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ابراهیم
اسرافیلیان
author
text
article
1991
per
Many Structures on a topological m- manifold M may be defined by means of an atlas of local coordinate systems for which the coordinate systems belong to some pseudo group P of transformations in the model space R.
To any symmetric affine connection ?on M there is associated a family of normal coordinate systems in a canonical way, via the exponential map. However, the coordinate transformations that occur within this family do not form a pseudo group of transformations in On the other hand, normal coordinate systems are »abundant« in the sense that there is at least one such system based at every point of M.
The purpose of this paper is to modify the pseudo group notion of structure to obtain a characterization of symmetric affine connections.
Journal of Science,University of Tehran(not publish)
پرديس علوم
1
v.
0
no.
1991
https://jos.ut.ac.ir/article_15919_484bc69ef1da7ef404c39fc6be2c38ca.pdf
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احمد
مأموریان
author
بیژن
شمس
author
text
article
1991
per
An earlier reported reault is extended. The main purpose of this work is to fill the gap between the linear and nonlinear systems of equations with two unknowns in the plane domains, the boundary va1ues problem of Riemann - Hubert and Hubert type for the system of equations, elliptic in the sense of Lavrentive has been studied.
Journal of Science,University of Tehran(not publish)
پرديس علوم
1
v.
0
no.
1991
https://jos.ut.ac.ir/article_15920_047a7d6729f62143f0bbdc057208119d.pdf
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دکترجبار
خلفی
author
دکتر
ج.م.بروس
author
ک.و.کر
author
text
article
1991
per
A series of new anthralin derivatives were synthesized in which the substituents control stability, disribution and can lead to the in situ generation of activating species.
Although normal alkyl and alkenyl chains have been shown in the representative structural formulae, branched and other types carrying a variety of substituents and functional groups can also be incorporated using the types of reaction outlined in this article.
Journal of Science,University of Tehran(not publish)
پرديس علوم
1
v.
0
no.
1991
https://jos.ut.ac.ir/article_15921_3de3962d856e8c7a0154c9c1ad05467c.pdf
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دکتر محمدولی ولی
زاده
author
عبدالرضا
جعفریان
author
text
article
1991
per
The Kouh.- e- Zar (Toroud) ‘s arc is made of a volcano- plutonic magmatic Complex, with andesitic and granodioritic composition. The Platons are tought to be in the forms of sub volcanic stocks intruding into pyroclastic deposits of the area. The magmatism of the suidied area is considered to be of calcoalcalin type, and its andesaites lay in orogenic andesites suit. The volcanism of the region is superficial manifestation of deep situated plutonics, which both originated from a unic magmatic source. According to the Ewart’s classification of magmas, the magmatic arc of the region is of compressional type. The widespread copper mineralization and its sulfied minerals in the region related to this volcano plutonic arc, that is presented here as a linear arrengement. The zonal alteration around the Baghou granodioritic stock is closely related to copper porphyry mineralization of the region.
Journal of Science,University of Tehran(not publish)
پرديس علوم
1
v.
0
no.
1991
https://jos.ut.ac.ir/article_15922_692fd80b5f98129ec0c436281bc0c530.pdf
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دکترخسرو
خسروتهرانی
author
عبدالعظیم حاج
ملاعلی
author
محمد باقر
فرهادیان
author
اسماعیل
صداقت
author
text
article
1991
per
La coupe stratigraphique étudiée, se situe a 15 K.m. a 1,ouest de la ville de Broudjerd (fig. 1) dans I a zone structurale de chevauchement du Zagros a W- S. W. d’ IRAN. Dans cette zone, les terrains paléozoiques et Mésoziques inférieurs chevauchent vers le Sud-Ouest ceux du Mésozoioue supérieur et du Tertiaire. Le style tectonique est caractérisé par un empilement d’ écailles. La zone de chevauchement est soulignée parfois par un complexse ophiolitique. reste d’ un fond oceaniques iranien, ou des soubassements simiques frotaux de la plaque arabique.
La coupe étudiée a été relevée et échantillodnner avec la collaboration de M. B. Farhadian, E. Sedaghat et A. Hadjmolla- Ali, les géoligues du service geologique d’ IRAN.
L étude des échantillons provenant de la coupe de Kuh- é - Michparvar, nous a conduit a bien détérminer les microfaciès, et les différents genres et espèces de foramimifères carateristiques, afin d’en tirer les résultats biostratigraphiques et paléogeographiques.
Journal of Science,University of Tehran(not publish)
پرديس علوم
1
v.
0
no.
1991
https://jos.ut.ac.ir/article_15923_b318a953bf90f8da85d6d381ca0e17e6.pdf
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دکتر حوری
سپهری
author
text
article
1991
per
Journal of Science,University of Tehran(not publish)
پرديس علوم
1
v.
0
no.
1991
https://jos.ut.ac.ir/article_15924_bcbee590bc1ed08e65351f9488d16f14.pdf
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دکتر احمد
مجد
author
text
article
1991
per
The effects of excess and intimely irrigation on the development of pollen granis an d their grower in soybeans (clark type) were investigated.
Excess irrigation specially in the preflowering and beginning the flowering stages jcauscd significant decrease in the number and growth power of pollen grains. Although the flowers appeared normal but the growth of anthers were abnormal. Many of the anthers before development of the pollen grains were destroyed, and approximately half of the pollen grains in the remained anthers did not show normal feature, size and growth .Most of the destruction happened during segregation of tetraspores and exine formation on the surface of the young microspores. A considerable number of the remained pollen grains lost their growth power and formation of the pollen grain tube.
It is concluded that a considerable decrease in the number of normal pollen grains and their growth power is due to excess and untim ely irrigation and it can be a factor in declining the frop.
Journal of Science,University of Tehran(not publish)
پرديس علوم
1
v.
0
no.
1991
https://jos.ut.ac.ir/article_15925_50f3b324b39c20108b6107e43c2d5a6c.pdf