Limpar
11.883.789 resultados

Acesso aberto

Tipo do recurso

Tipo de base de dados

Ano de criação

Produção nacional

Revisado por pares

Áreas

Idioma

Editores

Artigo

George Biddell Airy,

... a sphere of radius R and mean density D, surrounded by a spherical shell of thickness c and density d , so that the radius of the external surface ... shell is represented by 4π/3, R 3 D/R 2 = 4π/3 RD ; and the attraction ... represented by 4π/3, R 3 , R 3 D + (R+ c 3 ___ - R 3 ) d /(R+ c ) 2 , which to the first power ... RD(1 - 2 c /R + 3 c /R. d /D). Calling the gravity at those two points respectively ... G = 1 - 2 c /R + 3 c /R. d /D; from which d /D = R/3 c . g /G - (R/3 ...

Tópico(s): Geophysics and Gravity Measurements

1856 - Royal Society | Philosophical Transactions of the Royal Society of London

Imagens Acesso aberto

Wellcome Library, London. Series: Iconographic Collections.

0000 - Gale Group | NCCO Photography

Artigo Acesso aberto Revisado por pares

G. Wiedemann, R. Rühlmann,

... der Elektricität durch Gase G. Wiedemann, G. Wiedemann d. Bericht. d. Kgl. Sächs. Gesellsch. d. Wissensch., von HH. Verf. mitgetheiltSearch for more papers by this authorR. Rühlmann, R. Rühlmann d. Bericht. d. Kgl. Sächs. Gesellsch. d. Wissensch., von HH. Verf. mitgetheiltSearch for more papers by this author G. Wiedemann, G. Wiedemann d. Bericht. d. Kgl. Sächs. Gesellsch. d. Wissensch., von HH. Verf. mitgetheiltSearch for more papers by this authorR. Rühlmann, R. Rühlmann d. Bericht. d. Kgl. Sächs. Gesellsch. d. Wissensch., von ...

Tópico(s): Physics and Engineering Research Articles

1872 - Wiley | Annalen der Physik

Artigo Acesso aberto Revisado por pares

M. L. Sylow,

... NOI~VEaE.On sait que si l'ordre d'un groupe de substitutions est divisible par le ... premier n, le groupe contieat toujours une substitution d'ordre n.Ce thgorSme important est.contenu dans ... plus g&lgral qno voici: ,Si l'ordre d'un groupe est divisible par n ~ n grant ... le groupe contient u]a f~isceau partiel d'ordre n~".La d6.monstration m~,me du ... en 6coulent, dent quelques lines pourtant~ so]at d~j'~ connues par un travail de M. E. ... at eeux de M. C. J o r d a n .1. Si G est un groupe ... n, on salt que G contient une substitution d'ordre n~ mais nou~ pouvons supposer plus ggngralement ...

Tópico(s): semigroups and automata theory

1872 - Springer Nature | Mathematische Annalen

Artigo Acesso aberto

William Hamilton,

... if we meet the function S. ~r dr _ d S. d t ~, ...... (1.) we may see, in the first ... and direction in space; because the three symbols ~, d, d ~ are supposed to be themselves such vector forms, ... being constructed by three such lines; while S. d a" and S. ~,r~ are~ in the same ... Greek letter, accented or unaccented, for example to d", writing d" = o~ S. i d t --d S. d I ~ ...... (~.) Multiplying this equation by ¢d, and taking ...

Tópico(s): History and Theory of Mathematics

1846 - Taylor & Francis | The London Edinburgh and Dublin Philosophical Magazine and Journal of Science

Artigo Acesso aberto Revisado por pares

... alg^briquement.a Meraoire sur une classe particuliere d'equations resolubles algebriquement (Par Mr. N. H. Abel.) ... goneraliser cette remarque en supposant que deux racines d'une equation donnee soient tellement liees entre elles, ... Equation peut toujours ^tre r solue a Taide d'un certain nombre d'equations moins elevees.II y a meme des ... chose a lieu encere si toutes les racines d'une oquation peuvent 3tre exprimoes par χ, θχ, ... La meme propriete convient a une certaine classe d'4fjuatio»n$ qu'offre la theorie des fonctions ...

Tópico(s): Mathematical and Theoretical Analysis

1829 - De Gruyter | Journal für die reine und angewandte Mathematik (Crelles Journal)

Artigo Acesso aberto

W. F. Donkin,

The equation d 2 u / dx 2 + d 2 u / dy 2 + d 2 u / dz 2 = 0, transformed to polar coordinates by putting x = r sin θ cos ϕ , y = ... r cos θ , becomes, as is well known, d 2 u / dθ 2 + cot θ du / dθ + 1/(sin θ ) 2 d 2 u / dϕ 2 + r 2 d 2 u / dr 2 + 2 r du / dr = ... may be written in the form {(sin θ d / dθ ) 2 + ( d / dϕ ) 2 + (sin θ ) 2 r d / dr ( r d/dr + 1)} u = 0; . . . . (1.) and if it ...

Tópico(s): History and Theory of Mathematics

1857 - Royal Society | Philosophical Transactions of the Royal Society of London

Artigo Revisado por pares

M. H. Ranney,

... Univariate and Bivariate LinkageEmma E.M. Knowles, Ph.D. D. Reese McKay, Ph.D. Jack W. Kent, Jr.Ph.D. Emma Sprooten, Ph.D. Melanie A. Carless, Ph.D. Joanne E. Curran, Ph.D. Marcio A.A. de Almeida, Ph.D. Thomas D. Dyer, Ph.D. Harald H.H. Göring, Ph.D. Rene L. ...

Tópico(s): Child and Adolescent Psychosocial and Emotional Development

1857 - American Psychiatric Association | American Journal of Psychiatry

Artigo Acesso aberto Revisado por pares

M. Haure,

... notion de leur-genre.Soit P un point d'une pareille courbe; si l'on considère l' ... géomètres, particulièrement celles de MM.Schottky et Hurwitz, d'arriver à la détermination des divers systèmes d'ordres manquants qui peuvent se trouver dans les." courbes d'un genre déterminé et aussi à la définition ... qui en dérivent, ainsi, qu'à la démonstration d'un important théorème de M. Weierstrass (°), relatif à l'existence d'un système d'intégrales de première espèce, infiniment petites en A, ... Hurwitz ( 7 ), une méthode pour former des.tableaux d'ordres manquants; j'établis ensuite, d'après M. ...

Tópico(s): Advanced Numerical Analysis Techniques

1896 - Société Mathématique de France | Annales Scientifiques de l École Normale Supérieure

Artigo Acesso aberto

D. Vorländer, K. Hobohm,

... Mittheilungen Ueber die Condensation von Ketopentamethylen mit Aldehyden D. Vorländer, D. Vorländer Chemisches Institut der Universität Halle a. S. ... S.Search for more papers by this author D. Vorländer, D. Vorländer Chemisches Institut der Universität Halle a. S. ... Ges. 15, 594. Google Scholar p1836_3) Ann. d. Chem. 275, 312. Google Scholar p1836_4) Ber. ... Ges. 29, 1595. Google Scholar p1838_1) Ann. d. Chem. 21, 143; Google Scholar Journ. f. prakt. ... 11, 456. Google Scholar p1839_2) Völckel (Ann. d. Chem. 85, 65; Google Scholar Ann. d. Chem. ...

Tópico(s): Inorganic and Organometallic Chemistry

1896 - Wiley | Berichte der deutschen chemischen Gesellschaft

Artigo Acesso aberto

Ida Clendenin,

... M. Thambugala, Eleni Gentekaki, Alan J. L. Phillips, D. Jayarama Bhat, Dhanushka N. Wanasinghe, Nimali I. de Silva, Itthayakorn Promputtha, Kevin D. Hyde Taxonomic and phylogenetic contributions to Celtis formosana, ... 10.1007/s13225-021-00474-wSinang Hongsanan, Kevin D. Hyde, Rungtiwa Phookamsak, Dhanushka N. Wanasinghe, Eric H. ... V. Venkateswara Sarma, Robert Lücking, Saranyaphat Boonmee, Jayarama D. Bhat, Ning-Guo Liu, Danushka S. Tennakoon, Dhandevi ... I. de Silva, Vinodhini Thiyagaraja, Huang Zhang, Jadson D. P. Bezerra, Ricardo Miranda-González, André Aptroot, Hiroyuki ...

Tópico(s): Yeasts and Rust Fungi Studies

1896 - University of Chicago Press | Botanical Gazette