Acceleration effect of reduced graphene oxide on photoinduced synthesis of silver nanoparticles

The photoinduced growth reaction of silver nanoparticles was accelerated by reduced graphene oxide (RGO) produced from graphene oxide (GO) during the light irradiation process in aqueous solution. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy demonstrated that RGO was generated in the photoinduced process. The acceleration effect of RGO was investigated through monitoring the extinction spectra of silver nanoparticles during the synthesis process. Moreover, transmission electron microscopy (TEM) was employed to characterize the evolution of morphologies of silver nanoparticles at different irradiation times to demonstrate the effect of RGO. The results indicate that RGO accelerates the photoinduced synthesis of silver nanoparticles. It is proposed that the acceleration effect of RGO on the photoinduced reaction is attributed to the particular property of high electronic conductivit

Comparative genomics reveals adaptive evolution of Asian tapeworm in switching to a new intermediate host

Taenia saginata, Taenia solium and Taenia asiatica (beef, pork and Asian tapeworms, respectively) are parasitic flatworms of major public health and food safety importance. Among them, T. asiatica is a newly recognized species that split from T. saginata via an intermediate host switch ∼1.14 Myr ago. Here we report the 169- and 168-Mb draft genomes of T. saginata and T. asiatica. Comparative analysis reveals that high rates of gene duplications and functional diversifications might have partially driven the divergence between T. asiatica and T. saginata. We observe accelerated evolutionary rates, adaptive evolutions in homeostasis regulation, tegument maintenance and lipid uptakes, and differential/specialized gene family expansions in T. asiatica that may favour its hepatotropism in the new intermediate host. We also identify potential targets for developing diagnostic or intervention tools against human tapeworms. These data provide new insights into the evolution of Taenia parasites, particularly the recent speciation of T. asiatica

Distribution rules of conflict events and management countermeasures of large-scale construction engineering projects

The processes of large-scale construction projects implementation are often affected with various internal and external factors, which result in various conflict events in different stages of the project, and bring different degrees of harm to the construction project. In order to understand and master the distribution rules of various conflict events in different stages in large-scale construction projects, a massive investigation was carried out on 96 large-scale engineering construction units in China, and 325 effective research samples were obtained. Based on this investigation results, the mathematical analysis and summary of the conflict events of large construction engineering projects have been made by multiple statistical analyses, which reveal the distribution law and the primary and secondary relationship of various conflict events in each stage of engineering projects. Combined with the research results, the management countermeasures and suggestions of conflict events are put forward, which provide valuable references for the project managers to effectively manage the conflict events and improve the management level of engineering projects

Research on randomcity of conflict events in construction engineering projects

The conflict events that occurred in construction engineering projects (CEP) often bring about many adverse effects on project implementation and show a character of randomcity. To find out the occurring rule of conflict events, all sorts and occurring frequencies of conflict events in CEP are analyzed based on the investigation. The representing rule of conflict events in every stage has been revealed in a new concept referred to as the representation degree by the method of quantitative analysis combined with qualitative analysis. Then, according to the basic principle of the analytic hierarchy process, every stage’s judgment matrixes of conflict events are set up. Latent roots of these matrixes have revealed the influence order of cumulative results of conflict events at each stage. The harvest has obvious theoretical and practical value for forecasting conflict events, mastering the whole project situation, avoiding and reducing conflict events, and improving project management ability

Research on randomcity of conflict events in construction engineering projects

The conflict events that occurred in construction engineering projects (CEP) often bring about many adverse effects on project implementation and show a character of randomcity. To find out the occurring rule of conflict events, all sorts and occurring frequencies of conflict events in CEP are analyzed based on the investigation. The representing rule of conflict events in every stage has been revealed in a new concept referred to as the representation degree by the method of quantitative analysis combined with qualitative analysis. Then, according to the basic principle of the analytic hierarchy process, every stage’s judgment matrixes of conflict events are set up. Latent roots of these matrixes have revealed the influence order of cumulative results of conflict events at each stage. The harvest has obvious theoretical and practical value for forecasting conflict events, mastering the whole project situation, avoiding and reducing conflict events, and improving project management ability

Review of Image-Based 3D Reconstruction of Building for Automated Construction Progress Monitoring

With the spread of camera-equipped devices, massive images and videos are recorded on construction sites daily, and the ever-increasing volume of digital images has inspired scholars to visually capture the actual status of construction sites from them. Three-dimensional (3D) reconstruction is the key to connecting the Building Information Model and the project schedule to daily construction images, which enables managers to compare as-planned with as-built status and detect deviations and therefore monitor project progress. Many scholars have carried out extensive research and produced a variety of intricate methods. However, few studies comprehensively summarize the existing technologies and introduce the homogeneity and differences of these technologies. Researchers cannot clearly identify the relationship between various methods to solve the difficulties. Therefore, this paper focuses on the general technical path of various methods and sorts out a comprehensive research map, to provide reference for researchers in the selection of research methods and paths. This is followed by identifying gaps in knowledge and highlighting future research directions. Finally, key findings are summarized

Self-assembly and film stability of a micelle of a single-chain quaternary ammonium amphiphile containing azobenzene on mica

The self-assembling behavior of a single-chain quaternary ammonium amphiphile bearing azobenzene (C12AzoC6N+) on freshly cleaved mica sheet has been investigated by atomic force microscopy (AFM) method. Confocal microscopic Raman spectra confirm the adsorption of the self-assembled monolayer structure. Ex-situ AFM reveals that C12AzoC6N+ forms branch-like stripes indicating the fusion and reorganization of the micelles during drying in air as the in-situ AFM has revealed that surfactant forms spherical micelles on the mica surface. The nano-sized surface structure is strongly dependent on the change of molecular structure, which resulted from photo-induced isomerization. The nano-sized stripe is quite stable even being annealed at 90 &deg;C for 4 h.<br /

In situ observation of the aggregated morphology and interaction of dialkyldimethylammonium bromide with DNA at air/water interface by Brewster angle microscopy

The adsorption of DNA on the Langmuir film of a cationic surfactant, dioctadecyldimethylammonium bromide (DODA&middot;Br), and the change of the aggregation morphology of the composite monolayer with respect to surface pressure have been investigated by Brewster angle microscopy (BAM). In contrast with the case of DODA&middot;Br on pure water subphase, when DNA was dispersed into subphase, its adsorption to the interface monolayer through electrostatic interaction decreases the charge density and therefore promotes the formation of domain at low surface pressure. In addition, the electrostatic interaction changed the phase morphology of DODA&middot;Br Langmuir monolayer under different surface pressure, that is, from flower-shaped crystalline domain on the pure water subphase to circular domain on the subphase dispersed with DNA. The result also shows that the monolayer of the composite at air/water interface under the high pressure is not homogeneous, but consists of incompletely fused domains. For the Langmuir film of the surfactant with shorter alkyl-chains, similar morphology can be observed both under the high and low surface pressure. But the tight-stacked circular domain is no longer observed.<br /