Reordering Of States Research Articles

Clumped isotope analysis of zoned calcite cement, Carboniferous, Isle of Man

AbstractSequential analyses of δ13C, δ18O and Δ47 values of calcite and dolomite deposited in millimetre‐sized cavities are reported from the Ronaldsway Member packstones, Isle of Man. The Ronaldsway brachiopods have δ13C values of ca +2.3‰ and δ18O values of ca −7.2‰; carbon is like predicted Carboniferous values, while oxygen values are more negative. The brachiopods show preserved microstructure but have marginal alteration and a streaky cathodoluminescence pattern. Crinoid ossicles have δ13C values of ca +2.3‰ and one with a δ18O value of ca −3.1‰, compatible with Carboniferous marine precipitates; three samples have δ18O values of ca −6.5‰ and are 18O‐depleted. Calcite stages 1 and 2 have δ13C values ca +3.2‰ and δ18O values ca −2.5‰, compatible with Carboniferous sea water. Stage 1 and 2 have non‐luminescent to orange CL zones. Stage 1 and early stage 2 contain red luminescent dolomite micro crystals generated during Mg calcite stabilisation. The Δ47 values for stage 1 and 2 cements indicate temperatures of 86 and 105°C that occurred after the stabilisation of Mg calcite. Stage 3–8 zoned cements preserve their original growth surfaces and their δ13C and δ18O values suggest precipitation during burial and exhumation. The Δ47 values of the brachiopods and crinoids indicate temperatures between 85 and 140°C indicating they were either recrystallised at high temperatures or affected by solid state reordering. To evaluate these alternatives two quantitative models, water–rock reaction and reordering models are performed. The allochems and cements are progressively altered by porewater towards the fluid‐buffered behaviour. The quantitative evaluation of calcite and dolomite solid‐state reordering suggests the elevated clumped isotopic temperatures are produced by interaction with hydrothermal fluids. This study improves understanding by applying previously untried techniques; further Δ47 data and quantifying elemental variations would help further interpretation but the poorly documented post‐depositional history is a drawback.

Calculations of the relative energies of the low‐lying electronic states of 2,7‐naphthoquinodimethane and 2,7‐naphthoquinone. Substitution of oxygen for CH2 is predicted to increase the singlet‐triplet energy difference (ΔEST)

Abstract(12/12)CASSCF and CASPT2 calculations have been performed on the triplet and two lowest‐lying singlet states of the 2,7‐naphthoquinodimethane (NQDM) and 2,7‐naphthoquinone (NQ) diradicals. Both diradicals are predicted to have triplet ground states but to differ in the ordering of the two lowest singlet states, with E(1A1) < E(1B2) in NQDM, but E(1A1) > E(1B2) in NQ. The reason for the difference in ordering of the singlet states in these two diradicals is discussed. The state reordering is shown to be responsible for the prediction that the substitution of the oxygens in NQ for the CH2 groups in NQDM increases, rather than decreases, the singlet‐triplet energy separation (ΔEST).

Tuning Stilbene Photochemistry by Fluorination: State Reordering Leads to Sudden Polarization near the Franck–Condon Region

Spontaneous polarization of a nonpolar molecule upon photoexcitation (the sudden polarization effect) earlier discussed for 90°-twisted alkenes is observed and calculated for planar ring-fluorinated stilbenes, trans-2,3,5,6,2',3',5',6'-octofluorostilbene (tF2356) and trans-2,3,4,5,6,2',3',4',5',6'-decafluorostilbene (tF23456). Due to the fluorination, Franck-Condon states S1FC and S2FC are dominated by the quasi-degenerate HOMO-1 → LUMO and HOMO-2 → LUMO excitations, while their interaction gives rise to a symmetry-broken zwitterionic S1 state. After optical excitation of tF2356, one observes an ultrafast (∼0.06 ps) evolution that reflects relaxation from initial nonpolar S3FC to long-lived (1.3 ns in n-hexane and 3.4 ns in acetonitrile) polar S1. The polarity of S1 is evidenced by a solvatochromic shift of its fluorescence band. The experimental results provide a sensitive test for quantum-chemical calculations. In particular, our calculations agree with the experiment, and raise concerns about the applicability of the common TDDFT approach to relatively simple stilbenic systems.

Development, intervention, and international order

AbstractThe project of international development involves the reordering of states (or at least attempts to do so), it sits at the intersection between transnational forces and bounded political entities and it is a manifestation of the will to order of powerful states. It would seem then to be closely connected to practices of intervention. At times, the practices of development agencies have taken on a more interventionist character, but in recent years their relationship to many developing countries has taken on a more intricate, subtle, and everyday form. It has in important respects moved ‘beyond’ intervention. This has significance beyond international development. Development agencies have been recruited to wider projects of international ordering, especially the construction of regimes of global governance and the ‘development’ of post-intervention states.

Bit-error rate improvement of TLC NAND Flash using state re-ordering

Bit-error rate improvement of TLC NAND Flash using state re-ordering

Acceleration of association‐rule based markov decision processes

In this paper, we present a new approach for the estimation of Markov decision processes based on efficient association rule mining techniques such as Apriori. For the fastest solution of the resulting association‐rule based Markov decision process, several accelerating procedures such as asynchronous updates and prioritization using a static ordering have been applied. A new criterion for state reordering in decreasing order of maximum reward is also compared with a modified topological reordering algorithm. Experimental results obtained on a finite state and action‐space stochastic shortest path problem demonstrate the feasibility of the new approach.

Componentwise bounds for nearly completely decomposable Markov chains using stochastic comparison and reordering

This paper presents an improved version of a componentwise bounding algorithm for the state probability vector of nearly completely decomposable Markov chains, and on an application it provides the first numerical results with the type of algorithm discussed. The given two-level algorithm uses aggregation and stochastic comparison with the strong stochastic (st) order. In order to improve accuracy, it employs reordering of states and a better componentwise probability bounding algorithm given st upper- and lower-bounding probability vectors. Results in sparse storage show that there are cases in which the given algorithm proves to be useful.

Etaqa-MG1: an efficient technique for the analysis of a class of M/G/1-type processes by aggregation

We extend the Etaqa approach, initially proposed for the efficient numerical solution of a class of quasi-birth–death processes, to a more complex class of M/G/1-type Markov processes where arbitrary forward transitions are allowed but backward transitions must be to a single state to the previous level. The new technique reduces the exact solution of this class of M/G/1-type models to that of a finite linear system. We demonstrate the utility of our method by describing the exact computation of an extensive class of Markov reward functions that include the expected queue length or its higher moments. We also provide an algorithm that finds an appropriate state reordering satisfying our applicability conditions, if one such order exists. We illustrate the method, discuss its complexity and numerical stability, and present comparisons with other traditional techniques.

The interaction of deformation and metamorphism in slates

Abstract The distribution, microchemistry and internal structure of phases present in a slate are reported and used as a basis for a discussion of the interaction between deformation and metamorphism in slates. The study reveals details of the interactions between mechanical and chemical processes involved in slaty cleavage evolution. Evidence for the involvement of mechanical rotation, solution and crystallisation, recrystallisation and metamorphic reactions is presented and amalgamated into a model of cleavage development. The model involves a synchronous variation in the type, location and rate of cleavage evolution processes and a change in the importance of particular processes during the total history. The early stages of cleavage development are dominated by mechanical rotation associated with crenulation and possibly accompanied by grain boundary sliding and solution processes. Later stages of cleavage evolution are more heterogeneous and occur by a complex interaction of deformation and metamorphic growth processes which are concentrated at the interfaces between domains generated earlier in the strain history. The variations in grain chemistry and orientation together with changes in the strain rate (or stress level) are suggested to control the different deformation behaviour of different grains along these strain accommodation zones and to dictate whether grains bend, kink, dissolve, recrystallise or react and undergo growth. Evidence for the involvement of reactions, ranging from ionic exchange to crystallisation from solution, and solid state reordering is presented and the influence of deformation on the location and rates of these reactions discussed. Approximately ten potential reactions are involved in the cleavage evolution of the slate studied. The model presented incorporates these reactions into the deformation processes and accounts for the concentration of phengite and iron-poor chlorites in to one microstructural domain and paragonite, quartz and Fe-rich chlorites into the other domain. Two transformations appear to be fundamental in the slate studied: 1. (1) the transformation of illite to phengite 2. (2) the transformation of Fe-rich chlorite to Fe-poor chlorites, and both can be related to particular responses of grains to the reorientation processes at domain interfaces.

Solvent reordering of low lying triplet states in some aromatic carbonyls

Various parameters of the phosphorescent state of chromone, 4-chromanone and 3′,4′-dimethylacetophenone were examined in solvents of very different polarities. Phenomena examined were phosphorescence emission and excitation spectra, polarized phosphorescence spectra, phosphorescence lifetimes, singlet-triplet absorption under oxygen pressure, and EPR spectra of the triplet state. Analysis of the combined data from these studies indicate that low lying n,π * and π,π * triplet states of chromone and 3′,4′ dimethylacetophenone are nearly iso-energetic, very strongly mixed, and can be reordered by changing solvents. No such reordering of states was indicated for 4-chromanone, suggesting a somewhat greater energy gap between the n,π * and π,π * states.