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| 1 | Organic solvent-and phase transfer catalyst-free oxidation of cyclohexanol to cyclohexanone with dilute H_2O_2显示文摘The oxidation of cyclohexanol to cyclohexanone with 30% aqueous hydrogen peroxide by using peroxotung-state complexes formed in situ from sodium tungstate di-hydrate and various bidentate organic ligands as the catalysts, without organic solvents, halide and phase transfer catalyst has been carried out. The influence of 13 ligands on the oxidation is investigated. The maximum yield of cyclohexanone is obtained when using 1,10-phenanthroline (96%) and oxalic acid (95%) as the ligand. Very high yields (around 90%) have also been obtained for the instances of using salicylic acid, 3,5-dibromosalicylic acid, and 8-hydro- xylquino-line as ligands. A research to improve the reaction condition using cheap oxalic acid as the ligand indicates that the optimum condition is that the reaction mixture with a molar ratio of cycohexanol:tungstate dihydrate:oxalic acid: 30% H2O2=100:2:2:120 was stirred at 85-90℃ for 12 h. | WEI Junfa, SHI Xianying, HE Diping & ZHANG MinSchool of Chemistry and Material Science, Shaanxi Normal University, Xi’an 710062, China | 2002 | Chinese Science Bulletin2002，47，24： | 3 |
| 2 | Intelligent fire information system based on 3D GIS显示文摘Background This work aims to build a comprehensive and effective fire emergency management system based on the Internet of Things(IoT)and achieve an actual intelligent fire rescue.A smart fire protection information system was designed based on the IoT.A detailed analysis was conducted on the problem of rescue vehicle scheduling and the evacuation of trapped persons in the process of fire rescue.Methods The intelligent fire visualization platform based on the three-dimensional(3D)Geographic Information Science(GIS)covers project overview,equipment status,equipment classification,equipment alarm information,alarm classification,alarm statistics,equipment account information,and other modules.The live video accessed through the visual interface can clearly identify the stage of the fire,which facilitates the arrangement of rescue equipment and personnel.The vehicle scheduling model in the system primarily used two objective functions to solve the Pareto Non-Dominated Solution Set Optimization:emergency rescue time and the number of vehicles.In addition,an evacuation path optimization method based on the Improved Ant Colony(IAC)algorithm was designed to realize the dynamic optimization of building fire evacuation paths.Results The experimental results indicate that all the values of detection signals were significantly larger in the smoldering fire scene at t=17s than the initial value.In addition,the probability of smoldering fire and the probability of open fire were relatively large according to the probability function of the corresponding fire situation,demonstrating that this model could detect fire.Conclusions The IAC algorithm reported here avoided the passages near the fire and spreading areas as much as possible and took the safety of the trapped persons as the premise when planning the evacuation route.Therefore,the IoT-based fire information system has important value for ensuring fire safety and carrying out emergency rescue and is worthy of popularization and application. | Jinxing HU Zhihan LV Diping YUAN Bing HE Dongmei YAN | 2023 | Virtual Reality & Intelligent Hardware2023，5，2： | 0 |
| 3 | Functionalized TiO_2@ZrO_2@Y_2O_3:Eu^(3+) core-multishell microspheres and their photoluminescence properties显示文摘TiO2@ZrO2@Y2O3:Eu3+composite particles with a core-multishell structure were synthesized through the combination of a layer-by-layer(LBL) self-assembly method and a sol-gel process.The obtained samples were characterized with scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),and fluorescence spectrophotometry.The results showed that the composite particles had a core-multishell structure,spherical morphology,and a narrow size distribution.The presence of a ZrO2 layer on the TiO2 core can effectively prevent the reaction between the TiO2 core and a Y2O3 shell;the temperature for the reaction between the TiO2 core and the Y2O3 shell in the TiO2@ZrO2@Y2O3:Eu core-multishell phosphor can be elevated by 300℃ compared to that for TiO2@Y2O3:Eu.Upon excitation of the core-multishell particles in the ultraviolet(254 nm),the Eu^(3+)ion in the Y2O3:Eu^(3+) shell shows its characteristic red emission(611 nm,~5D0→~7F2),and the photoluminescence(PL) intensity of the phosphor with the core-multishell structure was obviously greater than that of the core-shell TiO2@Y2O3:Eu phosphor. | Jiali Sun Xuan Gao Diping He Juan Chen Xin Meng Qiao Zhang Lili Shen Huan Jiao | 2013 | Particuology2013，11，6： | 0 |
| 4 | A spatiotemporal intelligent framework and experimental platform for urban digital twins显示文摘Backgrounds This work emphasizes the current research status of the urban Digital Twins to establish an intelligent spatiotemporal framework.A Geospatial Artificial Intelligent(GeoAI)system is developed based on the Geographic Information System and Artificial Intelligence.It integrates multi-video technology and Virtual City in urban Digital Twins.Methods Besides,an improved small object detection model is proposed:YOLOv5-Pyramid,and Siamese network video tracking models,namely MPSiam and FSSiamese,are established.Finally,an experimental platform is built to verify the georeferencing correction scheme of video images.Result The MultiplyAccumulate value of MPSiam is 0.5B,and that of ResNet50-Siam is 4.5B.Besides,the model is compressed by 4.8times.The inference speed has increased by 3.3 times,reaching 83 Frames Per Second.3%of the Average Expectation Overlap is lost.Therefore,the urban Digital Twins-oriented GeoAI framework established here has excellent performance for video georeferencing and target detection problems. | Jinxing HU Zhihan LV Diping YUAN Bing HE Wenjiang CHEN Xiongfei YE Donghao LI Ge YANG | 2023 | Virtual Reality & Intelligent Hardware2023，5，3： | 0 |
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