Synthesis of amphiphilic magnetic microspheres by dispersion copolymerization of styrene and poly(ethylene oxide) macromonomer

Amphiphilic magnetic microspheres ranging in diameter from 5 to 100 µm were prepared by dispersion copolymerization of styrene and poly(ethylene oxide) vinylbenzyl (PEO‐VB) macromonomer (MPEO) in the presence of Fe₃O₄ magnetic fluid. The effects of various polymerization parameters on the average particle size were systematically investigated. The average particle size was found to increase with increasing styrene concentration and initiator concentration. It also increased with decreasing stabilizer concentration and molecular weight of MPEO. The content of the hydroxyl groups localized in the microspheres ranged from 0.01 to 0.2 mmol g^?1. © 2003 Society of Chemical Industry     

精细功能陶瓷的若干发展趋势

概括了分析自９０年代初以来精细功能陶瓷的发展趋势，提出了一些相关的研究领域。     

软X射线对血液有形成分表面电荷的影响——2、淋巴细胞和血小板膜电荷的变化

软X射线不仅能引起红细胞表面电荷的变化,同时也能导致淋巴细胞和血小板表面电荷下降,表现为照射后它们的电泳率下降。低剂量范围内,这种电荷的变化是暂时性的,照后4小时降到最低点,24小时后恢复到对照的水平。细胞电泳率的下降与辐射剂量相关。淋巴细胞是一个复杂的细胞群,正常状态下,按细胞在电场中泳动速度的快慢,可分为两个组分:快峰为T细胞,慢峰为B细胞。软X射线照射以后,T和B细胞的电泳率皆减慢,频数分布峰值下降,离散度加大。血小板成分单一,电泳率较一致。 从照射浓集的血小板再加回自身血浆中电泳率的下降较照射血浆再加到血小板中的电泳率下降大得多;受照射的血小板在磷酸缓冲液中电泳率下降较在血浆悬液中严重得多;2000 rad照后,悬浮于血浆中的血小板电泳率能恢复,而悬浮于磷酸缓冲液中则不能恢复,三个方面来看,血浆中可能存在抗辐射因子。超氧化物岐化酶能有效地预防血小板电泳率的下降,从而可阻止血小板的凝聚。     

春光油田现代油藏经营管理模式的

介绍并分析了春光油田现代油藏经营管理模式的构建与运作及实施效果.     

Average consensus in networks of dynamic agents with switching topologies and multiple time-varying delays

In this paper, we discuss average consensus problem in undirected networks of dynamic agents with fixed and switching topologies as well as multiple time-varying communication delays. By employing a linear matrix inequality method, we prove that all the nodes in the network achieve average consensus asymptotically for appropriate communication delays if the network topology is connected. Particularly, several feasible linear matrix inequalities are established to determine the maximal allowable upper bound of time-varying communication delays. Numerical examples are given to demonstrate the effectiveness and the sharpness of the theoretical results.     

赛汉塔拉凹陷滑塌浊积岩的发现与勘探意义

通过研究二连盆地赛汉塔拉凹陷中洼槽陡坡带的含鲕粒块状细砂岩从岩性特征、沉积结构及构造特征、粒度特征、测井曲线特征、地震反射特征以及对其形成机理的分析,认为赛83x含油砂岩体为在半深湖一深湖环境形成的滑塌浊积扇沉积.这种类型的滑塌浊积扇具备分选、磨圆度、物性较好等条件,尤其是此类砂岩体往往被形成于深湖一半深湖相还原环境的深灰色、灰黑色泥岩--成熟烃源岩所包围,易形成岩性圈闭,有利于油气的运移和聚集成藏,是断陷湖盆陡坡带油气勘探的重要目标.