A novel fluorene-based conjugated copolymer containing cyclobutenedione unit was synthesized by Suzuki reaction. Its structure and properties were characterized by FTIR, 1HNMR, elemental analysis, PL spectroscopy, DSC...A novel fluorene-based conjugated copolymer containing cyclobutenedione unit was synthesized by Suzuki reaction. Its structure and properties were characterized by FTIR, 1HNMR, elemental analysis, PL spectroscopy, DSC, TGA and cyclic voltammetry. The resulting polymer shows strong yellow PL emission (561 nm) and good solubility in polar aprotic solvents, i.e. THF, DMF, DMAC, DMSO, etc. DSC and TGA studies reveal that the novel polymer possesses excellent thermal stability with high glass transition temperature of 127℃ and onset decomposition temperature of 411℃. Cyclic voltammetry measurement demonstrated that the polymer has both hole and electron-transporting property.展开更多
面向水电站电缆管廊高温高湿环境,提出模块化巡检机器人系统及其关键技术。采用三级模块化架构,运动控制层实现闭环调速;导航层融合激光雷达与惯性测量单元(inertial measurement unit, IMU)紧耦合的同步定位与地图构建技术,结合轨迹跟...面向水电站电缆管廊高温高湿环境,提出模块化巡检机器人系统及其关键技术。采用三级模块化架构,运动控制层实现闭环调速;导航层融合激光雷达与惯性测量单元(inertial measurement unit, IMU)紧耦合的同步定位与地图构建技术,结合轨迹跟踪完成位姿解算;巡检层依托5G与内网实现远程监控;利用IMU预积分辅助激光雷达时序插值消除点云运动畸变,设计联合优化模型,通过IMU重力约束抑制16线激光雷达地面点稀疏导致的z轴漂移。试验结果表明,所提技术可提升定位鲁棒性,使高程误差累积降幅约55%、俯仰角波动约束在±0.8°。所提方案有效提升了机器人在复杂地形的定位精度与稳定性,具有工程应用价值。展开更多
Urbanization is a complex process reflecting the growth, formation and develop- ment of cities and their systems. Measuring regional urbanization levels within a long time series may ensure healthy and harmonious urba...Urbanization is a complex process reflecting the growth, formation and develop- ment of cities and their systems. Measuring regional urbanization levels within a long time series may ensure healthy and harmonious urban development. Based on DMSP/OLS night- time light data, a human-computer interactive boundary correction method was used to ob- tain information about built-up urban areas in the Bohai Rim region from 1992 to 2012. Con- sequently, a method was proposed and applied to measure urbanization levels using four measurement scale units： administrative division, land-sea location, terrain feature, and geomorphological types. Our conclusions are： 1） The extraction results based on DMSP/OLS nighttime light data showed substantial agreement with those obtained using Landsat TM/ETM＋ data on spatial patterns. The overall accuracy was 97.70% on average, with an average Kappa of 0.79, indicating that the results extracted from DMSP/OLS nighttime light data were reliable and could well reflect the actual status of built-up urban areas. 2） Bohai Rim＇s urbanization level has increased significantly, demonstrating a high annual growth rate from 1998 to 2006. Areas with high urbanization levels have relocated evidently from capital to coastal cities. 3） The distribution of built-up urban areas showed a certain degree of zonal variation. The urbanization level was negatively correlated with relief amplitude and altitude. A high level of urbanization was found in low altitude platforms and low altitude plains, with a gradual narrowing of the gap between these two geomorphological types. 4） The measure- ment method presented in this study is fast, convenient, and incorporates multiple perspec- tives. It would offer various directions for urban construction and provide reference values for measuring national-level urbanization.展开更多
Classical Mechanics using Einstein’s theories of relativity places a limit on speed as the speed of light. Quantum Mechanics has no such limitation. To understand space accelerating faster than the speed of light and...Classical Mechanics using Einstein’s theories of relativity places a limit on speed as the speed of light. Quantum Mechanics has no such limitation. To understand space accelerating faster than the speed of light and information being exchanged instantaneously between two entangled electrons separated by huge distances, one uses Planck’s length, Planck’s time, and Planck’s mass to indicate that space and time are discrete and therefore along with masses smaller than Planck’s mass are Quantum Mechanical in nature. Faster than the speed of light c = 3 × 10<sup>8</sup> m/s is a classical effect only in dimensions of space lower than our 3-D Universe, but it is a Quantum effect in all dimensions of space. Because space can oscillate sending out ripples from the source, it is the medium used for transporting light waves and gravity waves.展开更多
随着助产技术的发展,早产儿的生存率逐年上升。根据新生儿个性化发展护理和评估程序(newborn individualized developmental care and assessment program,NIDCAP)发育支持理论,光线对早产儿的健康和生长发育有重要的影响;然而由于治疗...随着助产技术的发展,早产儿的生存率逐年上升。根据新生儿个性化发展护理和评估程序(newborn individualized developmental care and assessment program,NIDCAP)发育支持理论,光线对早产儿的健康和生长发育有重要的影响;然而由于治疗的需要,难以在新生儿重症监护室(neonatal intensive care unit,NICU)内营造一个适合早产儿生长发育的光线环境。国外许多学会推荐在NICU内使用循环光线,且也有部分研究证实循环光线对早产儿生长发育的积极影响。因此,文章从循环光线的理论基础、定义、实施方法及其对早产儿生长发育的影响进行综述,以期为医护人员开展相关干预研究提供借鉴和指导。最后提出未来此类研究的发展方向,建议未来应进行更多设计良好且样本量足够大的研究,以明确循环光线的定义、优势及NICU内使用循环光线的有效性和必要性,其对早产儿长期的神经发育结果也值得随访探讨。展开更多
文摘A novel fluorene-based conjugated copolymer containing cyclobutenedione unit was synthesized by Suzuki reaction. Its structure and properties were characterized by FTIR, 1HNMR, elemental analysis, PL spectroscopy, DSC, TGA and cyclic voltammetry. The resulting polymer shows strong yellow PL emission (561 nm) and good solubility in polar aprotic solvents, i.e. THF, DMF, DMAC, DMSO, etc. DSC and TGA studies reveal that the novel polymer possesses excellent thermal stability with high glass transition temperature of 127℃ and onset decomposition temperature of 411℃. Cyclic voltammetry measurement demonstrated that the polymer has both hole and electron-transporting property.
文摘面向水电站电缆管廊高温高湿环境,提出模块化巡检机器人系统及其关键技术。采用三级模块化架构,运动控制层实现闭环调速;导航层融合激光雷达与惯性测量单元(inertial measurement unit, IMU)紧耦合的同步定位与地图构建技术,结合轨迹跟踪完成位姿解算;巡检层依托5G与内网实现远程监控;利用IMU预积分辅助激光雷达时序插值消除点云运动畸变,设计联合优化模型,通过IMU重力约束抑制16线激光雷达地面点稀疏导致的z轴漂移。试验结果表明,所提技术可提升定位鲁棒性,使高程误差累积降幅约55%、俯仰角波动约束在±0.8°。所提方案有效提升了机器人在复杂地形的定位精度与稳定性,具有工程应用价值。
基金Surveying and Mapping Geoinformation Nonprofit Specific Project,No.201512033National Natural Science Foundation of China,No.41171332+1 种基金Major State Basic Research Development Program of China,No.2015CB954101National Science Technology Basic Special Project,No.2011FY110400-2
文摘Urbanization is a complex process reflecting the growth, formation and develop- ment of cities and their systems. Measuring regional urbanization levels within a long time series may ensure healthy and harmonious urban development. Based on DMSP/OLS night- time light data, a human-computer interactive boundary correction method was used to ob- tain information about built-up urban areas in the Bohai Rim region from 1992 to 2012. Con- sequently, a method was proposed and applied to measure urbanization levels using four measurement scale units： administrative division, land-sea location, terrain feature, and geomorphological types. Our conclusions are： 1） The extraction results based on DMSP/OLS nighttime light data showed substantial agreement with those obtained using Landsat TM/ETM＋ data on spatial patterns. The overall accuracy was 97.70% on average, with an average Kappa of 0.79, indicating that the results extracted from DMSP/OLS nighttime light data were reliable and could well reflect the actual status of built-up urban areas. 2） Bohai Rim＇s urbanization level has increased significantly, demonstrating a high annual growth rate from 1998 to 2006. Areas with high urbanization levels have relocated evidently from capital to coastal cities. 3） The distribution of built-up urban areas showed a certain degree of zonal variation. The urbanization level was negatively correlated with relief amplitude and altitude. A high level of urbanization was found in low altitude platforms and low altitude plains, with a gradual narrowing of the gap between these two geomorphological types. 4） The measure- ment method presented in this study is fast, convenient, and incorporates multiple perspec- tives. It would offer various directions for urban construction and provide reference values for measuring national-level urbanization.
文摘Classical Mechanics using Einstein’s theories of relativity places a limit on speed as the speed of light. Quantum Mechanics has no such limitation. To understand space accelerating faster than the speed of light and information being exchanged instantaneously between two entangled electrons separated by huge distances, one uses Planck’s length, Planck’s time, and Planck’s mass to indicate that space and time are discrete and therefore along with masses smaller than Planck’s mass are Quantum Mechanical in nature. Faster than the speed of light c = 3 × 10<sup>8</sup> m/s is a classical effect only in dimensions of space lower than our 3-D Universe, but it is a Quantum effect in all dimensions of space. Because space can oscillate sending out ripples from the source, it is the medium used for transporting light waves and gravity waves.
文摘随着助产技术的发展,早产儿的生存率逐年上升。根据新生儿个性化发展护理和评估程序(newborn individualized developmental care and assessment program,NIDCAP)发育支持理论,光线对早产儿的健康和生长发育有重要的影响;然而由于治疗的需要,难以在新生儿重症监护室(neonatal intensive care unit,NICU)内营造一个适合早产儿生长发育的光线环境。国外许多学会推荐在NICU内使用循环光线,且也有部分研究证实循环光线对早产儿生长发育的积极影响。因此,文章从循环光线的理论基础、定义、实施方法及其对早产儿生长发育的影响进行综述,以期为医护人员开展相关干预研究提供借鉴和指导。最后提出未来此类研究的发展方向,建议未来应进行更多设计良好且样本量足够大的研究,以明确循环光线的定义、优势及NICU内使用循环光线的有效性和必要性,其对早产儿长期的神经发育结果也值得随访探讨。
