135 research outputs found

    Synthesis, Characterization, and Crystal Structure of the (η5-C5Ph5)Cr(CO)3 Radical

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    The reaction between Cr(CO)6 and Na(C5Ph5 ) in refluxing diglyme yields [Na(diglyme)3/2][(C5Ph5)Cr(CO)3], 1. Metathesis of 1 with [Ph3P=N=PPh3 ]Cl in CH2Cl2 yields [Ph3P=N=PPh3][(C5Ph5)Cr(CO)3], 2. Oxidation of 1 by AgBF4 in cold THF under an argon atmosphere produces (C5Ph5)Cr(CO)3, 3. Complexes 2 and 3 form a redox pair connected by a quasireversible one-electron process, E0 = -0.69 V vs ferrocene in CH2Cl2, E0 = -0.50 V in CH3CN, ks = 0.12 cm/s. ESR spectra of (C5Ph5)Cr(CO)3 in toluene at 90 K gave a rhombic g-tensor with components 2.1366, 2.0224, and 1.9953, consistent with the expected low-spin d5 electronic configuration. The largest g-tensor component was significantly temperature dependent, suggesting an equilibrium between conformations with 2A´ and 2A˝ ground states. Crystal structures of [Ph3P=N=PPh3][(C5Ph5)Cr(CO)3] and (C5Ph5)Cr(CO)3 were obtained

    On the pp-supports of a holonomic D\mathcal{D}-module

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    For a smooth variety YY over a perfect field of positive characteristic, the sheaf DYD_Y of crystalline differential operators on YY (also called the sheaf of PDPD-differential operators) is known to be an Azumaya algebra over TY,T^*_{Y'}, the cotangent space of the Frobenius twist YY' of Y.Y. Thus to a sheaf of modules MM over DYD_Y one can assign a closed subvariety of TY,T^*_{Y'}, called the pp-support, namely the support of MM seen as a sheaf on TY.T^*_{Y'}. We study here the family of pp-supports assigned to the reductions modulo primes pp of a holonomic D\mathcal{D}-module. We prove that the Azumaya algebra of differential operators splits on the regular locus of the pp-support and that the pp-support is a Lagrangian subvariety of the cotangent space, for pp large enough. The latter was conjectured by Kontsevich. Our approach also provides a new proof of the involutivity of the singular support of a holonomic D\mathcal{D}-module, by reduction modulo p.p.Comment: The article has been rewritten with much improved exposition as well as some additional results, e.g. Corollary 6.3.1. This is the final version, accepted for publication in Inventiones Mathematica

    Duality in the flat cohomology of curves

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46600/1/222_2005_Article_BF01390135.pd

    How does ethical leadership trickle down? Test of an integrative dual-process model

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    Although the trickle-down effect of ethical leadership has been documented in the literature, its underlying mechanism still remains largely unclear. To address this gap, we develop a cross-level dual-process model to explain how the effect occurs. Drawing on social learning theory, we hypothesize that the ethical leadership of high-level managers could cascade to middle-level supervisors via its impact on middle-level supervisors’ two ethical expectations. Using a sample of 69 middle-level supervisors and 381 subordinates across 69 sub-branches from a large banking firm in China, we found that middle-level supervisors’ ethical efficacy expectation and unethical behavior–punishment expectation (as one form of ethical outcome expectations) accounted for the trickle-down effect. The explanatory role of middle-level supervisors’ ethical behavior–reward expectation (as the other form of ethical outcome expectations), however, was not supported. The theoretical and practical implications are discussed

    Work-life balance in the police: the development of a self-management competency framework

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    Purpose Addressing a gap in the current work–life balance (WLB) literature regarding individual-focused approaches to inform interventions, we elicited behaviors used to self-manage WLB to draw up a competency-based WLB framework for relevant learnable knowledge, skills, and abilities (KSAs; Hoffmann, Eur J Ind Train 23:275–285, 1999) and mapping this against extant WLB frameworks. Design/Methodology/Approach Our participants were from a major UK police force, which faces particular challenges to the work–life interface through job demands and organizational cutbacks, covering a range of operational job roles, including uniformed officers and civilian staff. We took a mixed methods approach starting with semi-structured interviews to elicit 134 distinct behaviors (n = 20) and used a subsequent card sort task (n = 10) to group these into categories into 12 behavioral themes; and finally undertook an online survey (n = 356) for an initial validation. Findings Item and content analysis reduced the behaviors to 58, which we analyzed further. A framework of eight competencies fits the data best; covering a range of strategies, including Boundary Management, Managing Flexibility, and Managing Expectations. Implications The WLB self-management KSAs elicited consist of a range of solution-focused behaviors and strategies, which could inform future WLB-focused interventions, showing how individuals may negotiate borders effectively in a specific environment. Originality/Value A competence-based approach to WLB self-management is new, and may extend existing frameworks such as Border Theory, highlighting a proactive and solution-focused element of effective behaviors

    Do "protean" employees make better leaders? The answer is in the eye of the beholder

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    While the protean career (Hall 1976; 2002) has been lauded for its advantages in helping individuals adapt to changing career contexts, it is not clear how this career orientation may impact how others perceive a person’s leadership ability. In this study we hypothesized that those with a protean career orientation would receive higher leadership ratings from subordinates and superiors, but lower leadership ratings from peers, in part based upon social comparison theory. Using structural equation modeling, our hypotheses regarding subordinates and peers were supported, but not with respect to superiors, who along with peers rated those with a protean career orientation lower in terms of transformational leadership as measured by the MLQ. We discuss potential reasons for these findings and the consequences for research and theory. Also, we examine the implications of this research for leadership development, workforce recruitment and retention, and possible generational significance
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