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1.
三维荧光光谱(EEM)结合平行因子分析(PARAFAC)能够根据水体中有机物的荧光性质对荧光组分特征、种类进行区分。大量原始数据以及常规的手工处理方式直接影响着该方法的广泛应用。提出了一种基于Matlab软件的三维荧光光谱数据快速转化为荧光矩阵的思路与方法。该方法根据不同研究者测定参数的不同,结合不同校正方法,可快速地将大量样品的三维荧光数据整合为三维荧光矩阵,通过具体数据验证荧光矩阵形成进行平行因子分析。该方法能够实现整个过程操作简单,人工干预少,可达到快速、批量完成三维荧光光谱数据处理的目的。  相似文献   

2.
分析了市售柴油、机油、煤油、汽油及混合油水溶液的激发光和荧光光谱,研究了它们的光谱特性.在优化选择激发光波长和荧光波长下,对不同浓度的矿物油水混合液进行了荧光光谱分析,得到了荧光光谱强度与浓度的关系,并对实际环境的水样进行了测量分析.  相似文献   

3.
采用近红外光谱线性分析技术实现对鱼粉蛋白的快速检测,选择合适的波长变量是提高模型预测精度的关键。主要目的是建立一种稳健、简单的多元线性回归(MLR)模型,通过研究基于特征峰值的投影技术实现参与建模的波长优选。特征物质在近红外光谱区域的吸收特征,以鱼粉一阶导数光谱的峰谷波长点作为出发点,依次采用逐步多元线性回归(SMLR)和连续投影线性回归(SPA-MLR)方法完成两度特征信息波长筛选,进一步对备选的波长变量执行显著性检验,最终确定近红外线性分析的特征信息波长组合。结果表明,近红外长波区域中优选出53个特征信息波长变量,能够提高鱼粉蛋白近红外定量模型的预测精度,简化了模型,从而提高了模型的适用性和稳健性。  相似文献   

4.
针对目前质量监督领域中难以快速准确地识别食用油种类的问题,提出了一种激光诱导荧光技术结合连续投影算法的食用油光谱识别方法.实验搭建激光诱导荧光系统采集了5种食用植物油共计500组荧光光谱数据.首先,通过实验对比选择Savitzky-Golay卷积平滑算法对荧光光谱进行预处理;然后使用连续投影算法筛选特征波长;最后,将筛选出的特征波长送入建立的概率神经网络模型中进行训练和测试,并通过不同时间采集的油样组成独立验证集进行再次验证.结果表明:通过特征波长筛选,从全光谱2 048个波长中优选出11个,减少了冗余信息,波长数缩减为原来的0.54%.并且在概率神经网络模型中的训练样本准确率和测试样本准确率分别达到100%和95%,效果好于径向基函数神经网络和BP(Back Propagation)神经网络.在独立验证集的预测准确率也达到了91%.因此,将连续投影算法用于食用油激光诱导荧光光谱特征波长筛选并结合概率神经网络模型可以实现食用油的快速准确分类且具备通用性,并为进一步设计专用的在线式食用油种类识别仪提供了理论依据.  相似文献   

5.
视频压缩感知是解决无线多媒体网络中海量数据存储和传输问题的有效方法,但常规基于单帧处理的压缩重构质量较差,限制了应用效果。文中提出了基于BCS的结构预测和运动补偿的提高视频GOP序列重构质量的方法。对视频GOP序列,首先,利用分块压缩感知对关键帧和压缩帧分别进行压缩采样,并给出了一种视频稀疏性定量估算方法,实现了压缩采样率自适应选择;然后,基于迭代阈值投影重构算法,对关键帧和压缩帧分别进行压缩重构。在此基础上,利用视频帧区域块的结构相关性进行帧内结构预测,提高重构质量;最后,利用帧间的时间冗余性,通过运动估计和运动补偿进一步提高重构质量。仿真结果表明,结构预测和运动补偿能提高视频重构的峰值信噪比(PSNR)。该算法考虑了视频序列帧内和帧间相关性进行预测和补偿,提高了GOP序列的重构质量。  相似文献   

6.
测量了乙酰丙氨酸咪唑铕水溶液的三维荧光激发和发射光谱,分析了在不同波长激发光作用下的荧光特征,与配体N-乙酰-DL-丙氨酸、咪唑及氯化铕的荧光光谱进行了比较,讨论了配合物的发光机制,发现在10-2~10.4mol/L浓度范围内荧光强度与溶液浓度呈正相关.  相似文献   

7.
为提高土壤养分近红外光谱预测模型的鲁棒性和预测精度,提出一种基于改进遗传算法的近红外区间光谱特征波长变量选择方法.利用土壤速效磷近红外光谱全光谱波长变量纯度梯度的正负变化次数将全光谱划分为多个波长间隔,以偏最小二乘回归模型(PLS-R)输出的变量投影重要性系数(V_(VIP))大于1作为提取准则,提取对土壤养分预测目标量解释性较强的波长间隔,并合并成一个区间光谱.建立区间光谱特征波长变量(FWV)PLS-R模型,利用改进遗传算法选择PLS-R的均方根误差为最小对应的FWV为最优FWV.试验结果表明:该方法在区间光谱选择最优FWV,能提高回归模型的鲁棒性和预测精度,简化模型结构;改进遗传算法采用一种改进的实数编码差分变异算子,扩大了全局最优解搜索空间,提高了收敛速度.  相似文献   

8.
荧光分光光度计属于高精密仪器,因其具有测量精确,适用于固体和液体的光谱扫描等特点,在生物化学、化学、药品分析、食品检验、地理、冶金、医药、环境科学、生命科学等领域得到了广泛的应用。针对日立F-7000型荧光分光光度计波长扫描、时间扫描、光度值法、三维扫描和三维时间扫描的调试方法和分析方法进行了详细介绍,为仪器使用者提供技术支持。  相似文献   

9.
针对高光谱图像传输安全性问题,提出一种将最佳谱间预测、SPIHT编码和混沌映射相结合的高光谱图像压缩加密算法.该算法采用最佳谱间预测与SPIHT的编码算法对高光谱图像进行压缩.压缩过程中,首先由Tent映射置乱初始化LIP,然后利用Lorenz三维混沌映射产生混沌值生成比特序列,编码过程中实时加密对图像重构起重要作用的数据,在压缩过程中实现图像加密.仿真结果表明:该算法密钥空间大,对密钥和明文敏感,同时能有效提高图像存储和传输效率.  相似文献   

10.
采用表面活性剂协助自组装法合成了花棒状ZnO,利用X射线衍射、扫描电镜、红外光谱和荧光光谱对该化合物的晶体结构、样品形貌、振动光谱以及发射光谱进行了表征.结果表明:ZnO在表面活性剂的存在下,形成纤锌矿型的六方结构,晶体的生长是沿c轴[001]方向定向生长,并且聚集在某一中心的晶核向三维方向定向生长形成花状形貌.该ZnO晶体的晶胞参数为a=0.324 85(6)nm,c=0.520 43(8)nm,γ=120°.在测量波长范围内ZnO的发射光谱在315,400,473和560 nm左右出现荧光,这些发射光谱的波长位置不随激发光波长的增长而变化,而散射光谱峰的波长位置随激发光的波长增加而增加.  相似文献   

11.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

14.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

15.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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