Periodic solutions of the quasilinear beam vibration equation with homogeneous boundary conditions

We prove the existence of infinitely many time-periodic solutions of the quasilinear beam vibration equation with homogeneous boundary conditions for the case in which the nonlinear term has power-law growth. We also prove the existence of at least one periodic solution provided that the nonlinear term satisfies the resonance-free condition.     

Some Aspects of the Effective Detection of Ammonium Nitrate-Based Explosives by Pulsed NQR Method

The nuclear quadrupole resonance (NQR) method has been applied to ammonium nitrate (AN)-based explosives, ANFO and REOGEL+, to find an optimized multi-pulse technique for effective detection. The relaxation parameters and signal intensities for nitrogen-14 lines of these substances were measured. The experimental results of applying the proposed multi-pulse technique in these samples are presented and convincingly demonstrate a path toward efficient detection. A detection using sequences of this character could be achieved over real-world scan volumes for screening of goods. It was proven that the cross-polarization technique can significantly enhance the NQR signal for AN-based explosives.     

Kinetics and mechanism of reactions of arenes in the HVO3-sulfuric acid system: Extended compensation effect

Kinetics, activation parameters, and the kinetic isotope effect (KIE) of hydrogen have been determined for the first rate-limiting step of the reactions of benzene, monoalkylbenzenes, dimethylbenzenes, and trimethylbenzenes in HVO₃-sulfuric acid (54–70 wt % H₂SO₄) solutions. The effects of solution acidity on the rate constants (k) and KIE have been studied. The reactions begin with electron transfer from the arene to VO ₂ ⁺ and end with oxidative coupling: $PhCH_3 \xrightarrow{{VO_2^ + }}PhCH_3^{ + \cdot } \xrightarrow{{ - H^ \cdot }}PhCH_2^ + \xrightarrow{{PhCH_3 }}PhCH_2 C_6 H_4 CH_3 .$ logk is a linear function of the ionization potential of the arene (I _ArH). A three-parameter correlation is for the first time established between the activation energy (E), the logarithm of the preexponential factor (log A), and I _ArH: logA = 0.15E ? 0.058I _ArH + 49.1 (E and I _ArH are expressed in kJ/mol). The reactions of arenes with VO ₂ ⁺ , NO ₂ ⁺ , and Co³⁺ are intercompared.     

Pair production of exotic particles at\mathop p\limits^{( - )} p colliding beams

A maximally complete set of differential cross section has been obtained in Born approximation for pair production of exotic particles with various spinsJ=0,1/2, 1 and quantum numbers (colored and colorless) both inq \(\bar q\) - andgg-collisions. For vector boson processes we systematically use the connection of the unitary of their interaction with gauge invariance, factorization properties of nonabelian gauge amplitudes and the presence of kinematic zeros. Besides, the problem of admissibility of massless limit for these processes is being discussed. The, yields of exotic particle pairs at \(\mathop p\limits^{( - )} \) p colliding beams in TeV energy range have been calculated and limits for the accessible mass range have been found.     

Thermocapillary instability of a deformable liquid film

The instability of a plane liquid film with a uniform transverse temperature gradient under conditions of weightlessness is considered. The surface tension is assumed to depend linearly on the temperature. On the basis of an exact solution of the neutral perturbation problem for a layer with deformable boundaries, the instability domains, the dispersion curves, and the shape of the perturbations are determined. It is shown that on the interval of low Prandtl numbers both thermocapillary waves with predominantly longitudinal flow and capillary waves, supported by the thermocapillary effect, with intense transverse liquid flow can develop on the film.Perm'. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 5, pp. 30–36, September–October, 1996.     

Study of the interaction of hydrogen with palladium-containing catalysts of methane oxidation

The reaction of palladium-containing catalysts PdCl₂/SiO₂ [ratio of the components 0.3:100 (molar)] with H₂ (300°C) after methane oxidation leads to the formation of RH: methane, ethane, propane, n-butane, and isobutane. The sources of RH are PdC_x — products of incomplete oxidation of CH₄ — as well as organic impurities in silica gel. Additions of NaCl (NaCl:SiO₂ = 7:100) triple the yield of RH. Catalysts with additions of H₂SO₄ (H₂SO₄:SiO₂ = 40.100) are not hydrogenated to RH.L. M. Litvinenko Institute of Physico-Organic Chemistry and Coal Tar Chemistry, National Academy of Sciences of Ukraine, 70 R. Lyuksemburg Street, Donetsk 340114, Ukraine. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 32, No. 3, pp. 177–181, May–June, 1996. Original article submitted July 20, 1995.     

Electrochemical thiocyanation of dodecahydro-7,8-dicarba-<Emphasis Type="Italic">nido</Emphasis>-undecaborate and 7,8-dimethyldecahydro-7,8-dicarba-<Emphasis Type="Italic">nido</Emphasis>-undecaborate monoanions

Electrochemical thiocyanation of the dodecahydro-7,8-dicarba-nido-undecaborate and 7,8-dimethyldecahydro-7,8-dicarba-nido-undecaborate monoanions afforded thiocyanate derivatives of these compounds, which were isolated as alkylammonium salts. The structures of the synthesized compounds were determined by the data from IR, ¹H and ¹¹B NMR, and ¹¹B-¹¹B NMR COSY spectroscopy. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1553–1556, July, 2005.