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Neurotrophins and neural stem cells in posttraumatic brain injury repair

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Animal Models and Experimental Medicine 2024年第1期7卷 12-23页

作者： Wenwen Guo Ke Liu Yinghua Wang Xu Ge yifan ma Jing Qin Caiqin Zhang Ya Zhao Changhong Shi Laboratory Animal Center Fourth Military Medical UniversityXi'anP.R.China Gansu University of Traditional Chinese Medicine LanzhouP.R.China Medical College of Yan'an University Yan'anP.R.China

Traumatic brain injury(TBI)is the main cause of disability,mental health disorder,and even death,with its incidence and social costs rising *** different treatment strategies have been developed and tested to mitigate neurological decline,a definitive cure for these conditions remains *** have revealed that vari-ous neurotrophins represented by the brain-derived neurotrophic factor are the key regulators of neuroinflammation,apoptosis,blood-brain barrier permeability,neurite regeneration,and memory *** factors are instrumental in alleviating neu-roinflammation and promoting *** addition,neural stem cells(NSC)contribute to nerve repair through inherent neuroprotective and immunomodulatory properties,the release of neurotrophins,the activation of endogenous NSCs,and in-tercellular ***,innovative research proposals are emerging to combine BDNF and NSCs,enabling them to synergistically complement and promote each other in facilitating injury repair and improving neuron differentiation after *** this review,we summarize the mechanism of neurotrophins in promoting neurogen-esis and restoring neural function after TBI,comprehensively explore the potential therapeutic effects of various neurotrophins in basic research on TBI,and investigate their interaction with *** endeavor aims to provide a valuable insight into the clinical treatment and transformation of neurotrophins in TBI,thereby promoting the progress of TBI therapeutics.

关键词： mutual effect neural stem cells neurological function neurotrophins traumatic brain injury

不同粒径黑火药点火过程中与纤维素壳体材料的热相互作用

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兵工学报 2024年第5期45卷 1582-1592页

作者：李玉雪田小涛马伊凡刘佩进严启龙西北工业大学固体推进全国重点实验室陕西西安710072 西安现代控制技术研究所陕西西安710065

为了研究点火装置中纤维素外壳对不同粒径黑火药固相反应放热特性、反应气相产物、点火燃烧特性等方面的影响,制备系列黑火药/纤维素复合物样品,并采用扫描电子显微镜表征其微观结构和形貌。通过同步热分析仪和傅里叶变换红外光谱仪联用... 详细信息

为了研究点火装置中纤维素外壳对不同粒径黑火药固相反应放热特性、反应气相产物、点火燃烧特性等方面的影响,制备系列黑火药/纤维素复合物样品,并采用扫描电子显微镜表征其微观结构和形貌。通过同步热分析仪和傅里叶变换红外光谱仪联用,研究纤维素对黑火药热反应性能的影响。用氧弹量热仪测量各样品的爆热,利用综合燃烧诊断系统(高速相机和高速红外热像仪)获得黑火药及其纤维素复合物燃速与火焰温度分布。研究结果表明:纤维素会降低黑火药放热量,当纤维素含量为33.33%时,两种黑火药的总放热量分别降低了66.4%和58.5%;纤维素并未改变黑火药热解路径;黑火药的主要气相产物分别为H_(2)O、CO_(2)和NO_(2),与纤维素复合后除浓度变化外,气相产物种类保持不变;纤维素仅影响黑火药能量释放过程,但对不同粒径黑火药的能量释放影响的差别较小,与纤维素复合后能量释放变化仅相差3.1%。实验研究发现,小粒径黑火药及其纤维素复合物燃烧更剧烈,火焰面积更大、燃温更高;纤维素对黑火药的燃烧起消极作用,主要是降低黑火药的燃速和火焰辐射强度,火焰温度分别降低273.7℃和299.4℃;黑火药及其纤维素复合物的凝聚相产物形貌表明纤维素一定程度上促进了黑火药凝相产物团聚,即纤维素会降低其燃烧效率。

关键词：黑火药热相互作用分解产物燃速火焰结构

旋转弯曲和超声波循环加载高周疲劳性能对比分析

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航空材料学报 2024年第3期44卷 142-150页

作者：刘璐王生楠马一凡西北工业大学航空学院西安710072 西安航空学院飞行器学院西安710077

通过旋转弯曲(频率52.5 Hz,10^(3)~10^(8)周次)和超声波(频率20 kHz,5×10^(4)~10^(9)周次)轴向循环载荷疲劳实验,研究不同应力比(R)、加载方式和夹杂物对CL60钢高周、超高周疲劳性能的影响。结果表明:所有S-N曲线均呈现水平渐进趋势,... 详细信息

通过旋转弯曲(频率52.5 Hz,10^(3)~10^(8)周次)和超声波(频率20 kHz,5×10^(4)~10^(9)周次)轴向循环载荷疲劳实验,研究不同应力比(R)、加载方式和夹杂物对CL60钢高周、超高周疲劳性能的影响。结果表明:所有S-N曲线均呈现水平渐进趋势,并具有明确的疲劳极限;应力比R=-1情况下,通过超声波实验获得的疲劳强度(260~270MPa)比旋转弯曲获得的疲劳强度(400~410 MPa)低140~150 MPa,并且应力比R=0.3的超声波疲劳极限值在195~205 MPa的范围内;旋转弯曲疲劳实验的疲劳裂纹起源于试件的表面,超声波疲劳实验的表面和内部均有裂纹萌生,且裂纹均在MnS夹杂物附近产生,与应力比大小无关。采用有限元方法研究了MnS夹杂物对裂纹萌生和扩展的影响,椭圆MnS夹杂物的侧面相较于尖端位置应力集中水平更高,导致裂纹从夹杂物侧面萌生。

关键词： CL60钢高周疲劳应力比夹杂超声波循环

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带有状态/输入量化的无人船自适应模糊跟踪控制

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华南理工大学学报（自然科学版） 2024年第5期52卷 52-61页

作者：宁君马一帆李伟 †李铁山陈俊龙岳兴旺大连海事大学航海学院辽宁大连116026 电子科技大学自动化工程学院四川成都611730 华南理工大学计算机科学与工程学院广东广州510006

针对海上通讯带宽受限情况下无人船的航迹跟踪控制问题,设计了一种带有状态量化和输入量化的自适应反馈跟踪控制方案。在保证有效跟踪的同时,减少执行器执行频次,降低控制幅度。首先,在不考虑量化情况下基于自适应反步法设计了系统跟踪... 详细信息

针对海上通讯带宽受限情况下无人船的航迹跟踪控制问题,设计了一种带有状态量化和输入量化的自适应反馈跟踪控制方案。在保证有效跟踪的同时,减少执行器执行频次,降低控制幅度。首先,在不考虑量化情况下基于自适应反步法设计了系统跟踪控制律,并结合动态面技术有效降低了虚拟控制律的计算量膨胀问题。对于控制系统中存在的不确定项,利用模糊逻辑系统进行逼近。其次,采用均匀量化器分别对控制系统中的状态变量和输入变量进行量化,且量化后的状态反馈信息被用于无人船航迹跟踪控制器的设计。根据所得到的量化信息,给出了同时考虑状态量化和输入量化的无人船航迹跟踪控制律。在稳定性分析中,通过Lyapunov稳定性理论证明了在不考虑量化的情况下闭环控制系统的稳定性,并根据递归的方法证明了闭环控制系统中量化变量和非量化变量之间误差的有界性。基于给定的引理,最终证明了在同时考虑状态量化和输入量化的情况下,所设计的带有状态量化和输入量化的模糊自适应反馈跟踪控制系统的稳定性。最后,通过两组仿真实验验证了所提方案的实用性。即在同时考虑状态量化和输入量化的情况下,无人船仍能保持对理想轨迹良好的跟踪性能,并有效减轻了执行器的执行频次,更符合航海工程实践。

关键词：无人船航迹跟踪状态量化及输入量化模糊自适应控制量化误差

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基于蚁群算法的无人机协同任务规划研究

Environment drives the co-occurrence of bacteria and microeukaryotes in a typical subtropical bay

中国科技纵横 2024年第6期 48-51页

作者：马一凡中国人民解放军战略支援部队信息工程大学河南郑州 450004

无人机搜寻具有机动性强、定位精度高的优势.本文结合实际情况,模拟红蓝两方的无人机协同海域规划问题.一是协同搜索问题,利用BFS算法先将热力图可视化,根据蚁群算法将红方无人机最优搜索路线规划出来,再利用K-means聚类算法将多架无人... 详细信息

无人机搜寻具有机动性强、定位精度高的优势.本文结合实际情况,模拟红蓝两方的无人机协同海域规划问题.一是协同搜索问题,利用BFS算法先将热力图可视化,根据蚁群算法将红方无人机最优搜索路线规划出来,再利用K-means聚类算法将多架无人机分配到多个区域,实现无人机协同搜索.二是全区域覆盖问题,通过计算区域圆度是否大于0.86判断是用螺旋法还是割草法搜寻方式,实现全区域覆盖.根据不同的搜寻模式对热点区域进行分割处理,建立蓝方搜寻船的机动模型.

关键词：线性规划 BFS算法 K-means聚类算法蚁群算法几何分析法

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Journal of Oceanology and Limnology 2023年第6期41卷 2292-2308页

作者： yifan ma Lingfeng HUANG Wenjing ZHANG State Key Laboratory of marine Environmental Science Marine Biodiversity and Global Change Research CenterCollege of Ocean and Earth SciencesXiamen UniversityXiamen 361102China Xiamen Key Laboratory of Urban Sea Ecological Conservation and Restoration Xiamen UniversityXiamen 361102China Fujian Key Laboratory of Coastal Pollution Prevention and Control Xiamen UniversityXiamen 361102China Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems College of the Environment and EcologyXiamen UniversityXiamen 361102China

The co-occurrence of bacteria and microeukaryote species is a ubiquitous ecological phenomenon,but there is limited cross-domain research in aquatic *** conducted a network statistical analysis and visualization of microbial cross-domain co-occurrence patterns based on DNA sampling of a typical subtropical bay during four seasons,using high-throughput sequencing of both 18S rRNA and 16S rRNA ***,we found obvious relationships between network stability and network complexity *** example,increased cooperation and modularity were found to weaken the stability of cross-domain ***,we found that bacterial operational taxonomic units(OTUs)were the most important contributors to network complexity and stability as they occupied more nodes,constituted more keystone OTUs,built more connections,more importantly,ignoring bacteria led to greater variation in network ***,Alphaproteobacteria,Bacteroidetes,and Actinobacteria were the most ecologically important ***,we found that the environmental drivers most associated with cross-domain networks varied across seasons(in detail,the network in January was primarily constrained by temperature and salinity,the network in April was primarily constrained by depth and temperature,the network in July was mainly affected by depth,temperature,and salinity,depth was the most important factor affecting the network in October)and that environmental influence was stronger on bacteria than on microeukaryotes.

关键词： co-occurrence network cross-domain network stability network complexity subtropical bay

Homogeneous selection is not always important in bacterial community in the eutrophic enclosed bay

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Ecological Processes 2022年第1期11卷 363-373页

作者： Junwei Zhu yifan ma Lingfeng Huang Wenjing Zhang State Key Laboratory of marine Environmental Science Marine Biodiversity and Global Change Research CenterCollege of Ocean and Earth SciencesXiamen UniversityXiamenChina Xiamen Key Laboratory of Urban Sea Ecological Conservation and Restoration Xiamen UniversityXiamenChina Fujian Key Laboratory of Coastal Pollution Prevention and Control Xiamen UniversityXiamenChina Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems College of the Environment and EcologyXiamen UniversityXiamenChina

Background:Previous studies have found that coastal eutrophication increases the influence of homogeneous selection on bacterial community ***,whether seasonal changes affect the dominance of homogenous selection in bacterial community assembly in eutrophic bays remains *** Bay is an enclosed bay with ongoing eutrophication,located in the southeast coast of *** investigated the bacterial community composition at two depths of the enclosed bay across seasons and the seasonal variation in community assembly ***:Diversity analyses revealed that the bacterial community composition among seasons differed *** contrast,there was little difference in the community composition between the two *** temperature was the key environmental factor influencing the community *** null model indicated that the relative importance of homogeneous selection decreased in the following order:spring>winter>autumn>*** selection did not always dominate the community assembly among seasons in the eutrophic *** effects of pure spatial variables on the community assembly were prominent in autumn and ***:Our results showed the seasonal influence of eutrophication on bacterial community *** seasonal variation in composition and structure of bacterial communities eclipsed the vertical *** could enhance the importance of homogeneous selection in the assembly processes,but the seasonal environmental differences interfered with the steady-state maintained by ongoing eutrophication and changed the community assembly *** selection was not always important in bacterial community in the eutrophic enclosed *** bacterial community was the most complex in summer,because the composition differed from other seasons,and the assembly process was the most *** findings have contributed to understanding bacterial community composition and asse

关键词： Homogeneous selection Subtropical enclosed bay Assembly processes Bacteria community

基于雪岭云杉树轮宽度重建中天山巴仑台地区过去565年7~9月NDVI变化

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第四纪研究 2024年第4期44卷 869-881页

作者：马一凡刘禹宋慧明张权蔡秋芳任萌李珮中国科学院地球环境研究所黄土与第四纪地质国家重点实验室陕西西安710061 中国科学院大学北京100049 中国科学院第四纪科学与全球变化卓越创新中心陕西西安710061 西安交通大学人居环境与建筑工程学院陕西西安710054 西安地球环境创新研究院陕西西安710061 中国-巴基斯坦地球科学研究中心中国科学院和巴基斯坦高等教育委员会伊斯兰堡巴基斯坦45320

归一化植被指数(NDVI)对分析植被动态及其对气候的响应至关重要,但是对天山地区而言,现有的短时NDVI数据集不能满足长时间尺度的分析需要。因此,本研究利用天山南坡巴仑台地区雪岭云杉样本建立了树轮宽度年表(STD),发现其与7~9月的NDVI... 详细信息

归一化植被指数(NDVI)对分析植被动态及其对气候的响应至关重要,但是对天山地区而言,现有的短时NDVI数据集不能满足长时间尺度的分析需要。因此,本研究利用天山南坡巴仑台地区雪岭云杉样本建立了树轮宽度年表(STD),发现其与7~9月的NDVI显著相关(r=0.69,n=39,p<0.001),在此基础上,设计线性回归模型,重建了研究区1455~2019年7~9月NDVI变化,方差解释量为46%。结果显示,研究区在1455~2019年期间经历了5个植被覆盖高值期和8个植被覆盖低值期,其中1988~2019年植被生长处于历史最高水平;与周边其他重建序列对比结果表明NDVI变化存在空间差异性,中天山区域近30多年来NDVI呈现增加趋势,而西天山则呈现下降趋势;此外,分析表明降水是研究区NDVI的主要影响因素。天山地区降水主要受到海温异常和遥相关的影响,分析结果显示印度洋海温增暖和东大西洋遥相关型(EA)正相位可以使天山地区降水量增加,进而促进研究区植被的生长。该研究对理解中天山植被覆盖的长期动态变化具有一定的参考意义,并为未来植被动态演化预测提供基础数据。

关键词：树轮宽度归一化植被指数(NDVI) 重建中天山

Design and fabrication of a gecko-inspired surface for improving the grasping ability of a humanoid dexterous hand

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Science China(Technological Sciences) 2023年第3期66卷 784-792页

作者： JIANG ZhiHong SHEN MingHui ma yifan CHE JiangTao LI Hui School of Mechatronic Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Advanced Innovation Center for Intelligent Robots and Systems Beijing 100081China Key Laboratory of Biomimetic Robots and Systems Ministry of EducationBeijing 100081China China Electronics Standardization Institute Beijing 100007China

many studies have examined the design,fabrication and characteristics of gecko-inspired adhesives,but applied research on gecko-inspired surfaces in humanoid dexterous hands is relatively ***,a wedged slanted structure with a curved substrate suitable for humanoid dexterous fingers was designed and manufactured via ultraprecision machining and replica *** adhesion and friction properties of the wedged slanted structure show obvious anisotropic characteristics in the gripping and releasing directions,and the influence of structural parameters and motion parameters on the adhesion and friction was systematically *** humanoid dexterous fingers with gecko-inspired surfaces greatly increased the grasping force limit(increase to 4.02 times)based on the grasping of measuring cups with different volumes of water and improved the grasping stability based on the picking up of smooth steel balls of different *** study shows that this process,based on ultraprecision machining and replica molding,is a green,high-efficiency,and low-cost method to fabricate large-area biomimetic surfaces that has potential applications in dexterous humanoid hands to improve grasping ability,stability and adaptability.

关键词： gecko-inspired surface curved substrate ultraprecision machining friction humanoid dexterous hand