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The weakly-bound molecular clusters (D₂O)₂–CO and (D₂O)₃–CO are observed in the C–O stretch fundamental region (≈2150 cm−1), and their rotationally-resolved infrared spectra yield precise rotational parameters. The corresponding H2O clusters are also observed, but their bands are broadened by predissociation, preventing detailed analysis. The rotational parameters are insufficient in themselves to determine cluster structures, so ab initio calculations are employed, and good agreement between the experiment and theory is found for the most stable cluster isomers, yielding the basic cluster geometries as well as confirming the assignments to (D₂O)₂–CO and (D₂O)₃–CO. The trimer, (D₂O)₂–CO, has a near-planar geometry with one D atom from each D₂O slightly out of the plane. The tetramer, (D₂O)₃–CO, has the water molecules arranged in a cyclic quasi-planar ring similar to the water trimer, with the carbon monoxide located ‘above’ the ring and roughly parallel to its plane. The tunneling effects observed in the free water dimer and trimer are quenched by the presence of CO. The previously observed water–CO dimer together with the trimer and tetramer reported here represent the first three steps in the solvation of carbon monoxide.

We report observation of new infrared bands of (CS₂)₂ and (CS₂)₃ in the region of the CS₂ ν1 + ν₃ combination band (at 4.5 µm) using a quantum cascade laser. The complexes are formed in a pulsed supersonic slit-jet expansion of a gas mixture of carbon disulfide in helium. We have previously shown that the most stable isomer of (CS₂)₂ is a cross-shaped structure with D₂d symmetry and that for (CS₂)₃ is a barrel-shaped structure with D₃ symmetry. The dimer has one doubly degenerate infrared-active band in the ν₁ + ν₃ region of the CS₂ monomer. This band is observed to have a rather small vibrational shift of −0.844 cm−1. We expect one parallel and one perpendicular infrared-active band for the trimer but observe two parallel bands and one perpendicular band. Much larger vibrational shifts of −8.953 cm−1 for the perpendicular band and −8.845 cm−1 and +16.681 cm−1 for the parallel bands are observed. Vibrational shifts and possible vibrational assignments, in the case of the parallel bands of the trimer, are discussed using group theoretical arguments.

We report observation of new infrared bands of (CS2)2 and (CS2)3 in the region of the CS2 {\nu}1+ {\nu}3 combination band (at 4.5 cm-1) using a quantum cascade laser. The complexes are formed in a pulsed supersonic slit-jet expansion of a gas mixture of carbon disulfide in helium. We have previously shown that the most stable isomer of (CS2)2 is a cross-shaped structure with D2d symmetry and that for (CS2)3 is a barrel-shaped structure with D3 symmetry. The dimer has one doubly degenerate infrared-active band in the {\nu}1+ {\nu}3 region of the CS2 monomer. This band is observed to have a rather small vibrational shift of -0.846 cm-1. We expect one parallel and one perpendicular infrared-active band for the trimer but observe two parallel and one perpendicular bands. Much larger vibrational shifts of -8.953 cm-1 for the perpendicular band and -8.845 cm-1 and +16.681 cm-1 for the parallel bands are observed. Vibrational shifts and possible vibrational assignments, in the case of the parallel bands of the trimer, are discussed using group theoretical arguments., Comment: 24 pages, 5 figures and 2 tables

Infrared spectra of the CO₂─CO dimer are observed in the carbon monoxide CO stretch region (≈2150 cm⁻¹). Combination bands yield the first experimental determinations of intermolecular mode frequencies for the planar T-shaped C-bonded form (‘isomer 1’): 24.34 cm ⁻¹ for the in-plane CO rock and 43.96 cm ⁻¹ for the out-of-plane CO rock. These values are significantly higher than the analogous modes of the O-bonded form (‘isomer 2’), previously determined to be 14.19 and 22.68 cm ⁻¹, respectively. New results are also reported for both isomers of the¹²C¹⁸O₂-substituted form of the dimer. Weak ‘satellite bands’ observed for both isomers are tentatively assigned to the trimer He─CO₂─CO.

Infrared spectra in the carbon monoxide CO stretch region (≈2150 cm-1) are assigned to the previously unobserved O-bonded form of the CO2-CO dimer ("isomer 2"), which has a planar T-shaped structure like that of the previously observed C-bonded form ("isomer 1"), but with the CO rotated by 180°. The effective center of mass intermolecular distances are 3.58 Å for isomer 2 as compared to 3.91 Å for isomer 1. In addition to the fundamental band, two combination bands are observed for isomer 2, yielding values for two intermolecular vibrational modes: 14.19 cm-1 for the in-plane CO bend and 22.68 cm-1 for the out-of-plane bend.

While, prima facie, virtue/credit approaches in epistemology would appear to be in tension with distributed/extended approaches in cognitive science, Pritchard (2010) has recently argued that the tension here is only apparent, at least given a weak version of distributed cognition, which claims merely that external resources often make critical contributions to the formation of true belief, and a weak virtue theory, which claims merely that, whenever a subject achieves knowledge, his cognitive agency makes a significant contribution to the formation of a true belief. But the significance of the role played by the subject's cognitive agency in distributed cognitive systems is in fact highly variable: at one extreme, formation of a true belief seems clearly to be significantly creditable to the subject's agency; at the other extreme, however, the subject's agency plays such a peripheral role that it is at best unclear whether it should receive significant credit for formation of a true belief. The compatibility of distributed cognition and virtue epistemology thus turns on what it takes for a contribution to the formation of true belief to count as significant. This article argues that the inevitable vagueness of this notion suggests retreating from virtue epistemology to a form of process reliabilism and explores the prospects for a distributed reliabilist epistemology designed to fit smoothly with distributed cognition. In effect, distributed reliabilism radicalizes Goldberg's recent extended reliabilist view (Goldberg) by allowing the process the reliability of which determines the epistemic status of a subject's belief to extend to include not only processing performed by other subjects but also processing performed by non-human technological resources.

Spectra of Ne─C₂D₄ and Ar─C₂D₄ are studied in the ν11 fundamental band region of C₂D₄ (≈2200 cm⁻¹) using a tuneable quantum cascade laser to probe a pulsed supersonic slit jet expansion. The spectra are those of perpendicular bands of near-prolate asymmetric rotors, but with a doubling of transitions due to tunneling. These tunneling splittings are due to hindered internal rotation of C₂D₄ around its C─C axis, and are more prominent for Ne─C₂D₄ than for Ar─C₂D₄. The analysis yields the first direct measurement of the A rotational constants for these complexes, and shows that the vibrational shifts are very small (

Darwinian Theory depicts life as being overwhelmingly consumed by a fight for survival in a hostile environment. However, from a thermodynamic perspective, life is a dynamic, out of equilibrium process, stabilizing and coevolving in concert with its abiotic environment. The living component of the biosphere of greatest mass, the plants and cyanobacteria, are involved in the transpiration of vast amounts of water. Transpiration is part of the global water cycle, and it is this cycle that distinguishes Earth from its apparently life barren neighboring planets, Venus and Mars. The water cycle, including the absorption of sunlight in the biosphere, is by far the greatest entropy producing process occurring on Earth. Life, from this perspective, can therefore be viewed as performing an important thermodynamic function; acting as a dynamic catalyst by aiding process such as the water cycle, hurricanes, and ocean and wind currents to produce entropy. The role of animals in this view is that of unwitting but dedicated servants of the plants and cyanobacteria, helping them to grow and to spread into initially inhospitable areas., Comment: 19 pages, no figures, new evidences, new calculations, new references

The response of ecosystems to perturbations is considered from a thermodynamic perspective by acknowledging that, as for all macroscopic systems and processes, the dynamics and stability of ecosystems is subject to definite thermodynamic law. For open ecosystems, exchanging energy, work, and mass with the environment, the thermodynamic criteria come from non-equilibrium or irreversible thermodynamics. For ecosystems during periods in which the boundary conditions may be considered as being constant, it is shown that criteria from irreversible thermodynamic theory are sufficient to permit a quantitative prediction of ecosystem response to perturbation. This framework is shown to provide a new perspective on the population dynamics of real ecosystems. The formalism is applied to the problem of the population oscillations of the southern pine beetle., Comment: 25 pages, 4 figures

Positive pion absorption was studied in an almost 4p geometry allowing simultaneous measurements of various charge and neutral multiplicities. Total absorption cross sections and its decomposition into the most important channels is determined. The results are presented for N, Ar and Xe nuclei at incident pion energies of 118, 162 and 239 MeV. The role of multinucleon emission in the absorption process is emphasized.

Positive pion absorption was studied in an almost 4π geometry allowing simultaneous measurements of various charge and neutral multiplicities. Total absorption cross sections and its decomposition into the most important channels is determined. The results are presented for N, Ar and Xe nuclei at incident pion energies of 118,162 and 239 MeV. The role of multinucleon emission in the absorption process is emphasized., Proučava se pionska apsorpcija s blizu 4π detekcijom koja dozvoljava istovremeno mjerenje raznih nabojskih i neutralnih višestrukosti. Određuju se ukupni udarni presjeci i njihovo razlaganje u najvažnije kanale. Predstavljaju se rezultati za jezgre N, Ar i Xe na energijama 118,162 i 239 MeV. Ističe se uloga višenukleonske emisije u procesu apsorpcije.

Pion absorption in gasseus targets summary approach.

Results from a measurement of the reaction 2H(+,pp)  at T+ = 239 MeV are presented. Because two protons were detected, the measurement was sensitive to events which involved both nucleons in a substantial way. Differential distributions are compared to the predictions of simple models. An integrated cross section for SCX (single charge exchange), with the emmision of two protons each with kinetic energy >25 MeV, is presented

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A Large Acceptance Detector System (LADS) has been designed and built at the Paul Scherrer Institute to study multiparticle final states following pion-nucleus absorption. It consists of a 28-sector cylinder of plastic scintillators of 1.6 m active length and 1.4 m diameter, two cylindrical wire chambers, and two 14-sector plastic scintillator end-caps which close each end. The nearly 4pi solid angle coverage of this detector minimizes uncertaities associated with extrapolations over unmeasured regions of phase space. The design and the performance of the LADS detector are presented.

Measurements have been made of pi+ absorption on He3 at T_pi+ = 118, 162, and 239 MeV using the Large Acceptance Detector System (LADS). The nearly 4pi solid angle coverage of this detector minimizes uncertainties associated with extrapolations over unmeasured regions of phase space. The total absorption cross section is reported. In addition, the total cross section is divided into components in which only two or all three nucleons play a significant role in the process. These are the first direct measurements of the total and three nucleon absorption cross sections., 8 pages, LaTeX. 3 figures, anonymous ftp MITLNS.MIT.EDU, cd LADS. Submitted to PRL. PSI-PR-94-11 (Paul Scherrer Institute) and LNS 94-56 (MIT Lab. for Nucl. Sci.)

As applied to semantic memory, the idea that memory is preservative in this sense possesses a great deal of plausibility. This is the kind of memory that simply involves the retention of knowledge of propositions such as 'Paris is the capital of France', or 'Caesar crossed the Rubicon'. In order to acquire and retain such knowledge, the subject must already be able to grasp the concepts that figure in the relevant propositions; otherwise she won't understand and be able to commit them to memory in the first place. Adopting a conception of episodic memory as epistemically generative, thus, provides at least no straightforward strategy for fleshing out the Dependency Thesis. Memory is likely to play a prominent role in the anti-realist's account of our grasp of the meaning of the past tense, as a paradigmatic example of something that puts us in a position to verify sentences in the past tense.

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