Spectroscopic and Electrochemical Characterization of Cytochrome P450st‐DDAB Films on a Plastic‐Formed Carbon Electrode

We have studied the characterization of thermophilic cytochrome P450 (P450st)‐didodecyldimethylammonium bromide (DDAB) films by using UV‐vis absorption, resonance Raman spectroscopy, and electrochemical methods. The observed Raman spectrum indicated near‐native conformation of the heme iron in DDAB film on the surface of a glass slide, while on the surface of a plastic‐formed carbon (PFC) electrode, the conformation of P450st‐DDAB was very similar to that of heme‐DDAB film, suggesting the release of heme from P450st in DDAB films on PFC electrodes. When NaBr was added as salt to the casting solution, the result of Raman spectrum indicated near‐native conformation of P450st in DDAB film even on the PFC electrode, but no redox potential of P450st which has near native structure was observed. This study suggests the essential experimental conditions when working with heme protein‐DDAB films as, in some cases, heme iron from proteins is released on the surface of the electrode.     

Computation of heat capacities of solid state benzene,p-oligophenylenes and poly-p-phenylene

Heat capacities (C_p) of solid benzene, biphenyl,p-terphenyl,p-quaterphenyl, and poly-p-phenylene were analyzed using the ATHAS Scheme of computation. The calculated heat capacities based on approximate vibrational spectra of solid benzene and the series of oligomers containing additional phenylene groups were compared to experimental data newly measured and from the literature to identify possible additional large-amplitude motion. The skeletal heat capacity was fitted to the Tarasov equation to obtain the one- and three-dimensional vibration frequencies ₁ and ₃ using a new optimization approach. Their relationship to the number of phenylene groupsn is: ₁=426.0–150.3/n; and ₃=55.4+81.8/n. Except for benzene, the quantitative thermal analyses do not show significant contributions from large-amplitude motion below the melting temperatures.This work was financially supported by the Div. of Materials Res., NSF, Polymers Program, Grant # DMR 90-00520 and Oak Ridge National Laboratory, managed by Lockheed Martin Energy Research Corp. for the U. S. Department of Energy, under contract number DE-AC05-96OR22464.     

钇对金属陶瓷力学性能和组织的影响

研究了添加钇对Ｔｉ（Ｃ，Ｎ）基金属瓷力学性能和组织的影响。结果表明，加入适量的钇能提高Ｔｉ（Ｃ，Ｎ）基金属陶瓷的抗变强度和硬度，其原因是由于钇与杂质硫起反应在化合物，净化了陶瓷相－金属相，陶瓷相－陶瓷相界面提高子界面结合强度     

聚醚醚酮酮和含联苯聚醚醚酮酮共聚物的熔融热

根据Ｆｌｏｒｙ热力学统计理论和比容－熔融热作国法，由ＤＳＣ结果得到了不同联苯含量的聚醚醚酮酮－含联苯聚醚醚酮酮（ＰＥＥＫＫ－ＰＥＢＥＫＫ）共聚物的熔融热，两种方法获得的结果吻合。在此基础上给出了ＰＥＥＫＫ－ＰＥＢＥＫＫ共聚物不同联苯含量的熔点计算表达式。结果还表明，随着联苯含量ｎＢ，的变化，明显改变；当ｎＢ＝０．３５时，ＰＥＥＫＫＰＥＢＥＫＫ共聚物的值最小。     

Investigation of the thermophysical properties of polymers by the temperature wave technique

The technique of temperature waves to measure the complex thermophysical characteristics of materials has been proposed. The relations for the moduli and arguments of these characteristics for the case of plane temperature waves have been calculated. The temperature dependences of the moduli and arguments of complex thermophysical characteristics of polyvinylacetate (PVAc) at different frequencies and also the temperature dependences of its vibrational and configurational heat capacities have been determined. It has been shown that the vibrational heat capacity of PVAc in the region of softening grows sharply and its configurational heat capacity goes through a peak. The segmental mobility has been found to affect the heat transfer in the polymer in an ambivalent way causing both a decrease and increase of thermal conductivity.

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Zusammenfassung Zur Bestimmung der komplexen thermophysischen Eigenschaften von Stoffen wurde eine Temperaturwellentechnik vorgeschlagen. Für den Fall zweidimensionaler Temperatur-wellen wurden die Verhältnisse von Moduli und Argumenten dieser Eigenschaften berechnet. Die Temperaturabhängigkeit von Moduli und Argumenten der komplexen thermophysischen Eigen-schaften von Polyvinylacetat (PVAc) bei verschiedenen Frequenzen und auch die Temperatur-abhängigkeit seiner Vibrations- und Konfigurations-Wärmekapazitäten wurden bestimmt. Es wurde gezeigt, daß die Vibrations-Wärmekapazität von PVAc im Erweichungsbereich scharf zunimmt und die Konfigurations-Wärmekapazität durch einen Peak geht. Man fand, daß die Segment-Mobilität den Wärmetransport im Polymer auf eine ambivalente Weise beeinflußt, in dem die Wärmeleit-fähigkeit entweder gesenkt oder angehoben wird.

     

Synthesis, band structure, and optical properties of Ba2ZnV2O8

A novel compound Ba₂ZnV₂O₈ has been synthesized in high temperature solution reaction and its crystal structure has been characterized by means of single crystal X-ray diffraction analysis. It crystallizes in monoclinic system and belongs to space group P2₁/c with a=7.9050(16), b=16.149(3), , β=90.49(3). It builds up from 1-D branchy chains of [ZnV₂O₈⁴⁻]_∞, and the Ba²⁺ cations are located in the space among these chains. The IR spectrum, ultraviolet-visible diffuse reflection integral spectrum and fluorescent spectra of this compound have been investigated. The calculated results of energy band structure by the density functional theory method show that the solid-state compound of Ba₂ZnV₂O₈ is an insulator with direct band gap of 3.48 eV. The calculated total and partial density of states indicate that the top valence bands are contributions from the mixings of O-2p, V-3d, and Zn-3d states and low conduction bands mostly originate from unoccupied antibonding states between the V-3d and O-2p states. The V-O bonds are mostly covalence characters and Zn-O bonds are mostly ionic interactions, and the ionic interaction strength is stronger between the Ba-O than between the Zn-O. The refractive index of n_x, n_y, and n_z is estimated to be 1.7453, 1.7469, and 1.7126, respectively, at wavelength of 1060 nm for Ba₂ZnV₂O₈ crystal.     

Two—dimensional Network Crown Ether Complex.Synthesis and Crystal Structure of 18—Crown—6 Complex：[K（18—C—6）]2[Cd—（nmt）2]

The novel complex [K(18-C-6)]2[Cd(mnt)2][18-C-6-18-crown-6,nmt=1,2-dicyanoethene-1,2-dithiolate,C2S2-(CN)2^2-] was synthesized and characterized by elemental analysis,IR spectrum and X-ray diffraction analysis.The complex displays two-dimensional network structure of [K(18-C-6)] complex segments and [Cd(nmt)2] complex segment bridged by S-K-S,S-K-N and N-K-N interactions between adjacent[K(18-C-6)] and [Cd(mnt)2]units.     

湿热证动物模型微量元素、维生素E变化及清香散的调节作用

采用多因素造模方法复制成湿热证动物模型，观察了动物模型微量元素Zn、Cu、Fe、Se和维生素E代谢水平的变化。结果显示，模型动物血清Zn下降（P＜0．05），Cu升高（P＜0．05或P＜0．01），Fe变化不大（P＞0．05），血Se水平下降（P＜0．05），血浆维生素E含量减少（P＜0．01）。经清热祛湿的经验方清香散治疗后，治疗I组动物血清Zn、血Se、血浆维生素E明显升高（P＜0．05），血清Cu下降（P＜0．05）；治疗Ⅱ组血浆血清Cu有变化（P＜0．05）外，其余变化不大。     

Synthesis of photoreactive polyimide having indan structure

Polyimide containing an indan unit and alkyl moiety with a high molecular weight was prepared from 5,7‐diamino‐1,1,4,6‐tetramethylindan and 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride. This polyimide was amorphous and soluble in common organic solvents, such as tetrahydrofuran, chloroform, and cyclopentanone. Thermogravimetry of the polyimide showed good thermal stability, indicating that a 10% weight loss of the polyimide was observed at 500 °C in nitrogen. The glass‐transition temperature of the polyimide was not observed by DSC measurement between room temperature and 400 °C at a heating rate of 10 °C/min (Apparatus: DSC3100 MAC Science Co., Ltd.). Transparency of the polyimide at 365 nm was 80%. The polyimide acted as a photosensitive resist of negative type by UV radiation. The resist had a sensitivity of 31 mJ/cm² and a contrast of 2.3 when it was developed with cyclopentanone at room temperature. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 423–428, 2002     

Photophysical properties of (η2-C60)Pd(PPh3)2 complex in benzene. Picosecond and nanosecond laser photolysis

Absorption spectra of the photoexcited (²-C₆₀)Pd(PPh₃)₂ complex in benzene were obtained by picosecond and nanosecond laser photolysis. The spectra are compared with those observed for photoexcited states of fullerene C₆₀ and charge-transfer states of C₆₀ complexes with ternary amines. The relaxation kinetics of excited (²-C₆₀)Pd(PPh₃)₂ complex has three components with characteristic lifetimes ₁ = 43 ps, ₂ = 1500 ps, and ₃ = 1.17 s. The results are discussed in terms of the four-level scheme of the excited complex.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1163–1166, May, 1996.