Magnetorheological (MR) uids are a class of new intelligent materials whose rheological characteristics change rapidly and can be controlled easily in the presence of an applied magnetic eld. The devices based on MR uids, including dampers, brakes, clutches, polishing devices and hydraulic valves, etc., have a very promising potential future; some of them have been used commercially in engineering applications such as automobiles, polishing machines, exercise equipment, etc. In this paper, the modes of operation of MR uid devices are analysed. A comprehensive review is then presented of the principles, characteristics and engineering applications of the MR uid devices (especially dampers) studied in the last decade. Finally, the application prospects of MR uid devices are discussed.

No abstract

Several N-3 substituted carboranyl Thd analogs were synthesized. These agents as well as some non-boronated nucleosides were evaluated in phosphoryl transfer assays with recombinant human TK1 and TK2. For some carboranyl thymidine analogs, TK1 phosphorylation rates approached 38% that of thymidine. Their in vitro cytotoxicty appeared to correlate with the TK1 levels in the tested cells. In some cases increased uptake in tumor cell nuclei compared with the surrounding cytoplasm was detected in vitro.