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基于卷积神经网络和无人机倾斜摄影图像的单个高层建筑物高度测算方法

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测绘通报 2024年第3期 118-122页

作者：高桂棠郗连霞钟晓龙国核电力规划设计研究院有限公司勘测分公司北京100095 北京超图软件股份有限公司北京100600

为了提升单个高层建筑物高度测算效果,本文提出了基于卷积神经网络的无人机倾斜摄影图像的单个高层建筑物高度测算方法。首先,采用无人机倾斜摄影技术采集高层建筑物图像;然后,在卷积神经网络中输入高层建筑物图像,对其展开增强处理,提... 详细信息

为了提升单个高层建筑物高度测算效果,本文提出了基于卷积神经网络的无人机倾斜摄影图像的单个高层建筑物高度测算方法。首先,采用无人机倾斜摄影技术采集高层建筑物图像;然后,在卷积神经网络中输入高层建筑物图像,对其展开增强处理,提高图像的清晰度;最后,通过波段转换指数和阴影指数计算阴影长度,以此为依据测算单个高层建筑物的高度。试验结果表明,本文方法的图像增强处理效果较好、高度测算精度和效率较好。

关键词：卷积神经网络无人机倾斜摄影图像增强阴影提取高度测算

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激光诱导击穿光谱技术对水稻产地识别研究

光谱学与光谱分析 2024年第6期44卷 1553-1558页

作者：宋少忠符少燕刘园园齐春艳李景鹏高勋吉林工程技术师范学院数据科学与人工智能学院吉林长春130052 长春理工大学物理学院吉林长春130022 吉林省农业科学院水稻研究所吉林长春130033 中国科学院东北地理与农业生态研究所吉林长春130102

水稻是中国主要粮食作物,而水稻品质与其生长的外部环境如土壤特性、气候、日照时间和灌溉水等环境息息相关,高品质水稻的产地区域面积有一定地域限制,因此水稻可看成为是一个明显的地理标志物。市场常出现一些假冒或者贴牌的知名优质... 详细信息

水稻是中国主要粮食作物,而水稻品质与其生长的外部环境如土壤特性、气候、日照时间和灌溉水等环境息息相关,高品质水稻的产地区域面积有一定地域限制,因此水稻可看成为是一个明显的地理标志物。市场常出现一些假冒或者贴牌的知名优质水稻出售,损害了水稻品牌,降低了消费者的水稻品质保障,并且扰乱了市场稳定性,因此对于水稻产地快速识别技术的需求十分迫切。利用LIBS结合机器学习算法,对吉林省5个产地(大安、公主岭、前郭、松原、洮儿河)的水稻进行产地识别,建立了主成分分析(PCA)算法分别结合Bagged Trees、Weighted KNN、Quadratic SVM和Coarse Gaussian SVM共四种机器学习算法的水稻产地识别模型。实验选取了5个水稻产地共450组在200~900 nm的LIBS数据,对水稻LIBS光谱数据采用卷积平滑(S-G平滑)进行降噪和特征谱线归一化预处理,对水稻LIBS光谱数据进行主成分分析,实现了水稻产地具有较好的聚类空间集群分布,但部分水稻产地存在空间重叠。采用5倍交叉验证,采用PCA-Bagged Trees、PCA-Weighted KNN、PCA-Quadratic SVM和PCA-Coarse Gaussian SVM共四种机器学习模型,水稻产地的识别精度均达到91.8%以上,并且PCA-Quadratic SVM模型的识别精度高达97.3%。结果表明结合LIBS技术和机器学习算法能够高精度和高效率实现水稻产地的识别。

关键词：激光诱导击穿光谱机器学习算法水稻产地识别识别精度

The novel H1N1 Influenza A global airline transmission and early warning without travel containments

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Chinese Science Bulletin 2010年第26期55卷 3030-3036页

作者： CHANG ChaoYi cao ChunXiang WANG Qiao CHEN Yu cao ZhiDong ZHANG Hao DONG Lei ZHAO Jian XU Min GAO MengXu zhong ShaoBo HE QiSheng WANG JinFeng LI XiaoWen State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China The Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Satellite Environment Center Ministry of Environmental Protection Beijing 100012 China Key Laboratory of Complex Systems and Intelligence Science Institute of Automation Chinese Academy of Sciences Beijing 100190 China Center for Earth Observation and Digital Earth Chinese Academy of Sciences Beijing 100101 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China

A novel influenza A (H1N1) has been spreading worldwide. Early studies implied that international air travels might be key cause of a severe potential pandemic without appropriate containments. In this study, early outbreaks in Mexico and some cities of United States were used to estimate the preliminary epidemic parameters by applying adjusted SEIR epidemiological model, indicating transmissibility infectivity of the virus. According to the findings, a new spatial allocation model totally based on the real-time airline data was established to assess the potential spreading of H1N1 from Mexico to the world. Our estimates find the basic reproductive number R0 of H1N1 is around 3.4, and the effective reproductive number fall sharply by effective containment strategies. The finding also implies Spain, Canada, France, Panama, Peru are the most possible country to be involved in severe endemic H1N1 spreading.

关键词：国际航空安全壳流感旅行传播预警流行病模型航空公司

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水杨酸和低温复合处理对韭黄品质的影响

食品安全质量检测学报 2024年第4期15卷 122-130页

作者：冯星星仲念万鹏罗壮曹修春董玉玮徐州工程学院食品与生物工程学院徐州221018 徐州山崎农产品技术研发有限公司徐州221700

目的研究水杨酸(salicylic acid, SA)和低温复合保鲜对韭黄(Allium tuberosum)品质的影响。方法在SA和低温复合保鲜下,检测韭黄中蛋白质、维生素C (vitamin C, VC)、水分、持水力、总酸的含量,对韭黄中过氧化物酶(peroxide,POD)酶活... 详细信息

目的研究水杨酸(salicylic acid, SA)和低温复合保鲜对韭黄(Allium tuberosum)品质的影响。方法在SA和低温复合保鲜下,检测韭黄中蛋白质、维生素C (vitamin C, VC)、水分、持水力、总酸的含量,对韭黄中过氧化物酶(peroxide,POD)酶活、超氧化物歧化酶(superoxidedismutase,SOD)酶活、丙二醛(malondialdehyde,MDA)含量、过氧化氢酶(hydrogenperoxide,CAT)酶活进行测定。用TMS-Touch质构仪检测韭黄的嫩度、硬度等变化情况。结果经过SA和低温复合处理的韭黄,蛋白质含量在第14 d最高,第28 d降低至21.99 mg/100 g;VC含量一直下降,最终下降至15.07 mg/100 g;水分在第21 d上升到最高,为92.66%;持水力在第28 d增加到了78%;总酸含量一直升高,最终达到6.57g/kg;POD酶活在第7d上升至2105.36U/g,第28d降低至464.52 U/g;SOD酶活在第7 d达到76.53 U/g,第28 d降至61.24 U/g;MDA含量增加至8.55 mmolg/FW;CAT酶活下降至2.77 U/mg·prot;第28 d韭黄的硬度为24.28 N,嫩度为19.76 N/cm。结论 SA和低温复合保鲜能有效保持韭黄的贮藏品质,对韭黄采收后的保鲜具有较好的参考价值。

关键词：韭黄水杨酸营养物质保鲜品质

The capillary pressure curves from upscaling interfacial and unsaturated flows in porous layers with vertical heterogeneity

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Theoretical & Applied Mechanics Letters 2023年第4期13卷 287-290页

作者： zhong Zheng State Key Laboratory of Ocean Engineering School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China MOE Key Laboratory of Hydrodynamics School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

We provide the capillary pressure curves p_(c)(s)as a function of the effective saturation s based on the theoretical framework of upscaling unsaturated flows in vertically heterogeneous porous layers proposed recently(***,Journal of Fluid Mechanics,950,A17,2022).Based on the assumption of vertical gravitational-capillary equilibrium,the saturation distribution and profile shape of the invading fluid can be obtained by solving a nonlinear integral-differential *** capillary pressure curves p_(c)(s)can then be constructed by systematically varying the injection *** with the relative permeability curves k_(rn)(s)that are already *** can now provide quick estimates on the overall behaviours of interfacial and unsaturated flows in vertically-heterogeneous porous layers.

关键词： Flow upscaling Interfacial and unsaturated flow Wetting and capillary effects Porous layer Heterogeneity

A low-to-high friction transition in gradient nano-grained Cu and Cu–Ag alloys

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Friction 2021年第6期9卷 1558-1567页

作者： Xiang CHEN zhong HAN Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Nano and Heterogeneous Materials Center School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China

A unique low-to-high friction transition is observed during unlubricated sliding in metals with a gradient nano-grained(GNG)surface *** persisting in the low-friction state(0.2–0.4)for tens of thousands of cycles,the coefficients of friction in the GNG copper(Cu)and copper-silver(Cu–5Ag)alloy start to increase,eventually reaching a high level(0.6–0.8).By monitoring the worn surface morphology evolution,wear-induced damage accumulation,and worn subsurface structure evolution during sliding,we found that the low-to-high friction transition is strongly correlated with distinct microstructural instabilities induced by vertical plastic deformation and wear-off of the stable nanograins in the subsurface layer.A very low wear loss of the GNG samples was achieved compared with the coarse-grained sample,especially during the low friction *** results suggest that it is possible to postpone the initiation of low-to-high friction transitions and enhance the wear resistance in GNG metals by increasing the GNG structural stability against grain coarsening under high loading.

关键词： gradient nano-grained metals Cu and Cu–Ag alloy low-to-high friction transition subsurface plastic deformation wear

A novel two-dimensional nanoheterojunction via facilitating electron–hole pairs separation for synergistic tumor phototherapy and immunotherapy

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Nano Research 2023年第5期16卷 7148-7163页

作者： Xiaoge Zhang Xiaomei Chen Peng Zhang Meiting Li Miao Feng Yaqian Zhang Lili Cheng Junjie Tang Langtao Xu Yadong Liu Zhuoyin Liu zhong cao Jie Liu School of Biomedical Engineering Shenzhen Campus of Sun Yat-sen UniversityShenzhen 518107China

Nanomaterial-mediated phototherapy in tumor treatment has been developed rapidly in the past few years due to its noninvasive ***,the low energy conversion efficiency and high recombination rate of the photo-triggered electron–hole pairs of single nano-agent limit the phototherapy ***,we constructed a novel two-dimensional nanoheterojunction MoS_(2)-Ti_(3)C_(2)(MT),which allowed a high photothermal conversion efficiency(59.1%)as well as an effective separation of photo-triggered electron–hole pairs for reactive oxygen species(ROS)generation under single 808 nm laser *** the modification of the mitochondrial targeted molecule(3-proxycarboxylic)triphenyl phosphine bromide(TPP)and 4T1 cell membrane,m@MoS_(2)-Ti_(3)C_(2)/TPP(m@MTT)could effectively target to the tumor cell and further locate to the mitochondria to amplify tumor-specific oxidative stress,which not merely effectively inhibits the local tumor growth but also induces tumor immunogenic cell death(ICD)for activating antitumor immune ***,cytosine guanine dinucleotide(CPG),as a Toll-like receptor 9(TLR9)agonist,was further introduced to the system to boost adaptive immune responses,resulting in improved level of cytotoxic T cells as well as a decrease in the number of regulatory T *** vivo antitumor mechanism studies demonstrated that not only the primary and distant tumors in 4T1 bearing-tumor mice model were significantly inhibited,but also the lung metastasis of tumor was effectively ***,this work revealed the ROS generation mechanism of MT nanoheterojunction and provided a novel strategy to fabricate a biomedically applicable MT nanoheterojunction for tumor treatment.

关键词： two-dimensional nanoheterojunction mitochondrial targeting photothermal therapy photodynamic therapy immunotherapy

A self-powered piezoelectret sensor based on foamed plastic garbage for monitoring human motions

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Nano Research 2023年第1期16卷 1269-1276页

作者： Yujun Shi Kaijun Zhang Sen Ding Zhaoyang Li Yuhao Huang Yucong Pi Dazhe Zhao Yaowen Zhang Renkun Wang Binpu Zhou Zhi-xin Yang Junwen zhong Department of Electromechanical Engineering and Centre for Artificial Intelligence and Robotics University of MacaoMacao 999078China Joint Key Laboratory of the Ministry of Education Institute of Applied Physics and Materials EngineeringUniversity of MacaoAvenida da UniversidadeMacao 999078China State Key Laboratory of Internet of Things for Smart City and Department of Electromechanical Engineering University of MacaoMacao 999078China

Constructing piezoelectret based on foamed plastic garbage is an advisable strategy for obtaining self-powered flexible electromechanical sensors with good ***,a self-powered piezoelectret sensor with basic material of low density polyethylene(LDPE)foamed plastic garbage is proposed,with characteristics of easy fabrication,excellent flexibility,and high equivalent piezoelectric coefficient d33 value up to~1,100 pC/*** output stability is verified by continuously stimulating a sensor for~180,000 cycles under low and high applied pressure,and the variations of peak outputs are less than 5.5%.Applications for measuring low-and high-pressure signals from human body are *** with a wristband,a sensor is demonstrated for detecting the human pulse ***,real time human sitting information is wirelessly monitored with a smart chair based on 4 pixels sensors array.

关键词： wearable electronics piezoelectret self-powered pressure sensor mobile health

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增压方式对高原重型天然气发动机性能研究

内燃机与配件 2024年第14期 25-28页

作者：张松宁德忠曹晟潘月德覃玉峰文涛官维广西玉柴机器股份有限公司广西玉林537000 广西大学机械工程学院广西南宁530004

国六当量重型天然气发动机普遍采用单级废气涡轮对新鲜充量进行增压,在高原低压环境下,相对较低的进气密度,单级废气涡轮增压方式无法提供工况稳定高效运行所需要的增压需求,导致发动机动力下降问题突出。为研究不同增压方式对国六当量... 详细信息

国六当量重型天然气发动机普遍采用单级废气涡轮对新鲜充量进行增压,在高原低压环境下,相对较低的进气密度,单级废气涡轮增压方式无法提供工况稳定高效运行所需要的增压需求,导致发动机动力下降问题突出。为研究不同增压方式对国六当量重型天然气发动机高原性能的影响,通过发动机模拟高原台架测试,分析了单级废气涡轮增压和两级增压两种不同增压方式发动机在模拟高原低压环境下的性能表现。试验结果表明:两级增压方式可明显改善重型天然气发动机在高原低压环境下的动力下降问题。相比单级废气涡轮增压方式,在发动机安全运行的边界条件内,两级增压方式在平原环境下的功率密度可提升13.7%;2km海拔下发动机实现无功率损失,功率下降改善13%;2.5km海拔下发动机动力无损失;3km海拔下动力下降问题改善幅度较大,最大降幅由27.5%降低为10.2%。此外,高原低压环境下发动机增压器转速安全裕度的增加大大降低了增压器超速断轴问题的风险,提升了发动机运行的耐久可靠性。

关键词：当量天然气发动机高原环境增压方式发动机性能