The minimal degrees of faithful representations of all sporadic simple groups and their covering groups are determined in this paper.

Operational underwater noise emitted at 8 m s -1 by a 550 kW WindWorld wind-turbine was recorded from the sea and modified to simulate a 2 MW wind-turbine. The sound was replayed from an audio CD through a car CD-player and a J-13 transducer. The maximum sound energy was emitted between 30 and 800 Hz with peak source levels of 128 dB (re 1 µPa 2 Hz -1 at 1 m) at 80 and 160 Hz (1/3-octave centre frequencies). This simulated 2 MW wind-turbine noise was played back on calm days (<1 Beaufort) to free-ranging harbour porpoises Phocoena phocoena and harbour seals Phoca vitulina in Fortune Channel, Vancouver Island, Canada. Swimming tracks of porpoises and surfacings of seals were recorded with an electronic theodolite situated on a clifftop 14 m above sea level. Echolocation activity of harbour porpoises close to the sound source was recorded simultaneously via an electronic click detector placed below the transducer. In total we tracked 375 porpoise groups and 157 seals during play-back experiments, and 380 porpoise groups and 141 surfacing seals during controls. Both species showed a distinct reaction to wind-turbine noise. Surfacings in harbour seals were recorded at larger distances from the sound source (median = 284 vs 239 m during controls; p = 0.008, Kolmogorov-Smirnov test) and closest approaches increased from a median of 120 to 182 m (p < 0.001) in harbour porpoises. Furthermore, the number of time intervals during which porpoise echolocation clicks were detected increased by a factor of 2 when the sound source was active (19.6% of all 1 min intervals as opposed to 8.4% of all intervals during controls; p < 0.001).These results show that harbour porpoises and harbour seals are able to detect the low-frequency sound generated by offshore wind-turbines. Controlled exposure experiments such as the one described here are a first step to assess the impact on marine mammals of the new offshore wind-turbine industry.

An immensely broad scope of structural motifs is covered by the intriguing chemistry of boron-sulfur and boron-selenium compounds. Characteristic structural features of the binary boron sulfides can be applied to understand and rationalize the three-dimensional atomic arrangement in macromolecular anionic frameworks such as that of Li [B S ]S (x≈2, shown in the picture; ○: S, •: B, ○: Li). Of interest are also the ion dynamics of lithium thioborates and a persubstituted B icosahedron that was prepared by high-temperature synthesis and features a characteristic planar B Se ring at the chelating ligand.

For the first time perthioborates with trigonal planar coordination of boron were prepared. Na2B2S5 (Pnma, a = 12.545(2) Å, b = 7.441(1) Å, c = 8.271(1) Å, Z = 4) and Li2B2S5 (Cmcm, a = 15.864(1) Å, b = 6.433(1) Å, c = 6.862(1) Å, Z = 4) were obtained by reaction of the metal sulfides with stoichiometric amounts of boron and an excess of sulfur (effective molar ratio M:B:S = 1:1:4) at 600°C (650°C) and subsequent annealing. The non‐isotypic structures contain exactly planar [B2S5]2− groups consisting of five‐membered B2S3 rings with one additional exocyclic sulfur on each of the boron atoms. The alkaline metal cations are four‐coordinate (lithium) and (four + four)‐coordinate (sodium) respectively.

Professor Wolfgang Jeitschko zum 60. Geburtstag gewidmet Inhaltsiibersicht. Es wird iiber die beiden Orthothioborate Li,BS, (Pnma; a = 8,144(1) A, b = 20,063(2) A, 6,161(1) A; Z = 4) und LiSrBS, (Pnma; a = 7,557(1) A, b = 9,083(2) A, c = 7,049(1) A; Z = 4) berichtet. Die beiden neuen Phasen wurden durch Hochtemperatur-Schmelzreaktion aus den Metallsulfiden, amorphem Bor und Schwefel bei 700 "C darge-Li,BS, and LiSrBS,: New Orthothioborates wi Abstract. We report o,n the two new orthothioborates Li,BS, (Pnma; a = 8.144(1) A, b = 10.063(2) A, 6.161(1) A; Z = 4) and LiSrBS, (Pnma; a = 7.557(1) A, b = 9.083(2) A, c = 7.049(1) A; Z = 4). The two new phases were prepared by reaction of the metal sulfides, amorphous boron, and sulfur at 700 "C. Both compounds contain isolated, planar [BS,]'--stellt. Beide Verbindungen enthalten isolierte, planare [BS,]'--Anionen. Die Lithiumionen sind vierfach (Li3BS3) bzw. sechsfach (LiSrBS,) von Schwefel umgeben, das Strontiumion weist eine achtfache Schwefelkoordination auf. Li,BS, und LiSrBS, bilden neue A3BX3 bzw. AA ' BX,-Strukturtypen. h Trigonal Planar Boron Coordination anions. The lithium ions have fourfold (Li,BS,) and sixfold (LiSrBS,) sulfur coordination, the strontium ion shows an eightfold sulfur coordination. The two compounds represent new A,BX, resp. AA'BX, structure types.