bluuebunny/crossref_metadata_2025_split huggingface dataset:
Towards a Quantitative Interpretation of Polymer Distributions from MALDI‐TOF Spectra
Authors: Schnöll‐Bitai Irene , Hrebicek Thomas , Rizzi Andreas 
Published: March 2007

AbstractThe importance of proper conversion of MALDI‐MS signals into the number of polymers with a certain mass increment (by taking into account a nonconstant conversion factor) is demonstrated with calculated Schulz‐Zimm and Poisson distributions. Measurements of two narrow polystyrene standards were used to investigate the influence of measurement conditions (laser intensity, matrix) and data processing (signal conversion, baseline construction). We observed the following effects: (a) slightly broader distributions with DCTB as matrix at a given laser intensity in comparison to those obtained with all‐trans‐retinoic acid, (b) changes in the relative intensities of several peaks in a sample, and (c) a nonlinear baseline in the low molar mass region in most of the cases. Therefore, the implications of an assumed linear baseline instead of the correct one on the results were scrutinized experimentally and by simulations. In all, measurement of narrow distributions turned out to give reasonable results. Based on the assumption that the polymer standards can be described by Poisson distributions, overlap conditions between two distributions are rephrased. An alternative possibility of how mass discrimination could be determined, in principle, is presented, too.magnified image
Some remarks on rearrangements and functionals with non‐constant density
Authors: Landes Ruediger 
Published: March 2007

AbstractConditions on non‐constant densities of energy functionals are discussed, such that monotone rearrangement of functions decreases the value of the functional. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A symmetrization result for Monge–Ampère type equations
Authors: Brandolini Barbara , Trombetti Cristina 
Published: March 2007

AbstractIn this paper we prove some comparison results for Monge–Ampère type equations in dimension two. We also consider the case of eigenfunctions and we derive a kind of “reverse” inequalities. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quasi‐splitting subspaces in a pre‐Hilbert space
Authors: Buhagiar David , Chetcuti Emmanuel 
Published: March 2007

AbstractLet S be a pre‐Hilbert space. Two classes of closed subspaces of S that can naturally replace the lattice of projections in a Hilbert space are E (S) and F (S), the classes of splitting subspaces and orthogonally closed subspaces of S respectively. It is well‐known that in general the algebraic structure of E (S) differs considerably from that of F (S) and the two coalesce if and only if S is a Hilbert space. In the present note we introduce the class Eq (S) of quasi‐splitting subspaces of S. First it is shown that Eq (S) falls between E (S) and F (S). It is also shown that, in contrast to the other two classes, Eq (S) can sometimes be a complete lattice (without S being complete) and yet, in other examples Eq (S) is not a lattice. At the end, the algebraic structure of Eq (S) is used to characterize Hilbert spaces. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On finite elements in sublattices of Banach lattices
Authors: Chen Z. L. , Weber M. R. 
Published: March 2007

AbstractLet E be a Banach lattice. Let H stand for a sublattice, an ideal or a band in E, and denote by Φ1(E) and Φ1(H) the ideals of finite elements in the vector lattices E and H, respectively. In this paper we first present some sufficient conditions and some counterexamples for the inclusions Φ1(H) ⊂ Φ1(E) and Φ1(E) ∩ H ⊂ Φ1(H) to hold or not. For closed ideals (and therefore bands) H there always holds Φ1(H) ⊂ Φ1(E). If H is a projection band then even PH Φ1(E) = Φ1(E) ∩ H = Φ1(H). It is proved that every finite element of E is also finite both in its Dedekind completion Ê and in its bidual space E ″. Some results concerning the finite elements in direct sums of Banach lattices are also included. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On a linear differential equation with a proportional delay
Authors: Čermák Jan 
Published: March 2007

AbstractThis paper deals with the delay differential equation

We impose some growth conditions on c, under which we are able to give a precise description of the asymptotic properties of all solutions of this equation. Although we naturally have to distinguish the cases c eventually positive and c eventually negative, we show a certain resemblance between the asymptotic formulae corresponding to both cases. Moreover, using the transformation approach we generalize these results to the equation with a general form of a delay. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Weight of closed subsets topologically generating a compact group
Authors: Dikranjan Dikran , Shakhmatov Dmitri 
Published: March 2007

AbstractLetGbe a compact Hausdorff group. A subspaceXofG topologically generates GifGis the smallest closed subgroup ofGcontainingX. Definetgw(G) =ω· min{w(X):Xis closed inGand topologically generatesG},wherew(X) is the weight ofX, i.e., the smallest size of a base for the topology ofX. We prove that:(i)tgw(G) =w(G) ifGis totally disconnected,(ii)tgw(G) =$ \root \omega \of {w(G)} $= min{τ≥ω:w(G) ≤τω} in caseGis connected, and(iii)tgw(G) =w(G/c(G)) ·$ \root \omega \of {w(c(G))} $, wherec(G) is the connected component ofG.IfGis connected, then eithertgw(G) =w(G), or cf(tgw(G)) =ω(and, moreover,w(G) =tgw(G)+under the Singular Cardinal Hypothesis).We also prove thattgw(G) =ω· min{|X|:X⊆Gis a compact Hausdorff space with at most one non‐isolated point topologically generatingG}. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Anisotropic wavelet bases and thresholding
Authors: Hochmuth Reinhard 
Published: March 2007

AbstractWe consider thresholding with respect to anisotropic wavelet bases measuring the approximation error in anisotropic Hardy spaces $ H^a_p $ for p > 0, which are known to be equal to Lp for p > 1. In particular, we characterize those functions that provide a specific convergence rate by intrinsic smoothness properties. To this end we apply restricted nonlinear approximation, see [3], which is a generalization of n ‐term approximation in which a weight function is used to control the terms of the approximations. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Dirichlet problems for the Stokes resolvent equations in bounded and exterior domains in ℝn
Authors: Kohr Mirela 
Published: March 2007

AbstractThe Dirichlet problems for the Stokes resolvent equations are studied from the point of view of the theory of hydrodynamic potentials. Existence and uniqueness results as well as boundary integral representations of classical solutions are given for domains having compact but not connected boundaries of class C1,α (0 < α ≤ 1) in both the bounded and exterior cases. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Metric approximation properties and trace mappings
Authors: Lima Åsvald , Oja Eve 
Published: March 2007

AbstractWe establish necessary and sufficient conditions involving trace mappings and Hahn–Banach extension operators for a Banach space to have metric or metric compact approximation properties. We also study metric approximation properties for dual spaces. As an application, alternative (hopefully enlightening) proofs are given for the well‐known result that the dual space has the metric approximation property whenever it has the approximation property and the Radon–Nikodým property. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Some Lp analogues of Weyl's theorem of invariability
Authors: Osipov Andrey 
Published: March 2007

AbstractA well‐known result on Sturm–Liouville operators due to H. Weyl states that the property of all solutions of the equation‐(p (x)y ′)′ + q (x)y = λy, x ≥ 0, λ ∈ ℂ,to be in L2[0, ∞) is invariable with respect to the value of λ. Here we obtain some extensions of this theorem with the second order differential equation replaced by a quasi‐differential equation of an arbitrary order and the space L2 replaced by Lp , 1 ≤ p ≤ ∞. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Discrete canonical system and non‐Abelian Toda lattice: Bäcklund–Darboux transformation, Weyl functions, and explicit solutions
Authors: Sakhnovich A. L. 
Published: March 2007

AbstractA version of the iterated Bäcklund–Darboux transformation, where Darboux matrix takes a form of the transfer matrix function from the system theory, is constructed for the discrete canonical system and non‐Abelian Toda lattice. Results on the transformations of the Weyl functions, insertion of the eigenvalues, and construction of the bound states are obtained. A wide class of the explicit solutions is given. An application to the semi‐infinite block Jacobi matrices is treated. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Entropy of Sobolev embeddings of radial functions and radial eigenvalues of Schrödinger operators on isotropic manifolds
Authors: Skrzypczak Leszek , Tomasz Bernadeta 
Published: March 2007

AbstractWe consider Sobolev embeddings between Sobolev and Besov spaces of radial functions on noncompact symmetric spaces of rank one. An asymptotic behaviour of entropy numbers of the compact embeddings is described. The estimates are used for investigation of the negative spectrum of Schrödinger type operators. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The finite groups with thirteen and fourteen conjugacy classes
Authors: Vera–López A. , Sangroniz Josu 
Published: March 2007

AbstractUp to isomorphism, there are only finitely many finite groups with a given number of conjugacy classes. Those with up to twelve classes have already been classified. In this work we extend the classification to thirteen and fourteen classes. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Boundary value problems in edge representation
Authors: Liu Xiaochun , Schulze Bert‐Wolfgang 
Published: March 2007

AbstractEdge representations of operators on closed manifolds are known to induce large classes of operators that are elliptic on specific manifolds with edges, cf. [11]. We apply this idea to the case of boundary value problems. We establish a correspondence between standard ellipticity and ellipticity with respect to the principal symbolic hierarchy of the edge algebra of boundary value problems, where an embedded submanifold on the boundary plays the role of an edge. We first consider the case that the weight is equal to the smoothness and calculate the dimensions of kernels and cokernels of the associated principal edge symbols. Then we pass to elliptic edge operators for arbitrary weights and construct the additional edge conditions by applying relative index results for conormal symbols. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Developing heuristic‐based quality judgments: Blocking in consumer choice
Authors: Oxoby Robert J. , Finnigan Hugh 
Published: March 2007

AbstractThis article provides an experimental demonstration of how the sequential order in which consumers receive information can influence the way information is processed and affect consumers' decisions. Specifically, when participants initially receive information regarding brand/quality or price/quality associations, these associations can block consumers' attention to more relevant quality‐determining physical attributes. Moreover, this process of blocking can carry over to affect quality judgments pertaining to similarly branded or priced products beyond the product in which blocking was initiated. This implies that consumers' judgments of quality may be heavily dependent on first impressions that develop into brand and price heuristics. © 2007 Wiley Periodicals, Inc.
Isobutene Polymerization Using [CuII(NCMe)6]2+ with Non‐Coordinating Anions as Catalysts
Authors: Hijazi Ahmed K. , Yeong Hui Y. , Zhang Yanmei , Herdtweck Eberhardt , Nuyken Oskar , Kühn Fritz E. 
Published: March 2007

AbstractCuII compounds coordinated octahedrally with nitriles and associated with bulky, non‐coordinating counter ions can be applied in the polymerization of isobutene at 30 °C. High yields and a high content of terminal double bonds are reached in the resulting highly reactive polyisobutylenes, while the molecular masses are moderate. Two of the coordinating nitriles are more weakly coordinated than the other four, as can be concluded from an exemplary X‐ray structure and from vibrational spectra, thus providing easily accessible sites for substrate coordination.magnified image
Dissolution and Doping of Polyaniline Emeraldine Base in Imidazolium Ionic Liquids Investigated by Spectroscopic Techniques
Authors: Rodrigues Fabio , do Nascimento Gustavo M. , Santos Paulo S. 
Published: March 2007

AbstractPolyaniline is a model molecular system in the study of conductive polymers. Ionic liquids, on the other hand, are becoming more and more a very convenient alternative for conventional organic solvents. The dissolution of polyaniline‐emeraldine base (PANI‐EB) in imidazolium ILs leads to its doping, as indicated by optical and resonance Raman spectroscopies. In this study, it is proposed that the interaction of PANI‐EB and imidazolium ILs involves the specific interaction of the quinoid moiety of the former with the imidazolium ring of the latter, an interpretation that is also based on N K‐edge XANES measurements of neat PANI‐EB, neat ILs, and of their solutions.magnified image
Influence of Cyclodextrin and Temperature on the Kinetics of Free Radical Polymerization of N‐Adamantylacrylamide in Water
Authors: Steffens Christopher , Kretschmann Oliver , Ritter Helmut 
Published: March 2007

AbstractN‐Adamantylacrylamide (3) was complexed with randomly methylated β‐cyclodextrin (RAMEB) forming the water‐soluble host–guest monomer‐complex 3a. A 1:1 complex stoichiometry was proven by NMR titration (Job's method). We investigated the free radical polymerization of the complex 3a using the water‐soluble azoinitiator 2,2′‐azobis[2‐(2‐imidazolin‐2‐yl)‐propane]dihydrochloride (VA044) at different temperatures. We observed that, below Tcrit a solution polymerization of 3a takes place. Above Tcrit, a precipitation mechanism leads to an increase in the relative polymerization rate.magnified image
Water‐Soluble Methyl Orange Fibrils as Versatile Templates for the Fabrication of Conducting Polymer Microtubules
Authors: Dai Tingyang , Lu Yun 
Published: March 2007

AbstractOne‐dimensional methyl orange fibrils can be easily prepared. They are stable in acidic aqueous solutions and soluble in neutral water. When used to synthesize conducting polymer microtubules, the fibrils act as “hard templates” formally but as “soft templates” effectively. Microtubular structures of polypyrrole, polyaniline, and poly(3,4‐ethylenedioxythiophene) have been achieved successfully via such water‐soluble versatile templates.magnified image
Synthesis and Properties of Novel Polyimides Bearing Sulfonated Benzimidazole Pendant Groups
Authors: Álvarez‐Gallego Yolanda , Nunes Suzana Pereira , Lozano Angel E. , de la Campa José G. , de Abajo Javier 
Published: March 2007

AbstractA new diamine monomer containing benzimidazole‐5‐sulfonic acid has been synthesised. It has been reacted, alone or mixed with diaminodiphenyl ether, with naphthalenic dianhydride to attain polynaphthalimides in which the sulfonic acid functionality is borne by pendant benzimidazole groups. The presence of sulfonic and benzimidazole groups greatly affected the physical properties of the polyimides as the novel polymers were found to be soluble in polar organic solvents and exhibited a lower thermal resistance than their non‐sulfonated counterparts. The polymer films exhibited good mechanical properties with tensile strength in the range 100–120 MPa and with moduli in the range 2.2–3.1 GPa. Sulfonic and benzimidazole groups significantly enhanced the hydrophilicity of the copolyimides, which showed water uptake up to 39%.magnified image
Synthesis and Ionic Interactions of a Proton Donor Terminated Polyalkylene Ether
Authors: Savitsky Andrew , Tenkovtsev Andrey V. , Oertel Ulrich , Komber Hartmut , Böhme Frank 
Published: March 2007

AbstractA chromophore terminated aliphatic polyether was obtained by polymer analogous conversion of the amino groups of Jeffamine® ED‐600 with 4‐[5‐(4‐acetoxy‐phenyl)‐3‐oxo‐penta‐1,4‐dienyl]benzoic acid and subsequent saponification of the acetoxy group. UV/Vis spectroscopic investigations showed that deprotonation of the chromophoric groups by organic or inorganic bases as for example poly(1,8‐octamethyleneacetamidine) and NaOH, respectively, results in a distinct bathochromic shift of the chromophores longest wavelength absorption band by about 100 nm. This effect is discussed in terms of polymer blends where the covalently bound chromophore can act as optical probe for acid–base interactions between the components.magnified image
Tuning Mechanical Properties of Block Copolymer/Aluminosilicate Hybrid Materials
Authors: Verploegen Eric , Dworken Benjamin T. , Faught Marybeth , Kamperman Marleen , Zhang Yuanming , Wiesner Ulrich 
Published: March 2007

AbstractIn this work the primary mechanical property profiles of a specific class of nano‐structured polymer/inorganic hybrid materials are characterized. By utilizing sol‐gel aluminosilicate synthesis with amphiphilic polyisoprene‐block‐poly(ethylene oxide) block copolymers as structure‐directing agents, block copolymer/aluminosilicate hybrid materials are prepared with nanometer scale hexagonally packed cylinders and lamellae of the inorganic hybrid components, as evidenced by small‐angle X‐ray scattering. Systematic thermal and dynamic mechanical analyses are performed on these hybrids as well as on the constituting components. Results reveal two transitions from the low temperature, glassy state of the hybrids into high temperature elastic plateau regions, with moduli that vary over orders of magnitude as a function of compositionandmorphology. The first transition can be assigned to the glass transition of the PI domains while the second is ascribed to a temperature induced softening of the organic components within the PEO/hybrid domains. The results suggest that in the present nanostructured block copolymer/aluminosilicate hybrid materials compositionandmorphology provide a powerful tool to tailor mechanical property profiles.magnified image
Effect of Cocatalysts on the Catalytic Activities of Tantalum‐ and Niobium‐Based Catalysts for Ring‐Opening Metathesis Polymerization of Norbornene
Authors: Nakayama Yuushou , Tanimoto Masaya , Shiono Takeshi 
Published: March 2007

AbstractA series of pentavalent tantalum and niobium complexes with aryloxy ligands was prepared, and their catalytic behavior for the ROMP of norbornene was studied in the presence of an alkylaluminum cocatalyst. Tantalum complexes 1–4 showed very high activity for the ROMP of NBE in combination with iBu3Al to give high‐molecular‐weight polymers. In contrast, the niobium complexes 5 and 6, as well as NbCl5, exhibited very high activity upon activation with Me3Al to give high‐molecular‐weight polymers.magnified image
Stability and Drug Loading of Spontaneous Vesicles of Comb‐Like PEG Derivates
Authors: Li Xiaolin , Ji Jian , Wang Xiaoli , Wang Youxiang , Shen Jiacong 
Published: March 2007

AbstractA novel comb‐like derivative CPEG‐g‐cholesterol was prepared by the reaction of cholesteryl chloroformate with hydroxyl groups of CPEG. The TEM and SEM results showed that CPEG‐cholesterol spontaneously aggregated vesicles with the membrane thickness of 4.27 ± 0.48 nm. Compared with the vesicles formed by comb‐like PEG (CPEG), the derivation of cholesteryl chloroformate increased the thickness of vesicle membrane and developed corrugations. The hydrophobic doxorubicin (Dox) was added into the solution of CPEG and CPEG‐g‐cholesterol to test their vesicle stability. The drug‐loaded vesicles of CPEG‐g‐cholesterol still existed but those of CPEG disappeared, which indicated that stability of vesicles was enhanced by the derived cholesteryl chloroformate. The vesicles were further cross‐linked by the reaction between divinyl sulfone (DVS) and the hydroxy groups in the side chains of the CPEG and CPEG‐g‐cholesterol. Both cross‐linked vesicles of CPEG and CPEG‐g‐cholesterol entrapped considerable hydrophobic Dox in the vesicles membrane. The spontaneous vesicles of CPEG‐g‐cholesterol and the crosslinked vesicles of CPEG and CPEG‐g‐cholesterol might have great potential as a cargo of the hydrophobic drug.magnified image
Chemical One Step Method to Prepare Polyaniline Nanofibers with Electromagnetic Function
Authors: Zhang Zhiming , Deng Junying , Shen Jiaoyan , Wan Meixiang , Chen Zhaojia 
Published: March 2007

AbstractA “Chemical one step method” (COSM) is proposed to prepare electromagnetic functional composite nanofibers of polyaniline (PANI/γ‐Fe2O3) having a diameter of ≈20 nm. In this approach FeCl3 is acts as the oxidant either for polymerization of aniline or for preparation of γ‐Fe2O3 magnets. Besides, it also provides protons produced by the hydrolysis process for doping PANI. It is found that the composite nanofibers have a high conductivity (10−1 ∼ 100 S · cm−1) and super‐paramagnetic properties (Ms = 0.46 ∼ 6.03 emu · g−1 and Hc = 0) at room temperature, where the conductivity is mainly affected by the molar ratio of FeCl3 to aniline monomer whereas the magnetic properties are dominated by the amount of FeCl2.magnified image
Rings of Hydrogel Fabricated by a Micro‐Transfer Technique
Authors: Wang Bo , Hong Yi , Feng Jie , Gong Yihong , Gao Changyou 
Published: March 2007

AbstractMicrogel rings have been fabricated on a glass surface by a micro‐transfer technique. The polymer melt is transferred to the substrate surface in a confined space with a picoliter volume along the boundary of the polymeric stamp. The surface of the polymer features is smoothened by surface tension in an annealing cycle, which results in isotropic rings. After cross‐linking, the microgels respond swiftly when immersed in water. Asymmetric rings are also obtained by tilting the substrate. The microgels can detach from the substrate to form a suspension of the rings. Conjugated rings have also been fabricated by supplementing functional molecules into the poly(ethylene glycol) network.magnified image
Polymer‐Bound Thiol Groups on Poly(2‐oxazoline)s
Authors: Cesana Sonia , Kurek Alexander , Baur Markus A. , Auernheimer Jörg , Nuyken Oskar 
Published: March 2007

AbstractA new 2‐oxazoline monomer with a protected thiol group, 2‐[2‐(4‐methoxybenzylsulfanyl)ethyl]‐2‐oxazoline, MOB‐SOx, was synthesized from commercially available compounds. MOB‐SOx and 2‐ethyl‐2‐oxazoline (EtOx) were simultaneously polymerized yielding well defined copolymers with narrow molar mass distributions and target polymer chain length. The copolymerization was initiated by N‐methyl‐2‐methyl‐2‐oxazolinium triflate (MeOxOTf). After quantitative deprotection, poly(2‐oxazoline) with pendant thiol groups was obtained. The thiol groups were quantitatively added to the double bond of N‐phenyl‐acrylamide (PhA) and benzylmaleimide (BzM). Graft copolymers were obtained by reaction of those SH containing polymers with poly(2‐methyl‐2‐oxazoline)s bearing acrylamide (PMeOx10A) and maleimide (PMeOx10M) as terminal reactive groups.magnified image