检索结果-南通市图书馆

journal of Materials Science & Technology 2021年第20期79卷 171-177页

作者： j.Tang j.l.xu Z.G.Ye X.B.li j.M.luo School of Materials Science and Engineering Nanchang Hangkong UniversityNanchang330063China

Developing efficient,stable and economical electrocatalyst for oxygen evolution reaction(OER)is a significant pathway to produce clean energy from water ***,the promising and highly efficient porous CoCrFeNiMo high entropy alloys(HEAs)were prepared by microwave sintering using Mg space *** to unique properties of high entropy alloys and abundant active surface area,the porous CoCrFeNiMo-20 Mg exhibits excellent catalytic performance and prominent electrochemical stability with a low overpotential of 220 mV to reach current density of 10 mA cm^(-2),a small Tafel slope of 59.0 mV dec^(-1) and long-term durability for 24 h in 1.0 M *** results of microstructure and element states indicate that crystal defects,porous structure and villous hydroxides are the reasons for high OER performance of the *** work not only provides a new way to prepare electrocatalysts,but also proves the important application of high entropy alloys in functional materials.

关键词： CoCrFeNiMo High entropy alloys Electrocatalysts Oxygen evolution reaction Microwave sintering Mg space holder

Si-Al COATING ON PURE MOlYBDENUM SUBSTRATE AND ITS CYClIC OXIDATION BEHAVIOR

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English letters) 2004年第5期17卷 672-676页

作者： F.S.liu j.l.xu C.G.Zhou S.K.Gong H.B.xu SchoolofMaterialsScienceandEngineering BeijingUniversityofAeronauticsandAstronauticsBeijing100083China

The halide-activated pack cementation method is utilized to codeposit aluminum and silicon on Mo substrate. Emphasis is placed on the microstructure and elevated-temperature oxidation resistance of coatings. The results show that hexagonal Mo(Si, Al)2 as a main phase and a little amount of the lower disilicide Mo5Si3 was formed on Mo substrate through the halide-activated pack cementation method. The resultant Si-Al coating on Mo substrate exhibits excellent cyclic oxidation resistance. The excellent cyclic oxidation resistance of the coatings is attributed to the formation of alumina on the coatings during the oxidation.

关键词： Mo(Si Al)2 coating co-deposition cyclic oxidation resistance

Novel medium entropy perovskite oxide Sr(FeCoNiMo)_(1/4)O_(3−δ)for zinc-air battery cathode

在线全文

学校读者我要写书评

暂无评论

journal of Energy Chemistry 2024年第9期96卷 669-678页

作者： Kaixin li juntao Gao xu Han Qi Shao Zhe lü School of Physics Harbin Institute of TechnologyHarbin 150001HeilongjiangChina Heilongjiang Provincial Key laboratory of Advanced Quantum Functional Materials and Sensor Components Harbin 150001HeilongjiangChina

It is widely recognized that the development of ZABs is impeded by the kinetic bottleneck of oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).The application of conformational entropy strategy to oxides often involves introducing multiple elements with different properties,thereby providing outstanding bifunctional catalytic activity for OER/***,the possible underlying catalytic pathways and potential interactions between various components are still poorly *** paper presents an excellent medium-entropy perovskite oxide,Sr(FeCoNiMo)_(1/4)O_(3−δ)(lower overpotential of 301 mV at 10 mA cm^(−2)).Zinc-air batteries employing it as a cathode catalyst demonstrate excellent round-trip efficiency(62%).By combining theoretical calculation with experiments,we aim to establish the link between the electronic structure of perovskite oxides with different elemental compositions and their OER *** reveals that the conformational entropy strategy can simultaneously shift the O 2p-band center and metal d-band center of perovskite oxide towards the vicinity of the Fermi energy level,thereby triggering a more favorable lattice oxygen-participated mechanism(lOM)during the OER *** outcomes of this work provide crucial insights into the role of conformational entropy strategies in oxygen catalysis and offer potential avenues for constructing efficient and stable electrocatalysts.

关键词： Sr(FeCoNiMo)_(1/4)O_(3−δ) Bifunctional catalyst Medium entropy lOM Rechargeable zinc-air batteries

Strengthening method and glycosylated plant stalk the feasibility of hydrogen production

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

Strengthening method and glycosylated plant stalk the feasib...

Dissociation cross sections ofψ(3770),ψ(4040),ψ(4160),andψ(4415)mesons with nucleons

第九届全国氢能学术会议

作者： j.l.xu,X.Y.Wu,Y.F.li Shanghai University of Engineering Science,China

＜正＞Energy for the survival of mankind,the prosperity and social development is *** present the main human use of coal and oil and other fossil fuels as a primary energy,energy reserves faced on the one hand and lim...

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第4期76卷 93-112页

作者： Ruo-Qing Ding Xiao-Ming xu H j Weber Department of Physics Shanghai UniversityBaoshanShanghai 200444China Department of Physics University of VirginiaCharlottesvilleVA 22904United States of America

We study the dissociation of ψ(3770), ψ(4040), ψ(4160), and ψ(4415) mesons in collision with nucleons, which takes place in high-energy proton-nucleus collisions. The quark interchange between a nucleon and a ■ meson leads to the dissociation of the ■ meson. We consider the reactions:■, and■, where R stands for ψ(3770), ψ(4040), ψ(4160), or ψ(4415). A reaction of a neutron and a ■ meson corresponds to a reaction of a proton and the ■ meson by replacing the up quark with the down quark and vice versa. Transition-amplitude formulas are derived from the S-matrix *** cross sections are calculated with the transition amplitudes for scattering in the prior form and in the post form. The cross sections relate to nodes in the radial wave functions of ψ(3770), ψ(4040), ψ(4160), and ψ(4415) mesons.

关键词： inelastic nucleon-charmonium scattering quark interchange relativistic constituent quark potential model

Riverine sulfate sources and behaviors in arid environment,Northwest China:Constraints from sulfur and oxygen isotopes

在线全文

学校读者我要写书评

暂无评论

journal of Environmental Sciences 2024年第3期137卷 716-731页

作者： Yifu xu Wenjing liu Bing xu Zhifang xu Key laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

The fate of riverine sulfate ion (SO_(4)^(2-)) and its environmental effects in arid environment are difficult to evaluate due to its complicated sources and strongly coupled behaviors with water cycle which is significantly modified by *** understand the sulfur cycle in aquatic systems in arid environment,the chemical and sulfur and oxygen isotopic compositions (δ^(34)S_(SO4)and δ^(18)O_(SO4)) of major rivers around the Badain jaran Desert,northwestern China,were *** rivers had averaged SO_(4)^(2-)content at 1336μmol/l,over 10times higher than the global *** δ^(34)S_(SO4)and δ^(18)O_(SO4)values ranged from-5.3‰to+11.8‰and+1.6‰to+12.8‰,*** end-member analysis and the inverse model showed that riverine sulfate was mainly derived from evaporites dissolution (0-87%),sulfide oxidation (13%-100%) and precipitation (0-33%),indicating heterogeneity in sulfur sources and behaviors along the river drainage with the lithology variations and climate *** isotopic tools combining with hydro-chemistry compositions could be applied to reveal sulfur cycle in arid *** on the calculation,sulfide oxidation plays the primary role in the headwater and upstream in the Qilian-Mountains area,where sulfide is widely *** the proportion of evaporites dissolution contributing to riverine sulfate is much higher in downstream in a drier ***,less precipitation and higher temperature can lead to more intensive evaporation,affecting the process of sulfide oxidation and enhancing the rates of evaporites dissolution and sulfate precipitation in the basin.

关键词： Sulfur and oxygen isotopes Source apportionment Inverse model Arid environment Inland rivers Northwestern China

Boosting oxygen reduction activity and CO_(2) resistance on bismuth ferrite-based perovskite cathode for low-temperature solid oxide fuel cells below 600℃

在线全文

学校读者我要写书评

暂无评论

journal of Energy Chemistry 2024年第3期90卷 600-609,I0013页

作者： juntao Gao Zhiyun Wei Mengke Yuan Zhe Wang Zhe lü Qiang li lingling xu Bo Wei School of Physics Harbin Institute of TechnologyHarbin 150001HeilongjiangChina Key laboratory of Functional Inorganic Material Chemistry Ministry of EducationSchool of Chemistry and Materials ScienceHeilongjiang UniversityHarbin 150080HeilongjiangChina School of Physics and Electronic Engineering Harbin Normal UniversityHarbin 150025HeilongjiangChina

Developing efficient and stable cathodes for low-temperature solid oxide fuel cells(lT-SOFCs) is of great importance for the practical ***,we propose a series of Sm-modified Bi_(0.7-x)Sm_xSr_(0.3)FeO_(3-δ) perovskites as highly-active catalysts for *** doping can significantly enhance the electrocata lytic activity and chemical stability of *** 600℃,Bi_(0.675)Sm_(0.025)Sr_(0.3)FeO_(3-δ)(BSSF25) cathode has been found to be the optimum composition with a polarization resistance of 0.098 Ω cm^2,which is only around 22.8% of Bi_(0.7)Sr_(0.3)FeO_(3-δ)(BSF).A full cell utilizing BSSF25 displays an exceptional output density of 790 mW cm^(-2),which can operate continuously over100 h without obvious *** remarkable electrochemical performance observed can be attributed to the improved O_(2) transport kinetics,superior surface oxygen adsorption capacity,as well as O_(2)p band centers in close proximity to the Fermi ***,larger average bonding energy(ABE) and the presence of highly acidic Bi,Sm,and Fe ions restrict the adsorption of CO_(2) on the cathode surface,resulting in excellent CO_(2) *** work provides valuable guidance for systematic design of efficient and durable catalysts for lT-SOFCs.

关键词： low-temperature solid oxide fuel cell Perovskite cathode DFT calculations CO_(2) tolerance

Tomographic reconstruction of the Earth’s magnetosheath from multiple spacecraft:a theoretical study

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 204-214页

作者： A.M.jorgensen TianRan Sun Y.Huang l.li R.xu l.Dai Chi Wang New Mexico Institute of Mining and Technology SocorroNMUSA National Space Science Center Chinese Academy of SciencesBeijing 100190China Tsinghua University Beijing 100084China

Following our earlier work on tomographic reconstruction of the magnetosheath soft X-ray emissions with superposed epoch analysis of many images recorded from a single spacecraft we now explore the instantaneous reconstruction of the magnetosheath and magnetopause using a few images recorded simultaneously from a few *** work is motivated by the prospect of possibly having two or three soft X-ray imagers in space in the coming years,and that many phenomena which occur at the magnetopause boundary,such as reconnection events and pressure pulse responses,do not lend themselves as well to superposed epoch *** the reconstruction is successful-which we demonstrate in this paper that it can be-this collection of imagers can be used to reconstruct the magnetosheath and magnetopause from a single image from each spacecraft,allowing for high time resolution *** this paper we explore the reconstruction using,two,three,and four *** show that the location of the subsolar point of the magnetopause can be determined with just two satellites,and that volume emissions of soft X-rays,and the shape of the boundary,can be reconstructed using three or more satellites.

关键词： magnetosheath tomography soft X-ray imaging SMIlE

Evaluation of the Oxidation Reactivity and Behavior of Exhaust Soot Particles from Diesel Engines with Different Emission levels

在线全文

学校读者我要写书评

暂无评论

China Petroleum Processing & Petrochemical Technology 2024年第2期26卷 72-80页

作者： Wang Yajun lin lei Xing jianqiang lüxu Yang He Song Haiqing SINOPEC Research Institute of Petroleum Processing Co. Ltd.Beijing 100083China State Key laboratory of Engines Tianjin UniversityTianjin 300072China

The aim of this study was to investigate the oxidation reactivity and behavior of exhaust particulate matter(PM)from diesel *** samples from two diesel engines(1K,CY4102)with different emission levels were collected by a thermophoretic system and a quartz *** oxidation reactivity,oxidation behaviors,and physicochemical properties of the PM samples were analyzed using thermogravimetric analysis(TGA),high-resolution transmission electron microscopy(HRTEM),Fourier-transform infrared spectrometry(FTIR),and Raman *** results showed that there was a great difference in the oxidation reactivity of soot particles emitted by the two different diesel engines.A qualitative analysis of the factors influencing oxidation reactivity showed that the nanostructure,degree of graphitization,and relative concentration of aliphatic C—H functional groups were the most important factors,whereas no significant correlation was found between the primary particle size and activation energy of the diesel *** on the oxidation behavior analysis,the diesel soot particles exhibited both internal and surface oxidation modes during the oxidation *** oxidation was dominant during the initial stage,and as oxidation progressed,the mode gradually changed to internal *** oxidation mode of soot particles from the 1K engine was significantly higher than that of CY4102.

关键词： diesel engine soot particles oxidation reactivity oxidation behavior

A synthesis of the Cretaceous wildfire record related to atmospheric oxygen levels?

在线全文

学校读者我要写书评

暂无评论

journal of Palaeogeography 2024年第1期13卷 149-164页

作者： Da-Wei lü Wen-xu Du Zhi-Hui Zhang Yuan Gao Tian-Tian Wang jin-Cheng xu Ao-Cong Zhang Cheng-Shan Wang Shandong Provincial Key laboratory of Depositional Mineralization and Sedimentary Minerals College of Earth Sciences and EngineeringShandong University of Science and TechnologyQingdao 266590Shandong ProvinceChina School of Earth Sciences and Resources China University of GeosciencesBejing 100083China Institute of Earth Sciences China University of Geosciences(Bejing)Beijing 100083China

The Cretaceous was a significant greenhouse period in Earth's history with higher atmospheric CO_(2) levels and temperatures than today. Although evidence of combustion has been widely described from the Cretaceous deposits, our understanding of the spatiotemporal diversification pattern and process of the Cretaceous wildfires is still limited. In this study, we comprehensively synthesize a total of 271 published Cretaceous wildfire occurrences based on the by-products of burning, including fossil charcoal, pyrogenic inertinite(fossil charcoal in coal), and pyrogenic polycyclic aromatic hydrocarbons(PAHs). Spatially, the dataset shows a distinctive distribution of reported wildfire evidence characterized by high concentration in the middle latitudinal areas of the Northern Hemisphere(30°N-60°N) over the Cretaceous. Temporally, an overall increasing trend of the reported wildfire data from the Early Cretaceous to the late Cretaceous is coincident with higher atmospheric O_(2) levels. However, the spatial and temporal patterns may result from many types of factors, such as taphonomy, preservation, and researcher biases, instead of a real picture of the Cretaceous wildfire evolution. To better understand the spatiotemporal diversification of the Cretaceous wildfire, more investigations on the record of wildfire occurrences during this period would be necessary in the future.

关键词： Wildfire Cretaceous Atmospheric oxygen Taphonomy Charcoal