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FURTHER EXTENSIONS OF SOME TRUNCATED HECKE TYPE IDENTITIES

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Acta Mathematica Scientia 2022年第1期42卷 73-90页

作者： Helen w.j.ZHANG School of Mathematics Hunan UniversityChangsha 410082China

The main purpose of this paper is to generalize the study of the Hecke-Rogers type series,which are the extensions of truncated theorems obtained by Andrews,Merca,wang and *** proofs rely heavily on the theory of Bail... 详细信息

关键词： theta functions truncated series Bailey pair Bailey transform

One-step multi-compositional oxidation of YSi alloy:Experiments and ab initio computation

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journal of Materials Science & Technology 2023年第27期158卷 253-262页

作者： w.j.wang j.C.Luo L.Chen G.j.Yang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China Xi’an jiaotong University Suzhou Institute Suzhou 215123China

YSi alloy is a promising candidate as oxidation resistant coatings for both the bond coat of environmental barrier coatings(EBCs)and anti-ablation coatings at a high temperature of∼1300℃.In this study,a one-step multi-compositional oxidation by rapid heating oxidation mode is proposed to reduce the oxidation rate by 3.6 times compared to conventional slow heating oxidation *** show that preferentially formed Y_(2)O_(3) oxide initiates a multi-step oxidation,produces a cracking and porous oxides,and thereby resulting in a fast oxidation with *** one-step multi-compositional oxidation with a compact and dense Y_(2)Si_(2)O_(7)scale contributes to the much better oxidation resistance for rapid heating oxidation mode of YSi *** stable formation of Y_(2)Si_(2)O_(7)scale is comprehensively understood by the energy barrier,charge density and electronic level based on density functional *** study demonstrates a promising application of YSi alloy by rapid heating oxidation mode.

关键词： YSi alloy One-step oxidation Multi-compositional scale Y_(2)Si_(2)O_(7) Energy barrier

Did natural fission of^(235)U in the earth lead to formation of the supercontinent Columbia?

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Geoscience Frontiers 2012年第4期3卷 369-374页

作者： john j.w.Rogers Department of Geological Sciences University of North Carolina at Chapel HillChapel HillNC 27599-3315USA

Steady decline in the percentage of 235U in terrestrial uranium made natural fission impos- sible after about 1.8 Ga. Fission before 1.8 Ga disturbed the lead isotope system at various places world- wide, such as Oklo, Gabon, and may have caused the first lead isotope paradox. Fission in areas of high uranium concentration may also have generated enough heat to localize sparse Archean and Paleoproter- ozoic UHT belts. The oldest widespread orogenic systems formed at approximately 2.0-1.8 Ga after fission stopped contributing to the earth＇s heat flow. These early orogenic systems partly created the supercontinent Columbia.

关键词： Natural fission Archean Paleoproterozoic Columbia supercontinent Tectonics

3eta Diversity of Mbuna in Lake Malawi

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journal of Environmental Science and Engineering 2011年第11期5卷 1496-1506页

作者： L.G. Kanyumba w.j. Changadeya A.j.D. Ambali L.A. Kamwanja E.K.w. Kaunda Department of Biology University of Malawi Zomba Malawi NEPAD Planning and Coordinating Agency Pretoria South Africa University of Malawi Zomba 278 Malawi Department of Aquaculture and Fisheries Science University of Malawi Lilongwe Malawi

Molecular and field studies suggest that Mbuna have limited migration range and are restricted by habitat discontinuities especially in areas where rocky habitats are separated by stretches of sand. This study estimated regional diversity of Mbuna in Lake Malawi. The estimated fl-diversity for all sites was 114.5 Mbuna suggesting that there was high level of allopatrism for the species complex. Sympatric index was low in the two regions of southern and northern lake and the observed high-end richness strongly correlated with minimum species richness. The sympatric index for the whole lake was 0.8, with non-monotypic species complexes showing declining values of sympatric index and the decline was dependent on the geographical scale of the area covered. The northern region sites had mean habitat ranking of 84.5% while the southern sites had habitat ranking of 56.7% supporting the observation that there are more rocky habitats in the northern part of the lake than in the southern. Implications of habitat ranking are discussed in terms of species abundance and richness.

关键词： Mbuna beta diversity species richness species abundance

Ultrasound particle sizing:A review

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Particuology 2013年第2期11卷 135-147页

作者： Malcolm j.w.Povey School of Food Science and Nutrition The University of Leeds

Ultrasound spectrometry is one of very few methods that can size particles over the range 10 nm to I mm for optically opaque, undiluted materials. It has in-line, non-invasive capabilities which make it a serious contender for use in industrial process monitoring, with the potential for 100% inspection. In aqueous systems, it is more sensitive to nanoparticles than to particles in the micrometre range upwards because the scattering power varies as the inverse square of particle diameter, making it suitable for the detec- tion of nanoparticles in concentrated, mixed systems. Future development of ultrasound spectrometers suitable for widespread laboratory and industrial use depends on meeting the challenges of complex data interpretation and the need for considerable know how. In this review we provide a brief account of ultrasound propagation and scattering theory which underlies the ultrasound spectrometer, describe several types of spectrometer and demonstrate its successful use in the characterization of colloidal silica, whole milk and protein solutions.

关键词： Ultrasound Particle size Measurement instrumentation Review Acoustics Particle size distribution (PSD) Nanoparticles Colloids Ultrasound spectrometry

Kinetics of Hydrogen Molecules in MAGNUM-PSI

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Plasma Science and Technology 2008年第2期10卷 162-169页

作者： M.BAEVA w.j.GOEDHEER N.j.LOPES CARDOZO Leibniz Institute for Plasma Science and Technology Felix-Hausdorf-Str. 2 D-17489 Greifswald Germany FOM-Institute for Plasma Physics Rijnhuizen Association EURATOM-FOM Trilateral Euregio Cluster P. O. Box 1207 3430 BE Nieuwegein The Netherlands

Results from simulations of plasma and neutrals under conditions predictively characterizing the detached plasma regime in the linear machine MAGNUM-PSI are presented. The relaxation of the vibrationally excited hydrogen molecules is investigated in order to establish a relation between their relaxation and dwell times, and the role of the varions mechanisms of the molecular vibrational kinetics. Tile results obtained show that the individual vibrational states have to be inclllded in the transport code for neutrals as distinct species, since the relaxation time of tile vibrational states is sufficiently longer than the typical dwell time of hydrogen molecules in the detached plasma region. The parameters of plasma and neutrals are affected by the transport of the vibrationally excited hydrogen lnolecnles. Furthermore. the rate of molecular reconlbination is overestimated by a factor of - 5 provided that the transport of ilydrogen molecules only in their ground vibrational state is considered. The role of the various processes of vibrational kinetics is studied. The vibrational excitation through singlet electronic states ires a strong influence on the molecular densities for levels with vibrational quantum numbers v≥ 5. Vibration-vibration （V-V） collisions between vibrationally excited hydrogen molecules and vibration-translation （V-T） collisions between vibrationally excited hydrogen molecules and ground state molecules and atoms are of nlinor importance in MAGNUM-PSI.

关键词： vibrational relaxation hydrogen molecules. B2-Eirene simulation detached plasma

Sensorless control for hysteresis compensation of AFM scanner by modified Rayleigh model

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journal of Central South University 2010年第6期17卷 1243-1246页

作者： PARK j K MOON w K Department of Mechanical Engineering Changwon National UniversityChangwon 641-773Korea Department of Mechanical Engineering Pohang Unive rsity of Science and TechnologyPohang 790-784Korea

A novel modified Rayleigh model was developed for compensating hysteresis problem of an atomic force microscope(AFM) *** high driving fields,piezoelectric actuators that integrated a scanner have severe hysteresis,which can cause serious displacement *** hysteresis is from various origins including movement of defects,grain boundary effects,and displacement of ***,because its characteristic is stochastic,it is almost impossible to predict the piezoelectric hysteresis ***,it was predicted phenomenologically,which means that the relationship between inputs and outputs is *** typical phenomenological approach is the Rayleigh ***,the model has the discrepancy with experiment result as the fields *** overcome the demerit of the Rayleigh model,a modified Rayleigh model was *** the modified Rayleigh model,each coefficient should be defined differently according to the field direction due to the increase of the asymmetry in the high *** applying an inverse form of this modified Rayleigh model to an AFM scanner,it is proved that hysteresis can be compensated to a position error of less than 5%.This model has the merits of reducing complicated fitting procedures and saving computation time compared with the Preisach model.

关键词： piezoelectric stack actuator hysteresis compensation Rayleigh model atomic force microscopy

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高分子合成

高分子合成

THE INFLUENCE OF PRECURSOR VARIABLES ON THE PHASE FORMATION, MICROSTRUCTURE AND TRANSPORT PROPERTY OF Bi-2223/Ag TAPES

作者： w.j.·贝利(w.j. Bailey)

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Acta Metallurgica Sinica(English Letters) 2003年第2期16卷 84-89页

作者： C.H.jiang j.M.Yoo j.w.Ko G.w.Qiao Institute of Metal Research The Chinese Academy of SciencesShenyang 110016ChinaMaterials Engineering Dept.Korea Institute of Machinery&Materials66 Sangnam-DongChangwon641-010KoreaMaterials Engineering Dept.Korea Institute of Machinery&Materials66 Sangnam-DongChangwon641-010KoreaInstitute of Metal ResearchThe Chinese Academy of SciencesShenyang 110016China

The Bi-2223/Ag tapes were prepared with spray-died powders, which are of different particle sizes and phase assemblages by varying the annealing time in pure oxygen. Longer time annealing degraded the reactivity of precursor powder, which in turn resulted in an incomplete conversion from precursors to Bi-2223, porosity core and misaligned grains in fully processed tapes. The best jc in short pressed samples varied from 29.7 to 47kA/cm2 for the tapes made from different powders.

关键词： Bi-2223/Ag tape precursor powder critical current density