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Thermodynamic Assessment and Experimental Investigation of Fe-Al-C System

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Journal of Materials Science & Technology 2008年第5期24卷 771-774页

作者： Weiyan LU lin li li WANG Yanlin HE Shuigen HUANG School of Mat＇erial Science and Engineering Shanghai University Shanghai 200072 China Technology Center Steel Products Institute Baosteel Shenyang 201900 China MTM Katholieke Universiteit Leuven Heverlee B-3001 Belgium

Phase diagram information of the Fe-C, Fe-Al and Al-C systems are reviewed and the Fe-Al-C system is assessed. A FeAlC database is created by combining a set of thermodynamic parameters established by Kumar and ssOL database in Thermo-Calc software package. Ternary phase diagrams are calculated with FeAIC and the newly developed Thermo-Calc databases ssOL2 and ssOL4. The FeAIC database is the best one to describe the Fe-Al-C system. Al and A3 values on the vertical section containing 1.5 wt pct AI are calculated with the FeAIC database in this work. To validate the thermodynamic calculation, critical temperatures Ac1 and Ac3 are determined by using dilatometer analysis. There exist some errors between the calculated values and the experimental results. So further optimization of the Fe-Al-C system regarding bcc and fcc phases is necessary. The experimental data in this work could be of some value in further optimization.

关键词： Fe-Al-C Phase diagram TRIP steel

The decline process and major pathways of Microcystis bloom in Taihu Lake, China

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Chinese Journal of Oceanology and limnology 2012年第1期30卷 37-46页

作者： WANG Zhicong li Guowen li Genbao li Dunhai Institute of Hydrobiology Chinese Academy of SciencesWuhan 430072China Graduate University of Chinese Academy of Sciences Beijing 100049China

Eutrophication has become a serious concern in many lakes, resulting in cyanobacterial blooms. However, the mechanism and pathways of cyanobacteria decline are less understood. To identify and define the growth and decline of Microcystis blooms in Taihu Lake of China, and to illuminate the destination of surface floating blooms, we investigated the biomass distribution and variations in colony size, morphology, and floating velocity from October 2008 to September 2009. The results showed that the Microcystis bloom declined in response to biomass decrease, colony disaggregation, buoyancy reduction, and increased phytoplankton biodiversity, and these indicative parameters could be applied for recognition of the development phases of the bloom. Three major decline pathways were proposed to describe the bloom decline process, colony disaggregation （Pathway I）, colony settlement （Pathway II）, and cell lysis in colonies （Pathway III）. We proposed a strategy to define the occurrence and decline of Microcystis blooms, to evaluate the survival state under different stress conditions, and to indicate the efficiency of controlling countermeasures against algal blooms.

关键词： Microcystis blooms decline pathways morphological changes biomass distribution Taihu Lake

Preparation of graphene oxide/natural rubber composites by latex co-coagulation: Relationship between microstructure and reinforcement

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Chinese Journal of Chemical Engineering 2020年第4期28卷 1187-1193页

作者： Yingyan Mao ChaoWang li liu Beijing Institute of Ophthalmology Beijing Tongren Eye CenterBeijing Tongren HospitalCapital Medical UniversityBeijing 100730China National Engineering Research Center for Ophthalmology Beijing Tongren HospitalCapital Medical UniversityBeijing 100730China Beijing Special Equipment Inspection&Testing Center Beijing 100029China Beijing Engineering Research Center of Advanced Elastomers Beijing University of Chemical TechnologyBeijing 100029China

Graphene oxide(GO)has recently attracted substantial interest as a possible reinforcing agent for next generation rubber composite *** this research,GO was incorporated in natural rubber(NR)composites through latex co-coagulation *** microstructures of GO/NR composites were characterized through a combination of transmission electron microscope,scanning electron microscope,X-ray diffraction,Fourier transform infrared spectroscopy,and Differential scanning *** results showed that highly exfoliated GO sheets were finely dispersed into NR rubber matrix with strong interface interaction between GO and *** mechanical properties of the GO/NR composites were further *** results showed that the tensile strength,tear strength and modulus can be significantly improved at a content of less than 2 ***,GO exhibited specific reinforce mechanism in NR due to the stress-induced crystallization effects of *** stress transfer from the NR to the GO sheets and the hindrance of GO sheets to the stress-induced crystallization of NR were further displayed in stress-strain behavior of GO/NR *** enhanced properties were attributed to the high surface area of GO sheets and highly exfoliated microstructures of GO sheets in NR.

关键词： Graphene oxide Natural rubber Microstructure Stress-strain behavior Composites

Effect of temperature on electric-thermal properties of semiconductive shielding layer and insulation layer for high-voltage cable

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High Voltage 2021年第5期6卷 805-812页

作者： Yanhui Wei Mingyue liu Xuejing li Guochang li Naiyi li Chuncheng Hao Qingquan Lei Institute of Advanced Electrical Materials Qingdao University of Science and TechnologyQingdaoChina State Grid Zhejiang Electric Power Co. LtdResearch InstituteHangzhouChina

A semi‐conductive shielding layer plays an important role in the uniform electric field for a high‐voltage *** electric‐thermal properties of the semi‐conductive layer and insulation layer directly affect the overall insulation performance of the *** physicochemical performances of semi‐conductive composites are firstly analysed ***,electric‐thermal properties of the semi‐conductive layer and insulation layer are *** experimental results show that the thermal conductivity of the commercial semi‐conductive layer is about twice that of the insulation layer,owing to the effect of carbon *** thermal expansion coefficient of the insulation layer rises from 1.86×10^(−4)/K at 25℃ to 3.20×10^(−4)/K at 90℃.By contrast,the semi‐conductive layer begins to slowly decline at a certain temperature,and decreases signif-icantly to 2.25×10^(−4)/K at 80℃,owing to the effect of ethylene‐vinyl acetate copolymer(EVA).The electrical experiments show that the resistivity of semi‐conductive composite gradually rises with an increase in temperature,and gradually declines with an increase in the carbon black *** dc breakdown strength of the composite structure of the semi‐conductive layer/insulation layer decreases significantly with an increase in tem-perature,decreasing from 307 kV/mm at 25℃ to 203 kV/mm at 90℃.At four typical temperatures,the breakdown strength reaches the maximum value when the carbon black content is 25 *** is about 15%and 19%higher than carbon black contents of 20 and 30 *** findings have reference significance for high‐voltage cable breakdown fault analysis and material selection in cable design.

关键词： composite insulation composites

Review of PPP-RTK:achievements,challenges,and opportunities

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Satellite Navigation 2022年第3期3卷 16-37,I0002页

作者： Xingxing li Jiaxin Huang Xin li Zhiheng Shen Junjie Han linyang li Bo Wang School of Geodesy and Geomatics Wuhan University129 Luoyu RoadWuhan430079HubeiChina Technische Universitat Berlin(TUB) Straße Des 17.Juni10623BerlinGermany China Railway Siyuan Survey and Design Group Co. Ltd.WuhanChina

The PPP–RTK method,which combines the concepts of Precise of Point Positioning(PPP)and Real-Time Kinematic(RTK),is proposed to provide a centimeter-accuracy positioning service for an unlimited number of ***,the PPP–RTK technique is becoming a promising tool for emerging applications such as autonomous vehicles and unmanned logistics as it has several advantages including high precision,full flexibility,and good *** paper gives a detailed review of PPP–RTK focusing on its implementation methods,recent achievements as well as challenges and ***,the fundamental approach to implement PPP–RTK is described and an overview of the research on key techniques,such as Uncalibrated Phase Delay(UPD)estimation,precise atmospheric correction retrieval and modeling,and fast PPP ambiguity resolution,is ***,the recent efforts and progress are addressed,such as improving the performance of PPP–RTK by combining multi-GNss and multi-frequency observations,single-frequency PPP–RTK for low-cost devices,and PPP–RTK for vehicle ***,the system construction and applications based on the PPP–RTK method are ***,the main issues that impact PPP–RTK performance are highlighted,including signal occlusion in complex urban areas and atmosphere modeling in extreme weather *** new opportunities brought by the rapid development of low-cost markets,multiple sensors,and new-generation Low Earth Orbit(LEO)navigation constellation are also ***,the paper concludes with some comments and the prospects for future research.

关键词： PPP–RTK Ambiguity resolution Multi-GNss Smart device Multi-sensor fusion

An efficient ionic liquid supported divergent assembly of 3,6-branched glucosamine-containing pentasaccharide

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Chinese Chemical Letters 2014年第12期25卷 1525-1530页

作者： Ze-Shen Gao Sheng Sun Wei li Qing Ma Qing li Zhong-Jun li The State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking University

We utilized the glycosyl acceptor tagging method with ionic liquid support for synthesis of the core segment of Clostridium botulinum C2 toxin ligand through a divergent synthetic strategy without chromatographic *** total yield was 57.1% and the reaction was completed in 10 *** efficient ionic liquid supported glycosylation and purification procedure was applied for the synthesis of branched glucosamine-containing oligosaccharides for the first time,which expanded the scope of ionic liquid supported synthesis of biologically important oligosaccharides.

关键词： Ionic liquid Oligosaccharide Rapid assembling

Responses of Ammonia-Oxidizing Bacteria and Archaea in Two Agricultural Soils to Nitrification Inhibitors DCD and DMPP: A Pot Experiment

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Pedosphere 2013年第6期23卷 729-739页

作者： GONG Ping ZHANG li-li WU Zhi-Jie CHEN Zhen-Hua CHEN li-Jun Institute of Applied Ecology Chinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of Forest and Soil Ecology Institute of Applied EcologyChinese Academy of Sciences

Taking two important agricultural soils with different pH, brown soil （Hap-Udic Luvisol） and cinnamon soil （Hap-Ustic Luvisol）, from Northeast China, a pot culture experiment with spring maize （Zea mays L.） was conducted to study the dynamic changes in the abundance and diversity of soil ammonia-oxidizing bacteria （AOB） and ammonia-oxidizing archaea （AOA） populations during maize growth period in response to the additions of nitrification inhibitors dicyandiamide （DCD） and 3,4-dimethylpyrazole phosphate （DMPP） by the methods of real-time polymerase chain reaction （PCR） assay, PCR-denaturing gradient gel electrophoresis （DGGE）, and construction of clone library targeting the amoA gene. Four treatments were established, i.e., no urea （control）, urea, urea plus DCD, and urea plus DMPP. Both DCD and DMPP inhibited growth of AOB significantly, compared to applying urea alone. Soil bacterial amoA gene copies had a significant positive linear correlation with soil nitrate content, but soil archaeal amoA gene copies did not. In both soils, all AOB sequences fell within Nitrosospira or Nitrosospira-like groups, and all AOA sequences belonged to group 1.1b crenaxchaea. With the application of DCD or DMPP, community composition of AOB and AOA in the two soils had less change except that the AOB community composition in Hap-Udic Luvisol changed at the last two growth stages of maize under the application of DCD. AOB rather than AOA likely dominated soil ammonia oxidation in these two agricultural soils.

关键词： ammonium clone library denaturing gradient gel electrophoresis nitrate real-time polymerase chain reaction

An intricate regulation of Wbl A controlling production of silent tylosin analogues and abolishment of expressible nikkomycin

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Science China(life Sciences) 2023年第3期66卷 612-625页

作者： Yue li Hanye Guan Jingjing li Jihui Zhang Yanyan Wang Jine li Huarong Tan State Key Laboratory of Microbial Resources Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China

Genome sequencing has revealed that actinomycetes possess the potential to produce many more secondary metabolites than previously *** existing challenge is to devise efficient methods to activate these silent biosynthetic gene clusters(BGCs).In Streptomyces ansochromogenes,disruption of wbl A,a pleiotropic regulatory gene,activated the expression of cryptic tylosin analogues and abolished nikkomycin production *** pathway-specific regulatory genes tylR1 and tylR2 can also trigger the biosynthesis of silent tylosin analogues,in which TylR1 exerted its function via enhancing tylR2 *** one-hybrid system experiments unveiled that Wbl A directly inhibits the transcription of tylR1 and tylR2 to result in the silence of tylosin analogues ***,Wbl A can activate the nikkomycin production through up-regulating the transcription of pleiotropic regulatory gene adp *** interestingly,Adp A can activate san G(an activator gene in nikkomycin BGC)but repress wbl *** studies provide a valuable insight into the complex functions of pleiotropic regulators.

关键词： Streptomyces ansochromogenes silent gene cluster wblA tylosin analogues pleiotropic regulatory gene secondary metabolite biosynthesis

A positive feedback circuit for ROP-mediated polar growth

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Molecular Plant 2021年第3期14卷 395-410页

作者： En li Yu-ling Zhang Xuelian Shi Han li Xuefeng Yuan Sha li Yan Zhang State Key Laboratory of Crop Biology College of Life SciencesShandong Agricultural UniversityTai'an 271018China Shandong Province Key Laboratory of Agricultural Microbiology College of Plant ProtectionShandong Agricultural UniversityTai'an 271018China

Tip growth is a special type of polarized growth in which a single and unique polarization site is established and *** of Plants(ROP)proteins,which represent the only class of Rho GTPases in plants,regulate tip *** dynamic and asymmetric distribution of ROPs is critical for the establishment and maintenance of tip growth,and requires at least one positive feedback loop,which is still ***,we report a positive feedback circuit essential for tip growth of root hairs,in which ROPs,ROP activators and effectors,and AGC1.5 subfamily kinases are interconnected by sequential oligomerization and ***1.5 subfamily kinases interact with and phosphorylate two guanine nucleotide exchange factors(GEFs)of ROPs,RopGEF4 and *** also interact with two ROP effectors,ICR2/RIP3 and MIDD1/RIP4,which bridge active ROPs with *** loss of the AGC1.5 subfamily kinases or ICR2 and MIDD1 compromised root hair growth due to reduced ROP *** found that asymmetric targeting of RopGEF4 and RopGEF10 is controlled by AGC1.5-dependent ***,we discovered that the ROP effectors recruit AGC1.5 to active ROP domains at the plasma membrane during root hair growth and are critical for AGC1.5-dependent phosphorylation of *** the large number of AGC kinases in plants,this positive feedback circuit may be a universal theme for plant cell polar growth.

关键词： Rho GTPases AGC kinase membrane recruitment phosphorylation asymmetric growth