210 research outputs found
Nano-additive manufacturing of multilevel strengthened aluminum matrix composites
Nanostructured materials are being actively developed, while it remains an open question how to rapidly scale them up to bulk engineering materials for broad industrial applications. This study propose an industrial approach to rapidly fabricate high-strength large-size nanostructured metal matrix composites and attempts to investigate and optimize the deposition process and strengthening mechanism. Here, advanced nanocrystalline aluminum matrix composites (nanoAMCs) were assembled for the first time by a novel nano-additive manufacturing method that was guided by numerical simulations (i.e. the in-flight particle model and the porefree deposition model). The present nanoAMC with a mean grain size <50 nm in matrix exhibited hardness eight times higher than the bulk aluminum and shows the highest hardness among all Al–Al2O3 composites reported to date in the literature, which are the outcome of controlling multiscale strengthening mechanisms from tailoring solution atoms, dislocations, grain boundaries, precipitates, and externally introduced reinforcing particles. The present high-throughput strategy and method can be extended to design and architect advanced coatings or bulk materials in a highly efficient (synthesizing a nanostructured bulk with dimensions of 50 × 20 × 4 mm3 in 9 min) and highly flexible (regulating the gradient microstructures in bulk) way, which is conducive to industrial production and application
FISEdit: Accelerating Text-to-image Editing via Cache-enabled Sparse Diffusion Inference
Due to the recent success of diffusion models, text-to-image generation is
becoming increasingly popular and achieves a wide range of applications. Among
them, text-to-image editing, or continuous text-to-image generation, attracts
lots of attention and can potentially improve the quality of generated images.
It's common to see that users may want to slightly edit the generated image by
making minor modifications to their input textual descriptions for several
rounds of diffusion inference. However, such an image editing process suffers
from the low inference efficiency of many existing diffusion models even using
GPU accelerators. To solve this problem, we introduce Fast Image Semantically
Edit (FISEdit), a cached-enabled sparse diffusion model inference engine for
efficient text-to-image editing. The key intuition behind our approach is to
utilize the semantic mapping between the minor modifications on the input text
and the affected regions on the output image. For each text editing step,
FISEdit can automatically identify the affected image regions and utilize the
cached unchanged regions' feature map to accelerate the inference process.
Extensive empirical results show that FISEdit can be and
faster than existing methods on NVIDIA TITAN RTX and A100 GPUs
respectively, and even generates more satisfactory images.Comment: 12 pages, 7 figure
Construction of Nahm data and BPS monopoles with continuous symmetries
We study solutions to Nahm's equations with continuous symmetries and, under
certain (mild) hypotheses, we classify the corresponding Ans\"atze. Using our
classification, we construct novel Nahm data, and prescribe methods for
generating further solutions. Finally, we use these results to construct new
BPS monopoles with spherical symmetry.Comment: 36 pages, 1 table, 2 figures. Submitted version. Comments are
welcome
Copula approach to exchange-correlation hole in many-electron systems with strong correlations
Electronic correlation is a fundamental topic in many-electron systems. To
characterize this correlation, one may introduce the concept of
exchange-correlation hole. In this paper, we first briefly revisit its
definition and relation to electron and geminal densities, followed by their
intimate relations to copula functions in probability theory and statistics. We
then propose a copula-based approach to estimate the exchange-correlation hole
from the electron density. It is anticipated that the proposed scheme would
become a promising ingredient towards the future development of strongly
correlated electronic structure calculations.Comment: 5 page
Lithium niobate-enhanced laser photoacoustic spectroscopy
In this paper, the photoacoustic spectroscopy technique based on lithium
niobate crystals is initially reported, to our knowledge. A novel
dual-cantilever tuning fork structure and new electrodes have been designed
using Y-cut 128{\deg} blackened lithium niobate wafers. The tuning fork, with a
resonant frequency of only 10.46 kHz and a prong gap of 1 mm, is engineered to
achieve superior performance in photoacoustic spectroscopy. In the
demonstration experiment, acetylene was detected using a 1.53 um semiconductor
laser, achieving a detection limit of about 9 ppb within a one-second
integration time.Comment: 8 pages, 4 figure
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