heterogeneous ziegler-natta and homogeneous metallocene catalysts exhibit greatly different active sitenature in olefin polymerization. in our previous study, it was reported that mgcl2-supported titanocenecatalysts can generate both ziegler-natta-type and metallocene-type active sites according to the type of activators.the dual active site nature of the supported titanocene catalysts was furt...

Polypropylenes loaded with different alkyl ammonium-modified montmorillonite are prepared to utilize a melt-mixing technique in various ways. Two types of polypropylene and compatibilizer are incorporated to improve the dispersion of various types of nanoclay and the dyeing behavior of the nanocomposites with various disperses, so acid and basic dyes were studied. For the first time, the aim of...

?-or the practitioner.-By G. Divwio'cyi M.A., IW.D. (Cantab.), IH.R.C.P. (L,0I\ Limited, William Heinemann (Medical Books), 6s London. Pp. xlii plus 88. Illustrated. Price, The part played by rheumatic diseases ^US; l?ss of work and inefficiency is very i P ' ^uch has been written during recent yea 'the busy I vast subject, that it is very difficult for t . Practitioner, whose time is limited, ...

Justin Collings. Democracy’s Guardians: A History of the German Federal Constitutional Court, 1951–2001. Oxford University Press, 2015. Pp. xli, 331. £65. ISBN: 9780198753377. Michaela Hailbronner. Traditions and Transformations: The Rise of German Constitutionalism. Oxford University Press, 2015. Pp. xi, 211. £60. ISBN: 9780198735427. Falk Jaeger (ed.). Transparenz und Würde: Das Bundesverfass...

Backward and Feebleminded Children. By Edmund Burke Huey. Baltimore Warwick and York, 1912. Pp. xiii-j-221. Illus. "Years ago at Heidelberg," writes Dr. Huey, "Professor Kraepelin told me, with enthusiasm which I well remember, how much he thought might come from an intensive clinical study of a group of some thirty school children. On my way to Lincoln, Dr. Adolf Meyer encouraged me to underta...

We show that the permanent cannot be computed by uniform constantdepth threshold circuits of size T (n), for any function T such that for all k, T (n) = o(2). More generally, we show that any problem that is hard for the complexity class C=P requires circuits of this size (on the uniform constant-depth threshold circuit model). In particular, this lower bound applies to any problem that is hard...