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Summary of a Life in Observational Ultraviolet/Optical Astronomy

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Research in Astronomy and Astrophysics 2024年第1期24卷 1-43页

作者： Donald G.york department of Astronomy and Astrophysics The University of Chicago5801 South Ellis Ave.Chicago 60637ILUSA

I reminisce on my early life in Section 1;on my education in Sections 2 and 3;on the years at Princeton as a research astronomer in Section 4;on the years on the faculty at Chicago in Section 5;on research on Diffuse Interstellar Bands(DIBs) in Section 6;on construction of the 3.5 m telescope at Apache Point Observatory(APO)in Section 7;on work on the Sloan Digital Sky Survey(SDSS) in Section 8;on work in public education in Chicago in Section 9;and on my travels in Section 10. My main science research is of an observational nature,concerning Galactic and intergalactic interstellar gas. Highlights for me included my work on the orbiting telescope Copernicus, including the discovery of interstellar deuterium;early observations of absorption associated with fivetimes ionized oxygen;and discoveries concerning the phases of gas in the local interstellar medium, based on previously unobservable interstellar UV spectral lines. With other instruments and collaborations, I extended interstellar UV studies to the intergalactic cool gas using quasi-stellar object QSO absorption lines redshifted to the optical part of the spectrum;provided a better definition of the emission and morphological character of the source of absorption lines in QSO spectra;and pursued the identification of the unidentified DIBs. For several of these topics, extensive collaborations with many scientists were essential over many years. The conclusions developed slowly, as I moved from being a graduate student at Chicago, to a research scientist position at Princeton and then to a faculty position at Chicago. At each stage of life, I was exposed to new technologies adaptable to my science and to subsequent projects. From high school days, I encountered several management opportunities which were formative. I have been extremely fortunate both in scientific mentors I had and in experimental opportunities I encountered.

关键词： Interstellar Medium(ISM) Nebulae (galaxies:)quasars:absorption lines ultraviolet:stars

Mapping Problems,Fundamental Groups and Defect Measures

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Acta Mathematica Sinica,English Series 1999年第1期15卷 25-52页

作者： Fanghua LinCourant Institute of mathematics,new york university,new york,ny 10012,usa Courant Institute of mathematics New York University New York USA

We study all the possible weak limits of a minimizing sequence,for p-energy functionals, consisting of continuous maps between Riemannian manifolds subject to a Dirichlet boundary condition or a homotopy *** show that if p is not an integer,then any such weak limit is a strong limit and,in particular,a stationary p-harmonic map which is C1,α continuous away from a closed subset of the Hausdorff dimension ≤n-[p]-*** p is an integer,then any such weak limit is a weakly p-harmonic map along with a（n-p）-rectifiable Radon measure μ.Moreover,the limiting map is C1,α continuous away from a closed subset ∑=spt μ∪S with Hn-p（S）=***,we discuss the possible varifolds type theory for Sobolev mappings.

关键词： Defect measure Harmonic mapping Generalized varifold Rectifiability

Arithmetic of Shimura curves

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Science China mathematics 2010年第3期53卷 573-592页

作者： ZHANG Shou-Wu department of mathematics, Columbia university, new york, ny 10027, usa 1. department of mathematics Columbia University New York NY 10027 USA

This is the note for a series of lectures that the author gave at the Centre de Recerca Matemtica (CRM), Bellaterra, Barcelona, Spain on October 19–24, 2009. The aim is to give a comprehensive description of some recent work of the author and his students on generalisations of the Gross-Zagier formula, Euler systems on Shimura curves, and rational points on elliptic curves.

关键词： Shimura curves CM-points L-series

Coating powder beds with liquids and foams based on viscous formulations using a twin screw mixer:A continuous process study

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Particuology 2024年第10期93卷 364-376页

作者： Mohamed S.Manga Dimitrios Kontziampasis Mustafa Al-Maqdad Sean Clifford Serafim Bakalis David W.york school of Chemical and Process Engineering Faculty of Engineering and Physical SciencesUniversity of LeedsLeedsLS29JTUK school of Mechanical Engineering Faculty of Engineering and Physical SciencesUniversity of LeedsLeedsLS29JTUK school of Science and Engineering University of DundeeDD14HNDundeeScotlandUK Dundee International Institute of Central South university Tongzipo RoadCentral South UniversityChangshaHunan410013China department of Chemical Engineering School of EngineeringUniversity of NewcastleNewcastleNE17RUUK school of Chemical Engineering University of BirminghamBirminghamB152TTUK department of Chemical Engineering Faculty of EngineeringUniversity of NottinghamNG72RDUK

Coating with viscous formulations has been essential in numerous industries as it can be a means for providing functionalization, additional properties, as well as other benefits. However, there have been scarce studies that have investigated and proposed methodologies in literature. Continuous coating of powders with viscous liquids poses as a promising technology, which has been mentioned in some studies, but has not yet been thoroughly investigated. This paper employs the use of image processing and analysis, in combination with statistical analysis of particles to evaluate the effectiveness of foams and liquids as a means of coating powder beds. Two different sizes of twin screw mixers that are working in continuous operation are employed, and a new continuous foaming device is fabricated and used for the experiments of coating. The effect of materials and process parameters (as for example rotational speed, and flowrate) on the quality of coating are investigated. Image analysis is used to assess the coating quality. The results clearly showcase the potential of using twin screw mixers for coating purposes and not only for mixing. The hypothesis that using large bubble foams to improve the coating of viscous liquids on particles is proven correct, as they provide higher quality coatings compared to their equivalent liquids, when used in the twin screw mixer. Surprisingly, using a larger scale twin screw mixer, does not show a substantial effect on the mixing, regarding quality, however there is still a requirement for mix optimization for achieving scale-up of this process. These results provide a new pathway for coating powders with viscous formulations in industrial applications, requiring less energy and effort in this process, and can pave the way towards introducing more sustainable industrial methodologies for coating.

关键词： Powder coating Continuous processing Viscous liquid Foam Image analysis Positron emission particle traking(PEPT)

Aggregation and assembly of crescent foldamers

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Science China Chemistry 2010年第1期53卷 45-51页

作者： GONG Bing department of Chemistry,university at Buffalo,The State university of new york,Buffalo,new york 14260,usa 1. department of Chemistry University at Buffalo The State University of New York Buffalo New York 14260 USA

Recent studies have started to provide initial insights into the aggregation and assembly of two classes of back-rigidified foldamers with flat,curved backbones consisting of aromatic *** their persistent shape that presents large,well-defined aromatic surface areas,these crescent foldamers were found to undergo size-dependent aggregation in solution and pack into 1D assemblies in the solid *** aromatic oligoamides undergo stacking interactions not only in polar solvents but also in nonpolar ones,a unique property that is not associated with many other molecules that associate via π-π stacking *** stacking of oligo(m-phenylene ethynylenes) is similar to aromatic hydrocarbons,being promoted in polar solvents such as methanol while being discouraged in nonpolar solvents such as *** ready synthetic availability of crescent foldamers makes it possible to directly control the intermolecular interaction by tuning surface ***,the columnar assembly of these cavity-containing molecules provides a new strategy for constructing supramolecular nanotubular structures.

关键词： foldamer folding hydrogen bond π-π stacking aggregation assembly

On the Birch-Swinnerton-Dyer Conjecture of Elliptic Curves E_D:y^2=x^3-D^2x

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Acta Mathematica Sinica,English Series 2000年第2期16卷 229-236页

作者： Delang Li department of mathematics,Sichuan Union university,Chengdu 610064,P.R.China Ye Tian department of mathematics,Columbia university,new york,ny 10027,usa department of mathematics Sichuan Union University Chengdu 610064 P. R. China department of mathematics Columbia University New York NY 10027 USA

We prove in this paper that the BSD conjecture holds for a certain kind of elliptic curves.

关键词： Elliptic curve BSD conjecture Graph 2-component

The Faddeev knots as stable solitons: Existence theorems

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Science China mathematics 2004年第2期47卷 187-197页

作者： LIN Fanghua & YANG YisongCourant Institute of Mathematical Sciences, new york university, new york, new york 10012, U. S. A.school of mathematics, Institute for Advanced Study, Princeton, new Jersey 08540, U. S. A. department of mathematics, Polytechnic university, Brooklyn, new york 11201, U. S. A. 1.Courant Institute of Mathematical Sciences New York University 10012 New York New York U S A 2.School of Mathematics Institute for Advanced Study 08540 Princeton New Jersey U S A 3.Department of Mathematics Polytechnic University 11201 Brooklyn New York U S A

The problem of existence of knot-like solitons as the energy-minimizing configurations in the Faddeev model, topologically characterized by an Hopf invariant, Q, is considered. It is proved that, in the full space situation, there exists an infinite set S of integers so that for any m ∈ S, the Faddeev energy, E, has a minimizer among the class Q = m; in the bounded domain situation, the same existence theorem holds when S is the set of all integers. One of the important technical results is that E and Q satisfy the sublinear inequality E ≤ C|Q|3/4, where C > 0 is a universal constant, which explains why knotted (clustered soliton) configurations are preferred over widely separated unknotted (multisoliton) configurations when |Q| is sufficiently large.

关键词： knots, Hopf invariant, minimization, solitons.

On the Uniqueness of Heat Flow of Harmonic Maps and Hydrodynamic Flow of Nematic Liquid Crystals

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Chinese Annals of mathematics,Series B 2010年第6期31卷 921-938页

作者： Fanghua LIN Changyou WANG Courant Institute of Mathematical Sciences New York University New York NY 10012 USA department of mathematics University of Kentucky Lexington KY 40506 USA.

For any n-dimensional compact Riemannian manifold (M,g) without boundary and another compact Riemannian manifold (N,h), the authors establish the uniqueness of the heat flow of harmonic maps from M to N in the class C([0,T),W1,n). For the hydrodynamic flow (u,d) of nematic liquid crystals in dimensions n = 2 or 3, it is shown that the uniqueness holds for the class of weak solutions provided either (i) for n = 2, u ∈ Lt∞ L2x∩L2tHx1, ▽P∈ Lt4/3 Lx4/3 , and ▽d∈ L∞t Lx2∩Lt2Hx2; or (ii) for n = 3, u ∈ Lt∞ Lx2∩L2tHx1∩ C([0,T),Ln), P ∈ Ltn/2 Lxn/2 , and ▽d∈ L2tLx2 ∩ C([0,T),Ln). This answers affirmatively the uniqueness question posed by Lin-Lin-Wang. The proofs are very elementary.

关键词： Hydrodynamic flow Harmonic maps Nematic liquid crystals Uniqueness

Randomization of Q_(p) spaces on the unit ball of C^(n)

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Science China mathematics 2005年第z1期48卷 306-317页

作者： LI Bo & OUYANG Caiheng department of mathematics, State university of new york at Buffalo, Buffalo, ny 14260, usa Wuhan Institute of Physics and mathematics, Chinese Academy of Sciences, Wuhan 430071, China SUny Buffalo Dept Math Buffalo NY 14260 USA Chinese Acad Sci Wuhan Inst Phys & Math Wuhan 430071 Peoples R China

In this paper, we study the random power series of several complex variables,and give some sufficient conditions for random power series to belong to Qp and Qp,0spaces by means of their characterizations of Carleson m... 详细信息

关键词： random power series, function spaces, the unit ball.