为探究不同植物生长调节剂处理对辣椒挥发性香气物质的影响,采用顶空固相微萃取-气相色谱-质谱(headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry,HS-SPME-GC-MS)联用技术,通过化学计量学分...为探究不同植物生长调节剂处理对辣椒挥发性香气物质的影响,采用顶空固相微萃取-气相色谱-质谱(headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry,HS-SPME-GC-MS)联用技术,通过化学计量学分析对复硝酚钠、赤霉素、芸苔素内酯处理的辣椒以及对照辣椒挥发性香气物质进行综合评价。结果表明,在4种处理中共检测出43种挥发性香气物质,其中对照组38种、复硝酚钠组40种、芸苔素内酯和赤霉素组43种。芸苔素内酯和赤霉素处理提高了辣椒挥发性香气物质的总含量,复硝酚钠处理的总含量无差异。以PLS-DA模型的变量重要性投影VIP值>1.0为条件,共筛选出12种差异挥发物,对挥发性香气成分进行主成分分析并构建主成分综合评价函数,香气品质综合得分最高为芸苔素内酯组,其次为赤霉素组。研究结果为植物生长调节剂的合理、高效利用提供了理论依据,有助于促进辣椒优质产品的生产。展开更多
With the development of wireless communication,the fifth generation mobile communication technology(5G)has emerged as a hot topic in highspeed railway communication system and has moved towards industrial application....With the development of wireless communication,the fifth generation mobile communication technology(5G)has emerged as a hot topic in highspeed railway communication system and has moved towards industrial application.Investigating the radio propagation characteristics in 5G high-speed train(HST)scenarios is essential for enhancing wireless coverage and overall system performance.We propose a novel 5G passive sounding scheme to extract channel impulse responses(CIRs)using channel state information reference signals(CSI-RS)from the target 5G base station(BS).Detailed procedures for timefrequency synchronization,CSI-RS detection and extraction are presented through simulations.Through the laboratory work involving absolute power calibration,phase coherence calibration and power delay profile(PDP)validation,we validate the accuracy and performance of the developed platform.Furthermore,a measurement campaign was conducted in HST scenarios encompassing both residential and undeveloped areas.The path loss(PL)model and the channel characteristics including stationarity interval(SI),multipath components(MPCs),shadow fading(SF),Rician K-factor,root mean square(RMS)delay spread and received correlation coefficients are analyzed and fitted.The estimated channel characteristics and the statistical model presented in this paper will contribute to the research on HST radio propagation and the development of 5G railway communication systems.展开更多
为了解决铁路移动通信网络规划成本高且效率低的问题,满足铁路智能无线网络建设需求,以京沈客运专线为场景,研究了2.1 GHz频段下基于高性能射线跟踪的5G铁路专用移动通信(5G for railway, 5GR)智能无线网络规划技术.依托参考信号接收功...为了解决铁路移动通信网络规划成本高且效率低的问题,满足铁路智能无线网络建设需求,以京沈客运专线为场景,研究了2.1 GHz频段下基于高性能射线跟踪的5G铁路专用移动通信(5G for railway, 5GR)智能无线网络规划技术.依托参考信号接收功率(reference signal receiving power, RSRP)高性能射线跟踪仿真得到电磁波在特定环境下传播时的信道特性和路径损耗,进而精准预算无线链路的RSRP和下行传输速率;同时将规划问题建模为多目标优化求解问题,使用遗传算法对基站参数进行分级规划,在RSRP覆盖达标的前提下,最大化下行传输速率,智能输出基站工参最优解.仿真结果表明该技术可以满足RSRP覆盖率和最大化下行传输速率的规划目标,为后续实现精准高效的5G-R无线网络规划和优化提供仿真支撑和参考.展开更多
文摘为探究不同植物生长调节剂处理对辣椒挥发性香气物质的影响,采用顶空固相微萃取-气相色谱-质谱(headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry,HS-SPME-GC-MS)联用技术,通过化学计量学分析对复硝酚钠、赤霉素、芸苔素内酯处理的辣椒以及对照辣椒挥发性香气物质进行综合评价。结果表明,在4种处理中共检测出43种挥发性香气物质,其中对照组38种、复硝酚钠组40种、芸苔素内酯和赤霉素组43种。芸苔素内酯和赤霉素处理提高了辣椒挥发性香气物质的总含量,复硝酚钠处理的总含量无差异。以PLS-DA模型的变量重要性投影VIP值>1.0为条件,共筛选出12种差异挥发物,对挥发性香气成分进行主成分分析并构建主成分综合评价函数,香气品质综合得分最高为芸苔素内酯组,其次为赤霉素组。研究结果为植物生长调节剂的合理、高效利用提供了理论依据,有助于促进辣椒优质产品的生产。
基金supported by Fundamental Research Funds for the Central Universities(No.2024YJS078)the National Natural Science Foundation of China(No.62341127,62221001 and 62171021)+1 种基金the Fundamental Research Funds for the Natural Science Foundation of Jiangsu Province,Major Project(No.BK2021200)the Key Research and Development Program of Zhejiang Province(No.2023C01003)。
文摘With the development of wireless communication,the fifth generation mobile communication technology(5G)has emerged as a hot topic in highspeed railway communication system and has moved towards industrial application.Investigating the radio propagation characteristics in 5G high-speed train(HST)scenarios is essential for enhancing wireless coverage and overall system performance.We propose a novel 5G passive sounding scheme to extract channel impulse responses(CIRs)using channel state information reference signals(CSI-RS)from the target 5G base station(BS).Detailed procedures for timefrequency synchronization,CSI-RS detection and extraction are presented through simulations.Through the laboratory work involving absolute power calibration,phase coherence calibration and power delay profile(PDP)validation,we validate the accuracy and performance of the developed platform.Furthermore,a measurement campaign was conducted in HST scenarios encompassing both residential and undeveloped areas.The path loss(PL)model and the channel characteristics including stationarity interval(SI),multipath components(MPCs),shadow fading(SF),Rician K-factor,root mean square(RMS)delay spread and received correlation coefficients are analyzed and fitted.The estimated channel characteristics and the statistical model presented in this paper will contribute to the research on HST radio propagation and the development of 5G railway communication systems.
文摘为了解决铁路移动通信网络规划成本高且效率低的问题,满足铁路智能无线网络建设需求,以京沈客运专线为场景,研究了2.1 GHz频段下基于高性能射线跟踪的5G铁路专用移动通信(5G for railway, 5GR)智能无线网络规划技术.依托参考信号接收功率(reference signal receiving power, RSRP)高性能射线跟踪仿真得到电磁波在特定环境下传播时的信道特性和路径损耗,进而精准预算无线链路的RSRP和下行传输速率;同时将规划问题建模为多目标优化求解问题,使用遗传算法对基站参数进行分级规划,在RSRP覆盖达标的前提下,最大化下行传输速率,智能输出基站工参最优解.仿真结果表明该技术可以满足RSRP覆盖率和最大化下行传输速率的规划目标,为后续实现精准高效的5G-R无线网络规划和优化提供仿真支撑和参考.
