C18固相膜萃取-气相色谱法测定饮用水中12种有机氯农药

利用C18固相萃取膜提取水样，气相色谱法（电子捕获检测器）测定饮用水中12种有机氯农药。对洗脱液、水样pH值、萃取压力等条件进行了优化选择，并与液-液萃取做了比较。结果表明，与液-液萃取相比，固相膜萃取具有操作简单、富集倍数高、节省溶剂和耗时短等优点，是萃取水中有机氯农药的有效方法。12种有机氯农药的回收率为85．97％～127．7％，相对标准偏差（RSD，n=5）为4．74％～12．2％，方法检出限为0．014～0．047μg/L。     

一种强跟踪自适应状态估计器及其仿真研究

在噪声环境中,运动目标发生稳态突变会降低卡尔曼滤波器的滤波性能,进而导致组合导航的可靠性降低,导航系统抗干扰能力下降,影响导航的精确度。为了提高卡尔曼滤波器性能,提高抗干扰能力和导航精度,在采用基于卡尔曼滤波器的超紧耦合同时,提出一种新型的基于渐消因子的区间卡尔曼滤波器算法。该算法通过引入渐消因子和区间矩阵对滤波器增益矩阵进行实时调整,并利用区间运算中的交集运算将各种误差源约束到交集区间,进而保证在区间运算中保真集合映射的完备性并取得最优化。结果显示,该算法能够克服原有滤波器算法的缺陷,在噪声环境中提升对稳态突变目标的跟踪能力,且在噪声中滤波器效果提高,算法计算量没有明显增加。     

Evolution of the eastern margin of Korea: Constraints on the opening of the East Sea (Japan Sea)

We interpreted marine seismic profiles in conjunction with swath bathymetric and magnetic data to investigate rifting to breakup processes at the eastern Korean margin that led to the separation of the southwestern Japan Arc. The eastern Korean margin is rimmed by fundamental elements of rift architecture comprising a seaward succession of a rift basin and an uplifted rift flank passing into the slope, typical of a passive continental margin. In the northern part, rifting occurred in the Korea Plateau that is a continental fragment extended and partially segmented from the Korean Peninsula. Two distinguished rift basins (Onnuri and Bandal Basins) in the Korea Plateau are bounded by major synthetic and smaller antithetic faults, creating wide and considerably symmetric profiles. The large-offset border fault zones of these basins have convex dip slopes and demonstrate a zig-zag arrangement along strike. In contrast, the southern margin is engraved along its length with a single narrow rift basin (Hupo Basin) that is an elongated asymmetric half-graben. Analysis of rift fault patterns suggests that rifting at the Korean margin was primarily controlled by normal faulting resulting from extension rather than strike-slip deformation. Two extension directions for rifting are recognized: the Onnuri and Hupo Basins were rifted in the east-west direction; the Bandal Basin in the east–west and northwest–southeast directions, suggesting two rift stages. We interpret that the east–west direction represents initial rifting at the inner margin; while the Japan Basin widened, rifting propagated southeastward repeatedly from the Japan Basin toward the Korean margin but could not penetrate the strong continental lithosphere of the Korean Shield and changed the direction to the south, resulting in east–west extension to create the rift basins at the Korean margin. The northwest–southeast direction probably represents the direction of rifting orthogonal to the inferred line of breakup along the base of the slope of the Korea Plateau; after breakup the southwestern Japan Arc separated in the southeast direction, indicating a response to tensional tectonics associated with the subduction of the Pacific Plate in the northwest direction. No significant volcanism was involved in initial rifting. In contrast, the inception of sea floor spreading documents a pronounced volcanic phase which appears to reflect asthenospheric upwelling as well as rift-induced convection particularly in the narrow southern margin. We suggest that structural and igneous evolution of the Korean margin, although it is in a back-arc setting, can be explained by the processes occurring at the passive continental margin with magmatism influenced by asthenospheric upwelling.     

基于ALBERT模型的园林植物知识实体与关系抽取方法

园林植物知识图谱可为顾及区域适应性、观赏性和生态性等因子的绿化树种的选型提供知识支持.植物描述文本的实体识别及关系抽取是知识图谱构建的关键环节.针对植物领域未有公开的标注数据集,本文阐述了园林植物数据集的构建流程,定义了园林植物的概念体系结构,完成了园林植物语料库的构建.针对现有Word2vec、ELMo和BERT等语...     

SEISMIC RECORDING CHARACTER OF JCZ-1 ULTRA BROADBAND DIGITAL SEISMOMETER

分析讨论了     

Stationary phase approximation in the ambient noise method revisited

The method of extracting Green's function between stations from cross correlation has proven to be effective theoretically and experimentally.It has been widely applied to surface wave tomography of the crust and upmost mantle.However,there are still controversies about why this method works.Snieder employed stationary phase approximation in evaluating contribution to cross correlation function from scatterers in the whole space,and concluded that it is the constructive interference of waves emitted by the scatterers near the receiver line that leads to the emergence of Green's function.His derivation demonstrates that cross correlation function is just the convolution of noise power spectrum and the Green's function.However,his derivation ignores influence from the two stationary points at infinities,therefore it may fail when attenuation is absent.In order to obtain accurate noise-correlation function due to scatters over the whole space,we compute the total contribution with numerical integration in polar coordinates.Our numerical computation of cross correlation function indicates that the incomplete stationary phase approximation introduces remarkable errors to the cross correlation function,in both amplitude and phase,when the frequency is low with reasonable quality factor Q.Our results argue that the distance between stations has to be beyond several wavelengths in order to reduce the influence of this inaccuracy on the applications of ambient noise method,and only the station pairs whose distances are above several (5) wavelengths can be used.     

APPLICATION OF PATTERN RECOGNITION TO SPECIATION DATA OF HEAVY METALS IN SUSPENDED PARTICULATES OF URBAN AIR

In order to get a better knowledge of the air pollution levels of the urban air of Barcelona,twelvesamples from three stations of the air-monitoring control network were analysed.Each control station isrepresentative of a different environmental situation.Thus the station at Plaa Molina responds to asimple domestic and urban traffic situation;the station at Poble Nou to the influence of medium andsmall industries,mainly metallurgical;and the station at Montcada to a zone in which there existimportant industries,a cement factory,two highways and railroads.The total content of unsedimentable particles,three inorganic anions(chlorides,sulphates andnitrates)and six heavy metals(Fe,Pb,Cu,Mn,Cr and Cd)were determined on all the samples obtainedduring the same period of time.The use of an analytical scheme of sequential extraction has alsopermitted the subdivision of the total content of each metal into the following four fractions:(1)solubleor exchangeable;(2)associated with carbonates and/or with iron and manganese oxides;(3)bound toorganic matter;and(4)residual.The use of principal component analysis applied to the data as a whole showed the associations andcorrelations between the various parameters as well as between the different above mentioned fractions.The predominant presence of Cd in the‘soluble or exchangeable’fraction is confirmed,while the othermetals are mainly associated with the‘carbonates and/or Fe and Mn oxides’and‘bound to organicmatter’fractions.Hierarchical cluster analysis applied to the twelve samples showed clearly the presence of threedifferent classes closely related to the origin(station)of the samples.Thus it becomes feasible to proposefor each station a possible profile of the content in terms of the different parameters considered.     

山东省优势大地构造相划分初步方案

大地构造相是反映陆块区、造山系和叠加造山-裂谷相系形成演变过程中的一套岩石构造组合,是表达大陆岩石圈板块经历离散、聚合、碰撞、造山等动力学和地质构造作用过程而形成的综合产物。根据优势大地构造相的划分原则与沉积岩、火山岩、侵入岩和变质岩建造构造等特征,山东大地构造相可划分为3个相系(Ⅰ级)、4个大相(Ⅱ级)、17个相(Ⅲ级)和51个亚相(Ⅳ级)。     

北斗GEO卫星载波相位单差观测值的周期性分析

高精度的卫星定位测量中,由于卫星在测站上空的重复周期性运动,周期性误差是影响测量精度的重要误差源。恒星日滤波利用周期性误差的特点,提取前一天的周期性误差来改正后一天的定位结果,可滤波处理诸如多路径误差。本文从北斗GEO卫星载波相位观测值站间单差的角度来探讨其周期性特点,通过前后两天站间相位单差观测值进行对比,采用相关性分析方法,验证北斗GEO卫星载波相位单差观测值的周期性特征。     

高分辨率机载SAR影像判读实验

近年来机载SAR系统在国内得到快速发展。由于SAR系统具有不同于光学传感器的成像机理,因而可以提供全新的数据获取手段和不同的地物信息。利用高分辨率机载SAR影像进行解译时必须熟悉其成像机理和图像信息特点,充分了解SAR图像解译标志的特点和各类地物的解译规律。本文以高分辨率机载SAR数据为基础,对比光学影像,从SAR成像特点和地物散射特性出发,对SAR影像进行了目视解译,分析了SAR影像在地形地物要素识别中的应用潜力。