基于随机分块模型的静息态功能脑网络可信度优化

为了提高静息态功能脑网络可信度,引用基于随机分块模型的网络重构方法对脑网络进行重构。通过网络指标的分析,验证该方法在脑网络中的适用性,找到网络中的虚假边;采用网络最大联通子集的方法来分析虚假边对网络连通性的影响。实验结果表明,该方法可用于脑网络的重构,通过重构可以找到影响脑网络连通性的虚假边,提高了连通性的可信度。     

运动态人脑默认模式网络脑电信息传递动力学行为分析

为探究人体进行运动相关任务时大脑默认模式网络与其他脑区间的连接规律，基于运动及运动想象脑电信号公开数据集，通过快速傅里叶变换对不同状态下的脑电信号划分频段并进行滑动加窗处理，得到静息与运动态下同皮层不同频段的平均时间序列。采用动态传递熵的构造方法，分析默认模式网络到运动皮层、默认模式网络到前额叶皮层的信息交互，并在多个数据集下进行显著性检验。将动态传递熵的分析方法结合逻辑回归、决策树、XGBoost算法对不同任务进行分类研究，结果表明：大脑不同皮层功能区在进行不同任务时具有显著差异；相较于静息态，前额叶皮层和运动皮层在运动过程中更加活跃，γ频段相较其他频段也更加活跃；相较于静息态，运动态及运动想象态下默认模式网络到运动皮层、默认模式网络到前额叶皮层的信息交互都更强烈，其结果在不同样本空间的显著性检验P值小于0.025,此方法稳健；脑电信号动态传递熵方法可以将机器学习算法的分类准确率提高20%以上。研究可为运动态脑电信号辨识提供理论参考。     

孤独症儿童静息态脑电Gamma频段功能网络研究

有研究表明,孤独症儿童的功能障碍可能和脑电中的Gamma频段异常有关。通过采集17例孤独症儿童和17例正常儿童睁眼静息态脑电,利用定向传递函数方法计算导联间的因果连接,构建Gamma频段(35~50 Hz)功能网络。用图论方法分析两组差异。结果表明相同阈值下,孤独症儿童脑功能网络全局效率、局部效率以及节点度均低于正常对照组儿童。提示孤独症儿童认知、行为异常可能与其大脑Gamma频段连接较弱、信息整合效率较低有关。     

ICA+DMN方法在抑郁症诊断中的应用

功能磁共振成像(fMRI)作为一种工具,用于预测临床信息,如疾病的诊断及预测等,然而由于fMRI数据的高维性使得对其进行数据分析成为一个重要的研究课题,独立成分分析算法(ICA)常用于任务态下的fMRI数据的处理.本文提出将独立成分分析和默认模式脑网络(DMN)结合的方法,并将其应用于静息态的fMRI数据,可以根据大脑静息态下fMRI数据诊断出是否患有抑郁症,实验结果表明,此方法对处理静息态的fMRI数据的处理有一定的效果,正确率达到73.68%,可以为抑郁症患者提供辅助诊断治疗方法.     

基于解剖距离的功能脑网络建模方法研究

为了分析解剖距离对静息态功能脑网络建模的影响,在解剖距离的基础上将节点共同邻居引入到功能脑网络的建模中。设计三个模型,分别是基于解剖距离,节点共同邻居个数和解剖距离与节点共同邻居个数。借鉴残差的方法创建最优静息态功能模型网络评价标准。在每种模型网络中选出最优的模型网络。然后将每种模型中的最优网络与真实数据fMRI网络对比选出能够最大程度模拟真实网络的模型网络。结果证明在AAL模板下单独基于解剖距离建立的功能脑网络能最大化的模拟真实的网络。     

基于静息态fMRI的人脑功能网络的小世界特性

从19个健康志愿者静息态的功能磁共振成像中提取了时间序列,计算了90个脑区的功能相关性,设定阈值建立脑功能网络的无向简单图,然后计算了一些网络测度.结果显示人脑功能网络具有小世界特性;性别分层后并没有发现各网络测度在全脑水平有显著性的性别差异.     

静息态人脑功能网络的小世界特性

研究了静息态下健康人脑的功能连接模式有助于理解人脑在正常或疾病状态下的功能活动规律.利用小波变换从健康志愿者静息态的功能磁共振成像中提取时间序列,计算90个脑区的相关性,设定阈值建立脑功能网络的无向简单图,然后计算特征路径长度和聚类系数,并对度分布进行拟合.结果显示:脑功能网络具有规则网络的大聚集系数又具有随机网络的小特征路径长度,度的拟合显示具有指数截断幂律分布,即脑功能网络具有小世界特性.     

静息态亚健康失眠脑功能网络分析

针对亚健康失眠者根据匹兹堡睡眠质量指数筛选被试参与实验,利用128导脑电（EEG）分析仪,提取静息态64导脑电信号,通过多通道脑电信号同步性分析,脑功能网络的构建和分析,研究亚健康失眠者与健康人脑电信号的特异性差异,同时进一步比较分析亚健康失眠者与健康人脑电的负相关特性.分析结果表明亚健康失眠者与健康人相比,脑电信号同步性降低,脑功能网络的连接减弱,大脑的活跃度降低,并且这种差异性在脑电负相关特性中表现更为明显.     

青少年不良行为决策的双重加工模型

对双重加工理论模型的探讨是当前决策理论研究的热点,但分析加工与启发加工之间的关系、起源等问题并不清楚,本文回顾了脑功能和行为理论、认知-经验自我理论及原型意愿模型等国外主要的双重加工理论,对各理论的优点不足及对青少年不良行为决策的解释等方面做了探讨。     

情绪的神经生物研究

情绪的研究一直是一个重要领域,同时由于情绪的复杂性,使得情绪的研究具有相当的难度。近年来脑成像技术（fMRIPET）和事件相关电位（ERP）等技术的发展,推动了情绪与认知的神经生理基础的研究。本文从情绪的评定标准、被试的选取、实验材料的编制以及研究技术等方面介绍了情绪神经生物基础研究的基本方法;叙述了情绪刺激加工中情绪活动中,大脑半球的偏侧化效应,脑成像研究中发现正负效价情绪的加工由大量重叠神经通道负责,而不同性质的面部表情由不同的神经通道负责。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that