The FIELDS Instrument Suite for Solar Probe Plus: Measuring the Coronal Plasma and Magnetic Field, Plasma Waves and Turbulence, and Radio Signatures of Solar Transients.

NASA's Solar Probe Plus (SPP) mission will make the first in situ measurements of the solar corona and the birthplace of the solar wind. The FIELDS instrument suite on SPP will make direct measurements of electric and magnetic fields, the properties of in situ plasma waves, electron density and temperature profiles, and interplanetary radio emissions, amongst other things. Here, we describe the scientific objectives targeted by the SPP/FIELDS instrument, the instrument design itself, and the instrument concept of operations and planned data products

The selection, appraisal, and retention of social science data

The number of data collections produced in the social sciences prohibits the archiving of every scientific study. It is therefore necessary to make decisions regarding what can be preserved and why it should be preserved. This paper reviews the processes used by two data archives, one from the United States and one from the United Kingdom, to illustrate how data are selected for archiving, how they are appraised, and what steps are required to retain the usefulness of the data for future use. It also presents new initiatives that seek to encourage an increase in the long-term preservation of digital resources

A quantitative description of the binding equilibria of para-substituted aniline ligands and CdSe quantum dots

This paper describes the use of 1H NMR spectroscopy to measure the equilibrium constants for the solution-phase binding of two para-substituted aniline molecules (R-An), p-methoxyaniline (Me0-An) and p-bromoaniline (Br-An), to colloidal 4.1 nm CdSe quantum dots (QDs). Changes in the chemical shifts of the aromatic protons located ortho to the amine group on R-An were used to construct a binding isotherm for each R-An/QD system. These isotherms fit to a Langmuir function to yield Ka, the equilibrium constant for binding of the R-An ligands to the QDs; Ka almost equal to 150 M-1 and DeltaGads almost equal to -19 kJ/mol for both R = MeO and R = Br. 31P NMR indicates that the native octylphosphonate ligands, which, by inductively coupled plasma atomic emission spectroscopy, cover 90% of the QD surface, are not displaced upon binding of R-An. The MeO-An ligand quenches the photoluminescence of the QDs at much lower concentrations than does Br-An; the observation, therefore, that Ka,K-MeO-An almost equal to Ka,Br-An shows that this difference in quenching efficiencies is due solely to differences in the nature of the electronic interactions of the bound R-An with the excitonic state of the QD.</p

Polar Alignment of Λ‑Shaped Basic Building Units within Transition Metal Oxide Fluoride Materials

A series of pseudosymmetrical structures of formula K₁₀(M₂O_<i>n</i>F_{11–<i>n</i>})₃X (M = V and Nb, <i>n</i> = 2, X = (F₂Cl)_1/3, Br, Br_4/2,I_4/2; M = Mo, <i>n</i> = 4, X = Cl, Br_4/2, I_4/2) illustrates generation of polar structures with the use of Λ-shaped basic building units (BBUs). For a compound to belong to a polar space group, dipole moments of individual species must be partially aligned. Incorporation of d⁰ early transition metal polyhedral BBUs into structures is a common method to create polar structures, owing to the second-order Jahn–Teller distortion these polyhedra contain. Less attention has been spent examining how to align the polar moments of BBUs. To address alignment, we present a study on previously reported bimetallic BBUs and synthesized compounds K₁₀(M₂O_<i>n</i>F_{11–<i>n</i>})₃X. These materials differ in their (non)­centrosymmetry despite chemical and structural similarities. The vanadium compounds are centrosymmetric (space groups <i>P</i>3̅<i>m</i>1 or <i>C</i>2/<i>m</i>) while the niobium and molybdenum heterotypes are noncentrosymmetric (<i>Pmn</i>2₁). The difference in symmetry occurs owing to the presence of linear, bimetallic BBUs or Λ-shaped bimetallic BBUs and related packing effects. These Λ-shaped BBUs form as a consequence of the coordination environment around the bridging anion of the metal oxide fluoride BBUs

Polar Alignment of Λ‑Shaped Basic Building Units within Transition Metal Oxide Fluoride Materials

A series of pseudosymmetrical structures of formula K₁₀(M₂O_<i>n</i>F_{11–<i>n</i>})₃X (M = V and Nb, <i>n</i> = 2, X = (F₂Cl)_1/3, Br, Br_4/2,I_4/2; M = Mo, <i>n</i> = 4, X = Cl, Br_4/2, I_4/2) illustrates generation of polar structures with the use of Λ-shaped basic building units (BBUs). For a compound to belong to a polar space group, dipole moments of individual species must be partially aligned. Incorporation of d⁰ early transition metal polyhedral BBUs into structures is a common method to create polar structures, owing to the second-order Jahn–Teller distortion these polyhedra contain. Less attention has been spent examining how to align the polar moments of BBUs. To address alignment, we present a study on previously reported bimetallic BBUs and synthesized compounds K₁₀(M₂O_<i>n</i>F_{11–<i>n</i>})₃X. These materials differ in their (non)­centrosymmetry despite chemical and structural similarities. The vanadium compounds are centrosymmetric (space groups <i>P</i>3̅<i>m</i>1 or <i>C</i>2/<i>m</i>) while the niobium and molybdenum heterotypes are noncentrosymmetric (<i>Pmn</i>2₁). The difference in symmetry occurs owing to the presence of linear, bimetallic BBUs or Λ-shaped bimetallic BBUs and related packing effects. These Λ-shaped BBUs form as a consequence of the coordination environment around the bridging anion of the metal oxide fluoride BBUs

Polar Alignment of Λ‑Shaped Basic Building Units within Transition Metal Oxide Fluoride Materials

A series of pseudosymmetrical structures of formula K₁₀(M₂O_<i>n</i>F_{11–<i>n</i>})₃X (M = V and Nb, <i>n</i> = 2, X = (F₂Cl)_1/3, Br, Br_4/2,I_4/2; M = Mo, <i>n</i> = 4, X = Cl, Br_4/2, I_4/2) illustrates generation of polar structures with the use of Λ-shaped basic building units (BBUs). For a compound to belong to a polar space group, dipole moments of individual species must be partially aligned. Incorporation of d⁰ early transition metal polyhedral BBUs into structures is a common method to create polar structures, owing to the second-order Jahn–Teller distortion these polyhedra contain. Less attention has been spent examining how to align the polar moments of BBUs. To address alignment, we present a study on previously reported bimetallic BBUs and synthesized compounds K₁₀(M₂O_<i>n</i>F_{11–<i>n</i>})₃X. These materials differ in their (non)­centrosymmetry despite chemical and structural similarities. The vanadium compounds are centrosymmetric (space groups <i>P</i>3̅<i>m</i>1 or <i>C</i>2/<i>m</i>) while the niobium and molybdenum heterotypes are noncentrosymmetric (<i>Pmn</i>2₁). The difference in symmetry occurs owing to the presence of linear, bimetallic BBUs or Λ-shaped bimetallic BBUs and related packing effects. These Λ-shaped BBUs form as a consequence of the coordination environment around the bridging anion of the metal oxide fluoride BBUs