THE IZOD IMPACT FRACTURE-BEHAVIOR OF PHENOLPHTHALEIN POLY(ETHER KETONE)

The Izod impact fracture behaviour of notched specimens of phenolphthalein poly(ether ketone) (PEK-C) has been studied over a temperature range from room temperature to 240 degrees C by using an instrumented impact tester. The temperature dependence of the maximum load, total impact energy, initiation energy, propagation energy, ductility index (DI) and the relationships between these parameters and the relaxation processes have been investigated.

STUDY OF THE ELECTROCATALYTIC REDUCTION OF NITRITE WITH SILICOTUNGSTIC HETEROPOLYANION

Three couples of reversible redox waves of the SiW12O404- anion which are composed of two one-electron and one two-electron processes occur in the potential range +0.1 to -0.7 V in aqueous solutions. The first (most positive) and third (most negative) redox waves exhibit good electrocatalytic activities for nitrite reduction in acid solutions with pH < 2 for the former and with pH similar or equal to 4 for the latter. The behavior of the third catalytic wave, which is quite unusual, was studied in detail. The rate constant governing the reduction of NO2- by the first wave of SiW12O404- was measured by an ultramicrodisk electrode as 3.73 x 10(3) M(-1) s(-1).

MMgF_4：Eu（M＝Ca，Sr，Ba）体系中铕离子的发光中心及价态

合成了铕离子激活的ＭＭｇＦ４．磷光体，研究了Ｅｕ３＋离子的光谱特征与基质化合物的关系，存在三类发光中心，讨论了基质组成对铕离子价态的影响。

A STUDY ON POLYMER-POLYMER INTERACTIONS THROUGH MIXING CALORIMETRY

The aim of this work is to describe the most recent achievements in the field of the physical chemistry of mixing. The systems studied have been classified according to the amount of thermic effect due to the blending and its interpretation. When polystyrene (PS) and poly(alpha-methylstyrene) (P alpha MS) are blended, the interaction is weak and Delta(mix)H is close to zero. The presence of polar atoms and/or groups increases the stability of the blend and, therefore, Delta(mix)H becomes more negative. Poly(ethylene oxide) (PEO), poly(methyl acrylate) (PMA), poly(methyl methacrylate) (PMMA) and poly(vinylacetate) (PVAc), when mixed to form binary systems, show large differences from their properties when pure. If hydrogen bonding takes place, the interactions are readily detected and a large effect is calorimetrically determined. Cellulose diacetate (CDA) and poly(vinylpyrrolidone) (PVP) have been studied as an example of a strongly interacting system.

ESTIMATION OF THE RADIATION-INDUCED DAMAGE IN PTFE BY DEPRESSION OF THE MELTING AND CRYSTALLIZATION TEMPERATURES

The radiation induced depression of the melting and crystallization temperatures of PTFE irradiated at various temperatures followed by heat treatment at 380-degrees-C, and their relationship to structural changes, were investigated. The G(-units) values obtained in this work are different from those of samples which have not undergone heat treatment and seem to be more closely associated with radiation induced branched structures.

STUDIES ON THE REACTIONS OF TRANSITION-METAL HYDRIDES WITH HETEROCUMULENES .6. REACTION OF CP2ZR(H)CL WITH RNCS (R=C6H5, 2-C10H7, C-C6H11 AND N-C4H9)

The novel NS-containing zirconacycle complexes Cp2ZrCl[SC(H)NR] (1a, R = C6H5; 1b, R = 2-C10H7; 1c, R= C-C6H11; 1d; R = n-C4H9) were obtained by insertion reactions of Cp2Zr(H)Cl with RNCS. 1(a-d) could react further with Cp2Zr(H)Cl to yield a sulphur-bridging compleX (Cp2ZrCl)2S (2) and a Schiff base RN=CH2. The crystal structure of la has been determined by X-ray analysis.

四苯基卟啉及其金属配合物的裂解色谱研究

四苯基卟啉及其铁、锰等金属配合物是一类具有较大分子量、非挥发性的卟啉衍生物。由于结构和性能上的特点,这类物质成为有机合成中一种新型催化剂。关于这类物质的裂解研究尚未见有文献报道。本文用裂解色谱法(PGC)考察了它们的热裂解

CRYSTALLIZATION KINETICS OF MIXTURES OF POLY(EPSILON-CAPROLACTONE) AND POLY(STYRENE-CO-ACRYLONITRILE)

The crystallization kinetics in mixtures of poly(epsilon-caprolactone) (PCL) and poly(styrene-co-acrylonitrile) (SAN) has been investigated as the function of composition and crystallization temperature. The isothermal growth rates of PCL spherulites decrease with increasing concentration of SAN. Because of the miscibility of PCL/SAN mixtures, the radial growth rates of the spherulites are described by a kinetic equation including the interaction parameter and the free energy for the formation of crystal nuclei. The interaction parameter obtained from the fitting of the kinetic equation with experimental data is in good agreement with that obtained from melting point depression. Folding surface free energies decrease with the increase of SAN concentration. In light of these results, it is suggested that, for the PCL/SAN mixtures, the noncrystallizable SAN polymer reduces the mobility of crystallizable PCL polymer so that the growth rates decrease with the increase of noncrystallizable component fraction.

用于核磁共振波谱仪三调探头电路的设计

本文叙述了用于核磁共振谱仪的单线圈三调谐探头电路的设计。单线圈三调谐探头电路同时提供三个通道不同频率信号的发射和接收,氢(~1H)通道,碳(~13C)通道,氘通道三调谐电路如图1所示.氢通道的等效电路如图2a所示,碳通道等效电路如图2b所示,氘(~2D)

STUDY OF THE CHLORINATION REACTION OF Li2CO3 WITH NH4Cl

The chlorination reaction of Li2CO3 with NH4Cl has been studied in detail by a series of thermal analysis methods. When NH4Cl/Li2CO3 mole ratio equals 4, Li2CO3 can be transformed into LiCl quantitatively in a stream of Ar gas flow. All residual NH4Cl is decomposed completely at 400 degrees C and carried away from the reaction cell by Ar gas.Analysis by X-Ray diffraction and Ion Chromatography show that there are almost no NH4Cl remained in The LiCl product. It is interested that the chlorination reaction can be applied to the determinations of phase diagram by thermal analysis method and the preparation of Al-Li alloy by electrolysis in molten salt.

PMBP与P350对Nd(Ⅲ)的协同萃取

1-苯基-3-甲基-4-苯甲酰基吡唑酮-5(PMBP,以HA代表)作为一种优良的β—二酮类酸性螯合萃取剂,迄今已用于50多种元素的萃取分离、分析,它与其它试剂对金属的协同萃取也有报道。为研究不同中性磷萃取剂和无机酸介质对PMBP协同萃取稀土的影响,本文以盐酸体系中Nd(?)为被萃金属离子,选择甲基膦酸二甲庚酯(P350,以B代表)与PMBP组成新协同萃取体系,

HIPS/TiO_2复合材料的电子显微学研究

高抗冲聚苯乙烯树脂(HIPS)在实际应用中,往往要加入着色剂进行着色,钛白粉(TiO_2)是一种通用的白色着色剂。然而着色剂的加入对材料的力学性能有较大影响。本文对着色后的HIPS/TiO_2复合材料进行了电子显微学研究,明确了TiO_2影响HIPS力学性能的原因。 HIPS/TiO_2复合材料超薄切片的透射电子显微镜结果表明,TiO_2在样品中的分布很不均匀,局部区域TiO_2严重堆积(图1a)。扫描电子显微镜对HIPS/TiO_2冲击断面的组成观察得到了同样的结果(图1b。TiO_2在材料内部的堆积区域形成材料力学性能的弱点,材料受外力作用时首先从这些弱点处断裂,

Ce~(3+)在xMF_(2-y)YF_3体系中发射峰位置的变化

本文讨论了Ce~(3+)在xMF_2-yYF_3(M=Ca、Sr、Ba;x=0、1、2、y=0、1、2、)体系中的光谱行为及与其取代阳离子、邻位阳离子和 YF_3组分含量的变化关系,并与 Eu~(2+)的光谱行为进行了比较。

DRY-WEIGHT AND CHEMICAL-COMPOSITION (CHN) IN RELATION TO POPULATION-DENSITY OF CULTIVATED TISBE-HOLOTHURIAE (COPEPODA, HARPACTICOIDA)

CARBON