanostructured films as photoelectrodes. We show that under broad-spectrum UV-vis illumination, the photocurrent generated in the ZnO/Ag three-dimensional （3D） nanostructured films increases 3.75 times relative to the photocurrent generated in the pure ZnO films. We attribute the high photocurrent to the electric-field enhancement associated with the localized surface plasmon resonance of the Ag NPs, which are present at a high density in the 3D nanostructured films, and to the creation of photoexcited hot electrons in Ag that are transferred to ZnO, promoting electron-hole pair separation. We propose a mechanism to explain the observed enhancement of the photoelectric conversion efficiency.

关键词： photoelectric conversionefficiency localized surface plasmonresonance ZnO/Ag nanostructuredfilms Ag nanoparticles

Effect of electroacupuncture at Zusanli(ST 36) on dorsal root nerve signals in normal rats

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Journal of Traditional Chinese Medicine 2019年第5期39卷 685-691页

作者： Su Dongdong Geng Lianqi Zhang Jingsha Chen Yingyuan Liu yangyang yan lijuan Guo Yi Accupuncture Department Chinese Medicine Hospital of Tianjin Binhai New AreaTianjin 300451 China Chinese Medicine Hospital of Tianjin Binhai New Area Tianjin 300451China Tianjin University of Traditional Chinese Medicine Tianjin 300193China School of Automation and Electrical Eng. Tianjin UniversityTianjin 300072China

OBJECTIVE: To investigate how electroacupuncture (EA) at Zusanli (ST 36) with varying intensities of stimulation affects dorsal root nerve signals in normal rats. METHODS: Adult female Wistar rats were examined after drug-induced anesthesia and isolation of the L4 dorsal root associated with the Zusanli (ST 36) acupoint, using bipolar platinum electrodes. We applied EA at Zusanli (ST 36) with a continuous wave waveform for 1 min, and recorded action potentials in the L4 spinal cord dorsal root nerve with a frequency of 5 Hz and various current intensity levels (approximately 1-4 mA). In addition, we tested EA with a frequency of 15 Hz and current intensity of 1-4 mA. The L4 spinal cord dorsal nerve bundle action potentials were measured for 1 min of EA. To analyze the discharge frequency, we used the maximum Lyapunov exponent and Lempel-Ziv (LZ) complexity. RESULTS: At a fixed frequency, with increasing intensity of EA, dorsal root nerve filament discharge frequency revealed an initial increase, followed by a decreasing trend. A stimulation intensity of 3 mA induced a significantly greater discharge frequency, compared with stimulation intensities of 2 and 4 mA. EA stimulation evoked neuroelectric signals with chaotic characteristics. Increased intensity led to an initial increase in LZ complexity which then decreased, with a stimulation strength of 3 mA inducing the highest level of LZ complexity. CONCLUSION: EA of different intensities can induce nerve action potential encoding with different features.

关键词： Electroacupuncture Spinal nerve roots Point ST36 (Zusanli) Intensity Signal

Finite element method for one-dimensional rill erosion simulation on a curved slope

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International Soil and Water Conservation Research 2015年第1期3卷 28-41页

作者： lijuan yan Tingwu Lei Jing Zhang Qingwen Zhang Liqin Qu Bureau of Comprehensive Development Ministry of Water ResourcesBeijing 100053PR China Key Laboratory of Modern Precision Agriculture Integration Research College of Hydraulic and Civil EngineeringChina Agricultural UniversityBeijing 100083PR China Institute of Environment and Sustainable Development in Agriculture CAASBeijing 100081PR China International Research and Training Center on Erosion and Sedimentation Beijing 100048PR China

Rill erosion models are important to hillslope soil erosion prediction and to land use *** development of rill erosion models and their use has become increasingly of great *** purpose of this research was to develop mathematic models with computer simulation procedures to simulate and predict rill *** finite element method is known as an efficient tool in many other applications than in rill soil *** this study,the hydrodynamic and sediment continuity model equations for a rill erosion system were solved by the Galerkin finite element method and Visual Cþþ*** simulated results are compared with the data for spatially and temporally measured processes for rill erosion under different *** results indicate that the one-dimensional linear finite element method produced excellent predictions of rill erosion ***,this study supplies a tool for further development of a dynamic soil erosion prediction model.

关键词： Finite element method Simulation Rill erosion Dynamics Galerkin

An Improved Time Series Symbolic Representation Based on Multiple Features and Vector Frequency Difference

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Journal of Computer and Communications 2022年第6期10卷 44-62页

作者： lijuan yan Xiaotao Wu Jiaqing Xiao College of Mathematics and Statistics Huanggang Normal University Huanggang China

Symbolic Aggregate approXimation (SAX) is an efficient symbolic representation method that has been widely used in time series data mining. Its major limitation is that it relies exclusively on the mean values of segmented time series to derive the symbols. So, many important features of time series are not considered, such as extreme value, trend, fluctuation and so on. To solve this issue, we propose in this paper an improved Symbolic Aggregate approXimation based on multiple features and Vector Frequency Difference (SAX_VFD). SAX_VFD discriminates between time series by adopting an adaptive feature selection method. Furthermore, SAX_VFD is endowed with a new distance that takes into account the vector frequency difference between the symbolic sequence. We demonstrate the utility of the SAX_VFD on the time series classification task. The experimental results show that the proposed method has a better performance in terms of accuracy and dimensionality reduction compared to the so far published SAX based reduction techniques.

关键词： Time Series Representation SAX Feature Selection Classification