同步硝化反硝化脱氮的关键因素探讨

结合近年来国内外的研究成果,主要讨论了三个关键因子对同步硝化反硝化(SND)脱氮的影响,并为影响SND的研究提出今后的方向。     

Constant hue bands in boundary colors discovered using a new appearance model

Boundary colors are observed when light from a scene is dispersed by a prism or diffraction grating. We discovered that patterns with repeating black and white stripes can produce repeating bands of boundary colors with two hues. These hues are virtually constant as measured by chromaticity or CIELAB. We found seven cases of this kind using a new appearance model for boundary colors. The model correctly predicts that green and magenta bands recur as stripe widths and dispersion strength vary. The first green/magenta case in the sequence traces out an accurate ellipse in XYZ color space. Green and magenta bands are prominent in supernumerary rainbows and interference rings, and we explain why that might be the case. The explanation is based on an interesting property of the visible spectrum. In addition to the green/magenta cases, the other cases are orange/cyan, yellowish‐green/purple, and yellow/violet. The success of the boundary color appearance model implies that bands are perceived as if the wavelength responses of the cones were essentially independent, which contradicts the actual behavior of cones. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 135–146, 2015     

The incorporation of low-substituted hydroxypropyl cellulose into solid dispersion systems

While the use of amorphous solid dispersions to improve aqueous solubility is well documented, little consideration has traditionally been given to the finished dosage form. The objective of this study was to evaluate the dissolution performance of amorphous solid dispersions containing a dispersed superdisintegrant with binding properties. KinetiSol® dispersing was used to thermally process hypromellose acetate succinate-based compositions containing the drug substance nifedipine (NIF) and a highly compressible grade of low-substituted hydroxypropyl cellulose (New Binder Disintegrants; NBD-grade). Solid-state analysis demonstrated that compositions were rendered amorphous during processing. Tablets containing intra-dispersion NBD were found to exhibit non-sink dissolution performance similar to milled intermediate, demonstrating excellent disintegration characteristics. Conversely, tablets without intra-dispersion NBD were found to release significantly less NIF during dissolution analysis due to particle agglomeration. It was determined that compressibility and particle wetting increased as the level of intra-dispersion NBD increased.