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All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Slope inequalities for KSB‐stable and K‐stable families

Abstract We prove some higher dimensional generalizations of the slope inequality originally due to G. Xiao, and to M. Cornalba and J. Harris. We give applications to families of KSB‐stable and K‐stable pairs, as well as to the study of the ample cone of the moduli space of KSB‐stable varieties. Our proofs rely on the study of the Harder–Narasimhan filtration, and some generalizations of Castelnuovo's and Noether's inequalities.

Codogni, Giulio↗
DOE OSTI2020

Materials Data on KSb by Materials Project

KSb crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to six Sb1- atoms. There are a spread of K–Sb bond distances ranging from 3.58–3.76 Å. In the second K1+ site, K1+ is bonded in a 6-coordinate geometry to six Sb1- atoms. There are a spread of K–Sb bond distances ranging from 3.61–3.94 Å. There are two inequivalent Sb1- sites. In the first Sb1- site, Sb1- is bonded in a 8-coordinate geometry to six K1+ and two equivalent Sb1- atoms. There are one shorter (2.88 Å) and one longer (2.91 Å) Sb–Sb bond lengths. In the second Sb1- site, Sb1- is bonded in a 8-coordinate geometry to six K1+ and two equivalent Sb1- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KSb(PS3)2 by Materials Project

KSb(PS3)2 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. K1+ is bonded in a 9-coordinate geometry to nine S2- atoms. There are a spread of K–S bond distances ranging from 3.30–3.69 Å. Sb3+ is bonded in a distorted square pyramidal geometry to five S2- atoms. There are a spread of Sb–S bond distances ranging from 2.57–3.18 Å. There are two inequivalent P4+ sites. In the first P4+ site, P4+ is bonded in a trigonal non-coplanar geometry to three S2- atoms. There are a spread of P–S bond distances ranging from 1.97–2.08 Å. In the second P4+ site, P4+ is bonded in a trigonal non-coplanar geometry to three S2- atoms. There are a spread of P–S bond distances ranging from 2.00–2.09 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded in a 2-coordinate geometry to one K1+, one Sb3+, and one P4+ atom. In the second S2- site, S2- is bonded in a water-like geometry to one Sb3+ and one P4+ atom. In the third S2- site, S2- is bonded in a 1-coordinate geometry to two equivalent K1+, one Sb3+, and one P4+ atom. In the fourth S2- site, S2- is bonded in a 2-coordinate geometry to one K1+, one Sb3+, and one P4+ atom. In the fifth S2- site, S2- is bonded in a 1-coordinate geometry to three equivalent K1+ and one P4+ atom. In the sixth S2- site, S2- is bonded in a distorted single-bond geometry to two equivalent K1+, one Sb3+, and one P4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KSb(PSe3)2 by Materials Project

KSb(PSe3)2 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. K1+ is bonded in a 9-coordinate geometry to nine Se2- atoms. There are a spread of K–Se bond distances ranging from 3.47–3.87 Å. Sb3+ is bonded in a distorted square pyramidal geometry to five Se2- atoms. There are a spread of Sb–Se bond distances ranging from 2.69–3.24 Å. There are two inequivalent P4+ sites. In the first P4+ site, P4+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of P–Se bond distances ranging from 2.15–2.24 Å. In the second P4+ site, P4+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of P–Se bond distances ranging from 2.19–2.28 Å. There are six inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 2-coordinate geometry to one K1+, one Sb3+, and one P4+ atom. In the second Se2- site, Se2- is bonded in a 1-coordinate geometry to two equivalent K1+, one Sb3+, and one P4+ atom. In the third Se2- site, Se2- is bonded in a 1-coordinate geometry to three equivalent K1+ and one P4+ atom. In the fourth Se2- site, Se2- is bonded in a 2-coordinate geometry to one K1+, one Sb3+, and one P4+ atom. In the fifth Se2- site, Se2- is bonded in a water-like geometry to one Sb3+ and one P4+ atom. In the sixth Se2- site, Se2- is bonded in a 1-coordinate geometry to two equivalent K1+, one Sb3+, and one P4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KSb(SO4)2 by Materials Project

KSb(SO4)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.79–3.22 Å. Sb3+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Sb–O bond distances ranging from 2.05–2.31 Å. There are two inequivalent S6+ sites. In the first S6+ site, S6+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of S–O bond distances ranging from 1.45–1.58 Å. In the second S6+ site, S6+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of S–O bond distances ranging from 1.45–1.58 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+ and one S6+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent K1+ and one S6+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one Sb3+, and one S6+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+, one Sb3+, and one S6+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+ and one S6+ atom. In the sixth O2- site, O2- is bonded in a single-bond geometry to one S6+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Sb3+ and one S6+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+, one Sb3+, and one S6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KSb(PO4)2 by Materials Project

KSbP2O8 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. K1+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All K–O bond lengths are 2.99 Å. Sb5+ is bonded to six equivalent O2- atoms to form SbO6 octahedra that share corners with six equivalent PO4 tetrahedra. All Sb–O bond lengths are 1.99 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent SbO6 octahedra. The corner-sharing octahedral tilt angles are 44°. There is one shorter (1.49 Å) and three longer (1.58 Å) P–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent K1+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Sb5+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KSb(MoO4)2 by Materials Project

KSbMo2O8 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.73–2.81 Å. There are two inequivalent Mo6+ sites. In the first Mo6+ site, Mo6+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 1.74–1.89 Å. In the second Mo6+ site, Mo6+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Mo–O bond distances ranging from 1.74–2.49 Å. Sb3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Sb–O bond distances ranging from 2.03–2.64 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mo6+ and one Sb3+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one K1+ and one Mo6+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and two equivalent Mo6+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and one Mo6+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Mo6+ and two equivalent Sb3+ atoms. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one K1+, one Mo6+, and one Sb3+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+ and one Mo6+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Mo6+ and one Sb3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Sequence Length of HIV-1 Subtype B Increases over Time: Analysis of a Cohort of Patients with Hemophilia over 30 Years

We aimed to investigate whether the sequence length of HIV-1 increases over time. We performed a longitudinal analysis of full-length coding region sequences (FLs) during an HIV-1 outbreak among patients with hemophilia and local controls infected with the Korean subclade B of HIV-1 (KSB). Genes were amplified by overlapping RT-PCR or nested PCR and subjected to direct sequencing. Overall, 141 FLs were sequentially determined over 30 years in 62 KSB-infected patients. Phylogenetic analysis indicated that within KSB, two FLs from plasma donors O and P comprised two clusters, together with 8 and 12 patients with hemophilia, respectively. Signature pattern analysis of the KSB of HIV-1 revealed 91 signature nucleotide residues (1.1%). In total, 48 and 43 signature nucleotides originated from clusters O and P, respectively. Six positions contained 100% specific nucleotide(s) in clusters O and P. In-depth FL analysis for over 30 years indicated that the KSB FL significantly increased over time before combination antiretroviral therapy (cART) and decreased with cART. This increase occurred due to the significant increase in env and nef genes, originating in the variable regions of both genes. The increase in sequence length of HIV-1 over time suggests an evolutionary direction.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Constraining the masses of high-redshift clusters with weak lensing: Revised shape calibration testing for the impact of stronger shears and increased blending

Weak lensing measurements suffer from well-known shear estimation biases, which can be partially corrected for with the use of image simulations. Here we present an analysis of simulated images that mimic Hubble Space Telescope/Advance Camera for Surveys observations of high-redshift galaxy clusters, including cluster specific issues such as non-weak shear and increased blending. Our synthetic galaxies have been generated to have similar observed properties as the background-selected source samples studied in the real images. First, we used simulations with galaxies placed on a grid to determine a revised signal-to-noise-dependent (S/N KSB ) correction for multiplicative shear measurement bias, and to quantify the sensitivity of our KSB+ bias calibration to mismatches of galaxy or PSF properties between the real data and the simulations. Next, we studied the impact of increased blending and light contamination from cluster and foreground galaxies, finding it to be negligible for high-redshift (z > 0.7) clusters, whereas shear measurements can be affected at the ~1% level for lower redshift clusters given their brighter member galaxies. Finally, we studied the impact of fainter neighbours and selection bias using a set of simulated images that mimic the positions and magnitudes of galaxies in Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS) data, thereby including realistic clustering. While the initial SExtractor object detection causes a multiplicative shear selection bias of –0.028 ± 0.002, this is reduced to –0.016 ± 0.002 by further cuts applied in our pipeline. Given the limited depth of the CANDELS data, we compared our CANDELS-based estimate for the impact of faint neighbours on the multiplicative shear measurement bias to a grid-based analysis, to which we added clustered galaxies to even fainter magnitudes based on Hubble Ultra Deep Field data, yielding a refined estimate of ~ –0.013. Our sensitivity analysis suggests that our pipeline is calibrated to an accuracy of ~0.015 once all corrections are applied, which is fully sufficient for current and near-future weak lensing studies of high-redshift clusters. As an application, we used it for a refined analysis of three highly relaxed clusters from the South Pole Telescope Sunyaev-Zeldovich survey, where we now included measurements down to the cluster core (r > 200 kpc) as enabled by our work. Compared to previously employed scales (r > 500 kpc), this tightens the cluster mass constraints by a factor 1.38 on average.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2024

ASb 3 Mn 9 O 19 (A = K or Rb): New Mn-Based 2D Magnetoplumbites with Geometric and Magnetic Frustration

Magnetoplumbites are one of the most broadly studied families of hexagonal ferrites, typically with high magnetic ordering temperatures, making them excellent candidates for permanent magnets. However, magnetic frustration is rarely observed in magnetoplumbites. Herein, the discovery, synthesis, and characterization of the first Mn-based magnetoplumbite, as well as the first magnetoplumbite involving pnictogens (Sb), ASb 3 Mn 9 O 19 (A = K or Rb) are reported. The Mn 3+ ( S = 2) cations, further confirmed by DC magnetic susceptibility and X-ray photoelectron spectroscopy, construct three geometrically frustrated sublattices, including Kagome, triangular, and puckered honeycomb lattices. Magnetic properties measurements revealed strong antiferromagnetic spin–spin coupling as well as multiple low-temperature magnetic features. Heat capacity data does not show any prominent λ-anomaly, suggesting minimal associated magnetic entropy. Moreover, neutron powder diffraction (NPD) implied the absence of long-range magnetic ordering in KSb 3 Mn 9 O 19 down to 3 K. However, several magnetic peaks are observed in RbSb 3 Mn 9 O 19 at 3 K, corresponding to an incommensurate magnetic structure. Interestingly, strong diffuse scattering is seen in the NPD patterns of both compounds at low angles and is analyzed by reverse Monte Carlo refinements, indicating short-range spin ordering related to frustrated magnetism as well as 2D magnetic correlations in ASb 3 Mn 9 O 19 (A = K or Rb).

2-D magnetic correlation↗
DOE OSTI2026

Measurement of the QE Map

113 MHz SRF gun utilized CsK 2 Sb and Na 2 KSb cathodes, which were irradiated with a pulsed green laser with a wavelength of 0.53 microns. The drive laser generated 78 kHz pulses with an acousto-optic modulator selecting the desired number of pulses reaching the cathode. The operator can select the aperture size, defining the laser spot diameter on the cathode, and the power level, which is controlled by a rotating polarizer. The laser power reaching the cathode can be measured with a meter based on a photodiode. The quantum efficiency (QE) of a photocathode serves as a primary indicator of its state. Small QE renders the cathode unusable when the desired bunch charge cannot be achieved. Strong variations in the quantum efficiency on the cathode surface might lead to the growth of the beam emittance due to the space charge effects. We have created a routine to measure the distribution of the QE on the cathode. The operator selects the aperture size, the central spot location, and the scan ranges for both planes. The scan starts from the central spots and proceeds along a spiral-like trajectory, making N rounds. The number of rounds can be chosen, and the total number of measured points is (2N+1) 2 . The laser spot movement is shown in Fig. 1.

43 PARTICLE ACCELERATORS↗