Calculation and analysis of vibrational spectra of adenine–thymine,guanine–cytosine,and adenine–uracil complementary pairs in the condensed state

We have calculated the frequencies of the normal vibrations of the complementary nucleic acid base pairs adenine–thymine, guanine–cytosine, adenine–uracil, corresponding to the Watson–Crick structure, and the adenine–uracil pair, corresponding to the Hoogsteen structure, in condensed states and we interpret the spectra. We determine the contributions of hydrogen bonds to the vibrational modes of the complementary pairs. We have analyzed the nature of the relative displacements of the nucleic acid bases as integral molecular units along the hydrogen bonds. We show the role of hydrogen bonds in tautomeric interconversions of complementary nucleic acid base pairs. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 1, pp. 84–92, January–February, 2009.     

热带海洋与中低纬大气相互作用的信息传输特征分析

基于传递熵概念和方法定义气象场的信息源特征度、信息汇特征度和信息传输平衡特征度.使用海表温度和高度场资料计算海气相互作用过程中的信息传递.侧重分析赤道中东太平洋(20?S-20?N,170?E-100?W)与热带地区、北半球和南半球中高纬度地区大气之间的信息传递,给出信息传递的区域和全球分布特征;并提取海表温度指数和高度场指数分析赤道中东太平洋与大气信息传递特征的季节变化和年代际变化.研究结果表明,海洋信息源主要分布在热带地区,大气信息汇主要分布在中纬度地区,从热带地区到中纬度地区,海洋对大气的强迫作用在减弱,而大气对海洋的强迫作用在增强;不同区域不同层次的高度场对赤道中东太平洋海表温度有着不同的响应,热带中东太平洋上空高度场最大延迟为4个月.欧亚大陆中部上空和北美大陆上空高度场均随时间延迟呈现波动性变化:欧亚大陆中部上空高度场随时间延迟呈现增强的趋势,而北美大陆上空高度场随时间延迟呈现减弱的趋势.海表温度指数对热带中东太平洋上空850 hPa和欧亚大陆中部上空500 hPa高度场指数的传递熵以2000 s最弱,而海表温度指数对北美大陆上空700 hPa高度场指数的传递熵以2000 s最强.表明不同年代际背景下不同区域大气对赤道中东太平洋海表温度异常的响应是不同的.然而不同季节的响应却十分相似:冬季最强,秋季次之,春季再次,夏季最弱.     

Modeling the gain and amplified spontaneous emission spectra of erbium-doped fiber amplifiers

We have used a modified “black box” model to calculate the gain and amplified spontaneous emission spectra for an erbium-doped fiber amplifier. Based on this and using an occupation number model, we determined the limiting spectral efficiency of information transfer in such an amplifier. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 273–276, March–April, 2006.     

Longitudinal polarisation of Λ and Λ̄ hyperons in lepton–nucleon deep-inelastic scattering

We consider models for the spin transfers to Λ and Λ̄ hyperons produced in lepton–nucleon deep-inelastic scattering. We make predictions for longitudinal Λ and Λ̄ spin transfers for the COMPASS experiment and for HERA, and for the spin transfer to Λ hyperons produced at JLAB. We demonstrate that accurate measurements of the spin transfers to Λ and Λ̄ hyperons with COMPASS kinematics have the potential to probe the intrinsic strangeness in the nucleon. We show that a measurement of Λ̄ polarisation could provide a clean probe of the spin transfer from s̄ quarks and provides a new possibility to measure the antistrange quark distribution function. COMPASS data in a domain of x that has not been studied previously will provide valuable extra information to fix models for the nucleon spin structure. The spin transfer to Λ̄ hyperons, which could be measured by the COMPASS experiment, would provide a new tool to distinguish between the SU(6) and Burkardt–Jaffe (BJ) models for baryon spin structure. In the case of the HERA electron–proton collider experiments with longitudinally-polarised electrons, the separation between the target and current fragmentation mechanisms is more clear. It provides a complementary probe of the strange quark distribution and helps distinguish between the SU(6) and BJ models for the Λ and Λ̄ spin structure. Finally, we show that the spin transfer to Λ hyperons measured in a JLAB experiment would be dominated by the spin transfer of the intrinsic polarised-strangeness in the remnant nucleon, providing an independent way to check our model predictions. PACS 13.60.Rj; 13.87.Fh; 13.88.+e; 14.40.Ev; 14.20.Jn     

Time Resolved Fluorescence and Energy Transfer Analysis of Nd<Superscript>3+</Superscript>–Yb<Superscript>3+</Superscript>–Er<Superscript>3+</Superscript> Triply-Doped Ba–Al-Metaphosphate Glasses for an Eye Safe Emission (1.54 μm)

This paper reports on the preparation and systematic analysis of energy transfer mechanisms in Nd³⁺–Yb³⁺–Er³⁺ co-doped new series of barium-alumino-metaphosphate glasses. The time resolved fluorescence of Nd³⁺ in triply doped Ba–Al-metaphosphate glasses have revealed that, Yb³⁺ ions could function as quite efficient bridge for an energy transfer between Nd³⁺ and Er³⁺ ions. As a result, a fourfold emission enhancement at 1.54 μm of Er³⁺ ions has been achieved through an excitation of ⁴F_5/2 level of Nd³⁺ at 806 nm for the glass having 3 mol% Yb³⁺ with an energy transfer efficiency reaching up to 94%. Decay of donor (Nd³⁺) ion fluorescence has been analyzed based on theoretical models such as direct energy transfer model (Inokuti–Hirayama) and migration assisted energy transfer models (Burshtein’s hopping and Yokota–Tanimoto’s diffusion). The corresponding energy transfer parameters have been evaluated and discussed. Primarily, electrostatic dipole–dipole (s ~ 6) interactions are found to be responsible for the occurrence of energy transfer process in theses glasses.     

On Convexity of Generalized Wigner–Yanase–Dyson Information

The convexity of the Wigner–Yanase–Dyson information, as first proved by Lieb, is a deep and fundamental result because it leads to the strong subadditivity of quantum entropy. The Wigner–Yanase–Dyson information is a particular kind of quantum Fisher information with important applications in quantum estimation theory. But unlike the quantum entropy, which is the unique natural quantum extension of the classical Shannon entropy, there are many different variants of quantum Fisher information, and it is desirable to investigate their convexity. This article is devoted to studying the convexity of a direct generalization of the Wigner–Yanase–Dyson information. Some sufficient conditions are obtained, and some necessary conditions are illustrated. In a particular case, a surprising necessary and sufficient condition is obtained. Our results reveal the intricacy and subtlety of the convexity issue for general quantum Fisher information.      

Porphyrin analogs in bacterial photosynthesis

The electron transfer process in bacterial reaction centers is investigated. It is found that the side indole group Trp M252 in Rb sphaeroides (Trp M250 in Rps viridis) assists tunneling electron transfer by a distance of ∼14Å from pheophytin to quinone. Reported at the VIIIth International Conference on Spectroscopy of Porphyrins and Their Analogs, Minsk, September 22–26, 1998. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 496–500, July–August, 1999.     

Upconversion due to energy transfer involving Pr<Superscript>3+</Superscript> ions in pairs

Upconversion luminescence in triply ionized praseodymium-doped TeO₂–Li₂O glass using excitation at ∼590 nm into the ¹D₂ level from a dye laser pumped with the second harmonic of a pulsed Nd:YAG laser has been reported. The mechanism involved in the upconversion emission observed at ∼480 nm indicates that the most important contribution is energy transfer among praseodymium ions in pairs followed by the dipole–dipole interaction. The rate-equation model for the emission at ∼480 nm that provides direct information to determine the energy-transfer rates containing the pair of states involved in the upconversion process has been explored.     

Hydroquinone–Benzonitrile System: Intramolecular Charge-Transfer and Computational Studies

A novel intramolecular donor–acceptor system of hydroquinone–benzonitrile was synthesized. Its photo-induced intramolecular charge-transfer (ICT) transition was confirmed by (1) shift of its emission maximum with increasing solvent polarity, (2) high dipole moment for the ICT excited state calculated from the Lippert equation, and (3) its HOMO and LUMO. According to the extent of separation between HOMO and LUMO, it is suggested that substituent position (ortho, meta, or para) in the donor–acceptor biphenyls is not a key point for the photo-induced intramolecular charge transfer and the donor with two alkoxy or hydroxy groups has more photo-induced charge transfer transitions than the one with one alkoxy or hydroxy group. In other words, the hydroquinone–benzonitrile system displays more photo-induced charge transfer transitions than 4COB (4-cyano-4′-butyloxybiphenyl).     

Role of highly efficient collisions in collisional transfer of vibrational energy in benzophenone-foreign gas mixtures

Collisional losses of vibrational energy in mixtures of benzophenone excited by nitrogen laser radiation (λ=337 nm) and foreign gases (Ar, Kr, SF₆, C₅H₁₂) were studied by time-resolved delayed luminescence. It is established that the intensities and rates of decay of the fast and slow components of delayed luminescence can be used to evaluate the characteristics of V–V– and V–T–transfer of vibrational energy. For the V-V-process, the efficiencies and mean energies transferred in a collision are determined. It is shown that in the mixture with multiatomic gases, vibrational equilibrium is reached after a few collisions, the number of which decreases as the molecule of the foreign gas becomes more complicated. The V–V–process is characterized by high efficiencies of collisions typical for “supercollisions”. The experimental characteristics of V-V-transfer correlate well with ergodic transfer of vibrational energy predicted by statistical theories. 0120 0126 V 3 Institute of Molecular and Atomic Physics of the National Academy of Science of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 3, pp. 340–345, May–June, 1998.     

Notes on Superadditivity of Wigner–Yanase–Dyson Information

The classical Fisher information is superadditive in the sense that the Fisher information of a bivariate probability density is always not less than the sum of those of the marginals. The longstanding conjecture concerning the superadditivity of the Wigner–Yanase–Dyson information is a quantum analogue of this property. It is remarkable that Hansen constructed a numerical counterexample to the quantum case (J. Stat. Phys. 126: 643–648, 2007). However, the requirement of superadditivity of an information-theoretic quantity such as the Wigner–Yanase–Dyson information seems so intuitive, it is desirable to identify conditions as general as possible such that the superadditivity holds. In this paper, we establish the superadditivity in several physically significant cases.     

Analysis of adiabatic transfer in cavity quantum electrodynamics

A three-level atom in a Λ configuration trapped in an optical cavity forms a basic unit in a number of proposed protocols for quantum information processing. This system allows for efficient storage of cavity photons into long-lived atomic excitations, and their retrieval with high fidelity, in an adiabatic transfer process through the ‘dark state’ by a slow variation of the control laser intensity. We study the full quantum mechanics of this transfer process with a view to examine the non-adiabatic effects arising from inevitable excitations of the system to states involving the upper level of Λ, which is radiative. We find that the fidelity of storage is better, the stronger the control field and the slower the rate of its switching off. On the contrary, unlike the adiabatic notion, retrieval is better with faster rates of switching on of an optimal control field. Also, for retrieval, the behaviour with dissipation is non-monotonic. These results lend themselves to experimental tests. Our exact computations, when applied to slow variations of the control intensity for strong atom–photon couplings, are in very good agreement with Berry’s superadiabatic transfer results without dissipation.     

Improved laser-induced forward transfer of organic semiconductor thin films by reducing the environmental pressure and controlling the substrate–substrate gap width

Laser-induced forward transfer (LIFT) has been investigated for bilayer transfer material systems: silver/organic film (Alq₃ or PFO). The LIFT process uses an intermediate dynamic release layer of a triazene polymer. This study focuses on the effect of introducing a controlled donor–receiver substrate gap distance and the effect of doing the transfer at reduced air pressures, whilst varying the fluence up to ∼200 mJ/cm². The gap between ‘in-contact’ substrates has been measured to be a minimum of 2–3 μm. A linear variation in the gap width from ‘in contact’ to 40 μm has been achieved by adding a spacer at one side of the substrate–substrate sandwich. At atmospheric pressure, very little transfer is achieved for Alq₃, although PFO shows some signs of successful doughnut transfer (with a large hole in the middle) in a narrow fluence range, at gaps greater than 20 μm. For the transfer of Ag/PFO bilayers at atmospheric pressure, the addition of a PFO layer onto the receiver substrate improved the transfer enormously at smaller gaps and higher fluences. However, the best transfer results were obtained at reduced pressures where a 100% transfer success rate is obtained within a certain fluence window. The quality of the pixel morphology at less than 100 mbar is much higher than at atmospheric pressure, particularly when the gap width is less than 20 μm. These results show the promise of LIFT for industrial deposition processes where a gap between the substrates will improve the throughput.     

The Nambu–Jona–Lasinio model of light nuclei

The Nambu–Jona–Lasinio model of the deuteron suggested by Nambu and Jona–Lasinio (Phys. Rev. 124 (1961) 246) is formulated from the first principles of QCD. The deuteron appears as a neutron–proton collective excitation, i.e. a Cooper np–pair, induced by a phenomenological local four–nucleon interaction in the nuclear phase of QCD. The model describes the deuteron coupled to itself, nucleons and other particles through one–nucleon loop exchanges providing a minimal transfer of nucleon flavours from initial to final nuclear states and accounting for contributions of nucleon–loop anomalies which are completely determined by one–nucleon loop diagrams. The dominance of contributions of nucleon–loop anomalies to effective Lagrangians of low–energy nuclear interactions is justified in the large N _C expansion, where N _C is the number of quark colours. Received: 10 March 2000     

Investigation of heat transfer from a lead heat carrier to a tube streamlined longitudinally

Results of experimental studies on the local characteristics of heat transfer from a lead heat carrier to the surface of a cooled tube in an annular gap are shown at control and alteration of oxygen admixture content under the conditions of power circuits with heavy liquid-metal heat-transfer agent. This work is aimed at obtaining the grounded formulas for engineering calculations of heat transfer surfaces. Investigations were carried out at the lead temperature of 400–500 °C, the average velocity of heat-transfer agent of 0.1–1.5 m/s, the range of Prandtl number of 0.0123–0.0211 and Peclet numbers of 500–7000. The heat flux changed within 50–160 kW/m². Controllable changing content of oxygen admixture changed from the value of thermodynamic activity of oxygen from 10⁻⁵-10⁰ to saturation and higher with deposition of lead oxides near the heat-transferring surface.     

Phenomenological analysis connecting proton–proton and antiproton–proton elastic scattering

Based on the behavior of the elastic scattering data, we introduce an almost model-independent parameterization for the imaginary part of the scattering amplitude, with the energy and momentum transfer dependences inferred on an empirical basis and selected by rigorous theorems and bounds from axiomatic quantum field theory. The corresponding real part is analytically evaluated by means of dispersion relations, allowing connections between particle–particle and particle–antiparticle scattering. Simultaneous fits to proton–proton and antiproton–proton experimental data in the forward direction and also including data beyond the forward direction lead to a predictive formalism in both energy and momentum transfer. We compare our extrapolations with predictions from some popular models and discuss the applicability of the results in the normalization of elastic rates that can be extracted from present and future accelerator experiments (Tevatron, RHIC and LHC). PACS 13.85.Dz, 13.85.-t     

Microwave excited CO<Subscript>2</Subscript> laser with multiple units using orthogonal electric fields

The third order nonlinear optical properties of 4^′-methoxy chalcone and its derivatives have been investigated using a single-beam Z-scan technique with nanosecond laser pulses at 532 nm. The 4^′-methoxy chalcone and its derivatives are donor–acceptor–acceptor (D–A–A) and donor–acceptor–donor (D–A–D) type intramolecular charge transfer molecules. The nonlinear response in these molecules was found to increase with increase in (a) the electron acceptor strength in D–A–A type and (b) the donor strength of the substituted group in D–A–D type molecules. The χ⁽³⁾ value in these molecules is found to be of the order of 10^-13 esu. The observed increase in the third order nonlinearity in these molecules clearly indicates the electronic origin. The compounds exhibit good optical limiting at 532 nm. The best optical limiting behavior was observed with the molecule substituted by a strong electron donor. PACS 42.65.An; 42.70.Nq     

Environmental effects on electronic excitation energy transfer in organic liquid scintillators

The efficiency of electronic excitation energy transfer from toluene to a dissolved fluorescent indole, is determined experimentally in systems comprising neat toluene, 1:9 mixture of toluene-cyclohexane and 1:9 mixture of toluene-paraffin as a function of temperature in the range 293–353°K (viscosity range 0.6–39 cP). The results are discussed in terms of the influence of temperature, dilution and viscosity of the medium on the energy transfer efficiency in binary organic scintillator systems.     

Photophysical properties of mesonitrophenyl-substituted porphyrins and their dimers at 295 K

It is shown that at 295 K in meso-orthonitrophenyl-substituted octaethylporphyrins and their chemical dimers the steric interactions of the nitro-group and the volume substituents at β-positions of the pyrrole rings favor direct overlapping of molecular orbitals in a donor-acceptor pair. The efficient quenching of fluorescence of the nitroporphyrins in toluene is attributed to direct nonadiabatic electron transfer from the S₁-level of a porphyrin to the lower-lying state with charge transfer by the “through-space” mechanism. Quenching of the T₁-states is related with heat-stimulated transmission to the higher-lying states with charge transfer of the ion-radical pair as well as with enhancement of the probability of the nonradiative T₁→S₀-transition. To whom correspondence should be addressed. Reported at the VIIIth International Conference on Spectroscopy of Porphyrins and Their Analogs, Minsk, September 22–26, 1998. Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 4, pp. 531–535, July–August, 1999.     

Comments on Shimony’s “An Analysis of Stapp’s ‘A Bell-Type Theorem without Hidden Variables’ ”

The hidden-variable theorems of Bell and followers depend upon an assumption, namely the hidden-variable assumption, that conflicts with the precepts of quantum philosophy. Hence from an orthodox quantum perspective those theorems entail no faster-than-light transfer of information. They merely reinforce the ban on hidden variables. The need for some sort of faster-than-light information transfer can be shown by using counterfactuals instead of hidden variables. Shimony’s criticism of that argument fails to take into account the distinction between no-faster-than-light connection in one direction and that same condition in both directions. The argument can be cleanly formulated within the framework of a fixed past, open future interpretation of quantum theory, which neatly accommodates the critical assumptions that the experimenters are free to choose which experiments they will perform. The assumptions are compatible with the Tomonaga–Schwinger formulation of quantum field theory, and hence with orthodox quantum precepts, and with the relativistic requirement that no prediction pertaining to an outcome in one region can depend upon a free choice made in a region spacelike-separated from the first.