Triphenylphosphine oxide (TPPO) and oxalyl chloride ((COCl)
2
) are used as novel and high-efficiency coupling reagents for the esterification of alcohols with carboxylic acids via the TPPO/(COCl)
2
system at room temperature for 1 h. The reaction represents the first TPPO-promoted esterification under mild and neutral conditions with excellent yields. Furthermore, we proposed a plausible mechanism with the help of
31
P NMR spectroscopy.
A high efficient method is provided to count the number of kernels in an ear corn. PC camera captured a sequence of images around an ear corn using a simple device. The Otsu's algorithm was applied for background segmentation. An object processing area was obtained after contour extraction. The x-direction cumulative histogram was used to extract every row of the ear corn. The y-direction cumulative histogram was used to detect the number of corn kernels in a row. The number of rows was got by matching the edge of the current ear row with the first one. The time of detecting kernels for an ear corn was below 2 minutes and the average accuracy was about 95% in experiment. It shows that this method can detect the quantity of kernels directly in an ear corn quickly and effectively using a low-cost device.
AbstractIn this paper, the characteristic of a new preparation technique of activated carbon fiber (ACF) was discussed. The structures and properties of the ACF produced were investigated simultaneously. The experimental results indicated that this new technique is a high efficient method for the preparation of ACF. It needs simple facilities and is easy to be operated. The products obtained possess high specific surface area and adsorption capacity.
A rapid and efficient method for ‘one-pot’ synthesis of pyrazoles from (hetero)arenes and carboxylic acids via successive formation of ketones and β-diketones followed by heterocyclization with hydrazine has been developed.
A novel and highly efficient esterification process using triphenylphosphine oxide with oxalyl chloride