检索结果-南通市图书馆

Dynamic simulation and parametric influence analysis on thermal performance of a quartz tube solid particle receiver in solar tower power plants

在线全文

学校读者我要写书评

暂无评论

Particuology 2023年第8期79卷 161-171页

作者： Qiang Yu xueyan li Yihui Yang Zihao li Fuliang Nie College of Information and Electrical Engineering China Agricultural UniversityBeijing100083China Institute of Electrical Engineering Chinese Academy of SciencesBeijing100190China

Due to a higher operating temperature(≥800 ℃),Solar Particle Receiver(SPR)which uses particles as the working medium is considered as one of best candidates to improve the thermoelectric conversion efficiency of concentrating solar power *** this paper,a quartz tube solid particle receiver model is fully developed by using the discretized lumped parameter method,in which the calculation process of particle temperature and thermal loss is clearly *** order to improve the manipulation level of particle receiver during the operation,the dynamic characteristics of the quartz tube particle receiver are comprehensively studied by the disturbance test of selected input ***,in order to grasp the influence rule of key parameters on the thermal performance of particle receiver,the key parameters'sensitivity analysis is also deeply *** results show that the particle outlet temperature can reach as high as 810 ℃ under a relatively small value of solar flux 600 kW/m^(2),but the receiver efficiency is only about 75%;Besides,the receiver efficiency shows a variation tendency that it rises first falls afterwards with the increase of incident solar *** validity of proposed model is verified by a heating experi-mental system with a single quartz tube,and the relative error is not more than 7.9%.The research results are beneficial for understanding the dynamic characteristics and designing the particle receiver.

关键词： Solar thermal power plant Solid particle receiver Quartz tube Discretized lumped method Sensitivity analysis

Bifunctional 3D n-doped porous carbon materials derived from paper towel for oxygen reduction reaction and supercapacitor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science Bulletin 2018年第10期63卷 621-628页

作者： Xinyu Gao xueyan li Zhuang Kong Guozheng Xiao Ying Zhu Key Laboratory of Bio-inspired Smart Interracial Science and Technology of Ministry of Education School of Chemistry Beihang University. Belting 100191. China Beijing Advanced Innovation Center for Biomedical Engineering Beihang University. Beijing 100191 China

Designing and fabricating cheap and active bifunctional materials is crucial for the development of renewable energy *** this article,three-dimensional nitrogen-doped porous carbon materials(NDPC-X,in which X represents the pyrolysis temperature) were fabricated by simultaneous carbonization and activation of polypyrrole-coated paper towel protected by a silica layer followed by acid *** material had a high specific surface area(1,123.40 m^2/g).The as-obtained NDPC-900 displayed outstanding activity as a catalyst for the oxygen reduction reaction(ORR) as well as an electrode with a high specific capacitance in a supercapacitor in an alkaline *** NDPC-900 catalyst for the ORR exhibited a more positive reduction peak potential of à0.068 V(***|HgCl^2) than that of Pt/C(-0.121 V),as well as better cycling stability and stronger methanol ***,the NDPC-900 had a high specific capacitance of 379.50 F/g at a current density of 1 A/g,with a retention rate of 94.5% after 10,000 cycles in 6 mol/L KOH electrolyte when used as an electrode in a *** these results were attributed to the effect of a large surface area,which provided electrochemically active *** work introduces an effective way to use biomass-derived materials for the synthesis of promising bifunctional carbon material for electrochemical energy conversion and storage devices.

关键词： Paper towel Nitrogen-doped carbon Oxygen reduction reaction Supercapacitor

Synthesis of Bisboronic Acids and Their Selective Recognition of Sialyl Lewis X Antigen

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2018年第3期34卷 415-422页

作者： WANG Yan'en li xueyan CHEN Hua ZHU Mengyuan li Xiaoliu Key Laboratory of Chemical Biology of Hebei Province College of Chemistry and Environmental Science Hebei University Baoding 071002 P. R. China College of Science Agricultural University of Hebei Baoding 071001 19. R. China Department of Chemistry and Center for Diagnostics and Therapeutics Georgia State University Atlanta GA 30303 USA

The development of sensors that recognize Lewis oligosaccharides can help the diagnosis and early detection of cancer. Herein, we reported the design and synthesis of a series of anthracene-based bisboronic acids （9a-9e） with different N-substituents near the boronic acid unit. Among them, compound 9a could recognize sialyl Lewis X（sLex） with selectivity over other Lewis sugars, and could significantly stain sLeX-expressing HEPG2 cells with selectivity over the range of 0.1-10 μmol/L. Compound 9a possibly has two properly positioned boronic acids caused by the steric hindrance by the near N-benzyl substituent group, which empower its sLe^x selectivity and higher binding affinity.

关键词： Lewis sugar Bisboronic acid Anthracene-based fluorescent probe Biochemical recognition

Investigating the failure mechanism of solid electrolyte interphase in silicon particles from an electrochemical-mechanical coupling perspective

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advanced Powder Materials

Advanced Powder Materials 2024年第4期3卷 27-35页

作者： Junjie Ding xueyan li lili Gong Peng Tan Department of Thermal Science and Energy Engineering University of Science and Technology of China(USTC)Hefei230026China State Key Laboratory of Fire Science University of Science and Technology of China(USTC)Hefei230026China

Silicon is considered one of the most promising anode materials owing to its high theoretical energy density,however,the volume expansion/contraction during electrochemical lithiation/delithiation cycles leads to instability of the solid electrolyte interphase(SEI),which ultimately results in capacity ***,the local stress and deformation evolution status of an SEI layer on an anode particle are investigated through a quantitative electrochemical-mechanical *** impacts of structural uniformity,mechanical strength,and operating conditions on the stability of the SEI layer are investigated in *** simulation results demonstrate that when the silicon particle radius decreases from 800 nm to 600 and 400 nm,the failure time increases by 29%and 65%,respectively,of the original failure time;When the structural defect depth ratio is reduced from 0.6 to 0.4 and 0.2,the failure time increases by 72%and 132%,respectively;For the discharge rate,the condition at 0.1 C has 34%and 139%longer time to failure than that at 0.2 C and 0.3 C,*** work provides insight into the rational design of stable SEI layers and sheds light on possible methods for constructing silicon-based lithium-ion batteries with longer cycling lives.

关键词： Solid electrolyte interface Silicon electrode Structural failure lithium-ion battery Modeling and simulation

Comparison of UV and UV-LED activated sodium percarbonate for the degradation of O-desmethylvenlafaxine

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2023年第4期126卷 656-667页

作者： Jing Deng Anhong Cai Xiao ling Qian Sun Tianxin Zhu Qingsong li xueyan li Weizhu Chen College of Civil Engineering Zhejiang University of TechnologyHangzhou 310023China Affilicated Zhejiang Hospital Zhejiang University School of MedicineHangzhou 310013China Water Resources and Environmental Institute Xiamen University of TechnologyXiamen 361005China School of Environmental Science and Engineering Suzhou University of Science and TechnologySuzhou 215009China Third Institute of Oceanography Ministry of Natural ResourceXiamen 361005China

As an active metabolite of venlafaxine and emerging antidepressant,Odesmethylvenlafaxine(ODVEN) was widely detected in different water bodies,which caused potential harm to human health and environmental *** this study,the comparative work on the ODVEN degradation by UV(254 nm) and UV-LED(275 nm) activated sodium percarbonate(SPC) systems was systematically *** higher removal rate of ODVEN can be achieved under UV-LED direct photolysis(14.99%) than UV direct photolysis(4.57%) due to the higher values of photolysis coefficient at the wavelength *** synergistic effects were observed in the UV/SPC(80.38%) and UV-LED/SPC(53.57%) systems and the former exhibited better performance for the elimination of *** degradation of ODVEN all followed the pseudo-first-order kinetics well in these processes,and the pseudo-first-order rate constant(kobs) increased with increasing SPC *** quenching experiments demonstrated that both ·OH and CO_(3)·-were involved in the degradation of ODVEN and the second-order rate constant of ODVEN with CO_(3)·-(1.58 × 10^(8)(mol/L)-1sec-1) was reported for the first time based on competitive kinetic *** introduction of HA,Cl-,NO_(3)-and HCO_(3)-inhibited the ODVEN degradation to varying degrees in the both *** to quantum chemical calculation,radical addition at the ortho-position of the phenolic hydroxyl group was confirmed to be the main reaction pathways for the oxidation of ODVEN by·*** addition,the oxidation of ODVEN may involve the demethylation,H-abstraction,OH^(-)addition and C-N bond ***,the UV-LED/SPC process was considered to be more cost-effective compared to the UV/SPC process,although the UV/SPC process possessed a higher removal rate of ODVEN.

关键词： Advanced oxidation processes Sodium percarbonate Quantum chemical calculation Degradation pathways Electrical energy per order

Catalytic[3+3]Annulation ofβ-Ketoethers and Cyclopropenones via C(sp^(3))-O/C-C Bond Cleavage under Transition-Metal Free Conditions

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2021年第10期39卷 2769-2773页

作者： Dachang Bai Junyan Chen Bingbing Zheng xueyan li Junbiao Chang NMPA Key Laboratory for Research and Evaluation of Innovative Drug Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine ChemicalsSchool of Chemistry and Chemical EngineeringHenan Normal UniversityXinxiangHenan453007 China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

Main observation and conclusion The efficient cleavage of carbon-oxygen(C—O)bond is highly important for the transformation of oxygen-rich biomass and industry ***,an efficient[3+3]annulation ofβ-ketoethers with cyclopropenones in the presence of catalytic base has been developed,which proceeds through the C(sp^(3))—O bonds cleavage inβ-ketoethers and C—C bond cleavage in cyclopropenones under transition-metal free *** cleavage of C(sp^(3))—O bonds in alkyl alkyl ethers and aryl alkyl ethers was *** reaction featured excellent functional group compatibility and chemoselectivity,affording various 2-pyrones in good to excellent yields under mild conditions and simple operation.

关键词： C-O/C-C activation [3+3]Annulation β-Ketoethers Cyclopropenones Transition-metal free conditions

The parallel biosynthesis routes of hyperoside from naringenin in Hypericum monogynum

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Horticulture Research 2023年第9期10卷 247-259页

作者： Yingying Wang Zhirong Cui Qianqian li Shuai Zhang Yongyi li xueyan li lingyi Kong Jun Luo Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines Department of Traditional Chinese PharmacyChina Pharmaceutical UniversityNanjing 210009China

Hyperoside is a bioactive flavonoid galactoside in both medicinal and edible *** plays an important physiological role in the growth of flower ***,the hyperoside biosynthesis pathway has not been systematically elucidated in plants,including its original source,*** group found abundant hyperoside in the flower buds of Hypericum monogynum,and we sequenced its transcriptome to study the biosynthetic mechanism of *** gene screening and functional verification,four kinds of key enzymes were ***,HmF3Hs(flavanone 3-hydroxylases)and HmFLSs(flavonol synthases)could catalyze flavanones into dihydroflavonols,as well as catalyzing dihydroflavonols into *** could also convert flavanones into flavonols and flavones with varying ***3′H(flavonoid 3′-hydroxylase)was found to act broadly on 4′-hydroxyl flavonoids to produce 3′,4′-diydroxylated flavanones,dihydroflavonols,flavonols,and ***(flavonoid 3-O-galactosyltransferase)would transform flavonols into the corresponding 3-O-galactosides,including *** parallel hyperoside biosynthesis routes were thus depicted,one of which was successfully reconstructed in Escherichia coli BL21(DE3)by feeding naringenin,resulting in a hyperoside yield of 25 mg/***,this research not only helped us understand the interior catalytic mechanism of hyperoside in *** concerning flower development and bioactivity,but also provided valuable insights into these enzyme families.

关键词： interior concerning hyper

Inversion of ocean-bottom seismometer(OBS) waveforms for oceanic crust structure: a synthetic study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Science 2016年第4期29卷 203-213页

作者： xueyan li Yanbin Wang Yongshun John Chen Department of Geophysics School of Earth and Space SciencesPeking University

The waveform inversion method is applied-- using synthetic ocean-bottom seismometer （OBS） data--to study oceanic crust structure. A niching genetic algorithm （NGA） is used to implement the inversion for the thickness and P-wave velocity of each layer, and to update the model by minimizing the objective function, which consists of the misfit and cross-correlation of observed and synthetic waveforms. The influence of specific NGA method parameters is discussed, and suitable values are presented. The NGA method works well for various observation systems, such as those with irregular and sparse distribu- tion of receivers as well as single receiver systems. A strategy is proposed to accelerate the convergence rate by a factor of five with no increase in computational complex- ity; this is achieved using a first inversion with several generations to impose a restriction on the preset range of each parameter and then conducting a second inversion with the new range. Despite the successes of this method, its usage is limited. A shallow water layer is not favored because the direct wave in water will suppress the useful reflection signals from the crust. A more precise calculation of the air-gun source signal should be considered in order to better simulate waveforms generated in realistic situa- tions; further studies are required to investigate this issue.

关键词： Waveform inversion OBS Oceanic crustalstructure Niching genetic algorithm

Data error propagation in stacked bioclimatic envelope models

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2024年第2期19卷 262-276页

作者： xueyan li Babak NAIMI Peng GONG Miguel B.ARAÚJO Guangdong Provincial Key Laboratory of Remote Sensing and Geographical Information System Guangdong Open Laboratory of Geospatial Information Technology and ApplicationGuangzhou Institute of GeographyGuangdong Academy of ScienceGuangzhouChina ‘Rui Nabeiro’Biodiversity Chair CHANGE-MED InstituteUniversity ofÉvoraÉvoraPortugal Department of Geography and Department of Earth Sciences University of Hong KongHong KongChina Department of Biogeography and Global Change National Museum of Natural SciencesCSICMadridSpain

Stacking is the process of overlaying inferred species potential distributions for multiple species based on outputs of bioclimatic envelope models(BEMs).The approach can be used to investigate patterns and processes of species *** data limitations on individual species distributions are inevitable,but how do they affect inferences of patterns and processes of species richness?We investigate the influence of different data sources on estimated species richness gradients in *** fitted BEMs using species distributions data for 334 bird species obtained from(1)global range maps,(2)regional checklists,(3)museum records and surveys,and(4)citizen science data using presence-only(Mahalanobis distance),presence-background(MAXENT),and presence–absence(GAM and BRT)*** species predictions were stacked to generate species richness ***,we show that different data sources and BEMs can generate spatially varying gradients of species *** environmental predictors that best explained species distributions also differed between data *** using citizen-based data had the highest accuracy,whereas those using range data had the lowest *** richness patterns estimated by GAM and BRT models were robust to data *** multiple data sets exist for the same region and taxa,we advise that explicit treatments of uncertainty,such as sensitivity analyses of the input data,should be conducted during the process of modeling.

关键词： richness patterns species distribution stacked bioclimatic envelope models uncertainty