The growing interest in inorganic nanoparticles for a wide range of applications is spurring a need for synthesis methods that allow a highly specific tailoring of material properties. Synthesis in supercritical fluids holds great promise for solving this problem, but so far the fundamental chemical processes taking place under these conditions are to a large extent unknown. Here the design, construction and application of a versatile experimental setup are reported; this setup enables in situ synchrotron small‐angle X‐ray scattering/wide‐angle X‐ray scattering/pair distribution function (SAXS/WAXS/PDF) studies of the formation and growth of nanoparticles under supercritical fluid conditions.

Synchrotron powder X-ray diffraction data are used to determine the core electron deformation of diamond. Core shell contraction inherently linked to covalent bond formation is observed in close correspondence with theoretical predictions. Accordingly, a precise and physically sound reconstruction of the electron density in diamond necessitates the use of an extended multipolar model, which abandons the assumption of an inert core. The present investigation is facilitated by negligible model bias in the extraction of structure factors, which is accomplished by simultaneous multipolar and Rietveld refinement accurately determining an atomic displacement parameter (ADP) of 0.00181 (1) Å(2). The deconvolution of thermal motion is a critical step in experimental core electron polarization studies, and for diamond it is imperative to exploit the monatomic crystal structure by implementing Wilson plots in determination of the ADP. This empowers the electron-density analysis to precisely administer both the deconvolution of thermal motion and the employment of the extended multipolar model on an experimental basis.

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Nanocrystalline ZrO(2) samples with narrow size distributions and mean particle sizes below 10 nm have been synthesized in a continuous flow reactor in near and supercritical water as well as supercritical isopropyl alcohol using a wide range of temperatures, pressures, concentrations and precursors. The samples were comprehensively characterized by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS), and the influence of the synthesis parameters on the particle size, particle size distribution, shape, aggregation and crystallinity was studied. On the basis of the choice of synthesis parameters either monoclinic or tetragonal zirconia phases can be obtained. The results suggest a critical particle size of 5-6 nm for nanocrystalline monoclinic ZrO(2) under the present conditions, which is smaller than estimates reported in the literature. Thus, very small monoclinic ZrO(2) particles can be obtained using a continuous flow reactor. This is an important result with respect to improvement of the catalytic properties of nanocrystalline ZrO(2).

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Drought is an important factor limiting corn (Zea mays L.) yields in the Texas High Plains, and adoption of drought‐tolerant (DT) hybrids could be a management tool under water shortage. We conducted a 3‐yr field study to investigate yield, evapotranspiration (ET), and water use efficiency (WUE) in DT hybrids. One conventional (33D49) and 4 DT hybrids (P1151HR, P1324HR, P1498HR, and P1564HR) were grown at three water regimes (I100, I75, and I50, referring to 100, 75, and 50% ET requirement) and three planting densities (PD) (5.9, 7.4, and 8.4 plants m−2). Yield (13.56 Mg ha−1) and ET (719 mm) were the greatest at I100 but WUE (2.1 kg m−3) was the greatest at I75. Although DT hybrids did not always have greater yield and WUE than 33D49 at I100, hybrids P1151HR and P1564HR consistently had greater yield and WUE than 33D49 at I75 and I50. Compared to 33D49, P1151HR and P1564HR had 8.6 to 12.1% and 19.1% greater yield at I75 and I50, respectively. Correspondingly, WUE was 9.8 to 11.7% and 20.0% greater at I75 and I50, respectively. Greater PD resulted in greater yield and WUE at I100 and I75 but PD did not affect yield and WUE at I50. Yield and WUE in greater PD (8.4 plants m−2) were 6.3 to 8.3% greater than those in smaller PD (5.9 plants m−2). The results of this study demonstrated that proper selection of DT hybrids can increase corn yield and WUE under water‐limited conditions.

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Ruthenium nanoparticles have been synthesized by a novel pulsed-flow supercritical method using ethanol both as solvent and reducing agent. To improve the understanding of the formation and growth of Ru nanoparticles, the synthesis processes were also studied by in situ synchrotron radiation powder X-ray diffraction (SR-PXRD). Both the face-centered cubic (fcc) structure and the hexagonal close packed (hcp) structure of Ru can be synthesized in phase pure form by controlling the reaction conditions. When Ru(acac)3 is used as the precursor, fcc Ru is formed at a reaction temperature of 200 °C, while the hcp structure appears at higher temperatures. For syntheses with RuCl3 as the precursor, pure hcp Ru forms at all temperatures investigated, but an intermediate, yet unidentified, compound is detected in the reaction process at 200 °C. Both the pulsed-flow experiments and the in situ SR-PXRD experiments show that the reduction of the RuCl3 precursor proceeds faster than the reduction of the Ru(acac)3 precursor. Overall, the pulsed-flow supercritical approach provides a facile, green, and rapid synthesis of Ru nanoparticles with complete control of the allotropy.