Search

• A semantic SLAM system in indoor dynamic environments is proposed. • The depth masks of objects are obtained. • The noise blocks formed by moving objects are removed. Static environment is a prerequisite for most of visual simultaneous localization and mapping systems. Such a strong assumption limits the practical application of most existing SLAM systems. When moving objects enter the camera's view field, dynamic matching points will directly interrupt the camera localization, and the noise blocks formed by moving objects will contaminate the constructed map. In this paper, a semantic SLAM system working in indoor dynamic environments named Blitz-SLAM is proposed. The noise blocks in the local point cloud are removed by combining the advantages of semantic and geometric information of mask, RGB and depth images. The global point cloud map can be obtained by merging the local point clouds. We evaluate Blitz-SLAM on the TUM RGB-D dataset and in the real-world environment. The experimental results demonstrate that Blitz-SLAM can work robustly in dynamic environments and generate a clean and accurate global point cloud map simultaneously. [ABSTRACT FROM AUTHOR]

This paper studied the sources of food and the trophic levels of silver and bighead carps using stable isotopes (δ 13 C and δ 15 N) analysis in Lake Qiandao and Lake Taihu. The δ 13 C values of POM and phytoplankton indicated that Particulate Organic Matter (POM) is of terrestrial origin in LQ and phytoplankton origin in LT. The different signature of δ 15 N of phytoplankton and POM also showed the different extent of anthropogenic impacts on the two lakes, with higher impacts in LT than in LQ. In LQ the trophic levels of silver and bighead carps were significantly different (2.48 ± 0.19 and 2.66 ± 0.19, respectively), while in LT the difference was not significant (2.15 ± 1.54 and 2.36 ± 0.38, respectively). Using a mixing model, we found that silver and bighead carps consumed a major proportion on phytoplankton and/or POM in both lakes with higher contribution of phytoplankton in more eutrophic lake. Silver and bighead carps had clear differentiation in food resources with silver carp more on POM and bighead more on zooplankton in deep and mesotrophic lakes. Contrary to this, both carps fed primarily on phytoplankton (and POM) and may have more niche overlaps in shallow and eutrophic lakes. [ABSTRACT FROM AUTHOR]

Fe 3 O 4 is considered as an appealing anode material for constructing high-energy-density asymmetric supercapacitors owing to its high theoretical capacitance, large potential window, natural abundance and eco-friendliness. However, the dilemma of inadequate practical capacitance, low rate performance and unsatisfactory cycling stability of Fe 3 O 4 -based electrode materials significantly plagues their progress in supercapacitor applications. To well utilize the advantage of Fe 3 O 4 , herein, Fe 3 O 4 @onion-like carbons (OLCs) with covalently interconnected and few-shelled graphitic coatings were synthesized in a size-controllable manner from uniform-sized monodispersed nanoparticles of Fe 3 O 4 @oleic acid ligands. The ultrasmall-sized Fe 3 O 4 nanoparticles with a good size uniformity enable a high electrochemical activity and a pseudocapacitive-dominated electrochemical behavior. Meanwhile, the efficient ion/electron transportations are facilitated by the structural advantages including covalently interconnected graphitic layers, conformal and seamless graphitic coating with ultrathin thickness, and hierarchical pores. As a result of the synergistic cooperation of these merits, the Fe 3 O 4 @OLCs hybrid structure exhibits a high specific capacitance of 686.1 F g−1 at 1 A g−1 and a high rate capability with 71.3% capacitance retention at 10 A g−1, superior to most of the reported Fe 3 O 4 -based electrode materials. An asymmetric supercapacitor device assembled based on Fe 3 O 4 @ OLCs shows a high energy density of up to 63.1 Wh kg−1, which is still maintained as high as 39.1 Wh kg−1 at a high power density of 1.49 kW kg−1. Moreover, a high cycling stability (more than 80% of initial capacitance remained after 10,000 cycles) is obtained. This study offers a novel strategy for preparing high-performance Fe 3 O 4 /carbon hybrid structures for asymmetric supercapacitor applications. [Display omitted] • A size-controllable synthesis of covalently interconnected Fe 3 O 4 @OLCs hybrid structures was developed. • The ultrasmall Fe 3 O 4 size and graphitic structural advantages result in high capacitance and rapid ion/electron transfer. • The hybrid structure exhibits a high specific capacitance of 686.1 F g−1 with a high rate performance. • The asymmetric supercapacitor shows a high energy density of 63.1 Wh kg−1 and a good cycling stability. [ABSTRACT FROM AUTHOR]

Coilia nasus is widely distributed along the coast, and rivers and lakes that connect with the ocean in China. It is a diadromous fish but has residential populations in the middle and lower reach of the Yangtze River and its associated lakes such as Lake Taihu. These ecologically differentiated diadromous and residential populations are difficult to identify and separate, even with current molecular screening methods such as applying the mtDNA markers. The objective of the present study was to screen these populations by the means of the whole body elemental fingerprint analysis (EFA). Our results showed that the diadromous population had significantly lower concentrations of Al, B, Ca, Cr, Fe, K, Mg, Mn, P, S, and Zn, and significantly higher As than the residential populations. The spawners had lower concentrations of B, Cr, P, and S before laying eggs than after laying eggs. Advanced statistical models detected distinct spatial patterns between the diadromous and residential populations, and between groups before and after spawning. The current study showed that the whole body EFA can clearly distinguish C. nasus populations in the Yangtze River Basin and thus proved to be useful and may substitute the elemental fingerprint of fish otolith in future fish ecological studies that need to identify different populations. [ABSTRACT FROM AUTHOR]