Jump to Content
View Cart
Top 20 Most Read Articles
July 2008
The 20 articles with the most full-text downloads during the month, in descending order.
 |
Physical Properties of Ionic Liquids: Database and Evaluation J. Phys. Chem. Ref. Data 35, 1475 (2006); http://dx.doi.org/10.1063/1.2204959 (43 pages) Online Publication Date: 10 October 2006
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
A comprehensive database on physical properties of ionic liquids (ILs), which was collected from 109 kinds of literature sources in the period from 1984 through 2004, has been presented. There are 1680 pieces of data on the physical properties for 588 available ILs, from which 276 kinds of cations and 55 kinds of anions were extracted. In terms of the collected database, the structure-property relationship was evaluated. The correlation of melting points of two most common systems, disubstituted imidazolium tetrafluoroborate and disubstituted imidazolium hexafluorophosphate, was carried out using a quantitative structure-property relationship method.
|
|||
|
Show PACS
|
|||
|
|
J. Phys. Chem. Ref. Data 31, 387 (2002); http://dx.doi.org/10.1063/1.1461829 (149 pages) Online Publication Date: 7 June 2002
Full Text:
|
Download PDF
|
||
|
Show Abstract
In 1995, the International Association for the Properties of Water and Steam (IAPWS) adopted a new formulation called “The IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use”, which we abbreviate to IAPWS-95 formulation or IAPWS-95 for short. This IAPWS-95 formulation replaces the previous formulation adopted in 1984. This work provides information on the selected experimental data of the thermodynamic properties of water used to develop the new formulation, but information is also given on newer data. The article presents all details of the IAPWS-95 formulation, which is in the form of a fundamental equation explicit in the Helmholtz free energy. The function for the residual part of the Helmholtz free energy was fitted to selected data for the following properties: (a) thermal properties of the single-phase region (pρT) and of the vapor–liquid phase boundary (pσρ′ρ″T), including the phase-equilibrium condition (Maxwell criterion), and (b) the caloric properties specific isochoric heat capacity, specific isobaric heat capacity, speed of sound, differences in the specific enthalpy and in the specific internal energy, Joule–Thomson coefficient, and isothermal throttling coefficient. By applying modern strategies for optimizing the functional form of the equation of state and for the simultaneous nonlinear fitting to the data of all mentioned properties, the resulting IAPWS-95 formulation covers a validity range for temperatures from the melting line (lowest temperature 251.2 K at 209.9 MPa) to 1273 K and pressures up to 1000 MPa. In this entire range of validity, IAPWS-95 represents even the most accurate data to within their experimental uncertainty. In the most important part of the liquid region, the estimated uncertainty of IAPWS-95 ranges from ±0.001% to ±0.02% in density, ±0.03% to ±0.2% in speed of sound, and ±0.1% in isobaric heat capacity. In the liquid region at ambient pressure, IAPWS-95 is extremely accurate in density (uncertainty ⩽±0.0001%) and in speed of sound (±0.005%). In a large part of the gas region the estimated uncertainty in density ranges from ±0.03% to ±0.05%, in speed of sound it amounts to ±0.15% and in isobaric heat capacity it is ±0.2%. In the critical region, IAPWS-95 represents not only the thermal properties very well but also the caloric properties in a reasonable way. Special interest has been focused on the extrapolation behavior of the new formulation. At least for the basic properties such as pressure and enthalpy, IAPWS-95 can be extrapolated up to extremely high pressures and temperatures. In addition to the IAPWS-95 formulation, independent equations for vapor pressure, the densities, and the most important caloric properties along the vapor–liquid phase boundary, and for the pressure on the melting and sublimation curve, are given. Moreover, a so-called gas equation for densities up to 55 kg m−3 is also included. Tables of the thermodynamic properties calculated from the IAPWS-95 formulation are listed in the Appendix. © 2002 American Institute of Physics. |
|||
|
Show PACS
|
|||
|
|
Evaluated Kinetic Data for Combustion Modeling: Supplement II J. Phys. Chem. Ref. Data 34, 757 (2005); http://dx.doi.org/10.1063/1.1748524 (641 pages) Online Publication Date: 27 July 2005
Full Text:
|
Download PDF
|
||
|
Show Abstract
This compilation updates and expands two previous evaluations of kinetic data on elementary, homogeneous, gas phase reactions of neutral species involved in combustion systems [J. Phys. Chem. Ref Data 21, 411 (1992); 23, 847 (1994)]. The work has been carried out under the auspices of the IUPAC Commission on Chemical Kinetics and the UK Engineering and Physical Sciences Research Council. Individual data sheets are presented for most reactions but the kinetic data for reactions of C2, C, ethyl, i-propyl, t-butyl, and allyl radicals are summarized in tables. Each data sheet sets out relevant thermodynamic data, experimental kinetic data, references, recommended rate parameters with their error limits and a brief discussion of the reasons for their selection. Where appropriate the data are displayed on an Arrhenius diagram or by fall-off curves. Tables summarizing the recommended rate data and the thermodynamic data for the reactant and product species are given, and their sources referenced. As in the previous evaluations the reactions considered relate largely to the combustion in air of organic compounds containing up to three carbon atoms and simple aromatic compounds. Thus the data base has been expanded, largely by dealing with a substantial number of extra reactions within these general areas. © 2005 American Institute of Physics. |
|||
|
Show PACS
|
|||
|
|
Atomic Transition Probabilities of Aluminum. A Critical Compilation J. Phys. Chem. Ref. Data 37, 709 (2008); http://dx.doi.org/10.1063/1.2734564 (203 pages) Online Publication Date: 6 March 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
This compilation is the second in a series of updates to Atomic Transition Probabilities, Sodium through Calcium, published in 1969 by
Wiese et al. [Atomic Transition Probabilities, Vol. II, Vol. II: Sodium through Calcium, NSROS-NBS Vol. 2 (U.S. GPO, Washington, D.C., 1969)]
. Atomic transition probabilities have been critically evaluated and compiled for about 5000 spectral lines of aluminum (nuclear charge Z = 13). The cited values and their estimated uncertainties are based on our consideration of all available theoretical and experimental literature sources. All ionization stages (except for hydrogenic) are covered, and the data are presented in separate tables for each atom and ion. Separate listings are given for “allowed” (electric dipole) and “forbidden” (magnetic dipole plus electric and magnetic quadrupole) transitions. In each spectrum, lines are grouped into multiplets which are arranged in order of ascending lower- and upper-level energies, respectively. For each line, the emission transition probability Aki, the line strength S, and (for allowed lines) the absorption oscillator strength fik are given, together with the spectroscopic designation, the wavelength, the statistical weights, and the energy levels of the lower and upper states. The estimated relative uncertainties of the line strength are also indicated, as are the source citations. We include only those lines whose transition rates are deemed sufficiently accurate to qualify as reference values. Short introductions precede the tables for each ion.
|
|||
|
Show PACS
|
|||
|
|
Cross Sections for Electron Collisions with Hydrogen Molecules J. Phys. Chem. Ref. Data 37, 913 (2008); http://dx.doi.org/10.1063/1.2838023 (19 pages) Online Publication Date: 31 March 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
Cross section data have been compiled for electron collisions with hydrogen molecules based on 71 references. Cross sections are collected and reviewed for total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational, and electronic states, dissociation, ionization, emission of radiation, and dissociative attachment. For each process, the recommended values of the cross section are presented for use. The literature has been surveyed through the end of 2006.
|
|||
|
Show PACS
|
|||
|
|
CODATA recommended values of the fundamental physical constants: 2006 J. Phys. Chem. Ref. Data 37, 1187 (2008); http://dx.doi.org/10.1063/1.2844785 (98 pages) Online Publication Date: 15 July 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
This paper gives the 2006 self-consistent set of values of the basic constants and conversion factors of physics and chemistry recommended by the Committee on Data for Science and Technology (CODATA) for international use. Further, it describes in detail the adjustment of the values of the constants, including the selection of the final set of input data based on the results of least-squares analyses. The 2006 adjustment takes into account the data considered in the 2002 adjustment as well as the data that became available between 31 December 2002, the closing date of that adjustment, and 31 December 2006, the closing date of the new adjustment. The new data have led to a significant reduction in the uncertainties of many recommended values. The 2006 set replaces the previously recommended 2002 CODATA set and may also be found on the World Wide Web at physics.nist.gov/constants.
|
|||
|
Show PACS
|
|||
|
|
J. Phys. Chem. Ref. Data 37, 933 (2008); http://dx.doi.org/10.1063/1.2804088 (186 pages) Online Publication Date: 8 May 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
This paper is the fourth and final volume in the halate solubility series. The solubility data for halates of transition metals, lanthanides, actinides, ammonium, and metallic elements of the main groups 12–14 are reviewed. Where appropriate, binary, ternary, and multicomponent systems are critically evaluated. Most of the solubility results were obtained in water or aqueous solutions of electrolytes. The solubility in organic solvents and aqueous-organic solvent mixtures is also collected in this volume. All these data were critically examined for their reliability. The best values were selected on the basis of critical evaluations and presented in tabular form. Fitting equations and graphical plots are also provided. When numerical data were not reported in an original publication, they were read out from figures and digitized by the compilers. The quantities, units, and symbols used in this volume are in accord with IUPAC recommendations. We always reported the original data and, if necessary, transferred them into the IUPAC recommended units and symbols. The literature on the solubility data was researched through 2002. The halates of these metals play a role in industrial processes. For example, some halates are essential as catalysts, heat stabilizers, and blanching reagents for manufacturing polymer products such as textiles and resins. Some iodates are used in pyrotechnic compounds for weather modification and colored smoke generation. The nonlinear halate crystals are important in construction of optical devices.
|
|||
|
Show PACS
|
|||
|
|
Handbook of Basic Atomic Spectroscopic Data J. Phys. Chem. Ref. Data 34, 1559 (2005); http://dx.doi.org/10.1063/1.1800011 (701 pages) Online Publication Date: 28 September 2005
Full Text:
|
Download PDF
|
|||||||||||||||||
|
Show Abstract
© 2005 American Institute of Physics. |
||||||||||||||||||
|
Show PACS
|
||||||||||||||||||
|
|
J. Phys. Chem. Ref. Data 37, 1169 (2008); http://dx.doi.org/10.1063/1.2839272 (14 pages) Online Publication Date: 15 May 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
The mutual solubilities and related liquid-liquid equilibria of nine binary systems of C7–C14 ethers with water are exhaustively and critically reviewed. Reports of experimental determination of solubility that appeared in the primary literature prior to the end of 2006 are compiled. For three systems, sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units. In addition to the standard evaluation criteria used throughout the Solubility Data Series, a method based on the evaluation of all experimental data for a given series of ethers was used.
|
|||
|
Show PACS
|
|||
|
|
J. Phys. Chem. Ref. Data 33, 1005 (2004); http://dx.doi.org/10.1063/1.1691451 (7 pages) Online Publication Date: 28 October 2004
Full Text:
|
Download PDF
|
||
|
Show Abstract
A simple extended corresponding-states principle is used to represent the vapor pressure of ammonia and trideuteroammonia from the triple point to critical point and to describe the available experimental data along with extrapolation beyond their ranges of available experimental data. This work takes advantage of the adoption of the ITS-90 temperature scale and of the new critical parameters obtained from the extended corresponding-states principle. The vapor pressure data are described within their scatter in the entire temperature range. Comparisons with the available data show that the extended corresponding-states principle may calculate the vapor-pressure values within 0.05%–0.1% The substance-dependent characteristic parameters are given, such as critical temperature, critical density, critical pressure, acentric factor, and aspherical factor. The values of the pressures, along with their first and second derivatives as a function of temperature over the entire region from the triple point to the critical point are tabulated and recommended for scientific and practical uses. © 2004 American Institute of Physics. |
|||
|
Show PACS
|
|||
|
|
J. Phys. Chem. Ref. Data 37, 1183 (2008); http://dx.doi.org/10.1063/1.2904462 (1 page) Online Publication Date: 22 May 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Abstract Unavailable
|
|||
|
Show PACS
|
|||
|
|
J. Phys. Chem. Ref. Data 36, 1 (2007); http://dx.doi.org/10.1063/1.2360986 (18 pages) Online Publication Date: 8 February 2007
Full Text:
Read Online (HTML)
|
Download PDF
|
|||
|
Show Abstract
All the currently available experimental permittivity data for pure water are used to derive an interpolation function that precisely represents ε(ν,t,) at standard atmospheric pressure, for frequencies and temperatures in the ranges 0 ⩽ ν ⩽ 25 THz and 0 ⩽ t ⩽ 100 °C. The permittivity data is represented in terms of relaxations and resonances processes. There are three relaxations in the microwave region and two resonances in the far infrared. The temperature dependence of the relaxation and resonance parameters are determined. For example, at 25 °C the three relaxation frequencies are 18.56 GHz, 167.83 GHz, 1.944 THz and the two resonance frequencies are 4.03 and 14.48 THz.
|
||||
|
Show PACS
|
||||
|
|
IUPAC-NIST Solubility Data Series. 86. Ethers and Ketones with Water. Part 2. C6 Ethers with Water J. Phys. Chem. Ref. Data 37, 1147 (2008); http://dx.doi.org/10.1063/1.2839271 (22 pages) Online Publication Date: 14 May 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
The mutual solubilities and related liquid-liquid equilibria of C6 ethers with water are exhaustively and critically reviewed. Reports of experimental determination of solubility in binary systems that appeared in the primary literature prior to the end of 2006 are compiled. For four of the seven systems treated, sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units. In addition to the standard evaluation criteria used throughout the Solubility Data Series, a method based on the evaluation of all experimental data for a given series of ethers was used.
|
|||
|
Show PACS
|
|||
|
|
Evaluated Kinetic and Photochemical Data for Atmospheric Chemistry, Organic Species: Supplement VII J. Phys. Chem. Ref. Data 28, 191 (1999); http://dx.doi.org/10.1063/1.556048 (203 pages)
Full Text:
|
Download PDF
|
||
|
Show Abstract
This paper updates and extends part of the previous data base of critical evaluations of the kinetics and photochemistry of gas-phase chemical reactions of neutral species involved in atmospheric chemistry [J. Phys. Chem. Ref. Data 9, 295 (1980); 11, 327 (1982); 13, 1259 (1984); 18, 881 (1989); 21, 1125 (1992); 26, 521 (1997); 26, 1329 (1997)]. The present evaluation is limited to the organic family of atmospherically important reactions. The work has been carried out by the authors under the auspices of the IUPAC Subcommittee on Gas Phase Kinetic Data Evaluation for Atmospheric Chemistry. Data sheets have been prepared for 171 thermal and photochemical reactions, containing summaries of the available experimental data with notes giving details of the experimental procedures. For each thermal reaction, a preferred value of the rate coefficient at 298 K is given together with a temperature dependence where possible. The selection of the preferred value is discussed and estimates of the accuracies of the rate coefficients and temperature coefficients have been made for each reaction. For each photochemical reaction the data sheets list the preferred values of the photoabsorption cross sections and the quantum yields of the photochemical reactions together with comments on how they were selected. The data sheets are intended to provide the basic physical chemical data needed as input for calculations which model atmospheric chemistry. A table summarizing the preferred rate data is provided, together with an Appendix listing the available values of enthalpies of formation of the reactant and product species. © 1999 American Institute of Physics and American Chemical Society. |
|||
|
Show PACS
|
|||
|
|
J. Phys. Chem. Ref. Data 37, 7 (2008); http://dx.doi.org/10.1063/1.2789451 (90 pages) Online Publication Date: 23 January 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
Energy levels, with classifications and uncertainties, have been compiled for the spectra of the neutral atom and all positive ions of potassium (Z = 19). Wavelengths with classifications, intensities, and transition probabilities are also tabulated. In addition, ground states and ionization energies are listed. For many ionization stages experimental data are available; however for those for which only theoretical calculations or fitted values exist, these are reported.
|
|||
|
Show PACS
|
|||
|
|
IUPAC Critical Evaluation of Thermochemical Properties of Selected Radicals. Part I J. Phys. Chem. Ref. Data 34, 573 (2005); http://dx.doi.org/10.1063/1.1724828 (84 pages) Online Publication Date: 27 May 2005
Full Text:
|
Download PDF
|
||
|
Show Abstract
This is the first part of a series of articles reporting critically evaluated thermochemical properties of selected free radicals. The present article contains datasheets for 11 radicals: CH, CH2(triplet), CH2(singlet), CH3, CH2OH, CH3O, CH3CO, C2H5O, C6H5CH2, OH, and NH2. The thermochemical properties discussed are the enthalpy of formation, as well as the heat capacity, integrated heat capacity, and entropy of the radicals. One distinguishing feature of the present evaluation is the systematic utilization of available kinetic, spectroscopic and ion thermochemical data as well as high-level theoretical results. © 2005 American Institute of Physics. |
|||
|
Show PACS
|
|||
|
|
J. Phys. Chem. Ref. Data 29, 167 (2000); http://dx.doi.org/10.1063/1.556058 (100 pages)
Full Text:
|
Download PDF
|
||
|
Show Abstract
This paper updates and extends part of the previous data base of critical evaluations of the kinetics and photochemistry of gas-phase chemical reactions of neutral species involved in atmospheric chemistry [J. Phys. Chem. Ref. Data 9, 295 (1980); 11, 327 (1982); 13, 1259 (1984); 18, 881 (1989); 21, 1125 (1992); 26, 521 (1997); 26, 1329 (1997); 28, 191 (1999)]. The present evaluation is limited to the inorganic halogen family of atmospherically important reactions. The work has been carried out by the authors under the auspices of the IUPAC Subcommittee on Gas Phase Kinetic Data Evaluation for Atmospheric Chemistry. Data sheets have been prepared for 102 thermal and photochemical reactions, containing summaries of the available experimental data with notes giving details of the experimental procedures. For each thermal reaction, a preferred value of the rate coefficient at 298 K is given together with a temperature dependence where possible. The selection of the preferred value is discussed and estimates of the accuracies of the rate coefficients and temperature coefficients have been made for each reaction. For each photochemical reaction the data sheets list the preferred values of the photoabsorption cross sections and the quantum yields of the photochemical reactions together with comments on how they were selected. The data sheets are intended to provide the basic physical chemical data needed as input for calculations that model atmospheric chemistry. A table summarizing the preferred rate data is provided, together with an appendix listing the available values of enthalpies of formation of the reactant and product species. © 2000 American Institute of Physics and American Chemical Society. |
|||
|
Show PACS
|
|||
|
|
Atomic Transition Probabilities of Sodium and Magnesium. A Critical Compilation J. Phys. Chem. Ref. Data 37, 267 (2008); http://dx.doi.org/10.1063/1.2735328 (440 pages) Online Publication Date: 3 March 2008
Full Text:
Read Online (HTML)
|
Download PDF
|
||
|
Show Abstract
This compilation is the first in a series of updates to a critical compilation published in 1969 [
W. L. Wiese, M. W. Smith, and B. M. Miles, Atomic Transition Probabilities, Vol. II: Sodium through Calcium, NSRDS-NBS Vol. 2 (U.S. GPO, Washington, D.C., 1969)
]. Atomic transition probabilities have been critically evaluated and compiled for about 11 400 spectral lines of sodium and magnesium (nuclear charge Z = 11–12, respectively). The cited values and their estimated uncertainties are based on our consideration of all available theoretical and experimental literature sources. All ionization stages (except for hydrogenic) are covered, and the data are presented in separate tables for each atom and ion. Separate listings are given for “allowed” (electric dipole) transitions, on the one hand, and for “forbidden” (magnetic dipole plus electric and magnetic quadrupole) transitions, on the other. In each spectrum, lines are grouped into multiplets which are arranged in order of ascending lower and upper-level energies, respectively. For each line, the emission transition probability Aki, the line strength S, and (for allowed lines) the absorption oscillator strength fik are given, together with the spectroscopic designation, the wavelength, the statistical weights, and the energy levels of the lower and upper states. The estimated relative uncertainties of the line strength are also indicated, as are the source citations. We introduce a statistical method that we use to estimate these uncertainties for most of the cited transition rates. We only include those lines whose transition rates are deemed sufficiently accurate to qualify as reference values. Short introductions precede the tables for each ion. The general introduction contains a discussion of the principal criteria for our judgments and our method of data selection and evaluation.
|
|||
|
Show PACS
|
|||
|
|
Binding Energies in Atomic Negative Ions: III J. Phys. Chem. Ref. Data 28, 1511 (1999); http://dx.doi.org/10.1063/1.556047 (23 pages)
Full Text:
|
Download PDF
|
||
|
Show Abstract
This article updates a 14 yr old review on this subject [J. Phys. Chem. Ref. Data 14, 731 (1985)]. A survey of the electron affinity determinations for the elements up to Z = 94 is presented, and based upon these data, a set of recommended electron affinities is established. New developments in the experimental methods which yield accurate electron binding energies are described. Fine structure splittings and excited state energies of negative ions as well as lifetimes of metastable states are given. Progress in theoretical calculations of atomic electron affinities is documented by comparison with reliable experimental data. © 1999 American Institute of Physics and American Chemical Society. |
|||
|
Show PACS
|
|||
|
|
J. Phys. Chem. Ref. Data 29, 331 (2000); http://dx.doi.org/10.1063/1.1285884 (55 pages)
Full Text:
|
Download PDF
|
||
|
Show Abstract
A thermodynamic property formulation for standard dry air based upon available experimental p–ρ–T, heat capacity, speed of sound, and vapor–liquid equilibrium data is presented. This formulation is valid for liquid, vapor, and supercritical air at temperatures from the solidification point on the bubble-point curve (59.75 K) to 2000 K at pressures up to 2000 MPa. In the absence of reliable experimental data for air above 873 K and 70 MPa, air properties were predicted from nitrogen data in this region. These values were included in the determination of the formulation to extend the range of validity. Experimental shock tube measurements on air give an indication of the extrapolation behavior of the equation of state up to temperatures and pressures of 5000 K and 28 GPa. The available measurements of thermodynamic properties of air are summarized and analyzed. Separate ancillary equations for the calculation of dew and bubble-point pressures and densities of air are presented. In the range from the solidification point to 873 K at pressures to 70 MPa, the estimated uncertainty of density values calculated with the equation of state is 0.1%. The estimated uncertainty of calculated speed of sound values is 0.2% and that for calculated heat capacities is 1%. At temperatures above 873 K and 70 MPa, the estimated uncertainty of calculated density values is 0.5% increasing to 1.0% at 2000 K and 2000 MPa. In addition to the equation of state for standard air, a mixture model explicit in Helmholtz energy has been developed which is capable of calculating the thermodynamic properties of mixtures containing nitrogen, argon, and oxygen. This model is valid for temperatures from the solidification point on the bubble-point curve to 1000 K at pressures up to 100 MPa over all compositions. The Helmholtz energy of the mixture is the sum of the ideal gas contribution, the real gas contribution, and the contribution from mixing. The contribution from mixing is given by a single generalized equation which is applied to all mixtures used in this work. The independent variables are the reduced density and reduced temperature. The model may be used to calculate the thermodynamic properties of mixtures at various compositions including dew and bubble-point properties and critical points. It incorporates the most accurate published equation of state for each pure fluid. The mixture model may be used to calculate the properties of mixtures generally within the experimental accuracies of the available measured properties. The estimated uncertainty of calculated properties is 0.1% in density, 0.2% in the speed of sound, and 1% in heat capacities. Calculated dew and bubble-point pressures are generally accurate to within 1%. © 2000 American Institute of Physics and American Chemical Society. |
|||
|
Show PACS
|
|||
This Publication
Scitation
Google Scholar
PubMed