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81.
Janko Lu?nik Janez Pirnat Zvonko Trontelj 《Applied Physics A: Materials Science & Processing》2009,96(4):1023-1026
A mini-thermometer based on the 35Cl nuclear quadrupole resonance (NQR) frequency temperature dependence in the chlorates KClO3 and NaClO3 was built and successfully tested by measuring temperature and temperature gradient at 77 K and higher in about 100 mm3 active volume of a mini Joule–Thomson refrigerator. In the design of the tank-circuit coil, an array of small coils connected
in series enabled us (a) to achieve a suitable ratio of inductance to capacity in the NQR spectrometer input tank circuit,
(b) to use a single crystal of KClO3 or NaClO3 (of 1–2 mm3 size) in one coil as a mini-thermometer with a resolution of 0.03 K and (c) to construct a system for measuring temperature
gradients when the spatial coordinates of each chlorate single crystal within an individual coil are known. 相似文献
82.
Gregor DOLINAR Bojan KUZMA Janko MAROVT Burcu UNGOR 《Frontiers of Mathematics in China》2019,14(4):715
We study properties of a relation in *-rings, called the core-EP (pre)order which was introduced by H. Wang on the set of all n × n complex matrices [Linear Algebra Appl., 2016, 508: 289–300] and has been recently generalized by Y. Gao, J. Chen, and Y. Ke to *-rings [Filomat, 2018, 32: 3073–3085]. We present new characterizations of the core-EP order in *-rings with identity and introduce the notions of the dual core-EP decomposition and the dual core-EP order in-rings. 相似文献
83.
Nataliya A. Mishchuk Trond Heldal Tormod Volden Janko Auerswald Helmut Knapp 《Electrophoresis》2009,30(20):3499-3506
A microfluidic pump based on electroosmosis of the second kind was designed and fabricated. Experimental results using DC and AC voltages showed a close to second‐order relationship between flow and voltage, in good agreement with theory. The experimental flow rates were considerably lower than the predicted maximum for the micropumps, which can be attributed to the hydrodynamic resistance of the channel network. This also indicates that higher flow velocities are obtainable for modified pump designs. 相似文献
84.
In §2, we prove that if a 2-group G and all its nonabelian maximal sub-groups are two-generator, then G is either metacyclic or minimal non-abelian. In §3, we consider a similar question for p > 2. In §4 the 2-groups all of whose minimal nonabelian subgroups have order 16 and a cyclic subgroup of index 2, are classified.
It is proved, in §5, that if G is a nonmetacyclic two-generator 2-group and A, B, C are all its maximal subgroups with d(A) ≤ d(B) ≤ d(C), then d(C) = 3 and either d(A) = d(B) = 3 (this occurs if and only if G/G′ has no cyclic subgroup of index 2) or else d(A) = d(B) = 2. Some information on the last case is obtained in Theorem 5.3. 相似文献
85.
A mechanical system's modal parameters change when fatigue loading is applied to the system. In order to perform an accelerated vibration-based fatigue test these changes must be taken into account in order to maintain constant-stress loading. This paper presents an improved accelerated fatigue-testing methodology based on the dynamic response of the test specimen to the harmonic excitation in the near-resonant area with simultaneous monitoring of the modal parameters. The measurements of the phase angle and the stress amplitude in the fatigue zone are used for the real-time adjustment of the excitation signal according to the changes in the specimen's modal parameters. The presented methodology ensures a constant load level throughout the fatigue process until the final failure occurs. With the proposed testing methodology it is possible to obtain a S-N point of the Woehler curve relatively quickly and to simultaneously monitor the changes of the specimen's natural frequency and damping loss factor. The presented methodology with real-time control is verified on an aluminum Y-shaped specimen (106 load cycles are achieved in 21 min) and is applicable to a specimen with arbitrary geometry. Besides the faster completion of the fatigue test the methodology can be adopted for the validation of the vibrational fatigue analysis. 相似文献
86.
87.
M. Rakovič L. Janko J. Šeda K. Moltaš K. Bakos 《Journal of Radioanalytical and Nuclear Chemistry》1986,106(5):267-271
Preliminary phantom measurements were carried out for regional determination of calcium in the human forearm. Two paraffine phantoms /large and small/ were activated, either in the free space or surrounded by paraffine plates, by a252Cf neutron source. Differences between neutron flux densities in positions of the ulna and radius are discussed. 相似文献
88.
89.
P. Miller B. Janko B.L. Gyorffy 《Physica C: Superconductivity and its Applications》1993,210(3-4):343-349
We study a simple tight-binding (Hubbard) model for electrons interacting via a short range attractive potential. We show that on a cubic lattice, for a half-filled band the ground state may feature both superconductivity and a charge density wave. We examine the response of such a ground state to an external magnetic field and describe the effect of the charge density wave on the Meissner effect. 相似文献
90.
Zvonimir Janko 《Mathematische Zeitschrift》2006,253(2):419-420
In this note we determine finite nonabelian 2-groups G all of whose nonabelian subgroups are generated by involutions and show that such groups must be quasi-dihedral. This solves
the problem Nr. 1595 for p = 2 in [1]. 相似文献