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31.
Using a linear programming model for the financial planning of an organization requires the specification of a horizon date and a valuation of the firm at that date. Given perfect information about future opportunities, an exact valuation procedure should lead to the same optimal solution of the model regardless of the choice of horizon date. Even in the absence of perfect information, conventional valuations fall far shorter of this ideal than they need to. It is shown that for a modest increase in the size of the linear programme, better valuations can be achieved and, most importantly, valuations which consider the impact on the value of the firm of post horizon constraints and liabilities as well as post-horizon opportunities. 相似文献
32.
33.
Simone Mastrogiovanni Christos Karathanasis Jonathan Gair Gregory Ashton Stefano Rinaldi Hsiang-Yu Huang Gergely Dálya 《Annalen der Physik》2024,536(2):2200180
Standard sirens have been the central paradigm in gravitational-wave cosmology so far. From the gravitational wave signature of compact star binaries, it is possible to measure the luminosity distance of the source directly, and if additional information on the source redshift is provided, a measurement of the cosmological expansion can be performed. This review article discusses several methodologies that have been proposed to use gravitational waves for cosmological studies. Methods that use only gravitational-wave signals and methods that use gravitational waves in conjunction with additional observations such as electromagnetic counterparts and galaxy catalogs will be discussed. The review also discusses the most recent results on gravitational-wave cosmology, starting from the binary neutron star merger GW170817 and its electromagnetic counterpart and finishing with the population of binary black holes, observed with the third Gravitational-wave Transient Catalog GWTC–3. 相似文献
34.
Natasha S. Adamson Ashton G. Theakstone Lachlan C. Soulsby Egan H. Doeven Emily Kerr Conor F. Hogan Paul S. Francis Lynn Dennany 《Chemical science》2021,12(28):9770
We present a new approach to explore the potential-dependent multi-colour co-reactant electrochemiluminescence (ECL) from multiple luminophores. The potentials at both the working and counter electrodes, the current between these electrodes, and the emission over cyclic voltammetric scans were simultaneously measured for the ECL reaction of Ir(ppy)3 and either [Ru(bpy)3]2+ or [Ir(df-ppy)2(ptb)]+, with tri-n-propylamine as the co-reactant. The counter electrode potential was monitored by adding a differential electrometer module to the potentiostat. Plotting the data against the applied working electrode potential and against time provided complementary depictions of their relationships. Photographs of the ECL at the surface of the two electrodes were taken to confirm the source of the emissions. This provided a new understanding of these multifaceted ECL systems, including the nature of the counter electrode potential and the possibility of eliciting ECL at this electrode, a mechanism-based rationalisation of the interactions of different metal-complex luminophores, and a previously unknown ECL pathway for the Ir(ppy)3 complex at negative potentials that was observed even in the absence of the co-reactant.Exploration of potential-dependent, multi-colour co-reactant electrochemiluminescence from multiple luminophores at the working and counter electrodes reveals new pathways to emission. 相似文献
35.
36.
Rich and complex Raman scattering and Raman optical activity (ROA) spectra have been measured monitoring the pH induced alpha-helix-to-disordered conformational transition in poly(L-glutamic acid). Two-dimensional (2D) correlation techniques have been applied to facilitate a comprehensive analysis of these two complementary spectral sets. Synchronous contour plots have identified band assignments of alpha-helical and disordered conformations, and have revealed bands characteristic of changes in the protonation state of the polypeptide. Asynchronous plots, on the other hand, have probed the relative sequential orders of intensity changes indicating a decrease in intensity of alpha-helical bands in the backbone skeletal stretch region, followed by a subsequent decrease in intensity in the extended amide III and amide I regions, underlying the appearance of disordered structure, including poly(L-proline) II (PPII) helix. The application of a 2D correlation 'moving' window has also disclosed two distinct phases during helix unfolding in the alpha-helix-to-disordered transition, occurring at approximately pH 4.9 and approximately pH 5.2, possibly a result of the difference in helical stability between the end and central regions of the alpha-helix. This paper demonstrates the potential value of combining 2D Raman, 2D ROA and moving window correlation techniques for the detailed investigation of complex and subtle changes of secondary structure during the unfolding mechanisms of polypeptides and proteins. 相似文献
37.
The plasma copolymerization of pyrrole with hexamethyldisiloxane, hexamethyldisilane and hexamethyldisilazane was investigated with regard to the polymer deposition characteristics and the properties of the product films. Deposition rates were evaluated by monitoring the weight increase of the deposits over time, and the effect of varying the experimental set up parameters was determined. The results of deposition rates and quantitative IR analysis suggested that the increasing amounts of Si-components were incorporated into the polymer matrix as the supply ratio of the Si-monomer was increased. The Si-component in the copolymer brought some dramatic effects on the physical properties of the films and changed the hydrophobicity of the surfaces, as reflected in the advancing and receding contact angle measurements. The experimental results obtained are discussed in terms of the contribution of the polar and dispersion components of surface energy. 相似文献
38.
KM Varier AM Vinodkumar NVSV Prasad PV Madhusudhana Rao DL Sastry Lagy T Baby MC Radhakrishna NG Puttaswamy JJ Das P Sugathan N Madhavan AK Sinha DO Kataria 《Pramana》1999,53(3):529-533
Large enhancements have been observed in the sub-barrier fusion cross sections for Ti+Ni systems in our previous studies.
Coupled channel calculations incorporating couplings to 2+ and 3− states failed to explain these enhancements completely. A possibilty of transfer channels contributing to the residual enhancements
had been suggested. In order to investigate the role of relevant transfer channels, measurements of one- and two-nucleon transfer
were carried out for 46,48Ti+61Ni systems. The present paper gives the results of these studies. 相似文献
39.
Masumi Asakawa Peter R. Ashton Vincenzo Balzani Alberto Credi Christoph Hamers Gunter Mattersteig Marco Montalti Andrew N. Shipway Neil Spencer J. Fraser Stoddart Malcolm S. Tolley Margherita Venturi Andrew J. P. White David J. Williams 《Angewandte Chemie (International ed. in English)》1998,37(3):333-337
A mechanical switch in a [2]catenane , made up of a cyclobis(paraquat-p-phenylene) tetracation interlocked with a macrocyclic polyether containing a redox-active tetrathiafulvalene (TTF) unit and a 1,5-dioxynaphthalene ring system, can be thrown either chemically or electrochemically. The neutral TTF unit resides “inside” the tetracationic cyclophane in the reduced state and “alongside” it in the oxidized species (TTF+/ TTF2+). Switching between the reduced (I4+) and oxidized state (I5+(I6+)) is accompanied by a dramatic color change. 相似文献
40.
Anthony W. Ashton Yunjia Zhang Rosanna Cazzolli Kenneth V. Honn 《Molecules (Basel, Switzerland)》2022,27(19)
Over the last two decades, there has been an increasing awareness of the role of eicosanoids in the development and progression of several types of cancer, including breast, prostate, lung, and colorectal cancers. Several processes involved in cancer development, such as cell growth, migration, and angiogenesis, are regulated by the arachidonic acid derivative thromboxane A2 (TXA2). Higher levels of circulating TXA2 are observed in patients with multiple cancers, and this is accompanied by overexpression of TXA2 synthase (TBXAS1, TXA2S) and/or TXA2 receptors (TBXA2R, TP). Overexpression of TXA2S or TP in tumor cells is generally associated with poor prognosis, reduced survival, and metastatic disease. However, the role of TXA2 signaling in the stroma during oncogenesis has been underappreciated. TXA2 signaling regulates the tumor microenvironment by modulating angiogenic potential, tumor ECM stiffness, and host immune response. Moreover, the by-products of TXA2S are highly mutagenic and oncogenic, adding to the overall phenotype where TXA2 synthesis promotes tumor formation at various levels. The stability of synthetic enzymes and receptors in this pathway in most cancers (with few mutations reported) suggests that TXA2 signaling is a viable target for adjunct therapy in various tumors to reduce immune evasion, primary tumor growth, and metastasis. 相似文献