نتایج جستجو برای: fragmentation theory

تعداد نتایج: 814990  

2013
Ewelina Drabik Grzegorz Krasiński Marek Cypryk Roman Błaszczyk Tadeusz Gajda Marek Sochacki

Electron ionization mass spectrometry and density functional theory (DFT) calculations have been used to study the fragmentation of diastereoisomers of protected 1,2-diaminoalkylphosphonic acids. The loss of a diethoxyphosphoryl group and the elimination of diethyl phosphonate were found to be competitive fragmentation processes, which can be used to differentiate both stereoisomers. Selective ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه محقق اردبیلی - دانشکده علوم 1388

: بر اساس تحقیقات صورت گرفته، ترکیبات گیاهی دارای اثرات فارماکولوژی و دارویی فراوانی هستند. در این تحقیق، پودر ریشه گیاه prangos uloptera با دستگاه سوکسیله، توسط حلال های n-hexan، dichloromethan و methanol عصاره گیری شد. عصاره متانولی درفشارپایین ودردمای o45 سانتی گراد قرارگرفت تانهایتا یک ماده صمغی شکل مشاهده شد. بخشی از این ماده به وسیله کارتریج spe-c 18 و با استفاده از محلول هایی با غلطت ها...

2008

In this paper the relationship between three types of trade specialization is analyzed for the period 1990 to 2000. For nine East-Asian countries and the United States the developments in international fragmentation, export specialization and intra-industry specialization are investigated. Asian countries, and specifically China, now play a larger role in international trade. The formation of p...

Journal: :Eur. J. Comb. 2003
Mohammad Taghi Hajiaghayi Mahdi Hajiaghayi

In this paper, we introduce a new property for graphs called bounded fragmentation, by which we mean after removing any set of at most k vertices the number of connected components is bounded only by a function of k. We demonstrate how bounded fragmentation can be used to measure the reliability of a network and introduce several classes of bounded fragmentation graphs. Finally, we pose some op...

1994
R. L. Jaffe L. Randall

We present a QCD based interpretation of heavy quark fragmentation which utilizes the heavy quark mass expansion. By distinguishing between perturbative and non-perturbative QCD effects, we show how to reliably extract mass independent parameters characterizing the fragmentation function. Because these parameters are quark mass independent, this procedure should permit tests of heavy quark symm...

Journal: :Information Systems Research 2015
Frago Kourandi Jan Krämer Tommaso M. Valletti

Net neutrality is believed to prevent Internet fragmentation. We examine the relationship between net neutrality regulation and Internet fragmentation in a game-theoretic model that considers the interplay between termination fees, exclusivity and competition between two Internet Service Providers (ISPs) and between two Content Providers (CPs). An exclusivity arrangement between an ISP and a CP...

1999
Kingman Cheung

CDF recently measured the quantity σ(B + c ) σ(B+) BR(B c →J/ψlν) BR(B+→J/ψK+) , from which we determine the ratio σ(B + c ) σ(b̄) to be (2.08 −0.95) × 10−3. If we interpret this ratio as a fragmentation probability, we show that this ratio is consistent with the prediction by perturbative QCD Bc fragmentation function of Braaten, Cheung, and Yuan. We also estimate the parameter mc (charm quark ...

1993
R. Peschanski

Phenomenological and theoretical aspects of fragmentation for elementary particles (resp. nuclei) are discussed. It is shown that some concepts of classical fragmentation remain relevant in a microscopic framework, exhibiting non-trivial properties of quantum relativistic field theory (resp. lattice percolation).

Journal: :International Journal of Modern Physics A 2016

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید