Poled polymeric nonlinear optical materials
    94.
    发明授权
    Poled polymeric nonlinear optical materials 失效
    极化聚合物非线性光学材料

    公开(公告)号:US5371173A

    公开(公告)日:1994-12-06

    申请号:US981342

    申请日:1992-11-25

    IPC分类号: C08G73/12 G02F1/361 C08G73/10

    CPC分类号: G02F1/3617 C08G73/124

    摘要: The synthesis of a nonlinear chromophoric co-monomer 3,5-diamino-4'-nitrodiphenylamine and use as a reactive component in combination with a bismaleimide monomer in a NLO-active polyimide matrix is disclosed. After concurrent corona or contact poling and thermal polymerization, thin films of these chromophoric polyimides exhibit high second harmonic generation efficiencies and high DSC-determined glass transition temperatures. These poled polyimides also exhibit excellent SHG temporal stability, retaining 85-90% of the initial second harmonic efficiency after more than one month in air at 85.degree. C.

    摘要翻译: 公开了非线性发色共聚单体3,5-二氨基-4'-硝基二苯胺的合成,并将其用作与Nlo-活性聚酰亚胺基体中的双马来酰亚胺单体组合的反应性组分。 在共同电晕或接触极化和热聚合之后,这些发色聚酰亚胺的薄膜表现出高的二次谐波产生效率和高DSC测定的玻璃化转变温度。 这些极化的聚酰亚胺也具有优异的SHG时效性,在85℃的空气中保持一个月以上的初始二次谐波效率的85-90%。

    Homogeneous catalysts for stereoregular olefin polymerization
    95.
    发明授权
    Homogeneous catalysts for stereoregular olefin polymerization 失效
    用于立体规则烯烃聚合的均相催化剂

    公开(公告)号:US5330948A

    公开(公告)日:1994-07-19

    申请号:US860784

    申请日:1992-03-31

    摘要: The synthesis, and use as precatalysts of chiral organozirconium complexes for olefin polymerization are disclosed, having the structure (C.sub.5 R'.sub.4-x R*.sub.x) A (C.sub.5 R".sub.4-y R'".sub.y) M Q.sub.p, where x and y represent the number of unsubstituted locations on the cyclopentadienyl ring; R', R", R'", and R* represent substituted and unsubstituted alkyl groups having 1-30 carbon atoms and R* is a chiral ligand; A is a fragment containing a Group 13, 14, 15, or 16 element of the Periodic Table; M is a Group 3, 4, or 5 metal of the Periodic Table; and Q is a hydrocarbyl radical, or halogen radical, with 3.ltoreq.p.ltoreq.o. Related complexes may be prepared by alkylation of the corresponding dichorides. In the presence of methylalumoxane or triarylborane cocatalysts, these complexes form "cation-like" species which are highly active for olefin polymerization. In combination with a Lewis acid cocatalyst, propylene or other .alpha.-olefin polymerization can be effected with very high efficiency and isospecificity.

    摘要翻译: 公开了具有结构(C5R'4-xR * x)A(C5R''4-yR“'y)M Qp的合成和用作烯烃聚合的手性有机锆络合物的预催化剂,其中x和y表示 环戊二烯基环上未取代位置的数目; R',R“,R”'和R *表示取代和未取代的具有1-30个碳原子的烷基,R *是手性配体; A是含有元素周期表第13,14,15或16族元素的片段; M是元素周期表的第3,4或5族金属; 且Q为烃基或卤素基团,其中3≤n≤0。 相关络合物可以通过相应的二氯化碳的烷基化来制备。 在甲基铝氧烷或三芳基硼烷助催化剂存在下,这些络合物形成对于烯烃聚合具有高活性的“阳离子”物质。 与路易斯酸助催化剂组合,丙烯或其它α-烯烃聚合可以以非常高的效率和特异性实现。

    Process for uranium isotope separation
    96.
    发明授权
    Process for uranium isotope separation 失效
    铀同位素分离方法

    公开(公告)号:US4097384A

    公开(公告)日:1978-06-27

    申请号:US668829

    申请日:1976-03-22

    摘要: Separation of U.sup.235 and U.sup.238 isotopes by converting a mixture of these isotopes to organic compounds or to silicon compounds and then irradiating the isotope compounds selectively to change their chemical (and/or physical) properties, thereby to facilitate separation. In a preferred embodiment of the invention the uranium compounds are selected from the group having a chemical moiety R bonded directly to the U atom, the U-R bond having a fundamental, overtone, or combination virbational absorption frequency between 900 and 1100 cm.sup.-1. The selected U mixture is then irradiated with a frequency-selective CO.sub.2 laser.

    摘要翻译: 通过将这些同位素的混合物转化为有机化合物或硅化合物,然后选择性地照射同位素化合物来改变其化学(和/或物理)性质,从而便于分离,从而分离U235和U238同位素。 在本发明的一个优选实施方案中,铀化合物选自具有与U原子直接键合的化学部分R的基团,U-R键具有基本的,泛音,或者在900和1100cm -1之间的组合防晒吸收频率。 然后将所选的U混合物用频率选择性CO 2激光器照射。