有机固体废弃物化学链气化技术研究进展

化学链气化技术(CLG, Chemical looping gasification)是基于化学链燃烧技术(CLC, Chemical looping combustion)发展而来的一种新颖的固体燃料气化技术。相较于常规气化技术,化学链气化技术省去了氧气制备、且不需要燃料燃烧来提供热量,具有合成气不被氮气稀释、焦油及N/S/Cl等污染物含量低、能量梯级利用等优点。以有机固体废弃物(简称有机固废)种类、载氧体(OC, Oxygen carrier)类型和反应装置为切入点,较为系统地综述了化学链气化处理有机固废技术的发展现状,围绕有机固废的气化特性及相关反应机理与系统进行了较为全面的介绍,并对其未来的研究方向进行了展望。     

CFD modelling of air flow and thermal performance of an atrium integrated with photovoltaics

The thermal performance of an atrium integrated with photovoltaic (PV) modules has been evaluated. Computational fluid dynamics (CFD) was applied to the prediction of air flow and temperature distribution in the atrium. CFD was then used to investigate the effect of ventilation strategies on the performance of PV arrays. CFD modelling indicated that for effective cooling of roof PV arrays, cool outdoor air should be introduced through an opening positioned close to the roof or an air channel underneath the roof.     

Remote estimation of regional evapotranspiration

Three models are applied to estimating evapotranspiration in central Australia, using limited routine meteorological data and the NOAA-14 AVHRR overpass. By minimizing the difference between model predicted surface temperature and satellite derived temperature to adjust the estimated soil moisture, both an instantaneous physically based model and a one dimensional boundary layer simulation yielded consistent results. This highlights the sensitivity of surface temperature to soil moisture and suggests that radiometric surface temperature can be used to adjust simple water balance estimates of soil moisture providing a simple and effective means of estimating large scale evapotranspiration in remote arid regions.     

Dual Mesh Resampling

The dual of a 2-manifold polygonal mesh without boundary is commonly defined as another mesh with the same topology (genus) but different connectivity (vertex–face incidence), in which faces and vertices occupy complementary locations and the position of each dual vertex is computed as the center of mass (barycenter or centroid) of the vertices that support the corresponding face. This barycenter dual mesh operator is connectivity idempotent but not geometrically idempotent for any choice of vertex positions, other than constants. In this paper we construct a new resampling dual mesh operator that is geometrically idempotent for the largest possible linear subspace of vertex positions. We look at the primal and dual mesh connectivities as irregular sampling spaces and at the rules to determine dual vertex positions as the result of a resampling process that minimizes signal loss. Our formulation, motivated by the duality of Platonic solids, requires the solution of a simple least-squares problem. We introduce a simple and efficient iterative algorithm closely related to Laplacian smoothing and with the same computational cost. We also characterize the configurations of vertex positions where signal loss does and does not occur during dual mesh resampling and the asymptotic behavior of iterative dual mesh resampling in the general case. Finally, we describe the close relation existing with discrete fairing and variational subdivision, and define a new primal–dual interpolatory recursive subdivision scheme.     

River run: an interactive GIS and dynamic graphing website for decision support and exploratory data analysis of water quality parameters of the lower Cape Fear river

To visualize the water quality of the Lower Cape Fear River basin a Decision Support System (DSS) web site was developed which incorporates dynamic graphing and Geographic Information System (GIS) software. Together, these two software packages enable users to interact with water quality variables in order to investigate the spatial and temporal complexity of the data. The result of this research is that graphing and GIS technology are capable of being implemented over the Internet and that complex water quality data can be successfully disseminated using this medium. However, there remains a need to seamlessly link the graphing and GIS software which will make the visualization tools much more successful at communicating the complex spatial and temporal data.     

Carbide stoichiometry in TiCx and Cu–TiCx produced by self-propagating high-temperature synthesis

TiC_x and Cu–TiC_x have been formed by self-propagating high-temperature synthesis (SHS) from elemental powder mixtures with a range of C/Ti ratios. When no copper was present, the carbide stoichiometry closely followed that of the starting powders. In the presence of copper, formation of copper–titanium intermetallics and solid solutions resulted in a different carbide stoichiometry.     

The Discrepancy of Fatty Acid Composition of Astaxanthin Esters and Total Fatty Acids in Photoautotrophic and Heterotrophic Chlorella zofingiensis

Chlorella zofingiensis has great potential for astaxanthin and fatty acid production. This study investigated the accumulation of astaxanthin and total fatty acids (TFA), the fatty acid compositions of astaxanthin esters and TFA in photoautotrophic and heterotrophic C. zofingiensis, respectively. The results displayed that in photoautotrophic cells, 18:3 was the most predominant fatty acid, followed by 16:0, 18:2, and 18:1, while astaxanthin mono-esters (mono-AE) contained only 16:0 and 18:0, and astaxanthin di-esters (di-AE) contained 16:0 mostly, followed by 18:1, 18:0, 18:2, and 18:3. C. zofingiensis accumulated the highest level of astaxanthin and TFA under heterotrophic conditions fed with 30 g L⁻¹ glucose. The percentage of 18:1 in TFA, mono-AE, and di-AE increased from 10.05%, 0%, and 17.76% to 35.80%, 14.84%, and 50.12%, respectively; in contrast, the percentages of 18:3 in TFA and di-AE were observed to decrease from 40.42% and 7.59% to 9.56% and 1.30%, respectively, in comparison with those in photoautotrophic ones. The RNA sequencing (RNA-seq) results showed that the expressions of the genes in astaxanthin and fatty acid biosynthetic pathways were increased under this heterotrophic condition. These results indicated differential accumulation of AE and TFA, especially fatty acid compositions of TFA and AE in photoautotrophic and heterotrophic cells, suggesting a positive correlation between astaxanthin and fatty acid biosynthesis.     

低温等离子体对水产品常见微生物灭活效果影响的研究进展

水产品极易腐败变质,需要采取一定的措施抑制其腐败变质。低温等离子体（Cold Plasma,CP）作为一种新型高效的广谱冷杀菌技术,可以在大气压下实现均匀、稳定放电,且对常见水产品致病菌和腐败菌具有较好的杀灭效果,可以延长水产品的货架期。作者综述了CP产生方式、灭活微生物机制及影响其灭菌效果的因素,同时探讨了CP对不同种微生物的杀灭效果及对水产品品质的影响,以期为CP在水产品保鲜中的应用提供参考。     

Evaluating residents' satisfaction with market-oriented urban village transformation: A case study of Yangji Village in Guangzhou,China

The large-scale urban village transformation in China has had a profound influence on the livelihood and interests of residents, which has also affected the residents' satisfaction and the stability of the society. This study extends the connotation of residential satisfaction to evaluate residents' satisfaction with market-oriented urban village transformation and to establish a conceptual framework in evaluating the aspects of result satisfaction and process satisfaction. The study examines residents' satisfaction with the market-oriented urban village transformation and the factors that influence this satisfaction using data from a field investigation in Yangji Village, Guangzhou City. Results show that overall, the residents in Yangji Village are satisfied with the transformation and that the residents' satisfaction is influenced considerably by both the results and the process of transformation, that is, community environment and quality, government and enterprise behaviours and housing conditions. The market-oriented model contributes to residents' satisfaction. The study suggests that by considering the process and results of the transformation as well as giving full play to the market-oriented model and paying attention to the model's risks can improve residents' satisfaction with urban village transformation.