Uwe Meyer - Academia.edu (original) (raw)
Papers by Uwe Meyer
Spontaneous coal seam fires contribute significant to the CO2 emissions world wide. As the coal f... more Spontaneous coal seam fires contribute significant to the CO2 emissions world wide. As the coal fires are complicated regarding structure and dynamics it is not trivial to fins out how much CO2 is released by an individual fire. This value is basic also for a possible certificate trading in connection with the extinction of those fires in the context of CDM. Three basic methods were proposed to estimate the amount of CO2 emitted. 1. Direct gas measurements (direct approach) 2. Estimation of the coal burned (volume approach) 3. Energy releases (energy approach) The energy approach turned out to be the only practical solution. The energy balance of the fire is a composition of the components 1. Radiation 2. Energy release from subsurface to air 3. Energy transported by hot exhaust gases 4. Energy transported by matrix diffusion Those components are explained and a field case from a fire zone in China is presented.
GEOPHYSICS, 2015
Coastal areas such as the German Bight are at risk from storms and rising sea level that may affe... more Coastal areas such as the German Bight are at risk from storms and rising sea level that may affect the hydrogeologic setting. Because knowledge of the distribution of clayey sediments is important for understanding the current status of this dynamic setting, the German Federal Institute for Geosciences and Natural Resources (BGR) has focused on geophysical research projects on the North Sea coast applying airborne and ground geophysics. The airborne system operated by BGR was used to survey a 20- by 31-km large coastal area in Eastern Friesland, Germany, including the islands of Langeoog and Spiekeroog. Helicopter-borne electromagnetic (HEM) data were collected at six frequencies. In addition, the Leibniz Institute for Applied Geophysics commissioned a SkyTEM survey covering a 2-km-wide north–south strip. On the island of Langeoog, ground geophysical methods, such as transient electromagnetics (TEM) and magnetic resonance soundings (MRS) were used to investigate the hydrogeologic s...
Erkenntnis, 2001
In this paper I discuss a variant of the knowledge argument which is based upon Frank Jackson'... more In this paper I discuss a variant of the knowledge argument which is based upon Frank Jackson's Mary thought experiment. Using this argument, Jackson tries to support the thesis that a purely physical – or, put generally: an objectively scientific – perspective upon the world excludes the important domain of `phenomenal' facts, which are only accessible introspectively. Martine Nida-Rümelinhas formulated
ABSTRACT Helicopter-borne electromagnetics (HEM) is an important tool for hydrogeological questio... more ABSTRACT Helicopter-borne electromagnetics (HEM) is an important tool for hydrogeological questions. HEM investigations enable the differentiation of sandy and clayey sediments as well as saltwater and freshwater saturated sediments down to about 150 meters depth. The frequency-domain HEM system operated at the Federal Institute for Geosciences and Natural Resources (BGR) is the RESOLVE system manufactured by Fugro Airborne Surveys. In 2008 and 2009, BGR conducted airborne geophysical measurements for saltwater-freshwater investigation at several survey areas at the German North Sea coast. The surveys were carried out in cooperation with the Leibniz Institute for Applied Geosciences (LIAG) in frame of the project D-AERO. One of these survey areas covers the estuary of the Elbe river to the north-west of the city of Hamburg. Parts of the results of this survey are involved in the project KLIMZUG-NORD, where the Technical University Hamburg-Harburg investigates the environmental effects of the climate change on the estuary of the Elbe river. The HEM measurements reveal both the course of the Geest ridge (high-lying hinterland consisting of pleistocenic moraine sediments) and the swamp belt due to their elevated resistivities, whereas the Marsch land (plain holocenic wet land, alluvium) occurred more conductive. Here, an electrical conductivity anomaly was detected witch could neither be related with seawater intrusion nor with anthropogenic sources. The significant low-resistivity zone of about three square kilometers was identified as a saltwater-rising zone by water analyses of surface water and is an example for natural groundwater mineralization. A man-made groundwater mineralization was investigated by HEM in the Werra river valley in central Germany. About 1000 million cubic meters saline waste water from potash mining have been stored in a karstic limestone and dolomite bed to reduce the amount of saline water emissions directly into the river. BGR conducted surveys in 1996/97 and 2008 including an area where a test disposal of 9.5 million cubic meters saline waste water took place between 1999 and 2007. Changes of the near surface groundwater mineralization were monitored.
Within the framework of the Sino-German research initiative "Innovative technologies for exp... more Within the framework of the Sino-German research initiative "Innovative technologies for exploration, extinction and monitoring of coal fires in Northern China" a number of different geophysical methods have been applied to determine their use on coal fire detecting, accompanying the extinguishing processes, controlling of the extinction and finally monitoring the extinction success. It is known that the heating of coal resp. coal host rocks changes its electrical resistivity and magnetic susceptibility. Hence the methods of choice are airborne magnetics and frequency electromagnetics (AEM) for surveying large and inaccessible areas and ground based magnetics, transient electromagnetics (TEM), ground penetrating radar (GPR) and temperature measurements to obtain detailed local information. Ground based and airborne magnetics show positive anomalies on coal fire areas. Susceptibility of sandstone, coal and (burnt) clay samples were determined in-situ. The magnetisation was ...
Science of Computer Programming, 1999
An on-line partial evaluator for an imperative language is formally defined and proven to be corr... more An on-line partial evaluator for an imperative language is formally defined and proven to be correct. As far as we know, this is the first correctness proof of an on-line partial evaluator. The proof consists of several lemmata showing the correctness of partial evaluation of expression and the invariance of certain properties of the environments under partial/residual and total evaluation. The language the partial evaluator is based on contains functions as well as procedures with value, result, and reference parameters and side-effects.
Journal of Organometallic Chemistry, 1993
The chelate osmium complexes (C,H,Os[OC(O)CH(R)NH,KP'Prsl)X (3,4) and (C,H,Os[OC(O)CH(R)NH~~PMe'B... more The chelate osmium complexes (C,H,Os[OC(O)CH(R)NH,KP'Prsl)X (3,4) and (C,H,Os[OC(O)CH(R)NH~~PMe'Bu~))X (5-7) have been prepared almost quantitatively from [c,H,os(PR,)I,] precursors and a-aminocarboxylates. Owing to the NMR spectroscopic data, for L-alaninate as substrate one diastereoisomer and for D/L-phenylalaninate one pair of enantiomers is preferentially formed. The X-ray structural analysis of 6 (R = CH,; X = I) confirms the presence of the R,S, diastereoisomer in the crystal lattice. The reaction of the five-coordinate chloro(hydrido)metal compounds [MHCkCOXPMe'Bu,),] (M = Ru, OS) with glycinate and o/t_-phenylalaninate gives the octahedral complexes (MH[OC(O)CH(R)NH,KCOjfPMe'Bu,),] (10-12) in 7585% yield. Zusammenfassung Die Chelatosmium-Komplexe {C,H,Os[OCfO)CH(R)NH,~PiPr,))X (3,4) und {C,H,OS[OC(O)CH(R)NH~~~PM~'BU~))X (S-7) werden praktisch quantitativ durch Umsetzung von [C,H,Os(PR,)I,] mit cr-Aminocarboxylaten erhalten. Wie die NMR-Daten zeigen, wird fiir t_-Alaninat als Reaktionspartner bevorzugt nur ein Diastereomer und fiir D/t_-Phenylalaninat nur ein Enantiomerenpaar gebildet. Die Strukturanalyse von 6 (R = CH,, X = I) bestiitigt das Vorliegen des R,S,-Diastereomers im Kristallgitter. Die Reaktion der fiinffach koordinierten Chloro(hydridoJmetalI-Verbindungen [MHCI(COXPMe'Bu2)2] (M = Ru, OS) mit Glycinat und o/t_-Phenylalaninat liefert die oktaedrischen Komplexe (M~OCfO)CH(R)NH,XCOXPMe'Bu,)Z) (10-12) mit einer Ausbeute von 7585%. Als geeignete Ausgangssubstanzen zur Synthese von Metallkomplexen mit einem asymmetrisch substituierten Zentralatom unter Bevorzugung eines der beiden optischen Isomeren haben sich Aminoduren bzw. ihre Anionen erwiesen [l]. Ihr Vorzug ist, daS sie selbst iiber ein stereogenes Zentrum verfiigen und such leicht in enantiomerenreiner Form zuganglich sind. Uber die Darstellung von Komplexen mit Aminocarboxylat-Anionen als Chelatliganden existieren bereits zahlreiche Untersuchungen [1,2]. Dabei geht man h&fig von Halogenometall-Verbindungen aus, die im Sinne eines Austausches von Cl-(Br-, II) gegen H,NCH(R)CO,-mit Salzen von Aminosauren
![Research paper thumbnail of Insertion reaction of acetone-d6 into the osmium-hydrogen bond of [OsHCl(CO)(P-iso-Pr3)2]: experimental evidence for the hydrogen-transfer mechanism from alcohols to ketones](https://attachments.academia-assets.com/95165045/thumbnails/1.jpg)
](Inorganic Chemistry, 1991
Acetone in a similar amount was formed. (1 6) Plots of log rate versus log [catalyst] and log rat... more Acetone in a similar amount was formed. (1 6) Plots of log rate versus log [catalyst] and log rate versus log [substrate] yield straight lines of slopes 1 .O and 1.2, respectively. A related kinetic study using 1 as the catalyst is precluded by the slowness of the reaction.
Chemische Berichte, 1989
Die Carbonyl(hydrido)-Komplexe MHCl(CO)[PMe(tBu)2]2 (3: M = Ru; 4: M = Os) reagieren in hoher Aus... more Die Carbonyl(hydrido)-Komplexe MHCl(CO)[PMe(tBu)2]2 (3: M = Ru; 4: M = Os) reagieren in hoher Ausbeute mit Alkinen RCCH (R = H, Me, Ph) unter Insertion zu den funffach koordinierten Vinylmetall-Verbindungen M(E-CHCHR)Cl(CO)[PMe(tBu)2]2 (5–10). Auf ahnliche Weise werden bei Verwendung von MHCl(CO)(PiPr3)2 (11, 12) und RuHCl(CO)(PPh3)3 (15) als Ausgangssubstanzen die Komplexe M(E-CHCHMe)Cl(CO)(PiPr3)2 (13, 14) und Ru(E-CHCHR)Cl(CO)(PPh3)2 (16, 17) erhalten. Die Reaktionen von 3, 4 und 12 mit HCCCO2Me fuhren ebenfalls zur Bildung von Vinylmetall-Verbindungen, in denen die CO2Me-Gruppe entweder an das α- oder β-Kohlenstoff-Atom des Vinyl-Liganden gebunden ist. Die Kristallstruktur von (18) wurde bestimmt. Os(E-CHCHCO2Me)Cl(CO)(PiPr3)2 (22) lagert sich in Losung quantitativ in das Z-Isomere um, das eine chelatartig gebundene Vinyl-Gruppe enthalt. Die Hydrido- (3, 4) und die Vinylmetall-Verbindungen 5–10, 13, 16 und 31 reagieren mit Liganden L (CO, CNMe, CNCH2Ph und PMe3) zu den entsprechenden oktaedrischen Ruthenium- und Osmium-Komplexen 25–30 und 32–39. Die Darstellung von [Ru(E-CHCHPh)(CO)3(PiPr3)2]PF6 (41) wird auch beschrieben. Five- and Six-Coordinate Vinyl-Ruthenium and -Osmium Complexes by Alkyne Insertion from Hydrido-Metal Precursors The carbonyl-hydrido complexes MHCl(CO)[PMe(tBu)2]2 (3: M = Ru; 4: M = Os) react with alkynes RCCH (R = H, Me, Ph) by insertion to give the five-coordinate vinyl-metal compounds M(E-CHCHR)Cl(CO)[PMe(tBu)2]2 (5–10). in high yield. Using MHCl(CO)(PiPr3)2 (11, 12) and RuHCl(CO)(PPh3)3 (15) as starting materials, the complexes M(E-CHCHMe)Cl(CO)(PiPr3)2 (13, 14) and Ru(E-CHCHR)Cl(CO)(PPh3)2 (16: R Ph; 17: R H) are similarly prepared. The reactions of 3, 4, and 12 with HCCCO2Me also lead to the formation of vinyl-metal compounds in which the CO2Me group is either bound to the α or the β carbon atom of the vinyl ligand. The X-ray crystal structure of (18) has been determined. In solution, Os(E-CHCHCO2Me)Cl(CO)(PiPr3)2 (22) rearranges quantitatively to form the Z isomer 24 in which the vinyl group behaves as a chelating ligand. The hydrido complexes 3, 4, and the vinyl-metal compounds 5–10, 13, 16, and 31 react with L (CO, CNMe, CNCH2Ph and PMe3) to give the corresponding octahedral ruthenium and osmium derivatives 25–30 and 32–39. in almost quantitative yields. The ionic complex [Ru(E-CHCHPh)(CO)3(PiPr3)2]PF6 (41) has also been prepared.
Behavioral and Brain Sciences, 1990
The "radiator" theory of brain evolution is proposed to account for "mosaic evolution" whereby br... more The "radiator" theory of brain evolution is proposed to account for "mosaic evolution" whereby brain size began to increase rapidly in the genus Homo well over a million years after bipedalism had been selected for in early hominids. Because hydrostatic pressures differ across columns of fluid depending on orientation (posture), vascular systems of early bipeds became reoriented so that cranial blood flowed preferentially to the vertebral plexus instead of the internal jugular vein in response to gravity. The Hadar early hominids and robust australopithecines partly achieved this reorientation with a dramatically enlarged occipital/marginal sinus system. On the other hand, hominids in the gracile australopithecine through Homo lineage delivered blood to the vertebral plexus via a widespread network of veins that became more elaborate through time. Mastoid and parietal emissary veins are representatives of this network, and increases in their frequencies during hominid evolution are indicative of its development. Brain size increased with increased frequencies of mastoid and parietal emissary veins in the lineage leading to and including Homo, but remained conservative in the robust australopithecine lineage that lacked the network of veins. The brain is an extremely heatsensitive organ and emissary veins in humans have been shown to cool the brain under conditions of hyperthermia. Thus, the network of veins in the lineage leading to Homo acted as a radiator that released a thermal constraint on brain size. The radiator theory is in keeping with the belief that basal gracile and basal robust australopithecines occupied distinct niches, with the former living in savanna mosaic habitats that were subject to hot temperatures and intense solar radiation during the day.
Archives Of Phytopathology And Plant Protection, 1991
Page 1. Arch. Phytopathol. Pllanzenschutz, Bcrlin 27 (1991) 5. 353-360 Biologische Zcntralanstalt... more Page 1. Arch. Phytopathol. Pllanzenschutz, Bcrlin 27 (1991) 5. 353-360 Biologische Zcntralanstalt Bcrlin lnstitut fur Phytopathologie Ascherslebcn und Saatzuchtstation hf6ringcn HARTMJT KEGLER, BEKND WOLTEKSTORFF ...
Archives Of Phytopathology And Plant Protection, 1987
Archives Of Phytopathology And Plant Protection, 1991
Archives Of Phytopathology And Plant Protection, 1990
... Um diese Fehlerquelle wenigstens teilweise auszuschnlten, stellten wir die verschiedenen Ausg... more ... Um diese Fehlerquelle wenigstens teilweise auszuschnlten, stellten wir die verschiedenen Ausgangsmaterialien dem gleichen Virus-standard gegenuber ... Bereits BISHT (1963), FRIDLUND (1979) und AL KAI (1988) berichteten uber eine ungleich-miil3ige Verteilung des ApMV ...
Archives Of Phytopathology And Plant Protection, 1988
Archives Of Phytopathology And Plant Protection, 1988
Annals of Glaciology, 1999
Since the austral summer of 1994-95 the Alfred Wegener Institute has carried out airborne radio-e... more Since the austral summer of 1994-95 the Alfred Wegener Institute has carried out airborne radio-echo sounding (RES) measurements in Antarctica with its newly designed RES system. Since 1995-96 an ongoing pre-site survey for an ice-coring drill site in Dronning Maud Land has been carried out as part of the European Project for Ice Goring in Antarctica. The survey covers an area of 948 000 km2, with >49 500 km of airborne RES obtained from >200 hours of flight operation flown during the period 1994-97. In this paper, first results of the airborne RES survey are graphically summarized as newly derived maps of the ice thickness and subglacial topography, as well as a three-dimensional view of surface and subglacial bed and outcrop topography, revealing a total ice volume of 1.48 x 106 km3.
Spontaneous coal seam fires contribute significant to the CO2 emissions world wide. As the coal f... more Spontaneous coal seam fires contribute significant to the CO2 emissions world wide. As the coal fires are complicated regarding structure and dynamics it is not trivial to fins out how much CO2 is released by an individual fire. This value is basic also for a possible certificate trading in connection with the extinction of those fires in the context of CDM. Three basic methods were proposed to estimate the amount of CO2 emitted. 1. Direct gas measurements (direct approach) 2. Estimation of the coal burned (volume approach) 3. Energy releases (energy approach) The energy approach turned out to be the only practical solution. The energy balance of the fire is a composition of the components 1. Radiation 2. Energy release from subsurface to air 3. Energy transported by hot exhaust gases 4. Energy transported by matrix diffusion Those components are explained and a field case from a fire zone in China is presented.
GEOPHYSICS, 2015
Coastal areas such as the German Bight are at risk from storms and rising sea level that may affe... more Coastal areas such as the German Bight are at risk from storms and rising sea level that may affect the hydrogeologic setting. Because knowledge of the distribution of clayey sediments is important for understanding the current status of this dynamic setting, the German Federal Institute for Geosciences and Natural Resources (BGR) has focused on geophysical research projects on the North Sea coast applying airborne and ground geophysics. The airborne system operated by BGR was used to survey a 20- by 31-km large coastal area in Eastern Friesland, Germany, including the islands of Langeoog and Spiekeroog. Helicopter-borne electromagnetic (HEM) data were collected at six frequencies. In addition, the Leibniz Institute for Applied Geophysics commissioned a SkyTEM survey covering a 2-km-wide north–south strip. On the island of Langeoog, ground geophysical methods, such as transient electromagnetics (TEM) and magnetic resonance soundings (MRS) were used to investigate the hydrogeologic s...
Erkenntnis, 2001
In this paper I discuss a variant of the knowledge argument which is based upon Frank Jackson'... more In this paper I discuss a variant of the knowledge argument which is based upon Frank Jackson's Mary thought experiment. Using this argument, Jackson tries to support the thesis that a purely physical – or, put generally: an objectively scientific – perspective upon the world excludes the important domain of `phenomenal' facts, which are only accessible introspectively. Martine Nida-Rümelinhas formulated
ABSTRACT Helicopter-borne electromagnetics (HEM) is an important tool for hydrogeological questio... more ABSTRACT Helicopter-borne electromagnetics (HEM) is an important tool for hydrogeological questions. HEM investigations enable the differentiation of sandy and clayey sediments as well as saltwater and freshwater saturated sediments down to about 150 meters depth. The frequency-domain HEM system operated at the Federal Institute for Geosciences and Natural Resources (BGR) is the RESOLVE system manufactured by Fugro Airborne Surveys. In 2008 and 2009, BGR conducted airborne geophysical measurements for saltwater-freshwater investigation at several survey areas at the German North Sea coast. The surveys were carried out in cooperation with the Leibniz Institute for Applied Geosciences (LIAG) in frame of the project D-AERO. One of these survey areas covers the estuary of the Elbe river to the north-west of the city of Hamburg. Parts of the results of this survey are involved in the project KLIMZUG-NORD, where the Technical University Hamburg-Harburg investigates the environmental effects of the climate change on the estuary of the Elbe river. The HEM measurements reveal both the course of the Geest ridge (high-lying hinterland consisting of pleistocenic moraine sediments) and the swamp belt due to their elevated resistivities, whereas the Marsch land (plain holocenic wet land, alluvium) occurred more conductive. Here, an electrical conductivity anomaly was detected witch could neither be related with seawater intrusion nor with anthropogenic sources. The significant low-resistivity zone of about three square kilometers was identified as a saltwater-rising zone by water analyses of surface water and is an example for natural groundwater mineralization. A man-made groundwater mineralization was investigated by HEM in the Werra river valley in central Germany. About 1000 million cubic meters saline waste water from potash mining have been stored in a karstic limestone and dolomite bed to reduce the amount of saline water emissions directly into the river. BGR conducted surveys in 1996/97 and 2008 including an area where a test disposal of 9.5 million cubic meters saline waste water took place between 1999 and 2007. Changes of the near surface groundwater mineralization were monitored.
Within the framework of the Sino-German research initiative "Innovative technologies for exp... more Within the framework of the Sino-German research initiative "Innovative technologies for exploration, extinction and monitoring of coal fires in Northern China" a number of different geophysical methods have been applied to determine their use on coal fire detecting, accompanying the extinguishing processes, controlling of the extinction and finally monitoring the extinction success. It is known that the heating of coal resp. coal host rocks changes its electrical resistivity and magnetic susceptibility. Hence the methods of choice are airborne magnetics and frequency electromagnetics (AEM) for surveying large and inaccessible areas and ground based magnetics, transient electromagnetics (TEM), ground penetrating radar (GPR) and temperature measurements to obtain detailed local information. Ground based and airborne magnetics show positive anomalies on coal fire areas. Susceptibility of sandstone, coal and (burnt) clay samples were determined in-situ. The magnetisation was ...
Science of Computer Programming, 1999
An on-line partial evaluator for an imperative language is formally defined and proven to be corr... more An on-line partial evaluator for an imperative language is formally defined and proven to be correct. As far as we know, this is the first correctness proof of an on-line partial evaluator. The proof consists of several lemmata showing the correctness of partial evaluation of expression and the invariance of certain properties of the environments under partial/residual and total evaluation. The language the partial evaluator is based on contains functions as well as procedures with value, result, and reference parameters and side-effects.
Journal of Organometallic Chemistry, 1993
The chelate osmium complexes (C,H,Os[OC(O)CH(R)NH,KP'Prsl)X (3,4) and (C,H,Os[OC(O)CH(R)NH~~PMe'B... more The chelate osmium complexes (C,H,Os[OC(O)CH(R)NH,KP'Prsl)X (3,4) and (C,H,Os[OC(O)CH(R)NH~~PMe'Bu~))X (5-7) have been prepared almost quantitatively from [c,H,os(PR,)I,] precursors and a-aminocarboxylates. Owing to the NMR spectroscopic data, for L-alaninate as substrate one diastereoisomer and for D/L-phenylalaninate one pair of enantiomers is preferentially formed. The X-ray structural analysis of 6 (R = CH,; X = I) confirms the presence of the R,S, diastereoisomer in the crystal lattice. The reaction of the five-coordinate chloro(hydrido)metal compounds [MHCkCOXPMe'Bu,),] (M = Ru, OS) with glycinate and o/t_-phenylalaninate gives the octahedral complexes (MH[OC(O)CH(R)NH,KCOjfPMe'Bu,),] (10-12) in 7585% yield. Zusammenfassung Die Chelatosmium-Komplexe {C,H,Os[OCfO)CH(R)NH,~PiPr,))X (3,4) und {C,H,OS[OC(O)CH(R)NH~~~PM~'BU~))X (S-7) werden praktisch quantitativ durch Umsetzung von [C,H,Os(PR,)I,] mit cr-Aminocarboxylaten erhalten. Wie die NMR-Daten zeigen, wird fiir t_-Alaninat als Reaktionspartner bevorzugt nur ein Diastereomer und fiir D/t_-Phenylalaninat nur ein Enantiomerenpaar gebildet. Die Strukturanalyse von 6 (R = CH,, X = I) bestiitigt das Vorliegen des R,S,-Diastereomers im Kristallgitter. Die Reaktion der fiinffach koordinierten Chloro(hydridoJmetalI-Verbindungen [MHCI(COXPMe'Bu2)2] (M = Ru, OS) mit Glycinat und o/t_-Phenylalaninat liefert die oktaedrischen Komplexe (M~OCfO)CH(R)NH,XCOXPMe'Bu,)Z) (10-12) mit einer Ausbeute von 7585%. Als geeignete Ausgangssubstanzen zur Synthese von Metallkomplexen mit einem asymmetrisch substituierten Zentralatom unter Bevorzugung eines der beiden optischen Isomeren haben sich Aminoduren bzw. ihre Anionen erwiesen [l]. Ihr Vorzug ist, daS sie selbst iiber ein stereogenes Zentrum verfiigen und such leicht in enantiomerenreiner Form zuganglich sind. Uber die Darstellung von Komplexen mit Aminocarboxylat-Anionen als Chelatliganden existieren bereits zahlreiche Untersuchungen [1,2]. Dabei geht man h&fig von Halogenometall-Verbindungen aus, die im Sinne eines Austausches von Cl-(Br-, II) gegen H,NCH(R)CO,-mit Salzen von Aminosauren
Inorganic Chemistry, 1991
Acetone in a similar amount was formed. (1 6) Plots of log rate versus log [catalyst] and log rat... more Acetone in a similar amount was formed. (1 6) Plots of log rate versus log [catalyst] and log rate versus log [substrate] yield straight lines of slopes 1 .O and 1.2, respectively. A related kinetic study using 1 as the catalyst is precluded by the slowness of the reaction.
Chemische Berichte, 1989
Die Carbonyl(hydrido)-Komplexe MHCl(CO)[PMe(tBu)2]2 (3: M = Ru; 4: M = Os) reagieren in hoher Aus... more Die Carbonyl(hydrido)-Komplexe MHCl(CO)[PMe(tBu)2]2 (3: M = Ru; 4: M = Os) reagieren in hoher Ausbeute mit Alkinen RCCH (R = H, Me, Ph) unter Insertion zu den funffach koordinierten Vinylmetall-Verbindungen M(E-CHCHR)Cl(CO)[PMe(tBu)2]2 (5–10). Auf ahnliche Weise werden bei Verwendung von MHCl(CO)(PiPr3)2 (11, 12) und RuHCl(CO)(PPh3)3 (15) als Ausgangssubstanzen die Komplexe M(E-CHCHMe)Cl(CO)(PiPr3)2 (13, 14) und Ru(E-CHCHR)Cl(CO)(PPh3)2 (16, 17) erhalten. Die Reaktionen von 3, 4 und 12 mit HCCCO2Me fuhren ebenfalls zur Bildung von Vinylmetall-Verbindungen, in denen die CO2Me-Gruppe entweder an das α- oder β-Kohlenstoff-Atom des Vinyl-Liganden gebunden ist. Die Kristallstruktur von (18) wurde bestimmt. Os(E-CHCHCO2Me)Cl(CO)(PiPr3)2 (22) lagert sich in Losung quantitativ in das Z-Isomere um, das eine chelatartig gebundene Vinyl-Gruppe enthalt. Die Hydrido- (3, 4) und die Vinylmetall-Verbindungen 5–10, 13, 16 und 31 reagieren mit Liganden L (CO, CNMe, CNCH2Ph und PMe3) zu den entsprechenden oktaedrischen Ruthenium- und Osmium-Komplexen 25–30 und 32–39. Die Darstellung von [Ru(E-CHCHPh)(CO)3(PiPr3)2]PF6 (41) wird auch beschrieben. Five- and Six-Coordinate Vinyl-Ruthenium and -Osmium Complexes by Alkyne Insertion from Hydrido-Metal Precursors The carbonyl-hydrido complexes MHCl(CO)[PMe(tBu)2]2 (3: M = Ru; 4: M = Os) react with alkynes RCCH (R = H, Me, Ph) by insertion to give the five-coordinate vinyl-metal compounds M(E-CHCHR)Cl(CO)[PMe(tBu)2]2 (5–10). in high yield. Using MHCl(CO)(PiPr3)2 (11, 12) and RuHCl(CO)(PPh3)3 (15) as starting materials, the complexes M(E-CHCHMe)Cl(CO)(PiPr3)2 (13, 14) and Ru(E-CHCHR)Cl(CO)(PPh3)2 (16: R Ph; 17: R H) are similarly prepared. The reactions of 3, 4, and 12 with HCCCO2Me also lead to the formation of vinyl-metal compounds in which the CO2Me group is either bound to the α or the β carbon atom of the vinyl ligand. The X-ray crystal structure of (18) has been determined. In solution, Os(E-CHCHCO2Me)Cl(CO)(PiPr3)2 (22) rearranges quantitatively to form the Z isomer 24 in which the vinyl group behaves as a chelating ligand. The hydrido complexes 3, 4, and the vinyl-metal compounds 5–10, 13, 16, and 31 react with L (CO, CNMe, CNCH2Ph and PMe3) to give the corresponding octahedral ruthenium and osmium derivatives 25–30 and 32–39. in almost quantitative yields. The ionic complex [Ru(E-CHCHPh)(CO)3(PiPr3)2]PF6 (41) has also been prepared.
Behavioral and Brain Sciences, 1990
The "radiator" theory of brain evolution is proposed to account for "mosaic evolution" whereby br... more The "radiator" theory of brain evolution is proposed to account for "mosaic evolution" whereby brain size began to increase rapidly in the genus Homo well over a million years after bipedalism had been selected for in early hominids. Because hydrostatic pressures differ across columns of fluid depending on orientation (posture), vascular systems of early bipeds became reoriented so that cranial blood flowed preferentially to the vertebral plexus instead of the internal jugular vein in response to gravity. The Hadar early hominids and robust australopithecines partly achieved this reorientation with a dramatically enlarged occipital/marginal sinus system. On the other hand, hominids in the gracile australopithecine through Homo lineage delivered blood to the vertebral plexus via a widespread network of veins that became more elaborate through time. Mastoid and parietal emissary veins are representatives of this network, and increases in their frequencies during hominid evolution are indicative of its development. Brain size increased with increased frequencies of mastoid and parietal emissary veins in the lineage leading to and including Homo, but remained conservative in the robust australopithecine lineage that lacked the network of veins. The brain is an extremely heatsensitive organ and emissary veins in humans have been shown to cool the brain under conditions of hyperthermia. Thus, the network of veins in the lineage leading to Homo acted as a radiator that released a thermal constraint on brain size. The radiator theory is in keeping with the belief that basal gracile and basal robust australopithecines occupied distinct niches, with the former living in savanna mosaic habitats that were subject to hot temperatures and intense solar radiation during the day.
Archives Of Phytopathology And Plant Protection, 1991
Page 1. Arch. Phytopathol. Pllanzenschutz, Bcrlin 27 (1991) 5. 353-360 Biologische Zcntralanstalt... more Page 1. Arch. Phytopathol. Pllanzenschutz, Bcrlin 27 (1991) 5. 353-360 Biologische Zcntralanstalt Bcrlin lnstitut fur Phytopathologie Ascherslebcn und Saatzuchtstation hf6ringcn HARTMJT KEGLER, BEKND WOLTEKSTORFF ...
Archives Of Phytopathology And Plant Protection, 1987
Archives Of Phytopathology And Plant Protection, 1991
Archives Of Phytopathology And Plant Protection, 1990
... Um diese Fehlerquelle wenigstens teilweise auszuschnlten, stellten wir die verschiedenen Ausg... more ... Um diese Fehlerquelle wenigstens teilweise auszuschnlten, stellten wir die verschiedenen Ausgangsmaterialien dem gleichen Virus-standard gegenuber ... Bereits BISHT (1963), FRIDLUND (1979) und AL KAI (1988) berichteten uber eine ungleich-miil3ige Verteilung des ApMV ...
Archives Of Phytopathology And Plant Protection, 1988
Archives Of Phytopathology And Plant Protection, 1988
Annals of Glaciology, 1999
Since the austral summer of 1994-95 the Alfred Wegener Institute has carried out airborne radio-e... more Since the austral summer of 1994-95 the Alfred Wegener Institute has carried out airborne radio-echo sounding (RES) measurements in Antarctica with its newly designed RES system. Since 1995-96 an ongoing pre-site survey for an ice-coring drill site in Dronning Maud Land has been carried out as part of the European Project for Ice Goring in Antarctica. The survey covers an area of 948 000 km2, with >49 500 km of airborne RES obtained from >200 hours of flight operation flown during the period 1994-97. In this paper, first results of the airborne RES survey are graphically summarized as newly derived maps of the ice thickness and subglacial topography, as well as a three-dimensional view of surface and subglacial bed and outcrop topography, revealing a total ice volume of 1.48 x 106 km3.