In the oligotrophic environment of the Mariana Trench, alkanes as carbohydrates are important for the ecosystem, but their spatial and periodic spreading in deep waters has never been reported. Alkane-degrading bacteria such as Alcanivorax spp. are biological signals of the alkane distribution. In the present study, Alcanivorax was abundant in some waters, at depths of up to 6,000 m, in the Mariana Trench. Genomic, transcriptomic, and chemical analyses provide evidence for the presence and activities of Alcanivorax jadensis in deep sea zones. The periodic spreading of alkanes, probably from the subductive plates, might have fundamentally modified the local microbial communities, as well as perhaps the deep sea microenvironment.

The rapid aggregation of modern urban population and the rapid growth of car travel lead to traffic congestion, environmental pollution, and other problems. In view of the limited land resources in our country, it is impractical to meet residents’ travel demand by blindly increasing traffic supply. Therefore, addressing the urban road congestion problem for sustainable development of modern cities, the paper makes research on residents’ travel behavior characteristics and travel preference under the condition of multimodal transportation to formulate reasonable traffic demand management strategy for the guide on public traffic demand, bus priority strategy, and congestion management. The operation characteristic of each transportation mode is analyzed by comparing its related traffic and economic characteristics. Multimode traffic choice behavior is discussed by establishing multiple logistic regression models to analyze the main influencing factors to travelers’ social and economic attributes, travel characteristics, and preference based on travel survey data of urban residents. The paper proposes the development of an urban public transportation system and travelling mode shift from cars to public transportation as reasonable travel structure for congestion management and sustainable development of modern cities.

ZnS:F quantum dots (QDs) capping with and without L-cys were synthesized by a solid-state method at low temperature, and the influence of L-cys on the properties of ZnS:F QDs were investigated. The crystal structure, surface morphology and luminescent properties of the samples were analyzed by X-ray diffractometer (XRD), transmission electron microscope (TEM), fourier transform infrared (FTIR), photoluminescence spectrometer (PL) and ultraviolet-visible spectrometer (UV-Vis). The results showed that all samples had a zinc blende structure with particle size in the range of 2-6 nm. The emission intensity was significantly enhanced after capping with L-cys, and the strongest luminescence was obtained when the ratio of L-cys/ZnS:F was 0.8:1, and was about 2.5 times of that of ZnS:F QDs. The capping of L-cys increased the grain size of ZnS:F QDs and their water solubility.