{"title":"Nouvelles méthodes optiques de mesure de la biabsorbance dans les milieux cristallins transparents","authors":"G. Toubeau","doi":"10.3406/barb.1962.65430","DOIUrl":"https://doi.org/10.3406/barb.1962.65430","url":null,"abstract":"La mesure optique de la biabsorbance des minéraux transparents est possible à l'aide de différentes méthodes exposées dans la présente note. Sans nécessiter un appareillage compliqué, ces méthodes élargissent considérablement le champ d'application du microscope polarisant. \u0000 La mesure de la biabsorbance, caractéristique de nombreuses espèces minérales, complète utilement la mesure d'autres grandeurs optiques et peut parfois s'y substituer.","PeriodicalId":296277,"journal":{"name":"Bulletin de la Classe des sciences","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125547070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On a new multivariate distribution and its properties","authors":"Prem Chandra Consul","doi":"10.3406/barb.1965.65284","DOIUrl":"https://doi.org/10.3406/barb.1965.65284","url":null,"abstract":"We define a new statistic U as a difference of two different variates which are both distributed in the form of Bessel functions of purely imaginary argument as obtained by Bhattacharya (1946). Then the principle of Characteristic functions and the method of operational calculus has been utilised to determine the probability distribution and sampling distribution of U. Though the distributions are some-what complex, their moments and cumulants indicate that they are symmetrical and leptokurtic in form and that they approximate to the normal distribution when the sample sizes are large.","PeriodicalId":296277,"journal":{"name":"Bulletin de la Classe des sciences","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126754831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Note sur la polarisation dans l'interaction à quatre fermions","authors":"J. Nuyts","doi":"10.3406/barb.1961.68162","DOIUrl":"https://doi.org/10.3406/barb.1961.68162","url":null,"abstract":"On the basis of the known Bouchiat — Michel formula, we give a generalisation which permits a covariant description of the 202 polarisation matrix density of fermions in arbitrary systems of reference. This formalism gives the most useful results when the outgoing state has the same fermion configuration as the ingoing one.","PeriodicalId":296277,"journal":{"name":"Bulletin de la Classe des sciences","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126779609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Une configuration formée par trois suites de Laplace","authors":"L. Godeaux","doi":"10.3406/barb.1966.62550","DOIUrl":"https://doi.org/10.3406/barb.1966.62550","url":null,"abstract":"Résumé. — Construction de trois suites de Laplace dont deux sont doublement inscrites dans deux autres.","PeriodicalId":296277,"journal":{"name":"Bulletin de la Classe des sciences","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126870336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sur l'application d'une représentation hyperspatiale de l'espace réglé à l'étude de certaines questions de géométrie différentielle","authors":"P. Vincensini","doi":"10.3406/barb.1954.69211","DOIUrl":"https://doi.org/10.3406/barb.1954.69211","url":null,"abstract":"Dans des Notes antérieures (1) j'ai utilisé une certaine correspondance entre les droites de l'espace métrique enclidien E3 à trois dimensions (supposé rapporté aux axes rectangulaires Ox1x2x3 et les points d'un espace métrique euclidien à quatre dimensions (Ox1x2x3x4) dont E3 serait la section par l'hyperplan x4= 0. \u0000 En elle-même cette correspondance n'est sans doute pas une grande nouveauté (il suffit par exemple de songer à une projection stéréographique d'une section hyperplane de l'hyperquadrique (FORMULE), \u0000 X où les X1 seraient les coordonnées de Klein d'une droite de E3). Mais elle permet d'aborder avec fruit un certain nombre de questions de géométrie projective réglée en les ramenant à des questions de géométrie métrique, ce qui permet parfois à l'intuition de s'exercer plus librement et à la théorie générale métrique des surfaces d'offrir le service de ses résultats. \u0000 Le développement qui suit a pour objet d'illustrer le point de vue signalé, en complétant opportunément certains résultats antérieurs.","PeriodicalId":296277,"journal":{"name":"Bulletin de la Classe des sciences","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126923543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Étude de l'écoulement permanent rectiligne de fluides visqueux non-newtoniens incompressibles","authors":"Georges Mayné","doi":"10.3406/barb.1968.62073","DOIUrl":"https://doi.org/10.3406/barb.1968.62073","url":null,"abstract":"Le mouvement rectiligne permanent d'un fluide de Reiner-Rivlin n'est possible que dans un tube dont la section droite est à courbure constante. Ce résultat, conjecturé par J.L. Ericksen et par A.E. Green et R.S. Rivlin, est établi à partir d'une analyse qui reste valable dans les cas caractéristiques. On utilise le référentiel (lignes isovitesses et lignes orthogonales) adopté par D.E. Stone dans le cas particulier k1 = k(-II)-1/2, k2 = l(— II)-1.\u0000 On montre que le cas caractéristique k1 = k(— II)-1/2 conduit soit à une solution non uniforme soit à l'indétermination. La solution du deuxième cas caractéristique k2 = l(— II)-1/2 est obtenue pour une fonction k1 quelconque.","PeriodicalId":296277,"journal":{"name":"Bulletin de la Classe des sciences","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114929674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Constantes réticulaires du phosphate secondaire hydraté de strontium","authors":"R. Plumier, H. Brasseur","doi":"10.3406/barb.1957.68624","DOIUrl":"https://doi.org/10.3406/barb.1957.68624","url":null,"abstract":"Étude radiographique comparative de CaHPO4 • 2H2O et SrHPO4 • 2H2O.","PeriodicalId":296277,"journal":{"name":"Bulletin de la Classe des sciences","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115535847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sur les surfaces de genres arithmétique et géométrique nuls possédant une courbe bicanonique effective","authors":"L. Godeaux","doi":"10.3406/barb.1958.68914","DOIUrl":"https://doi.org/10.3406/barb.1958.68914","url":null,"abstract":"On démontre que si le système canonique d'une surface algébrique est un faisceau et si la surface contient une involution cyclique privée de points unis dont l’image est privée de courbe canonique, les courbes canoniques sont elliptiques et la surface image possède une courbe bicanonique formée de deux courbes elliptiques.","PeriodicalId":296277,"journal":{"name":"Bulletin de la Classe des sciences","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115549550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Two causes contributing to the periodic fluctuation in the length of the day","authors":"Andrew Young","doi":"10.3406/barb.1951.70685","DOIUrl":"https://doi.org/10.3406/barb.1951.70685","url":null,"abstract":"Variations in the moment of inertia of the Earth are calculated from atmospheric pressure variations, and the resulting variations in the length of the day are obtained. \u0000 The effect of polar waters released by differential seasonal melting is estimated.","PeriodicalId":296277,"journal":{"name":"Bulletin de la Classe des sciences","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122399886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sur la suite de Laplace associée à une surface et dont trois points appartiennent à l’hyperquadrique de Klein","authors":"L. Godeaux","doi":"10.3406/barb.1953.69982","DOIUrl":"https://doi.org/10.3406/barb.1953.69982","url":null,"abstract":"Étude de la suite de Laplace de l’espace réglé associée à une surface lorsque l’un de ses points, distinct de ceux qui représentent les tangentes asymptotiques à la surface, appartient à l’hyperquadrique de Klein.","PeriodicalId":296277,"journal":{"name":"Bulletin de la Classe des sciences","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122570660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}