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Lagoda, Tatiana S.; Kaplan, M. A.; Krivosheev, Ya. V.; Zhavoronkov, L P; Taraban, V. B.; Bokova, M. B.; Bondar, A. M.; Posadskaya, V. M.

doi:10.1023/a:1012958115198

Cited by 3 publications

(2 citation statements)

References 3 publications

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“…The correct operation, adapted to the existing mining and geological conditions of the housing depends mainly on the safety of the crew, and in the further consequence the rhythmicity of the mining process. The problem of housings designed for work in difficult mining and geological conditions, and especially in thawed deposits, is of particular importance [1,5,7]. This is a very serious problem because currently about 50% of active hard coal mining walls in Poland are exploited in rock blast beds [6,8].…”

Section: Introductionmentioning

confidence: 99%

Application of hydraulic press for testing powered roof prop supports

Kipczak

Władzielczyk

2019

E3S Web Conf.

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The report presents the possibility of using press forging, used in a smelter in the crushing and forming steel ingots processes, to the operation of compression powered roof supports. Press have been redeveloped which is to construct, to produce and to exchange handles so that they can be mounted in these housing racks in an upright position.Given the capability of measured quantities, measurement procedure and methodology of the study. There were presented some exemplary results of the tests.

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Section: Introductionmentioning

confidence: 99%

Application of hydraulic press for testing powered roof prop supports

Kipczak

Władzielczyk

2019

E3S Web Conf.

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“…Tetraaza-substituted tetrapyrrolic compounds such as tetraazaporphyrins (TAPs), phthalocyanines (Pcs), and naphthalocyanines (NPcs) demonstrate remarkable photophysical and photochemical properties, such as high photostability, 1,2 ability to photosensitize cells, 3,4 strong one-photon absorption (1PA) in the red (650-750 nm), 1, 2 as well as strong two-photon absorption (2PA) in near-IR (750-1000 nm). [5][6][7][8] These molecules are very attractive for applications based on nonlinear absorption, such as optical power limiting, 9,10 high-density volumetric data storage, 11,12 and deep tissue photodynamic therapy.…”

Section: Introductionmentioning

confidence: 99%

Alternative selection rules for one- and two-photon transitions in tribenzotetraazachlorin: Quasi-centrosymmetrical π-conjugation pathway of formally non-centrosymmetrical molecule

Makarov

Drobizhev

Wicks

et al. 2013

The Journal of Chemical Physics

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We compare the two-photon absorption (2PA) spectra of non-centrosymmetrical metal-free tribenzotetraazachlorin (H 2 TBTAC) and analogous symmetrical tetra-tert-butyl-phthalocyanine (H 2 TtBuPc). Surprisingly, despite formal lack of center of inversion, the 2PA spectrum of H 2 TBTAC displays a two-photon allowed transition at 935 nm, similar to gerade-gerade (g-g) transitions observed in H 2 TtBuPc and in other symmetrical phthalocyanines. This transition is even better resolved in the singlet-singlet excited-state absorption spectrum. We tentatively explain the survival of the g-g transition in H 2 TBTAC by assuming that the main π -electron conjugation pathway in the tetraazasubstituted tetrapyrrole macrocycle bypasses the outer parts of the two oppositely located isoindole rings and thus renders the optically responsive core of the chromophore quasi-centrosymmetrical. By using the independently measured ground-and excited-state absorption extinction coefficients, we also show that the two-photon absorptivity can be quantitatively explained by a simple threelevel model with the lowest energy Q 1 state serving as an intermediate level.

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Near-infrared two-photon absorption in phthalocyanines: Enhancement of lowest gerade-gerade transition by symmetrical electron-accepting substitution

Drobizhev

Makarov

Stepanenko

et al. 2006

The Journal of Chemical Physics

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This paper presents, to the best of our knowledge, the first study of two-photon absorption (2PA) spectra of a number of symmetrically substituted phthalocyanines in the excitation wavelength region from lambda(ex)=800 to 1600 nm. The selected molecules vary by position of substitution (alpha or beta), number of substituent groups (4, 8, or 16), and presence or absence of metal (Zn or Al) in the center. For all phthalocyanines we find a moderately strong (sigma(2) approximately 100-200 GM), pure electronic, gerade-gerade (g-g) 2PA transition, which shows up as a well-resolved relatively narrow peak in the energy region between Q and B bands (lambda(ex)=870-1100 nm). In metallophthalocyanines (MPcs) this lowest g-g transition is followed by the onset of other higher-frequency 2PA transitions. In some metal-free phthalocyanines (H(2)Pcs) we also reveal a second, broader 2PA transition at slightly higher frequency. In both MPcs and H(2)Pcs, we find a strong monotonic increase of integrated strength of the lowest g-g transition as a function of electron-accepting ability of peripheral substituents, expressed as their aggregated Hammett constant. By using few essential states models (three states for MPcs and four states for H(2)Pcs) we demonstrate the primary role of excited-state transition dipole moment in this effect.

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Cited by 3 publications

References 3 publications

Application of hydraulic press for testing powered roof prop supports

Application of hydraulic press for testing powered roof prop supports

Alternative selection rules for one- and two-photon transitions in tribenzotetraazachlorin: Quasi-centrosymmetrical π-conjugation pathway of formally non-centrosymmetrical molecule

Near-infrared two-photon absorption in phthalocyanines: Enhancement of lowest gerade-gerade transition by symmetrical electron-accepting substitution

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