Unselective regrowth of 1.5-μm InGaAsP multiple-quantum-well distributed-feedback buried heterostructure lasers

Unselective regrowth for fabricating 1.5-μm InGaAsP multiple-quantum well (MQW) distributed-feedback (DFB) buried heterostructure (BH) lasers is developed. The experimental results exhibit superior characteristics, such as a low threshold of 8.5mA, high slope efficiency of 0.55mW∕mA, circular-like far-field patterns, the narrow linewidth of 2.5MHz, etc. The high performance of the devices effectively proves the feasibility of the new method to fabricate buried heterostructure lasers

A comparative study on physicochemical properties of Chinese-type soy sauces prepared using pure koji and mixed kojis

Proximate indices, water soluble peptides distribution, free amino acids (FAAs) and aroma active compounds in soy sauces prepared using Aspergillus oryzae koji (SSAO) and mixed kojis (SSAON, A. oryzae koji: Aspergillus niger koji = 3:1, w/w) were determined. Results showed that SSAON resulted in 6.14, 5.97, 10.40, 71.59 and 9.62% of increases in contents of formaldehyde nitrogen, total FAAs, glutamic acid, peptides (≤1 kDa) and reducing sugar when compared with those in SSAO, whereas there were no significant differences in contents of aroma active compounds except for 2-methoxy-4- vinylphenol between these two kinds of soy sauces. The higher activities of acid protease, glucoamylase present in the mixed kojis, were the main reason for the increases of formaldehyde nitrogen, total FAAs, glutamic acid, peptides (≤1 kDa) and reducing sugar in SSAON. Moreover, results from sensory evaluation clarified that the taste of soy sauce prepared using mixture of A. oryzae koji and A. niger koji was obviously improved. Based on the results from the present study, soy sauce preparation using mixed kojis is an effective approach to improve its taste.Key words: Chinese-type soy sauce, Aspergillus oryzae, Aspergillus niger, free amino acid, aroma active compound

Adaptive segmentation of textured images by using the coupled Markov random field model

Author name used in this publication: (David) Dagan FengCentre for Multimedia Signal Processing, Department of Electronic and Information Engineering2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Morphology-based multifractal estimation for texture segmentation

Author name used in this publication: (David) Dagan FengCentre for Multimedia Signal Processing, Department of Electronic and Information Engineering2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Parametric study of cavity length and mirror reflectivity in ultralow threshold quantum well InGaAs/AlGaAs lasers

Record low CW threshold currents of 16 μA at-room temperature and 21 μA at cryogenic temperature have been demonstrated in buried heterostructure strained layer, single quantum well InGaAs/AlGaAs lasers with a short cavity length and high reflectivity coatings

Discrepant gene functional potential and cross-feedings of anammox bacteria Ca. Jettenia caeni and Ca. Brocadia sinica in response to acetate

© 2019 Elsevier Ltd Although the enhancement of anammox performance for wastewater treatment due to the addition of small amount of acetate has been reported, discrepant metabolic responses of different anammox species have not been experimentally evaluated. Based on metagenomics and metatranscriptomic data, we investigated the competitiveness between two typical anammox species, Candidatus Jettenia caeni (J. caeni) and Candidatus Brocadia sinica (B. sinica), in anammox consortia under mixotrophic condition, where complex metabolic interactions among anammox bacteria and heterotrophs also changed with acetate addition. Contrary to J. caeni, the dissimilatory nitrate reduction to ammonium pathway of B. sinica was markedly stimulated for improving nitrogen removal. More acetate metabolic pathways and up-regulated AMP-acs expression for acetyl-CoA synthesis in B. sinica contributed to its superiority in acetate utilization. Interestingly, cross-feedings, including the nitrogen cycle, amino acid cross-feeding and B-vitamin metabolic exchange between B. sinica and other heterotrophs seemed to be enhanced with acetate addition, contributing to a reduction in metabolic energy cost to the whole community. Our work not only clarified the mechanism underlying discrepant responses of different anammox species to acetate, but also suggests a possible strategy for obtaining higher nitrogen removal rates in wastewater treatment under low C/N ratio

Building stock dynamics and its impacts on materials and energy demand in China

China hosts a large amount of building stocks, which is nearly 50 billion square meters. Moreover, annual new construction is growing fast, representing half of the world's total. The trend is expected to continue through the year 2050. Impressive demand for new residential and commercial construction, relative shorter average building lifetime, and higher material intensities have driven massive domestic production of energy intensive building materials such as cement and steel. This paper developed a bottom-up building stock turnover model to project the growths, retrofits and retirements of China's residential and commercial building floor space from 2010 to 2050. It also applied typical material intensities and energy intensities to estimate building materials demand and energy consumed to produce these building materials. By conducting scenario analyses of building lifetime, it identified significant potentials of building materials and energy demand conservation. This study underscored the importance of addressing building material efficiency, improving building lifetime and quality, and promoting compact urban development to reduce energy and environment consequences in China