Construction d'une base antisymétrique dans l'espace idéal

1969 ◽  
Vol 47 (23) ◽  
pp. 2645-2650 ◽  
Author(s):  
P. A. Simard

An antisymmetric basis has been set up in the ideal space as a combination of one boson and one ideal quasi-particle state; in this way a three quasi-particle system may be studied. The knowledge of solutions of linearized equations for two quasi-particles is a requisite for the setting up of this basis. The exclusion principle is thus introduced correctly. The spurious states coming from the non-conservation of the number of particles are separated out and can be rejected easily. The method can be used only in QTD approximation. The one-shell case is discussed as a verification of the method.

1967 ◽  
Vol 45 (10) ◽  
pp. 3241-3245 ◽  
Author(s):  
P. A. Simard

A method is presented in the scheme of the boson approximation such that the antisymmetry between the quasi-particles is introduced naturally. Based on the transcription of the quasi-particle into the ideal space, the method enables one to give a unified description of the anharmonic corrections in the even–even and odd spherical nuclei.


1970 ◽  
Vol 48 (7) ◽  
pp. 819-826 ◽  
Author(s):  
M. Banville ◽  
P. A. Simard

The transcription of the quasi-particle in the ideal space has been studied in such a way that all terms in the Hamiltonian in the QTD approximation for the system of four quasi-particles can be found. It is found that an infinity of solutions exists which verify the commutator {α, α+} while yielding correct Hamiltonian matrix elements. Finally, particular solutions which do not verify this commutator are found. Their particular invariance properties under canonical transformations make them relatively easy to obtain. Nonphysical states are eliminated by these transcriptions and all the physical states appear properly antisymmetrized.


1969 ◽  
Vol 47 (1) ◽  
pp. 103-111 ◽  
Author(s):  
P. A. Simard

A transcription of the quasi-particle into the ideal space is written in such a way that all the terms which contribute for the three quasi-particles system in QTD approximation can be found. Canonical transformations between the ideal quasi-particles are studied. An application to one shell is done with the result that the boson method gives exactly the same spectra as the Kuo method.


2020 ◽  
pp. 97-107
Author(s):  
Quyen Vu Viet ◽  
Trang Vu Thi Thu ◽  
Nam Nguyen Duong ◽  
Binh Duong Ngoc ◽  
Huy Tran Duc

The magnesium and magnesium alloys has applied widely in different industrial aspects in Vietnam in the modern life. Especially, the products from magnesium alloys implementing in the automotive have increased rapidly since the car elements tend to be generated by the light alloys in order to save the fuel. However, in the current time, Vietnam has no factories to produce the magnesium to adapt the domestic demand although it owns an enrich resource of raw materials. This research indicates the possibility of using the dolomite ore in Thanhhoa – Vietnam to make the magnesium as well as evaluate the primary factors like recovering temperature, reducing agent rate, recovering time having effect on the reduction efficiency of Thanhhoa dolomite by metallothermic method in vacuum (Pidgeon Process). This is basic process, low investment and suitable for the small and medium scales in Vietnam. The experiment includes heating, indicating the chemical ingredients and recovering experiment on the dolomite after calcination (dolime) by using ferrosilicon. The thermodynamic model is created to estimate the recovering efficiency in the Pidgeon. The result shows that the CaO/MgO molar ratio of calcination dolomite in Thanhhoa is nearly 1.5 which is suitable to produce magnesium in the case of highly-required efficiency and pureness. Besides, the result from the furnace of the experiment is lower than the one in the model. The samples are set up to check the influence of the rate of ferrosilicon in the compound. The result indicates that the ideal efficiency reaches 85 % with 30 % ferrosilicon. Moreover, the study confirms that the optimal operating conditions in this process are recovering during three hours at 1200 °C and 100 Pa pressure. This result proves the potential application of Thanhhoa dolomite in the industry suitable with the current condition in Vietnam


Author(s):  
Hallie M. Franks

In the Greek Classical period, the symposium—the social gathering at which male citizens gathered to drink wine and engage in conversation—was held in a room called the andron. From couches set up around the perimeter of the andron, symposiasts looked inward to the room’s center, which often was decorated with a pebble mosaic floor. These mosaics provided visual treats for the guests, presenting them with images of mythological scenes, exotic flora, dangerous beasts, hunting parties, or the specter of Dionysos, the god of wine, riding in his chariot or on the back of a panther. This book takes as its subject these mosaics and the context of their viewing. Relying on discourses in the sociology and anthropology of space, it argues that the andron’s mosaic imagery actively contributed to a complex, metaphorical experience of the symposium. In combination with the ritualized circling of the wine cup from couch to couch around the room and the physiological reaction to wine, the images of mosaic floors called to mind other images, spaces, or experiences, and, in doing so, prompted drinkers to reimagine the symposium as another kind of event—a nautical voyage, a journey to a foreign land, the circling heavens or a choral dance, or the luxury of an abundant past. Such spatial metaphors helped to forge the intimate bonds of friendship that are the ideal result of the symposium and that make up the political and social fabric of the Greek polis.


Author(s):  
Michael P. Lynch

This chapter argues that academic freedom is justified because it is an inherently epistemic practice that serves the ideals of democracy. With Dewey, it is argued that “The one thing that is inherent and essential [to the idea of a university] is the ideal of truth.” But far from being apolitical, the value of pursuing truth and knowledge—the value that justifies academic freedom, both within and without the public mind—is a fundamental democratic value, and for three reasons: the practices of academic inquiry exemplify rational inquiry of the kind needed for democratic deliberation; those practices serve to train students to pursue that kind of inquiry; and those practices are important engines of democratic dissent.


Author(s):  
Frank S. Levin

Surfing the Quantum World bridges the gap between in-depth textbooks and typical popular science books on quantum ideas and phenomena. Among its significant features is the description of a host of mind-bending phenomena, such as a quantum object being in two places at once or a certain minus sign being the most consequential in the universe. Much of its first part is historical, starting with the ancient Greeks and their concepts of light, and ending with the creation of quantum mechanics. The second part begins by applying quantum mechanics and its probability nature to a pedagogical system, the one-dimensional box, an analog of which is a musical-instrument string. This is followed by a gentle introduction to the fundamental principles of quantum theory, whose core concepts and symbolic representations are the foundation for most of the subsequent chapters. For instance, it is shown how quantum theory explains the properties of the hydrogen atom and, via quantum spin and Pauli’s Exclusion Principle, how it accounts for the structure of the periodic table. White dwarf and neutron stars are seen to be gigantic quantum objects, while the maximum height of mountains is shown to have a quantum basis. Among the many other topics considered are a variety of interference phenomena, those that display the wave properties of particles like electrons and photons, and even of large molecules. The book concludes with a wide-ranging discussion of interpretational and philosophic issues, introduced in Chapters 14 by entanglement and 15 by Schrödinger’s cat.


2021 ◽  
Vol 37 (01) ◽  
pp. 045-052
Author(s):  
Mario Bazanelli Junqueira Ferraz ◽  
Guilherme Constante Preis Sella

AbstractNasal dorsal preservation surgery was described more than 100 years ago, but recently has gained prominence. Our objective is to show the surgical technique, the main indications and counterindications, and the complications. It is a technique that does not cause the detachment of the upper lateral cartilage (ULC) from the nasal septum, and has the main following sequence: preparation of the septum and its resection can be at different levels (high or low, i.e., SPAR [septum pyramidal adjustment and repositioning] A or B); preparation of the pyramid; transversal osteotomy; lateral osteotomy(s); and septopyramidal adjustment. The result is a nose with a lower radix than the original, a deprojection of the nasal dorsum tending to maintain its original shape; an increase in the interalar distance (IAD) and enlargement of the nasal middle ⅓; and loss of projection of the nasal tip and roundness of the nostrils. Thus, the ideal candidate is the one who benefits from such side effects, that is: tension nose, that is, high radix with projected dorsum, projected anterior nasal septal angle (ANSA), narrow middle ⅓, narrow IAD, thin nostrils and straight perpendicular plate of the ethmoid (PPE), and, depending on the characteristics, the deviated nose. The counterindications are low radix, irregularities in the nasal dorsum, ANSA lower than rhinion, and a wide middle ⅓. And the main stigmas are: a nose with a very low radix, middle ⅓ enlarged, residual hump, and saddling of the supratip area. Other issues of this technique are: the shape of the radix; the need or not to remove PPE; wide dorsum; irregular dorsum; ANSA lower than rhinion; weak cartilages; long nasal bone; deviated PPE; and obsessive patient. We conclude that this is a great technique for noses with characteristics suitable to it; care must be taken with the stigmas it can cause.


2008 ◽  
Vol 10 (1) ◽  
pp. 22-27 ◽  
Author(s):  
Roch Plewik ◽  
Piotr Synowiec ◽  
Janusz Wójcik

Two-phase CFD simulation of the monodyspersed suspension hydraulic behaviour in the tank apparatus from a circulatory pipe The hydrodynamics in fluidized-bed crystallizers is studied by CFD method. The simulations were performed by a commercial packet of computational fluid dynamics Fluent 6.x. For the one-phase modelling (15), a standard k-ε model was applied. In the case of the two-phase flows the Eulerian multi-phase model with a standard k-ε method, aided by the k-ε dispersed model for viscosity, has been used respectively. The collected data put a new light on the suspension flow behaviour in the annular zone of the fluidised bed crystallizer. From the presented here CFD simulations, it clearly issues that the real hydraulic conditions in the fluidised bed crystallizers are far from the ideal ones.


Author(s):  
Phan Thành Nam ◽  
Marcin Napiórkowski

AbstractWe consider the homogeneous Bose gas on a unit torus in the mean-field regime when the interaction strength is proportional to the inverse of the particle number. In the limit when the number of particles becomes large, we derive a two-term expansion of the one-body density matrix of the ground state. The proof is based on a cubic correction to Bogoliubov’s approximation of the ground state energy and the ground state.


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