Quantum observable

Perhaps quantum mechanics is viewed as the most remarkable development in 20th century physics. Each successful theory is exclusively concerned about "results of measurement". Quantum mechanics point of view is completely different from classical physics in measurement, because in microscopic world of quantum mechanics, a direct measurement as classical form is impossible. Therefore, over the years of developments of quantum mechanics, always challenging part of quantum mechanics lies in measurements.
0p cucdai_1 16102012 29 9 Download

At the end of the 19th century, physics was at its most confidence situation. Classical phyics, as formulated in Newton’s law of mechanics and Maxwell’s theory of electromagnetism, have proved very successful in solving every problem. →At that time there seemed to be no question for which physics could not provide an answer !!! But then it came as a great shock when some simple phenomena were observed which could not be explained by classical physics →a new theory, quantum theory, was developed at the beginning of the 20th century...
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The characteristics lines in Xray spectra result from electronic transitions between inner atomic orbitals. The Xray spectra for most heavy elements are much simpler than the UV/Vis spectra observed in ICPOES, for example. (Only a few lines!!!) Big difference between Xray and UVVis: The radiation is ionizing, and doesn’t just excite electrons to higher levels. Moseley’s law: Predicts the basic relationship of atom number and the frequency of the characteristic lines
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Since the discovery of carbon nanotubes about a decade and a half ago by Sumio Iijima, the scientiﬁc community involved in various aspects of research related to carbon nanotubes and related technologies has observed a steady progress of the science, as is typical for any new and novel material.
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Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Observation of strong anisotropic forbidden transitions in (001) InGaAs/GaAs singlequantum well by reflectancedifference spectroscopy and its behavior under uniaxial strain
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For many classically chaotic systems it is believed that the quantum wave functions become uniformly distributed, that is the matrix elements of smooth observables tend to the phase space average of the observable. In this paper we study the ﬂuctuations of the matrix elements for the desymmetrized quantum cat map. We present a conjecture for the distribution of the normalized matrix elements, namely that their distribution is that of a certain weighted sum of traces of independent matrices in SU(2).
20p noel_noel 17012013 22 5 Download

Various mesoscopic systems have their own unique characteristics, some of which are of importance due to bridging function over classical and quantum mechanics. It is quite natural that human beings living in macroscopic world could hardly grasp the phenomena occurring in the microscopic world in an intuitive manner. This situation offers a vital sense in the "observation" problem necessarily accompanied with the classical means. The fundamental core of the argument between EinsteinPodolskyRosen and Bohr starting in 1935 actually lies in this point.
206p chuyenphimbuon 21072012 31 10 Download

Arapkina and Yuryev Nanoscale Research Letters 2011, 6:345 http://www.nanoscalereslett.com/content/6/1/345 NANO EXPRESS Open Access CMOScompatible dense arrays of Ge quantum dots on the Si(001) surface: hut cluster nucleation, atomic structure and array life cycle during UHV MBE growth Larisa V Arapkina and Vladimir A Yuryev* Abstract We report a direct observation of Ge hut nucleation on Si(001) during UHV molecular beam epitaxy at 360°C. Nuclei of pyramids and wedges were observed on the wetting layer (WL) (M × N) patches starting from the coverage of 5.
13p dauphong13 09022012 25 5 Download

Peres et al. Nanoscale Research Letters 2011, 6:378 http://www.nanoscalereslett.com/content/6/1/378 NANO EXPRESS Open Access Effect of Euimplantation and annealing on the GaN quantum dots excitonic recombination Marco Peres1, Sérgio Magalhães1,2, Vincent Fellmann3, Bruno Daudin3, Armando José Neves1, Eduardo Alves2,4, Katharina Lorenz2,4 and Teresa Monteiro1* Abstract Undoped selfassembled GaN quantum dots (QD) stacked in superlattices (SL) with AlN spacer layers were submitted to thermal annealing treatments.
6p dauphong13 09022012 20 3 Download

Traditionally astrophysics has concerned itself with minimum timescales measured in hours rather than seconds. This was understandable as the available recording media were slow; e.g. chart recorders and photographic plates. In the 1950s, 60s and 70s wavebands away from the optical were developed; from ground based radio studies to space and balloon borne high energy work. In contrast to optical wavelengths instrumentation in these (high and low energy) regimes was capable of time resolutions of less than a second....
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One of the major advances of science in the 20th century was the discovery of a mathematical formulation of quantum mechanics by Heisenberg in 1925 [94].1 From a mathematical point of view, this transition from classical mechanics to quantum mechanics amounts to, among other things, passing from the commutative algebra of classical observables to the noncommutative algebra of quantum mechanical observables. To understand this better we recall that in classical mechanics an observable of a system (e.g. energy, position, momentum, etc.
239p thienbinh1311 13122012 21 2 Download

We developed the synthesis of the caged oxygen donor (lperoxo)(lhydroxo)bis[bis(bipyridyl)cobalt(III)] complex (HPBC) as nitrate salt,which has,compared with the perchlorateform described previously [MacArthur,R., Sucheta,A.,Chong,F.F. & Einarsdottir,O¨ . (1995) Proc. Natl Acad. Sci. USA, 92,8105–8109],greatly enhanced solubility. Now,the quantum efficiency of the photolytical release of dioxygenwas determined tobe 0.4 per photon at a laser wavelength of 308 nm,which was used to observe biological reactions....
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