检索结果-南通市图书馆

New Membranes Based on Polybenzimidazole for Polymer Fuel Cells

在线全文

学校读者我要写书评

暂无评论

复旦学报（自然科学版） 2007年第5期46卷 679-页

作者： P.Mustarelli E.Quartarone S Grandi A.Carollo S.Leonardi A.Magistris deparment of physical Chemistry University of Pavia

1 Results Acid-doped polybenzimidazoles[1] are particularly appealing because of high proton conductivity with no or low humidification and promising fuel cells performances. PBI, in fact, contains basic functional groups which can easily interact with strong oxo-acids, such as H3PO4 and H2SO4. The acid partially protonates the polymer and partially is freely dispersed in the polymer backbone, so allowing proton migration via Grotthuss mechanism along the anionic chains[2]. Anyway, a technological limit...

关键词： fuel cells polymer composites PBI

Source of inorganic N affects the cost of growth in a legume tree species(Virgilia divaricata)from the Mediterrean-type Fynbos ecosystem

在线全文

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2016年第6期9卷 752-761页

作者： Anathi Magadlela María A.Pérez-Fernández Aleysia Kleinert Léanne L.Dreyer Alex J.Valentine Botany and Zoology Department University of StellenboschPrivate Bag X1Matieland 7602South Africa deparment of physical Chemical and Natural SystemsUniversidad Pablo de OlavideCarretera de Utrera Km 141013 SevilleSpain

Aims In Mediterranean-type ecosystem,the Cape Fynbos,legumes may be able to switch between soil N and atmospheric N_(2) sources during growth to adjust the carbon costs of N *** study investigated the utilization of different inorganic N sources by Virgilia divaricata,a native legume from the Mediterranean-type ecosystem of the Cape Floristic *** Plants were cultivated in sterile quartz sand,supplied with 25%strength Long Ashton nutrient solution,modified to contain 500μM *** the phosphate level(500μM),plants were treated with 500μM NH_(4)NO_(3)(treatment named N),or grown in N-free nutrient solution and inoculated with effective Burkholderia sp.(Bact.)or treated with combined N sources(500μM NH_(4)NO_(3))and inoculated with effective Burkholderia sp.(N+Bact.).Important Findings The application of NH_(4)NO_(3) to the legumes resulted in a greater increase in plant dry *** construction costs were higher in plants that were supplied with mineral and symbiotic N *** photosynthetic rates per leaf area was maintained,irrespective of the N *** the plant roots were nodulated,the plant dependence on N_(2) fixation decreased with addition of *** and nodules of the plants solely reliant on N_(2) fixation showed an increase in glutamine *** results show that *** is highly adapted for growth at the forest *** and possibly anthropic soils by utilizing both atmospheric and soil N sources.

关键词： phosphate deficiency Virgilia divaricata N_(2)fixation mineral N C construction costs asparagine

Magnetically tunable atom-exchange process involving ultracold weakly bound Feshbach molecules

维普期刊数据库评论

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 China(Physics,Mechanics & Astronomy) 2020年第5期63卷 31-38页

作者： Jue Nan Bo Zhao Hefei National Laboratory for physical Sciences at Microscale and deparment of Modern Physics University of Science and Technology of ChinaHefei 230026China Shanghai Branch CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum PhysicsUniversity of Science and Technology of ChinaShanghai 201315China

Chemical reactions at ultracold temperatures have attracted great interest in recent years. The atom-exchange reaction between an atom and a weakly bound Feshbach molecule near overlapping Feshbach resonances presents a simple and ideal example of the controlled ultracold chemistry. The energy released in the reaction can be tuned to be very small and thus the reaction products can be trapped and detected, allowing the study of state-to-state reaction dynamics. The reaction can be tuned from the exothermic regime to the endothermic regime, which allows to study the threshold behavior of an endothermic reaction. In this paper, we review the recent progress in studying the atom-exchange reaction involving Feshbach molecules in ultracold atomic gases.

关键词： Feshbach molecule atom-exchange process ultracold collision

Nano-Structured Proton Exchange Membrane for Fuel Cell

在线全文

学校读者我要写书评

暂无评论

复旦学报（自然科学版） 2005年第5期44卷 694-696页

作者： Chu Peter P deparment of Chemistry National Centre University Chung-Li Taiwan 32054China

Nano-structured materials are characterized by long range ordering of the nano-dimensioned quantum dot units. They have been found to deliver substantially different (electric, optical, magnetic and physical) properties from that of the bulk. The differences are mainly due to the increases of surface charge with large fraction of grain boundaries, and the periodical potential field created by the ordered nano-domains. Specifically,the issues considered in "nano ionics" are the degree of interaction, the charge distribution on the interfaces where they become obvious in ionic properties and thermodynamics such as mobility of charge carriers. Major efforts in this direction are focused on.

关键词：燃料电池质子交换隔膜纳米结构聚合体锂电池

Towards electrochemical hydrogen storage in liquid organic hydrogen carriers via proton-coupled electron transfers

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2022年第10期31卷 292-300,I0007页

作者： Hamid Ghorbani Shiraz Mikhail Vagin Tero-Petri Ruoko Viktor Gueskine Krzysztof Karon Mieczystaw tapkowski Tobias Abrahamsson Thomas Ederth Magnus Berggren Xavier Crispin Laboratory of Organic Electronics Department of Science and Technology(ITN)Linkoping UniversitySE-60174 NorrkopingSweden Smart Photonic Materials Facuty of Engineering and Natural SciencesTampere UniversiyPBox 541.Tampere Fl-33101Finland Silesian University of Technology.Faculty of Chemistry Deparment of Physical Chemistry and Technology of PolymersM.Strzody 9.44-100 GliwicePoland dDepartment of Physics Chemistry and Biology(IFM)Linkoping UniversiySE-58183 LinkopingSweden

Green hydrogen is identified as one of the prime clean energy carriers due to its high energy density and a zero emission of CO_(2).A possible solution for the transport of H_(2)in a safe and low-cost way is in the form of liquid organic hydrogen carriers(LOHCs).As an alternative to loading LOHC with H_(2)via a two-step procedure involving preliminary electrolytic production of H_(2)and subsequent chemical hydrogenation of the LOHC,we explore here the possibility of electrochemical hydrogen storage(EHS)via conversion of proton of a proton donor into a hydrogen atom involved in covalent bonds with the LOHC(R)via a protoncoupled electron transfer(PCET)reaction:2nH^(+)+2ne^(-)+Rox■n H_(2)^(0)*** chose 9-fluorenone/fluorenol(Fnone/Fnol)conversion as such a model PCET *** electrochemical activation of Fnone via two sequential electron transfers was monitored with in-situ and operando spectroscopies in absence and in presence of different alcohols as proton donors of different reactivity,which enabled us to both quantify and get the mechanistic insight on *** possibility of hydrogen extraction from the loaded carrier molecule was illustrated by chemical activation.

关键词： Proton-coupled electron transfer Electrochemical hydrogen storage Hydrogen bonding agent Anion-radical Comproportionation

Features and clinical nursing of heart failure in elderly patients during perioperative period

在线全文

学校读者我要写书评

暂无评论

South China Journal of Cardiology 2010年第2期11卷 104-108页

作者：韩翔黄志锋 deparment of surgery Sanzao Hospital China deparment of Burns surgery Guangdong Academy Medical Sciences Guangdong General Hospital

Heart failure is a common condition in elderly *** further population aging,incidence of heart failure is constantly *** heart failure occurs in this group of patients,clinical symptoms may vary vastly,rendering difficulty for the treatment process and leading to poor efficacy and *** gain better under-standing on clinical symptoms and signs of heart failure in elderly patients,to provide prevention and treatment against heart failure for elderly patients in terms of nursing care and to improve success rate of salvage treatment as well as nurs-ing *** Retrospective analysis was performed in 141 patients with heart failure who were treated in our hospital during January 2005 and December *** aged > 60 years were assigned to elderly group while those aged physical and laboratory *** Clinical symptoms and signs of heart failure tended to be a-typical in elderly *** including cough,sputum,increased heart rate and mental disorder were frequent, and a substantial proportion of patients had pulmonary congestion and *** Prevention and specific nursing measures should be aggressively taken based on the features of heart failure in elderly *** of in-spection particularly observation on atypical symptoms should be increased to provide intensive monitoring.

关键词： heart failure elderly patients nursing

Comparative investigation of the resistance and ability to trigger high voltage discharge for single and multiple femtosecond filaments in air

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第3期22卷 372-374页

作者：郭凯敏郝作强林景全孙长凯高勋赵振明 School of Science Changchun University of Science and Technology School of physical Science and Technology Baotou Teachers College

A comparative investigation of the resistance and ability to trigger high voltage（HV） discharge for a single filament（SF） and multiple filaments（MFs） has been carried *** experimental results show that the trend of the breakdown threshold of the SF exactly follows that of its resistance,but this is not the case for the *** MF＇s resistance is much smaller than the SF＇***,the MF shows a slightly higher HV breakdown threshold than the *** underlying physics is that the measured resistance of the MF is collectively contributed by every filament in the MF while the HV breakdown threshold is determined by only one single discharging path.

关键词： femtosecond filament resistance high voltage breakdown threshold

Band gap engineered polymeric-inorganic nanocomposite catalysts:Synthesis, isothermal stability, photocatalytic activity and photovoltaic performance

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2017年第6期33卷 547-557页

作者： Umair Baig M.A.Gondal A.M.Ilyas M.M.Sanagi Laser Research Group Physics Department & Center of Excellence in Nanotechnology King Fahd University of Petroleum and Minerals Center of Excellence for Scientific Research Collaboration with MIT King Fahd University of Petroleum and Minerals deparment of Chemistry Faculty of Science Universiti Technologi Malaysia

Polymeric-inorganic nanocomposite catalysts were synthesized by facile one-pot chemical polymerization of pyrrole in the presence of titanium dioxide nanoparticles. The electrical, optical, photovoltaic performance of dye sensitized solar cell（DSSC） and visible light driven photocatalytic activities of the nanocomposite were investigated. The prepared nanocomposite displays excellent photo-activity, attaining 100% degradation of methyl orange dye in 60 min under visible light source while 55% for pure TiO_2 under similar experimental conditions. The photovoltaic performance of the polypyrrole-titanium dioxide（PPy-TiO_2） nanocomposite has a 51.4% improvement with a photo-conversion efficiency of 8.07% as compared to pure TiO_2 based DSSC. By comparing the physical mixture of the PPy-TiO_2 nanocomposite and pristine TiO_2, the enhanced activity of the PPy-TiO_2 nanocomposite can be attributed to the reduced charge transfer resistance, outstanding electrical conductance of the PPy, the nano-sized structure of TiO_2 and their synergetic effect. Furthermore, the PPy-TiO_2 nanocomposite shows excellent electrical conductivity and isothermal stability under ambient conditions below 110？C.

关键词： Nanocomposite Electrical conductivity Isothermal stability Visible light active Photo-degradation

Electrical Load Forecasting Using Fuzzy System

在线全文

学校读者我要写书评

暂无评论

Journal of Computer and Communications 2019年第9期7卷 27-37页

作者： Mahir Faysal Md. Jahirul Islam Md. Mohiuddin Murad Md. Imdadul Islam M. Ruhul Amin Department of Electronics and Communications Engineering East West University Dhaka Bangladesh Department of Computer Science and Engineering Jahangirnagar University Savar Bangladesh deparment of Mathematical and physical Sciences East West University Dhaka Bangladesh

To cope with the demand and supply of electrical load of an interconnected power system of a country, we need to forecast its demand in advance. In this paper, we use a fuzzy system to forecast electrical load on short-term basis. Here, we consider temperature, humidity, seasons of a year and time segments of a day as the parameters, which govern the demand of electrical load. For each of the parameter, we use several membership functions (MFs) and then apply the Mamdani rule on MFs and the output is determined by using the centroid method. Finally, the surface plot reveals the real scenario of the load demand. The difference between actual load and the output of the fuzzy system is found as +1.65% to -13.76%. The concept of the paper can be applied in interconnected power system of Bangladesh to reduce power loss, especially when generation is higher than the demand.

关键词： Defuzzification Fuzzy Inference Centroid Method Surface Plot APE