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关键词： 1-Laplacian operator   Quasilinear elliptic operator  

摘要： In this paper, we use minimax methods, comparison arguments, and an approximation result to show the existence and multiplicity of solutions for the following class of problems: {-Delta(1)nu = lambda f(nu) in Omega, nu >= 0 in Omega, nu = 0 on partial derivative Omega, where Omega is a bounded smooth domain of R-N, N >= 1, lambda > 0 is a parameter and the non-linearity f : R -> R is a continuous function that can change sign and satisfies an area condition.

关键词： development   mass spectrometry   pathways   proteome   seed   soybean  

摘要： Using high throughput tandem mass tag (TMT) based tagging technique, we identified 4172 proteins in three developmental stages: early, mid, and late seed filling. We mapped the identified proteins to metabolic pathways associated with seed filling. The elevated abundance of several kinases was observed from the early to mid-stages of seed filling, indicating that protein phosphorylation was a significant event during this period. The early to late seed filling stages were characterized by an increased abundance of proteins associated with the cell wall, oil, and vacuolar-related processes. Among the seed storage proteins, 7S (beta-subunit) and 11S (Gy3, Gy4, Gy5) steadily increased in abundance during early to late stages of seed filling, whereas 2S albumin exhibited a decrease in abundance during the same period. An increased abundance of proteases, senescence-associated proteins, and oil synthesis proteins was observed from the mid to late seed filling stages. The mid to late stages of seed filling was also characterized by a lower abundance of transferases, transporters, Kunitz family trypsin, and protease inhibitors. Two enzymes associated with methionine synthesis exhibited lower abundance from early to late stages. This study unveiled several essential enzymes/proteins related to amino acid and protein synthesis and their accumulation during seed development. All data can be accessed through this link: . (Accession MSV000087577)

关键词： remote sensing   full-connection graph   hyperspectral images   hyperspectral abnormal targets   nearest neighbour methods   Gaussian kernel function   Laplacian matrix graph   abnormal pixel detection   nearest neighbour matrix   abnormal target detection   matrix inversion   spatial information   data handling   Laplace transforms   object detection   matrix inversion calculation   geophysical image processing   spectral information   anomaly target detection   hyperspectral imaging   graph signal   graph theory  

摘要： To improve the accuracy of abnormal target detection in hyperspectral images, an abnormal target detection method based on Laplacian matrix graph (LGD) is proposed. The method makes full use of the spatial and spectral information of hyperspectral abnormal targets by constructing the full-connection graph and the nearest neighbour matrix obtained by the Gaussian kernel function. In the graph, the total variation of the graph signal calculated by the Laplacian matrix is taken as the evaluation function to judge the abnormal target, so as to realize the detection of abnormal pixels. It avoids the matrix inversion calculation that must be carried out in the conventional detection algorithms and the complexity is reduced. Compared with other detection algorithms on three different data sets, the experiment results show that the proposed algorithm presents obvious advantages in detection accuracy and excellent utility in practice.

关键词： 计算机算法  

ISBN: (纸本)9787564199173

摘要： 本书是在作者的博士论文基础上修订而成的。研究试题库的选题策略, 是一项自然科学与教育科学, 学术研究与教学研究相结合的研究课题, 运用心理测量学、心理统计学、智能技术的理论和方法, 建立科学的成卷理论。本书对量子智能算法用于测验选题的可行性和特性进行探索, 将普通遗传算法和量子遗传算法、普通粒子群算法和量子粒子群算法、普通蚁群算法和量子蚁群算法的选题性能进行两两比较。各算法得到的选题结果采用方差分析进行差异显著性检验, 分析影响选题结果的参数、得到算法的最优参数组合。

关键词： Variational methods   (p, q)- Laplacian   Multiplicity results   Concentration-compactness   Symmetric solutions  

摘要： We prove existence and multiplicity results in R-N for an elliptic problem of (p, q)-Laplacian type with a nonlinearity involving both a critical term and a subcritical term with a positive real parameter lambda. In particular, nonnegative nontrivial weights satisfying some symmetry conditions with respect to a certain group T are included in the nonlinearity. We prove first the existence of at least one solution with positive energy for lambda sufficiently small using Mountain Pass Theorem, then we obtain the existence of infinitely many weak solutions with positive (finite) energy for every lambda positive applying Fountain Theorem. Our proofs use variational methods and concentration compactness principles.

关键词： Energy   Predissociation   Mathematical methods   Computational chemistry   Molecules  

摘要： We perform trajectory-based simulations of the vibrational predissociation of the ArBr2 (B,nu=16...25 van der Waals triatomic complex, constrained to the T-shape geometry. To this aim, we employ a 2-fold mapping of the quantum dynamics into classical-like dynamics in an extended phase space. The effective phase space comprises two distinct sets of degrees of freedom, namely a collection of coupled harmonic oscillators and an ensemble of quantum trajectories. The time evolution of these variables represent bound and unbound motions of the quantum system, respectively. Quantum trajectories are propagated within the interacting trajectory representation. The comparison between the lifetimes of the predissociating complexes computed using the trajectory-based approach and the experimental results available for the target systems indicates that the present method is competitive with wavepacket propagation techniques. The competition between several simultaneous vibrational relaxation pathways was found to have a direct impact on the time scales of vibrational predissociation. Likewise, the analysis of the time evolution of the trajectories reveals the existence of regions in the effective phase space where transitions to vibrational states of higher energy are more likely to occur. The size and location of these regions influence the transient vibrational distributions and therefore the computed lifetimes. Furthermore, the mechanisms of energy redistribution along the dissociation coordinate are analyzed.

关键词： 短暂性脑缺血发作   动脉自旋标记   脑血流量  

摘要： 目的 探讨双时相三维动脉自旋标记(3 D-ASL)成像联合磁共振血管成像(MRA)在评估短暂性脑缺血发作(TIA)中的临床应用价值.方法 选取经临床确诊为TIA的患者72例,另选取对照组48例.行MRI常规序列、扩散加权成像(DWI)、3D-ASL及MRA检查,图像传输工作站后处理得到脑血流量(CBF)伪彩图,比较2种标记延迟时间(PLD)1.5 s及2.5 s参数下3D-ASL成像的灵敏度和特异度,阳性预测值和阴性预测值,比较2种PLD参数下3D-ASL成像检出率、MRA不同狭窄程度中异常灌注比例及低灌注面积的差异.结果 TIA组中3D-ASL成像在PLD 1.5 s及2.5 s时检出异常灌注分别为46例(63.9％)及32例(44.4％);对照组中分别检出6例(12.5％)及2例(4.2％).PLD 1.5 s时3D-ASL成像对TIA的检出率较高,差异有统计学意义(P<0.05).2种PLD时3D-ASL成像对TIA诊断的灵敏度和特异度,阳性预测值和阴性预测值分别为63.89％、87.5％、88.46％、61.76％及44.44％、95.83％、94.11％、53.49％.2种PLD时异常灌注面积差异无统计学意义(P>0.05).按MRA狭窄程度分组,2种PLD 3D-ASL成像异常灌注病例均在中度组中分布最多,分别为22例及18例;正常或轻度组次之,分别为18例及8例;重度组最少,均为6例.其中PLD 1.5 s时正常或轻度组和中度组差异有统计学意义(P<0.05).中度组和重度组的差异无统计学意义(P>0.05).PLD 2.5 s时正常或轻度组和中度组差异有统计学意义(P<0.05).中度组和重度组的差异无统计学意义(P>0.05).3D-ASL成像检出低灌注病例与轻度、中度及重度组狭窄血管的责任关系符合例数各自为4例、14例及6例.结论 双时相3 D-ASL成像能在早期发现TIA患者的灌注异常,联合MRA技术能很好地为临床诊断及鉴别诊断提供影像学依据.

关键词： 光的波粒二象性   启示  

摘要： 波粒二象性由光的研究而来,主要验证了光既有波的性质,也具有粒子的特点,是量子力学中的关键内容之一.本文主要结合笛卡儿、格里马第、牛顿、惠更斯、赫兹、爱因斯坦等多位物理学家理论,探究波粒二象性理论的研究进程,并分析波粒二象性研究过程带给当代高中生的启示.