1,078 research outputs found
Multiple quantum NMR dynamics in a gas of spin-carrying molecules in fluctuating nanopores
The effect of Gaussian fluctuations of nanopores filled with a gas of
spin-carrying molecules () on the multiple quantum (MQ) NMR dynamics is
investigated at different variances and correlation times of the fluctuations.
We show that the fluctuations smooth out the evolution of MQ NMR coherence
intensities which rapidly oscillate as functions of time in the absence of
fluctuations. The growth and decay of the MQ coherence clusters in the
fluctuating nanopore are also investigated.Comment: 10 pages, 3 figure
The multiple quantum NMR dynamics in systems of equivalent spins with the dipolar ordered initial state
The multiple quantum (MQ) NMR dynamics in the system of equivalent spins with
the dipolar ordered initial state is considered. The high symmetry of the MQ
Hamiltonian is used in order to develop the analytical and numerical methods
for an investigation of the MQ NMR dynamics in the systems consisting of
hundreds of spins from "the first principles". We obtain the dependence of the
intensities of the MQ NMR coherences on their orders (profiles of the MQ NMR
coherences) for the systems of spins. It is shown that these
profiles may be well approximated by the exponential distribution functions. We
also compare the MQ NMR dynamics in the systems of equivalent spins having two
different initial states, namely the dipolar ordered state and the thermal
equilibrium state in the strong external magnetic field.Comment: 11 pages 4 figure
The high probability state transfers and entanglements between different nodes of the homogeneous spin 1/2 chain in inhomogeneous external magnetic field
We consider the high probability state transfers and entanglements between
different nodes of the spin-1/2 chains governed by the XXZ-Hamiltonian using
the inhomogeneous stationary external magnetic field. Examples of three-,
four-, ten- and twenty-node chains are represented. A variant of realization of
the proper inhomogeneous magnetic field is discussed.Comment: 16 pages, 2 figure
MODERN EDUCATION TEACHING METHODOLOGY IMPACT
Universitatea de Stat de Medicină şi Farmacie „Nicolae Testemiţanu”, Chişinău, Republica MoldovaIntroducere. Educația modernă de calitate, orientată spre finalități și perspective academice remarcabile este posibilă grație metodelor, strategiilor activ-participative, a tehnicilor și procedeelor variate utilizate în funcție de nevoile, aptitudinile și potențialul fiecărui student. Scopul lucrării. Determinarea corelației dintre tipul și frecvența metodologiei utilizate în studierea limbii engleze medicale, paradigmă aplicată în contextul educațional inovativ, democratic și colaborativ. Materiale și metode. Au fost utilizate publicații științifice naționale și internaționale cu referire la metodologia inovațională praxiologică, implementată în studierea limbii engleze. Rezultate. Profesorul și studenții sunt coparticipanți în procesul de studiu. În activitatea de predare a limbajului englez medical profesorul aplică diverse metode funcționale, productive și eficiente, selectate în funcție de stilul, motivația și competențele studenților. Aceste metode transformă procesul de predare-învățare în unul comprehensibil contextual, soldat cu cunoștințe valoroase, abordare procedurală și rezultate remarcabile la evaluare sumativă, formativă sau longitudinală. Punctăm o varietate de metode eficiente interactiv-creative, de învățare prin colaborare și de evaluare: hărțile conceptuale, metoda SINELG, tehnica 3-2-1, freewriting, metoda Frisco, metoda RAI, utilizarea TIC, metoda audiolinguală, metoda comunicativă, modelul investigației de grup etc. Concluzii. Organizarea procesului de studiu din perspectiva studenților și crearea metodologiei și a traseului personal de învățare a studentului, sporesc motivația, inteligența emoțională, abilitățile academice de comunicare, valorificând cunoștințele procedurale, declarative și condiționale.Background. Quality education oriented towards outstanding academic goals and perspectives is possible thanks to various active-participatory and interactive methods, strategies, techniques and procedures, chosen and used depending on the current level of development i.e. the needs, skills and potential of each student. Objective of the study. To determine the correlation between the type and frequency of the methodology used in the study of medical English, a paradigm applied in the innovative and collaborative educational context. Material and Methods. National and international scientific publications on innovative praxiological methodology implemented in English language study were used. Results. The teacher and the students are co-participants in the study process. Various functional, productive, effective methods in teaching medical English, carefully selected by the teacher depending on the style, motivation, performance, skills of students turn the teaching-learning process into a comprehensive and contextual one with valuable knowledge, , remarkable results in summative, formative, longitudinal evaluation. We point out a variety of effective interactive-creative, collaborative learning, critical thinking development, assessment methods: concept maps, SINELG method, 3-2-1 technique, freewriting, Frisco method, RAI method, audiolingual method, Communicative Language Teaching, Group Investigation Model etc. Conclusions. Organizing the study process from the students’ perspective and creating the methodology, strategies specific to the students’ profile and personal learning path in a flexible, diverse, and cooperative learning environment, increase motivation, emotional intelligence, academic communication skills, valuing procedural, declarative and conditional knowledge
Multiple Quantum NMR Dynamics in Dipolar Ordered Spin Systems
We investigate analytically and numerically the Multiple Quantum (MQ) NMR
dynamics in systems of nuclear spins 1/2 coupled by the dipole-dipole
interactions in the case of the dipolar ordered initial state. We suggest two
different methods of MQ NMR. One of them is based on the measurement of the
dipolar temperature in the quasi-equilibrium state which establishes after the
time of order T2 after the MQ NMR experiment. The other method uses an
additional resonance 45^0 -pulse after the preparation period of the standard
MQ NMR experiment in solids. Many-spin clusters and correlations are created
faster in such experiments than in the usual MQ NMR experiments and can be used
for the investigation of many-spin dynamics of nuclear spins in solids.Comment: 11 pages, 3 figures. accepted for publication in Physical Review
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