一种跳频扩时码的构造及性能分析

以一维二次同余码(QCC)作为扩时模式，以光正交码(OOC)和QCC码作为频域跳频模式，通过时域和频域的组合，构造了适用于光码分多址(OCDMA)系统的QCC/QCC和QCC/OOC 2种跳频扩时码，并对码的容量及其相关性进行了分析。与一维QCC码相比，QCC/QCC跳频扩时码的容量扩大了p 1倍（p为码重），相关性得到改善，并且码字异相自相关限λa=1，互相关限λc=2；QCC/OOC跳频扩时码具有更大的码容量和更好的相关性，码字异相自相关限λa=0，所有码字按一定规律可分成p 1组（p为码重），每组内码字的互相关限λa=1，不同组间码字的互相关限λa=2。所得结果为光码分多址系统中跳频扩时码的构造提供了一种新的方法。     

Correlations of two protons in relativisticdp-collisions

Two-proton correlations in thedpppn collisions of relativistic deuterons with protons are considered. These correlations give more information than inclusive proton spectra described in the framework of different deuteron structure function models because of uncertainty in the calculation of secondary interaction contribution (rescattering processes and final state interactions). We present the predictable calculations which show different behaviour of the correlation function for different deuteron structure function models in the kinematic region where contributions of secondary interactions are negligible.     

分子间相互作用对核酸碱基中17O屏蔽张量与四极耦合常数影响的理论计算研究

通过高精度量子化学理论计算的方法研究了分子间弱的非键相互作用对胸腺嘧啶、尿嘧啶、胞嘧啶和鸟嘌呤四种核酸碱基中~(17)O核的屏蔽张量(σO)和四极耦合常数(QCC)的影响.计算结果表明分子间强的氢键作用以及弱的范德华(vd W)相互作用都对~(17)O核的化学位移(δO)具有较大的影响.随着分子间氢键作用的逐渐增强,δO逐渐减小,当采用包含所有弱相互作用的周期性模型进行计算时,理论结果与实验值吻合.进一步的电荷分析显示,~(17)O核化学位移的减小主要是由于分子间氢键作用强度增加导致~(17)O原子的负电荷密度逐渐增加.此外,计算结果表明碱基中分子间氢键网络和弱的范德华作用对碱基~(17)O QCC也具有显著的影响.周期性模型下,碱基上氧原子的局域结构环境得到平衡,~(17)O QCC达到最小值,与实验结果最为接近.以核酸碱基为例,说明了分子间的氢键网络以及分子间弱的相互作用对于准确计算生物样品的核磁共振(NMR)参数非常重要,以小的团簇模型来计算生物体系的核磁参数将会产生较大的偏差.     

Computer simulations of particle flux and energy peaking

A computer simulation of the channeling of 300 keV deuterons in a niobium lattice has been performed. The model calculations included: binary Thomas-Fermi interaction between projectiles and lattice atoms, thermal displacements of the lattice atoms in the transverse plane of particle motion, electron scattering of the deuterons dependent on the local electron density, and electronic energy loss dependent on the local electron density. Flux distributions and mean particle energy distributions of the deuterons were calculated in their development with penetration depth. Flux peaking and energy peaking was found to depend sensitively on the local variation of the electron density in the crystal.     

High-resolution investigation of the 112Sn(p,d)111Sn reaction

The ¹¹²Sn(p, d)¹¹¹Sn reaction was studied at a proton energy of 27.45 MeV. The outgoing deuterons were momentum analyzed with an Enge split-pole spectrograph and recorded with position-sensitive solid-state detectors with a total resolution between 12 and 16 keV. Angular distributions were compared with DWBA calculations in order to extract l-values, spectroscopic factors, single-quasiparticle energies and occupation probabilities. In the gross structure between 3 and 6 MeV, which was interpreted as being due to the pickup of deeply bound neutrons, several discrete peaks were also found with an angular distribution characteristic for l = 1 or 4 transfer. The excitation of core-coupled states was investigated by performing two-step DWBA calculations. The results of the present experiment are compared with previous experimental results and with number-projected BCS calculations.     

Potential energy landscape of monolayer-surface systems governed by repulsive lateral interactions: the case of (3 x 3)-I-Pt(111)

Combined density functional theory (DFT) and Monte Carlo (MC) approach is applied to study the potential energy landscape of four iodine atoms adsorbed on the Pt(111) surface in a (3 x 3) unit cell. Three critical points were identified: (3 x 3)-sym and (3 x 3)-asym, corresponding to structures well known from experimental studies, while the third one (3 x 3)-zigzag is a new structure not reported before. An interaction model fitted to DFT calculations allows us to explain the difference between arrangements of iodine monolayer in vacuum, air, and solution environments as a result of different repulsion regimes.     

库的量子关联相干辅助系统能量提取的研究

基于单模微腔与二能级原子系综(库)构成的混合动力学模型,探索了非平衡库中量子关联相干(quantum correlated coherence, QCC)[Tan K C, et al. 2016 Phys. Rev. A 94, 022329])对系统动力学的影响.推导了量子关联相干库下系统演化的动力学方程.借助于含QCC的类GHZ库及其对应的参考库,清晰地揭示了非平衡库中QCC扮演着热力学资源的角色——能够有效辅助系统从库中提取更多能量.同时,结合解析与数值模拟方法研究了类GHZ库的有效温度和系统与库间的耦合参数对QCC能量效应的影响.研究发现, QCC对腔场的能量贡献不仅依赖于库的有效温度,而且也和系统与库间的耦合参数有关.这与二能级原子构成的传统的热库的情况(腔场从热库中提取的能量仅仅依赖于库的有效温度即二能级原子的热布局)完全不同.此外,研究发现QCC可视作一类优质的热力学资源,在特定条件下其对系统的能量贡献远大于原子热布局的贡献.因此, QCC将是高输出功率或高效率量子热机设计中的一类重要燃料.     

Phase-shift analysis of spin-correlation coefficients in p-d scattering: A solution to the 2S defect

A phase-shift analysis of combined cross-section and spin-correlation data has been performed for the elastic scattering of protons by deuterons. Reliable doublet phases have been extracted and compared with extensive Faddeev-type calculations using different rank-one separable interactions. The effect of P-wave N-N forces is discussed and intrinsic strengths and range are deduced.     

Neutron hole states in 138La and 140Pr

Protons accelerated to 30 MeV were used to investigate low-lying states in the odd-odd nuclei ¹³⁸La and ¹⁴⁰Pr with (p, d) reactions. The elastic scattering of 30 MeV protons and 23 MeV deuterons was also studied to determine optical potentials. Experimental angular distributions are compared with distorted-wave Born approximation calculations to extract spin, parity, and spectroscopic factors for levels up to 432 keV of excitation in ¹⁴⁰Pr and 530 keV in ¹³⁸La. Comparisons with the simple shell-model predictions and extended shell-model calculations are presented. The ¹⁴⁰Pr levels appear experimentally to have an almost pure particle-hole structure whereas the ¹³⁸La levels exhibit substantial mixing.     

Study of nuclear-coulomb interference effects in inelastic deuteron scattering on 238U

The angular distributions of elastically and inelastically scattered deuterons from ²³⁸U at E = 17 MeV are compared to coupled-channel calculations. The cross sections at small scattering angles are strongly influenced by nuclear-Coulomb interference effects and allow a simultaneous extraction of nuclear (optical potential) and charge quadrupole deformation parameters. Two different deformed Coulomb potentials and the parameters of the optical model are discussed.     

Relativistic deuterons: Their dynamics and structure in collisions with nucleons and nuclei

A wide range of problems associated with investigating the structure and dynamics of relativistic deuterons in (d,p) processes on protons and atomic nuclei are considered. Experimental data include the proton momentum distributions and tensor analyzing power of these reactions on various nuclei and at various energies measured in beams of unpolarized and polarized deuterons at the JINR synchrophasotron. The experimental results are interpreted with an emphasis on using the light-front dynamics, which is well-suited for analyzing the data in terms of the wave function. The application of this approach for analyzing the A(d,p)X reaction is shown to be convenient for obtaining new important information on the deuteron structure at small distances and describing adequately its behavior at relativistic energies. The difficulties arising in this approach are also indicated. The suggestions for setting up new experiments in the designed polarized deuterons beam at Nuclotron are made.     

Level structure of 76As

The energy-level structure of ⁷⁶As has been studied by the ⁷⁵As(d, p) reaction with 12.0 MeV incident deuterons. Eighty-seven excited energy levels up to 2.5 MeV have been identified. The angular distributions for thirty-nine of the observed transitions are compared with distorted-wave Born approximation calculations. Angular momentum transfers are determined and spectroscopic strengths are deduced from the data. The results are compared with shell-model sum rules and with (d, p) results on N = 42 isotones. Possible spin values are assigned for some of the levels based on the present results, (n, γ), (p, n) and (p, nγ) studies.     

Szintillationslicht von Anthrazen bei Anregung mit Deuteronen in Abhängigkeit von Einschußrichtung,Deuteronenenergie, Kristalltemperatur und Beobachtungsrichtung

The scintillation light of anthracene by bombardment with deuterons in the energy range from 7.5 MeV to 27.0 MeV at the temperature of liquid nitrogen and at room temperature has been measured. Comparing the experimental data with theoretical data based on the Voltz formula get knowledge of the quenching parameter for various directions of the incident deuterons. In difference to former measurements here only scintillation light has been taken into account which was emitted (within an angle of ±7.5°) perpendicular to one of the three crystal planes (ab), (bc′), (ac′) and the two optical planes (xy), (yz) of anthracene. By changing the direction of the incident deuterons within the above five planes the anisotropy and the fine structure peak of the scintillation light has been determined.     

Synthesis,Spectral, Solvent Dependent Linear and Nonlinear Optical Characteristics of (E)-N-(3-(3-(4(dimethylamino)phenyl)acryloyl) phenyl)quinolone-2-carboxamide

This paper presents the synthesis of novel organic compound (E)-N-(3-(3-(4(dimethylamino)phenyl)acryloyl)phenyl)quinolone-2-carboxamide, also known as Quinolinecarboxamide Chalcone (QCC) using aldol condensation and carboxamide formation method. The organic sample QCC was examined by FT-IR, ¹H NMR, ¹³C NMR and mass spectroscopic techniques, respectively. Linear and third-order nonlinear optical (TNLO) properties of QCC dissolved in polar solvents such as DMSO, DMF and Ethanol have also been studied. The order of nonlinear refractive index and nonlinear absorption coefficient of QCC was measured to be 10^?11 m²/W and 10^?5 m/W. The nonlinear refractive index (n₂) of QCC was attributed to negative nonlinearity due to self-defocusing effect, and nonlinear absorption coefficient (β) indicates the behaviors of saturable absorption (SA) and reverse saturable absorption (RSA). The real and imaginary features of the TNLO susceptibility (χ⁽³⁾) of QCC in polar solvents were calculated to be the order of 10^─7 esu. The spectral characteristics of solvent on TNLO susceptibility of QCC were discussed. The results divulged that the synthesized organic compound is a novel nonlinear optical (NLO) material for applications in photonics and optoelectronics.

     

Populations of sublevels 24Mg(2+) nucleus formed in the reaction 24Mg(d,d1γ)24Mg at E d = 15.3 MeV

Angular dependences of density matrix spin tensors and sublevel populations are experimentally reconstructed for the ²⁴Mg(2⁺, 1.369 MeV) nucleus formed in the inelastic scattering of deuterons by ²⁴Mg at E _d = 15.3 MeV and deuteron emission angles from 25° to 165° (lab). The experimental results are compared to those from calculations using different versions of the coupled-channel method.     

Recoil products from p+118Sn and d+118Sn at 3.65 GeV/A

The recoil properties of the product nuclei from the interaction of 3.65-GeV/nucleon protons and deuterons from the Nuclotron and Synchrophasotron of the Laboratory of High Energies (LHE), Joint Institute for Nuclear Research (JINR) at Dubna, with a ¹¹⁸Sn target have been studied using catcher foils. The experimental data were analyzed using the mathematical formalism of the standard two-step vector model. The analysis of kinematical characteristics of the light and medium-mass reaction products confirmed the contribution of fragmentation (or multifragmentation) processes in the production of these nuclei. The comparison of the results for protons and deuterons was made. The longitudinal momenta transferred to the target in the interaction with protons and deuterons were similar and was shown to depend only on the velocity, but not on the mass of projectile. Three different Los Alamos versions of the quark—gluon-string model (LAQGSM) were used for the discussion of our experimental results. The text was submitted by the authors in English.     

Influence of the hydrogen bonding on the basicity of selected macrocyclic amines

The optimized minimum‐energy geometries of different macrocyclic amines and their protonated structures were determined by using ab initio and density functional theory (DFT) calculations. All the gas phase optimizations and energy calculations were performed at the DFT/B3LYP/6‐311++G(d,p) level of theory. The HF/6‐31 + G(d,p) level was used for all single point calculations in the solution phase. Geometry optimizations indicate that the most stable structures are stabilized by intramolecular hydrogen bonds. The proton affinity (PA) of macrocyclic amines is controlled by the strength of intramolecular hydrogen bonds of macrocyclic amines. These hydrogen bonds strongly influence the basicity of heteroatoms in macrocycles. The highest PA value among the studied macrocyclic amines was found to be 264.9 kcal mol^?1 for structure 7. This is comparable with PA of proton sponges such as 1,8‐bis(dimethylamino)naphthalene. The solution phase calculations were carried out in the dimethyl sulfoxide solution as a commonly used solvent in organic reactions. Natural bond orbital analysis was performed to calculate the charge transfers and the second‐order interaction energies (E⁽²⁾) between the donor and acceptor. Quantum theory of atoms in molecules (QTAIM) was also applied to determine the nature of hydrogen bonds. QTAIM studies showed that the intramolecular hydrogen bonds in these structures are electrostatic (closed‐shell) interactions as well as partially covalent and partially electrostatic in nature. Copyright © 2012 John Wiley & Sons, Ltd.     

UV-Raman study and theoretical analogue of picolinic acid in aqueous solution

High quality Raman spectrum of picolinic acid aqueous solution with ultraviolet (UV) excitation of 325 nm was obtained in this article. The state of picolinic acid in aqueous solution has been investigated over a wide range of solution pH values. The distinct changes of UV-Raman spectra accompanied with the pH variations indicate the changes of molecule structure. The calculations based on density functional theory were used to analyze the states of picolinic acid in aqueous solution. By comparing the experimental frequencies with the calculated ones, it can be concluded that when pH value varies from high to low, the picolinic acid tends to change from the anion form to the zwitterion that have the intermolecular hydrogen COOH?N bond.     

High resolution investigation of 91Mo and 92Mo via (p,d) and (p,t) reactions on 90Mo

The (p, d) and (p, t) reactions on ⁹²Mo have been studied at a proton energy of 28.0 MeV. Using an Enge split-pole spectrograph, resolutions of 11–15 keV for the detected deuterons and tritons were obtained. A total of 87 levels up to 4.9 MeV in ⁹¹Mo and 25 levels up to 4.0 MeV in ⁹⁰Mo were found, several of which were previously unknown. By comparing the measured angular distributions with DWBA calculations l-values and spectroscopic factors were determined. The results are compared with data from previous experiments on ⁹¹Mo and ⁹⁰Mo, with experiments on other N = 49 and 48 nuclei, and with theoretical calculations.     

The Estimation of the Difference Between d(d,n)3He and d(d,p)T Cross Sections in the Cold Fusion

The difference between two reaction cross sections of d(d, p)T and d(d, n)³He has been estimated in the cold fusion. It is caused by the different potential wall transmission and the angular distribution due to the structure.of deuterons. The rough estimation indicates that the branching ratio b about two orders of magnitude.