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31.
Dontchev et al. [4] introduced the notion of ℐ-g-closed sets. In [16], the further properties of ℐ-g-closed sets are investigated. In this paper, we introduce the notion of ℐ-mg-closed sets and obtain the unified characterizations for certain families of subsets between *-closed sets and ℐ-g-closed sets in an ideal topological space. 相似文献
32.
I. Ursu I. Apostol M. Dinescu I. N. Mihăilescu A. Popa A. M. Prokhorov V. I. Konov N. I. Chapliev 《Applied Physics A: Materials Science & Processing》1984,34(2):133-138
Progressive damage of aluminium mirrors subjected to microsecond pulsed TEA-CO2 laser irradiation in air, at incident intensity levels lower than the thresholds for melting induction and air breakdown ignition, was evidenced by electron microscopy investigations. A simple model was developed accounting for the results of our experimental studies. 相似文献
33.
Conclusions
From Stachys annua L. have been isolated the diacetate and two monoacetates of a new diterpenoid C20H32O3, which has been named stachysolone. It has been shown that stachysolone is a bicyclic ,-unsaturated ketone containing secondary and tertiary hydroxy groups.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 1, pp. 7–10, 1969 相似文献
34.
A microsecond periodic pulse was applied on thin probes in a positive column of a neon or helium glow discharge. The local transient phenomena provoked by this pulse were detected by a photomultiplier and presented in a time-distance display. They are qualitatively described and explained. The results are in good agreement with previous theories. 相似文献
35.
In this paper we consider two von Neumann subalgebras and of a type II1 factor . For a map φ on , we define
36.
A. P. Nizovtsev S. Ya. Kilin F. Jelezko I. Popa A. Gruber C. Tietz J. Wrachtrup 《Optics and Spectroscopy》2003,94(6):848-858
The spin-selective photokinetics of a single matrix-isolated impurity molecule with a triplet-triplet optical transition, T 0–T 1, is considered and the manifestations of the photokinetics in the fluorescence excitation spectra and intensity autocorrelation functions g (2)(τ) of the molecule undergoing narrow-band optical excitation is studied to resolve the fine structure of the transition. The rates of intersystem crossings (ISCs) T 1→S→T 0 to and from a nonradiating singlet state S of the molecule and the rate of population relaxation among the ground (T 0) state sublevels can be obtained from the spectra and g (2)(τ) using the analytical expressions obtained. New experiments on an individual NV defect center in nanocrystals of diamond, where, for the first time, the fine structure of its triplet-triplet 3 A-3 E zero-phonon optical transition (~637 nm) at 1.4 K was resolved, are interpreted. It is concluded that the rate of the ISC transition from the m S =0 sublevel of the excited 3 E state to the singlet 1 A state (~1 kHz) is much slower than the rates from the m S =±1 substates, while the rates of ISC transitions to different m S substates of the ground 3 A state are close to each other (~1 Hz). As a result, only the optical transition between m S =0 sublevels in the 3 A-3 E manifold contributes strongly to the fluorescence. The experimentally observed double-exponential decay of the g (2)(τ) function is explained by the two pathways available to the center for it to leave the S state: (i) the S→ T 0(m S )=0) transition and (ii) the S→T 0(m S =±1) transitions followed by the slow spin-lattice relaxation T 0(m S =±1)→T 0(m S =0) (rate ~0.1 Hz). The work is important for studies where the NV center is used as a single photon source or for quantum information processing. 相似文献
37.
Zinc selenide (ZnSe) thin films (d = 0.11-0.93 μm) were deposited onto glass substrates by the quasi-closed volume technique under vacuum. Their structural characteristics were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). The experiments showed that the films are polycrystalline and have a zinc blende (cubic) structure. The film crystallites are preferentially oriented with the (1 1 1) planes parallel to the substrate surface. AFM images showed that the films have a grain like surface morphology. The average roughness, Ra = 3.3-6.4 nm, and the root mean square roughness, Rrms = 5.4-11.9 nm, were calculated and found to depend on the film thickness and post-deposition heat treatment.The spectral dependence of the absorption coefficient was determined from transmission spectra, in the range 300-1400 nm.The values of optical bandgap were calculated from the absorption spectra, Eg = 2.6-2.7 eV.The effect of the deposition conditions and post-deposition heat treatment on the structural and optical characteristics was investigated. 相似文献
38.
39.
We describe a simple method for tracking the course of microbial degradation of polysaccharide-rich feedstocks. The method
involves determining total polysaccharides present in the feedstock, measured in glucose equivalents, relative to the fractional
component of polysaccharides exhibiting 2,3-dinitrosalycylic acid aldehyde activity. The ratio of total polysaccharide to
aldehyde activity, defined as the end-point fragmentation (EPF) index, is then calculated and tracked as it shifts as microbial
degradation of polysaccharide-rich feedstock progresses. While degradation occurs, the EPF index falls. It bottoms out at
an asymptotic limit marking the point in time where further degradation of the polysaccharide-rich feedstock has ceased. The
EPF index can be used to follow the progressive breakdown of composting polysaccharide-rich waste. It may also have applicability
as a means of tracking the turnover of polysaccharides in other complex environments including soil, sediments, wetlands,
and peat bogs. 相似文献
40.
We prove that the existence of a global prime integral leads, in appropriate conditions, to the Hyers–Ulam stability of a linear partial differential equation of first order. 相似文献