Dynamic Demand Forecast and Assignment Model for Bike-and-Ride System

Bike-and-Ride (B&R) has long been considered as an effective way to deal with urbanization-related issues such as traffic congestion, emissions, equality, etc. Although there are some studies focused on the B&R demand forecast, the influencing factors from previous studies have been excluded from those forecasting methods. To fill this gap, this paper proposes a new B&R demand forecast model considering the influencing factors as dynamic rather than fixed ones to reach higher forecasting accuracy. This model is tested in a theoretical network to validate the feasibility and effectiveness and the results show that the generalised cost does have an effect on the demand for the B&R system.</p

Facile spray drying synthesis of porous structured ZnFe2O4 as high-performance anode material for lithium-ion batteries

Porous ZnFe2O4 nanorods have been successfully prepared by a simple spray-drying process followed by sintering. The structure and morphology of the samples were characterized by X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. The porous structured ZnFe2O4 materials are successfully used as potential anode material for lithium-ion batteries. Electrochemical results show that the anodes exhibit good cycling performance and rate capability. The anode exhibits initial discharge capacity of approximately 1459 mAh g−1 with an initial coulombic efficiency of 77.8% at a constant density of 100 mA g−1. The discharge capacity of the ZnFe2O4 retained 1458 mA h g−1 after 120 cycles at the current rate of 100 mA g−1 and 456 mA h g−1 could be obtained at the current density of 5000 mA g−1 after 200 cycles. The discharge capacities can still be as high as 778 mAh g−1 at a high rate of 3000 mA g−1. Such remarkable electrochemical properties could be ascribed to the unique porous morphology with large surface area and porosity that were beneficial to facilitate the diffusion of Li ions and electrolyte into the electrodes, meanwhile prevent volume expansion/contraction during lithiation/dislithiation processes

Occurrence of polychlorinated biphenyls (PCBs) together with sediment properties in the surface sediments of the Bering Sea, Chukchi Sea and Canada Basin

The spatial distribution and potential source of polychlorinated biphenyls (PCBs) in surface sediments from Bering Sea, Chukchi Sea, and Canada Basin and the relationship between PCBs and sedimentary properties including grain size, water content, loss on ignition, total organic carbon, and black carbon were explored. Sigma PCBs (the sum of the detected PCB congeners) concentrations fluctuated in the study area, ranging from 22-150,60-640 and 24-600 pg g(-1) dry weight for the Bering Sea, Chukchi Sea, and Canada Basin. A similar homologue pattern was observed at different locations, with tri-chlorinated PCBs being the dominant homologue, implying that the PCBs came mainly from the atmospheric transportation and deposition and ocean current transportation. No apparent co-relationships between PCB concentrations and sediment properties were obtained, indicating that the distribution of PCBs was not only controlled by their source, but also by the multi-factors such as atmospheric transport and depositing, mixing, partitioning and sorption in the water column and sediments. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.National Natural Science Foundation of China (NSFC) [40776040, 40306012]; Ocean Public Welfare Scientific Research Project, the State Oceanic Administration of China [200805095