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Electrochemical potassium ion sensor based on DNA G-quadruplex conformation and gold nanoparticle amplification

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Rare Metals 2013年第4期32卷 369-374页

作者： li-dong li Xiao-Qing Huang lin Guo School of Chemistry and Environment Beijing University of Aeronautics and Astronautics

A simple, rapid, highly sensitive electrochem-ical sensor for potassium ion （K^＋） based on the confor-mationai change of DNA sequence containing guanine-rich segments is presented. In the presence of K^＋, guanine-rich DNA sequence folds to G-quadruplex structure, allowing a ferrocene tag to transfer electrons to the electrode. Gold nanoparticles （AuNPs）, which are self-assembled on the surface of a bare gold electrode by using 4-aminothio-phenol as a medium, offer a big surface area to immobilize a large number of aptamers and improve the sensitivity of the sensor. The square-wave voltammetry peak current increases with K^＋ concentration. The plots of peak current against K^＋ concentration and the logarithm of K^＋ con- centration are linear over the range from 0.1 to 1.0 mmol·L^-1 and from 1 to 30 mmol·L^-1, respectively. A lower detection limit of 0.1 mmol·L^-1 K^＋ is obtained for AuNPs-modified sensor, which greatly surpasses that （100 mmol·L^-1） of the sensor without AuNPs modification by three orders of magnitude. Thus, the sensor with AuNPs amplification is expected to open new opportunities for highly sensitive detection of other biomolecules in the future.

关键词： Electrochemistry G-quadruplex Gold nanoparticles Potassium Sensor

Optical and gas sensing properties of mesoporous hollow ZnO microspheres fabricated via a solvothermal method

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Chinese Chemical Letters 2015年第3期26卷 304-308页

作者： Yan li dong-li li Jin-Cheng liu College of Science Civil Aviation University of China Materials and Chemical Engineering Hai Nan University

Mesoporous,hollow Zn O microspheres were synthesized via a hydrothermal method,using glycerol and zinc acetate as the starting *** and FESEM analysis showed that the surface morphology of the spheres with a Wurtzite structure could be reasonably adjusted by varying the weight ratio（Rw） of Zn（CH3COO）2 2H2O：H2O：*** responses of the gas sensor based on the spheres to 100 ppm ethanol and 100 ppm acetone are 18.9 and 10.4,*** response and recovery times of the sensor to ethanol and acetone are 2 s and 3 s,3 s and 5 s,*** hollow spheres show an intense UV emission at 392 nm and a broad blue-green emission at 488 ***,a light trapping phenomenon is revealed by UV emission and scattering measurements on the microspheres,which can be attributed to the mesoporous shell and hollow structure of the microsphere.

关键词： hollow spheres hydrothermal microsphere attributed ethanol acetate starting glycerol FESEM

An energy efficient clustering routing algorithm for wireless sensor networks

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The Journal of China Universities of Posts and Telecommunications 2006年第3期13卷 71-75页

作者： li li dong Shu-song WEN Xiang-ming Institute of Continuing Education School Beijing University of Posts and Telecommunications Beijing 100876 China

This article proposes an energy efficient clustering routing （EECR） algorithm for wireless sensor network. The algorithm can divide a sensor network into a few clusters and select a cluster head base on weight value that leads to more uniform energy dissipation evenly among all sensor nodes. Simulations and results show that the algorithm can save overall energy consumption and extend the lifetime of the wireless sensor network.

关键词： wireless sensor network clustering routing energy

The reversal of surface air temperature anomalies in China between early and late winter 2021/2022:Observations and predictions

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Advances in Climate Change Research 2023年第5期14卷 660-670页

作者： Chong-Bo ZHAO Qing-Quan li Yu NIE Fang WANG Bing XIE li-li dong Jie WU China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CenterBeijing 100081China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China

During winter of 2021/2022,the temperature in China is characterized by a warm-to-cold transition,and the average temperature anomaly in February 2022 is−1.6℃,the coldest February in *** revealed the circulation regimes and physical mechanisms associated with this reversal event and demonstrated the advantage of a regional model downscaling over the use of the global model alone in *** early winter,the warm anomalies are mainly related to an anomalous anticyclonic system downstream of a PNA-like(Pacific-North America)Rossby-wave train induced by La Niñ*** late winter,due to the circulation response to the central Pacific warming and negative tropical Indian Ocean Dipole(TIOD),two‘−+−’Rossby-wave trains from high latitudes and the tropical Indian Ocean jointly lead to an anomalous cyclonic system in ***,an anticyclonic blocking system on the northern side of Baikal brings strong and cold air to *** two systems together cause a significant drop in surface air temperature anomaly in China during the late *** Beijing Climate Center climate system model(BCC_CSM1.1 m)can essentially predict this temperature reversal in China about five months in ***,the reversal amplitude is weaker due to warm deviations over the tropical Pacific Ocean and equatorial Indian *** dynamic downscaling,a regional Climate-Weather Research and Forecasting(CWRF)model correctly predicts the cold SAT anomalies in late winter 2021/*** regional model depicts more realistic circulation patterns in East Asia;the anomalous cyclonic system in Inner Mongolia accompanied by the northerly anomalies contribute to a lower-than-normal SAT over *** study reveals the cooperative effect of wave trains from high latitudes and the tropics on the subseasonal temperature reversal and demonstrates a possible solution to improve the forecast skill by dynamic downscaling according to precise characterization of local surface information.

关键词： 2021/2022 winter Dynamical downscaling prediction CWRF BCC_CSM1.1 m Reversal of SAT anomalies

STUDY OF DYE-SENSITIZED SYSTEMS FOR PHOTOIMAGING

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Chinese Journal of Polymer Science 2001年第1期19卷 79-83页

作者： Fang Gao Chun-ying Zhao Yong-yuan Yang li-dong li Insatute of Photographic Chemistry Chinese Academy of Sciences Beijing 100101 China Insatute of Photographic Chemistry Chinese Academy of Sciences Beijing 100101 China Insatute of Photographic Chemistry Chinese Academy of Sciences Beijing 100101 China Insatute of Photographic Chemistry Chinese Academy of Sciences Beijing 100101 China

o-Chloro-hexaarylbiimidazole (o-CI-HABI) can be sensitized efficiently by cyanine dyes, the cyclopentanone and cyclohexanone dyes, when exposed to xenon lamp (use filter cut lambda less than or equal to 400 nm). The photoreaction between the photoinitiator and the dyes was completed through an electron transfer process. Excellent results have been obtained in photoimaging studies, e.g. the resolution of the image can reach 7 mum. The influence of the content of the dyes and the heat after the exposure on the resolution of the image was investigated.

关键词： photopolymer photoimaging hexaarylbiimidazole printing plate

Study on the inclusion interaction of methylated-β-cyclodextrins with albendazole by spectrofluorimetry and its application

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Chinese Chemical Letters 2008年第8期19卷 951-954页

作者： Guo Yan Zhao Hao Wu Sheng li dong li Ming Du Analytical and Testing Center Shanxi Normal University Linfen 041004 China

The inclusion interaction between three types of methylated-β-cyclodextrins （Me-β-CDs） and albendazole （ABZ） was studied by spectrofluorimetry. The result showed that Me-β-CDs reacted with ABZ to form an inclusion complex, 1： 1 stoichiometry for Me- β-CDs-ABZ complex was established and its association constant have been determined from fluorescence data by Benesi- Hildebrand＇s method （double reciprocal plots）. It was noted that 2,6-DM-β-CD exhibited stronger binding ability than other Me-β- CDs. Based on the significant enhancement of fluorescence intensity of inclusion complex, a simple and highly sensitive fluorimetric method is proposed for the determination of ABZ in the presence of 2,6-DM-β-CD. The proposed method was successfully applied to the determination of ABZ in tablets and human urine.

关键词： Methylated-β-cyclodextrins Albendazole Spectrofluorimetry

Application of Et_3NHCl-AlCl_3 Ionic liquid as an Initiator in Cationic Copolymerization of 1, 3-Pentadiene with Styrene

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Chinese Chemical Letters 2006年第1期17卷 117-120页

作者： Yuan Yuan WANG Hui SUN Juan li dong JIANG li Yi DAI Center for the Chemistry of Ionic liquids East China Normal University （E.C.N.U） Shanghai 200062

The random copolymer poly （1, 3-pentadiene-co-styrene） formed through cationic copolymerization using the ~ethylamine hydrochloride and hydrous aluminium chloride （Et3NHCl-AlCl3） room temperature ionic liquid as initiating agent in toluene was analyzed using IR spectra in conjunction with gel permeation chromatography （GPC）. The room temperature ionic liquid was found to have high initiatic activity for copolymerization.

关键词： Et3NHCl-AlCl3 ionic liquid 1 3-pentadiene styrene cationic copolymerization.

Preliminary study of the effects of EVA coupling agents on properties of wood-plastic composites

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Forestry Studies in China 2010年第2期12卷 90-94页

作者： li dong-fang li li li Jian-zhang College of Materials Science and Technology Beijing Forestry University Beijing 100083 P. R. China

As a hot-melt adhesive, ethylene-vinyl-acetate （EVA） has been used in many industrial applications. But studies of the application of EVA in wood-plastic composites （WPC） are relatively few, so we have investigated the proposition of whether EVA is a suitable coupling agent for WPC or not. The results show that EVA with 8% VA is not a suitable coupling agent, because it reduces the mechanical properties of WPC without any significant effect on its physical properties. With an increase in the amount of wood powder, the mechanical properties of WPC decrease and the ability of water absorption of WPC increases.

关键词： wood-plastic composites ethylene-vinyl-acetate coupling agent property

Does hemorrhoidal artery embolization really benefit patients with hemorrhoids?

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World Journal of Gastroenterology 2024年第42期30卷 4569-4575页

作者： Miao-lin Lei li-li dong Hui-Peng Zhang Yan-Bo Yu Department of Gastroenterology Laboratory of Translational GastroenterologyQilu HospitalShandong UniversityJinan 250012Shandong ProvinceChina Department of Gastroenterology Affiliated Qingdao Third People’s HospitalQingdao UniversityQingdao 266001Shandong ProvinceChina

This letter offers commentary on an article published in a recent issue of the World Journal of *** artery embolization is a promising approach to severe hemorrhoidal bleeding treatment,but inappropriate patient selection and the use of different embolization procedures may affect the clinical efficacy and cause serious *** this article,the most appropriate candidate patients,embolization materials,embolization methods,and clinical evaluation methods are discussed to improve the safety and effectiveness of the procedure.

关键词： Hemorrhoidal artery embolization Indications Contraindications Complications Effectiveness