Transient DSC,a Novel and Rapid Method for Assessing Pharmaceutical Powder Compacts

The previously described method involving the use of transient DSC was applied to pharmaceutical powder compacts and to ceramic powder compacts. The samples were prepared by compressing powders of pentaerythritol tetraacetate and two kinds of alumina powder (differing in particle size distribution) up to a pressure of 20 MPa by using a jig. For pentaerythritol tetraacetate, a linear relationship was obtained between the parameter obtained by DSC and the compaction pressure. This revised version was published online in August 2006 with corrections to the Cover Date.     

Reindarstellung von Erbiumoxid durchCraig-Verteilung

1.6 kg of yttrium earth mixtures (4–6% Er) were concentrated to 60% erbium oxide by repeatedCraig-distributions with 4M HNO₃ lower phase for separation of yttrium, and with 11M for separation of holmium and thulium. During these experiments the optimal conditions were studied with regard to acidity and input. The 60% Er₂O₃ was further purified by using 4M followed by 11M HNO₃ lower phase several times. There resulted nearly 20 g Er₂O₃ 99.9% pure. The concept of the effective distribution coefficients characterising preparativeCraig-distributions was further verified by discussion of the values of selected separations.

Dem Vorstand des Instituts, Herrn Prof. Dr.K. L. Komarek, mit den besten Wünschen zum 60. Geburtstag gewidmet.     

一种新的p-V关系测量技术

 本工作利用新建立的p（压力）-V（体积）关系测量技术测定了Fe和Bi在4.5 GPa内的p-V关系。实验结果表明，采用这种新的测量技术可以提高p-V关系测量的精度和工作效率。     

Optical nonlinearity of organic dyes as studied by Z-scan and transient grating techniques

The excited state absorption cross-section of 5,5′-dichloro-11-diphenyl-amino-3,3′-diethyl-10, 12-ethylinethiatricarbocyanine perchlorate (IR140) have been measured by using a single beam transmission technique. Z-scan experiments have been used to find out a few nonlinear parameters. The excited state relaxation times have also been measured by using laser induced transient grating (LITG) technique.     

Multivariable structural characterization of semicrystalline polymer blends by small‐angle light scattering

A new multi‐variable‐measurement approach for characterizing and correlating the nanoscale and microscale morphology of crystal‐amorphous polymer blends with melt‐phase behavior is described. A vertical small‐angle light scattering (SALS) instrument optimized for examining the scattering and light transmitted from structures ranging from 0.5 to 50 μm, thereby spanning the size range characteristic of the initial‐to‐late stages of thermal‐phase transitions (e.g., melt‐phase separation and crystallization) in crystal‐amorphous polymer blends, was constructed. The SALS instrument was interfaced with differential scanning calorimetry (DSC), and simultaneous SALS/DSC/transmission measurements were performed. We show that the measurement of transmitted light and SALS under H_V (cross‐polarized) optical alignments during melting can be used to reliably measure the thermodynamic (e.g., crystal melting and melt‐phase separation temperatures) and structural variables (e.g., crystalline fraction within the superstructures and volume fraction of superstructures) necessary for describing the multiphase behavior of crystal‐amorphous blends in one combined measurement. We also evaluate the orientation correlations of crystalline volume elements within the superstructures. Our results indicate that simultaneous measurement of transmitted light can provide a reliable estimate of the total scattering from density and orientation fluctuations and the melt‐phase separation temperature of polymer blends. For solution‐cast poly(?‐caprolactone)/poly(D,L‐lactic acid) blends, our multivariable measurements during melting provide the parameters necessary to generate a crystal–liquid and liquid–liquid phase diagram and characterize the solid‐state morphology. This opens up the challenge to explore use of our vertical SALS instrument as a rapid and convenient method for developing structure–property relationships for crystal‐amorphous polymer blends. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2714–2727, 2002     

The Influence of the Renormalization Condition to the Equation of State of the Nuclear Matter

In the relativistic σ-ω model, the influences of the parameters b, c, d in the potential U(σ) = (1/2!)bo2 - -(1/3!)cσ3 (1/4!)dσ4 to the incompressibility, effective mass and binding energy of the nuclear matter are studied in detail.The calculation of equation of state of nuclear matter shows that the values of b, c, d depend on the renormalization condition, we also find that a soft equation of state of nuclear matter can be obtained in a suitable renormalization condition, and the experimental incompressibility coefficient can be reproduced. These results are also used to study the thermal properties of hot A-resonant nuclear matter.self-interaction of σ meson, renormalization, hot and dense hadronic matter ``     

Mössbauer studies on ultraporous Fe-Oxide/SiO2 aerogel

Magnetic aerogels with very low volume density of ～0.2 g/cm³ were prepared by sol-gel method and supercritical drying. The resulting materials were monolithic and displayed high surface area. By X-ray diffraction and Mössbauer spectroscopy the crystalline phase formed inside the mesopores of the SiO₂ matrix was identified as a spinel iron oxide. Comparison of the magnetic measurements with Mössbauer spectra at various temperatures contributed to the elucidation of the magnetic state of this nanocomposite system with restricted magnetic interactions, in particular its transition to a superparamagnetic state.     

强外电场作用下二甲基硅酮的分子结构和激发态

采用密度泛函(DFT)方法B3P86在6 311++G(d,p)基组水平上优化得到了分子轴方向不同电偶极 场(-0.04～0.04a.u.)作用下,二甲基硅酮的基态电子状态、几何结构、电偶极矩和分子总能量.在优化构型下 用同样的基组采用杂化CIS DFT方法(CIS B3P86)研究了同样外电场条件下对二甲基硅酮的激发能和振子强度 的影响.计算结果表明,分子几何构型与电场大小和方向呈现强烈的依赖,正向电场下基态偶极矩随电场强度线 性增加,分子总能量降低,当反向电场大于0.03a.u.时,偶极距方向改变,总能量增加;激发能随电场增加急剧减 小,且对电场方向的依赖呈现出不对称性,满足Grozema关系.电场对振子强度的影响比较复杂,但仍满足跃迁选 择定则.     

13C CP MAS NMR of halogenated (Cl,Br, I) pharmaceuticals at ultrahigh magnetic fields

This work reports significantly improved spectral resolution of ¹³C CP MAS NMR spectra of chlorinated, brominated and iodinated solid organic compounds when such spectra are recorded at ultrahigh magnetic field strengths. The cause of this is the residual dipolar coupling between carbon atoms and quadrupolar halogen nuclides (chlorine‐35/37, bromine‐79/81 or iodine‐127), an effect inversely proportional to the magnetic field strength which declines in importance markedly at 21.1 T as compared to lower fields. In favorable cases, the fine structure observed can be used for spectral assignment, e.g. for Cl‐substituted aromatics where the substituted carbon as well as the ortho‐carbons show distinct doublets. The experimental results presented are supported by theoretical modeling and calculations. The improved spectral resolution in the studied systems and similar halogenated materials will be of particular interest and importance for polymorph identification, drug discovery and quality control in the pharmaceutical industry. Copyright © 2009 John Wiley & Sons, Ltd.