共查询到20条相似文献,搜索用时 15 毫秒
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为了提高LED光源色温和亮度的调节精度和准确度,结合色温由低向高变化时光色所呈现的渐变特点,提出了一种低色温白光LED灯珠、高色温白光LED灯珠加红绿蓝光LED灯珠补偿式调光的方法.将色温分成三个部分进行调节,每个部分选用不同的LED灯珠组合来进行调光.实验结果表明:不同组合情况下的LED光源的初始输出色温相对于目标值的偏差范围在1%以内;亮度可以在保证色温不变的情况下独立进行调节,初始输出值与目标值的偏差范围在1%以内;经过微调之后可以达到目标值;达到了色温和亮度独立调节的要求;光源发光稳定,不会因为长时间工作而影响调节精度. 相似文献
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Muonic and pionic X-rays of the L- and M-series in C and O have been measured with a Si(Li) detector in the energy range between 7 keV and 60 keV. The target consisted of mylar (C5H4O2). Energies and intensities of 21 transitions have been determined. The strong interaction shift of the pionic 2p level in O was measured and found to be +4.1 ±2.3 eV. The measured width of this level is 11±6 eV. The measured yields have been compared with cascade calculations. 相似文献
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A technique combining image processing and laser interferometry for visualizing and detecting the deformation of transparent cylindrical and spherical sample is proposed. This deformation includes geometric deformation such as volume transition in profilometry and physical deformation such as refractive index change in tomography. Phase contour lines are used for quantitative analysis and graphical representation of the deformation. This method allows us to visually detect the spatial variation of the deformation field and to evaluate the test quality such as misalignment of optical system. A theoretical analysis using phase contour map to characterize the deformation field is described in detail. A method using phase contour map to qualify the interferometric test is proposed. Analysis of test examples is carried out. Suggestions on using phase contour line method to ameliorate test system design are finally discussed. 相似文献
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We show that good approximations to the exact equivalent local potential (ELP) and damping factor of a nonlocal Perey-Buck potential can be calculated in the partial wave WKB approximation of Horiuchi. The exact ELP and damping factor are obtained by means of a method previously given by one of us. We also confirm that an approximate ELP proposed by Bauhoff et al. is of comparable accuracy as the Horiuchi approximation. Thesel-dependent ELP's exhibit reduced attraction in the interior and provide a test for higher order WKB approximations. We subsequently obtain an equivalent velocity dependent potential (EVDP) which is even exactly wave function equivalent to the original nonlocal potential. This almost local potential, unlike the trivial equivalent local potential, is smooth and well-behaved and is therefore particularly useful in nuclear reactions where the off-shell behaviour of the potential is important. 相似文献
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Mario Rabinowitz 《International Journal of Theoretical Physics》2009,48(3):706-722
Discrepancies and accords between quantum (QM) and classical mechanics (CM) related to expectation values and periods are
generally found for both the harmonic oscillator (SHO) and a free particle in a box (FPB), which may apply generally. These
indicate non-locality is expected throughout QM. The FPB energy states violate the Correspondence Principle. Previously unexpected
accords are found and proven that 〈x
2〉
CM
=〈x
2〉
QM
and τ
CM
=τ
QMb
(beat period i.e. beats between the phases for adjoining energy states) for the SHO for all quantum numbers, n. However, for the FPB the beat periods differ at small n. It is shown that a particle’s velocity in an infinite square well varies, no matter how wide the box, nor how far the particle
is from the walls. The quantum free particle variances share an indirect commonality with the Aharonov-Bohm and Aharonov-Casher
effects in that there is a quantum action in the absence of a force. The concept of an “Expectation Value over a Partial Well
Width” is introduced. This paper raises the question as to whether these inconsistencies are undetectable, or can be empirically
ascertained. These inherent variances may need to be fixed, or nature is manifestly more non-classical than expected. 相似文献
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Sergio Doplicher 《Foundations of Physics》2010,40(7):719-732
It was shown in the early seventies that, in Local Quantum Theory (that is the most general formulation of Quantum Field Theory,
if we leave out only the unknown scenario of Quantum Gravity) the notion of Statistics can be grounded solely on the local
observable quantities (without assuming neither the commutation relations nor even the existence of unobservable charged field
operators); one finds that only the well known (para)statistics of Bose/Fermi type are allowed by the key principle of local
commutativity of observables. In this frame it was possible to formulate and prove the Spin and Statistics Theorem purely
on the basis of First Principles. 相似文献
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Stanford Goldman 《Foundations of Physics》1982,12(9):907-917
This is a further development of the author's paper A Unified Theory of Biology and Physics. It is found that male and female in biology, as well as particle and antiparticle in physics, are analogues of symmetrical sideband pairs in communication theory. This gives a new point of view from which to investigate the significance and characteristics of these different paired entities.These findings are intimately related to the fact that there are two transform domains of representation of entities in all the cases involved. They are the somatic and the genetic domains in biology, the configuration domain and the domain of conserved observables in physics, and the time and frequency domains in communication. 相似文献
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The relative stability of alternative carbon nanoparticles with icosahedral symmetry, such as diamond-like nanocrystallites and multiwalled fullerenes (onions), is investigated using the parametric model and the density functional tight-binding (DFTB) method. It is demonstrated that an increase in the size of particles and their hydrogenation favor the stabilization of diamond-like nanocrystallites. The formation of “intermediate” nanostructures consisting of diamond-like nanocrystallites inside the fullerene cage is revealed. The electronic spectra of icosahedral carbon nanoparticles are calculated. 相似文献
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N. V. Lyanguzov V. E. Kaidashev V. B. Shirokov E. M. Kaidashev 《Technical Physics》2012,57(10):1411-1416
Ag and Au nanoparticles are obtained by magnetron sputtering and pulsed laser deposition under different conditions, and the features of their absorption spectra associated with plasmon resonances are investigated. Optimal deposition conditions for obtaining small (5?C10 nm) silver nanoparticles with a high density of surface distribution include an increased argon pressure (2.5 × 10?2 Torr) and a low discharge voltage (100 V). Gold nanoparticle arrays obtained by pulsed laser deposition at a temperature of 200°C in vacuum are more uniformly distributed on the substrates than those deposited at room temperature in argon. It is shown that the maximum of the plasmon absorption shifts toward shorter wavelengths with a decrease in the equivalent thickness of metal films and depends not only on this thickness but also on the type of substrate, which is responsible for the morphology of nanoparticle arrays. 相似文献
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国外超导材料技术研究政策和方向 总被引:1,自引:1,他引:0
超导材料技术是21世纪具有战略意义的高新技术,极具发展潜力和市场前景。世界各发达国家纷纷制定研发计划,给予高度重视和大力支持,加快超导材料技术的基础研究和产业化发展。主要从美国、日本、欧洲国家、韩国等国家的相关研发计划、政策以及主要科研机构的研发概况出发,阐明目前国外超导材料技术的研究政策和方向。 相似文献
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We present detailed measurements of the electrical resistivity for terbium and holmium dihydrides and dideuterides. An analysis of the thermal variation, ?(T), permits to separate two contributions, one stemming from the acoustic or host metal ion vibration and a second which is related to the optical H (or D) vibrations and which is strongly isotope dependent. The thermal variations can be reasonably well represented by a Debye spectrum as concerns the acoustic phonons and by an Einstein spectrum as concerns the optical phonons. We find also that the strength of the electron-phonon coupling is much weaker for the optical phonons as compared to the acoustic ones, in agreement with recent estimates from the theory. 相似文献