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混合物填充速度对火焰加速及DDT转变特性实验

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航空动力学报 2024年第9期39卷 256-265页

作者：张永辉张启斌赵明皓王可范明华范玮西北工业大学动力与能源学院西安710072 西北工业大学陕西省航空动力系统热科学重点实验室西安710129

为研究脉冲爆震发动机中燃料/氧化剂混合物填充速度对火焰加速与缓燃向爆震转变过程(DDT)的影响,以乙烯为燃料、氧气体积分数为40%的富氧空气为氧化剂,进行了实验研究。采用不同的燃烧室构型、不同点火位置和不同的障碍物数量,在混合物... 详细信息

为研究脉冲爆震发动机中燃料/氧化剂混合物填充速度对火焰加速与缓燃向爆震转变过程(DDT)的影响,以乙烯为燃料、氧气体积分数为40%的富氧空气为氧化剂,进行了实验研究。采用不同的燃烧室构型、不同点火位置和不同的障碍物数量,在混合物填充速度为0、2.5、5.7、8.9 m/s和14.1 m/s的条件下,均成功获得充分发展的爆震波。结果表明:混合物填充速度越大,火焰发展也越快,对于能够起爆的工况,缓燃向爆震转变的时间最多可降低至填充速度为0 m/s时的38.9%;填充速度为8.9 m/s时,使火焰成功转变为爆震燃烧所需的障碍物数量由3对可减少为2对。提高混合物填充速度后,缩短DDT长度与点火段长度,依然能够成功建立爆震波,这对优化脉冲爆震发动机燃烧室构型,进而减少发动机长度和质量、提升推进性能具有一定的指导意义。

关键词：缓燃向爆震转变爆震火焰加速填充速度高速摄影

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High-resolution reconstruction of April-September precipitation and major extreme droughts in China over the past∼530 years

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Science Bulletin 2024年第17期69卷 2756-2764页

作者： Yongxiang zhang Hongli Wang Xuemei Shao Hongbin Liu Haifeng Zhu Lily Wang Eryuan Liang Zhixin Hao Xiuqi Fang qibin zhang Jinjian Li Xinghe Shi Yujiang Yuan Feng Chen Tongwen zhang Ruibo zhang Huaming Shang Jianfeng Peng National Climate Centre China Meteorological AdministrationBeijing 100081China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Beijing New Epoch School the Administrative Bureau of Chinese Academy of SciencesBeijing 100086China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Alpine Ecology Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China School of Atmospheric Sciences Plateau Atmosphere and Environment Key Laboratory of Sichuan ProvinceChengdu University of Information TechnologyChengdu 610225China Qinghai Climate Centre Xining 810001 China Key Laboratory of Tree-Ring Physical and Chemical Research of China Meteorological Administration Key Laboratory of Tree-Ring Ecology of Xinjiang Uygur Autonomous RegionInstitute of Desert MeteorologyChina Meteorological AdministrationUrumqi 830002China Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security Institute of International Rivers and Eco-SecurityYunnan UniversityKunming 650000China College of Geography and Environmental Science Henan UniversityKaifeng 475004China

Extreme drought events have increased,causing serious losses and damage to the social economy under current warming ***,short-term meteorological data limit our understanding and projection of these *** the accumulation of proxy data,especially tree-ring data,large-scale precipitation field reconstruction has provided opportunities to explore underlying mechanisms *** point-by-point regression,we reconstructed the April-September precipitation field in China for the past~530 years on the basis of 590 proxy records,including 470 tree-ring width chronologies and 120 drought/flood *** regression models explained average 50%of the variance in *** the statistical test on calibration and verification,our models passed the significance level that assured reconstruction *** reconstruction data performed well,showing consistency and better quality than previously reported *** first three leading modes of variability in the reconstruction revealed the main distribution modes of precipitation over ***/drought and extremely wet/drought years accounted for 12.81%/10.92%(68 years/58 years)and 1.69%/3.20%(9 years/17 years)of the past~530 years in China,*** extreme drought events can be identified explicitly in our *** detailed features of the Chongzhen Great Drought(1637-1643),the Wanli Great Drought(1585-1590),and the Ding-Wu Great Famine(1874-1879),indicated the existence of potentially different underlying mechanisms that need further *** further improvements can be made for remote uninhabited areas and large deserts,our gridded reconstruction of April-September precipitation in China over the past~530 years can provide a solid database for studies on the attribution of climate change and the mechanism of extreme drought events.

关键词： Precipitation reconstruction Tree rings Historical documents Precipitation variability Extreme droughts

邯郸西部生态空间网络结构时空演变及其与固碳功能相关性研究

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农业机械学报 2024年第9期55卷 226-237+248页

作者：宋宏利王悦悦张启斌李倩田正于强河北工程大学地球科学与工程学院河北工程大学园林与生态工程学院北京林业大学精准林业北京市重点实验室

构建生态空间网络是优化区域景观结构、提升生态系统服务功能的常用方法，但对于生态空间网络结构与特定生态系统服务功能间的关系鲜有报道。本研究基于多源遥感数据产品，以邯郸西部为研究区，分析了固碳功能及生态空间网络的时空演变... 详细信息

构建生态空间网络是优化区域景观结构、提升生态系统服务功能的常用方法，但对于生态空间网络结构与特定生态系统服务功能间的关系鲜有报道。本研究基于多源遥感数据产品，以邯郸西部为研究区，分析了固碳功能及生态空间网络的时空演变特征，研究了生态空间网络拓扑结构特征与固碳功能之间的相关性。结果表明，2000—2020年间，研究区植被净初级生产力总量平均值为2.17×10～8 kg/（m2·a）,固碳功能呈上升趋势；研究区生态空间网络整体连接性较高，模块结构明显，不均匀性极强，20年间结构变化趋势显示，网络连接性基本稳定，不均匀性略有升高；研究区节点介数、PageRank、度3个指标与固碳功能之间存在明显的正相关性，其中节点介数相关性最为明显，PageRank和度次之，这3个指标为生态空间网络中节点固碳功能的潜在有效判断指标。研究结果对于生态空间网络构建与优化、区域固碳功能提升具有重要参考价值。

关键词：生态空间网络时空演变固碳功能相关性邯郸西部

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青藏高原高寒草地土壤速效氮矿化能力对温度和有机肥添加的响应

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草业科学 2024年第5期41卷 1048-1056页

作者：郭雅婧李辉鹏张其斌白璐张伟陈宝林桑建辉李渊沈禹颖甘肃省高新技术创业服务中心甘肃兰州7303013 甘肃省子午岭林业管理局合水分局甘肃庆阳745400 兰州大学草地农业科技学院/草种创新与草地农业生态系统全国重点实验室/甘肃庆阳草地农业生态系统国家野外科学观测研究站甘肃兰州730020

青藏高原高寒草地土壤氮素矿化是影响全球碳氮循环和草地生态系统演替的关键过程。本研究通过不同温度(5、15和25℃)和有机氮添加梯度(0、15、45和75 kg·hm^(−2))的室内培养试验,测定土壤氮矿化速率、矿化势以及矿化反应速率常数对处... 详细信息

青藏高原高寒草地土壤氮素矿化是影响全球碳氮循环和草地生态系统演替的关键过程。本研究通过不同温度(5、15和25℃)和有机氮添加梯度(0、15、45和75 kg·hm^(−2))的室内培养试验,测定土壤氮矿化速率、矿化势以及矿化反应速率常数对处理的响应,旨在探究温度和有机肥添加对青藏高原高寒草地土壤速效氮供应能力的影响。结果表明:土壤氮素矿化量随温度的升高而增加,25℃下明显高于15和5℃;有机氮添加(15~45 kg·hm^(−2))显著提高了土壤铵态氮的矿化量,继续增加至75 kg·hm^(−2)时,氮素矿化能力降低;土壤氮矿化速率随培养时间的增加先增加后降低,添加有机氮可以增加高寒草地土壤氮素矿化速率,在氮素添加量为45 kg·hm^(−2)时达到峰值;温度决定了高寒草地土壤氮素矿化势,对矿化速率常数k没有明显影响。综上所述,添加15~45 kg·hm^(−2)有机氮及较高的温度条件有利于提高青藏高原高寒草地土壤速效氮的矿化能力,这为高寒草原地区的草地管理和有机肥施用提供了理论依据。

关键词：高寒草甸氮素添加有机氮氮素矿化速率氮素矿化潜力室内培养温度

Feature extension and matching for mobile robot global localization

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Journal of Systems Engineering and Electronics 2015年第4期26卷 840-846页

作者： Peng Wang qibin zhang Zonghai Chen Department of Automation University of Science and Technology of China

This paper introduces an indoor global localization method by extending and matching features. In the proposed method, the environment is partitioned into convex subdivisions. Local extended maps of the subdivisions are then built by exten- ding features to constitute the local extended map set. While the robot is moving in the environment, the local extended map of the current local environment is established and then matched with the local extended map set. Therefore, global localization in an indoor environment can be achieved by integrating the position and ori- entation matching rates. Both theoretical analysis and comparison experimental result are provided to verify the effectiveness of the proposed method for global localization.

关键词： feature extension global localization feature match-ing mobile robot.

西藏昂仁县树龄超过300年和1000年的古树树木年轮学论证

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西藏科技 2024年第7期46卷 14-18,39页

作者：旦增欧珠喻武郑嘉诚张齐兵西藏农牧学院资源与环境学院林芝860000 中国科学院植物研究所北京100093

西藏西部地区由于生境严酷,很难发现树龄特大的古树。笔者在2023年对昂仁县的古树资源调查中,发现了两棵树龄特大的大果圆柏(Juiperus tibetica Kom.)古树。一棵古树位于达局乡甘丹塔空寺内,采集到的树芯样本接近树干髓心,通过树木年轮... 详细信息

西藏西部地区由于生境严酷,很难发现树龄特大的古树。笔者在2023年对昂仁县的古树资源调查中,发现了两棵树龄特大的大果圆柏(Juiperus tibetica Kom.)古树。一棵古树位于达局乡甘丹塔空寺内,采集到的树芯样本接近树干髓心,通过树木年轮学方法鉴定其树龄约为306年(起始于1716年)。另一棵古树位于多白乡谢村,其胸围高达8.5米,仅采集到12厘米的树芯样本上有216个年轮,推算这棵古树的树龄超过了千年。两株古树的树木年轮数据既反映了区域气候变化信号,也反映了局地小生境和人们对古树的保护信号,同时显示了古树目前生长处于健康状态。研究结果丰富了昂仁县古树本底资源信息,对认识西藏西部地区古树文化、生态、气候、科研和社会价值具有重要意义。

关键词：古树资源千年古树古树生长历史大果圆柏

Exhumation history and preservation of the Jiaojia giant gold deposit, Jiaodong Peninsula

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Science China Earth Sciences 2022年第6期65卷 1161-1177页

作者： qibin zhang Mingchun SONG Zhengjiang DING Meili GUO Mingling ZHOU Changguo DAI Guang HUO Peng zhang CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China University of Chinese Academy of Sciences Beijing 100049China Shandong Provincial No.6 Exploration Institute of Geology and Mineral Resources Weihai 264209China

The Jiaojia giant gold deposit is the largest gold deposit in China, with a total gold reserve of approximately 1200 *** now, the knowledge of the exhumation history of post-mineralization period is limited, in particular for the low-temperature thermochronology studies of samples below-1000 m. In this work, we combined zircon fission-track(ZFT) and apatite fission-track(AFT) dating of samples between-1100 and-2000 m to determine the post-mineralization cooling and exhumation history of the Jiaojia giant gold deposit. The ZFT ages ranged from 144.2±6.3 to 124.4±5.5 Ma, representing the cooling period and the disturbance of ore-forming fluid. The AFT ages ranged from 28.1±2.6 to 16.2±1.0 Ma, recording the exhumation and cooling processes. With reference to previous low-temperature thermochronology studies in the Jiaojia goldfield, we estimated the exhumation rate and amount of the Jiaojia giant gold deposit and reconstructed its exhumation and preservation history. The exhumation history was divided into four stages, rapid exhumation(~120–95 Ma), relatively slow exhumation(~95–50 Ma),slow exhumation(~50–30 Ma) and relatively rapid exhumation(since 30 Ma). Each stage corresponds to geological events related to the basin-mountain coupling that have occurred since the Cretaceous in the Jiaodong area, namely, a strong tectonic extension and volcanic eruption in the Jiaolai Basin, subsidence of the Jiaolai Basin and Wangshi Group molasse sedimentary,tectonic quiescence, and the Linqu Group basalt eruption of the Jiaobei uplift. Our results show that the exhumation of the Jiaojia giant gold deposit is ~5.2±1.2 km and the orebody erosion degree is relatively low, indicating huge prospecting potential deep in the Jiaojia giant gold deposit. These findings have significance and practical value for deep prospecting in the Jiaodong area.

关键词： Fission-track Exhumation history Deposit preservation Jiaojia giant gold deposit Jiaodong

基于RSEI的长时序区域生态安全格局构建——以太行山区河北段为例

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河北工程大学学报（自然科学版） 2024年第2期41卷 105-112页

作者：张贝贝张晓楠张启斌李悦宋宏利河北工程大学地球科学与工程学院河北邯郸056038 河北工程大学矿业与测绘工程学院河北邯郸056038

以太行山区河北段为研究对象,计算遥感生态指数(Remote Sensing Ecological Index,RSEI),进而识别生态源地,选取土地利用类型、归一化植被指数、高程、坡度等多源空间数据进行综合阻力评价,采用电路理论模型提取生态廊道和生态夹点,构... 详细信息

以太行山区河北段为研究对象,计算遥感生态指数(Remote Sensing Ecological Index,RSEI),进而识别生态源地,选取土地利用类型、归一化植被指数、高程、坡度等多源空间数据进行综合阻力评价,采用电路理论模型提取生态廊道和生态夹点,构建“源地-廊道-节点”的长时序区域生态安全格局。结果表明:(1)研究区2002年、2007年、2012年、2017年、2021年的RSEI均值分别为0.507、0.538、0.554、0.493、0.541,20年间RSEI呈现“上升-下降-上升”的变化趋势;(2)研究区源地总面积逐期增加,初期至末期面积增加5705 km^(2),面积占比由2.66%增加至18.56%,源地斑块RSEI均值由0.774上升为0.834;(3)研究区主要生态廊道呈现南北纵向分布,研究末期识别生态源地16个,生态廊道21条,生态夹点5个。

关键词：生态安全格局遥感生态指数(RSEI) 电路理论太行山区

Fantastic voyage: The journey of NLRP3 inflammasome activation

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Genes & Diseases 2024年第2期11卷 819-829页

作者： Xiangyong Que Sihao Zheng qibin Song Huadong Pei Pingfeng zhang Cancer Center Renmin Hospital of Wuhan UniversityWuhanHubei 430060China Department of Oncology Georgetown Lombardi Comprehensive Cancer CenterGeorgetown University Medical CenterWashingtonDC 20057USA

NLRP3 inflammasome,an intracellular multiprotein complex,can be activated by a range of pathogenic microbes or endogenous hazardous *** activation results in the release of cytokines such as IL-1β and IL-18,as well as Gasdermin D which eventually causes *** activation of NLRP3 inflammasome is under strict control and regulation by numerous pathways and *** excessive activation can lead to a persistent inflammatory response,which is linked to the onset and progression of severe *** studies have revealed that the subcellular localization of NLRP3 changes significantly during the activation *** this review,we review the current understanding of the molecular mechanism of NLRP3 inflammasome activation,focusing on the subcellular localization of NLRP3 and the associated regulatory *** aim to provide a comprehensive understanding of the dynamic transportation,activation,and degradation processes of NLRP3.

关键词： Inflammasome activation Innate immunity NLRP3 NLRP3 inflammasome Subcellular localization