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融合改进Bi-RRT和DWA算法的无人机动态路径规划

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电光与控制 2024年第5期31卷 77-82页

作者：罗毅陈新洲华北电力大学控制与计算机工程学院北京100000

为解决无人机在复杂环境中的避障问题,提出一种融合改进Bi-RRT和DWA的无人机动态路径规划算法。通过设置启发式函数、动态步长和安全距离改进Bi-RRT算法,提升全局路径的搜索效率和安全性;之后,修剪路径中的冗余路段并对修剪后的路径进... 详细信息

为解决无人机在复杂环境中的避障问题,提出一种融合改进Bi-RRT和DWA的无人机动态路径规划算法。通过设置启发式函数、动态步长和安全距离改进Bi-RRT算法,提升全局路径的搜索效率和安全性;之后,修剪路径中的冗余路段并对修剪后的路径进行插值与平滑操作获得全局最优路径;对DWA修正障碍物距离评价函数并引入目标点距离评价函数,提升局部预测轨迹评分的准确性;然后,实时输出速度指令控制无人机跟踪全局最优路径并实现局部动态避障。仿真实验表明,改进Bi-RRT算法生成的路径更短更平滑、安全性更高且规划时间更少;在同时存在动、静态障碍物的复杂环境中,所提融合算法能控制无人机精准地跟踪全局最优路径并高效地完成局部动态避障。

关键词：无人机路径规划 Bi-RRT算法 DWA 融合算法

Reactive molecular dynamics insight into the thermal decomposition mechanism of 2,6-Bis(picrylamino)-3,5-dinitropyridine

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Defence Technology（防务技术） 2024年第3期33卷 134-146页

作者： Jianbo Fu Hui Ren xinzhou Wu Yongjin chen Mi Zhang Yazhi cheng State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

2,6-bis(picrylamino)-3,5-dinitropyridine(PYX)has excellent thermostability,which makes its thermal decomposition mechanism receive much attention.In this paper,the mechanism of PYX thermal decomposition was investigated thoroughly by the ReaxFF-lg force field combined with DFT-B3LYP(6-311++G)method.The detailed decomposition mechanism,small-molecule product evolution,and cluster evolution of PYX were mainly analyzed.In the initial stage of decomposition,the intramolecular hydrogen transfer reaction and the formation of dimerized clusters are earlier than the denitration reaction.With the progress of the reaction,one side of the bitter amino group is removed from the pyridine ring,and then the pyridine ring is cleaved.The final products produced in the thermal decomposition process are CO_(2),H_(2)O,N_(2),and H_(2).Among them,H_(2)O has the earliest generation time,and the reaction rate constant(k_(3))is the largest.Many clusters are formed during the decomposition of PYX,and the formation,aggregation,and decomposition of these clusters are strongly affected by temperature.At low temperatures(2500 K-2750 K),many clusters are formed.At high temperatures(2750 K-3250 K),the clusters aggregate to form larger clusters.At 3500 K,the large clusters decompose and become small.In the late stage of the reaction,H and N in the clusters escaped almost entirely,but more O was trapped in the clusters,which affected the auto-oxidation process of PYX.PYX's initial decomposition activation energy(E_(a))was calculated to be 126.58 kJ/mol.This work contributes to a theoretical understanding of PYX's entire thermal decomposition process.

关键词： PYX Thermal decomposition ReaxFF-lg MD simulations Excellent thermostable explosives

维生素D联合布地奈德预防早产儿支气管肺发育不良效果及对肺功能的影响

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中国当代医药 2024年第10期31卷 88-91页

作者：黄荷付道勇温雪风易红易飞陈新宙江西省宜春市人民医院儿科江西宜春336000

目的探讨维生素D联合布地奈德预防早产儿支气管肺发育不良(BPD)的效果及对肺功能的影响。方法选取2022年7月至2023年5月宜春市人民医院新生儿科收治的60例BPD高危早产儿作为研究对象,采用随机数字表法分为A组、B组和C组,各20例;A组给予... 详细信息

目的探讨维生素D联合布地奈德预防早产儿支气管肺发育不良(BPD)的效果及对肺功能的影响。方法选取2022年7月至2023年5月宜春市人民医院新生儿科收治的60例BPD高危早产儿作为研究对象,采用随机数字表法分为A组、B组和C组,各20例;A组给予氧疗、营养支持等常规对症治疗,B组在A组基础上给予常规剂量(400 U/d)维生素D联合布地奈德治疗,C组在A组基础上给予大剂量(800 U/d)维生素D联合布地奈德治疗;比较三组BPD发生情况、呼吸支持情况、潮气呼吸肺功能、免疫球蛋白3项及不良反应情况。结果C组BPD发生率低于A组,差异有统计学意义(P<0.017)。B组和C组氧疗时间均低于A组,差异有统计学意义(P<0.05)。三组早产儿治疗后的达峰时间比(TPEF/TE)、达峰容积比(VPEF/VE)、50%潮气量时呼气流速(TEF50)、75%潮气量时呼气流速(TEF75)均高于本组治疗前,B组和C组早产儿治疗后的TPEF/TE、VPEF/VE、TEF50和TEF75水平均高于A组,差异有统计学意义(P<0.05)。B组和C组早产儿治疗后的免疫球蛋白A(IgA)、免疫球蛋白G(IgG)和免疫球蛋白M(IgM)水平均高于本组治疗前,C组早产儿治疗后的IgA、IgG和IgM水平高于A组和B组,差异有统计学意义(P<0.05)。结论维生素D联合布地奈德预防BPD效果明显,其中大剂量维生素D相比常规剂量在呼吸支持及肺功能方面未见明显改善,但有助于提高免疫功能。

关键词：早产儿支气管肺发育不良维生素D 布地奈德肺功能

Single-cell transcriptomics reveals the ameliorative effect of rosmarinic acid on diabetic nephropathy-induced kidney injury by modulating oxidative stress and inflammation

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Acta Pharmaceutica Sinica B 2024年第4期14卷 1661-1676页

作者： Junhui chen Qian Zhang Jinan Guo Di Gu Jing Liu Piao Luo Yunmeng Bai Jiayun chen xinzhou Zhang Sheng Nie Chunbo chen Yulin Feng Jigang Wang National Pharmaceutical Engineering Center for Solid Preparation of Chinese Herbal Medicine Jiangxi University of Chinese MedicineNanchang 330006China Department of Pulmonary and Critical Care Medicine Shenzhen Institute of Respiratory Diseasesand Shenzhen Clinical Research Centre for GeriatricsShenzhen People's HospitalFirst Affiliated Hospital of Southern University of Science and TechnologySecond Clinical Medical College of Jinan UniversityShenzhen 518020China School of Traditional Chinese Medicine and School of Pharmaceutical Sciences Southern Medical UniversityGuangzhou 510515China Department of Urology and Shenzhen Clinical Research Centre for GeriatricsShenzhen People's Hospitalthe First Affiliated HospitalSouthern University of Science and TechnologyShenzhen 518020China Department of Urology the First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou 510230China Department of Nephrology Shenzhen Key Laboratory of Kidney Diseasesand Shenzhen Clinical Research Centre for GeriatricsShenzhen People's Hospitalthe First Affiliated HospitalSouthern University of Science and TechnologyShenzhen 518020China Department of Nephrology Nanfang Hospitalthe First Affiliated Hospital of Southern Medical UniversityGuangzhou 510515China Department of Critical Care Medicine Shenzhen People's Hospital(the Second Clinical Medical CollegeJinan Universitythe First Affiliated HospitalSouthern University of Science and Technology)Shenzhen 518020China State Key Laboratory for Quality Esurance and Sustainable Use of Dao-di Herbs Artemisinin Research Centerand Institute of Chinese Materia MedicaChina Academy of Chinese Medical SciencesBeijing 100700China Department of Oncology the Affiliated Hospital of Southwest Medical UniversityLuzhou 646000China

Diabetic nephropathy(DN)is a severe complication of diabetes,characterized by changes in kidney structure and function.The natural product rosmarinic acid(RA)has demonstrated therapeutic effects,including anti-inflammation and anti-oxidative-stress,in renal damage or dysfunction.In this study,we characterized the heterogeneity of the cellular response in kidneys to DN-induced injury and RA treatment at single cell levels.Our results demonstrated that RA significantly alleviated renal tubular epithelial injury,particularly in the proximal tubular S1 segment and on glomerular epithelial cells known as podocytes,while attenuating the inflammatory response of macrophages,oxidative stress,and cytotox-icity of natural killer cells.These findings provide a comprehensive understanding of the mechanisms by which RA alleviates kidney damage,oxidative stress,and inflammation,offering valuable guidance for the clinical application of RA in the treatment of DN.

关键词： Rosmarinic acid Diabetic nephropathy scRNA sequencing Injury Oxidative stress Infiammation Proteomics

Atomically Dispersed Ruthenium Catalysts with Open Hollow Structure for Lithium-Oxygen Batteries

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Nano-Micro Letters 2024年第2期16卷 154-164页

作者： Xin chen Yu Zhang Chang chen Huinan Li Yuran Lin Ke Yu Caiyun Nan chen chen Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Solid State ChemistryUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China Engineering Research Center of Advanced Rare Earth Materials Department of ChemistryTsinghua UniversityBeijing 100084People’s Republic of China Beijing Key Laboratory of Energy Conversion and Storage Materials Institution College of ChemistryBeijing Normal UniversityBeijing 100875People’s Republic of China

Lithium–oxygen battery with ultrahigh theoretical energy density is considered a highly competitive next-generation energy storage device,but its practical application is severely hindered by issues such as difficult decomposition of discharge products at present.Here,we have developed N-doped carbon anchored atomically dispersed Ru sites cathode catalyst with open hollow structure(h-RuNC)for Lithium–oxygen battery.On one hand,the abundance of atomically dispersed Ru sites can effectively catalyze the formation and decomposition of discharge products,thereby greatly enhancing the redox kinetics.On the other hand,the open hollow structure not only enhances the mass activity of atomically dispersed Ru sites but also improves the diffusion efficiency of catalytic molecules.Therefore,the excellent activity from atomically dispersed Ru sites and the enhanced diffusion from open hollow structure respectively improve the redox kinetics and cycling stability,ultimately achieving a high-performance lithium–oxygen battery.

关键词： Atomically dispersed Open hollow structure Discharge product Lithium Oxygen battery

Advances in the application of hydrogel-based scaffolds for tendon repair

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Genes & Diseases 2024年第4期11卷 296-313页

作者： Renqiang chen Fanglin chen Kenian chen Jian Xu Department of Orthopedics The First Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiang 310003China Department of Orthopedics The Fourth Affiliated Hospital of Guangxi Medical UniversityLiuzhou Guangxi 545005China

Tendon injuries often lead to joint dysfunction due to the limited self-regeneration capacity of tendons.Repairing tendons is a major challenge for surgeons and imposes a signif-icant financial burden on society.Therefore,there is an urgent need to develop effective stra-tegies for repairing injured tendons.Tendon tissue engineering using hydrogels has emerged as a promising approach that has attracted considerable interest.Hydrogels possess excellent biocompatibility and biodegradability,enabling them to create an extracellular matrix-like growth environment for cells.They can also serve as a carrier for cells or other substances to accelerate tendon repair.In the past decade,numerous studies have made significant prog-ress in the preparation of hydrogel scaffolds for tendon healing.This review aims to provide an overview of recent research on the materials of hydrogel-based scaffolds used for tendon tis-sue engineering and discusses the delivery systems based on them.

关键词： Application Hydrogel-based Repairscaffolds Review Tendon injury Tissue engineering

Photodegradation of xylene isomers:Kinetics,mechanism,secondary pollutant formation potential and health risk evaluation

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Journal of Environmental Sciences 2024年第2期136卷 658-669页

作者： Xiaoyan chen Weikun Zhu Sufen Feng Jiangyao chen Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control Guangdong Technology Research Center for Photocatalytic Technology Integration and Equipment EngineeringInstitute of Environmental Health and Pollution ControlGuangdong University of TechnologyGuangzhou 510006China Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and HealthSchool of Environmental Science and EngineeringGuangdong University of TechnologyGuangzhou 510006China

Photodegradation technology has been widely applied in the purification of industrial aromatic hydrocarbons.However,whether this technology efficiently removes the pollutants to prevent secondary pollution and health risk is still unclear.Here,the photodegradation processes of three xylenes were compared under designed reaction atmospheres and light sources.Xe lamp showed poor photodegradation ability toward xylenes,no matter in N_(2) or N_(2)+O_(2)system,while much higher photodegradation performance of xylenes were obtained under ultraviolet(UV)and vacuum ultraviolet(VUV)irradiation,especially in N_(2)+O_(2)+VUV system,where 97.9%of m-xylene,99.0%of o-xylene or 87.5%of p-xylene with the initial concentration of 860 mg/m^(3) was removed within 240 min.The xylenes underwent three processes of photo-isomerization,photodecomposition and photo-oxidation to produce intermediates of aromatics,alkanes and carbonyls.Among them,the photo-isomerization products showed the highest concentration percentage(e.g.,≥50%in o-xylene system),confirming that photo-isomerization reaction was the dominated photodegradation process of xylenes.Moreover,these isomerized products not only contributed about 97%and91%to the formation potential of O3(OFP)and secondary organic aerosols(SOAFP),but also displayed obvious non-carcinogenic risk,although one of photodecomposition product—benzene showed the highest occupational exposure risk.Therefore,the secondary pollution and health risks of photodegradation products of xylenes were non-ignorable,although the OFP,SOAFP and health risks of the generated products reduced at least 4.5 times in comparison with that of the degraded xylenes.The findings are helpful for the appropriate application of this technology in the purification of industrial organic waste gas.

关键词： Isomer aromatics Photodegradation Ozone formation Secondary organic aerosols Health risk

Isotopic characteristics and source analysis of atmospheric ammonia during agricultural periods in the Xichuan area of the Danjiangkou Reservoir

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Journal of Environmental Sciences 2024年第2期136卷 460-469页

作者： Xiaoshu chen Tongqian Zhao Chunyan Xiao Xiaoming Guo Feihong chen Institute of Resources and Environment Henan Polytechnic UniversityJiaozuo 454000China

Nitrogen deposition is an important means of exogenous nitrogen input in reservoir water.Agricultural activities around the reservoir lead to a sharp increase in the concentration of ammonia in the atmosphere,which poses a threat to the reservoir water body.Clarifying the contribution of agricultural ammonia release to atmospheric NH_(x)(gaseous NH_(3)and particulate NH_(4)^(+)),in the reservoir area can provide a theoretical foundation for local reactive nitrogen control.We collected atmospheric NH_(3)and NH_(4)^(+)samples during the agricultural periods and analyzed the isotopic characteristics of atmospheric NH_(x)and the contribution rates of different ammonia sources in the Xichuan area of the Danjiangkou Reservoir.The results showed that the initialδ~(15)N values of NH_(3)(-30.0‰to–7.2‰)and particulate NH_(4)^(+)(–33‰to+4.9‰for finer and coarser particles,respectively)are different,and their contribution ratios from dissimilar ammonia sources are also different,among which NH_(4)^(+)is more susceptible to meteorological factors.However,since the atmospheric NH_(x)in the Xichuan area is mainly gaseous NH_(3),the final sources of atmospheric ammonia nitrogen source depend on gaseous NH_(3).Agricultural sources(59%-74%)were the main NH_(3)sources in this area.Among them,the fertilizer use emission was dominant;it had the highest contribution rate in summer during the agricultural period and a more prominent impact in areas with less human interference.Reasonable regulation of the application of high-ammonia releasing fertilizer,especially during the agricultural period in summer,is an effective way to reduce the threat of atmospheric ammonia to water health.

关键词： Danjiangkou reservoir Atmospheric ammonia nitrogen Isotope Ammonia source analysis Agricultural sources

Meridional deflection of global eddy propagation derived from tandem altimetry: Mechanism and implication

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Science China Earth Sciences 2024年第3期67卷 811-825页

作者： Ge chen Xiaoyan chen Frontiers Science Center for Deep Ocean Multispheres and Earth System School of Marine TechnologyOcean University of ChinaQindao 266100China Laboratory for Regional Oceanography and Numerical Modeling Laoshan LaboratoryQindao 266237China

A common view on meridional deflection of eddy propagation is poleward for cyclones and equatorward for anticyclones. This widely accepted polarity-sensitive pattern has been increasingly undermined given that it is systematically violated on both zonal and regional scales as recently reported. Here, we approach the problem by exploring these violations in terms of eddy effects of spatiotemporal geostrophy, thermal fading, and flow dragging, yielding the following main conclusions.(1) The polarity-dependent deflection discrepancy is a pseudo feature resulting from a biased fit to the normalized eddy tracks which are spatially asymmetric(though azimuthally symmetric) between the two signs;Instead, the primary pattern of eddy deflection appears to be geographically correlated and polarity independent.(2) Geostrophic adjustment plays a critical role in defining the meridional movement of an eddy. Specifically, a consistent poleward(equatorward) trajectory bending of spatially(temporally) ageostrophic eddies is observed irrespective of their polarity.(3) The mechanism of eddy deflection is also determined by its zonal propagation direction. Westward propagating eddies are substantially affected by thermal fading, while opposite ones by flow dragging. A realistic and comprehensive understanding of eddy deflection mechanisms serves as a significant contribution to the prediction of eddy trajectory, and the protection of ocean environment.

关键词： Mesoscale eddies Eddy propagation Eddy meridional deflection Satellite observation Geostrophic adjustment