Generalized treatment of skew-cosh-Gaussian lasers for bifocal terahertz radiation

A generalized treatment of skew-cosh-Gaussian lasers with skewness parameters n and s is provided for obtaining bifocal terahertz radiation in a realistic plasma having electron-neutral collisions. In order to find and control the focusing of the radiation, a relation is established between the position of the peak of the radiation field and the parameters n and s. The significant role of these parameters in getting bifocal radiation or its conversion to unifocal radiation (or vice-versa) with a proposal for enhanced efficiency of the scheme is discussed in detail for its medical applications.     

Polymer complexes. LXXI. Spectroscopic studies,thermal properties,DNA binding and antimicrobial activity of polymer complexes

Polymer complexes of Co(II), Ni(II), Mn(II), Cr(III) and Cd(II) were prepared by the reaction of 3‐allyl‐5‐[(4‐nitrophenylazo)]‐2‐thioxothiazolidine‐4‐one (HL) with metal ions. The structure of polymer complexes was characterized by elemental analysis, IR, UV–Vis spectra, X‐ray diffraction analysis, magnetic susceptibility, conductivity measurements and thermal analysis. Reaction of HL with Co(II), Ni(II), Mn(II), Cr(III) and Cd(II) ions (acetate or chloride) give polymer complexes ( 1–5 ) with general stoichiometric [M(L)(O₂CCH₃)(H₂O)₂]_n (where L = anionic of HL and M = Co(II) (1) or Ni(II) (2) ), [Mn(HL)₂(OCOCH₃)₂]_n (3) , [Cr(L)₂(Cl)(H₂O)]_n (4) and [Cd(HL)(O₂CCH₃)₂]_n (5) . The value of HOMO–LUMO energy gap (ΔE) for forms (A‐C) of monomer (HL) is 2.529, 2.296 and 2.235 eV, respectively. According to ΔE value, compound has minimum ΔE is the more stable, so keto hydrazone form (C) is more stable than the other forms (azo keto form (A), azo enol form (B)). The interaction between HL, polymer complexes of Co(II), Ni(II), Mn(II), Cr(III) and Cd(II) with Calf thymus DNA showed hypochromism effect. The HL and its polymer complexes were tested against some bacterial and fungal species. The results showed that the Cr(III) polymer complex (4) has more antibacterial activity than HL and polymer complexes (1–3 and 5) against Bacillus subtilis, Staphylococcus aureus and Salmonella typhimurium.     

Synthesis and characterization of a hydrogen-bonded nematic network based on 4-propoxybenzoic acid side groups grafted onto a polysiloxane

A polymethylsiloxane with 4-propoxybenzoic acid side groups was prepared by hydrosilylation of polymethylhydrosiloxane and methyl 4-allyloxybenzoate followed by hydrolysis. The existence of strong hydrogen bonding interactions in this polymer due to dimerization of the carboxylic acid groups was demonstrated by FTIR. The polymer exhibits a nematic mesophase at elevated temperatures due to the self-assembly of hydrogen-bonded mesogens (dimers). After cooling from its nematic melt, a stable hydrogen-bonded nematic network structure was formed, as demonstrated by differential scanning calorimetry, polarizing optical microscopy, and X-ray diffraction. Temperature-variable FTIR analysis presents a convincing interpretation for the DSC thermogram of the polymer, and furthermore assists in understanding the process of formation of the nematic network and the reversibility of such hydrogen-bonded networks.     

Influence of low concentration silver nanoparticles on the electrical and electro-optical parameters of nematic liquid crystals

Thermodynamical, optical, dielectric and electro-optical characterisation of nematic liquid crystals (LCs) and silver nanoparticle (NP) composites have been carried out. Transition temperatures of pure and composites systems have been measured. Thermodynamical studies suggest increase of clearing temperature of the composite material as compared to the pure material. Threshold voltage for switching from bright to dark state and splay elastic constant of the pure and composite materials have been determined. From frequency dependence of dielectric measurements, permittivity, loss, relaxation frequency and dielectric strength of flip-flop mechanism of LC molecules in the nematic phase have been calculated. Dielectric properties of composites have been explained in reference of Maier and Meier theory. The effects of doping of NPs on dielectric and electro-optic properties of LC-NP composites have been discussed.     

The Significance of the Δkl Parameters in the Vibration-Rotational Energies of Diatomic Molecules

We discuss the physical significance of the parameters Δ_kl that arise from mostly the adiabatic and nonadiabatic effects in the vibration-rotational energles of diatomic molecules for which data from isotopic variants are available. Examples are given of the use c f these parameters to derive radial functions for HC1 and LiH. Similar to those for the U_kl coefficients, relations among the Δ_kl coefficients have been developed, but caution is urged in their use.     

Voltammetry and Spectroscopy Study of In Vitro Interaction of Fenitrothion with DNA

The interaction of Fenitrothion with DNA has been studied using the voltammetric and spectroscopic methods. An irreversible reduction was concluded from the CV data of Fenitrothion. The values of (αn)_f=1.91 and (αn)_b=2.06 were measured and the reduction process of Fenitrothion was performed with 4 electrons. By using non‐linear regression analysis of CV data, the binding constant, binding site size, and diffusion coefficient for free Fenitrothion (D_f) and DNA‐Fenitrothion (D_b) were calculated as: 1.03×10⁴, 1.204, 5.2×10^?4 and 1.72×10^?5, respectively. Also the voltammetric, spectroscopic, thermodynamic and activation energy of DNA‐Fenitrothion complex revealed that the mode of interaction might be partial‐intercalative and complex formation is entropy favored.     

磷光寿命法研究无保护流体室温磷光的重原子效应和发光动力学参数

以两种卤代萘为模型化合物，基于磷光寿命的定义τ＝τ^-，τ0＝1／kp和其与各速率常数的关系，导出了一种类似于Stern-Volmer方程的线性方程：τ0／τ＝（kp_kic)/kp=1 kic/kp=1 Ksv.c。通过测定不同重原子微扰剂浓度时的磷光寿命，探讨了从两种途径计算流体室温磷光发射相关动力学参数的可行性和方法，通过这些参数对比讨论了KI和TINO3两种重原子微扰剂对这两种卤代萘无保护流体室温磷光发射的重原子效应的差异。     

排水固结法的优化设计

经过排水固结法的经济分析及软土排水固结过程中的强度分析，提出了砂井参数及加载计划（工期）的优化设计方法。     

高度自动化获取书籍扫描图像畸变参数的理论

提出一种利用打印直线获取书籍扫描图像畸变校正所用参数的新方法,可提高畸变参数获取的自动化程度。对于打印在纸张上的直线,当打印纸夹在书籍中扫描图像时,打印纸随着书籍页面弯曲成曲面,它也随之弯曲成空间曲线,其扫描图像则为平面曲线,包含了页面弯曲状态的信息。理论上分析了该平面曲线与畸变参数之间的关系。利用这种关系及最小二乘法原理,对该平面曲线上的点进行曲线拟合,可自动计算出对应页面的畸变参数,不再像以前那样必须进行人工调整。