bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Incorporation of Transition Metal Atoms into Thiostannates: Synthesis, Crystal Structures and Spectroscopic Properties of [Ni(en)3]2Sn2S6, [Ni(dap)3]2Sn2S6 · 2 H2O, [Co(tren)]2Sn2S6, and [Ni(tren)]2Sn2S6
Authors: Behrens Malte , Scherb Sandra , Näther Christian , Bensch Wolfgang 
Published: July 2003

AbstractThe four new thiostannates [Ni(en)3]2Sn2S6 (1) (en = ethylenediamine), [Ni(dap)3]2Sn2S6 · 2 H2O (2) (dap = 1, 2‐diaminopropane), [Co(tren)]2Sn2S6 (3) and [Ni(tren)]2Sn2S6 (4) (tren = tris(2‐aminoethyl)amine) were prepared under solvothermal conditions. In all compounds [Sn2S6]4— anions are observed as the common structural motif. This anion is composed of two SnS4 tetrahedra sharing a common edge. In compounds 1 and 2 the transition metal cations are coordinated each by three amine ligands and therefore solvent separated complex cations as well as discrete [Sn2S6]4— anions are found. In compounds 3 and 4 the coordination around the transition metal ions cannot be completed by the organic ligands and the [Sn2S6]4— anions are connected to the transition metal cations via terminal S atoms. In both compounds the [Sn2S6]4— anion acts as a bidentate ligand connecting two transition metal cations by terminal S atoms. The Co2+ cations in compound 3 are in a fivefold environment of one tetradentate tren ligand and one S atom forming discrete[Co(tren)]2Sn2S6 units. In compound 4 the Ni2+ ions are in a sixfold environment of one tetradentate tren ligand and two S atoms of two symmetry related [Sn2S6]4— anions. This connection mode leads to formation of “zig‐zag‐like” Ni—Sn2S6 chains which are directed along the crystallographic c‐axis. The spectroscopic properties of compounds 1 to 3 were investigated using Raman spectroscopy. Differences in the spectra of 1 and 2 compared to 3 are observed which are caused by the covalent bonding between the Co2+ ions and the Sn2S64— anions in 3.
Crystal Structures and Properties of the Thiostannates Eu2SnS4 and Sr2SnS4 and the Selenogermanate γ‐Sr2GeSe4
Authors: Pocha R. , Tampier M. , Hoffmann R.‐D. , Mosel B. D. , Pöttgen R. , Johrendt Dirk 
Published: July 2003

AbstractEu2SnS4, Sr2SnS4, and Sr2GeSe4 have been synthesized by heating the elements or binary precursors at 1073 K and their crystal structures were determined by single crystal methods. Eu2SnS4 crystallizes with a new structure type (Pnma, a = 11.187(2), b = 8.768(2), c = 7.538(2)Å, Z = 4), consisting of distorted [SnS4]4— tetrahedra and sevenfold coordinated Eu2+ ions. Sr2SnS4 and γ‐Sr2GeSe4 are isostructural and form a new structure type likewise (Ama2, Z = 4, Sr2SnS4: a = 9.977(1), b = 10.311(2), c = 7.243(1)Å, Sr2GeSe4: a = 10.284(2), b = 10.543(2), c = 7.411(1)Å) with more regular tetrahedral anions and strontium coordinated by seven and eight chalcogen atoms, respectively. Eu2SnS4 is a Curie‐Weiss paramagnet (7.80(2) μB/Eu; θ = 4.2(2) K) and orders antiferromagnetically at TN = 5.5(2) K with a magnetization of 6.56(5) μB/Eu at 5.5 T. The divalent nature of europium is also evident from 151Eu Mössbauer spectra which show a single signal at an isomer shift of —12.2(1) mm/s at 78 K. Full magnetic hyperfine field splitting (19.5(2) T at the europium nuclei) is observed at 4.2 K. The 119Sn spectrum shows one signal at 1.25(9) mm/s subject to quadrupole splitting of 0.76(2) mm/s. At 4.2 K a transferred hyperfine field of 3(1) T is detected at the tin site.
Synthesis and Characterization of a Series of 1, 2‐Phenylenedioxoborylcyclopentadienes
Authors: Avent Anthony G. , Davies Michael J. , Hitchcock Peter B. , Lappert Michael F. 
Published: July 2003

AbstractTreatment of 1, 2‐C6H4O2BCl [B(CAT)Cl], 4‐tert‐butyl‐1, 2‐phenylenedioxo‐chloro‐borane [B(CATt)Cl] (1) or its 3, 5‐But2‐analogue [B(CATtt)Cl] (2) with the appropriate Me3Si‐cyclopentadienyllithium compound afforded in good yield C5H4(BCAT)SiMe3 (3), C5H4(BCATt)SiMe3 (4), C5H4(BCATtt)SiMe3 (5), C5H3(BCAT)(SiMe3)2 (6), C5H3(BCATt)(SiMe3)2 (7), C5H3(BCATtt)(SiMe3)2 (8), or Me2Si{μ‐C5H3(BCAT)(SiMe3)}2 (9). Compounds C5H3(SiMe3)(1, 4‐BCAT)2 (10), its B(CATt)2 (11) or B(CATtt)2 (12) analogues were prepared from C5H3(SiMe3)(SnMe3)2 and B(CAT)Cl, 1, or 2, respectively. Single crystal X‐ray diffraction on crystalline 3 and 6 established their structures. In toluene‐d8, 3, 4 and 5 exist as mixtures of up to 5 isomers. Compounds 6—12 exist as only single isomers, compound 9 shows inequivalent cyclopentadienyl rings at 223 K which exchange with each other via a sigmatropic [1, 5]‐trimethylsilyl shift exchange process at higher temperatures.
Siliciumhaltige Ringverbindungen des Galliums und Indiums — Neue Hydridogallanate
Authors: Linti Gerald , Çoban Stella , Rodig Alexander , Sandholzer Norbert 
Published: July 2003

AbstractDurch Umsetzung des sonochemisch erzeugten Galliumsubiodids “GaI” mit K(THF)2Si(SiMe3)3 entsteht neben bekannten Galliumclustern das anionische 1, 3, 2, 4‐Disiladigalletan‐Derivat [{(Me3Si)3SiGaSi(SiMe3)2}2H]—K+(triglyme). Mit KOtBu reagiert GaI unter Disproportionierung zum Hydridogallanat [KHGa(OtBu)3]2 mit Käfigstruktur. Das 1, 3, 2, 4‐Disiladiindetan‐Derivat [(Me3Si)3SiInSi(SiMe3)2]2 bildet sich aus Indium(I)iodid und Li(THF)3Si(SiMe3)3. Alle Verbindungen wurden mittels Einkristall‐Röntgenstrukturanalyse untersucht.
Zwitterionic Molecules with Stanna‐closo‐dodecaborate
Authors: Ronig Benno , Pantenburg Ingo , Wesemann Lars 
Published: July 2003

AbstractA series of zwitterionic molecules was synthesized by nucleophilc substitution between stanna‐closo‐dodecaborate and a series of alkyliodides like (ω‐iodo‐alkyl)trialkyl‐ammoniumiodides and 1‐(4‐iodobutyl)pyridiniumiodide. The structures in the solid state have been determined by X‐ray crystal structure analysis for Bu3N‐C3H6‐SnB11H11 (3), Pr3N‐C4H8‐SnB11H11 (6), Bu3N‐C4H8‐SnB11H11 (7) and C5H5N‐C4H8‐SnB11H11 (9).
Hexacoordinate Silicon(IV) Complexes Containing Thiocyanato‐N Ligands — Syntheses, Structural Characterization, and Computational Studies
Authors: Seiler Oliver , Bertermann Rüdiger , Buggisch Nele , Burschka Christian , Penka Martin , Tebbe David , Tacke Reinhold 
Published: July 2003

AbstractThe hexacoordinate silicon(IV) complexes [NEt4]2[Si(NCS)6] (2), [K(18‐crown‐6)]2[Si(NCS)6]·2CH3CN (3·2CH3CN), and cis‐[(acac)2Si(NCS)2] (cis‐4; acac = acetylacetonato‐O, O) were synthesized, starting from Si(NCS)4 (1). Compounds 1, 2, 3·2CH3CN, and cis‐4 were structurally characterized in the solid state (13C, 15N (cis‐4 only), and 29Si MAS NMR; crystal structure analyses) and in solution (1H, 13C, and 29Si NMR; cis‐4 only). The experimental investigations were complemented by computational studies (RI‐MP2 geometry optimizations of 1, [Si(NCS)6]2—, cis‐4, and trans‐4; calculations of the 29Si NMR chemical shifts using the optimized structures).
Die Dodekahydro‐closo‐Dodekaborate M2[B12H12] der schweren Alkalimetalle (M+ = K+, Rb+, NH4+, Cs+) und ihre formalen Iodid‐Addukte M3I[B12H12] (≡ MI · M2[B12H12])
Authors: Tiritiris Ioannis , Schleid Thomas 
Published: July 2003

AbstractDie wasserfreien Dodekahydro‐closo‐Dodekaborate M2[B12H12] der schweren Alkalimetalle (M = K — Cs, NH4) sowie ihre formalen Iodid‐Addukte M3I[B12H12] (≡ MI · M2[B12H12]) sind durch Umsetzung einer wäßrigen Lösung von (H3O)2[B12H12] mit den entsprechenden Alkalimetallhydroxiden (MOH) oder Ammoniak (NH3) bzw. den entsprechenden Alkalimetalliodiden (MI) zugänglich. Durch Umkristallisieren aus wäßriger Lösung wurden farblose Einkristalle erhalten, die sich mittels Röntgenbeugung bei Raumtemperatur strukturell charakterisieren ließen. Die isotypen Verbindungen M2[B12H12] kristallisieren kubisch in der Raumgruppe Fm3¯ (K: a = 1062, 90(8) pm; Rb: a = 1086, 74(8) pm; NH4: a = 1087, 81(9) pm; Cs: a = 1128, 12(7) pm; Z = 4). Der Aufbau läßt sich im Sinne einer anti‐CaF2‐Struktur beschreiben, wobei die anionischen [B12H12]2—‐Cluster eine kubisch dichteste Kugelpackung bilden, in der die M+‐Kationen sämtliche Tetraederlücken besetzen. Die gemischtanionischen Verbindungen M3I[B12H12] (≡ MI · M2[B12H12]) kristallisieren allesamt isotyp in der trigonalen Raumgruppe R3¯m (K: a = 1023, 96(7), c = 1127, 83(9) pm; NH4: a = 1036, 43(7), c = 1144, 38(9) pm; Rb: a = 1040, 43(7), c = 1155, 48(9) pm; Cs: a = 1067, 80(7), c = 1197, 20(9) pm; Z = 3), wobei sich ihre Kristallstruktur auf eine trigonale Verzerrungsvariante der anti‐Perowskit‐Struktur, dem anti‐LaAlO3‐Typ, zurückführen läßt. Hierbei bilden die quasi‐ikosaedrischen [B12H12]2—‐Anionen und die M+‐Kationen gemeinsam eine kubisch dichteste Kugelpackung, in der die I—‐Anionen alle Oktaederlücken besetzen, die nur aus M+‐Kationen aufgebaut sind. Der thermische Abbau der schweren Alkalimetall‐Dodekahydro‐closo‐Dodekaborate M2[B12H12] sowie deren gemischtanionischer Iodid‐Derivate M3I[B12H12] wurde im Temperaturbereich zwischen 30 und 1200 °C mittels DTA/TG‐Methoden thermoanalytisch untersucht.
Herstellung von Eisen(II)—sulfid—Nano‐ und —Mikropartikeln in inversen Micellen
Authors: Dörr M. , Petzold H. , Kreisel G. , Völksch G. , Weigand Wolfgang 
Published: July 2003

AbstractPreparation of Iron(II) Sulfide Nano‐ and Microparticles in Inverse MicellsIron sulfide micro‐ and nanoparticles have been prepared in n‐heptane‐sodium bis(2‐ethylhexyl) sulfosuccinate (AOT) reverse micelles at room temperature. The particles obtained are 50‐900 nm in size and form a stable dispersion for at least three months. The synthesized iron sulfide aggregates were charaterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDX) and X‐ray diffractometry (XRD).
Polyol‐Metall‐Komplexe. 44 Phenylboronsäureester der C4‐Zuckeralkohole Erythrit und L‐Threit
Authors: Klüfers Peter , Labisch Oliver 
Published: July 2003

AbstractPhenylboronsäure reagiert mit Erythrit (Eryt) und L‐Threit (L‐Thre) zu den kristallinen Estern (PhB)2(ErytH_O1, 3, O2, 4) (1a) and (PhB)2(L‐ThreH_O1, 3, O2, 4) (2a). Das Ci‐symmetrische 1a hat nach Dichtefunktionalrechnungen ähnliche Stabilität wie das entsprechende O1, 2, O3, 4‐Chelatfünfringisomer. In Lösung werden NMR‐spektroskopisch dementsprechend beide Isomere beobachtet. Der Energieunterschied zwischen dem C2‐symmetrischen 2a und dem entsprechenden Chelatfünfring‐Isomer ist dagegen größer, so dass 2a die deutlich dominierende Lösungsspezies ist.
Cationic Borabenzene Complexes as Electron Accepting Groups for Molecular Material with Nonlinear Optical Properties
Authors: Behrens U. , Meyer‐Friedrichsen T. , Heck J. 
Published: July 2003

AbstractThe dinuclear dipolar borabenzene complexes [(η5‐C5H5)Fe{μ‐(η5‐C5H4)C2(η6‐BC5H5)}ML]X [ML = Ru(η6‐C6H6), X = Cl (4aCl), PF6 (4aPF6), B(C6H5)4 (4aBPh4); ML = Rh(η5‐C5Me5), X = Cl (4bCl), PF6 (4bPF6); ML = Ir(η5‐C5Me5), X = Cl (4cCl), PF6 (4cPF6)] were synthesized by a nucleophilic substitution reaction of the trimethylphosphane adduct of borabenzene (1) with lithium ferrocenylacetylide, subsequent lithium‐thallium exchange and coordination of the appropriate ML unit obtained from [Ru(η6‐C6H6)Cl(μ‐Cl)]2, [M(η5‐C5Me5)Cl(μ‐Cl)]2 (M = Rh, Ir); the formed chloride salts, which are soluble in water, were transformed to the PF6 salts by adding [NH4][PF6] to the corresponding water solution. BPh4 salts can be produced, when a methanolic solution of Na[BPh4] were added to CH2Cl2‐solutions of the appropriate PF6 salt. X‐ray structure analyses of single crystals of 4aBPh4 and 4bPF6 were successful, illustrating the cation 4a+ in an ideal cis‐conformation, whereas 4b+ displays a cis‐ and trans‐conformation. Spectroscopic and cyclic voltammetry studies reveal a small but distinct donor‐acceptor interaction between the ferrocenyl donor and the cationic borabenzene complex acceptor which increases in the order 4aPF6 < 4cPF6 < 4bPF6. The nonlinear optical properties of these donor‐acceptor complexes were studied by means of hyper‐Rayleigh scattering (HRS), resulting in the determination of small values for the first hyperpolarisability ß, which increase in the same order as the donor‐acceptor interaction.
Kristallstrukturanalyse und Natriumionenleitung von wasserfreiem α‐Natriumtrifluoromethylsulfonat
Authors: Sofina Natalia , Peters Eva‐Maria , Jansen Martin 
Published: July 2003

AbstractDer Einkristallstrukturanalyse bei —173 °C zufolge kristallisiert α‐NaSO3CF3 triklin in der Raumgruppe P1¯ mit den Gitterparametern a = 9, 6592(11), b = 11, 1752(12), c = 11, 2768(12) Å, α = 101, 878(2)°, β = 105, 292(2)°, γ = 110, 501(3)°, bei Raumtemperatur (22 °C) ergeben sich die Werte a = 9, 81304(18), b = 11, 3179(2), c = 11, 5910(2) Å, α = 102, 066(2)°, β = 105, 634(2)°, γ = 110, 205(2)° (Synchrotron‐Pulverdaten). In der Kristallstruktur liegen Doppelschichten aus Triflatanionen vor, in denen die unpolaren CF3‐Gruppen einander zugewandt sind. Die Natriumatome besetzen fünf verschiedene kristallographische Lagen. α‐NaSO3CF3 ist ein fester Elektrolyt, dessen spezifische Leitfähigkeit im Bereich von 1, 75·10—8 Ω—1cm—1 bei 140 °C bis 8, 78·10—6 Ω—1cm—1 bei 237 °C liegt.
Synthesen und Kristallstrukturen neuer heterobimetallischer Tantal‐Nickel‐ und Tantal‐Cobalt‐Chalkogenido‐Cluster
Authors: Pätow Richard , Isaac Ibrahim , Fenske Dieter 
Published: July 2003

AbstractDurch die Reaktion von Tantalsalzen mit Nickel‐ bzw. Cobaltsalzen und silylierten Chalkogenverbindungen in Anwesentheit von Phosphanen können neue heterobimetallische kubanartige Ta—M—Chalkogen‐Cluster (M = Co, Ni) synthetisiert werden. Es werden die Verbindungen [Ta2Ni2S4Cl4(PPh3)2(MeCN)2] · MeCN (1), [Ta2Ni2Se4Cl4(PPh3)2(MeCN)2]·MeCN (2) und [TaCo3S4(NCS)3(PtBu3)3]·PtBu3·0, 5 MeCN (3) beschrieben, deren Strukturen durch Einkristall‐Röntgenstrukturanalyse aufgeklärt werden konnten.
Realstrukturen von Defektvarianten des Zinkblendetyps
Authors: Kienle Lorenz , Duppel V. , Simon A. , Deiseroth H. J. 
Published: July 2003

AbstractIn den Realstrukturen binärer und ternärer Defektvarianten des Zinkblendetyps treten Kristalldefekte in ungewöhnlich großer Dichte auf, die mittels hochauflösender Transmissionselektronenmikroskopie (HRTEM) und Elektronenbeugung charakterisiert werden können. Im Falle der ternären Verbindungen (CuGa3Ch5, Ch = Se, Te) beobachteten wir neben einer systematischen Verdrillingung unterschiedliche Ordnungen der Kationen in separierten Domänen der Kristalle. Die Baueinheiten von Strukturvarianten der Verbindung Ga2Te3 sind {111}‐Ebenen, in denen die Ga‐Plätze nur partiell besetzt sind. Für die Interpretation der Realstruktur werden zwei Modelle diskutiert, die auf Stapelvarianten gleicher {111}‐Ebenen oder einer Aggregation von Leerstellen in {111}‐Ebenen beruhen. Die Realstruktur kann durch die Synthesebedingungen definiert modifiziert werden. Abgeschreckte Proben sind partiell geordnet, da ebene {111}‐Defekte ein zufälliges Muster bilden. Tempern führt zu einer 10‐fachen Überstruktur längs <111>*, die in hochaufgelösten Abbildungen der <11o>‐Orientierung als geordnetes Rautenmuster aus jeder zehnten {111}‐Ebene erscheint. In Proben der Bruttozusammensetzung CaGa6Te10 finden sich als Nebenprodukt der Synthese ungewöhnliche Kristallnadeln von Ga2Te3, die zwei unterschiedlichen Varianten der Realstruktur zugeordnet werden können. Eine ist ähnlich wie die getemperte Probe geordnet, aber die Rauten in den {110}‐Abbildungen sind kleiner, da es sich vor allem um 7‐ oder 8‐fache Überstrukturen längs <111>* handelt. Die zweite Variante ist durch eine partielle Ordnung der Realstruktur charakterisiert, die sich von derjenigen bei abgeschreckten Proben unterscheidet.
Die Insertion von Chalkogenatomen in die Gallium‐Gallium‐Bindung von Acetat‐verbrückten Digallanen
Authors: Uhl Werner , Cuypers Lars , Spies Thomas , Weller Frank , Harbrecht Bernd , Conrad Matthias , Greiner Andreas , Puchner Mario , Wendorff Joachim H. 
Published: July 2003

AbstractDie Dialkyldigallium(II)‐Verbindung R2Ga2(μ‐OOCCH3)2 2 [R = CH(SiMe3)2] enthält eine kurze Ga—Ga‐Einfachbindung, die durch zwei Acetatliganden überbrückt wird. Durch die chelatartige Koordination der Carboxylato‐Gruppen sind die Galliumatome mit einer Koordinationszahl von vier koordinativ gesättigt. Die Umsetzung von 2 mit Chalkogenatom‐Donoren wie Propylensulfid, Triethylphosphoniumselenid und ‐tellurid führt zur Insertion von Schwefel‐, Selen‐ oder Telluratomen in die Ga—Ga‐Bindung, wobei unter Oxidation der Galliumatome Verbindungen mit gewinkelten Ga—S—Ga‐ (3), Ga—Se—Ga‐ (4) und Ga—Te—Ga‐Einheiten (5) entstehen. In allen Fällen behalten die Carboxylato‐Gruppen ihre verbrückende Position zwischen zwei Galliumatomen bei. Die Tellurverbindung 5 zeigt einen Phasenübergang im festen Zustand, der durch Röntgenpulveraufnahmen und DSC‐Methoden eingehend untersucht wurde.
Effects of damping on mode‐coupling instability in friction induced oscillations
Authors: Hoffmann N. , Gaul L. 
Published: July 2003

AbstractThe mode‐coupling instability has generally been acknowledged as one of the most prominent mechanisms leading to self‐excited oscillations in sliding friction systems. The influence of structural damping on this type of instability mechanism however has not yet been fully clarified. The objective of the present work therefore is to investigate qualitative and quantitative aspects of the mode‐coupling instability in the presence of structural damping, which will be assumed as linear viscous. For the sake of simplicity a two‐degree‐of‐freedom minimal model is set up and analyzed. It is shown that under specific conditions the mode‐coupling instability may be regarded as a viscous instability in the sense that an increase in structural damping may render a stable system unstable. An explanation for this behavior is given by two lines of argument: First a description and explanation is given in terms of eigenvalue‐analysis. Due to the mathematical formality of this approach, the insight gained remains phenomenological. Second, a feedback‐loop formalism is developed that allows a more detailed understanding of the underlying mechanical processes. Based on this formalism, necessary and in sum sufficient conditions for the onset of instability can be deduced and also the role of damping can be clarified.
Small time approximations of Green's functions for one‐dimensional heat conduction problems with convective boundaries
Authors: Yen D.H.Y. , Beck J.V. 
Published: July 2003

AbstractSmall time approximations are obtained for Green's functions in one‐dimensional heat conduction problems with convective boundaries. The method of images similar to those for cases with Dirichlet or Neumann boundaries is used. Multiple reflections in this method generate infinite series representations for the Green's functions whose general terms involve convolution integrals with integrable singularities. We truncate the series after single and double reflections (n = 1, 2) and transform the convolution integrals to known closed‐form expressions. Numerical results are presented for n = 1, 2 and compared with exact results obtained using the classical separation of variables. It is seen that results with n = 1, 2 provide accurate approximations for dimensionless time α t / L2 up to 0.3 and complementary to those obtained by separation of variables.
Compound‐matrix Riccati method for solving boundary‐value problems
Authors: Ivansson S. 
Published: July 2003

AbstractNumerically difficult boundary‐value problems for linear ODE systems can be solved with the compound‐matrix and Riccati methods. A drawback with the compound‐matrix method is that the dimensions of the ODE systems for the compound quantities can become large. Explicit quadratic relations, with relevance to quadrics in Grassmannian manifold theory, are derived for these quantities and used to reduce the system dimensions, whereby the “compound‐matrix Riccati” method appears. Compared to the traditional Riccati method, an additional forward‐sweep equation is included, which allows reconstruction of all compound‐vector elements. The well‐known singularity problems with the Riccati method are thereby removed. In particular, argument‐variation techniques for determination of eigenvalues become applicable. Seismo‐acoustic wave propagation in laterally homogeneous anisotropic media is considered as an example. The example indicates that region‐dependent mode classification, previously shown for isotropic fluid‐solid media, can be generalized to the anisotropic case. This generalization is subsequently made theoretically.
On the maximum and comparison principles for a steady‐state nonlinear heat conduction problem
Authors: Křížek M. , Liu L. 
Published: July 2003

AbstractWe examine a Dirichlet boundary value problem of elliptic type which serves as a model for a stationary heat conduction in nonlinear, inhomogeneous, and anisotropic media. We prove a comparison principle and obtain the maximum principle as a direct consequence. We also show that the standard trilinear finite elements do not preserve a discrete maximum principle.
Elastische Roboter
Authors: Bremer H. 
Published: July 2003

AbstractEine grundsätzliche Vereinfachung der Bewegungsgleichungen elastischer Roboter erhält man durch die Verwendung nichtholonomer Geschwindigkeitsvariablen. Die direkte Anwendung des Hamilton‐Prinzips bleibt jedoch auch dann extrem arbeitsaufwendig und birgt zudem mancherlei Missdeutungs‐ und damit Fehlerquellen. Eine entsprechende Auswertung führt auf die Projektionsgleichung für elastische Systeme, die wesentlich einfacher zu handhaben ist und eindeutige Ergebnisse liefert. Der Einfluss schneller Starrkörperbewegungen kann dabei auf die Wirkung einer einzigen symmetrischen Rückstellmatrix zurückgeführt werden. Die Einführung von Zwischenvariablen führt auf eine Operatordarstellung der partiellen Bewegungsdifferentialgleichungen und ihrer Randbedingungen. Für eine Näherungslösung wird ein direktes Ritz‐Verfahren vorgeschlagen. Die entsprechenden Bewegungsgleichungen sind einfach strukturiert, wenngleich natürlich hochgradig nichtlinear. Ihre Struktur lässt aber unmittelbar den Einsatz eines rekursiven Verfahrens zur numerischen Integration zu.A fundamental simplification of the motion equations of elastic robots is obtained by the use of nonholonomic velocity variables. However, applying Hamilton's Principle still requires extreme effort and contains, additionally, sources of misinterpretations and thus possible mistakes. An adequate evaluation leads to the Projection Equation for elastic multibody systems which is much easier to handle and which delivers unique results. Thereby, the influence of fast rigid body motion dynamics is represented by one symmetric restoring matrix. Intermediate variables lead to an operator description of corresponding partial differential equations along with its boundary conditions. A direct Ritz approach is proposed for solution. The corresponding motion equations are simple in structure but, of course, highly nonlinear. Its structure, however, gives direct access to a recursive numerical integration routine.
Observations on the reproductive cycle of the black scabbardfish (Aphanopus carbo Lowe, 1839) in the NE Atlantic
Authors: Figueiredo I , Bordalo-Machado P , Reis S , Sena-Carvalho D , Blasdale T , Newton A , Gordo L.S 
Published: July 2003

AbstractBlack scabbardfish is a deep-water species, common in the NE Atlantic at depths between 450 and 1300 m, currently exploited by some European countries. Between May 1998 and April 2000, specimens collected at three different locations in the NE Atlantic—NW of Scotland, Sesimbra (mainland Portugal) and Funchal (Madeira)—were analysed. The evolution of maturity of both sexes throughout the year was studied based on the macroscopic and microscopic analysis of the gonads. Specimens with the largest total length were found in Funchal, whereas the smallest size was recorded in the NW of Scotland. Neither spawners nor post-spawners were ever observed in NW of Scotland and Sesimbra. In Sesimbra, only a few individuals attained pre-spawning stage and most of the early developing females exhibited atresia in their ovaries. In Funchal, all the maturity stages were found; spawners occurred from September to December (females) and from August to December (males). Length of first maturity for females was estimated to be around 1000 mm. Two groups of spawners with different sizes were observed during the spawning period off Madeira.