检索结果-南通市图书馆

利用FY-4B地球静止气象卫星观测南海北部内孤立波及传播速度

在线全文

学校读者我要写书评

暂无评论

海洋学报 2024年第7期46卷 1-15页

作者：李熙莹孟俊敏孙丽娜张昊贺凯飞自然资源部第一海洋研究所山东青岛266061 中国石油大学(华东)海洋与空间信息学院山东青岛266580 自然资源部海洋遥测技术创新中心山东青岛266061

本文利用中国新一代静止轨道气象卫星FY-4B数据开展了南海北部海域内孤立波观测及传播速度研究。首先使用500 m分辨率的全圆盘ARGI数据对FY-4B卫星可观测内波区域进行了讨论,确认了南海北部为研究区域。之后利用250 m分辨率的GHI数据使... 详细信息

本文利用中国新一代静止轨道气象卫星FY-4B数据开展了南海北部海域内孤立波观测及传播速度研究。首先使用500 m分辨率的全圆盘ARGI数据对FY-4B卫星可观测内波区域进行了讨论,确认了南海北部为研究区域。之后利用250 m分辨率的GHI数据使用多时相图像比较法(Multitemporal Image Comparison Method,MTI)计算了南海北部内孤立波的传播速度,其平均传播速度为1.78 m/s,东部深海区平均传播速度为3.02 m/s,向西传播至东沙群岛附近后平均速度减小至1.90 m/s,经过东沙群岛分裂后南部比北部传播速度更快,分别为2.08 m/s和1.54 m/s;最终在向西传播到近岸区域后内孤立波传播速度减小至0.42 m/s,直至最终消散。将MTI方法与两层模式下扩展KdV方程(extended Korteweg-de Vries,eKdV)计算得到的理论传播速度进行了对比,二者相关系数达到了0.89,证明eKdV理论方程对南海北部内孤立波传播速度反演的可行性,但仍具有一定的局限。最后将实测数据与遥感影像匹配计算内孤立波传播速度的结果与单一遥感影像计算内孤立波传播速度的结果进行了比较,两者相关性达到了0.93。本文验证了静止轨道卫星光学遥感数据的高时间分辨率特点对内孤立波传播速度研究具有的较大优势,对南海北部内孤立波参数反演等研究工作具有一定意义。

关键词：内孤立波 FY-4B地球静止气象卫星多时相图像比较法(MTI) eKdV方程南海北部

A Novel Improved Bat Algorithm in UAV Path Planning

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2019年第7期61卷 323-344页

作者： na Lin Jiacheng Tang Xianwei Li Liang Zhao School of computer science Shenyang Aerospace UniversityShenyang110000China School of Information Engineering Suzhou UniversitySuzhou215000China Global Information and Telecommunication Institute Waseda UniversityTokyo169-0051Japan

Path planning algorithm is the key point to UAV path planning *** traditional path planning methods still suffer from low convergence rate and insufficient *** this paper,three main methods are contributed to solving these ***,the improved artificial potential field(APF)method is adopted to accelerate the convergence process of the bat’s position ***,the optimal success rate strategy is proposed to improve the adaptive inertia weight of bat *** chaos strategy is proposed to avoid falling into a local *** with standard APF and chaos strategy in UAV path planning scenarios,the improved algorithm CPFIBA(The improved artificial potential field method combined with chaotic bat algorithm,CPFIBA)significantly increases the success rate of finding suitable planning path and decrease the convergence *** results show that the proposed algorithm also has great robustness for processing with path planning ***,it overcomes the shortcomings of the traditional meta-heuristic algorithms,as their convergence process is the potential to fall into a local *** the simulation,we can see also obverse that the proposed CPFIBA provides better performance than BA and DEBA in problems of UAV path planning.

关键词： UAV path planning bat algorithm the optimal success rate strategy the APF method chaos strategy

Seasonal variations of air-sea heat fluxes and sea surface temperature in the northwestern Pacific marginal seas

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2014年第3期33卷 101-110页

作者： LIU na WU Dexing LIN Xiaopei MENG Qingjia Key Laboratory of Research on Marine Hazards Forecasting National Marine Environmental Forecasting CenterState Oceanic Administration LASG Institute of Atmospheric Physics Chinese Academy of Sciences Physical Oceanography Laboratory Ocean University of China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences

Using a net surface heat flux （Qnet） product obtained from the objectively analyzed air-sea fluxes （OAFlux） project and the international satellite cloud climatology project （ISCCP）, and temperature from the simple ocean data assimilation （SODA）, the seasonal variations of the air-sea heat fluxes in the northwestern Pa cific marginal seas （NPMS） and their roles in sea surface temperature （SST） seasonality are studied. The seasonal variations of Qnet, which is generally determined by the seasonal cycle of latent heat flux （LH）, are in response to the advection-induced changes of SST over the Kuroshio and its extension. Two dynamic regimes are identified in the NPMS： one is the area along the Kuroshio and its extension, and the other is the area outside the Kuroshio. The oceanic thermal advection dominates the variations of SST and hence the sea-air humidity plays a primary role and explains the maximum heat losing along the Kuroshio. The heat transported by the Kuroshio leads to a longer period of heat losing over the Kuroshio and its Extension. Positive anomaly of heat content corresponds with the maximum heat loss along the Kuroshio. The oceanic advection controls the variations of heat content and hence the surface heat flux. This study will help us understand the mechanism controlling variations of the coupled ocean-atmosphere system in the NPMS. In the Kuroshio region, the ocean current controls the ocean temperature along the main stream of the Ku roshio, and at the same time, forces the air-sea fluxes.

关键词： heat flux seasonal variations Kuroshio heat content

N_2O and NH_3 emissions from a bioreactor landfill operated under limited aerobic degradation conditions

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2011年第6期23卷 1011-1019页

作者： Pinjing He na Yang Huili Gu Hua Zhang Liming Shao State Key Laboratory of Pollution Control and Resources Reuse Key Laboratory of Yangtze River Water Environment College of Environmental Science and Engineering Tongji University Shanghai 200092 China

The combination of leachate recirculation and aeration to landfill may be an efficient way for in-situ nitrogen ***,nitrogenous substances contained in the landfill layer are concomitantly transformed into N2O and NH3,leading to increased emissions into the *** the present study,the emissions of N2O and NH3 were measured under conditions of fresh or partially stabilized refuse with or without leachate recirculation or intermittent *** results showed that the largest N2O emission（12.4 mg-N/L of the column） was observed in the aerated column loaded with partially stabilized refuse and recycled with the leachate of low C/N ratio;while less than 0.33 mg-N/L of the column was produced in the other columns.N2O production was positively correlated with the prolonged aerobic time and negatively related with the C/N ratio in the recycled ***3 volatilization increased with enhanced gas flow and concentration of free ammonia in the leachate,and the highest cumulative volatilization quantity was 1.7 mg-N/L of the column.

关键词： municipal solid waste bioreactor landfill aeration N2O emission NH3 volatilization

Synthesis,in vitro antibacterial and antifungal evaluation of novel 1,3,4-oxadiazole thioether derivatives bearing the 6-fluoroquinazolinylpiperidinyl moiety

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2020年第2期31卷 434-438页

作者： Jun Shi na Luo Muhan Ding Xiaoping Bao State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural BioengineeringMinistry of EducationCenter for Research and Development of Fine ChemicalsGuizhou UniversityGuiyang 550025China

A series of structurally novel 1,3,4-oxadiazole thioether derivatives(6a-6z) containing a 6-fluoroquinazolinylpiperidinyl moiety were designed and synthesized using pharmacophore hybrid approach,and their structures were fully characterized by ^1H NMR,^(13)C NMR and HRMS *** them,the structure of compound 6 d was further corroborated via single-crystal X-ray diffraction *** vitro antibacterial bioassays showed that compounds 6 a,6 g,6 u and 6 v possessed EC_(50) values of 30.4,30.6,27.5 and 26.0 μg/mL against phytopathogenic bacterium Xanthomonas oryzae ***,respectively,which were significantly superior to that of commercially-available bactericide Bismerthiazol(85.1 μg/mL).Moreover,in vitro antifungal bioassays indicated that seven compounds demonstrated broad-spectrum fungicidal acitivties against six types of phytopathogenic fungi at 50 μg/*** present work showed the potential of 1,3,4-oxadiazole thioether derivatives carrying a 6-fluoroquinazolinylpiperidinyl moiety as effective antimicrobial agents for crop protection,deserving further investigations in the future.

关键词： 1,3,4-Oxadiazole thioether Fluoroquinazolinylpiperidinyl Synthesis Antibacterial activity Antifungal activity

Metalloporphyrin-based covalent organic frameworks composed of the electron donor-acceptor dyads for visible-light-driven selective CO2 reduction

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2020年第9期63卷 1289-1294页

作者： Haowei Lv Rongjian sa Pengyue Li Daqiang Yuan Xinchen Wang Ruihu Wang State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Institute of Oceanography Ocean CollegeMinjiang UniversityFuzhou 350108China State Key Laboratory of Photocatalysis on Energy and Environment Fuzhou UniversityFuzhou 350108China

The visible-light-driven photocatalytic CO2 reduction with high efficiency is highly desirable but ***,we present porphyrin-tetraphenylethene-based covalent organic frameworks(MP-TPE-COF,where M=H2,Co and Ni;TPE=4,4′,4″,4?-(ethane-1,1,2,2-tetrayl)tetrabenzaldehyde;COF=covalent organic framework)as ideal platforms for understanding photocatalytic CO2 reduction at molecular *** and theoretical investigations have demonstrated crucial roles of metalloporphyrin units in selective adsorption,activation and conversion of CO2 as well as in the separation of charge carriers and electron transfer,thus allowing for flexible modulation of photocatalytic activity and *** P-TPE-COF exhibits high CO evolution rate of 2,414μmol g-^1 h^-1 with the selectivity of 61%over H2 generation under visible-light irradiation,while Ni P-TPE-COF provides CO evolution rate of 525μmol g^-1 h^-1 and 93%selectivity with superior ***,the photocatalytic system is feasible for the simulated flue gas,which provides CO evolution rate of 386μmol g-1 h-1 and selectivity of 77%.This work provides in-depth insight into the structure-activity relationships toward the activation and photoreduction of CO2.

关键词： covalent organic frameworks photocatalysis porous materials CO2reduction metalloporphyrin

Decomposition Analysis on Direct Material Input and Dematerialization of Mining Cities in Northeast China

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2009年第2期19卷 104-112页

作者： QIU fangdao TONG Lianjun ZHANG Huimin ZHANG na School of Urban and Environmental Sciences Xuzhou Normal University Xuzhou 221116 China College of Urban and Environment Science Northeast Normal University Changchun 130024 China Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changehun 130012 China

Material dematerialization is a basic approach to reduce the pressure on the resources and environment and to realize the sustainable development. The material flow analysis and decomposition method are used to calculate the direct material input (DMI) of 14 typical mining cities in Northeast China in 1995–2004 and to analyze the demateri- alization and its driving factors in the different types of mining cities oriented by coal, petroleum, metallurgy and multi-resources. The results are as follows: 1) from 1995 to 2006, the increase rates of the DMI and the material input intensity of mining cities declined following the order of multi-resources, metallurgy, coal, and petroleum cities, and the material utilizing efficiency did following the order of petroleum, coal, metallurgy, and multi-resources cities; 2) during the research period, all the kinds of mining cities were in the situation of weak sustainable development in most years; 3) the pressure on resources and environment in the multi-resources cities was the most serious; 4) the petro- leum cities showed the strong trend of sustainable development; and 5) in recent years, the driving function of eco- nomic development for material consuming has continuously strengthened and the controlling function of material utilizing efficiency for it has weakened. The key approaches to promote the development of circular economy of min- ing cities in Northeast China are put forward in the following aspects: 1) to strengthen the research and development of the technique of resources’ cycling utilization, 2) to improve the utilizing efficiency of resources, and 3) to carry out the auditing system of resources utilization.

关键词： direct material input material flow analysis dematerialization decomposition method mining cities Northeast China

在线全文

学校读者我要写书评

暂无评论

生菜镉污染可见-近红外光谱分析模型

光谱学与光谱分析 2024年第10期44卷 2805-2811页

作者：周雷进雨周丽娜陈丽梅孔丽娟乔建磊李明堂吉林农业大学工程技术学院吉林长春130118 吉林农业大学园艺学院吉林长春130118 吉林农业大学资源与环境学院吉林长春130118

为了快速无损监测生菜受镉污染的程度,利用可见-近红外光谱进行生菜镉污染的分类监测。将土壤镉污染样品设置为0(CK,对照组)、 5、 10和20 mg·kg^(-1),以不同污染程度下种植的生菜为研究对象,采集生菜叶片的可见-近红外反射光谱,分析... 详细信息

为了快速无损监测生菜受镉污染的程度,利用可见-近红外光谱进行生菜镉污染的分类监测。将土壤镉污染样品设置为0(CK,对照组)、 5、 10和20 mg·kg^(-1),以不同污染程度下种植的生菜为研究对象,采集生菜叶片的可见-近红外反射光谱,分析镉污染下生菜叶片可见-近红外光谱反射率的变化规律。光谱信息经分析表明,在510~730 nm波段之间,随着土壤中镉含量的增加,生菜叶片的可见-近红外光谱反射率表现为先降低后增加;在730~799.53 nm波段之间,5和20 mg·kg^(-1)镉胁迫下生菜叶片反射率高于CK组,10 mg·kg^(-1)镉胁迫下生菜叶片反射率低于CK组;且在762.199 nm处出现了一个吸收谷。首先采用平滑(SG)、多元散射校正(MSC)、标准正态化(SNV)、平均归一化(MN)、 SG+MSC、 SG+SNV、 SG+MN、 SG+一阶导数(FD)、 SG+二阶导数(SD)方法对原始光谱进行预处理,以提高信噪比。然后通过主成分分析(PCA)对原始光谱和各种预处理的光谱进行降维处理,最后将降维处理后的数据按照4∶1的比例划分训练集和测试集,分别与粒子群优化随机森林(PSO-RF)、遗传算法优化支持向量机(GA-SVM)、 BP神经网络(BP-NN)、极限学习机(ELM)、朴素贝叶斯(naive Bayes)结合建立生菜镉污染的分类监测模型,并进行分析比较。结果表明,在不同的模型中,PSO-RF(SG)模型的识别效果最佳,其次是GA-SVM(SG+FD)模型和ELM(MSC)模型,PSO-RF(SG)、 GA-SVM(SG+FD)、 ELM(MSC)模型训练集的准确率均为100%,而测试集的准确率分别为100%、 83.33%和79.17%;BP-NN模型和naive Bayes模型的效果较差,BP-NN(SNV)模型训练集的准确率为42.72%,测试集准确率为50%;naive Bayes(SG+FD)模型训练集准确率为71.84%,测试集准确率为83.33%。说明采用可见-近红外光谱结合粒子群优化随机森林建模能够为生菜重金属污染监测提供一种新思路。

关键词：镉重金属污染反射光谱随机森林监测模型

Joint range ambiguity resolving and multiple maneuvering targets tracking in clutter via MMPHDF-DA

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2014年第8期57卷 117-128页

作者： TAN ShunCheng WANG GuoHong WANG na YU HongBo Institute of Information Fusion Technology Naval Aeronautical and Astronautical University Unit 92941 93 Element

It is difficult to track multiple maneuvering targets of which the number is unknown and timevarying,especially when there is range *** random finite sets(RFS)based probability hypothesis density filter(PHDF)is an effective solution to the problem of multiple targets ***,when tracking multiple targets via the range ambiguous radar,the problem of range ambiguity has to be *** this paper,a multiple model PHDF and data association(MMPHDF-DA)based method is proposed to address multiple maneuvering targets tracking with range ambiguous radar in ***,by introducing the turn rate of target and the discrete pulse interval number(PIN)as components of target state vector,and modeling the incremental variable of the PIN as a three-state Markov chain,the problem of multiple maneuvering targets tracking with range ambiguity is converted into a hybrid state filtering ***,by implementing a novel"track-estimate"oriented association with the filtering results of the hybrid filter,target tracks are provided at each time *** results demonstrate that the MMPHDF-DA can estimate target state as well as the PIN simultaneously,and succeeds in multiple maneuvering target tracking with range ambiguity in *** results also demonstrate that the MMPHDF-DA can overcome the limitation of the Chinese Remainder Theorem for range ambiguity resolving.

关键词： probability hypothesis density particle filter range ambiguity maneuvering target tracking data association