导电聚合物膜修饰电极的研究 Ⅲ.杂多酸掺杂聚吡咯膜电极的电子自旋共振(ESR)特性研究

本文通过对不同条件下的Co(W_2O_7)_6~(10-)和CuW_(12)O_(40)~(6-)掺杂聚吡膜ESR谱线的分析并以相同条件下NO_3~-掺杂聚吡咯膜作为参照,表明杂聚阴离子不仅起着中和电性的作用,而且与聚吡咯分子链相作用形成某种加合物,它影响聚吡咯的电结构,这种加合物在过正或过负的电位下均不稳定.首次发现在CuW_(12)O_(40)~(6-)掺杂的干态聚吡咯膜具有Dysonian线型,表明膜中其它电结构的存在.

杂多酸在活性炭上的固载化 Ⅱ．几种国产活性炭的表面性质对杂多酸吸附作用的影响

本文研究了四种具有Ｋｅｇｇｉｎ结构的杂多酸在五种国产改性活性炭载体上的吸附作用．实验结果表明，不同的杂多酸在活性炭上的吸附量是不同的，并且不同的活性炭对杂多酸的吸附等温线和吸附能力也不同．活性炭的表面化学性质显著地影响杂多酸在其上的吸附。

二价铕中性芳烃配合物［Eu（C_6Me_6）（AlCl_4）_2_4·Me_4

首次合成了二价铕中性芳烃配合物［Ｅｕ（Ｃ６Ｍｅ６（ＡｌＣｌ４）２］·Ｍｅ４Ｃ６Ｈ２，并经红外光谱，激发光谱和荧光光谱表征，测定了晶体结构。配合物属单斜晶系，Ｐ２／ｃ空间群，晶胞参数ａ＝１．７６５２（４）ｎｍ，ｂ＝１．５９１８（４）ｎｍ，ｃ＝１．８７５２（５）ｎｍ；β＝９７．６１（５）°，Ｚ＝２，Ｒ＝０．０４９６，Ｒｗ＝０．０４６２。

INVESTIGATION OF THE ELECTRICAL AND MAGNETIC-PROPERTIES OF YSR2-XCAXV3O9-Y

All the members of the solid solution of YSr2-xCaxV3O9-y have the orthorhombic symmetry. Their electrical and magnetic properties have been studied. The magnetic susceptibility and electrical resistivity increase gradually with x. The system shows paramagnetic behavior both at 300 K and at 77 K. It is shown that a change of valence state of vanadium obviously affects the electrical and magnetic properties of the solid solution.

THE THERMAL-STABILITY OF POLYETHYLENE BLENDS DURING HEAT-PROCESSING AND SHORT-TERM PHOTOOXIDATION

The melt flow behaviour of LDPE/HDPE blends with various compositions have been determined by melt flow index (MFI) measurement. The effects of stabilizers, photo-sensitizers, multiple extrusions and short-term photooxidation have been studied. The results show that there is no marked thermal stability difference between homopolymers and blends without multiple extrusions, no matter whether stabilizers or photo-sensitizers are added. Multiple extrusions or photo-sensitizers reduce their thermal stability, shown by the decrease in MFI. The decrease in MFI of photooxidized samples does not imply serious structural change and shows that the active species formed during photooxidation induce a crosslinking reaction in the melt indexer. Multiple extrusions increase the number of active species formed in LDPE or blends and lead to an obvious decrease in MFI. It is suggested that LDPE and LDPE-rich blends after short-term photooxidation can be characterized by MFI measurement. In contrast, HDPE cannot be characterized by this method due to its linear structure.

聚吡咯电化学掺杂过程的拉曼光谱研究

共轭导电聚合物经过掺杂,电导率可以提高十几个数量级,由绝缘体变为导体.但是,掺杂对聚合物链结构的影响方面,人们目前尚所知甚少.从实验的角度看,由于物性测量结果和材料的制备过程密切相关,往往不容易重复,有时还会出现一些令人困惑的假象.电化学现场物性测量技术可以针对同一样品,由电化学方法改变掺杂最,就可

旋光性聚酰胺的合成、表征及其手性识别能力

用天然酒石酸与不同芳香二胺成盐后,经高温缩聚反应,合成了五种新的旋光性聚酰胺,讨论了聚合条件对聚合物的[α]_D~(20)值的影响以及聚合物的旋光稳定性、热稳定性。~1H-NMR及园二色(CD)谱显示聚合物的分子链存在某种有序构象。手性拆分实验初步显示所合成的聚酰胺对苯丙氨酸有手性识别能力。

EPITAXIAL CRYSTALLIZATION OF TRANS-1,4-POLYBUTADIENE ON HIGHLY ORIENTED ISOTACTIC POLY(PROPYLENE) FILMS

Epitaxial crystallization of trans-1,4-polybutadiene (PBD) on highly oriented isotactic poly(propylene) (iPP) has been investigated at different crystallization temperatures and rates. From electron microscopy and electron diffraction, it is confirmed that epitactic growth of the low-temperature modification (monoclinic) with microcrystals of PBD on the iPP films takes place with their chain directions about +/- 50-degrees apart. No epitaxial relationship occurs between the high-temperature modification (hexagonal) of PBD and the iPP substrate. Thermal analyses of PBD-PP layered films indicate that the epitaxy has an important effect on the formation of the high-temperature modification of PBD.

铁(Ⅲ)-邻菲啰啉体系流动注射-分光光度法测定药品中的抗坏血酸

本文基于抗坏血酸还原铁(Ⅲ)-邻菲啰啉为红色铁(Ⅱ)-邻菲啰啉,建立了流动注射分光光度法测定药品中抗坏血酸的方法。本法体系简单,操作方便、快速,标准加入试验的回收率为92～103％。

高分辨~(13)C NMR在聚合物辐射化学中的应用

综述了高分辨~(13)C核磁共振谱(~(13)C NMR)在聚合物辐射化学研究中的应用。重点介绍了用固体高分辨~(13)C NMR研究聚合物辐射交联结构途径和应用范围。

论科技学术期刊稿件录用率的调控

科技学术期刊的稿件录用率是当前影响期刊出版时滞的关键因素之一.稿件录用与否和录用率的高低当由编辑部根据论文质量和期刊特点来全面衡量和确定.提出调控录用率和出版时滞的指导原则和具体方法.认为对论文进行全程质量控制,降低录用率而增加单位空间的有效信息量,可使科技期刊取得稿源充分而出版时滞又短的双赢.

衬钽管石墨炉中分子背景的调查

调查了钾、钠、钙的化合物在热解管(PGT)和衬钽管(TaT)中的分子背景。结果表明,衬钽管对NaCl、KCl、CaCl_2、Ca(NO_3)_2的背景吸收均具有明显抑制作用。

Generation and evolution of magma beneath the East Pacific Rise: Constraints from U-series disequilibrium and plagioclase-hosted melt inclusions

Mid-ocean ridge basalt (MORB) samples from the East Pacific Rise (EPR 12 degrees 50'N) were analyzed for U-series isotopes and compositions of plagioclase-hosted melt inclusions. The Ra-226 and Th-230 excesses are negatively correlated; the Ra-226 excess is positively correlated with Mg# and Sm/Nd, and is negatively correlated with La/Sm and Fe-8; the Th-230 excess is positively correlated with Fe-8 and La/Sm and is negatively correlated with Mg# and Sm/Nd. Interpretation of these correlations is critical for understanding the magmatic process. There are two models (the dynamic model and the "two-porosity" model) for interpreting these correlations, however, some crucial parameters used in these models are not ascertained. We propose instead a model to explain the U-series isotopic compositions based on the control of melt density variation. For melting either peridotite or the "marble-cake" mantle, the FeOt content, Th-230 excess and La/Sm ratio increases and Sm/Nd decreases with increasing pressure. A deep melt will evolve to a higher density and lower Mg# than a shallow melt, the former corresponds to a long residence time, which lowers the Ra-226 excess significantly. This model is supported by the existence of low Ra-226 excesses and high Th-230 excesses in MORBs having a high Fe-8 content and high density. The positive correlation of Ra-226 excess and magma liquidus temperature implies that the shallow melt is cooled less than the deep melt due to its low density and short residence time. The correlations among Fe-8, Ti-8 and Ca-8/Al-8 in plagioclase-hosted melt inclusions further prove that MORBs are formed from melts having a negative correlation in melting depths and degrees. The negative correlation of Ra-226 excess vs. chemical diversity index (standard deviation of Fe-8, Ti-8 and Ca-8/Al-8) of the melt inclusions is in accordance with the influence of a density-controlled magma residence time. We conclude that the magma density variation exerts significant control on residence time and U-series isotopic compositions. (c) 2010 Elsevier B.V. All rights reserved.

A unified criterion for initiation of sediment motion and inception of sheet flow under water waves

A unified criterion is developed for initiation of non-cohesive sediment motion and inception of sheet flow under water waves over a horizontal bed of sediment based on presently available experimental data. The unified threshold criterion is of the single form, U-o = 2 pi C[1 + 5(T-R/T)(2)](-1/4), where U-o is the onset velocity of sediment motion or sheet flow, T is wave period, and C and T-R are the coefficients. It is found that for a given sediment, U-o initially increases sharply with wave period, then gradually approaches the maximum onset velocity U-o = 2 pi C and becomes independent of T when T is larger. The unified criterion can also be extended to define sediment initial motion and sheet flow under irregular waves provided the significant wave orbital velocity and period of irregular waves are introduced in this unified criterion.