Design and motion control analysis of double helix wall climbing robot

For the detection environment of complex walls such as high-rise buildings,a double helix wall climbing robot(DHWCR)with strong adsorption force and good stability is designed and developed,which uses symmetrical propellers to provide adsorption force.The symmetrical driving structure can provide smooth thrust for the DHWCR,so that the robot can be absorbed to the wall surface with different roughness.A left and right control frame with multiple degrees of freedom is designed,which can adjust the fixed position of the brushless propeller motor in the front and back directions,realize the continuous adjustable thrust direction of the robot,and improve the flexibility of the robot movement.Using the front wheel steering mechanism with universal joint,the steering control of the DHWCR is realized by differential control.In the vertical to ground transition,the front and rear brushless motors can provide the pull up and oblique thrust,so that the DHWCR can smoothly transition to the vertical wall.The motion performance and adaptability of the DHWCR in the horizontal ground and vertical wall environment are tested.The results show that the DHWCR can switch motion between the horizontal ground and vertical wall,and can stably adsorb on the vertical wall with flexible attitude control.The DHWCR can move at a fast speed.The speed on the horizontal ground is higher than that on the vertical wall,which verifies the feasibility and reliability of the DHWCR moving stably on the vertical wall.

Cascaded electron transition in CuWO4/CdS/CDs heterostructure accelerating charge separation towards enhanced photocatalytic activity

CuWO4,as an n-type oxide semiconductor with a bandgap of 2.2 eV,has stimulated enormous interest as a potential broad-spectrum-active photocatalyst for environmental pollution remediations.However,rapid charge recombination greatly hinders its practical applications.Herein,we present a cascaded electron transition pathway in a ternary heterostructure consisting of CdS quantum dots,carbon dots(CDs)and CuWO4 hollow spheres,which proves to greatly facilitate the photogenerated electron-hole separation,and eventually boosts the degradation efficiency of phenol and congo red by 100%and 46%compared to bare CuWO4.The enhanced performance of the CuWO4/CdS/CDs heterostructure mainly originates from the unidirectional electron migration from CdS to CuWO4 and then to the organics through CDs.This work elucidates the electron transfer kinetics in multi-phase system and provides a new design paradigm for optimizing the properties of CuWO4 based photocatalysts.

MHGCN:Multiview Highway Graph Convolutional Network for Cross-Lingual Entity Alignment

Knowledge graphs(KGs)provide a wealth of prior knowledge for the research on social networks.Crosslingual entity alignment aims at integrating complementary KGs from different languages and thus benefits various knowledge-driven social network studies.Recent entity alignment methods often take an embedding-based approach to model the entity and relation embedding of KGs.However,these studies mostly focus on the information of the entity itself and its structural features but ignore the influence of multiple types of data in KGs.In this paper,we propose a new embedding-based framework named multiview highway graph convolutional network(MHGCN),which considers the entity alignment from the views of entity semantic,relation semantic,and entity attribute.To learn the structural features of an entity,the MHGCN employs a highway graph convolutional network(GCN)for entity embedding in each view.In addition,the MHGCN weights and fuses the multiple views according to the importance of the embedding from each view to obtain a better entity embedding.The alignment entities are identified based on the similarity of entity embeddings.The experimental results show that the MHGCN consistently outperforms the state-of-the-art alignment methods.The research also will benefit knowledge fusion through cross-lingual KG entity alignment.

The Prevalence, Genetic Characterization, and Evolutionary Analysis of Porcine Pegivirus in Guangdong, China

Porcine pegivirus(PPgV)is a member of the Pegivirus genus in the Flaviviridae family.PPg V is an emerging virus that has been discovered in swine herds in Germany,the United States,China,Poland,Italy,and the United Kingdom,indicating a wide geographical distribution.In this retrospective study,339 pig serum samples were collected from 20 different commercial swine farms located in nine cities in Guangdong Province,China,from 2016 to 2018,to investigate the prevalence and genetic diversity of PPg V in this geographical region.PPg V was detected in 55%(11/20)of the farms using nested reverse transcription PCR,with 6.2%(21/339)of pigs testing positive for PPg V.The yearly PPg V-positive rate increased from 2.6%to 7.5%between 2016 and 2018.Sequencing of PPg V-positive samples identified two complete polyprotein genes and seven partial NS5 B genes from different farms.Comparative analysis of the polyprotein genes revealed that PPg V sequences obtained in this study showed 87.4%–97.2%similarity at the nucleotide level and 96.5%–99.4%similarity at the amino acid level with the reference sequences.Sequence alignment and phylogenetic analysis of the complete polyprotein gene and partial NS5 B and NS3 genes demonstrated a high genetic similarity with the samples from the USA.The finding of the wide distribution of PPg V in swine herds in Guangdong Province will contribute to the understanding of the epidemiological characteristics and genetic evolution of PPg V in China.

Visible light-assisted peroxydisulfate activation via hollow copper tungstate spheres for removal of antibiotic sulfamethoxazole

The contamination of antibiotics in aqueous environment causes increasing concerns recently.Lightassisted activation of peroxydisulfate(PDS)has been demonstrated as an efficient technology for re moval of contamination in water.Herein,a hollow sphere of CuWO_(4)(h-CuWO_(4))was employed as a visible lightactivated photocatalyst for the activation of PDS,and following with high removal efficiency(98%)of antibiotic sulfamethoxazole(SMX).Under visible light irradiation,the degradation rate on hollow structures system is nearly 2 times higher than the traditional solid CuWO_(4) spheres.Furthermore,the underlying mechanism and detailed pathway of SMX degradation were proposed based on density functional theory(DFT)calculations and liquid chromatography-mass spectrometry(LC-MS).This work provides a new feasible way for advanced oxidation processes to remove antibiotics SMX in heterogeneous system,and open up new application possibilities of CuWO_(4)-based materials.