Location of Electric Vehicle Charging Station Based on Spatial Clustering and Multi-hierarchical Fuzzy Evaluation

For the charging station construction of electric vehicle,location selecting is a key issue.There are two problems in location selection of the electric vehicle charging station.One is determining the location of charging station;the other is evaluating the location of charging station.To determine the charging station location,an spatial clustering algorithm is proposed and programmed.The example simulation shows the effectiveness of the spatial clustering algorithm.To evaluate the charging station location,a multi-hierarchical fuzzy method is proposed.Based on the location factors of electric vehicle charging station,the hierarchical evaluation structure of electric vehicle charging station location is constructed,including three levels,4first-class factors and 14second-class factors.The fuzzy multi-hierarchical evaluation model and algorithm are built.The analysis results show that the multi-hierarchical fuzzy method can reasonably complete the electric vehicle charging station location evaluation.

Multi-hierarchical flexible composites towards superior fire safety and electromagnetic interference shielding

Vast amounts of electromagnetic waves are generated in modern society,which severely endanger human health and cause instrument disturbance.Furthermore,practical application of electromagnetic shielding polymer-based materials aspires to flame retardancy.Herein,cellulose acetate butyrate modified ammonium polyphosphate(CAPP)and phosphoramide flame retardant decorated short carbon fiber(MSCF)were synthesized separately and then simultaneously blended into thermoplastic polyurethane(TPU)to prepare a series of flame retardant TPU composites.Then,the multi-hierarchical flexible TPU/CAPP/MSCF composites were fabricated via our self-developed air-assisted thermocompression method.The results revealed that the TPU/CAPP/MSCF showed improved thermal stability.Moreover,the TPU/10CA/2.5F incorporated with 10.0 wt.%CAPP and 2.5 wt.%MSCF respectively exhibited 77.8%and 58.6%reduction in peak of heat release rate(PHRR)and total heat release(THR),compared to those of pure TPU.In addition,the TPU/10CA/2.5F passed the UL-94 V-0 rating test and achieved a higher limit oxygen index(LOI)(27.3%)than pure TPU(21.7%).In the case of electromagnetic interference shielding effectiveness(EMI SE),the TPU/10CA/10.0F-SW with 10 wt.%CAPP and 10 wt.%MSCF dispersed in the surface layer and Ti_(3)C_(2)Tx MXene intercalated in the interlayer exhibited EMI SE of 43.8 dB in X band and 32.0 dB in K band.Summarily,synergistic effect between CAPP and MSCF together with scattered and multiply adsorbed effect of MSCF,MXene and CAPP was responsible for fire safety and EMI shielding property improvements.This work provides a fascinating strategy for fabricating multi-hierarchical flexible TPU composites with outstanding flame retardant and EMI shielding performances.

Dike Breach Risks of Different Flood Conditions in the Lower Yellow River

Based on the analysis of hanging rivers' actuality in the lower Yellow River and researches related to the evaluation of dike breach risks,it is put forward that the influencing factors of dike beach risks in the lower Yellow River should involve four aspects,the flow and sediment movement,the regional crustal stability,the variation of river regime and the stability of river dikes.With this,the evaluation indexes system of dike breach risks is established,and with the support of geographic information systems technology,the model of multi-hierarchical fuzzy comprehensive judgment is applied to estimate the dike beach risks of the hanging rivers in the lower Yellow River under different flood conditions.The evaluation results of dike breach risks show the following distributing regularities of dike breach risks in the lower Yellow River:(1) Dike breach risks increase with the increase of the flood.(2) Dike breach risks decrease with the changes of river patterns along the channel.(3) There are great risks of dike breach in the wandering reaches,and it is relatively higher in the south bank than in the north in wandering reaches.(4) There is a higher dike breach risk in the north bank than in the south in winding reaches.Simultaneously,the evaluation results manifest that the evaluation indexes system established from the flow and sediment movement,the regional crustal stability,the variation of river regime and the stability of river dikes can represent the actual situation of the lower Yellow River more comprehensively.The application of multihierarchical fuzzy comprehensive judgment can preferably resolve the problem of hanging river dike breach,which has numerous influencing factors and complicated functionary mechanisms.The applications of geographic information systems technology with powerful spatial analysis functions make dike beach risks quantificationally displayed in different spatial positions,and reflect the differences of dike beach risks in different spatial positions of the channel in the lower Yellow River.

Wet-spinning fabrication of shear-patterned alginate hydrogel microfibers and the guidance of cell alignment

Native tissue is naturally comprised of highly-ordered cell-matrix assemblies in a multi-hierarchical way,and the nano/submicron alignment of fibrous matrix is found to be significant in supporting cellular functionalization.In this study,a self-designed wet-spinning device appended with a rotary receiving pool was used to continuously produce shear-patterned hydrogel microfibers with aligned submicron topography.The process that the flow-induced shear force reshapes the surface of hydrogel fiber into aligned submicron topography was systematically analysed.Afterwards,the effect of fiber topography on cellular longitudinal spread and elongation was investigated by culturing rat neuron-like PC12 cells and human osteosarcoma MG63 cells with the spun hydrogel microfibers,respectively.The results suggested that the stronger shear flow force would lead to more distinct aligned submicron topography on fiber surface,which could induce cell orientation along with fiber axis and therefore form the cell-matrix dual-alignment.Finally,a multi-hierarchical tissue-like structure constructed by dual-oriented cell-matrix assemblies was fabricated based on this wet-spinning method.This work is believed to be a potentially novel biofabrication scheme for bottom-up constructing of engineered linear tissue,such as nerve bundle,cortical bone,muscle and hepatic cord.