Search NASA⌕ Search

SEARCH · Search NASA

Results for “CrCo”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

Materials Data on CrCo(PO4)2 by Materials Project

CrCo(PO4)2 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Cr3+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent CoO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–49°. There are a spread of Cr–O bond distances ranging from 1.97–2.11 Å. Co3+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with four equivalent CrO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–49°. There are a spread of Co–O bond distances ranging from 1.93–2.16 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one CoO6 octahedra, corners with three equivalent CrO6 octahedra, and an edgeedge with one CoO6 octahedra. The corner-sharing octahedra tilt angles range from 43–57°. There are a spread of P–O bond distances ranging from 1.52–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one CrO6 octahedra, corners with three equivalent CoO6 octahedra, and an edgeedge with one CrO6 octahedra. The corner-sharing octahedra tilt angles range from 47–55°. There is two shorter (1.52 Å) and two longer (1.60 Å) P–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr3+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Co3+ and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Cr3+, one Co3+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cr3+, one Co3+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Co3+ and one P5+ atom.

36 MATERIALS SCIENCE↗

Materials Data on CrCo by Materials Project

CoCr is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Cr is bonded in a body-centered cubic geometry to eight equivalent Co atoms. All Cr–Co bond lengths are 2.47 Å. Co is bonded in a body-centered cubic geometry to eight equivalent Cr atoms.

36 MATERIALS SCIENCE↗

Regulation of photoprotection gene expression in Chlamydomonas by a putative E3 ubiquitin ligase complex and a homolog of CONSTANS

Photosynthetic organisms use nonphotochemical quenching (NPQ) mechanisms to dissipate excess absorbed light energy and protect themselves from photooxidation. In the model green alga Chlamydomonas reinhardtii , the capacity for rapidly reversible NPQ (qE) is induced by high light, blue light, and UV light via increased expression of LHCSR and PSBS genes that are necessary for qE. Here, we used a forward genetics approach to identify SPA1 and CUL4, components of a putative green algal E3 ubiquitin ligase complex, as critical factors in a signaling pathway that controls light-regulated expression of the LHCSR and PSBS genes in C. reinhardtii . The spa1 and cul4 mutants accumulate increased levels of LHCSR1 and PSBS proteins in high light, and unlike the wild type, they express LHCSR1 and exhibit qE capacity even when grown in low light. The spa1-1 mutation resulted in constitutively high expression of LHCSR and PSBS RNAs in both low light and high light. The qE and gene expression phenotypes of spa1-1 are blocked by mutation of CrCO, a B-box Zn-finger transcription factor that is a homolog of CONSTANS, which controls flowering time in plants. CONSTANS-like cis -regulatory sequences were identified proximal to the qE genes, consistent with CrCO acting as a direct activator of qE gene expression. We conclude that SPA1 and CUL4 are components of a conserved E3 ubiquitin ligase that acts upstream of CrCO, whose regulatory function is wired differently in C. reinhardtii to control qE capacity via cis -regulatory CrCO-binding sites at key photoprotection genes.

59 BASIC BIOLOGICAL SCIENCES↗

Nano-phase formation accompanying phase separation in undercooled CoCrCuFeNi-3 at.% Sn high entropy alloy

Highlights: • Undercooled multi-component CoCrCuFeNi-3 at.% Sn high-entropy alloy was studied. • Accompanying phase separation, the nano-precipitates were detected. • The effect of Sn on the microstructures and properties was clarified. • The microhardness increased markedly with the increase of undercooling. - Abstract: Highly undercooled multi-component CoCrCuFeNi-3 at.% Sn high-entropy alloy was studied by adopting molten glass purification combined with cycle superheating methods. Based on the critical undercooling ΔT{sup ⁎}, the characteristic of liquid-phase separation was researched at different undercoolings. Accompanying phase separation, two phases (CoCrFeNi-rich and CuNi-rich) and three kinds of nano-precipitates (CrCo-rich, CrSn-rich and Sn-rich nano-precipitates) were detected. The microhardness of undercooled CoCrCuFeNi-3 at.% Sn high-entropy alloys increased markedly with the increase of undercooling. The effect of Sn on the microstructure evolution and properties in the process of phase separation was clarified with the aid of nano-precipitates.

36 MATERIALS SCIENCE↗

Materials Data on CrCoH18(CN2)6 by Materials Project

CrCo(NH3)6(CN)6 crystallizes in the trigonal R-3 space group. The structure is zero-dimensional and consists of three azane;cobalt molecules, three chrom molecules, and eighteen hydrogen cyanide molecules.

36 MATERIALS SCIENCE↗