Perennial grass-legume mixtures have been extensively used to restore degraded grasslands,increasing grassland productivity and forage quality.Tillage is crucial for seedbed preparation and sustainable weed management...Perennial grass-legume mixtures have been extensively used to restore degraded grasslands,increasing grassland productivity and forage quality.Tillage is crucial for seedbed preparation and sustainable weed management for the establishment of grass-legume mixtures.However,a common concern is that intensive tillage may alter soil characteristics,leading to losses in soil organic carbon(SOC).We investigated the plant community composition,SOC,soil microbial biomass carbon(MBC),soil enzyme activities,and soil properties in long-term perennial grass-legume mixtures under two different tillage intensities(once and twice)as well as in a fenced grassland(FG).The establishment of grass-legume mixtures increased plant species diversity and plant community coverage,compared with FG.Compared with once tilled grassland(OTG),twice tilled grassland(TTG)enhanced the coverage of high-quality leguminous forage species by 380.3%.Grass-legume mixtures with historical tillage decreased SOC and dissolved organic carbon(DOC)concentrations,whereas soil MBC concentrations in OTG and TTG increased by 16.0%and 16.4%,respectively,compared with FG.TTG significantly decreased the activity of N-acetyl-β-D-glucosaminidase(NAG)by 72.3%,whereas soil enzymeβ-glucosidase(βG)in OTG and TTG increased by 55.9%and 27.3%,respectively,compared with FG.Correlation analysis indicated a close association of the increase in MBC andβG activities with the rapid decline in SOC.This result suggested that MBC was a key driving factor in soil carbon storage dynamics,potentially accelerating soil carbon cycling and facilitating biogeochemical cycling.The establishment of grass-legume mixtures effectively improves forage quality and boosts plant diversity,thereby facilitating the restoration of degraded grasslands.Although tillage assists in establishing legume-grass mixtures by controlling weeds,it accelerates microbial activity and organic carbon decomposition.Our findings provide a foundation for understanding the process and effectiveness of restoration management in degraded grasslands.展开更多
“Bahasa jiwa bangasa”goes a Malay proverb,dubbing language the soul of a nation.Language and cultural exchange serve not only as a bridge for closer friendship between peoples around the world but also as a driver t...“Bahasa jiwa bangasa”goes a Malay proverb,dubbing language the soul of a nation.Language and cultural exchange serve not only as a bridge for closer friendship between peoples around the world but also as a driver to promote broader and deeper international cooperation in various fields.Mutual understanding of language and culture is a prerequisite for people-to-people connectivity.展开更多
针对无人驾驶车辆路径规划问题,基于快速扩展随机树(rapidly-exploring random tree,RRT)算法,提出了1种5次多项式曲线(quintic polynomial curve)与MT-RRT(multi-targeting rapidly-exploring random tree)的融合算法,即QPC-MT-RRT算...针对无人驾驶车辆路径规划问题,基于快速扩展随机树(rapidly-exploring random tree,RRT)算法,提出了1种5次多项式曲线(quintic polynomial curve)与MT-RRT(multi-targeting rapidly-exploring random tree)的融合算法,即QPC-MT-RRT算法。该算法根据无人驾驶车辆路径规划的相关理论,建立无人驾驶车辆路径规划问题的车辆运动学模型,为规划无人驾驶车辆最优、最高效、最安全路径提供理论依据。将上述算法在MATLAB上仿真,并在平均路径长度、平均路径规划时间、平均采样节点个数及节点利用率4个方面与基本RRT算法及MT-RRT算法进行了对比。仿真结果表明:5次多项式曲线与MT-RRT算法的融合算法具有最高的性能,可以规划出最优路径。展开更多
目的采用氢核磁脉冲宽度定量法(Pulse length based concentration determination,PULCON)对玄参对照提取物中的哈巴苷、安格洛苷C和哈巴俄苷进行定性及定值研究,探讨玄参对照提取物代替相应对照品在提升玄参复方制剂质量控制水平的可...目的采用氢核磁脉冲宽度定量法(Pulse length based concentration determination,PULCON)对玄参对照提取物中的哈巴苷、安格洛苷C和哈巴俄苷进行定性及定值研究,探讨玄参对照提取物代替相应对照品在提升玄参复方制剂质量控制水平的可行性。方法采用Bruker Avance III HD 700超导核磁共振波谱仪,以DMSO-d6为溶剂,苯甲酸为外标物,利用PULCON法比较苯甲酸定量峰(δ_(H)7.94)的峰面积和不同批次玄参对照提取物中3种化学成分的不同定量峰(哈巴苷δ_(H)6.24、安格洛苷Cδ_(H)7.08和哈巴俄苷δ_(H)5.97)的峰面积,测定不同批次中3种成分的含量,并采用配对t检验将测定结果与高效液相色谱法(High performance liquid chromatography,HPLC)的定值结果进行比对。分别以已知含量的玄参对照提取物和3个相应对照品为对照,建立增液汤的HPLC含量测定方法,采用配对t检验对2种方法所得结果进行比较。结果采用PULCON法测得3种成分的含量与HPLC法的定值结果基本一致,以玄参对照提取物为对照,3种成分的线性关系相关系数均大于0.9997,平均回收率为99.36%~102.31%。t检验结果显示,2种方法测定的哈巴苷、安格洛苷C、哈巴俄苷含量P值分别为0.279、0.105、0.623,均大于0.05,表明2种含量测定方法差异无统计学意义。结论PULCON法可在无对照品且无需分离的条件下,直接、快速、准确地分析玄参对照提取物成分的物质组成和含量,并将已标定准确含量的玄参对照提取物用于玄参复方制剂的质量控制,为中药对照提取物在中药质量研究中的应用提供了科学依据。展开更多
文摘目的分析治疗心悸的组方规律及核心药物组合的作用靶点和通路。方法收集2023年3月至2024年3月李亚平治疗心悸的处方,对药物的性、味、归经和功效进行频次统计,利用SPSS Modeler 18.0和SPSS 26.0软件进行药物的Apriori算法、关联规则及聚类分析。检索核心药物成分及疾病靶点,对其治疗心悸作用靶点进行基因本体(gene ontology,GO)和京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)分析。结果共收集中药处方220首,涉及中药192味,累计用药频次3978次,高频药物18味。治疗心悸用药以补虚药、安神药、活血化瘀药为主;药性以温、寒、平为主,药味以甘、苦、辛为主,归经以心、肝、脾经居多。关联规则分析显示,当归、丹参、甘草、麦冬和黄芪等为核心药物。聚类分析显示有3个聚类组合。网络药理学分析显示,药物组合与疾病交集靶点共181个。KEGG分析显示,核心药物治疗心悸主要涉及磷脂酰肌醇3激酶/蛋白激酶B、缺氧诱导因子-1、丝裂原活化蛋白激酶、白细胞介素-17等信号通路,GO分析显示,共包括1000条GO途径,其中生物过程760条,细胞组分93条,分子功能147条。结论李亚平治疗心悸主张益气通阳、化瘀祛浊、通络安神,强调“双心同调”,心肝同治,兼顾脾胃,核心药物组合可通过多成分、多靶点、多作用途径干预心悸病程,对临床心悸的治疗具有重要意义。
基金funded by the National Natural Science Foundation of China(32271776,32171616)the Special Sichuan Postdoctoral Research Projectsthe National Natural Science Foundation of Sichuan Province,China(2024NSFSC0309,2022NSFSC1769,2022NSFSC0110).
文摘Perennial grass-legume mixtures have been extensively used to restore degraded grasslands,increasing grassland productivity and forage quality.Tillage is crucial for seedbed preparation and sustainable weed management for the establishment of grass-legume mixtures.However,a common concern is that intensive tillage may alter soil characteristics,leading to losses in soil organic carbon(SOC).We investigated the plant community composition,SOC,soil microbial biomass carbon(MBC),soil enzyme activities,and soil properties in long-term perennial grass-legume mixtures under two different tillage intensities(once and twice)as well as in a fenced grassland(FG).The establishment of grass-legume mixtures increased plant species diversity and plant community coverage,compared with FG.Compared with once tilled grassland(OTG),twice tilled grassland(TTG)enhanced the coverage of high-quality leguminous forage species by 380.3%.Grass-legume mixtures with historical tillage decreased SOC and dissolved organic carbon(DOC)concentrations,whereas soil MBC concentrations in OTG and TTG increased by 16.0%and 16.4%,respectively,compared with FG.TTG significantly decreased the activity of N-acetyl-β-D-glucosaminidase(NAG)by 72.3%,whereas soil enzymeβ-glucosidase(βG)in OTG and TTG increased by 55.9%and 27.3%,respectively,compared with FG.Correlation analysis indicated a close association of the increase in MBC andβG activities with the rapid decline in SOC.This result suggested that MBC was a key driving factor in soil carbon storage dynamics,potentially accelerating soil carbon cycling and facilitating biogeochemical cycling.The establishment of grass-legume mixtures effectively improves forage quality and boosts plant diversity,thereby facilitating the restoration of degraded grasslands.Although tillage assists in establishing legume-grass mixtures by controlling weeds,it accelerates microbial activity and organic carbon decomposition.Our findings provide a foundation for understanding the process and effectiveness of restoration management in degraded grasslands.
文摘“Bahasa jiwa bangasa”goes a Malay proverb,dubbing language the soul of a nation.Language and cultural exchange serve not only as a bridge for closer friendship between peoples around the world but also as a driver to promote broader and deeper international cooperation in various fields.Mutual understanding of language and culture is a prerequisite for people-to-people connectivity.
文摘针对无人驾驶车辆路径规划问题,基于快速扩展随机树(rapidly-exploring random tree,RRT)算法,提出了1种5次多项式曲线(quintic polynomial curve)与MT-RRT(multi-targeting rapidly-exploring random tree)的融合算法,即QPC-MT-RRT算法。该算法根据无人驾驶车辆路径规划的相关理论,建立无人驾驶车辆路径规划问题的车辆运动学模型,为规划无人驾驶车辆最优、最高效、最安全路径提供理论依据。将上述算法在MATLAB上仿真,并在平均路径长度、平均路径规划时间、平均采样节点个数及节点利用率4个方面与基本RRT算法及MT-RRT算法进行了对比。仿真结果表明:5次多项式曲线与MT-RRT算法的融合算法具有最高的性能,可以规划出最优路径。
文摘目的采用氢核磁脉冲宽度定量法(Pulse length based concentration determination,PULCON)对玄参对照提取物中的哈巴苷、安格洛苷C和哈巴俄苷进行定性及定值研究,探讨玄参对照提取物代替相应对照品在提升玄参复方制剂质量控制水平的可行性。方法采用Bruker Avance III HD 700超导核磁共振波谱仪,以DMSO-d6为溶剂,苯甲酸为外标物,利用PULCON法比较苯甲酸定量峰(δ_(H)7.94)的峰面积和不同批次玄参对照提取物中3种化学成分的不同定量峰(哈巴苷δ_(H)6.24、安格洛苷Cδ_(H)7.08和哈巴俄苷δ_(H)5.97)的峰面积,测定不同批次中3种成分的含量,并采用配对t检验将测定结果与高效液相色谱法(High performance liquid chromatography,HPLC)的定值结果进行比对。分别以已知含量的玄参对照提取物和3个相应对照品为对照,建立增液汤的HPLC含量测定方法,采用配对t检验对2种方法所得结果进行比较。结果采用PULCON法测得3种成分的含量与HPLC法的定值结果基本一致,以玄参对照提取物为对照,3种成分的线性关系相关系数均大于0.9997,平均回收率为99.36%~102.31%。t检验结果显示,2种方法测定的哈巴苷、安格洛苷C、哈巴俄苷含量P值分别为0.279、0.105、0.623,均大于0.05,表明2种含量测定方法差异无统计学意义。结论PULCON法可在无对照品且无需分离的条件下,直接、快速、准确地分析玄参对照提取物成分的物质组成和含量,并将已标定准确含量的玄参对照提取物用于玄参复方制剂的质量控制,为中药对照提取物在中药质量研究中的应用提供了科学依据。
