bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zur Chemie der Glühlampe
Authors: Rabenau A. 
Published: July 2007

AbstractSeit einiger Zeit sind Halogenlampen im Handel, die im Begriff sind, in vielen Bereichen außerhalb der Allgebrauchs‐( = Haushalt‐)Glühlampe die konventionelle Lampe zu verdrängen. Ihre verhältnismäßig kleinen Kolben enthalten neben einer Inertgasfüllung kleine Mengen Halogen. Bei der Jodlampe konnte der Mechanismus, der hier die Anwesenheit von Spuren Sauerstoff erfordert, geklärt werden: Von der Wendel verdampfendes Wolfram wird in einem Kreisprozeß über ein Wolframoxid und WO2J2an die Wendel zurückgeführt. Im Kolben einer solchen Lampe schlägt sich während der gesamten Lebensdauer kein Wolfram nieder. — Ein regenerativer Kreisprozeß, bei dem das verdampfte Wolfram sich an den heißesten (und dadurch am meisten gefährdeten) Stellen der Wendel abscheidet, läßt sich im Prinzip unter Verwendung von Fluor‐Verbindungen verwirklichen.
Benzoloxid‐Oxepin‐Valenztautomerie
Authors: Vogel E. , Günther H. 
Published: July 2007

AbstractBenzoloxid und das potentielle 8π‐Elektronensystem Oxepin stehen im Valenztautomerie‐Gleichgewicht, an dem die Komponenten annähernd gleichen Anteil haben. Durch NMR‐Spektroskopie wird der Nachweis erbracht, daß die Einstellung des Gleichgewichts sehr schnell erfolgt (Aktivierungsenergien von Hin‐ und Rückreaktion 9,1 bzw. 7,2 kcal·mol−1), Benzoloxid‐Oxepin somit ein System mit fluktuierenden Bindungen darstellt. Nach den bisher bekannten Eigenschaften des Oxepins ist es gerechtfertigt, die Verbindung als ein „Heterotropiliden”︁ aufzufassen. Geeignete Substitution ermöglicht es, das Benzoloxid‐Oxepin‐Gleichgewicht extrem nach der einen oder anderen Seite zu verlagern. Die Chemie von Arenoxid‐Oxepin‐Systemen wird durch die Oxidkomponente als dem gegenüber den meisten Agentien reaktiveren Partner beherrscht. Beim 1,6‐Oxido‐[10]annulen – formal ein 2,7‐überbrücktes Oxepin – ist der Oxepincharakter durch die Bildung eines delokalisierten 10π‐Elektronensystems im C10‐Perimeter völlig unterdrückt. Existenzfähigkeit und aromatische Natur von 1,6‐Oxido‐[10] annulen führen zur Konzeption einer homologen Reihe sauerstoffüberbrückter Annulene (1,6; 8,13‐Bisoxido‐[14]annulen, 1,6; 8,17; 10,15‐Trisoxido‐[18]annulen usw.), die wie die ihnen zugrundeliegenden Acene (4n + 2)π‐Elektronen enthalten. Molekülmodellen zufolge ist bei einer syn‐ bzw. all‐syn‐Anordnung der Sauerstoffbrücken eine weitgehende Einebnung der C4n+2‐Perimeter erreichbar und demnach die Voraussetzung für Aromatizität gegeben. Synthese und Eigenschaften von syn‐1,6; 8,13‐Bisoxido‐[14]annulen bestätigen diese Vorstellungen auf eindrucksvolle Weise.
Neuere Methoden der präparativen organischen Chemie VI. Isocyaniddihalogenid‐Synthesen
Authors: Kühle E. , Anders B. , Zumach G. 
Published: July 2007

AbstractDie Methoden zur Herstellung von Isocyaniddihalogeniden, insbesondere von Isocyaniddichloriden, werden beschrieben. Anwendungsbreite und Reaktionsverlauf der einzelnen Verfahren werden diskutiert.
A study on the sorption of NO3− and F− on the carboxymethylated starch‐based hydrogels loaded with Fe2+ ions
Authors: Chauhan Ghanshyam S. , Kumar Rajeev , Verma Monika 
Published: July 2007

AbstractUsing the principle of geochemistry of fluoride, green and cost effective anion adsorbents were developed for the removal of F− from water systems. The scheme was further applied for the removal of NO3− also. Carboxymethylated starch functionalized through network formation with acrylamide was used as adsorbent, and the resultant hydrogels were loaded with Fe2+ ions to generate anchorage for the anions. Sorption of Fe2+ was studied as a function of different factors such as time, temperature, pH, and ion strength. The network having the highest Fe2+ uptake was loaded with the Fe2+ ions under optimum conditions and used for the sorption of F− and NO3−. High efficiency has been observed for F−, as even up to 100% uptake has been observed within just 10 minutes. The support shows high selectivity for NO3−, which was used as anion reference. Thermodynamics of sorption confirms low order and low energy processes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Functional measurement approach to self‐estimation in multiattribute evaluation
Authors: Anderson Norman H. , Zalinski James 
Published: July 2007

AbstractMultiattribute analysis depends on measurement of values and weights. Unless these measures reflect the decision maker's true values and weights, the multiattribute formula may put a less‐preferred alternative in first place. To avoid such disordinality requires stringent measurement conditions: First, the values and weights must be on linear (equal interval) or ratio (known zero) scales. Second, these scales must satisfy a condition of common unit across disparate attribute dimensions. Most methods of range adjustment beg both of these measurement questions. Functional measurement theory can solve both problems and so can be useful in multiattribute analysis. Past work has established the operation of a general cognitive algebra as an empirical reality. The averaging model, in particular, makes possible the definition and estimation of weights and values as distinct psychological parameters. It can also solve the problem of common unit. Cognitive algebra thus provides a grounded theoretical foundation on which to develop self‐estimation methodology, in which decision makers provide direct estimates of their values and weights. The logic is straightforward. Functional measurement can analyze global judgments to obtain validated psychological scales. These scales may then be used as validational criteria for the self‐estimates. Procedures to eliminate biases in the self‐estimates can thus be tested and refined in well‐learned multiattribute tasks, such as judgments of meals, in which global judgments are trustworthy. Once developed, such self‐estimation procedures may be used with some confidence for general multiattribute analysis. A number of studies from 20‐odd years of work on the theory of information integration are summarized to show good, although not unmixed promise for self‐estimation.
An availability bias in professional judgment
Authors: Dube‐Rioux Laurette , Russo J. Edward 
Published: July 2007

AbstractWhen branches of a fault tree are pruned, subjects do not fully transfer the probability of those branches to the ‘all other’ category. This underestimation of the catch‐all probability has been interpreted as an ‘out of sight, out of mind’ form of the availability bias. The present work replicates this underestimation bias with professional managers. It then demonstrates the effectiveness of a corrective tactic, extending the tree by generating additional causes, and also reveals that more easily retrieved short‐term causes dominate the generation process. These results do not differ across managers' culture, education or experience. After evaluating such alternative explanations as category redefinition, we conclude that availability is a major cause, though possibly not the sole cause, of the underestimation bias.
Estimation of indifference curves in the Marschak‐Machina triangle a direct test of the “fanning out” hypothesis
Authors: Hey John D. , Strazzera Elisabetta 
Published: July 2007

AbstractThe ongoing debate on the correct modelling of economic behaviour under risk makes heavy expositional use of the 'Marschak‐Machina Triangle'. This has also been used when constructing tests of the various competing theories. In this paper, we adopt a more direct approach ‐ by estimating subjects' indifference maps in the Triangle. Employing an interview technique, we find that most subjects have maps which are nearly consistent with those implied by Subjective Expected Utility theory.
Problem structuring aids for quantitative estimation
Authors: Macgregor Donald G. , Lichtenstein Sarah 
Published: July 2007

AbstractAn important part of decision making in many contexts is the estimation of numerical values for uncertain quantities, such as the projected costs of a development project or the number of people who use illegal drugs. In previous research, estimation accuracy for such quantities was found to be improved by algorithmic decomposition. The present study examines (a) the estimation performance of individuals using extended algorithms in which component estimates are produced by multiple methods, and (b) the effectiveness of algorithms produced by individuals after receiving training in algorithmic decomposition. The extended algorithm approach yielded some improvement in estimation performance. Subjects trained in algorithmic decomposition were able to produce algorithms, the effectiveness of which were dependent upon the presence of misinformation about components of the quantity to be estimated. The results are discussed in terms of the information processing demands imposed by detailed problem structuring.
Do medical decision analyses' largest gains grow from the smallest trees?
Authors: Politser Peter E. 
Published: July 2007

AbstractSome decision analysts recommend reserving their models for careful, complete study of complex problems. Others believe simple problem analyses provide the greatest gains. To clarify these issues, I tested: (1) whether simple published analyses compared to complex ones, produced results as non‐intuitive; and (2) whether non‐intuitiveness represented analytic gain (or equivalently, intuitive loss). Very limited data also examined (3) the gain from adding model intricacy for a given problem vs. selecting more complex problems for analysis.To assess two non‐intuitiveness measures, 75 subjects (33 physicians and 42) non‐physicians stated their intuitive preferences in 40 (22 published and 18 unpublished) medical dilemmas. For both physicians and non‐physicians, simpler models (those with lees than 30 terminal branches in the decision tree) had about one third the non‐intuitiveness of more complex ones. Three tests also supported the premise that analyses outperform intuition, therefore that on average the formers' non‐intuitiveness reflects less analytic gain. In addition, for different models of the same problem, tree complexity did not correlate with gain. Thus, simpler trees may not generally gain less because they inadequately describe problems. Instead, simpler analyses may represent simpler problems, with more similar intuitive and formal solutions. If so, these findings may help us avoid some costly but unnecessary simple analyses.
Fuzzy‐trace theory and framing effects in choice: Gist extraction, truncation, and conversion
Authors: Reyna Valerie F. , Brainerd Charles J. 
Published: July 2007

AbstractIn the first section of this paper, we analyze classic framing effects according to principles of fuzzy‐trace theory. The key principle of the theory is that reasoning prefers to operate on simple gist, as opposed to exact details. Then, we introduce new data in three experiments designed to test this fuzzy‐processing assumption. In the first experiment, framing effects were conserved when numerical information was omitted from standard problems, arguing against a critical role for numerical processing. In the second experiment, evidence is presented that some subjects simplified framing problems by mentally truncating linguistically redundant complements in gambles. Experimentally deleting parts of gambles mimiced such effects, and choices varied depending on the information that remained explicit. In the third experiment, truncation effects were also demonstrated for mixed‐frame problems, in which one option is positive and the other is negative. The data disconfirmed a ‘halo’ hypothesis that subjects merely selected the positive option over the negative one. Instead, choices were accounted for by conversion, that is, transforming problems into uniformly positive representations to avoid the complexity of negation. In all three experiments, choices could be explained as a consequence of radically simplifying decision information.
Multi‐attribute choice and affect: The influence of naturally occurring and manipulated moods on choice processes
Authors: Lewinsohn Shai , Mano Haim 
Published: July 2007

AbstractBased on a two‐dimensional model of affect that views Pleasantness and Arousal as affect's two primary dimensions, this study investigates the effects of emotions on choice processes and outcomes. In Study 1, subjects first described their naturally occurring emotional state and then performed two multi‐attribute product choice tasks. Subjects in more pleasant mood deliberated longer, used more decision‐related information, re‐examined more previously examined information, and made more interdimensional moves. Subjects in more aroused mood spent less time deliberating, revealed less information, ignored more product‐describing attributes, and re‐examined less of previously examined information. Study 2 replicated many of these effects with experimentally manipulated emotions and using a managerial decision‐making task. The results are interpreted in terms of (1) a congruency between one's hedonic state and selected decision strategy and (2) a restriction in attentional capacity induced by increased Arousal.
The impact of using forced decision‐making strategies on post‐decisional confidence
Authors: Zakay Dan , Tsal Yehoshua 
Published: July 2007

AbstractThe impact of motivational and cognitive factors on post‐decisional confidence (PDC) level was tested in two experiments. In the first experiment, subjects were first identified as having an intuitive preference toward using either a compensatory or a noncompensatory decision strategy and later on were forced to use either a compatible or a non‐compatible strategy. PDC level decreased after using a noncompensatory strategy, and the decrease was higher when it was a noncompatible strategy. In a second experiment, subjects received feedback about their preferred strategy but were not later forced to use any specific strategy. Most subjects continued to utilize their preferred strategy and PDC level was not changed. Overall, intuitive PDC was not found to be sensitive to differences between compensatory and noncompensatory strategies. The result suggested that PDC is a function of an internal cost‐benefit analysis which includes both cognitive and motivational factors.
The origins and function of the reference point in risky group decision making the case of the Cuban missile crisis
Authors: Whyte Glen , Levi Ariel S. 
Published: July 2007

AbstractThis case study explores reference level effects on group decision making during the Cuban missile crisis of 1962. The group is composed of American President John F. Kennedy and his advisers. The results are consistent with much experimental evidence showing that reference levels play an important role in determining preferences. The results also extend the notion of reference‐dependent risky choice to the group level, where the group consists of seasoned experts who each have a different role to play within the group and who are dealing with an issue of great importance.
Solid Catalyst with Ionic Liquid Layer (SCILL) – A New Concept to Improve Selectivity Illustrated by Hydrogenation of Cyclooctadiene
Authors: Kernchen U. , Etzold B. , Korth W. , Jess A. 
Published: July 2007

AbstractA new concept of a solid catalyst with ionic liquid layer (SCILL) as a novel method to improve the selectivity of heterogeneous catalysts is presented. The sequential hydrogenation of cyclooctadiene (COD) to cyclooctene (COE) and cyclooctane on a commercial Ni catalyst coated with the ionic liquid [BMIM][n‐C8H17OSO3] was tested as first model system. Compared to the original catalyst, the coating of the internal surface with the ionic liquid (IL) strongly enhances the maximum intrinsic COE yield from 40 to 70 %. This effect is already achieved for a pore filling degree of only 10 % and cannot be explained by pore diffusion, as shown by experiments with different particle sizes and theoretical considerations. The IL layer is very robust and no leaching into the organic phase was detectable.
9‐Borabarbaralanes
Authors: Herberich Gerhard E. , Marx Han‐W. , Moss Stefan , Schleyer Paul Von Ragué , Wagner Trixie 
Published: July 2007

AbstractThe reaction of MgCOT(thf)x with tBuBF2 or PhBCl2 affords the first 9‐borabarbaralanes 2 (C8H8BR, a: R = tBu; b: RPh). With the aminoboron dihalides BCl2NiPr2 and BCl2N(SiMe3)tBu 9‐borabicyclo[4.2.1]‐nona‐2,4,7‐trienes 3 (a: RNiPr2, b: RN(SiMe3)tBu) and the trans‐9‐borabicyclo[4.3.0]nona‐2,4,7‐triene 4 are obtained. The bicyclic compounds 3a and 3 b are converted into 9‐borabarbaralanes 2c and 2 d, respectively, by irradiation in solution as well as by heating. All 9‐borabarbaralanes 2 are fluxional in solution. In the crystalline state, the B‐phenyl derivative 2b displays a well‐ordered van der Waals crystal structure. The theoretical prediction that the degenerate Cope rearrangement in barbaralanes will be retarded by π‐acceptor groups in the 9 position has been verified. Quantum chemical calculations employing density functional theory support and help interpret the experimental findings. The isoelectronic 9‐barbaralyl cations, in contrast, have such high Cope barriers that other rearrangement pathways are followed instead.
Conformers of Saturated Chains: Matrix Isolation, Structure, IR and UV Spectra of n‐Si4Me10
Authors: Albinsson Bo , Teramae Hiroyuki , Downing John W. , Michl Josef 
Published: July 2007

AbstractInfrared and ultraviolet spectra of the gauche and anti conformers of matrix‐isolated permethyl‐n‐tetrasilane have been obtained separately by taking advantage of thermally induced gauche‐to‐anti conversion and of wavelength‐selective photochemical destruction of either conformer. The resolved UV spectrum of the gauche conformer provides the first piece of experimental evidence in favor of the recently proposed reinterpretation of conformational effects on tetrasilane electronic states. According to this, it is not the energy but the intensity of the lowest singlet excitation that changes dramatically as the SiSiSiSi dihedral angle is varied, as a result of an avoided crossing between s̀s̀* and s̀π* states. Implications for the general understanding of sigma conjugation in simple terms are discussed. Unconstrained MP2/6‐31 G* optimization predicts the existence of a third backbone conformer (ortho), with a dihedral angle of about 90°. Its predicted (HF/3‐21 G*) mid‐IR spectrum is indistinguishable from that of the gauche conformer, and the matrix‐isolation spectra thus provide no evidence for or against its presence.
Asymmetric Control in the Pictet–Spengler Reaction by Means of N‐Protected Amino Acids as Chiral Auxiliary Groups
Authors: Schmidt Gunther , Waldmann Herbert , Henke Henning , Burkard Michael 
Published: July 2007

AbstractAromatic and aliphatic Schiff bases of tryptamine react with Fmoc‐ or phthaloyl‐protected amino acid chlorides to form N‐acyliminium intermediates, which, in the presence of titanium alkoxides at room temperature, undergo Pictet–Spengler reactions to give tetrahydro‐β‐carbolines with diastereomeric ratios of up to 99:1. The chiral auxiliary can be removed from the Pictet–Spengler adducts by means of a simple reduction. To rationalize the observed stereoselectivity a transition‐state model is proposed in which the titanium atom coordinates both the carbonyl group of the N‐acyliminium ion and the amino acid protecting group.
Simple Mechanical Molecular and Supramolecular Machines: Photochemical and Electrochemical Control of Switching Processes
Authors: Ashton Peter R. , Ballardini Roberto , Balzani Vincenzo , Boyd Sue E. , Credi Alberto , Gandolfi Maria T. , Gómez‐López Marcos , Iqbal Sayeedha , Philp Douglas , Preece Jon A. , Prodi Luca , Ricketts Howard G. , Stoddart J. Fraser , Tolley Malcolm S. , Venturi Margherita , Venturi Margherita , White Andrew J. P. , Williams David J. 
Published: July 2007

AbstractPhotochemical control of a self‐assembled supramolecular 1:1 pseudorotaxane (formed between a tetracationic cyclophane, namely the tetrachloride salt of cyclobis(paraquat‐p‐phenylene), and 1,5‐bis[2‐(2‐(2‐hydroxy)ethoxy)ethoxy]naphthalene) has been achieved in aqueous solution. The photochemical one‐electron reduction of the cyclophane to the radical trication weakens the noncovalent bonding interactions between the cyclophane and the naphthalene guest—π‐π interactions between the π‐electron‐rich and π‐electron‐poor aromatic systems, and hydrogen‐bonding interactions between the acidic α‐bipyridinium hydrogen atoms of the cyclophane and the polyether oxygen atoms of the naphthalene derivative—sufficiently to allow the guest to dethread from the cavity; the process can be monitored by the appearance of naphthalene fluorescence. The radical tricationic cyclophane can be oxidized back to the tetracation in the dark by allowing oxygen gas into the system. This reversible process is marked by the disappearance of naphthalene fluorescence as the molecule is recomplexed by the tetracationic cyclophane. This supramolecular system can be chemically modified such that the π‐electron‐rich unit, either a naphthalene derivative or a hydroquinone ring, and the tetracationic cyclophane are covalently linked. We have demonstrated that the π‐electron‐rich residue in this system is totally “self‐complexed” by the cyclophane to which it is covalently attached. Additionally, the self‐complexation can be switched “off” and “on” by electrochemical two‐electron reductions and oxidations, respectively, of the tetracationic cyclophane component. Thus, we have achieved the construction of two switches at the nanoscale level, one driven by photons and the other by electrons.
Addition of Organozincate Reagents to Imines Derived from (S)‐1‐Phenylethylamine and Ethyl (S)‐Valinate—Synthesis of (S)‐1‐(2‐Pyridyl)Alkylamines
Authors: Alvaro Giuseppe , Pacioni Paolo , Savoia Diego 
Published: July 2007

AbstractTriorganozincates were added to aliphatic aldimines derived from (S)‐1‐phenylethylamine and (S‐valine esters in the presence of boron trifluoride to give secondary amines with low diastereoselectivies. From mixed zincates, most alkyl groups (methyl, ethyl, 1‐heptynyl, but not tert‐butyl) could be transferred. No addition to benzaldimines was observed, but the imines prepared from 2‐pyridinecarboxaldehyde did not require activation by BF3 and underwent selective group transfer from mixed zincates at — 78°C. Excellent diastereoselectivities were observed in the reactions of the 2‐pyridine imine derived from ethyl (S)‐valinate with mixed zincates, in which the methyl group was used as nontransferable ligand, allowing the transfer of alkyl and vinyl groups with excellent to complete selectivity. However, dimethyl(aryl)‐ and dimethyl‐(1‐heptynyl)zincates did not react. (S)‐1‐(2‐Pyridyl)alkylamines were prepared with high optical purity by subsequent removal of the chiral auxiliary.
Structure and Chemical Bonding in K14Cd9Tl21, a Compound Containing Both Isolated Tl7‐11 Clusters and 2[Cd9Tl7‐10] Metallic Layers
Authors: Tillard‐Charbonnel Monique , Chahine Abdelkrim , Belin Claude , Rousseau Roger , Canadell Enric , Rousseau R. 
Published: July 2007

AbstractThe compound K14Cd9Tl21 has been prepared by fusion of the elements in a tantalum reactor followed by slow cooling at the rate of 6° per hour to enable crystal growth. The X‐ray crystal structure (hexagonal, P2m; a = 9.884(3), c =17.173(5) Å; Z = 2) was refined to reliability factors of R1 = 5.09, wR2 = 11.64%. The anionic substructure contains both isolated clusters of Tl7‐11 and a layered network based on Cd5Tl2 pentagonal bipyramids. The structure‐electron count relationship for the Tl7‐11 cluster was analyzed in detail. The Cd9Tl7‐10 layers are found to confer metallic properties to the material, and the bonding within such layers is found to be highly delocalized.