bluuebunny/crossref_metadata_2025 huggingface dataset:
Über die Konstitution einiger Halogenverbindungen des Rhodiums
Authors: Meyer Julius , Kawozyk Margarete , Hoehne Karl
Published: January 2005

Mit Hilfe der potentiometrischen Titration und der Leitfähigkeitsmessung konnte nachgewiesen werden, daß dcm Rhodiumchlorid‐äthylendiaminhydrochlorid und ähnlichen Verbindungen keine Komplexsalzstruktur zuzuschreiben ist, sondern daß sie als Doppelsalze sus nichtionisierbarem Rhodiumchlorid und ionisierbarem Äthylendiaminhydrochlorid zu betrachten sind. Wir schreiben demnach diesen Salzen die Formeln RhCl3 · 2 C2H4N2H6Cl2, RhBr3 · 2C2H4N2H6Br2, RhBr · 2C3H6N2H6Br2 und 2RhBr3‐ 3 CH3NH3Br zu.
Studien an Alkaliphosphaten und ‐arsenaten. III. Tertiäre Natriumarsenate
Authors: Menzel Heinrich , Hagen Werner
Published: January 2005

Das Zustandsdiagramm des Systems Na2O–As2O5–H2O wurde bei 20° vom Primärarsenatpunkt bis ins hochalkalische Randgebiet unter Feststellung der im Gleichgewicht befindlichen Lösungen und Bodenkörper aufgenommen. Die Existenzgebiete der einheitlichen und kongruent‐löslichen Kristallarten NaH2AsO4 · H2H2O und Na2HAsO4 · 12H2O werden durch die Umwandlungspunkte Primär‐⇄ Sekundär‐ und Sekundär‐⇄ Tertärarsenat abgegrenzt. An das Sekundärsalz schließt sich zunächst mit einer schmalen Existenzzone und im Gleichgewicht mit relativ säurereicheren Lösungen (Na : As etwa 2,3‐2,5:1) das von und als Orthotertiärsalz bezeichnete normale Na3AsO4 · 12 H2O an; dieser Orthosalzbodenkörper geht ohne irgendwelche Unstetigkeit in der Löslichkeitskurve allmählich unter zunehmendem relativem Alkalianteil in eine Reihe homogener Kristallphasen variabler Zusammensetzung, sogenannter Pseudotertiärsalze über, wobei das Molverhältnis Na : As rascher auf den Wert 3,20 : 1 anwächst und dann immer verzögerter und asymptotisch einem Grenzwert 3,2531 zustrebt. Die Glieder dieser Reihe zwischen Ortho‐ und Grenzpseudozusammensetzung unterscheiden sich praktisch weder morphologisch noch röntgenographisch voneinander. Ψ‐Na3AsO4 · 12 H2O erstreckt sein Existenzbereich bis zu ziemlich alkalischen (etwa 27% Na2O !), an Arsensäure stark verarmten Mutterlaugen, wo sich dann mit steigender Alkalität der Lösungen das Gebiet eines alkalireicheren niederen Hydrates und von 32% Na2O‐haltigen Laugen ab das weitere eines noch wasserärmeren Bodenkörpers anschließt. Die früher von uns im Phosphatsystem festgestellte Anomalie des Pseudotertiärsalz‐12‐Hydrates wiederholt sich also bei Na‐Arsenat und erstreckt sich auch hier über ein weites Temperaturbereich zwischen 0° über 50° hinaus. Auf Grund des 20°‐Zustandsdiagramms lassen sich Na3AsO4‐12‐Hydrat von jedem zwischen Ortho‐ und Grenzpseudo‐ Zusammensetzung liegenden Na2O : As2O5‐Verhältnis darstellen.
Photolyse des Natriumchlorides durch Röntgen sowie β‐ und γ‐Strahlen
Authors: Hoffmann Josef
Published: January 2005

Natriumchloridpulver enthält stets Wasserspuren. Auch weitgehend entwässertes Natriumchlorid neigt zum Zusammenschließen der Teilchen und Klumpenbildung, und zwar auch dann, wenn die Mikroreaktion auf; Magnesia negativ ist. Sind bei Temperaturen bis 400° und vielleicht darüber Kristalloberflächen‐Wasserhäutchen für das Verkitten der Salzteilchen nicht ausschließbar, so treten bei höheren Temperaturen echte Sintererscheinungen auf, denen zufolge beim Schütteln nicht mehr rollendes Salz entsteht. Durch Bestrahlung mit weichen Röntgen‐ oder β‐γ‐Strahlen verändert sich die Alkalität unter Verfärbung des Salzes bis PH3,5. Bei Bestrahlung in Luft ist ein stechender Geruch wahrnehmbar. Zum Unterschied von Steinsalz zerlegen weiche Röntgenstrahlen Natriumchloridpulver in freies, chemisch nachweisbares Chlor und Natrium. Wasserhaltiges Natriumchlorid verbackt während der Röntgenbestrahlung unter Dunkel‐graubraunfärbung derart, daß ein fester kompakter Salzkuchen entsteht. Es ist nachgewiesen worden, daß auch absolut wasserfreies, im Hochvakuurn erschmolzenes Natriumchlorid der Photolyse durch weiche Röntgenstrahlung unterliegt. Die Ergebnisse der Photolyse des Steinsalzes durch Röntgenstrahlen und Radiumstrahlen sind in der vorstehenden Übersicht (Tabelle S. 195) zusammengefaßt.
Komplexverbindungen des Kupfer(II)‐azids. IV. Anlagerungsverbindungen [Cuprate]
Authors: Straumanis M. , Cïrulis A.
Published: January 2005

Es wurden folgende Azidocuprate dargestellt und ihre eigenschaften beschrieben:

1. Verbindungen der Formel Me14[Cu(N3)6]:

Lithium‐hexazido‐euprat mit 3H2O und wasserfrei.
Beitrag zur quantitativen Fluorbestimmung
Authors: Geyer Rudolf
Published: January 2005

1. Zur gravimetrischen Bestimmung des Fluor eignet sich am besten die Fällung als CaF2 aus schwach essigasurer, natriumacetatgepufferter Lösung. Der durch die Löslichkeit des CaF2 bedingte Fehler wird durch Absorption von Calciumsalzen kompensiert.

2. Ein einfaches maßanalytisches Verfahren beruht auf der Abscheidung des Fluor als PbFCl und Rücktitration dea zur Fällung im Überschuß angewandten NaCl mit AgNO3‐Lösung unter Verwendung von Diphenylaminblau als Indikator.

3. Die Trennung des Fluor von den wichtigsten Elementen läßt sich am einfachsten durch Destillation als H2SiF6 erreichen. Im Destillat kann das Fluor sofort mit AlCl3‐ oder Th(NO3)4‐Lösung titriert werden. Auch kleine Fluormengen lassen sich nach dieser Methode genau bestimmen.
Uber die Löslichkeit von Salzen und Salzgemischen bei Temperaturen oberhalb von 100°
Authors: Benrath A.
Published: January 2005

In den Systemen KNO3‐NaNO3‐H2O, KClKNO3H2O, NaClNaNO3H2O, KclKClO4H2O, KNO3K2SO4H2O und NaNO3Na2SO4H2O werden nach der früher angegebenen Methode die Zweisalzpunkte bei höheren Temperaturen bestimmt und die vollständigen Zustandsdiagramme gegeben. Die Verhältnisse in derartigen Systemen nähern sich zum Teil denen der magmatischen Schmelzen.
Linking empirically based theory and evaluation: The family bereavement program
Authors: Sandler Irwin N. , West Stephen G. , Baca Louise , Pillow David R. , Gersten Joanne C. , Rogosch Fred , Virdin Lynn , Beals Janette , Reynolds Kim D. , Kallgren Carl , Tein Jenn-Yun , Kriege Gary , Cole Eloise , Ramirez Rafael
Published: January 2005

Conclusion

We have illustrated how our “small theory” (Lipsey, 1990) of bereavement guided the development and evaluation of a preventive intervention for bereaved children. Our small theory, based on prior empirical research, enabled us to identify family processes that appeared to mediate the effects of parental death on child mental health. Our intervention was designed to attempt to change these processes. The evaluation of our experimental trial of the intervention assessed changes on these processes as well as the more distal mental health outcomes. The experimental trial showed some‐what encouraging results, in terms of the program's ability to modify the warmth of the parent–child relationship and to decrease symptomatology in the adolescent children. We also obtained further empirical support for our underlying theoretical model. Finally, implications for redesign of the program were derived from assessing the adequacy of the program components to change each of the mediators in the theoretical model.
Community treatment for the seriously mentally ill: Is this community psychology?
Authors: Mowbray Carol T.
Published: January 2005

Conclusions

Community treatment for seriously mentally ill individuals fits well into the philosophy of community psychology. Community psychologists have skills and experiences with other populations that represent assets in improving the ACT service model and producing richer and more useful research results for the future. Maybe we should ask ourselves why community psychologists have obviously avoided this intervention area and the population of seriously mentally ill individuals. Does this represent an adolescent reaction to the parent discipline — clinical psychology? Is the label “mentally ill” as stigmatizing to community psychologists as it is to the general population? Are these individuals written off as not worthy of or capable of benefiting from preventive interventions? Advocates for the seriously mentally ill are mounting a backlash against prevention services. We would be well advised at this time to become involved in community treatment and demonstrate that community psychology is forall vulnerable and at‐risk population groups. If the truth of the matter is that “community psychology is not doing much of a job of empowering people” (Berkowitz, 1990), maybe the truth of the matter is also that we need to reach out to more disenfranchised populations with research to show that community psychologycan do the job of empowering some.
New Low‐ and High‐Tech Calendar Methods of Family Planning
Authors: Fehring Richard J.
Published: January 2005

Calendar‐based methods are not usually considered effective or useful methods of family planning among health professionals. However, new “high‐” and “low”‐tech calendar methods have been developed, which are easy to teach, to use, and may be useful in helping couples avoid pregnancy. The low‐tech models are based on a fixed‐day calendar system. The high‐tech models are based on monitoring urinary metabolites of female reproductive hormones. Both systems have high levels of satisfaction. This article describes these new models of family planning and the research on their effectiveness. The author proposes a new algorithm for determining the fertile phase of the menstrual cycle for either achieving or avoiding pregnancy.
Medical Students' Knowledge of Midwifery Practice After Didactic and Clinical Exposure
Authors: Hanson Lisa , Tillett Jackie , Kirby Russell S.
Published: January 2005

Information concerning the student outcomes of interdisciplinary education is limited. The purpose of this study was to identify the knowledge of third‐year medical students regarding the practice of certified nurse‐midwives (CNMs). A 1‐page survey instrument was developed and pretested. The instrument was administered as a pre‐ and posttest at the beginning and end of 7 Obstetrics and Gynecology rotations at 2 medical school clinical campuses of a large Midwestern medical school. Direct interaction with CNMs improved knowledge of collaborative practice arrangements and roles. This was particularly evident in knowledge areas related to CNM prescriptive authority. The medical students who had direct experience with CNMs expressed more interest in working with them in the future than those who lacked the exposure. Collaborative, interdisciplinary education of medical students appeared to promote improved understanding of roles and capabilities.
δ13C and δ15N comparisons among different co-occurring lichen species from littoral rocky substrata
Authors: Riera Pascal
Published: January 2005

The distributions of natural stable isotopes of carbon and nitrogen have been extensively investigated in a variety of primary producers such as vascular plants and algae to provide baseline information of the trophic structure of various ecosystems (Currin et al. 1995). However, there have been few attempts to use this ecological approach to characterize lichens which frequently constitute the principal vegetation in many rocky habitats (Gilbert 2000). Rocky sea shores are characterized by a vertical zonation of biological communities which fall into three major zones: supralittoral, mediolittoral and infralittoral. The supralittoral zone is rarely submerged and is typically covered by a vegetation of lichens and cyanobacteria (Lewis 1964; Russel 1991).
Pannaria isabellina (Vain.) comb. nov., a remarkable lichen species from Chile
Authors: ELVEBAKK Arve , BJERKE Jarle W.
Published: January 2005

Pannaria isabellina is transferred from Psoroma to Pannaria as it lacks the amyloid apical ascus structure characteristic of Psoroma. However, it has an isolated position within Pannaria because of its lichenized squamules developing horizontally on a thin, filmy prothallus, and its thallus chemistry characterized by the norstictic acid chemosyndrome. It also has a sclerenchymatous epicortex and a characteristic perispore with gibbose wall swellings and long flagella-like apical extensions; both characters are not often found and are still insufficiently studied within the genus Pannaria. The gelatinous, long flagella-like apical extensions of the perispores probably serve to anchor the ascospores to thin and vertical substrata; the species seems to be concentrated in forest margins of evergreen forests along the coast of Chile, except in the Valdivian rainforest region where it extends further east.
Generic delimitations in the family Stictidaceae (Ostropales, Ascomycota): the Stictis–Conotrema problem
Authors: WEDIN Mats , DÖRING Heidi , KÖNBERG Kristina , GILENSTAM Gunnar
Published: January 2005

The family Stictidaceae (Ostropales, Ascomycota) contains both lichenized and non-lichenized fungi. Here, we test if Conotrema (lichenized) and Stictis (non-lichenized) as currently delimited are distinct monophyletic genera, by parsimony and parsimony jackknifing analyses of combined nuclear rDNA (ITS and partial LSU rDNA) and mitochondrial SSU rDNA sequence data matrices. The study includes four species of Stictis, three species of Conotrema, and representatives of the related Schizoxylon (lichenized), Odontotrema, Carestiella (at least sometimes associated with algae), Cryptodiscus and Thelotrema (lichenized). In all analyses, the Conotrema species were nested within Stictis with high support. Thus, we conclude that Conotrema are only lichenized representatives of Stictis. The type species of the two generic names, C. urceolatum and S. radiata, are sister taxa in our analyses. Furthermore, the analysis gave no support for the present infrageneric classification of Stictis. Carestiella socia (the type of Carestiella) and the two representatives of Schizoxylon studied were also nested within Stictis s. lat. The Odontotremataceae is the sister group to the Stictidaceae, and Cryptodiscus foveolaris groups with Thelotrema rather than with the Stictidaceae. We conclude that lichenization in the Stictidaceae does not characterize natural groups, and that Conotrema should be considered a synonym to Stictis, as predicted by anatomical characteristics. The new combinations Stictis urceolatum and Stictis populorum are made.
A class of exact two‐dimensional kinetic current sheet equilibria
Authors: Yoon Peter H. , Lui Anthony T. Y.
Published: January 2005

The present paper discusses a class of exact two‐dimensional kinetic current sheet equilibria. The general solution to the two‐dimensional Grad‐Shafranov equation was first obtained by Walker in 1915 in terms of the generating function g(ζ) (ζ = X + iZ), where X and Z are two dimensionless spatial coordinates. There are infinite choices of g(ζ), but not every solution yields physically meaningful or mathematically useful form. The known solutions to date with geophysical application include those by Harris [1962], Fadeev et al. [1965], Kan [1973], Manankova et al. [2000], and Brittnacher and Whipple [2002]. In this paper, these solutions are reviewed systematically, and several new solutions are proposed. These include a generalization of the Harris‐Fadeev‐Kan‐Manankova line of model, a model for an isolated X‐line alternative to that of Brittnacher‐Whipple, and finally a model which represents an isolated magnetic island.
Seasonal migration of cirrus clouds over the Asian Monsoon regions and the Tibetan Plateau measured from MODIS/Terra
Authors: Chen Baode , Liu Xiaodong
Published: January 2005

By using a 4‐year data set of the Moderate Resolution Imaging Spectroradiometer (MODIS) cirrus cloud reflectance, the seasonal migration of cirrus clouds over the Asian Monsoon regions and the Tibetan Plateau has been studied. There are two distinct regions with large amount of high clouds. One is located between the equator and 20°N, where intensified high clouds show clear northward and southward movements in association with the monsoon. The other is over the Tibetan Plateau, where large amount of cirrus clouds occurs in March to April and shows a more standing feature. Moreover, the significant amount of high clouds over two regions appears to be independent of each other. The one over the Tibetan Plateau is believed to be generated by relatively warm and moist air being slowly lifted over a large area by an approaching cold front and topographic lifting, and the other by the outflow or remains of cirroform anvils of cumulonimbi associated with deep convection in the Inter‐tropical Convergence Zone (ITCZ) and monsoon systems.
Convective plumes and the scarcity of Titan's clouds
Authors: Lorenz Ralph D. , Griffith Caitlin A. , Lunine Jonathan I. , McKay Christopher P. , Rennò Nilton O.
Published: January 2005

We show that simple thermodynamic models of convective plumes predict the area fraction of convective plumes (i.e., updrafts) in Titan's atmosphere to be ∼12 smaller than on Earth. This result is in agreement with predictions by sophisticated dynamical models and with the relative tropospheric cloud cover, which is only ∼1% on Titan. Rainstorms on Titan, being so rare, may be violent.
Influence of lithospheric thickness variations on 3‐D crustal velocities due to glacial isostatic adjustment
Authors: Latychev Konstantin , Mitrovica Jerry X. , Tamisiea Mark E. , Tromp Jeroen , Moucha Robert
Published: January 2005

Predictions of 3‐D crustal velocities driven by glacial isostatic adjustment (GIA) have generally been based on spherically symmetric Earth models. We adopt a finite‐volume formulation to explore the impact of lateral variations in elastic plate strength, including lithospheric thickness changes across the continent‐ocean interface and plate boundary weak zones, on these predictions. Weak zones introduce horizontal rate perturbations with a plate scale coherency and amplitudes reaching 1–2 mm/yr; radial velocity perturbations can be as large, but are geographically isolated to the weak zones (specifically, the North Atlantic Ridge). A discontinuity in ocean‐continent lithospheric thickness significantly impacts rates along continental margins (order 1 mm/yr for radial rates and generally about half this for tangential rates). We conclude that lateral variations in lithospheric strength should be included in future GIA analyzes of space‐geodetic survey results and in assessing the impact of GIA on the stability of geodetic reference frames.
The Formation of Negative Ions of Sulfur Hexafluoride
Authors: Ahearn A. J. , Hannay N. B.
Published: January 2005

Negative ion production in SF6 has been studied in a mass spectrometer; SF6−, SF5−, F2−, and F− were identified. The SF6− and SF5− are produced in very large quantities by a resonance capture process at an electron energy of about 2 ev, and are formed in approximately equal amounts.

At higher electron energies, the same capture occurs by a secondary process, in which low energy electrons released by other excitation and ionization processes suffer the resonance capture.

Partial dissociation after electron capture accounts for the appearance of F− and F2− ions below 16 ev. Above this energy, other processes will also produce these ions.

Possible explanations of the primary resonance capture mechanism are discussed.
Dielectric Dispersion in the Microwave Region of Six Tetrasubstituted Methanes in the Solid State
Authors: Powles J. G. , Williams D. E. , Smyth C. P.
Published: January 2005

A method is described for the measurement of dielectric constant and loss at microwave frequencies and low temperatures. The dielectric constant and loss at 3.22 cm wavelength (9.32×109 cycles/sec) have been measured over a range of temperature in the solid state and in the liquid near the melting point for t-butyl chloride, t-butyl bromide, 2,2-dichloropropane, methyl chloroform, 2-chloro−2-nitropropane, and 2,2-dinitropropane. 1,1-Dichloro−1-nitropropane also has been measured as a supercooled liquid. The six tetrasubstituted methanes, previously found to show molecular orientational freedom in the solid state for some distance below the melting point, give evidence of very short dielectric relaxation times in this region. The relaxation times increase from a very low value for t-butyl chloride to values such that large dielectric loss is observed near 3 cm for 2-chloro−2-nitropropane and 2,2-dinitropropane. The relaxation times in the solid rotator phases and in the liquid are compared, and the results are discussed in terms of intermolecular forces which give rise to potential energy barriers restricting rotation.
The Infrared Spectra and the Molecular Structure of Pyramidal Molecules
Authors: Nielsen Harald H.
Published: January 2005

It is necessary to have explicit expressions for the rotational term values for the vibration states ν2 and ν4 in order to make use of the analysis of the data on the low frequency bands in the spectra of pyramidal XH3 molecules. These frequencies are coupled by a Coriolis interaction which gives rise to a submatrix, for each value of J, in the complete energy matrix which has 3(2J+1) rows and columns. These submatrices further break up into smaller ones which have at most three rows and columns. Explicit relations for the term values ν2 and ν4 require that these be diagonalized independently.

It has been possible to expand the determinants of these submatrices in special cases where, for example, the quantum number K=J and where K=0 so that explicit relations for these states may readily be had. Using the frequency positions of lines involving transitions to these states permits the evaluation of the Coriolis factor ζ4(z). The structure of the molecules may also be fixed if then B(xx) and ζ3(z) can be determined, use being made of the zeta-sum for XH3 molecules, i.e., ζ3(z)+ζ4(z)=−1+B(xx)/2B(zz).
Thermal Diffusion in Isotopic Mixtures in the Critical Region
Authors: Caskey F. E. , Drickamer H. G.
Published: January 2005

Thermal diffusion ratios have been measured for the system C14O2–CO2 temperature range −15°C to +50°C and to 160-atmospheres pressure. One isotherm at −15°C has also been measured for the system CH4–CH3H3. The results deviate completely from the predictions of the kinetic theory of Enskog and Chapman and correspond closely to the previous results for the xenon-ethane system. The thermodynamics of irreversible processes qualitatively predicts the results obtained.
Atomic Excitation in Beta-Decay
Authors: Schwartz H. M.
Published: January 2005

The excitation and ionization of the daughter atom coming from a beta-decay, which is of interest in connection with some hot atom studies and possibly also in connection with beta-recoil experiments, is the subject of an introductory discussion (Secs. 1, 3, 4, and 5) with explicit calculations given only in the case of one-electron hydrogenlike wave function representation of atomic states (Sec. 2). The latter correct results in the literature, the only ones so far published on this subject. The present discussion is confined to direct effects of the beta-process itself and does not evaluate those resulting from Auger processes (Sec. 5).
Millimeter Wavelength Dispersion of Water Vapor
Authors: Birnbaum George
Published: January 2005

Dispersion due to water vapor in the wavelength region ∞ to 0.6 mm is computed by means of quantum-mechanical formulas. The dispersion is attributed to: (1) The contributions of the 11 rotational lines in the region considered; these are obtained with a dispersion equation characteristic of collision theory specialized to sharp lines. (2) The combined contribution of all rotational lines of shorter resonance wavelength. This is obtained with the aid of the well-known shape factor (νn2—ν2)−1, which is shown to be valid for sharp lines independent of any special model.

The strongest line, 31−4−3, occurs at 0.794 mm, and it gives rise to a maximum change in susceptibility ε′−1 of 8.2×10−6 for 1 atmos of air containing 1 percent water molecules. The increase in ε′−1 from ∞ to 0.6 mm is about twice this value. If the very small effect of the 1.35-cm line is neglected, a simple equation for ε′−1 holds from ∞ to 2 mm.
Molecular Images with the Projection Microscope. The Ionization Potential of Zinc Phthalocyanine
Authors: Gomer Robert , Speer Donald A.
Published: January 2005

The current emerging from single molecules of zinc phthalocyanine in field emission has been measured as a function of voltage. The data permit estimation of the ionization potential at ca 7 volts. Comparison of the experiments with a simple theory based on the emission of electrons from the molecule itself supports this view of image formation. It is shown that the images found are not diffraction patterns, but the result of electron optical effects. Emission measurements on molecules adsorbed on clean tungsten substrates show that irregularities of 5–10A exist on the best and cleanest of these surfaces.
The Volume Exclusion Effect in Flexible Chains
Authors: James Hubert M.
Published: January 2005

The volume exclusion effect in a chain of small impenetrable spheres is treated by two methods—one based on derivation of a Fokker-Planck equation by consideration of the number of ways in which a chain can be extended by adding another sphere without violating the volume exclusion condition, and the other based on the calculation of the number of excluded configurations as a function of chain extension. Both approaches lead, in the first approximation, to the same simple analytic form for the distribution of chain extensions r, and to the prediction that 〈r2〉 will increase faster than the number of spheres in the chain. Volume exclusion does not merely change the distribution function by a scale factor, as is assumed in the theory of Flory; there is a relatively large decrease in the probability of small extensions. The present theory is compared in detail with that of Hermans, Klamkin, and Ullman, which is superficially similar in appearance, but fundamentally quite different in character and result.
Absorption Coefficients of Gases in the Vacuum Ultraviolet. Part III. CO2
Authors: Inn Edward C. Y. , Watanabe K. , Zelikoff Murray
Published: January 2005

Quantitative absorption coefficient measurements have been made for CO2 in the region 1050–1800A using a 1-meter vacuum monochromator with a phosphor-coated photomultiplier tube as detector. The absorption spectra obtained consisted of three continua (λmax at 1121, 1332, 1475A) and possibly a fourth, all being superposed by many bands. For each continuum f values have been calculated. The results have been compared with some theoretical formulations by Mulliken. Upper limits of dissociation energies of the excited states of CO2 are estimated.
Absorption Coefficients of Gases in the Vacuum Ultraviolet. Part IV. Ozone
Authors: Tanaka Yoshio , Inn Edward C. Y. , Watanabe K.
Published: January 2005

Absorption coefficients of ozone gas (purity 90–95 percent) were obtained in the region 1050–2200A by a method described previously. Several strong continua, as well as weak bands, were observed. The curve for absorption intensity shows a minimum (8 cm−1) at about 2015A. Below this wavelength, the absorption coefficient increases gradually to a weak maximum (23 cm−1) at about 1725A and then rapidly to a strong maximum (420 cm−1) at about 1330A. In the region 1050–1450A, the absorption intensity does not fall below the value 130 cm−1. The results were compared with Mulliken's treatment of the electronic spectrum of ozone.
The Specific Heat of Graphite from 13° to 300°K
Authors: DeSorbo W. , Tyler W. W.
Published: January 2005

The specific heat of high-purity Acheson graphite prepared by the National Carbon Company has been measured from 13° to 300°K. In the region 13° to 54°K the Cp data follows a T2 dependence quite accurately in agreement with previous experimental work and recent theoretical investigations of specific heat in strongly anisotropic solids.

On the basis of some recent studies for other highly anisotropic solids, it is suggested that the specific heat of graphite will eventually follow a T3 dependence at still lower temperatures.

The derived thermodynamic functions, entropy, enthalpy, and free energy, have been determined by graphical integration and tabulated at integral values of temperature up to 300°K. The entropy of graphite at 298.16°K is 1.372±0.005 cal/g-atom deg, of which 0.004 is extrapolated from 13° to 0°K assuming the third law and the T2 dependence.
Proton Magnetic Resonance of the CH3 Group. I. Investigation of Six Tetrasubstituted Methanes
Authors: Powles J. G. , Gutowsky H. S.
Published: January 2005

Measurements have been made of the proton magnetic resonance absorption in methyl chloroform, 2,2-dinitropropane, 2-chloro−2-nitropropane, t-butyl chloride, t-butyl bromide, and neopentane, in the solid state. In all the materials at −196°C, except neopentane, the absorption corresponds to CH3 groups effectively fixed in the lattice. The narrowing of the absorption lines with rising temperature in methyl chloroform, 2,2-dinitropropane, and 2-chloro−2-nitropropane is attributable to the increasing rate of motion of the CH3 groups about their C3 symmetry axis. In methyl chloroform at higher temperatures, and in t-butyl chloride, t-butyl bromide, and neopentane an additional motion of the CH3 groups is required to explain the observed absorption, and possible motions are suggested. In all the polar materials the line becomes very narrow at the thermal transition at which the dielectric constant rises to a high value, marking the onset of over-all molecular rotation. In neopentane the line is narrower than expected for the rigid lattice at −196°C. With rising temperature, the line narrows to a very small value between the thermal transition and melting points. Theoretical analyses are given of the effects of external broadening upon the line shapes of fixed and rotating CH3 systems, and the results are used in interpreting the experimental data.
Microwave Spectra and Molecular Structures of HSiCl3, CH3SiCl3, and (CH3)3SiCl
Authors: Mockler Richard C. , Bailey Jep H. , Gordy Walter
Published: January 2005

From measurements of pure rotational transitions in the microwave region, the following molecular constants have been obtained. The B0 values are in Mc/sec, 2472.45±0.04 for HSi28Cl335; 2346.07±0.04 for HSi28Cl337; 1769.84±0.03 for C12H3SI28Cl335; 1699.79±0.03 for C12H3Si28Cl337; 2197.44±0.04 for (C12H3)3Si28Cl35; and 2147.88±0.03 for (C12H3)3Si28Cl37. With dSiH=1.47A (assumed), it is found for SiHCl3 that dSiCl=2.021A and ∠ClSiCl=109°22′. With the CH3 configuration assumed as in methane and ∠ClSiCl as in SiHCl3 it is found for CH3SiCl3 that dSiC=1.876A and dSiCl=2.021A. With all bond angles assumed to be tetrahedral and the CH distance to be that in methane, it is found for (CH3)3SiCl that dSiC=1.87A and dSiCl=2.03A.
Investigation of Pyrolyses of Benzyl Benzoate, Acetate, and Formate
Authors: Szwarc M. , Taylor J. Watson
Published: January 2005

The pyrolysis of benzyl benzoate, benzyl acetate, and benzyl formate has been studied by means of ``toluene carrier gas'' technique. It has been shown that benzyl-benzoate decomposes according to the equation Ph·CH2·O·CO·Ph→Ph·CH2·+Ph·COO.The Ph·CH2–O·CO·Ph bond dissociation energies have been estimated as less than 69 kcal/mole. Decompositions of benzyl acetate and of benzyl formate are more complicated; the dissociation into radicals is accompanied by some decompositions into smaller molecules.

Our data enable us to determine the relative rates of reactions, Ph·+C6H5·CH3→Ph·H+C6H5·CH2.and Ph·+C6H5·CH2·O·CO·C6H5→Ph·H4+C6H5·CH·O·CO·C6H5·.the latter reaction appears to be twice as rapid the former.
Absorption in the Low-Frequency Wing of the NH3 Inversion Spectrum
Authors: Birnbaum G. , Maryott A. A.
Published: January 2005

The absorption due to the low-frequency wings of the NH3 inversion lines was measured accurately at 2800 Mc for a pressure of 10-cm Hg. At this pressure, where the shift in inversion frequency has not set in, the absorption was about 40 percent larger than that calculated by summing the Van Vleck-Weisskopf expression over the rotational states using known resonance frequencies and line widths. A similar discrepancy was found in comparing the theoretical absorption with previously obtained data at 9000 Mc, while at resonance, 24 000-Mc theory and experiment were in very good agreement. To investigate various features of pressure broadening, the variation of absorption with pressure (5 to 30-cm Hg), temperature (−12 to 100°C), and frequency (1200 to 2800 Mc) was examined. These functional variations are interpretable, for the most part, by the Van Vleck-Weisskopf relation.
The Fundamental Absorption Bands in the Infrared Spectrum of Phosphine
Authors: McConaghie V. M. , Nielsen H. H.
Published: January 2005

The four fundamental bands in the infrared spectrum of PH3 have been analyzed. The bands ν1 and ν3 yield values of B(xx) and [(1—ζ2(z))B(zz)—B (xx)] as well as values for the centers of the bands. The method of Nielsen for arriving at explicit expressions for the rotation term values of ν2 and ν4 has permitted the evaluation also of the quantity (1—ζ4(z))B(zz) and to infer the centers of these bands. The structure of the molecule has been derived from this information and the zeta sums. The PH distance r0 obtained is equal to 1.42A, and the H–P–H angle is equal to 93° 50′.
Comparative Retentions of the Nuclear Isomers of Br80 in the Propyl Bromides
Authors: Capron P. C. , Crèvecoeur E.
Published: January 2005

By experiments on retention, which is defined as the fraction of the radioactivity resisting aqueous extraction, we find, for propyl bromides irradiated in paraffin at a distance of two centimeters from the source with unfiltered neutrons: R(Br80(18 min))R(Br80(4.4 hr))Normal propyl bromide0.72±0.050.85±0.05Isopropyl bromide0.37±0.020.58±0.03

The different sources of error are examined and eliminated.

The addition of free bromine, with the purpose of blocking the impurities, left a difference in the retention of the two isomers.

An interpretation is suggested.

The percentage of Br(18 min) of isomeric transition in the free state proceeding from Br(4.4 hr) in the bound state, is found to be 16 percent for the normal propyl bromide and 40 percent for the isopropyl bromide.
Work Function in Field Emission. Chemisorption
Authors: Gomer Robert
Published: January 2005

Analogs to the contact potential are calculated for the work function increase in field emission caused by polar chemisorbates. It is found that the discreteness of the dipoles constituting the layer leads to a work function increment smaller than the corresponding contact potential. The discrepancy becomes more marked at low coverages and high fields. A simple Fermi-Thomas calculation for estimating the depolarization of the electron cloud at a metal surface is given. It is probable that observed depolarizations of oxygen and nitrogen on tungsten can be explained in terms of this factor. The effect of the high fields used in cold emission on the work function is estimated and found to be of the order of 0.1 volt. Arguments are presented to show that a recent explanation of the fall in heats of chemisorption with coverage may need revision.
Magnetic Study on High Polymers. I. Diamagnetic Anisotropy of Natural Rubber
Authors: Isihara Akira , Kusumoto Hazime , Nagano Hiroshi , Oshima Keichi
Published: January 2005

The magnetic anisotropy of natural rubber was measured by Krishnan's oscillation method. In the first place, the anisotropy was measured by varying the time of vulcanization and was found to decrease with the time of vulcanization. In the second place, the anisotropy was measured as a function of temperature. Similar to the breadth of nuclear magnetic resonance line, an abrupt change in the slope of the anisotropy versus temperature curve was observed at the second-order transition temperature. Above and below this transition temperature, its change with temperature was not so strong.
Vapor Heat Capacities Determined by the Use of Vapor Pressure Equations
Authors: Barrow Gordon M.
Published: January 2005

Vapor pressure equations have proven useful in providing quantitative data on heats of vaporization but the heat capacity term, occurring in equations of the Rankine type, has been usually treated as an empirical constant. This term represents Cpvap—Cpliq for a vapor obeying the ideal gas laws and it is shown that even for a real gas the same result may be expected to hold. This conclusion is tested for twelve compounds for which data are available. The values of Cp0 calculated from the heat capacities of the liquid and the difference in heat capacities from the vapor pressure equation are in good agreement with those directly measured and would therefore be of use for thermodynamic calculations.
The Vibrational Spectrum of Chlorotrifluoroethylene
Authors: Mann D. E. , Acquista N. , Plyler Earle K.
Published: January 2005

The infrared spectrum of gaseous F2C:CFCl has been reinvestigated in greater detail and over a more extensive region than in earlier work. Three hitherto unobserved bands have been found at 369, 338, and 194 cm−1. These data, together with the previously available Raman spectrum, have made possible the achievement of a new and more satisfactory fundamental assignment: 1792 (ν CC), 1336 (ν CF), 1215 (ν CF), 1058 (ν CF), 689 (ν CCl), 517 (δ CF2), 463 (ρ CF2), 338 (δ CFCl), 194 (ρ CFCl) for the planar vibrations; and 538 (β CF2), 369 (β CFCl), 158 (τ) for the out-of-plane modes. The ideal-gas entropy value based on the present assignment agrees with that obtained calorimetrically.
Paramagnetic Resonance Absorption in Solutions of K and Na in Liquid NH3
Authors: Hutchison Clyde A. , Pastor Ricardo C.
Published: January 2005

Paramagnetic resonance absorption in solutions of K and Na in liquid NH3 has been investigated. The resonance has been studied at a frequency of approximately 7.0·106 cycle sec−1 and a magnetic field of 2.5 gauss. The measurements have been made at 240°K, 274°K, and 298°K and over a concentration range from 0.004 M to 0.7 M. The intensities and susceptibilities, spectroscopic splitting factors, widths, shapes, and extents of saturation of the resonances have been determined. The paramagnetic parts of the magnetic susceptibilities in static fields have been calculated from the rf data and have been compared with the susceptibilities measured in static fields by other investigators. The relations of the trapped electron model of such solutions to these quantitative measurements on the paramagnetic resonance absorption have been considered.
Lattice Dynamics of Body-Centered and Face-Centered Cubic Metallic Elements
Authors: de Launay Jules
Published: January 2005

The body-centered and face-centered cubic monatomic metals are represented by a model consisting of an ion point lattice embedded in an electron gas. The Born-von Kármán lattice dynamics are modified to include the role which the conduction electrons play in acoustical wave motion. This leads to relations connecting the dynamic parameters with the elastic constants, and yields the Fuchs relations in an elementary manner. The discrepancy in the Cauchy relation is shown to be just the bulk modulus of the electron gas.

In studying the contribution of the conduction electrons to the thermal motion, two extreme cases are treated: 1.—the electron gas does not partake of the thermal motion appreciably; 2.—the electron gas follows the ion motion almost exactly. The secular equations are given for both cases. The Debye characteristic temperature in the T3 region of atomic heat is computed analytically for both cases when the departure of the elastic constants from the isotropy condition is not too large.
Infrared and Raman Spectra of Tetramethylmethane-d12
Authors: Shull E. R. , Oakwood T. S. , Rank D. H.
Published: January 2005

In order to study further the molecular vibrations of tetramethylmethane and of hydrocarbons in general, tetramethylmethane-d12 was synthesized, and its Raman and infrared absorption spectra were obtained. The missing nondegenerate mode, ν2(a1), in ordinary tetramethylmethane was predicted by the Teller-Redlich product rule to lie at about 1430 cm−1 where it would be obscured by a strong depolarized Raman band at 1451 cm−1. A unique narrowness in the 1200 cm−1 infrared absorption bands of tetramethylmethane and tetramethylmethane-d12 and double maxima of small separation in the band of tetramethylmethane resulted in assigning these frequencies to methyl wagging modes of unsymmetrical character. The over-all results of this investigation cast doubt on the validity of extending theoretical considerations of tetrahedral XY4 systems to the tetrahedral tetramethyl molecules with the assumption of the methyl groups as point masses.
Exchange Between Rotational and Translational Energy in Gas Molecules
Authors: Beckerle John C.
Published: January 2005

Rotational relaxation times for the gases H2 and D2 have been calculated with the quantum mechanical method of distorted waves using a one-dimensional collision model and an exponential repulsive interaction potential. The potential constants were determined by fitting to the data of Hirschfelder, et al. and certain theoretical potential calculations for H2 by Margenau.

The calculations indicate that more than one relaxation time is required to describe rotational relaxation phenomena in these gases. The theoretical relaxation times are 15 to 35 times shorter than the experimental values when one averages with the velocity distribution for a Maxwellian beam of particles. The relative values of the calculated relaxation times compare favorably with those obtained from experiments. Averaging with a one-dimensional velocity distribution instead of that of a Maxellian beam of prticles at temperature T yields calculated values of the relaxation times that are a factor 7 to 19 shorter than the experimental values. One expects the calculated values to be shorter than the experimental values in view of the one-dimensional collision model.

The method used in treating H2 collisions is not applicable to N2 and O2. Results of another approximation method for these gases indicate that more complicated techniques must be used.
The Statistical Mechanical Theory of Transport Processes. VI. A Calculation of the Coefficients of Shear and Bulk Viscosity of Liquids
Authors: Zwanzig Robert W. , Kirkwood John G. , Stripp Kenneth F. , Oppenheim Irwin
Published: January 2005

The theory of the coefficients of shear and bulk viscosity of liquids developed in the third article of this series is applied to the calculation of the coefficients of viscosity of liquid argon at its normal boiling point. The theory of the bulk viscosity, including a previously omitted term due to the rate of dilatation, is presented. With the use of the Lennard-Jones potential, a radial distribution function which is a much better approximation than the previously used one, and a new approximation to the friction constant, values are obtained for the coefficients of viscosity.
Theory of Intermolecular Potential and Second Virial Coefficient of Hydrogen at Low Temperature
Authors: Mizushima Masataka , Ohno Kimio , Ohno Akiko
Published: January 2005

The intermolecular potential between hydrogen molecules is calculated taking into account its dependence on the relative orientation of the molecules. Assuming that the rotational quantum number of each molecule is a good quantum number throughout collision at low temperature, the matrix elements of the repulsive short-range intermolecular potential and the London potential are calculated. If the intermolecular potential depends on the relative orientation of colliding molecules, the resulting matrix element depends on the rotational quantum number. Thus it is pointed out that the second virial coefficient of ordinary hydrogen (which is, at low temperature, a mixture of 75 percent of J = 1 molecule and 25 percent of J = 0 molecules, where J is the rotational quantum number), and pure para hydrogen (which consists of only J = 0 molecules at low temperature) must be different, even if there were no statistical effect. The virial coefficient is calculated for very low temperature by solving the Schrödinger equation numerically.
Nuclear Magnetic Resonance in Metals. II. Temperature Dependence of the Resonance Shifts
Authors: McGarvey B. R. , Gutowsky H. S.
Published: January 2005

The temperature dependence of the nuclear resonance shift in metals has been investigated in lithium, sodium, rubidium, cesium, and gallium. The resonance shifts were found to change by no more than 5 to 6 percent over temperature ranges of 200°, including the melting point. For sodium, the observed temperature dependence of the resonance shift is correlated directly with the volume dependence predicted theoretically for the mass magnetic susceptibility due to the conduction electrons. In the other metals, effects appear which are related apparently to the volume dependence of the wave functions for electrons at the top of the conduction band. The room temperature resonance shifts of Sn117 and Sn119 and the temperature dependence of the Rb87 line width are also reported for the metals. The resonance shift of tin is 0.705×10−2. The estimation of activation energies for self-diffusion from the temperature dependence of the line widths is discussed.
Note on the Interaction of Methane and Water Vapor in the Hydrogen-Oxygen Reaction
Authors: Levy Arthur
Published: January 2005

The influence of methane on the hydrogen-oxygen reaction was studied in the region of the second-explosion limit. The experimental data show that there exists a critical concentration of methane, below which both methane and water vapor produce an identical reduction of the explosion limit. Observations on the course of the slow reaction also show that the accelerating effects of these additives on the rate of combination of hydrogen and oxygen are directly related to one another. It is postulated, on the basis of both the explosion and slow reaction rate data, that methane and water vapor influence the kinetics of the hydrogen-oxygen reaction by similar processes.
The Infrared Spectrum and Molecular Constants of Sulfur Dioxide
Authors: Shelton R. D. , Nielsen A. H. , Fletcher W. H.
Published: January 2005

By means of an infrared prism-grating spectrometer equipped with a multiple-path cell, seventeen vibration-rotation absorption bands of SO2 have been observed and recorded. Seven bands exhibiting rotational structure were analyzed for the rotational constants of the upper and lower vibrational states. Harmonic and anharmonic constants in the vibrational energy expression have been calculated, and suitable values for the force constants in a four-constant potential function have been obtained. No bands ascribable to S34O216 were found.
The Assignments of the Raman and Infrared Frequencies of 1,2-Dichloroethane Observed in the Gaseous, Liquid, and Solid States
Authors: Nakagawa Ichiro , Mizushima San-ichiro
Published: January 2005

Based on the normal vibration calculation of the trans and the gauche molecules of 1,2-dichloroethane as an eight-body problem, the assignments of the Raman and infrared frequencies of this substance observed in the gaseous, liquid, and solid states have been made. The vibrational modes of these frequencies have been discussed.
A Calculation of the Diamagnetic and Paramagnetic Susceptibility of N2 by the Statistical Method
Authors: Bonet J. V. , Bushkovitch A. V.
Published: January 2005

The diamagnetic and the paramagnetic term in the susceptibility of N2 are calculated using the statistical method of Thomas and Fermi corrected for exchange and correlation effects. A statistical electron density of N2, corrected for exchange and correlation, is used in the evaluation of the integral ∫ ρr2dv, which defines the mean square position of the electronic charge of the molecule appearing in the diamagnetic term. A statistical distribution function of the square electronic angular momentum of the molecule is derived, and the mean square electronic angular momentum of the molecule, appearing in the paramagnetic term, is defined in terms of the distribution function. This procedure leads to a result which, although approximately two times larger than the observed value, still is fully as good as similar calculations for atoms.