Image detail enhancement is critical to the performance of infrared imaging systems because the original images generally suffer from low contrast and a low signal-to-noise ratio. Although conventional decomposition-based methods have advantages in enhancing image details, they also have clear disadvantages, which include intensive computations, over-enhanced noise, and gradient reversal artifacts. In this paper, we propose to accelerate enhancement processing by using a fast guided filter and plateau equalization. Our method consists of image decomposition, base and detail layers processing, and projection of the enhanced image to an 8-bit dynamic range. Experimental results demonstrated that our proposed method achieves a good balance among detail enhancement performance, noise and gradient reversal artifacts suppression, and computational cost, with a frame rate around 30 fps for
640
×
512
infrared images.
In the last 15 years, copper-catalyzed borylative transformations
utilizing boryl–copper have been established as a powerful
activation mode in organic synthesis and catalysis, enabling direct
transformations of various π-systems. Although many of these
transformations use NHC (N-heterocyclic carbene) ligands, these studies
have been almost exclusively limited to the derivatives of imidazol-2-ylidenes.
However, the molecular properties of N-aryl-imidazol-2-ylidenes,
such as IPr (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene),
are limited by (1) the high degree of heteroatom stabilization and
(2) symmetrical substitution of the nitrogen atoms. Herein, we report
a study on Cu(I)–thiazol-2-ylidenes, thiazole analogues of
imidazol-2-ylidenes, which (1) feature a distinct half-umbrella shape
of the coordinating ligand and (2) exhibit lower heteroatom stabilization
of the ancillary ligand through reduced π-donation from sulfur.
We present the development of a family of stable Cu(I)–thiazol-2-ylidenes,
where the combined sterics of thiazol-2-ylidenes lead to monomers
[Cu(NHC)X] or bridged-halo dimers [Cu(NHC) (μ-X)]2, their crystallographic characteristics, and application to the
hydroboration of alkynes to afford trisubstituted vinylboronates by
β-hydroboration of internal alkynes or terminal vinylboronates
by β-hydroboration of terminal alkynes. Application to the late-stage
modification and detailed mechanistic studies on the catalyst structure
and activation are presented. Most crucially, Cu(I)–thiazol-2-ylidenes
show a much higher β-selectivity in the hydroboration of alkynes
than that of classical imidazol-2-ylidenes, affording vinylborons
in excellent yields at ambient conditions. The unique “half-umbrella”
shape of thiazol-2-ylidenes reverses the α/β regioselectivity
observed with imidazol-2-ylidenes in the hydroboration of terminal
alkynes. Kinetic studies demonstrate that Cu(I)–thiazol-2-ylidenes
supersede imidazol-2-ylidenes. Considering the significant utility
of borylative transformations of π-systems, we anticipate that
Cu(I)–thiazol-2-ylidenes will advance the synthetic transformations
of boryl–copper in organic synthesis and catalysis.
Sorghum (Sorghum bicolor (L.) Moench) is one of the most important cereals in the Northeast China. The physicochemical, pasting, texture, and cooking properties of 21 sorghum varieties were determined, which were mainly cultivated in Northeast China. Then, the evaluation of edible quality of sorghum was based on principal component analysis and fitted with the score of sensory evaluation. Five principal components (PCs) with a cumulative contribution rate of 86.19% could be picked out to describe the taste, pasting, flavor, cooking, and variety of sorghum, respectively. And a comprehensive equation of sorghum edible quality in Northeast China was constructed which was Z = 0.45F1 + 0.25F2 + 0.12F3 + 0.10F4 + 0.08F5. The edible quality of No. 14 and No. 15 was the best. The sensory evaluation was used to verify the above equation with the fitting coefficient of 0.81, which indicated that the equation could be more accurate to evaluate the edible quality of sorghum in Northeast China.
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