bluuebunny/crossref_metadata_2025 huggingface dataset:
Why Smart People Can Be So Foolish
Authors: Sternberg Robert J.
Published: September 2004

Not only stupid people act foolishly: Smart people can act foolishly by virtue of their thinking they are too smart to do so. Such people tend to act foolishly through the commission of one or more of five cognitive fallacies: (1) unrealistic optimism, whereby they believe that they are so smart that they can do whatever they want and not worry about it; (2) egocentrism, whereby they focus on themselves and what benefits them while discounting or even totally ignoring their responsibilities to others; (3) omniscience, whereby they believe they know everything, instead of knowing what they do not know; (4) omnipotence, whereby they believe they can do whatever they want because they are all-powerful; and (5) invulnerability, whereby they believe that they will get away with whatever they do, no matter how inappropriate or irresponsible it may be. The antidote to foolishness is wisdom. The balance theory of wisdom proposes that people are wise to the extent they apply their intelligence, creativity, and wisdom toward a common good by balancing their own interests, the interests of others, and the interests of organizations or other supra-individual entities; over the long and short terms; through the infusion of values; to adapt to, shape, and select environments.
Mothers' Nonauthoritarian Child-Rearing Attitudes in Early Childhood and Children's Adult Values
Authors: Flouri Eirini
Published: September 2004

This study used longitudinal data from the 1970 British Cohort Study (BCS70) to examine links between mothers' nonauthoritarian child-rearing attitudes, assessed when children were aged 5, and children's values at age 30 (antiracism, right-wing beliefs, support for authority, support for traditional marital values, support for working mothers, political cynicism, environmentalism, and support for the work ethic). Mothers' nonauthoritarian child-rearing attitudes were positively related to cohort members' antiracism and environmentalism, and were negatively related to cohort members' support for authority, support for traditional marital values, and support for the work ethic even after mothers' values (liberalism and support for working mothers) and known early (parental social class, socioeconomic disadvantage, family structure, general ability, and emotional and behavioral problems) and concurrent (social class, partner status, religiosity, self-reported physical health, and depressed mood) confounding factors were controlled for.
Men Who Abuse Drugs and Their Experience of Loneliness
Authors: Orzeck Tricia , Rokach Ami
Published: September 2004

Loneliness is a prevailing experience particularly familiar to adolescents and young adults. It is a subjective experience, influenced by one's personality, life experiences, and situational variables. The present study examined the influence of drug cessation on the experience of loneliness. Drug abusers during their stay in detox centers were compared to drug abusers who were in a methadone maintenance program, and those two groups were again compared to a group of adults in the general population who are nonusers of drugs. A total of 304 participants from all three groups volunteered to answer a 30-item yes/no questionnaire, reflecting on their experience of loneliness and what it meant to them. The factors which compose the multidimensional loneliness experience are emotional distress, social inadequacy and alienation, growth and discovery, interpersonal isolation, and self-alienation. Results revealed significant differences between the scores of the three groups, however only the detox and the general population samples had significantly different subscale scores.
The History of the Psychology of Work and Organization in Czech and Slovak Industry
Authors: Paulík Karel
Published: September 2004

This article focuses on the application of the psychology of work and organization to the situation in the industrial areas of the former Czechoslovakia and neighboring Central European countries over the last eight decades. The psychology of work and organization in the country has passed through a series of changes, both favorable and unfavorable. The development of work and organizational psychology in Czechoslovakia can be divided into three stages according to certain features which characterize each stage: 1918-1945, 1945-1990, from 1990 to the present.
Searching for a New Vision and Professional Identity—The Slovenian Psychological Association 1999-2003
Authors: Rus Velko S. , Zupančič Agata , Podobnik Nuska
Published: September 2004

This article presents the structure, processes, climate, and culture of the Slovenian Psychological Association (SPA) in the period from 1999 to 2003. The contribution of the former leadership of the SPA to Slovenian psychology as a profession, science, and academic discipline is discussed. International promotion of the SPA is also covered, as are the following themes: law on psychological practice, Slovenian psychological congresses, financial affairs, some aspects of interpersonal relations, and activities related to the Euro-diploma.
Stress permutations: Three‐dimensional distinct element analysis accounts for a common phenomenon in brittle tectonics
Authors: Hu Jyr‐Ching , Angelier Jacques
Published: September 2004

Using three‐dimensional (3‐D) distinct element modeling, we explored a variety of simulations to characterize and interpret the stress permutations in brittle tectonics. Stress inversions of fault slip data or earthquake focal mechanisms often revealed such permutations. The main aim of our study is to produce simple, mechanically consistent 3‐D models that account for these switches between the principal stress axes σ1/σ2 or σ2/σ3. Even with simple boundary conditions the stress changes induced by variations in rheology are large enough to modify the local tectonic behavior and to produce permutations of principal stress axes. Rather than simple directional changes of stress axes, which exist but often remain limited, the relative variations in principal stress magnitudes are the major cause of permutations σ1/σ2 and σ2/σ3. In nature, permutations being left apart, the orientations of axes often remain tightly clustered. In our experiments we adopted a ratio Φ = (σ2 − σ3)/(σ1 − σ3) of 0.5, which makes permutations difficult (low Φ favors σ2/σ3 permutations, high Φ favors σ1/σ2 permutations), and we explored a variety of tectonic situations involving compression, extension, and strike slip. Our experiments indicate that the major causes of stress permutations are the heterogeneity of the brittle deformation (e.g., intact rock massifs between heavily faulted deformation zones) and the anisotropy of the mechanical properties that results from fracturing and faulting, which concur to modify the mechanical balance inside the analyzed volume and to produce stress permutations. Our models show that contrasts and anisotropy in rock properties favor stress permutations. Of major importance is the existence of relatively resistant zones at tips of the deformed zones, acting as channels where stress concentrates and switches occur. Because in nature such zones move in time and space, it is not surprising that stress permutations are so pervasive.
Seismic heterogeneous structure in the lowermost mantle beneath the southwestern Pacific
Authors: Kito Tadashi , Krüger Frank , Negishi Hiroaki
Published: September 2004

The P and S wave velocity structure of the D″ layer beneath the southwestern Pacific was investigated by using short‐period data from 12 deep events in the Tonga‐Fiji region recorded by the J‐Array and the Hi‐net (two large‐aperture seismic arrays) in Japan. Reflected wave beam forming (RWB) and a migration method were used to extract weak signals originating from heterogeneities in the lowermost mantle. In order to acquire high resolution a double‐array method was applied to the data. The results of the RWB method indicate that seismic energy is reflected at discontinuities near the depths of 2520 and 2650 km, which have a negative P wave velocity contrast of 1% at the most. In addition, there is a positive seismic discontinuity at a depth of 2800 km. In the case of the S wave, reflected energy is produced almost at the same depth (2550 km depth). An apparent depth shift (50 km) of the discontinuity at the depth of 2850 km may indicate that the S wave velocity reduction in the lowermost mantle is ∼2–3 times stronger than that of P. A two‐dimensional cross section, constructed with the RWB method, suggests that the observed discontinuities can be characterized as intermittent lateral heterogeneities whose lateral extent is a few hundred kilometers. The migration shows weak evidence of scattering objects which belong to the seismic discontinuities detected by the RWB method. These anomalous structures may represent a part of hot plume generated beneath the southwestern Pacific in the lowermost mantle.
Temporal variation in the shear wave anisotropy detected using the Accurately Controlled Routinely Operated Signal System (ACROSS)
Authors: Ikuta Ryoya , Yamaoka Koshun
Published: September 2004

Temporal variation in shear wave anisotropy was detected in a monitoring experiment using an accurately controlled, routinely operated signal system (Accurately Controlled Routinely Operated Signal System, ACROSS). We conducted an experiment that lasted for 15 months between January 2000 and April 2001 at a site near the Nojima fault, which ruptured during the 1995 Kobe earthquake (Mw 7.2) [Yamaoka et al., 2001; Ikuta et al., 2002]. Two vibration sources that generated 2 × 105 N with centrifugal force, which were firmly fixed on the ground, were used to emit elastic waves. Seismometers deployed at the bottom of 800‐m‐ and 1700‐m‐deep boreholes near the ACROSS sources were used to receive the signal. We extracted small temporal changes in the travel time of the P and S wave by calculating cross‐spectral density among the records every hour. During the experiment, sudden delays in travel times for the S wave were observed when the 2000 western Tottori earthquake (Mw 6.6) and the 2001 Geiyo earthquake (Mw 6.4) occurred. Their epicenters were 165 and 215 km away from the site, respectively. The travel times of the S waves between the surface and the bottom of 800‐m‐deep borehole abruptly slowed down and gradually speeded up with each earthquake. The delay in S was about 0.4% and 0.1% of the absolute travel time for the western Tottori earthquake and the Geiyo earthquake, respectively. The delays were polarized in a direction perpendicular to the Nojima fault in both cases. This indicates that the density of the cracks parallel to the fault increased in association with the earthquakes. These cracks can be regarded as opened by the increase in pore pressure. The small changes in P wave velocities support this interpretation. An additional experiment to determine the static anisotropy revealed that there was a preferred orientation of the cracks that was enhanced with the strong shaking of earthquakes in the middle distance.
Influence of equatorial diatom processes on Si deposition and atmospheric CO2 cycles at glacial/interglacial timescales
Authors: Dugdale R. C. , Lyle M. , Wilkerson F. P. , Chai F. , Barber R. T. , Peng T.‐H.
Published: September 2004

The causes of the glacial cycle remain unknown, although the primary driver is changes in atmospheric CO2, likely controlled by the biological pump and biogeochemical cycles. The two most important regions of the ocean for exchange of CO2 with the atmosphere are the equatorial Pacific and the Southern Ocean (SO), the former a net source and the latter a net sink under present conditions. The equatorial Pacific has been shown to be a Si(OH)4‐limited ecosystem, a consequence of the low source Si(OH)4 concentrations in upwelled water that has its origin in the SO. This teleconnection for nutrients between the two regions suggests an oscillatory relationship that may influence or control glacial cycles. Opal mass accumulation rate (MAR) data and δ15N measurements in equatorial cores are interpreted with predictions from a one‐dimensional Si(OH)4‐limited ecosystem model (CoSINE) for the equatorial Pacific. The results suggest that equatorial Pacific surface CO2 processes are in opposite phase to that of the global atmosphere, providing a negative feedback to the glacial cycle. This negative feedback is implemented through the effect of the SO on the equatorial Si(OH)4 supply. An alternative hypothesis, that the whole ocean becomes Si(OH)4 poor during cooling periods, is suggested by low opal MAR in cores from both equatorial and Antarctic regions, perhaps as a result of low river input. terminations in this scenario would result from blooms of coccolithophorids triggered by low Si(OH)4 concentrations.
Variability and potential sources of predictability of North American runoff
Authors: Maurer Edwin P. , Lettenmaier Dennis P. , Mantua Nathan J.
Published: September 2004

Understanding the space‐time variability of runoff has important implications for climate because of the linkage of runoff and evapotranspiration and is a practical concern as well for the prediction of drought and floods. In contrast to many studies investigating the space‐time variability of precipitation and temperature, there has been relatively little work evaluating climate teleconnections of runoff, in part because of the absence of data sets that lend themselves to commonly used techniques in climate analysis like principal components analysis. We examine the space‐time variability of runoff over North America using a 50‐year retrospective spatially distributed data set of runoff and other land surface water cycle variables predicted using a calibrated macroscale hydrology model, thus avoiding some shortcomings of past studies based more directly on streamflow observations. We determine contributions to runoff variability of climatic teleconnections, soil moisture, and snow for lead times up to a year. High and low values of these sources of predictability are evaluated separately. We identify patterns of runoff variability that are not revealed by direct analysis of observations, especially in areas of sparse stream gauge coverage. The presence of nonlinear relationships between large‐scale climate changes and runoff pattern variability, as positive and negative values of the large‐scale climate indices rarely show opposite teleconnections with a runoff pattern. Dry soil moisture anomalies have a stronger influence on runoff variability than wet soil. Snow, and more so soil moisture, in many locations enhance the predictability due to climatic teleconnections.
An 8–10 Ma tectonic event on the Cocos Plate offshore Costa Rica: Result of Cocos Ridge collision?
Authors: Silver Eli , Costa Pisani Patrizia , Hutnak Michael , Fisher Andrew , DeShon Heather , Taylor Barrie
Published: September 2004

Upper oceanic crust within the Cocos Plate offshore northwestern Costa Rica is dominated by sill intrusions of various ages, recognized regionally as smooth, high amplitude seismic reflections at the base of the sedimentary sequence and locally by dolerites and microgabbros recovered by drilling. Earlier interpretation of seafloor magnetic anomalies documented a set of spreading ridge jumps at 19.5 and 14.5 Ma, continuing to the present. In addition to these events, we present evidence for a widespread tectonic event in the period 8–10 Ma displayed in reflection seismic data recorded during the Ticoflux 1 and 2 experiments and dated by seismic correlation to ODP Site 1039. The 8–10 Ma events may have been triggered by collision of the Cocos Ridge at this time and facilitated by widespread sill intrusion associated with the Galapagos Hot Spot.
Shear‐wave splitting in Ethiopia: Precambrian mantle anisotropy locally modified by Neogene rifting
Authors: Gashawbeza Ewenet M. , Klemperer Simon L. , Nyblade Andrew A. , Walker Kristoffer T. , Keranen Katie M.
Published: September 2004

Twenty‐six broadband seismic stations in an areal array spanning 500 × 500 km across Ethiopia were used for shear‐wave splitting studies. Our results show small‐to‐moderate delay times (0.5–1.7s) with fast‐polarization azimuths sub‐parallel to the orientation of the East African Rift (NNE‐SSW) and also to the Proterozoic tectonic fabric across the entire studied area. Our results imply Ethiopian upper‐mantle anisotropy is controlled largely by the Proterozoic accretion of the Mozambique belt, with possible minor effects within the rift due to aligned cracks or melt pockets parallel to the rift axis. Our observations are not consistent with anisotropy created by asthenospheric flow parallel either to the Cenozoic extension direction (NW‐SE) or to the modern absolute plate motion direction (NNW‐SSE), or to asthenospheric radial flow from the “Afar” plume.
Cloud‐free shortwave aerosol radiative effect over oceans: Strategies for identifying anthropogenic forcing from Terra satellite measurements
Authors: Christopher Sundar A. , Zhang Jianglong
Published: September 2004

Using the Single Scanner Footprint (SSF) data that combines the multi‐spectral Moderate Resolution Imaging Spectroradiometer (MODIS) cloud and aerosol products with the Clouds and the Earth's Radiant Energy System (CERES) top of atmosphere broadband radiative fluxes, we first provide observational estimates of the instantaneous cloud‐free shortwave aerosol radiative forcing (SWARF) over the global oceans. Different from our previous research, we corrected for both the sample biases and the diurnal cycle of SWARF and the cloud‐free diurnally averaged SWARF is −5.3 ± 1.7 Wm−2, a value that is consistent with previous studies. Furthermore, we partition the CERES shortwave flux as a function of MODIS aerosol optical thickness and the fraction of fine mode aerosol to the total aerosol optical depth (η). Since η is related to particle size and is a good surrogate for aerosol type, we present strategies for estimating the radiative forcing of anthropogenic aerosols from MODIS and CERES measurements that is important for quantifying the climate forcing of aerosols.
Pacific Ocean circulation rebounds
Authors: McPhaden Michael J. , Zhang Dongxiao
Published: September 2004

Recent observations indicate that the shallow meridional overturning circulation in the tropical Pacific Ocean has rebounded since 1998, following 25 years of significantly weaker flow. Convergence of cold interior ocean pycnocline water towards the equator increased to 24.1 ± 1.8 × 106 m3 s−1 during 1998–2003 from a low of 13.4 ± 1.6 × 106 m3 s−1 during 1992–98. Intensified circulation led to the development of anomalously cool tropical Pacific sea surface temperatures, which may have affected Pacific marine ecosystems and global climate. The abruptness of the rebound also obscures presumed anthropogenic warming trends in the instrumental temperature record of the tropical Pacific.
Role of electron temperature anisotropy in the onset of magnetic reconnection
Authors: Karimabadi H. , Daughton W. , Quest K. B.
Published: September 2004

Predictions of tearing saturation in a neutral sheet range from minute amplitude to explosive growth. It is shown that in 2D, single island tearing saturates at very small amplitudes due to preferential electron heating in the parallel direction. However, the presence of multiple unstable modes allows the system to get past the stabilization and grow to ion scales. In 3D there are two current aligned instabilities that can affect the tearing mode. One is the Weibel instability driven by electron anisotropy T⊥e/T∥e < 1 and the other is the lower hybrid drift instability (LHDI). The Weibel instability is shown to at most increase the single island tearing saturation amplitude up to the singular layer thickness. On the other hand, recent studies suggest that LHDI can affect tearing through the generation of T⊥e/T∥e > 1 within the current layer. In this limit, the parallel Weibel instability merges with tearing to give rise to anisotropic tearing, which becomes the dominant electron anisotropy driven mode with a broad angular spectrum. The level of electron anisotropy generated by the LHDI can significantly enhance the tearing growth rate and extend the spectrum to very short wavelength which expedites the transition to large scale reconnection. Thus LHDI's main contribution to reconnection onset is not through anomalous resistivity but through its effect on tearing mode.
Variations in the Earth's oblateness during the past 28 years
Authors: Cheng Minkang , Tapley Byron D.
Published: September 2004

Analysis of satellite laser ranging (SLR) data indicates that the Earth's dynamic oblateness (J2) has undergone significant variations during the past 28 years. The dominant signatures in the observed variations in J2 are (1) a secular decrease with a rate of approximately −2.75 × 10−11 yr−1, (2) seasonal annual variations with a mean amplitude of 2.9 × 10−10, (3) significant interannual variations with timescales of 4–6 years, and (4) a variation with period of ∼21 years and an amplitude of ∼1.4 × 10−10 with minimum in December 1988. Two large interannual variations are related to the strong El Niño‐Southern Oscillation events during the periods of 1986–1991 and 1996–2002, and it appears that another interannual cycle may have started in late 2002. The superposition of the decadal variation on the interannual signal makes the J2 fluctuation appear to be anomalously large during the 1996–2002 period. Contemporary models of the mass redistributions in the atmosphere, ocean, and surface water can explain a major part of the 4‐ to 6‐year fluctuations. However, the cause of the decadal variation remains unknown.
Influence of the Southern Annular Mode on the sea ice–ocean system
Authors: Lefebvre W. , Goosse H. , Timmermann R. , Fichefet T.
Published: September 2004

The global sea ice–ocean model ORCA2‐LIM, driven by the NCEP/NCAR (National Centers for Environmental Prediction‐National Center for Atmospheric Research) reanalysis daily 2‐m air temperatures and 10‐m winds and by monthly climatologies for precipitation, cloud cover, and relative humidity, is used to investigate the impact of the Southern Annular Mode (SAM) on the Antarctic sea ice‐ocean system. Our results suggest that the response of the circumpolar Southern Ocean consists of an annular and a non‐annular component. For the sea ice cover, the non‐annular component seems to be the most important. The annular component strongly affects the overall patterns of the upper ocean circulation. When the SAM is in its positive phase, a northward surface Ekman drift, a downwelling at about 45°S, and an upwelling in the vicinity of the Antarctic continent are simulated. The non‐annular component has a significant impact at the regional scale, especially in the Weddell, Ross, Amundsen, and Bellingshausen Seas. In those regions, the pressure pattern associated with the SAM induces meridional winds which advect warmer air in the Weddell Sea and around the Antarctic Peninsula and colder air in the Amundsen and Ross Seas. This implies a dipole response of sea ice to the SAM, with on average a decrease in ice area in the Weddell Sea and around the Antarctic Peninsula and an increase in the Ross and Amundsen Seas during years with a high SAM index. The long‐term trend in the observed sea ice area does not appear to be related to the trend in the SAM index.
Iron control of past productivity in the coastal upwelling system off the Atacama Desert, Chile
Authors: Dezileau Laurent , Ulloa Osvaldo , Hebbeln Dierk , Lamy Frank , Reyss Jean‐Louis , Fontugne Michel
Published: September 2004

Biogenic opal and organic carbon vertical rain rates in sediment cores reveal a strong cyclicity in the productivity of the upwelling system off presently arid northern Chile during the last 100,000 years. Changes in productivity are found to be in phase with the precessional cycle (∼20,000 years) and with inputs of iron from the continent. During austral summer insolation maxima, increased precipitation and river runoff in the region appear to have brought high inputs of iron, mainly from the Andes, to the coastal ocean enhancing primary productivity there. We interpret our results as providing evidence for iron control of past productivity in this upwelling system and for a tight link between productivity and orbital forcing at midlatitudes.
Dynamics of evapotranspiration in semiarid grassland and shrubland ecosystems during the summer monsoon season, central New Mexico
Authors: Kurc Shirley A. , Small Eric E.
Published: September 2004

To understand the coupled water and energy cycles in semiarid environments, we measured temporal fluctuations of evapotranspiration (ET) and identified key sources of the observed variability. Flux measurements are made using the Bowen ratio method, accompanied by measurements of soil moisture and radiation. We present data from semiarid grassland and shrubland sites, situated within 2 km of each other in New Mexico. The study includes three summer monsoon seasons. Midday available energy (Qa) is higher at the grassland than at the shrubland by 20% or 70 W m−2 because of differences in net radiation (Rn) and soil heat flux (G). At both sites, midday evaporative fraction and daily ET are strongly correlated with surface soil moisture (θ0–5cm) but poorly correlated with water content at greater depths or averaged throughout the entire root zone. The sensitivity of EF to θ0–5cm is 30% lower at the grassland site. The differences in Qa and EF cancel, yielding similar time series of ET at the two sites. Decreases in θ0–5cm, ET, and EF following rainfall events are rapid: exponential time constants are less than 3 days. With the exception of the largest storms, infiltration following rainfall events only wets the top 10 cm of soil. Therefore the surface soil layer is the primary reservoir for water storage and source for ET during the monsoon season, suggesting that direct evaporation is a large component of ET. Given these results, predicting ET based on root zone–averaged soil moisture is inappropriate in the semiarid environments studied here.
Ab initio study of AmCl+: f–f spectroscopy and chemical binding
Authors: Tilson Jeffrey L. , Naleway Conrad , Seth Michael , Shepard Ron , Wagner Albert F. , Ermler Walter C.
Published: September 2004

A valence full configuration interaction study with a polarized double-ζ quality basis set has been carried out for the lowest 49 electronic states of AmCl+. The calculations use a pseudopotential treatment for the core electrons and incorporate a one-electron spin–orbit interaction operator. Electrons in the valence s, p, d, and f subshells were included in the active space. The resulting electronic potential energy curves are largely repulsive. The chemical bonding is ionic in character with negligible participation of 5f electrons. The molecular f–f spectroscopy of AmCl+ arises essentially from an in situ Am2+ core with states slightly redshifted by the presence of chloride ion. Am++Cl asymptotes which give rise to the few attractive potential energy curves can be predicted by analysis of the f–f spectroscopy of isolated Am+ and Am2+. The attractive curves have substantial binding energies, on the order of 75–80 kcal/mol, and are noticeably lower than recent indirect measurements on the isovalent EuCl+. An independent empirical correlation supports the predicted reduction in AmCl+ binding energy. The energies of the repulsive curves are strongly dependent on the selection of the underlying atomic orbitals while the energies of the attractive curves do not display this sensitivity. The calculations were carried out using our recently developed parallel spin–orbit configuration interaction software.
Excitations in photoactive molecules from quantum Monte Carlo
Authors: Schautz Friedemann , Buda Francesco , Filippi Claudia
Published: September 2004

Despite significant advances in electronic structure methods for the treatment of excited states, attaining an accurate description of the photoinduced processes in photoactive biomolecules is proving very difficult. For the prototypical photosensitive molecules, formaldimine, formaldehyde, and a minimal protonated Schiff base model of the retinal chromophore, we investigate the performance of various approaches generally considered promising for the computation of excited potential energy surfaces. We show that quantum Monte Carlo can accurately estimate the excitation energies of the studied systems if one constructs carefully the trial wave function, including in most cases the reoptimization of its determinantal part within quantum Monte Carlo. While time-dependent density functional theory and quantum Monte Carlo are generally in reasonable agreement, they yield a qualitatively different description of the isomerization of the Schiff base model. Finally, we find that the restricted open shell Kohn-Sham method is at variance with quantum Monte Carlo in estimating the lowest-singlet excited state potential energy surface for low-symmetry molecular structures.
Normal mode analysis using the driven molecular dynamics method. II. An application to biological macromolecules
Authors: Kaledin Martina , Brown Alex , Kaledin Alexey L. , Bowman Joel M.
Published: September 2004

The driven molecular-dynamics (DMD) method, recently proposed by Bowman, Zhang, and Brown [J. Chem. Phys. 119, 646 (2003)], has been implemented into the TINKER molecular modeling program package. The DMD method yields frequencies and normal modes without evaluation of the Hessian matrix. It employs an external harmonic driving term that can be used to scan the spectrum and determine resonant absorptions. The molecular motions, induced by driving at resonant frequencies, correspond to the normal-mode vibrations. In the current work we apply the method to a 20-residue protein, Trp-cage, that has been reported by Neidigh, Fesinmeyer, and Andersen [Nature Struct. Biol. 9, 425 (2002)]. The structural and dynamical properties of this molecule, such as B-factors, root-mean square fluctuations, anisotropies, vibrational entropy, and cross-correlations coefficients, are calculated using the DMD method. The results are in very good agreement with ones calculated using standard normal-mode analysis method. Thus, the DMD method provides a viable alternative to the standard Hessian-based method and has considerable potential for the study of large systems, where the Hessian-based method is not feasible.
Gold emissivities for hydrocode applications
Authors: Bowen C. , Wagon F. , Galmiche D. , Loiseau P. , Dattolo E. , Babonneau D.
Published: September 2004

The Radiom model [M. Busquet, Phys Fluids B 5, 4191 (1993)] is designed to provide a radiative-hydrodynamic code with non-local thermodynamic equilibrium (non-LTE) data efficiently by using LTE tables. Comparison with benchmark data [M. Klapisch and A. Bar-Shalom, J. Quant. Spectrosc. Radiat. Transf. 58, 687 (1997)] has shown Radiom to be inaccurate far from LTE and for heavy ions. In particular, the emissivity was found to be strongly underestimated. A recent algorithm, Gondor [C. Bowen and P. Kaiser, J. Quant. Spectrosc. Radiat. Transf. 81, 85 (2003)], was introduced to improve the gold non-LTE ionization and corresponding opacity. It relies on fitting the collisional ionization rate to reproduce benchmark data given by the Averroès superconfiguration code [O. Peyrusse, J. Phys. B 33, 4303 (2000)]. Gondor is extended here to gold emissivity calculations, with two simple modifications of the two-level atom line source function used by Radiom: (a) a larger collisional excitation rate and (b) the addition of a Planckian source term, fitted to spectrally integrated Averroès emissivity data. This approach improves the agreement between experiments and hydrodynamic simulations.
Infrared absorptions of the H2O⋯H2 complex trapped in solid neon
Authors: Forney Daniel , Jacox Marilyn E. , Thompson Warren E.
Published: September 2004

When a sample of neon to which have been added less than 1% each of H2 and H2O is deposited at 4.3 K, the infrared spectrum of the resulting solid includes an absorption by the vibrational fundamental of H2, which is normally infrared inactive. New absorptions are also associated with the vibrational fundamentals of the H2O in the sample. Similar results are obtained for deuterium-enriched samples. The new peaks are assigned to the van der Waals complex of H2O with H2. As has been found in earlier theoretical, gas-phase, and solid-state studies of this and closely related systems, the infrared absorptions arise principally from complexes involving ortho-H2, for which J=1.
The nucleation rate of crystalline ice in amorphous solid water
Authors: Safarik D. J. , Mullins C. B.
Published: September 2004

The kinetics of crystalline ice nucleation and growth in nonporous, molecular beam deposited amorphous solid water (ASW) films are investigated at temperatures near 140 K. We implement an experimental methodology and corresponding model of crystallization kinetics to decouple growth from nucleation and quantify the temperature dependence and absolute rates of both processes. Nucleation rates are found to increase from ∼3×1013 m−3 s−1 at 134 K to ∼2×1017 m−3 s−1 at 142 K, corresponding to an Arrhenius activation energy of 168 kJ/mol. Over the same temperature range, the growth velocity increases from ∼0.4 to ∼4 Å s−1, also exhibiting Arrhenius behavior with an activation energy of 47 kJ/mol. These nucleation rates are up to ten orders of magnitude larger than in liquid water near 235 K, while growth velocities are ≈109 times smaller. Crystalline ice nucleation kinetics determined in this study differ significantly from those reported previously for porous, background vapor deposited ASW, suggesting the nucleation mechanism is dependent upon film morphology.
Low-energy electron collisions with sulfur hexafluoride, SF6
Authors: Winstead C. , McKoy V.
Published: September 2004

We report calculated cross sections for elastic and electronically inelastic collisions of low-energy electrons with sulfur hexafluoride, SF6. Elastic cross sections are computed within the fixed-nuclei approximation, with polarization effects incorporated. Inelastic cross sections for nine low-lying states are computed in a few-channel approximation. We compare our cross sections to previous experimental and computational results where possible.
On the computation of space-time correlations by large-eddy simulation
Authors: He Guo-Wei , Wang Meng , Lele Sanjiva K.
Published: September 2004

The effect of subgrid-scale (SGS) modeling on velocity (space-) time correlations is investigated in decaying isotropic turbulence. The performance of several SGS models is evaluated, which shows superiority of the dynamic Smagorinsky model used in conjunction with the multiscale large-eddy simulation (LES) procedure. Compared to the results of direct numerical simulation, LES is shown to underpredict the (un-normalized) correlation magnitude and slightly overpredict the decorrelation time scales. This can lead to inaccurate solutions in applications such as aeroacoustics. The underprediction of correlation functions is particularly severe for higher wavenumber modes which are swept by the most energetic modes. The classic sweeping hypothesis for stationary turbulence is generalized for decaying turbulence and used to analyze the observed discrepancies. Based on this analysis, the time correlations are determined by the wavenumber energy spectra and the sweeping velocity, which is the square root of the total energy. Hence, an accurate prediction of the instantaneous energy spectra is most critical to the accurate computation of time correlations.
Transient two-dimensional infrared spectroscopy: Exploring the polarization dependence
Authors: Bredenbeck Jens , Helbing Jan , Hamm Peter
Published: September 2004

We present a general expression for the polarization dependence of transient two-dimensional IR spectroscopy (T2D-IR), a technique designed to measure 2D-IR spectra of transient species. T2D-IR is a UV pump narrowband-IR-pump broadband-IR-probe experiment of fifth order in the laser field which involves up to three different transition dipole moments. The UV pulse adds an additional degree of freedom in polarization as compared to 2D-IR spectroscopy and increases the versatility of signal manipulation and the potential structural information content of the signals. The polarization conditions leading to a maximum of structural information are discussed. Important special cases of polarization conditions are formulated. The application of polarization selectivity is demonstrated for different types of T2D-IR experiments on photo triggered metal-to-ligand charge transfer in the model system [Re(CO)3(dmbpy)Cl].
Hyperfine structures of the 2 3Σg+, 3 3Σg+, and 4 3Σg+ states of Na2
Authors: Liu Yaoming , Li Li , Lazarov Guenadiy , Lazoudis Angelos , Lyyra A. Marjatta , Field Robert W.
Published: September 2004

The hyperfine structures of the 2 3Σg+, 3 3Σg+, and 4 3Σg+ states of Na2 have been resolved with sub-Doppler continuous wave perturbation facilitated optical-optical double resonance spectroscopy via A 1Σu+∼b 3Πu mixed intermediate levels. The hyperfine patterns of these three states are similar. The hyperfine splittings of the low rotational levels are all very close to the case bβS limit. As the rotational quantum number increases, the hyperfine splittings become more complicated and the coupling cases become intermediate between cases bβS and bβJ due to spin-rotation interaction. We present a detailed analysis of the hyperfine structures of these three Σg+3 states, employing both case bβS and bβJ coupling basis sets. The results show that the hyperfine splittings of the Σg+3 states are mainly due to the Fermi-contact interaction. The Fermi contact constants for the two dσ Rydberg states, the 2 3Σg+ and 4 3Σg+, are 245±5 MHz and 225±5 MHz, respectively, while the Fermi contact constant of the sσ 3 3Σg+ Rydberg state is 210±5 MHz. The diagonal spin-spin and spin-rotation constants, and nuclear spin-electronic spin dipolar interaction parameters of the 3 3Σg+ and 4 3Σg+ states are also obtained.
Electron hole formation in acidic zeolite catalysts
Authors: Solans-Monfort Xavier , Branchadell Vicenç , Sodupe Mariona , Sierka Marek , Sauer Joachim
Published: September 2004

The formation of an electron hole on an AlO4H center of the H-ZSM-5 zeolite has been studied by a hybrid quantum mechanics/shell-model ion-pair potential approach. The Becke-3-Lee-Yang-Parr (B3LYP) and Becke-Half&Half-Lee-Yang-Parr (BHLYP) hybrid density functionals yield electron holes of different nature, a delocalized hole for B3LYP and a hole localized on one oxygen atom for BHLYP. Comparison with coupled cluster calculations including single and double substitutions and with perturbative treatment of triple substitutions CCSD(T) and with experimental data for similar systems indicate that the localized description obtained with BHLYP is more accurate. Generation of the electron hole produces a substantial geometry relaxation, in particular an elongation of the Al-O distance to the oxygen atom with the unpaired electron. The zeolite framework stabilizes the positive charge by long-range effects. Our best estimates for the vertical and adiabatic ionization energies are 9.6–10.1 and 8.4–8.9 eV, respectively. Calculations for silicalite, the all-silica form of ZSM-5, also yield a localized electron hole, but the energy cost of the process is larger by 0.6–0.7 eV. The deprotonation energy of H-ZSM-5 is found to decrease from 12.86 to 11.40 eV upon electron hole formation.
Rapid and convenient method for preparing masters for microcontact printing with 1–12 μm features
Authors: Zilch Lloyd W. , Husseini Ghaleb A. , Lua Yit-Yian , Lee Michael V. , Gertsch Kevin R. , Cannon Bennion R. , Perry Robert M. , Sevy Eric T. , Asplund Matthew C. , Woolley Adam T. , Linford Matthew R.
Published: September 2004

Mechanical scribing can be employed to create surfaces with recessed features. Through replica molding elastomeric copies of these scribed surfaces are created that function as stamps for microcontact printing. It is shown that this new method for creating masters for microcontact printing can be performed with a computer-controlled milling machine (CNC), making this method particularly straightforward and accessible to a large technical community that does not need to work in a particle free environment. Thus, no clean room, or other specialized equipment is required, as is commonly needed to prepare masters. Time-of-flight secondary ion mass spectrometry confirms surface pattering by this method. Finally, it is shown that feature size in the scribed master can be controlled by varying the force on the tip during scribing.
Sound attenuation, shear viscosity, and mutual diffusivity behavior in the nitroethane-cyclohexane critical mixture
Authors: Behrends R. , Iwanowski I. , Kosmowska M. , Szala A. , Kaatze U.
Published: September 2004

The shear viscosity ηs, mutual diffusion coefficient D, and ultrasonic attenuation spectra of the nitroethane-cyclohexane mixture of critical composition have been measured at various temperatures near the critical temperature Tc. The relaxation rate of order parameter fluctuations resulting from a combined evaluation of the ηs and D data follows power law behavior with the theoretical exponent and with the large amplitude Γo=(156±2)×109 s−1. The ultrasonic spectra have been evaluated in terms of a critical contribution and a noncritical background contribution. The amplitude of the former exhibits a temperature dependence, in conformity with a temperature dependence in the adiabatic coupling constant (|g|=0.064 near Tc and 0.1 at T−Tc=3 K). If the variation of the critical amplitude with T is taken into account the experimental attenuation coefficient data display a scaling function which nicely fits to the theoretical prediction from the Bhattacharjee–Ferrell dynamic scaling model [R. A. Ferrell and J. K. Bhattacharjee, Phys. Rev. A 31, 1788 (1985)].
Femtosecond study of Cu(H2O) dynamics
Authors: Muntean Felician , Taylor Mark S. , McCoy Anne B. , Lineberger W. Carl
Published: September 2004

The short-time nuclear dynamics of Cu(H2O) is investigated using femtosecond photodetachment-photoionization spectroscopy and time-dependent quantum wave packet calculations. The Cu(H2O) dynamics is initiated in the electronic ground state of the complex by electron photodetachment from the Cu−(H2O) complex, where hydrogen atoms are oriented toward Cu. Several time-resolved resonant multiphoton ionization schemes are used to probe the ensuing reorientation and dissociation. Immediately following photodetachment, the neutral complex is far from its minimum energy geometry and possesses an internal energy comparable to the Cu-H2O dissociation energy and undergoes both large-amplitude H2O motion and dissociation. Dissociation is observed to occur on three distinct time scales: 0.6, 8, and 100 ps. These results are compared to the results of time-dependent J=0 wave packet calculations, propagating the initial anion vibrational wave functions on the ground-state potential of the neutral complex. An excellent agreement is obtained between the experimental results and the ionization signals derived from the calculated probability amplitudes. Related experiments and calculations are carried out on the Cu(D2O) complex, with results very similar to those of Cu(H2O).
A theoretical and computational study of the anion, neutral, and cation Cu(H2O) complexes
Authors: Taylor Mark S. , Muntean Felician , Lineberger W. Carl , McCoy Anne B.
Published: September 2004

An ab initio investigation of the potential energy surfaces and vibrational energies and wave functions of the anion, neutral, and cation Cu(H2O) complexes is presented. The equilibrium geometries and harmonic frequencies of the three charge states of Cu(H2O) are calculated at the MP2 level of theory. CCSD(T) calculations predict a vertical electron detachment energy for the anion complex of 1.65 eV and a vertical ionization potential for the neutral complex of 6.27 eV. Potential energy surfaces are calculated for the three charge states of the copper-water complexes. These potential energy surfaces are used in variational calculations of the vibrational wave functions and energies and from these, the dissociation energies D0 of the anion, neutral, and cation charge states of Cu(H2O) are predicted to be 0.39, 0.16, and 1.74 eV, respectively. In addition, the vertical excitation energies, that correspond to the 4 2P←4 2S transition of the copper atom, and ionization potentials of the neutral Cu(H2O) are calculated over a range of Cu(H2O) configurations. In hydrogen-bonded, Cu-HOH configurations, the vertical excitation and ionization energies are blueshifted with respect to the corresponding values for atomic copper, and in Cu-OH2 configurations where the copper atom is located near the oxygen end of water, both quantities are redshifted.
Dissociative recombination cross section and branching ratios of protonated dimethyl disulfide and N-methylacetamide
Authors: Al-Khalili A. , Thomas R. , Ehlerding A. , Hellberg F. , Geppert W. D. , Zhaunerchyk V. , af Ugglas M. , Larsson M. , Uggerud E. , Vedde J. , Adlhart C. , Semaniak J. , Kamińska M. , Zubarev R. A. , Kjeldsen F. , Andersson P. U. , Österdahl F. , Bednarska V. A. , Paál A.
Published: September 2004

Dimethyl disulfide (DMDS) and N-methylacetamide are two first choice model systems that represent the disulfide bridge bonding and the peptide bonding in proteins. These molecules are therefore suitable for investigation of the mechanisms involved when proteins fragment under electron capture dissociation (ECD). The dissociative recombination cross sections for both protonated DMDS and protonated N-methylacetamide were determined at electron energies ranging from 0.001 to 0.3 eV. Also, the branching ratios at 0 eV center-of-mass collision energy were determined. The present results give support for the indirect mechanism of ECD, where free hydrogen atoms produced in the initial fragmentation step induce further decomposition. We suggest that both indirect and direct dissociations play a role in ECD.
Degeneracy in discrete variable representations: General considerations and application to the multiconfigurational time-dependent Hartree approach
Authors: van Harrevelt Rob , Manthe Uwe
Published: September 2004

Problems appear in discrete variable representations (DVRs) based on general basis sets when the coordinate matrix has degenerate eigenvalues. Then the DVR is not uniquely defined. This paper shows that this problem can be caused by symmetry. Taking the symmetry into account when constructing the DVR solves the problem. The symmetry effect can be particularly important for the time-dependent DVR used in multiconfigurational time-dependent Hartree calculations employing the correlation DVR (CDVR) approach. Problems reported previously for the initial-state selected treatment of the H+H2 reaction can be attributed to this symmetry effect. They can be solved by using a symmetry-adapted approach to construct the time-dependent DVR. Thus, the present paper shows that the CDVR scheme can be employed also in initial-state selected scattering calculations if the symmetry of the system is properly taken into account in the construction of the time-dependent DVR.
High level ab initio study of the structure and vibrational spectra of HO2NO2
Authors: Matthews Jamie , Sinha Amitabha , Francisco Joseph S.
Published: September 2004

A high-level ab initio study has been performed on the conformational structure and vibrational spectra of HO2NO2. Calculations carried out with coupled-cluster methods using a series of Pople and Dunning basis sets reveal that there is a significant basis set dependence on the predicted ab initio structure. Higher angular momentum basis sets are shown to be necessary in order to bring the calculated structure into agreement with experimental rotational constants. Harmonic vibrational frequencies of HO2NO2 are computed at the CCSD(T)/aug-cc-pVTZ level of theory while the corresponding vibrational anharmonicities are calculated at the MP2/cc-pVTZ level. In addition, the absorption cross sections of OH stretching overtones in HO2NO2 are calculated using a dipole function computed at the QCISD level of theory and found to be in good agreement with the available experimental data.