检索结果-南通市图书馆

Effects of bimetallic catalysts on synthesis of nitrogen-doped carbon nanotubes as nanoscale energetic materials

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2011年第5期9卷 465-470页

作者： Hao Liu Yong Zhang Ruying Li Xueliang Sun Hakima Abou-Rachid Department of Mechanical and Materials Engineering University of Western Ontario London ON N6A 5B9 Canada Defense Research ＆ Development Canada 2459 Boulevard PieXI Nord Quebec QC G3J IX5 Canada

Well aligned nitrogen-doped carbon nanotubes （CNx-NTs）, as energetic materials, are synthesized on a silicon substrate by aerosol-assisted chemical vapor deposition, Tungsten （W） and molybdenum （Mo） metals are respectively introduced to combine with iron （Fe） to act as a bimetallic co-catalyst layer. Cor- relations between the composition and shape of the co-catalyst and morphology, size, growth rate and nitrogen doping amount of the synthesized CNx-NTs are investigated by secondary and backscattered electron imaging in a field emission scanning electron microscope （FESEM） and X-ray photoelectron spectrometer （XPS）. Compared to pure iron catalyst, W-Fe co-catalyst can result in lower growth rate, larger diameter and wider size distribution of the CNx-NTs; while incorporation of molybdenum into the iron catalyst layer can reduce the diameter and size distribution of the nanotubes. Compared to the sole iron catalyst, Fe-W catalyst impedes nitrogen doping while Fe-Mo catalyst promotes the incorporation of nitrogen into the nanotubes. The present work indicates that CNx-NTs with modulated size, growth rate and nitrogen doping concentration are expected to be synthesized by tuning the size and composition of co-catalysts, which may find great potential in producing CNx-NTs with controlled structure and properties,

关键词： Nitrogen doped carbon nanotubes Chemical vapor deposition Bimetallic catalyst

Insights into enhanced electrochemiluminescence of a multiresonance thermally activated delayed fluorescence molecule

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

SmartMat 2023年第2期4卷 106-119页

作者： Liuqing Yang Lihui Dong David Hall Mahdi Hesari Yoann Olivier Eli Zysman‐Colman Zhifeng Ding Department of Chemistry Western UniversityOntarioLondonCanada Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology School of Chemistry and Chemical EngineeringGuangxi UniversityNanningChina Organic Semiconductor Centre EaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeUK Laboratory for Chemistry of Novel Materials University of MonsMonsBelgium Laboratory for Computational Modeling of Functional Materials Namur Institute of Structured MatterUniversity of NamurNamurBelgium

The electrochemiluminescence(ECL)behavior of a multiresonance thermally activated delayed fluorescence molecule has been investigated for the first time by means of ECL‐voltage curves,newly designed ECL‐time observatory,and ECL *** compound,Mes3DiKTa,shows complex ECL behavior,including a delayed onset time of 5 ms for ECL generation in both the annihilation pathway and the coreactant route,which we attribute to organic long‐persistent ECL(OLECL).Triplet‐triplet annihilation,thermally activated delayed fluorescence and uncompensated solution resistance cannot be ruled out as contributing mechanisms to the ECL.A very long ECL emission decay was attributed to OLECL as *** absolute ECL efficiencies of Mes3DiKTa were enhanced and reached 0.0013%in annihilation route and 1.1%for the coreactant system,which are superior to those of most other organic ECL *** is plausible that ECL materials with comparable behavior as Mes3DiKTa are desirable in applications such as ECL sensing,imaging,and light‐emitting devices.

关键词： electrochemiluminescence multiresonant thermally activated delayed fluorescence organic long‐persistent electrochemiluminescence triplet‐triplet annihilation

Recent Advances in Graphene Quantum Dots as Bioimaging Probes

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 Analysis and Testing 2018年第1期2卷 45-60页

作者： Ruizhong Zhang Zhifeng Ding Department of Chemistry The University of Western Ontario1151 Richmond StreetLondonON N6A 5B7Canada

The emerging graphene quantum dots(GQDs)have gained tremendous attention for their enormous potential in biological applications,owing to their unique and tunable photoluminescence properties,exceptional physicochemical features,high biocompatibility,small sizes and low *** mini review aims to update the latest results in rapidly evolving bioimaging research and to provide critical insights into exciting future *** firstly provide a brief review of their synthesis and optical properties and then place emphasis on both in vitro and in vivo imaging applications.

关键词： Graphene quantum dots Photoluminescence Bioimaging probe In vitro imaging In vivo imaging

All-Solid-State Lithium Metal Batteries with Sulfide Electrolytes:Understanding Interfacial Ion and Electron Transport

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Accounts of Materials Research 2022年第1期3卷 21-32页

作者： Changhong Wang Keegan Adair Xueliang Sun Department of Mechanical&Materials Engineering University of Western OntarioLondonON N6A 5B9Canada

CONSPECTUS:With the ever-growing demand for high energy density and high safety of energy storage technologies,all-solid-state lithium metal batteries(ASSLMBs)including all-solid-state lithium ion batteries(ASSLIBs)and all-solid-state lithium−sulfur batteries(ASSLSBs)have received considerable attention in recent *** realize ASSLMBs,various solid-state electrolytes have been rapidly *** them,sulfide electrolytes(SEs)demonstrate the highest ionic conductivity(>10 mS·cm−1)and the most favorable mechanical ***,the commercialization of SE-based ASSLMBs has been stymied by sluggish interfacial ion and electron transport kinetics,which arises from the detrimental interfacial reactions,poor interfacial solid−solid contact,and lithium dendrite *** overcome the interfacial challenges,an insightful understanding of the complex interfacial ion and electron transport processes in SE-based ASSLMBs is of the foremost *** most of the previous review papers underscored the interfacial challenges and summarized the corresponding strategies,a fundamental understanding of the interfacial ions and electron-transport kinetics in SE-based ASSLMBs has not yet been *** Account therefore primarily summarizes our recent understanding of SE-based ASSLMBs from the perspectives of interfacial ion and electron transport,aiming to provide an insightful understanding of interfacial *** first compare various solid-state electrolytes including SEs,oxide electrolytes,halide electrolytes,polymer electrolytes,borohydride electrolytes in terms of their ionic conductivity,electrochemical stability windows,and mechanical properties,aiming to justify the advantages of SEs in ***,the interfacial challenges at both cathode and anode interfaces of SE-based ASSLIBs and SE-based ASSLSBs are presented,*** interfacial challenges significantly hinder the interfacial ion and electron *** boost the interfacial c

关键词： lithium kinetics summarized

Recent advances and strategies in the stabilization of single-atom catalysts for electrochemical applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Carbon Energy 2020年第4期2卷 488-520页

作者： Junjie Li Lei Zhang Kieran Doyle-Davis Ruying Li Xueliang Sun Department of Mechanical and Materials Engineering University of Western OntarioLondonOntarioCanada

Owing to the rapidly increasing consumption of fossil fuels,finding clean and reliable new energy sources is of the utmost ***,developing highly efficient and low-cost catalysts for electrochemical reactions in energy conversion devices is ***-atom catalysts(SACs)with maximum metal atom utilization efficiency and superior catalytic performance have attracted significant attention,especially for electrochemical ***,because of the highly unsaturated coordination environment,the stability of SACs can be a challenge for practical *** this review,we will summarize the strategies to increase the stability of SACs and synthesizing stable SACs,as well as the application of SACs in electrochemical ***,we offer a perspective on the development of advanced SACs through rational design and a deeper understanding of SACs with the help of in situ or operando techniques in electrochemical reactions.

关键词： electrochemical reaction single-atom catalyst stability

Utilizing the full capacity of carbon black as anode for Na-ion batteries via solvent co-intercalation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2017年第12期10卷 4378-4387页

作者： Wei Xiao Qian Sun Jian Liu Biwei Xiao Per-Anders Glans Jun Li Ruying Li Jinghua Guo Wanli Yang Tsun-Kong Sham Xueliang Sun Department of Mechanical & Materials Engineering University of Western Ontario London Ontario N6ASB9 Canada Department of Chemistry University of Western Ontario London Ontario N6ASB7 Canada Advanced Light Source Lawrence Berkeley National Laboratory Berkeley California 94720 USA

Carbonaceous materials have long been considered promising anode materials for Na-ion batteries. However, the electrochemical performance of conventional carbon anodes is generally poor because the sodium ion storage solely relies on the disordered region of the carbon materials in a carbonate-based electrolyte. The solvent co-intercalation mechanism for Na ions has been recently reported in natural graphite anodes for Na-ion batteries with ether-based electrolytes, but their capacities are still unsatisfactory. We show here for the first time that by combining regular Na ion storage in the disordered carbon layer and solvent co-intercalation mechanism in the graphitized layer of a commercial N330 carbon black as an anode material for Na-ion batteries in ether-based electrolyte, the reversible capacity could be fully realized and doubled in magnitude. This unique sodium intercalation process resulted in a significantly improved electrochemical performance for the N330 electrode with an initial reversible capacity of 234 mAh.g-1 at 50 mA.g-1 and a superior rate capability of 105 mAh.g-1 at 3,200 mA-g-1. When cycled at 3,200 mA.g-1 over 2,000 cycles, the electrode still exhibited a highly reversible capacity of 72 mAh.g-1 with a negligible capacity loss per cycle （0.0167%）. Additionally, surface-sensitive C K-edge X-ray absorption spectroscopy, with the assistance of electrochemical and physicochemical characterizations, helped in identifying the controlled formation and evolution of a thin and robust solid electrolyte interphase film. This film not only reduced the resistance for sodium ion diffusion, but also maintained the structural stability of the electrode for extended cycle reversibility. The superior electrochemical performance of N330 carbon black strongly demonstrated the potential of applying ether-based electrolytes for a wide range of carbon anodes apart from natural graphite.

关键词： carbon black anode sodium-ion batteries ether-based electrolyte co-intercalation

Single atom catalyst by atomic layer deposition technique

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Catalysis 2017年第9期38卷 1508-1514页

作者： Niancai Cheng Xueliang(Andy) Sun Department of Mechanical and Materials Engineering University of Western Ontario London ON N6A 5B9 Canada College of Materials Science and Engineering Fuzhou University Fuzhou 350108 Fujian China

Noble single‐atom catalysts have rapidly been attracting attention due to their unique catalytic properties and maximized *** layer deposition(ALD)is an emerging powerful technique for large‐scale synthesis of stable single *** this review,we summarize recent developments of single atom synthesized by ALD as well as explore future research direction and trends.

关键词： Single‐atom Atomic layer deposition Catalysis Noble catalyst Mechanism

Estimating and Mapping Extreme Ice Accretion Hazard and Load Due to Freezing Rain at Canadian Sites

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Disaster Risk Science 2023年第1期14卷 127-142页

作者： Chao Sheng Qian Tang H.P.Hong Department of Civil and Environmental Engineering University of Western OntarioLondonOntarioN6A 5B9Canada

The ice accretion load in Canadian structural design codes is developed based on an operational ice accretion prediction *** the present study,three models are employed to predict the ice accretion amount on a flat surface and horizontal wire at Canadian *** results confirm that the model used by Canadian practice for predicting ice accretion leads to a conservative estimate as compared to the remaining two *** results also indicate that the use of the Gumbel distribution for the annual maximum ice accretion is adequate for regions prone to ice accretion and that the lognormal distribution may be considered for regions with a moderate or negligible amount of ice *** of the ice accretion hazard at five selected Canadian sites are *** analysis of an equivalent wind speed that is concurrent with the iced wire is carried out,showing that the concurrent wind speed for the 50-year return period value of the annual maximum ice accretion amount is smaller than the 50-year return period value of the annual maximum wind *** is shown that the statistical characteristics of the annual maximum concurrent wind speed on iced wire differ from that of the annual maximum wind speed.

关键词： Canada Concurrent wind speed Hazard mapping Ice accretion Probabilistic analysis

Sitagliptin in patients with non-alcoholic steatohepatitis: A randomized, placebo-controlled trial

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2017年第1期23卷 141-150页

作者： Tisha R Joy Charles A McKenzie Rommel G Tirona Kelly Summers Shannon Seney Subrata Chakrabarti Neel Malhotra Melanie D Beaton Department of Medicine Division of EndocrinologySt.Joseph’s HospitalWestern University Department of Medical Biophysics Western University Department of Physiology and Pharmacology Western University Department of Microbiology and Immunology Western University Department of Pathology and Laboratory Medicine Western University Department of Medicine Division of GastroenterologyLondon Health Sciences CentreWestern University

AIMTo evaluate the effect of sitagliptin vs placebo on histologic and non-histologic parameters of non-alcoholic steatohepatitis (NASH).METHODSTwelve patients with biopsy-proven NASH were randomized to sitagliptin (100 mg daily) (n = 6) or placebo (n = 6) for 24 wk. The primary outcome was improvement in liver fibrosis after 24 wk. Secondary outcomes included evaluation of changes in NAFLD activity score (NAS), individual components of NAS (hepatocyte ballooning, lobular inflammation, and steatosis), glycemic control and insulin resistance [including measurements of glycated hemoglobin (HbA1C) and adipocytokines], lipid profile including free fatty acids, adipose distribution measured using magnetic resonance imaging (MRI), and thrombosis markers (platelet aggregation and plasminogen activator inhibitor 1 levels). We also sought to determine the correlation between changes in hepatic fat fraction (%) [as measured using the Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation (IDEAL) MRI technique] and changes in hepatic steatosis on liver *** was not significantly better than placebo at reducing liver fibrosis score as measured on liver biopsy (mean difference between sitagliptin and placebo arms, 0.40, P = 0.82). There were no significant improvements evident with the use of sitagliptin vs placebo for the secondary histologic outcomes of NAS total score as well as for the individual components of NAS. Compared to baseline, those patients who received sitagliptin demonstrated improved HbA1C (6.7% ± 0.4% vs 7.9% ± 1.0%, P = 0.02), and trended towards improved adiponectin levels (4.7 ± 3.5 μg/mL vs 3.9 ± 2.7 μg/mL, P = 0.06) and triglyceride levels (1.26 ± 0.43 mmol/L vs 2.80 ± 1.64 mmol/L, P = 0.08). However, when compared with placebo, sitagliptin did not cause a statistically significant improvement in HbA1C (mean difference, -0.7%, P = 0.19) n

关键词： Sitagliptin Randomized controlled trial Non-alcoholic fatty liver disease Non-alcoholic steatohepatitis Fibrosis Magnetic resonance imaging Hepatic steatosis Insulin resistance Platelet aggregation