检索结果-南通市图书馆

Comparison of room-temperature multiferroics in Bi_4Fe_2TiO_(12) film and bulk

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2008年第6期15卷 782-785页

作者： jun Lu Lijie qiao Wuyang Chu Department of Materials Physics School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

It was reported that both dielectricity and magnetism at room temperature were appreciably improved in Bi4Fe2TiO12 film compared with Bi4Fe2TiO12 bulk. X-ray diffraction profiles reveal similar crystalline nature and random orientation of the two, but X-ray photoelectron spectroscopy （XPS） experiments indicate that it is 1.4 eV lower binding energy of core-state Ols in the film relative to that of the bulk, so the improvement of multiferroics in the film is attributed to oxygen vacancies and high fraction of interface. The results have promising applications in multifunctional integrated devices.

关键词： multiferroic film X-ray photoelectron spectroscopy (XPS) oxygen vacancy magnetism dielectric property

Upper bounds on vertex distinguishing chromatic index of some Halin graphs

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2012年第3期27卷 329-334页

作者： ZHU jun-qiao BU Yue-hua Xingzhi College Zhejiang Normal UniversityJinhua 321004China College of Mathematics Physics and Information EngineeringZhejiang Normal UniversityJinhua 321004China

A vertex distinguishing edge coloring of a graph G is a proper edge coloring of G such that any pair of vertices has the distinct sets of colors. The minimum number of colors required for a vertex distinguishing edge coloring of a graph C is denoted by Xs＇8（G）. In this paper, we obtained upper bounds on the vertex distinguishing chromatic index of 3-regular Halin graphs and Halin graphs with △（G） ≥ 4, respectively.

关键词： vertex distinguishing edge coloring Halin graph upper bound planar graph.

Dendritic and spherical crystal reinforced metallic glass matrix composites

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2013年第4期20卷 386-392页

作者： jun-wei qiao Yong Zhang Hui-jun Yang Sheng-bo Sang Laboratory of Applied Physics and Mechanics of Advanced Materials College of Materials Science and Engineering Taiyuan University of Technology Key Laboratory of Interface Science and Engineering in Advanced Materials (Ministry of Education) Taiyuan University of Technology State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing MicroNano System Research Center Taiyuan University of Technology

Zr-based bulk metallic glass matrix composites （BMGMCs） with a composition of Zr60.0Ti14.7Nb5.3Cu5.6Ni4.4- Be10.0 （at%） were fabricated by an innovative process, i.e., semisolid processing plus Bridgman solidification. Different morphologies, distributions, and volume fractions of the crystalline phases can be achieved by tailoring the withdrawal velocity. The largest fi-acture strain of Zr60.0Ti14.7Nb5.3Cu5.6Ni4.4Be10.0 （at%） composites with the withdrawal velocity of 1.0 mm/s was found to be 16.7%. The mechanism of plasticity improvement is mainly attributed to the interpenetrated structure of the crystalline phase, which greatly confines the rapid propagation of shear bands.

关键词： metallic glass composite materials mechanical properties plastic deformation

OPTIMAL RESERVE PRICE IN STATIC AND DYNAMIC SPONSORED SEARCH AUCTIONS

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science and Systems Engineering 2013年第4期22卷 440-456页

作者： Wei YANG jun qiao Youyi FENG Baichun XIAO College of Management College of Marketing and Logistics Management Nanjing University of Finance and Economics Zaragoza Logistics Center

Sponsored search advertising is a significant revenue source for search engines. To ameliorate revenues, search engines often set fixed or variable reserve price to in influence advertisers＇ bidding. This paper studies the optimal reserve price for a generalized second-price auction （GSP） under both static and dynamic settings. We show that if advertisers＇ per-click value has an increasing generalized failure rate, the search engine＇s revenue rate is quasi-concave and hence there exists an optimal reserve price under both settings. Different from a static GSP auction where the optimal reserve price is proved to be constant, in a dynamic setting the optimal reserve price is dependent on not only advertisers＇ per-click values, but also the number of ad links sold. A search engine should gradually raise reserve price as more qualified advertisers arrive, and maintain the same threshold after all first-page positions are occupied.

关键词： Sponsored search advertising symmetric Nash equilibrium generalized failure rate generalized second-price auction reserve price

Statistical analysis on strain-rate effects during serrations in a Zr-based bulk metallic glass

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2017年第4期24卷 455-461页

作者： Bo Yuan Jiao-jiao Li jun-wei qiao College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024ShanxiChina Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024ShanxiChina

By means of statistical analysis,the deformation mechanisms taking place in elastic loading and plastic shearing stages during serrated flows on the stress-strain curves for bulk metallic glasses were studied *** serration number presented a linear increasing tendency with the decrease of applied strain rates due to the reduction of free *** excellent plastic deformation was illustrated from the influences of structure arrangement with activation *** using mean-field theory（MFT）,maximum elastic-energy density at different strain rates could be predicted by MFT besides maximum stress drops during *** results were helpful for understanding the serrated flow behavior or designing decent schemes to improve the plasticity of bulk metallic glasses at room temperature.

关键词： Bulk metallic glass Shear band Mean-field theory Serration

Twinning induced remarkable strain hardening in a novel Fe_(50)Mn_(20)Cr_(20)Ni_(10) medium entropy alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2021年第11期28卷 1463-1470页

作者： Ming-jie Qin Xi Jin Min Zhang Hui-jun Yang jun-wei qiao College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024ShanxiChina Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024ShanxiChina State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

The microstructures and tension properties of Fe_(50)Mn_(20)Cr_(20)Ni_(10) medium entropy alloy(MEA)were investigated,which was produced by vacuum induction melting and subsequently was homogenized at 1200 C for 6 *** characterization shows the single-phase solid solution with face-centered cubic structure by means of transmission electron microscopy and scanning electron microscopy combined with energy disperse *** Fe-MEA has an ultimate tensile strength of 550±10 MPa and a high strain hardening exponent,n,of 0.41 as well as a higher ductility(60%)than those of CrMnFeCoNi *** single-phase solid solution deforms plastically via dislocations and *** boundaries associated with deformation twinning impede dislocation motion,enhancing the strain hardening *** article focuses on the insights into the concept of Fe-MEAs and provides a potential direction for the future development of high entropy alloys and MEAs.

关键词： Medium entropy alloy Alloy design Labusch model Twinning induced plasticity Strain hardening

Alice-Bob Peakon Systems

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

Chinese Physics Letters 2017年第6期34卷 1-4页

作者： Sen-Yue Lou Zhi-jun qiao Center for Nonlinear Science and Department of Physics Ningbo University Ningbo 315211 Shanghai Key Laboratory of Trustworthy Computing East China Normal University Shanghai 200062 School of Mathematical and Statistical Science University of Texas TX 78539 USA

We study the Alice-Bob peakon system generated from an integrable peakon system using the strategy of the so- called Alice-Bob non-local KdV approach [Scientific Reports 7 （2017） 869]. Nonlocal integrable peakon equ... 详细信息

关键词： ABP Alice-Bob Peakon Systems

同方期刊数据库

Deformation behavior and plastic instability of boronized Al0.25CoCrFeNi high-entropy alloys

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2020年第10期27卷 1363-1370页

作者： Jin-xiong Hou Jing Fan Hui-jun Yang Zhong Wang jun-wei qiao College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Interface Science and Engineering in Advanced Materials(Ministry of Education Taiyuan University of TechnologyTaiyuan 030024China

Using thermochemical treatments,boronized layers were successfully prepared on Al0.25CoCrFeNi high-entropy alloys(HEAs).The thickness of the boronized layers ranged widely from 20 to 50μm,depending on the heat treatment *** remarkably improved the surface hardness from HV 188 to HV 1265 after treating at 900°C for 9 ***,boronizing enhanced the yield strength of HEAs from 195 to 265 MPa but deteriorated the tensile *** crackings in the boride layers significantly decreased the *** insufficient work-hardening capacity essentially facilitated the plastic instability of the boronized *** decreasing substrate thickness,the fracture modes gradually transformed from dimples to quasi-cleavage and eventually to cleavage.

关键词： boronizing high-entropy alloys boride layers tensile strength cleavage fracture

Bioremediation of highly contaminated oilfield soil： Bioaugmentation for enhancing aromatic compounds removal

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2014年第2期8卷 293-304页

作者： jun qiao Chengdong ZHANG Shuiming LUO Wei CHEN College of Environmental Science and Engineering Nankai University Tianjin 300071 China College of-Chemistry and Environmental Engineering shanxi Datong University~Datong 03'7009 China Tianjin Key Laboratory of Environmental l~emediation and Pollution Control -Tianjin 300071 China Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria Tianjin 300071 China

This study evaluated the effectiveness of different amendments--including a commercial NPK fertilizer, a humic substance （HS）, an organic industrial waste （NovoGro）, and a yeast-bacteria consortium--in the remediation of highly contaminated （up to 6% of total petroleum hydrocarbons） oilfield soils. The concentrations of hydrocarbon, soil toxicity, physicochemical properties of the soil, microbial population numbers, enzyme activities and microbial community structures were examined during the 90-d incubation. The results showed that the greatest degradation of total petroleum hydro- carbons （TPH） was observed with the biostimulation using mixture of NPK, HS and NovoGro, a treatment scheme that enhanced both dehydrogenase and lipase activities in soil. Introduction of exogenous hydrocarbon-degrading bacteria （in addition to biostimulation with NPK, HS and NovoGro） had negligible effect on the removal of TPH, which was likely due to the competition between exogenous and autochthonous microorganisms. None- theless, the addition of exogenous yeast-bacteria consor- tium significantly enhanced the removal of the aromatic fraction of the petroleum hydrocarbons, thus detoxifying the soil. The effect of bioaugmentation on the removal of more recalcitrant petroleum hydrocarbon fraction was likely due to the synergistic effect of bacteria and fungi.

关键词： bioremediation petroleum hydrocarbon bios- timulation bioaugmentation