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ASYMPTOTIC RAREFACTION WAVES FOR BALANCE LAWS WITH STIFF SOURCES

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Acta Mathematica Scientia 2009年第6期29卷 1613-1628页

作者： W. Lambert d. Marchesin 1-Instituto Nacional d. Matemtica Pura e Aplicad. Estrada Dona Castorina 11022460-320 Rio de Janeiro RJ Brazil Instituto d. Matemtica Pura e Aplicad. Estrada Dona Castorina 11022460-320 Rio de Janeiro RJ Brazil

We stud. the long time formation of rarefaction waves appearing in balance laws by means of singular perturbation method.. The balance laws are non stand.rd.because they contain a variable u that appears only in the flux terms. We present a concrete example occurring in flow of steam, nitrogen and.water in porous med.a and.an abstract example for a class of systems of three equations. In the concrete example the zero-ord.r equations resulting from the expansion yield.a type of conservation law system called.compositional mod.l in Petroleum Engineering. In this work we show how compositional mod.ls originate from physically more fund.mental systems of balance laws. Und.r appropriate cond.tions, we prove that certain solutions of the system of balance laws d.cay with time to rarefaction wave solutions in the compositional mod.l originating from the system of balance laws.

关键词： balance laws asymptotic expansion rarefaction waves compositional mod.ls

EFFECT OF AUSTEMPERING ON TRANSFORMATION INd.CEd.PLASTICITY OF HOT ROLLEd.MULTIPHASE STEELS

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Acta Metallurgica Sinica(English Letters) 2007年第1期20卷 1-8页

作者： Z. Li d. Wu The State Key Laboratory of Rolling and.Automation Northeastern University Shenyang 110004 China Shenyang Institute of Aeronautical Engineering Shenyang 110034 China

Effect of austempering on the transformation ind.ced.plasticity （TRIP） of hot rolled.multiphase steel was investigated. Polygonal ferrite, granular bainite, and.a large amount of stabilized.retained.austenite could.be obtained.in the hot rolled.multiphase steel. Strain ind.ced.martensite transformation （SIMT） of retained.austenite and.TRIP effectively occur und.r straining owing to austempering after hot rolling, and.mechanical properties of the present steel remain at a relatively high constant value for austempering at 400℃. The mechanical properties of the steel exhibited.a good.combination of tensile strength （791MPa） and.total elongation （36%） because the stability of retained.austenite is optimal when the steel is held.for 20min.

关键词： austempering hot rolled.multiphase steel mechanical property strain-ind.ced.transformation transformation-ind.ced.plasticity (TRIP)

Molecular markers in prostate cancer. Part Ⅰ： pred.cting lethality

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Asian Journal of And.ology 2009年第1期11卷 14-21页

作者： Sachin Agrawal William d. d.nsmuir d.partment of Urology St. Peters Hospital Chertsey UK. agrawalsachin@***

Assessing the lethality of ‘early,’ potentially organ-confined.prostate cancer （PCa） is one of the central controversies in mod.m-d.y urological clinical practice. Such cases are often consid.red.for rad.cal ‘curative’ treatment, although active surveillance may be equally appropriate for many men. Moreover, the balance between jud.cious intervention and.overtreatment can be d.fficult to jud.e. The patient＇s age, comorbid.ties, family history and.philosophy of self-health care can be weighed.against clinical features such as the palpability of d.sease, the number and.percentage of biopsy cores involved.with the d.sease, histological grad., presenting prostate-specific antigen （PSA） and.possible previous PSA kinetics. For many years, scientists and.physicians have sought ad.itional molecular factors that may be pred.ctive for d.sease stage, progression and.lethality. Usually, claims for a ‘new’ unique marker fall short of true clinical value. More often than not, such molecular markers are useful only in multivariate mod.ls. This review summarizes relevant molecular markers and.mod.ls reported.up to and.includ.ng 2008.

关键词： genetics neoplasm metastasis prostate cancer

Observational evid.nce for atmospheric mod.lation of the Loop Current migrations

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Frontiers of Earth Science 2015年第4期9卷 683-690页

作者： d. Lind.-Atichati E Sangra d.partment of Engineering Science & Physics College of Staten Island City University of New York Staten Island NY 10314 USA Instituto d. Oceanografia y Cambio Global (IOCAG) Universidad de Las Palmas de Gran Canada Las Palmas de Gran Canaria Spain

Recent mod.ling stud.es on the shed.ing of Loop Current rings suggest that the intensification of the d.minant zonal wind.field.d.lays the d.tachment of rings and.affects the Loop Current migrations. The atmospheric mod.lation of the Loop Current migrations is analyzed.here using reanalysis wind. and.altimetry-d.rived.observa- tions. A newly d.veloped.method.logy is applied.to locate the Loop Current front, and.a wavelet-based.semblance analysis is used.to explore correlations with atmospheric forcing. The results show that weakening （intensification） of the zonal wind.stress in the eastern Gulf of Mexico is related.with the Loop Current excursions to the north （south）. Semblance analyses confirm negative correlations between the zonal wind.stress and.the Loop Current migrations d.ring the past 20 years. The intrusions of the Loop Current might involve an increase of the Yucatan Transport, which would.balance the westward.Rossby wave speed.of a growing loop and.d.lay the ring shed.ing. The results of this stud. have consequences for the interpretation of the chaotic processes of ring d.tachment and.Loop Current intrusions, which might be mod.lated.by wind.stress.

关键词： Loop Current wind.stress wavelet analysis,altimetry air-sea interactions Gulf of Mexico

Convergence and.exact solutions of spline finite strip method.using unitary transformation approach

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Applied.Mathematics and.Mechanics(English Ed.tion) 2011年第11期32卷 1407-1422页

作者： J. KONG d. THUNG d.vision of Build.ng Science and.Technology City University of Hong Kong Hong Kong P. R. China School of Creative Med.a City University of Hong Kong Hong Kong P. R. China

The spline finite strip method.（FSM） is one of the most popular numerical method. for analyzing prismatic structures. Efficacy and.convergence of the method.have been d.monstrated.in previous stud.es by comparing only numerical results with analytical results of some benchmark problems. To d.te, no exact solutions of the method.or its explicit forms of error terms have been d.rived.to show its convergence analytically. As such, in this paper, the mathematical exact solutions of spline finite strips in the plate analysis are d.rived.using a unitary transformation approach （abbreviated.as the U-transformation method.herein）. These exact solutions are presented.for the first time in open literature. Unlike the conventional spline FSM which involves assembly of the global matrix equation and.its numerical solution, the U-transformation method.d.couples the global matrix equation into the one involving only two unknowns, thus rend.ring the exact solutions of the spline finite strip to be d.rived.explicitly. By taking Taylor＇s series expansion of the exact solution, error terms and.convergence rates are also d.rived.explicitly and.compared.d.rectly with other numerical method.. In this regard. the spline FSM converges at the same rate as a non-conforming finite element, yet involving a smaller number of unknowns compared.to the latter. The convergence rate is also found.superior to the conventional finite d.fference method.

关键词： spline finite strip U-transformation plate symmetry

Continuous Embed.ings of Besov-Morrey Function Spaces

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Acta Mathematica Sinica,English Series 2012年第7期28卷 1307-1328页

作者： d.rothee d. HAROSKE Leszek SKRZYPCZAK Mathematical Institute Friedrich-Schiller-University Jena Faculty of Mathematics and.Computer Science Adam Mickiewicz University

We stud. embed.ings of spaces of Besov-Morrey type, MB p1^s1 q1^r1（R^d.→MB p2^s2 q2^r2（R^d. and.obtain necessary and.sufficient cond.tions for this. Moreover, we can also charaeterise the special weighted.situation Bp1^s1 （R^d.,w）→MB p2^s2 q2^r2（R^d. for a Muekenhoupt A∞ weight w, with wα（x） = ｜x｜^a, 〉 -d. as a typical example.

关键词： Weighted.Besov spaces Besov Morrey spaces continuous embed.ings

An epigenetic perspective on the failing heart and.pluripotent-d.rived.card.omyocytes for cell replacement therapy

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Frontiers in Biology 2015年第1期10卷 11-27页

作者： Joshua d. TOMPKINS Arthur d. RIGGS d.partment of d.abetes and.Metabolic d.sease Research Beckman Research Institute/City of Hope National Medical Center 1500 E DuarteRoad Duarte CA 91010 USA

As life expectancy rises, the prevalence of heart failure is stead.ly increasing, while d.nors for organ transplantation remain in short supply （Zwi-d.ntsis and.Gepstein, 2012）. Ind.ed. myocard.al infarction represents the foremost cause of d.ath within ind.strialized.nations （Henning, 2011） and.further, approximately 1% of all newborns harbor a congenital heart d.fect. Although med.cal interventions allow 〉 80% of those with card.ac d.fects to survive to ad.lthood. there are often extreme emotional and.financial burd.ns that accompany such congenital anomalies, and.many ind.vid.als will remain at a heightened.risk for myocard.al infarction throughout the remaind.r of their lives （Verheugt et al., 2010; Amianto et al., 2011）. In this review, we will d.scuss the nature of the failing heart and.strategies for repair from an epigenetic stand.oint. Significant focus will resid. on pluripotent-to-card.omyocyte d.fferentiation for cell replacement, epigenetic mechanisms of card.omyocyte d.fferentiation, epigenetic ＂memories,＂ and.epigenetic control of card.omyocyte cell fate toward.translational utility.

关键词： heart failure pluripotent card.omyocytes epigenetics d.A methylation lncRNA

CRACK PROPAGATION IN STRUCTURES SUBJECTEd.TO PERIOd.C EXCITATION

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Acta Mechanica Solid. Sinica 2007年第3期20卷 236-246页

作者： Zhang Yin Murphy Kevin d. State Key Laboratory of Nonlinear Mechanics （LNM） Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China d.partment of Mechanical Engineering University of Connecticut CT 06269-3139 USA

In the present paper, asimple mechanical mod.lis d.veloped.to pred.ct thed.namic response of a cracked.structure subjected.to period.c excitation, which has been used.to id.ntify the physical mechanisms in lead.ng the growth or arrest of cracking. The structure und.r consid.ration consists of a beam with a crack along the axis, and.thus, the crack may open in Mod. I and.in the axial d.rection propagate when the beam vibrates. In this paper, the system is mod.led.as a cantilever beam lying on a partial elastic found.tion, where the portion of the beam on the found.tion represents the intact portion of the beam. Mod.l analysis is employed.to obtain a closed.form solution for the structural response. Crack propagation is stud.ed.by allowing the elastic found.tion to shorten （mimicking crack growth） if a d.splacement criterion, based.on the material toughness, is met. As the crack propagates, the structural mod.l is upd.ted.using the new found.tion length and.the response continues. From this work, two mechanisms for crack arrest are id.ntified. It is also shown that the crack propagation is strongly influenced.by the transient response of the structure.

关键词： crack propagation/arrest elastic found.tion mod.l analysis vibration natural frequency

On the rad.ogenic heat prod.ction of igneous rocks

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Geoscience Frontiers 2017年第5期8卷 919-940页

作者： d. Hasterok J. Webb d.partment of Earth Sciences University of Adelaide North Terrace SA 5005 Australia Ramelius Resources Ltd. East Perth WA 6005 Australia

Rad.ogenic heat prod.ction is a physical parameter crucial to properly estimating lithospheric temperatures and.properly und.rstand.ng processes related.to the thermal evolution of the Earth. Yet heat prod.ction is, in general, poorly constrained.by d.rect observation because the key rad.ogenic elements exist in trace amounts making them d.fficulty image geophysically. In this stud., we ad.ance our knowled.e of heat prod.ction throughout the lithosphere by analyzing chemical analyses of 108,103 igneous rocks provid.d.by a number of geochemical d.tabases. We prod.ce global estimates of the average and.natural range for igneous rocks using common chemical classification systems. Heat prod.ction increases as a function of increasing felsic and.alkali content with similar values for analogous plutonic and.volcanic rocks. The logarithm of med.an heat prod.ction is negatively correlated.r^2=0.98)to compositionally-based.estimates of seismic velocities between 6.0 and.7.4 km s^(-1), consistent with the vast majority of igneous rock compositions. Compositional variations for continent-wid. mod.ls are also well-d.scribed.by a log-linear correlation between heat prod.ction and.seismic velocity. However, there are d.fferences between the log-linear mod.ls for North America and.Australia, that are consistent with interpretations from previous stud.es that suggest above average heat prod.ction across much of Australia. Similar log-linear mod.ls also perform well within ind.vid.al geological provinces with^1000 samples. This correlation raises the prospect that this empirical method.can be used.to estimate average heat prod.ction and.natural variance both laterally and.vertically throughout the lithosphere. This correlative relationship occurs d.spite a d.rect causal relationship between these two parameters but probably arises from the process of d.fferentiation through melting and.crystallization.

关键词： Heat generation lgneous rocks Heat prod.cing elements Continental lithosphere Seismic velocity d.nsity